INTRODUCTION

Distal humeral hemiarthroplasty (DHH) was first described in 1947, yet over the past 60 years there have been only a few small series reporting on this technique.^{1,14,17,25–28} Early series reported treatment of a variety of pathologic conditions, including trauma, inflammatory arthritis, and tumor. Prostheses included both custom-made (of various materials) and nonanatomic humeral components from total elbow systems (capitellocondyllar, kudo) and anatomic components (Street). These early surgeries met with mixed results. The past decade has witnessed renewed interest in DHH with advancements in our understanding of elbow biomechanics and with growing experience in the difficulty of achieving effective outcomes in treating complex distal humerus fractures. This technique provides a treatment alternative that bridges the gap between internal fixation and total elbow arthroplasty (TEA) in unsalvageable distal humeral articular surface pathologies.

INDICATIONS AND CONTRAINDICATIONS

The indications for DHH are evolving, both in terms of what is achievable and what is appropriate (Table 52-1). Initial experience has been in the younger patient or the physically active older patient with a comminuted intra-articular distal humeral fracture (sometimes combined with a column fracture) that involves both trochlea and capitellum, where an adequate reduction and internal fixation cannot be achieved. Open reduction internal fixation (ORIF) remains the gold standard of operative treatment; however, patient factors and bone architecture may limit the surgeon’s ability to reconstruct the elbow. Series reporting on ORIF of comminuted intra-articular fractures indicate a substantial rate of unsatisfactory outcomes and a significant complication rate in complex cases.^{1,14,17,23,24}

TABLE 52-1 Indications and Contraindications for Humeral Hemiarthroplasty

INTRODUCTION

Recognition and focused management of radiohumeral joint arthrosis has emerged over the past several years. Herein we describe the concept and the rationale for capitellar replacement, placing this option in the context of other potential nonprosthetic interventions. One feature that characterizes virtually all of these possibilities is the lack of clinical data of outcomes at this point in time. With the next edition of the book, this whole topic will be much better elucidated. The reader should bear in mind that the information offered here is principally to call attention to the process and to highlight emerging options without claiming at this time that this is the ultimate or final solution to the problem.

ETIOLOGY

Like so many other pathologic conditions, it seems as though the process is more frequent once we are attuned to investigate for its presence. In general, as a condition, primarily osteoarthritis at the elbow, generally considered uncommon in the past, is today well recognized in the orthopedic community.^3,6,10,11 Pathology of the radiohumeral joint occurs from primary osteoarthritis, as a sequelae to osteochondritis dissecans, following capitellar fracture, or secondarily to radial head fracture either ignored, treated by open reduction and internal fixation, or by prosthetic replacement. Finally, the condition is seen after split T and Y type of fractures of the distal humerus resulting in malalignment (Fig. 52-8).

FIGURE 52-8 Radiohumeral arthritis with primary involvement of the capitellum after capitellar fracture is treated by resection (A). The distal T-condylar fracture resulting in isolated radiohumeral involvement (B).

The frequency and impact of these various conditions is not readily available in today’s literature. There has been some interesting studies referable to primary osteoarthritis of the radiohumeral joint that are worth noting. Ortner¹³ examined the elbow of a population of Eskimos and South American Indians. As a result of this investigation, the authors describe several forms of osteoarthritis at the radiohumeral joint including (1) hypertrophic bone formation peripheral to the articular surface; (2) hypertrophic bone formation in the radial fossa; (3) increased porosity and hypertrophy of the lateral condylar ridge; (4) porosity of the capitellum and; (5) eburnation of the capitellum. These authors note interestingly and accurately that the narrowing of the ulnohumeral joint is not a characteristic of primary osteoarthritis but is more frequently seen at the radiohumeral joint. On the other hand, the osteophyte formation is more commonly observed in the margin of the trochlea and at the coronoid and tip of the olecranon. Subsequently, Goodfellow et al¹¹ documented the increasing incidence of osteoarthritis of the radiohumeral joint with aging and emphasized the early development of the process at the posterior medial ridge separating the trochlea and the capitellum (Fig. 52-9).⁴ Occupation risks in foundry workers was documented. In general, heavy, repetitive use of the extremity places the joint at risk.

FIGURE 52-9 In some instances joint narrowing of the radiohumeral joint is exhibited as shown by the radiograph and CT (A and B).

Typically, this process appears to be relatively asymptomatic, but with enhanced awareness and closer scrutiny, the presence of radiohumeral joint symptoms is being increasingly appreciated. These observations have been confirmed somewhat in the recent documentation of intervention for primary osteoarthritis of the elbow. Kelly et al⁷ described radiohumeral narrowing and instances in which the ulnohumeral joint was débrided arthroscopically. They noted that the radial humeral involvement often typically appears to be well tolerated and need not be directly assessed. Others emphasize the technical ability to débride the ulnohumeral joint but do not comment to any extent on the radiohumeral joint. Although both closed^7–9 and open procedures^1,14,16 are well-accepted means of treating primary osteoarthritis of the elbow, few make reference specifically to the management of the radial head.^7,9 Radiographically, however, the radial head involvement has been documented by Dalal.² In this study of 50 patients with primary osteoarthritis, radial head involvement was present in approximately 85% but was not typically symptomatic. Some narrowing of the joint was present in approximately 60% compared with only 15% narrowing of the ulnohumeral joint. Savoie’s group is one group that has addressed the radiohumeral component of primary osteoarthritis. These authors perform radial head resection through the arthroscope and, in so doing, document improved motion in both flexion and extension and pronation and supination.⁹ The long-term impact, however, of removing the radial head in the presence of ulnohumeral joint arthrosis is unknown. This is one of the major issues that prompts one to consider possibly replacing this joint if it is symptomatic enough to deserve treatment on its own merits.

TREATMENT OPTIONS

Experience to date on the treatment of isolated radiohumeral arthrosis or particularly a capitellar arthritis is limited. In general, the treatment options include débridement versus reconstruction. The reconstructive options have relatively little data, but these consist of resecting the capitellum, analogous to isolated resection of the radial head but with little data regarding its outcome. Débridement is effective in those with symptomatic osteochondritis dissecans, particularly when the fragment is loose and causing mechanical symptoms (see Chapters 19 and 38).

Biologic interposition arthroplasty or prosthetic replacement of the capitellum and/or the capitellum and radial head is a consideration. When the capitellum has been destroyed as a result of fracture, often with resorption, a unique problem exists for which there is no good solution. We have performed allograft replacement with or without interposition arthroplasty in a few of these patients. We have also performed an anconeus rotational plasty in patients with deficient or arthritic capitellum and this does seem to be an effective modality. This procedure does not, however, provide axial stability.¹² Without question, one of the greatest problems with the radiohumeral joint relates to problems at the articulation after the radial head has been fractured and treated by fixation or prosthetic replacement. Under these circumstances, the radial head is typically excised or the prosthesis is removed. If the medial collateral ligament is stable, this is adequate treatment. If, however, the medial collateral ligament is unstable, then the major indication for consideration of a prosthetic implant exists. This is intended to satisfy the need to stabilize the “lateral column” in instances in which there is deficient medial collateral ligament or axial instability such as an Essex-Lopresti lesion. There is some, but limited, experience with prosthetic replacement to date (Pooley J, personal communication).

