Structural properties of the intact proximal hamstring origin and evaluation of varying avulsion repair techniques: an in vitro biomechanical analysis

Pathogenesis and Diagnosis of Proximal Hamstring Tendinopathies

The proximal hamstring complex is a highly vulnerable area that is especially prone to injury. Proximal hamstring tendinopathies (PHTs) remain challenging in diagnosis, treatment, rehabilitation, and prevention due to a large variety of different injuries, slow healing response, persistent symptoms, and functional impairments. PHTs are often misdiagnosed or underdiagnosed, leading to delayed treatment and therapy failure. In addition, many athletes are at a high risk of PHT recurrence, a leading cause of prolonged rehabilitation and impaired individual performance. Until now, there have been no clear criteria for the diagnosis and classification of PHT. Tendinopathies can be graded based on their symptoms and onset. Additionally, radiological characteristics exist that describe the severity of tendinopathies. The diagnosis usually includes a battery of pain provocation tests, functional tests, and imaging to ensure a proper classification. Understanding the specific tasks in the pathogenesis and diagnostic process of PHT requires knowledge of functional anatomy, injury pattern and pathophysiological mechanisms as well as examination and imaging techniques. This work provides a structured overview of the pathogenesis and diagnostic work-up of PHT, emphasizing structured examination and imaging to enable a reliable diagnosis and rapid treatment decisions.

Hamstring Injuries: A Current Concepts Review: Evaluation, Nonoperative Treatment, and Surgical Decision Making

The purpose of this current concepts review is to highlight the evaluation and workup of hamstring injuries, nonoperative treatment options, and surgical decision-making based on patient presentation and injury patterns. Hamstring injuries, which are becoming increasingly recognized, affect professional and recreational athletes alike, commonly occurring after forceful eccentric contraction mechanisms. Injuries occur in the proximal tendon at the ischial tuberosity, in the muscle belly substance, or in the distal tendon insertion on the tibia or fibula. Patients may present with ecchymoses, pain, and weakness. Magnetic resonance imaging remains the gold standard for diagnosis and may help guide treatment. Treatment is dictated by the specific tendon(s) injured, tear location, severity, and chronicity. Many hamstring injuries can be successfully managed with nonoperative measures such as activity modification and physical therapy; adjuncts such as platelet-rich plasma injections are currently being investigated. Operative treatment of proximal hamstring injuries, including endoscopic or open approaches, is traditionally reserved for 2-tendon injuries with >2 cm of retraction, 3-tendon injuries, or injuries that do not improve with 6 months of nonoperative management. Acute surgical treatment of proximal hamstring injuries tends to be favorable. Distal hamstring injuries may initially be managed nonoperatively, although biceps femoris injuries are frequently managed surgically, and return to sport may be faster for semitendinosus injuries treated acutely with excision or tendon stripping in high-level athletes.

Biomechanical Comparison Between Double-Row Repair and Soft Tissue Tenodesis for Treatment of Proximal Rectus Femoris Avulsions

Background

Some patients with proximal rectus femoris (PRF) avulsions require surgical treatment after failed nonoperative treatment. There is no consensus on the superiority of suture anchor repair with the suture-bridge repair (SBR) technique versus tenodesis repair (TR) for PRF avulsions.

Purpose

To compare the failure load and elongation at failure between SBR and TR and to compare the stiffness of these 2 repair techniques versus the native state.

Study Design

Controlled laboratory study.

Methods

Seven pairs of human cadaveric hemipelvises were dissected to the PRF and sartorius origins. Each specimen underwent preconditioning followed by a distraction test to determine the stiffness of the native specimen. One specimen of each pair received one of the repair methods (SBR or TR), while the other specimen in the pair received the other repair technique. After repair, each specimen underwent preconditioning followed by a pull to failure. The failure load, elongation at failure, stiffness, mode of failure, and stiffness as a percentage of the native state were determined for each repair.

Results

The SBR group exhibited a stronger failure load (223 ± 51 N vs 153 ± 32 N for the TR group; P = .0116) and significantly higher stiffness as a percentage from the native state (70.4% ± 19% vs 33.8% ± 15.5% for the TR group; P = .0085). While the stiffness of the repair state in the SBR group (41.5 ± 9.4 N/mm) was not significantly different from that of the native state (66.2 ± 36 N/mm), the stiffness of the repair state in the TR group (20.3 ± 7.5 N/mm) was significantly lower compared with that of the native state (65.4 ± 22.1 N/mm; P < .001) and repair state in the SBR group (41.5 ± 9.4 N/mm; P = .02). The SBR group primarily failed at the repair site (71%), and the TR group primarily failed at the suture-sartorius interface (43%) and at the muscle (29%).

