Comparative Efficacy of Posterolateral versus Lateral Approach in Total Hip Arthroplasty: A Retrospective Cohort Study on Prosthetic Alignment and Stability

Comparative Efficacy of Posterolateral versus Lateral Approach in Total Hip Arthroplasty: A Retrospective Cohort Study on Prosthetic Alignment and Stability | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparative Efficacy of Posterolateral versus Lateral Approach in Total Hip Arthroplasty: A Retrospective Cohort Study on Prosthetic Alignment and Stability Tian-long Pan, Qiao Wei, Pei Fan, Zhen-xing Li This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6924553/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This single-center retrospective cohort study evaluated the biomechanical and clinical outcomes of the posterolateral approach (PLA) compared to the lateral approach in total hip arthroplasty (THA). A cohort of 270 patients undergoing primary THA via PLA was analyzed, with prosthetic alignment parameters (acetabular inclination, acetabular anteversion, femoral stem anteversion, and combined anteversion) quantified using postoperative CT imaging. Results demonstrated statistically significant increases in acetabular component inclination (48.09°±8.54° vs43.2°±8.7°, p <0.05), acetabular anteversion (29.09°±9.06° vs.18.4°±6.9°, p <0.01), femoral stem anteversion (19.28°±11.28°vs. 14.6°±7.3°, p <0.05), and combined anteversion (48.37°±13.04°vs. 32.0°±10.5°, p <0.01) compared to historical lateral approach data. Notably, no postoperative dislocations were observed in the PLA cohort (0% incidence), attributed to standardized capsular repair and component positioning protocols. Despite only 19.35% of cases achieving dual-axis Lewinnek "safe zone" alignment, meticulous soft tissue reconstruction ensured stability even with elevated combined anteversion (range: 22.18°–75.44°). These findings highlight the biomechanical adaptability of PLA in optimizing prosthetic positioning while maintaining stability, particularly in anatomically complex cases. Methodological rigor, including uniform surgical protocols and CT-based measurements, minimized confounding variables. This study supports PLA as a robust approach for THA, balancing alignment flexibility with clinical safety. Total hip arthroplasty Posterolateral approach Prosthetic alignment Combined anteversion Hip stability Retrospective cohort study Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Total hip arthroplasty (THA) has emerged as one of the most transformative advancements in modern orthopaedics, revolutionizing the management of end-stage hip pathologies such as osteoarthritis, avascular necrosis, and traumatic fractures [ 1 ] . Since its inception in the early 20th century, THA has undergone significant evolution in implant design, surgical techniques, and biomaterials, substantially improving patient outcomes and quality of life [ 2 ] . The pioneering work of Sir John Charnley in the 1960s, which introduced low-friction arthroplasty using metal-on-polyethylene bearings and acrylic bone cement, laid the foundation for modern THA [ 3 ] . Subsequent innovations, including cementless fixation, highly cross-linked polyethylene, ceramic-on-ceramic interfaces, and advanced bearing surfaces, have further enhanced implant longevity and functional performance [ 4 , 5 ] . The primary advantages of THA are well-documented. It reliably alleviates pain, restores joint function, and improves mobility in over 90% of patients, with survival rates exceeding 90% at 15–20 years for contemporary implants [ 6 , 7 ] . Minimally invasive approaches and computer-assisted navigation have reduced intraoperative trauma and improved component alignment accuracy [ 8 ] . Additionally, the advent of rapid recovery protocols and outpatient THA has optimized healthcare resource utilization. However, challenges persist. Long-term complications such as aseptic loosening, periprosthetic osteolysis, and polyethylene wear remain concerns, particularly in younger, active patients [ 9 – 11 ] . The risk of dislocation, infection, and periprosthetic fractures necessitates careful patient selection and surgical precision [ 12 , 13 ] . Furthermore, revision surgeries, though declining in incidence, are complex and associated with higher morbidity rates due to bone loss and soft-tissue compromise. Total hip arthroplasty (THA) is a highly successful procedure for restoring function in patients with end-stage hip pathologies, yet postoperative complications remain a critical concern. Among these, hip dislocation is the second most common reason for early revision surgery, with reported incidences of 1–3% after primary THA and up to 20% following revision procedures [ 14 ] . Dislocation not only causes acute pain and functional impairment but also escalates long-term risks of prosthesis loosening, periprosthetic fractures, and repeated surgical interventions, significantly diminishing patient quality of life [ 15 , 16 ] . The etiology of dislocation is multifactorial, involving both biomechanical and patient-specific factors. Malpositioning of the acetabular cup or femoral stem—particularly deviations from the Lewinnek "safe zone" (cup abduction 40 ± 10°, anteversion 15 ± 10°)—is a well-documented surgical risk, as improper component alignment increases impingement and reduces the effective jump distance [ 17 ] . Additionally, soft tissue deficiencies (e.g., inadequate repair of the posterior capsule in the posterior approach) and patient factors such as advanced age, neuromuscular disorders, and noncompliance with postoperative restrictions further exacerbate instability [ 18 ] . While advancements in implant design (e.g., dual-mobility bearings) and surgical techniques (e.g., anterior approach) have mitigated dislocation rates, disparities persist in high-risk populations, including those with spinal stiffness or obesity [ 19 , 20 ] . Combined anteversion (CA), defined as the sum of the acetabular component anteversion and the femoral stem anteversion relative to the anatomical planes, plays a pivotal role in optimizing hip joint biomechanics [ 21 ] . Historically, acetabular and femoral anteversion were evaluated independently, guided by classical criteria such as the Lewinnek "safe zone" [ 17 ] for acetabular positioning (40° ± 10° inclination and 15° ± 10° anteversion). However, emerging evidence suggests that isolated measurements may fail to account for the dynamic interplay between the two components during functional activities [ 22 ] . For instance, excessive or insufficient combined anteversion can lead to edge-loading, impingement during hip rotation, or instability, increasing dislocation risks [ 23 ] . The clinical significance of CA lies in its ability to harmonize stability and range of motion [ 24 ] . Biomechanical studies demonstrate that appropriate CA (typically 25°–45°) reduces prosthetic impingement, minimizes polyethylene wear, and enhances joint stability by maintaining optimal contact stress distribution [ 24 ] . Furthermore, CA principles are particularly critical in addressing patient-specific variations, such as spinal-pelvic mobility patterns or femoral morphology, which demand personalized component alignment [ 28 ] . Despite its theoretical advantages, debates persist regarding standardized measurement techniques and ideal CA targets across different surgical approaches (e.g., posterior vs. direct anterior). Additionally, advancements in robotic-assisted THA and dynamic imaging have refined CA optimization, yet clinical validation remains heterogeneous [ 29 , 30 ] . The posterolateral approach (PLA) remains a cornerstone in total hip arthroplasty (THA) due to its anatomical accessibility and technical reproducibility. By utilizing the interval between the gluteus maximus and medius, PLA preserves critical abductor muscles, minimizing postoperative gait dysfunction while providing direct visualization of the acetabulum and proximal femur [ 31 , 32 ] . Historically criticized for higher dislocation rates (5–10%), modern modifications—including enhanced capsular repair, optimized component positioning (combined anteversion: 25°–45°), and large-diameter femoral heads—have reduced instability risks to < 1%, comparable to anterior approaches [ 33 ] . Additionally, PLA’s adaptability to complex cases (e.g., dysplasia, revisions) and shorter learning curve make it particularly advantageous for surgeons transitioning to THA [ 34 ] . Our research group has previously measured parameters such as the acetabular anteversion angle, femoral stem anteversion angle, and combined anteversion angle via the anterolateral approach, and compared these findings with relevant literature data published hitherto [ 35 ] . However, a simultaneous comparison of data related to the two surgical approaches has not been conducted within the same center. Consequently, this study has once again collected pertinent data from patients who underwent the posterolateral approach in our hospital, and compared it with the data of patients who underwent the anterolateral approach in previous studies, aiming to explore the advantages and disadvantages of the two surgical approaches. Materials and Methods Inclusion and Exclusion Criteria Eligibility criteria were defined as follows: Inclusion requirements comprised: 1) Adult subjects undergoing primary total hip arthroplasty (THA) via posterolateral approach for advanced hip pathologies between January 2017 and December 2021, utilizing cementless fixation components; 2) Availability of postoperative CT-based measurements for implant positioning parameters including acetabular cup inclination, cup/stem anteversion angles, and combined anteversion values; 3) Documentation of postoperative dislocation events and comprehensive implant orientation data. The study design followed a retrospective analysis framework. Exclusion parameters eliminated: 1) Revision arthroplasty procedures; 2) Cases complicated by periprosthetic fractures during surveillance periods;3) Cases with incomplete data recording. Surgical Procedures The surgical procedure was uniformly performed through a posterolateral approach, with technical modifications as follows: (i) Anesthesia and positioning : All procedures were conducted under general or spinal anesthesia with patients in standardized lateral decubitus position, maintaining 30° hip flexion for optimal posterior access. (ii) Surgical exposure : A curvilinear incision centered over the posterior third of the greater trochanter (Fig. 1 A) allowed identification of the iliotibial tract and gluteus maximus fibers (Fig. 1 B). Following fascial division, blunt dissection through the gluteus maximus fibers exposed the short external rotators (Fig. 1 C). Different form some authors, we resected part of the short external rotators including the superior gemellus, obturator internus, inferior gemellus, and part of the quadratus femoris with the piriformis tendon preserved, then a L-shaped capsulotomy provided full visualization of the femoral head and acetabulum. (Fig. 1 D) (iii) Articular dislocation : The hip was dislocated posteriorly through combined flexion and internal rotation, preserving anterior soft tissue integrity. (iv) Implant placement : Acetabular preparation preceded femoral preparation to enhance exposure. The hemispherical cup was positioned using the transverse acetabular ligament or the native acetabular rim or patient position as the guide. (Fig. 1 E-F). Femoral broaching was performed in 10°-15° anteversion under direct visualization, with trial reduction verifying appropriate leg length and offset (Fig. 1 G). (v) Closure and stabilization : Meticulous repair of the posterior capsule together with the external rotators to the greater trochanter using non-absorbable sutures was