What is Thumb Carpometacarpal Joint Osteoarthritis (CMCJ OA)?
Thumb carpometacarpal joint (CMCJ) osteoarthritis (OA) is the most prevalent area for OA to occur in the hand, causing significant pain and impacting daily function (Bertozzi et al. 2015; Bulher et al. 2019). OA is the most common form of arthritis in Australia resulting from repetitive loading, traumatic injury, degenerative change and is more frequent in people above 30 years of age (AIHW, 2022). Ladd et al. 2014, reports women’s reproductive hormones play a role in CMCJ OA due to increasing laxity in ligaments.
Diagnosis of CMCJ OA includes a combination of X-rays, objective, and subjective measurements alongside clinical experience.
Unraveling Thumb CMCJ OA: Understanding the Degenerative Changes in the Saddle Joint
Thumb CMCJ OA is defined as degenerative joint change along the carpometacarpal saddle joint, causing joint and cartilage change, osteophytes, and inflammation (Villafane et al. 2013; Villafane et al. 2013). The saddle joint aligns with the trapezium and interphalangeal bone, the shape of the trapezium allows for complex thumb movements including flexion/extension, abduction/adduction, and pronation/supination allowing the hand to grip and grasp objects (Ladd et al. 2014). In combination with the saddle joint the ligaments and muscles assist the joint’s role with stability, laxity, and proprioception (Ladd et al. 2014).
The main ligaments of the CMCJ are the anterior oblique, ulna, volar and dorsal ligaments contributing to the stabilisation of the CMCJ (Ladd et al. 2014). Ligament laxity is a primary cause of instability of the CMCJ causing pain and joint change (Gillis et al. 2011). The adductor muscles attribute to thumb CMCJ pain having a large amount of pull which can force the rotation of the CMCJ alongside the radial nerve increasing pain stimuli (Villafane et al. 2013).
Subjective measurements of the patient include the type of pain experienced, the person’s daily occupations and functional activities, and age.
Depending on the length of time the CMCJ aggravation and pain has occurred can influence the overall outcome.
Questionnaires such as the Quick Dash or the Auscan are a useful tool to assist with determining how CMCJ OA pain is impacting a person’s daily functions (Gillis et al. 2011).
Important objective measures to take during the initial session and RV sessions include grip, pinch, and tripod strength. These measurements are reliable and valid as they can be compared to the general population and the non affected hand (Gillis et al., 2011). As CMCJ OA decreases thumb ROM a person’s thumb can appear to be sitting in further adduction. X-rays assist with identifying the positioning of the CMCJ and any degenerative change through opaqueness at the joint (Kennedy et al. 2016). The Eaton-Littler classification is a guide that can be used with an X-ray to categorise the progression of the CMCJ OA (Kennedy et al. 2016).
Treatment options for Thumb Carpometacarpal Joint Osteoarthritis (CMCJ OA)
Hand therapists incorporate a range of conservative treatments to reduce pain, stabilise ligaments, increase range of motion and strength to assist with hand function (Bertozzi et al. 2015; Gillis et al. 2011). Villafane et al. (2013), reports a study completed with patients having reduced CMCJ pain from 4-6 sessions in two weeks of conservative treatment compared to a group with no conservative management.
Splinting the hand assist allows for support, increasing web space and immobilization of the CMCJ correcting the positioning and reducing pain (Bani et al. 2013). Bulher et al. (2019) discussed and compared splints vs pain, finding a significant difference with wearing a splint and the reduction in pain alongside increased function using the splints in the long term. Bani et al., (2013), found custom made splints improve pain, strength, and hand function.
Gradual exercises provided to patients aim to assist with increasing ROM while maintaining reduced pain at the CMCJ (Villafane et al. 2013). Villafane et al. (2013) found that radial glides can assist with reducing sensitivity to pain stimulation of the CMCJ OA. Overall, a combination of splinting, exercises relating to strength and nerve mobilisation is favourable to decrease pain, however will not increase all patients grip/pinch strength. (Villafane et al. 2013).
Australian institute of health and welfare. (2022). Osteoarthritis. Retrieved from https://www.aihw.gov.au/reports/chronic-musculoskeletal-conditions/osteoarthritis/contents/what-is-osteoarthritis
Bertozzi, L., Valdes, K., Vanti, C., Negrini, S., Pillastrini, P., & Villafañe, J. H. (2015). Investigation of the effect of conservative interventions in thumb carpometacarpal osteoarthritis: systematic review and meta-analysis. Disability and Rehabilitation, 37(22), 2025–2043. https://doi.org/10.3109/09638288.2014.996299
Buhler, M., Chapple, C. M., Stebbings, S., Sangelaji, B., & Baxter, G. D. (2019). Effectiveness of splinting for pain and function in people with thumb carpometacarpal osteoarthritis: a systematic review with meta-analysis. Osteoarthritis and Cartilage, 27(4), 547–559. https://doi.org/10.1016/j.joca.2018.09.012
Gillis, J., Calder, K., & Williams, J. (2011). Review of thumb carpometacarpal arthritis classification, treatment and outcomes. The Canadian Journal of Plastic Surgery = Journal Canadien de Chirurgie Plastique, 19(4), 134–138. https://doi.org/10.1177/229255031101900409
Kennedy, C. D., Manske, M. C., & Huang, J. I. (2016). Classifications in Brief: The Eaton-Littler Classification of Thumb Carpometacarpal Joint Arthrosis. Clinical Orthopaedics and Related Research, 474(12), 2729–2733. https://doi.org/10.1007/s11999-016-4864-6
Ladd, Amy & Weiss, Arnold Peter & Crisco, Joseph & Hagert, Elisabet & Wolf, Jennifer & Glickel, Steven & Yao, Jeffrey. (2013). The Thumb Carpometacarpal Joint: Anatomy, Hormones, and Biomechanics. Instructional course lectures. 62. 165-79.
Villafane, J. H., Bishop M. D., Fernández-de-las-Peñas, C., & Langford, D. (2013). Radial nerve mobilisation had bilateral sensory effects in people with thumb carpometacarpal osteoarthritis: a randomised trial. Journal of physiotherapy, 49(1), 15-30. https://doi.org/10.1016/S1836-9553(13)70143-7
Villafañe, J. H., Cleland, J. A., & Fernández-de-las-Peñas, C. (2013). The Effectiveness of a Manual Therapy and Exercise Protocol in Patients With Thumb Carpometacarpal Osteoarthritis: A Randomized Controlled Trial. Journal of Orthopaedic & Sports Physical Therapy, 43(4), 204–213. https://doi.org/10.2519/jospt.2013.4524