Carpal Ligament Injury
The carpal bones are small bones in the wrist fixed together by a complex web of ligaments, which greatly contribute to the overall stability and mobility of the wrist joint. Ligament injuries such as pulls, ruptures or partial ruptures that have not been recognised and treated cause so-called structural instability that can lead to permanent and improper stress on the joint surfaces. Over the course of the years this inevitably leads to osteoarthritis of the wrist. The most common ligament injury is to the scapholunate ligament, which is located between the carpal and lunate bones (see also SLAC wrist I-III).
In most cases this injury comes as a result of a fall on outstretched hands. Pain and swelling appear in the wrist, which could be all too easily taken for a sprain. During conservative therapy measures, it becomes apparent that the actual ligament injury has gone unnoticed for years. So, a trivial incident is often the trigger for the presence of serious symptoms originating from improper stressing of the wrist joint, which ultimately results in a hidden development of advanced osteoarthritis.
Therefore, in the case of a sprain to the hand, should there be any reasonable grounds to suspect ligament injury, further special tests to aid clinical investigation, such as for example, the “Ballottement test” or the “Watson scaphoid shift test” should be carried out. In this way, any existing instability can possibly be recognized in time. Structural and dynamic instability can be identified through x-rays (stress x-rays). Fresh ligament injuries can be detected using MRI scans, but the validity of these for older injuries is not always confirmative. Ultimate certainty can be achieved through an arthroscopic examination of the wrist joint. In this way the ligament damage can be accurately located and quantified. In addition, fresh and old ligament injuries can be distinguished, which is essential for surgical planning.
As long as no structural instability exists, fresh ruptures can be treated conservatively through immobilisation in a cast. Complete carpal ligament tears can rarely be directly sutured or anchored to the bone due to the structural size. Therefore, to ensure safe healing, Kirschner wires are used to fix the wrist joint. These can be removed after approximately 8 weeks. A cast is also required for this duration.
In cases in which the injuries are old, the ligaments cannot be repaired anymore as pathological carpal bone mobility usually exists. Capsulodesis is therefore conducted to stabilize it. This is a corrective operation in which the joint capsule on the affected joint is strongly tightened in order to give the corresponding hold. If a high degree of osteoarthritis is already present, then reconstructive measures to the ligaments are no longer sensible (SLAC wrist I-III).