Knee Pain and Functional Outcomes after Retrograde Femoral Nailing: A Retrospective Review

To investigate the incidence and severity of knee pain following retrograde intramedullary nailing offemur fractures and to better understand functional outcomes using validated patient-reported outcome measures.  Fifty-three patients with OTA 32 or 33 fractures treated by retrograde nail at a single academic Level 1 trauma center between 2009 and 2020 were retrospectively reviewed. Patients verbally completed the Oxford Knee Score (OKS) and Patient-Reported Outcome Measurement Information System (PROMIS) Short Form 6b, minimum one year postoperatively. Thirty-four (64%) patients reported the presence of pain. Of those reporting pain, 16 (47.1%) reported their pain as mild. Compared to those without pain, patients with knee pain had lower OKS (30.38 +/- 10.65, versus 41.95 +/- 6.87; P <0.001) and higher PROMIS scores (14.65 +/- 6.76 versus 10.95 +/- 7.09; P=0.066).  The increasing severity of pain was inversely correlated with functional status as measured by patientreported measures. At present, the reliability, high union rates, and otherwise low complication rates associated with retrograde femoral nailing justify its continued use. However, knee pain and functional outcomes should remain an integral part of the preoperative discussion with the patient. Level of evidence: III