Conclusion

SBR and TR specimens were significantly weaker than the native tendon. The stiffness of the SBR was equivalent to that of the native tendon, while TR was significantly less stiff than the native tendon. The SBR was superior to TR in terms of failure load, stiffness, and percentage stiffness from the native state.

Clinical Relevance

SBR may be a better surgical option than TR to optimize failure load and stiffness for PRF avulsions.

Biomechanical Comparison of Proximal Hamstring Reconstruction Using Distal Hamstring Graft Versus Fascia Lata Graft for Treatment of Chronic Hamstring Injury

BACKGROUND

Surgical reconstruction using autografts is often required in treating chronic proximal hamstring injuries where the hamstring has retracted >5 cm. There is a paucity of evidence that evaluates reconstructive procedures using the 2 most popular autografts, distal hamstring and fascia lata.

PURPOSE

To (1) compare failure load and elongation at failure between the proximal hamstring tendon reconstruction with distal hamstring and fascia lata grafts and (2) compare the stiffness between these reconstructions and the native state.

STUDY DESIGN

Controlled laboratory study.

METHODS

Seven pairs of human cadaveric hemipelvises (mean age, 60.4 ± 5.0 years; 6 male, 1 female) with no evidence of previous injury or abnormality were dissected to the proximal hamstring origin. Through use of a dynamic tensile testing system, each specimen underwent preconditioning followed by a distraction test to determine the native specimen stiffness. Each pair of specimens was assigned to undergo proximal hamstring reconstruction with distal hamstring and reconstruction with fascia lata. Each specimen then underwent preconditioning followed by pull to failure. The failure load, elongation at failure, mode of failure, and stiffness were determined for each repair.

RESULTS

The distal hamstring group exhibited a greater failure load (mean, 334 ± 108 N; P = .031) and higher stiffness (mean, 47.6 ± 16.0 N/mm; P = .009) compared with the fascia lata group (mean, 179 ± 78 N and 23.0 ± 11.2 N/mm, respectively). Although the stiffness of the repair state in the distal hamstring group (mean, 61.4 ± 13.4 N/mm) was not significantly different from that of the native state (mean, 47.6 ± 16.0 N/mm), the stiffness of the repair state in the fascia lata group (mean, 23.0 ± 11.2 N/mm) was significantly lower than that of the native state (mean, 60.1 ± 17.7 N/mm) (P < .0001). The elongation at failure of the distal hamstring graft group (mean, 33.0 ± 6.6 mm) was not significantly different from that of the fascia lata graft group (mean, 29.2 ± 14.9 mm) (P = .58). The most common modes of failure for the distal hamstring group (29% each) were at the repair site, at the graft-muscle interface, and at the muscle, while the most common modes of failure for the fascia lata graft were at the tendon-graft interface.

CONCLUSION

The distal hamstring group achieved higher failure load and stiffness than the fascia lata group, and stiffness of the distal hamstring group was not significantly different from that of the native tendon. Elongation at failure was not different between repair techniques. Although distal hamstring graft failure predominantly occurred in 3 distinct locations, failure of the fascia lata repair occurred predominantly at the tendon-graft interface. These cadaveric results suggest that it may be more clinically appropriate to use distal hamstring versus fascia lata for proximal hamstring reconstruction.

CLINICAL RELEVANCE

Our time-zero study suggests that the proximal hamstring reconstruction with distal hamstring could be the preferred surgical treatment for chronic hamstring injury over reconstruction with fascia lata. The failure load of reconstruction with distal hamstring was inferior to that of primary suture anchor, suggesting that rehabilitation after reconstruction should not be more aggressive than the standard postoperative rehabilitation protocol for acute repair.

