PATHOLOGY OF ELBOW STIFFNESS (ARTHROFIBROSIS)

Arthrofibrosis of the elbow is defined as a loss of both extension and flexion of the elbow due to intrinsic and extrinsic abnormalities produced by fractures, dislocations, arthritic conditions, burns, head injury, or cerebral palsy.^{5,13,24,49,52,55} Intrinsic factors include intra-articular damage, fractures, loose bodies, synovitis, and foreign bodies whereas extrinsic factors include contractures due to scarring of the capsule or collateral ligaments, flexor or extensor musculature, instability, heterotopic bone, and skin contractures. Peripheral problems including head injuries, cerebral palsy, and neurologic dysfunction may also result in muscular contracture and spasticity with resultant loss of motion.

In managing a patient with contracture of the elbow, all etiologies must be considered before treatment. Patients with skin contracture or muscle spasticity must obviously be managed in a different fashion from those with intra-articular fracture or arthritic conditions. Commonly, more than one problem is involved in producing a stiff elbow. Each should be evaluated and managed appropriately. Arthroscopic treatment of flexion contracture of the elbow allows the surgeon to address the intrinsic intra-articular causes of elbow contracture, as well as those extrinsic causes that may be safely reached by this technique, including capsular and collateral ligament damage as well as problems with the extensor musculature. The risk of nerve injury, including post-erior interosseous nerve and ulnar nerve injury, is real in these stiff elbows and should be considered by the operative surgeon before undertaking arthroscopic management of this condition. Additionally, in the most contracted elbows, the restoration of motion may also produce late problems with the surrounding nerves, specifically the ulnar nerve. This complication of tardy ulnar nerve palsy may be prevented by arthroscopic or open ulnar nerve release at the time of the index surgery to restore motion (Box 40-1).

HISTORY OF ARTHROSCOPIC MANAGEMENT OF THE STIFF ELBOW

In 1931 and 1932, Burman^6,7 described the use of the arthroscope in cadaveric elbow specimens. The use of arthroscopic techniques for the elbow lagged behind the knee and shoulder until the 1980s, during which time Andrews and Carson² and Poehling et al⁴⁸ reported on techniques for supine and prone arthroscopy. The 1990s brought about more work in elbow arthroscopy, with pioneering articles presented by O’Driscoll and Morrey, Baker, and McGinty.^3,45 The first reports on the arthroscopic treatment of stiff elbows were by Nowicki and Shall,⁴⁴ Jones and Savoie,²⁷ and Byrd⁹ in the early 1990s. As techniques evolved, more reports by Kelly et al, Timmerman and Andrews, Ball et al and numer-ous others were presented.^4,29,61 The works of O’Driscoll and Savoie spearheaded the advance of improved safety and surgical techniques that led to both improved results and expanded indications. Sporadic reports of neurologic injuries have occurred, emphasizing the need for caution and experience when dealing with these difficult problems.^19,27,39

INDICATIONS FOR TREATMENT

Loss of motion of the elbow may cause significant morbidity.^16,65 The American Academy of Orthopaedic Surgeons defines normal flexion of the elbow as 0 to 146 degrees of flexion.⁶⁵ In 1981 Morrey et al⁴² defined a functional arc of motion of the elbow as 30 to 130 degrees of flexion. This 100-degree arc of motion is the arc in which most activities of daily living (ADLs) are performed, and motion less than this results in an inability to perform even minimal ADLs. Certain activities may require more motion, including tying shoes, eating, personal hygiene, and sporting activities. Treatment is indicated for those contractures with a loss of extension of 30 degrees of motion, a loss of flexion of similar nature, and in those patients in whom a greater range of motion is required. As in all areas of the body, pain and functional impairment refractory to nonoperative management represent the primary indication for surgical treatment.

ANATOMIC CONSIDERATIONS

The altered anatomy of the contracted elbow joint makes a thorough understanding of the pathogenesis of contracture and how the anatomy is altered of paramount importance to the surgeon. Because the contracted joint does not distend normally with inflow, neurovascular structures about the elbow may not be safely displaced from the joint during insufflation.

