Vitamin D Deficiency and Outcomes After Ankle Fusion: A Short Report

Considerations Regarding Vitamin D in Foot and Ankle Treatment and Surgery

Although the impact that vitamin D has on bone healing is uncertain in foot and ankle (F&A) surgery, there is support for vitamin D supplementation (2000 IU/day) with calcium (1 g/day) to promote bone healing. Although orthopedic F&A surgeons are frequently the first provider to detect the harbingers of osteoporosis by the occurrence of fragility fractures, this should trigger referral to the appropriate specialist for assessment and treatment. There is circumstantial evidence suggesting a role of hypovitaminosis D in bone marrow edema syndrome and possibly osteochondritis dissecans. There should be a low threshold for assessing vitamin D levels in such patients.

The Ankle Joint: Revision Ankle Fusion Options, Nonunion, Malunion, Protocol for Best Outcome

Ankle arthrodesis has been a time-tested procedure for osteoarthritis, avascular necrosis of the talus, deformity correction, and significant trauma of the ankle. Technique guides have created dissection pearls, ease of fixation, and arthroscopic techniques to mitigate complications of the procedure. Major complications, such as nonunion, malunion, or implant infection are the most worrisome and cumbersome complications to handle. The aim of this article is to provide the practicing surgeon evidence to provide innovative management techniques for nonunion, malunion, and infection following primary ankle arthrodesis.

Association of Preexisting Triple Fusion and Arthroscopic Ankle Arthrodesis nonunion

BACKGROUND

Arthroscopic ankle arthrodesis (AAA) is a successful treatment for end-stage ankle arthritis. A significant early complication of AAA is symptomatic nonunion. Published nonunion rates range from 8% to 13%. Longer term, there is concern that it predisposes to subtalar joint (STJ) fusion. To better understand these risks, we undertook a retrospective investigation of primary AAA.

METHODS

All adult AAA cases conducted at our institution over a 10-year period were reviewed. A total of 284 eligible AAA cases in 271 patients were analyzed. The primary outcome measure was radiographic union. Secondary outcome measures included reoperative rate, postoperative complications and subsequent STJ fusion. Univariate and multivariate logistic regression analysis was performed to identify nonunion risk factors.

RESULTS

The overall nonunion rate was 7.7%. Smoking (odds ratio [OR] 4.76 [1.67, 13.6], P = .004) and previous triple fusion (OR 40.29 [9.46, 171.62], P < .001) were independent risk factors on univariate analysis. Only prior triple fusion persisted as a major risk factor associated with nonunion on multivariate analysis (OR 18.3 [3.4, 99.7], P < .001). Seventy percent of patients with a previous triple fusion went on to develop nonunion compared to 5.5% of those without. Increasing age, obesity, surgical grade, diabetes, postoperative weightbearing plan, steroid use, and inflammatory arthropathy were not significant risk factors. The leading cause of reoperation was hardware removal (18%). There were 5 superficial (1.8%) and 4 deep (1.4%) infections. Eleven (4.2%) required subsequent STJ fusion. The "survivorship" of STJ post AAA was 98%, 85%, and 74% at 2, 5, and 9 years, respectively.

CONCLUSION

As the largest study of AAA in the literature, our findings suggest prior triple fusion is a major independent risk factor for AAA nonunion. These patients should be counseled of this high risk and may benefit from alternative surgical options.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.