THE PFNATM PROXIMAL FEMORAL NAIL ANTIROTATION WITH HELICAL BLADE IN THE TREATMENT OF PROXIMAL FEMORAL EXTRACAPSULAR FRACTURES IN THE ELDERLY: ABOUT 98 CASES

Abstract

Fundaments: The surgical management of proximal femoral extra-capsular fractures in the elderly remains controversial. Bone quality and purchase of the cephalic screw are the main limitations of the currently available therapeutic options, dynamic hip screws-blade and proximal femoral nailing systems being the standard fixation Methods: which however report a revision rate of 7% due to mechanical failures. Main complications include implant-related fractures and cut out of the head-neck device with subsequent penetration into the acetabulum. The new PFNATM helical blade appears to improve the stability of the whole construct by providing better compaction of the cephalic cancellous bone around the blade.

Hypothesis, Type of Study: We conducted a retrospective radiographic-clinical study of a series of PFNATM osteosyntheses. Assessment of the mid-term results was based on the hypothesis that the PFNATM would reduce the occurrence of secondary deviations.

Materials and Methods: Between 2006 and 2008, 108 osteosyntheses were performed. Only traumatic fractures were included in this study. Parker’s quality of life scoring system (0 to 9) and Harris hip score (0 to 100) were used for functional evaluation. The PFNA blade position was assessed using intraoperative radiographs while a postoperative radiographic control was performed during follow-up to evaluate the occurrence of complications.

Results: 98 patients (98 hips) were reviewed at a mean follow-up of 5.3 months +/− 1.5. At last follow-up, the mean Parker score had decreased by 2.3 points and the Harris hip score by 24 points. All fractures united at an average time of 10.4 weeks (+/− 2.1). Six complications were reported (6.1%). They included 3 infections of the operative site and 3 cut-out of the femoral head. Three patients required reoperation for removal of the helical blade (3%): Two for significant migration and one for intra-acetabular penetration.

No statistically significant risk factors could be observed. However, the three cut-out of the femoral head occurred in unstable fractures (type 31-A.2 and 31-A.3 according to the AO classification) with mispositioning of the helical blade.

Discussion: Extra-capsular proximal femoral fractures are common in the elderly population but there is currently no ideal implant available. Unstable fractures as well as mispositioning of the head/neck device are considered risk factors for secondary varus deviation and external rotation. The new PFNATM helical blade has been rarely studied. It appears as a reliable osteosynthesis option since it reports encouraging results at a mean follow-up of 6 months. However, our results do not give evidence of the superiority of the helical blade over the neck screw.