Abstract
Background:
Hamstring injuries at the musculotendinous junction are relatively common. However, injuries to the proximal hamstring account for just 12% of hamstring injuries. Surgical repair of these injuries including both open and endoscopic techniques are becoming increasingly more common.
Indications:
Surgical intervention is generally reserved for cases with 2 or more torn tendons and at least 2 centimeters of retraction.
Technique Description:
The combined open and endoscopic technique utilizes direct posterior and posterolateral portals. After visualizing the posterior femoral cutaneous (PFCN) and sciatic nerves (SN), the proximal hamstring tear is identified, and the shaver is used to remove any surrounding adhesions and aid in clearing any hematoma. The ischial tuberosity is prepared using a shaver, radiofrequency ablation, and a 5.5 mm, round arthroscopic burr. Two, 4.5 mm, doubled-loaded anchors are placed into the ischium. The incision for the open portion of the case is created by incising the skin between the direct posterior and posterolateral portals. A dissection is continued down to the gluteal fascia, and the gluteal fascia is incised in line with the surgical incision. The gluteus maximus is retracted then the hamstring stump is secured with a stay suture and brought outside the surgical incision for inspection. The double-loaded sutures are passed in a running locking technique. The other suture limbs are then passed through the central aspect of the tendon and tensioned to reduce the proximal hamstring onto the prepared tuberosity.
Results:
Significant postoperative improvements in patient-reported outcomes have been reported for open and endoscopic repairs in isolation, but to date there are no outcomes studies on the combined “Scopen” technique. Postoperative complications may include numbness or neuropraxia, re-rupture, infection, and deep vein thrombosis (DVT).
Discussion:
The endoscopic portion allows an improved view and preservation of the SN and PFCN, as well as a detailed view of the ischial tuberosity for decortication and anchor placement in comparison with a purely open approach. In comparison with a purely endoscopic approach, this combined approach can be used in patients with retraction >4 cm, and can also be utilized for chronic, retracted tears as well.
This is a visual representation of the abstract.
Video Transcript
The following video describes a combined endoscopic and open technique for the treatment of hamstring tears.
These are our disclosures.
We will begin with a background on hamstring tears, followed by a case presentation, where we will discuss preoperative planning, as well as surgical technique for our scope-to-open hamstring repair. The video will then conclude with postoperative management guidelines, as well as return to sport guidelines, followed by a review of patient outcomes in the literature.
Hamstring injuries represent one of the most common musculoskeletal pathologies in sports, accounting for 12% to 29% of all athletic injuries, with the potential for substantial disability and morbidity. 1 While injury to the hamstring complex is common, only 12% of these injuries involve the proximal hamstring, and 9% of injuries are full-thickness tears. While historically proximal hamstring injuries were treated nonoperatively, the management of these injuries is evolving with a trend toward operative intervention. 2
Hamstring tears are most frequently reported as a result of participation in sport. Tearing is commonly a result of eccentric, forced contraction of the hip in flexion with concurrent knee extension, placing the hamstring muscle complex on maximal tension.
The hamstring muscle complex consists of 3 muscles (semimembranosus, semitendinosus, long head of the biceps femoris), originating from 2 distinct footprints on the ischial tuberosity, inserting distally below the proximal tibia. Importantly, the sciatic nerve lies approximately ≤1 cm from the lateral aspect of the hamstring origin on the tuberosity.
Nonoperative management in the form of rest, ice, elevation, activity modification, anti-inflammatory medication, and graduated physical therapy is generally indicated for single tendon tears with minimal retraction. Operative intervention is considered with ≥2 tendons are torn with ≥2 cm of retraction.
Patients commonly present with load dependent buttock pain; however, they may also describe groin and medial thigh pain. Patients often describe a snapping, clunking, or locking sensation of the hip joint while taking long strides. On physical examination, pain with passive extension, adduction, and external rotation of the hip is the most common test of choice. The long-stride walking test has also been described for ischiofemoral impingement, which consists of pain provoked with the patient taking large steps. Patients often also display compensatory abduction of the impaired leg to increase the distance between the lesser trochanter and the ischium.
