Substantial disability 3 months after arthroscopic partial meniscectomy: A prospective study of patient-relevant outcomes

Substantial Disability 3 Months After Arthroscopic Partial Meniscectomy: A Prospective Study of Patient-Relevant Outcomes Ewa M. Roos, P.T., Ph.D., Harald P. Roos, M.D., Ph.D., Leif Ryd, M.D., Ph.D., and L. Stefan Lohmander, M.D., Ph.D.

Summary: To our knowledge, this is the first prospective study using validated questionnaires to assess patient-relevant outcomes after arthroscopic partial meniscectomy. Data from the Knee Injury and Osteoarthritis Outcome Score (KOOS), the SF-36 Medical Outcomes Study Short-Form Health Survey, and the Lysholm Knee Scoring Scale were available for 74 consecutive patients (50 males, 24 females; mean age, 45 years) with isolated meniscus tear (n ⫽ 47) or meniscus tear combined with cartilage damage (n ⫽ 27). At postoperative follow-up (mean, 14.4 weeks) significant improvement was seen, but despite only minor pain and other symptoms postoperatively, significant physical disability and handicap were reported. Postoperatively, 30% of patients were active in sports compared with 63% before injury. A sedentary lifestyle was reported by 38% compared with 9% before injury. We conclude that patient-relevant outcomes provide additional information and should be assessed after arthroscopic partial meniscectomy. We further suggest that preoperative information for the meniscectomy patient should include a realistic expected functional outcome. Key Words: Meniscectomy—Patient-relevant outcomes—KOOS—SF-36 —Activity level.

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ince arthroscopy was introduced, the time to recovery after meniscectomy has decreased dramatically. Generally, good functional recovery has been reported, and preinjury activity levels are reported to be resumed 3 to 4 weeks after arthroscopic partial meniscectomy.1-6 Associated cartilage damage, increased knee laxity, older age, long duration of symptoms, type of tear, Workers’ Compensation, and worse preoperative physical functional status are factors re-

From the Departments of Physical Therapy and Orthopaedics, Lund University, Lund, Sweden. Supported by grants from The Medical Faculty and University Hospital in Lund, The Swedish Foundation for Health Care Sciences and Allergy Research, The Swedish Rheumatism Association, The Swedish Sports Confederation (Sports Research Council), The Zoega Foundation, and the Swedish Medical Research Council. Address correspondence and reprint requests to Ewa M. Roos, P.T., Ph.D., Department of Orthopaedics, Lund University Hospital, S-22185 Lund, Sweden. E-mail: [email protected] © 2000 by the Arthroscopy Association of North America 0749-8063/00/1606-2302$3.00/0 doi: 10.1053/jars.2000.4818

ported to be associated with worse functional outcome.1,2,5,7,8 Traditionally, measures of impairment, such as pain, swelling, and mechanical problems, are assessed after meniscectomy since these are the symptoms the procedure is supposed to alleviate. However, to ensure that our treatment also satisfies the needs of the patients, there has been a call for the use of patientrelevant outcomes, emphasizing disability and handicap,9 as primary outcomes in clinical studies.10-13 Assessing disability and handicap suggests the addition of questions regarding functional aspects and quality of life. Studies of orthopaedic patients have also suggested that these questions should be answered by the patient because a significant positive observer bias has been reported when doctors or independent observers have interviewed patients compared with when the patients themselves have answered the questions.14-16 The objective of this study was to assess patient-relevant outcomes preoperatively and 3 months after arthroscopic partial meniscectomy.

Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 16, No 6 (September), 2000: pp 619 – 626

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E. M. ROOS ET AL. MATERIALS AND METHODS

Subjects During a 6-month period, self-administered questionnaires were mailed to 200 consecutive patients on the waiting list for knee arthroscopy at the Department of Orthopaedics at Lund University, Sweden. Patients who had undergone an arthroscopic partial meniscectomy as the only intervention and were able to complete questionnaires in Swedish were included. Exclusion criteria were back problems, injury to the anterior cruciate ligament (ACL), or other lower extremity problem that could affect lower extremity function. Of 85 patients who fulfilled inclusion and exclusion criteria, 11 did not return preoperative questionnaires; thus, baseline data were available for 74 patients (92% of patients eligible). The operating surgeon filled out a standardized arthroscopy record form. One orthopaedic surgeon reviewed the record forms and classified the subjects with regard to arthroscopic findings. Of the study group (n ⫽ 74), 47 patients had isolated meniscus tears (MTs) and 27 had MTs with associated cartilage damage as seen at the arthroscopy. MTs were regarded as significant if they required surgery. In 70% of the total group, the medial meniscus was partially resected, in 26% the lateral, and in 4% both menisci were partially resected. The corresponding numbers for the 47 patients with isolated MTs were 79%, 17%, and 4%, respectively. Cartilage damage was classified according to the French Arthroscopy Association17 and defined as open lesion with bone contact (determined with a probe) or exposed bone. Cartilage damage was found on tibia, femur, or both joint surfaces. The mean age of the total group was 45 years (range, 14 to 75 years); 50 patients were male and 24 were female. Four patients did not work because of their knee problems. In both the total group and in the patients with isolated MTs, the median duration from onset of symptoms to arthroscopy was 6 to 12 months, ranging from less than 3 months to more than 5 years. Patient characteristics are found in Table 1. Postoperative questionnaire data from only 63 subjects (85%) were available because 11 patients failed to return the questionnaires during the study period. The patients available for follow-up did not differ from the original 74 with respect to diagnostic subgroup, preoperative scores, activity level, or other baseline data. Preoperatively, all patients received standardized written information regarding the procedure and the postoperative care. Postoperatively, the patients were encouraged to carry out exercises at home to improve

TABLE 1. Number of Patients, Number of Females, and Mean Ages of Patients With Isolated MT or MT With Cartilage Damage Age (yr)

Total group MT MT with cartilage damage

N

Females

Mean

Range

74 47

24 11

44.7 40.5

14-75 14-75

27

13

52.3

38-69

strength, range of motion, and balance. Initially, the exercises were open-chain, with a gradual shift to closed-chain exercises. The patients were informed that, in most cases, it would be possible to return to normal activities and to gradually start jogging within 1 to 2 weeks. The Ethics Committee of the Medical Faculty of Lund University approved the study. Survey Among Orthopaedic Surgeons Because little information is found in the literature on recovery time after arthroscopic partial meniscectomy, a survey among 17 Scandinavian orthopaedic surgeons was carried out. Six of the surgeons reported performing 11 to 50 arthroscopic partial meniscectomies a year, 8 reported 51 to 100 a year, and 3 reported performing more than 100 arthroscopic partial meniscectomies a year. They were asked how long a recovery time the average patient with an isolated MT could expect. Nine surgeons answered 2 to 4 weeks, 6 surgeons answered 6 to 8 weeks, and 1 surgeon answered 12 weeks (mean, 5.1 weeks; median, 3.8 weeks). They were also asked which factors would require at least twice as long recovery time. Female gender was considered to be such a factor by all 17 surgeons. Associated injury to the cartilage or ACL was considered a factor by 13 of the 17 surgeons, injury to the lateral meniscus by 7 surgeons, type of tear by 6 surgeons, age over 35 years by 5 surgeons, long duration from onset to arthroscopy by 4 surgeons, and not being active in sports before the injury by 1 surgeon. Based on the survey and information available in the literature, 12 weeks was regarded as sufficient time for follow-up of arthroscopic partial meniscectomy. Study Design Three questionnaires, the generic Medical Outcomes Study Short-Form Health Survey (SF-36), the disease-specific Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Lysholm Knee Scoring

