Sprain: A sprain is produced by stretching of the joint. The ligaments are taught by the force of stretch. Both the ligaments and the capsules are involved and suffer from partial rupture but most of the ligamentous and capsular fibers remain intact.
Mechanism of Injury: The joints may be exposed to a severe strain by any direct or indirect force. This leads to maximum stretching of the ligaments. In case of a sprain, they undergo partial rupture, but the joint remains stable. The capsule also suffers from the same process of injury as the ligaments. The deeper strain may involve the synovial membrane which can be torn because of which haemo-arthrosis develops. The ligament can be completely ruptured when the stretching force exceeds the limit of sprain. The joint in this cas4e becomes unstable.
Physical Examination: The physical condition depends upon the severity of the lesion. Nature of injury must be ascertained. There may be ecchymosis, pain, and swelling. Localised tenderness can be elicited over the affected ligament. Movements which increase the stretching of the affected ligament aggravate the pain.
X-ray: Radiological evidence remains inclusive as no bony injury can be elicited.
The joint must be protected from further injury. This can produce a complete tear of the ligament thereby leading to joint instability.
Pain and swelling are treated by rest, elevation of the part and application of ice pack.
Immobilisation: Strapping with Elastoplast can be applied in cases of moderate sprain whereas application of plaster cast in severe cases for a period of 3-4 weeks is enough for the healing of the torn ligaments and capsule.
DISLOCATION AND SUBLUXATOIN:
Dislocation: In this condition, the joint is completely disrupted. The articular surfaces are severely displaced. The ligaments and the capsule which bind the two articular surfaces together are ruptured.
Subluxation: There is disruption of the components of the joint but the articular surfaces remain in partial contact with each other.
Diagnosis of Dislocation and Subluxation
Clinical features: The nature of an injury, pain, swelling, and instability to move the joint rouse the suspicion. There may be characteristic deformity produced by the partial displacement of the joint when this is situated in a more superficial position. The displaced bone can produce compression of the neurovascular system which passes round the joint.
X-ray: X-ray must be taken in two views; Single radiological finding may be misleading and can lead to the wrong diagnosis. There may be an associated fracture at the margin of the articular surface. Unless careful attention is paid, there is the likelihood of overlooking the marginal fracture.
Acute dislocation of the joint must be reduced as an early procedure.
- Neurovascular compression: Delay may produce irreversible damage to the neurovascular system by the prolonged pressure of the displaced bone.
- Aseptic necrosis: Blood supply to the articular end of the bone may be jeopardized which leads to aseptic necrosis of the bone.
Reduction: Reduction can be achieved more satisfactorily under general anesthesia. Sometimes local anesthesia or regional nerve block may be effective to help the process of reduction.
Immobilization: The joint must be immobilized for a period of 2-6 weeks depending on the joint involved. This is essential as the traumatized capsule and ligament heal during this period. Different methods have been adopted for providing rest to the joint, which include cuff and collar sling, strapping and splintage in a stable position.
Physiotherapy: Many joints, especially in elderly patients, may undergo stiffness. Active exercise must be encouraged to regain the full range of movement.
This article was edited by Siora Surgical Pvt. Ltd, a leading orthopedic implants manufacturer. This company is in India and provide supplying services across the world.