Our patient is a 31-year-old man with left hamstring pain after a wakeboarding injury 2 weeks prior. He was initially treated conservatively by his primary care doctor, and was subsequently referred to our clinic for further management.
On physical examination, he had an antalgic gait with bruising/ecchymosis on the posterior thigh. There was a palpable defect in the proximal hamstring with significant weakness with resisted knee flexion.
Radiographs did not reveal any bony involvement.
Coronal T2 weighted imaging revealed a full thickness proximal hamstring tear with approximately 5 cm of retraction. These findings were evident on saggital and axial imaging as well.
In patient with a full-thickness proximal hamstring tear such as this one, a combined endoscopic and open approach may be considered, as it combines the advantages of both approaches. The endoscopic portion allows an improved view and preservation of the sciatic and posterior femoral cutaneous nerves, as well as a detailed view of the ischial tuberosity for decortication and anchor placement in comparison with a purely open approach. In comparison with a purely endoscopic approach, this combined approach can be used in patients with retraction >4 cm, and can also be utilized for chronic, retracted tears as well.
Following intubation, patients are placed prone on a Wilson frame. Towels and pillows under the feet allow for knee flexion to relax the hamstring tendons and sciatic nerve. Careful attention must be paid to pad all bony prominences. Prior to prepping and draping, preoperative fluoroscopy shots should be obtained to ensure the ischial tuberosity can be visualized. Often, the Wilson frame may need to be adjusted to adequately visualize the tuberosity.
The direct posterior and posterolateral working portals in the gluteal fold, 2 cm medial and 2 cm lateral to the ischial tuberosity. These portal incisions are planned such that they may later be connected together to create the incision for the open approach. The medial portal is performed using fluoroscopic guidance, with the needle aimed toward the ischial tuberosity at approximately a 30° angle in relation to the thigh. The lateral portal is created under direct visualization with care to come in at the lateral border of the ischial tuberosity to ensure safety with respect to the sciatic nerve.
An oscillating shaver is used to create a submuscular plane. The posterior femoral cutaneous nerve is then identified, as seen in the center of this picture here. The posterior cutaneous nerve is often seen superficial and distal following establishment of the portals.
The sciatic nerve is then identified primarily using blunt dissection with a switching stick. An oscillating shaver is used sparingly to release resistant bands of tissue. The sciatic nerve is often found proximally and laterally, draping 1.2 cm lateral to the ischial tuberosity. In this part of the video, the switching stick is pointing to the underlying sciatic nerve.
The proximal hamstring tear is then identified, this can often be done by following the tendon sheath distally. Once the proximal hamstring stump is identified, any surrounding adhesions can be dissected with the shaver, which can also aid in clearing any hematoma. Meticulous lysis of adhesions and hematoma evacuation during this step can pay dividends later for the open approach.
The ischial tuberosity is then prepared using a combination of a shaver, radiofrequency ablation, and a 5.5 mm, round arthroscopic burr. The hood of the burr can be utilized to protect from iatrogenic damage.
Two, 4.5 mm, doubled-loaded anchors are then placed into the ischium, taking care to space the anchors out appropriately along the footprint.
We now proceed with the open portion of the case. The incision is created by incising the skin between the direct posterior and posterolateral portals along the gluteal fold. A dissection is continued down to the gluteal fascia, and the gluteal fascia is incised in line with the surgical incision.
The gluteus maximus is retracted, and with proper exposure during the endoscopic portion of the case the hamstring stump will be readily identified. Here, the hamstring stump has been secured with a stay suture and brought outside the surgical incision for inspection.
The double-loaded sutures previously placed are then passed, with 1 strand from each anchor passed up and down the edge of the tendon in a running locking technique. The other suture limbs are then passed through the central aspect of the tendon.
