Abstract
Introduction
The trapezio-metacarpal joint (TMCJ) is subject to constant multiplanar forces and is stabilised by the bony anatomy and ligamentous structures. Ligament reconstruction can correct the hypermobility and potentially prevent osteoarthritis. Eaton and Littler proposed a surgical technique to reconstruct the volar ligamentous support of this joint. In our cadaveric biomechanical study, we aimed to evaluate the resultant effect of this technique on the mobility of the thumb metacarpal.
Materials and method
Seventeen cadaveric hands were prepared and placed on a custom-made jig. Movements at the trapeziometacarpal joint were created using weights. Static digital photographs were taken with intact anterior oblique (AOL) and ulnar collateral ligaments(UCL) and compared with those taken after sectioning these ligaments and following Eaton-Littler reconstructive technique. The photographic records were analyzed using Scion. Image™. Paired T-test was used to establish statistical significance with a p<0.05.
Results
AOL and UCL stabilised the TMCJ in extension. Division of these ligaments produced a significant degree of subluxation of the metacarpal at this joint with the thumb in a neutral position. Reconstruction of the ligamentous supports, using the Eaton-Littler technique, reduced the degree of extension.
Conclusion
The primary stabilising ligament of the TMCJ is a subject of debate. Our study objectively evaluates the effect of reconstruction of AOL and UCL on various movements at the TMCJ comparing with sectioned and unsectioned specimens. It confirms the role AOL and UCL in resisting extension and utility of the Eaton-Littler procedure in decreasing hyperextension at this joint. This may have clinical utility in traumatic injury and degenerative laxity, by reducing pain and potentially slowing or even preventing the progression of osteoarthritis.