ANCONEUS ARTHROPLASTY

Indications

In general, this technique is employed in instances when the proximal radial ulnar or ulnohumeral dysfunction occurs following trauma or resection, or after primary osteoarthrosis. This procedure was designed for two clinical circumstances: (1) radiohumeral impingement, in which the goal is to buffer the proximal radiocapitellar articulation; and (2) rotatory radioulnar impingement.

Anatomy

It is important to recognize that the mean length of the anconeus is rather significant, averaging 9 to 10 cm, with a mean width of 3 cm (Fig. 52-10).^12,15 The neurovascular survival is by way of a continuation of a branch of the distal radial nerve.

FIGURE 52-10 The anconeus muscle is of substantial length, frequently measuring 9 to 10 cm, and is innervated by a terminal branch of the radial nerve distally.

The Surgery

1. The patient is supine, and the arm is brought across the chest. Kocher’s interval is entered and extended proximally past the lateral epicondyle for a distance of about 4 cm. The anconeus is exposed, and the fascia investing the anconeus is split.

2. The muscle is then harvested from distal to the proximal, leaving the proximal pedestal for its neurovascular supply (Fig. 52-11).

3. The anconeus for either application is brought under the lateral collateral ligament.

4. If the goal is to provide a space-occupying buffer between the proximal radius and the distal capitellum, drill holes are placed from posterior to anterior through the capitellum. The anconeus is folded several times on itself in an “anchovy” type of fashion (Fig. 52-12). It is inserted between the radius and the capitellum, and the sutures are securely tied.

5. If the goal is to serve as an interposition between the proximal radius and the ulna, the distal portion of the anconeus is brought distally between the radius and the ulna. A drill hole is placed in the radius, and the anconeus is wrapped around the proximal radius. The fascia is closed with a running suture.

FIGURE 52-11 The anconeus muscle is reflected from distal to proximal by maintaining its attachment to the triceps to maintain its neurovascular integrity.

FIGURE 52-12 By folding the anconeus on itself and stabilizing with a suture through the capitellum, the muscle serves as a buffer against proximal radial migration.

Aftercare

The patient is protected in a splint for approximately 5 to 7 days. Passive motion is then allowed for 2 to 3 weeks. Active full motion is encouraged, starting at about 1 month following surgery.

Outcomes

We have reported this technique and our experience in 14 patients who had been treated with one of these types of anconeus interposition arthroplasty with surveillance of at least 2 years (mean, 6.1 years). Twelve of 14 rated their outcome as a success. This included 4 of 5 with Essex-Lopresti injuries (Fig. 52-13).¹²

FIGURE 52-13 This patient with an Essex-Lopresti lesion was managed by an anconeus interposition arthroplasty. At 1 year, the proximal radial migration is still present, and there are minimal wrist symptoms as well as minimal symptoms at the elbow. Anteroposterior (AP) view of the wrist (A); AP view of the elbow (B).

CAPITELLAR PROSTHETIC REPLACEMENT

Indications

Specific indications are those instances in which the radiohumeral joint is painful and arthritic and when simple excision of the radial head is not adequate owing to the need to stabilize the lateral joint. The most compelling indications are (1) a need to stabilize the lateral column due to deficiency of the medial collateral ligament or (2) in those in whom there is axial radial instability in the face of capitellar arthrosis or deficiency. The capitellum may be replaced to articulate with the native radial head (Fig. 52-14) or in conjunction with a radial head replacement (Fig. 52-15). The latter requires a polyethylene articulation to articulate with the metallic capitellar device (Fig. 52-16).

FIGURE 52-14 This patient has traumatic arthritis of the capitellum (A and B). Although the radial head is involved, it is maintained because it is believed to be a more reliable articulation than a prosthetic radial head (C and D).

FIGURE 52-15 Patient with a medial collateral ligament laxity and lateral column instability due to significant resection of the radial head and neck (A). Patient treated with capitellar implant and an augmented neck radial head prosthetic replacement. Note a normal ulnohumeral relationship has been restored (B).

FIGURE 52-16 The radiocapitellar replacement includes a metallic articulation of the capitellum and a polyethylene articulation of the radial head.

Surgical Technique

Step 1: Incision. The patient is placed under a general or a regional anesthesia, and a tourniquet is employed. An arm table may be used or the arm may be brought across the chest.

A classic Kocher skin incision is made, identifying the interval between the anconeus and the extensor carpi ulnaris. The incision extends approximately 6 to 7 cm. The dissection is carried down to the joint capsule.

Step 2: Exposure. If the elbow is stable, the capsule is exposed by elevating a portion of the extensor carpi ulnaris sufficiently to allow identification of the lateral collateral ligament complex (Fig. 52-17). Alternatively, the extensor carpi ulnaris may be split longitudinally, with its fibers staying anterior to the humeral attachment of the lateral collateral ligament. The lateral collateral ligament can be refleced off the lateral epicondyle to expose the capitellum. If the ligament has been disrupted, then the exposure progresses through the site of disruption to expose the radiohumeral joint. The common extensor tendon and elbow joint capsule are retracted as needed to maximize exposure.

FIGURE 52-17 The radial head is exposed in a typical fashion. We employ the Kocher’s interval. The capsule is entered and the attachment to the humerus is released sufficiently to provide adequate exposure for the intended surgery.

Note: If the radial head is not replaced, a greater amount of soft tissue release is necessary for adequate exposure.

Step 3. Axis of Rotation. Attach the appropriate sized capitellum template to the drill guide, and align the template to the curvature of the capitellum (Fig. 52-18). The curvature of the edge of the template should align with the most distal articular surface of the original capitellum. Once alignment is achieved, insert a 0.062 K-wire through the drill guide, and advance medially to the midline of the distal humerus (Fig. 52-19). Leaving the K-wire in place, remove the axis of rotation locator clamp and template.

FIGURE 52-18 The anatomic center of rotation of elbow flexion is identified laterally by the tubercle of the lateral epicondyle (A). The curvature of the capitellum is matched by the template, which corresponds to the axis of rotation (B).

FIGURE 52-19 (A and B) The axis of rotation is replicated by a .062 K-wire, which is inserted by the use of a targeting guide.

Step 4: Capitellar Resection. There are two resection guide sizes: small and large. Based on the size of the capitellum, place the appropriate resection guide. Align the resection guide handle so that it is parallel with the long axis of the humerus (Fig. 52-20).

FIGURE 52-20 The resection is of a Chevron type. A distal guide is employed initially to avoid excessive resection.

