Portal Placement and Biomechanical Performance of Endoscopic Proximal Hamstring Repair

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.

Clinical Outcomes After Open and Endoscopic Repair of Proximal Hamstring Tendon Tears at a Minimum Follow-up of 5 Years

Background

Current evidence supports favorable short-term clinical outcomes with few complications after surgical management of proximal hamstring injuries; however, the durability of clinical benefits beyond approximately 2 years after surgery is unknown.

Purpose

To evaluate patient-reported clinical outcomes and complication rates associated with open and endoscopic repair of proximal hamstring tears at minimum 5-year follow-up.

Study Design

Case series; Level of evidence, 4.

Methods

A single-surgeon registry of patients was queried between October 1, 2014, and December 31, 2017, to identify patients who underwent open or endoscopic repair of a proximal hamstring tear. Patients who reported minimum 5-year follow-up data were included. Multiple patient-reported outcome measures, including the Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sports-Specific (HOS-SS) subscales, 12-Item International Hip Outcome Tool (iHOT-12), and Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain domains, along with surgical complications, were analyzed.

Results

Among 35 eligible patients (65.7% female; mean age, 52.3 ± 8.4 years), 24 had full-thickness tears and 11 had partial-thickness tears. There were 23 open repairs and 12 endoscopic repairs. Mean duration from symptom onset to surgical intervention was 37.9 weeks (range, 1.3-306.9 weeks). At a mean follow-up of 69.0 months (range, 60.0-95.0 months), mean postoperative outcome scores were as follows: HOS-ADL, 86.8 ± 12.7; HOS-SS, 83.1 ± 19.5; iHOT-12, 86.3 ± 14.9; PROMIS-PF, 50.0 ± 11.8; and PROMIS-Pain, 50.2 ± 7.9. Regarding complications, 28.6% of patients had a complication including persistent peri-incisional numbness (11.4%), wound infection (11.4%), postoperative neuropathy (8.6%), and revision surgery (2.9%).

Conclusion

Both open and endoscopic surgical techniques for repair of proximal hamstring injuries produced favorable patient-reported clinical outcomes at a minimum 5-year follow-up.

Endoscopic Partial Proximal Hamstring Repair

The contemporary treatment of hamstring avulsions has been evolving, as more patients are being identified as having persistently symptomatic partial hamstring tears recalcitrant to nonoperative treatment. The endoscopic hamstring repair allows surgeons improved visualization of the footprint, as well as safe dissection of the sciatic nerve. The present technique article provides a step-by-step technical note to allow for safe and effective surgical treatment of partial hamstring tears.

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.

The safe zones for endoscopic proximal hamstring repair: a cadaveric assessment of standard portal placement and their relationship to major neurovascular structures

PURPOSE

To define the anatomical relationship of the major neurovascular structures to the standard endoscopic portals used in endoscopic hamstring repair. A secondary outcome was to determine the safest angle of insertion from each standard portal.

METHODS

Endoscopic portals were established in the 3 standard locations (lateral, medial, and inferior) and Steinmann pins inserted at various angles. Each hip was dissected and the distance between the pins and the pertinent anatomy measured.

RESULTS

The lateral portal placed the sciatic and posterior femoral cutaneous (PFC) nerves at greatest risk: direct injury to the sciatic nerve was seen in 11/30 (37%) of the lateral portals sited. A lateral portal with an approach at 60° was the most dangerous orientation with a mean distance of 0.36 ± 0.49 mm and 4.30 ± 2.69 mm from the sciatic and PFC nerves, respectively (p < 0.001). The 60° medial portal was the safest of all portals measured, at a mean distance of 67.37 ± 11.06mm (range, 47-78 mm) from the sciatic nerve and 58.90 ± 10.57 mm (range 40-70 mm) from the PFC nerve.

CONCLUSIONS

While currently described techniques recommend establishing the standard lateral portal first, this study shows that it carries the highest risk of injury if used blind. We recommend that the standard medial endoscopic portal is established first to identify the neurovascular structures and minimise iatrogenic neurovascular injury. The inferior and lateral portals can then be established created under direct vision. The lateral portal should be inserted in a more horizontal orientation to decrease the risk of nerve injury.

[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.