First Episode of Dislocation and Simple Instability: Management and Rehabilitation

Abstract

The definition of elbow dislocation is still debated both with regard to its classification and to the difference between subluxation and dislocation. Even though the present chapter addresses simple dislocation, it is useful to view it against a broader background. As noted by Dr. Rotini in his contribution, the first major divide is between subluxation/dislocation and instability: “we can describe dislocation/subluxation as a static condition of joint incongruence, generally produced by a lesion of a number of stabilizers, and instability as a dynamic condition where—due to the lesion of one or more stabilizers—a reduced joint can lose its congruence (dislocation/subluxation)”(Rotini R, An overview about elbow instability. Musculoskelet Surg 98(Suppl 1):S1–S3, 2014). In both subluxation/dislocation and instability, the following key criteria must be considered:

• severity (simple or complex elbow instability)

• direction of displacement and mechanism of injury

• timing of the injury.

Simple elbow instability involves dislocation with soft tissue disruption but no fracture(Hildebrand et al., Acute elbow dislocation: simple and complex. Orthop Clin North Am 30(1):63–79, 1999; de Haan et al., Simple elbow dislocations: a systematic review of the literature. Arch Orthop Trauma Surg 130:241–249, 2010a), whereas in complex elbow instability the ligament lesion is associated with a periarticular bone fracture.

Simple dislocations may be:

• Anterior: elbow hyperextension injury (1% of dislocations)

• Posterior: associated with a fall on the outstretched hand with the wrist supinated, the forearm externally rotated, and the shoulder internally rotated (99% of cases)

• Divergent: the ulna and radio diverge in opposite directions, also injuring the interosseous membrane (< 1%).