Proximal Hamstring Repair Strength: A Biomechanical Analysis at 3 Hip Flexion Angles

Proximal Hamstring Repair With All-Suture Anchors and an Accelerated Rehabilitation and Bracing Protocol Demonstrates Good Outcomes at 1-Year Follow-Up

Purpose

To evaluate patient-reported outcomes and risk for rerupture after surgical treatment of proximal hamstring tendon ruptures using all-suture anchors and a unique postoperative bracing strategy.

Methods

A retrospective review of a prospectively collected database was conducted of patients undergoing proximal hamstring repair or reconstruction from 2020 to 2022 at a tertiary, academic institution. Patients were included if they reached minimum 1-year follow-up and completed postoperative patient-reported outcomes. The surgical protocol for proximal hamstring repairs included all-suture anchors placed either in an open or endoscopic fashion in the ischial tuberosity. After surgery, all patients underwent an accelerated rehabilitation protocol, including 6 weeks touchdown weight-bearing in a hinged knee brace locked in extension for ambulation, allowing passive knee flexion to 90° while seated. Descriptive statistics were used to analyze the data.

Results

Twenty-one patients were included (mean age 50.4 ± 9.5 years, body mass index 24.4 ± 3.5, 66.7% female). Lower Extremity Functional Scale score achieved postoperatively was 74.2 ± 7.5 (out of 80). Patients had minimal pain (mean visual analog scale pain score of 0.9 ± 1.2). 61.9% of patients were able to return to the same level of activity after based on Tegner score by 1 year. Postoperative Single Assessment Numeric Evaluation activity of daily living was 94.3 ± 8.3, and Single Assessment Numeric Evaluation Sports was 82.3 ± 19.0. Mean Short Form Survey (SF-12) postoperative scores were 51.6 ± 6.8 for SF-12 Physical Component Score and 53.9 ± 9.7 for Mental Component Score. 95.2% (20 of 21) patients were satisfied with their outcome. There were no reruptures, infections, or reoperations. One patient of 21 (4.8%) incurred a postoperative deep venous thrombosis, which was treated with therapeutic anticoagulation for 3 months.

Conclusions

All-suture anchors for proximal hamstring repair with a unique accelerated postoperative rehabilitation and bracing protocol result in good outcomes and patient satisfaction with minimal risk of complications.

Level of Evidence

Level IV, case series, therapeutic.

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.

Systematic Review of Bracing After Proximal Hamstring Repair

Background

Traditionally, postoperative rehabilitation protocols after proximal hamstring repair (PHR) for avulsion of the proximal hamstring tendon from its ischial insertion recommend bracing the hip and/or knee to protect the fixation. However, because of the cumbersome nature of these orthoses, recent studies have investigated outcomes in patients with postoperative protocols that do not include any form of postoperative bracing.

Purpose

To synthesize the current body of evidence concerning bracing versus nonbracing postoperative management of PHR.

Study Design

Systematic review; level of evidence, 4.

Methods

Using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we conducted a thorough search of the PubMed/Medline, Cochrane, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Embase (OVID) databases on March 24, 2023. We analyzed complication rates, reoperation rates, patient satisfaction, return to sport, and patient-reported outcomes of studies that used postoperative bracing versus studies that used no postoperative bracing after PHR with at least 12 months of follow-up. A total of 308 articles were identified after initial search.

Results

In total, 25 studies were included in this review: 18 studies (905 patients) on bracing and 7 studies (291 patients) on nonbracing after PHR. The overall complication rate in the braced patients was found to be 10.9%, compared with 12.7% in nonbraced patients. The rate of reoperation due to retear of the proximal hamstring was found to be 0.05% in braced patients and 3.1% in nonbraced patients. Patient-reported outcome measures were found to be higher at the final follow-up in braced versus nonbraced patients, and patient satisfaction was found to be 94.7% in braced studies compared with 88.9% in nonbraced studies. The rate of 12-month return to sport in athletic patients was 88.4% with bracing and 82.7% without bracing.

Conclusion

The findings of this review demonstrated lower complication and reoperation rates, higher patient-reported outcome scores, higher patient satisfaction, and a higher rate of return to sport in braced patients compared with nonbraced patients.

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.

[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.

Biomechanical Comparison of Anterograde and Retrograde Lesser Trochanter Avulsion Repair

Background:

Lesser trochanter avulsions are rare injuries in adolescents. Severe cases with relevant fragment displacement can be treated surgically. However, no standard approach is available in the literature. Operative techniques are presently limited to anterograde fixations. A new retrograde approach to reduce operative difficulty and postoperative morbidity has been proposed. So far, no biomechanical comparison of these techniques is available.

Hypothesis:

Retrograde repair of the lesser trochanter with a titanium cortical button will produce superior stability under load to failure and similar displacement under cyclic loading compared with anterograde fixation with titanium suture anchors.

Study Design:

Controlled laboratory study.

