Poster 193: Long-Term Outcomes of Partial Proximal Hamstring Avulsion Repair: Average 10-Year Follow-Up

Abstract

Objectives:

While a growing body of literature supports the benefit of surgical repair of complete proximal hamstring avulsions involving all 3 tendons, the optimal treatment for partial proximal hamstring avulsions remains uncertain. Initial nonoperative management of partial proximal hamstring avulsions is typically recommended, but several recent studies have shown improved pain and function at short- and mid-term follow-up. However, the durability of surgical repair at long-term follow-up is unknown. The purpose of this study was to report the long-term outcomes of partial proximal hamstring avulsion repair compared to outcomes at midterm follow-up. It was hypothesized that hamstring function and patient satisfaction would remain stable over time.

Methods:

All patients who underwent surgical repair of a partial proximal hamstring avulsion by a single surgeon between 2006 and 2018 with a minimum 5-year follow-up were included. Institutional review board approval was obtained prior to study initiation, and all patients signed informed consent. Exclusion criteria were complete avulsions involving all 3 hamstring tendons, retraction > 2 cm, or magnetic resonance imaging (MRI) findings of isolated tendinopathy. All patients had first attempted nonoperative treatment, including nonsteroidal anti-inflammatory drugs and physical therapy.

Patient characteristics were collected including age, sex, injury, laterality, sports played, level of participation, length of time from injury to intervention, and length of follow-up. Patients completed a HIPPA-compliant online questionnaire (REDCap) containing the patient-reported outcomes scores of the Lower Extremity Functional Score (LEFS), Marx Activity Rating Scale, custom LEFS (%), and custom Marx (%). A Total Proximal Hamstring Score was calculated by averaging the custom Marx score and the custom LEFS. Patient satisfaction with surgical outcome (yes/no) was also determined. A portion of the included patients had the same outcome measures available from a previous study entailing a minimum 2-year follow-up, with an average follow-up of 6.2 years. Paired comparisons of current outcome scores with earlier scores were performed using a paired Mann-Whitney U test for continuous variables and Fisher exact test for categorical variables.

Results:

Fifty-three patients (57 hamstrings) with a mean age at surgery of 47.4 years were included at an average follow-up time of 10.1 years. Of the 53 patients, 4 had bilateral injuries and 4 underwent revision surgery. The right (n = 29) and left (n = 28) hamstrings were equally affected with a predominance of female patients (41 female, 16 male). Running was the most common sport at the time of injury (Table 1). Excellent functional outcomes were seen at average 10.1 years (Table 2). 91.2% of patients were satisfied with the results of surgery and were able to return to their desired sport at an average of 10.9 months after surgery. Nearly 88% of hamstrings considered their strength to be >75% strength of the contralateral side, with approximately 58% of hamstrings reporting equal (100%) strength. When comparing the 44 partial hamstring repairs with outcome scores available at both midterm (6.2 years) and long-term follow-up (10.7 years), only the Marx and custom Marx scores were found to decline with time. Scores for LEFS, custom LEFS, Total Proximal Hamstring, satisfaction, and subjective strength were unchanged between midterm and long-term follow-up (Table 3).

Conclusions:

Excellent patient-reported outcomes and high levels of satisfaction were found at 10-year follow-up following partial proximal hamstring avulsion repair. Notably, the LEFS and custom LEFS, which are the most common patient-reported outcome measures used to assess hamstring function following injury, remained high at midterm and long-term follow-up. The Marx (12.5 vs. 8.5) and custom Marx scores (100% vs. 94%) did achieve statistically significant differences between time points, with lower scores at long-term follow-up possibly in part due to self-determined reduction in strenuous activities with aging. Patient-reported satisfaction and subjective strength remained high at long-term follow-up. Surgical repair of partial proximal hamstring avulsions remains a successful and durable treatment strategy in active patients who have failed nonoperative measures at an average follow-up exceeding 10 years.