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Arthroscopic Synovectomy of the Ankle in Rheumatoid Arthritis
Arthroscopic Synovectomy of the Ankle in Rheumatoid Arthritis Woo Jin Choi, M.D., Gi Won Choi, M.D., and Jin Woo Lee, M.D., Ph.D.
Purpose: To evaluate the outcome of arthroscopic synovectomy of the ankle joint in patients with early-stage rheumatoid arthritis (RA). Methods: Between 2005 and 2009, 18 consecutive patients with RA involving the ankle underwent arthroscopic synovectomy. Pain was measured using a visual analog scale (VAS), and clinical outcome was determined by calculating the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score with a mean follow-up of 5 years (60 months). Assessments were performed preoperatively, at 6 and 12 months postoperatively, and then yearly thereafter. Clinical success was defined as the absence of synovitis symptoms or when patients demonstrated good or excellent outcomes (AOFAS Ankle-Hindfoot Scale score 80) with >50% improvement in VAS score for pain. Demographic, laboratory, and radiological variables were evaluated to determine possible factors predicting clinical outcome. Results: VAS and AOFAS scores were significantly improved at the final follow-up (60 months; P < .0001). The greatest improvements in clinical scores were observed after 12 months; thereafter, they steadily declined. Of the 18 patients examined, 14 (77.8%) were considered to have had clinical success with no reintervention. Variables predictive of clinical success were short duration of symptoms (P ¼ .042) and minimal radiographic changes based on the Larsen grading system (P ¼ .030). Conclusions: Arthroscopic synovectomy is a safe and successful procedure in ankle joints affected by RA. The best clinical outcomes are achieved when the procedure is performed early in the disease course and when there is no evidence of cartilage degeneration. Level of Evidence: Level IV, prognostic case series.
S
ynovectomy of joints in patients with rheumatoid arthritis (RA), principally the knee, helps reduce pain and prevent or delay articular cartilage destruction.1-3 Previous research has yielded very little information on the success of open ankle synovectomy in patients with RA.4-7 Although most of these studies report significant pain relief, concerns remain with respect to the long rehabilitation period and the risk of postoperative joint stiffness.5,6 Arthroscopic synovectomy is associated with a low rate of complications and is often successfully performed in the knee and other joints.1-3 Currently, few published data exist concerning arthroscopic synovectomy of the ankle joint in patients with RA.8 The purpose
of this study was to examine the level of pain and clinical outcomes after ankle synovectomy in patients with RA. We also assessed the rates of treatment failure and the prognostic factors affecting clinical outcomes. Although arthrodesis or total ankle arthroplasty is often successful in providing pain relief and functional improvement in advanced disease,9-11 we hypothesized that arthroscopic synovectomy would provide longlasting pain relief and improvement of ankle function in patients in the earlier stages of the disease process according to the internationally established Larsen grading system.12,13
Methods From Department of Orthopaedic Surgery (W.J.C., J.W.L.), Yonsei University College of Medicine, and Deparment of Orthopaedic Surgery (G.W.C.), Seoul Veterans Hospital, Seoul, South Korea. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received February 14, 2012; accepted June 19, 2012. Address correspondence to Jin Woo Lee, M.D., Ph.D., Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul 120-752, South Korea. E-mail: [email protected] Ó 2013 by the Arthroscopy Association of North America 0749-8063/12100/$36.00 http://dx.doi.org/10.1016/j.arthro.2012.06.018
A computer-assisted search of the surgical database at Yonsei University College of Medicine was performed from September 2005 to December 2009 to identify patients who had a preoperative diagnosis of RA according to the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria (Table 1)14 and underwent unilateral arthroscopic synovectomy of the ankle. Twenty-four consecutive patients were identified. The Institutional Review Board for human research approved this retrospective study. Inclusion criteria included the presence of
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 29, No 1 (January), 2013: pp 133-140
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Table 1. The 2010 American College of Rheumatology/ European League Against Rheumatism Classification Criteria for Rheumatoid Arthritis Score Target population (who should be tested?): Patients who 1) have at least 1 joint with definite clinical synovitis (swelling) 2) with the synovitis not better explained by another disease Classification criteria for RA (score-based algorithm: add score of categories A-D; a score of 6/10 is needed for classification of a patient as having definite RA) A. Joint involvement 1 large joint 2e10 large joints 1e3 small joints (with or without involvement of large joints) 4e10 small joints (with or without involvement of large joints) >10 joints (at least 1 small joint) B. Serology (at least 1 test result is needed for classification) Negative RF and negative ACPA Low-positive RF or low-positive ACPA High-positive RF or high-positive ACPA C. Acute-phase reactants (at least 1 test result is needed for classification) Normal CRP and normal ESR Abnormal CRP or abnormal ESR D. Duration of symptoms <6 weeks 6 weeks
0 1 2 3 5
0 2 3
0 1 0 1
RF, rheumatoid factor; ACPA, anti-citrullinated protein antibody; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate.
pain and dysfunction in the ankle as a result of synovitis, which had not responded to systemic treatment for at least 6 months, and radiographic changes of grade 3 or less according to the Larsen grading system (Table 2).12 Exclusion criteria included a history of trauma, previous surgery, and severe radiographic destruction or gross deformity. A total of 18 patients undergoing arthroscopic synovectomy met the inclusion criteria and were analyzed through a systematic review of office and
Table 2. Radiographic Grading System for Rheumatoid Arthritis* Grade 0 1 2 3 4 5
Description Intact bony outlines and normal joint space Erosion less than 1 mm in diameter or joint space narrowing One or several small erosions, diameter more than 1 mm Marked erosions Severe erosions, where there is usually no joint space left, and the original bony outlines are partly preserved Mutilating changes, where the original bony outlines have been destroyed
*Data from Larsen et al.12,13
operative records. During the study, all patients received systemic antirheumatic medications including antiinflammatory drugs; disease-modifying antirheumatic drugs, such as sulfasalazine, hydroxychloroquine, penicillamine, and methotrexate; and low-dose prednisolone. No attempt was made to standardize the patients’ medical treatment before or after the arthroscopic synovectomy. Clinical Analysis Pain was evaluated using a visual analog scale (VAS; on which 10 points indicated intolerable pain). The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale15 was used to evaluate pain (maximum: 40 points), function (maximum: 50 points), and alignment (maximum: 10 points), with a high score indicative of no pain, maximum function, and normal alignment. Range of motion (ROM) was measured by the use of a hand-held goniometer positioned along the lateral aspect of the lower leg and foot and centered on the talar neck area. Study patients were evaluated before the surgery, at 6 and 12 months after surgery, and then yearly thereafter with the same outcome scale. Each assessment was performed by one of the authors who had not performed the operation, in a blinded fashion. In its original form, the scale score did not provide a cutoff between good and poor outcomes. For the purpose of this study, in line with other clinical studies using the AOFAS scale score,16,17 the clinical outcome criteria were categorized as excellent (90 to 100 points), good (80 to 89 points), fair (70 to 79 points), or poor (<70 points). Clinical success was defined as the absence of synovitis symptoms (including pain, tenderness, and swelling of the ankle joint) or, in cases of excellent or good outcome (AOFAS score 80), with 50% improvement in VAS score for pain. Clinical failure was defined if any of these criteria were met: (1) persistent synovitis, (2) fair or poor outcome (AOFAS score <80), (3) <50% improvement in VAS score, or (4) additional surgery was performed. Laboratory Analysis The following laboratory investigations were performed before arthroscopic synovectomy and at the final follow-up visit, and the preoperative data were considered baseline: erythrocyte sedimentation rate (ESR, normal <30 mm/h), C-reactive protein (CRP, normal <6 mg/L), and rheumatoid factor (RF, >20 IU/ mL considered positive). Radiologic Analysis All patients had anteroposterior and lateral radiographs of both ankles taken in a weight-bearing position for the detection of arthritic changes before the surgery and at every follow-up visit after surgery. Radiographic data were graded according to the
ANKLE SYNOVECTOMY IN RA
method described by Larsen (see Table 2),12 and the results were then compared among the patients with each grade. To avoid potential bias, an independent observer who was not involved in the care of the patients and who was blinded to the intention of this study performed the evaluations. Operative Technique Ankle arthroscopy was performed under regional or general anesthesia and with a tourniquet. Noninvasive distraction was applied using a foot strap. All surgeries in this study were performed with use of standard anterolateral, anteromedial, and posterolateral skin portals. After diagnostic arthroscopy, debridement of hypertrophic synovial tissue was conducted using an oscillating shaver and a cautery/ablation device (Fig 1). Rough articular cartilage was shaved, and loose debris was removed. Attempts were made to perform a complete synovectomy of all tissue that appeared pathologic, and hemostasis was achieved before completion of the surgery. The synovium located on the posterior back corner (blind areas that cannot be visualized by the anterior portal) was also resected using the posterolateral portal. After surgery, weight bearing, as tolerated, was permitted using a cane, crutches, or walker. ROM and muscle-strengthening exercise were initiated as soon as possible, and a supervised physical therapy program was prescribed in all cases.