Insert a sawblade into the chosen slot in the resection guide, and remove the appropriate amount of capitellum surface. The cut should not involve the trochlea.

Step 5: Capitellum Trial. Place and stabilize the capitellum trial flush against the resected surfaces (Fig. 52-21). Insert the reference K-wire, which serves as the alignment pin for subsequent preparation.

FIGURE 52-21 A trial reduction allows the insertion of a reference pin, which is used with a cannulated drill, followed by a cannulated rasp.

Step 6: Broaching of the Distal Humerus. Remove the trial capitellum leaving the reference K-wire. Pass the cannulated 0.35-mm drill over the center K-wire to create the broach pilot hole into the distal humerus. Align the broach with the apex of the Chevron cut, insert broach into the pilot hole and advance until the teeth are at the same level as the capitellum osteotomy (Fig. 52-22). Care should be taken to ensure proper alignment and not to overbroach the distal humerus.

FIGURE 52-22 The cannulated rasp is carefully aligned to match the apex of the Chevron cut. This provides proper orientation for insertion of the capitellar replacement.

Step 7: Implanting the Final Component. Once broaching is complete, the definitive implant can be inserted (Fig. 52-23). Distraction of the proximal radius as well as flexion of the elbow may be necessary to allow sufficient access for capitellum insertion.

FIGURE 52-23 The capitellum is inserted from distal laterally (A) and is impacted proximal medially (B).

Note: The capitellum may be press-fit or cemented according to surgeon preference.

Step 8: C Closure. A No. 5 absorbable suture is placed at the humeral origin of the lateral collateral ligament, and a running locked stitch proceeds distally through the ulnar attachment, then back proximally, ending at the humeral origin of the ligament (Fig. 52-24). The forearm is placed in full or partial pronation, a valgus stress is applied, and the suture tied.

FIGURE 52-24 It is important to stabilize the joint following insertion. We typically employ a running locked stitch using a heavy No. 5 nonabsorbable suture.

Aftercare

Passive flexion and extension is allowed on the second day, assuming the elbow is considered stable. The goal of radial head replacement and soft tissue repair is to achieve elbow stability. Both flexion/extension and pronation/supination arcs are typically allowed without restriction. Active motion can begin by day 5.

INTRODUCTION

Total elbow arthroplasty is indicated for pain and functional limitations secondary to inflammatory arthritis, osteoarthritis, post-traumatic arthritis, acute distal humeral fractures, distal humeral nonunions, tumors, osteonecrosis, and dysfunctional instability. Currently available prostheses can be subclassified as linked, unlinked, or convertible implants, which can be interchanged between a linked or unlinked design. This part of the chapter focuses on the design considerations, techniques, and results of unlinked total elbow arthroplasty.

DESIGN CONSIDERATIONS

Polyethylene wear and aseptic loosening of linked total elbow arthroplasties is a significant problem with longer follow-up, particularly in younger and more active patients.¹¹ When a linked arthroplasty reaches the limits of its intrinsic laxity, forces are transmitted to the linkage mechanism and thereby to the stems and the bone implant interface, contributing to bearing wear and implant loosening.³⁰ The concept of unlinked total elbow arthroplasty is that there is a sharing of load between the prosthesis and the capsule, ligaments, and muscles in an effort to decrease the stresses in the articulation and the stems. A necessary prerequisite for an unlinked arthroplasty is the presence of adequate ligaments and bone stock with which the implant can be stabilized after insertion. Unlinked total elbows were initially referred to as resurfacing devices primarily because most were designed without a humeral stem. Owing to the high incidence of implant loosening with these early designs, most unlinked prostheses now incorporate stems on the components in an effort to improve implant longevity (Fig. 52-25).

FIGURE 52-25 Five and a half years after insertion of an unstemmed humeral component, a fracture has occurred across the distal humeral condyles at the site of fixation of a 39-year-old patient with rheumatoid arthritis.

(By permission of Mayo Foundation.)

Unlinked total elbow arthroplasties are sometimes referred to as unconstrained devices, whereas loose-hinge linked devices are often referred to as being semiconstrained; however, this is a misnomer. All joint arthroplasties have some element of intrinsic constraint by virtue of the shape and interaction of their articular surfaces. The intrinsic constraint of the ulnotrochlear joint of five unlinked total elbow arthroplasty designs were compared and found to vary markedly between implant types.¹⁵ Surprisingly, the implants that more closely resembled the articular geometry of the native articulation tended to less accurately replicate the intrinsic constraint of the human elbow (Fig. 52-26). In a series of cadaveric studies, the kinematics and stability of unlinked and linked total elbow arthroplasties have been evaluated.^{1,13,14,18,30,35,43} The mechanical behavior of these prostheses has been found to vary markedly depending on their articular design.

FIGURE 52-26 The intrinsic constraint of the ulnohumeral joints of five different unlinked total elbow arthroplasties were compared with that of the native elbow joint in an in vitro biomechanical study (A). The torque (bar graphs) and angular displacement (line graphs) of the Souter and Kudo implants were most similar to the human elbow (B).

In an effort to improve their stability and load transfer, some unlinked designs have incorporated a radial head replacement (Fig. 52-27). The radial head component has been shown to improve the stability of both the Sorbie and Pritchard ERS prostheses in in vitro biomechanical studies.^13,35 Although theoretically improving soft tissue balance and load transfer across the elbow, the experience with radial head components in total elbow arthroplasty has been variable. For example, the radial head component of the capitellocondylar prosthesis was abandoned owing to concerns about radiolucent lines around the implant stem, but a subsequent study reported that the outcome was better if a radial head component was used.⁵⁶ One possible explanation of the variable results with radial head prostheses in unlinked implants to date may be that, in many cases, their designs have been suboptimal. Furthermore, the addition of a third component complicates the surgical technique, making it more challenging to perform correctly, particularly because the instrumentation available to position unlinked total elbows has been lacking relative to other joints such as the hip and knee. Incorrect positioning of a radial head component will result in eccentric motions during prosupination and therefore shear forces across the radiocapitellar articulation. These abnormal kinematics and loads may cause polyethylene wear and early loosening of the radial component. A bipolar radial head component may be more forgiving in this setting because it will compensate for some of the eccentric motions through the bipolar articulation.

FIGURE 52-27 The theoretical advantages of distributing forces that pass across the elbow through both columns of the humerus are obvious.

(By permission of Mayo Foundation.)

Functional and balanced collateral ligaments are a key feature of a successful unlinked total elbow arthroplasty. Incompetent ligaments result in articular maltracking, joint subluxation, or dislocation. This has been demonstrated in an in-vitro cadaveric study and observed clinically.^14,18 Maltracking of the arthroplasty leads to excessive polyethylene wear, osteolysis, and aseptic loosening. During the insertion of most unlinked designs, one or both of the collateral ligaments are usually released to achieve adequate exposure. Careful repair and successful ligament healing are needed if an unlinked arthroplasty is to be stable and articulate normally.

