Surgical treatment of distal hamstring tendon injuries yield a higher return-to-sports rate: A systematic review.

PURPOSE: The purpose of this study is to compare the patient-reported outcomes and return to sports of the conservative and surgical treatment of distal hamstring tendon injuries. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, two reviewers searched PubMed, Scopus and Virtual Health Library databases in January 2023. Clinical studies evaluating conservative or surgical management outcomes of distal hamstring tendon injuries were considered eligible for this systematic review if predefined criteria were fulfilled: (1) published in English or Spanish; (2) evaluated any of the following: patient-reported outcomes, return-to-sports rate (RTS-R) or return-to-sports time (RTS-T). Data were presented in tables using absolute values from individual studies and derived pooled percentages. RESULTS: Eighteen studies were included for 67 patients and 68 distal hamstring tendon injuries. Initially, 39 patients (58.2%) underwent surgical treatment, whereas 28 (41.8%) were treated conservatively. Among conservative treatment patients, 15 failed and had to be operated on (53.6%), all with distal semitendinosus tendon injuries. Anchor fixation was the technique of choice in 20 lesions (36.4%), tenodesis in 16 (29.1%), tenectomy in 14 (25.5%) and sutures were preferred in five (9%). Thirteen out of 28 patients (46.4%) undergoing initial conservative treatment returned to sports at a mean of 3.6 months (range 1 week to 12 months), in contrast to surgical treatment, in which 36 out of 39 patients (92.3%) returned at a mean of 4.2 months (range 6 weeks to 12 months). Additionally, 14 of 15 patients (93.3%) converted to surgical treatment after failed conservative treatment returned to sports at a mean of 7.6 months after injury. CONCLUSION: Initial surgical treatment of distal hamstring tendon injuries yields a high RTS-R (92.3%) at a mean of 4.2 months. Furthermore, 15 out of 28 patients (53.6%) initially treated conservatively had to be operated on, delaying the RTS-T (mean 7.6 months after injury) without affecting their RTS-R. LEVEL OF EVIDENCE: IV.

No difference in clinical outcomes between operative and nonoperative management of minimally retracted proximal hamstring ruptures.

PURPOSE: The indications for surgical treatment of proximal hamstring ruptures are continuing to be refined. The purpose of this study was to compare patient-reported outcomes (PROs) between patients who underwent operative or nonoperative management of proximal hamstring ruptures. METHODS: A retrospective review of the electronic medical record identified all patients who were treated for a proximal hamstring rupture at our institution from 2013 to 2020. Patients were stratified into two groups, nonoperative or operative management, which were matched in a 2:1 ratio based on demographics (age, gender, and body mass index), chronicity of the injury, tendon retraction, and number of tendons torn. All patients completed a series of PROs including the Perth Hamstring Assessment Tool (PHAT), Visual Analogue Scale for pain (VAS), and the Tegner Activity Scale. Statistical analysis was performed using multi-variable linear regression and Mann-Whitney testing to compare nonparametric groups. RESULTS: Fifty-four patients (mean age = 49.6 ± 12.9 years; median: 49.1; range: 19-73) with proximal hamstring ruptures treated nonoperatively were successfully matched 2:1 to 27 patients who had underwent primary surgical repair. There were no differences in PROs between the nonoperative and operative cohorts (n.s.). Chronicity of the injury and older age correlated with significantly worse PROs across the entire cohort (p < 0.05). CONCLUSIONS: In this cohort of primarily middle-aged patients with proximal hamstring ruptures with less than three centimeters of tendon retraction, there was no difference in patient-reported outcome scores between matched cohorts of operatively and nonoperatively managed injuries. LEVEL OF EVIDENCE: Level III.

Modified surgical anchor refixation in older patients with acute proximal hamstring rupture: clinical outcome, patient satisfaction and muscle strength.