Fixation of the Proximal Hamstring Tendon Using an All-Suture Tensionable Knotless Technique

Proximal hamstring injuries are a common sports and recreational injury among the active patient population. Surgical fixation of the tendons of the hamstring muscle complex, as opposed to conservative treatment alone, has shown improved patient outcomes, prompting the evolution of the suture anchors utilized in these repairs. Previous studies investigating the biomechanical properties of hamstring repair anchors have focused on double-row knotless techniques, in which the fixation of the overall construct relies on each individual anchor to maintain fixation. While these constructs have demonstrated biomechanical strength and clinical durability, each suture anchor represents a potential point of failure for the entire construct due to the crossed stitch anchor configuration. To address this limitation, recent tensionable knotless all-suture anchor designs have been implemented with success due to their smaller size and biomechanical strength. The aim of this technical note is, thus, to describe a technique for proximal hamstring repair using a tensionable knotless all-suture anchor construct that has 5 independent mattress sutures and, in doing so, employs the biomechanical strength of knotless fixation but eliminates the potential single point of failure seen with current knotless suture anchor designs.

Endoscopic Repair of Proximal Hamstring Insertion With Sciatic Nerve Neurolysis

Open surgical repair of proximal hamstring avulsions has been the standard of care for a long time, when surgery is needed. Endoscopic repair is a relatively new surgery, and its popularity increased in the last 10 years. This technique allows the surgeon an anatomic repair and a safe sciatic nerve exploration with small incisions and dissection. As a new technique, it has its limitations, mostly in chronic retracted tears, and long follow-up series are needed to assess long-term outcomes. We present an endoscopic repair of a right proximal hamstring avulsion performed along with a sciatic nerve neurolysis.

Prognosis of Incomplete Avulsion of the Proximal Hamstring Tendon Is Determined by the Avulsion Location of the Proximal Hamstring Tendon Footprint

OBJECTIVE

To test the hypothesis that prognosis of incomplete avulsion of the proximal hamstring tendon would be worse whether avulsion location reached the proximal part of the conjoined tendon (CJ) footprint or not.

DESIGN

Retrospective chart review.

SETTING

Outpatient specialty clinic.

PATIENTS

We reviewed 345 consecutive athletes with hamstring injury.

INTERVENTIONS

Based on magnetic resonance imaging, incomplete avulsion of the proximal hamstring tendon was divided into 2 cases according to avulsion location without (cases A) or with (cases B) avulsion of the proximal part of the CJ footprint.

OUTCOME MEASURES

We compared the time until return to play, subjective outcomes, and success rate of avoiding surgery between cases.

RESULTS

Incomplete avulsion of the proximal hamstring tendon was detected in 47 athletes (13.6%). Thirty-four athletes were classified as cases A, and 13 as cases B. Forty-two athletes (89.4%) were followed up until return to play. The median time from pain onset to return to play was significantly longer in cases B than in cases A (B, 39.3 weeks; A, 8.0 weeks; P = 0.00015). Subjective outcomes at return to play were significantly poorer in cases B than in cases A (P = 0.00054). Success rate of avoiding surgery were significantly poorer in cases B (55%) than in cases A (100%) (P = 0.00062).

CONCLUSIONS

Incomplete avulsion of the proximal hamstring tendon was observed in 13.6% of hamstring injuries. Return to play, subjective outcomes, and success rate of avoiding surgery were significantly poorer with avulsion of the proximal part of the CJ footprint.

[Avulsion of the hamstring muscles]

BACKGROUND

Avulsion injuries of the proximal hamstring muscles are rare but very severe injuries to the dorsal thigh musculature.

OBJECTIVE

Due to improved diagnostics and experience in treatment, the decision for surgical treatment is becoming more and more frequent. Presentation of the surgical method, follow-up treatment and outcome.

MATERIAL AND METHODS

Description of the anatomy, origin, diagnostics and treatment of avulsions of the hamstring musculature.

RESULTS

Due to improvement of knowledge and diagnostics, avulsion injuries of the hamstring muscles are identified more frequently. The rapid expansion of the diagnostics, including magnetic resonance imaging (MRI) is decisive for a better identification of the extent and severity of the injury. Even if the differences in long-term results between surgical and conservative treatment are not significant in the literature, there is a clear improvement in function and resilience after surgical treatment of avulsion injuries of the hamstring muscles.

CONCLUSION

In view of the poor results of nonsurgical treatment and the clearly positive reports of surgical success, open refixation is recommended for recent proximal hamstring ruptures.

