One study found that one-third of patients undergoing surgery for adult spinal deformity (ASD) also have severe hip dysfunction. osteoarthritis (OA), which can lead to poor spinal alignment and physical function.
The study findings were published in The Journal of Bone and Joint Surgery.
These differences persist even after operative treatment of ASD, according to new research from Alan H. Daniels, MD, and Basel Diebo, MD, of Brown University and colleagues from 20 North American spinal surgery centers. “Concomitant hip and spine disease are common, yet they remain challenging for joint arthroplasty spinal cord Surgeons,” the researchers write.
Also read: World Spine Day 2023: 7 important myths and facts about spine health you must know
Adult spinal deformities refer to various abnormalities of the curvature and alignment of the spinal cord. Since some of these deformities result from wear and tear over time, they are likely to occur more frequently in the aging population. For patients with ASD who do not improve with non-operative treatment, spinal realignment surgery may be indicated.
Previous studies have reported higher rates of hip OA in those with ASD. However, little is known about how OA affects patient characteristics and outcomes of surgery for ASD – both in terms of spinal alignment and patient-reported outcomes such as physical functioning and disability.
Drs. Daniels and Diebo and colleagues analyzed rates and outcomes of hip OA in 520 older adults who underwent surgery for ASD at one of 13 US and Canadian centres. About two-thirds of the patients were women, and the average age was 59 years. Consistent with previous studies, 34% of patients were classified as having severe OA involving both hips.
The researchers compared the characteristics of ASD patients with and without severe hip OA, including key patient-reported outcome measures. Characteristics and outcomes at postoperative follow-up were also compared in 165 patients: 68 with severe bilateral hip OA, 32 with severe OA of only one hip, and 65 without severe OA in both hips.
On preoperative analysis, patients with severe bilateral hip OA were older (mean age, 68 years) than patients with unilateral (66 years) and non-severe hip OA (60 years). Patients with severe hip OA also received higher scores on standard assessments of weakness.
At one-year follow-up, there was similar improvement in lordosis in all three groups. However, based on a radiographic measurement called the sagittal vertebral axis (SVA), spinal alignment was poor in patients with severe hip OA. The difference in SVA was significant both preoperatively and at follow-up.
Many patient-reported outcomes were also found to be worse in patients with severe bilateral hip OA, who had lower scores for physical functioning both preoperatively and at follow-up. Although overall disability scores did not differ significantly between groups, severe hip OA was associated with persistent reductions in activities such as walking, traveling, and climbing stairs. Frailty contributed to differences in functional outcomes.
This is “the first study to examine the alignment and functional outcomes of patients with concomitant hip OA at the time of surgery for severe ASD,” the researchers wrote. The findings show that ASD patients with severe OA of both hips are older and weaker and have worse physical functioning and disability scores, even after correction of their spinal deformity.
,[G]Despite the complexity of the concomitant hip and spine disease and the relatively weak condition of these patients, they warrant careful evaluation and post-operative optimization,” Dr. Daniels and co-authors conclude. They add: ”Further research is needed to clarify how to optimize outcomes in this complex patient population.”