Outcomes

The outcomes literature concerning MCP ar-throplasty is replete with retrospective reports with limited clinical and radiographic data. These reports, of varying follow-up duration, have typically included clinical information on finger alignment and joint range of motion with radiographic data including implant fracture rate. The reports (Table 1) have provided valuable data that have, on most issues, been homogeneous. At less than 10-year follow-up, improved function was noted in 60% to 75% of patients, improved appearance was noted in 42% to 82% of patients, and pain was present in up to 50% of patients [4-14]. These data have been used by most investigators to justify silicone implant arthroplasty but, for at least one set of investigators, these data have led to a discontinuance of the procedure [12].

The specific data from the most recent long-term follow-up investigation provide a review of

Table 1

Intermediate and long-term outcomes of MCP arthroplasty

Table 1

Intermediate and long-term outcomes of MCP arthroplasty

Investigation

# joints

F/U (years)

Active MCP ROM

Implant fracture

Mannerfelt et al [10]

144

2.5

40

4/144 (3%)

Beckenbaugh et al [4]

186

2.8

38

31/186 (16%)

Blair et al [6]

115

4.5

43

24/115 (21%)

Bieber et al [5]

210

5

39

0/210 (0%)

Maurer et al [11]

137

8.4

39

Kirshenbaum et al [9]

144

8.5

44

15/144 (10%)

Wilson et al [3]

185

9.5

29

Olsen et al [12]

60

7

30

13/60 (22%)

Hansraj et al [8]

170

5.2

27

12/170 (7%)

Schmidt et al [13]

102

10.1

35

28/102 (28%)

Goldfarb and Stern [7]

208

14.2

36

134/208 (63%)

this information [7]. In this investigation, 36 patients who had 208 MCP joint arthroplasties were evaluated at an average of 14 years after surgery. Active MCP motion improved after surgery, and the MCP joints were held in a more extended, and thus more functional, posture. The preoperative MCP joint arc of motion was 57° to 87° (arc 30°), the immediate postoperative arc of motion was 11° to 57° (arc 46°), and the final arc of motion was 23° to 59° (arc 36°). Although the total motion improved only 6°, the arc of motion was moved approximately 30° toward extension. MCP joint axial alignment was not maintained at final follow-up. Preoperative ulnar deviation averaged 26°, immediate postoperative values were less than 5°, and final follow-up, ulnar deviation averaged 16°. Those patients who had implant fractures had a greater degree of ulnar drift recurrence: 10° versus 20° of ulnar drift. The implant fracture rate was 63%, and another 22% of the implants were deformed. The Sutter implants were fractured in 52% of joints compared with 67% in the Swanson implants. Table 1 summarizes these reports.

Although these outcome reports provide valuable information, the literature has been deficient in several areas. The lack of prospective, randomized studies using validated outcomes instruments that target the outcome measures most important to RA patients has hindered our ability to truly understand patient outcome. These deficits are, at least in part, responsible for the significant difference between rheumatologists and hand surgeons in their opinions of the effectiveness of MCP joint arthroplasty and hand surgery in general for RA patients. A mailed survey of 500 hand surgeons and 500 rheumatologists was used to assess current practice and beliefs regarding RA and hand surgery [25,26]. The data demonstrated a marked disparity in opinions between the two groups. Seventy percent of the rheumatologists felt that the hand surgeons had deficient knowledge of medical treatment, and 74% of the surgeons felt the rheumatologists' knowledge of surgical options was deficient. The study noted that there was minimal cross-training between the two groups. Age of the survey responders and other biographical information did not significantly affect the results.

The two groups had a dramatic difference of opinion concerning the indications for and opinions of outcomes of hand surgery in RA. Opinions were different for all procedures, including extensor synovectomy, distal ulna resection, wrist fusion, small joint synovectomy, and small-joint, soft-tissue correction. The findings for MCP arthroplasty highlight the differences in opinions between hand surgeons to rheumatologists. Eighty-two percent of hand surgeons felt that MCP arthroplasty improves function, compared with 34% of rheumatologists; 95% of hand surgeons felt that MCP arthroplasty improves hand aesthetics, compared with 67% of rheumatolo-gists; and 33% of hand surgeons felt that surgery improves strength, compared with 24% of rheumatologists. Training and interpretation of the data in the literature may explain the difference in these opinions.

