Surgical treatment of reversed oblique trochanteric femur fractures: Clinical outcome and introduction of a novel surgical classification.

Abstract

The reverse oblique fracture patterns accounts for about 5-10 % of all intertrochanteric fractures. This type of fracture is regarded as highly unstable and is still associated with high complication and failure rates. Cut-off values for the use of short or long implants are not yet defined. An easy-to-use and comprehensive classification system is still lacking. This study was performed as a single center retrospective data analysis. Between 2008 and 2018, 4003 patients with per/subtrochanteric fractures, were screened. A total of 286 (7 %) patients with a reverse-oblique fracture pattern were included. Fracture patterns were analyzed and classified according to a new classification system with 4 main types (I-IV), which are subdivided in to subtypes a and b. The choice of implants, complication rates, revision surgery and time of surgery were raised. Radiological outcome parameters (TAD, calTAD, Parker's Ratio) and loss of reduction were measured. The distribution between the various subgroups was IIa and IVa (21 %), IIb (20 %), Ia (12 %), IVb (9 %), IIIa (8 %), Ib (6 %) and IIIb (3 %). A rate of 39 (14 %) complications, which needed revision surgery were recorded. Open reduction significantly increased the complication rate (p= 0.0356) as well as an increase in time of surgery (p = 0.0107). The additional use of cerclage wires had no additional influence. There was a trend to more complications after the use of a long implant in patients with type-a fractures (p= 0.056). Radiological parameters did not have any predictive value. Loss of reduction of the medial or lateral cortex shows a trend to a higher complication rate. After a primary complication, the necessity of repeating revision surgery is likely to happen. The novel classification system depicts all relevant fracture patterns. Open reduction and prolonged time of surgery increase the complication rate. In type-a fractures, the use of short implants is recommended. Additional use of cerclage wires does not have a negative impact on outcome.