Session III - Hip / Femur

Fri., 10/11/13 Hip/Femur, PAPER #53, 11:07 am OTA 2013

Implication of Subgrouping in Valgus Femoral Neck Fractures: Comparison of 31-B1.1 With 31-B1.2 Fracture in OTA Classification

Kyu Hyun Yang, MD1; Hyung Keun Song, MD2; Hyun Cheol Oh, MD3; You Gun Won, MD1;
1Department of Orthopaedic Surgery, Gangnam Severance Hospital,
Yonsei University, Seoul, Korea;
2Ajou University Hospital, Suwon, Korea;
3National Health Insurance Corporation Hospital, Goyang, Korea

Purpose: This study aimed to identify the clinical implications of valgus impacted femoral neck fractures and compare fractures with >15° of impaction (31-B1.1) against fractures with <15° of impaction (31-B1.2).

Methods: Between February 2005 and November 2010, 89 femoral neck fractures with valgus deformity (31-B1.1 and 31-B1.2) were treated by screw osteosynthesis. The valgus impaction was not disimpacted; however, posterior tilt of the capital fragment (apex anterior angulation) was reduced by internally rotating the leg and applying pressure from the front. A total of 78 patients were followed for >12 months. We evaluated the clinical and radiographic outcomes.

Results: 36 patients sustained 31-B1.1 fractures, and 42 patients sustained 31-B1.2 fractures. The average follow-up period was 15 months, and bony union occurred in all cases. The mean femur neck shortening was 8.88 mm for B1.1 and 3.70 mm for B1.2 fractures (P <0.001). The mean sliding distance of the screw (SS) was 3.36 mm for B1.1 fractures and 1.38 mm for B1.2 fractures (P <0.001). The mean Harris Hip Score was 82.0 for B1.1 and 88.8 for B1.2 fractures (P = 0.029). Osteonecrosis (ON) of the femoral head occurred in 4 patients with B1.1 fractures and none with B1.2 fractures (P = 0.041). 18 of the 78 patients required a second operation and 15 of them were included in 31-B1.1 fracture (P = 0.003). Three patients underwent arthroplasty due to ON, and 15 patients required hardware removal due to pain after bony union.

Conclusion: More femoral neck shortening and less functional recovery should be expected in the valgus impacted femoral neck fracture patient based on the severity of initial deformity. Even though we could obtain bony union in all of the cases, the risk of ON and second operation after bony union was higher with greater initial deformity.

Alphabetical Disclosure Listing

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.