[Clinical results after refixation of proximal hamstring tendon ruptures comparing different anchor systems]

BACKGROUND

Injuries to the hamstring muscles and tendon complex are among the most frequent muscular injuries with proximal hamstring tendon avulsion being a particularly severe form. The surgical treatment of these injuries is superior to conservative management with respect to patient satisfaction, recovery of muscle strength and function as well as return to sport rates. It is therefore the method of choice.

OBJECTIVE

Presentation and comparison of the surgical results after treatment with titanium, polyether ether ketone (PEEK) and all suture anchors.

MATERIAL AND METHODS

A systematic search was carried out in the PubMed medical database and the results are summarized.

RESULTS

All systems exhibit comparable biomechanical properties regarding elongation and ultimate failure load. Tendon repair with these anchors results in good to excellent clinical outcomes and shows high return to sport and low complication rates. Patient satisfaction after hamstring tendon repair is reported to be over 90% and return to sport rate is 80-100%. The muscle strength recovers to 80-90% in comparison to the contralateral side.

CONCLUSION

All available anchors systems provide good to excellent clinical outcomes and an explicit advantage for one anchor system could so far not be shown.

Reconstruction of Chronic Proximal Hamstring Tear: Description of a Surgical Technique

While proximal hamstring tears at the myotendinous junction are common sports-related injuries that are often successfully treated nonoperatively, complete avulsions from the origin on the ischial tuberosity are less common and better treated with surgical repair to prevent significant functional limitations and ongoing weakness. The diagnosis can be easily missed, leading patients to present several months after the initial injury. In addition, some patients decide on nonoperative management initially but later present requesting surgical intervention. The delayed cases are challenging due to often significant tendon retraction, making direct repair difficult if not impossible. Techniques using allograft and autograft reconstruction have been described for this clinical situation. This Technical Note describes the use of 2 Achilles tendon allografts fixed via 5 suture anchors to reconstruct a chronic complete avulsion injury of the proximal hamstring with >5-cm retraction.

2019 Marathon of Rome. Hamstring injuries in long distance runners: influence of age, gender, weight, height, numbers of marathon and impact profile

BACKGROUND

Hamstring diseases are one of the most widespread diseases in athletes, especially in runners, sprinters, and endurance athletes. Notwithstanding the importance of the problem, risk factors are still marginally known. This transversal study analyzes the correlation between Hamstring tendinopathy and hamstring strains and age, gender, weight, height, number of marathons, and impact profile in athletes who took part in the 2019 Rome Marathon.

METHODS

At the 2019 Marathon of Rome, 700 runners (484 males and 216 females; mean age: 43.6 years, range 17-80 years) filled the VISA-H and FASH questionnaires. An adequately skilled orthopedic surgeon made a diagnosis of Hamstring tendinopathy and Hamstring strain injuries in line with clinical criteria.

RESULTS

A diagnosis of Hamstring tendinopathy was made in 537 participants while in 624 of hamstring strains. There was evidence of a positive correlation statistically significant between age, weight and impact profile with Hamstring strain injuries, while there was no association between sex and number of marathons and the Hamstring strains. No statistically significant positive correlation was found between all of the parameters analyzed and VISA-H. The association between VISA-H score and FASH score has resulted statistically significant.

CONCLUSIONS

In marathon athletes, there was not found evidence of a statistically significant correlation between gender, weight, height, number of marathons, impact profile and Hamstring tendinopathy. Nonetheless, age, weight and impact profile were associated with Hamstring strains, while sex and number of marathons had not shown statistically significant positive association with Hamstring strain injuries.

Endoscopic-Assisted Anatomic Reconstruction of Chronic Proximal Hamstring Avulsion With Achilles Allograft

Hamstring injuries commonly occur at the musculotendinous junction; however, they can occur as proximal avulsion injuries. A lack of recognition can lead to proximal hamstring injuries being frequently misdiagnosed, resulting in delayed treatment. Chronic proximal hamstring tears are often retracted and scarred to the surrounding soft tissues. Owing to the poor quality of tissue at the torn ends of the tendon, an augmented reconstruction using an allograft may be required. In cases with poor visualization of the ischial tuberosity and proximal hamstring footprint, an Achilles tendon allograft can be secured directly to the tuberosity with suture anchors. However, visualization of the footprint can be optimized using an arthroscope. This report describes a technique for endoscopic-assisted anatomic reconstruction using an Achilles allograft with both knotless and knotted suture anchors for chronic complete avulsions of the proximal hamstring.

