Osetosynthesis of Fractures neck femur with cannulated screws: Evaluation of risk factors for post-operative complications

Objective To evaluate the risk factors for postoperative complications in fracture neck femur treated with cannulated screws. Methods This cross sectional series was performed at the Department of Trauma and Orthopaedics, Jinnah Postgraduate Medical Centre, Karachi from January 2015 to December 2019. A Total of 149 patients with close fracture neck femur of either gender between 20-60 years of age were included in the study. Patients with hip arthritis and pathological fractures such as tumours were excluded. Minimum three cannulated screws were used to fix the fracture with parallel configuration in compression mode. Patients were followed and evaluated for fracture healing and related complications such as nonunion and Avascular necrosis for two years. Descriptive statistics were calculated and stratification was done. Post stratification chi square test was applied taking p-value ? ≤0.05 as statistically significant. Results There were 113 (75.8%) male and 36 (24.2%)female patients. Mean age was 37.54±10.66 years. Mean operation time was 38.56±4.61 minutes. Out of these, 93 (62.4%) injuries were caused by motor vehicle accident, 34(22.8%) fall and 22(14.8%) by sports injury. Garden type III fracture was observed in 69 (46.3%) patients followed by 41 (27.5%) fractures of grade-IV. Fracture union was observed in 126 (84.6%) patients at a mean time of 4.0±1.1months and non-union in 23 (15.4%) cases whereas rate of avascular necrosis was noted in 28 (18.8%) cases and were significantly associated with age, injury mode, time from injury to surgery and fracture classification. Non-union was significantly associated with open reduction and delayed fixation of fracture for more than 24 hours. Conclusions Although cannulated screws are a universally accepted method of fixation for femoral neck fractures, the incidence of complications such as Avascular necrosis and non-union is quite high particularly in young males meeting a motor vehicle accident, undergoing open reduction for displaced fractures even with early diagnosis and treatment.