Fig 1. A 38-year-old woman with Larsen grade 2 rheumatoid arthritis. (A) Coronal contrast-enhanced, fat-suppressed, magnetic resonance image and its reformatted (B) sagittal and (C) axial images show synovial thickening and enhancement in the ankle joint. (D) Arthroscopic findings confirm the presence of synovitis in the anteromedial gutter. Arthroscopic view of the anteromedial aspect of the ankle joint as seen from the anterolateral portal. Proliferative synovial tissue is visible over the talus.
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Statistical Analysis Data are expressed as mean SD. Data from paired samples (preoperative and postoperative scores) were subjected to the nonparametric Wilcoxon signed rank test. Differences between groups were analyzed by the Mann-Whitney U-test for continuous variables and the c2 test, or Fisher exact test (used when the expected frequency count in the cell <5) for categorical variables, as appropriate. The primary outcome variables were defined according to VAS and AOFAS scores at 6 and 12 months after surgery and then yearly thereafter. A secondary analysis was performed to assess the potential role of each variable as a predictor of a good response. Kaplan-Meier survival analysis curves were constructed for the estimated probabilities of clinical success. The date of arthroscopic synovectomy was considered as the entry point and the date of the last follow-up evaluation or the time of clinical failure (persistent synovitis, AOFAS score <80, <50% improvement in VAS score, or required additional surgery) as the end point. Age, sex, duration of symptoms, baseline laboratory data, and Larsen grade were included in the assessment of statistical comparisons with the clinical outcomes. Age, duration of symptoms, and RF levels were classified as a high- or low-group relative to the median value, whereas ESR and CRP levels were divided between the normal and abnormal groups. Larsen grade was grouped as early (grade 0 or
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1) versus advanced (grade 2 or 3).18 The post hoc power analysis was used by convention, generally 80% (b ¼ .20) and 5% (a ¼ .05), respectively to calculate effective sample size. A value of P < .05 was considered statistically significant. All statistical analyses were performed with the Statistical Package for Social Sciences (version 18.0; SPSS Inc, Chicago, Illinois).
Results The clinical characteristics of the 18 patients are summarized in Table 3. Four men and 14 women with a mean age of 51 years (range, 28 to 82 years) comprised the patient group. The mean duration of RA before the operation was 6.5 years (range, 2 to 11.2 years), and the mean duration of ankle symptoms was 13 months (range, 6 to 24 months). Laboratory examinations at baseline demonstrated that ESR levels were elevated in 5 patients (27.7%), CRP levels were elevated in 2 patients (11.1%), and RF was positive in all of 18 patients (100%). The mean preoperative ESR level was 26.5 22.28 mm/h, and the level decreased to 18.3 18.1 mm/h at the final follow-up. The mean CRP level reduced from 2.6 6.1 to 1.1 2.6 mg/L. The mean postoperative follow-up period was 5 years (range, 2 to 8.6 years). No complications, such as neurovascular injury, superficial infection, or persistent drainage from portals, occurred during or after the procedure. Clinical Outcomes The mean VAS score for pain decreased from 5.6 points (range, 4-6 points) preoperatively to 2.2 points (range, 0-4 points) at the final follow-up, demonstrating that pain was significantly less after the operation (P < .0001). The mean AOFAS score improved from 65.2 4.4 points preoperatively to 85.7 6.7 points at the final follow-up evaluation (P < .0001). Table 4 presents clinical outcome measures from before surgery to the 4 follow-up intervals. There were significant improvements in VAS and AOFAS scores by 1 year; however, no further significant improvements occurred beyond 1 year. VAS continued to trend higher up to the final follow-up. The AOFAS score trended down from 1 year to 2 years following surgery. Although the mean VAS and AOFAS scores at the final follow-up had worsened from the 1-year follow-up, they were significantly improved in comparison to the preoperative assessments. Clinical outcome criteria based on the AOFAS score were excellent in 5 patients, good in 9 patients, fair in 3 patients, and poor in 1 patient. The rate of clinical failure after arthroscopic synovectomy was 5.5% (1 patient) at 6 months, 11.1% (2 patients) at 12 months, and 22.2% (4 patients) 2 years (Fig 2). Of the 4 patients with clinical failure, 3 had undergone further procedures. The procedures included 1 revision arthroscopy 13 months after the
