IntroductionWe evaluated the outcome, functional recovery, and complications of intramedullary nailing for fractures of the femoral shaft fractures. MethodsA prospective observational study was conducted at the National Hospital of Sri Lanka. Patients with isolated femoral shaft fractures undergoing intramedullary nailing were followed up prospectively to assess the factors associated with better functional recovery (measured by Harris Hip Score (HHS) and Western Ontario and McMaster University osteoarthritis index (WOMAC)). ResultsOf 46 patients, the median age was 40(IQR=26-59) years. Majority had simple (n=34,73.9%), closed (n=39,84.8%) fractures while seven (15.2%) had Gustilo Type I open fractures. Surgery was performed at a median of 9.5(IQR=6-14) days after the injury. Approximately two-thirds of the patients required reamed nailing (n=30,65.2%). Three patients developed surgical site infections. X-rays obtained at four months demonstrated features of non-union in 13(28.3%). Leg length discrepancy (LLD) was present in 16(34.8%), and rotational deformity in one patient. Full and partial weight-bearing at six weeks was achieved in six and 23 patients respectively while 17 patients were unable to bear weight. The median HHS and WOMAC at four months were 66.5 and 36, respectively. Patients with proximal or distal diaphyseal fractures, female patients and those with full weight-bearing six weeks showed the best WOMAC index. ConclusionProximal or distal diaphyseal fractures, female sex and ability to bear weight at six weeks post-surgery were associated with better functional outcomes at four months postoperatively.