Clinical Management of Low Motion Joint Pain: Facilitating Ankylosis and Surgical Arthrodesis

Introduction
The exact definition of “low motion joint” is unclear but the joints of the equine distal limb normally associated with this definition are: the proximal interphalangeal joint and the two small distal tarsal joints (centrodistal and tarsometatarsal joints). Other joints have a reduced range of motion but either because they have complex anatomical features or because the synovial space consistently communicates with an adjacent “high motion joint” they are not seen clinically as low motion joints, examples of these are the carpometacarpal and proximal intertarsal joints.

True low motion joints from an evolutionary perspective should be leading to fusion of the adjacent bones as the joint becomes mechanically obsolete. However, the mechanical importance of two cartilage covered surfaces to the damping of impact through the limb must not be underestimated and should be taken into clinical consideration when performing arthrodesis procedures.

The reduced range of motion along with evidence of naturally occurring ankylosis of the TMT-CDT and the PIP joints has lead surgeons to seek methods to achieve fusion of this joints either by internal fixation techniques (arthrodesis) or by facilitating the ankylosis process. These methods have been applied in both the management of intractable osteoarthritis or following traumatic events which leave these joints unstable or severely damaged.  [...]