INTRODUCTION: After conventional surgical refixation of the hamstrings after proximal hamstring rupture, patients frequently experience pain while sitting and deficits in hamstring muscle strength of the operated side. To improve these outcomes, we have modified the surgical anchor placement and have carried out a thorough follow-up examination. MATERIALS AND METHODS: Thirteen older patients (8 female, 5 males) with a median age of 64.2 (range, 52.1-80.4) years were surgically treated for acute proximal hamstring rupture using modified anchor placement and participated in a follow-up assessment at a median of 46.2 (11.2-75.0) months after surgery. Patients completed the Perth Hamstring Assessment Tool (PHAT), quality of life questionnaire (EQ-5D-5L) and the Lower Extremity Functional Scale (LEFS), and rated their satisfaction level on a scale from 0 to 100%. Local tenderness on the ischial tuberosity and maximum passive hip flexion were measured on both limbs. Maximum isokinetic knee flexor muscle strength was measured bilaterally using a dynamometer. RESULTS: The median (range) PHAT, EQ-5D-5L and LEFS score were 78.8/100 (54.6-99.8), 0.94/1 (0.83-1) and 88.75/100 (61.25-100). The median satisfaction was 100% (90-100%). Only one patient felt discomfort when the ischial tuberosity was palpated. Neither maximum passive hip flexion nor maximum isokinetic flexor muscle strength differed between the operated and non-operated side (P > 0.58). Clinical scores did not correlate with the leg symmetry index of knee flexor muscle strength (Spearman's rho < 0.448, P > 0.125). There were no tendon re-ruptures, or postoperative sciatic radiculopathy, at the time of follow-up. CONCLUSIONS: The modified extra-anatomical anchor placement resulted in good clinical and functional outcome of surgical repair of acute proximal hamstring rupture. Especially the absence of postoperative pain while sitting and the comparable muscle strength to the contralateral side is promising. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04867746, registered.

Anatomical retraction of the semitendinosus muscle following harvest of the distal semitendinosus tendon for ACL reconstruction.

PURPOSE: Retraction of semitendinosus muscle has been reported after reconstruction of the anterior cruciate ligament with semitendinosus/gracilis-graft. However, very little data exist on the natural variation in side-to-side length symmetry. The purpose of this study was to investigate the side-to-side asymmetry of semitendinosus muscle length in individuals with ACL reconstruction (ACLR) using the semitendinosus/gracilis-graft compared to a group of healthy control subjects to establish the level of retraction that can confidently be ascribed the surgery. METHODS: Eleven subjects aged 30 (19-39) years, with previous unilateral ACLR with the combined semitendinosus/gracilis tendon graft were recruited. Average follow-up was 6.8 years (0.3-13.0) after reconstruction. Ten healthy subjects aged 30 years (23-36) with no previous knee surgery served as controls. Bilateral magnetic resonance imaging (MRI) scans were obtained of the thigh from 60 mm below the knee joint and 700 mm proximal to this point with a slice thickness of 5 mm with 5 mm inter-slice distance. Semitendinosus length was measured on both legs between the distal and proximal musculotendinous junction of the semitendinosus. Length difference between legs was calculated for all participants. Percentage of shortening was expressed relative to the healthy leg. RESULTS: Subjects who had undergone ACLR had on average 81 mm (25%) shortening of the semitendinosus on the reconstructed leg compared to the non-reconstructed side. The healthy subjects all had less than 10 mm difference between legs (< 3%). The side-to-side difference was significantly different between the reconstructed patients and the healthy subjects (p < 0.001). CONCLUSION: This study indicates that retraction larger than 10 mm is a consequence of the tendon harvest and not natural variation. It also supports that persistent retraction of the semitendinosus muscle occurs following harvest of the semitendinosus tendon for ACL graft. LEVEL OF EVIDENCE: Level IV.

Differences in cellular and microstructural properties of the semitendinosus muscle tendon between young and adult patients.

