Posterior cruciate ligament repair in acute knee instabilities with internal bracing: midterm follow up for clinical and kinematic results

Posterior cruciate ligament repair in acute knee instabilities with internal bracing: midterm follow up for clinical and kinematic results | 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 Posterior cruciate ligament repair in acute knee instabilities with internal bracing: midterm follow up for clinical and kinematic results Eike Martens, Tilmann Krackhardt, Lino Wicke, Stefan Kratzenstein, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3209293/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 Background : Injuries of the PCL are comparably rare. They occur with or without accompanying injuries of the knee and frequently occur in multi-ligament knee instability. Internal bracing is a recent treatment option for acute PCL tears. For low-grade instability, a conservative therapy is recommended while severe instability in multi-ligament injuries is mostly addressed by surgical reconstruction. Recent evaluations of internal bracing demonstrate good options for both isolated ligamentous and multiligamentous injuries. The aim of this study was to assess general outcomes in joint function and stability as well as activity and quality of life by clinical examination and functional gait analysis. Methods: A total of 19 patients were examined after internal bracing of an acute II/III° PCL- injury between 2017 and 2021. Included were patients with MRI-proven unilateral PCL tear. In addition to clinical tests for mobility and posterior drawer test, a IMU based kinematic gait analysis was performed. Further IKDC-Score, TAS and Lysholm Score were examined. Regular stress radiographs of both knee joints were included for further evaluation. Results : Follow-up examination took place after 29.40 ± 10.47 months. The mean ROM of the injured knee showed 0. 79° ± 1,9 ° for extension and 138,4° ± 3,4° for flexion. In gait and walking analysis, no significant movement restrictions for either knee joint remained. IKDC amounted to 53,2 ± 4,2% after injury and 91.7 ± 7,4% at follow-up. The Lysholm Score was 95.5% ± 8,3% . The TAS showed no significant difference ( 5,5 ± 1.30 pt pre-injury and 5,2 ± 1.2 pt at follow-up). The mean difference of posterior tibial translation reached 2,5 ± 1,5 mm in clinical examination and demonstrated significant difference to the healthy side. 1 patient needed revision surgery by complete PCL- reconstruction due to grade II-Instability postoperative but no other complications occurred. Conclusions: Internal bracing can offer good treatment for acute grade II and grade III PCL-instabilities, especially when further meniscal or ligamentous injuries require surgical repair. Despite the limited evidence-based results and applications to date, restoration of joint mobility and a minor residual posterior tibial translation can be confirmed. Results for everyday and sports activities are comparable with conservative and established surgical procedures. PCL-tear internal bracing posterior instability of the knee management of PCL-instability gait analysis Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Background Injuries to the posterior cruciate ligament (PCL) often pose challenges to the treating surgeon. In comparison to anterior cruciate ligament ruptures, PCL tears are rare and may be overlooked in the context of multi-ligament trauma. Most commonly, these injuries occur during sport, usually involving hyperextension trauma of the knee or by dashboard injury ( 1 ). The age- and gender-adjusted annual incidence of isolated, complete cruciate ligament tears is estimated to be 1.8 per 100,000 ( 2 ). Nevertheless in a considerable number of cases PCL tear may be diagnosed as an isolated injury or with additional meniscal and collateral ligament ruptures ( 3 ). There have been controversial reports on the surgical management of these types of injuries ( 4 , 5 ). Results of conservative therapy for isolated tears show subjective patient satisfaction, although significant instability can remain ( 6 – 8 ). Initial surgical procedures by direct suture have been predominantly superseded by full ligament reconstruction procedures in multiligamentous injuries ( 9 ). Within the last years PCL-saving augmentation techniques have evolved, and internal bracing, which is a common procedure for collateral ligament repair has been applied for the posterior cruciate injury. Internal bracing aims to re-constitute anatomic biomechanics and creates primary stability by anterior counterforce that allows the injured ligament to heal while preserving the anatomical structures and proprioception ( 3 ). An advantage of the procedure is the lesser invasiveness and shorter operation time compared to full reconstruction ( 10 ). Recent recommendations for internal bracing include acute isolated PCL ruptures, PCL ruptures in the context of high grade multiligamentous injuries or PCL injuries with meniscal lesions that require surgical treatment ( 5 ). Initial follow-up studies of this procedure show promising results for both acute isolated or multiligamentous injuries ( 4 , 11 , 12 ). Studies on outcomes are limited, but the procedure could deliver promising results with low invasiveness and be used frequently in the future ( 4 ). In our study we focused on activity, clinical and kinematic results after internal bracing of PCL in grade II and III Instabilities. Methods Patient selection A total of 32 patients underwent internal bracing at the study center from 2017 to 2021, of which 19 patients consented to study follow-up and met the inclusion criteria. Included were patients who suffered a unilateral PCL tear with a healthy opposite knee which met the indication criteria for internal bracing. Indication for this procedure were an MRI-secured complete or partial rupture of the PCL. In the injured knee joint a grade II instability represented an indication for surgery. Diagnosis was secured using clinical examination and an MRI scan (Fig 1). All surgical procedures were performed by three surgeons. Patients with an operated contralateral knee, a radiologically confirmed fixed posterior translation and patients after revision surgery with reconstruction procedure were excluded from the study. Surgical technique Patient is positioned in supine position, with the leg in a leg holder, torniquet, standard anteromedial and anterolateral portals are established. After arthroscopic verification of the diagnosis, the footprint is debrided. Then, under vision from the anterolateral side, the posteromedial recess is visualized. A posteromedial access is established. The pericapsular layer behind the tibial head is dissected. Then the camera is transferred posteromedial, from anteromedial the tibial targeting device for the posterior cruciate ligament is inserted, placed about 15 mm below the joint level. An oblique skin incision is made ventrally, first predrilling with the drill, then overdrilling with the 4.0 mm cannulated drill. A shuttle loop is advanced, using ring grasping forceps it is shuttled and secured with a small clamp. Now with view from anteromedial over anterolateral the target drill is inserted into the femoral ventral attachment of the posterior cruciate ligament at the medial condyle. A Pre-drill is advanced with perforation of the counter cortex. Then it is overdrilled with the 4.0 mm drill, measuring the bone distance. The bracing is prepared with TightRope RT and Fibertape (Arthrex, Munich, Germany). The tape is pulled through, and the button flipped. Finally, the Fibertape is pulled into the tibial drill channel. An ABS button (Arthrex, Munich, Germany) is knot tightly against the tibial head while holding an anterior drawer. The procedure is completed by testing for stability and a final arthroscopic control. Postoperative protocol The patients were kept non-weight-bearing for 4 weeks. From week 5 to 6, 50% weight bearing was allowed. From 7 th week, full weight bearing was allowed. A rigid PTS (posterior tibial support, medi GmbH,Bayreuth, Germany ) splint with a calf pad was applied postoperatively for 6 weeks. From 7 th to 12th postoperative week, a PCL splint with full range of motion was worn during the day. At night, the PTS orthosis had to be worn further. From 1st to 4th week, physiotherapy was performed out of the rigid orthosis exclusively in prone position up to 90 °. After that, flexion could be gradually increased. Knee Score examination Each clinical examination was performed by the same study physician after prior routine follow-up. To assess current quality of life and activity level, the subjective IKDC-, Tegner and Lysholm score were determined at baseline. The scores provide information about patient satisfaction and recovery of everyday activity. -IKDC-Score The IKDC is an evaluation form to assess a variety of knee symptoms. It contains seven items for knee symptoms (37 points), two items for knee function (10 points) and two items on sports activities (40 points). To score the current form of the IKDC, simply add the score for each item and divide by the maximum possible score which is 87. then the score is transferred to a scale that ranges from 0 to 100. It had the advantage of being adaptable to a large number of knee pathologies. (13). Any variation of at least 11.5 points (on the 100-point scale) is regarded as a significant clinical improvement or worsening (14) -Tegner Activity scale TAS is recommended for evaluating sports and daily activity level. The scale ranges from 0, which represented a massive disability by knee symptoms to 10, which can be similar to international level of soccer players. One through 5 includes work or recreational sports from sedentary jobs to heavy manual labor or amateur sports (i.e. swimming, cycling and jogging in relation to the number and intensity of sport sessions per week), 6 through 9 represents competitive sports (athletics, tennis, alpine skiing, basketball, handball) . {(13) } -Lysholm score The Lysholm Score is a frequently used questionnaire about knee function in everyday life after an ACL injury. It includes 8 items (limping, aids used, locking, instability, pain, swelling, stair climbing and knee bending) to produce an overall score on a point scale of 0 to 100.(15) Results are categorized in descending order of performance into “excellent”, “good”, “fair” and “poor”. Clinical examination -Posterior tibial translation Tibial translation was obtained by a Rolimeter (Aircast Europe, Rosenheim, Germany). The results of many studies suggest that Rolimeter is a reliable device in objectively evaluating knee joint laxity. The measurement was performed according to the standard instructions but in 90° Knee-flexion. (16) The Rolimeter was positioned on the patella proximally and distally on the tibia, fixed with a strap. The reader-bar was centered on the tuberosity of the tibia. First, the total tibial translation of the healthy and operated side was measured. Three repeated measurements were made in each knee. The mean value of the two highest results on each knee was used for further analysis. Posterior tibial translation of the operated side was determined then by subtracting the mean result on the operated side from the mean result on the non-operated side. To better assess posterior tibial displacement, stress radiographs of both knee joints in kneeling view were used to determine the grade of postoperative ligament insufficiency (Fig. 2). Patients with a fixed posterior drawer could thereby be excluded. -ROM All patients underwent clinical examination of both knee joints. Extension and Flexion in supine position were measured in degrees using a goniometer. -Motion analysis To evaluate kinematic joint parameters, gait and walking analysis was performed using a treadmill (H/p/cosmos sports & medical GmbH, Germany) and inertial measurement units (IMUs). IMU is a small, body-worn, sensor-based technology that can track the motion and orientation of an object in space. IMU systems, which include accelerometers, gyroscopes, and magnetometers, use sensor fusion algorithms and biomechanical modelling techniques to extract kinematic and spatiotemporal gait and walking parameters (Hansen et. al. 2023). 