Vitamin D and the accuracy of nuclear medicine imaging in patients with prosthetic hip and knee joints - a retrospective study.

OBJECTIVE: Nuclear medicine is a well-established modality for assessing infection or loosening of prosthetic joint replacements. However, previous research suggests that loosening and low-grade periprosthetic infection can appear similar. Patients with vitamin D deficiency have been noted to have poorer outcomes postsurgery for both infection and loosening. Patients with low-grade uptake and low vitamin D levels may be mismanaged if imaging is inaccurate. This study evaluated the association between nuclear medicine imaging accuracy and vitamin D levels in patients with prosthetic joint replacements.

METHODS: A retrospective single-center cohort study was carried out. Data were collected anonymously with 298 cases including knee and hip prostheses. Clinical findings were split into two categories: matched, whereby scan reports agreed with clinical findings, and unmatched, whereby they did not match and therefore imaging was inaccurate. Chi-squared and Fisher's exact tests were performed to assess statistical significance.

RESULTS: Analysis shows a statistically significant association between imaging accuracy of prosthetic joint replacements and vitamin D level (P < 0.001). There was no significant difference between prosthesis types. Patients with low vitamin D were 2.61 times more likely to have inaccurate results.

CONCLUSION: There was an association between vitamin D levels and nuclear medicine imaging accuracy, and imaging results in cases with low vitamin D levels were two times more likely to be inaccurate. Prospective research would be appropriate to further confirm this. Vitamin D levels could be used as an indicator for the accuracy of imaging results, or low vitamin D levels could be managed before imaging.