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Long-term follow-up of Swanson's silastic arthroplasty of the metacarpophalangeal joints in rheumatoid arthritis
LONG-TERM FOLLOW-UP OF SWANSON’S SILASTIC ARTHROPLASTY OF THE METACARPOPHALANGEAL JOINTS IN RHEUMATOID ARTHRITIS Y. G. WILSON,
P. J. SYKES and N. S. NIRANJAN
From the South Wales Regional Centrefor Plastic and Reconstructive Surgery, Chepstow, Gwent 77
patients with rheumatoid arthritis, 62 female and 15 male, underwent metacarpophalangeal joint arthroplasty on 375 joints using the Swanson design silicone rubber spacer between 1976 and 1985. Retrospectively, 48 of these patients were evaluated by postal questionnaire and 35 of them also underwent objective assessment at intervals ranging from five to 14 years post-operatively. Objective variables recorded included range of active motion, recurrence of ulnar drift and radiographic appearances. Both in the early and late stages, the vast majority of patients were satisfied with the outcome, with abolition of pain, correction of deformity and improved range of motion. There was some loss of mobility with time. However, functional improvementwas maintained in the majority. Complication rates compare favourably with other reported series and no case of silicone synovitis was diagnosed. We agree with previous studies that the procedure is useful for lasting relief of pain and enhancement of a patient’s sense of well-being and is associated with few complications. Journal of Hand Surgery (British and European Volume, 1993) 18B: 81-91
The use of silicone rubber for small joint replacement in the hand is well established (Swanson, 1968, 1969a, 1969b, 1981; Millender and Nalebuff, 1973, 1975; CaFenoff and Stromberg, 1973; Kleinert and Lister, 1986). Efforts have mainly concentrated on reconstruction of the metacarpophalangeal joint because it is the key joint for finger function and is most amenable to treatment by arthroplasty (Swanson, 1972). It is also the most commonly involved joint in rheumatoid arthritis (Nalebuff, 1969). MP joint replacement remains the cornerstone of silicone implant surgery in the hand and is a reliable and effective method of treatment, used to provide a painless joint with a functional range of motion and satisfactory joint stability (Feldon and Belsky, 1987). The Swanson silicone prosthesis is probably the most successful form of arthroplasty. It acts as a flexible hinge and as a dynamic joint spacer, maintaining joint alignment and allowing early motion whilst a fibrous capsule matures around the prosthesis. The encapsulation occurs during healing and stabilizes the implant so that other internal fixation devices are not required. The implant is not attached to the bone and therefore relies on a telescoping effect as the flexible silicone stem glides in the medullary canal (Weingarden, 1974). The great majority of patients with implants achieve improvement in power and dexterity and are relieved from pain in addition to obtaining a cosmetically more acceptable hand (Rhodes et al, 1972; Weingarden, 1974). Eventual recurrence of deformity and fractures of the prostheses have caused concern (Kleinert and Lister, 1986). Complications due specifically to the implant do occur and include fracture, subluxation and dislocation (Kleinert and Lister, 1986). In the 1970s and early 198Os, reports started emerging of giant cell reactive synovitis and lymphadenitis due apparently to shedding of silicone
particles (Aptekar et al, 1974; Christie et al, 1977; Kircher, 1980; Groff et al, 1981; Worsing et al, 1982; Gordon and Bullo’ugh, 1982; Rosenthal et al, 1983; Harvey and Leahy, 1984; Kleinert and Lister, 1986). It was our impression from experience at this centre that silicone synovitis is not as common as has been suggested ; neither was it clear that the other long-term complications mentioned are troublesome. The recent suggestion that we should be reverting to older forms of arthroplasty to avoid the long-term problems of a prosthesis prompted us to review patients who had undergone MP joint arthroplasty in this centre up to 15 years ago. PATIENTS AND METHODS 77 patients underwent Swanson’s MP joint arthroplasty between 1976 and 1985. These included 62 women and 15 men and all had deranged joint function secondary to rheumatoid arthritis. The series included 100 hands and 375 joints. The hospital notes of all these patients were available for inspection. Patients were submitted to surgery for pain and loss of function at the MP joint level. Patients were each sent a postal questionnaire (Fig 1) which acted as a subjective assessment of satisfaction regarding improvements in pain and function and included a section requesting information on current capabilities in activities of daily living. For objective assessment, patients were invited to attend the out-patient clinic at which measurements of extension lag and active arc of flexion were recorded. We did not undertake measurements of grip strength and pinch because we felt there were too many difficulties associated with interpretation of results in patients with rheumatoid arthritis who might have other joints affected in the hand, leading to poorer performance than would be expected from the state of the MP joints alone. The 81
82
THE JOURNAL OF HAND SURGERY VOL. 18B No. 1 FEBRUARY 1
Fig
The postal questionnaire
Please answer the following questions where possible: 1. Can you remember if the operation to replace your knuckle joints improved the function in your hands in the first year? 2. Would you say the joints are working as well now as they were in the first year after your operation? 3. If “no” to (2) above, in what way are the joints not working so well, e.g. painful or stiff? 4. If “no” to (2) above, can you remember at what stage in the last 9 or more years the joints stopped working so well? 5. Have you had any complications in the knuckle joints since your operation, e.g. infection or fracture of the joints? 6. Have you had to have more than one operation on the knuckle joints? 7. If “yes” to (6) above, when was the secondary surgery and what sort of operation was it?
1993
4. Careful selection and handling of the prosthesis. 5. Careful soft tissue repair or relocation for maintaining correct alignment to rebalance the joint. 6. Post-operative dressings/splints to maintain the correction. 7. A supervised exercise programme. Our technique followed that of Swanson (Swanson, 1969b), but, using longitudinal dorsal skin incisions over each MP joint and with the emphasis on adequate soft tissue release to correct volar subluxation and ulnar deviation. Closure was without drainage after repairing the radial collateral ligament, dividing abductor digiti minimi and where necessary, the ulnar intrinsic tendons, and after overlapping the extensor aponeuroses to relocate the long extensor tendon. The tourniquet was released after closure and application of dressings.
8. Have you had to have the artificial joints removed and if so, when? 9. Can you carry out the following activities : (a) Carry a kettle/full saucepan? yes/no/with difficulty* fb) Do uv buttons? yes/no/with difficulty* (c) Do up laces? ye&o/with difficulty* (d) Put on socks/stockings? yes/no/with difficulty* (e) Do ironing? yes/no/with difficulty* (f) Open door handles? yes/no/with difficulty* (g) Wash/brush your hair? yes/no/with difficulty* yes/no/with difficulty* (h) Turn a key in a door? yes/no/with difficulty* (i) Do gardening? yes/no/with difficulty* (j) Drive a car? (* Delete as appropriate) If “no” to any of the above questions, please indicate if the difficulty is due to a specific problem in the knuckle joints or is it really due to a problem in other joints, e.g. wrist or shoulder? >I
A
Name:.......................... Thank you for your help. Please return this questionnaire in the envelope provided.
clinic attendance enabled direct questioning about pain and examination to estimate tenderness, deformity and functional capability. The opportunity was also taken to X-ray the involved joints to look for complications such as fracture of the prothesis, bone resorption, recurrence of ulnar drift and subluxation or dislocation of the prosthesis, features which are not always clinically apparent. Surgical principles For the period covered by the study, all patients underwent surgery according to a standard technique. The principles required for a successful arthroplasty were strictly adhered to and are as follows (Millender and Nalebuff, 1975): 1. Complete soft tissue release. 2. Bone resection to restore full MP alignment. 3. Adequate preparation of the space to accept the prosthesis.
