Establishing the Radiological Safety Zone in the Ischium to Prevent Neurovascular Injury During Endoscopic Hamstring Tendon Repair: A Cadaveric Study

Establishing the Radiological Safety Zone in the Ischium to Prevent Neurovascular Injury During Endoscopic Hamstring Tendon Repair: A Cadaveric Study | 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 Establishing the Radiological Safety Zone in the Ischium to Prevent Neurovascular Injury During Endoscopic Hamstring Tendon Repair: A Cadaveric Study Selahaddin Aydemir, Hakan Cici, Mustafa Celtik, Gulsah Zeybek Phd, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5461491/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 This study aimed to establish safe zones for arthroscopic hamstring repair by pinpointing the radiological borders of the proximal hamstring tendon. These landmarks will aid surgeons in positioning anchors safely, minimizing the risk of nerve and vascular damage, and lowering the potential for intraoperative complications. Materials and Methods In this anatomical and radiological study, five human cadavers fixed with formaldehyde (10 hips) were analyzed. Marking pins were placed at the borders of the proximal hamstring tendon footprint to determine its anatomical boundaries. Pelvis PA and hip PA radiographs were then taken to determine the radiological boundaries of the tendon footprint and its relationship with the ischial tuberosity. The distances from the tendon’s superior, medial, lateral, and inferior borders to the line joining the ischial tuberosities and the ischial apex were calculated. The accuracy of hip and pelvis radiographs was compared to assess their usefulness in surgical planning. Statistical analysis was performed using the Mann-Whitney U test. Results Four of the five cadavers were male, with a mean age of 67 years. The distances of the hamstring tendon to the line joining the ischium and to the ischial apex were determined with similar measurements on PA radiographs of the pelvis and hip. The distances of the superior, medial, lateral, and inferior borders to the line joining the ischium were 35.3 mm, 22.5 mm, 30.3 mm, and 17.5 mm, respectively, in the pelvis radiograph. In comparison, these values were 35.3 mm, 22.1 mm, 29.7 mm, and 18.9 mm in the hip radiograph. The distances of the superior, medial, lateral, and inferior borders to the ischial apex were 47.7 mm, 33.9 mm, 43.3 mm, and 31.4 mm, respectively, in the pelvic radiograph. In comparison, these values were 47.9 mm, 32.7 mm, 44 mm, and 33.2 mm in the hip radiograph. The distances between the medial and lateral borders and the distances between the superior and inferior borders were also similar. Conclusion Defining the radiological margins of the hamstring tendon provides a critical reference for portal opening and safe and anatomical anchor placement in arthroscopic hamstring repairs. The findings suggest that consistent identification of these boundaries by preoperative imaging and intraoperative fluoroscopy may reduce the risk of neurovascular injury and improve surgical success. The difference in distance between pelvis and hip PA radiographs was not statistically significant, supporting the reliability and reproducibility of both methods. Trial registration: Not applicable. Proximal hamstring injuries Arthroscopic hamstring repair Radiological safety zone Figures Figure 1 Figure 2 Figure 3 Introduction Proximal hamstring injuries are among the common muscle injuries, mainly affecting the muscle-tendon junction or the muscles themselves [ 1 ], [ 2 ]. A less common but more severe injury is the rupture of the proximal tendons at their origin on the ischial tuberosity [ 3 ], [ 4 ], [ 5 ]. Although commonly seen in athletes, these injuries can also occur during daily activities and are more prevalent among middle-aged individuals and those participating in high-risk sports such as rugby and skiing [ 6 ], [ 7 ]. Adverse outcomes such as persistent pain, loss of function, sciatic nerve symptoms, and difficulty returning to sport have been reported in the conservative treatment of proximal hamstring tears [ 8 ], [ 9 ], [ 10 ]. Therefore, the general approach in the literature suggests that surgical repair is a more effective method for both acute and chronic ruptures [ 3 ], [ 4 ], [ 7 ], [ 9 ], [ 11 ], [ 12 ], [ 13 ], [ 14 ], [ 15 ], [ 16 ], [ 17 ], [ 18 ]. The preferred surgical approach has shifted towards minimally invasive techniques. Arthroscopic hamstring tendon repair has emerged as a preferred option due to lower complication rates and faster recovery times compared to open surgery [ 19 ], [ 20 ], [ 21 ], [ 22 ], [ 23 ], [ 24 ], [ 25 ], [ 26 ]. However, the complex anatomy of the hamstring origin, especially its proximity to the sciatic nerve, requires meticulous attention during anchor placement to prevent iatrogenic injury [ 27 ], [ 28 ]. For a stable structure, up to 5 anchors in total are recommended [ 3 ], [ 12 ], [ 23 ], [ 29 ], [ 30 ], [ 31 ]. An essential element of secure and effective arthroscopic repair is identifying a ‘ safe zone ,’ a radiological reference point crucial for guiding safe and anatomical anchor placement. In regions with elevated risks to neurovascular structures, efforts have been made to identify and establish safe radiological zones using intraoperative fluoroscopy or preoperative imaging to reduce complications. [ 32 ], [ 33 ], [ 34 ] Although arthroscopic techniques have improved, standardized radiological guidelines for identifying the safe zone during surgery are still lacking, especially for proximal hamstring injuries, where anatomical variations may complicate the procedure. This study aims to provide a comprehensive overview of the radiological limits of the tendon footprint, its anatomical significance, and the importance of this landmark in ensuring the safety and efficacy of arthroscopic hamstring tendon repair. We also aim to discuss the need to develop standardized protocols for safe and anatomical anchor placement based on precise anatomical and radiological studies, ultimately reducing the risk of complications such as sciatic nerve injury. Our hypothesis posits that a comprehensive understanding of the anatomical correlation between the radiological footprint and surrounding structures may enhance surgical training and mitigate the learning curve associated with arthroscopic techniques. Material method After approval of the local ethics committee, five formaldehyde-fixed human cadavers (10 paired hips) were included in the study (Dokuz Eylul University). Four of the cadavers were male, and one was female, with a mean age of 67 ± 3 years. The cadavers had no history of hip pathology or surgery. All specimens were brought to room temperature and placed in the prone position. The skin and subcutaneous tissues were dissected, the gluteal and hamstring musculature were exposed, the gluteus maximus muscle was crossed, and the proximal tendon attachment points on the ischial tubercle were reached. The common tendon of the semitendinosus and biceps femoris and the semimembranosus tendon were carefully demarcated and separated from the bony attachment site. Marker pins were placed on the hamstring tendon footprint's medial, lateral, anterior, and superior borders (Fig. 1 ). Two senior orthopedists and one anatomist (SA, AKA, GZ) performed the dissection and marking process. For neutral pelvis radiography, the pelvis, symphysis pubis, and bilateral anterior superior iliac spines were positioned on a flat radiology cassette to mimic the anatomical frontal plane [ 35 ], [ 36 ]. The focal-to-cassette distance of the X-ray tube was 120 cm, the tube was aligned over the symphysis pubis, and one size-specific metal was placed (Fig. 2 ). The appropriateness of a neutral posterior-anterior pelvic radiograph was confirmed by the symmetrical appearance of the bilateral obturator foramen and iliac wings, with the tip of the sacrum positioned 1–3 cm above the symphysis pubis. After pelvic radiography, the laser pointer was