initial arthroscopy, 1 ankle arthrodesis 27 months after arthroscopy, and 1 total ankle arthroplasty 32 months after arthroscopy. One patient experienced persistent synovitis at the 6-month follow-up and refused to undergo further surgery. After a mean follow-up of 5 years, 14 patients (77.8%) remained a clinical success without any reintervention. The mean ROM did not significantly change (preoperatively, 60.0 9.8 ; final follow-up, 61.1 9.7 , P ¼ .279). Radiologic Outcomes On preoperative radiographs, 4 patients (22.2%) presented with an ankle of Larsen grade 0, 6 (33.3%) with an ankle of grade 1, 5 (27.8%) with an ankle of grade 2, and 3 (16.7%) with an ankle of grade 3. At final follow-up, 10 patients (55.6%) had an ankle of Larsen grade 1, 4 (22.2%) had an ankle of grade 2, 1 (5.6%) had an ankle of grade 3, and 3 (16.6%) had an ankle of grade 4. Compared with the preoperative radiographs, a progression in degenerative changes in the ankle was observed in 8 patients (44.4%), and no change was detected in 10 patients (55.6%). Correlations Between Prognostic Factors and Clinical Outcomes A strong and significant correlation existed between clinical outcomes and radiographic severity. The rate of clinical failure was significantly higher in the ankles of patients at Larsen grade 2 or 3 compared with those of grade 0 or 1 (4/10 patients versus 0/8 patients; P ¼ .023). All 10 patients with an ankle of grade 0 or 1 at the time of surgery demonstrated an improved VAS pain score and AOFAS score during the follow-up period. ROM improved in the ankles of 4 patients and did not change in the ankles of 6 patients. Among the 8 patients with an ankle of grade 2 or 3 at the time of surgery, the clinical outcome and amount of pain also improved for 12 months after the arthroscopic synovectomy. However, VAS and AOFAS scores deteriorated during the follow-up period in the ankles of 4 patients. Patients who had an ankle with a lower Larsen grade demonstrated a better clinical outcome following arthroscopic synovectomy: VAS score (.9 .9 versus 2.6 1.7; P ¼ .027), AOFAS score (89.2 3.6 versus 82.6 7.9; P ¼ .034), improvement in the AOFAS score (23.7 4.4 versus 16.5 7.1; P ¼ .030), and ROM (68.0 2.5 versus 52.7 10.7; P ¼ .005) for grade 0 or 1 versus grade 2 or 3 ankles, respectively. Furthermore, we also investigated the relationship between clinical outcomes and other prognostic factors (Table 5). Ten patients who underwent arthroscopic synovectomy within 1 year of symptom onset had more improvement in the AOFAS scores than did the 8 patients who underwent the procedure >1 year after symptom onset (22.8 5.4 versus. 16.1 8.4; P ¼ .042). In contrast, there was no significant difference in postoperative VAS
Table 3. Patient Characteristics and Detailed Results of All Patients* Larsen Grade
ESR (mm/h)
CRP (mg/L)
RF (IU/mL)
VAS
ROM ( )
AOFAS
Sex
Age (yr)
Side
Duration of Symptom (m)
Follow-up (m)
Preop
Final Follow-up
Preop
Final Follow-up
Preop
Final Follow-up
Preop
Preop
Final Follow-up
Preop
Final Follow-up
Preop
Final Follow-up
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
F F F M F F F F F M F F M F F F F M
59 40 82 59 64 57 28 38 50 38 46 61 35 56 60 59 56 59
L R R L R L R L R R R L L R L R L R
24 7 11 24 12 24 9 12 6 8 6 6 6 7 24 24 7 24
74 44 74 68 26 63 64 63 75 24 49 56 104 47 68 74 47 68
0 3 3 0 2 2 1 2 1 2 1 1 2 0 3 0 1 1
1 4 4 1 2 3 1 2 1 2 1 1 2 1 4 1 1 1
28 39 11 5 13 84 33 11 59 16 65 22 13 19 7 28 19 5
19 17 23 2 5 53 7 2 59 10 52 3 5 16 20 19 16 2
0.45 0.84 19.3 0 0 0.52 0.23 19.3 0.34 1.63 0.51 0.76 1.61 0.2 0.31 0.45 0.2 0
0 0 0.2 0 0 3.01 0.2 0.2 2.26 0.5 11.33 0 1.27 0.3 1.22 0 0.3 0
42.3 20.2 70.1 61.8 56.7 42.7 37.9 345 235 23.2 21.7 20.9 20.2 20.6 22.2 42.3 20.8 61.8
4 6 6 6 5 6 6 4 6 6 6 6 6 6 6 4 6 6
1 3 4 0 0 4 2 2 0 2 0 2 1 2 5 0 2 0
61 63 61 65 62 66 68 72 69 66 71 65 74 65 56 61 65 65
88 79 78 95 95 78 91 85 87 84 91 87 84 85 69 88 85 95
70 45 40 65 60 60 70 55 60 65 70 60 55 70 40 60 65 70
70 55 40 65 60 50 70 55 60 70 70 65 60 70 40 65 65 70
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No.
ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; RF, rheumatoid factor; VAS, visual analog scale; AOFAS, American Orthopaedic Foot and Ankle Society; ROM, range of motion in degrees. *Mean follow-up of 5 years (range: 2e8.6 years).
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Table 4. Preoperative and Postoperative Clinical Outcomes Clinical Outcomes VAS AOFAS score ROM ( )
Before Surgery
6 Months
1 Year
2 Years
Final Follow-up*
P valuey
5.6 0.7 65.2 4.4 60.0 9.8
2.0 0.6 84.8 2.1 62.0 9.4
1.2 1.1 87.6 5.6 62.5 8.5
1.6 1.5 86.3 6.6 61.5 9.2
2.2 1.4 85.7 6.7 61.1 9.7
<.0001z <.0001z .279
VAS, visual analog scale; AOFAS, American Orthopaedic Foot and Ankle Society; ROM, range of motion in degrees. *Mean follow-up of 5 years (range: 2e8.6 years). yP value for final follow-up versus before surgery. zStatistically significant (P < .05).
score between the 2 groups (1.2 .9 versus 2.3 2.0; P ¼ .211). No clear relationship was detected between response to treatment and other demographic and laboratory variables (P > .05). Patients with normal ESR had an improvement in the AOFAS score of 21.5 7.3 versus 17.8 4.1 for those with high ESR (17.8 4.1 [P ¼ .198]). Similarly, patients with normal CRP showed much improvement in the AOFAS score of 21.1 6.8 versus 15.0 2.8 (P ¼ .104). In patients with RF <30 IU/mL, improvement in the AOFAS was 17.3 4.1; in those with RF 30 IU/mL, it was 23.0 7.5 (P ¼ .063). This trend is not statistically significant because the post hoc power analysis showed a sample size of at least 64 patients in each group would be needed to show a significant difference.
Discussion The general approach for RA treatment includes the use of nonsteroidal anti-inflammatory drugs and disease-modifying antirheumatic drugs as first-line therapy. However, when a patient is refractory to such treatment or conservative modalities do not control the inflammatory processes, second-line agents such as
Fig 2. Kaplan-Meier survival curve of the cumulative clinical success rate.
