INTRODUCTION: The effects of hip disease on lumbar spine degeneration have been established previously. The goal of this study was to examine degenerative lumbar spines and their corresponding hips to determine if lumbar spine pathology leads to accelerated hip pathology.
METHODS: Using an osteological collection, 236 specimens without spondylolysis and 88 specimens with L5 spondylolysis were examined as well as their corresponding femora. Degeneration of the L5/S1 junction was evaluated using the Eubanks modification of the Kettler classification of facet joint degeneration. Specific attention was paid to the degree of femoral head arthritis and deformation. Heads were classified as mild, moderate or severe for both arthritis and deformation. The neck‐shaft angles of each femur were also measured and recorded. Linear regression analysis was used to analyze the relationship between hip degeneration and the presence of spondylolysis. The analysis was corrected for age, sex, and degeneration at the L5/S1 level.
RESULTS: The association of osteoarthritis of the femoral head in the presence of spondylolysis was found to be significant (p=0.02). Head deformation in the presence of spondylolysis in subjects age > 35 was also found to be significant (p=0.04). The association between head deformation and osteoarthritis of the femoral head was significant (p=0.01). No significant association was found between the neck‐shaft angle and the presence of sponylolysis.
DISCUSSION: The altered spine biomechanics in L5 spondylolysis has a direct effect on accelerating hip degeneration. Patients with lumbar instability should be closely observed for the development of hip degeneration.