The functional effect of lesser trochanter involvement in hip fractures: a prospective cohort study

Abstract Introduction: Hip fractures are the most common fractures amongst frail older patients. Earlier studies have indicated an impaired hip flexion strength in patients with fractures that include detachment of the lesser trochanter. These patients may experience protracted functional impairment and longer recovery time, causing prolonged rehabilitation journeys This study aimed to evaluate the effects of a detached lesser trochanter in trochanteric fractures on the recovery of hip function. Method: A prospective observational cohort study was performed between 2016 and 2019. Community dwelling patients aged 70 years or older with AO 31A1-A3 trochanteric fractures were included. Patients followed routine care and were treated with a DHS or PFNA. The groups with and without involvement of the lesser trochanter were analysed. The primary outcome was hip function assessed at 6 weeks, 3 months and 1 year after surgery with the Harris Hip Score. Secondary outcomes included the Ludloff's test, complications, rehabilitation time, and pain-, independence-, and quality of life scores. A propensity score was used to adjust for any baseline differences between the two groups. Results: A total of 114 patients were included, 51 (44.7%) with involvement of the lesser trochanter and 63 (55.3%) without. Minor differences were observed in the baseline characteristics. No significant difference was observed for the Harris Hip Score (coefficient estimate: 3.31; 95% CI, -5.09-11.72; P = 0.43). The flexion function of the iliopsoas muscle was more often normal with the Ludloff's test in patients without involvement of the lesser trochanter (OR, 2.33; 95% CI, 1.241-4.387; P = 0.009). However, no differences were observed for any of the other secondary outcomes. Conclusion: Although no differences in overall hip function were found, more hip fracture patients with involvement of the lesser trochanter showed prolonged impaired flexion of the hip. The absence of long-term, clinically relevant disadvantages however, proves fixing the lesser trochanter to be redundant.