Methods:

Sixteen paired hemipelvic cadaveric specimens (mean age, 62.5 ± 10.7 years) were dissected to isolate the lesser trochanter and iliopsoas muscle. After repair of a simulated lesser trochanter avulsion, specimens were tested under cyclic loading between 10 and 125 N at 1 Hz for 1500 cycles before finally being loaded to failure at a rate of 120 mm/min in a material testing machine. Motion tracking was used to assess displacement at the superior and inferior aspects of the iliopsoas tendon under cyclic loading.

Results:

Load to failure was significantly greater for the retrograde repair compared with the anterograde repair (1075.24 ± 179.39 vs 321.85 ± 62.45 N; P = .012). Mean displacement at the superior repair aspect (retrograde vs anterograde: 3.29 ± 1.84 vs 4.39 ± 4.50 mm; P = .779) and mean displacement at the inferior aspect (3.54 ± 2.13 vs 4.22 ± 4.48 mm; P = .779) of the iliopsoas tendon did not significantly differ by the type of repair. Mode of failure was tendon tearing by the sutures for each retrograde repair and anchor pullout for each anterograde repair.

Conclusion:

Surgical repair of lesser trochanter avulsion fractures with retrograde fixation using a titanium cortical button demonstrated superior load to failure and similar displacement under cyclic loading compared with anterograde fixation using suture anchors.

Clinical Relevance:

The retrograde approach provides a biomechanically validated alternative to other surgical techniques for this injury.

Relationship Between Spinal-Pelvic Sagittal Balance and Pelvic-Femoral Injuries in Professional Soccer Players

Background

Pelvic-femoral injuries are a common problem in football (soccer) players. However, the risk factors for these injuries are unclear. Our knowledge of spinal-pelvic sagittal balance has increased considerably over the past few years, notably as a result of new radiographic techniques such the EOS radiographic imaging system.

Purpose

To investigate the link between spinal-pelvic sagittal balance on EOS imaging and the incidence of pelvic-femoral injuries.

Study Design

Cohort study; Level of evidence, 2.

Methods

Players in a League 1 professional soccer team were observed for 5 consecutive seasons. All players included in the study underwent EOS radiographic imaging. All acute and microtraumatic injuries to the pelvic-femoral complex were recorded prospectively: hamstrings, psoas, quadriceps, adductors, obturators, and pubic symphysis. We analyzed the relationship between injury incidence and key radiographic parameters involved in pelvic balance.

Results

A total of 61 players were included (mean age, 24.5 years; n = 149 injuries; mean pelvic tilt, 9.08° ± 5.6°). A significant link was observed between the incidence of pelvic-femoral injuries and pelvic tilt (P = .02). A significant link was also observed between the incidence of acute pelvic-femoral injuries and pelvic tilt (P = .05). In both cases, a high pelvic tilt was associated with a low incidence of injuries.

Conclusion

In professional soccer players, a low pelvic tilt was associated with a high incidence of all pelvic-femoral injuries as well as acute pelvic-femoral injuries. These results could lead to new preventive methods for these musculotendinous injuries through physical therapy.

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.

A combined endoscopic and open surgical approach for chronic retracted proximal hamstring avulsion

Proximal hamstring avulsion is an uncommon injury which usually requires surgical intervention. When possible, primary surgical fixation is recommended. In chronic hamstring avulsion with significant retraction of the tendon, hamstring reconstructions using an autograft or allograft are required in order to bridge the gap. This is mainly performed using an open surgical technique. We describe a combined endoscopic and open surgical approach to hamstring reconstruction surgery.

Accelerated rehabilitation results in good outcomes following acute repair of proximal hamstring ruptures

PURPOSE

To assess outcomes of patients who underwent proximal hamstring repair utilizing an accelerated rehabilitation protocol with immediate weight bearing as tolerated and no bracing.

METHODS

Retrospective chart review identified 47 proximal hamstring tendon repairs with suture anchors in 43 patients performed during 2008-2015. Rehabilitation included no immobilization or limited weightbearing. Patients were contacted by phone to assess outcomes utilizing the lower extremity functional score (LEFS), single-assessment numeric evaluation (SANE), and Marx activity scale. Overall patient-reported scores were calculated and results of acute and chronic repairs compared.

RESULTS

Thirty-four patients (38 repairs, 80.8%) were available for follow-up at mean of 4.1 ± 2.0 years following repair. There were two re-tears: one complete rupture 5 weeks postoperative and one partial rupture 10 weeks postoperative in the chronic group. Patients in general reported low pain and good function with a mean LEFS score of 87 ± 21%, a mean SANE score of 88.1 ± 11.6, and a mean numeric pain score of 8.5 ± 15.3 in the last week and 12.2 ± 21.1 with activity. The acute repair group was noted to have a higher mean LEFS score (93.7 versus 79.8%, p = 0.004) and SANE score (91.3 versus 83.8, p = 0.047), and lower pain with activity (21.7 versus 4.8, p < 0.001) as compared to the chronic group.

CONCLUSIONS

Repair of acute proximal hamstring ruptures results in good function and pain relief with the use of a rehabilitation protocol that does not require weight-bearing restrictions or bracing.

LEVEL OF EVIDENCE

III, therapeutic.

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.

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.