Optimal component positioning improves the outcome of an unlinked total elbow arthroplasty.^44,54 Replication of the axis of motion to the native state restores the muscle moment arms and the soft tissue tension of the collateral ligaments, which ensures more normal articular tracking and implant loading. Malpositioning of the humeral component has been demonstrated to alter the in vitro kinematics and stability of the capitellocondylar arthroplasty.¹⁴ It has also been reported that correct medial-lateral and proximal-distal positioning of the Souter implant had a lower incidence of loosening.⁴⁴ Another study evaluating the same implant, however, was unable to demonstrate a relationship between humeral component position and aseptic loosening.⁵⁸ Current techniques to identify and replicate the flexion-extension axis are prone to error. In one study, the surgeon’s ability to select the flexion-extension axis resulted in errors in axis orientation of up to 10 degrees in normal humerii. These errors are likely greater in clinical practice, where the anatomy is more distorted and the exposure of the landmarks is compromised.² Perhaps the use of computer or image-assisted surgery will improve the accuracy of elbow component placement in the future, such as has been reported for the hip and knee.

In summary, the premise of unlinked designs is that much of their stability is afforded by the geometry of the implant and the surrounding soft tissues rather than the intrinsic constraint of the articulation.¹ The goal of an unlinked arthroplasty is to divert the forces that are transferred across the articulation away from the bone implant interface to the surrounding soft tissues. By virtue of their need for adequate ligaments and bone stock, the indications for unlinked designs are narrower than linked arthroplasties and the instability rate is greater. Although the loosening rate should theoretically be lower with unlinked verses linked prostheses, this has yet to be proven in clinical studies.

INDICATIONS

The indications for an unlinked total elbow arthroplasty are similar to those for any design of elbow arthroplasty. The necessary prerequisites to choose an unlinked implant are the presence of sufficient bone stock to support the implant and intact medial and lateral collateral ligaments. The presence of functioning elbow flexor and extensor muscles are particularly important with an unlinked design, which requires muscle balance to maintain implant stability. In the absence of sufficient bone stock or ligamentous constraints, a linked arthroplasty should be used. Typical indications include inflammatory arthritis (rheumatoid, psoriatic, hemophilic), primary or post-traumatic osteoarthritis, osteonecrosis, periarticular tumors and comminuted distal humeral articular fractures in elderly patients.

CONTRAINDICATIONS

Active infection is an absolute contraindication to elbow arthroplasty. The absence of functioning muscles to move the elbow and a nonfunctional hand are relative contraindications. Poor skin quality must be corrected before or at the same time as the arthroplasty. Unstable elbows with poor ligaments or deficient bone stock should be managed with a linked device. Gross deformity is an indication for a linked device because achieving precise soft tissue balancing is typically not possible with an unlinked arthroplasty. As for any total elbow arthroplasty, patients who are unwilling to live within the activity and weight restrictions which are thought to be needed for implant longevity should be managed with an alternative treatment.

SURGICAL CONSIDERATIONS OF UNLINKED DESIGNS

There are a number of unlinked designs that have been developed and employed. The design features and surgical considerations of a few of the more commonly used devices will be reviewed. The capitellocondylar implant designed by Ewald consists of a cobalt-chrome humeral component with 5-, 10-, and 15-degree valgus angulations⁸ (Fig. 52-28) (Johnson and Johnson, Raynham, MA). The ulnar component has two polyethylene thicknesses available. A radial head implant was developed for this system but was abandoned owing to concerns about radiolucent lines around the stems.⁵⁶ The ulnohumeral joint has a low magnitude of intrinsic constraint, making it prone to maltracking and dislocation.^15,17 The implant is most commonly inserted through an extended Kocher approach, with elevation of the triceps off the olecranon from lateral to medial. The medial collateral ligament is preserved, whereas the lateral collateral ligament is cut and repaired during closure. Although excellent results were reported by the inventor, the experience of others has been less favorable owing to problems with instability^9,31,40,61 (Fig. 52-29).

FIGURE 52-28 The capitellocondylar implant employs a metal backed ulnar component and varying humeral angles to accommodate anatomic variation.

FIGURE 52-29 Lateral radiograph 2 years after surgery of a patient with rheumatoid arthritis treated with a capitellocondylar implant.

The Pritchard ERS arthroplasty (DePuy, Warsaw, IN) consists of humeral, ulnar, and radial components (Fig. 52-30).³⁴ It can be inserted through either an extended Kocher or a Bryan-Morrey triceps reflecting approach.^3,28,32 One or both collateral ligaments are divided during the approach and then carefully repaired during closure. The radial head component is important for elbow stability.³⁵ The clinical outcome of this prosthesis is largely unknown, with little available information provided in the literature³⁴ (Fig. 52-31).

FIGURE 52-30 The Pritchard ERS implant allows for replacement of the radial head with a modular system providing for some flexibility with regard to thickness of the implants.

FIGURE 52-31 Anteroposterior (A) and lateral (B) radiographs of a 44-year-old woman with rheumatoid involvement 1 year after a Pritchard ERS implant demonstrates no pain and an almost normal range of motion.

(With permission Mayo Foundation.)

The Souter-Strathclyde arthroplasty (Stryker, Mahwah, NJ) consists of a cobalt-chrome humeral and an all polyethylene ulnar component⁴⁸ (Fig. 52-32). The humeral component aims to replicate the shape of the native trochlea and maintain the integrity of the supracondylar ridges and their attached collateral ligaments.⁴⁷The ulnar component is closely congruous with the humeral component, making the implant relatively constrained when loaded.^15,43 The short-stem humeral component has a fin, which is carefully fitted into the medial supracondylar ridge, and a peg that is inserted into the capitellum (Fig. 52-33). The system has long-stem humeral components and long-stem metal-backed ulnar components available to manage bone loss and revision situations. A snap-fit ulnar component is also available that converts the implant into a linked device. The prosthesis is inserted using a posterior approach, typically using a triceps turndown. The medial collateral ligament is preserved, but the lateral ligament is typically divided to obtain sufficient exposure to allow dislocation and radial head excision. Careful repair of the triceps tendon and lateral collateral ligament is essential. Instability of this implant has been less frequent than other unlinked designs; however, loosening of the short-stemmed humeral component has been a common clinical problem.⁵⁴

FIGURE 52-32 Standard (A) and long-stem (B) Souter humeral and ulnar components.

FIGURE 52-33 Anteroposterior (A) and lateral (B) radiographs 1 year after a well-functioning Souter total elbow replacement in a patient with rheumatoid arthritis.

