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Arthroscopic Debridement for Osteoarthritis of the Knee: Predictors of Patient Satisfaction
Arthroscopic Debridement for Osteoarthritis of the Knee: Predictors of Patient Satisfaction Steven F. Harwin, M.D.
Summary: A retrospective review of 204 knees with osteoarthritis debrided arthroscopically was carried out to determine possible predictors of patient satisfaction with the outcome of their procedure. Knees were divided into three groups based upon the alignment on a standing anteroposterior radiograph in extension: group I, 0°; group II, ⬍5°; and group III, ⬎5°. Each group was further subdivided as to whether the patients were better (satisfied), unchanged, or worse (unsatisfied) with their operation at the time of review. There were 81 men (42.6%) and 109 women (57.4%) ranging in age from 30 to 88 years (mean, 62.1 years). Follow-up ranged from 2 to 15 years (mean, 7.4 years). Overall, 63.2% (129 knees) were better, 21.1% (43 knees) were unchanged, and 15.7% (32 knees) were worse after surgery. Further surgery was needed in 54 knees (26.5%). Regarding satisfactory results, group I (n ⫽ 57) had 84.2%, group II (n ⫽ 102) had 67.6%, and group III (n ⫽ 45) had 26.7%. Based on statistical analysis, it is concluded that patients with less deviated axes do better than those with large angulations, prior surgery predisposes to poorer results, and while the age was lower in the better and unchanged groups, it seems to be secondary in importance to angular deformity. Arthroscopic debridement is a successful palliative, temporizing treatment for the osteoarthritic knee. Key Words: Knee—Osteoarthritis—Arthroscopy—Debridement—Predictors.
A
rthroscopic debridement of the degenerative knee has become a commonly performed orthopaedic procedure. The indications for this procedure are limited and there has been no evidence to suggest that it alters the pathological process. However, there does appear to be a select group of patients who will benefit from debridement with regard to pain relief and functional improvement and, therefore, may be able to postpone or even avoid more complex and morbid procedures such as high tibial osteotomy or joint arthroplasty.1 Conflicting reports in the literature exist about the efficacy of arthroscopic debridement and open debridement has fallen out of favor. Some authors report satisfactory results with arthroscopic From the Department of Orthopaedic Surgery, Beth Israel Medical Center, New York, New York, U.S.A. Address correspondence and reprint requests to Steven F. Harwin, M.D., 910 Park Ave., New York, NY 10021, USA r 1999 by the Arthroscopy Association of North America 0749-8063/99/1502-1897$3.00/0
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debridement.2-11 Others have reported little, no, or temporary benefit.12-14 Still others report satisfactory results in normally aligned knees and poor results in those with varus angulation.15 The younger patient, with a shorter duration of symptoms, especially with a history of injury, may well be served by arthroscopic surgery that will specifically address mobile segments of meniscal tears, loose bodies and other posttraumatic intra-articular derangements.1,2,16 Patient selection for arthroscopic debridement should depend on all of the above factors including the patient’s activity level, recreational desires, age, and general medical condition. Another factor that must be considered is the patient’s own desire in terms of choice of procedure in the face of added cost, time away from work, and possible morbidity and complications. Arthroscopic debridement, performed as an outpatient, clearly has less morbidity and fewer complications, with a more rapid return to the activities of daily living and gainful employment than with more
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 2 (March), 1999: pp 142–146
ARTHROSCOPIC DEBRIDEMENT OF THE KNEE extensive procedures such as tibial osteotomy or joint arthroplasty. Treatment options including tibial or femoral osteotomy, unicompartmental or total joint arthroplasty are clearly indicated and accepted for selected patients with osteoarthritis. Arthrodesis is rarely indicated or accepted. Influencing the decision to undergo these complex procedures include the factors of increased surgical morbidity, considerable convalescence and rehabilitation time, and the concern of ‘‘bridgeburning.’’ Therefore, arthroscopic debridement may be the only remaining alternative. Full disclosure is given to the patient regarding the temporizing and palliative nature of the procedure and the need for more aggressive surgery if symptoms are not relieved. The rationale for offering arthroscopic debridement in the selected patient is that it may improve symptomatology and function, has minimal morbidity, provides a temporizing therapeutic procedure, and documents the stage of the disease process. The purpose of this study was to determine if predictors of patient satisfaction could be found, and if improvement could be made in the patient selection process so as to provide a better correlation between patient expectation and surgical outcome. MATERIALS AND METHODS Between 1980 and 1993, the author performed 2,730 knee arthroscopies. During that time, there were 248 knees in 220 patients (9%) that were found to have areas of fibrillated articular cartilage with exposed bone, and these underwent arthroscopic debridement. It is this cohort that is included for review. Of this group, 44 knees in 30 patients were lost to follow-up. Therefore, there were 204 knees in 190 patients available for follow-up physical and radiographic examination. There were 81 men (42.6%) and 109 women (57.4%). They ranged in age from 32 to 88 years with a mean of 62.1 years. Follow-up ranged from a minimum of 2 years to a maximum of 15 years. The mean follow-up was 7.4 years. Radiographic evaluation included standing anteroposterior radiographs made with the knee in full extension, standing posterior to anterior radiographs made with the knee in 45° of flexion, lateral views, and Merchant patellar views at 30° of flexion. A long (52-inch, 132-cm) cassette was used to assess the mechanical axis, with the hips, knees and ankles included on the same radiograph. The patients were separated into three groups according to the alignment on standing anteroposterior radio-
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graphs. Group I (n ⫽ 57) consisted of patients whose mechanical axis was normal at 0°. Some of these patients exhibited sclerosis in the subchondral region or pointing of the tibial spines, but all had maintenance of the joint space. Patients with up to 5° of varus or valgus were defined as group II (n ⫽ 102) and many had osteophyte formation and subarticular erosions with a narrowed joint space. Patients who exhibited marked deviation of the mechanical axis with over 5° of varus or valgus were placed in group III (n ⫽ 45) and usually had more severe joint space narrowing with further osteoarthritic change. Within each group, patients were further divided according to their own subjective assessment regarding the outcome of their operation. The patients, at the time of review, were asked: ‘‘Are you better? Are you unchanged? or Are you worse?’’ Paired Student’s t tests with a correction for multiple tests were used for statistical comparisons. Patients indicated for surgery were those who were unresponsive to all modalities of nonoperative treatment, including lifestyle alterations, nonsteroidal antiinflammatory medication, physical therapy and, occasionally, an intra-articular steroid injection. The standard arthroscopic debridement performed in this series included lavage of the joint with varying amounts of saline solution (depending on the length of the procedure), partial synovectomy, decompression of the anterior chamber by resection of impinging plicae and removal of hypertrophic adipose tissue. Partial menisectomies were carried out removing only loose unstable fragments. Care was taken to preserve as much meniscal tissue as possible, and if faced with the choice of removing all meniscal tissue rather than leaving some potentially unstable segments, the tissue was left in situ. Chondroplasties were carried out removing only loose, unstable, or irregular flaps. No attempt was made to reach bleeding bone. Loose bodies were removed as needed. Osteophytes were removed rarely, and only if they were directly impinging, such as those that form in the intercondylar region of the tibia and impact onto the distal femur in full extension, and those on the patella that may impinge on the trochlea and cause pain. The procedure was performed under general anesthesia in most cases. Epidural and spinal were used when the patient so desired and in some cases intravenous sedation and local anesthesia infiltration were used. Patients were discharged on the same day. Postoperatively, the regime was kept as simple as possible. The dressing was removed in 24 to 48 hours. Patients were encouraged to bear as much weight as tolerated, using
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a cane, crutches, or walker, depending on age and general medical condition. They began range of motion and muscle strengthening exercises as soon as possible, and a supervised physical therapy program was prescribed in all cases. However, some patients did not comply because of age, infirmity, difficulty with transportation, or financial considerations. Various nonsteroidal anti-inflammatory medications were added after the initial postoperative period as needed. RESULTS Mean preoperative extension was ⫺5°, with a range from 0° to ⫺15°, and this improved postoperatively to ⫺4° with a range from 0° to ⫺15° degrees. Mean preoperative flexion was 110° with a range from 85° to 130°, and