Persistent knee complaints after retrograde unreamed nailing of femoral shaft fractures

Retrograde nailing is an attractive method for stabilisation of femoral shaft fractures in cases of polytrauma, ipsilateral pelvic, acetabular, tibial and femoral neck fractures, bilateral femoral fractures, obese and pregnant patients. However, retrograde nailing may result in complaints about the knee. The purpose of this study was to evaluate the incidence and risk factors of lasting knee pain, and its relation to knee function deficits.We conducted a retrospective study of 75 patients in whom 82 femoral shaft fractures were treated with retrograde intramedullary nailing.Complaints of pain about the knee during follow-up were present in 17 patients (23%). The mean age of patients with knee pain was significantly lower (26 years) than the age of those without knee pain (41 years) (p = 0.0002). Both groups, with and without pain about the knee, were not significantly different according to gender, injury severity score, AO type of fracture, associated ipsilateral injuries, open fractures, or type of nail used. In addition, the range of motion did not differ. Although 49% of all patients had also presented ipsilateral pelvis, acetabulum or lower leg fractures, the majority (89%) had a knee flexion >= 120 degrees.Complaints of knee pain after retrograde intramedullary nailing of femoral fractures were found to be rather common. Younger age appeared to be a risk factor for knee pain. Nevertheless, the majority of patients had excellent knee function.