placed in the center of the tendon attachment sites in both hips, and posterior-anterior (PA) radiographs were taken. To determine the radiological boundaries of the tendon footprint, the distances of these boundaries from the ischial tubercle were measured with marker pins placed on each of the four edges. Specifically, the perpendicular distance from each edge of the tendon to the line connecting the ischial tubercle was calculated, as well as the distance from the lowest point of the ischial tubercle (Fig. 3 ). The SPSS 23.0 package program was used for the statistical analysis of the study data. Descriptive findings were evaluated using the mean, standard deviation, minimum, and maximum values. The ‘Mann-Whitney U test’ was used in binary, continuous variable comparisons when parametric assumptions were unmet. Type 1 error was accepted as 0.05 in analyses. Results Four of the five cadavers belonged to male donors. The donors were, on average, 67 ± 3 years old at the time of death. The distance of the hamstring tendon from the line joining the ischium was 35.3 ± 2.8mm for the superior border, 22.5 ± 2.3 mm for the medial border, 30.3 ± 2.4 mm for the lateral border, and 17.5 ± 2.3 mm for the inferior border, respectively. The distance of the hamstring tendon from the lowest distance of the ischium was 47.7 ± 3 mm for the superior border, 33.9 ± 5.7 mm for the medial border, 43.3 ± 5.1 mm for the lateral border, and 31.4 ± 3.4 mm for the inferior border, respectively (Table 1 ). The distance of the hamstring tendon from the line joining the ischium was 35.3 ± 3.6 mm for the superior border, 22.1 ± 2.3 mm for the medial border, 29.7 ± 3.4 mm for the lateral border, and 18.9 ± 4.6 mm for the inferior border, respectively. For the hip PA radiograph, the distance of the hamstring tendon from the lowest distance of the ischium was 47.9 ± 4.5 mm for the superior border, 32.7 ± 4.3 mm for the medial border, 44 ± 5.3 mm for the lateral border, and 33.2 ± 5.1 mm for the inferior border, respectively (Table 1 ). The distance between the medial and lateral borders of the footprint was 10.6 ± 4.4 mm in the PA radiograph of the pelvis and 11.1 ± 4.4 mm in the PA radiograph of the hip. In addition, the distance between the superior and inferior borders was 19.3 ± 3.1 mm in the PA radiograph of the pelvis and 19.5 ± 3.3 mm in the PA radiograph of the hip (Table 1 ). Table 1 Hamstring Tendon Measurements for Pelvis PA and Hip PA Graphs Measurement* Pelvis PA Graph (mm) Hip PA Graph (mm) SB- ITL 35.3 ± 2.8 35.3 ± 3.6 MB-ITL 22.5 ± 2.3 22.1 ± 2.3 LB-ITL 30.3 ± 2.4 29.7 ± 3.4 IB-ITL 17.5 ± 2.3 18.9 ± 4.6 SB-IA 47.7 ± 3 47.9 ± 4.5 MB-IA 33.9 ± 5.7 32.7 ± 4.3 LB-IA 43.3 ± 5.1 44 ± 5.3 IB-IA 31.4 ± 3.4 33.2 ± 5.1 LB-MB 10.6 ± 4.4 11.1 ± 4.4 SB-IB 19.3 ± 3.1 19.5 ± 3.3 * SB- ITL: Shortest distance from the superior border of the hamstring tendon to the ischial tuberosity line. MB-ITL: Shortest distance from the medial border of the hamstring tendon to the ischial tuberosity line. LB-ITL: Shortest distance from the lateral border of the hamstring tendon to the ischial tuberosity line. IB-ITL: Shortest distance from the inferior border of the hamstring tendon to the ischial tuberosity line. SB-IA: Distance from the superior border of the hamstring tendon to the lowest end of the tuber ischiadicum (ischial apex). MB-IA: Ischial apex distance of the medial border of the hamstring tendon. LB-IA: Ischial apex distance of the lateral border of the hamstring tendon. IB-TI: Ischial apex distance of the inferior border of the hamstring tendon. LB-MB: The distance between the medial border and the lateral border of the footprint. SB-IB: The distance between the superior boundary and the inferior boundary of the footprint. When the distances measured for the superior, medial, lateral, and inferior margins on PA radiographs of the pelvis and hip were compared, no significant differences were observed between the margins in both sets of radiographs (Table 2 ). This indicates that both methods provide comparable accuracy in the anatomical positioning of the tendon structure. Table 2 P-values for comparison of pelvis and hip radiographs Superior Border Inferior Border Lateral Border Medial Border Distance to iscial tuber line* 0.940 0.472 0.910 0.762 Distance to ischial apex** 0.910 0.473 0.796 0.280 * The distance of each border (superior, inferior, lateral, medial) of the hamstring tendon from the ischial tuber line was not statistically significant in pelvis and hip radiographs (p > 0.05) ** The distance of each border of the hamstring tendon (superior, inferior, lateral, medial) from the ischial apex was not statistically significant in pelvis and hip radiographs (p > 0.05) There was no significant difference in the distance between the lateral-medial and superior-inferior borders when compared between the pelvis and hip PA radiographs (p:0.850, 0.910). Discussion Our findings contribute to the preservation of critical structures during surgical procedures by demonstrating in radiological detail the tendon insertion's precise location at various anatomical sites and its association with the ischial tubercle. The distance difference between the PA radiographs of the pelvis and hip was not significant, indicating that both methods are safe and reproducible. This may increase the effectiveness of minimally invasive methods during surgery and reduce surgical complications. The sciatic nerve is located in the lateral and anterior parts of the proximal hamstring tendons, 1.2 cm from the most lateral point of the ischial tuberosity [ 28 ]. The posterior femoral cutaneous branch divides from the upper part of the ischial tuberosity and travels laterally into the subcutaneous tissues in the gluteal fold and can be traced backward along the sciatic nerve [ 28 ]. The inferior gluteal nerve and artery are located 5 cm proximal to the ischial tuberosity, deep in the gluteus maximus muscle [ 28 ]. In our radiological analyses, the shortest distance of the superior border of the tendon to the ischial apex was approximately 47 ± 3 mm, and the shortest distance of the lateral border was approximately 43 ± 5 mm superolaterally. At the shortest distance to the line joining the ischium, the superior border of the tendon was 35 ± 3 mm, and the lateral border was 30 ± 3 mm at the superior boundary. The distance between the superior border and the inferior border was approximately 19 ± 3 mm, and the distance between the lateral border and the medial border was approximately 11 ± 4 mm. These findings enabled the anatomical boundaries of the footprint to be determined radiologically. The origin of the hamstring tendon is located near the center of these critical neurovascular structures and should be carefully protected during surgical interventions. Although arthroscopic visualization is possible, radiologically determined ‘landmarks’ will provide safe guidance to the surgeon to minimize complications, allowing more precise and safe surgical interventions in the anatomical region. Endoscopic techniques in surgical repair of proximal hamstring tears have minimized wound site complications associated with open surgery. However, during the procedure, there remains a risk of injuring the posterior femoral cutaneous, inferior gluteal, and sciatic nerves [ 15 ]. The sciatic nerve requires special protection due to its proximity to the ischial tuberosity. It has been observed that placement of the lateral portal at right angles increases the risk of injury to both the sciatic nerve (SN) and posterior femoral cutaneous (PFC) nerve, and it is recommended that the portal be placed at a more horizontal angle to reduce this risk [ 27 ]. In this portal, 37% of direct sciatic nerve injury was observed [ 27 ]. The benefits of endoscopic surgical techniques for protecting the sciatic nerve, along with minimally invasive approaches, suggest that safe surgical procedures can be performed without fluoroscopy [ 20 ], [ 22 ], [ 23 ], [ 24 ], [ 25 ]. Laskovski et al. [ 20 ] recommended