The outcome of conservative management of tibial shaft fractures in Kenyatta National Hospital

Abstract

INTRODUCTION Tibial shaft fractures are the most common long bone fractures encountered all over the world, motor vehicles accident being the most common single cause. Closed reduction and cast immobilization has been regarded as the standard treatment for low energy tibial shaft fracture. This mode of treatment has proved to be generally successful and offers reliable healing without the risks seen in operative procedures. A subset of patients however have less than satisfactory outcome with this modality of treatment but literature remains ambiguous in identifying the fractures best managed operatively. MATERIALS AND METHODS A prospective study was conducted looking at the conservative management of tibial shaft fractures. Patients were recruited from casualty or in the wards and consents' were taken if they satisfied the inclusion criteria. Patients were recruited from April 2005 to December 2005 and followed up to June 2006. Patients were classified as per the dynamism of injury, severity of soft tissue damage, geographical location of the fracture, fracture geometry and Gustilo classification. The extent of alignment, angulations and limb shortening of the fracture were determined. A cast of plaster was applied and the patients were followed up over a period of six months with repeated check x-rays and re evaluation of alignment, angulations, limb length, callus formation and time to union. RESULTS One hundred and seventy patients with 178 fractures, 154 (90.6%) male and 16 (9.4%) female patients were recruited. There were 108 (60.7%) fractures followed up. Most of the injuries were sustained from RTA, 116 (65.2%) cases. There was a mean time to union of 15.85 weeks and a union range of 4 to 38 weeks. There was a rate of union by 20 weeks of 81.5%. There was a non union rate of 7.4%, a mal-union rate of 17.6% and delayed union rate of 11.1%. The infection rate was 6.6%. The fracture geometry, alignment and angulations were the main causes of complications. DISCUSSION The mean time to union of 15.85 weeks and a union range of 4 to 38 weeks compares very well with the internationally reported outcome of tibial shaft fracture management therefore the outcome of our management is in conformity with reported data elsewhere. This result is further evidenced by the rate of union at 20 weeks of 81.5%. The non union rate of 7.4 in our study is in conformity with internationally reported data. The malunion rate of 17.6% and delayed union rate of 11.1% conform to the reported data. The infection rate of 6.6% compares well with reported results. Simple fractures with < 25% alignment, fracture angulations > 7.SOor limb shortening more than 2cm after plaster cast immobilization are more likely to unite after 18 weeks compared to alignment > 25%, angulations < 7.50 or limb shortening < 2cm. Simple fractures with < 25% alignment, fracture angulations > 7.50 or limb shortening more than 2cm are more prone to complications compared to fractures with> 25% alignment, < 7.50 angulations or < 2cm reduction in limb length. This can be the basis of determining which type of simple fractures require open management Fracture alignment < 25% is an important prognostic indicator for complications and delayed union, hence patients who have this kind of alignment require open reduction and internal fixation. Anteroposterior and lateral angulations > 7.50 are important prognostic indicators for complications, patients who have this kind of angulation require open reduction and internal fixation.