this improved postoperatively to 112° with a range from 88° to 130°. The mean preoperative HSS knee score was 66 with a range from 58 to 72, and the postoperative score improved to 73 with a range from 58 to 85. Patients’ mechanical axes varied from 0° to ⫺22° (varus) with a mean of ⫺3.5°. There were 180 knees (88.2%) with medial compartment osteoarthritis including 154 knees (85.5%) that had patellofemoral involvement as well. There were 24 knees (11.8%) with lateral compartment osteoarthritis including 18 knees (75%) that had patellofemoral involvement. With regard to prior surgery, in the medial group (n ⫽ 180), 30 knees (16.7%) had undergone prior medial meniscectomy (8 open, 22 arthroscopic). Six knees (3.3%) had undergone prior lateral meniscectomy (2 open, 4 arthroscopic). In the lateral group (n ⫽ 24), one knee (4.2%) had undergone a prior arthroscopic medial meniscectomy and 12 knees (50%) had undergone prior lateral meniscectomy (4 open, 8 arthroscopic). Statistical analysis revealed that the mean age of the patients who were better and unchanged by the operation was lower than those who were worse since the operation (P ⫽ .055). The mean mechanical axis of those patients who were unchanged by the surgery was significantly more deviated from normal than those who were better (P ⫽ .001). Additionally, the mean mechanical axes of the patients who were better and unchanged, were significantly less deviated from normal than those patients who were worse (P ⬍ .0001 and P ⬍ .001), respectively (Table 1). Additional findings revealed that there were fewer patients in the better and unchanged groups who had prior meniscectomies than in the group that was worse (P ⫽ .019 and P ⫽ .007, respectively). As commonly
TABLE 1. Parameters Studied Result
Better
No Change
Worse
Mean Age (yr) Mechanical Axis HSS Score
61.3 ⫺1.6° ⫹9.4
60.1 ⫺2.9° ⫹7.5
69.8 ⫺7.3° ⫹2.5
seen, meniscectomy often results in increasing deformity and a narrowed joint space in the arthritic knee.21 Considering that the majority of patients who had undergone previous meniscectomies already had group II or group III deviation of the mechanical axis, it is impossible to statistically assess the effect of prior meniscectomy alone. Regardless of the patient’s age, when the mean difference in the HSS knee score from preoperatively to postoperatively is computed (Table 1), the quantitative increase in the score for those worse is smaller than the increase for those better and unchanged (P ⫽ .145, P ⫽ .083, respectively). These P values are not below .05 primarily because of the large standard deviations associated with this type of mixed subjective and objective scoring system. Other parameters analyzed in this cohort included the percentage of patients who were either unchanged or who were worse at the time of follow-up, and whether or not further surgery was performed and what type. In group I patients (n ⫽ 57) there were 9 (15.8%) who were either unchanged or worse at the time of follow-up (Table 2). Ten patients (17.6%) went on to have a repeat arthroscopic procedure and 2 of these patients (3.5%) required osteotomy (Table 3). Of the patients in group II (n ⫽ 102) 33 patients (32.4%) were unchanged or worse at time of follow-up (Table 2). Fifteen patients (14.7%) underwent repeat arthroscopic procedures. Five patients (4.9%) went on to other procedures (two osteotomies and three joint arthroplasties) (Table 3). In group III (n ⫽ 45), there were 33 patients (73.3%) who were either unchanged or worse at follow-up examination (Table 2). In that group, there were 22 patients (48.8%) who went on to TABLE 2. Clinical Outcome Group (n)
Better
No Different
Worse
I (57) II (102) III (45) Total (204)
48 (84.2%) 69 (67.6%) 12 (26.7%) 129 (63.2%)
7 (12.3%) 24 (23.5%) 12 (26.7%) 43 (21.1%)
2 (3.5%) 9 (8.9%) 21 (46.6%) 32 (15.7%)
ARTHROSCOPIC DEBRIDEMENT OF THE KNEE TABLE 3. Further Surgery Group (n)
Unchanged or Worse
Repeat Arthroscopy
Other Surgery
I (57) II (102) III (45)
9 (15.8%) 33 (32.4%) 33 (73.3%)
10 (17.6%) 15 (14.7%) 0
2 (3.6%) 5 (4.9%) 22 (48.8%)
further surgery; all of these subsequent operations were joint arthroplasties (Table 3). The time interval between the index arthroscopic debridement and subsequent surgery was variable but in no case was it performed before 6 months. The mean time to repeat arthroscopic surgery was 3.2 years with a range from 6 months to 12 years; for osteotomy, 3.5 years with a range from 2 to 6 years; and for total knee arthroplasty, 4.2 years, with a range of 6 months to 10 years. The clinical response in those unchanged or worse was likewise variable, with some experiencing initial improvement and later deterioration, and others who had minimal change in their symptomatology. Overall in the entire cohort (n ⫽ 204), 63.2% (129 patients) were better, 21.1% (43 patients) were unchanged, and 15.7% (32 patients) were worse. Complications included four hemarthroses (2%) that required aspiration and one case of postoperative deep venous thrombosis (0.5%). This patient was treated with a short course of intravenous heparin and subsequent warfarin therapy for 3 months with no sequelae. There were no postoperative infections. DISCUSSION Whereas 63.2% of all patients were satisfied and felt they were better than before their surgery, there still remains 36.8% of the patients who were either unchanged by the procedure or, at this point, were doing less well than they were before the surgery. In studies with shorter follow-up, Bonamo et al.3 found 83% patient satisfaction at a mean follow-up of 3.3 years. McLaren et al.17 found 65% improvement of symptoms with an average 2-year follow-up. Gross et al.5 found 72% good results at an average of 2 years postoperatively. Olgilvie-Harris and Fitsialos7 found that 68% of patients were improved at 2 years and 53% were improved at 4.1 years. McEldowney and Weicker18 reported 9 of 11 satisfying results at a mean of 6 years following an open Magnuson-type debridement. Mosely et al.14 reported a possible placebo effect from arthroscopic debridement as well. In this series, a weak predictor (just failing to reach
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statistical significance) for better outcome was the younger patient (P ⫽ .055) but strong factors for success included a more normal mechanical axis (P ⬍ .0001, P ⬍ .001) and fewer prior surgeries (P ⫽ .019, P ⫽ .007). These findings are in agreement with authors who have studied these variables.15,19 It is important to note that of group III patients (more axial deviation and more arthritic change), only 26.7% were better after this procedure, leaving 73.3% of patients either unchanged or worse after arthroscopic debridement. In addition, 48.8% of these patients required total knee arthroplasty within the follow-up period. These patients should be counseled as to the poorer prognosis and that they may be better served by either osteotomy or total knee arthroplasty, if they are willing to assume the added risks. Another important observation that should be shared with patients considering arthroscopic debridement is that 26.5% of patients required at least one further operation within the reported follow-up period.
CONCLUSIONS In this cohort, it has been shown that 63.2% of a heterogeneous patient population with varying degrees of osteoarthritis will feel better after arthroscopic debridement at a mean of 7.4 years after surgery. Statistically, younger patients do somewhat better than older patients (weak predictor) and those patients with larger angular deformities did worse than those with less deviation (strong predictor). It has also been shown that patients who have had prior meniscectomies did less well compared with those who had no prior surgery (strong predictor). Patients must be made aware that the procedure is not curative and that it is quite possible that they will need further surgery in the future. The ideal indication for arthroscopic debridement appears to be the younger patient who has had no prior surgery, with an angular deformity of less than 5°. The older patient, who may have had prior surgery, with an angular deformity of greater than 5° may be better served by other procedures such as osteotomy or total knee replacement if they will accept the risks associated with them. Considering that alternative, more complex surgical procedures carry greater morbidity, require a more lengthy recuperative process, and are more costly, arthroscopic debridement represents a reasonably successful temporizing, palliative procedure. However, the patient must have a clear understanding of the
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prospects of success and the benefits, risks and alternatives. REFERENCES 1. Burks RT. Arthroscopy and degenerative arthritis of the knee: A review of the literature. Arthroscopy 1990;6:43-47. 2. Baumgartner MR, Cannon DC, Vitton JM, Schmidt ES, Mauer RC. Arthroscopic debridement of the arthritic knee. Clin Orthop 1990;253:197-202. 3. Bonamo JJ, Kessler KJ, Noah J. Arthroscopic meniscectomy in patients over 40. Am J Sports Med 1992;20:422-428. 4. Burman MS, Finklestein H, Mayer L. Arthroscopy of the knee joint. J Bone Joint Surg 16:255, 1934. 5. Gross DE, Brenner SL, Esformes I, Gross ML. Arthroscopic treatment of degenerative joint disease of the knee. Orthopedics 1991;14:1317-1321. 6. Insall JN. Intra-articular surgery for degenerative arthritis of the knee. A report of the work of the late KH Pridie. J Bone Joint Surg Br 1967;49:211-218. 7. Ogilvie-Harris DJ, Fitsialos DP. Arthroscopic management of the degenerative knee. Arthroscopy 1991;7:151-157. 8. Rand JA. Arthroscopic management of degenerative meniscus tears in patients with degenerative arthritis. Arthroscopy 1985; 1:253-258. 9. Rand JA. Role of arthroscopy in osteoarthritis of the knee. Arthroscopy 1991;7:358-363.
