Ligaments are like taut shrouds which connect the bones and allow the joint surfaces to stay in perfect contact during motion. The wrist has eight bones. Intrinsic ligaments connect small bones to each other while extrinsic ligaments join the carpal bones to the radius and to the metacarpal bones.

The reflex which consists in cushioning a fall by extending the palm of the hand causes hyperextension of the wrist joint. The ligaments that hold together the wrist bones are then subject to excessive stretching, beyond their natural limitations, which in turn causes a sprain. Less often, sprains may also happen during a fall on the back of the hand with the wrist in flexion. Be aware that a wrist sprain may be combined with a fracture of the wrist bones.

There is no direct relationship between the seriousness of a lesion and the feeling of pain. It is often said that serious strains cause little pain, which unfortunately delays early medical attention. When the sprain is isolated, there is no wrist deformity. A hematoma or edema (i.e. subcutaneous tissue swelling) may appear on the dorsal side of the wrist. At times, there aren’t any clinical signs, except for pain when direct pressure is exerted on the affected area. In case of doubt, the wrist should always be immobilized in an anterior splint and referred to a specialized doctor

Are X-rays necessary?

They are indeed necessary, but standard X-rays are likely to be negative. In fact, partial lesions of intrinsic ligaments such as the scapholunate ligament or the lunotriquetral ligament do not cause any instability and produce no radiologic signs in their initial stage. However, the injury is serious and should be treated early, when treatments are the most likely to be successful. If pain persists after a few days, standard AP and lateral view X-rays with no special preparation must be performed, as well as dynamic X-rays (AP view in radial and ulnar deviation, and lateral view in volar and dorsi-flexion). These X-rays are not sufficient but at times show small signs that suggest a lesion, such as a loss of normal bone alignment, abnormal gap between the scaphoid and semilunar bones, horizontalization of the scaphoid, dorsal or ulnar deviation of the semilunar bone on lateral views...

Arthrography and especially arthro-CT scan exams are the standard. They must be performed in very specific medical conditions by experienced radiologists. They require injecting a radiocontrast agent in the midcarpal joint, between the first and second rows of carpal bones. After a few movements, the images may show the radiocontrast agent diffusing to the other wrist joints. This demonstrates an abnormal tear of the intrinsic ligament. However, this exam produces at times false negative and false positive results.

MRI has become more efficient in detecting wrist sprain. The newer probes seem to be of higher quality and produce better results.

Wrist arthroscopy involves inserting a small camera in the wrist joint in order to precisely assess ligament lesions. It is the only examination which allows to establish the exact and definite diagnosis of a ligament tear and of its extent, and potentially to treat it within the same surgical procedure. Arthroscopy is a true surgical procedure which must be performed by specialized physicians. It is carried out in case of documented concern regarding a ligament injury.

The difficulty of the diagnosis lies in the capacity of asserting that a sprain is benign (i.e. without ligament tear). If so, a conservative treatment with three weeks of immobilization is sufficient. In other cases, or in case of doubt, a wrist arthroscopy should be performed in order to detect a ligament injury and to maintain the best chances of recovery of the wrist’s complex ligament system.

For acute lesions, arthroscopy is necessary. It is usually performed as an outpatient procedure under locoregional anesthesia, allowing patients to leave the hospital on the same day and with a simple splint. The arthroscopy, which will be carried out by an experienced physician, involves checking all wrist joints (the distal radioulnar joint between the head of the ulna and the radius, the radiocarpal joint between the radius, the triangular ligament (TFCC), and the first row of carpal bones, and the mediocarpal joint between the first and second rows of carpal bones). This analysis, which is methodical, aims at establishing an exact diagnosis of possible bone or cartilage lesion but most of all at assessing all ligaments in search for a possible tear. In case of intrinsic ligament (for example scapholunate or lunotriquetral) lesion, the treatment will involve realigning the affected bones, suturing the ligament and sometimes immobilizing the joint with metallic rods (“K-wires”) which will be kept for an average of a month and a half. As long as it is carried out early enough (within 45 days of the trauma), such treatment yields excellent results, allowing satisfactory healing of the torn ligaments.

The treatment of chronic lesions is more complex. Chronic lesions usually develop in patients who neglected a seemingly benign sprain which later worsened because of regular wrist use. Most often, the chronic lesion is discovered because of a new incident, at an advanced stage. Treatment of such lesions depends on the patient’s age, his functional needs and the condition of the cartilage. Depending on these components, either a complex reconstruction or a palliative procedure may be carried out, aiming at maintaining sufficient mobility. Among the numerous techniques available, the physicians will choose one based on his experience and adapted to the patient’s needs.

Total wrist arthrodesis, which remains the most extreme technique, aims at blocking the joint in order to suppress pain. Physicians avoid this technique as much as possible, but it may sometimes be the only effective solution.

Since it may cause damage to the ligament system, any impact on the wrist may lead to a sprain. As clinical signs are usually poor, more extensive medical investigations such as MRI or arthroscopy should be carried out in case of doubt. When sprains are treated early, results are often very good, even for severe sprains.