17 Participants in our study were recorded walking and running on a treadmill using an IMU system (Noraxon USA inc., myoMOTION, Scottsdale, AZ, USA). Five IMUs were attached to the body (lower leg, thigh, sacrum (Fig. 3)) with elastic straps. Data were acquired at 200 Hz in a commercial software package (Noraxon MR3.16). Calibration of the biomechanical model was performed according to the standard protocol of the supplier of the commercial system. Study participants were required to stand in a neutral position for 5 seconds for static referencing. Immediately thereafter, participants began to walk 5 m in one direction and then returned to the same calibration position, a new static calibrate occurred to compensate for the effects of magnetic interference on each sensor. IMU orientation was estimated using a sensor fusion algorithm. -Motion assessment Prior to recording the gait and running analysis, an acceleration-based functional calibration procedure was performed to correct for the effects of any magnetic field interference. Participants began walking on the treadmill at a self-selected speed. After a walking speed comfortable to the participant was established, the investigator recorded 23 walking cycles on the treadmill after a signal to the participant. The same procedure was performed for walking at a self-selected walking speed. -IMU derived variables The IMU system automatically detects motion cycle events using an acceleration-based algorithm. Spatiotemporal motion parameters, as well as range of motion (ROM) for hip and knee joint angles in the sagittal plane were recorded per participant. Inter-limb coordination was compared by cross-referencing the recorded data. Data analysis Statistics were carried out using SPSS 14.0 for Windows. Results are presented as mean with standard deviation. As this was a single cohort study with no control group, no power analysis was performed. In the intraindividual comparison between the non-operated and the operated joint, significance was set at p < 0.05 using a student´s t-test. Results A total of 19 patients were included in our study, 4 women (21 %) and 15 men (79 %). A gait analysis was performed by 17 patients. The mean age was 42 ± 15,7 years. The youngest subject was 16 years old and the oldest 69. Mean age at time of surgery amounted 39 ± 15,8 years. Follow-up examination took place after 29.40 ± 10.47 months. Intraoperatively and in MRI 11 partial and 8 full substance tears of the PCL were found. 1 PCL was distally ruptured, 6 ligaments were proximally ruptured, and 12 ligaments were torn in midsubstance. 2 patients suffered from an internal meniscal tear and 2 patients from a partial MCL rupture classified as a Schenck Type I knee dislocation. Surgery was performed within 1,8 ± 3,5 months after trauma. The mean operating time was 56 ± 11,6 min. Motion analysis Clinical examination for ROM was not significantly reduced compared to the un-operated (control-) Knee (p>0,05). The average result for terminal knee extension showed 0,79 ± 1,9 ° compared to 0 ° for the non-operated site (Fig. 4). Terminal flexion values amounted to 138,4 ± 3,4 ° for the operated side and 139,5 ± 2,3 ° for the non-operated side (Fig. 5). The standard deviation of control values was lower than for the treated side. There were 2 patients with an extension deficit of less than 5 ° and one patient with a combination of extension (5 °) and flexion (130 °) deficit. Analysis of ROM using an IMU system revealed a mean ROM for gait analysis of 55.57 ± 7.54 ° for the operated knees and 57.91 ± 5.64 ° for the non-operated knees. The difference in ROM between the operated and non-operated knee was not significant (p=0.1566) (Tab.1). The ROM of the IMU data of the hip range of motion was 31.88 ± 9.15 ° in the non-injured side and 32.43 ± 5.12 ° in the injured limb, respectively. There was no significant difference in the comparison of the hip range of motion (p=0.157). The speed of the subjects on the treadmill was 0.88 ± 0.07 m/s on the treadmill. The analysis of ROM during running also revealed no significant differences in the intraindividual comparison of limb joints (hip: p=4938; knee: p=0.6716). Self-selected running speed was 1.74 ± 0.43 m/s. The IMU-derived parameters of gait analysis and running analysis and the corresponding p-values are shown in Table 1. Table 1: Motion analysis of walking and running presented in ROM of joints in degrees (mean ± SD). Correlation analysis of the presented parameters. IMU derived parameters Gait (°) (mean ± SD) p-value Run (°) (mean ± SD) p-value ROM Hip injured 32.43 ± 5.12 0.157 35.27 ± 6.39 0.4938 ROM Hip not injured 31.88 ± 9.15 35.32 ± 9.51 ROM Knee injured 55.57 ± 7.54 0.1566 65.03 ± 10.01 0.6716 ROM Knee not injured 57.91 ± 5.64 63.44 ± 9.38 For visual demonstration and interpretation IMU-derived parameters are exemplarily shown. Angle coordination between thigh and shank IMUs shows no differences between the operated and non-operated leg which punctuates the great functional outcome after surgery (Fig. 6,7). Running analysis showed mean maximum knee angles of the operated leg of 63.44 ° compared to 65.03° of the non-operated leg. Hip angles were 35.32 ° and 35.27 ° (Fig. 7). The difference was not significant (p=0.6716; p=0.4938). Knee Scoring Systems/Scales We further differentiated between pre-injury and post-intervention ADLs by applying the TAS. A mean TAS of 5,5 ± 1.30 pt was obtained pre-injury and 5.2 ± 1.2 pt at follow-up (Fig. 8). The results did not differ significantly at a threshold p-value of 0.06, so that a return to the pre-injury level can be assumed. The mean value of Lysholm score amounted to 95.5 ± 8,3 % at the follow-up. The IKDC-Score showed a result of 53.2 ± 4,2 % pre -op (after injury) and 91.7 ± 7,4 % post-op (Fig. 9). There was no significant correlation between age and IKDC score. Posterior tibial translation had no significant correlation with age or IKDC. Knee stability In posterior translation test the average dorsal tibial translation (operated knee 5,5 ±1,6 mm, un-operated knee 2,9 ± 0,9 mm) showed significantly different results whereat the total mean difference from side to side amounted to 2,5 ± 1,5 mm (p<0,05) (Fig. 10, Tab. 2). Mean preoperative posterior tibial translation was 8,4 ± 1,9 mm on the injured side. 12 patients (63%) had grade II and 7 (37%) grade III instability before surgery. Preoperative tibial translation significantly differed from the examinations at follow-up. In an x-ray stress test the operated side showed a mean difference in posterior drawer of 3,3 ± 2,3 mm (Table 2). None of the patients had abnormal medial or lateral collateral ligament laxity at follow-up. In one patient a postoperative instability grade III (showing 7 mm posterior tibial translation and 11 mm in stress radiography) was observed. Gait and running analyse on treadmill were not performed. Table 2: posterior tibial translation both sides in clinical and stress radiograph examination Knee side Total Tibial translation (°) Mean difference p Injured side 5,5mm 2,5mm <0,05 Un-operated side 2,9 mm Injured side stress radio 7,8mm 3,2mm <0,05 Unoperated side stress radio 4,6mm Adverse Effects/non-favourable outcome In our study, a total of 2 patients (10,5 %) had a slight extension deficit of less than 5 °. In 1 patient there was no ligamentous healing leading to III °-PCL- Instability with extension (5 °) and flexion (130 °) lag. He received a PCL-reconstruction later. We further identified no injuries of the popliteal artery and saphenous nerve. There were no postoperative infections or wound healing disorders. Discussion The indication for surgical or conservative therapy of PCL tears is still being discussed. The lack of reliable recommendations for therapy is due to the rarity of PCL tears and the fact that they are difficult to recognize and evaluate in the context of multiligamentous injury patterns ( 17 ). The posterior cruciate ligament has a high intrinsic healing potential, so that a sufficient function can be assumed after both, conservative and operative treatment ( 4 , 18 ). For isolated PCL tears conservative treatment among top athletes and average patients showed a subjectively good function, with residual instability remaining in clinical tests ( 18 , 19 ). A healing process leading to the formation of a remaining posterior drawer is assumed if the posterior counterforce is insufficient. Likewise, the surgical principle of internal bracing is based on the self-healing tendency of the PCL but uses the implementation of stable FibreTape (Arthex, Munich, Germany) in the anatomical course of the injured structures to create primary stability during recovery phase. For high-grade injuries such as grade III instabilities or severe multi-ligament knee injuries, reconstruction procedures in single or double bundle technique have been preferred so far ( 20 ). The users of ligament bracing consider both, acute multi-ligament and isolated injuries of the PCL to be suitable for this relatively new procedure, although in the authors' opinion it can only be recommended for certain individual cases due to the insufficient evidence to date. In addition, it is recommended that ligament bracing be performed within 14 days because of the assumed healing potential that decreases with time after injury. ( 5 ) In our study time between trauma and operation is 54 days on average. This is well in keeping with similar representative studies ( 4 , 11 ). The delay is probably due to the above-mentioned difficulty in diagnosing and assessing the injury. However, the ideal timing for surgical treatment is currently being discussed ( 20 ). Overall, natural mobility of the injured knee joint was regularly restored in our patients. This was shown by clinical and kinematic examination on a treadmill at follow-up. The mean range of motion for the operated knee joint was 1 ° for extension and 138 ° for flexion. Motion analysis showed a balanced, symmetrical gait and running. Hip and knee joint mobility were not significantly impaired leading to the conclusion of a competent PCL bracing and an adaptive gait strategy ( 21 , 22 ). Current studies showed that similar recent modified measurement methods with IMU produced valid results for detecting knee joint instability or osteoarthritis ( 23 ). With regard to the analysis of movement, it is important to mention that after surgical procedures, joint stiffness or limitation of movement in extension or flexion may occur ( 18 , 24 ). We were able to examine a total of three patients (16%) with an extension deficit of 5 °. All 3 patients were treated within the first 2 years after we began to utilize the technique. The deficit was attributed to insufficient counterforce of the tape and missed rehabilitation. Naturally a learning curve is associated with a new technique and initial less favourable outcomes may be seen in this context. Some investigations have shown inferior outcomes for ROM in early PCL reconstructions, i.e. a loss of mean flexion by 8 ° compared to the contralateral knee was obtained in a series of 25 arthroscopically assisted PCL repairs ( 24 ). The comparatively poorer results could be attributed to a higher rate of severe instabilities and multi-ligament injuries. Patel et al. reported an average flexion of 138 ° (range,130–150) and an average