Suture Bridge Repair of Proximal Hamstring Avulsion: A Case Report

Proximal hamstring avulsion injuries can represent a challenging problem and lead to severe patient morbidity if not treated appropriately. The most common method for acute surgical fixation involves the use of between two and five suture anchors in a variety of configurations. The five-anchor fixation has become the gold standard due to the increased biomechanical stability. However, the technique has also been criticized due to the need for greater exposure and technical difficulty. We report on an individual with a proximal hamstring avulsion injury who was managed with a modified approach, utilizing only three anchors in a suture bridge technique. The patient had good clinical outcomes at their 3-month follow-up visit, demonstrating this technique to be a viable option that is less technically demanding.

Practice patterns for the treatment of acute proximal hamstring ruptures

Objective: Proximal ischial hamstring avulsion injuries are relatively uncommon. As such, the management of these injuries is often highly variable. Consensus agreement is lacking for the indications for repair, along with the operative technique, and post-operative rehabilitation. The purpose of this study was to survey surgeons who treat proximal hamstring avulsion injuries to identify current trends in the management of this injury.Methods: After IRB approval, a 46-question cross-sectional survey was distributed using a secure electronic survey portal. The survey sought to determine surgeon experience, diagnostic preferences, treatment patterns, surgical indications/technique, perceived patient outcomes, surgical complications, as well as post-operative management and rehab protocols. Surveys were completed electronically and anonymously, with invitations distributed to members of the American Orthopedic Society for Sports Medicine (AOSSM) and Arthroscopy Association of Canada (AAC).Results: A total of 108 surgeons who manage proximal hamstring injuries completed the survey. Most respondents (77%) treat one to five of these injuries per year. MRI was the preferred imaging modality to confirm diagnosis. Despite 98% of respondents indicating that there was a role for surgical management of proximal hamstring avulsions, operative treatment was reportedly undertaken in only 50% of cases seen by each respondent. The top three reported surgical indications were: number of tendons involved (most important factor = 42%, second most = 26%, third most = 13%), amount of tendon retraction (28%, 41%, 16%), and patient activity level (16%, 18%, 24%).Conclusion: Based on the practice patterns of the surgeons who completed the survey, there is continued disparity in the management of proximal hamstring avulsions. A lack of agreement exists with regards to surgical indications, operative technique, and post-operative protocols. Most striking is the rate of non-operative treatment and perceived rate of poor outcomes within this cohort. Future research should focus on objective evaluation of non-operative management, and additional variables involved in surgical treatment and post-operative rehabilitation.

Biomechanical Evaluation of Proximal Hamstring Repair: All-Suture Anchor Versus Titanium Suture Anchor

Background:

Proximal hamstring avulsions are severe tendon injuries and are commonly sports-related. Open and endoscopic techniques as well as different anchor configurations have already been described for proximal hamstring repair. Novel all-suture anchors have been developed to provide decreased bone loss during placement and reduced occupied bone volume when compared with titanium suture anchors.

Hypothesis:

Complete proximal hamstring avulsions repaired with all-suture anchors will demonstrate equal load to failure and comparable displacement under cyclic loading when compared with titanium suture anchors.

Study Design:

Controlled laboratory study.

Methods:

Complete proximal hamstring avulsions were created in 18 paired cadaveric specimens (mean ± SD age, 63.0 ± 10.4 years). Either all-suture anchors or titanium suture anchors were used for repair. Cyclic loading from 10 to 125 N at 1 Hz was performed for 1500 cycles with a material testing machine. Displacement was assessed along anterior and posterior aspects of the tendon repair with optical tracking. Specimens were loaded to failure at a rate of 120 mm/min. Displacement, load to failure, and repair construct stiffness were compared between matched pairs with the Wilcoxon signed-rank test. Correlations were determined by Spearman rho analysis.

Results:

The all-suture anchors showed significantly higher load-to-failure values when compared with the titanium anchor repairs (799.64 ± 257.1 vs 573.27 ± 89.9 N; P = .008). There was no significant difference in displacement between all-suture anchors and titanium suture anchors at the anterior aspect (6.60 ± 2.2 vs 5.49 ± 1.1 mm; P = .26) or posterior aspect (5.87 ± 2.08 vs 5.23 ± 1.37 mm; P = .678) of the repaired hamstring tendons.

