Changes in Fall Risk After Total Hip Arthroplasty for Dysplastic Hip Osteoarthritis

Total hip arthroplasty (THA) improves function in patients with dysplastic hip osteoarthritis (DHOA). However, its effect on reducing fall risk remains unclear. This study aimed to evaluate fall risk following THA in patients with DHOA.

This retrospective cohort study included 85 patients who had DHOA and underwent THA between September 2019 and September 2022 and were evaluated as having a preoperative fall risk (Fall Risk Index 5 items [FRI-5] ≥ 6). They were categorized into two groups according to the FRI-5 score 1 year postoperatively. Evaluation parameters included FRI-5 score, age, sex, body mass index (BMI), Harris hip score (HHS), perceived leg length discrepancy (P-LLD), and radiographic parameters. Logistic regression was used to assess risk factors for postoperative falls.

The FRI-5 score significantly decreased from 7.79 (6.0-13.0) preoperatively to 4.56 (0-13.0) postoperatively (p < 0.001). The number of falls during the year decreased from 36 (42.4%) to 18 (21.2%) after surgery (p = 0.005). The high-risk and low-risk groups comprised 33 and 52 individuals, respectively. The high-risk group was significantly older than the low-risk group (p = 0.006). Postoperative P-LLD was significantly large in the high-risk group compared to that in the low-risk group (p = 0.005). Preoperative and postoperative sagittal vertical axes (SVA) were significantly larger and preoperative lumbar lordosis (LL) was significantly lower in the high-risk group than in the low-risk group (p = 0.039, p = 0.034, and p = 0.021, respectively). Logistic regression analysis identified age (OR: 1.2, 95% CI: 1.05-1.36, p = 0.006), preoperative low LL (OR: 0.944, 95% CI: 0.892-0.999, p = 0.046), and postoperative P-LLD (OR: 5.81, 95% CI: 1.23-27.5, p = 0.026) as significant factors associated with fall risk.

THA for patients who have DHOA at high risk of falls reduces the likelihood for falls. Therefore, surgeons should plan surgeries considering the risk factors post-THA.