extension of 1 ° (range,0–4) in a study of conservatively treated isolated partial and complete ruptures of the PCL. The proportion of post-traumatic movement restrictions remained low ( 25 ). Our results come along with these findings. In addition, we have referred to the commonly used knee scores. The Lysholm Knee Function Scale is frequently used for ligamentous or meniscal injuries of the knee, although its effectiveness for ligament injuries is often debated ( 26 ). Therefore we supplement the TAS to get a more accurate and reliable view of the patient’s condition. At follow-up, our collective reached a mean score of 95.5 points in the Lysholm Scale and 5.14 in the TAS, with the pre-accident condition reaching a mean score of 5.4. The results on TAS do not differ significantly to pre-op (p > 0,05) and on reflect adequate return-to-pre-injury-level. Results of different other studies show TAS to follow up examination of 6,6 + 1,8 ( 25 ) and 7,2 (range, 5 to 10) ( 27 ), as opposed to 7 (range, 4 to 10) and 7,5 (range, 5 to 10), respectively. The higher values pre-injury and after treatment are particularly noticeable here, probably the collective was different to ours. In addition, Lysholm score showed 85,2 (+ 10) and 94 (range, 88 to 100) after 24 months in both evaluations although both authors observed a slight but significant decrease ( 25 , 27 ). At the same time, our collective showed a highly significant increase in IKDC due to internal bracing. Shelbourne et al. show 73 points in IKDC evaluation after conservative treatment of isolated PCL tears at a mean follow-up of 17,1 years ( 19 ). Similar results are shown for conservative treatment by Ahn et al., whose follow-up was 51 months on average and an IKDC of 83 was achieved ( 28 ). At shorter follow-up intervals, Patel et al. confirmed a higher IKDC of 93 after 24 months ( 25 ). There seems to be a decrease in knee scores in the further follow-up, but due to our midterm review it remains unclear whether the permanent stabilization by internal bracing offers an advantage. In keeping with this discrepancy of the results can also be caused by the subjective part and the different perception of pain, which lead to a different evaluation. Moreover, a large number of follow-up studies after treatment of PCL tears showed no correlation between good subjective scores and the stability of the knee joint. We similarly observed no strong correlation between increased posterior tibial translation and IKDC results. Hence some authors have questioned whether posterior translation as such can be seen as an indicator for inferior outcome ( 19 ). On the other hand, long-term studies of conservative procedures reported an increased incidence of osteoarthritis associated with posterior instability ( 9 ). Wang et al concluded that conservative treatment in grade I and II isolated injuries can lead to sufficient subjective results, although residual instability bears a risk of meniscal tears and osteoarthritis ( 29 ). Understandably within a short follow-up no degenerative changes were noted, most osteoarthritic changes in conservatively treated groups can only detected after 5–14 years ( 9 , 30 ). In knee stability test our average post operative difference for tibial translation was 2,5 mm, which was significantly less than before surgery. By comparison, Jacobi et al. determined the anteroposterior translation similar with a Rolimeter of 3.2mm after 24 months ( 27 ). In relation to the initial posterior sag of 7.1mm (range, 5 to 10 mm), there was a significant improvement here as well. Conversely Ahn et al. examined isolated PCL lesions with grade I and II instability after conservative procedures using the KT-1000 arthrometer with a side-to-side difference of 5.2 mm (range, 2 to 10 mm) at the latest follow-up ( 28 ). Despite different measuring instruments, a relatively good comparability of our solid values can be assumed, as the Rolimeter in particular provides accurate results for tibial translation from 80 degrees of knee flexion ( 31 ). Due to our limited number of MLKI´s it is difficult to make a statement on outcomes by internal bracing. For MLKI´s and grade III Instability Otto et al. found adequate but overall worse results in a collective of 17 patients using a KT 2000 arthrometer ( 4 ). Regarding the complex nature of this injury, recent suture augmentation, a combination of arthroscopic PCL suture and augmentation by internal bracing, appears to be superior for proximal and distal PCL-tears ( 17 , 32 , 33 ). However, in most evaluations there remains a low side-to-side difference( 11 , 17 ). Likewise, we can confirm a significant side-to-side difference for tibial translation, but no instability (< 4 mm) in the mean. In our study, stress radiographs were additionally used to confirm a significant lateral difference of tibial translation postoperatively. There are several studies that demonstrate a substantial difference in translation values using this radiologic method ( 11 , 19 , 27 , 30 ). It is difficult to compare stress radiographs because different measurement methods are used. One evaluation of conservative treatment uses lateral view in 70 ° knee flexion with contraction of hamstring muscles and achieved 3,4 mm (range,1,1 to 8,1 mm) after 24 months ( 27 ). Stress radiographs performed by a Telos stress device (Austin & Associates, Fallston, MD, USA) showed for conservative-treated PCL-injuries a reduction of posterior tibial translation to 3.5 mm (range,0.7–8 mm) at the last follow-up (at least 2 years) ( 34 ). It can be observed that our results are comparable to conservative treatment procedures despite the inclusion of grade III-PCL-instabilities and meniscal or collateral ligamentous lesions while peri- and postoperative risk remains low. In consideration of the currently limited number of studies conservative therapy can be recommended for isolated PCL-injuries in the authors opinion, but if additional injury requiring intervention or at least a grade II instability is present, internal bracing should be particularly considered for higher secure stabilization and risk minimization. However, the results of this study are limited. Firstly, we cannot refer to a control group, but compare to the contralateral knee joint. Secondly, follow-up time also varies. On the other hand, strength of the study is certainly the inhomogeneous patient collective with athletes and non-athletes that may represent a population average. Using IMU-devices to detect movement restrictions in gait and running analyse support clinical findings in mobility examination of both knee joints. Conclusion Internal bracing can offer a good treatment for acute grade II and III - PCL-instabilities, especially when further meniscal or ligamentous injuries require surgical repair. Despite the limited evidence-based results and applications to date, restoration of joint mobility and a minor residual posterior tibial translation can be confirmed. Results for everyday and sports activities are comparable with conservative and established surgical procedures. The intra- and postoperative risk as well as the revision rate is low in the hands of the experienced surgeon. However, long-term results should be awaited and must subsequently be further investigated on an evidence-based level to reach better understanding of indication. Abbreviations ADLs: Activities of daily living DEG: degrees IKDC: International Knee Documentation Score IMU: inertial measurement unit MLKI: multi-ligament knee injury Min: minutes MRI: Magnetic resonance imaging PCL: posterior cruciate ligament PTS: posterior tibial splint PT: points ROM: Range of motion TAS: Tegner Activity Scale Declarations Ethics approval and consent to participate: The study was conducted according to the guidelines of the Declaration of Helsinki. Ethics approval was obtained from the ethics committee of the Christian-Albrechts-University Kiel: Christian-Albrechts-Univiersity Kiel Ethics committee Arnold-Heller-Straße 3, 24105 Kiel, Germany Reference Nr. (D418/21) Informed consent was obtained from all subjects and/or their legal guardian(s) Consent for publication Not applicable. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing of interest The authors declare that they have no competing interests. Funding The authors assure that no funding was received to assist with the preparation of this manuscript. Author´s contribution E.M. wrote the article, collected the data and invented study design T.K. conceived and designed the analyse and wrote the article L.W. collected and contributed the data S.K. contributed tools and data M.W: collected the data and invented study design as well as wrote the article S.L. invented study design, conceived the analyse and wrote the article Acknowledgements We would like to thank the staff of the “Lubinus Aktiv Foundation” for carrying out the gait analysis under the direction of Frank Naeve as well as the advisory colleagues Gero Benning, Peter Behrendt and Maciej Simon. References Fowler PJ, Messieh SS. Isolated posterior cruciate ligament injuries in athletes. Am J Sports Med. 1987 Nov;15(6):553–7. 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Posterior cruciate ligament reconstruction with independent internal brace reinforcement: surgical technique and clinical outcomes with a minimum two year follow-up. Int Orthop. 2022 Sep 1;46(9):2019–28. Kon E, Altadonna G, Filardo G, Matteo BD, Marcacci M. Knee Scoring Systems. In: Bentley G, editor. European Surgical Orthopaedics and Traumatology [Internet]. Berlin, Heidelberg: Springer Berlin Heidelberg; 2014 [cited 2023 Apr 16]. p. 3371–88. Available from: http://link.springer.com/10.1007/978-3-642-34746-7_120 Responsiveness of the International Knee Documentation Committee Subjective Knee Form - James J. Irrgang, Allen F. Anderson, Arthur L. Boland, Christopher D. Harner, Philippe Neyret, John C. Richmond, K. Donald Shelbourne, , International Knee Documentation Committee, International Knee Documentation Committee, 2006 [Internet]. [cited 2023 Apr 16]. Available from: https://journals.sagepub.com/doi/abs/10.1177/0363546506288855?journalCode=ajsb Wirth B, Liffert F, de Bruin ED. [Development and evaluation of a German version of the Lysholm score for measuring outcome after anterior cruciate ligament injuries]. Sportverletz Sportschaden. 2011 Mar 1;25(1):37–43. A New Mechanical Testing Device for Measuring Anteroposterior Knee Laxity - Andreas J. Schuster, Mike J. Mcnicholas, Stefan W. Wachtl, Douglas W. McGurty, Roland P. Jakob, 2004 [Internet]. [cited 2023 Apr 16]. Available from: https://journals.sagepub.com/doi/abs/10.1177/0363546504267050?journalCode=ajsb Vermeijden HD, van der List JP, DiFelice GS. Arthroscopic Primary Repair of the Posterior Cruciate Ligament. J Knee Surg. 2021 Apr;34(05):478–85. Vaquero-Picado A, Rodríguez-Merchán EC. Isolated posterior cruciate ligament tears: an update of management. EFORT Open Rev. 2017 Apr;2(4):89–96. Shelbourne KD, Clark M, Gray T. Minimum 10-year follow-up of patients after an acute, isolated posterior cruciate ligament injury treated nonoperatively. Am J Sports Med. 2013 Jul;41(7):1526–33. Winkler PW, Hughes JD, Irrgang JJ, Karlsson J, Musahl V. Posterior cruciate ligament injuries: what do we really know? Knee Surg Sports Traumatol Arthrosc. 2021 Mar;29(3):669–71. Zhang L, Liu G, Han B, Wang Z, Yan Y, Ma J, et al. Knee Joint Biomechanics in Physiological Conditions and How Pathologies Can Affect It: A Systematic Review. Appl Bionics Biomech. 2020 Apr 3;2020:7451683. McCarthy I, Hodgins D, Mor A, Elbaz A, Segal G. Analysis of knee flexion characteristics and how they alter with the onset of knee osteoarthritis: a case control study. BMC Musculoskelet Disord. 