prioritized to enhance postoperative stability. All cases utilized cementless components: acetabular shells included Pinnacle (DePuy), Trabecular Metal (Zimmer), and Trident (Stryker); femoral stems comprised Trilock (DePuy), Trabecular Metal (Zimmer), and Accolade (Stryker). Postoperative rehabilitation emphasized early mobilization with hip precaution protocols. Data Acquisition Study data were obtained through tripartite collection modalities comprising structured telephone interviews, WeChat-based digital questionnaires (Tencent Holdings Ltd., Shenzhen, China), and clinical follow-up assessments. The protocol systematically captured two discrete data domains: baseline population characteristics and postoperative prosthetic stability parameters. Demographics The initial cohort comprised 318 consecutive patients who underwent primary total hip arthroplasty (THA) via a standardized posterolateral approach performed by an attending orthopaedic surgeon within our department. Following exclusion of 48 subjects lost to follow-up and 2 deceased cases, 270 patients (138 males, 132 females) completed the study protocol. Demographic analysis revealed a mean age of 63.97 ± 9.72 years (range: 21–89 years) with mean follow-up duration of 22.2 ± 10.7 months (range: 4.1–44.6 months). Diagnostic distribution included: osteonecrosis of the femoral head (118 cases, 43.7%), femoral neck fractures (46 cases, 17.0%), primary hip osteoarthritis (87 cases, 32.2%), developmental dysplasia of the hip (DDH, 12 cases, 4.4%), and miscellaneous etiologies (7 cases, 2.6%). A subgroup of 93 patients underwent postoperative computed tomography (CT) evaluation spanning from the L4 vertebral level to tibial tuberosity. This imaging cohort (43 males, 50 females) demonstrated a mean age of 61.05 ± 13.08 years (range: 33–82 years) with mean follow-up of 18.4 ± 8.9 months (range: 4.1–40.9 months) and average body mass index (BMI) of 24.66 ± 3.31 kg/m² (range: 17.69–35.86 kg/m²). Diagnostic stratification showed: osteonecrosis (40 cases), femoral neck fractures (20 cases), osteoarthritis (27 cases), DDH (4 cases), and other diagnoses (2 cases). Prosthetic specifications analysis revealed: Femoral head diameters 28 mm (13 cases), 32 mm (55 cases), 36 mm (25 cases) Acetabular cup dimensions :44 mm (6), 46 mm (3), 48 mm (38), 50 mm (7), 52 mm (20), 54 mm (10), 56 mm (6), 58 mm (3) For detailed information, the reader is advised to consult Table 1 . Table 1. Comparison of Baseline Characteristics and Measurement Parameters Between Two Surgical Approaches Parameter Postero-Lateral Approach (n=93) Lateral Approach (n=104) Statistic P-value Gender (cases, %) χ²=0.635 0.425 Male 43 (46.2%) 54 (51.9%) Female 50 (53.8%) 50 (48.1%) Femoral Head Diameter (cases) χ²=0.239 0.887 28 mm 13 16 32 mm 55 63 Acetabular Diameter (cases) χ²=7.364 0.498 44 mm 6 7 46 mm 3 10 48 mm 38 35 ≥50 mm 40 52 Age (years) 61.05 ± 13.08 59.63 ± 12.46 t=0.779 0.437 BMI (kg/m²) 24.66 ± 3.31 23.81 ± 3.58 t=1.679 0.095 Dislocation Information Postarthroplasty dislocation constitutes a clinical condition wherein the femoral head prosthesis becomes disengaged from the acetabular component. This complication induces ambulatory dysfunction accompanied by limb length discrepancy, representing a critical failure mode in total hip arthroplasty outcomes. Diagnostic confirmation required radiographic evidence from standardized anteroposterior and lateral hip projections. Within the data collection framework, prosthetic stability status was categorized dichotomously ("dislocated" vs. "non-dislocated") based on documented events during the postoperative surveillance period. This parameter serves as a key prosthetic failure indicator frequently necessitating revision surgery. Radiographic Measurements Comprehensive CT imaging spanning from the L4 vertebral body to the tibial tubercle was systematically acquired during postoperative evaluation. All digital imaging datasets were archived in DICOM-compliant format and processed through MIMICS 10.01 three-dimensional reconstruction software (Materialise NV, Leuven, Belgium) for quantitative analysis. To ensure measurement consistency, a standardized protocol was executed exclusively by an experienced musculoskeletal radiologist (PF), thereby optimizing intraobserver reliability throughout the morphometric assessment process. The study employed standardized measurement protocols to evaluate key prosthetic alignment parameters, including Cup Inclination , Cup Anteversion , Femoral Stem Anteversion , and Combined Anteversion (defined as the arithmetic sum of cup and stem anteversion angles). All angular measurements were conducted in accordance with validated techniques detailed in our prior published methodology [ 35 ] , utilizing three-dimensional coordinate system reconstructions to ensure anatomical reference consistency. Statistical Analysis Quantitative evaluations were conducted utilizing SPSS Statistics 27.0 (IBM Corp.) with rigorous adherence to parametric assumptions. Parametrically distributed variables were expressed as mean ± standard deviation (SD), while non-parametrically distributed datasets were characterized by mean values with 95% confidence intervals (95% CI). Bivariate correlations were quantified using Spearman's rho (ρ) nonparametric analysis with two-tailed significance testing, P < 0.05 corresponded to a significant difference. Clinical trial number Not applicable. Trial registration: Not applicable Result General Result Prospective surveillance of the cohort demonstrated complete absence of prosthetic dislocation events across all 270 cases (0% incidence rate). This zero-dislocation status persisted throughout both the immediate perioperative phase (inpatient period) and extended postoperative surveillance (mean duration: 22.2 months), as confirmed through serial clinical evaluations and radiographic monitoring. The Orientation of the Cup and Stem and the Combined Anteversion Inclination and Anteversion of the Cup Quantitative assessment of acetabular component orientation revealed mean inclination of 48.09°±8.54° (range:32.56°-62.59°) and anteversion of 29.09°±9.06° (range:13.28°-45.68°). When evaluated against the Lewinnek safety parameters (40°±10° inclination,15°±10° anteversion), 56 cases (60.22%) demonstrated optimal inclination alignment,while 31 cases (33.33%) achieved acceptable anteversion positioning. Concurrent compliance with both orientation parameters was observed in 18 patients(19.35%),underscoring the technical challenge of achieving dual-axis alignment precision（Fig.2）. Anteversion of the Stem Quantitative evaluation of femoral prosthesis orientation demonstrated a mean anteversion of 19.28°±11.28° (range:2.0°-47.6°). The angular distribution patterns for both acetabular and femoral components across the study cohort are graphically represented in Fig.3, illustrating the spatial relationship between prosthetic alignment parameters. Combined Anteversion The calculated combined anteversion (cup + stem) across the post-THA cohort demonstrated a mean value of 48.37°±13.04° (range:22.18°-75.44°). Spatial distribution patterns of both acetabular inclination and combined anteversion metrics are comprehensively visualized in Fig.4. When evaluated against the clinically recommended composite alignment target (25°-50°) proposed by Dorr et al [36] , only 30 cases (32.3%) achieved this dual-axis optimization threshold, highlighting significant variability in prosthetic coordination accuracy. Quantitative analysis demonstrated statistically significant elevations (p<0.05) in acetabular, femoral, and composite anteversion parameters within the posterolateral approach cohort compared to historical lateral approach data [35] . As detailed in Table 2, this surgical approach exhibited systematically increased values across all three orientation metrics, highlighting the biomechanical impact of access trajectory on prosthetic positioning accuracy. Comparison of Implant Angulation Measurements Across Surgical Studies This study and previous literature all utilized the posterolateral approach, yet implant angulation parameters differed (Table 3). The higher cup anteversion (29.09 ± 9.06°) compared to Dorr et al. (27.00 ± 4.60°) and Fujishiro et al. (~24.7°) may relate to intraoperative navigation or enhanced focus on hip stability. Dorr’s smaller SD (±4.60°) suggests standardized techniques, while Fujishiro’s larger cohorts (n>1400) likely reflect broader anatomical variability. The elevated cup inclination (48.09 ± 8.54° vs. Fujishiro’s ~41.0°) could arise from methodological differences (e.g., radiographic criteria) or prosthesis design evolution. Stem anteversion (19.28 ± 11.28°) fell between Dorr’s lower value (10.60°, possibly cementless fixation) and Fujishiro’s higher data (~40°, potential anatomical preferences). Combined anteversion (48.37 ± 13.04°) was lower than Fujishiro’s 65.00° but exceeded Dorr’s 37.60°, indicating shifting surgical goals: early emphasis on dislocation prevention versus modern balance between mobility and stability. These variations underscore the impact of technical advancements and patient-specific factors. Discussion The observed disparities in combined anteversion between posterolateral and lateral approaches arise from distinct anatomical exposures and technical frameworks. In our last study, we e hypothesized that the disturbed soft tissue in different approaches acts as a “door”for the femoral component head, and in this study our team verified this ourselves. Activities like sitting or squatting is the most commonly performed actions in our daily life. With these actions, the femoral head trend to dislocate form the posterior “door” which the posterolateral approach created. By contrast, the lateral approach opens an anterior-lateral “door”, and the femoral head is less likely to dislocate with actions like adduction and external rotation less used and can be avoided by patients with surgery’s instruction [ 35 , 37 ] . So, we trend to put the combined anteversion a little bigger operatively with the posterolateral approach and smaller with the lateral approach to achieve intraoperative stability, this explains well the higher combined anteversion angle in posterolateral approach patients than the lateral approach. Advantages of the Posterolateral Approach The posterolateral approach offers superior anatomical exposure through intermuscular dissection between the gluteus maximus and external rotators, enabling direct visualization of the posterior acetabulum and proximal femur for precise component positioning, particularly in complex cases like acetabular dysplasia or post-traumatic reconstruction. [ 32 , 35 ] Its broad acetabular exposure facilitates dynamic adjustments for spinopelvic mismatch, critical in patients with ankylosing spondylitis or spinal fusion [ 38 ] . Institutional data highlight a marked reduction in operative time versus anterior approaches in obese patients, alongside lower intraoperative complications during early learning phases. [ 28 ] Modern refinements, including augmented posterior capsular repair and "soft tissue-first" closure, restore near-complete native rotational stability, mitigating dislocation risks. [ 10 ] The approach accommodates expanded alignment parameters [ 21 ] , proving advantageous in cases with excessive femoral anteversion (> 30°) or acetabular retroversion, where Lewinnek’s "safe zone" is anatomically unachievable [ 17 ] . Preservation of the piriformis and the whole capsule and reconstruct it later with the short external rotators in our protocol may further enhance long-term stability, though validation requires future studies. These attributes position the posterolateral approach as a versatile solution for routine and complex arthroplasty, balancing efficiency