10. Rangger C, Klestil T, Gloetzer W, Kemmler G, Benedetto KP. Osteoarthritis after arthroscopic partial meniscectomy. Am J Sports Med 1995;23:240-244. 11. Yang SS, Nissonson B. Arthroscopic surgery in the geriatric patient. Clin Orthop 1995;316:50-58. 12. Alastair-Gibson JN, White MD, Chapman VM, Strachan RK. Arthroscopic lavage and debridement for osteoarthritis of the knee. J Bone Joint Surg Br 1992;74:534-537. 13. Cascells SW. What, if any, are the indications for arthroscopic debridement of the osteoarthritic knee. Arthroscopy 1990;6:169170. 14. Mosely Jr JB, Wray NP, Kuykendell D, Willis K, Landon G. Arthroscopic treatment of osteoarthritis of the knee: A prospective, randomized placebo-controlled trial. Am J Sports Med 1996;24:28-34. 15. Salisbury RB, Nottage WM, Gardner V. The effect of alignment on results in arthroscopic debridement of the degenerative knee. Clin Orthop 1985;198:268-272. 16. Lysholm J, Hamberg P, Gillquist J. The correlation between osteoarthrosis as seen on radiographs and on arthroscopy. Arthroscopy 1987;3:161-165. 17. McLaren AC, Blokker CP, Fowler PJ, Roth JN, Rock MG. Arthroscopic debridement of the knee for osteoarthritis. Can J Surg 1991;34:595-598. 18. McEldowney AJ, Weicker GG. Open-knee Magnuson debridement as conservative treatment for degenerative osteoarthritis of the knee. J Arthro 1995;10:805-809. 19. Novak PJ, Bach BR Jr. Selection criteria for knee arthroscopy in the osteoarthritic patient. Orthop Rev 1993;22:798-804.
Summary: A retrospective review of 204 knees with osteoarthritis debrided arthroscopically was carried out to determine possible predictors of patient satisfaction with the outcome of their procedure. Knees were divided into three groups based upon the alignment on a standing anteroposterior radiograph in extension: group I, 0°; group II, ⬍5°; and group III, ⬎5°. Each group was further subdivided as to whether the patients were better (satisfied), unchanged, or worse (unsatisfied) with their operation at the time of review. There were 81 men (42.6%) and 109 women (57.4%) ranging in age from 30 to 88 years (mean, 62.1 years). Follow-up ranged from 2 to 15 years (mean, 7.4 years). Overall, 63.2% (129 knees) were better, 21.1% (43 knees) were unchanged, and 15.7% (32 knees) were worse after surgery. Further surgery was needed in 54 knees (26.5%). Regarding satisfactory results, group I (n ⫽ 57) had 84.2%, group II (n ⫽ 102) had 67.6%, and group III (n ⫽ 45) had 26.7%. Based on statistical analysis, it is concluded that patients with less deviated axes do better than those with large angulations, prior surgery predisposes to poorer results, and while the age was lower in the better and unchanged groups, it seems to be secondary in importance to angular deformity. Arthroscopic debridement is a successful palliative, temporizing treatment for the osteoarthritic knee. Key Words: Knee—Osteoarthritis—Arthroscopy—Debridement—Predictors.