The Kudo total elbow arthroplasty (Biomet, Warsaw, IN) has evolved significantly since it was first introduced.²¹ Initially, the prosthesis had an all-polyethylene ulnar component and an unstemmed humeral component with a cylindrical articulation. Owing to a high incidence of early loosening, both the humeral and ulnar components were redesigned (Fig. 52-34). The current Kudo type 5 prosthesis consists of a 5-degree valgus cobalt-chrome humeral component with a titanium porous coating that is typically inserted uncemented and a metal-backed cemented ulnar component (Fig. 52-35). The humeral articulation has a saddle-shaped design that allows for medial-lateral translation of the ulnar component. The prosthesis is implanted with sectioning of the collateral ligaments and excision of the radial head. The reported results with the current design are favorable, although instability has been problematic owing to the low intrinsic stability relative to other designs^{19,20,29,33,50–52} (Fig. 52-36).

FIGURE 52-34 The original Kudo arthroplasty had a stemless humeral component, an all-polyethelyene ulnar component, which was prone to loosening.

FIGURE 52-35 The current Kudo type 5 total elbow arthroplasty has a stemmed component and a metal-backed ulnar component.

FIGURE 52-36 Anteroposterior (A) and lateral (B) radiographs of a well functioning Kudo type 5 total elbow arthroplasty.

The Sorbie-Questor total elbow arthroplasty (Wright Medical Technology, Arlington, TN) was designed to replicate the normal anatomy of the elbow (Fig. 52-37).^45,46 The humeral component has an angled cobalt-chrome stem. A metal-backed ulnar component is available with two polyethylene thicknesses. The radial head component is a stemmed monoblock design. Originally designed without a humeral stem, loosening was a problem until the stem was added. The implant is inserted though an extended Kocher approach with sectioning of the lateral collateral ligament. There are no published results of the outcome of this device (Fig. 52-38).

FIGURE 52-37 The Sorbie-Questor total elbow arthroplasty has a stemmed humeral component and metal-backed radial and ulnar components.

(Reproduced with permission Wright Medical Technology, Arlington, TN.)

FIGURE 52-38 Anteroposterior (A) and lateral (B) radiographs of a well-functioning Sorbie total elbow arthroplasty 5 years postoperatively in a patient with rheumatoid arthritis. The bone cement interface is quiet.

SURGICAL TECHNIQUE

The precise surgical technique and approach depends on the design of the unlinked prosthesis selected and the surgeons’ preference. It is recommended that a linked implant system be available in the operating room whenever an unlinked prosthesis is planned. This will allow conversion to a linked design if the elbow is unstable or the articulation is maltracking following trial placement of the unlinked components. The surgical technique of the Kudo type 5 total elbow arthroplasty is presented.

The patient is positioned supine with the arm across the chest. A sterile tourniquet is employed and placed high on the upper arm. A midline posterior skin incision is used placed just medial to the tip of the olecranon. The ulnar nerve is isolated and transposed anteriorly into a subcutaneous pocket.

The management of the triceps is based on surgeon preference. A distally based triceps flap is recommended by the designer. Both the lateral and medial collateral ligaments are divided from their humeral insertions, and the elbow is dislocated. The radial head is excised. The distal humerus is prepared primarily freehand with minimal bone resection (Fig. 52-39). The ulna is prepared using a barrel reamer, burr, and rasps (Fig. 52-40). A trial reduction of the prosthesis is performed to evaluate soft tissue balance and articular tracking. Repositioning of one or both components should be performed, if necessary, to achieve soft tissue tensioning and optimal articular congruency. The humeral component is inserted uncemented if a good press fit is achieved, whereas the ulnar component is routinely cemented. After reduction of the elbow, the triceps and the fascial layers are meticulously repaired. The collateral ligaments are not routinely repaired.

FIGURE 52-39 Humeral preparation for insertion of the Kudo total elbow arthroplasty. Cutting the distal humerus with a double-bladed chisel (A); rasping the humeral canal (B); insertion of the trial component (C).

FIGURE 52-40 Ulnar preparation for insertion of the Kudo total elbow arthroplasty. A barrel reamer prepares the greater sigmoid notch (A); a burr opens the medullary canal of the ulna (B); rasping the ulnar canal (C); insertion of the trial component (D).

The elbow is splinted in 90 degrees of flexion and immobilized for 1 week postoperatively. Active and active-assisted exercises are then commenced as the soft tissues allow.

RESULTS

The reported outcome of unlinked total elbow arthroplasty consists primarily of retrospective case series. Typical complications of elbow arthroplasty such as ulnar neuropathy, infection, triceps failure and wound healing problems are discussed in Chapter 61 and will not be highlighted in this chapter. There are no prospective randomized trials comparing the outcome of different unlinked arthroplasties.²⁴ Little et al²⁵ compared the outcome of the Souter, Kudo, and Coonrad-Morrey designs in a nonrandomized prospective cohort study design. The authors were unable to demonstrate a significant difference between the Kudo and Souter designs with respect to outcome or complications. The linked Coonrad-Morrey implant had outcome that was similar to the unlinked designs, with a lower incidence of instability. The loosening rate did not differ between the three designs at an average of 5 years postoperatively.

There have been a number of case series reporting the outcome of the capitellocondylar prosthesis.^{4,6–10,31,40,42,55,56,61} Collectively, these studies demonstrate a reliable improvement in pain and function, with a modest improvement in motion. The incidence of loosening has been low in most series; however, instability has been a problem, particularly in the hands of surgeons other than the inventor (Fig. 52-41).

FIGURE 52-41 Anteroposterior (A) and lateral (B) radiographs of an unstable capitellocondylar arthroplasty in a 56-year-old patient with rheumatoid arthritis 2 years postoperatively. Wear of the retrieved ulnar component can be seen due to gross instability (C). Anteroposterior (D) and lateral (E) radiographs 1 year following successful revision to a linked Coonrad-Morrey total elbow arthroplasty.

Ewald, the surgeon inventor, reported a 3% revision rate out of 202 elbows at an average of 6.7 years.⁹ Only 1.5% of the elbows had sufficient instability to require revision, and 1.5% developed loosening. Schemitsch et al⁴² reported that the incidence of instability was higher and pain relief was lower in a matched cohort of patients with a prior radial head excision and synovectomy. Trepman and coworkers,⁵⁶ also from the same center, reported that the presence of a radial head implant lowered the incidence of instability of this design.

The experience with the capitellocondylar prosthesis reported by other investigators is less favorable owing to a higher incidence of instability. Weiland et al⁶¹ reported a malarticulation rate of 29% in 40 prostheses followed for 7.2 years. Although most of these elbows remained functional, maltracking of the articulation was a cause for concern due to polyethylene wear at longer follow-up. Similarly, studies by Tranik et al⁵⁵ and Davis et al⁶ reported instability rates of 9% and 13%, respectively, although most could be managed without revision. Ring et al³⁸ demonstrated that ligament reconstruction was unreliable in restoring stability of this unlinked arthroplasty, whereas revision to a linked prosthesis had a high complication rate. Collectively, the aseptic loosening rates for the capitellocondylar prosthesis in these studies have been low. In the most recent reported experience with this implant, Ovesen et al³¹ reported that 83% of 51 prostheses were functional at an average of 6.9 years postoperatively. Seven prostheses required revision, with instability and infection being the most frequent cause of failure.

