Abstract
Background:
Hamstring injuries are commonly considered the number one reason for delayed return to play and return to sport (RTS) across several sport disciplines. Traditionally, they are treated conservatively. However, recent literature has shown surgical intervention to improve recovery and expedite RTS. One potential explanation behind this phenomenon is conservative treatment does not address the disrupted length-tendon relationship, which can cause hamstring re-injury.
Indications:
Operative indications for tendon excision include patients with distal semitendinosus avulsions tear with retraction, especially patients who had already failed conservative management. Elite athletes with distal hamstring tears who have experienced a delayed RTS or desired activity level should also be considered for distal hamstring excision.
Technique Description:
A distal 4-cm incision, which was longitudinal in line with the semitendinosus, was made over the posterior knee at the measured level of the avulsed tendon stump, 2 cm proximal to the knee flexion crease. Blunt dissection was used for the subcutaneous layers, and the overlying hypertrophic and fibrotic tendon sheath was sharply incised. The torn and retracted tendon tissue was exteriorized. An allis clamp was used to provide tension on the distal semitendinosus, and mobilization of the avulsed tendon was performed. Sheath tissue surrounding the injured tendon was removed. The stump was whipstitched to provide further traction, and the hypertrophied portion of the tendon was excised. An open tendon stripper was implemented to exercise both limbs of the semitendinosus. The subcutaneous tissue and skin were closed, and an incisional wound vac was placed.
Discussion/Conclusion:
Distal avulsion tears of semitendinosus tendons can lead to unsatisfactory results with conservative treatment, with delayed RTS and recurrence of symptoms. Resection of hamstring tendon tissue may eliminate the recurrence of injury, along with inflammation, fibrosis, and hemorrhage associated with retraction reinjuries.
Patient Consent Disclosure Statement:
The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
This is a visual representation of the abstract.
Video Transcript
The following is a video presentation describing a technique for open Hamstring Tendon Excision following a Distal Semitendinosus Avulsion Tear.
We have no relevant disclosures, and any potential conflicts of interest can be found at the American Academy of Orthopaedic Surgeons’ website.
In this video, we will provide a brief overview of distal semitendinous avulsion tears and a potential treatment technique. We will then discuss a case presentation, our postoperative management, and return-to-sport (RTS) guidelines, and finally review published outcomes.
Hamstring injuries are commonly considered the number one reason for delayed return to play and RTS across several sport disciplines. 1 Traditionally, they are treated conservatively. Among hamstring injuries, 32% to 37% involve the semitendinosus tendon. 6
The mechanism behind different hamstring injuries can vary significantly. Muscle belly injuries are more likely caused by concentric contraction, while proximal and distal avulsion tears are likely initiated by eccentric overload. 3 Specifically, distal semitendinosus avulsion tears, the injury affecting our patient, are commonly observed in elite athletes.3,4 Magnetic resonance imaging (MRI) and intraoperative photographs from a published case report of such an injury are shown to the right.
To review treatment options for distal semitendinosus tears, we begin with a retrospective review from Cooper and Conway. 2 They found that surgical recovery significantly expedited athlete return to play, from 17 weeks down to 7 weeks, compared with patients who underwent more conservative treatment options.
One potential explanation behind this phenomenon is conservative treatment does not address the disrupted length-tendon relationship, which can cause hamstring re-injury. Furthermore, tendon excision can potentially prevent aberrant scarring, thereby reducing delay in RTS. The surgical technique we demonstrate is a modification of the hamstring excision technique, described by Rebolledo and Cooper. 4
In this case presentation, a 47-year-old male patient presented with 5 months of left knee pain following an injury, while running down the sideline of a high school football game. The patient reported that he noticed a sharp posterior knee pain, swelling, and subsequent calf pain at the time of the injury. At presentation, he rated his pain as 5 out of 10 with movement and rated his total knee function as 20% of normal.
Physical examination of the left knee and distal posterior thigh was notable for 2+ tenderness to palpation of the distal hamstring tendon, 4+/5 hamstring strength, and a palpable mass just proximal to the posterior knee flexion crease. Of note, the patient endorsed pain with hamstring activation.
Operative indications for tendon excision include patients with distal semitendinosus avulsions tear with retraction, especially patients who had already failed conservative management. Elite athletes with distal hamstring tears who have experienced a delayed RTS or desired activity level should also be considered for distal hamstring excision.
