Semiconstrained Elbow Replacement: Results in Traumatic Conditions

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CHAPTER 57 Semiconstrained Elbow Replacement: Results in Traumatic Conditions

Alberto G. Schneeberger, Bernard F. Morrey

INTRODUCTION

Damage or loss of the articular cartilage of the elbow joint may occur in comminuted intra-articular fractures. Late osteoarthrosis may develop as a result of traumatic cartilaginous damage or joint incongruence of insufficiently reduced intra-articular fractures or subluxed unstable elbows.

The treatment of choice for most displaced intra-articular fractures of the elbow joint is open reduction and internal fixation.^28,^32,³³ In a review of nine studies of osteosynthesis of distal humerus fractures, fair to poor outcomes were reported in 25%, with a high complication rate.²⁸ Secondary procedures were required in 70% of the cases. In the elderly, open reduction and internal fixation can be particularly difficult because of marked osteoporosis and extensive comminution.^28,^33,⁶⁸

In elderly patients, the use of hip arthroplasty for fracture of the femoral neck is well accepted.¹³ Similarly, hinged semiconstrained total elbow replacement got wide acceptance in the recent years as an excellent alternative to open reduction and internal fixation of comminuted fractures of the distal humerus, and might be considered the treatment of first choice in properly selected cases of extensively comminuted fractures in patients older than 65 years of age.^*

Post-traumatic osteoarthrosis, however, differs from acute traumatic conditions in several aspects and poses greater treatment difficulties. This chronic painful condition is usually characterized by stiffness, joint and bone deformity with extensive soft tissue contractures, bone loss, and instability. Typically, one or more previous procedures have resulted in a poor soft tissue envelope, infection, and nerve injury.⁵⁹

Few options exist for salvage of severe post-traumatic osteoarthrosis. Arthrodesis reliably relieves pain ⁴¹ but results in great functional impairment,⁵⁴ and hence, is rarely considered a viable option (see Chapter 70).^15,⁴⁶ Interposition arthroplasty may be considered for a young patient, particularly one who has stiffness. Restoration of motion and relief of pain can be achieved with a reasonable (62% to 70%) but unpredictable rate of success.^8,^19,^37,^44,⁶⁵ However, this procedure has an even higher rate of complications than that associated with semiconstrained total elbow replacement (see Chapter 69).^8,⁵⁰ Interposition arthroplasty also is not considered suitable for patients who perform strenuous physical labor.³⁷ Varying results have been reported for allograft replacement of the entire elbow joint.^1,^11,^14,⁶⁶ Concern about the complication rate, instability, continued degenerative changes and fragmentation, and neurotrophic changes of the allograft explain why this procedure has not found wide acceptance (see Chapter 67).

For all of the aforementioned reasons, total elbow replacement using the semiconstrained Coonrad-Morrey prosthesis has become, in our hands, the treatment of choice in these difficult problems in the elderly patient. Our favorable results with surveillance over 12 years are outlined below.

INDICATIONS

ACUTE TRAUMA

The treatment of choice for acute fractures of the distal humerus is open reduction and internal fixation, if possible.^32,³³ The indication for semiconstrained total joint replacement for acute fractures of the distal humerus is mainly limited to patients older than about 65 years of age with an extensively comminuted fracture that is not amenable to an adequate and stable osteosynthesis. The usual findings are as follows: (1) a large number of small fragments, (2) poor mechanical quality of severe osteoporotic bone, (3) significant loss of joint fragments in open injuries, and (4) pre-existing joint damage in patients with rheumatoid arthritis or other inflammatory joint diseases.

TRAUMATIC ARTHROSIS

For post-traumatic osteoarthrosis, total joint replacement using the semiconstrained Coonrad-Morrey prosthesis is, in our hands, the treatment of choice in selected cases. These cases include advanced destruction of the ulnohumeral joint with marked narrowing or loss of the joint space. This pathology is believed to preclude other reliable treatment modalities, such as débridement or ulnohumeral arthroplasty, and only for those patients who are older than 60 years of age. For patients younger than 60 years, total elbow replacement should be performed only with reservation, if no other suitable alternatives of operative treatments are available or for those in whom other reconstructive procedures have failed, such as interposition arthroplasty.⁵ Furthermore, replacement is reserved only for those patients who do not perform strenuous physical activities.

Our experience with the semiconstrained Coonrad-Morrey prosthesis for the treatment of post-traumatic osteoarthritis revealed mechanical complications of the implant in 17% of the cases, most occurring in patients younger than 60 years of age.⁵⁹ Hence, membership in this group, participation in heavy physical work, and anticipated noncompliance are considered relative contraindications for this procedure. For young patients with a severe post-traumatic osteoarthrosis, interposition arthroplasty may be considered the treatment of first choice, rather than total joint replacement (see Chapter 69). In cases of failed interposition arthroplasty, total joint replacement is the treatment of choice for most patients.

