INTRODUCTION

The ankylosed elbow occurs spontaneously or after formal intent. In either instance, the functional outcome is usually not well tolerated. The reason for this is, first, there is no “optimum” position for elbow fusion. The joint is designed to position the hand in space and to one’s self. Second, the other joints compensate poorly for loss of elbow motion. Analysis of compensatory motion after an elbow arthrodesis has documented a compromised ability to complete activities, despite a significantly increased dependence on spine and wrist motion (Fig. 58-1).¹⁰ Furthermore, the shoulder plays only a modest role in compensation. For these reasons, there is continued value and interest in managing the stiff elbow by prosthetic replacement. The goal is to attain a functional arc of motion.⁷

FIGURE 58-1 The shoulder functions as a ball and joint, whereas the elbow is a hinge allowing flexion and extension. The conal or circumferential motion of the shoulder does not compensate for the to-and-fro motion of the elbow.

INDICATIONS AND PATIENT SELECTION

The primary goal of total elbow arthroplasty is to restore motion to improvement function. We prefer a patient older than 60 years of age if the pathology follows trauma.⁸ However, pathologic and functional considerations may prompt replacement at an earlier age, especially in those with inflammatory conditions. Of note is that the extent of comorbidities that tends to exist in these patients further complicates the execution of the procedure.

Radioulnar, radiohumeral, or a combination of these synostoses, with complete loss of forearm rotation, may occur in more than 33% of patients (Fig. 58-2).¹¹ The incidence of additional joint involvement in the ipsilateral and contralateral extremities was 77% and 46%, respectively, in our experience. In fact, in our experience, an isolated elbow fusion occurred in less than 10% of patients.

FIGURE 58-2 Loss of forearm rotation is common in patients with ankylosed elbows following spontaneous fusion from inflammatory conditions.

Post-traumatic neuropathies are also common and may occur in as many as 40% of patients. As a matter of fact, two patients in our published series had previous Volkmann’s ischemic contracture. These complications mitigate the age factor when considering this procedure.

CONTRAINDICATIONS

Subacute sepsis is an absolute contraindication for conversion of a fused to a total elbow replacement. Chronic sepsis must be carefully assessed with a sedimentation rate and C-reactive protein studies. A staged procedure is performed if there is any question about active infection.

Poor skin coverage is a relative contraindication that can be addressed by soft tissue procedures before the joint replacement (Fig. 58-3). Unwillingness to comply with the 5-kg single event, 1-kg repetitive weight restriction is a reason not to perform total elbow replacement. This implies those involved with heavy use of the extremity such as construction workers should not be offered this operation.

FIGURE 58-3 Because of poor soft tissue in many patients, a preoperative soft tissue reconstruction is essential in order to avoid wound problems after the surgery.

PREOPERATIVE ASSESSMENT

The patient’s functional demands are carefully documented. The precise daily limitations and the impact to one’s daily existence is precisely determined. Presence and ability of the triceps to contract is noted. The examination also specifically evaluates the neurovascular status of the extremity. The quality of the skin is noted. The function of the contralateral elbow and the ipsilateral shoulder, hand, and wrist is documented. The flexibility of the cervical spine is assessed.

RADIOGRAPHIC EVALUATION

Usually, plane films are adequate. Size and quality of the bone, and angular deformity is noted. We pay close attention to the presence of the olecranon and determine by physical examination if the triceps is attached. The size of the medullary canal and presence and relevance of fixation devices is considered (Fig. 58-4).

FIGURE 58-4 A, Gross angular deformity is common. The presence of internal fixation devices increases the likelihood of infection. B, Ectopic bone is the most common postoperative problem that prevents maintenance of functional motion.

EXPECTATIONS

Before surgery, the goals, limitations, and risks are very carefully explained to the patient. Expected outcomes are described based on our experience with approximately 20 cases.^5,11

The high degree of osseous and soft tissue involvement adds a high level of complexity to the procedure. The operative time exceeds 2 hours and, in many instances, requires serial application and release of the tourniquet.

SURGICAL TECHNIQUE

The skin incision is seriously considered because prior surgery is common. Ideally, we incorporate any prior incision. Alternatively, the greatest distance from a prior approach that can not be incorporated is sought.

In all instances the ulnar nerve must be identified and protected. If ulnar nerve symptoms are present, the nerve is dissected distally to its motor branches, and placed in a protected subcutaneous environment. Ectopic osseous entrapment can impede decompression. If the ulnar nerve is not asymptomatic, it is identified proximally, and its course is defined. Protecting the nerve from the operative field obviates any further dissection.

Management of the triceps muscle depends upon the integrity of the triceps attachment and status of the distal humerus. If the condyles are present, or if significant contracture of the extensor mechanism exists, then a triceps sparing approach is employed via a technique previously described.¹

Note: The reattachment occurs with the elbow in 9 degrees of flexion. If the condyles are absent, or if the triceps remains adequately compliant, efforts are made to preserve the existing attachment.

Contractures may be released by entering Kocher’s interval and mobilizing the anconeus along with the extensor mechanism. Medially, the flexor pronator mass is elevated to expose the fused joint site.

Determining the axis of rotation of the implant is a key technical consideration, and in most instances, the remnant of the radial head is used as the landmark laterally. Medially, the prominence of the coronoid is employed as the landmark. The osteotomy begins at this level and follows a curved trajectory emerging posteriorly at a level that ensures the triceps attachment is maintained. Meticulous care is taken to recreate or preserve an olecranon process, providing a functional lever arm for the triceps and protecting the skin from erosion by the implant.