that patients be positioned up to 45 degrees of abduction and suggested an additional superior portal for anchor management. Fletcher et al. [ 22 ] demonstrated better visualization and safe anchor placement without fluoroscopy by adding accessory portals in combination with optimal positioning that reduces tension on the sciatic nerve. Other authors aim to create portals from lateral to medial, making it possible to protect the sciatic nerve by directing it to the ischial tuberosity under fluoroscopic guidance [ 23 ], [ 25 ]. Gomez-Hoyos et al. suggested that it can be performed safely with neuromonitoring [ 24 ]. In arthroscopic hamstring surgery, which has a steep learning curve and a limited visualization area, it is crucial to define radiological safe surgical margins that can provide better guidance in the anatomical region, especially for new surgeons in cases where fibrosis is intense and hemostasis cannot be achieved. Another critical point in endoscopic repair is that placing the anchors securely in the ischial tuberosity is essential to ensuring healing and minimizing complications. In repair, 2 to 5 anchors can be placed [ 3 ], [ 12 ], [ 23 ], [ 29 ], [ 30 ], [ 31 ]. Hamming et al. [ 29 ] emphasized that the number of suture anchors in proximal hamstring repair is critical for biomechanical durability. In particular, repairs using five small anchors showed the closest durability to the intact tendon. The fact that methods using two small or two large anchors have lower failure loads emphasizes the importance of using more anchors to ensure optimal structural integrity [ 29 ]. In partial proximal hamstring ruptures, endoscopic anatomical surgery has been recommended for patients who have failed conservative treatment [ 25 ], [ 37 ]. Exposure of the cortical bone is recommended to create a suitable healing surface [ 25 ]. The tendons will appear intact on the ischium in partial tears with no retraction and only subsurface tearing. Therefore, recognizing the radiological limits of the hamstring insertion will guide to perform precise ischial cortical exposure and anatomical tendon repair. Careful determination of the radiological safe zone for this procedure in a limited and dangerous area will be vital to stay within the anatomical limits during anchor placement, protecting the surrounding nerve and vascular structures and reducing possible complications. The ideal preoperative or intraoperative planning radiograph [ 35 ], [ 36 ] would be an anterior-posterior view of the pelvis centered on the pubic symphysis. In our study, there was no statistically significant difference between PA radiography of the pelvis and PA radiography of the hip centered on the hamstring tendon. Considering the limitations of pelvic PA fluoroscopy during surgery, hip PA radiography may be more useful during surgery by providing a more focused image. This method can potentially shorten the operation time and reduce radiation exposure. Among the limitations of this article, the study's limited sample size is noteworthy; using only five cadavers may limit the universality of the overall results. Positioning during anchor placement, such as abduction to prevent sciatic nerve injury, will cause differences in radiological evaluation. The radiological boundaries of the tendon footprint were determined by fluoroscopy, and the 3-dimensional structure of the posterolaterally located hamstring tendon should not be forgotten. The mean age of the specimens was 65 years, and due to age-related muscle atrophy, our findings may not be representative of the younger athletic population who usually require treatment for proximal hamstring tears. Conclusions Defining the radiological margins of the hamstring tendon provides a critical reference for portal opening and safe and anatomical anchor placement in arthroscopic hamstring repairs. The findings suggest that consistently identifying these boundaries by preoperative imaging and intraoperative fluoroscopy may reduce the risk of neurovascular injury and improve surgical success. The difference in distance between pelvis and hip PA radiographs was not statistically significant, supporting that both methods are reliable and reproducible. Abbreviations PA Posterior-Anterior GM Gluteus Maximus SN Sciatic Nerve SM Semimembranosus SB Superior Border MB Medial Border LB Lateral Border IB Inferior Border ITL Ischial Tuberosity Line IA Ischial Apex PFC Posterior Femoral Cutaneous Declarations Ethics approval and consent to participate: Approval numbered 2023/19-16 was obtained from Dokuz Eylül University Faculty of Medicine Ethics Committee for this study. Consent for publication: Not applicable. Availability of data and materials: The datasets generated and/or analysed during the current study are not publicly available due (confidentiality agreements, patient privacy concerns, or institutional restrictions) but are available from the corresponding author on reasonable request. Competing interests: The authors declare that they have no competing interests. Funding: This study did not receive financial support. Authors' contributions: All authors contributed to study design. S.A, H.C. and O.H.: study design. 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Operative management of partial-thickness tears of the proximal hamstring muscles in athletes. Am J Sports Med. 2013;41(6):1363–71. 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-5461491","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":379498877,"identity":"72fd39c4-430c-4435-8114-57661557878d","order_by":0,"name":"Selahaddin Aydemir","email":"data:image/png;base64,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","orcid":"","institution":"Kastamonu Research and Training Hospital","correspondingAuthor":true,"prefix":"","firstName":"Selahaddin","middleName":"","lastName":"Aydemir","suffix":""},{"id":379498878,"identity":"c70d75a3-e940-4703-bba7-963276bc9ff0","order_by":1,"name":"Hakan Cici","email":"","orcid":"","institution":"Demokrasi University","correspondingAuthor":false,"prefix":"","firstName":"Hakan","middleName":"","lastName":"Cici","suffix":""},{"id":379498882,"identity":"3dbcb22b-369c-4dbd-b83f-510e6a0e6e56","order_by":2,"name":"Mustafa Celtik","email":"","orcid":"","institution":"Ankara Oncology Research and Training Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mustafa","middleName":"","lastName":"Celtik","suffix":""},{"id":379498884,"identity":"02040f0d-1430-448e-a70f-74606461df44","order_by":3,"name":"Gulsah Zeybek Phd","email":"","orcid":"","institution":"Dokuz Eylul University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Gulsah","middleName":"","lastName":"Zeybek","suffix":"Phd"},{"id":379498886,"identity":"85ad18ed-96c8-4a1c-bd48-f574b466c559","order_by":4,"name":"Ahmet Kaan Arslan","email":"","orcid":"","institution":"Dokuz Eylul University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Ahmet","middleName":"Kaan","lastName":"Arslan","suffix":""},{"id":379498887,"identity":"bfe987c0-c06c-496d-8d41-128454d3cf22","order_by":5,"name":"Raif Can Yarol","email":"","orcid":"","institution":"Dokuz Eylul University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Raif","middleName":"Can","lastName":"Yarol","suffix":""},{"id":379498888,"identity":"1a6a0374-7466-4c30-85da-f506fdcb7d4e","order_by":6,"name":"Ali Balci","email":"","orcid":"","institution":"Dokuz Eylul University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Ali","middleName":"","lastName":"Balci","suffix":""},{"id":379498889,"identity":"9c1e36d9-3279-41d5-99b0-5249011966c9","order_by":7,"name":"Onur Hapa","email":"","orcid":"","institution":"Dokuz Eylul University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Onur","middleName":"","lastName":"Hapa","suffix":""}],"badges":[],"createdAt":"2024-11-15 15:23:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5461491/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5461491/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":71805920,"identity":"59af5460-5d15-4f54-9d99-4db0e636ec33","added_by":"auto","created_at":"2024-12-18 17:32:33","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":4387387,"visible":true,"origin":"","legend":"\u003cp\u003eGM: Oblique viewpoint. GM: Gluteus maximus muscle. SN: Sciatic nerve. CJ: Conjoint Tendon. SM:Semimembranosus. The borders of the hamstring tendon footprint (marked with a red circle). 