Abstract
INTRODUCTION: Intra-medullary devices are the most common mode of fixation of inter-trochanteric fractures. Short proximal femur nails (PFN) used for fixing these fractures, unlike the long nails, are non-anatomic and are usually straight with no curvature in antero-posterior plane. As a result, there is always a chance of the nail tip impinging against the anterior cortex of femur. MATERIALS AND METHODS: A total of 80 patients with trochanteric fractures (AO 31A2 and 31A3), operated with short PFN, were followed up retrospectively and prospectively from 2019 to 2021, for a period of 6 months. All fractures were fixed with PFNs, with nails ranging from 170 to 250 mm. Radiological analysis was done on hip lateral X-rays (taken at 6 months) using Angle at Distant Axis (ADA) and Nail Tip Position (NTP). Functional outcome analysis was done using Harris Hip Score. Patients were graded into 2 groups according to ADA (ADA>4° and ADA<4°). Incidence of anterior thigh pain was noted in patients on follow up and was statistically evaluated with nail size, nail diameter, ADA and NTP. RESULTS: Mean ADA was 4.19° ± 1.45; mean NTP grade was 1.98 ± 1.11. Mean nail size was 201.87 mm with a mean nail diameter of 9.76 mm. Twenty patients complained of anterior thigh pain on follow-up. Twenty-five patients had NTP grade 3 or above of which 16 complained of anterior thigh pain (p < 0.001). Fifty-five patients had nail diameter of 10 mm or above of which 14 had anterior thigh pain (p < 0.01). Fifty-three patients had a nail length of 200 mm or above of which 16 patients complained of thigh pain on follow up (p < 0.01). CONCLUSION: There is a mismatch of short PFNs with anterior bow of femur. Use of shorter nails with narrow diameters will avoid this mismatch to an extent.