Purpose: To compare the short-term ambulatory function of elderly patients after fixation of unstable intertrochanteric fractures with either the AO-ASIF proximal femoral nail anti-rotation (PFNA) device or the dynamic hip screw (DHS).
Methods: 63 patients aged 60 years or older underwent fixation for unstable intertrochanteric fractures (AO types A2 and A3) using the PFNA (n=25) or DHS (n=38). The decision for the type of implant used was based on the lead surgeon's preference, according to perceived fracture stability and clinical experience. In patients having PFNA fixation, weight bearing ambulation and rehabilitation was commenced on day 2. The extent of weight bearing was decided by the lead surgeon based on the stability of the fracture. In patients having DHS fixation, non-weight bearing and ambulation with a walking aid was commenced on day 2. Ambulatory function before injury and after surgery was measured using the Parker Mobility Score (PMS). The 2 groups were compared in terms of the PMS, ambulatory independence, and environmental mobility.
Results: Respectively in PFNA and DHS patients, 32% and 13% (p=0.035) were ambulant with a walking frame at discharge; the remainder were wheelchair bound. Patients treated with PFNA had significantly higher median PMS at 6 months (4 vs. 2, p=0.002), median ambulatory independence score at 6 months (4 vs. 3, p=0.004) and at 12 months (5 vs. 4, p=0.001), and median environmental mobility score at 6 months (2 vs. 1, p=0.007). They also had significantly higher percentage of patients able to ambulate outdoor and in community at 6 months (64% vs. 29%, p=0.02) and able to walk independently or with a walking aid at 12 months (96% vs. 69%, p=0.01). There were 3 complications. Two patients treated with PFNA had blade cut-out, owing to poor fracture reduction. One patient treated with DHS had screw cut-out and subsequently developed avascular necrosis of the femoral head.
Conclusion: Unstable intertrochanteric fractures in elderly patients with good pre-fracture ambulatory function stabilised with the PFNA resulted in better short-term ambulatory function.
Keywords: fracture fixation, intramedullary; hip fractures; treatment outcome.