Injuries to the ligaments of the wrist usually occur in a similar way to fractures to the wrist and scaphoid bone – through a fall or impact onto an outstretched hand, with the wrist in an extended position.
The key ligament that can be injured in this way is the one that binds the scaphoid and lunate bones together – the scapholunate ligament. A similar ligament that binds the other side of the lunate to the triquetrum, the lunotriquetral ligament, can also be injured, although this is less common. A structure known as the Triangular Fibro-cartilage Complex (TFCC), which sits between the end of the ulna and the lunate and triquetrum, is also vulnerable, sometimes even after a seemingly innocuous injury. This structure has a number of functions, including binding the radius to the ulna and contributing to the stability of the distal radio-ulnar joint.
Unfortunately, diagnosis of these injuries is not always straightforward. A spectrum of injury exists, from a partial tear that might just cause an annoying niggling discomfort for a few months, to a complete rupture of a ligament. TFCC tears can cause persisting pain on the outer side of the wrist, or even difficulty with rotational movements of the forearm.
Mr. Gidwani will be able to formulate a provisional diagnosis after examining your wrist and reviewing the results of your X-rays and MRI scans. The most accurate way of assessing these structures however is through arthroscopy of the wrist joint. This may be purely a diagnostic procedure, which will allow planning of any definitive surgery that might be necessary. However some injuries, such as TFCC tears, can be treated at the same sitting.
The wrist is suspended by attaching finger traps to two fingers. Four small cuts (‘portals’) are made in specific positions on the back of the wrist, two for the radiocarpal joint and two for the midcarpal joint. This allows the insertion of a 2.7mm arthroscope, with the other portal for each joint being used to insert a probe or a 2.5mm shaver. The cartilage surfaces of the bones and the TFCC, and the ligaments binding the bones, can be carefully inspected and probed to check for injury. The shaver can be used to debride (remove) torn pieces of tissue, for example from the TFCC. In certain cases it is possible to carry out an ‘arthroscopic’ repair of the TFCC, if a tear exists at its attachment to the capsule of the wrist joint.