BACKGROUND: Poor outcomes associated with anterior cruciate ligament reconstruction in paediatric patients are a major concern. The tendon structure and its cellular characteristics are key factors that affect the mechanical properties of tendons. This study aimed to evaluate the effects of growth on the cellular and microstructural properties of the tendon of the semitendinosus muscle in humans. METHODS: Semitendinosus muscle tendon samples from 76 patients who underwent ligament reconstruction were examined and divided into three groups: immature (10.8 ± 2.7 years old), young (16.5 ± 1.8 years old), and adult (35.2 ± 8.6 years old), based on age and the state of the epiphyseal plate in the distal femur. The number of tendon cells per unit area was assessed, and the major-to-minor-length ratio of the tendon cell nuclei was calculated to evaluate the shape of the nuclei using haematoxylin and eosin staining. The collagen fibril diameter and distribution were determined using electron microscopy. RESULTS: The major-to-minor-length ratio of the tendon cell nuclei significantly increased with age (p-value; immature vs. young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The shape of the tendon cell nuclei was rounder in the immature group and more elongated in the adult group. A significant decrease in the number of tendon cells was observed with age (immature: 565 ± 134/mm2, young: 356 ± 105/mm2, adult: 272 ± 81/mm2; p-value: immature vs young: 0.001, young vs adult: 0.012, immature vs adult: 0.001). The mean fibril diameter in the immature group was significantly smaller (p-value: immature vs young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The distribution of the collagen fibrils changed from right skewed in the immature group to flat in the adult group. CONCLUSIONS: The characteristics of the tendon cells and the microstructure of collagen in muscle tendons significantly changed with age.

Proximal sciatic neuropathy secondary to hamstring tendon avulsion.

We herein present the exceptional case of a patient, who injured a sciatic nerve due to avulsion of proximal hamstring tendon in a motorcycle accident. The 63-year-old man was diagnosed firstly with an incomplete fracture of distal femur. A foot drop on the right side was observed when the full-length cast was removed two months later. The patient was referred to the neurology clinic and was diagnosed with a sciatic nerve lesion at the proximal level of the biceps femoris. Magnetic resonance imaging of the thigh showed a proximal avulsion of hamstring muscles tendon. The patient did not improve by short-term physiotherapy and neurosurgical intervention. Sciatic nerve injury can be a result of proximal hamstring avulsion in events such as motorcycle accidents even in the absence of complete or major femur fracture.

Proximal Hamstring Tendon Injuries: Diagnosis and Management.

Proximal hamstring tendon injuries are common among active and athletic populations and exist on a spectrum ranging from proximal tendinopathy to partial tears to complete avulsions. Imaging should include plain radiography as bony avulsions have been observed in skeletally immature patients. Magnetic resonance imaging is diagnostic in the setting of both partial tears and complete tears. A high-intensity (on T2-weighted images), crescent-shaped signal at the tendon-bone interface ("sickle sign") is indicative of a partial-thickness tear of the proximal hamstring tendons. In the setting of complete avulsions, magnetic resonance imaging is also useful in demonstrating the extent of tendon avulsion and quantifying the number of tendons torn. Nonoperative treatment for proximal tendinopathy, acute partial tears, and complete tears with minimal tendon retraction includes activity modification, eccentric stretching and strengthening, and potentially platelet rich plasma injections. Surgical repair should be considered for partial tears refractory to nonoperative management, acute tears with greater than 2 cm of distal retraction, and/or chronic retracted tears. The surgical approach is generally made through a transverse incision within the gluteal crease, which can be extended distally in a "T" configuration in the setting of chronic retracted tears. In the setting of chronic retracted tears, a sciatic nerve neurolysis may be required owing to scarring. Following the surgical procedure, a graduated rehabilitation protocol is commenced with the expectation for a return to full, unrestricted activities by 6 months postoperative, and excellent outcomes can be anticipated. Compared with repair of chronic tears, acute repairs have improved functional outcomes and lower re-tear rates.

The identification and treatment of snapping posterior tendons of the knee improves patient clinical outcomes.

