Preoperative Osteoporosis and its Association with Postoperative Outcomes Following Hindfoot, Midfoot, and Ankle Arthrodesis

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Osteoporosis, a common comorbid condition among older patients, is characterized by reduced bone mineral density. While several studies have explored the association of osteoporosis and outcomes following hip and knee joint arthroplasty, few have evaluated its influence on ankle surgery. Our study aims to investigate if preoperative osteoporosis influences postsurgical outcomes in patients undergoing midfoot, hindfoot, or ankle arthrodesis. Methods: The TriNetX database (2006-2024) was retrospectively queried to identify patients who underwent open hindfoot arthrodesis. Three groups were created to include patients with untreated osteoporosis (C1), treated osteoporosis (C2), and no osteoporosis or treatment within 1 year of their surgery. Propensity score matching, at a 1:1 ratio was based on preoperative demographics and comorbidities resulted in 1,185 patients between C1 and C3 and 698 patients between C2 and C3. Results were studied at 6-month and 2-year postoperative periods. Results: At the 6-month postoperative period, untreated osteoporosis (C1) had a significantly increased risk of pneumonia (p=0.0240, Risk Difference (RD)=1.266%, 95% Confidence Interval (CI)=0.168%,2.364%), deep vein thrombosis (DVT) (p=0.0167, RD=1.688%, 95% CI=0.307%,3.068%), and readmission (p=0.0455, RD=2.025%, 95% CI=0.042%,4.008%) compared to C3. When comparing treated osteoporosis (C2) to C3 at the 6-month period, there is an increased risk of readmission (p=0.0214, RD=3.009%, 95% CI=0.45%,5.567%), DVT (p=0.0083, RD=2.865%, 95% CI=0.743%,4.988%), reoperation for wound dehiscence (p=0.0015, RD=1.433%, 95% CI=0.551%,2.314%), and UTI (p=0.0028, RD=3.438, 95% CI=1.187%,5.69%). At the 2-year postoperative period, there is no difference postoperative complications between C1 and C3. However, C2 had an increased risk of nonunion or malunion (p=0.0015, RD=1.433%, 95% CI=0.551%,2.314%) and implant-related pain (p=0.0175, RD=3.009%, 95% CI=0.533%,5.485%) compared to C3. Conclusion: Osteoporosis is associated with an increased risk of short-term postoperative complications following hindfoot arthrodesis. However, while treatment for osteoporosis may reduce the risk of certain complications, it is also linked to a higher incidence of wound-related issues, infections, and an increased risk of nonunion or malunion in the long term. These findings suggest that while osteoporosis management is important, its impact on surgical outcomes remains complex. Further research is needed to better understand these findings.