Proximal hamstring tendon avulsion treatment choice depends on a combination of clinical and imaging-related factors: a worldwide survey on current clinical practice and decision-making

Proximal Hamstring Tendon Avulsions: A Survey of Orthopaedic Surgeons’ Current Practices in the Nordic Countries

Background and purpose

Evidence guiding the decision on whether to treat proximal hamstring tendon avulsions (PHA) operatively or non-operatively is very limited. The aim of this study was to identify the current practices and the rationale behind PHA treatment decisions in the Nordic countries.

Methods

A survey was sent to orthopaedic surgeons in Sweden, Norway, Finland and Denmark. The study population consisted of responding surgeons with exposure to surgical treatment of PHA (n = 125). The questions covered surgeon and unit characteristics, and surgeons’ understanding of the evidence for treatment, and they explored which patient and injury factors influence treatment allocation.

Results

Although some surgeons indicated a preference for one of the treatments, 84% stated that the treatment decision was based on patient and injury-related factors. Severe obesity, drug abuse, a sedentary lifestyle, age > 60 years and delayed diagnosis (> 6 weeks) were considered contraindications to surgical treatment. Also, there was agreement that patients expressing a preference for non-operative treatment should not be operated. Complete avulsions with tendon dislocation ≥ 2–3 cm on MRI were relative indications for surgical treatment.

The majority of surgeons did not believe that operatively treated patients did better than non-operatively treated patients and experienced that patients, generally, were satisfied with the treatment result, regardless of the type of treatment. Most surgeons had experienced significant complications to operative treatment.

Conclusion

Current practices varied among different units, and despite the lack of evidence for their prognostic value, several factors were inconsistently being used as decision modifiers when selecting patients for surgical treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00439-6.

Proximal hamstring tendon avulsions: comparable clinical outcomes of operative and non-operative treatment at 1-year follow-up using a shared decision-making model

OBJECTIVE

To prospectively evaluate 1-year clinical and radiological outcomes after operative and non-operative treatment of proximal hamstring tendon avulsions.

METHODS

Patients with an MRI-confirmed proximal hamstring tendon avulsion were included. Operative or non-operative treatment was selected by a shared decision-making process. The primary outcome was the Perth Hamstring Assessment Tool (PHAT) score. Secondary outcome scores were Proximal Hamstring Injury Questionnaire, EQ-5D-3L, Tegner Activity Scale, return to sports, hamstring flexibility, isometric hamstring strength and MRI findings including proximal continuity.

RESULTS

Twenty-six operative and 33 non-operative patients with a median age of 51 (IQR: 37-57) and 49 (IQR: 45-56) years were included. Median time between injury and initial visit was 12 (IQR 6-19) days for operative and 21 (IQR 12-48) days for non-operative patients (p=0.004). Baseline PHAT scores were significantly lower in the operative group (32±16 vs 45±17, p=0.003). There was no difference in mean PHAT score between groups at 1 year follow-up (80±19 vs 80±17, p=0.97). Mean PHAT score improved by 47 (95% CI 39 to 55, p<0.001) after operative and 34 (95% CI 27 to 41, p<0.001) after non-operative treatment. There were no relevant differences in secondary clinical outcome measures. Proximal continuity on MRI was present in 20 (95%, 1 recurrence) operative and 14 (52%, no recurrences) non-operative patients (p=0.008).

CONCLUSION

In a shared decision-making model of care, both operative and non-operative treatment of proximal hamstring tendon avulsions resulted in comparable clinical outcome at 1-year follow-up. Operative patients had lower pretreatment PHAT scores but improved substantially to reach comparable PHAT scores as non-operative patients. We recommend using this shared decision model of care until evidence-based indications in favour of either treatment option are available from high-level clinical trials.

Good Interrater Reliability for Standardized MRI Assessment of Tendon Discontinuity and Tendon Retraction in Acute Proximal Full-Thickness Hamstring Tendon Injury

BACKGROUND

Proximal full-thickness free hamstring tendon injury (ie, tendon avulsion or rupture) is a severe injury. Treatment decision making relies on clinical factors and magnetic resonance imaging (MRI) variables; it specifically relies on which tendons are injured as well as the extent of tendon retraction. According to a worldwide evaluation of current practice, discontinuity of both proximal tendons and retraction of >2 cm are used as surgical indications. However, both the diagnosis and the use of MRI variables in decision making may be fraught with uncertainty in clinical practice. A reliable standardized MRI assessment is required.

