Surgical treatment of femoroacetabular impingement: evaluation of the effect of the size of the resection. Surgical technique.
BACKGROUND
In patients with symptomatic hip impingement, surgical resection of the femoral head-neck junction may improve the range of motion and relieve pain. A risk of this procedure is fracture. We evaluated the amount of resection of the anterolateral aspect of the femoral head-neck junction that can be done safely.


METHODS
Cadaveric proximal femoral specimens (fifteen matched pairs) were divided into three groups: 10%, 30%, or 50% of the diameter of one femoral neck was removed, and the contralateral femoral neck was left intact to serve as the control. A compressive load was applied directly to the femoral head. Peak load, stiffness, and energy to fracture were compared among the groups.


RESULTS
The energy to fracture differed significantly (p = 0.0015) among the 10%, 30%, and 50% resection groups. The peak load after the 50% resection was significantly less (p = 0.0025) than that after the 10% or 30% resection. With the numbers available, there was no significant difference in peak load between the 10% and 30% resections.


CONCLUSIONS
Resection of up to 30% of the anterolateral quadrant of the head-neck junction did not significantly alter the load-bearing capacity of the proximal part of the femur. However, a 30% resection significantly decreased the amount of energy required to produce a fracture. Thirty percent should be considered to be the greatest feasible amount of resection because of the change in the pattern of the femoral head-neck response to axial loads that we observed.
Mardones
Rodrigo M
RM
Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA. drmarpeter@entelchile.net
Gonzalez
Carlos
C
Chen
Qingshan
Q
Zobitz
Mark
M
Kaufman
Kenton R
KR
Trousdale
Robert T
RT
D000077:Acetabulum / Q000473:pathology / Q000601:surgery*; D001178:Arthroplasty / Q000009:adverse effects / Q000379:methods*; D002102:Cadaver; D003646:Debridement / Q000009:adverse effects / Q000379:methods*; D005269:Femur / Q000473:pathology / Q000601:surgery*; D006621:Hip Joint / Q000473:pathology / Q000601:surgery; D006801:Humans; D007592:Joint Diseases / Q000473:pathology / Q000601:surgery*; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods*