Abstract
Background Thumb carpometacarpal joint (CMCJ) osteoarthritis is common and can lead to significant
morbidity making it a condition frequently treated by hand surgeons when initial conservative
measures fail. The surrounding ligamentous structures are complex and important to
maintain thumb CMCJ stability.
Objectives The aim of this study was to review the normal and arthritic anatomy of the thumb
CMCJ, focusing on morphology and position of osteophytes and the gap between metacarpal
bases, and the effect of these on intermetacarpal ligament integrity. This may be
the sole ligament suspending the first metacarpal following trapeziectomy and could
determine the need for further stabilization during surgery, avoiding potential future
failures.
Methods Computed tomography (CT) scans of a normal cohort and those with arthritic changes
who had undergone trapeziectomy following the scan were identified. The three-dimensional
reconstructions were examined for osteophyte position on the saddle and the intermetacarpal
distance.
Results A total of 55 patients, 30 normal and 25 arthritic, were identified and studied.
The most common anatomic position for osteophytes was the intermetacarpal ulnar aspect
of the trapezium. The intermetacarpal distance increased by an average of 2.1 mm in
the presence of the arthritic process.
Conclusions The findings point to an increase in the intermetacarpal distance, and hence lengthening
of the ligament with potential damage, possibly secondary to osteophyte formation
and wear. Further prospective research is required to determine whether using preoperative
CT scanning to define osteophyte position and measure the intermetacarpal distance
would predict probable damage to the ligament, hence providing an indication for stabilization
and reconstruction in trapeziectomy surgery.
Level of Evidence This is a Level III, retrospective cohort study.
Keywords
thumb carpometacarpal joint - CMCJ arthritis - osteophyte - trapeziectomy - intermetacarpal
ligament