interleukin-1 receptor agonists or tumor necrosis factor antagonists are indicated. In patients with persistent synovitis, arthroscopic synovectomy is indicated for the wrist, elbow, and knee joints after failure of an adequate trial of medical management.1-3 For optimum results, these patients should have little or no degenerative changes on radiographs and a functional class I or II according to the American College of Rheumatology criteria.1,2,19 However, the indication for arthroscopic treatment of the ankle in patients with RA remains controversial. In most of the research conducted thus far, a considerable improvement in pain, swelling, and function has been reported with the use of arthroscopic synovectomy.2,3,19 Over a long-term period, however, the radiologic outcomes of joints gradually worsen.1,3,20,21 Several researchers have concluded that early synovectomy leads to better results compared with late synovectomy.22,23 The more advanced the disease, the poorer are the results and the greater is the risk of recurrence. Few studies have reported the efficacy of synovectomy in the ankles of patients with RA. Indications for this procedure are unclear, and long-term follow-up data are lacking. Only one such study, by Akagi et al,5 assessed the results of 20 open ankle joint synovectomy procedures in 15 patients with RA.5 The authors of this study reported that good results were achieved in 90% of patients. However, the disadvantages associated with open synovectomy, including the risk of wound breakdown, infection, and joint stiffness because of difficulty in rehabilitation due to pain or instability, were not considered in this study. More recently, Takagi et al8 reported results of arthroscopic synovectomy using a holmium: YAG laser in the ankle joint of 8 patients with RA. At the 2-year follow-up, all 8 ankles of Larsen grade 2 or 3 exhibited less pain and swelling. Predictors of poor outcome in this study were high inflammatory activity and advanced cartilage degeneration. In the present study, we applied the abovementioned predictive factors and investigated only those patients with early-stage RA. The results indicate that arthroscopic synovectomy is a safe procedure for the majority of patients with RA who have an affected ankle. However, the procedure in this study was not
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ANKLE SYNOVECTOMY IN RA Table 5. Relationship Between Preoperative Variables and Postoperative AOFAS Scores AOFAS Score Sex Female (n ¼ 14) Male (n ¼ 4) Age <55 yrs (n ¼ 7) 55 yrs (n ¼ 11) Duration of symptom <12 months (n ¼ 10) 12 months (n ¼ 8) ESR at baseline <30 mm (n ¼ 12) 30 mm (n ¼ 6) CRP at baseline <6 mg/L (n ¼ 16) 6 mg/L (n ¼ 2) RF at baseline <30 IU/mL (n ¼ 8) 30 IU/mL (n ¼ 10) Larsen grade 0 and 1 (n ¼ 10) 2 and 3 (n ¼ 8)
Before Surgery*
Final Follow-upy
Improvement (D)
64.6 4.4 67.5 4.3
84.7 6.7 89.5 6.3
22.0 9.7 20.0 6.0
66.0 3.7 65.9 3.0
86.7 4.4 86.0 7.9
20.7 4.3 20.1. 7.1
66.9 3.7 65.2 4.6
88.7 3.6 81.3 9.0
22.8 5.4 16.1 8.4
64.4 4.7 67.4 3.0
86.4 7.2 85.8 5.5
21.5 7.3 17.8 4.1
65.1 4.2 66.5 7.7
86.8 6.7 81.5 4.9
21.1 6.8 15.0 2.8
65.6 5.3 65.0 3.8
83.7 7.0 88.3 5.9
17.3 4.1 23.0 7.5
65.5 3.1 65.0 5.8
89.2 3.6 82.6 7.9
23.7 4.4 16.5 7.1
P valuez .729
.849
.042x
.198
.104
.063
.030x
ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; RF, rheumatoid factor; AOFAS, American Orthopaedic Foot and Ankle Society; D, difference between before surgery and final follow-up value. *No significant difference between variables (P > .05). yMean follow-up of 5 years (range: 2e8.6 years). zP value for improvement of AOFAS score. xStatistically significant (P < .05).
effective in all patients: 4 of 18 patients (22.2%) relapsed within 2 years after arthroscopic synovectomy. Significantly, 14 of 18 patients (77.8%) remained as clinical successes at the last evaluation, an average of 5 years after the procedure was performed. At the time of arthroscopy, these patients had early-stage RA with no signs of cartilage degeneration, which was confirmed with preoperative radiographs and arthroscopic findings. Disease duration before arthroscopic synovectomy was variable among the patients, ranging from 2 to 11.2 years. The patient with the longest disease duration had several relapses in the same ankle and was always treated with nonsteroidal anti-inflammatory drugs and intra-articular steroid injections. She underwent arthroscopic synovectomy 11 years after disease onset, and the outcome was very poor. The differential response associated with symptom duration may be due to histologic changes during the course of disease. During the first months of disease, synovial lining hyperplasia and proliferation of blood vessels are prevalent, and the sublining inflammatory infiltrate is mild.24,25 The second phase, subacute, is characterized by formation of granular tissue and a dramatic increase in the cellular infiltrate, largely macrophages, and the presence of these cells seems to correlate with erosive changes. The third stage, chronic, is characterized by the formation of pannus, a “tumor-like fibrotic proliferation” with potential invasiveness and ability to destroy the joint. Moreover,
articular cartilage itself has limited regenerative potential. Chondrocytes physiologically regulate matrix formation and cleavage; under the influence of synovial cytokines and reactive nitrogen intermediates, cartilage is progressively deprived of chondrocytes, which undergo apoptosis.26 These processes ultimately lead to the destruction of the surface cartilage and the radiographic appearance of joint space narrowing. It is possible that the mechanical removal of synovial tissue during the subacute phase of RA may prevent pannus formation and lead to complete, long-standing remission of arthritis. The limitations in this study are the small number of patients and the lack of a control group. Additionally, because this is a retrospectively designed study, there was no comparison with another treatment modality. A prestudy power analysis would have determined the number of patients required for more statistical validity. However, patients with RA with recalcitrant ankle symptom with minimal radiographic changes are relatively rare and reporting outcomes is limited with respect to sample size. Another weakness was that despite its use in other studies, the AOFAS scoring system has not been validated and is no longer recommended.27 We look to future studies to address this concern with a standard validated outcome measure. Despite the shortcomings, there are also several strengths to our study. First, given the lack of previously
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published data on arthroscopic synovectomy of the ankle in RA patients, the results of this study may be used to assess the rates of treatment failure as well as the risk factors for unsatisfactory clinical outcomes. Second, this is a consecutive series of patients followed up more than 2 years, which contains accurate preoperative and postoperative demographic and laboratory data. In addition, this was a single-surgeon series, using identical surgical techniques and a standardized postoperative rehabilitation protocol.
11.
12.
13.
14.
Conclusions Arthroscopic synovectomy is a safe and successful procedure in ankle joints affected by RA. The best clinical outcomes are achieved when the procedure is performed early in the disease course and when there is no evidence of cartilage degeneration.
References 1. Horiuchi K, Momohara S, Tomatsu T, et al. Arthroscopic synovectomy of the elbow in rheumatoid arthritis. J Bone Joint Surg Am 2002;84A:342-347. 2. Kim SJ, Jung KA, Kim JM, et al. Arthroscopic synovectomy in wrists with advanced rheumatoid arthritis. Clin Orthop Relat Res 2006;449:262-266. 3. Klug S, Wittmann G, Weseloh G. Arthroscopic synovectomy of the knee joint in early cases of rheumatoid arthritis: follow-up results of a multicenter study. Arthroscopy 2000;16:262-267. 4. Chalmers PN, Sherman SL, Raphael BS, Su EP. Rheumatoid synovectomy: does the surgical approach matter? Clin Orthop Relat Res 2011;469:2062-2071. 5. Akagi S, Sugano H, Ogawa R. The long-term results of ankle joint synovectomy for rheumatoid arthritis. Clin Rheumatol 1997;16:284-290. 6. Mohing W. Synovectomy of the ankle joint. Int Orthop 1982;6:117-121. 7. Tanaka N, Sakahashi H, Hirose K, et al. Arthroscopic and open synovectomy of the elbow in rheumatoid arthritis. J Bone Joint Surg Am 2006;88:521-525. 8. Takagi T, Koshino T, Okamoto R. Arthroscopic synovectomy for rheumatoid arthritis using a holmium: YAG laser. J Rheumatol 2001;28:1518-1522. 9. Kofoed H, Lundberg-Jensen A. Ankle arthroplasty in patients younger and older than 50 years: a prospective series with long-term follow-up. Foot Ankle 1999;20: 501-506. 10. Kofoed H, Sørensen TS. Ankle arthroplasty for rheumatoid arthritis and osteoarthritis: prospective long-term
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24. 25.