A
rthroscopic debridement of the degenerative knee has become a commonly performed orthopaedic procedure. The indications for this procedure are limited and there has been no evidence to suggest that it alters the pathological process. However, there does appear to be a select group of patients who will benefit from debridement with regard to pain relief and functional improvement and, therefore, may be able to postpone or even avoid more complex and morbid procedures such as high tibial osteotomy or joint arthroplasty.1 Conflicting reports in the literature exist about the efficacy of arthroscopic debridement and open debridement has fallen out of favor. Some authors report satisfactory results with arthroscopic From the Department of Orthopaedic Surgery, Beth Israel Medical Center, New York, New York, U.S.A. Address correspondence and reprint requests to Steven F. Harwin, M.D., 910 Park Ave., New York, NY 10021, USA r 1999 by the Arthroscopy Association of North America 0749-8063/99/1502-1897$3.00/0
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debridement.2-11 Others have reported little, no, or temporary benefit.12-14 Still others report satisfactory results in normally aligned knees and poor results in those with varus angulation.15 The younger patient, with a shorter duration of symptoms, especially with a history of injury, may well be served by arthroscopic surgery that will specifically address mobile segments of meniscal tears, loose bodies and other posttraumatic intra-articular derangements.1,2,16 Patient selection for arthroscopic debridement should depend on all of the above factors including the patient’s activity level, recreational desires, age, and general medical condition. Another factor that must be considered is the patient’s own desire in terms of choice of procedure in the face of added cost, time away from work, and possible morbidity and complications. Arthroscopic debridement, performed as an outpatient, clearly has less morbidity and fewer complications, with a more rapid return to the activities of daily living and gainful employment than with more
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 2 (March), 1999: pp 142–146
ARTHROSCOPIC DEBRIDEMENT OF THE KNEE extensive procedures such as tibial osteotomy or joint arthroplasty. Treatment options including tibial or femoral osteotomy, unicompartmental or total joint arthroplasty are clearly indicated and accepted for selected patients with osteoarthritis. Arthrodesis is rarely indicated or accepted. Influencing the decision to undergo these complex procedures include the factors of increased surgical morbidity, considerable convalescence and rehabilitation time, and the concern of ‘‘bridgeburning.’’ Therefore, arthroscopic debridement may be the only remaining alternative. Full disclosure is given to the patient regarding the temporizing and palliative nature of the procedure and the need for more aggressive surgery if symptoms are not relieved. The rationale for offering arthroscopic debridement in the selected patient is that it may improve symptomatology and function, has minimal morbidity, provides a temporizing therapeutic procedure, and documents the stage of the disease process. The purpose of this study was to determine if predictors of patient satisfaction could be found, and if improvement could be made in the patient selection process so as to provide a better correlation between patient expectation and surgical outcome. MATERIALS AND METHODS Between 1980 and 1993, the author performed 2,730 knee arthroscopies. During that time, there were 248 knees in 220 patients (9%) that were found to have areas of fibrillated articular cartilage with exposed bone, and these underwent arthroscopic debridement. It is this cohort that is included for review. Of this group, 44 knees in 30 patients were lost to follow-up. Therefore, there were 204 knees in 190 patients available for follow-up physical and radiographic examination. There were 81 men (42.6%) and 109 women (57.4%). They ranged in age from 32 to 88 years with a mean of 62.1 years. Follow-up ranged from a minimum of 2 years to a maximum of 15 years. The mean follow-up was 7.4 years. Radiographic evaluation included standing anteroposterior radiographs made with the knee in full extension, standing posterior to anterior radiographs made with the knee in 45° of flexion, lateral views, and Merchant patellar views at 30° of flexion. A long (52-inch, 132-cm) cassette was used to assess the mechanical axis, with the hips, knees and ankles included on the same radiograph. The patients were separated into three groups according to the alignment on standing anteroposterior radio-
143
graphs. Group I (n ⫽ 57) consisted of patients whose mechanical axis was normal at 0°. Some of these patients exhibited sclerosis in the subchondral region or pointing of the tibial spines, but all had maintenance of the joint space. Patients with up to 5° of varus or valgus were defined as group II (n ⫽ 102) and many had osteophyte formation and subarticular erosions with a narrowed joint space. Patients who exhibited marked deviation of the mechanical axis with over 5° of varus or valgus were placed in group III (n ⫽ 45) and usually had more severe joint space narrowing with further osteoarthritic change. Within each group, patients were further divided according to their own subjective assessment regarding the outcome of their operation. The patients, at the time of review, were asked: ‘‘Are you better? Are you unchanged? or Are you worse?’’ Paired Student’s t tests with a correction for multiple tests were used for statistical comparisons. Patients indicated for surgery were those who were unresponsive to all modalities of nonoperative treatment, including lifestyle alterations, nonsteroidal antiinflammatory medication, physical therapy and, occasionally, an intra-articular steroid injection. The standard arthroscopic debridement performed in this series included lavage of the joint with varying amounts of saline solution (depending on the length of the procedure), partial synovectomy, decompression of the anterior chamber by resection of impinging plicae and removal of hypertrophic adipose tissue. Partial menisectomies were carried out removing only loose unstable fragments. Care was taken to preserve as much meniscal tissue as possible, and if faced with the choice of removing all meniscal tissue rather than leaving some potentially unstable segments, the tissue was left in situ. Chondroplasties were carried out removing only loose, unstable, or irregular flaps. No attempt was made to reach bleeding bone. Loose bodies were removed as needed. Osteophytes were removed rarely, and only if they were directly impinging, such as those that form in the intercondylar region of the tibia and impact onto the distal femur in full extension, and those on the patella that may impinge on the trochlea and cause pain. The procedure was performed under general anesthesia in most cases. Epidural and spinal were used when the patient so desired and in some cases intravenous sedation and local anesthesia infiltration were used. Patients were discharged on the same day. Postoperatively, the regime was kept as simple as possible. The dressing was removed in 24 to 48 hours. Patients were encouraged to bear as much weight as tolerated, using
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S. F. HARWIN
a cane, crutches, or walker, depending on age and general medical condition. They began range of motion and muscle strengthening exercises as soon as possible, and a supervised physical therapy program was prescribed in all cases. However, some patients did not comply because of age, infirmity, difficulty with transportation, or financial considerations. Various nonsteroidal anti-inflammatory medications were added after the initial postoperative period as needed. RESULTS Mean preoperative extension was ⫺5°, with a range from 0° to ⫺15°, and this improved postoperatively to ⫺4° with a range from 0° to ⫺15° degrees. Mean preoperative flexion was 110° with a range from 85° to 130°, and this improved postoperatively to 112° with a range from 88° to 130°. The mean preoperative HSS knee score was 66 with a range from 58 to 72, and the postoperative score improved to 73 with a range from 58 to 85. Patients’ mechanical axes varied from 0° to ⫺22° (varus) with a mean of ⫺3.5°. There were 180 knees (88.2%) with medial compartment osteoarthritis including 154 knees (85.5%) that had patellofemoral involvement as well. There were 24 knees (11.8%) with lateral compartment osteoarthritis including 18 knees (75%) that had patellofemoral involvement. With regard to prior surgery, in the medial group (n ⫽ 180), 30 knees (16.7%) had undergone prior medial meniscectomy (8 open, 22 arthroscopic). Six knees (3.3%) had undergone prior lateral meniscectomy (2 open, 4 arthroscopic). In the lateral group (n ⫽ 24), one knee (4.2%) had undergone a prior arthroscopic medial meniscectomy and 12 knees (50%) had undergone prior lateral meniscectomy (4 open, 8 arthroscopic). Statistical analysis revealed that the mean age of the patients who were better and unchanged by the operation was lower than those who were worse since the operation (P ⫽ .055). The mean mechanical axis of those patients who were unchanged by the surgery was significantly more deviated from normal than those who were better (P ⫽ .001). Additionally, the mean mechanical axes of the patients who were better and unchanged, were significantly less deviated from normal than those patients who were worse (P ⬍ .0001 and P ⬍ .001), respectively (Table 1). Additional findings revealed that there were fewer patients in the better and unchanged groups who had prior meniscectomies than in the group that was worse (P ⫽ .019 and P ⫽ .007, respectively). As commonly
TABLE 1. Parameters Studied Result
Better
No Change
Worse
Mean Age (yr) Mechanical Axis HSS Score
61.3 ⫺1.6° ⫹9.4
60.1 ⫺2.9° ⫹7.5
69.8 ⫺7.3° ⫹2.5
seen, meniscectomy often results in increasing deformity and a narrowed joint space in the arthritic knee.21 Considering that the majority of patients who had undergone previous meniscectomies already had group II or group III deviation of the mechanical axis, it is impossible to statistically assess the effect of prior meniscectomy alone. Regardless of the patient’s age, when the mean difference in the HSS knee score from preoperatively to postoperatively is computed (Table 1), the quantitative increase in the score for those worse is smaller than the increase for those better and unchanged (P ⫽ .145, P ⫽ .083, respectively). These P values are not below .05 primarily because of the large standard deviations associated with this type of mixed subjective and objective scoring system. Other parameters analyzed in this cohort included the percentage of patients who were either unchanged or who were worse at the time of follow-up, and whether or not further surgery was performed and what type. In group I patients (n ⫽ 57) there were 9 (15.8%) who were either unchanged or worse at the time of follow-up (Table 2). Ten patients (17.6%) went on to have a repeat arthroscopic procedure and 2 of these patients (3.5%) required osteotomy (Table 3). Of the patients in group II (n ⫽ 102) 33 patients (32.4%) were unchanged or worse at time of follow-up (Table 2). Fifteen patients (14.7%) underwent repeat arthroscopic procedures. Five patients (4.9%) went on to other procedures (two osteotomies and three joint arthroplasties) (Table 3). In group III (n ⫽ 45), there were 33 patients (73.3%) who were either unchanged or worse at follow-up examination (Table 2). In that group, there were 22 patients (48.8%) who went on to TABLE 2. Clinical Outcome Group (n)
