ANATOMIC STUDY OF THE PROXIMAL THIRD OF THE FEMUR: FEMOROACETABULAR IMPACT AND THE CAM EFFECT

Pedro José Labronici; Sergio Delmonte Alves; Anselmo Fernandes da Silva; Gilberto Ribeiro Giuberti; Justino Nóbrega de Azevedo Neto; Jorge Luiz Mezzalira Penedo

doi:10.1016/S2255-4971(15)30058-6

ANATOMIC STUDY OF THE PROXIMAL THIRD OF THE FEMUR: FEMOROACETABULAR IMPACT AND THE CAM EFFECT

Rev Bras Ortop. 2015 Nov 16;44(2):120-4. doi: 10.1016/S2255-4971(15)30058-6. eCollection 2009 Jan.

Authors

Pedro José Labronici¹, Sergio Delmonte Alves², Anselmo Fernandes da Silva³, Gilberto Ribeiro Giuberti², Justino Nóbrega de Azevedo Neto², Jorge Luiz Mezzalira Penedo⁴

Affiliations

¹ Universidade Federal de São Paulo, Escola Paulista de Medicina; Dr. Donato D'Angelo's Orthopedics and Traumatology Clinic, Hospital Santa Teresa, Petrópolis, RJ, Brazil.
² Hip Group, Dr. Donato D'Angelo's Orthopedics and Traumatology Clinic, Hospital Santa Teresa, Petrópolis, RJ, Brazil.
³ Hip Group, Orthopedics and Traumatology, Dr. Donato D'Angelo's Orthopedics and Traumatology Clinic, Hospital Santa Teresa, Petrópolis, RJ, Brazil.
⁴ Hip Surgery Group, National Institute of Traumatology and Orthopedics (INTO, Instituto Nacional de Traumatologia e Ortopedia), Rio de Janeiro, RJ, Brazil.

Abstract

To analyze anatomical variations of the proximal end of femur that could cause a femoroacetabular impact.

Methods: 199 skeletically mature anatomical specimens of femurs were used. The femurs were measured in order to determine the anteversion angle of the femoral neck, neckshaft angle, sphericity of the femoral head at anteroposterior and superoinferior, angle between epiphysis and the anterior femoral neck, angle between epiphysis and the neck at lateral plane, anteroposterior distance at 5mm of the head and neck junction and anteroposterior distance of the neck base.

Results: we found that the impact subgroup presented a significantly larger junction diameter of 5mm (p = 0.0001) and cam-head (%) (p= 0.0001), while base-cam (%) (p = 0.0001) showed a significantly smaller diameter than the subgroup without impact. It was identified that cam-head (%) ≤ 80 e base-cam (%) ≤ 73 were identified as the optimal impact points.

Conclusion: our study showed that the effect cam, caused by anatomical variations of the proximal femoral end focused the head-neck junction and base of the neck-junction head-neck. These rates can be predictive factors of the impact.

Keywords: Femur; Hip joint/pathology; Osteoarthritis, hip.