Post-operative therapy At the end of the procedure, bulky padded dressings were applied with the fingers slightly flexed over a volar slab, keeping the MP joints aligned. The limb was rested and elevated for about 48 hours and early mobilization under supervision was begun on the fourth post-operative day. Prior to 1979, patients were fitted with an outrigger for protected post-operative mobilization according to Swanson’s recommended regime. Early active mobilization was achieved more readily in the methods adopted after 1979. The change in post-operative therapy came about when an unpublished comparison of results showed a significant improvement in range of movement at six months to one year in the group treated without an outrigger and this is no longer used (Fig 2). Early mobilization now involves supervised active physiotherapy from the fourth post-operative day using a static resting splint. RESULTS Of the 77 patients identified, 21 had died and seven could not be traced. Of the remaining 49 patients, 14 were unable to attend the clinic because of illness or difficulties in mobility, leaving 35 patients. Of the 14, 11 completed postal questionnaires, allowing at least a subjective assessment of the outcome of their arthroplasty. The remaining 35 patients attended the clinic and were assessed objectively. These patients had between them 50 hands and 185 joints requiring scrutiny. 48 patients could be subjectively assessed (35 in the clinic, 11 by postal questionnaire and two who had died, but whose relatives completed the questionnaire on their behalf). These 48 patients had between them 67 hands and 246 joints. The average age of the female patients at operation was 55.5 years (range 23-78 years). The average age of the male patients at operation was 56.4 years (range 4073 years). The average duration of rheumatoid disease at
SWANSON’S
83
MP ARTHROPLASTY
their pain had been abolished and in no case was the discomfort made worse. Of those who felt there had been improvement, 70% felt that this was maintained longterm. The remaining 30% felt that any deterioration was attributable to increasing stiffness leading to loss of range of movement, rather than due to a return of pain. 27% of patients were able to carry out activities of daily living without any restriction. 19% of patients were unable to carry out any of the activities listed (Fig 1) as they had become so incapacitated with their disease, and 54% found activities difficult. In none of those patients who were limited or unable to carry out activities of daily living was the restriction due to the MP joints; most felt that the restriction was due to other joints and in the overall group (48 patients), 79% mentioned difficulty with other joints (Table 2). EARLY MOBILISATION WITH STATIC SPLINT FROM DAY 4 LATE MOBILISATION (2
Table 2-Restrictions in other joints causing limitations in completing activities of daily living
WEEKS)
WITH OUTRIGGER
Fig 2
Number ofpatients
Joint afjkcted
The effect of a dynamic outrigger and late mobilization on the post-operative range of motion. ??Early mobilization with static splint from day four. lJ Late mobilization (two weeks) with outrigger.
operation was 14.5 years (range 4-37 years). The mean follow-up interval was 9.6 years (range 5-14.3 years). Table 1 gives the distribution of operations through the digits in the whole group and in those surviving and attending clinic. Figure 3 shows the distribution of operations through the years of the series. Subjective assessment Subjective assessment was carried out on 48 patients using the postal questionnaire (Fig 1). 96% of patients in this sample were convinced that there had been definite improvement in the first year following their operation; 4% felt there had been no improvement, but they were certainly no worse. The vast majority of patients felt that
Wrist Interphalangeal Elbow Shoulder Knee All joints
11 5 2 8 5 I
Total
Table 3-Late each hand
38
average post-operative
ranges of motion for each joint in
Left
Right
Au. Ex. Lag/Arc
Au. Ex. Lag/Arc
Index Middle Ring Little
31124 29126 25126 17131
21126 16128 19127 14126
Overall
24129
19129
Digit
Figures in degrees. Overall (left and right): 21/29.
Objective assessment Table l-Distribution
MPJ
of operation according to MP joint
Overall group (77pts)
Surviving group (48pts)
Thumb Index Middle Ring Little
2 94 95 92 92
0 46 41 46 46
Total
315
185
Objective assessment was carried out on the 35 patients who attended the clinic. The late post-operative ranges of movement are given in Table 3 and expressed diagramatically in Figure 4. (The range of movement is expressed as extensor lag/arc of motion). There was some increase in extensor lag and some loss of active arc of flexion with time. i.e. 9”/46” in the early post-operative period (three months) compared with 21”/29” at the time of the study. However, as demonstrated by the high satisfaction rate, an absolute increased range of move-
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VOL. 18B No. 1 FEBRUARY
70 60 50 40 30 20 10 0 1976
1977
1978
1979
1980
1981
1982
1983
1984
YEAR m Fig 3
Distribution
Fig 4
Diagrammatic
of operations
Series
1
+EEEi
Series
from 1976 to 1985. Series 1: no. pts,iseries
representations
of extensor
2
(:
Series
2: no. hands, series 3; no. joints.
lag and active arc of motion for each digit and each hand.
3
1985
1993
SWANSON’S
85
MP ARTHROPLASTY
Table 4-Summary
of previous series reviews for comparison with the Chepstow review Series
Swanson
(1972)
Length FU Max
No. pts
No. hands
No. joints
Au. ROM
358
2.5164
: 5 years
4 years
36
43
159
I56
2.5 years
50
50
144
9149
Ferlic et al (1975)
9 years
45
Beckenbaugh
2.5 years
Weingarden Mannerfelt
et al (1974) et al (1975)
et al (1976)
119
1.9% # rate 0.56% infect. 0.56% revised No complications 2.8% # rate 0.7% infect. 9% # rate 1.2% infect. 1.9% revised
162
149
Complication
530
lo/48
26% # rate 0.6% infect. 2.4% revised
115
13156
21% # rate 2.6% infect.
210
I39
0 #‘S 0.9% infect.
Blair et al (1984)
Max: 10 years
28
Bieber et al (1986)
Max: 8 years
46
Jensen et al (1986)
Max
: 7 years
22
74
13142
5.4% # rate 2.7% infect.