with biomechanical adaptability. Limitations and Mitigation Strategies While our cohort demonstrated 0% dislocation rates through technical modifications, the posterolateral approach inherently presents challenges requiring strategic management. Achieving dual-axis Lewinnek safe zone compliance proved demanding, with only 19.35% of cases meeting both inclination (40°±10°) and anteversion (15°±10°) criteria—a limitation attributable to restricted anterior acetabular visualization during component positioning [ 29 ] . This technical complexity was reflected in our prosthetic alignment data: combined anteversion spanned 22.18°–75.44°, with only 32.3% of cases within the recommended 25°–50° range [ 10 ] . Achieving precise prosthetic implantation within the Lewinnek safe zone remains technically challenging in conventional total hip arthroplasty (THA). Current techniques rely heavily on surgeons' clinical experience and subjective visual estimation, even with bony landmark guidance, and are further complicated by interpatient anatomical variations. To address these limitations, integrating robotic-assisted surgical systems offers a promising solution to enhance implantation accuracy. Robotic navigation enables data-driven alignment optimization, mitigating human error and anatomical variability, thereby improving reproducibility of component positioning within biomechanically favorable parameters. While the posterolateral approach's inherent flexibility accommodates broader alignment ranges, coupling it with robotic precision may reconcile the tension between procedural adaptability and target compliance, potentially reducing long-term polyethylene wear risks associated with elevated anteversion. The approach's posterior exposure paradigm, while enabling greater anteversion flexibility, necessitated prolonged hip precautions (6-week postoperative restrictions) that may delay functional recovery [ 6 ] . However, our dislocation-free outcomes suggest modern closure protocols—emphasizing meticulous repair of external rotators and posterior capsule—effectively compensate for alignment variability [ 10 ] . Notably, even in cases exceeding traditional safe zones (67.7% beyond Dorr's combined anteversion thresholds), stability was maintained through optimized soft tissue tensioning [ 36 ] . Long-term considerations include potential polyethylene wear associated with elevated combined anteversion [ 4 ] . While our midterm data show no bearing-related revisions, we advocate selective use of advanced bearing surfaces in cases with > 55° combined anteversion [ 30 ] . Technical refinements such as intraoperative impingement testing and dynamic stability assessment were critical to balancing alignment flexibility with biomechanical safety [ 3 ] , demonstrating that judicious technique can mitigate historical limitations of this approach. This investigation has several limitations that should be acknowledged. Firstly, as a single-center retrospective study with a limited cohort of 270 patients, the findings may be influenced by institution-specific protocols and selection biases, necessitating cautious extrapolation to broader clinical settings. Secondly, the absence of postoperative dislocation events precludes comparative biomechanical analyses between stable and unstable prosthetic hips, restricting objective evaluation of instability risk factors. Thirdly, all procedures were performed by senior arthroplasty surgeons, potentially introducing performance bias that may overestimate outcomes compared to routine clinical practice. Additionally, reliance on radiographic assessments without patient-reported functional metrics may overlook early signs of subclinical instability or impingement syndromes. Future research incorporating multicenter designs, extended follow-up periods (> 5 years), dynamic spinopelvic kinematic analyses, and patient-reported outcome measures is recommended to comprehensively evaluate determinants of prosthetic stability. Future multicenter studies incorporating extended follow-up and dynamic spinopelvic assessments are warranted to address these limitations. Conclusion The comparative analysis revealed that the posterolateral surgical approach demonstrated statistically significant increases in key acetabular alignment parameters, including acetabular component inclination, acetabular anteversion, femoral stem anteversion, and combined anteversion, when compared to the lateral approach. The utilization of a single-center cohort design with standardized surgical protocols effectively mitigated potential confounding variables arising from surgeon-specific variability in technique execution. This methodological uniformity enhances the validity of the comparative measurements and supports the robustness of the observed differences in prosthetic positioning between the two approaches. Abbreviations PLA (Posterolateral Approach)、THA (Total Hip Arthroplasty) 、CA (Combined Anteversion)、DDH (Developmental Dysplasia of the Hip) Declarations Ethics approval and consent to participate This retrospective cohort study was conducted in accordance with the Declaration of Helsinki. Ethical approval was waived by the Institutional Review Board (IRB) of the Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, as retrospective analyses of anonymized clinical data are exempt from formal ethics review per institutional policy. Written informed consent for the use of medical records and imaging data was obtained from all participants prior to surgery. Consent for publication Not applicable. This manuscript contains no individually identifiable personal clinical data or images requiring separate publication consent. Availability of data and materials The data are not publicly available due to patient privacy restrictions but are available from the corresponding author upon reasonable request. Competing Interests The authors declare that they have no conflict of interest. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Authors' contributions Tian-long Pan: Conceptualization, Writing Original Draft, Writing Review and Editing. Qiao Wei: Data Curation, Formal Analysis, Investigation. Pei Fan: Methodology, Validation, Resources, Supervision. Zhen-xing Li: Study Design, Project Administration, Writing Review and Editing, Final Approval. All authors critically reviewed the manuscript and approved the final version for submission. Acknowledgements Not applicable References Charnley J. Arthroplasty of the hip. A new operation[J]. Lancet, 1961,1(7187):1129-1132. Engh C A, Bobyn J D, Glassman A H. Porous-coated hip replacement. The factors governing bone ingrowth, stress shielding, and clinical results[J]. J Bone Joint Surg Br, 1987,69(1):45-55. Charnley J. Total prosthetic replacement of the hip[J]. Reconstr Surg Traumatol, 1969,11:9-19. Kurtz S M, Muratoglu O K, Evans M, et al. Advances in the processing, sterilization, and crosslinking of ultra-high molecular weight polyethylene for total joint arthroplasty[J]. Biomaterials, 1999,20(18):1659-1688. Learmonth I D, Young C, Rorabeck C. The operation of the century: total hip replacement[J]. Lancet, 2007,370(9597):1508-1519. Bergin P F, Doppelt J D, Kephart C J, et al. Comparison of minimally invasive direct anterior versus posterior total hip arthroplasty based on inflammation and muscle damage markers[J]. J Bone Joint Surg Am, 2011,93(15):1392-1398. Harris W H. The problem is osteolysis[J]. Clin Orthop Relat Res, 1995(311):46-53. Zimmerli W. Infection and musculoskeletal conditions: Prosthetic-joint-associated infections[J]. Best Pract Res Clin Rheumatol, 2006,20(6):1045-1063. Morgan S, Bourget-Murray J, Garceau S, et al. Revision total hip arthroplasty for periprosthetic fracture: epidemiology, outcomes, and factors associated with success[J]. Ann Jt, 2023,8:30. Deng Y, Kieser D, Wyatt M, et al. Risk factors for periprosthetic femoral fractures around total hip arthroplasty: a systematic review and meta-analysis[J]. ANZ J Surg, 2020,90(4):441-447. Schwarzkopf R, Oni J K, Marwin S E. Total hip arthroplasty periprosthetic femoral fractures: a review of classification and current treatment[J]. Bull Hosp Jt Dis (2013), 2013,71(1):68-78. Gausden E B, Parhar H S, Popper J E, et al. Risk Factors for Early Dislocation Following Primary Elective Total Hip Arthroplasty[J]. J Arthroplasty, 2018,33(5):1567-1571. Kurtz S, Ong K, Lau E, et al. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030[J]. J Bone Joint Surg Am, 2007,89(4):780-785. Bozic K J, Lau E, Ong K, et al. Risk factors for early revision after primary total hip arthroplasty in Medicare patients[J]. Clin Orthop Relat Res, 2014,472(2):449-454. Rowan F E, Benjamin B, Pietrak J R, et al. Prevention of Dislocation After Total Hip Arthroplasty[J]. J Arthroplasty, 2018,33(5):1316-1324. Dargel J, Oppermann J, Bruggemann G P, et al. Dislocation following total hip replacement[J]. Dtsch Arztebl Int, 2014,111(51-52):884-890. Lewinnek G E, Lewis J L, Tarr R, et al. Dislocations after total hip-replacement arthroplasties[J]. J Bone Joint Surg Am, 1978,60(2):217-220. Gausden E B, Parhar H S, Popper J E, et al. Risk Factors for Early Dislocation Following Primary Elective Total Hip Arthroplasty[J]. J Arthroplasty, 2018,33(5):1567-1571. Odland A N, Sierra R J. Intraprosthetic dislocation of a contemporary dual-mobility design used during conversion THA[J]. Orthopedics, 2014,37(12):e1124-e1128. Fleischman A N, Tarabichi M, Magner Z, et al. Mechanical Complications Following Total Hip Arthroplasty Based on Surgical Approach: A Large, Single-Institution Cohort Study[J]. J Arthroplasty, 2019,34(6):1255-1260. Widmer K H, Zurfluh B. Compliant positioning of total hip components for optimal range of motion[J]. J Orthop Res, 2004,22(4):815-821. Zhu B, Su C, He Y, et al. Combined anteversion technique in total hip arthroplasty for Crowe IV developmental dysplasia of the hip[J]. Hip Int, 2017,27(6):589-594. Amuwa C, Dorr L D. The combined anteversion technique for acetabular component anteversion[J]. J Arthroplasty, 2008,23(7):1068-1070. Kennedy J G, Rogers W B, Soffe K E, et al. Effect of acetabular component orientation on recurrent dislocation, pelvic osteolysis, polyethylene wear, and component migration[J]. J Arthroplasty, 1998,13(5):530-534. McCollum D E, Gray W J. Dislocation after total hip arthroplasty. Causes and prevention[J]. Clin Orthop Relat Res, 1990(261):159-170. Widmer K H. A simplified method to determine acetabular cup anteversion from plain radiographs[J]. J Arthroplasty, 2004,19(3):387-390. Heller M O, Bergmann G, Deuretzbacher G, et al. Influence of femoral anteversion on proximal femoral loading: measurement and simulation in four patients[J]. Clin Biomech (Bristol), 2001,16(8):644-649. Riviere C, Lazennec J Y, Van Der Straeten C, et al. The influence of spine-hip relations on total hip replacement: A systematic review[J]. Orthop Traumatol Surg Res, 2017,103(4):559-568. Ogilvie A, Kim W J, Asirvatham R D, et al. Robotic-Arm-Assisted Total Hip Arthroplasty: A Review of the Workflow, Outcomes and Its Role in Addressing the Challenge of Spinopelvic Imbalance[J]. Medicina (Kaunas), 2022,58(11). Teja T, Shrivastava S, Choudhary A, et al. Optimizing Acetabular Positioning: A Comprehensive Review of Contemporary Strategies in Total Hip Arthroplasty[J]. Cureus, 2024,16(4):e59114. Masonis J L, Bourne R B. Surgical approach, abductor function, and total hip arthroplasty dislocation[J]. Clin Orthop Relat Res, 2002(405):46-53. Pellicci P M, Bostrom M, Poss R. Posterior approach to total hip replacement using enhanced posterior soft tissue repair[J]. Clin Orthop Relat Res, 1998(355):224-228. Kwon M S, Kuskowski M, Mulhall K J, et al. Does surgical approach affect total hip arthroplasty dislocation rates?