The effect of degenerative scoliosis and spinopelvic parameters on dislocation of hip hemiarthroplasty.

Background: Degeneration of the spine may affect pelvic parameters and hip mobility. This study aimed to evaluate the effects of degenerative scoliosis and spinopelvic parameters on hip hemiarthroplasty dislocations.

Methods: A retrospective analysis was conducted on patients who underwent hemiarthroplasty for intracapsular hip fracture over a twenty-year period. Demographic data, dislocation incidence, degenerative scoliosis (DS) status, type of hemiarthroplasty, surgical intervention to the hip, femoral head size, cement use, American Society of Anesthesiologists (ASA) score, body mass index (BMI), and in-hospital mortality were evaluated. The Cobb angle (CA), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), and thoracic kyphosis (TK) angles were measured and analyzed.

Results: A total of 284 patients were evaluated, with a mean age of 79.07 (±8.21) years. The frequency of hemiarthroplasty dislocation was 13% (n=37). Degenerative scoliosis was detected in 25.4% of the cases and was significantly more common in patients with degenerative scoliosis (p=0.001). Advanced age, higher BMI, higher ASA score, unipolar and cementless hemiarthroplasty, smaller femoral head size, and the posterior approach significantly increased dislocation frequency (p=0.004, p=0.001, p=0.03, p=0.001, p=0.001, and p=0.026, respectively). The mean PI, SS, PT, LL, and TK angles were significantly reduced in patients with dislocation and degenerative scoliosis (dislocation: p=0.001, p=0.001, p=0.001, p=0.003, p=0.048; degenerative scoliosis: p=0.001, p=0.001, p=0.001, p=0.001, p=0.001; respectively).

Conclusion: The presence of degenerative scoliosis and low pelvic incidence, sacral slope, pelvic tilt, thoracic kyphosis, and lumbar lordosis angles may increase the frequency of hemiarthroplasty dislocations. The posterior approach and small femoral head size may also elevate the risk of posterior dislocation.