The reported experience with the Pritchard ERS total elbow prosthesis has been limited to date.³⁴ The experience at the Mayo Clinic has not been favorable, with a 10-year Kaplan Meier survival of only 54% out of 46 prostheses. Instability, wear, and aseptic loosening were the most common causes for failure (Fig. 52-42). Ulnohumeral component malpositioning was thought to be the most common reason for instability. The failure rate was much greater if the radial head was not replaced; however, technical issues with positioning the radial head component were common. Preservation of the native radial head provided the longest functioning implants.

FIGURE 52-42 Anteroposterior (A) and lateral (B) radiographs of a loose Pritchard ERS prosthesis in a 73-year-old patient with rheumatoid arthritis 7 years postoperatively. Wear of the ulnar component can be appreciated on the retrieved implant (C).

The results of the Souter total elbow arthroplasty have been widely reported from multiple centers other than that of the surgeon inventor.^* The outcome has been uniformly favorable, with a high incidence of improvement in pain and function with a modest improvement in elbow flexion but not extension. In general, instability has been less common than reports of other unlinked designs. Humeral component loosening has been more common than the ulnar component when the short-stem humeral stems were employed⁵³ (Fig. 52-43). The most recent series was reported by Landor et al,²³ with 58 elbows followed for an average of 9.5 years. The Mayo elbow performance index improved from 30 to 82 points. The revision rate was 22%, with loosening being the most common cause. Only one elbow was revised for instability. The Kaplan-Meier survival was 70% at 10 years and 53% at 16 years.

FIGURE 52-43 Lateral radiograph of a Souter total elbow arthroplasty with aseptic loosening and extension of the short-stem humeral component, the typical mode of failure of this prosthesis.

Van Der Lugt et al⁵⁹ reported the results of a prospective study of 204 Souter prostheses inserted for rheumatoid arthritis and followed for an average of 6.4 years. Twelve percent of the prostheses were revised, with loosening of the humeral component being the most common indication. The Kaplan-Meier survival was 77% at 10 years and 65% at 18 years. Trail and coworkers⁵³ evaluated the outcome of 186 prostheses and reported a 12-year survival rate of 87%. Seventy-five percent of the revisions were due to humeral loosening. The use of a long-stem humeral component was subsequently reported to have a much lower incidence of loosening than the short-stem design.⁵⁴ The use of a snap-fit ulnar component that converts the prosthesis from an unlinked to a linked design was shown to result in a higher incidence of aseptic loosening.

The outcome of the Kudo total elbow arthroplasty has largely been reported from the surgeon-inventor, and has reflected the evolution of the prosthesis design.^† The early type 1 and 2 prostheses used an unstemmed humeral component, which had a high incidence of loosening.²² Experience with the later designs has been more promising with a low incidence of instability and loosening. The uncemented humeral component has been more reliable than the ulnar component, in which cement and metal backing has improved the success. Thillemann and coworkers⁵² reported 67% survival of 17 Kudo three elbows followed for an average of 9.5 years. Two had been revised due to loosening of the ulnar component and one for instability. Progressive valgus tilting of the elbow at longer follow-up raised concerns regarding polyethylene wear of the ulnar component at longer follow-up (Fig. 52-44).

FIGURE 52-44 Anteroposterior radiograph of an unstable Kudo total elbow arthroplasty.

Professor Kudo and his colleagues have reported excellent results, particularly with the current type 5 prosthesis. Tanaka et al demonstrated that the outcome of a metal-backed cemented ulnar component was superior to an all polyethylene design.⁵¹ Mori and coworkers²⁹ reported successful outcomes of the type 5 unlinked design at an average of 8 years, even in the presence of mutilating rheumatoid arthritis with bone loss. Tanaka et al⁵⁰ reported a 90% survival rate at 13 years using the type 3 prosthesis. Preservation of the medial collateral ligament at surgery was not found to influence the long-term outcome.

Potter et al³³ reported on the outcome of 35 Kudo type 5 prostheses at an average of 6 years. Although none of the prostheses had been revised, two were loose at follow-up with a Kaplan-Meier survival of 89% at 5 years. One postoperative dislocation was successfully treated with a closed reduction. Willems et al⁶² reported on the outcome of 36 Kudo prostheses at an average of 5 years. Although the clinical outcome was good or excellent in the majority of patients, 17% had been revised, most commonly for aseptic loosening at longer follow-up.

There are no peer review studies documenting the outcome of the Sorbie total elbow arthroplasty to date. In a prospective study of 48 elbows, infection has been the most common complication in the experience of the surgeon inventor (15%) (Personal communication, Dr. Charles Sorbie). The high initial infection rate was attributed to the use of unsterile tourniquets because there have been no further infections since these were replaced by sterile tourniquets in the latter part of the series. Six percent of the patients have needed a revision for loosening and 4% for instability at an average follow-up of 6.8 years (Fig. 52-45).

FIGURE 52-45 Anteroposterior (A) and lateral (B) radiographs of a loose Sorbie total elbow arthroplasty in a 53-year-old man with rheumatoid arthritis 5 years postoperatively. The patient admitted to chopping firewood and golfing with his prosthetic elbow. Anteroposterior (C) and lateral (D) radiographs 1 year following revision to a long-stem linked Coonrad-Morrey total elbow arthroplasty.

In summary, the outcome of unlinked total elbow arthroplasties are similar to those reported for linked prostheses.^25,63 Although the loosening rates of the more unconstrained devices are low, the incidence of instability has been problematic in some series. It is likely that patient selection and surgeon experience plays a critical role in the outcome of elbow replacement in general and unlinked devices in particular. Unlinked prostheses are less forgiving than linked designs owing to the need to accurately position the components, balance the soft tissues, and achieve ligament healing. Randomized clinical trials are needed to accurately compare the complications and longevity of elbow prostheses.

DESIGN CONSIDERATIONS

As has been outlined earlier in this chapter, unlinked total elbow arthroplasties have a theoretical advantage over linked devices owing to a sharing of load across the articulation between the prosthesis and the joint capsule, ligaments, and muscles. Although the majority of patients with elbow arthritis can be managed with an unlinked elbow arthroplasty, there are patients who require a linked prosthesis due to a lack of adequate bone stock or functional collateral ligaments. Although typically this can be predicted preoperatively, it is always desirable to have a linkable implant immediately available in the operating room whenever a surgeon is planning to perform an unlinked total elbow arthroplasty. If an unlinked implant is not stable or is not articulating congruously intraoperatively, then it should be converted to a linked design. If this is recognized before the unlinked components are cemented, then a different design of linked arthroplasty can be used, although repeat bony preparation will be needed, which is time consuming. The advantage of a convertible prosthesis is significant in this setting because rather than changing prosthesis designs, a linkage mechanism can simply be applied to the same prosthesis for which the bony resection has been completed. If the stems have already been cemented, then the ability to couple an unlinked prosthesis without removing the stems makes a convertible implant system even more appealing. The advantage of having one implant system to manage the majority of clinical situations is also helpful for hospitals by reducing inventories and cost. For surgeons, a convertible design means that only one implant system needs to be mastered.