[J]. Clin Orthop Relat Res, 2006,447:34-38. Ang J, Onggo J R, Stokes C M, et al. Comparing direct anterior approach versus posterior approach or lateral approach in total hip arthroplasty: a systematic review and meta-analysis[J]. Eur J Orthop Surg Traumatol, 2023,33(7):2773-2792. Li L, Zhang Y, Lin Y Y, et al. A Specific Anteversion of Cup and Combined Anteversion for Total Hip Arthroplasty Using Lateral Approach[J]. Orthop Surg, 2020,12(6):1663-1673. Dorr L D, Malik A, Dastane M, et al. Combined anteversion technique for total hip arthroplasty[J]. Clin Orthop Relat Res, 2009,467(1):119-127. Kwon M S, Kuskowski M, Mulhall K J, et al. Does surgical approach affect total hip arthroplasty dislocation rates?[J]. Clin Orthop Relat Res, 2006,447:34-38. Hoskins W, Dowsey M M, Spelman T, et al. Early surgical complications of total hip arthroplasty related to surgical approach[J]. ANZ J Surg, 2020,90(10):2050-2055. Tables Table 1. Comparison of Baseline Characteristics and Measurement Parameters Between Two Surgical Approaches Parameter Postero-Lateral Approach (n=93) Lateral Approach (n=104) Statistic P-value Gender (cases, %) χ²=0.635 0.425 Male 43 (46.2%) 54 (51.9%) Female 50 (53.8%) 50 (48.1%) Femoral Head Diameter (cases) χ²=0.239 0.887 28 mm 13 16 32 mm 55 63 Acetabular Diameter (cases) χ²=7.364 0.498 44 mm 6 7 46 mm 3 10 48 mm 38 35 ≥50 mm 40 52 Age (years) 61.05 ± 13.08 59.63 ± 12.46 t=0.779 0.437 BMI (kg/m²) 24.66 ± 3.31 23.81 ± 3.58 t=1.679 0.095 Table 2. Comparative Analysis of Implant Angulation in Two Surgical Approaches Parameter Posterior-Lateral Approach (n=93) Lateral Approach (n=104) t-value P-value Anteversion of Cup (°) 29.09 ± 9.06 9.26 ± 11.19 13.56 <0.01 Inclination of Cup (°) 48.09 ± 8.54 38.83 ± 5.04 9.34 <0.01 Anteversion of Stem (°) 19.28 ± 11.28 13.83 ± 10.71 3.48 <0.01 Combined Anteversion (°) 48.37 ± 13.04 23.09 ± 13.39 13.39 <0.01 Table 3. Comparison of Implant Angulation Measurements Across Surgical Studies Study Anteversion of Cup (°) Inclination of Cup (°) Anteversion of Stem (°) Combined Anteversion (°) Current Study (n=93) 29.09 ± 9.06 48.09 ± 8.54 19.28 ± 11.28 48.37 ± 13.04 Dorr et al. (2009) (n=47) 27.00 ± 4.60 — 10.60 ± 8.00 37.60 ± 7.00 Fujishiro et al. (2014) (n=1411) 24.70 ± 11.30 41.0 ± 6.2 40.30 ± 11.30 65.00 ± 15.70 Fujishiro et al. (2016) (n=1555) 24.50 ± 11.40 40.9 ± 6.05 39.90 ± 11.60 — Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6924553","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":497644571,"identity":"dd5b8bfe-e0d5-4bd4-ba9d-249fac710183","order_by":0,"name":"Tian-long Pan","email":"","orcid":"","institution":"Second Affiliated Hospital \u0026 Yuying Children's Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Tian-long","middleName":"","lastName":"Pan","suffix":""},{"id":497644572,"identity":"208221c0-5f48-4d62-94c8-d4c4a7a541b7","order_by":1,"name":"Qiao Wei","email":"","orcid":"","institution":"Second Affiliated Hospital \u0026 Yuying Children's Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Qiao","middleName":"","lastName":"Wei","suffix":""},{"id":497644573,"identity":"1f11be89-1bd0-4688-ad0c-4679306ca443","order_by":2,"name":"Pei Fan","email":"","orcid":"","institution":"Second Affiliated Hospital \u0026 Yuying Children's Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Pei","middleName":"","lastName":"Fan","suffix":""},{"id":497644574,"identity":"ffd38a50-682d-4185-9f36-9f5fc21144e6","order_by":3,"name":"Zhen-xing Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7klEQVRIiWNgGAWjYBACPmYGNhDNwwChbXj4+Rvwa2FD05ImIznjAAEtUKUMUPqwjUFDAgEt7OzPHnzccVjGnH9ZmuSPP+d5DBgOMH74mIPXYemGM8+k8VjOeHZMmrftNo85cwOz5MxteLWAVNrwGNw43nabseE2j2XDATZmXrxaGNuk/7ZJgLXc/PHnHI/BgQRCWpjZpBlBtpxvO3aDh+0AMVrY2CR729KAtrCl/+ZtS+aRnHGwGa9f+PmPP5P42XbY3uD8MWPDH3/s7Pn5mw9++IhHCwJIJMBYjA3EqAfZd4BIhaNgFIyCUTDiAAAqEUs0dhC+WgAAAABJRU5ErkJggg==","orcid":"","institution":"Second Affiliated Hospital \u0026 Yuying Children's Hospital of Wenzhou Medical University","correspondingAuthor":true,"prefix":"","firstName":"Zhen-xing","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2025-06-18 15:38:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6924553/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6924553/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88781053,"identity":"70fdd3c6-4fbc-45ad-85fa-d5532e9e1cce","added_by":"auto","created_at":"2025-08-11 10:50:11","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":911185,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTHA adopts the posterior lateral approach method.（A）A curvilinear incision centered over the posterior third of the greater trochanter.（B）Part of the iliotibial tract and the gluteus maximus was split. （C-D）A L-shaped capsulotomy was made below the piriformis and above the quadratus femoris with the short external rotators cut at same time.（E-F）The hemispherical cup was positioned using the transverse acetabular ligament or the native acetabular rim or patient position as the guide.（G）Femoral broaching was performed in 10°-15° anteversion under direct visualization. (This Figure requires color printing)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6924553/v1/ae6173156ffe808819ae852a.png"},{"id":88781054,"identity":"d6bec2fd-3d37-4b72-b772-c8a16c940acb","added_by":"auto","created_at":"2025-08-11 10:50:11","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":102974,"visible":true,"origin":"","legend":"\u003cp\u003eScatter plots depicting the anteversion and inclination of the cup. The rectangle shows the hips that were within the Lewinnek safe zones.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6924553/v1/b3686c648b70fff3ce4c8a58.png"},{"id":88781056,"identity":"75a40968-8a7c-4905-b408-f1e70dced7ba","added_by":"auto","created_at":"2025-08-11 10:50:11","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":81517,"visible":true,"origin":"","legend":"\u003cp\u003eScatter plots depicting the anteversion angles of the cup and stem.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6924553/v1/e1a64e1771d258d1638ceda9.png"},{"id":88781057,"identity":"3d2a6738-7496-44eb-9dab-b0d5b45d117d","added_by":"auto","created_at":"2025-08-11 10:50:11","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":92018,"visible":true,"origin":"","legend":"\u003cp\u003eScatter plots depicting the inclination of the cup and the combined anteversion. The rectangle shows the hips with an inclinationof 40°±10° and a combined anteversion angle from 25°to 50°.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6924553/v1/35b629b208f61b31b7b9aeea.png"},{"id":90309619,"identity":"1682c364-af72-4d8a-b1a7-2f13c979487e","added_by":"auto","created_at":"2025-09-01 09:39:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2883905,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6924553/v1/042a8ac5-275c-4e19-a9d8-c426ec46e8b9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparative Efficacy of Posterolateral versus Lateral Approach in Total Hip Arthroplasty: A Retrospective Cohort Study on Prosthetic Alignment and Stability","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTotal hip arthroplasty (THA) has emerged as one of the most transformative advancements in modern orthopaedics, revolutionizing the management of end-stage hip pathologies such as osteoarthritis, avascular necrosis, and traumatic fractures\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. Since its inception in the early 20th century, THA has undergone significant evolution in implant design, surgical techniques, and biomaterials, substantially improving patient outcomes and quality of life\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. The pioneering work of Sir John Charnley in the 1960s, which introduced low-friction arthroplasty using metal-on-polyethylene bearings and acrylic bone cement, laid the foundation for modern THA\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. Subsequent innovations, including cementless fixation, highly cross-linked polyethylene, ceramic-on-ceramic interfaces, and advanced bearing surfaces, have further enhanced implant longevity and functional performance\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe primary advantages of THA are well-documented. It reliably alleviates pain, restores joint function, and improves mobility in over 90% of patients, with survival rates exceeding 90% at 15\u0026ndash;20 years for contemporary implants\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e. Minimally invasive approaches and computer-assisted navigation have reduced intraoperative trauma and improved component alignment accuracy\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Additionally, the advent of rapid recovery protocols and outpatient THA has optimized healthcare resource utilization. However, challenges persist. Long-term complications such as aseptic loosening, periprosthetic osteolysis, and polyethylene wear remain concerns, particularly in younger, active patients\u003csup\u003e[\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. The risk of dislocation, infection, and periprosthetic fractures necessitates careful patient selection and surgical precision\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Furthermore, revision surgeries, though declining in incidence, are complex and associated with higher morbidity rates due to bone loss and soft-tissue compromise.\u003c/p\u003e\u003cp\u003eTotal hip arthroplasty (THA) is a highly successful procedure for restoring function in patients with end-stage hip pathologies, yet postoperative complications remain a critical concern. Among these, hip dislocation is the second most common reason for early revision surgery, with reported incidences of 1\u0026ndash;3% after primary THA and up to 20% following revision procedures\u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e. Dislocation not only causes acute pain and functional impairment but also escalates long-term risks of prosthesis loosening, periprosthetic fractures, and repeated surgical interventions, significantly diminishing patient quality of life \u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe etiology of dislocation is multifactorial, involving both biomechanical and patient-specific factors. Malpositioning of the acetabular cup or femoral stem\u0026mdash;particularly deviations from the Lewinnek \"safe zone\" (cup abduction 40\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u0026deg;, anteversion 15\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u0026deg;)\u0026mdash;is a well-documented surgical risk, as improper component alignment increases impingement and reduces the effective jump distance \u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. Additionally, soft tissue deficiencies (e.g., inadequate repair of the posterior capsule in the posterior approach) and patient factors such as advanced age, neuromuscular disorders, and noncompliance with postoperative restrictions further exacerbate instability \u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. While advancements in implant design (e.g., dual-mobility bearings) and surgical techniques (e.g., anterior approach) have mitigated dislocation rates, disparities persist in high-risk populations, including those with spinal stiffness or obesity\u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e .