1: Superior border, 2: medial border, 3: Inferior border, 4: Lateral border.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-5461491/v1/5fd38fc20b81bb00690c7946.png"},{"id":71805919,"identity":"bcaf01b2-1ac2-4a0f-b62f-a0196cf106df","added_by":"auto","created_at":"2024-12-18 17:32:33","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":344893,"visible":true,"origin":"","legend":"\u003cp\u003ePosteroanterior (PA) radiograph of the pelvis, obtained with a focus-to-cassette distance of 120 cm using a laser pointer focused on the pubic symphysis. The hip PA radiograph was similarly obtained with the laser pointer focused at the centre of the hamstring tendon footprint at the same distance.\u003c/p\u003e","description":"","filename":"Figure21.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-5461491/v1/e6bee45c1900a0d08562fe58.jpeg"},{"id":71805921,"identity":"8cfd8187-1439-4993-939b-2af59e71cf5a","added_by":"auto","created_at":"2024-12-18 17:32:33","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1419719,"visible":true,"origin":"","legend":"\u003cp\u003eA: The shortest distance from each border of the proximal hamstring tendon footprint to the apex of the ischium was measured on the pelvis PA radiograph. The same measurement approach was applied to the hip PA radiograph.\u003c/p\u003e\n\u003cp\u003eB: On the hip PA radiograph, the shortest distance from each border of the left proximal hamstring tendon footprint to a line joining the ischial tuberosities was calculated. This measurement method was also applied to the pelvic PA radiograph.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-5461491/v1/688fb5ad5507ac4cb30a4372.png"},{"id":91616728,"identity":"2093fadf-44d3-4441-882c-c2a933ef6ea7","added_by":"auto","created_at":"2025-09-18 10:40:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":8615926,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5461491/v1/52f6f46c-af5c-41af-b9a4-f43f86892be3.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Establishing the Radiological Safety Zone in the Ischium to Prevent Neurovascular Injury During Endoscopic Hamstring Tendon Repair: A Cadaveric Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eProximal hamstring injuries are among the common muscle injuries, mainly affecting the muscle-tendon junction or the muscles themselves [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. A less common but more severe injury is the rupture of the proximal tendons at their origin on the ischial tuberosity [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Although commonly seen in athletes, these injuries can also occur during daily activities and are more prevalent among middle-aged individuals and those participating in high-risk sports such as rugby and skiing [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Adverse outcomes such as persistent pain, loss of function, sciatic nerve symptoms, and difficulty returning to sport have been reported in the conservative treatment of proximal hamstring tears [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Therefore, the general approach in the literature suggests that surgical repair is a more effective method for both acute and chronic ruptures [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. The preferred surgical approach has shifted towards minimally invasive techniques. Arthroscopic hamstring tendon repair has emerged as a preferred option due to lower complication rates and faster recovery times compared to open surgery [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. However, the complex anatomy of the hamstring origin, especially its proximity to the sciatic nerve, requires meticulous attention during anchor placement to prevent iatrogenic injury [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor a stable structure, up to 5 anchors in total are recommended [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e], [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e], [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. An essential element of secure and effective arthroscopic repair is identifying a \u0026lsquo;\u003cem\u003esafe zone\u003c/em\u003e,\u0026rsquo; a radiological reference point crucial for guiding safe and anatomical anchor placement. In regions with elevated risks to neurovascular structures, efforts have been made to identify and establish safe radiological zones using intraoperative fluoroscopy or preoperative imaging to reduce complications. [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e], [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e], [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] Although arthroscopic techniques have improved, standardized radiological guidelines for identifying the \u003cem\u003esafe zone\u003c/em\u003e during surgery are still lacking, especially for proximal hamstring injuries, where anatomical variations may complicate the procedure. This study aims to provide a comprehensive overview of the radiological limits of the tendon footprint, its anatomical significance, and the importance of this landmark in ensuring the safety and efficacy of arthroscopic hamstring tendon repair. We also aim to discuss the need to develop standardized protocols for safe and anatomical anchor placement based on precise anatomical and radiological studies, ultimately reducing the risk of complications such as sciatic nerve injury.\u003c/p\u003e \u003cp\u003eOur hypothesis posits that a comprehensive understanding of the anatomical correlation between the radiological footprint and surrounding structures may enhance surgical training and mitigate the learning curve associated with arthroscopic techniques.\u003c/p\u003e"},{"header":"Material method","content":"\u003cp\u003eAfter approval of the local ethics committee, five formaldehyde-fixed human cadavers (10 paired hips) were included in the study (Dokuz Eylul University). Four of the cadavers were male, and one was female, with a mean age of 67\u0026thinsp;\u0026plusmn;\u0026thinsp;3 years. The cadavers had no history of hip pathology or surgery. All specimens were brought to room temperature and placed in the prone position. The skin and subcutaneous tissues were dissected, the gluteal and hamstring musculature were exposed, the gluteus maximus muscle was crossed, and the proximal tendon attachment points on the ischial tubercle were reached. The common tendon of the semitendinosus and biceps femoris and the semimembranosus tendon were carefully demarcated and separated from the bony attachment site. Marker pins were placed on the hamstring tendon footprint's medial, lateral, anterior, and superior borders (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Two senior orthopedists and one anatomist (SA, AKA, GZ) performed the dissection and marking process.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFor neutral pelvis radiography, the pelvis, symphysis pubis, and bilateral anterior superior iliac spines were positioned on a flat radiology cassette to mimic the anatomical frontal plane [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e], [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. The focal-to-cassette distance of the X-ray tube was 120 cm, the tube was aligned over the symphysis pubis, and one size-specific metal was placed (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The appropriateness of a neutral posterior-anterior pelvic radiograph was confirmed by the symmetrical appearance of the bilateral obturator foramen and iliac wings, with the tip of the sacrum positioned 1\u0026ndash;3 cm above the symphysis pubis.