Better
No Different
Worse
I (57) II (102) III (45) Total (204)
48 (84.2%) 69 (67.6%) 12 (26.7%) 129 (63.2%)
7 (12.3%) 24 (23.5%) 12 (26.7%) 43 (21.1%)
2 (3.5%) 9 (8.9%) 21 (46.6%) 32 (15.7%)
ARTHROSCOPIC DEBRIDEMENT OF THE KNEE TABLE 3. Further Surgery Group (n)
Unchanged or Worse
Repeat Arthroscopy
Other Surgery
I (57) II (102) III (45)
9 (15.8%) 33 (32.4%) 33 (73.3%)
10 (17.6%) 15 (14.7%) 0
2 (3.6%) 5 (4.9%) 22 (48.8%)
further surgery; all of these subsequent operations were joint arthroplasties (Table 3). The time interval between the index arthroscopic debridement and subsequent surgery was variable but in no case was it performed before 6 months. The mean time to repeat arthroscopic surgery was 3.2 years with a range from 6 months to 12 years; for osteotomy, 3.5 years with a range from 2 to 6 years; and for total knee arthroplasty, 4.2 years, with a range of 6 months to 10 years. The clinical response in those unchanged or worse was likewise variable, with some experiencing initial improvement and later deterioration, and others who had minimal change in their symptomatology. Overall in the entire cohort (n ⫽ 204), 63.2% (129 patients) were better, 21.1% (43 patients) were unchanged, and 15.7% (32 patients) were worse. Complications included four hemarthroses (2%) that required aspiration and one case of postoperative deep venous thrombosis (0.5%). This patient was treated with a short course of intravenous heparin and subsequent warfarin therapy for 3 months with no sequelae. There were no postoperative infections. DISCUSSION Whereas 63.2% of all patients were satisfied and felt they were better than before their surgery, there still remains 36.8% of the patients who were either unchanged by the procedure or, at this point, were doing less well than they were before the surgery. In studies with shorter follow-up, Bonamo et al.3 found 83% patient satisfaction at a mean follow-up of 3.3 years. McLaren et al.17 found 65% improvement of symptoms with an average 2-year follow-up. Gross et al.5 found 72% good results at an average of 2 years postoperatively. Olgilvie-Harris and Fitsialos7 found that 68% of patients were improved at 2 years and 53% were improved at 4.1 years. McEldowney and Weicker18 reported 9 of 11 satisfying results at a mean of 6 years following an open Magnuson-type debridement. Mosely et al.14 reported a possible placebo effect from arthroscopic debridement as well. In this series, a weak predictor (just failing to reach
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statistical significance) for better outcome was the younger patient (P ⫽ .055) but strong factors for success included a more normal mechanical axis (P ⬍ .0001, P ⬍ .001) and fewer prior surgeries (P ⫽ .019, P ⫽ .007). These findings are in agreement with authors who have studied these variables.15,19 It is important to note that of group III patients (more axial deviation and more arthritic change), only 26.7% were better after this procedure, leaving 73.3% of patients either unchanged or worse after arthroscopic debridement. In addition, 48.8% of these patients required total knee arthroplasty within the follow-up period. These patients should be counseled as to the poorer prognosis and that they may be better served by either osteotomy or total knee arthroplasty, if they are willing to assume the added risks. Another important observation that should be shared with patients considering arthroscopic debridement is that 26.5% of patients required at least one further operation within the reported follow-up period.
CONCLUSIONS In this cohort, it has been shown that 63.2% of a heterogeneous patient population with varying degrees of osteoarthritis will feel better after arthroscopic debridement at a mean of 7.4 years after surgery. Statistically, younger patients do somewhat better than older patients (weak predictor) and those patients with larger angular deformities did worse than those with less deviation (strong predictor). It has also been shown that patients who have had prior meniscectomies did less well compared with those who had no prior surgery (strong predictor). Patients must be made aware that the procedure is not curative and that it is quite possible that they will need further surgery in the future. The ideal indication for arthroscopic debridement appears to be the younger patient who has had no prior surgery, with an angular deformity of less than 5°. The older patient, who may have had prior surgery, with an angular deformity of greater than 5° may be better served by other procedures such as osteotomy or total knee replacement if they will accept the risks associated with them. Considering that alternative, more complex surgical procedures carry greater morbidity, require a more lengthy recuperative process, and are more costly, arthroscopic debridement represents a reasonably successful temporizing, palliative procedure. However, the patient must have a clear understanding of the
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