Recent reports have added significant new information toward our understanding of MCP arthroplasty. Mandl and colleagues [16] evaluated the outcome of 26 patients (160 joints) at an average 5.5 years, based on the subjective assessment of pain, appearance, work, activities of daily living, and satisfaction with function. An objective examination was performed on 18 of the patients. This report found that postoperative patient satisfaction was most correlated with hand appearance. Pain and, to a lesser degree subjective assessment of function, were also correlated with satisfaction. Objective measures such as strength and range of motion were only minimally correlated with patient satisfaction [16]. This investigation emphasizes that patient determinants of success must be used in assessing surgical outcome.

Chung and coworkers [15] have reported the early outcome of MCP arthroplasty in a prospective assessment at 6 months and 12 months using a functional assessment, the Michigan Hand Questionnaire (MHQ), and the Arthritis Impact Measurement Scale (AIMS). At 1 year, there was no significant difference in grip strength, the Jebsen test, or MCP joint range of motion (although improved by an average of 13°). Ulnar drift was significantly improved. Most notably, MHQ scores were significantly improved in all areas (function, activities of daily living [ADL], pain, aesthetics, and satisfaction) except work. This investigation also emphasizes the importance of patient-centered determinants of outcome; patients were clearly subjectively improved at 1 year after surgery [15]. Both this study and the Mandl investigation are optimistic about the outcomes of MCP arthroplasty if specific, patient-centered measures are used.

The Swanson silicone MCP arthroplasty was introduced in 1962, and the Sutter implant was introduced in 1987 [17]. The Sutter implant

(currently marketed under the name Avanta) is similar to the Swanson implant but has a different geometric design, with a center of flexion palmar to the longitudinal axis. It was thought that these changes would allow more flexion and better postoperative function. The new implant had been widely adopted until Bass and Stern [27] reported a markedly higher fracture rate (45% at 3 years) compared with the Swanson implant at short-term assessment. The study authors concluded that they could not, therefore, recommend the use of the implant. Interestingly, a recent investigation with 14 year follow-up [7] found similar fracture rates when comparing the Swanson with the Sutter implant (58% and 52%, respectively).

Recently, a prospective, randomized assessment of the two implants in 30 patients was reported with 2-year follow-up. Similar to the findings in the Chung [15] and the Mandl [16] investigations, objective measures of grip strength and hand function were unchanged. Visual analog scales demonstrated significant subjective improvements in pain, hand function, grip strength, and appearance. Flexion and ulnar deviation deformity improved in both groups to a significant degree. Although the Avanta implant group demonstrated an arc of motion 7° greater than the arc of motion in the Swanson group, this difference was not significant. The Avanta fractures rate was greater (12 fractures, 20%) than the Swanson (8 fractures, 13%) implants, but this difference did not reach statistical significance [28].

The incidence of radiographic osteolysis after MCP arthroplasty was evaluated with a prospective, randomized evaluation of the Swanson and the Sutter prostheses [29]. Seventy-five Swanson implants and 99 Sutter implants were radiograph-ically evaluated at 58 months postoperatively. The osteolytic changes were graded from I to IV. The Sutter group had a significantly increased rate of osteolysis when compared with the Swanson implants. The study authors suggested use of implant arthroplasty only when other surgical alternatives are not available. They also suggested that, even at short-term follow-up, the use of the Sutter implant was questionable. The affect of sil-icone arthroplasty on the adjacent bone has been noted in other investigations as well. Metacarpal and proximal phalanx shortening, osteolysis around the implants, and subsidence were all noted to be problematic at long-term follow-up. Additionally, certain patients were more severely affected with marked shortening of the metacar-pals in 6 of 18 hands [7].

The silicone implant arthroplasty can be an effective treatment option for in RA with severe disease at the MCP joints. Ideally, medical management is used to bring the systemic disease under control before arthroplasty. Although objective improvement after MCP arthroplasty may be limited, the use of patient-centered data has confirmed the utility of the procedure. MCP joint arthroplasty is an effective treatment option from a patient-centered perspective, in that it can improve appearance, pain, and function. The use of DMARDS has made the surgical treatment of RA less common; however, in those patients that undergo MCP arthroplasty, implants are needed that will provide long-term stability with minimal bone reaction.

Was this article helpful?

0 0

Post a comment