Maurer et al (1990)
9 years
105
446
9148
15% # rate 3.6% revised
Wilson et al (1992)
Max
375
21129
3.2% # rate 1.3% infect. 2.9% revised
: 14 years
77
ment is not a sine qua non for operative success. Functional improvement can still be obtained by improvement in the PIP joint function and freedom from pain (Rhodes et, 1972). Ulnar drift greater than 20” measured both clinically and radiologically recurred in 15 patients (43%). The MP joints in the remaining patients were well aligned. On radiological assessment, five patients (14%) had cortical erosions due to stem impingement, but none of these patients was functionally affected. Six patients (17%) had subluxation/dislocation on X-Ray and of these, two (6%) appeared to have fractured prostheses. One patient had a good range of motion despite the fracture. Figures 5 and 6 illustrate some of the normal and abnormal radiographic appearances, together with photographic evidence of pre- and post-operative appearances. Complications
As hospital records were available for all 77 patients, it was possible to ascertain complication rates for the whole group. No operative or pre-operative deaths occurred. There were no significant medical or anaesthetic complications. Eight patients had complications necessitating removal or revision of 11 prostheses. In five patients the cause was infection affecting one prosthesis each and revision surgery was required in the early post-operative phase. In five patients, revision was required because of
55
100
fracture/subluxation in six prostheses. In one of these patients, a further five prostheses were known to be fracture/dislocated, but, no further action was needed as function was maintained and the patient remained painfree. In a sixth patient with a subluxed prosthesis after a fall, no action was required as there was no functional deficit. It is possible that if all the prostheses could have been X-rayed, the fracture rate might have been higher. However, those fractures significant enought to warrant removal of the prosthesis tended to present early on in the post-operative course and in fact, none of those patients who were X-rayed in the Clinic had fractured prostheses requiring removal and/or revision. The overall complication rate was 4.58% (17 out of 375 prostheses), with a 3.2% known fracture/dislocation rate (i.e. fractures requiring removal and/or revision) and a 1.3% infection rate. 1.06% of prostheses required revision and 1.9% of prostheses were removed, but not replaced. These rates compare favourably with complication rates quoted in other series (Table 4). There were no cases of silicone synovitis in the patients examined and there was no radiological evidence of this potential complication. DISCUSSION
The ideal joint implant must reflect a compromise between engineering and biomechanical considerations, material characteristics, anatomical and physiological
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Fig 5
1993
(a) Radiographic appearances of Swanson MP joint replacement 13 years post-operatively, showing maintenance of alignment. (b) Radiograph of hand 11 years post-operatively, showing subluxation of right ring and little finger prostheses. (There had been no recurrc :nce of pain and functionally the patient was little disturbed). (c) Radiograph illustrating cortical erosion by stems of prostheses in proxi ma1 phalanges of right index and middle fingers, 12 years post-operatively. (The right ring prosthesis had been previously removed becaus ie of infection). (d) Radiograph of hand 13 years post-operatively, showing dislocation of the right ring and little finger prostheses and of all I the left-sided prostheses with probable fracture of the left index and middle finger prostheses. (Functionally, no gross deficit).
SWANSON’S
MP ARTHROPLASTY
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Fig 6
THE JOURNAL OF HAND SURGERY VOL. 18B No. 1 FEBRUARY 1993
Preoperative (a and b) and postoperative (c and d) appearances of hand deformity in one patient.
SWANSON’S
MP ARTHROPLASTY
89
90
considerations and the patients’ needs (Swanson et al, 1973). It must be pain-free, mobile, stable and durable (Swanson, 1969b, 1972; Mannerfelt et al, 1975). Our findings support the general impression that the Swanson MP arthroplasty, or “load-distributing flexible hinge” as he calls it, is a successful method of treatment using the criteria: range of motion, correction of deformity, improvement of stability, abolition of pain and subjective increase of well-being (Bieber et al, 1986). The end result is not a normal articulation, but a painless arthroplasty with a useful arc of motion (Beckenbaugh, 1983). Carefully supervised therapy has long been an essential component of a successful procedure (Bieber et al, 1986). The operation should be avoided in severely disorganized hands as rehabilitation is very lengthy and could contribute to further dysfunction (Kay et al, 1978). Despite the deterioration in range of motion with time noted in this series, patients generally felt that they had a successful result, with relief of pain, correction of ulnar deformity and subluxation and an improved range of movement. Loss of correction was partly related to severity and progression of the disease process, involving other joints in the upper limb, rather than a failure of the prosthesis. The involvement of adjacent joints and tendons responsible for the initial deformity may nullify the benefits of surgery (Bieber et al, 1986), but, the majority of patients in this study felt the improvement was maintained. It is our impression that the patients achieved the level of function required for them to carry out activities of daily living. Thus hand dominance and the state of the IP joints and wrist joints may all have a significant bearing on the arc of motion achieved in the MP joints post-operatively, depending on how much movement is “needed” and how much can be compensated for by the other joints. A cosmetically more acceptable hand is of psychological benefit (Rhodes et al, 1972) and patients in our study appreciated this aspect in addition to the physical benefits. The radiological findings with cortical erosions and fractures reflect the host bone’s response to stress (Blair et al, 1984). As in Blair’s study, the radiological changes, though frequent, were of low magnitude and did not appear to impair function significantly. The 14% rate of cortical erosion revealed by this study compares with 41% in Blair’s review and 100% in Hagert’s study (Hagert et al, 1975), but, his review made use of tomograms. In Swanson’s series most patients were unaware of having fractured implants because the fracture did not seem to affect function significantly. Many of these cases have continued to present very satisfactory, functional, painfree resection arthroplasties, supporting the concept of the main role of the implant as being a “spacing device for the joint”, which guides the “encapsulation process” (Swanson, 1972). Many of the early silicone implants of the late 1960s and early 1970s have reached a period when material fatigue predisposes to fracture (Groff et al, 1981) and with continued follow-up we might encounter more fractures.
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Although we have seen no cases of silicone synovitis so far in our series, it is possible that it may develop at a later date also. However, the symptoms and signs attributed to silicone synovitis highlighted in the papers quoted earlier had often appeared within five years and certainly within ten years. Therefore, our study upholds the impression that silicone synovitis is not a troublesome complication even allowing for the difficulties in distinguishing destructive bone changes from progression of rheumatoid arthritis. Silicone synovitis is manifested as recurrent pain, synovial thickening, erythema around the joint, painful limitation of movement and/or nontender axillary lymphadenopathy. The infection rate compares favourably with other series that have been reported. Infection after MP joint arthroplasty is much less devastating than with larger joints because the prosthesis can be removed and rapid wound healing ensues with minimum morbidity. The patient then functions with a resection arthroplasty, usually with good alignment and some motion (Millender et al, 1975). Resection arthroplsty with silastic spacers remains the most widely used operative procedure in the reconstruction of the rheumatoid MP joint. Knowledge of the benefits and limitations of this procedure will permit patient and surgeon to approach surgery with realistic expectations. The Swanson design is basically a nonfixed, flexible hinge, intramedullary stemmed spacer which improves the stability of resection arthroplasties. Patients and surgeons can be confident in its long-term reliability and the functional benefits are consistent.
