- Email: [email protected]
Factors influencing the results of implant surgery in the rheumatoid hand
Review Article FACTORS INFLUENCING SURGERY IN THE
THE RESULTS RHEUMATOID
OF IMPLANT HAND
E. A. NALEBUFF Chief of the Hand Surgical Service, New England Baptist Hospital, Boston, Massachusetts, U.S.A. The use of implants to restore or to preserve hand function in the rheumatoid arthritis patient is well accepted. The diversity of the disease and its involvement of multiple tissues make it impossible to carry out meaningful co:mparisons of results. However, many factors (Table 1) contribute to the final outcome of an implant arthroplasty within the hand or wrist. Too often, an unsatisfactory result is blamed upon the implant or the lack of supervised post-operative therapy. In my opinion, the implant itself is the least influential of the many factors leading to the final outcome. Of the various prostheses available, I favour the Swanson flexible implants because they are “spacers”, and, therefore, the least intrusive. The therapist who works diligently with a patient during the post-operative period may influence the outcome as much as the surgeon who gets more credit. However, neither the surgeon’s nor therapist’s role in achieving success is as profound as that of the patient. Motivation, response to pain, and elasticity of tissues, are only a few features that are unique to each patient, and are criticalto the surgical result. This helps to explain the interesting phenomenon of patients frequently obtaining similar results when bilateral procedures are performed. We all have patients who make the surgeon look good. They are usually well-motivated, with a high pain threshold, and often have thin elastic skin with slight tendency to form scar. In fact, one of the dangers of Table l-Implant
surgery
Importantfactors M
Stare of hand Adjacent joints Controlling tendons Stablising structures *
Patient Motivation Pain threshold Tissue elasticity *
Surgeon Judgement Technical skill
M
Therapist *
Implant
The number of stars indicates
VOL.
the importance
15B No. 4 NOVEMBER
1990
of that factor.
implant surgery in these patients is achieving too much motion, leading to ultimate implant fracture. The most important factors influencing the final outcome are the pre-operative state of the hand and wrist. This includes the condition of the adjacent joints, the controlling tendons and stabilising structures. Therefore, those supporting surgical procedures which address these structures deserve our attention. The supporting procedures to correct alignment of adjacent joints include soft-tissue surgery, fusions and arthroplasties. Tendon function can be restored when needed by repairs, transfers or tenolysis. Other procedures such as collateral ligament repair, dermadesis, tenodesis and capsulodesis may be performed to provide joint stability. Before doing implant surgery, it is vital to consider the adjacent joints. For the M.P. joint implant, we’ must evaluate and consider the wrist and the P.I.P. joints. For a P.I.P. implant, attention must be directed to the M.P. and D.I.P. joints, while an implant at the carpometacarpal joint requires attention to the adjacent M.P. joint. For example, an unstable, painful or malaligned wrist should be treated before M.P. implants are inserted. A severe flexion deformity of a P.I.P. joint will adversely affect the final motion at the M.P. level, as the patient will tend to keep the M.P. joint in extension, with ultimate loss of motion. Thus, correction of a P.I.P. joint flexion contracture should be carried out either before or simultaneously with an M.P. arthroplasty. For this reason, staged procedures are often advisable with multiple level involvement. A highly motivated patient requiring operation in two stages because of deformities at three levels is shown in Figure 1. In contrast, a stiff extended P.I.P. joint would enhance the motion achieved at the M.P. level and its correction could be delayed until after motion is obtained at the M.P. level (Fig. 2). Arthroplasties of the basal joint of the thumb are adversely affected by a hyper-extended M.P. joint, so temporary pinning or permanent methods such as fusion or capsulodesis to correct the hyperextension are necessary to allow the implant to achieve its full purpose. Patients requiring implants need intact tendons with sufficient excursion. Thus, M.P. arthroplasties to restore passive M.P. extension should be carried out prior to extensor tendon transfers, while flexor tendon repairs or transfers should be done before arthroplasty. With stiff 395
E. A. NALEBUFF
Fig. 1
396
Patient with deformities at multiple levels requiring staged procedures. (a) Pre-operative appearance of hand. (b) Pre-operative X-rays show subluxed wrist and M.P. joints, with boutonniere deformity of the middle finger. (c and d) Post-operative appearance and function following two-stage procedure: wrist fusion and correction of boutonniere deformity carried out prior to M.P. arthroplasties.
THE JOURNAL
OF HAND
SURGERY
REVIEW
ARTICLE
Fig. 2
fingers, the flexor tendons are often adherent and lack full excursion. Thus, an exploration and tenolysis is a supporting procedure that is essential when the condition of the flexors is not known before operation and should be a routine part of the implant surgery at the P.I.P. joint (Fig. 3). Correction of a “swan neck” deformity of the
Fig. 3
VOL.