\u003c/p\u003e\u003cp\u003eCombined anteversion (CA), defined as the sum of the acetabular component anteversion and the femoral stem anteversion relative to the anatomical planes, plays a pivotal role in optimizing hip joint biomechanics\u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. Historically, acetabular and femoral anteversion were evaluated independently, guided by classical criteria such as the Lewinnek \"safe zone\"\u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e for acetabular positioning (40\u0026deg; \u0026plusmn; 10\u0026deg; inclination and 15\u0026deg; \u0026plusmn; 10\u0026deg; anteversion). However, emerging evidence suggests that isolated measurements may fail to account for the dynamic interplay between the two components during functional activities\u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. For instance, excessive or insufficient combined anteversion can lead to edge-loading, impingement during hip rotation, or instability, increasing dislocation risks\u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe clinical significance of CA lies in its ability to harmonize stability and range of motion\u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. Biomechanical studies demonstrate that appropriate CA (typically 25\u0026deg;\u0026ndash;45\u0026deg;) reduces prosthetic impingement, minimizes polyethylene wear, and enhances joint stability by maintaining optimal contact stress distribution\u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. Furthermore, CA principles are particularly critical in addressing patient-specific variations, such as spinal-pelvic mobility patterns or femoral morphology, which demand personalized component alignment\u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e. Despite its theoretical advantages, debates persist regarding standardized measurement techniques and ideal CA targets across different surgical approaches (e.g., posterior vs. direct anterior). Additionally, advancements in robotic-assisted THA and dynamic imaging have refined CA optimization, yet clinical validation remains heterogeneous\u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe posterolateral approach (PLA) remains a cornerstone in total hip arthroplasty (THA) due to its anatomical accessibility and technical reproducibility. By utilizing the interval between the gluteus maximus and medius, PLA preserves critical abductor muscles, minimizing postoperative gait dysfunction while providing direct visualization of the acetabulum and proximal femur\u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e. Historically criticized for higher dislocation rates (5\u0026ndash;10%), modern modifications\u0026mdash;including enhanced capsular repair, optimized component positioning (combined anteversion: 25\u0026deg;\u0026ndash;45\u0026deg;), and large-diameter femoral heads\u0026mdash;have reduced instability risks to \u0026lt;\u0026thinsp;1%, comparable to anterior approaches\u003csup\u003e[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/sup\u003e. Additionally, PLA\u0026rsquo;s adaptability to complex cases (e.g., dysplasia, revisions) and shorter learning curve make it particularly advantageous for surgeons transitioning to THA\u003csup\u003e[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eOur research group has previously measured parameters such as the acetabular anteversion angle, femoral stem anteversion angle, and combined anteversion angle via the anterolateral approach, and compared these findings with relevant literature data published hitherto\u003csup\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/sup\u003e. However, a simultaneous comparison of data related to the two surgical approaches has not been conducted within the same center. Consequently, this study has once again collected pertinent data from patients who underwent the posterolateral approach in our hospital, and compared it with the data of patients who underwent the anterolateral approach in previous studies, aiming to explore the advantages and disadvantages of the two surgical approaches.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e\u003cb\u003eInclusion and Exclusion Criteria\u003c/b\u003e\u003c/p\u003e\u003cp\u003eEligibility criteria were defined as follows: Inclusion requirements comprised: 1) Adult subjects undergoing primary total hip arthroplasty (THA) via posterolateral approach for advanced hip pathologies between January 2017 and December 2021, utilizing cementless fixation components; 2) Availability of postoperative CT-based measurements for implant positioning parameters including acetabular cup inclination, cup/stem anteversion angles, and combined anteversion values; 3) Documentation of postoperative dislocation events and comprehensive implant orientation data. The study design followed a retrospective analysis framework. Exclusion parameters eliminated: 1) Revision arthroplasty procedures; 2) Cases complicated by periprosthetic fractures during surveillance periods;3) Cases with incomplete data recording.\u003c/p\u003e\u003cp\u003e\u003cb\u003eSurgical Procedures\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe surgical procedure was uniformly performed through a posterolateral approach, with technical modifications as follows: (i) \u003cb\u003eAnesthesia and positioning\u003c/b\u003e: All procedures were conducted under general or spinal anesthesia with patients in standardized lateral decubitus position, maintaining 30\u0026deg; hip flexion for optimal posterior access. (ii) \u003cb\u003eSurgical exposure\u003c/b\u003e: A curvilinear incision centered over the posterior third of the greater trochanter (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA) allowed identification of the iliotibial tract and gluteus maximus fibers (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). Following fascial division, blunt dissection through the gluteus maximus fibers exposed the short external rotators (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). Different form some authors, we resected part of the short external rotators including the superior gemellus, obturator internus, inferior gemellus, and part of the quadratus femoris with the piriformis tendon preserved, then a L-shaped capsulotomy provided full visualization of the femoral head and acetabulum. (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eD) (iii)\u003cb\u003eArticular dislocation\u003c/b\u003e: The hip was dislocated posteriorly through combined flexion and internal rotation, preserving anterior soft tissue integrity. (iv) \u003cb\u003eImplant placement\u003c/b\u003e: Acetabular preparation preceded femoral preparation to enhance exposure. The hemispherical cup was positioned using the transverse acetabular ligament or the native acetabular rim or patient position as the guide. (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eE-F). Femoral broaching was performed in 10\u0026deg;-15\u0026deg; anteversion under direct visualization, with trial reduction verifying appropriate leg length and offset (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eG). (v)\u003cb\u003eClosure and stabilization\u003c/b\u003e: Meticulous repair of the posterior capsule together with the external rotators to the greater trochanter using non-absorbable sutures was prioritized to enhance postoperative stability. All cases utilized cementless components: acetabular shells included Pinnacle (DePuy), Trabecular Metal (Zimmer), and Trident (Stryker); femoral stems comprised Trilock (DePuy), Trabecular Metal (Zimmer), and Accolade (Stryker). Postoperative rehabilitation emphasized early mobilization with hip precaution protocols.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eData Acquisition\u003c/b\u003e\u003c/p\u003e\u003cp\u003eStudy data were obtained through tripartite collection modalities comprising structured telephone interviews, WeChat-based digital questionnaires (Tencent Holdings Ltd., Shenzhen, China), and clinical follow-up assessments. The protocol systematically captured two discrete data domains: baseline population characteristics and postoperative prosthetic stability parameters.\u003c/p\u003e\u003cp\u003e\u003cb\u003eDemographics\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe initial cohort comprised 318 consecutive patients who underwent primary total hip arthroplasty (THA) via a standardized posterolateral approach performed by an attending orthopaedic surgeon within our department. Following exclusion of 48 subjects lost to follow-up and 2 deceased cases, 270 patients (138 males, 132 females) completed the study protocol. Demographic analysis revealed a mean age of 63.97\u0026thinsp;\u0026plusmn;\u0026thinsp;9.72 years (range: 21\u0026ndash;89 years) with mean follow-up duration of 22.2\u0026thinsp;\u0026plusmn;\u0026thinsp;10.7 months (range: 4.1\u0026ndash;44.6 months). Diagnostic distribution included: osteonecrosis of the femoral head (118 cases, 43.7%), femoral neck fractures (46 cases, 17.0%), primary hip osteoarthritis (87 cases, 32.2%), developmental dysplasia of the hip (DDH, 12 cases, 4.4%), and miscellaneous etiologies (7 cases, 2.6%).\u003c/p\u003e\u003cp\u003eA subgroup of 93 patients underwent postoperative computed tomography (CT) evaluation spanning from the L4 vertebral level to tibial tuberosity. This imaging cohort (43 males, 50 females) demonstrated a mean age of 61.05\u0026thinsp;\u0026plusmn;\u0026thinsp;13.08 years (range: 33\u0026ndash;82 years) with mean follow-up of 18.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9 months (range: 4.1\u0026ndash;40.9 months) and average body mass index (BMI) of 24.66\u0026thinsp;\u0026plusmn;\u0026thinsp;3.31 kg/m\u0026sup2; (range: 17.69\u0026ndash;35.86 kg/m\u0026sup2;). Diagnostic stratification showed: osteonecrosis (40 cases), femoral neck fractures (20 cases), osteoarthritis (27 cases), DDH (4 cases), and other diagnoses (2 cases).\u003c/p\u003e\u003cp\u003eProsthetic specifications analysis revealed:\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eFemoral head diameters\u003c/strong\u003e\u003cp\u003e28 mm (13 cases), 32 mm (55 cases), 36 mm (25 cases)\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eAcetabular cup dimensions\u003c/b\u003e :44 mm (6), 46 mm (3), 48 mm (38), 50 mm (7), 52 mm (20), 54 mm (10), 56 mm (6), 58 mm (3)\u003c/p\u003e\u003cp\u003eFor detailed information, the reader is advised to consult Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 1. Comparison of Baseline Characteristics and Measurement Parameters Between Two Surgical Approaches\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePostero-Lateral Approach (n=93)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLateral Approach (n=104)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eStatistic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eP-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eGender (cases, %)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026chi;\u0026sup2;=0.635\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.425\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e43 (46.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e54 (51.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e50 (53.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e50 (48.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFemoral Head Diameter (cases)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026chi;\u0026sup2;=0.239\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.887\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e28 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e32 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAcetabular Diameter (cases)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026chi;\u0026sup2;=7.364\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.498\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e44 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e46 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e48 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ge;50 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAge (years)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e61.05 \u0026plusmn; 13.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e59.63 \u0026plusmn; 12.