Fracture reduction with positive medial cortical support: a key element in stability reconstruction for the unstable pertrochanteric hip fractures

PURPOSE: To introduce the concept of fracture reduction with positive medial cortical support and its clinical and radiological correlation in geriatric unstable pertrochanteric fractures. METHODS: A retrospective analysis of 127 patients (32 men and 95 women, with mean age 78.7 years) with AO/OTA 31A2.2 and 2.3 hip fractures treated with cephalomedullary nail (PFNA-II or Gamma-3) between July 2010 and June 2013 was performed. They were classified into three groups according the grade of medial cortical support in postoperative fracture reduction (positive, neutral, and negative). The positive cortex support was defined that the medial cortex of the head-neck fragment displaced and located a little bit superomedially to the medial cortex of the shaft. If the neck cortex is located laterally to the shaft, it is negative with no cortical buttress, and if the two cortices contact smoothly, it is in neutral position. The demographic baseline, postoperative radiographic femoral neck-shaft angle and neck length, rehabilitation progress and functional recovery scores of each group were recorded and compared. RESULTS: There were 89 cases (70 %) in positive, 26 in neutral, and 12 in negative support. No statistical differences were found between the three groups among patient age, sex ratio, prefracture score of activity of daily living, walking ability score, ASA physical risk score, number of medical comorbidities, osteoporosis Singh index, fracture reduction quality (Garden alignments), and the position of lag screw or helical blade in femoral head (TAD). In follow-up, patients in positive medial cortical support reduction group had the least loss in neck-shaft angle and neck length, and got ground-walking much earlier than negative reduction group, with good functional outcomes and less hip-thigh pain presence. CONCLUSION: Fracture reduction with nonanatomic positive medial cortical support allows limited sliding of the head-neck fragment to contact with the femur shaft and achieve secondary stability, providing a good mechanical environment for fracture healing.