[Treatment of Subtrochanteric Fractures, Our Experience, Complications].

PURPOSE OF THE STUDY The study gives a retrospective assessment of the outcomes of surgical treatment in patients who sustained a subtrochanteric fracture. MATERIAL AND METHODS In the period 2010-2018, a total of 118 patients with a subtrochanteric fracture, namely 75 males and 43 females, the mean age 61 years, were treated at our department. The study group included the patients who met the following inclusion criteria: age 18+, fracture treated by intramedullary nailing, follow-up for at least 12 months, in case of impaired healing and need for revision surgery follow-up until complete healing was achieved. Exclusion criteria - pathological fractures, periprosthetic fractures, pertrochanteric fractures with extension into subtrochanteric region, intertrochanteric fractures, fractures during bisphosphonate treatment, incomplete radiological documentation, non-compliance with the condition of 12-month follow-up. In 54 patients (46%) the injury was caused by high-energy impact, in the remaining 64 patients (54%) the fracture was the consequence of low energy mechanism. In 51 patients (43%) closed reduction was performed and 67 patients (57%) underwent open reduction. In 27 patients (23%) a small incision laterally was necessary to insert the reduction instrument in order to achieve correct position of the fracture. In 40 patients (34%) lateral approach was used for the reduction and proper placement of fragments was ensured by one or more cerclage wires prior to nailing. Nails made by Synthes were used for osteosynthesis: PFN A Long in 95 patients, PFN A in 11 patients and LFN in 12 patients. RESULTS In 76 patients (64%) fractures healed within 6 months, in 107 patients (90%) within 9 months. In 11 patients (10%) nonunion was observed that required another surgery. The outcomes were assessed using the Sanders and Regazzoni scoring system. Excellent outcome was achieved in 79 cases (67%), good outcome in 25 cases (21%), satisfactory outcome in 13 cases (11%), poor outcome in 1 case (1%). DISCUSSION At any age subtrochanteric fractures are always treated surgically. Currently, intramedullary nailing is the method of choice. The outcome of the surgery depends on correct reduction and fixation which shall ensure the balance of compression forces transmitted to the medial cortical bone, traction forces transmitted to the lateral femoral cortical bone. Intramedullary nailing has biomechanical advantages which outweigh the often difficult closed reduction. The nail decreases the position vector (of the force moment) and reduces torsional forces at the fracture site. Open reduction and additional cerclage wires are described as a risk factor for impaired healing. Nevertheless, the achievement of anatomical reduction offsets the risk of poor blood supply at the fracture site. Persistent displacement disturbs the balance of forces and results in impaired healing and implant failure. CONCLUSIONS Treatment of subtrochanteric fractures relies on precise reduction. Today, when minimally invasive methods of treatment are preferred, the most commonly used are the intramedullary implants. Displacement to varosity, flexion displacement or a combination of both cause impaired healing with non-union and failed osteosynthesis. Treatment of non-union is extremely challenging and always consists in the correction of anatomical relationships. Key words: subtrochanteric fractures, surgical treatment, outcomes, complications.