2013 May 21;14(1):169. Na A, Buchanan TS. Validating Wearable Sensors Using Self‐Reported Instability among Patients with Knee Osteoarthritis. PM&R. 2021 Feb;13(2):119–27. Zawodny SR, Miller MD. Complications of Posterior Cruciate Ligament Surgery. Sports Med Arthrosc Rev. 2010 Dec;18(4):269–74. Patel DV, Allen AA, Warren RF, Wickiewicz TL, Simonian PT. The nonoperative treatment of acute, isolated (partial or complete) posterior cruciate ligament-deficient knees: an intermediate-term follow-up study. HSS J Musculoskelet J Hosp Spec Surg. 2007 Sep;3(2):137–46. Tegner Y, Lysholm J. Rating Systems in the Evaluation of Knee Ligament Injuries. Clin Orthop Relat Res 1976-2007. 1985 Sep;198:42. Jacobi M, Reischl N, Wahl P, Gautier E, Jakob RP. Acute isolated injury of the posterior cruciate ligament treated by a dynamic anterior drawer brace: A PRELIMINARY REPORT. J Bone Joint Surg Br. 2010 Oct;92-B(10):1381–4. Hwan Ahn J, Hak Lee S, Hee Choi S, Ho Wang J, Won Jang S. Evaluation of Clinical and Magnetic Resonance Imaging Results After Treatment With Casting and Bracing for the Acutely Injured Posterior Cruciate Ligament. Arthrosc J Arthrosc Relat Surg. 2011 Dec 1;27(12):1679–87. Wang J, Zhu Y, Zhang F, Chen W, Tian Y, Zhang Y. Meta-analysis suggests that reverse shoulder arthroplasty in proximal humerus fractures is a better option than hemiarthroplasty in the elderly. Int Orthop. 2016 Mar;40(3):531–9. LaPrade CM, Civitarese DM, Rasmussen MT, LaPrade RF. Emerging Updates on the Posterior Cruciate Ligament: A Review of the Current Literature. Am J Sports Med. 2015 Dec;43(12):3077–92. Schuster AJ, McNicholas MJ, Wachtl SW, McGurty DW, Jakob RP. A new mechanical testing device for measuring anteroposterior knee laxity. Am J Sports Med. 2004;32(7):1731–5. van der List JP, DiFelice GS. Arthroscopic Primary Posterior Cruciate Ligament Repair With Suture Augmentation. Arthrosc Tech. 2017 Oct 1;6(5):e1685–90. Heitmann M, Gerau M, Hötzel J, Giannakos A, Frosch KH, Preiss A. Ligament bracing – Augmentierte Primärnaht bei multiligamentären Verletzungen des Kniegelenks. Oper Orthop Traumatol. 2014 Feb 1;26(1):19–29. Jung YB, Tae SK, Lee YS, Jung HJ, Nam CH, Park SJ. Active non-operative treatment of acute isolated posterior cruciate ligament injury with cylinder cast immobilization. Knee Surg Sports Traumatol Arthrosc. 2008 Aug 1;16(8):729–33. 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-3209293","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":228777545,"identity":"19497cbe-d65a-437b-8d1d-ce17761f6a30","order_by":0,"name":"Eike Martens","email":"","orcid":"","institution":"Lubinus Clinicum","correspondingAuthor":false,"prefix":"","firstName":"Eike","middleName":"","lastName":"Martens","suffix":""},{"id":228777546,"identity":"e402463b-08b9-45d7-aaa7-6abe8f1181cc","order_by":1,"name":"Tilmann Krackhardt","email":"","orcid":"","institution":"Lubinus 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Schleswig-Holstein","correspondingAuthor":false,"prefix":"","firstName":"Sebastian","middleName":"","lastName":"Lippross","suffix":""}],"badges":[],"createdAt":"2023-07-27 10:14:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3209293/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3209293/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":42312764,"identity":"fe450c6d-7eb0-49c6-b6cf-c509f1466f69","added_by":"auto","created_at":"2023-08-29 14:45:18","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":327679,"visible":true,"origin":"","legend":"\u003cp\u003eT2 sagittal view of MRI secured PCL-lesion in young patient\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/6c342ad30ed8be4da0158bfe.png"},{"id":42311895,"identity":"542b9599-77c5-4957-900e-ad7e5b8fa80f","added_by":"auto","created_at":"2023-08-29 14:37:19","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":202637,"visible":true,"origin":"","legend":"\u003cp\u003eknee joint in kneeling view\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/ca1214893650200797a038be.png"},{"id":42312765,"identity":"3f5d2a5b-3e53-4730-b53a-b2bbdedcb7b9","added_by":"auto","created_at":"2023-08-29 14:45:18","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":662007,"visible":true,"origin":"","legend":"\u003cp\u003ePlacement of the IMUs on the participants during the measurement.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/991fdea9fe8bda5d1e6b5927.png"},{"id":42311885,"identity":"bee99d2b-d811-43ab-a870-5b318a264b79","added_by":"auto","created_at":"2023-08-29 14:37:18","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":12797,"visible":true,"origin":"","legend":"\u003cp\u003eSide to side extension values for fit (nop) and injured (op) knee joint\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/88677efa4b935649ba1e4fee.png"},{"id":42311887,"identity":"beb0ef38-f67a-482b-85b6-8d7bd3dc89fa","added_by":"auto","created_at":"2023-08-29 14:37:18","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":13878,"visible":true,"origin":"","legend":"\u003cp\u003eSide to side flexion values for fit (nop) and injured (op)knee joint\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/f81ad0f2e39430961302dd7d.png"},{"id":42313385,"identity":"2a1e5274-30d0-4b12-a2cb-54ece7bebe4c","added_by":"auto","created_at":"2023-08-29 14:53:18","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":36029,"visible":true,"origin":"","legend":"\u003cp\u003eIMU measurement of ROM\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/fd6f39bb35675a245c468fae.png"},{"id":42311891,"identity":"fc6cbd45-f4b5-4e22-94fd-2e1a4532a360","added_by":"auto","created_at":"2023-08-29 14:37:18","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":35984,"visible":true,"origin":"","legend":"\u003cp\u003eIMU Measurement of ROM\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/ce9fea6e8c1bc8487639a499.png"},{"id":42311894,"identity":"ca48202d-4a71-4d13-8cea-bd47b6c78bf4","added_by":"auto","created_at":"2023-08-29 14:37:18","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":15942,"visible":true,"origin":"","legend":"\u003cp\u003eTAS for status post-op and pre-injury\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/57b607ee0267d887a2033f14.png"},{"id":42311888,"identity":"5778148d-a847-4397-a37b-2c09fc99280c","added_by":"auto","created_at":"2023-08-29 14:37:18","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":12499,"visible":true,"origin":"","legend":"\u003cp\u003eIKDC-Scale for status preopereative (pre-op) and postoperative (post-op)\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/08b5e9df931e00fbc2532006.png"},{"id":42312766,"identity":"e1b9de2c-92a7-4ccb-a58d-7f88c043646a","added_by":"auto","created_at":"2023-08-29 14:45:18","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":12093,"visible":true,"origin":"","legend":"\u003cp\u003eSide to side difference in posterior tibial translation for fit (nop) and injured (op) side\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/c7b7582bbbb87826526db278.png"},{"id":43247979,"identity":"dc5f074c-3543-4eaa-a4c9-76a8a5b9072c","added_by":"auto","created_at":"2023-09-17 05:52:31","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1536630,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3209293/v1/15aa0c23-d79a-495e-8dfa-ea7b1e529f35.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Posterior cruciate ligament repair in acute knee instabilities with internal bracing: midterm follow up for clinical and kinematic results","fulltext":[{"header":"Background","content":"\u003cp\u003eInjuries to the posterior cruciate ligament (PCL) often pose challenges to the treating surgeon. In comparison to anterior cruciate ligament ruptures, PCL tears are rare and may be overlooked in the context of multi-ligament trauma. Most commonly, these injuries occur during sport, usually involving hyperextension trauma of the knee or by dashboard injury (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). The age- and gender-adjusted annual incidence of isolated, complete cruciate ligament tears is estimated to be 1.8 per 100,000 (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Nevertheless in a considerable number of cases PCL tear may be diagnosed as an isolated injury or with additional meniscal and collateral ligament ruptures (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). There have been controversial reports on the surgical management of these types of injuries (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Results of conservative therapy for isolated tears show subjective patient satisfaction, although significant instability can remain (\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Initial surgical procedures by direct suture have been predominantly superseded by full ligament reconstruction procedures in multiligamentous injuries (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWithin the last years PCL-saving augmentation techniques have evolved, and internal bracing, which is a common procedure for collateral ligament repair has been applied for the posterior cruciate injury. Internal bracing aims to re-constitute anatomic biomechanics and creates primary stability by anterior counterforce that allows the injured ligament to heal while preserving the anatomical structures and proprioception (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). An advantage of the procedure is the lesser invasiveness and shorter operation time compared to full reconstruction (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRecent recommendations for internal bracing include acute isolated PCL ruptures, PCL ruptures in the context of high grade multiligamentous injuries or PCL injuries with meniscal lesions that require surgical treatment (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eInitial follow-up studies of this procedure show promising results for both acute isolated or multiligamentous injuries (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Studies on outcomes are limited, but the procedure could deliver promising results with low invasiveness and be used frequently in the future (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn our study we focused on activity, clinical and kinematic results after internal bracing of PCL in grade II and III Instabilities.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003ePatient selection\u003c/p\u003e\n\u003cp\u003eA total of 32 patients underwent internal bracing at the study center from 2017 to 2021, of which 19 patients consented to study follow-up and met the inclusion criteria. Included were patients who suffered a unilateral PCL tear with a healthy opposite knee which met the indication criteria for internal bracing. Indication for this procedure were an MRI-secured complete or partial rupture of the PCL. In the injured knee joint a grade II instability represented an indication for surgery. Diagnosis was secured using clinical examination and an MRI scan (Fig 1). All surgical procedures were performed by three surgeons. Patients with an operated contralateral knee, a radiologically confirmed fixed posterior translation and patients after revision surgery with reconstruction procedure were excluded from the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSurgical technique\u003c/p\u003e\n\u003cp\u003ePatient is positioned in supine position, with the leg in a leg holder, torniquet, standard anteromedial and anterolateral portals are established. After arthroscopic verification of the diagnosis, the footprint is debrided. Then, under vision from the anterolateral side, the posteromedial recess is visualized. A posteromedial access is established. The pericapsular layer behind the tibial head is dissected. Then the camera is transferred posteromedial, from anteromedial the tibial targeting device for the posterior cruciate ligament is inserted, placed about 15 mm below the joint level. An oblique skin incision is made ventrally, first predrilling with the drill, then overdrilling with the 4.0 mm cannulated drill. A shuttle loop is advanced, using ring grasping forceps it is shuttled and secured with a small clamp. Now with view from anteromedial over anterolateral the target drill is inserted into the femoral ventral attachment of the posterior cruciate ligament at the medial condyle.