PURPOSE: To assess the most common presenting symptoms, clinical outcomes, and patient satisfaction following treatment of either snapping medial pes anserinus hamstrings or snapping lateral biceps femoris tendons. METHODS: Consecutive patients with a minimum 2-year follow-up after isolated medial hamstring release for a diagnosis of medial snapping pes anserinus tendons or patients treated with primary biceps repair for lateral snapping biceps femoris tendons were evaluated. Clinical outcome scores of the following domains were collected: SF12, WOMAC score, Lysholm Knee Survey, and a simple numeric patient satisfaction score (0-10). Statistical analysis was performed with paired t-tests between preoperative and postoperative scores. RESULTS: At an average follow-up of 4.6 years (range 2.0-8.6 years) with two patients lost to follow-up, six consecutive patients (three male, three female) with seven knees were diagnosed with medial snapping pes anserinus tendons and treated with semitendinosus and gracilis tenotomies. Seven knees in seven patients (three male, four female) were diagnosed with lateral snapping biceps femoris tendons and were treated with an isolated biceps femoris repair. Nine of 13 patients were able to return to full desired activities/pre-operative level of sporting activities (4/6 medial, 5/7 lateral. Lysholm and SF-12 scores improved from preoperative to post-operative status for patients with snapping biceps femoris. Only patients undergoing primary biceps repair showed improvement across all WOMAC domains. Patients with medial hamstring tenotomy demonstrated improvement in Lysholm scores. Median postoperative satisfaction for both pathologies was 7 out of 10. CONCLUSION: Medial hamstring release for snapping pes anserinus and isolated biceps repair for lateral snapping biceps femoris yields improvement in patient satisfaction and clinical outcomes at mid-term follow-up. LEVEL OF EVIDENCE: IV.

No significant histological or ultrastructural tendinosis changes in the hamstring tendon in patients with mild to moderate osteoarthritis of the knee?

PURPOSE: To investigate the periarticular degenerative changes of the knee joint in association with osteoarthritis (OA). More tendinosis was expected to be found in the semitendinosus tendon in patients with knee OA than in patients without knee OA. METHODS: Samples from 41 patients were included between January 2016 and October 2017. Twenty-one patients median age 53 (33-63) years with mild to moderate OA underwent high tibial osteotomy (HTO) and 20 patients median age 38 (31-57) years without OA underwent anterior cruciate ligament reconstruction (ACLR). Biopsies from the semitendinosus tendon were obtained at the time of surgery and examined histologically, morphologically and ultrastructurally using light and electron microscope. RESULTS: The histological evaluation of the semitendinosus tendon revealed the presence of more hemosiderin in the ACLR group. No significant morphological or ultrastructural differences were shown between patients in the HTO and ACLR group. CONCLUSION: Patients with mild and moderate medial compartment knee OA displayed no more degenerative changes in their semitendinosus tendon than patients without OA, as seen in both the light and the electron microscope. LEVEL OF EVIDENCE: III.

[Clinical results after refixation of proximal hamstring tendon ruptures comparing different anchor systems]. / Klinische Ergebnisse nach Refixation proximaler Hamstring-Sehnen-Rupturen unter Berücksichtigung verschiedener Ankersysteme.

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.

Excellent clinical outcome and low complication rate after proximal hamstring tendon repair at mid-term follow up.

PURPOSE: Proximal hamstring tendon avulsions lead to a significant loss of strength and a functional deficit of the respective lower limb and surgery is the recommended treatment. Only little is known about the clinical outcomes and complications when comparing acute and chronic management as well as partial and complete tears. Therefore, the purpose of this study was to investigate the clinical results and the complication rate of patients after surgical treatment of proximal hamstring tendon injuries. It was hypothesized that surgical treatment of an acute proximal hamstring avulsion would lead to a superior clinical outcome with a low complication rate and high return to sports rate compared to chronic cases and partial avulsions. METHODS: Patients who underwent proximal hamstring tendon repair between 2008 and 2015 were retrospectively evaluated with a minimum follow up of 2 years. Outcome measurements were obtained by means of Lysholm score, Harris Hip Score, Visual Analog Scale, and Tegner Activity Scale. Return to sports (RTS) rate was determined. Postoperative adverse events were recorded and complications reported. Patients' outcomes were compared between acute/chronic repair and partial/complete injury patterns. RESULTS: Ninety-four of 120 (78.3%) were available for final assessment at a mean follow-up of 56.2 ± 27.2 months. Clinical outcome measures were excellent and did not differ between the treatment groups or between the different injury patterns. RTS was achieved by 86.2% of the patients and was significantly superior after acute treatment (p < 0.05). The overall complication rate was 8.5% and significantly higher in complete tears compared to partial tears and in delay compared to acute surgery (p < 0.05). CONCLUSION: Surgical treatment of proximal hamstring tendon avulsions results in excellent clinical outcome scores and a high RTS rate. Open surgical treatment has shown to be a safe procedure with a low complication rate. Surgical timing is important, as early surgical intervention provides a higher RTS rate and a lower complication rate than delayed surgery and should therefore be preferred in clinical practice. Repair of partial and complete tears lead to similar clinical outcome, but a higher complication rate in complete avulsions. LEVEL OF EVIDENCE: Level IV.