References APTEKAR, R. G., DAVIE, J. M. and CATTELL, H. S. (1974). Foreign body reaction to silicone robber: Complication of a finger joint implant. Clinical Orthooaedics and Related Research. 98: 231-232. BECKENBAUGH, R. D., DOBYNS, J: H., LINSCHEID, R. L. and BRYAN, R. S. (1976). Review and analysis of silicone-rubber metacarpophalangeal implants. Journal of Bone and Joint Surgery, 58A: 4: 483-487. BECKENBAUGH, R. D. (1983). Implant arthroplasty in the rheumatoid hand and wrist: Current state of the art in the United States. Journal of Hand Surgery, 8 : 5 : 675-678. BIEBER, E. J., WEILAND, A. J. and VOLENEC-DOWLING, S. (1986). Silicone-rubber implant arthroplasty of the metacarpophalangeal joints for rheumatoid arthritis. Journal of Bone and Joint Surgery, 68A: 2: 206209. BLAIR, W. F., SHURR, D. G. and BUCKWALTER, J. A. (1984). Metacarpophalangeal joint implant arthroplasty with a silastic spacer. Journal of Bone and Joint Surgery, 66A : 3 : 365-370. CALENOFF,L. and STROMBERG, W. B. (1973). Siliconerubberarthroplasties of the hand. Radiology, 107 : 29-34. CHRISTIE, A. J., WEINBERGER, K. A. andDIETRICH, M. (1977). Silicone lymphadenopathy and synovitis: Complications of silicone elastomer finger joint prostheses. Journal of the American Medical Assocation, 237: 14: 1463-1464. FELDON, P. and BELSKY, M. R. (1987). Degenerative diseases of the metacarpophalangeal joints. Hand Clinics, 3 : 3 : 429445. FERLIC, D. C., CLAYTON, M. L. and HOLLOWAY, M. (1975). Complications of silicone implant surgery in the metacarpophalangeal joint. Journal of Bone and Joint Surgery, 57A: 7: 991-994. GORDON, M. and BULLOUGH, P. G. (1982). Synovial and osseous inflammation in failed silicone-rubber prosthesis: report of six cases. Journal of Bone and Joint Surgery, 64A: 4: 574-580. GROFF, G. D., SCHNED, A. R. and TAYLOR, T. H. (1981). Silicone-induced adenopathy eight years after metacarpophalangeal arthroplasty. Arthritis and Rheumatism, 24: 12: 1578-1581.
SWANSON’S MP ARTHROPLASTY HAGERT, C. G., EIKEN, O., OHLSSON, N. M., ASCHAN, W. and MOVIN, A. (1975). Metacarpophalangeal joint implants: 1. Roentgenographic study on the silastic finger joint implant, Swanson design. Scandinavian Journal of Plastic and Reconstructive Surgery, 9: 147-157. HARVEY,T. andLEAHY,M. (1984). Siliconelymphadenopathy:acomplication of silicone elastomer finger joint prostheses. Journal of Rheumatology, 11: 104-105. JENSEN, C. M., BOECKSTYNS, M. E. H. and KRISTJANSEN, B. (1986). Silastic arthroplasty in rheumatoid MCP-Joints. Acta Orthropaedica Scandinavica, 57: 13X-140. KAY, A. G. L., JEFFS, J. V. and SCOTT, J. T. (1978). Experience with silastic prostheses in the rheumatoid hand: A 5-year follow-up. Annals of the Rheumatic Diseases, 37: 255-258. KIRCHER, T. (1980). Silicone lymphadenopathy: a complication of silicone elastomer finger joint prostheses. Human Pathology, 11: 240-244. KLEINERT, J. M. and LISTER, G. D. (1986). Silicone implants. Hand Clinics, 2: 2: 271-290. MANNERFELT, L. and ANDERSSON, K. (1975). Silastic arthroplasty of the rnetacarpophalangeal joints in rheumatoid arthritis: long-term results. Journal of Bone and Joint Surgery, 57A : 4: 484489. MAURER, R. J., RANAWAT, C. S., McCORMACK, R. R., INGLJS, A. E. and STRAUB, L. R. (1990). Long-term follow-up of the Swanson MP &hroplasty for rheumatoid arthritis. Journal of Hand Surgery, 15A: 5 : 810;JI 1 MIL&NDER, L. H. and NALEBUFF, E. A. (1973). Metacarpophalangeal ,;oint arthroplasty utilizing the silicone rubber prosthesis. Orthopaedic Clinics #ofNorth America, 4: 2: 349-371. MILIENDER, L. H. and NALEBUFF, E. A. (1975). Reconstructive surgery in the rheumatoid hand. Orthopaedic Clinics of North America, 6: 3: 709-732. MILLENDER, L. H., NALEBUFF, E. A., HAWKINS, R. B. and ENNIS, R. i 1975). Infection after silicone prosthetic arthroplasty in the hand. Journal of Bone and Joint Surgery, 57A: 6: 825-829. NAI_EBUFF, E. A. (1969). Metacarpophalangealsurgery in rheumatoid arthritis. Surgical Clinics of North America, 49: 4: 823-832.
91 RHODES, K., JEFFS, J. V. and SCOTT, J. T. (1972). Experience with silastic prostheses in rheumatoid hands. Annals of the Rheumatic Diseases, 31: 103108. ROSENTHAL, D. I., ROSENBERG, A. E., SCHILLER, A. L. and SMITH, R. J. (1983). Destructive arthritis due to silicone: a foreign-body reaction. Radiology, 149: 69-72. SWANSON, A. B. (1968). Silicone rubber implants for replacement of arthritic or destroyed joints in the hand. Surgical Clinics of North America, 48 : 5 : 1113-1126. SWANSON, A. B. (1969a). Silicone rubber implants for replacement of arthritic or destroyed joints. Hand, 1: 38-39. SWANSON, A. B. (1969b). Fingerjoint replacement by silicone rubber implants and the concept of implant fixation by encapsulation. Annals of the Rheumatic Diseases, 28 (Supplement): 47-55. SWANSON, A. B. (1972). Flexible implant arthroplasty for arthritic fingerjoints: Rationale, technique and results of treatment. Journal of Bone and Joint Surgery, 54A: 3: 435455. SWANSON, A. B., MEESTER, W. D., SWANSON, G. de G., RANGASWAMY, L. and SCHUT, G. E. D. (1973). Durability of silicone implantsan in viva study. Orthopedic Clinics of North America, 4: 4: 1097-l 112. SWANSON, A. B. (1981). Implant arthroplasty in the hand and upper extremity and its future. Surgical Clinics of North America, 61: 2: 369-382. WEINGARDEN, T. L. (1974). Rheumatoid arthritis of the hand: A review of silastic prosthesis arthroplasty in 36 patients. Journal of the American Orthopaedic Association, 74: 209-216. WORSING, R. A., ENGBER, W. D. and LANGE, T. A. (1982). Reactive synovitis from particulate silastic. Journal of Bone and Joint Surgery, 64A: 4: 581-585.