Note: Although all cases will have some loss of architecture to some degree, a custom device is usually not necessary. Preoperative planning will provide insight into appropriate sizing of the stem, which frequently demands modifications such as bending or cutting in order to account for canal deformity.

In those instances when the ankylosis or fusion has resulted in malorientation of the forearm referable to the humerus, specific care is taken to release the soft tissue contracture of the flexors and extensors to avoid an imbalance at the articulation (Fig. 58-5). Likewise, accurate positioning of the ulnohumeral implant will avoid excessive wear that otherwise occurs with maloriented components.

FIGURE 58-5 Aggressive release of the capsule as well as the flexor and pronator muscle mass is essential in order to both balance the elbow and to gain as much motion as possible.

(With permission, Mayo Foundation.)

We have not found a need to perform tenotomy of the biceps or brachialis muscles. In some instances, shortening of the humerus may be required to enhance elbow extension. Two centimeters of shortening generally is adequate to decompress the soft tissue contractureand tends to improve extension by 15 to 20 degrees. Given that these elbows are ankylosed, implications of cosmesis due to shortening are not relevant.

POSTOPERATIVE CARE

The elbow is placed in an anterior splint and is elevated overnight. Physical therapists do not participate in the rehabilitation process. A program of static adjustable splinting employs the Mayo Elbow Brace (AirCast DJO, Vista, CA). A permanent lifting restriction of 5 kg is emphasized, and formal strengthening exercises are discouraged. Prophylaxis for heterotopic ossification in the form of single-beam external radiation of 700 cGy is administered to patients with moderate to severe ectopic bone before surgery without postoperative wound complications or rheumatoid disease. Examination under anesthesia for perioperative elbow stiffness is a common adjuvant to our postoperative management.

RESULTS

Small numbers of ankylosed elbows have been included in the reported results of several previous elbow studies. Similar to our experience, Figgie et al.¹¹ reported a mean arc of motion of 80 degrees (35 to 115 degrees) that was maintained for an average of 5 years.² A 26% complication rate was reported, which was also similar to our experience.

The outcomes, particularly those based on our experience as described below, must be placed in the context of alternative procedures. The only viable one is distraction interposition arthroplasty.⁶ In our practice, the effectiveness of this procedure for patients with an arc of motion averaging approximately 30 degrees before surgery is approximately 80%.⁶ The complication rate is similar.

MAYO EXPERIENCE

Initial evaluation of efforts to treat the stiff elbow by total elbow arthroplasty was reported by Mansat and Morrey in 2000.⁵ Fourteen elbows were evaluated a mean of more than 5 years after surgery. The mean preoperative arc averaged 7 degrees, and nine of the 14 elbows were fused. The other five had less than 30 degrees of motion. After the surgery, the mean arc of motion averaged 67 degrees. These authors emphasized the development of ectopic bone around the joint, which was observed to adversely affect outcomes. We also recorded seven complications in five of the 14 patients. These included superficial infection in three, and a deep infection in two. Overall, approximately 78% of patients indicated they were satisfied with the outcome.

RECENT EXPERIENCE

We have recently updated our experience and reported on 13 consecutive patients with complete ankylosis in 13 elbows. All were treated with a linked semiconstrained noncustom total elbow implant (Coonrad-Morrey, Zimmer, Warsaw, IN) (Fig. 58-6).

FIGURE 58-6 A, This patient with a devastating injury demonstrates angular deformity and a one-bone forearm. B and C, Eight years after implantation without cement on the humeral side, the implant is well fixed. There is no wear. The arc of motion is 80 degrees.

The mean age at the time of the surgery was 54 years (range, 24 to 80 years). The stiffness was a consequence of trauma in 10, juvenile rheumatoid arthritis in one, and rheumatoid arthritis in two elbows.

Patients were followed for a mean of more than 11 years, being evaluated clinically and radiographically. An average arc of 81 degrees from 37 degrees extension to 118 degrees of flexion was achieved. Objective outcomes were good or excellent in only seven of 13 elbows (55%) at final surveillance. Subjectively, 10 patients felt better or much better after surgery and would elect to undergo the procedure a second time.

Complications required reoperation in more than half of patients. Two elbows developed wound healing problems requiring débridement. Implant revision was required in only one elbow owing to failure of the ulnar component. In spite of prophylactic measures undertaken to prevent heterotopic ossification that were not successful in this series, we could not be certain of the efficiency of this treatment.

Only one patient required revision for implant failure due to progressive loosening of a polymethylmethacrylate precoat ulnar component with subsequent fatigue fracture at 5 years, 8 months postoperatively.⁴ Ectopic ossification was present to varying degrees in four elbows despite the administration of prophylactic external-beam radiation in three of the four.

COMPLICATIONS

The complication rate of total elbow replacement approaches 20% in most series.^3,9,12 In our practice, three of the 13 elbows encountered a periprosthetic complication including soft tissue compromise in two and infection in another. One elbow developed skin necrosis requiring débridement and coverage with a myocutaneous latissimus flap. Another elbow required débridement and primary closure for superficial dermal lysis.

CONCLUSION

Total elbow replacement as a salvage for a dysfunctional ankylosed elbow should be performed with caution. However, the outcome can be reliable and durable, having a dramatically positive impact on patient function and satisfaction. The high potential for complications, however, must be considered. We consider this an acceptable procedure in select patients with reasonable expectations. Use of a linked implant is essential. Custom devices are unnecessary.