(a) Appearance
of implant
15B No. 4 NOVEMBER
1990
in P.I.P. joint, showing
proper
Post-operative range of motion following M.P. arthroplasties, demonstrating effect of limited P.I.P. joint motion. (a) Active extension. (b) Greater range of M.P. joint flexion in ring finger with stiff P.I.P. joint.
P.I.P. joint with an implant requires volar stability or the deformity will recur and the patient will have difficulty initiating flexion due to the hyperextension of the P.I.P. joint. To overcome this, a volar supporting procedure may be required to allow the implant to function to its potential. A patient with a failed implant at the P.I.P.
fit. (b) Testing joint motion
by traction
on flexor tendon
in palm.
397
E. A. NALEBUFF
joint who had a salvage shown in Figure 4.
procedure
to restore
motion
is
Salvage surgery The indications for salvage surgery are limited motion, pain, infection and symptomatic fracture or dislocation of the implant. The salvage procedures fall into three groups : revisions (implant replacement), conversion to resection arthroplasty (implant removal) or fusion of the joint. A revision arthroplasty is considerably more than just replacing one implant with another. It is axiomatic that an adequate joint space for the replacement prosthesis be prepared. However, before proceeding, the surgeon should reflect on the previous operation. Were the adjacent joints considered and realigned before the implant was inserted? Are the controlling tendons intact with sufficient excursion to mobilise the joints? After considering these factors, the surgeon is then ready to proceed with the revision arthroplasty. Figure 5 shows a patient who demonstrates the factors previously discussed. The conversion of a failure to restoration of extraordinary motion, using the same type of implant, confirms the relative importance of supporting procedures over the implant or post-operative therapy. Removal of a failed implant and conversion to a resection arthroplasty is the procedure of choice following infection at the M.P. level. The infection rapidly responds to
398
removal of the implant and the resected joint maintains a functional range of motion. This choice of salvage is also quite effective at the carpo-metacarpal joint. However, simple implant removal is not indicated at the P.I.P. joint or in the wrist. Stability is especially important in these areas and fusion becomes the salvage procedure of choice, though it is not easy to achieve bony fusion following implant removal. Intramedullary bone pegs are particularly helpful. Examples of this technique are shown in Figures 6 and 7. Conclusion Each patient undergoing an implant arthroplasty is a unique case. The final result will depend upon many factors, some of which are beyond the surgeon’s control. With severe involvement of adjacent joints or supporting structures, the ultimate range of motion or correction of deformity may be less than desired. A clear understanding of the many factors affecting the result of implant surgery will guide the surgeon to obtain the best result possible for the conditions encountered. It will also make it possible to predict when the result (by joint measurements) may seem to fall short, but may actually be as good as can be achieved in a particular patient. In case of failure, the Swanson flexible implant is retrievable. It can be replaced, converted to a resection arthroplasty, or fused without the difficulties encountered with other implants, particularly with those that are cemented in place. ? ?
THE
JOURNAL
OF HAND
SURGERY
REVIEW
Fig. 4
ARTICLE
Patient with swan-neck deformity with failed implant. (a) Limited active flexion of P.I.P. joint. (b) Improved motion obtained at revision operation. (c) Tenodesis of superficial flexor tendon to Al pulley. (d) Active motion with dorsal block splint. (e and f) Improved range of motion following revision.
VOL. 1SB No. 4 NOVEMBER
1990
399
E. A. NALEBUFF
400
THE
JOURNAL
OF HAND
SURGERY
REVIEW
ARTICLE
F%g. 5
VOL. 15B No. 4 NOVEMBER
1990
This was considered a complete failure, with spontaneous fusion around implants of P.I.P. joints. (a) Pre-operative deformity with stiff P.I.P. joints. (b) Bony fusion of P.I.P. joints with implants in place. (c) Revision surgery, with checking of flexor tendon of index finger through volar plate. (d) Osteotomies were required to remove implants and perform revision. (e) Full passive motion obtained in all digits. (f and g) Excellent restoration of motion, showing the importance of supporting procedures rather than implant in determining final result.
40
E. A. NALEBUFF
Fig. 6
402
(a) Infected
prosthesis.
(b) Salvage
by fusion with intramedullary
bone peg and Kirschner
wire.
THE JOURNAL
OF HAND SURGERY
REVIEW
Fig. 7
ARTICLE
This patient had a failed Swanson flexible wrist implant and was treated by wrist fusion using the intramedullary peg technique. (a) Preoperative deformity. (b) X-ray shows lateral deviation of wrist with bone collapse. (c) The prosthesis was not fractured but was deformed by wrist tendon imbalance. (d) intramedullary bone graft with intramedullary Steinmann pm fixation. (e) Pin inserted through third metacarpal and additional cancellous bone added to fusion site. (f) Wrist realigned.