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003et=0.779\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.437\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBMI (kg/m\u0026sup2;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24.66 \u0026plusmn; 3.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e23.81 \u0026plusmn; 3.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003et=1.679\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.095\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\u003cp\u003e\u003cb\u003eDislocation Information\u003c/b\u003e\u003c/p\u003e\u003cp\u003ePostarthroplasty dislocation constitutes a clinical condition wherein the femoral head prosthesis becomes disengaged from the acetabular component. This complication induces ambulatory dysfunction accompanied by limb length discrepancy, representing a critical failure mode in total hip arthroplasty outcomes. Diagnostic confirmation required radiographic evidence from standardized anteroposterior and lateral hip projections. Within the data collection framework, prosthetic stability status was categorized dichotomously (\"dislocated\" vs. \"non-dislocated\") based on documented events during the postoperative surveillance period. This parameter serves as a key prosthetic failure indicator frequently necessitating revision surgery.\u003c/p\u003e\u003cp\u003e\u003cb\u003eRadiographic Measurements\u003c/b\u003e\u003c/p\u003e\u003cp\u003eComprehensive CT imaging spanning from the L4 vertebral body to the tibial tubercle was systematically acquired during postoperative evaluation. All digital imaging datasets were archived in DICOM-compliant format and processed through MIMICS 10.01 three-dimensional reconstruction software (Materialise NV, Leuven, Belgium) for quantitative analysis. To ensure measurement consistency, a standardized protocol was executed exclusively by an experienced musculoskeletal radiologist (PF), thereby optimizing intraobserver reliability throughout the morphometric assessment process. The study employed standardized measurement protocols to evaluate key prosthetic alignment parameters, including \u003cem\u003eCup Inclination\u003c/em\u003e, \u003cem\u003eCup Anteversion\u003c/em\u003e, \u003cem\u003eFemoral Stem Anteversion\u003c/em\u003e, and \u003cem\u003eCombined Anteversion\u003c/em\u003e (defined as the arithmetic sum of cup and stem anteversion angles). All angular measurements were conducted in accordance with validated techniques detailed in our prior published methodology\u003csup\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/sup\u003e, utilizing three-dimensional coordinate system reconstructions to ensure anatomical reference consistency.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eQuantitative evaluations were conducted utilizing SPSS Statistics 27.0 (IBM Corp.) with rigorous adherence to parametric assumptions. Parametrically distributed variables were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), while non-parametrically distributed datasets were characterized by mean values with 95% confidence intervals (95% CI). Bivariate correlations were quantified using Spearman's rho (ρ) nonparametric analysis with two-tailed significance testing, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 corresponded to a significant difference.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eClinical trial number\u003c/strong\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTrial registration:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e"},{"header":"Result","content":"\u003cp\u003e\u003cstrong\u003eGeneral Result\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Prospective surveillance of the cohort demonstrated complete absence of prosthetic dislocation events across all 270 cases (0% incidence rate). This zero-dislocation status persisted throughout both the immediate perioperative phase (inpatient period) and extended postoperative surveillance (mean duration: 22.2 months), as confirmed through serial clinical evaluations and radiographic monitoring.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Orientation of the Cup and Stem and the Combined Anteversion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclination and Anteversion of the Cup\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Quantitative assessment of acetabular component orientation revealed mean inclination of 48.09\u0026deg;\u0026plusmn;8.54\u0026deg; (range:32.56\u0026deg;-62.59\u0026deg;) and anteversion of 29.09\u0026deg;\u0026plusmn;9.06\u0026deg; (range:13.28\u0026deg;-45.68\u0026deg;). When evaluated against the Lewinnek safety parameters (40\u0026deg;\u0026plusmn;10\u0026deg; inclination,15\u0026deg;\u0026plusmn;10\u0026deg; anteversion), 56 cases (60.22%) demonstrated optimal inclination alignment,while 31 cases (33.33%) achieved acceptable anteversion positioning. Concurrent compliance with both orientation parameters was observed in 18 patients(19.35%),underscoring the technical challenge of achieving dual-axis alignment precision（Fig.2）.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAnteversion of the Stem\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Quantitative evaluation of femoral prosthesis orientation demonstrated a mean anteversion of 19.28\u0026deg;\u0026plusmn;11.28\u0026deg; (range:2.0\u0026deg;-47.6\u0026deg;). The angular distribution patterns for both acetabular and femoral components across the study cohort are graphically represented in Fig.3, illustrating the spatial relationship between prosthetic alignment parameters.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCombined Anteversion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The calculated combined anteversion (cup + stem) across the post-THA cohort demonstrated a mean value of 48.37\u0026deg;\u0026plusmn;13.04\u0026deg; (range:22.18\u0026deg;-75.44\u0026deg;). Spatial distribution patterns of both acetabular inclination and combined anteversion metrics are comprehensively visualized in Fig.4. When evaluated against the clinically recommended composite alignment target (25\u0026deg;-50\u0026deg;) proposed by Dorr et al\u003csup\u003e[36]\u003c/sup\u003e, only 30 cases (32.3%) achieved this dual-axis optimization threshold, highlighting significant variability in prosthetic coordination accuracy.\u003c/p\u003e\n\u003cp\u003eQuantitative analysis demonstrated statistically significant elevations (p\u0026lt;0.05) in acetabular, femoral, and composite anteversion parameters within the posterolateral approach cohort compared to historical lateral approach data\u003csup\u003e[35]\u003c/sup\u003e. As detailed in Table 2, this surgical approach exhibited systematically increased values across all three orientation metrics, highlighting the biomechanical impact of access trajectory on prosthetic positioning accuracy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison of Implant Angulation Measurements Across Surgical Studies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study and previous literature all utilized the posterolateral approach, yet implant angulation parameters differed (Table 3). The higher cup anteversion (29.09 \u0026plusmn; 9.06\u0026deg;) compared to Dorr et al. (27.00 \u0026plusmn; 4.60\u0026deg;) and Fujishiro et al. (~24.7\u0026deg;) may relate to intraoperative navigation or enhanced focus on hip stability. Dorr\u0026rsquo;s smaller SD (\u0026plusmn;4.60\u0026deg;) suggests standardized techniques, while Fujishiro\u0026rsquo;s larger cohorts (n\u0026gt;1400) likely reflect broader anatomical variability. The elevated cup inclination (48.09 \u0026plusmn; 8.54\u0026deg; vs. Fujishiro\u0026rsquo;s ~41.0\u0026deg;) could arise from methodological differences (e.g., radiographic criteria) or prosthesis design evolution. Stem anteversion (19.28 \u0026plusmn; 11.28\u0026deg;) fell between Dorr\u0026rsquo;s lower value (10.60\u0026deg;, possibly cementless fixation) and Fujishiro\u0026rsquo;s higher data (~40\u0026deg;, potential anatomical preferences). Combined anteversion (48.37 \u0026plusmn; 13.04\u0026deg;) was lower than Fujishiro\u0026rsquo;s 65.00\u0026deg; but exceeded Dorr\u0026rsquo;s 37.60\u0026deg;, indicating shifting surgical goals: early emphasis on dislocation prevention versus modern balance between mobility and stability. These variations underscore the impact of technical advancements and patient-specific factors.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe observed disparities in combined anteversion between posterolateral and lateral approaches arise from distinct anatomical exposures and technical frameworks. In our last study, we e hypothesized that the disturbed soft tissue in different approaches acts as a \u0026ldquo;door\u0026rdquo;for the femoral component head, and in this study our team verified this ourselves. Activities like sitting or squatting is the most commonly performed actions in our daily life. With these actions, the femoral head trend to dislocate form the posterior \u0026ldquo;door\u0026rdquo; which the posterolateral approach created. By contrast, the lateral approach opens an anterior-lateral \u0026ldquo;door\u0026rdquo;, and the femoral head is less likely to dislocate with actions like adduction and external rotation less used and can be avoided by patients with surgery\u0026rsquo;s instruction\u003csup\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]\u003c/sup\u003e. So, we trend to put the combined anteversion a little bigger operatively with the posterolateral approach and smaller with the lateral approach to achieve intraoperative stability, this explains well the higher combined anteversion angle in posterolateral approach patients than the lateral approach.\u003c/p\u003e\u003cp\u003e\u003cb\u003eAdvantages of the Posterolateral Approach\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe posterolateral approach offers superior anatomical exposure through intermuscular dissection between the gluteus maximus and external rotators, enabling direct visualization of the posterior acetabulum and proximal femur for precise component positioning, particularly in complex cases like acetabular dysplasia or post-traumatic reconstruction.\u003csup\u003e[\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/sup\u003e Its broad acetabular exposure facilitates dynamic adjustments for spinopelvic mismatch, critical in patients with ankylosing spondylitis or spinal fusion\u003csup\u003e[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]\u003c/sup\u003e. Institutional data highlight a marked reduction in operative time versus anterior approaches in obese patients, alongside lower intraoperative complications during early learning phases.\u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e Modern refinements, including augmented posterior capsular repair and \"soft tissue-first\" closure, restore near-complete native rotational stability, mitigating dislocation risks.\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e The approach accommodates expanded alignment parameters \u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e, proving advantageous in cases with excessive femoral anteversion (\u0026gt;\u0026thinsp;30\u0026deg;) or acetabular retroversion, where Lewinnek\u0026rsquo;s \"safe zone\" is anatomically unachievable \u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. Preservation of the piriformis and the whole capsule and reconstruct it later with the short external rotators in our protocol may further enhance long-term stability, though validation requires future studies. These attributes position the posterolateral approach as a versatile solution for routine and complex arthroplasty, balancing efficiency with biomechanical adaptability.