Although most patients who undergo an unlinked total elbow arthroplasty have an excellent outcome, there are some patients who develop elbow instability postoperatively, which is often difficult to manage.^3,8,10 When this occurs early, a closed reduction and a period of immobilization may allow the ligaments to heal and the prosthesis to function normally. However, when presenting as a chronic problem, attempts at ligament reconstruction have not been reliable. The concept of having an unlinked elbow arthroplasty that can be linked in the setting of postoperative elbow instability is desirable because removal of a well-fixed unlinked elbow arthroplasty to revise it to a linked arthroplasty is technically difficult with a significant risk of complications.¹⁰

Hemiarthroplasty of the distal humerus is becoming more popular to manage comminuted articular fractures of the distal humerus, nonunions, and avascular necrosis, as discussed in Chapter 52. Should the patient develop instability or ulnar subsidence, or have persistent pain, the ability to convert a humeral hemiarthroplasty to either a linked or unlinked total elbow arthroplasty without removing a well-fixed humeral component is attractive.

INDICATIONS

The indications for a convertible total elbow arthroplasty are similar to those for any design of elbow arthroplasty. Typical indications include inflammatory arthritis, primary or post-traumatic osteoarthritis, osteonecrosis, periarticular tumors, dysfunctional instability, distal humeral nonunions, and comminuted distal humeral articular fractures in the elderly. Because these implant systems are convertible between linked and unlinked configurations, these designs have the ability to deal with a wide spectrum of pathologies ranging from the situation of well-preserved bone stock and ligaments, in which an unlinked arthroplasty might be used, to the situation where there is extensive bone loss or ligamentous insufficiency, where a linked design would be preferable. In some cases, the final decision as to whether to perform an unlinked or linked prosthesis is made intraoperatively—a convertible total elbow design provides the surgeon the option to choose at any time during the procedure.

CONTRAINDICATIONS

As for all elbow arthroplasties, the presence of active infection is an absolute contraindication to convertible elbow arthroplasty. Patients who are unwilling or unable to live within the activity and weight restrictions necessary for an elbow arthroplasty should be managed with an alternative treatment such as a synovectomy, débridement, interposition arthroplasty, or arthrodesis. Poor skin coverage, inadequate muscle function of the elbow, and a nonfunctional hand are relative contraindications to elbow arthroplasty.

SURGICAL CONSIDERATIONS OF CONVERTIBLE DESIGNS

Two convertible total elbow arthroplasties have been developed and used to date. The Acclaim (Depuy, Warsaw, IN) is a cobalt-chrome implant with humeral and ulnar components. (Fig. 52-46) The humeral component has fins to resist rotation. The articulation is centralized to the long axis of the humeral component, which results in a lateral shift of the ulna with respect to the humerus, thereby tightening the medial collateral ligament. This lateral shift is thought to better balance the forces across the implant because it does not incorporate a radial head replacement. The unlinked articulation can be converted to a linked version by partial removal of the epicondyles, exchange of the bobbin to a polyethylene yoke, replacement of the polyethylene ulnar insert with a hinged component, and insertion of a polyethylene pin mechanism.

FIGURE 52-46 Unlinked (A) and linked (B) versions of the Acclaim total elbow arthroplasty.

The Latitude System (Tornier Inc., Stafford, TX) is a modular device with the option to be configured as a humeral hemiarthroplasty and an unlinked or linked total elbow arthroplasty (Fig. 52-47). The cobalt-chrome implant has a modular humeral component, which incorporates fins and an anterior flange to resist axial rotation and posterior displacement. The axis bolt of the humeral component is cannulated to facilitate secure stable collateral ligament repair to the implant and adjacent bone. The ulnar component is metal backed with thick polyethylene and an extended coronoid process to resist dislocation. A bipolar radial head is available for use when the radial head is arthritic and requires excision. The conversion between an unlinked to a linked device can be accomplished easily by adding a locking cap during the initial surgery or subsequently through a minimally invasive approach to manage postoperative instability.

FIGURE 52-47 Unlinked (A), linked (B), and hemiarthroplasty (C) versions of the Latitude total elbow arthroplasty.

(Courtesy of Tornier Inc., Stafford, TX.)

SURGICAL TECHNIQUE

The surgical technique for the Latitude total elbow arthroplasty is outlined here.⁴ The patient is placed supine, with the arm across the chest. A sterile tourniquet is employed and prophylactic antibiotics administered before tourniquet inflation. A midline posterior elbow incision is placed just medial to the tip of the olecranon, and full-thickness flaps are developed on the deep fascia. The ulnar nerve is identified, mobilized, and transposed anteriorly.

Management of the triceps tendon varies according to the preference of the surgeon. The implant can be placed by elevating the triceps from medial to lateral, as in the Bryan-Morrey approach, from lateral to medial, as in the extended Kochler approach, or through a triceps splitting approach, where the triceps is elevated from the olecranon both medially and laterally.^1,6,9,12 The design of the instrumentation also allows for the bony preparation to be performed and the implants to be inserted while preserving the attachment of the triceps to the olecranon. The ‘triceps-on’ approach reduces the risk of triceps insufficiency with postoperative weakness and pain that can occur when the triceps tendon is detached to perform an elbow arthroplasty.^2,9 Unfortunately, the triceps-on approach does compromise visualization to some extent, but it can be a useful technique, particularly when there is epicondylar bone loss or when the joint is not too tight. The medial and lateral collateral ligaments and their corresponding common flexor and extensor origins are tagged for later repair and then sharply released from the epicondyles as much as necessary to achieve joint dislocation.

The correct sizing of the implant is best achieved by matching the anatomical spool size to the articular surfaces of the ulna and radius and the distal humerus. The key to sizing the Latitude system is choosing the correct joint width such that with the anatomic spool sitting in the trochlear groove, the radial head articulates congruously with the capitellum of the spool (Fig. 52-48). This approach will ensure that the native radial head (or a radial head component) will articulate congruously with the capitellum of the humeral component. There are four prosthesis sizes available for the total elbow arthroplasty and six sizes available for the anatomic distal humeral hemiarthroplasty.

FIGURE 52-48 The width of the articulation is key to sizing the Latitude prosthesis. This can be judged using the distal humerus (A) or the proximal radius and ulna (B).