Comparison of the Results of Primary Versus Repeat Hamstring Surgical Lengthening in Cerebral Palsy.

BACKGROUND: Hamstring surgical lengthening (HSL) has been frequently performed for the correction of knee flexion deformity in cerebral palsy (CP), although recurrence is described in long-term follow-up. Repeat hamstring surgical lengthening (RHSL) can be an option for recurrent knee flexion deformity; however, the results of this approach are still controversial. The purpose of this study was to compare the results of primary HSL and RHSL in CP. METHODS: Patients with spastic diplegic CP, Gross Motor Function Classification System levels I to III, underwent bilateral medial HSL with complete documentation in the gait laboratory before and after the intervention, were included in the study. A total of 229 subjects met the inclusion criteria and were divided into 2 groups: group A was formed by those who received medial HSL for the first time (185 patients), and group B was composed of individuals who underwent RHSL (44 patients). Clinical and kinematic parameters were evaluated before and after the intervention, and the results compared. RESULTS: The groups were matched with regard to sex distribution, Gross Motor Function Classification System levels, and follow-up time (>2 y). Popliteal angle was reduced in groups A (60.3 to 51.4 degrees, P<0.001) and B (56.1 to 51.5 degrees, P=0.001) after the intervention. Knee flexion at initial contact was reduced from 40.8 to 28.9 degrees in group A (P<0.001) and from 40.4 to 35.1 degrees in group B (P=0.001). Reduction of minimum knee flexion in the stance phase (24.9 to 17.5 degrees, P<0.001) and improvement of the Gait Deviation Index (52.9 to 60.2, P<0.001) occurred only in group A. Anterior pelvic tilt (APT) increased in groups A (from 17 to 19.5 degrees, P<0.001) and B (from 14.9 to 19.4 degrees, P<0.001) after treatment. Finally, in the comparison between groups, the reduction of knee flexion at initial contact was more significant in group A (P<0.001), whereas the increase of APT was higher in group B. CONCLUSIONS: In the present study, the improvement of knee extension during the stance phase was observed only after the primary medial HSL. Moreover, the increase of APT was more significant when RHSL was performed. LEVEL OF EVIDENCE: Level III.

Long-term muscle changes after hamstring lengthening in children with bilateral cerebral palsy.

AIM: To evaluate short-term (1y postoperatively; E1) and long-term (at least 4y postoperatively; E2) changes in hamstring muscle-tendon length (MTL) and lengthening velocity after hamstring lengthening in children with bilateral cerebral palsy (CP). METHOD: Three-dimensional gait analysis was performed in 19 children (16 males, 3 females; 36 limbs; mean age at surgery 9y [SD 3y]; range 6-10y) with flexed knee gait, preoperative ankle dorsiflexion lower than 20 degrees, and CP before bilateral hamstring lengthening (E0), at E1 and E2. Hamstring MTL (normalized by leg length) and velocity were assessed via OpenSim software. RESULTS: MTL increased from E0 to E1 (p=0.004) and decreased from E1 to E2 (p<0.020). Hamstring lengthening velocity did not change. In the subgroup with short, not slow hamstrings, the increase in MTL was maintained at E2. INTERPRETATION: Hamstring lengthening is an efficient procedure to lengthen short and/or slow hamstrings short-term. The desired outcome with maintenance of the postoperative changes in hamstring MTL is only achieved for preoperatively short, not slow hamstrings. WHAT THIS PAPER ADDS: Surgical hamstring lengthening can be confirmed via musculoskeletal modelling in OpenSim software. Surgical hamstring lengthening in cerebral palsy does not change hamstring lengthening velocity. Short, not slow hamstrings present a long-lasting muscle-tendon length (MTL) increase after hamstring lengthening. Changes in MTL after hamstring lengthening cannot be maintained for slow hamstrings. MTL does not change after hamstring lengthening for neither short nor slow hamstrings.