26. 27.
study of cemented replacements. J Bone Joint Surg Br 1998;80B:328-332. Sammarco VJ. Ankle arthrodesis in rheumatoid arthritis: techniques, results, and complications. Foot Ankle Clin 2007;12:475-495. Larsen A. How to apply Larsen score in evaluating radiographs of rheumatoid arthritis in longterm studies. J Rheumatol 1995;22:1974-1975. Larsen A, Dale K, Eek M. Radiological evaluation of rheumatoid arthritis and related conditions by standard reference films. Acta Radiol Diagn (Stockh) 1977;18:481-491. Aletaha D, Neogi T, Silman A, et al. 2010 Rheumatoid arthritis classification criteria. Arthritis Rheum 2010;62: 2569-2581. Kitaoka HB, Alexander I, Adelaar RS, et al. Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int 1994:349-353. Choi WJ, Kim BS, Lee JW. Osteochondral lesion of the talus: could age be an indication for arthroscopic treatment? Am J Sports Med 2012;40:419-424. Saxena A, Eakin C. Articular talar injuries in athletes: results of microfracture and autogenous bone graft. Am J Sports Med 2007;35:1680-1687. Fiocco U, Cozzi L, Rigon C, et al. Arthroscopic synovectomy in rheumatoid and psoriatic knee joint synovitis: long-term outcome. Br J Rheumatol 1996;35:463-470. Ogilvie-Harris DJ, Basinski A. Arthroscopic synovectomy of the knee for rheumatoid arthritis. Arthroscopy 1991;7: 91-97. Nemoto K, Arino H, Yoshihara Y, Fujikawa K. Arthroscopic synovectomy for the rheumatoid elbow: a short-term outcome. J Shoulder Elbow Surg 2004;13: 652-655. Smith AM, Sperling JW, O’Driscoll SW, Cofield RH. Arthroscopic shoulder synovectomy in patients with rheumatoid arthritis. Arthroscopy 2006;22:50-56. Jensen CM, Poulsen S, Østergren M, Hansen KH. Early and late synovectomy of the knee in rheumatoid arthritis. Scand J Rhematol 1991;20:127-131. Mohing W, Richter R. Die frühsynovektomie des kniegelenkes. Verh Dtsch Ges Rheumatol 1981;7:141-144 (in Dutch). Fassbender HG. What destroys the joint in rheumatoid arthritis? Arch Orthop Trauma Surg 1998;117:2-7. Firenstein GA. Rheumatoid synovitis and pannus. In: Klippel JH, Dieppe PA, eds. Rheumatology. London, UK: Mosby, 1998. McInnes IB, Schett G. The pathogenesis of rheumatoid arthritis. N Engl J Med 2011;365:2205-2219. Pinsker E, Daniels TR. AOFAS position statement regarding the future of the AOFAS Clinical Rating Systems. Foot Ankle Int 2011;32:841-842.
Purpose: To evaluate the outcome of arthroscopic synovectomy of the ankle joint in patients with early-stage rheumatoid arthritis (RA). Methods: Between 2005 and 2009, 18 consecutive patients with RA involving the ankle underwent arthroscopic synovectomy. Pain was measured using a visual analog scale (VAS), and clinical outcome was determined by calculating the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score with a mean follow-up of 5 years (60 months). Assessments were performed preoperatively, at 6 and 12 months postoperatively, and then yearly thereafter. Clinical success was defined as the absence of synovitis symptoms or when patients demonstrated good or excellent outcomes (AOFAS Ankle-Hindfoot Scale score 80) with >50% improvement in VAS score for pain. Demographic, laboratory, and radiological variables were evaluated to determine possible factors predicting clinical outcome. Results: VAS and AOFAS scores were significantly improved at the final follow-up (60 months; P < .0001). The greatest improvements in clinical scores were observed after 12 months; thereafter, they steadily declined. Of the 18 patients examined, 14 (77.8%) were considered to have had clinical success with no reintervention. Variables predictive of clinical success were short duration of symptoms (P ¼ .042) and minimal radiographic changes based on the Larsen grading system (P ¼ .030). Conclusions: Arthroscopic synovectomy is a safe and successful procedure in ankle joints affected by RA. The best clinical outcomes are achieved when the procedure is performed early in the disease course and when there is no evidence of cartilage degeneration. Level of Evidence: Level IV, prognostic case series.
S
ynovectomy of joints in patients with rheumatoid arthritis (RA), principally the knee, helps reduce pain and prevent or delay articular cartilage destruction.1-3 Previous research has yielded very little information on the success of open ankle synovectomy in patients with RA.4-7 Although most of these studies report significant pain relief, concerns remain with respect to the long rehabilitation period and the risk of postoperative joint stiffness.5,6 Arthroscopic synovectomy is associated with a low rate of complications and is often successfully performed in the knee and other joints.1-3 Currently, few published data exist concerning arthroscopic synovectomy of the ankle joint in patients with RA.8 The purpose
of this study was to examine the level of pain and clinical outcomes after ankle synovectomy in patients with RA. We also assessed the rates of treatment failure and the prognostic factors affecting clinical outcomes. Although arthrodesis or total ankle arthroplasty is often successful in providing pain relief and functional improvement in advanced disease,9-11 we hypothesized that arthroscopic synovectomy would provide longlasting pain relief and improvement of ankle function in patients in the earlier stages of the disease process according to the internationally established Larsen grading system.12,13
Methods From Department of Orthopaedic Surgery (W.J.C., J.W.L.), Yonsei University College of Medicine, and Deparment of Orthopaedic Surgery (G.W.C.), Seoul Veterans Hospital, Seoul, South Korea. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received February 14, 2012; accepted June 19, 2012. Address correspondence to Jin Woo Lee, M.D., Ph.D., Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul 120-752, South Korea. E-mail: [email protected] Ó 2013 by the Arthroscopy Association of North America 0749-8063/12100/$36.00 http://dx.doi.org/10.1016/j.arthro.2012.06.018
A computer-assisted search of the surgical database at Yonsei University College of Medicine was performed from September 2005 to December 2009 to identify patients who had a preoperative diagnosis of RA according to the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria (Table 1)14 and underwent unilateral arthroscopic synovectomy of the ankle. Twenty-four consecutive patients were identified. The Institutional Review Board for human research approved this retrospective study. Inclusion criteria included the presence of
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Table 1. The 2010 American College of Rheumatology/ European League Against Rheumatism Classification Criteria for Rheumatoid Arthritis Score Target population (who should be tested?): Patients who 1) have at least 1 joint with definite clinical synovitis (swelling) 2) with the synovitis not better explained by another disease Classification criteria for RA (score-based algorithm: add score of categories A-D; a score of 6/10 is needed for classification of a patient as having definite RA) A. Joint involvement 1 large joint 2e10 large joints 1e3 small joints (with or without involvement of large joints) 4e10 small joints (with or without involvement of large joints) >10 joints (at least 1 small joint) B. Serology (at least 1 test result is needed for classification) Negative RF and negative ACPA Low-positive RF or low-positive ACPA High-positive RF or high-positive ACPA C. Acute-phase reactants (at least 1 test result is needed for classification) Normal CRP and normal ESR Abnormal CRP or abnormal ESR D. Duration of symptoms <6 weeks 6 weeks
0 1 2 3 5
0 2 3
0 1 0 1
RF, rheumatoid factor; ACPA, anti-citrullinated protein antibody; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate.