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAfter pelvic radiography, the laser pointer was placed in the center of the tendon attachment sites in both hips, and posterior-anterior (PA) radiographs were taken.\u003c/p\u003e \u003cp\u003eTo determine the radiological boundaries of the tendon footprint, the distances of these boundaries from the ischial tubercle were measured with marker pins placed on each of the four edges. Specifically, the perpendicular distance from each edge of the tendon to the line connecting the ischial tubercle was calculated, as well as the distance from the lowest point of the ischial tubercle (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe SPSS 23.0 package program was used for the statistical analysis of the study data. Descriptive findings were evaluated using the mean, standard deviation, minimum, and maximum values. The \u0026lsquo;Mann-Whitney U test\u0026rsquo; was used in binary, continuous variable comparisons when parametric assumptions were unmet. Type 1 error was accepted as 0.05 in analyses.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eFour of the five cadavers belonged to male donors. The donors were, on average, 67\u0026thinsp;\u0026plusmn;\u0026thinsp;3 years old at the time of death. The distance of the hamstring tendon from the line joining the ischium was 35.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8mm for the superior border, 22.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3 mm for the medial border, 30.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4 mm for the lateral border, and 17.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3 mm for the inferior border, respectively. The distance of the hamstring tendon from the lowest distance of the ischium was 47.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mm for the superior border, 33.9\u0026thinsp;\u0026plusmn;\u0026thinsp;5.7 mm for the medial border, 43.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 mm for the lateral border, and 31.4\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4 mm for the inferior border, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe distance of the hamstring tendon from the line joining the ischium was 35.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6 mm for the superior border, 22.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3 mm for the medial border, 29.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4 mm for the lateral border, and 18.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6 mm for the inferior border, respectively. For the hip PA radiograph, the distance of the hamstring tendon from the lowest distance of the ischium was 47.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5 mm for the superior border, 32.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3 mm for the medial border, 44\u0026thinsp;\u0026plusmn;\u0026thinsp;5.3 mm for the lateral border, and 33.2\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 mm for the inferior border, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe distance between the medial and lateral borders of the footprint was 10.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4 mm in the PA radiograph of the pelvis and 11.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4 mm in the PA radiograph of the hip. In addition, the distance between the superior and inferior borders was 19.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1 mm in the PA radiograph of the pelvis and 19.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3 mm in the PA radiograph of the hip (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHamstring Tendon Measurements for Pelvis PA and Hip PA Graphs\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMeasurement*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePelvis PA Graph (mm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHip PA Graph (mm)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSB- ITL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e35.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e35.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMB-ITL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e22.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e22.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLB-ITL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e30.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e29.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIB-ITL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e17.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e18.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSB-IA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e47.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e47.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMB-IA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e33.9\u0026thinsp;\u0026plusmn;\u0026thinsp;5.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e32.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLB-IA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e43.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e44\u0026thinsp;\u0026plusmn;\u0026thinsp;5.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIB-IA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e31.4\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e33.2\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLB-MB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e10.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e11.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSB-IB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e19.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e19.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e* SB- ITL: Shortest distance from the superior border of the hamstring tendon to the ischial tuberosity line. MB-ITL: Shortest distance from the medial border of the hamstring tendon to the ischial tuberosity line. LB-ITL: Shortest distance from the lateral border of the hamstring tendon to the ischial tuberosity line. IB-ITL: Shortest distance from the inferior border of the hamstring tendon to the ischial tuberosity line. SB-IA: Distance from the superior border of the hamstring tendon to the lowest end of the tuber ischiadicum (ischial apex). MB-IA: Ischial apex distance of the medial border of the hamstring tendon. LB-IA: Ischial apex distance of the lateral border of the hamstring tendon. IB-TI: Ischial apex distance of the inferior border of the hamstring tendon. LB-MB: The distance between the medial border and the lateral border of the footprint. SB-IB: The distance between the superior boundary and the inferior boundary of the footprint.\u003c/p\u003e \u003cp\u003eWhen the distances measured for the superior, medial, lateral, and inferior margins on PA radiographs of the pelvis and hip were compared, no significant differences were observed between the margins in both sets of radiographs (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). This indicates that both methods provide comparable accuracy in the anatomical positioning of the tendon structure.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eP-values for comparison of pelvis and hip radiographs\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSuperior Border\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInferior Border\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLateral Border\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMedial Border\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDistance to iscial tuber line*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.940\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.472\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.910\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.762\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDistance to ischial apex**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.910\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.473\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.796\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.280\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e* The distance of each border (superior, inferior, lateral, medial) of the hamstring tendon from the ischial tuber line was not statistically significant in pelvis and hip radiographs (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05)\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e** The distance of each border of the hamstring tendon (superior, inferior, lateral, medial) from the ischial apex was not statistically significant in pelvis and hip radiographs (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThere was no significant difference in the distance between the lateral-medial and superior-inferior borders when compared between the pelvis and hip PA radiographs (p:0.850, 0.910).