A cohort study on early outcomes of femur shaft fractures in adults treated by interlocking intramedullary nails at the university teaching hospital, Lusaka.

Abstract

The management of femur shaft fractures has evolved from the historical non-operative methods to the most recent intramedullary nail fixation. Interlocking nails have broadened the roles for closed intramedullary nailing of femur fractures. Early ambulation after fractures of the femur shaft has been shown to have a significant advantage in terms of both joint mobility and economic impact, which are very well attained by the use of interlocking nails. Shortening of the limb and malalignment along with contractures of the knees due to prolonged immobilization have traditionally plagued the Orthopaedic surgeons’ management of patients with these injuries.

The proportion of Femur shaft fractures seen at the University Teaching Hospital (UTH) is anecdotally high. In keeping with this, the use of interlocking nails has equally increased. However, the outcomes of the use of interlocking nails in this setting are not documented. This study looked at the early outcomes of femur shaft fractures treated by interlocking intramedullary nails at UTH. Femur shaft fractures are serious injuries that generally result in short-term disability and pain; but also have a high risk of long term deformity and disability. This study was aimed at evaluating the early outcomes of using interlocking intramedullary nails in the treatment of patients with closed femoral shaft fractures at the University Teaching Hospital, Lusaka. The objective was to explore the early outcomes of closed fractures of the shaft of the femur that were treated using interlocking intramedullary nails at the University Teaching Hospital, Lusaka.

The study was a prospective cohort study carried out between August 2019 and February 2020 at the University Teaching Hospital, Lusaka. During this period, a total of 63 patients that underwent interlocking intramedullary nailing were followed up for 6 weeks. The study participants were evaluated using the Thoresen criteria for short term outcomes.

The rotational deformity was the most prevalent outcome, with 68% of participants having rotational deformity, external rotation was the most common (40%) deformity. There was a statistically significant correlation (p-.006) between comminution and rotational deformity. Infection was very low, as only one participant (1.6%) had recorded a superficial infection. A limb shortening prevalence of 59% was found in this study, significant shortening (more than 2cm) was 7.9%. However, 92 per cent had combined good or excellent Thoresen outcome scores. An overall knee flexion of less than 90 degrees was found in 24% of the patients in this study.

The early outcomes of treatment using interlocking IMN for femur shaft fractures at UTH is good to excellent (based on the Thoresen score criteria) in terms of limb length discrepancy, rotational deformity and knee flexion combined. The proportion of post-surgery infection among patients with femoral shaft fracture treated with interlocking IMN was low (1.6% -superficial infection).