pain and dysfunction in the ankle as a result of synovitis, which had not responded to systemic treatment for at least 6 months, and radiographic changes of grade 3 or less according to the Larsen grading system (Table 2).12 Exclusion criteria included a history of trauma, previous surgery, and severe radiographic destruction or gross deformity. A total of 18 patients undergoing arthroscopic synovectomy met the inclusion criteria and were analyzed through a systematic review of office and
Table 2. Radiographic Grading System for Rheumatoid Arthritis* Grade 0 1 2 3 4 5
Description Intact bony outlines and normal joint space Erosion less than 1 mm in diameter or joint space narrowing One or several small erosions, diameter more than 1 mm Marked erosions Severe erosions, where there is usually no joint space left, and the original bony outlines are partly preserved Mutilating changes, where the original bony outlines have been destroyed
*Data from Larsen et al.12,13
operative records. During the study, all patients received systemic antirheumatic medications including antiinflammatory drugs; disease-modifying antirheumatic drugs, such as sulfasalazine, hydroxychloroquine, penicillamine, and methotrexate; and low-dose prednisolone. No attempt was made to standardize the patients’ medical treatment before or after the arthroscopic synovectomy. Clinical Analysis Pain was evaluated using a visual analog scale (VAS; on which 10 points indicated intolerable pain). The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale15 was used to evaluate pain (maximum: 40 points), function (maximum: 50 points), and alignment (maximum: 10 points), with a high score indicative of no pain, maximum function, and normal alignment. Range of motion (ROM) was measured by the use of a hand-held goniometer positioned along the lateral aspect of the lower leg and foot and centered on the talar neck area. Study patients were evaluated before the surgery, at 6 and 12 months after surgery, and then yearly thereafter with the same outcome scale. Each assessment was performed by one of the authors who had not performed the operation, in a blinded fashion. In its original form, the scale score did not provide a cutoff between good and poor outcomes. For the purpose of this study, in line with other clinical studies using the AOFAS scale score,16,17 the clinical outcome criteria were categorized as excellent (90 to 100 points), good (80 to 89 points), fair (70 to 79 points), or poor (<70 points). Clinical success was defined as the absence of synovitis symptoms (including pain, tenderness, and swelling of the ankle joint) or, in cases of excellent or good outcome (AOFAS score 80), with 50% improvement in VAS score for pain. Clinical failure was defined if any of these criteria were met: (1) persistent synovitis, (2) fair or poor outcome (AOFAS score <80), (3) <50% improvement in VAS score, or (4) additional surgery was performed. Laboratory Analysis The following laboratory investigations were performed before arthroscopic synovectomy and at the final follow-up visit, and the preoperative data were considered baseline: erythrocyte sedimentation rate (ESR, normal <30 mm/h), C-reactive protein (CRP, normal <6 mg/L), and rheumatoid factor (RF, >20 IU/ mL considered positive). Radiologic Analysis All patients had anteroposterior and lateral radiographs of both ankles taken in a weight-bearing position for the detection of arthritic changes before the surgery and at every follow-up visit after surgery. Radiographic data were graded according to the
ANKLE SYNOVECTOMY IN RA
method described by Larsen (see Table 2),12 and the results were then compared among the patients with each grade. To avoid potential bias, an independent observer who was not involved in the care of the patients and who was blinded to the intention of this study performed the evaluations. Operative Technique Ankle arthroscopy was performed under regional or general anesthesia and with a tourniquet. Noninvasive distraction was applied using a foot strap. All surgeries in this study were performed with use of standard anterolateral, anteromedial, and posterolateral skin portals. After diagnostic arthroscopy, debridement of hypertrophic synovial tissue was conducted using an oscillating shaver and a cautery/ablation device (Fig 1). Rough articular cartilage was shaved, and loose debris was removed. Attempts were made to perform a complete synovectomy of all tissue that appeared pathologic, and hemostasis was achieved before completion of the surgery. The synovium located on the posterior back corner (blind areas that cannot be visualized by the anterior portal) was also resected using the posterolateral portal. After surgery, weight bearing, as tolerated, was permitted using a cane, crutches, or walker. ROM and muscle-strengthening exercise were initiated as soon as possible, and a supervised physical therapy program was prescribed in all cases.
Fig 1. A 38-year-old woman with Larsen grade 2 rheumatoid arthritis. (A) Coronal contrast-enhanced, fat-suppressed, magnetic resonance image and its reformatted (B) sagittal and (C) axial images show synovial thickening and enhancement in the ankle joint. (D) Arthroscopic findings confirm the presence of synovitis in the anteromedial gutter. Arthroscopic view of the anteromedial aspect of the ankle joint as seen from the anterolateral portal. Proliferative synovial tissue is visible over the talus.
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Statistical Analysis Data are expressed as mean SD. Data from paired samples (preoperative and postoperative scores) were subjected to the nonparametric Wilcoxon signed rank test. Differences between groups were analyzed by the Mann-Whitney U-test for continuous variables and the c2 test, or Fisher exact test (used when the expected frequency count in the cell <5) for categorical variables, as appropriate. The primary outcome variables were defined according to VAS and AOFAS scores at 6 and 12 months after surgery and then yearly thereafter. A secondary analysis was performed to assess the potential role of each variable as a predictor of a good response. Kaplan-Meier survival analysis curves were constructed for the estimated probabilities of clinical success. The date of arthroscopic synovectomy was considered as the entry point and the date of the last follow-up evaluation or the time of clinical failure (persistent synovitis, AOFAS score <80, <50% improvement in VAS score, or required additional surgery) as the end point. Age, sex, duration of symptoms, baseline laboratory data, and Larsen grade were included in the assessment of statistical comparisons with the clinical outcomes. Age, duration of symptoms, and RF levels were classified as a high- or low-group relative to the median value, whereas ESR and CRP levels were divided between the normal and abnormal groups. Larsen grade was grouped as early (grade 0 or
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1) versus advanced (grade 2 or 3).18 The post hoc power analysis was used by convention, generally 80% (b ¼ .20) and 5% (a ¼ .05), respectively to calculate effective sample size. A value of P < .05 was considered statistically significant. All statistical analyses were performed with the Statistical Package for Social Sciences (version 18.0; SPSS Inc, Chicago, Illinois).