Accepted: 18 February
1992 MI P. J. Sykes, St Lawrence Hospital, Chepstow, Newport, &vent.
0 1993 The British Society for Surgery of the Hand
P. J. SYKES and N. S. NIRANJAN
From the South Wales Regional Centrefor Plastic and Reconstructive Surgery, Chepstow, Gwent 77
patients with rheumatoid arthritis, 62 female and 15 male, underwent metacarpophalangeal joint arthroplasty on 375 joints using the Swanson design silicone rubber spacer between 1976 and 1985. Retrospectively, 48 of these patients were evaluated by postal questionnaire and 35 of them also underwent objective assessment at intervals ranging from five to 14 years post-operatively. Objective variables recorded included range of active motion, recurrence of ulnar drift and radiographic appearances. Both in the early and late stages, the vast majority of patients were satisfied with the outcome, with abolition of pain, correction of deformity and improved range of motion. There was some loss of mobility with time. However, functional improvementwas maintained in the majority. Complication rates compare favourably with other reported series and no case of silicone synovitis was diagnosed. We agree with previous studies that the procedure is useful for lasting relief of pain and enhancement of a patient’s sense of well-being and is associated with few complications. Journal of Hand Surgery (British and European Volume, 1993) 18B: 81-91
The use of silicone rubber for small joint replacement in the hand is well established (Swanson, 1968, 1969a, 1969b, 1981; Millender and Nalebuff, 1973, 1975; CaFenoff and Stromberg, 1973; Kleinert and Lister, 1986). Efforts have mainly concentrated on reconstruction of the metacarpophalangeal joint because it is the key joint for finger function and is most amenable to treatment by arthroplasty (Swanson, 1972). It is also the most commonly involved joint in rheumatoid arthritis (Nalebuff, 1969). MP joint replacement remains the cornerstone of silicone implant surgery in the hand and is a reliable and effective method of treatment, used to provide a painless joint with a functional range of motion and satisfactory joint stability (Feldon and Belsky, 1987). The Swanson silicone prosthesis is probably the most successful form of arthroplasty. It acts as a flexible hinge and as a dynamic joint spacer, maintaining joint alignment and allowing early motion whilst a fibrous capsule matures around the prosthesis. The encapsulation occurs during healing and stabilizes the implant so that other internal fixation devices are not required. The implant is not attached to the bone and therefore relies on a telescoping effect as the flexible silicone stem glides in the medullary canal (Weingarden, 1974). The great majority of patients with implants achieve improvement in power and dexterity and are relieved from pain in addition to obtaining a cosmetically more acceptable hand (Rhodes et al, 1972; Weingarden, 1974). Eventual recurrence of deformity and fractures of the prostheses have caused concern (Kleinert and Lister, 1986). Complications due specifically to the implant do occur and include fracture, subluxation and dislocation (Kleinert and Lister, 1986). In the 1970s and early 198Os, reports started emerging of giant cell reactive synovitis and lymphadenitis due apparently to shedding of silicone
particles (Aptekar et al, 1974; Christie et al, 1977; Kircher, 1980; Groff et al, 1981; Worsing et al, 1982; Gordon and Bullo’ugh, 1982; Rosenthal et al, 1983; Harvey and Leahy, 1984; Kleinert and Lister, 1986). It was our impression from experience at this centre that silicone synovitis is not as common as has been suggested ; neither was it clear that the other long-term complications mentioned are troublesome. The recent suggestion that we should be reverting to older forms of arthroplasty to avoid the long-term problems of a prosthesis prompted us to review patients who had undergone MP joint arthroplasty in this centre up to 15 years ago. PATIENTS AND METHODS 77 patients underwent Swanson’s MP joint arthroplasty between 1976 and 1985. These included 62 women and 15 men and all had deranged joint function secondary to rheumatoid arthritis. The series included 100 hands and 375 joints. The hospital notes of all these patients were available for inspection. Patients were submitted to surgery for pain and loss of function at the MP joint level. Patients were each sent a postal questionnaire (Fig 1) which acted as a subjective assessment of satisfaction regarding improvements in pain and function and included a section requesting information on current capabilities in activities of daily living. For objective assessment, patients were invited to attend the out-patient clinic at which measurements of extension lag and active arc of flexion were recorded. We did not undertake measurements of grip strength and pinch because we felt there were too many difficulties associated with interpretation of results in patients with rheumatoid arthritis who might have other joints affected in the hand, leading to poorer performance than would be expected from the state of the MP joints alone. The 81
82
THE JOURNAL OF HAND SURGERY VOL. 18B No. 1 FEBRUARY 1
Fig
The postal questionnaire
Please answer the following questions where possible: 1. Can you remember if the operation to replace your knuckle joints improved the function in your hands in the first year? 2. Would you say the joints are working as well now as they were in the first year after your operation? 3. If “no” to (2) above, in what way are the joints not working so well, e.g. painful or stiff? 4. If “no” to (2) above, can you remember at what stage in the last 9 or more years the joints stopped working so well? 5. Have you had any complications in the knuckle joints since your operation, e.g. infection or fracture of the joints? 6. Have you had to have more than one operation on the knuckle joints? 7. If “yes” to (6) above, when was the secondary surgery and what sort of operation was it?
1993
4. Careful selection and handling of the prosthesis. 5. Careful soft tissue repair or relocation for maintaining correct alignment to rebalance the joint. 6. Post-operative dressings/splints to maintain the correction. 7. A supervised exercise programme. Our technique followed that of Swanson (Swanson, 1969b), but, using longitudinal dorsal skin incisions over each MP joint and with the emphasis on adequate soft tissue release to correct volar subluxation and ulnar deviation. Closure was without drainage after repairing the radial collateral ligament, dividing abductor digiti minimi and where necessary, the ulnar intrinsic tendons, and after overlapping the extensor aponeuroses to relocate the long extensor tendon. The tourniquet was released after closure and application of dressings.
8. Have you had to have the artificial joints removed and if so, when? 9. Can you carry out the following activities : (a) Carry a kettle/full saucepan? yes/no/with difficulty* fb) Do uv buttons? yes/no/with difficulty* (c) Do up laces? ye&o/with difficulty* (d) Put on socks/stockings? yes/no/with difficulty* (e) Do ironing? yes/no/with difficulty* (f) Open door handles? yes/no/with difficulty* (g) Wash/brush your hair? yes/no/with difficulty* yes/no/with difficulty* (h) Turn a key in a door? yes/no/with difficulty* (i) Do gardening? yes/no/with difficulty* (j) Drive a car? (* Delete as appropriate) If “no” to any of the above questions, please indicate if the difficulty is due to a specific problem in the knuckle joints or is it really due to a problem in other joints, e.g. wrist or shoulder? >I
A
Name:.......................... Thank you for your help. Please return this questionnaire in the envelope provided.
clinic attendance enabled direct questioning about pain and examination to estimate tenderness, deformity and functional capability. The opportunity was also taken to X-ray the involved joints to look for complications such as fracture of the prothesis, bone resorption, recurrence of ulnar drift and subluxation or dislocation of the prosthesis, features which are not always clinically apparent. Surgical principles For the period covered by the study, all patients underwent surgery according to a standard technique. The principles required for a successful arthroplasty were strictly adhered to and are as follows (Millender and Nalebuff, 1975): 1. Complete soft tissue release. 2. Bone resection to restore full MP alignment. 3. Adequate preparation of the space to accept the prosthesis.
