Radiological alignment following fin nail treatment for femoral shaft fractures at Muhimbili Orthopedic Institute, Dar es salaam, Tanzania

Abstract

Background The Surgical Implant Generation Network(SIGN) Fin nail may have decreased challenges of intramedullary nailing for femoral shaft fractures since it removes the need for proximal interlocking screws when placed in a retrograde fashion. The Fin nail has an ability to fit within the proximal femoral canal and thus achieve stability. Angular malalignment is one of the complications of antegrade and retrograde nailing. Malalignment can lead to malunion, nonunion and deformity. The incidence of malalignment has been reported to range from 0-37%. This study aims to determine the immediate postoperative radiological alignment of femoral shaft fractures treated with Fin nail. Objectives To assess the radiological alignment of Fin nail in patients with femoral shaft fractures at Muhimbili Orthopaedic Institute, Dar es Salaam. Methodology A descriptive retrospective cross-sectional study was done from April 2020 to September 2020 which enrolled all adult patients 18 years and above of age with femoral shaft fractures(32A-B) from January 2010 to December 2019 in the SIGN online surgical database(SOSD). Fractures with AO/OTA Type 32C, patients with no postoperative radiograph, patients with radiographic evidence of pathological fracture and prior surgery of affected femur were excluded from the study. After ethical clearance, relevant data such as age and sex of the patient, fracture type, pattern and treatment approach were obtained from the SOSD. Radiological films were obtained from the SOSD and postoperative alignment was calculated by using the Radiant software. The postoperative radiological alignment was quantified by measuring the deviation from the normal anatomical axis of the femur. These numbers were recorded as the DFAA with units in degrees. Later confirmed by radiologist. Data entry was done using Microsoft Excel spreadsheets and analysis by importing the data into SPSS. Statistical significance was set at p-value < 0.05. Results This study had a total of 97 patients, with male predominance who were mainly below 30 years of age, with closed mid shaft transverse fractures treated with Fin nails via retrograde approach. Only 3.1% showed radiological malalignment with 1 being >10 degrees. Proximal femur shaft fractures and antegrade both constituted 20% of radiological malalignment. Conclusion This study showed that majority of the patients with simple femoral shaft fractures treated with fin nail were male with mean age of 30.9 years. Fin nail fixation did not cause significant malalignment and hence is an option for simple femoral shaft fracture treatment via the retrograde and possibly also the antegrade approach. Future larger scale studies need to investigate the long term postoperative alignment, long term clinical and functional outcomes post fin nail fixation.