CAMBIOS MUSCULARES A LARGO PLAZO DESPUÉS DEL ALARGAMIENTO DE LOS ISQUIOTIBIALES EN NIÑOS CON PARÁLISIS CEREBRAL BILATERAL: OBJETIVO: Evaluar los cambios a corto plazo (un año después de la operación; E1) y a largo plazo (al menos cuatro años después de la operación; E2) de la longitud del tendón muscular de los isquiotibiales (LT) y la velocidad de alargamiento después del estiramiento en niños con parálisis cerebral bilateral (PC). MÉTODO: Se realizó un análisis tridimensional de la marcha en 19 niños (16 varones, tres mujeres; 36 extremidades; edad media en la cirugía 9 años [DS 3 años]; rango 6-10 años) con la marcha en flexión de la rodilla, dorsiflexión preoperatoria del tobillo inferior a 20 grados, antes del alargamiento bilateral de los isquiotibiales (E0), en E1 y E2. El LT de los músculos isquiotibiales (normalizado por la longitud de la pierna) y la velocidad fueron evaluadas mediante el OpenSim. RESULTADOS: El LT aumentó de E0 a E1 (p = 0,004) y disminuyó de E1 a E2 (p<0,020). La velocidad de alargamiento de los isquiotibiales no cambió. En el subgrupo con isquiotibiales cortos, pero no lentos, el aumento de la LT se mantuvo en E2. INTERPRETACIÓN: El alargamiento de los isquiotibiales es un procedimiento eficiente para los isquiotibiales cortos y/o lentos a corto plazo. El resultado deseado con el mantenimiento de los cambios postoperatorios en la longitud de los isquiotibiales solo se logra para los isquiotibiales cortos no lentos antes de la operación.

ALTERAÇÕES MUSCULARES A LONGO PRAZO APÓS ALONGAMENTO DE ISQUIOTIBIAIS EM CRIANÇAS COM PARALISIA CEREBRAL BILATERAL: OBJETIVO: Avaliar a curto (um ano de pós-operatório; E1) e longo prazo (no mínimo quatro anos de pós-operatório; E2) alterações no comprimento do tendão do músculo (CTM) isquiotibial e a velocidade de estiramento após alongamento do isquiotibial em crianças com paralisia cerebral bilateral (PC). MÉTODO: Foi realizada a análise tridimensional da marcha em 19 crianças (16 meninos, três meninas; 36 membros; média de idade de cirurgia de 9 anos [DP 3 anos]; variação de 6-10 anos) com marcha com flexão de joelho, ângulo de dorsiflexão de tornozelo menor que 20o no pré-operatório, e PC antes do alongamento bilateral dos isquiotibiais (E0), em E1 e E2. CTM dos isquiotibiais (normalizado pelo comprimento da perna) e a velocidade foram avaliados pelo OpenSim. RESULTADOS: CTM aumentou de E0 para E1 (p=0,004) e diminuiu de E1 para E2 (p<0,020). A velocidade de estiramento do isquiotibial não mudou. No subgrupo com isquiotibial encurtado e não lento, o aumento no CTM foi mantido em E2. INTERPRETAÇÃO: O alongamento do músculo isquiotibial é um procedimento eficiente para alongar isquitotibiais encurtados e/ou lentos a curto prazo. O resultado desejado com a manutenção das alterações no pós-operatório no CTM do isquiotibial é atingida somente para isquiotibial curto e não lento no pré-operatório.

Abduction in Proximal Hamstring Tendon Avulsion Injury Mechanism: A Report on 3 Athletes.