Conclusion:

All-suture anchors demonstrated similar displacement and superior load to failure when compared with titanium suture anchors.

Clinical Relevance:

The results of this study suggest that all-suture anchors are an equivalent alternative to titanium suture anchors for proximal hamstring avulsion repair.

Portal Placement and Biomechanical Performance of Endoscopic Proximal Hamstring Repair

BACKGROUND

Proximal hamstring tendon avulsions are debilitating and commonly cause pain, weakness, and functional limitations. Open surgical repair has been the standard, but improved endoscopic techniques have enabled proximal hamstring fixation with decreased risk of infection and numbness, without the morbidity of a large incision.

PURPOSE/HYPOTHESIS

The purpose was to (1) describe pertinent anatomy surrounding the proximal hamstring origin in relation to 4 endoscopic portal sites and (2) test for biomechanical differences between open and endoscopic repair. It was hypothesized that (1) endoscopic proximal hamstring repair is efficacious with respect to commonly used portals and (2) there is no biomechanical difference between open and endoscopic techniques.

STUDY DESIGN

Descriptive and controlled laboratory study.

METHODS

Proximal hamstring ruptures were simulated endoscopically in 10 fresh-frozen human cadaveric pelvis specimens. Endoscopic repair was then completed on 1 limb from each specimen through 4 portals. After repair, each specimen was dissected in layers and measurements from portal tracts to pertinent anatomy were obtained. Open repair was performed on all contralateral limbs, followed by cyclical biomechanical tensile testing to failure of both the open and endoscopically repaired hamstring tendons to assess failure load and local tissue strain.

RESULTS

On average, no portal tract was closer than 2.0 cm to the sciatic nerve or inferior gluteal neurovascular bundle. Anatomic landmarks were identified that could improve the reproducibility and safety of the procedure. Biomechanical testing revealed no differences between the open and endoscopic repair techniques for any measured parameter.

CONCLUSION

This study supports the safety and efficacy of endoscopic proximal hamstring repair through anatomic and biomechanical analyses and helps establish reproducible and recognizable landmarks that define a safe working zone.

CLINICAL RELEVANCE

This study maps the anatomic landscape of the proximal hamstring as encountered endoscopically and demonstrates equivalent biomechanical strength of endoscopic proximal hamstring repair, supporting this technique's safety and efficacy.

Proximal Hamstring Repair: A Biomechanical Analysis of Variable Suture Anchor Constructs

Background:

Despite an abundance of literature regarding construct strength for a myriad of anchors and anchor configurations in the shoulder, there remains a paucity of biomechanical studies detailing the efficacy of these implants for proximal hamstring repair.

Purpose:

To biomechanically evaluate the ultimate failure load and failure mechanism of knotless and knotted anchor configurations for hamstring repair.

Study Design:

Controlled laboratory study.

Methods:

A total of 17 cadaveric specimens divided into 3 groups composed of intact hamstring tendons as well as 2 different anchor configurations (all-knotted and all-knotless) underwent first cyclic loading and subsequent maximal loading to failure. This protocol entailed a 10-N preload, followed by 100 cycles incrementally applied from 20 to 200 N at a frequency of 0.5 Hz, and ultimately followed by a load to failure with a loading rate of 33 mm/s. The ultimate failure load and mechanism of failure were recorded for each specimen, as was the maximal displacement of each bone-tendon interface subsequent to maximal loading. Analysis of variance was employed to calculate differences in the maximal load to failure as well as the maximal displacement between the 3 study groups. Holm-Sidak post hoc analysis was applied when necessary.

Results:

The all-knotless suture anchor construct failed at the highest maximal load of the 3 groups (767.18 ± 93.50 N), including that for the intact tendon group (750.58 ± 172.22 N). There was no statistically significant difference between the all-knotless and intact tendon groups; however, there was a statistically significant difference in load to failure when the all-knotless construct was compared with the all-knotted technique (549.56 ± 20.74 N) (P = .024). The most common mode of failure in both repair groups was at the suture-tendon interface, whereas the intact tendon group most frequently failed via avulsion of the tendon from its insertion site.