Post-operative therapy At the end of the procedure, bulky padded dressings were applied with the fingers slightly flexed over a volar slab, keeping the MP joints aligned. The limb was rested and elevated for about 48 hours and early mobilization under supervision was begun on the fourth post-operative day. Prior to 1979, patients were fitted with an outrigger for protected post-operative mobilization according to Swanson’s recommended regime. Early active mobilization was achieved more readily in the methods adopted after 1979. The change in post-operative therapy came about when an unpublished comparison of results showed a significant improvement in range of movement at six months to one year in the group treated without an outrigger and this is no longer used (Fig 2). Early mobilization now involves supervised active physiotherapy from the fourth post-operative day using a static resting splint. RESULTS Of the 77 patients identified, 21 had died and seven could not be traced. Of the remaining 49 patients, 14 were unable to attend the clinic because of illness or difficulties in mobility, leaving 35 patients. Of the 14, 11 completed postal questionnaires, allowing at least a subjective assessment of the outcome of their arthroplasty. The remaining 35 patients attended the clinic and were assessed objectively. These patients had between them 50 hands and 185 joints requiring scrutiny. 48 patients could be subjectively assessed (35 in the clinic, 11 by postal questionnaire and two who had died, but whose relatives completed the questionnaire on their behalf). These 48 patients had between them 67 hands and 246 joints. The average age of the female patients at operation was 55.5 years (range 23-78 years). The average age of the male patients at operation was 56.4 years (range 4073 years). The average duration of rheumatoid disease at
SWANSON’S
83
MP ARTHROPLASTY
their pain had been abolished and in no case was the discomfort made worse. Of those who felt there had been improvement, 70% felt that this was maintained longterm. The remaining 30% felt that any deterioration was attributable to increasing stiffness leading to loss of range of movement, rather than due to a return of pain. 27% of patients were able to carry out activities of daily living without any restriction. 19% of patients were unable to carry out any of the activities listed (Fig 1) as they had become so incapacitated with their disease, and 54% found activities difficult. In none of those patients who were limited or unable to carry out activities of daily living was the restriction due to the MP joints; most felt that the restriction was due to other joints and in the overall group (48 patients), 79% mentioned difficulty with other joints (Table 2). EARLY MOBILISATION WITH STATIC SPLINT FROM DAY 4 LATE MOBILISATION (2
Table 2-Restrictions in other joints causing limitations in completing activities of daily living
WEEKS)
WITH OUTRIGGER
Fig 2
Number ofpatients
Joint afjkcted
The effect of a dynamic outrigger and late mobilization on the post-operative range of motion. ??Early mobilization with static splint from day four. lJ Late mobilization (two weeks) with outrigger.
operation was 14.5 years (range 4-37 years). The mean follow-up interval was 9.6 years (range 5-14.3 years). Table 1 gives the distribution of operations through the digits in the whole group and in those surviving and attending clinic. Figure 3 shows the distribution of operations through the years of the series. Subjective assessment Subjective assessment was carried out on 48 patients using the postal questionnaire (Fig 1). 96% of patients in this sample were convinced that there had been definite improvement in the first year following their operation; 4% felt there had been no improvement, but they were certainly no worse. The vast majority of patients felt that
Wrist Interphalangeal Elbow Shoulder Knee All joints
11 5 2 8 5 I
Total
Table 3-Late each hand
38
average post-operative
ranges of motion for each joint in
Left
Right
Au. Ex. Lag/Arc
Au. Ex. Lag/Arc
Index Middle Ring Little
31124 29126 25126 17131
21126 16128 19127 14126
Overall
24129
19129
Digit
Figures in degrees. Overall (left and right): 21/29.
Objective assessment Table l-Distribution
MPJ
of operation according to MP joint
Overall group (77pts)
Surviving group (48pts)
Thumb Index Middle Ring Little
2 94 95 92 92
0 46 41 46 46
Total
315
185
Objective assessment was carried out on the 35 patients who attended the clinic. The late post-operative ranges of movement are given in Table 3 and expressed diagramatically in Figure 4. (The range of movement is expressed as extensor lag/arc of motion). There was some increase in extensor lag and some loss of active arc of flexion with time. i.e. 9”/46” in the early post-operative period (three months) compared with 21”/29” at the time of the study. However, as demonstrated by the high satisfaction rate, an absolute increased range of move-
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VOL. 18B No. 1 FEBRUARY
70 60 50 40 30 20 10 0 1976
1977
1978
1979
1980
1981
1982
1983
1984
YEAR m Fig 3
Distribution
Fig 4
Diagrammatic
of operations
Series
1
+EEEi
Series
from 1976 to 1985. Series 1: no. pts,iseries
representations
of extensor
2
(:
Series
2: no. hands, series 3; no. joints.
lag and active arc of motion for each digit and each hand.
3
1985
1993
SWANSON’S
85
MP ARTHROPLASTY
Table 4-Summary
of previous series reviews for comparison with the Chepstow review Series
Swanson
(1972)
Length FU Max
No. pts
No. hands
No. joints
Au. ROM
358
2.5164
: 5 years
4 years
36
43
159
I56
2.5 years
50
50
144
9149
Ferlic et al (1975)
9 years
45
Beckenbaugh
2.5 years
Weingarden Mannerfelt
et al (1974) et al (1975)
et al (1976)
119
1.9% # rate 0.56% infect. 0.56% revised No complications 2.8% # rate 0.7% infect. 9% # rate 1.2% infect. 1.9% revised
162
149
Complication
530
lo/48
26% # rate 0.6% infect. 2.4% revised
115
13156
21% # rate 2.6% infect.
210
I39
0 #‘S 0.9% infect.
Blair et al (1984)
Max: 10 years
28
Bieber et al (1986)
Max: 8 years
46
Jensen et al (1986)
Max
: 7 years
22
74
13142
5.4% # rate 2.7% infect.