The medial epicondyle and medial intramuscular septum are usually preserved in most cases and are used as a guide to the initial entrance to the elbow joint. The proximal anteromedial portal is generally made in an outside-in manner and kept superiorly and also posterior to the entirety of the brachialis muscle because this approach provides an extra margin of safety that protects the median nerve and brachial artery from possible damage. Distal lateral elbow trauma or contracture may cause hypertrophy or adhesions that may bind the posterior interosseous nerve, increasing the risk of damage from a primary lateral portal. Using the inside-out technique with an anterior superior lateral portal decreases the risk of injury to this structure. Unlike a normal elbow, portal establishment in a contracted elbow joint requires cautious and careful placement of the canula, not only through the skin, but during joint entrance to prevent misdirection by the hypertrophied tissue with resultant soft tissue injury. In severe cases, it may be necessary to develop the tissue plane between the brachialis muscle and the capsule, and secondarily incise and then excise the capsule. It is essential that the anterior neurovascular structures and brachialis muscle be protected by retractors if this approach is attempted. Posteriorly, an adherent medial capsule or extensive olecranon deformity may displace the ulnar nerve, making the initial insertion through a posterior central portal into the olecranon fossa an increased risk. In these cases, it is essential to insert the canula directly into the olecranon fossa and avoid medial displacement that may put this neurologic structure at risk.

During the capsular release and excision, the surgeon must remember the relationship of the capsule to the neurovascular structures. In the anterior procedures, the brachialis muscle lies between the capsule and the anterior neurovascular structures (median nerve, radial nerve, and brachial artery). Thus, arthroscopic capsular release and excision should be continued from within the joint until brachialis muscle fibers are visible but no further. Shaver blades and cutting instruments must be kept in close proximity to the humerus at all times to avoid straying too far anteriorly and potentially into the neurovascular structures by brachialis muscle penetration. Using accessory anterior portals to place protective retractors to hold the brachialis muscle and anterior neurovascular structures away from the operative field is helpful in preventing potential complications. On the lateral aspect of the elbow, the radial nerve courses between the brachioradialis and brachialis muscles. It divides into the superficial radial nerve and the posterior interosseous nerve at the level of the elbow joint. The posterior interosseous nerve courses distally and laterally to the brachialis muscle, and becomes immediately adjacent to the anterior joint capsule in the distal half of the elbow. Scar tissue and hypertrophied joint capsule from injury to this area may tether the posterior interosseous nerve and allow damage to it during release. In these cases, the nerve should be identified by the perineural fat and retracted before continuing the excision distally. Until the location of the nerve is identified, extension of the capsular excision should remain proximal to the radial head. Posteriorly, the ulnar nerve should be identified and protected throughout the procedure. This may be accomplished arthroscopically by incising the capsule under the nerve, locating it, and retracting it, or by a small open incision over the nerve to do the same.

ETIOLOGY

The loss of motion in arthrofibrosis centers around soft tissue trauma,⁶² an injury, or a disease process that produces a synovitic reaction, hemorrhage, and inflammation of the capsule. In arthrofibrosis, the capsular tissues respond to this by thickening and becoming rigid. Attempts to aggressively stretch the capsule produces tearing, creating more hemorrhage and increased stiffness. The elbow is held in a flexed position to accommodate the hemarthrosis and the painful swelling in the capsular tissues. Physical therapy and splinting in this inflammatory phase may actually result in worsening conditions rather than improvement because of the repeated damage inflicted upon the capsule. Collateral ligament injury can further contribute to elbow contracture by allowing abnormal movement, producing further pressure on the damaged capsule.^8,18,40,62 Additional problems occur with the scarring between the triceps tendon and the humerus, restricting flexion and extension by its tethering effect. This effect is more noticeable in the post-traumatic contractures and seems to be especially prevalent after open reduction internal fixation of periarticular fractures of the elbow.

Post-traumatic arthrofibrosis of the elbow may also be secondary to other intra-articular causes. Fractures and osteochondral lesions, articular incongruities, loose bodies, and foreign material may stimulate an inflammatory response in the capsule and result in a mechanical limitation to elbow motion. On the lateral side of the joint, this is often caused by residual deformity in the capitellum, radial fossa, or radial head following osteochondritis or trauma.²⁶ On the medial side of the joint, a more congruous relationship of articular surface exists. Less severe injures to the coronoid or olecranon may produce bony incongruity, resulting in a painful arc of motion and subsequent loss of motion.