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur findings contribute to the preservation of critical structures during surgical procedures by demonstrating in radiological detail the tendon insertion's precise location at various anatomical sites and its association with the ischial tubercle. The distance difference between the PA radiographs of the pelvis and hip was not significant, indicating that both methods are safe and reproducible. This may increase the effectiveness of minimally invasive methods during surgery and reduce surgical complications.\u003c/p\u003e \u003cp\u003eThe sciatic nerve is located in the lateral and anterior parts of the proximal hamstring tendons, 1.2 cm from the most lateral point of the ischial tuberosity [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The posterior femoral cutaneous branch divides from the upper part of the ischial tuberosity and travels laterally into the subcutaneous tissues in the gluteal fold and can be traced backward along the sciatic nerve [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The inferior gluteal nerve and artery are located 5 cm proximal to the ischial tuberosity, deep in the gluteus maximus muscle [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. In our radiological analyses, the shortest distance of the superior border of the tendon to the ischial apex was approximately 47\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mm, and the shortest distance of the lateral border was approximately 43\u0026thinsp;\u0026plusmn;\u0026thinsp;5 mm superolaterally. At the shortest distance to the line joining the ischium, the superior border of the tendon was 35\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mm, and the lateral border was 30\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mm at the superior boundary. The distance between the superior border and the inferior border was approximately 19\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mm, and the distance between the lateral border and the medial border was approximately 11\u0026thinsp;\u0026plusmn;\u0026thinsp;4 mm. These findings enabled the anatomical boundaries of the footprint to be determined radiologically. The origin of the hamstring tendon is located near the center of these critical neurovascular structures and should be carefully protected during surgical interventions. Although arthroscopic visualization is possible, radiologically determined \u0026lsquo;landmarks\u0026rsquo; will provide safe guidance to the surgeon to minimize complications, allowing more precise and safe surgical interventions in the anatomical region.\u003c/p\u003e \u003cp\u003eEndoscopic techniques in surgical repair of proximal hamstring tears have minimized wound site complications associated with open surgery. However, during the procedure, there remains a risk of injuring the posterior femoral cutaneous, inferior gluteal, and sciatic nerves [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. The sciatic nerve requires special protection due to its proximity to the ischial tuberosity. It has been observed that placement of the lateral portal at right angles increases the risk of injury to both the sciatic nerve (SN) and posterior femoral cutaneous (PFC) nerve, and it is recommended that the portal be placed at a more horizontal angle to reduce this risk [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. In this portal, 37% of direct sciatic nerve injury was observed [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The benefits of endoscopic surgical techniques for protecting the sciatic nerve, along with minimally invasive approaches, suggest that safe surgical procedures can be performed without fluoroscopy [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eLaskovski et al. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] recommended that patients be positioned up to 45 degrees of abduction and suggested an additional superior portal for anchor management. Fletcher et al. [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] demonstrated better visualization and safe anchor placement without fluoroscopy by adding accessory portals in combination with optimal positioning that reduces tension on the sciatic nerve. Other authors aim to create portals from lateral to medial, making it possible to protect the sciatic nerve by directing it to the ischial tuberosity under fluoroscopic guidance [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Gomez-Hoyos et al. suggested that it can be performed safely with neuromonitoring [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In arthroscopic hamstring surgery, which has a steep learning curve and a limited visualization area, it is crucial to define radiological safe surgical margins that can provide better guidance in the anatomical region, especially for new surgeons in cases where fibrosis is intense and hemostasis cannot be achieved. Another critical point in endoscopic repair is that placing the anchors securely in the ischial tuberosity is essential to ensuring healing and minimizing complications. In repair, 2 to 5 anchors can be placed [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e], [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e], [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Hamming et al. [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] emphasized that the number of suture anchors in proximal hamstring repair is critical for biomechanical durability. In particular, repairs using five small anchors showed the closest durability to the intact tendon. The fact that methods using two small or two large anchors have lower failure loads emphasizes the importance of using more anchors to ensure optimal structural integrity [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn partial proximal hamstring ruptures, endoscopic anatomical surgery has been recommended for patients who have failed conservative treatment [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Exposure of the cortical bone is recommended to create a suitable healing surface [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. The tendons will appear intact on the ischium in partial tears with no retraction and only subsurface tearing. Therefore, recognizing the radiological limits of the hamstring insertion will guide to perform precise ischial cortical exposure and anatomical tendon repair. Careful determination of the radiological \u003cem\u003esafe zone\u003c/em\u003e for this procedure in a limited and dangerous area will be vital to stay within the anatomical limits during anchor placement, protecting the surrounding nerve and vascular structures and reducing possible complications.\u003c/p\u003e \u003cp\u003eThe ideal preoperative or intraoperative planning radiograph [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e], [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e] would be an anterior-posterior view of the pelvis centered on the pubic symphysis. In our study, there was no statistically significant difference between PA radiography of the pelvis and PA radiography of the hip centered on the hamstring tendon. Considering the limitations of pelvic PA fluoroscopy during surgery, hip PA radiography may be more useful during surgery by providing a more focused image. This method can potentially shorten the operation time and reduce radiation exposure.