Conclusion:

Under biomechanical laboratory testing conditions, proximal hamstring repair using all-knotless suture anchors outperformed the all-knotted suture anchor configuration with regard to elongation during cyclic loading and maximal load to failure. Failure in the all-knotted repair group was at the suture-tendon interface in most cases, whereas the all-knotless construct failed most frequently at the musculotendinous junction.

Clinical Relevance:

No biomechanical studies have clearly identified the optimal anchor configuration to avert proximal hamstring repair failure. Delineating this ideal suture anchor construct and its strength compared with an intact hamstring tendon may alter the current standards for postoperative rehabilitation, which remain extremely conservative and onerous for these patients.

Avulsion fracture of the ischial tuberosity treated with the suture bridge technique: a case report

Background

In cases of avulsion fracture of the ischial tuberosity in which the bone fragments are substantially displaced, nonunion may cause pain in the ischial area. Various surgical procedures have been reported, but achieving sufficient fixation strength is difficult.

Case presentation

We treated a 12-year-old male track-and-field athlete with avulsion fracture of the ischial tuberosity by suture anchor fixation using the suture bridge technique. The boy felt pain in the left gluteal area while running. Radiography showed a left avulsion fracture of the ischial tuberosity with approximately 20-mm displacement. Union was not achieved by conservative non-weight-bearing therapy, and muscle weakness persisted; therefore, surgery was performed. A subgluteal approach was taken via a longitudinal incision in the buttocks, and the avulsed fragment was fixed with five biodegradable suture anchors using the suture bridge technique.

Conclusions

Although the majority of avulsion fractures of the ischial tuberosity can be treated conservatively, patients with excessive displacement require surgical treatment. The suture bridge technique provided secure fixation and enabled an early return to sports activities.

Anatomy of the Pudendal Nerve and Other Neural Structures Around the Proximal Hamstring Origin in Males

PURPOSE

To define the anatomy of the pudendal nerve in relationship to the proximal hamstring and other nearby neurological structures during proximal hamstring repair.

METHODS

Six fresh-frozen human cadaveric hemi-pelvises from male patients ages 64.0 ± 4.1 years were dissected in prone position with hips in 10° flexion to identify the relationship of proximal hamstring origin to surrounding neurologic structures including the pudendal nerve, sciatic nerve, and posterior femoral cutaneous nerve. Two independent observers used digital calipers to measure distances.

RESULTS

The pudendal nerve emerged at the inferior border of the piriformis muscle 6.3 ± 1.4 cm from the superior aspect of the proximal hamstring origin. It passed the superior border of the sacrotuberous ligament 3.0 ± 0.6 cm from the superior aspect and 3.9 ± 0.7 cm from the medial aspect of the hamstring origin. It crossed the inferior border of the sacrotuberous ligament 3.0 ± 0.4 cm from the superior aspect and 2.7 ± 0.7 cm from the medial aspect of the proximal hamstring origin. The shortest distance from the hamstring origin to the pudendal nerve was 2.6 ± 0.5 cm from the superior aspect and 2.3 ± 0.8 cm from the medial aspect. The shortest distance from the hamstring origin to the pudendal nerve was located deep to the sacrotuberous ligament in all cadavers. The sciatic nerve was an average of 1.1 ± 0.1 cm lateral to the lateral aspect of the proximal hamstring origin. The posterior femoral cutaneous nerve was located between the hamstring origin and the sciatic nerve, 0.7 ± 0.2 cm lateral to the lateral aspect of the proximal hamstring origin.

CONCLUSIONS

The proximal hamstring origin lies in close proximity to surrounding nerves, including the pudendal, sciatic, and posterior femoral cutaneous nerves.

CLINICAL RELEVANCE

Knowledge that the pudendal nerve lies 2 to 3 cm superior and medial to the proximal hamstring origin may help to prevent iatrogenic damage during surgical dissection and retraction when performing proximal hamstring repair or deep gluteal space endoscopy.

A Novel Technique to Repair Acute and Chronic Proximal Hamstring Avulsions

Treatment of proximal hamstring avulsions is challenging regarding both timing and choice of repair. In chronic situations, the tissue can become attenuated, bringing into question the need for adjunctive allograft. In general, proximal hamstring avulsions are affixed back to the ischial tuberosity with suture anchors, with allograft used as needed for chronic situations. This article reports on a novel technique of suspensory fixation with a unicortical button but without allograft to repair both acute and chronic proximal hamstring avulsions. Three patients, all of whom regained full strength and functionality 1 year postoperatively, are described. [Orthopedics. 2018; 41(2):116-119.].