Maurer et al (1990)
9 years
105
446
9148
15% # rate 3.6% revised
Wilson et al (1992)
Max
375
21129
3.2% # rate 1.3% infect. 2.9% revised
: 14 years
77
ment is not a sine qua non for operative success. Functional improvement can still be obtained by improvement in the PIP joint function and freedom from pain (Rhodes et, 1972). Ulnar drift greater than 20” measured both clinically and radiologically recurred in 15 patients (43%). The MP joints in the remaining patients were well aligned. On radiological assessment, five patients (14%) had cortical erosions due to stem impingement, but none of these patients was functionally affected. Six patients (17%) had subluxation/dislocation on X-Ray and of these, two (6%) appeared to have fractured prostheses. One patient had a good range of motion despite the fracture. Figures 5 and 6 illustrate some of the normal and abnormal radiographic appearances, together with photographic evidence of pre- and post-operative appearances. Complications
As hospital records were available for all 77 patients, it was possible to ascertain complication rates for the whole group. No operative or pre-operative deaths occurred. There were no significant medical or anaesthetic complications. Eight patients had complications necessitating removal or revision of 11 prostheses. In five patients the cause was infection affecting one prosthesis each and revision surgery was required in the early post-operative phase. In five patients, revision was required because of
55
100
fracture/subluxation in six prostheses. In one of these patients, a further five prostheses were known to be fracture/dislocated, but, no further action was needed as function was maintained and the patient remained painfree. In a sixth patient with a subluxed prosthesis after a fall, no action was required as there was no functional deficit. It is possible that if all the prostheses could have been X-rayed, the fracture rate might have been higher. However, those fractures significant enought to warrant removal of the prosthesis tended to present early on in the post-operative course and in fact, none of those patients who were X-rayed in the Clinic had fractured prostheses requiring removal and/or revision. The overall complication rate was 4.58% (17 out of 375 prostheses), with a 3.2% known fracture/dislocation rate (i.e. fractures requiring removal and/or revision) and a 1.3% infection rate. 1.06% of prostheses required revision and 1.9% of prostheses were removed, but not replaced. These rates compare favourably with complication rates quoted in other series (Table 4). There were no cases of silicone synovitis in the patients examined and there was no radiological evidence of this potential complication. DISCUSSION
The ideal joint implant must reflect a compromise between engineering and biomechanical considerations, material characteristics, anatomical and physiological
THE JOURNAL OF HAND SURGERY VOL. 18B No. 1 FEBRUARY
Fig 5
1993
(a) Radiographic appearances of Swanson MP joint replacement 13 years post-operatively, showing maintenance of alignment. (b) Radiograph of hand 11 years post-operatively, showing subluxation of right ring and little finger prostheses. (There had been no recurrc :nce of pain and functionally the patient was little disturbed). (c) Radiograph illustrating cortical erosion by stems of prostheses in proxi ma1 phalanges of right index and middle fingers, 12 years post-operatively. (The right ring prosthesis had been previously removed becaus ie of infection). (d) Radiograph of hand 13 years post-operatively, showing dislocation of the right ring and little finger prostheses and of all I the left-sided prostheses with probable fracture of the left index and middle finger prostheses. (Functionally, no gross deficit).
SWANSON’S
MP ARTHROPLASTY
88
Fig 6
THE JOURNAL OF HAND SURGERY VOL. 18B No. 1 FEBRUARY 1993
Preoperative (a and b) and postoperative (c and d) appearances of hand deformity in one patient.
SWANSON’S
MP ARTHROPLASTY
89
90
considerations and the patients’ needs (Swanson et al, 1973). It must be pain-free, mobile, stable and durable (Swanson, 1969b, 1972; Mannerfelt et al, 1975). Our findings support the general impression that the Swanson MP arthroplasty, or “load-distributing flexible hinge” as he calls it, is a successful method of treatment using the criteria: range of motion, correction of deformity, improvement of stability, abolition of pain and subjective increase of well-being (Bieber et al, 1986). The end result is not a normal articulation, but a painless arthroplasty with a useful arc of motion (Beckenbaugh, 1983). Carefully supervised therapy has long been an essential component of a successful procedure (Bieber et al, 1986). The operation should be avoided in severely disorganized hands as rehabilitation is very lengthy and could contribute to further dysfunction (Kay et al, 1978). Despite the deterioration in range of motion with time noted in this series, patients generally felt that they had a successful result, with relief of pain, correction of ulnar deformity and subluxation and an improved range of movement. Loss of correction was partly related to severity and progression of the disease process, involving other joints in the upper limb, rather than a failure of the prosthesis. The involvement of adjacent joints and tendons responsible for the initial deformity may nullify the benefits of surgery (Bieber et al, 1986), but, the majority of patients in this study felt the improvement was maintained. It is our impression that the patients achieved the level of function required for them to carry out activities of daily living. Thus hand dominance and the state of the IP joints and wrist joints may all have a significant bearing on the arc of motion achieved in the MP joints post-operatively, depending on how much movement is “needed” and how much can be compensated for by the other joints. A cosmetically more acceptable hand is of psychological benefit (Rhodes et al, 1972) and patients in our study appreciated this aspect in addition to the physical benefits. The radiological findings with cortical erosions and fractures reflect the host bone’s response to stress (Blair et al, 1984). As in Blair’s study, the radiological changes, though frequent, were of low magnitude and did not appear to impair function significantly. The 14% rate of cortical erosion revealed by this study compares with 41% in Blair’s review and 100% in Hagert’s study (Hagert et al, 1975), but, his review made use of tomograms. In Swanson’s series most patients were unaware of having fractured implants because the fracture did not seem to affect function significantly. Many of these cases have continued to present very satisfactory, functional, painfree resection arthroplasties, supporting the concept of the main role of the implant as being a “spacing device for the joint”, which guides the “encapsulation process” (Swanson, 1972). Many of the early silicone implants of the late 1960s and early 1970s have reached a period when material fatigue predisposes to fracture (Groff et al, 1981) and with continued follow-up we might encounter more fractures.
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Although we have seen no cases of silicone synovitis so far in our series, it is possible that it may develop at a later date also. However, the symptoms and signs attributed to silicone synovitis highlighted in the papers quoted earlier had often appeared within five years and certainly within ten years. Therefore, our study upholds the impression that silicone synovitis is not a troublesome complication even allowing for the difficulties in distinguishing destructive bone changes from progression of rheumatoid arthritis. Silicone synovitis is manifested as recurrent pain, synovial thickening, erythema around the joint, painful limitation of movement and/or nontender axillary lymphadenopathy. The infection rate compares favourably with other series that have been reported. Infection after MP joint arthroplasty is much less devastating than with larger joints because the prosthesis can be removed and rapid wound healing ensues with minimum morbidity. The patient then functions with a resection arthroplasty, usually with good alignment and some motion (Millender et al, 1975). Resection arthroplsty with silastic spacers remains the most widely used operative procedure in the reconstruction of the rheumatoid MP joint. Knowledge of the benefits and limitations of this procedure will permit patient and surgeon to approach surgery with realistic expectations. The Swanson design is basically a nonfixed, flexible hinge, intramedullary stemmed spacer which improves the stability of resection arthroplasties. Patients and surgeons can be confident in its long-term reliability and the functional benefits are consistent.