\u003c/p\u003e\n\u003cp\u003eA Pre-drill is advanced with perforation of the counter cortex. Then it is overdrilled with the 4.0 mm drill, measuring the bone distance. The bracing is prepared with TightRope RT and Fibertape (Arthrex, Munich, Germany). The tape is pulled through, and the button flipped. Finally, the Fibertape is pulled into the tibial drill channel. An ABS button (Arthrex, Munich, Germany) is knot tightly against the tibial head while holding an anterior drawer. The procedure is completed by testing for stability and a final arthroscopic control.\u003c/p\u003e\n\u003cp\u003ePostoperative protocol\u003c/p\u003e\n\u003cp\u003eThe patients were kept non-weight-bearing for 4 weeks. From week 5 to 6, 50% weight bearing was allowed. From 7 th week, full weight bearing was allowed. A rigid PTS (posterior tibial support, medi GmbH,Bayreuth, Germany ) splint with a calf pad was applied postoperatively for 6 weeks. From 7 th to 12th postoperative week, a PCL splint with full range of motion was worn during the day. At night, the PTS orthosis had to be worn further. From 1st to 4th week, physiotherapy was performed out of the rigid orthosis exclusively in prone position up to 90 \u0026deg;. After that, flexion could be gradually increased.\u003c/p\u003e\n\u003cp\u003eKnee Score examination\u003c/p\u003e\n\u003cp\u003eEach clinical examination was performed by the same study physician after prior routine follow-up.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo assess current quality of life and activity level, the subjective IKDC-, Tegner and Lysholm score were determined at baseline. The scores provide information about patient satisfaction and recovery of everyday activity.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-IKDC-Score\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe IKDC is an evaluation form to assess a variety of knee symptoms. It contains seven items for knee symptoms (37 points), two items for knee function (10 points) and two items on sports activities (40 points). To score the current form of the IKDC, simply add the score for each item and divide by the maximum possible score which is 87. then the score is transferred to a scale that ranges from 0 to 100. It had the advantage of being adaptable to a large number of knee pathologies.\u0026nbsp;(13). Any variation of at least 11.5 points (on the 100-point scale) is regarded as a significant clinical improvement or worsening\u0026nbsp;(14)\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-Tegner Activity scale\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eTAS is recommended for evaluating sports and daily activity level. The scale ranges from 0, which represented a massive disability by knee symptoms to 10, which can be similar to international level of soccer players. One through 5 includes work or recreational sports from sedentary jobs to heavy manual labor or amateur sports (i.e. swimming, cycling and jogging in relation to the number and intensity of sport sessions per week), 6 through 9 represents competitive sports (athletics, tennis, alpine skiing, basketball, handball) .\u0026nbsp;{(13)\u0026nbsp;}\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-Lysholm score\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe Lysholm Score is a frequently used questionnaire about knee function in everyday life after an ACL injury. It includes 8 items (limping, aids used, locking, instability, pain, swelling, stair climbing and knee bending) to produce an overall score on a point scale of 0 to 100.(15)\u0026nbsp;Results are categorized in descending order of performance into \u0026ldquo;excellent\u0026rdquo;, \u0026ldquo;good\u0026rdquo;, \u0026ldquo;fair\u0026rdquo; and \u0026ldquo;poor\u0026rdquo;.\u003c/p\u003e\n\u003cp\u003eClinical examination\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-Posterior tibial translation\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eTibial translation was obtained by a Rolimeter (Aircast Europe, Rosenheim, Germany). The results of many studies suggest that Rolimeter is a reliable device in objectively evaluating knee joint laxity. The measurement was performed according to the standard instructions but in 90\u0026deg; Knee-flexion. (16)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe Rolimeter was positioned on the patella proximally and distally on the tibia, fixed with a strap. The reader-bar was centered on the tuberosity of the tibia. First, the total tibial translation of the healthy and operated side was measured. Three repeated measurements were made in each knee. The mean value of the two highest results on each knee was used for further analysis. Posterior tibial translation of the operated side was determined then by subtracting the mean result on the operated side from the mean result on the non-operated side. To better assess posterior tibial displacement, stress radiographs of both knee joints in kneeling view were used to determine the grade of postoperative ligament insufficiency (Fig. 2). Patients with a fixed posterior drawer could thereby be excluded.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-ROM\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAll patients underwent clinical examination of both knee joints. Extension and Flexion in supine position were measured in degrees using a goniometer.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-Motion analysis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eTo evaluate kinematic joint parameters, gait and walking analysis was performed using a treadmill (H/p/cosmos sports \u0026amp; medical GmbH, Germany) and inertial measurement units (IMUs). IMU is a small, body-worn, sensor-based technology that can track the motion and orientation of an object in space. IMU systems, which include accelerometers, gyroscopes, and magnetometers, use sensor fusion algorithms and biomechanical modelling techniques to extract kinematic and spatiotemporal gait and walking parameters (Hansen et. al. 2023).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e17 Participants in our study were recorded walking and running on a treadmill using an IMU system (Noraxon USA inc., myoMOTION, Scottsdale, AZ, USA). Five IMUs were attached to the body (lower leg, thigh, sacrum (Fig. 3)) with elastic straps. Data were acquired at 200 Hz in a commercial software package (Noraxon MR3.16).\u003c/p\u003e\n\u003cp\u003eCalibration of the biomechanical model was performed according to the standard protocol of the supplier of the commercial system. Study participants were required to stand in a neutral position for 5 seconds for static referencing. Immediately thereafter, participants began to walk 5 m in one direction and then returned to the same calibration position, a new static calibrate occurred to compensate for the effects of magnetic interference on each sensor. IMU orientation was estimated using a sensor fusion algorithm.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-Motion assessment\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003ePrior to recording the gait and running analysis, an acceleration-based functional calibration procedure was performed to correct for the effects of any magnetic field interference. Participants began walking on the treadmill at a self-selected speed.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAfter a walking speed comfortable to the participant was established, the investigator recorded 23 walking cycles on the treadmill after a signal to the participant.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe same procedure was performed for walking at a self-selected walking speed.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e-IMU derived variables\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe IMU system automatically detects motion cycle events using an acceleration-based algorithm. Spatiotemporal motion parameters, as well as range of motion (ROM) for hip and knee joint angles in the sagittal plane were recorded per participant. Inter-limb coordination was compared by cross-referencing the recorded data.\u003c/p\u003e\n\u003cp\u003eData analysis\u003c/p\u003e\n\u003cp\u003eStatistics were carried out using SPSS 14.0 for Windows. Results are presented as mean with standard deviation. As this was a single cohort study with no control group, no power analysis was performed. In the intraindividual comparison between the non-operated and the operated joint, significance was set at \u003cem\u003ep\u003c/em\u003e\u0026lt; 0.05 using a student\u0026acute;s t-test.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 19 patients were included in our study, 4 women (21 %) and 15 men (79 %).\u0026nbsp;A gait analysis was performed by 17 patients.\u0026nbsp;The mean age was 42\u0026nbsp;\u0026plusmn;\u0026nbsp;15,7 years.\u0026nbsp;The youngest subject was 16 years old and the oldest 69. Mean age at time of surgery amounted 39\u0026nbsp;\u0026plusmn;\u0026nbsp;15,8 years. Follow-up examination took place after 29.40\u0026nbsp;\u0026plusmn;\u0026nbsp;10.47 months. Intraoperatively and in MRI 11 partial and 8 full substance tears of the PCL were found. 1 PCL was distally ruptured, 6 ligaments were proximally ruptured, and 12 ligaments were torn in midsubstance.\u0026nbsp;2 patients suffered from an internal meniscal tear and 2 patients from a partial MCL rupture classified as a Schenck Type I knee dislocation.\u0026nbsp;Surgery was performed within\u0026nbsp;1,8\u0026nbsp;\u0026plusmn; 3,5\u0026nbsp;months after trauma. The mean operating time was 56\u0026nbsp;\u0026plusmn; 11,6\u0026nbsp;min.\u003c/p\u003e\n\u003cp\u003eMotion analysis\u003c/p\u003e\n\u003cp\u003eClinical examination for ROM was not significantly reduced compared to the un-operated (control-) Knee (p\u0026gt;0,05). The average result for terminal knee extension showed 0,79 \u0026plusmn; 1,9 \u0026deg; compared to 0 \u0026deg; for the non-operated site (Fig. 4). Terminal flexion values amounted to 138,4 \u0026plusmn; 3,4 \u0026deg; for the operated side and 139,5 \u0026plusmn; 2,3 \u0026deg; for the non-operated side (Fig. 5). The standard deviation of control values was lower than for the treated side. There were 2 patients with an extension deficit of less than 5 \u0026deg; and one patient with a combination of extension (5 \u0026deg;) and flexion (130 \u0026deg;) deficit.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAnalysis of ROM using an IMU system revealed a mean ROM for gait analysis of 55.57 \u0026plusmn; 7.54 \u0026deg; for the operated knees and 57.91 \u0026plusmn; 5.64 \u0026deg; for the non-operated knees. The difference in ROM between the operated and non-operated knee was not significant (p=0.1566) (Tab.1). The ROM of the IMU data of the hip range of motion was 31.88 \u0026plusmn; 9.15 \u0026deg; in the non-injured side and 32.43 \u0026plusmn; 5.12 \u0026deg; in the injured limb, respectively. There was no significant difference in the comparison of the hip range of motion (p=0.157). The speed of the subjects on the treadmill was 0.88 \u0026plusmn; 0.07 m/s on the treadmill.\u003c/p\u003e\n\u003cp\u003eThe analysis of ROM during running also revealed no significant differences in the intraindividual comparison of limb joints (hip: p=4938; knee: p=0.6716). Self-selected running speed was 1.74 \u0026plusmn; 0.43 m/s. The IMU-derived parameters of gait analysis and running analysis and the corresponding p-values are shown in Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1:\u0026nbsp;\u003c/strong\u003eMotion analysis of walking and running presented in ROM of joints in degrees (mean \u0026plusmn; SD). Correlation analysis of the presented parameters.