What's in a name: Radiology and surgical techniques for CMC thumb joint OA

The carpometacarpal thumb joint (CMC-1) is responsible for the unique function of the thumb, due to the freedom of mobility and forces transmitted through the joint. This makes the joint also very prone for osteoarthritis (OA). The pain and functional deficit can have a disabling effect on daily life for patients. A simplified radiological classification system can help in choosing the right treatment. Thumb height can be measured with the thumb height ratio. Thumb height maintenance is important for keypinch after treatment of CMC thumb joint OA. Radiological follow up after implant interposition is not useful in absence of clinical complaints.
Surgical treatment options are a hemi- or full trapeziectomy, with possible suspension and/or interposition (of an implant or autologous tendon) (LRTI), denervation of the joint or an arthrodesis. Although trapeziectomy is considered as golden standard, hemi-trapeziectomy can be a better option, in which a arthroscopic treatment does not provide benefits over the open technique after 2 years follow up. After 5 years follow up of the pyrocarbon disc interposition, power and range of movement measurements reached almost 100% of the contralateral hand. Patient satisfaction is correlated to the main complaint before surgery, which is seen in different techniques. Further investigation is needed to provide a custom-made treatment per patient.