References APTEKAR, R. G., DAVIE, J. M. and CATTELL, H. S. (1974). Foreign body reaction to silicone robber: Complication of a finger joint implant. Clinical Orthooaedics and Related Research. 98: 231-232. BECKENBAUGH, R. D., DOBYNS, J: H., LINSCHEID, R. L. and BRYAN, R. S. (1976). Review and analysis of silicone-rubber metacarpophalangeal implants. Journal of Bone and Joint Surgery, 58A: 4: 483-487. BECKENBAUGH, R. D. (1983). Implant arthroplasty in the rheumatoid hand and wrist: Current state of the art in the United States. Journal of Hand Surgery, 8 : 5 : 675-678. BIEBER, E. J., WEILAND, A. J. and VOLENEC-DOWLING, S. (1986). Silicone-rubber implant arthroplasty of the metacarpophalangeal joints for rheumatoid arthritis. Journal of Bone and Joint Surgery, 68A: 2: 206209. BLAIR, W. F., SHURR, D. G. and BUCKWALTER, J. A. (1984). Metacarpophalangeal joint implant arthroplasty with a silastic spacer. Journal of Bone and Joint Surgery, 66A : 3 : 365-370. CALENOFF,L. and STROMBERG, W. B. (1973). Siliconerubberarthroplasties of the hand. Radiology, 107 : 29-34. CHRISTIE, A. J., WEINBERGER, K. A. andDIETRICH, M. (1977). Silicone lymphadenopathy and synovitis: Complications of silicone elastomer finger joint prostheses. Journal of the American Medical Assocation, 237: 14: 1463-1464. FELDON, P. and BELSKY, M. R. (1987). Degenerative diseases of the metacarpophalangeal joints. Hand Clinics, 3 : 3 : 429445. FERLIC, D. C., CLAYTON, M. L. and HOLLOWAY, M. (1975). Complications of silicone implant surgery in the metacarpophalangeal joint. Journal of Bone and Joint Surgery, 57A: 7: 991-994. GORDON, M. and BULLOUGH, P. G. (1982). Synovial and osseous inflammation in failed silicone-rubber prosthesis: report of six cases. Journal of Bone and Joint Surgery, 64A: 4: 574-580. GROFF, G. D., SCHNED, A. R. and TAYLOR, T. H. (1981). Silicone-induced adenopathy eight years after metacarpophalangeal arthroplasty. Arthritis and Rheumatism, 24: 12: 1578-1581.
SWANSON’S MP ARTHROPLASTY HAGERT, C. G., EIKEN, O., OHLSSON, N. M., ASCHAN, W. and MOVIN, A. (1975). Metacarpophalangeal joint implants: 1. Roentgenographic study on the silastic finger joint implant, Swanson design. Scandinavian Journal of Plastic and Reconstructive Surgery, 9: 147-157. HARVEY,T. andLEAHY,M. (1984). Siliconelymphadenopathy:acomplication of silicone elastomer finger joint prostheses. Journal of Rheumatology, 11: 104-105. JENSEN, C. M., BOECKSTYNS, M. E. H. and KRISTJANSEN, B. (1986). Silastic arthroplasty in rheumatoid MCP-Joints. Acta Orthropaedica Scandinavica, 57: 13X-140. KAY, A. G. L., JEFFS, J. V. and SCOTT, J. T. (1978). Experience with silastic prostheses in the rheumatoid hand: A 5-year follow-up. Annals of the Rheumatic Diseases, 37: 255-258. KIRCHER, T. (1980). Silicone lymphadenopathy: a complication of silicone elastomer finger joint prostheses. Human Pathology, 11: 240-244. KLEINERT, J. M. and LISTER, G. D. (1986). Silicone implants. Hand Clinics, 2: 2: 271-290. MANNERFELT, L. and ANDERSSON, K. (1975). Silastic arthroplasty of the rnetacarpophalangeal joints in rheumatoid arthritis: long-term results. Journal of Bone and Joint Surgery, 57A : 4: 484489. MAURER, R. J., RANAWAT, C. S., McCORMACK, R. R., INGLJS, A. E. and STRAUB, L. R. (1990). Long-term follow-up of the Swanson MP &hroplasty for rheumatoid arthritis. Journal of Hand Surgery, 15A: 5 : 810;JI 1 MIL&NDER, L. H. and NALEBUFF, E. A. (1973). Metacarpophalangeal ,;oint arthroplasty utilizing the silicone rubber prosthesis. Orthopaedic Clinics #ofNorth America, 4: 2: 349-371. MILIENDER, L. H. and NALEBUFF, E. A. (1975). Reconstructive surgery in the rheumatoid hand. Orthopaedic Clinics of North America, 6: 3: 709-732. MILLENDER, L. H., NALEBUFF, E. A., HAWKINS, R. B. and ENNIS, R. i 1975). Infection after silicone prosthetic arthroplasty in the hand. Journal of Bone and Joint Surgery, 57A: 6: 825-829. NAI_EBUFF, E. A. (1969). Metacarpophalangealsurgery in rheumatoid arthritis. Surgical Clinics of North America, 49: 4: 823-832.
91 RHODES, K., JEFFS, J. V. and SCOTT, J. T. (1972). Experience with silastic prostheses in rheumatoid hands. Annals of the Rheumatic Diseases, 31: 103108. ROSENTHAL, D. I., ROSENBERG, A. E., SCHILLER, A. L. and SMITH, R. J. (1983). Destructive arthritis due to silicone: a foreign-body reaction. Radiology, 149: 69-72. SWANSON, A. B. (1968). Silicone rubber implants for replacement of arthritic or destroyed joints in the hand. Surgical Clinics of North America, 48 : 5 : 1113-1126. SWANSON, A. B. (1969a). Silicone rubber implants for replacement of arthritic or destroyed joints. Hand, 1: 38-39. SWANSON, A. B. (1969b). Fingerjoint replacement by silicone rubber implants and the concept of implant fixation by encapsulation. Annals of the Rheumatic Diseases, 28 (Supplement): 47-55. SWANSON, A. B. (1972). Flexible implant arthroplasty for arthritic fingerjoints: Rationale, technique and results of treatment. Journal of Bone and Joint Surgery, 54A: 3: 435455. SWANSON, A. B., MEESTER, W. D., SWANSON, G. de G., RANGASWAMY, L. and SCHUT, G. E. D. (1973). Durability of silicone implantsan in viva study. Orthopedic Clinics of North America, 4: 4: 1097-l 112. SWANSON, A. B. (1981). Implant arthroplasty in the hand and upper extremity and its future. Surgical Clinics of North America, 61: 2: 369-382. WEINGARDEN, T. L. (1974). Rheumatoid arthritis of the hand: A review of silastic prosthesis arthroplasty in 36 patients. Journal of the American Orthopaedic Association, 74: 209-216. WORSING, R. A., ENGBER, W. D. and LANGE, T. A. (1982). Reactive synovitis from particulate silastic. Journal of Bone and Joint Surgery, 64A: 4: 581-585.
Accepted: 18 February
1992 MI P. J. Sykes, St Lawrence Hospital, Chepstow, Newport, &vent.
0 1993 The British Society for Surgery of the Hand