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"604\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.768595041322314%\" valign=\"top\"\u003e\n \u003cp\u003eIMU derived parameters\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.644628099173552%\" valign=\"top\"\u003e\n \u003cp\u003eGait (\u0026deg;) (mean \u0026plusmn; SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.066115702479339%\" valign=\"top\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.66115702479339%\" valign=\"top\"\u003e\n \u003cp\u003eRun (\u0026deg;) (mean \u0026plusmn; SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.859504132231404%\" valign=\"top\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.768595041322314%\" valign=\"top\"\u003e\n \u003cp\u003eROM Hip injured\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.644628099173552%\" valign=\"top\"\u003e\n \u003cp\u003e32.43 \u0026plusmn; 5.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.066115702479339%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.157\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.66115702479339%\" valign=\"top\"\u003e\n \u003cp\u003e35.27 \u0026plusmn; 6.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.859504132231404%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.4938\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"39.06976744186046%\" valign=\"top\"\u003e\n \u003cp\u003eROM Hip not injured\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.86046511627907%\" valign=\"top\"\u003e\n \u003cp\u003e31.88 \u0026plusmn; 9.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"29.069767441860463%\" valign=\"top\"\u003e\n \u003cp\u003e35.32 \u0026plusmn; 9.51\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.768595041322314%\" valign=\"top\"\u003e\n \u003cp\u003eROM Knee injured\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.644628099173552%\" valign=\"top\"\u003e\n \u003cp\u003e55.57 \u0026plusmn; 7.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.066115702479339%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.1566\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.66115702479339%\" valign=\"top\"\u003e\n \u003cp\u003e65.03 \u0026plusmn; 10.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.859504132231404%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.6716\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"39.06976744186046%\" valign=\"top\"\u003e\n \u003cp\u003eROM Knee not injured\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.86046511627907%\" valign=\"top\"\u003e\n \u003cp\u003e57.91 \u0026plusmn; 5.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"29.069767441860463%\" valign=\"top\"\u003e\n \u003cp\u003e63.44 \u0026plusmn; 9.38\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eFor visual demonstration and interpretation IMU-derived parameters are exemplarily shown. Angle coordination between thigh and shank IMUs shows no differences between the operated and non-operated leg which punctuates the great functional outcome after surgery (Fig. 6,7).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eRunning analysis showed mean maximum knee angles of the operated leg of 63.44 \u0026deg; compared to 65.03\u0026deg; of the non-operated leg. Hip angles were 35.32 \u0026deg; and 35.27 \u0026deg; (Fig. 7). The difference was not significant (p=0.6716; p=0.4938).\u003c/p\u003e\n\u003cp\u003eKnee Scoring Systems/Scales\u003c/p\u003e\n\u003cp\u003eWe further differentiated between pre-injury and post-intervention ADLs by applying the TAS. A mean TAS of 5,5 \u0026plusmn; 1.30 pt was obtained pre-injury and 5.2 \u0026plusmn; 1.2 pt at follow-up (Fig. 8). The results did not differ significantly at a threshold p-value of 0.06, so that a return to the pre-injury level can be assumed.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe mean value of Lysholm score amounted to 95.5 \u0026plusmn; 8,3 % at the follow-up.\u003c/p\u003e\n\u003cp\u003eThe IKDC-Score showed a result of 53.2\u0026nbsp;\u0026plusmn; 4,2\u0026nbsp;% pre -op (after injury) and 91.7\u0026nbsp;\u0026plusmn; 7,4\u0026nbsp;% post-op (Fig. 9).\u003c/p\u003e\n\u003cp\u003eThere was no significant correlation between age and IKDC score. Posterior tibial translation had no significant correlation with age or IKDC.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eKnee stability\u003c/p\u003e\n\u003cp\u003eIn posterior translation test the average dorsal tibial translation (operated knee 5,5\u0026nbsp;\u0026plusmn;1,6\u0026nbsp;mm, un-operated knee 2,9\u0026nbsp;\u0026plusmn; 0,9\u0026nbsp;mm) showed significantly different results whereat the total mean difference from side to side amounted to 2,5\u0026nbsp;\u0026plusmn; 1,5\u0026nbsp;mm (p\u0026lt;0,05) (Fig. 10, Tab. 2). Mean preoperative posterior tibial translation was 8,4\u0026nbsp;\u0026plusmn;\u0026nbsp;1,9 mm on the injured side. 12 patients (63%) had grade II and 7 (37%) grade III instability before surgery.\u0026nbsp;Preoperative tibial translation significantly differed from the examinations at follow-up.\u003c/p\u003e\n\u003cp\u003eIn an x-ray stress test the operated side showed a mean difference in posterior drawer of 3,3 \u0026plusmn; 2,3 mm (Table 2). None of the patients had abnormal medial or lateral collateral ligament laxity at follow-up.\u003c/p\u003e\n\u003cp\u003eIn one patient a postoperative instability grade III (showing 7 mm posterior tibial translation and 11 mm in stress radiography) was observed. Gait and running analyse on treadmill were not performed.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 2: posterior tibial translation both sides in clinical and stress radiograph examination\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"511\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.35616438356164%\" valign=\"top\"\u003e\n \u003cp\u003eKnee side\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.26614481409002%\" valign=\"top\"\u003e\n \u003cp\u003eTotal Tibial translation (\u0026deg;)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.35225048923679%\" valign=\"top\"\u003e\n \u003cp\u003eMean difference\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.025440313111545%\" valign=\"top\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.35616438356164%\" valign=\"top\"\u003e\n \u003cp\u003eInjured side\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.26614481409002%\" valign=\"top\"\u003e\n \u003cp\u003e5,5mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.35225048923679%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e2,5mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.025440313111545%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0,05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"61.25%\" valign=\"top\"\u003e\n \u003cp\u003eUn-operated side\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"38.75%\" valign=\"top\"\u003e\n \u003cp\u003e2,9 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.35616438356164%\" valign=\"top\"\u003e\n \u003cp\u003eInjured side stress radio\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.26614481409002%\" valign=\"top\"\u003e\n \u003cp\u003e7,8mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.35225048923679%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e3,2mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.025440313111545%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0,05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"61.25%\" valign=\"top\"\u003e\n \u003cp\u003eUnoperated side stress radio\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"38.75%\" valign=\"top\"\u003e\n \u003cp\u003e4,6mm\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAdverse Effects/non-favourable outcome\u003c/p\u003e\n\u003cp\u003eIn our study, a total of 2 patients (10,5 %) had a slight extension deficit of less than 5 \u0026deg;. In 1 patient there was no ligamentous healing leading to III \u0026deg;-PCL- Instability with extension (5 \u0026deg;) and flexion (130 \u0026deg;) lag. He received a PCL-reconstruction later. We further identified no injuries of the popliteal artery and saphenous nerve. There were no postoperative infections or wound healing disorders.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe indication for surgical or conservative therapy of PCL tears is still being discussed. The lack of reliable recommendations for therapy is due to the rarity of PCL tears and the fact that they are difficult to recognize and evaluate in the context of multiligamentous injury patterns (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). The posterior cruciate ligament has a high intrinsic healing potential, so that a sufficient function can be assumed after both, conservative and operative treatment (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). For isolated PCL tears conservative treatment among top athletes and average patients showed a subjectively good function, with residual instability remaining in clinical tests (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). A healing process leading to the formation of a remaining posterior drawer is assumed if the posterior counterforce is insufficient. Likewise, the surgical principle of internal bracing is based on the self-healing tendency of the PCL but uses the implementation of stable FibreTape (Arthex, Munich, Germany) in the anatomical course of the injured structures to create primary stability during recovery phase.\u003c/p\u003e \u003cp\u003eFor high-grade injuries such as grade III instabilities or severe multi-ligament knee injuries, reconstruction procedures in single or double bundle technique have been preferred so far (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe users of ligament bracing consider both, acute multi-ligament and isolated injuries of the PCL to be suitable for this relatively new procedure, although in the authors' opinion it can only be recommended for certain individual cases due to the insufficient evidence to date. In addition, it is recommended that ligament bracing be performed within 14 days because of the assumed healing potential that decreases with time after injury. (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eIn our study time between trauma and operation is 54 days on average. This is well in keeping with similar representative studies (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). The delay is probably due to the above-mentioned difficulty in diagnosing and assessing the injury. However, the ideal timing for surgical treatment is currently being discussed (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eOverall, natural mobility of the injured knee joint was regularly restored in our patients. This was shown by clinical and kinematic examination on a treadmill at follow-up. The mean range of motion for the operated knee joint was 1 \u0026deg; for extension and 138 \u0026deg; for flexion. Motion analysis showed a balanced, symmetrical gait and running. Hip and knee joint mobility were not significantly impaired leading to the conclusion of a competent PCL bracing and an adaptive gait strategy (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Current studies showed that similar recent modified measurement methods with IMU produced valid results for detecting knee joint instability or osteoarthritis (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWith regard to the analysis of movement, it is important to mention that after surgical procedures, joint stiffness or limitation of movement in extension or flexion may occur (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). We were able to examine a total of three patients (16%) with an extension deficit of 5 \u0026deg;. All 3 patients were treated within the first 2 years after we began to utilize the technique. The deficit was attributed to insufficient counterforce of the tape and missed rehabilitation. Naturally a learning curve is associated with a new technique and initial less favourable outcomes may be seen in this context.