Complex elbow Instability: treatment and rehabilitation

Complex elbow instability represent a challenging injury even for expert elbow surgeons. Chronic instability, posttraumatic osteo-arthritis, stiffness and poor functional outcomes are frequent if these injuries are not adequately treated. A correct preoperative evaluation includes X-rays, CT scan with 2D and 3D reconstruction and stability tests under fluoroscopy in order to recognize all osseous and ligamentous lesions. The most common patterns of complex elbow instability includes: (1) radial head fractures associated with lateral and medial collateral ligaments lesions; (2) coronoid fractures and lateral collateral ligament lesion; (3) Terrible Triad; (4) fracture-dislocations of the proximal ulna and radius, also referred to as transolecranon fracture-dislocations and Monteggia-like lesions; and (5) humeral shear fractures associated with lateral and medial collateral ligament lesions. The main goals of the treatment are (1) to perform a stable osteosynthesis of all fractures, (2) to obtain concentric and stable reduction of the elbow throught the repair of soft tissue constraint lesions and (3) to allow early motion. All the patterns of complex elbow instability share the same therapeutic algorithm based on seven main principles: 1) the proximal ulna must be anatomically reduced and fixed; 2) the radial head or humeral shear fracture must be repaired or replaced, 3) bone length, alignment and rotation of ulnar and radial shaft fractures must be recovered; 4) the lateral collateral ligament complex must be repaired to obtain elbow stability; 5) the medial collateral ligament must be repaired if persistent instability is observed after lateral collateral ligament repair; 6) an hinged external fixator must be considered if the elbow remains unstable or the protection of the joint reconstruction is required; 7) re-evaluation of the surgical steps if congruent ulno-humeral and radio-humeral joints have not been achieved. Following the surgical treatment an adequate rehabilitation programme should be started promptly and continued for at least 6 months since a significant improvement of the range of motion occurs prevalently in this period, which should be considered the critical time period to obtain a functional elbow.