Proximal hamstring tendon avulsion injuries occur predominately in middle-aged patients with distinct gender differences: epidemiologic analysis of 263 surgically treated cases

Abstract

Purpose: Epidemiologic data of proximal hamstring avulsions have mainly been reported in relatively small patient cohorts. Detailed information on patient demographics, injury mechanism, and injury patterns is lacking in the literature. Since these injuries are rare and frequently misdiagnosed, a better understanding may help to increase awareness and to improve diagnosis of proximal hamstring avulsions.

Methods: A chart review was performed to identify all patients who had undergone surgical repair for complete proximal hamstring avulsions between 01/2006 and 02/2019 at the authors' institution. The following demographic and injury-specific data were obtained: Sex, age, body mass index (BMI), cause of injury (sports, activities of daily living, and others), presence of neurologic symptoms referable to the sciatic nerve, time to surgery, injury pattern (affected tendons), tendon retraction, and type of injury according to Wood et al.`s classification (Type 1: osseous avulsions, Type 2: tear at the musculotendinous junction, Type 3: incomplete avulsion from bone, Type 4: complete avulsion with only minimal retraction, and Type 5: complete avulsion with retraction > 2 cm). Data were analyzed for the entire study population and group comparison was performed with regard to sex, cause of injury, and the type of injury.

Results: A total of 263 patients were included (53% male). The mean age was 49 ± 13 years with most patients (56%) aged between 45-59 years. Most injuries occurred while participating in sports (52%) and injury type 5 was most commonly diagnosed (66%). Five percent of patients had sensory deficits referable to the sciatic nerve. Gender comparison showed that female patients were significantly older, predominantly represented in the age group 45-59 years, and most commonly injured during activities of daily living, whereas male patients were significantly more often represented in younger age groups, and the most common cause of injury was sports. Compared to Type 4 and 5 injuries, patients with a Type 1 injury were significantly younger and had a significantly longer time to surgery.

Conclusion: Proximal hamstring avulsion occurs predominately in the middle-aged patient and only rarely in patients under the age of 30 years. No gender dominance exists. Female patients are typically older and get injured during activities of daily living, whereas male patients are younger and get injured more often during sports. These epidemiologic data may help physicians to make an accurate and early diagnosis.

Level of evidence: IV.

Keywords: Avulsion; Epidemiology; Proximal hamstring tendons; Rupture.