\u003c/p\u003e \u003cp\u003eSome investigations have shown inferior outcomes for ROM in early PCL reconstructions, i.e. a loss of mean flexion by 8 \u0026deg; compared to the contralateral knee was obtained in a series of 25 arthroscopically assisted PCL repairs (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). The comparatively poorer results could be attributed to a higher rate of severe instabilities and multi-ligament injuries.\u003c/p\u003e \u003cp\u003ePatel et al. reported an average flexion of 138 \u0026deg; (range,130\u0026ndash;150) and an average extension of 1 \u0026deg; (range,0\u0026ndash;4) in a study of conservatively treated isolated partial and complete ruptures of the PCL. The proportion of post-traumatic movement restrictions remained low (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Our results come along with these findings.\u003c/p\u003e \u003cp\u003eIn addition, we have referred to the commonly used knee scores. The Lysholm Knee Function Scale is frequently used for ligamentous or meniscal injuries of the knee, although its effectiveness for ligament injuries is often debated (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). Therefore we supplement the TAS to get a more accurate and reliable view of the patient\u0026rsquo;s condition.\u003c/p\u003e \u003cp\u003eAt follow-up, our collective reached a mean score of 95.5 points in the Lysholm Scale and 5.14 in the TAS, with the pre-accident condition reaching a mean score of 5.4. The results on TAS do not differ significantly to pre-op (p\u0026thinsp;\u0026gt;\u0026thinsp;0,05) and on reflect adequate return-to-pre-injury-level.\u003c/p\u003e \u003cp\u003eResults of different other studies show TAS to follow up examination of 6,6\u0026thinsp;+\u0026thinsp;1,8 (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e) and 7,2 (range, 5 to 10) (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e), as opposed to 7 (range, 4 to 10) and 7,5 (range, 5 to 10), respectively. The higher values pre-injury and after treatment are particularly noticeable here, probably the collective was different to ours. In addition, Lysholm score showed 85,2 (+\u0026thinsp;10) and 94 (range, 88 to 100) after 24 months in both evaluations although both authors observed a slight but significant decrease (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAt the same time, our collective showed a highly significant increase in IKDC due to internal bracing. Shelbourne et al. show 73 points in IKDC evaluation after conservative treatment of isolated PCL tears at a mean follow-up of 17,1 years (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Similar results are shown for conservative treatment by Ahn et al., whose follow-up was 51 months on average and an IKDC of 83 was achieved (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). At shorter follow-up intervals, Patel et al. confirmed a higher IKDC of 93 after 24 months (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). There seems to be a decrease in knee scores in the further follow-up, but due to our midterm review it remains unclear whether the permanent stabilization by internal bracing offers an advantage. In keeping with this discrepancy of the results can also be caused by the subjective part and the different perception of pain, which lead to a different evaluation.\u003c/p\u003e \u003cp\u003eMoreover, a large number of follow-up studies after treatment of PCL tears showed no correlation between good subjective scores and the stability of the knee joint. We similarly observed no strong correlation between increased posterior tibial translation and IKDC results. Hence some authors have questioned whether posterior translation as such can be seen as an indicator for inferior outcome (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). On the other hand, long-term studies of conservative procedures reported an increased incidence of osteoarthritis associated with posterior instability (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Wang et al concluded that conservative treatment in grade I and II isolated injuries can lead to sufficient subjective results, although residual instability bears a risk of meniscal tears and osteoarthritis (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e). Understandably within a short follow-up no degenerative changes were noted, most osteoarthritic changes in conservatively treated groups can only detected after 5\u0026ndash;14 years (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn knee stability test our average post operative difference for tibial translation was 2,5 mm, which was significantly less than before surgery.\u003c/p\u003e \u003cp\u003eBy comparison, Jacobi et al. determined the anteroposterior translation similar with a Rolimeter of 3.2mm after 24 months (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). In relation to the initial posterior sag of 7.1mm (range, 5 to 10 mm), there was a significant improvement here as well.\u003c/p\u003e \u003cp\u003eConversely Ahn et al. examined isolated PCL lesions with grade I and II instability after conservative procedures using the KT-1000 arthrometer with a side-to-side difference of 5.2 mm (range, 2 to 10 mm) at the latest follow-up (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). Despite different measuring instruments, a relatively good comparability of our solid values can be assumed, as the Rolimeter in particular provides accurate results for tibial translation from 80 degrees of knee flexion (\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDue to our limited number of MLKI\u0026acute;s it is difficult to make a statement on outcomes by internal bracing. For MLKI\u0026acute;s and grade III Instability Otto et al. found adequate but overall worse results in a collective of 17 patients using a KT 2000 arthrometer (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRegarding the complex nature of this injury, recent suture augmentation, a combination of arthroscopic PCL suture and augmentation by internal bracing, appears to be superior for proximal and distal PCL-tears (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e). However, in most evaluations there remains a low side-to-side difference(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Likewise, we can confirm a significant side-to-side difference for tibial translation, but no instability (\u0026lt;\u0026thinsp;4 mm) in the mean.\u003c/p\u003e \u003cp\u003eIn our study, stress radiographs were additionally used to confirm a significant lateral difference of tibial translation postoperatively. There are several studies that demonstrate a substantial difference in translation values using this radiologic method (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e). It is difficult to compare stress radiographs because different measurement methods are used. One evaluation of conservative treatment uses lateral view in 70 \u0026deg; knee flexion with contraction of hamstring muscles and achieved 3,4 mm (range,1,1 to 8,1 mm) after 24 months (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eStress radiographs performed by a Telos stress device (Austin \u0026amp; Associates, Fallston, MD, USA) showed for conservative-treated PCL-injuries a reduction of posterior tibial translation to 3.5 mm (range,0.7\u0026ndash;8 mm) at the last follow-up (at least 2 years) (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIt can be observed that our results are comparable to conservative treatment procedures despite the inclusion of grade III-PCL-instabilities and meniscal or collateral ligamentous lesions while peri- and postoperative risk remains low. In consideration of the currently limited number of studies conservative therapy can be recommended for isolated PCL-injuries in the authors opinion, but if additional injury requiring intervention or at least a grade II instability is present, internal bracing should be particularly considered for higher secure stabilization and risk minimization.\u003c/p\u003e \u003cp\u003eHowever, the results of this study are limited. Firstly, we cannot refer to a control group, but compare to the contralateral knee joint. Secondly, follow-up time also varies. On the other hand, strength of the study is certainly the inhomogeneous patient collective with athletes and non-athletes that may represent a population average. Using IMU-devices to detect movement restrictions in gait and running analyse support clinical findings in mobility examination of both knee joints.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eInternal bracing can offer a good treatment for acute grade II and III - PCL-instabilities, especially when further meniscal or ligamentous injuries require surgical repair. Despite the limited evidence-based results and applications to date, restoration of joint mobility and a minor residual posterior tibial translation can be confirmed. Results for everyday and sports activities are comparable with conservative and established surgical procedures. The intra- and postoperative risk as well as the revision rate is low in the hands of the experienced surgeon.\u003c/p\u003e \u003cp\u003eHowever, long-term results should be awaited and must subsequently be further investigated on an evidence-based level to reach better understanding of indication.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eADLs: Activities of daily living\u003c/p\u003e\n\u003cp\u003eDEG: degrees\u003c/p\u003e\n\u003cp\u003eIKDC: International Knee Documentation Score\u003c/p\u003e\n\u003cp\u003eIMU: inertial measurement unit\u003c/p\u003e\n\u003cp\u003eMLKI: multi-ligament knee injury\u003c/p\u003e\n\u003cp\u003eMin: minutes\u003c/p\u003e\n\u003cp\u003eMRI: Magnetic resonance imaging\u003c/p\u003e\n\u003cp\u003ePCL: posterior cruciate ligament\u003c/p\u003e\n\u003cp\u003ePTS: posterior tibial splint\u003c/p\u003e\n\u003cp\u003ePT: points\u003c/p\u003e\n\u003cp\u003eROM: Range of motion\u003c/p\u003e\n\u003cp\u003eTAS: Tegner Activity Scale\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was conducted according to the guidelines of the Declaration of Helsinki. Ethics approval was obtained\u0026nbsp;from the ethics committee of the Christian-Albrechts-University Kiel:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eChristian-Albrechts-Univiersity Kiel\u003c/p\u003e\n\u003cp\u003eEthics committee\u003c/p\u003e\n\u003cp\u003eArnold-Heller-Stra\u0026szlig;e 3, 24105 Kiel, Germany\u003c/p\u003e\n\u003cp\u003eReference Nr.\u0026nbsp;(D418/21)\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all subjects and/or their legal guardian(s)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting of interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors assure that no funding was received to assist with the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor\u0026acute;s contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eE.M. wrote the article, collected the data and invented study design\u003c/p\u003e\n\u003cp\u003eT.K. conceived and designed the analyse and wrote the article\u003c/p\u003e\n\u003cp\u003eL.W. collected and contributed the data\u003c/p\u003e\n\u003cp\u003eS.K. contributed tools and data\u003c/p\u003e\n\u003cp\u003eM.W: collected the data and invented study design as well as wrote the article\u003c/p\u003e\n\u003cp\u003eS.L. invented study design, conceived the analyse and wrote the article\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank the staff of the \u0026ldquo;Lubinus Aktiv Foundation\u0026rdquo; for carrying out the gait analysis under the direction of Frank Naeve as well as the advisory colleagues Gero Benning, Peter Behrendt and Maciej Simon.