Comparison of supraintercondylar and supracondylar femur fractures treated with condylar buttress plates

Background Treatment of supraintercondylar (AO/OTA 33-C) and supracondylar (AO/OTA 33-A) femur fractures is generally challenging. Standard treatments include open reduction and internal fixation. However, optimal implants are now being well-defined. This study focus on the comparison between clinical and functional outcomes of fractures treated with condylar buttress plates (CBPs). Methods We treated 87 patients with supraintercondylar or supracondylar femur fracture from 2004 to 2008, including 30 supraintercondylar and 24 supracondylar fractures treated with CBPs. Both knee and function scores (per Knee Society) were given to clinical and functional outcomes, and concomitant knee function was assessed per Mize criteria. Results Union rate of supraintercondylar fractures was 90 % (27/30) and supracondylar fractures was 91.7 % (22/24) ( P = 0.68). In supraintercondylar group, 16.7 % revealed postoperative varus deformity, whereas none in supracondylar group ( P = 0.045). Knee Society knee score was 73.6 in supraintercondylar group and 85.5 in supracondylar group ( P = 0.009); and function score was 62.5 in supraintercondylar group and 83.1 in supracondylar group ( P = 0.023). A satisfactory result based on modified Mize criteria was achieved in 50 % of supraintercondylar fractures and in 79.1 % of supracondylar fractures ( P = 0.09). Conclusions Use of CBPs for supraintercondylar and supracondylar femur fractures treatment led to a high union rate. However, a high rate of varus deformity occurred in patients with supraintercondylar but not supracondylar fractures. Moreover, CBP treatment in patients with supracondylar fractures led to better functional outcomes than those with supraintercondylar fractures.