PURPOSE

To propose an MRI assessment for acute proximal full-thickness free hamstring tendon injury and to evaluate its interater reliability.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

We included 40 MRI scans of patients with acute (≤4 weeks of injury) proximal full-thickness free hamstring tendon injury. Three musculoskeletal radiologists assessed proximal full-thickness free hamstring tendon discontinuity using the novel "dropped ice cream sign" and tendon retraction (in mm). Quantification of tendon retraction (in mm) was performed using 2 different methods: (1) a direct (ie, shortest distance between the center of the hamstring origin and the tendon stump) method and (2) a combined craniocaudal/mediolateral measurement method. Absolute and relative interrater reliability were calculated.

RESULTS

We found an almost perfect interrater agreement (kappa = 0.87) for assessment of full-thickness tendon discontinuity using the dropped ice cream sign. Interrater agreement for the direct and craniocaudal retraction measurements was good for both the conjoint (intraclass correlation coefficient [ICC], 0.88 and 0.83) and the semimembranosus tendons (ICC, 0.81 and 0.79). The mediolateral retraction measurement yielded only moderate to poor reliability for the conjoint (ICC, 0.53) and semimembranosus tendons (ICC, 0.41).

CONCLUSION

The standardized MRI assessment to identify proximal hamstring tendon discontinuity and quantify tendon retraction is reliable. We recommend using the novel dropped ice cream sign and the direct retraction measurement in clinical practice and research.

Reliability of MRI in Acute Full-thickness Proximal Hamstring Tendon Avulsion in Clinical Practice

In clinically suspected acute full-thickness proximal hamstring tendon avulsions, MRI is the gold standard for evaluating the extent of the injury. MRI variables such as full-thickness free tendon discontinuity, extent of tendon retraction (>20 mm), and continuity of the sacrotuberous ligament with the conjoint tendon (STL-CT) are used in treatment decision-making. The objective was to assess the intra- and inter-rater reliability of these relevant MRI variables after acute full-thickness proximal hamstring tendon avulsion. Three musculoskeletal radiologists assessed MRIs of 40 patients with an acute full-thickness proximal hamstring tendon avulsion. MRI variables included assessment of free tendon discontinuity and continuity of the STL-CT and extent of tendon retraction. Absolute and relative intra- and inter-rater reliability were calculated. Intra- and inter-rater reliability for the assessment of tendon discontinuity was substantial (Kappa [ĸ]=0.78;0.77). For the retraction measurement of the conjoint and semimembranosus tendons, intra-rater reliability was moderate and poor (Intraclass correlation coefficient (ICC)=0.74;0.45), inter-rater reliability was moderate (ICC=0.73;0.57). Intra- and inter-rater reliability of the STL-CT continuity assessment was substantial and fair (ĸ=0.74;0.31). In conclusion, MRI assessment for full-thickness free tendon discontinuity is reliable. However, assessment of extent of tendon retraction and STL-CT continuity is not reliable enough to guide the treatment decision-making process.

Proximal hamstring tendon avulsion: state of the art

Complete proximal hamstring tendon avulsions from the ischial tuberosity, though infrequent, are the most severe type of hamstring muscle injury in the field of sport medicine. These serious injuries are commonly associated with a delayed or even misdiagnosis, despite obvious clinical findings. The published literature favours surgical repair even though the studies represent lower levels of evidence. Non-surgical treatment is a viable option for lower physical demand patients. This state-of-the-art article reviews the relevant anatomy, the clinical assessment including specific physical examination signs and diagnostic testing in patients suspected of a proximal hamstring avulsion. Up-to-date evidence is reviewed to address surgical and non-surgical treatment options and outcome assessment. The authors provide a detailed description of what would be considered the current worldwide standard of care; an open, suture-anchor-based repair of the avulsed tendon complex (semitendinosus, long head of biceps femoris and semimembranosus) securely to the ischial tuberosity. Also included are surgical tips and tricks, with advice on postsurgical management and rehabilitation. Future perspectives should involve higher quality, prospective research to better define the indications for surgery, evaluate the emerging role of endoscopic repair and disclose complications along with measuring patient-reported outcomes.