\u003c/p\u003e\u003cp\u003e\u003cb\u003eLimitations and Mitigation Strategies\u003c/b\u003e\u003c/p\u003e\u003cp\u003eWhile our cohort demonstrated 0% dislocation rates through technical modifications, the posterolateral approach inherently presents challenges requiring strategic management. Achieving dual-axis Lewinnek safe zone compliance proved demanding, with only 19.35% of cases meeting both inclination (40\u0026deg;\u0026plusmn;10\u0026deg;) and anteversion (15\u0026deg;\u0026plusmn;10\u0026deg;) criteria\u0026mdash;a limitation attributable to restricted anterior acetabular visualization during component positioning\u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/sup\u003e. This technical complexity was reflected in our prosthetic alignment data: combined anteversion spanned 22.18\u0026deg;\u0026ndash;75.44\u0026deg;, with only 32.3% of cases within the recommended 25\u0026deg;\u0026ndash;50\u0026deg; range\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eAchieving precise prosthetic implantation within the Lewinnek safe zone remains technically challenging in conventional total hip arthroplasty (THA). Current techniques rely heavily on surgeons' clinical experience and subjective visual estimation, even with bony landmark guidance, and are further complicated by interpatient anatomical variations. To address these limitations, integrating robotic-assisted surgical systems offers a promising solution to enhance implantation accuracy. Robotic navigation enables data-driven alignment optimization, mitigating human error and anatomical variability, thereby improving reproducibility of component positioning within biomechanically favorable parameters. While the posterolateral approach's inherent flexibility accommodates broader alignment ranges, coupling it with robotic precision may reconcile the tension between procedural adaptability and target compliance, potentially reducing long-term polyethylene wear risks associated with elevated anteversion.\u003c/p\u003e\u003cp\u003eThe approach's posterior exposure paradigm, while enabling greater anteversion flexibility, necessitated prolonged hip precautions (6-week postoperative restrictions) that may delay functional recovery\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. However, our dislocation-free outcomes suggest modern closure protocols\u0026mdash;emphasizing meticulous repair of external rotators and posterior capsule\u0026mdash;effectively compensate for alignment variability\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. Notably, even in cases exceeding traditional safe zones (67.7% beyond Dorr's combined anteversion thresholds), stability was maintained through optimized soft tissue tensioning\u003csup\u003e[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eLong-term considerations include potential polyethylene wear associated with elevated combined anteversion\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. While our midterm data show no bearing-related revisions, we advocate selective use of advanced bearing surfaces in cases with \u0026gt;\u0026thinsp;55\u0026deg; combined anteversion\u003csup\u003e[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e. Technical refinements such as intraoperative impingement testing and dynamic stability assessment were critical to balancing alignment flexibility with biomechanical safety\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e, demonstrating that judicious technique can mitigate historical limitations of this approach.\u003c/p\u003e\u003cp\u003eThis investigation has several limitations that should be acknowledged. Firstly, as a single-center retrospective study with a limited cohort of 270 patients, the findings may be influenced by institution-specific protocols and selection biases, necessitating cautious extrapolation to broader clinical settings. Secondly, the absence of postoperative dislocation events precludes comparative biomechanical analyses between stable and unstable prosthetic hips, restricting objective evaluation of instability risk factors. Thirdly, all procedures were performed by senior arthroplasty surgeons, potentially introducing performance bias that may overestimate outcomes compared to routine clinical practice. Additionally, reliance on radiographic assessments without patient-reported functional metrics may overlook early signs of subclinical instability or impingement syndromes. Future research incorporating multicenter designs, extended follow-up periods (\u0026gt;\u0026thinsp;5 years), dynamic spinopelvic kinematic analyses, and patient-reported outcome measures is recommended to comprehensively evaluate determinants of prosthetic stability. Future multicenter studies incorporating extended follow-up and dynamic spinopelvic assessments are warranted to address these limitations.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe comparative analysis revealed that the posterolateral surgical approach demonstrated statistically significant increases in key acetabular alignment parameters, including acetabular component inclination, acetabular anteversion, femoral stem anteversion, and combined anteversion, when compared to the lateral approach. The utilization of a single-center cohort design with standardized surgical protocols effectively mitigated potential confounding variables arising from surgeon-specific variability in technique execution. This methodological uniformity enhances the validity of the comparative measurements and supports the robustness of the observed differences in prosthetic positioning between the two approaches.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003ePLA (Posterolateral Approach)、THA (Total Hip Arthroplasty) 、CA (Combined Anteversion)、DDH (Developmental Dysplasia of the Hip)\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis retrospective cohort study was conducted in accordance with the Declaration of Helsinki. Ethical approval was\u0026nbsp;waived\u0026nbsp;by the Institutional Review Board (IRB) of the Second Affiliated Hospital and Yuying Children\u0026rsquo;s Hospital of Wenzhou Medical University, as retrospective analyses of anonymized clinical data are exempt from formal ethics review per institutional policy. Written informed consent for the use of medical records and imaging data was obtained from all participants prior to surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable. This manuscript contains no individually identifiable personal clinical data or images requiring separate publication consent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data are not publicly available due to patient privacy restrictions but are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; Tian-long Pan: Conceptualization, Writing Original Draft, Writing Review and Editing.\u003cbr\u003e\u0026nbsp; \u0026nbsp;Qiao Wei: Data Curation, Formal Analysis, Investigation.\u003cbr\u003e\u0026nbsp; \u0026nbsp;Pei Fan: Methodology, Validation, Resources, Supervision.\u003cbr\u003e\u0026nbsp; \u0026nbsp;Zhen-xing Li: Study Design, Project Administration, Writing Review and Editing, Final Approval.\u003c/p\u003e\n\u003cp\u003eAll authors critically reviewed the manuscript and approved the final version for submission.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eCharnley J. Arthroplasty of the hip. A new operation[J]. Lancet, 1961,1(7187):1129-1132.\u003c/li\u003e\n\u003cli\u003eEngh C A, Bobyn J D, Glassman A H. Porous-coated hip replacement. The factors governing bone ingrowth, stress shielding, and clinical results[J]. J Bone Joint Surg Br, 1987,69(1):45-55.\u003c/li\u003e\n\u003cli\u003eCharnley J. Total prosthetic replacement of the hip[J]. Reconstr Surg Traumatol, 1969,11:9-19.\u003c/li\u003e\n\u003cli\u003eKurtz S M, Muratoglu O K, Evans M, et al. Advances in the processing, sterilization, and crosslinking of ultra-high molecular weight polyethylene for total joint arthroplasty[J]. Biomaterials, 1999,20(18):1659-1688.\u003c/li\u003e\n\u003cli\u003eLearmonth I D, Young C, Rorabeck C. The operation of the century: total hip replacement[J]. Lancet, 2007,370(9597):1508-1519.\u003c/li\u003e\n\u003cli\u003eBergin P F, Doppelt J D, Kephart C J, et al. Comparison of minimally invasive direct anterior versus posterior total hip arthroplasty based on inflammation and muscle damage markers[J]. J Bone Joint Surg Am, 2011,93(15):1392-1398.\u003c/li\u003e\n\u003cli\u003eHarris W H. The problem is osteolysis[J]. Clin Orthop Relat Res, 1995(311):46-53.\u003c/li\u003e\n\u003cli\u003eZimmerli W. Infection and musculoskeletal conditions: Prosthetic-joint-associated infections[J]. Best Pract Res Clin Rheumatol, 2006,20(6):1045-1063.\u003c/li\u003e\n\u003cli\u003eMorgan S, Bourget-Murray J, Garceau S, et al. Revision total hip arthroplasty for periprosthetic fracture: epidemiology, outcomes, and factors associated with success[J]. Ann Jt, 2023,8:30.\u003c/li\u003e\n\u003cli\u003eDeng Y, Kieser D, Wyatt M, et al. Risk factors for periprosthetic femoral fractures around total hip arthroplasty: a systematic review and meta-analysis[J]. ANZ J Surg, 2020,90(4):441-447.\u003c/li\u003e\n\u003cli\u003eSchwarzkopf R, Oni J K, Marwin S E. Total hip arthroplasty periprosthetic femoral fractures: a review of classification and current treatment[J]. Bull Hosp Jt Dis (2013), 2013,71(1):68-78.\u003c/li\u003e\n\u003cli\u003eGausden E B, Parhar H S, Popper J E, et al. Risk Factors for Early Dislocation Following Primary Elective Total Hip Arthroplasty[J]. J Arthroplasty, 2018,33(5):1567-1571.\u003c/li\u003e\n\u003cli\u003eKurtz S, Ong K, Lau E, et al. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030[J]. J Bone Joint Surg Am, 2007,89(4):780-785.\u003c/li\u003e\n\u003cli\u003eBozic K J, Lau E, Ong K, et al. Risk factors for early revision after primary total hip arthroplasty in Medicare patients[J]. Clin Orthop Relat Res, 2014,472(2):449-454.\u003c/li\u003e\n\u003cli\u003eRowan F E, Benjamin B, Pietrak J R, et al. Prevention of Dislocation After Total Hip Arthroplasty[J]. J Arthroplasty, 2018,33(5):1316-1324.\u003c/li\u003e\n\u003cli\u003eDargel J, Oppermann J, Bruggemann G P, et al. Dislocation following total hip replacement[J]. Dtsch Arztebl Int, 2014,111(51-52):884-890.\u003c/li\u003e\n\u003cli\u003eLewinnek G E, Lewis J L, Tarr R, et al. Dislocations after total hip-replacement arthroplasties[J]. J Bone Joint Surg Am, 1978,60(2):217-220.\u003c/li\u003e\n\u003cli\u003eGausden E B, Parhar H S, Popper J E, et al. Risk Factors for Early Dislocation Following Primary Elective Total Hip Arthroplasty[J]. J Arthroplasty, 2018,33(5):1567-1571.\u003c/li\u003e\n\u003cli\u003eOdland A N, Sierra R J. Intraprosthetic dislocation of a contemporary dual-mobility design used during conversion THA[J]. Orthopedics, 2014,37(12):e1124-e1128.\u003c/li\u003e\n\u003cli\u003eFleischman A N, Tarabichi M, Magner Z, et al. Mechanical Complications Following Total Hip Arthroplasty Based on Surgical Approach: A Large, Single-Institution Cohort Study[J]. J Arthroplasty, 2019,34(6):1255-1260.\u003c/li\u003e\n\u003cli\u003eWidmer K H, Zurfluh B. Compliant positioning of total hip components for optimal range of motion[J]. J Orthop Res, 2004,22(4):815-821.\u003c/li\u003e\n\u003cli\u003eZhu B, Su C, He Y, et al. Combined anteversion technique in total hip arthroplasty for Crowe IV developmental dysplasia of the hip[J]. Hip Int, 2017,27(6):589-594.\u003c/li\u003e\n\u003cli\u003eAmuwa C, Dorr L D. The combined anteversion technique for acetabular component anteversion[J]. J Arthroplasty, 2008,23(7):1068-1070.\u003c/li\u003e\n\u003cli\u003eKennedy J G, Rogers W B, Soffe K E, et al. Effect of acetabular component orientation on recurrent dislocation, pelvic osteolysis, polyethylene wear, and component migration[J]. J Arthroplasty, 1998,13(5):530-534.\u003c/li\u003e\n\u003cli\u003eMcCollum D E, Gray W J. Dislocation after total hip arthroplasty. Causes and prevention[J]. Clin Orthop Relat Res, 1990(261):159-170.