The central suture limbs are then tensioned to reduce the proximal hamstring onto the prepared tuberosity, The respective sutures from each suture anchor are then tied on top of the tendon, such that the tendon attaches directly to the bone.
The arthroscope can be placed into the open wound to confirm appropriate repair of the hamstring tendon. The wounds are then closed in a routine fashion.
Our preferred tips for this procedure first involve proper preoperative patient positioning. A fluoroscopy shot is taken before prepping and draping to ensure that the operative ischial tuberosity is adequately visualized. The knee is flexed to release tension on the hamstring and sciatic nerve. The operative extremity is prepped in so that it can be easily manipulated during the case. We take care to identify the sciatic nerve endoscopically in every case so it can be periodically monitored to avoid injury. We also prefer to identify the hamstring stump endoscopically, rather than in the open component as it is often easier to identify in the endoscopic portion of the procedure. Last, careful hemostasis is obtained throughout the case using electrocautery, so that fluid pressures can remain low in efforts to prevent thigh compartment syndrome.
Postoperative complications include numbness or neuropraxia around the surgical incision side, or with involvement of the posterior femoral cutaneous nerve. Patient may continue to have functional limitations with eccentric hamstring exercises. Rerupture, infection, and deep vein thrombosis have also been reported in the literature.
Postoperative rehabilitation is staged into 4 phases: protection, range of motion, strengthening, and endurance. Postoperative rehabilitation begins with toe-touch weight-bearing restrictions, preventing active hamstring motion for 4 to 6 weeks after surgery. Patients are instructed to ambulate with crutches and a knee orthosis. An extension stop is set to 45° on the knee orthosis and gradually brought to full extension over a period of 4 to 6 weeks. Knee flexion can be left open to allow for ease of transition between sitting and standing.
Advancements in hip and knee motion, as well as increased weight bearing and core strengthening, begin at 6 weeks after surgery. Concentric strengthening is permitted after 8 weeks, and eccentric strengthening may be initiated at 3 months postoperatively. Light jogging, light short sprints, and closed chain plyometrics begin between 3 and 6 months postoperatively. Sport-specific drills and activity begin at 4 to 6 months after surgery. Return to competitive sport is allowed when athletes are able to perform multiplane activities at high velocity without pain or swelling. They must also display <10° deficit in comparison with the contralateral side on functional testing profile.
Patients show improved outcomes following endoscopic and open proximal hamstring repair. In a sample of 20 hips, Kurowicki et al 3 report a statistically significant improvement in modified Harris hip scores, UCLA activity score, and visual analog scale pain score an average one year postoperative. Maldonado et al 5 report similar improvements in functional outcome scores at a minimum 2 years of postoperative follow-up. While results have been reported for open and endoscopic repairs in isolation, there has been no prior outcomes studies on the combined “Scopen” technique. 4
Here are the references cited for this video.
We would like to thank you for your time and watching this technique video for the combined endoscopic and open technique, or “Scopen” technique, for the treatment of hamstring tears.
Thank you.
Footnotes
Submitted October 30, 2021; accepted February 24, 2022.
One or more of the authors has declared the following potential conflict of interest or source of funding: S.J.N. received non-financial support from Allosource, American Orthopaedic Association, American Orthopaedic Society for Sports Medicine, Arthrex, Inc, Arthroscopy Association of North America, Athletico, DJ Orthopaedics, Linvatec, Miomed, and Smith & Nephew; and received personal fees support from Ossur, Springer, and Stryker. M.J.S. is a paid consultant for Stryker. R.C.M.III. received financial support from Stryker, Regeneration Technologies, North Carolina Orthopaedic Association, International Society of Hip Arthroscopy, and Arthroscopy Association of North America. J.C. received financial support from Arthrex, Smith and Nephew, Ossur, CONMED Linvatec, International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine, Arthroscopy Association of North America and the American Orthopaedic Society for Sports Medicine. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