Standard knee radiographs were obtained and demonstrated well-preserved medial, lateral, and patellofemoral joint space. No fractures or foreign bodies were noted. Axial T2 MRI confirmed a distal hamstring tear with retraction showing injury to the semitendinosus tendon with surrounding scar formation. The yellow box highlights the injured tendon, as it runs proximal to distal. The distal hamstring tear was again visualized on sequential sagittal and coronal images. Given the patient's symptoms and clinical findings, he was indicated for open excision of distal semitendinosus tendon with ultrasound localization.
In the operating room, the patient was placed in the prone position. Under ultrasound visualization, the anatomical structures of the posterior aspect of the knee and distal thigh were evaluated. The stump of the semitendinosis was identified and marked. A distal 4-cm incision, which was longitudinal in line with the semitendinosus, was made over the posterior knee at the measured level of the avulsed tendon stump, 2 cm proximal to the knee flexion crease. Blunt dissection was used for the subcutaneous layers, and the overlying hypertrophic and fibrotic tendon sheath was sharply incised. Care was taken to identify and preserve the gracilis tendon and the saphenous nerve, which is at risk with this approach.
The torn and retracted tendon tissue was exteriorized. Notably, it was bulbous and significantly hypertrophied to approximately 3 times its normal width. An allis clamp was used to provide tension on the distal semitendinosus, and mobilization of the avulsed tendon was performed. Sheath tissue surrounding the injured tendon was removed. This step is crucial as it decreases the likelihood of truncation of the tissue once the tendon stripper is utilized in subsequent steps. The stump was whipstitched to provide further traction, and the hypertrophied portion of the tendon was then excised.
The residual tendon tissue split longitudinally. Because of the extensive tendinosis and hypertrophy of the tissue, we extended the longitudinal split to facilitate removal of the large volume of tissue. This tendon had an unusually large diameter of 10 mm. Typically, the tendon tissue can be resected with a single whipstitch and passed with the tendon stripper.
#2 polyester suture was utilized to throw 2 whipstitches through the bifurcated tissue. An open tendon stripper was implemented to excise both limbs of the semitendinosus. The entirety of the tendon and intramuscular portion can be visualized on the mayo stand. The subcutaneous tissue was closed with 2-0 Vicryl, and skin was closed with vertical mattress 3-0 nylon sutures. An incisional wound vac was placed, to prevent seroma formation, close dead space, and facilitate wound healing.
Four tips and tricks will ensure successful completion of the procedure. First, ultrasound should be implemented to precisely locate the semitendinosus tendon stump to decrease the incision length. It is important to not cross the knee flexion crease perpendicularly to prevent soft tissue contracture. Second, it is critical to ensure surrounding tendon sheath and scar tissue is removed, prior to tendon stripping. This will reduce the likelihood of tissue truncation. Next, with larger tendons that may have bifurcated, consider whipstitching twice and undergoing a 2-step excision process. Finally, wound vac implementation can help reduce the high risk of dehiscence and subsequent infection associated with posterior knee incisions.
Postoperatively, patients are immobilized with a wound vac for the first 1 to 2 days. Mobilization begins on days 3 to 5 with a wound check by 1 week. Active and passive read-only memory is initiated by 2 weeks postoperatively. Sport-specific training can begin as early as 2 months postoperatively, with a RTS when the patient is pain-free.
Currently, the patient is 3 months postoperative and reports significant improvement in pain and overall function. He resumed coaching and normal activities within 2 months after surgery.
Outcome data following treatment of distal hamstring excision are extremely limited. In a case series of 10 patients with hamstring injuries, Sonnery-Cottet et al. 5 reported positive outcomes with operative intervention for recurrent hamstring injury. Inclusion criteria included athletes who had failed at least 3 months of conservative treatment for a recurrent musculotendinous hamstring injury. Among these 10 patients, 4 had distal semitendinosus injuries, which were treated by distal tenotomy with a stripping device—in a similar fashion shown in this video technique. Within this subgroup of 4 patients, there was an average return to play of 3.5 months. At a mean follow-up of 28.7 months, none of the athletes had suffered a recurrence, and no surgical complication was encountered.
In conclusion, distal avulsion tears of semitendinosus tendons may lead to unsatisfactory results with conservative treatment, with delayed RTS and recurrence of symptoms. Resection of hamstring tendon tissue may eliminate recurrence of injury, along with inflammation, fibrosis, and hemorrhage associated with retraction reinjuries. Furthermore, excision may allow the muscle to heal to the adjacent muscle bellies in a tension-free manner, promoting more optimal recovery and function.
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Footnotes
Submitted May 4, 2023; accepted April 29, 2023.
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. 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.