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eFowler PJ, Messieh SS. Isolated posterior cruciate ligament injuries in athletes. Am J Sports Med. 1987 Nov;15(6):553\u0026ndash;7. \u003c/li\u003e\n\u003cli\u003eSanders TL, Pareek A, Barrett IJ, Kremers HM, Bryan AJ, Stuart MJ, et al. Incidence and long-term follow-up of isolated posterior cruciate ligament tears. Knee Surg Sports Traumatol Arthrosc. 2017 Oct;25(10):3017\u0026ndash;23. \u003c/li\u003e\n\u003cli\u003eHeusdens CHW. 1 Primary Posterior Cruciate Ligament Repair With The Novel Suture Tape 2 Augmentation Technique. :16. \u003c/li\u003e\n\u003cli\u003eOtto A, Helal A, Imhoff FB, Mehl J, Herbst E, Achtnich AE, et al. Promising clinical and magnetic resonance imaging results after internal bracing of acute posterior cruciate ligament lesions in multiple injured knees. Knee Surg Sports Traumatol Arthrosc. 2020 Aug;28(8):2543\u0026ndash;50. \u003c/li\u003e\n\u003cli\u003eAchtnich A, Imhoff AB, Schmitt A, Beitzel K. Ligament-Bracing des hinteren Kreuzbands: Operationstechnik. Arthroskopie. 2017 Jun;30(2):138\u0026ndash;41. \u003c/li\u003e\n\u003cli\u003eWang D, Graziano J, Williams RJ, Jones KJ. Nonoperative Treatment of PCL Injuries: Goals of Rehabilitation and the Natural History of Conservative Care. Curr Rev Musculoskelet Med. 2018 Jun;11(2):290\u0026ndash;7. \u003c/li\u003e\n\u003cli\u003eSun Y, Li L, Dai J, Wang T. Treatment of complex proximal humeral fracture: plate and tension band fixation versus conservative therapy. Int J Clin Exp Med. 2015;8(5):7143\u0026ndash;51. \u003c/li\u003e\n\u003cli\u003eMontgomery SR, Johnson JS, McAllister DR, Petrigliano FA. Surgical management of PCL injuries: indications, techniques, and outcomes. Curr Rev Musculoskelet Med. 2013 Jun;6(2):115\u0026ndash;23. \u003c/li\u003e\n\u003cli\u003eWang SH, Chien WC, Chung CH, Wang YC, Lin LC, Pan RY. Long-term results of posterior cruciate ligament tear with or without reconstruction: A nationwide, population-based cohort study. Zhao C, editor. PLOS ONE. 2018 Oct 3;13(10):e0205118. \u003c/li\u003e\n\u003cli\u003eMoatshe G, Chahla J, LaPrade RF, Engebretsen L. Diagnosis and treatment of multiligament knee injury: state of the art. J ISAKOS. 2017 May;2(3):152\u0026ndash;61. \u003c/li\u003e\n\u003cli\u003eDabis J, Wilson A. Repair and Augmentation with Internal Brace in the Multiligament Injured Knee. Clin Sports Med. 2019 Apr 1;38(2):275\u0026ndash;83. \u003c/li\u003e\n\u003cli\u003eZhao X, Duan MY, Chen SQ, Wang J, Li W, Lv Y, et al. Posterior cruciate ligament reconstruction with independent internal brace reinforcement: surgical technique and clinical outcomes with a minimum two year follow-up. Int Orthop. 2022 Sep 1;46(9):2019\u0026ndash;28. \u003c/li\u003e\n\u003cli\u003eKon E, Altadonna G, Filardo G, Matteo BD, Marcacci M. Knee Scoring Systems. In: Bentley G, editor. European Surgical Orthopaedics and Traumatology [Internet]. Berlin, Heidelberg: Springer Berlin Heidelberg; 2014 [cited 2023 Apr 16]. p. 3371\u0026ndash;88. Available from: http://link.springer.com/10.1007/978-3-642-34746-7_120\u003c/li\u003e\n\u003cli\u003eResponsiveness of the International Knee Documentation Committee Subjective Knee Form - James J. Irrgang, Allen F. Anderson, Arthur L. Boland, Christopher D. Harner, Philippe Neyret, John C. Richmond, K. Donald Shelbourne, , International Knee Documentation Committee, International Knee Documentation Committee, 2006 [Internet]. [cited 2023 Apr 16]. Available from: https://journals.sagepub.com/doi/abs/10.1177/0363546506288855?journalCode=ajsb\u003c/li\u003e\n\u003cli\u003eWirth B, Liffert F, de Bruin ED. [Development and evaluation of a German version of the Lysholm score for measuring outcome after anterior cruciate ligament injuries]. Sportverletz Sportschaden. 2011 Mar 1;25(1):37\u0026ndash;43. \u003c/li\u003e\n\u003cli\u003eA New Mechanical Testing Device for Measuring Anteroposterior Knee Laxity - Andreas J. Schuster, Mike J. Mcnicholas, Stefan W. Wachtl, Douglas W. 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Knee Surg Sports Traumatol Arthrosc. 2021 Mar;29(3):669\u0026ndash;71. \u003c/li\u003e\n\u003cli\u003eZhang L, Liu G, Han B, Wang Z, Yan Y, Ma J, et al. Knee Joint Biomechanics in Physiological Conditions and How Pathologies Can Affect It: A Systematic Review. Appl Bionics Biomech. 2020 Apr 3;2020:7451683. \u003c/li\u003e\n\u003cli\u003eMcCarthy I, Hodgins D, Mor A, Elbaz A, Segal G. Analysis of knee flexion characteristics and how they alter with the onset of knee osteoarthritis: a case control study. BMC Musculoskelet Disord. 2013 May 21;14(1):169. \u003c/li\u003e\n\u003cli\u003eNa A, Buchanan TS. Validating Wearable Sensors Using Self‐Reported Instability among Patients with Knee Osteoarthritis. PM\u0026amp;R. 2021 Feb;13(2):119\u0026ndash;27. \u003c/li\u003e\n\u003cli\u003eZawodny SR, Miller MD. Complications of Posterior Cruciate Ligament Surgery. Sports Med Arthrosc Rev. 2010 Dec;18(4):269\u0026ndash;74. \u003c/li\u003e\n\u003cli\u003ePatel DV, Allen AA, Warren RF, Wickiewicz TL, Simonian PT. The nonoperative treatment of acute, isolated (partial or complete) posterior cruciate ligament-deficient knees: an intermediate-term follow-up study. HSS J Musculoskelet J Hosp Spec Surg. 2007 Sep;3(2):137\u0026ndash;46. \u003c/li\u003e\n\u003cli\u003eTegner Y, Lysholm J. Rating Systems in the Evaluation of Knee Ligament Injuries. Clin Orthop Relat Res 1976-2007. 1985 Sep;198:42. \u003c/li\u003e\n\u003cli\u003eJacobi M, Reischl N, Wahl P, Gautier E, Jakob RP. Acute isolated injury of the posterior cruciate ligament treated by a dynamic anterior drawer brace: A PRELIMINARY REPORT. J Bone Joint Surg Br. 2010 Oct;92-B(10):1381\u0026ndash;4. \u003c/li\u003e\n\u003cli\u003eHwan Ahn J, Hak Lee S, Hee Choi S, Ho Wang J, Won Jang S. Evaluation of Clinical and Magnetic Resonance Imaging Results After Treatment With Casting and Bracing for the Acutely Injured Posterior Cruciate Ligament. Arthrosc J Arthrosc Relat Surg. 2011 Dec 1;27(12):1679\u0026ndash;87. \u003c/li\u003e\n\u003cli\u003eWang J, Zhu Y, Zhang F, Chen W, Tian Y, Zhang Y. Meta-analysis suggests that reverse shoulder arthroplasty in proximal humerus fractures is a better option than hemiarthroplasty in the elderly. Int Orthop. 2016 Mar;40(3):531\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eLaPrade CM, Civitarese DM, Rasmussen MT, LaPrade RF. Emerging Updates on the Posterior Cruciate Ligament: A Review of the Current Literature. Am J Sports Med. 2015 Dec;43(12):3077\u0026ndash;92. \u003c/li\u003e\n\u003cli\u003eSchuster AJ, McNicholas MJ, Wachtl SW, McGurty DW, Jakob RP. A new mechanical testing device for measuring anteroposterior knee laxity. Am J Sports Med. 2004;32(7):1731\u0026ndash;5. \u003c/li\u003e\n\u003cli\u003evan der List JP, DiFelice GS. Arthroscopic Primary Posterior Cruciate Ligament Repair With Suture Augmentation. Arthrosc Tech. 2017 Oct 1;6(5):e1685\u0026ndash;90. \u003c/li\u003e\n\u003cli\u003eHeitmann M, Gerau M, H\u0026ouml;tzel J, Giannakos A, Frosch KH, Preiss A. Ligament bracing \u0026ndash; Augmentierte Prim\u0026auml;rnaht bei multiligament\u0026auml;ren Verletzungen des Kniegelenks. Oper Orthop Traumatol. 2014 Feb 1;26(1):19\u0026ndash;29. \u003c/li\u003e\n\u003cli\u003eJung YB, Tae SK, Lee YS, Jung HJ, Nam CH, Park SJ. Active non-operative treatment of acute isolated posterior cruciate ligament injury with cylinder cast immobilization. Knee Surg Sports Traumatol Arthrosc. 2008 Aug 1;16(8):729\u0026ndash;33. \u003c/li\u003e\n\u003c/ol\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":"PCL-tear, internal bracing, posterior instability of the knee, management of PCL-instability, gait analysis","lastPublishedDoi":"10.21203/rs.3.rs-3209293/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3209293/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eInjuries of the PCL are comparably rare. They occur with or without accompanying injuries of the knee and frequently occur in multi-ligament knee instability. Internal bracing is a recent treatment option for acute PCL tears.\u003c/em\u003e \u003cem\u003eFor low-grade instability, a conservative therapy is recommended while severe instability in multi-ligament injuries is mostly addressed by surgical reconstruction. Recent evaluations of internal bracing demonstrate good options for both isolated ligamentous and multiligamentous injuries.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThe aim of this study was to assess general outcomes in joint function and stability as well as activity and quality of life by clinical examination and functional gait analysis.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eA total of 19 patients were examined after internal bracing of an acute II/III° PCL- injury between 2017 and 2021. Included were patients with MRI-proven unilateral PCL tear. In addition to clinical tests for mobility and posterior drawer test, a IMU based kinematic gait analysis was performed. Further IKDC-Score, TAS and Lysholm Score were examined. Regular stress radiographs of both knee joints were included for further evaluation.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eFollow-up examination took place after 29.40 \u003c/em\u003e±\u003cem\u003e 10.47 months. The mean ROM of the injured knee showed 0.\u003c/em\u003e79° ± 1,9\u003cem\u003e° for extension and 138,4° \u003c/em\u003e± 3,4°\u003cem\u003e for flexion. In gait and walking analysis, no significant movement restrictions for either knee joint remained. IKDC amounted to \u003c/em\u003e53,2 ± 4,2% \u003cem\u003eafter injury and \u003c/em\u003e91.7 ± 7,4% \u003cem\u003eat follow-up. The Lysholm Score was \u003c/em\u003e95.5% ± 8,3%\u003cem\u003e. The TAS showed no significant difference (\u003c/em\u003e5,5 ± 1.30 pt \u003cem\u003epre-injury and\u003c/em\u003e 5,2 ± 1.2\u003cem\u003e pt at follow-up). The mean difference of posterior tibial translation reached 2,5 \u003c/em\u003e± 1,5 \u003cem\u003emm in clinical examination and demonstrated significant difference to the healthy side. 1 patient needed revision surgery by complete PCL- reconstruction due to grade II-Instability postoperative but no other complications occurred.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eInternal bracing can offer good treatment for acute grade II and grade III PCL-instabilities, especially when further meniscal or ligamentous injuries require surgical repair. Despite the limited evidence-based results and applications to date, restoration of joint mobility and a minor residual posterior tibial translation can be confirmed. Results for everyday and sports activities are comparable with conservative and established surgical procedures.\u003c/em\u003e\u003c/p\u003e","manuscriptTitle":"Posterior cruciate ligament repair in acute knee instabilities with internal bracing: midterm follow up for clinical and kinematic results","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-08-29 14:37:14","doi":"10.21203/rs.3.rs-3209293/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":"5ac45f3f-d237-493e-9120-f187e3039667","owner":[],"postedDate":"August 29th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2023-09-17T05:44:21+00:00","versionOfRecord":[],"versionCreatedAt":"2023-08-29 14:37:14","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3209293","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3209293","identity":"rs-3209293","version":["v1"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}