VOL. 15B No. 4 NlOVEMBER
1990
403
THE RESULTS RHEUMATOID
OF IMPLANT HAND
E. A. NALEBUFF Chief of the Hand Surgical Service, New England Baptist Hospital, Boston, Massachusetts, U.S.A. The use of implants to restore or to preserve hand function in the rheumatoid arthritis patient is well accepted. The diversity of the disease and its involvement of multiple tissues make it impossible to carry out meaningful co:mparisons of results. However, many factors (Table 1) contribute to the final outcome of an implant arthroplasty within the hand or wrist. Too often, an unsatisfactory result is blamed upon the implant or the lack of supervised post-operative therapy. In my opinion, the implant itself is the least influential of the many factors leading to the final outcome. Of the various prostheses available, I favour the Swanson flexible implants because they are “spacers”, and, therefore, the least intrusive. The therapist who works diligently with a patient during the post-operative period may influence the outcome as much as the surgeon who gets more credit. However, neither the surgeon’s nor therapist’s role in achieving success is as profound as that of the patient. Motivation, response to pain, and elasticity of tissues, are only a few features that are unique to each patient, and are criticalto the surgical result. This helps to explain the interesting phenomenon of patients frequently obtaining similar results when bilateral procedures are performed. We all have patients who make the surgeon look good. They are usually well-motivated, with a high pain threshold, and often have thin elastic skin with slight tendency to form scar. In fact, one of the dangers of Table l-Implant
surgery
Importantfactors M
Stare of hand Adjacent joints Controlling tendons Stablising structures *
Patient Motivation Pain threshold Tissue elasticity *
Surgeon Judgement Technical skill
M
Therapist *
Implant
The number of stars indicates
VOL.
the importance
15B No. 4 NOVEMBER
1990
of that factor.
implant surgery in these patients is achieving too much motion, leading to ultimate implant fracture. The most important factors influencing the final outcome are the pre-operative state of the hand and wrist. This includes the condition of the adjacent joints, the controlling tendons and stabilising structures. Therefore, those supporting surgical procedures which address these structures deserve our attention. The supporting procedures to correct alignment of adjacent joints include soft-tissue surgery, fusions and arthroplasties. Tendon function can be restored when needed by repairs, transfers or tenolysis. Other procedures such as collateral ligament repair, dermadesis, tenodesis and capsulodesis may be performed to provide joint stability. Before doing implant surgery, it is vital to consider the adjacent joints. For the M.P. joint implant, we’ must evaluate and consider the wrist and the P.I.P. joints. For a P.I.P. implant, attention must be directed to the M.P. and D.I.P. joints, while an implant at the carpometacarpal joint requires attention to the adjacent M.P. joint. For example, an unstable, painful or malaligned wrist should be treated before M.P. implants are inserted. A severe flexion deformity of a P.I.P. joint will adversely affect the final motion at the M.P. level, as the patient will tend to keep the M.P. joint in extension, with ultimate loss of motion. Thus, correction of a P.I.P. joint flexion contracture should be carried out either before or simultaneously with an M.P. arthroplasty. For this reason, staged procedures are often advisable with multiple level involvement. A highly motivated patient requiring operation in two stages because of deformities at three levels is shown in Figure 1. In contrast, a stiff extended P.I.P. joint would enhance the motion achieved at the M.P. level and its correction could be delayed until after motion is obtained at the M.P. level (Fig. 2). Arthroplasties of the basal joint of the thumb are adversely affected by a hyper-extended M.P. joint, so temporary pinning or permanent methods such as fusion or capsulodesis to correct the hyperextension are necessary to allow the implant to achieve its full purpose. Patients requiring implants need intact tendons with sufficient excursion. Thus, M.P. arthroplasties to restore passive M.P. extension should be carried out prior to extensor tendon transfers, while flexor tendon repairs or transfers should be done before arthroplasty. With stiff 395
E. A. NALEBUFF
Fig. 1
396
Patient with deformities at multiple levels requiring staged procedures. (a) Pre-operative appearance of hand. (b) Pre-operative X-rays show subluxed wrist and M.P. joints, with boutonniere deformity of the middle finger. (c and d) Post-operative appearance and function following two-stage procedure: wrist fusion and correction of boutonniere deformity carried out prior to M.P. arthroplasties.
THE JOURNAL
OF HAND
SURGERY
REVIEW
ARTICLE
Fig. 2
fingers, the flexor tendons are often adherent and lack full excursion. Thus, an exploration and tenolysis is a supporting procedure that is essential when the condition of the flexors is not known before operation and should be a routine part of the implant surgery at the P.I.P. joint (Fig. 3). Correction of a “swan neck” deformity of the
Fig. 3
VOL.
