Intra-articular calcium crystal deposition increases frequency and intensity of knee pain
In knee osteoarthritis (OA) cases, intra-articular (IA) calcium crystal deposition is common. A recent study published in Arthritis and Rheumatology has demonstrated a two-times higher likelihood of frequent knee pain and more intermittent or constant pain in patients with intra-articular mineralization.
Low-grade, crystal-related inflammation may contribute to knee pain. In the present study, researchers examined the longitudinal relation of CT-detected IA mineralization to the development of knee pain using data from the NIH-funded longitudinal Multicenter Osteoarthritis (MOST) Study.
At baseline, participants had knee radiographs and bilateral knee CTs. For two years, for every eight months, a pain assessment was done. CT images were scored using the Boston University Calcium Knee Score (BUCKS). They used generalized linear mixed-effects models to examine CT-detected IA mineralization in relation to the risk of frequent knee pain (FKP)/intermittent/constant knee pain worsening and pain severity worsening.
The key results of the study are:
- The study included two thousand ninety-three participants with a mean age of 61 years, 57% female having a mean BMI of 28.8 kg/m2.
- 10.2% of knees had IA mineralization.
- The presence of any IA mineralization in the cartilage has two times higher odds of having FKP.
- IA mineralization was associated with 1.86 times more frequent intermittent or constant pain.
- Similar results were seen for IA mineralization in the meniscus/ joint capsule.
- A higher burden of IA mineralization anywhere within the knee was related to higher odds of all pain outcomes. The OR ranged from 2.14-2.21.
Jean W. Liew, MD MS, lead author of this study, said Patients with IA mineralization had greater odds of demonstrating frequent and worsening knee pain. Therapies targeting crystal deposition should be developed to improve knee osteoarthritis symptoms.
Further reading:
Liew, J. W., Jarraya, M., Guermazi, A., Lynch, J., Wang, N., Rabasa, G., Jafarzadeh, S. R., Nevitt, M. C., Torner, J. C., Lewis, C. E., Felson, D. T., & Neogi, T. (2023). Relation of intra‐articular mineralization to knee pain in knee osteoarthritis: A longitudinal analysis in the MOST study. Arthritis & Rheumatology. https://doi.org/10.1002/art.42649