FURTHER CONSIDERATIONS

AGE, OCCUPATION, AND PHYSICAL ACTIVITY

Because the total elbow prosthesis is a mechanical device, it is subjected to wear, particularly of the polyethylene bushings.⁶⁷ In our series, those with post-traumatic osteoarthrosis who were younger than 60 years of age had a higher rate of complications (35% versus 17%) and, accordingly, a lower proportion of satisfactory results (78% compared to 89%).⁵⁹ The prosthesis does not tolerate the stress of heavy physical work; thus, after a total elbow replacement, we always advise the patient to avoid single-event lifting of objects that weigh more than 5 kg as well as the repetitive lifting of any object that weighs more than 1 kg. We discourage the playing of golf and other impact sports.

INSTABILITY

Acute or post-traumatic instability is not a contraindication to elbow replacement that involves the use of the semiconstrained Coonrad-Morrey implant ^53,⁵⁹; in fact, the condition is well managed with this device.⁵⁶ Owing to its hinge design, this implant yields immediate and durable stability. In contrast to certain other semiconstrained implants,²⁵ the Coonrad-Morrey device provides valgus-varus and axial stability without the tendency for the components to disassemble. This topic is discussed further in Chapter 53.

BONE LOSS

Significant bone stock deficiency was present in 13 of the 41 patients in our series with post-traumatic osteoarthrosis.⁵⁹ Only the humeral diaphysis is required to obtain secure fixation of the Coonrad-Morrey prosthesis. Rotational and anteroposterior stability is maintained by the anterior flange and bone graft (Fig. 57-1). Thus, this implant does not require the condyles for mechanical support. In acute injuries, the fractured condyles are completely removed, as in the treatment of nonunions (see Chapter 59).⁴⁸ In post-traumatic osteoarthrosis, loss of the condyles does not require their re-construction. This enormously facilitates total elbow replacement and constitutes a great advantage over those total elbow prostheses that need the condyles for stability.^24,^25,⁶⁴

FIGURE 57-1 The implant sits in the nominal location with the absence of all of the distal humeral articulation, approximately 3 cm of bone loss. Use of the long flange allows engagement of the native bone even in the presence of an additional 3 cm of bone loss by allowing the implant not to be fully seated across the deficient 3 cm of distal humeral bone. A total of 8 cm of distal humeral bone loss can be addressed with a noncustom long-flange version of the implant by allowing shortening of 2 cm.

A loss of the distal humerus up to 6 to 8 cm can easily be managed by the noncustom Coonrad-Morrey device.³⁵ The length of the condyles is approximately 3 cm. If the bone loss extends into the supracondylar area and into the shaft of the humerus, the Coonrad-Morrey humeral component with the long anterior flange can be used compensating for another 3 cm of bone loss. In addition, the humeral component can be cemented up to 2 cm more proximally into the shaft. This results, however, in shortening of the humerus with potential weakening of the muscles crossing the elbow joint.³⁰ However, in chronic situations, this might not be appreciated by patients because of muscle contracture or preoperative weakness from pain. In a retrospective analysis, Hildebrand and coauthors²⁹ measured the extensor muscle strength in 16 patients after Coonrad-Morrey elbow replacement for traumatic or posttraumatic conditions. Although the patients had approximately a three times weaker extension strength of the replaced compared with the contralateral elbows, the patient satisfaction with the result of elbow arthroplasty was very high, and triceps weakness did not seem to be clinically appreciated by the patients. Similarly, McKee and coauthors⁴² measured the muscle strength of the elbow, forearm, wrist, and hand muscles in 16 patients with Coonrad-Morrey total elbow replacement that had resection of both condyles and compared the values with 16 cases that had intact condyles. They found no significant differences between the two groups with regard to the various strength measurements and with regard to the Mayo Elbow Performance score.

Traumatic loss of the proximal ulna is a difficult problem and requires reconstruction with allograft or autograft from the iliac crest to restore the site of insertion of the extensor mechanisms (see Chapter 66).