(a) Appearance
of implant
15B No. 4 NOVEMBER
1990
in P.I.P. joint, showing
proper
Post-operative range of motion following M.P. arthroplasties, demonstrating effect of limited P.I.P. joint motion. (a) Active extension. (b) Greater range of M.P. joint flexion in ring finger with stiff P.I.P. joint.
P.I.P. joint with an implant requires volar stability or the deformity will recur and the patient will have difficulty initiating flexion due to the hyperextension of the P.I.P. joint. To overcome this, a volar supporting procedure may be required to allow the implant to function to its potential. A patient with a failed implant at the P.I.P.
fit. (b) Testing joint motion
by traction
on flexor tendon
in palm.
397
E. A. NALEBUFF
joint who had a salvage shown in Figure 4.
procedure
to restore
motion
is
Salvage surgery The indications for salvage surgery are limited motion, pain, infection and symptomatic fracture or dislocation of the implant. The salvage procedures fall into three groups : revisions (implant replacement), conversion to resection arthroplasty (implant removal) or fusion of the joint. A revision arthroplasty is considerably more than just replacing one implant with another. It is axiomatic that an adequate joint space for the replacement prosthesis be prepared. However, before proceeding, the surgeon should reflect on the previous operation. Were the adjacent joints considered and realigned before the implant was inserted? Are the controlling tendons intact with sufficient excursion to mobilise the joints? After considering these factors, the surgeon is then ready to proceed with the revision arthroplasty. Figure 5 shows a patient who demonstrates the factors previously discussed. The conversion of a failure to restoration of extraordinary motion, using the same type of implant, confirms the relative importance of supporting procedures over the implant or post-operative therapy. Removal of a failed implant and conversion to a resection arthroplasty is the procedure of choice following infection at the M.P. level. The infection rapidly responds to
398
removal of the implant and the resected joint maintains a functional range of motion. This choice of salvage is also quite effective at the carpo-metacarpal joint. However, simple implant removal is not indicated at the P.I.P. joint or in the wrist. Stability is especially important in these areas and fusion becomes the salvage procedure of choice, though it is not easy to achieve bony fusion following implant removal. Intramedullary bone pegs are particularly helpful. Examples of this technique are shown in Figures 6 and 7. Conclusion Each patient undergoing an implant arthroplasty is a unique case. The final result will depend upon many factors, some of which are beyond the surgeon’s control. With severe involvement of adjacent joints or supporting structures, the ultimate range of motion or correction of deformity may be less than desired. A clear understanding of the many factors affecting the result of implant surgery will guide the surgeon to obtain the best result possible for the conditions encountered. It will also make it possible to predict when the result (by joint measurements) may seem to fall short, but may actually be as good as can be achieved in a particular patient. In case of failure, the Swanson flexible implant is retrievable. It can be replaced, converted to a resection arthroplasty, or fused without the difficulties encountered with other implants, particularly with those that are cemented in place. ? ?
THE
JOURNAL
OF HAND
SURGERY
REVIEW
Fig. 4
ARTICLE
Patient with swan-neck deformity with failed implant. (a) Limited active flexion of P.I.P. joint. (b) Improved motion obtained at revision operation. (c) Tenodesis of superficial flexor tendon to Al pulley. (d) Active motion with dorsal block splint. (e and f) Improved range of motion following revision.
VOL. 1SB No. 4 NOVEMBER
1990
399
E. A. NALEBUFF
400
THE
JOURNAL
OF HAND
SURGERY
REVIEW
ARTICLE
F%g. 5
VOL. 15B No. 4 NOVEMBER
1990
This was considered a complete failure, with spontaneous fusion around implants of P.I.P. joints. (a) Pre-operative deformity with stiff P.I.P. joints. (b) Bony fusion of P.I.P. joints with implants in place. (c) Revision surgery, with checking of flexor tendon of index finger through volar plate. (d) Osteotomies were required to remove implants and perform revision. (e) Full passive motion obtained in all digits. (f and g) Excellent restoration of motion, showing the importance of supporting procedures rather than implant in determining final result.
40
E. A. NALEBUFF
Fig. 6
402
(a) Infected
prosthesis.
(b) Salvage
by fusion with intramedullary
bone peg and Kirschner
wire.
THE JOURNAL
OF HAND SURGERY
REVIEW
Fig. 7
ARTICLE
This patient had a failed Swanson flexible wrist implant and was treated by wrist fusion using the intramedullary peg technique. (a) Preoperative deformity. (b) X-ray shows lateral deviation of wrist with bone collapse. (c) The prosthesis was not fractured but was deformed by wrist tendon imbalance. (d) intramedullary bone graft with intramedullary Steinmann pm fixation. (e) Pin inserted through third metacarpal and additional cancellous bone added to fusion site. (f) Wrist realigned.
VOL. 15B No. 4 NlOVEMBER
1990
403