Occurrence and clinical outcome of lateral wall fractures in proximal femoral fractures whose fracture line runs from femoral basal neck to subtrochanteric area.

Treatment methods for proximal femoral fractures, when the fractures run from the femoral basal neck to the subtrochanteric area, have not yet been fully reported. Thus, we aimed to clarify osteosynthesis methods based on the fracture frequency and clinical results. We classified the proximal femoral fractures using the Area classification method based on the location (area) of the fracture line. The proximal femur has 4 areas with 3 boundaries; the center of the femoral neck, the boundary between femoral neck and trochanter, and the plane connecting the lower ends of the greater trochanter and the lesser trochanter. Fractures occurring only in Area-1 (proximal from the center of the femoral neck) were classified as Type 1; those in both Areas 1 and 2 (base of the femoral neck) were classified as Type 1-2. Therefore, fractures running from femoral basal neck to the subtrochanteric area were classified as Type 2-3-4. We targeted 60 Type 2-3-4 cases (average age 81 years, 10 men, 50 women) out of 1042 proximal femoral fracture cases who visited 8 hospitals in 2 years. We investigated the presence or absence of lateral trochanteric wall fractures, the selection of internal fixator, and the proportion of poor results. The lateral trochanteric wall fracture was observed in 48% of subjects. Long nails were selected to treat 46% cases, and nails with 2 or 3 proximal lag screws were used in 58% cases. Long nails and those with 2 or 3 lag screws were also used in 59% and 69% of lateral trochanteric wall fractures. Poor results such as cutout or excessive telescoping of lag screw occurred in 11.7% of cases and 17.2% of lateral trochanteric wall fractures. Even in cases where long nails and multiple lag screws were used for femoral trochanteric fractures whose fracture line ran from the femoral basal neck to subtrochanteric area were used, the failure rate was high in the presence of a lateral wall fracture. Therefore, it is necessary to consider careful post-operative treatment for proximal femoral fractures with lateral wall fracture, whose fracture line runs from femoral basal neck to subtrochanteric area.