\u003c/li\u003e\n\u003cli\u003eWidmer K H. A simplified method to determine acetabular cup anteversion from plain radiographs[J]. J Arthroplasty, 2004,19(3):387-390.\u003c/li\u003e\n\u003cli\u003eHeller M O, Bergmann G, Deuretzbacher G, et al. Influence of femoral anteversion on proximal femoral loading: measurement and simulation in four patients[J]. Clin Biomech (Bristol), 2001,16(8):644-649.\u003c/li\u003e\n\u003cli\u003eRiviere C, Lazennec J Y, Van Der Straeten C, et al. The influence of spine-hip relations on total hip replacement: A systematic review[J]. Orthop Traumatol Surg Res, 2017,103(4):559-568.\u003c/li\u003e\n\u003cli\u003eOgilvie A, Kim W J, Asirvatham R D, et al. Robotic-Arm-Assisted Total Hip Arthroplasty: A Review of the Workflow, Outcomes and Its Role in Addressing the Challenge of Spinopelvic Imbalance[J]. Medicina (Kaunas), 2022,58(11).\u003c/li\u003e\n\u003cli\u003eTeja T, Shrivastava S, Choudhary A, et al. Optimizing Acetabular Positioning: A Comprehensive Review of Contemporary Strategies in Total Hip Arthroplasty[J]. Cureus, 2024,16(4):e59114.\u003c/li\u003e\n\u003cli\u003eMasonis J L, Bourne R B. Surgical approach, abductor function, and total hip arthroplasty dislocation[J]. Clin Orthop Relat Res, 2002(405):46-53.\u003c/li\u003e\n\u003cli\u003ePellicci P M, Bostrom M, Poss R. Posterior approach to total hip replacement using enhanced posterior soft tissue repair[J]. Clin Orthop Relat Res, 1998(355):224-228.\u003c/li\u003e\n\u003cli\u003eKwon M S, Kuskowski M, Mulhall K J, et al. Does surgical approach affect total hip arthroplasty dislocation rates?[J]. Clin Orthop Relat Res, 2006,447:34-38.\u003c/li\u003e\n\u003cli\u003eAng J, Onggo J R, Stokes C M, et al. Comparing direct anterior approach versus posterior approach or lateral approach in total hip arthroplasty: a systematic review and meta-analysis[J]. Eur J Orthop Surg Traumatol, 2023,33(7):2773-2792.\u003c/li\u003e\n\u003cli\u003eLi L, Zhang Y, Lin Y Y, et al. A Specific Anteversion of Cup and Combined Anteversion for Total Hip Arthroplasty Using Lateral Approach[J]. Orthop Surg, 2020,12(6):1663-1673.\u003c/li\u003e\n\u003cli\u003eDorr L D, Malik A, Dastane M, et al. Combined anteversion technique for total hip arthroplasty[J]. Clin Orthop Relat Res, 2009,467(1):119-127.\u003c/li\u003e\n\u003cli\u003eKwon M S, Kuskowski M, Mulhall K J, et al. Does surgical approach affect total hip arthroplasty dislocation rates?[J]. Clin Orthop Relat Res, 2006,447:34-38.\u003c/li\u003e\n\u003cli\u003eHoskins W, Dowsey M M, Spelman T, et al. Early surgical complications of total hip arthroplasty related to surgical approach[J]. ANZ J Surg, 2020,90(10):2050-2055.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 1. Comparison of Baseline Characteristics and Measurement Parameters Between Two Surgical Approaches\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePostero-Lateral Approach (n=93)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLateral Approach (n=104)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eStatistic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eP-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eGender (cases, %)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026chi;\u0026sup2;=0.635\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.425\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e43 (46.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e54 (51.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e50 (53.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e50 (48.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFemoral Head Diameter (cases)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026chi;\u0026sup2;=0.239\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.887\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e28 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e32 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAcetabular Diameter (cases)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026chi;\u0026sup2;=7.364\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.498\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e44 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e46 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e48 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ge;50 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAge (years)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e61.05 \u0026plusmn; 13.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e59.63 \u0026plusmn; 12.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003et=0.779\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.437\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBMI (kg/m\u0026sup2;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24.66 \u0026plusmn; 3.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e23.81 \u0026plusmn; 3.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003et=1.679\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.095\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 2. Comparative Analysis of Implant Angulation in Two Surgical Approaches\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"554\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 171px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePosterior-Lateral Approach (n=93)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLateral Approach (n=104)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e\u003cstrong\u003et-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eP-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 171px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnteversion of Cup (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e29.09 \u0026plusmn; 9.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e9.26 \u0026plusmn; 11.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e13.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 171px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eInclination of Cup (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e48.09 \u0026plusmn; 8.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e38.83 \u0026plusmn; 5.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e9.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 171px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnteversion of Stem (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e19.28 \u0026plusmn; 11.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e13.83 \u0026plusmn; 10.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e3.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 171px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCombined Anteversion (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e48.37 \u0026plusmn; 13.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 115px;\"\u003e\n \u003cp\u003e23.09 \u0026plusmn; 13.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e13.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 77px;\"\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 3. Comparison of Implant Angulation Measurements Across Surgical Studies\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eStudy\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAnteversion of Cup (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eInclination of Cup (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAnteversion of Stem (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCombined Anteversion (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eCurrent Study (n=93)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e29.09 \u0026plusmn; 9.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e48.09 \u0026plusmn; 8.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19.28 \u0026plusmn; 11.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e48.37 \u0026plusmn; 13.04\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eDorr et al. (2009) (n=47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e27.00 \u0026plusmn; 4.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10.60 \u0026plusmn; 8.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e37.60 \u0026plusmn; 7.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFujishiro et al. (2014) (n=1411)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24.70 \u0026plusmn; 11.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e41.0 \u0026plusmn; 6.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e40.30 \u0026plusmn; 11.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e65.00 \u0026plusmn; 15.70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFujishiro et al. (2016) (n=1555)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24.50 \u0026plusmn; 11.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e40.9 \u0026plusmn; 6.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e39.90 \u0026plusmn; 11.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Total hip arthroplasty, Posterolateral approach, Prosthetic alignment, Combined anteversion, Hip stability, Retrospective cohort study","lastPublishedDoi":"10.21203/rs.3.rs-6924553/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6924553/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis single-center retrospective cohort study evaluated the biomechanical and clinical outcomes of the posterolateral approach (PLA) compared to the lateral approach in total hip arthroplasty (THA). A cohort of 270 patients undergoing primary THA via PLA was analyzed, with prosthetic alignment parameters (acetabular inclination, acetabular anteversion, femoral stem anteversion, and combined anteversion) quantified using postoperative CT imaging. Results demonstrated statistically significant increases in acetabular component inclination (48.09°±8.54° vs43.2°±8.7°, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.05), acetabular anteversion (29.09°±9.06° vs.18.4°±6.9°, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.01), femoral stem anteversion (19.28°±11.28°vs. 14.6°±7.3°, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.05), and combined anteversion (48.37°±13.04°vs. 32.0°±10.5°, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.01) compared to historical lateral approach data. Notably, no postoperative dislocations were observed in the PLA cohort (0% incidence), attributed to standardized capsular repair and component positioning protocols. Despite only 19.35% of cases achieving dual-axis Lewinnek \"safe zone\" alignment, meticulous soft tissue reconstruction ensured stability even with elevated combined anteversion (range: 22.18°–75.44°). These findings highlight the biomechanical adaptability of PLA in optimizing prosthetic positioning while maintaining stability, particularly in anatomically complex cases. Methodological rigor, including uniform surgical protocols and CT-based measurements, minimized confounding variables. This study supports PLA as a robust approach for THA, balancing alignment flexibility with clinical safety.\u003c/p\u003e","manuscriptTitle":"Comparative Efficacy of Posterolateral versus Lateral Approach in Total Hip Arthroplasty: A Retrospective Cohort Study on Prosthetic Alignment and Stability","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-11 10:50:06","doi":"10.21203/rs.3.rs-6924553/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"114049c4-1b0c-4d03-88b3-1d0c670c1137","owner":[],"postedDate":"August 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-01T09:39:23+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-11 10:50:06","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6924553","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6924553","identity":"rs-6924553","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}