Results The clinical characteristics of the 18 patients are summarized in Table 3. Four men and 14 women with a mean age of 51 years (range, 28 to 82 years) comprised the patient group. The mean duration of RA before the operation was 6.5 years (range, 2 to 11.2 years), and the mean duration of ankle symptoms was 13 months (range, 6 to 24 months). Laboratory examinations at baseline demonstrated that ESR levels were elevated in 5 patients (27.7%), CRP levels were elevated in 2 patients (11.1%), and RF was positive in all of 18 patients (100%). The mean preoperative ESR level was 26.5 22.28 mm/h, and the level decreased to 18.3 18.1 mm/h at the final follow-up. The mean CRP level reduced from 2.6 6.1 to 1.1 2.6 mg/L. The mean postoperative follow-up period was 5 years (range, 2 to 8.6 years). No complications, such as neurovascular injury, superficial infection, or persistent drainage from portals, occurred during or after the procedure. Clinical Outcomes The mean VAS score for pain decreased from 5.6 points (range, 4-6 points) preoperatively to 2.2 points (range, 0-4 points) at the final follow-up, demonstrating that pain was significantly less after the operation (P < .0001). The mean AOFAS score improved from 65.2 4.4 points preoperatively to 85.7 6.7 points at the final follow-up evaluation (P < .0001). Table 4 presents clinical outcome measures from before surgery to the 4 follow-up intervals. There were significant improvements in VAS and AOFAS scores by 1 year; however, no further significant improvements occurred beyond 1 year. VAS continued to trend higher up to the final follow-up. The AOFAS score trended down from 1 year to 2 years following surgery. Although the mean VAS and AOFAS scores at the final follow-up had worsened from the 1-year follow-up, they were significantly improved in comparison to the preoperative assessments. Clinical outcome criteria based on the AOFAS score were excellent in 5 patients, good in 9 patients, fair in 3 patients, and poor in 1 patient. The rate of clinical failure after arthroscopic synovectomy was 5.5% (1 patient) at 6 months, 11.1% (2 patients) at 12 months, and 22.2% (4 patients) 2 years (Fig 2). Of the 4 patients with clinical failure, 3 had undergone further procedures. The procedures included 1 revision arthroscopy 13 months after the
initial arthroscopy, 1 ankle arthrodesis 27 months after arthroscopy, and 1 total ankle arthroplasty 32 months after arthroscopy. One patient experienced persistent synovitis at the 6-month follow-up and refused to undergo further surgery. After a mean follow-up of 5 years, 14 patients (77.8%) remained a clinical success without any reintervention. The mean ROM did not significantly change (preoperatively, 60.0 9.8 ; final follow-up, 61.1 9.7 , P ¼ .279). Radiologic Outcomes On preoperative radiographs, 4 patients (22.2%) presented with an ankle of Larsen grade 0, 6 (33.3%) with an ankle of grade 1, 5 (27.8%) with an ankle of grade 2, and 3 (16.7%) with an ankle of grade 3. At final follow-up, 10 patients (55.6%) had an ankle of Larsen grade 1, 4 (22.2%) had an ankle of grade 2, 1 (5.6%) had an ankle of grade 3, and 3 (16.6%) had an ankle of grade 4. Compared with the preoperative radiographs, a progression in degenerative changes in the ankle was observed in 8 patients (44.4%), and no change was detected in 10 patients (55.6%). Correlations Between Prognostic Factors and Clinical Outcomes A strong and significant correlation existed between clinical outcomes and radiographic severity. The rate of clinical failure was significantly higher in the ankles of patients at Larsen grade 2 or 3 compared with those of grade 0 or 1 (4/10 patients versus 0/8 patients; P ¼ .023). All 10 patients with an ankle of grade 0 or 1 at the time of surgery demonstrated an improved VAS pain score and AOFAS score during the follow-up period. ROM improved in the ankles of 4 patients and did not change in the ankles of 6 patients. Among the 8 patients with an ankle of grade 2 or 3 at the time of surgery, the clinical outcome and amount of pain also improved for 12 months after the arthroscopic synovectomy. However, VAS and AOFAS scores deteriorated during the follow-up period in the ankles of 4 patients. Patients who had an ankle with a lower Larsen grade demonstrated a better clinical outcome following arthroscopic synovectomy: VAS score (.9 .9 versus 2.6 1.7; P ¼ .027), AOFAS score (89.2 3.6 versus 82.6 7.9; P ¼ .034), improvement in the AOFAS score (23.7 4.4 versus 16.5 7.1; P ¼ .030), and ROM (68.0 2.5 versus 52.7 10.7; P ¼ .005) for grade 0 or 1 versus grade 2 or 3 ankles, respectively. Furthermore, we also investigated the relationship between clinical outcomes and other prognostic factors (Table 5). Ten patients who underwent arthroscopic synovectomy within 1 year of symptom onset had more improvement in the AOFAS scores than did the 8 patients who underwent the procedure >1 year after symptom onset (22.8 5.4 versus. 16.1 8.4; P ¼ .042). In contrast, there was no significant difference in postoperative VAS
Table 3. Patient Characteristics and Detailed Results of All Patients* Larsen Grade
ESR (mm/h)
CRP (mg/L)
RF (IU/mL)
VAS
ROM ( )
AOFAS
Sex
Age (yr)
Side
Duration of Symptom (m)
Follow-up (m)
Preop
Final Follow-up
Preop
Final Follow-up
Preop
Final Follow-up
Preop
Preop
Final Follow-up
Preop
Final Follow-up
Preop
Final Follow-up
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
F F F M F F F F F M F F M F F F F M
59 40 82 59 64 57 28 38 50 38 46 61 35 56 60 59 56 59
L R R L R L R L R R R L L R L R L R
24 7 11 24 12 24 9 12 6 8 6 6 6 7 24 24 7 24
74 44 74 68 26 63 64 63 75 24 49 56 104 47 68 74 47 68
0 3 3 0 2 2 1 2 1 2 1 1 2 0 3 0 1 1
1 4 4 1 2 3 1 2 1 2 1 1 2 1 4 1 1 1
28 39 11 5 13 84 33 11 59 16 65 22 13 19 7 28 19 5
19 17 23 2 5 53 7 2 59 10 52 3 5 16 20 19 16 2
0.45 0.84 19.3 0 0 0.52 0.23 19.3 0.34 1.63 0.51 0.76 1.61 0.2 0.31 0.45 0.2 0
0 0 0.2 0 0 3.01 0.2 0.2 2.26 0.5 11.33 0 1.27 0.3 1.22 0 0.3 0
42.3 20.2 70.1 61.8 56.7 42.7 37.9 345 235 23.2 21.7 20.9 20.2 20.6 22.2 42.3 20.8 61.8
4 6 6 6 5 6 6 4 6 6 6 6 6 6 6 4 6 6
1 3 4 0 0 4 2 2 0 2 0 2 1 2 5 0 2 0
61 63 61 65 62 66 68 72 69 66 71 65 74 65 56 61 65 65
88 79 78 95 95 78 91 85 87 84 91 87 84 85 69 88 85 95
70 45 40 65 60 60 70 55 60 65 70 60 55 70 40 60 65 70
70 55 40 65 60 50 70 55 60 70 70 65 60 70 40 65 65 70
ANKLE SYNOVECTOMY IN RA
No.
ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; RF, rheumatoid factor; VAS, visual analog scale; AOFAS, American Orthopaedic Foot and Ankle Society; ROM, range of motion in degrees. *Mean follow-up of 5 years (range: 2e8.6 years).
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Table 4. Preoperative and Postoperative Clinical Outcomes Clinical Outcomes VAS AOFAS score ROM ( )
Before Surgery
6 Months
1 Year
2 Years
Final Follow-up*
P valuey
5.6 0.7 65.2 4.4 60.0 9.8
2.0 0.6 84.8 2.1 62.0 9.4
1.2 1.1 87.6 5.6 62.5 8.5
1.6 1.5 86.3 6.6 61.5 9.2
2.2 1.4 85.7 6.7 61.1 9.7
<.0001z <.0001z .279
VAS, visual analog scale; AOFAS, American Orthopaedic Foot and Ankle Society; ROM, range of motion in degrees. *Mean follow-up of 5 years (range: 2e8.6 years). yP value for final follow-up versus before surgery. zStatistically significant (P < .05).
score between the 2 groups (1.2 .9 versus 2.3 2.0; P ¼ .211). No clear relationship was detected between response to treatment and other demographic and laboratory variables (P > .05). Patients with normal ESR had an improvement in the AOFAS score of 21.5 7.3 versus 17.8 4.1 for those with high ESR (17.8 4.1 [P ¼ .198]). Similarly, patients with normal CRP showed much improvement in the AOFAS score of 21.1 6.8 versus 15.0 2.8 (P ¼ .104). In patients with RF <30 IU/mL, improvement in the AOFAS was 17.3 4.1; in those with RF 30 IU/mL, it was 23.0 7.5 (P ¼ .063). This trend is not statistically significant because the post hoc power analysis showed a sample size of at least 64 patients in each group would be needed to show a significant difference.