\u003c/p\u003e \u003cp\u003eAmong the limitations of this article, the study's limited sample size is noteworthy; using only five cadavers may limit the universality of the overall results. Positioning during anchor placement, such as abduction to prevent sciatic nerve injury, will cause differences in radiological evaluation. The radiological boundaries of the tendon footprint were determined by fluoroscopy, and the 3-dimensional structure of the posterolaterally located hamstring tendon should not be forgotten. The mean age of the specimens was 65 years, and due to age-related muscle atrophy, our findings may not be representative of the younger athletic population who usually require treatment for proximal hamstring tears.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eDefining the radiological margins of the hamstring tendon provides a critical reference for portal opening and safe and anatomical anchor placement in arthroscopic hamstring repairs. The findings suggest that consistently identifying these boundaries by preoperative imaging and intraoperative fluoroscopy may reduce the risk of neurovascular injury and improve surgical success. The difference in distance between pelvis and hip PA radiographs was not statistically significant, supporting that both methods are reliable and reproducible.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePosterior-Anterior\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGluteus Maximus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSN\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSciatic Nerve\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSemimembranosus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSuperior Border\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMedial Border\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLateral Border\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInferior Border\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eITL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eIschial Tuberosity Line\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eIschial Apex\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePFC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePosterior Femoral Cutaneous\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e Approval numbered 2023/19-16 was obtained from Dokuz Eyl\u0026uuml;l University Faculty of Medicine Ethics Committee for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e Not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e The datasets generated and/or analysed during the current study are not publicly available due (confidentiality agreements, patient privacy concerns, or institutional restrictions) but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e The authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This study did not receive financial support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u003c/strong\u003e All authors contributed to study design. S.A, H.C. and O.H.: study design. S.A and A.K.A: ethical approval. S.A, A.K.A, G.Z.: anatomical dissection and surgical procedure. S.A, M.C.: data analysis and statistical analysis. S.A, M.C.: preparation of manuscript, tables and figures. R.C.Y. and A.B.: Radiological imaging and radiological evaluations. S.A., A.K.A, R.C.Y.: Data collection O.H., A.B., S.A and H.C.: revision of the manuscript, tables and figures. Final version approved by all authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u003c/strong\u003e Not applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDe Smet AA, Best TM. MR imaging of the distribution and location of acute hamstring injuries in athletes. Am J Roentgenol. 2000;174(2):393\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDegen RM. Proximal hamstring injuries: management of tendinopathy and avulsion injuries. Curr Rev Musculoskelet Med. 2019;12:138\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCohen S, Bradley J. Acute proximal hamstring rupture. JAAOS-Journal Am Acad Orthop Surg. 2007;15(6):350\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLempainen L, et al. Clinical principles in the management of hamstring injuries. Knee Surg Sport Traumatol Arthrosc. 2015;23:2449\u0026ndash;56.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoulouris G, Connell D. Evaluation of the hamstring muscle complex following acute injury. Skeletal Radiol. 2003;32:582\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIrger M, Willinger L, Lacheta L, Pogorzelski J, Imhoff AB, Feucht MJ. Proximal hamstring tendon avulsion injuries occur predominately in middle-aged patients with distinct gender differences: epidemiologic analysis of 263 surgically treated cases. Knee Surg Sport Traumatol Arthrosc. 2020;28(4):1221\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarnett AJ, Negus JJ, Barton T, Wood DG. Reattachment of the proximal hamstring origin: outcome in patients with partial and complete tears. Knee Surg Sport Traumatol Arthrosc. 2015;23:2130\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCross MJ, Vandersluis R, Wood D, Banff M. Surgical repair of chronic complete hamstring tendon rupture in the adult patient. Am J Sports Med. 1998;26(6):785\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHarris JD, Griesser MJ, Best TM, Ellis TJ. Treatment of proximal hamstring ruptures\u0026ndash;a systematic review. Int J Sports Med. 2011;32(07):490\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSallay PI, Friedman RL, Coogan PG, Garrett WE. Hamstring muscle injuries among water skiers: functional outcome and prevention. Am J Sports Med. 1996;24(2):130\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhmad CS, Redler LH, Ciccotti MG, Maffulli N, Longo UG, Bradley J. Evaluation and management of hamstring injuries. Am J Sports Med. 2013;41(12):2933\u0026ndash;47.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBirmingham P, Muller M, Wickiewicz T, Cavanaugh J, Rodeo S, Warren R. Functional outcome after repair of proximal hamstring avulsions. JBJS. 2011;93(19):1819\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrucker PU, Imhoff AB. Functional assessment after acute and chronic complete ruptures of the proximal hamstring tendons. Knee Surg Sport Traumatol Arthrosc. 2005;13(5):411\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCohen SB, Rangavajjula A, Vyas D, Bradley JP. Functional results and outcomes after repair of proximal hamstring avulsions. Am J Sports Med. 2012;40(9):2092\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLempainen L, Sarimo J, Heikkil\u0026auml; J, Mattila K, Orava S. Surgical treatment of partial tears of the proximal origin of the hamstring muscles. Br J Sports Med. 2006;40(8):688\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLempainen L, Sarimo J, Orava S. Recurrent and chronic complete ruptures of the proximal origin of the hamstring muscles repaired with fascia lata autograft augmentation. Arthrosc J Arthrosc Relat Surg. 2007;23(4):441\u0026ndash;e1.