Reduction of trochanteric fractures in lateral view is significant predictor for radiological and functional result after six months

The goal of our retrospective study was to determine which radiological parameter after fixation of trochanteric fractures type AO 31 A2 is most important for the position of the fracture after six months. The additional goal was to find how the end position influences mechanical failure and the mobility of the patients.

We analysed 92 patients operated in one-year period for A 2 type trochanteric fractures with sliding hip screw or proximal femur intramedullary nail. They were divided in two groups according to the radiological position of the proximal fragment six months after the surgery. In group A we had 46 patients with satisfactory and in group B 46 patients with unsatisfactory position. In anteroposterior view we evaluated neck-shaft angle (NSA) and medial cortical support (MCS) and in lateral view anterior cortical support (ACS). Unsatisfactory position was recognized if NSA was in varus or ACS or MCS were negative. We compared the groups regarding basic patients characteristics (age, gender, ASA score, preinjury mobility, and degree of osteoporosis), type and quality of fixation, the position of the fracture (postoperatively and after 6 months), mechanical failure and mobility after 6 months. Statistical significance level was set to p ≤ 0.05.

Basic patients' characteristics as well as type and quality of fixation did not significantly differ between the groups. After the injury the difference between the groups in reduction quality was significant in lateral view (ACS; p=0.001), while after half a year there were significant differences in both views: NSA (p=0.003), ACS and MCS (both p<0.001). Proximal fragment position after six months statistically significant correlated with postoperative ACS in B group (r = 0.386, p = 0.008), but not with NCA nor with MCS. There were also significantly more fixation failures in group B (p<0.001) and less patients regain preinjury mobility (p=0.029).

In trochanteric fractures reduction in lateral view is the most important prognostic factor for favourable radiological result after half a year. Unsatisfactory position of the proximal fragment after six months influences mechanical failures and walking ability.