Proximal hamstring tendon avulsions are typically sustained during forced hip hyperflexion combined with knee extension. We present 3 cases of athletes with a proximal hamstring tendon avulsion caused by an alternative injury mechanism that also involves a considerable hip abduction component (flexion-abduction injury mechanism). All cases had at least one concurrent injury of the medial thigh muscles, either on the ipsilateral or contralateral side. The 2 elite athletes with this injury mechanism returned to sport at preinjury level relatively quickly. A history of the flexion-abduction mechanism should raise suspicion of a hamstring tendon avulsion with concomitant injury of the medial thigh muscles. The magnetic resonance imaging (MRI) protocol should include both legs, and any concurrent injury may need to be addressed as well. In future studies, it would be interesting to investigate whether injury mechanism holds prognostic value in proximal hamstring tendon avulsions.

Anatomy of proximal attachment, course, and innervation of hamstring muscles: a pictorial essay.

Hamstring injuries are very common in sports medicine. Knowing their anatomy, morphology, innervation, and function is important to provide a proper diagnosis, treatment as well as appropriate prevention strategies. In this pictorial essay, based on anatomical dissection, the detailed anatomy of muscle-tendon complex is reviewed, including their proximal attachment, muscle course, and innervation. To illustrate hamstrings' role in the rotational control of the tibia, the essay also includes the analysis of their biomechanical function.Level of evidence V (expert opinion based on laboratory study).

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.

Reconstruction of chronic proximal hamstring avulsion injuries using ipsilateral distal hamstring tendons results in good clinical outcomes and patient satisfaction.

PURPOSE: To report outcomes following proximal hamstring reconstruction employing an ipsilateral distal hamstring tendon autograft, in patients with chronic proximal ruptures. METHODS: Six patients presenting with a chronic proximal hamstring avulsion and a medial time from injury of 11.0 months (range 7-18), confirmed via magnetic resonance imaging, underwent proximal hamstring repair using a free graft harvested from the ipsilateral distal hamstrings. Patients were evaluated at 6, 12 and 24 months post-surgery, via the Perth Hamstring Assessment Tool, the Short Form Health Survey, the Lower Extremity Functional Scale, a Patient Satisfaction Questionnaire, the Active Knee Extension and 6 min walk tests, the single and triple hop tests for distance, and isokinetic knee extensor and flexor strength. Knee strength was assessed at 180° and 240°/s (total work, peak and average torque), and both mean absolute scores and limb symmetry indices (LSIs) comparing the operated and non-operated limbs were presented. RESULTS: Patients demonstrated good clinical improvement throughout the post-operative timeline in all subjective and objective outcomes. Mean knee extensor LSIs had recovered by 12 and 24 months. At 24 months post-surgery, while mean LSIs for knee flexor peak and average torque were at (or above) 90%, a significant difference still existed between the operated and non-operated limbs in knee flexor total work. At 24 months, five patients (83%) were satisfied with the results of the surgery, as well as their ability to return to recreational and sporting activities. There were two adverse events including an early deep vein thrombosis and a secondary surgery to remove a loosened staple. CONCLUSIONS: While isokinetic hamstring strength had not fully recovered by 24 months, this surgical technique demonstrated a high level of patient satisfaction and return to function, in patients with chronic proximal hamstring ruptures. As the clinical relevance, this surgical technique provides a viable option with good post-operative outcomes for patients with chronic proximal hamstring tears that cannot be approximated back to the ischium. LEVEL OF EVIDENCE: IV.

Patient-determined outcomes after arthroscopic rotator cuff repair with and without biceps tenodesis utilizing the PITT technique.