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSarimo J, Lempainen L, Mattila K, Orava S. Complete proximal hamstring avulsions: a series of 41 patients with operative treatment. Am J Sports Med. 2008;36(6):1110\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKlingele KE, Sallay PI. Surgical repair of complete proximal hamstring tendon rupture. Am J Sports Med. 2002;30(5):742\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDierckman BD, Guanche CA. Endoscopic proximal hamstring repair and ischial bursectomy. Arthrosc Tech. 2012;1(2):e201\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaskovski JR, Kahn AJ, Urchek RJ, Guanche CA. Endoscopic proximal hamstring repair and ischial bursectomy using modified portal placement and patient positioning. Arthrosc Tech. 2018;7(11):e1071\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKurowicki J, et al. Short-term outcomes following endoscopic proximal hamstring repair. Arthrosc J Arthrosc Relat Surg. 2020;36(5):1301\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFletcher AN, Lau BC, Mather RC III. Endoscopic proximal hamstring tendon repair for nonretracted tears: an anatomic approach and repair technique. Arthrosc Tech. 2020;9(4):e483\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDomb BG, Linder D, Sharp KG, Sadik A, Gerhardt MB. Endoscopic Repair of Proximal Hamstring Avulsion. Arthrosc Tech. Feb. 2013;2(1):e35\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.eats.2012.10.003\u003c/span\u003e\u003cspan address=\"10.1016/j.eats.2012.10.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG\u0026oacute;mez-Hoyos J, Reddy M, Martin HD. Dry endoscopic-assisted mini-open approach with neuromonitoring for chronic hamstring avulsions and ischial tunnel syndrome. Arthrosc Tech. 2015;4(3):e193\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJackson TJ, Trenga A, Lindner D, El-Bitar Y, Domb BG. Endoscopic transtendinous repair for partial-thickness proximal hamstring tendon tears. Arthrosc Tech. 2014;3(1):e127\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFletcher AN, Pereira GF, Lau BC, Mather RC. Endoscopic proximal hamstring repair is safe and efficacious with high patient satisfaction at a minimum of 2-year follow-up. Arthrosc J Arthrosc Relat Surg. 2021;37(11):3275\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSu CA, et al. The safe zones for endoscopic proximal hamstring repair: a cadaveric assessment of standard portal placement and their relationship to major neurovascular structures. Hip Int. 2023;33(3):533\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMiller SL, Gill J, Webb GR. The proximal origin of the hamstrings and surrounding anatomy encountered during repair: a cadaveric study. JBJS. 2007;89(1):44\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamming MG, et al. Structural properties of the intact proximal hamstring origin and evaluation of varying avulsion repair techniques: an in vitro biomechanical analysis. Am J Sports Med. 2015;43(3):721\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePombo M, Bradley JP. Proximal hamstring avulsion injuries: a technique note on surgical repairs. Sports Health. 2009;1(3):261\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRust DA, Giveans MR, Stone RM, Samuelson KM, Larson CM. Functional outcomes and return to sports after acute repair, chronic repair, and allograft reconstruction for proximal hamstring ruptures. Am J Sports Med. 2014;42(6):1377\u0026ndash;83.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChip MLC Jr, Simonian PT, Agnew SG, Mann FA. Radiographic recognition of the sacral alar slope for optimal placement of iliosacral screws: a cadaveric and clinical study. J Orthop Trauma. 1996;10(3):171\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSimsek S et al. Safe zone for C1 lateral mass screws: anatomic and radiological study, \u003cem\u003eNeurosurgery\u003c/em\u003e, vol. 65, no. 6, pp. 1154\u0026ndash;1160, 2009.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIbrahim A, Kumar S, Patil AR, Aishwarya JG, Shah AS, Nair S. Radiological and cadaveric study of anatomical safe zone for transoral base of tongue surgery. J Robot Surg. 2021;15(5):711\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaruyama M, Feinberg JR, Capello WN, D\u0026rsquo;Antonio JA. Morphologic Features of the Acetabulum and Femur: Anteversion Angle and Implant Positioning. Clin Orthop Relat Res. 2001;393:52\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi RT, Hu E, Gould H, Valentin N, Salata MJ, Liu RW. Does pelvic rotation alter radiologic measurement of anterior and lateral acetabular coverage? Arthrosc J Arthrosc Relat Surg. 2019;35(4):1111\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBowman KF Jr, Cohen SB, Bradley JP. Operative management of partial-thickness tears of the proximal hamstring muscles in athletes. Am J Sports Med. 2013;41(6):1363\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e\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":"Proximal hamstring injuries, Arthroscopic hamstring repair, Radiological safety zone","lastPublishedDoi":"10.21203/rs.3.rs-5461491/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5461491/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThis study aimed to establish safe zones for arthroscopic hamstring repair by pinpointing the radiological borders of the proximal hamstring tendon. These landmarks will aid surgeons in positioning anchors safely, minimizing the risk of nerve and vascular damage, and lowering the potential for intraoperative complications.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e \u003cp\u003eIn this anatomical and radiological study, five human cadavers fixed with formaldehyde (10 hips) were analyzed. Marking pins were placed at the borders of the proximal hamstring tendon footprint to determine its anatomical boundaries. Pelvis PA and hip PA radiographs were then taken to determine the radiological boundaries of the tendon footprint and its relationship with the ischial tuberosity. The distances from the tendon\u0026rsquo;s superior, medial, lateral, and inferior borders to the line joining the ischial tuberosities and the ischial apex were calculated. The accuracy of hip and pelvis radiographs was compared to assess their usefulness in surgical planning. Statistical analysis was performed using the Mann-Whitney U test.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eFour of the five cadavers were male, with a mean age of 67 years. The distances of the hamstring tendon to the line joining the ischium and to the ischial apex were determined with similar measurements on PA radiographs of the pelvis and hip. The distances of the superior, medial, lateral, and inferior borders to the line joining the ischium were 35.3 mm, 22.5 mm, 30.3 mm, and 17.5 mm, respectively, in the pelvis radiograph. In comparison, these values were 35.3 mm, 22.1 mm, 29.7 mm, and 18.9 mm in the hip radiograph. The distances of the superior, medial, lateral, and inferior borders to the ischial apex were 47.7 mm, 33.9 mm, 43.3 mm, and 31.4 mm, respectively, in the pelvic radiograph. In comparison, these values were 47.9 mm, 32.7 mm, 44 mm, and 33.2 mm in the hip radiograph. The distances between the medial and lateral borders and the distances between the superior and inferior borders were also similar.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eDefining the radiological margins of the hamstring tendon provides a critical reference for portal opening and safe and anatomical anchor placement in arthroscopic hamstring repairs. The findings suggest that consistent identification of these boundaries by preoperative imaging and intraoperative fluoroscopy may reduce the risk of neurovascular injury and improve surgical success. The difference in distance between pelvis and hip PA radiographs was not statistically significant, supporting the reliability and reproducibility of both methods.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e \u003cp\u003eNot applicable.\u003c/p\u003e","manuscriptTitle":"Establishing the Radiological Safety Zone in the Ischium to Prevent Neurovascular Injury During Endoscopic Hamstring Tendon Repair: A Cadaveric Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-18 17:32:28","doi":"10.21203/rs.3.rs-5461491/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":"33e162b7-1d1a-4a7c-a882-4b8fb9b78d65","owner":[],"postedDate":"December 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-18T10:39:42+00:00","versionOfRecord":[],"versionCreatedAt":"2024-12-18 17:32:28","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5461491","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5461491","identity":"rs-5461491","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}