DEFORMITY

Deformity is a feature often encountered in post-traumatic osteoarthrosis expressed as angular abnormalities of more than 30 degrees or translational problems (Fig. 57-2; see also Fig. 57-9).^59,⁶¹ Long-standing deformity results in asymmetrical soft tissue contractures. Unlinked resurfacing total elbow prostheses usually cannot correct this type of deformity, and instability is common. Although hinged semiconstrained prostheses have the major advantage of being able to correct deformity, this correction may be at the expense of persistent or increased asymmetrical loads imparted by the distorted soft tissues, causing an increased wear of the prosthesis. Overall, in our experience, a marked preoperative deformity of the elbows was associated with a significantly higher rate of complications (P = .02).⁵⁹

FIGURE 57-2 A, Preoperative radiograph showing marked osseous deformity in a 41-year-old man who had sustained a supracondylar fracture in his childhood. He had severe pain and moderate instability. B, Anteroposterior radiograph, made 4 years postoperatively, showing worn bushings with recurrence of the valgus deformity. The patient had returned to his previous job as a construction worker, which involved lifting as much as 150 kg on a regular basis, against the advice of the surgeon. C, Postoperative anteroposterior radiograph made after exchange of the bushings. Both the humeral and the ulnar components were found to be solidly fixed.

FIGURE 57-9 A, A 58-year-old farmer showing extensive preoperative osseous deformity owing to a malunited supracondylar fracture from age 10 years. The patient had moderate pain and marked loss of motion. B, Fracture of the ulnar component 9 years after implantation of the prosthesis. The patient had had no pain and had full function during these 9 years, and he had returned to his previous strenuous activities, regularly lifting weights of more than 50 kg, against the advice of the surgeon.

TECHNIQUE: TRAUMATIC CONDITIONS

The operative technique for the implantation of the semiconstrained Coonrad-Morrey prosthesis is described in Chapter 53.⁴⁷ However, some features are unique to this type of prosthesis and should be emphasized. An open type II or III compound fracture should first be irrigated and débrided to avoid wound infection. Total elbow replacement is then performed in a second stage. A type I wound may be treated in a single stage after careful and thorough débridement.

A posterior midline incision is used, including posterior scars from previous procedures. Alternatively, prior medial and lateral incisions can be used for exposure. The ulnar nerve is always identified and transposed anteriorly in a subcutaneous pocket, if the procedure has not already been performed. If condyles are present, the recommended operative technique includes a triceps-sparing approach, which is accomplished by the release and lateral reflection of the triceps from the olecranon in continuity with the ulnar periosteum and the fascia of the forearm, along with the anconeus, as described by Bryan and Morrey.⁷ Alternatively, particularly in acute fractures involving the condyles, the triceps insertion is left intact.³⁵ Overall, triceps strength measurements are not different between the elbows in which the triceps was left on the olecranon and those in which the triceps was reflected and then reattached to the olecranon.²⁹

If contracted soft tissue persists, the humeral component is inserted more proximally after removal of additional humeral bone. All soft tissues are released from the humeral fragments, which are then excised (Fig. 57-3). Cultures are taken if there has been prior surgery. The collateral ligaments are detached from the epicondyles, which allows complete exposure of the elbow joint. The repair of the collateral ligaments is not necessary.

FIGURE 57-3 A and B, For acute fractures, the fracture fragments are completely excised, allowing implantation without removal of the triceps.

Usually, resection of the tip of the coronoid process is necessary to avoid impingement with the anterior flange, which would cause considerable distraction forces on the ulnar component.⁶¹ Too deep insertion of the ulnar component is another potential cause of anterior impingement (Fig. 57-4).

FIGURE 57-4 A, Graph showing correct depth of insertion of the ulnar component. The tip of the coronoid process (1) is resected. There is clearance between the coronoid process and the anterior flange of the humeral component (2). Flexion is unrestricted. B, Too deep insertion of the ulnar component resulting in anterior impingement between the coronoid process (1) and the anterior flange of the humeral component. Flexion is restricted. C, Correct depth of insertion of the ulnar component but the coronoid osteophyte (1) has not been resected resulting in anterior impingement and restricted flexion.

(Redrawn from Schneeberger, A. G., Meyer, D. C., and Yian, E. H.: Coonrad-Morrey total elbow replacement for primary and revision surgery: A 2 to 7.5 year follow-up study. J. Shoulder Elbow Surg. 16(3 Suppl):47, 2007.)

An intramedullary injecting system is used for optimal insertion of cement to which 1 g of vancomycin has been added for every 40 g of cement.¹⁶ An important element is the placement of a bone graft between the anterior flange and the distal part of the humerus to resist, after ingrowth, posterior displacement and rotational stresses on the humeral component. Ingrowth of this bone graft is consistently observed, confirming its role in absorbing mechanical loads.⁵⁹

Significant bone stock deficiencies with the lack of one or both epicondyles do not change or complicate the implantation of the humeral component. This device requires only the humeral diaphysis to obtain secure fixation. Therefore, the reconstruction of the condyles is not required.

The device offers three lengths of humeral component: 10, 15, and 20 cm in standard, small, and extra small sizes with a regular or long anterior flange (Fig. 57-5

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