The specific components of arthrofibrosis may vary according to the mechanism of injury and postinjury treatment.^50,60 Each factor must be considered in managing the arthrofibrotic elbow.

NONOPERATIVE MANAGEMENT

Management options for the contracted elbow include both conservative and surgical management. All patients with this disorder should undergo an extended trial of nonoperative therapy before surgery is considered. Selective Celestone injections, protected range of motion using a double-hinged elbow brace, and physical therapy including gentle stretching, icing, and joint mobilization, may prove to be beneficial.^11,17 Static splinting is often helpful in obtaining a function arc of motion in the elbow. Caution should always be exercised during therapy to prevent additional capsular damage and worsening of the arthrofibrotic condition.

INDICATIONS FOR SURGERY

Surgical treatment is indicated for those patients who are refractory to conservative management. Both the surgeon and patient should play an active role in the decision to undergo surgical management of the stiff elbow. The etiology of the condition, potential risks, expected results, and possible complications, including the risk of nerve damage, should be understood by both the surgeon and the patient before undertaking operative intervention.

In the past, several authors have described open surgical release techniques for correction of elbow flexion contractures. These techniques include osteotomy of the medial epicondyle with complete anterior capsulectomy and lengthening of the biceps, limited lateral approach with capsulotomy, limited medial approach, and extensive posterior approach.^16,65 Urbaniek and associates⁶⁴ found a decrease in preoperative flexion contracture from 48 to 19 degrees with a lateral approach. Husband and Hastings²⁵ found extension improved from a mean of 45 degrees preoperatively to 12 degrees postoperatively and flexion increased from 116 degrees to 129 degrees.

Open surgical release of elbow flexion contracture produces increased soft tissue trauma from the dissection, postoperative scarring of the capsule and anterior structures that may add to the risk of contracture recurrence, and additional elbow trauma above and below the elbow when an external fixator is used. Potentially increased time before physical therapy may be initiated due to surgical pain and scarring. Additionally, it is difficult to address the entire intrinsic joint pathology without a combined approach of the elbow. In contrast to open release techniques, the arthroscopic release allows the surgeon a complete examination and treatment avenue for intrinsic, intra-articular joint pathology. Removal of intra-articular adhesions, release of asso-ciated scarring, and capsular resection anteriorly and posteriorly can all be accomplished arthroscopically. Evaluation, management, and release of medial and lateral gutter adhesions, as well as collateral ligament release, can also be accomplished arthroscopically, reducing the risk of recurrence and allowing early initiation of a physical therapy program. The main contraindication to capsular release for arthrofibrosis is a lack of experience with elbow arthroscopy. This procedure can be extremely difficult with a high risk of nerve injury and should be attempted only by experienced arthroscopic surgeons.

SURGICAL TECHNIQUE: AUTHORS’ PREFERRED METHOD

The arthroscopic setup for surgical release of the elbow flexion contracture is that of a standard elbow arthroscopy (Box 40-2). A 4.5-mm arthroscope and shaver are used along with standard camera and video recording equipment. We prefer the prone position because it allows better access to both the anterior and posterior capsular structures, but certainly either the lateral decubitus or supine position can be used at the surgeon’s preference. In patients in whom there is quite a bit of scarring around the ulnar nerve or the posterior interosseous nerve, each of these may be approached through a small incision and a Penrose drain used to surround the nerve before attempting arthroscopy to protect the nerve from possible intraoperative damage. Indications for doing this include anteriorly displaced radial head fractures and anterior heterotopic bone for the posterior interosseous nerve, and large osteophytes and extra-articular fragments over the ulnar nerve. If this is deemed necessary by the preoperative evaluation, the posterior interosseous nerve (PIN) is approached through the transbrachioradialis approach of Lister with minimal damage to the surrounding musculature. The ulnar nerve is approached through a small incision posterior to the medial epicondyle. In each case, the arthroscopy can still be accomplished but with an increased margin of safety. The author usually prefers to attempt to expose the nerve arthroscopically in most cases but will use one of the above-mentioned approaches immediately if there is any distortion of normal anatomy near the normal course of the nerve.