Prevalence and factors associated with limb length discrepancy following intramedullary nailing of femur shaft fractures in adults at Mulago National Referral Hospital

Abstract

Background. Limb length discrepancy (LLD) is a recognized complication following intramedullary nailing (IMN) of femoral shaft fractures, with a reported global incidence of 20–43%. In sub-Saharan Africa, limited access to intraoperative imaging, and fracture tables heightens this risk. In Uganda, the burden of LLD following IMN remains poorly characterized, creating an evidence gap. Complications such as gait disturbance, early arthritis and psychological distress may occur in patients with LLD. Objectives. The objective of this study was to determine the prevalence of LLD and to identify the factors associated with LLD following IMN of femoral shaft fractures among adults at Mulago National Referral Hospital (MNRH), Kampala, Uganda. Methods. An analytical cross-sectional study was conducted at Mulago National Referral Hospital from October 2025 to February 2026. 101 consecutive adult patients (≥18 years) who had undergone IMN for femur shaft fractures were enrolled on their first post-operative day. Limb length was measured radiologically using CT-scanogram. LLD was categorized as mild LLD (<2 cm), moderate (2–5 cm), or severe (>5 cm). Ordinal logistic regression adjusted for clustering at the surgical team level was used for bivariate and multivariable analysis in STATA version 15. Results. The overall prevalence of LLD was 38.6% [95% CI (29.1,49.8)], 23.8%[95% CI (15.9,33.3)] had mild LLD and 14.8% [95% CI (8.6,23.3)] had moderate LLD; In multivariable ordinal logistic regression, greater trochanter nail entry (aOR 2.79, 95% CI 1.99,3.90, p<0.001), absence of pre-operative traction (aOR 3.96, 95% CI 3.04,5.17, p<0.001), comminuted fractures with (aOR 13.62, 95% CI 2.14,86.74, p=0.006), Fracture location (mid-third aOR 0.21; distal aOR 0.12, both p<0.001), Mid-thigh circumference (aOR 1.11, 95% CI 1.07,1.14, p<0.001),were independently associated with LLD. Surgical delay was strongly associated with worse LLD in bivariate analysis (OR 84.00, 95% CI 21.73,324.64, p<0.001) though model instability due to sparse data. precluded its inclusion in the final multivariable model. Conclusions. LLD is a complication following femur fractures after IMN at MNRH, affecting 38.6% of patients on the first post-operative day. Complex fracture patterns, absence of pre-operative traction, and greater trochanter nail entry were independently associated with LLD. Reducing time to surgery, standardizing pre-operative traction for all patients awaiting IMN, and improving access to intraoperative fluoroscopy are the most actionable interventions to reduce the LLD burden at this institution.