Discussion The general approach for RA treatment includes the use of nonsteroidal anti-inflammatory drugs and disease-modifying antirheumatic drugs as first-line therapy. However, when a patient is refractory to such treatment or conservative modalities do not control the inflammatory processes, second-line agents such as
Fig 2. Kaplan-Meier survival curve of the cumulative clinical success rate.
interleukin-1 receptor agonists or tumor necrosis factor antagonists are indicated. In patients with persistent synovitis, arthroscopic synovectomy is indicated for the wrist, elbow, and knee joints after failure of an adequate trial of medical management.1-3 For optimum results, these patients should have little or no degenerative changes on radiographs and a functional class I or II according to the American College of Rheumatology criteria.1,2,19 However, the indication for arthroscopic treatment of the ankle in patients with RA remains controversial. In most of the research conducted thus far, a considerable improvement in pain, swelling, and function has been reported with the use of arthroscopic synovectomy.2,3,19 Over a long-term period, however, the radiologic outcomes of joints gradually worsen.1,3,20,21 Several researchers have concluded that early synovectomy leads to better results compared with late synovectomy.22,23 The more advanced the disease, the poorer are the results and the greater is the risk of recurrence. Few studies have reported the efficacy of synovectomy in the ankles of patients with RA. Indications for this procedure are unclear, and long-term follow-up data are lacking. Only one such study, by Akagi et al,5 assessed the results of 20 open ankle joint synovectomy procedures in 15 patients with RA.5 The authors of this study reported that good results were achieved in 90% of patients. However, the disadvantages associated with open synovectomy, including the risk of wound breakdown, infection, and joint stiffness because of difficulty in rehabilitation due to pain or instability, were not considered in this study. More recently, Takagi et al8 reported results of arthroscopic synovectomy using a holmium: YAG laser in the ankle joint of 8 patients with RA. At the 2-year follow-up, all 8 ankles of Larsen grade 2 or 3 exhibited less pain and swelling. Predictors of poor outcome in this study were high inflammatory activity and advanced cartilage degeneration. In the present study, we applied the abovementioned predictive factors and investigated only those patients with early-stage RA. The results indicate that arthroscopic synovectomy is a safe procedure for the majority of patients with RA who have an affected ankle. However, the procedure in this study was not
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ANKLE SYNOVECTOMY IN RA Table 5. Relationship Between Preoperative Variables and Postoperative AOFAS Scores AOFAS Score Sex Female (n ¼ 14) Male (n ¼ 4) Age <55 yrs (n ¼ 7) 55 yrs (n ¼ 11) Duration of symptom <12 months (n ¼ 10) 12 months (n ¼ 8) ESR at baseline <30 mm (n ¼ 12) 30 mm (n ¼ 6) CRP at baseline <6 mg/L (n ¼ 16) 6 mg/L (n ¼ 2) RF at baseline <30 IU/mL (n ¼ 8) 30 IU/mL (n ¼ 10) Larsen grade 0 and 1 (n ¼ 10) 2 and 3 (n ¼ 8)
Before Surgery*
Final Follow-upy
Improvement (D)
64.6 4.4 67.5 4.3
84.7 6.7 89.5 6.3
22.0 9.7 20.0 6.0
66.0 3.7 65.9 3.0
86.7 4.4 86.0 7.9
20.7 4.3 20.1. 7.1
66.9 3.7 65.2 4.6
88.7 3.6 81.3 9.0
22.8 5.4 16.1 8.4
64.4 4.7 67.4 3.0
86.4 7.2 85.8 5.5
21.5 7.3 17.8 4.1
65.1 4.2 66.5 7.7
86.8 6.7 81.5 4.9
21.1 6.8 15.0 2.8
65.6 5.3 65.0 3.8
83.7 7.0 88.3 5.9
17.3 4.1 23.0 7.5
65.5 3.1 65.0 5.8
89.2 3.6 82.6 7.9
23.7 4.4 16.5 7.1
P valuez .729
.849
.042x
.198
.104
.063
.030x
ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; RF, rheumatoid factor; AOFAS, American Orthopaedic Foot and Ankle Society; D, difference between before surgery and final follow-up value. *No significant difference between variables (P > .05). yMean follow-up of 5 years (range: 2e8.6 years). zP value for improvement of AOFAS score. xStatistically significant (P < .05).
effective in all patients: 4 of 18 patients (22.2%) relapsed within 2 years after arthroscopic synovectomy. Significantly, 14 of 18 patients (77.8%) remained as clinical successes at the last evaluation, an average of 5 years after the procedure was performed. At the time of arthroscopy, these patients had early-stage RA with no signs of cartilage degeneration, which was confirmed with preoperative radiographs and arthroscopic findings. Disease duration before arthroscopic synovectomy was variable among the patients, ranging from 2 to 11.2 years. The patient with the longest disease duration had several relapses in the same ankle and was always treated with nonsteroidal anti-inflammatory drugs and intra-articular steroid injections. She underwent arthroscopic synovectomy 11 years after disease onset, and the outcome was very poor. The differential response associated with symptom duration may be due to histologic changes during the course of disease. During the first months of disease, synovial lining hyperplasia and proliferation of blood vessels are prevalent, and the sublining inflammatory infiltrate is mild.24,25 The second phase, subacute, is characterized by formation of granular tissue and a dramatic increase in the cellular infiltrate, largely macrophages, and the presence of these cells seems to correlate with erosive changes. The third stage, chronic, is characterized by the formation of pannus, a “tumor-like fibrotic proliferation” with potential invasiveness and ability to destroy the joint. Moreover,
articular cartilage itself has limited regenerative potential. Chondrocytes physiologically regulate matrix formation and cleavage; under the influence of synovial cytokines and reactive nitrogen intermediates, cartilage is progressively deprived of chondrocytes, which undergo apoptosis.26 These processes ultimately lead to the destruction of the surface cartilage and the radiographic appearance of joint space narrowing. It is possible that the mechanical removal of synovial tissue during the subacute phase of RA may prevent pannus formation and lead to complete, long-standing remission of arthritis. The limitations in this study are the small number of patients and the lack of a control group. Additionally, because this is a retrospectively designed study, there was no comparison with another treatment modality. A prestudy power analysis would have determined the number of patients required for more statistical validity. However, patients with RA with recalcitrant ankle symptom with minimal radiographic changes are relatively rare and reporting outcomes is limited with respect to sample size. Another weakness was that despite its use in other studies, the AOFAS scoring system has not been validated and is no longer recommended.27 We look to future studies to address this concern with a standard validated outcome measure. Despite the shortcomings, there are also several strengths to our study. First, given the lack of previously
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published data on arthroscopic synovectomy of the ankle in RA patients, the results of this study may be used to assess the rates of treatment failure as well as the risk factors for unsatisfactory clinical outcomes. Second, this is a consecutive series of patients followed up more than 2 years, which contains accurate preoperative and postoperative demographic and laboratory data. In addition, this was a single-surgeon series, using identical surgical techniques and a standardized postoperative rehabilitation protocol.
11.
12.
13.
14.
Conclusions Arthroscopic synovectomy is a safe and successful procedure in ankle joints affected by RA. The best clinical outcomes are achieved when the procedure is performed early in the disease course and when there is no evidence of cartilage degeneration.
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