New Sub-Classification of Vancouver B2 Periprosthetic Hip Fractures According to Fracture Pattern.

Introduction: There is currently a debate on whether all Vancouver type B2 (V-B2) periprosthetic hip fractures (PPHF) should be revised. Vancouver classification takes into account fracture location, implant stability and bone stock, but it does not distinguish between fracture patterns. The aim of our work was to study the different fracture patterns of V-B2 PPHF and to analyze if there is any pattern that presents lower osteosynthesis failure rates.

Material And Methods: All patients with V-B2 PPHF treated by osteosynthesis between January 2009 and January 2019 were included in the study. Using the Gruen system the proximal femur was divided into 3 zones. The lateral zone (Gruen 1±2±3), medial zone (Gruen 5±6±7), and distal zone (Gruen 4±3±5) were analysed and it was determined whether each of the 3 zones was fractured.

Results: 56 patients were included in the study. Their mean age was 79 years (R 45 - 92). The chosen treatment was: 39 Open reduction and internal fixation (ORIF), 10 Stem revision and 7 nonoperatively treatment. In ORIF group, no implant complications (0/24) were found in patients with a single fractured zone, while 5 implant complications (5/15) were discovered in patients with two or more fractured areas; this difference was significant (p=0.0147). All patients treated by stem revision had a fracture that involved two or more zones. In the nonoperatively group, the fracture pattern did not influence the treatment because of all of them had a very precarious functional and medical situation.

Conclusions: V-B2 PPHF treated via ORIF affecting only one zone (medial, lateral, or distal) have a lower risk of complication than those affecting two or more zones. We propose a sub-classification of Vancouver B2 type fractures: B2.1 (1 fractured zone) and B2.2 (≥2 fractured zones).

Level Of Evidence: Historical cohorts. Level III.