Correlation Between Femoroacetabular Impingement and Hamstring Tendon Pathology on Magnetic Resonance Imaging and Arthrography

Femoroacetabular impingement (FAI) is an abnormality of the femoral head or acetabulum that leads to an increased incidence of cartilaginous injury in the hip. Femoroacetabular impingement has been associated with several structural abnormalities, including osteitis pubis and hip flexor dysfunction. The authors propose that, additionally, FAI may lead to increased damage of the hamstring tendon due to the additional stress placed on the tendon from the limited range of motion of the hip. The authors conducted a retrospective matched-pair study with the magnetic resonance imaging and magnetic resonance arthrography images of 40 patients' hamstrings with FAI and 45 age-matched controls. Images were identified and reviewed by 2 musculoskeletal radiologists for various signs of hamstring tendon pathology. Fisher's exact test and an odds ratio were used to assess for a difference in the occurrence of hamstring tendon pathology in the FAI patient cohort compared with the age-matched controls. The results showed a statistically significant increase in the occurrence of hamstring tendon pathology in the FAI patient cohort compared with the age-matched controls (P<.001). The odds ratio for hamstring tendon pathology in a subject with confirmed FAI vs control subjects was 8.30 (95% confidence interval, 3.20-21.5), indicating a significant increase in the risk of developing hamstring tendon pathology among patients with FAI (P<.001). This study suggests that there may be an increased occurrence of hamstring tendon pathology in patients with FAI. The kinetic chain of motion, where restricted rotation at the hip joint increases the stress on the hamstring tendons, leading to damage, may explain this increase. [Orthopedics. 2017; 40(6):e1086-e1091.].

A New Technique for Surgical Treatment of Proximal Hamstring Tendinopathy in a Triathlon Athlete

Introduction:

Proximal hamstring tendinopathy (PHT) is the result of chronic overload caused by repetitive eccentric contraction. Surgical treatment becomes an option for patients with chronic symptoms that do not respond to conservative treatment.

Case Report:

This report describes a case of a 48-year-old man, an amateur triathlete, with deep gluteal pain in the left hip for 12 months, leading to a decline in sports performance. Magnetic resonance imaging revealed abnormalities that suggested a PHT. Surgery was indicated following the failure of conservative treatments. Debridement of the conjoint tendon and its reinsertion associated with semimembranosus tenotomy showed good results and is thus an option for the treatment of this pathology after 12 months of follow-up.

Conclusion:

This article provides surgeons with a new surgical option for this debilitating condition with clinical and functional improvement after 12 months of follow-up.

Repair of Proximal Hamstring Tears: A Surgical Technique

Proximal hamstring tears are among the most common sports-related injuries. These injuries often occur as strains or partial tears at the proximal muscle belly or the musculotendinous junction, with avulsion injuries of the proximal attachment occurring less frequently. Regardless of the mechanism, they produce functional impairment and negatively affect an athlete's performance. Various classifications for these injuries are reported in the literature. Early surgical treatment is recommended for patients with either a 2-tendon tear/avulsion with more than 2 cm retraction or those with complete 3-tendon tears. Surgery can be performed in the chronic phase but it is technically demanding because of scar formation and tendon retraction. This Technical Note describes a biomechanically validated surgical technique for repair of the proximal hamstring tears.

Proximal Hamstring Tendinopathy: Clinical Aspects of Assessment and Management

Synopsis Proximal hamstring tendinopathy (PHT) typically manifests as deep buttock pain at the hamstring common origin. Both athletic and nonathletic populations are affected by PHT. Pain and dysfunction are often long-standing and limit sporting and daily functions. There is limited evidence regarding diagnosis, assessment, and management; for example, there are no randomized controlled trials investigating rehabilitation of PHT. Some of the principles of management established in, for example, Achilles and patellar tendinopathy would appear to apply to PHT but are not as well documented. This narrative review and commentary will highlight clinical aspects of assessment and management of PHT, drawing on the available evidence and current principles of managing painful tendinopathy. The management outline presented aims to guide clinicians as well as future research. J Orthop Sports Phys Ther 2016;46(6):483-493. Epub 15 Apr 2016. doi:10.2519/jospt.2016.5986.