CHAPTER 7 The Stiff Elbow: Arthrofibrosis
The elbow is particularly prone to stiffness following trauma. This propensity has been attributed to several factors, including the congruous nature of the joint, the presence of three articulations within a synovium-lined cavity, and the close relationship of the joint capsule to the intracapsular ligaments and surrounding muscles.1 Because of these factors, post-traumatic loss of motion is the most common complication after injury to the elbow joint. Arthroscopic techniques can improve motion and function in selected cases that fail conservative measures.
The capsule of the elbow is normally thin and transparent and has a high degree of elasticity (Fig. 7-1). However, after even relatively minor trauma, the capsule can undergo structural and biochemical alterations, leading to thickening, decreased compliance, and loss of motion.2 Prolonged immobilization after trauma may be a separate risk factor for the development of stiffness. In addition to capsular changes, the concavities of the humerus above the trochlea—the olecranon and coronoid fossae—can become filled with scar and fibrous tissue after injury. These fossae must be clear to accept the coronoid and olecranon processes at terminal elbow flexion and extension, respectively. In long-standing cases, secondary contracture of the brachialis and triceps muscles can limit motion.
FIGURE 7-1 A, Anterior view of a cadaveric elbow specimen shows that the anterior muscles have been removed, revealing the elbow capsule. Notice that the normal capsule is thin and partially transparent. B, The capsule has been released and reflected distally, exposing the articular surfaces. The capsule originates well proximal to the trochlear cartilage along the anterior humerus. After trauma, this thin membrane can become thick and contracted, limiting joint mobility.
History and Physical Examination
Patients with post-traumatic stiffness typically present with limitation of motion. Important aspects of the history include the mechanism of trauma, the initial treatment, and whether they have plateaued in their motion during rehabilitation. Loss of elbow extension is more common than loss of flexion. The examination must include observation of the upper extremity, looking specifically for deformity, swelling, atrophy, and other diagnostic characteristics.
Range-of-motion evaluation should include the hand, wrist, forearm, and elbow. Motion should be compared with the contralateral, uninjured side. Motor and sensory testing is required to evaluate nerve function. In patients with elbow stiffness, it is important to evaluate the ulnar nerve in the cubital tunnel. The nerve lies along the medial elbow joint capsule, and it can become scarred and adherent to the surrounding soft tissues along the medial joint line after trauma. Although some patients may report tingling and numbness in their ulnar digits (especially with elbow flexion), traction neuritis can manifest as medial elbow pain alone. It may even be a factor contributing to elbow stiffness. It is important to document ulnar nerve sensitivity to percussion (i.e., Tinel’s sign) and any medial joint pain or neurologic symptoms that occur at maximum elbow flexion.
Plain radiographs of the elbow should include frontal, lateral, and oblique projections. In some cases, such as after fracture, advanced imaging can help to define joint congruity. A requirement for elbow release surgery includes a congruous joint with an adequate ulnohumeral joint space, at least centrally. This can typically be determined by plain radiographs. Occasionally, computed tomography is required to document joint congruency, especially in the post-traumatic setting. It also can document that there is no bony impingement or overgrowth in the olecranon and coronoid fossae.
Indications and Contraindications
Patients are candidates for contracture release if they have restricted elbow motion, with a flexion contracture of at least 25 to 30 degrees or less than 110 to 115 degrees of flexion, or both. Patients typically should have failed a course of supervised therapy, including proper splinting. A congruous ulnohumeral joint is required, as is adequate soft tissue coverage of the operative site. An interval from injury to operation of at least 3 to 4 months allows for resolution of post-traumatic inflammation.
Relative contraindications to arthroscopic elbow release include severe elbow contractures with minimal joint motion, prior ulnar nerve transposition surgery, and the presence of significant heterotopic bone. Surgical release of a contracted elbow is also contraindicated if a patient is deemed unable or unwilling to comply with the extensive program of postoperative therapy. Operative results depend on participation in a structured rehabilitation program. This is especially true for adolescents, who may not be dedicated to improving their elbow motion. If the ulnohumeral joint is incongruous, a simple release of the joint may not lead to improved motion and may worsen pain. Although pain at the extremes is common, patients who are candidates for elbow release surgery typically are pain free within their allowable arc of motion. If advanced post-traumatic arthritis exists in the ulnohumeral articulation, salvage-type procedures are required if surgery is undertaken.3
Patients who are candidates for elbow release surgery should undergo a course of structured rehabilitation. This ensures compliance and helps document that they have reached a plateau in their motion and function. In the past, dynamic splints that apply a constant tension to the soft tissues over long periods (e.g., 23 hours per day) were popular. However, patient-adjusted static braces are more effective for the elbow (Fig. 7-2). These braces use the principle of passive progressive stretch, allowing for stress relaxation of the soft tissues. They are applied for much shorter periods and are better tolerated by patients. Only when conservative measures fail and there remains a significant loss of mobility is surgical intervention considered.
Arthroscopic release of a post-traumatic elbow is much more difficult and complicated than arthroscopy for simpler conditions, such as loose bodies. The technique requires experience and knowledge of elbow stiffness surgery and demands advanced skills in elbow arthroscopy. Multiple portals are required, fluid management is essential, and arthroscopic joint retractors are helpful to aid in visualization. This is especially true after capsulectomy, when joint distention is more difficult.
Specialized instruments can be helpful, such as cannulas that do not have any holes near the tip (Fig. 7-3). Because the elbow is smaller than, for example, the knee, and has less intra-articular space, standard cannulas can lead to fluid inadvertently entering the soft tissues while visualizing the joint.
FIGURE 7-3 Close-up view shows the arthroscopic cannulas used for the elbow. Traditional cannulas (top) for larger joints commonly have an oblique end with holes near the tip to facilitate flow. Specialized cannulas (bottom) for the elbow do not have outflow holes. This is important because the distance between the cannula tip and the joint capsule can be quite small in the elbow, allowing fluid to extravasate inadvertently into the soft tissues. Fluid management is important when performing an elbow release arthroscopically.
In very experienced hands, the procedure appears equivalent to more traditional open methods. However, there is clearly a learning curve, and potential complications must be appreciated. They include nerve injury, excessive fluid extravasation, and iatrogenic chondral damage.4–9 If there is a question regarding visualization or safely, the surgeon must be prepared to convert the procedure to an open approach.10–13
From a purely mechanical standpoint, to improve elbow extension, posterior impingement must be removed between the olecranon tip and the olecranon fossa. Anteriorly, tethering soft tissues, such as the anterior joint capsule and any adhesions between the brachialis and the humerus, must be released (Fig. 7-4