As for any total elbow arthroplasty, reproduction of the flexion-extension axis is crucial for a successful result.^5,11 With the Latitude system, all subsequent steps are based on the accurate determination of this axis. Using a circular guide, the lateral point of isometry is determined at the center of the arc of the capitellum when viewed from the lateral side. The anteroinferior aspect of the medial epicondyle is the medial landmark. The intercondylar portion of the distal humerus is removed, with a saw up to the proximal aspect of the olecranon fossa to facilitate central axis pin placement. An axis guide is used to insert the pin, which marks the flexion-extension axis of the elbow (Fig. 52-49A).

FIGURE 52-49 Humeral preparation is shown. A, An axis pin is inserted at the flexion-extension axis of the elbow. The intercondylar portion (B) and (C) distal portion of the distal humerus are prepared using cutting blocks based off this axis. D, The trial humeral component is then inserted.

The medullary canal is opened with a burr, and the offset of the axis of the medullary canal with the flexion-extension axis is determined. Anterior, centered, and posterior offset humeral configurations are available. The distal humeral cuts are made using a mechanized series of jigs based off the flexion-extension and medullary axes (see Fig. 52-49B and C). The humeral canal is rasped and trial placement of the humeral component is performed (see Fig. 52-49D).

Preparation of the radius and ulna is accomplished using a cutting guide and the anatomic spool, which is seated into the articular dish of the radial head and the guiding ridge of the olecranon. If the radial head is to be excised, this is done with a sagittal saw and the trochlear cut is made with a bell-shaped saw from lateral to medial (Fig. 52-50A and B). If the native radial head is to be preserved, then the bell-shaped saw is used to cut the ulna from medial to lateral. The ulnar canal is then opened with a burr and prepared using flexible reamers and rasps. After inserting the trial ulnar component, the radius is broached and an appropriate sized radial head trial is placed. The bipolar radial head accommodates for ±10 degrees of angular rotation but cannot substitute for malalignment of the proximal radius to the capitellum (see Fig. 52-50C and D).

FIGURE 52-50 Ulnar preparation is shown. A, The radial and ulnar cutting jig is oriented using the anatomic spool and secured in place. The radial head is resected, if desired. B, Using the bell saw, the proximal ulnar cut is performed. C, After preparation of the ulnar canal, the trial ulnar component is inserted. The radial neck is rasped. D, The trial bipolar radial head is attached, and the elbow is reduced and evaluated for alignment and articular tracking.

The elbow is moved through a range of motion with the trial components, and the articular tracking and joint stability are evaluated. If there are adequate soft tissue and bony structures and the elbow prosthesis is tracking well, then an unlinked arthroplasty is performed. If the radial head prosthesis is maltracking on the capitellum and repositioning of the components is unable to correct this problem, a radial head replacement should not be performed and the implant should probably be linked. In the setting of significant bone loss or incompetent collateral ligaments, then a linked prosthesis is routinely selected.

Cement restrictors are inserted and pulsatile lavage is used to prepare the medullary canals for component insertion. Antibiotic cement is injected into the humerus, ulna, and radius using a cement gun in a retrograde fashion and the components are inserted. A cancellous bone graft is placed behind the anterior flange of the humeral component after the cement is set; similarly linkage of the components, if indicated, is not performed until the cement is cured. Articular tracking of the components and the stability of the elbow is reassessed. If the prosthesis is to be linked, the locking cap is inserted and secured in position with a torque screwdriver.

The collateral ligaments are repaired back to the epicondyles using nonabsorbable Krackow sutures passed through the cannulated screw, which is located at the axis of rotation of the implant (Fig. 52-51A). When tied on the contralateral side of the elbow, these sutures securely approximate the ligaments to their attachment sites while avoiding problems with sutures pulling through the often weak bone of the epicondyles. An additional suture can be placed through the cannulated screw of the implant and through a drill hole in the proximal ulna to act as a temporary artificial ligament to prevent instability in the postoperative period while the collateral ligaments are healing (see Fig. 52-51B). The triceps is carefully secured to the olecranon if it was detached. Drains are placed if indicated and the elbow is placed in a well-padded splint in relative extension.

FIGURE 52-51 A, Sutures are placed in the medial and lateral collateral ligaments and passed through the axis screw of the humeral component to provide for secure initial fixation. B, A suture can also be placed through a drill hole in the ulna and the humeral component to provide for immediate stability in the postoperative period.

REHABILITATION

As soon as the wound allows for safe mobilization, active range of motion is permitted. If the triceps was detached during surgery extension should be performed with gravity assistance only. In most cases, patients can be taught their exercises before discharge; home therapy is typically not required. A nighttime extension splint helps to gain maximum elbow extension. Strengthening should not be instituted for at least 10 weeks postoperatively to ensure secure ligament healing has occurred.

COMPLICATIONS

The complications of a convertible total elbow arthroplasty are similar to any arthroplasty and are discussed in Chapter 53. These include infection, ulnar neuropathy, fractures, triceps avulsion, and problems with soft tissue healing. The complications specific to the unlinked configuration would be similar to those for any unlinked device, most importantly being instability, whereas for a linked device, it would presumably be polyethylene wear of the linkage mechanism.

RESULTS

The initial experience with the Acclaim total elbow has been favorable, with a significant improvement in pain and motion⁷ (Fig. 52-52). The preliminary experience with 65 prostheses reported four intraoperative fractures and one dislocation. There are no studies available as of yet documenting the survivorship of this prosthesis.

FIGURE 52-52 Anteroposterior (A) and lateral (B) radiographs of a 39-year-old patient with juvenile rheumatoid arthritis. Anteroposterior (C) and lateral (D) radiographs following an unlinked Acclaim total elbow arthroplasty.

(Courtesy of Dr. John Stanley.)

There are no reports documenting the results of the Latitude convertible total elbow arthroplasties. The author’s experience with the Latitude system to date has been favorable because the implant has been able to deal with a wide variety of pathologies and patient profiles. The hemiarthroplasty has been used to manage acute distal humeral fractures, nonunions, and avascular necrosis. Patients with relatively well-preserved bone stock and ligaments are typically managed with the unlinked version of the arthroplasty and this is the author’s current preference (Fig. 52-53). Patients with poor bone stock or ligaments, particularly related to previous trauma, are typically managed with a linked arthroplasty (Fig. 52-54). The radial head is replaced if it is damaged by disease, such as in rheumatoid arthritis, but is retained if it is relatively well preserved, for example in post-traumatic arthritis or acute distal humeral fractures.

FIGURE 52-53 Anteroposterior (A) and lateral radiographs (B) of a 70-year-old patient with rheumatoid arthritis. Anteroposterior (C) and lateral (D) radiographs 2 years following an unlinked Latitude total elbow arthroplasty.

FIGURE 52-54 Anteroposterior (A) and lateral (B) radiographs of an 82-year-old patient with an articular fracture of the distal humerus. C, CT scan demonstrating the comminuted nature of the fracture. Anteroposterior (D) and lateral (E) radiographs following a linked Latitude total elbow arthroplasty.