HYPOTHESIS AND BACKGROUND: The percutaneous intra-articular transtendon technique (PITT) is a simple, rapid, and low-cost method of performing a biceps tenodesis. Few studies exist that examine the patient-determined outcomes of this technique in general or in patients undergoing arthroscopic rotator cuff repair (RCR) with and without biceps tenodesis. We hypothesized that patients undergoing an isolated arthroscopic RCR would have equivalent outcomes to those undergoing RCRs with PITT biceps tenodesis. METHODS: We compared preoperative, patient-determined outcomes scores on patients undergoing primary arthroscopic RCR with and without a PITT biceps tenodesis with postoperative scores at a minimum of 2 years. These scores included the Western Ontario Rotator Cuff score (WORC), American Shoulder and Elbow Surgeons score (ASES), Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test (SST), and Shoulder Activity Level (SAL). Indication for a concomitant biceps tenodesis was a partial long head biceps tendon tear or biceps instability/subluxation. RESULTS: A total of 153 patients underwent an isolated RCR and 131 patients underwent RCR with biceps tenodesis (RCRBT). Both groups had improvements in WORC, ASES, SANE, and SST (P < .0001) and deteriorations in the SAL (P ≤ .005). There was no difference in the change in outcome scores between the groups (RCRBT vs. RCR, respectively) for WORC (46 vs. 47; P = .85), ASES (46 vs. 47; P = .82), SANE (53 vs. 51; P = .35), SST (5.8 vs. 5.8; P = .93), and SAL (-0.9 vs. -1.4; P = .46). There was no difference between the groups in complications that required revision surgery (1.5% vs. 1.3%; P = .91). CONCLUSIONS: Arthroscopic PITT RCRBT is safe and effective with equivalent patient-determined outcomes compared with patients undergoing RCR without biceps tenodesis.

Prediction of quadriceps strength recovery after anterior cruciate ligament reconstruction with a hamstring autograft: Decision tree analysis.

BACKGROUND: The wide variations in patient demographics and concomitant injuries make the prediction of which patients will regain strength quickly following anterior cruciate ligament (ACL) reconstruction challenging. This study aimed to identify the dominant factor affecting quadriceps strength recovery after ACL reconstruction with a hamstring tendon autograft and to construct a predictive model for quadriceps strength recovery using decision tree analysis. METHODS: Three hundred and eighty-six patients who underwent ACL reconstruction with a hamstring tendon autograft were included in this study. The isokinetic quadriceps strength at 60°/s was measured preoperatively and at 6 months after surgery. The quadriceps strength index (QSI) was calculated by normalising the peak torque of the involved leg with the uninvolved leg and multiplying it by 100. A stepwise multiple linear regression and a decision tree analysis were performed to assess whether or not the following parameters affect quadriceps strength recovery at 6 months: socio-demographic data and maximum isokinetic quadriceps strength. RESULTS: The preoperative QSI, age, and pre-injury Tegner activity scale were independently correlated with quadriceps strength recovery at 6 month after surgery. The decision tree analysis demonstrated that patients were expected to have a QSI ≥85% at 6 months after surgery if they met one of the following conditions: (1) age <23 years with a preoperative QSI ≥78.8%, (2) age ≥29 years with a preoperative QSI ≥98.0%, or (3) age <16 years with a preoperative QSI <58.5% and pre-injury Tegner activity scale ≥9. By contrast, patients ≥29 years with a preoperative QSI <98.0% were likely to achieve a quadriceps strength index <70% at 6 months after surgery. CONCLUSIONS: Based on the results of the decision tree analysis, younger patients could achieve good quadriceps recovery even if they have a lower preoperative QSI, whereas patients ≥29 years need a higher preoperative QSI to obtain good muscle recovery.

Bilateral snapping biceps femoris tendon: a case report and review of the literature.

Snapping biceps femoris tendon is an uncommon cause of lateral knee pain. We report the case of a 15-year-old athlete with bilateral snapping biceps femoris tendons, painful over his right lateral leg during exercise. He underwent elective exploration of the right knee which revealed an accessory biceps femoris tendon with attachment to the anterolateral tibia. The accessory tendon was released and reinserted onto the fibular head with a Krackow suture. There were no perioperative complications, and he returned to full sporting activities within 3 months. We describe the operative technique used and summarise the existing literature. Restoring the anatomy with release of the accessory tendon and reinsertion onto the fibular head is an effective technique in the management of knee pain due to snapping biceps femoris tendon. Other approaches include simple release of the anomalous tendon without reinsertion or partial resection of the fibular head. Partial resection of the fibular head is the only technique described in the literature with complication requiring a further operation on the same site. There remains a paucity of evidence in the literature regarding long-term outcomes required to inform the best operative approach. Further anatomical, intraoperative and radiological studies are required to delineate the true pathology of this condition.