PATIENT-RELEVANT OUTCOMES OF MENISCECTOMY TABLE 2. Self-Reported Working Conditions Which Description Describes Your Working Conditions the Best? Please Mark One Alternative 6 5 4 3 2 1 0

Heavy work (lumber jack, fire fighter, construction worker, etc) Moderately heavy work (truck driver, scrubbing floors, etc) Moderate work (nurse, preschool teacher, housework with kids, etc) Light work (hairdresser, sales person, etc) Sedentary work (secretary, desk work, student, etc) Do not work for reasons other than my knee Sick leave or disability pension because of my knee

Scale, were mailed to the patients preoperatively and 3 months postoperatively to determine health status, disease-specific symptoms, and knee function. In addition, data including duration of knee problems and preinjury and current physical activity level of work (Table 2) and recreation (Table 3) were collected. Another question asked the subjects to report current activity level (work and recreation) compared with before the knee injury on a 5-point Likert scale ranging from much lower to much higher. If a change in activity level was experienced, the patients noted the reason(s) as knee problems, other reasons, or both. In the postoperative questionnaire, the question concerning current activity level was compared with the activity level before arthroscopy. The patients were reminded by 1 telephone call if the questionnaires were not returned. The preoperative evaluation was filled out at an average of 2.4 weeks (range, 0 to 10 weeks) before the arthroscopy and the mean follow-up time after arthroscopy was 14.5 weeks (range, 11 to 23 weeks). The KOOS was considered the primary outcome measure.

TABLE 3. Self-Reported Recreational Activities Which Description Describes Your Recreational Activities the Best? Please Mark One Alternative 6 5 4 3 2 1 0

Competitive sports (soccer, racquet sports, track and field, skiing, etc) Recreational sports (jogging, skiing, racquet sports, etc) Golf, dancing, hiking, water aerobics Heavy yard work, heavy household work, walking on even ground Light yard work, light household work, shopping Minimal household work: card games, sewing No household work: TV, reading

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KOOS KOOS is a 42-item self-administered questionnaire based on the WOMAC Osteoarthritis Index,18 proven valid for subjects with knee injury undergoing reconstruction of the ACL19 and knee arthroscopy.20 The KOOS assesses 5 separate dimensions: pain, symptoms, activities of daily living (ADL), sport and recreation function (Sport/Rec), and knee-related quality of life (QOL). A percentage score from 0% to 100% is calculated for each dimension, 100% representing the best possible score, and the result is presented as an outcome profile. The Swedish version LK 1.0 was used.20 Data from the KOOS reference group obtained in a previous study21 (n ⫽ 50; mean age, 53 years; age range, 37 to 79 years) with no clinical signs of injury to the menisci or ACL, and no radiographic signs of osteoarthritis, were used for comparison. SF-36 The 36-item SF-36 is a widely used measure of general health status that comprises 8 subscales: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health.22 A score from 0-100 points is calculated for each dimension, 100 representing the best result. The Swedish Acute version 1.0 was used.23 Reference data given in the Swedish manual from a sample of the Swedish general population (n ⫽ 8,930) were used for comparison.23 Lysholm Knee Scoring Scale The Lysholm Knee Scoring Scale is an 8-item questionnaire, originally developed to assess symptoms and function disabilities resulting from an ACL injury.24 However, the Lysholm scale has frequently been used to assess functional outcome of meniscectomy. All 8 items (pain, instability, locking, stairs, swelling, squat, limp, and support) are aggregated into 1 score from 0 to 100 points, where 100 indicates normal knee function. The Lysholm is intended to aid the physician in assessing patients’ knee function and is meant to be observer-administered. No instructions to the patient are provided. In this study, the Lysholm Knee Scoring Scale was patient-administered and the subjects were given 1 instruction: they were asked to consider the previous week when answering the questionnaire. Statistics For comparisons of preoperative and postoperative questionnaire data, the Wilcoxon signed-rank test was used. For comparisons between the group with MT

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and the group with MT and cartilage damage, the Mann-Whitney test was used. No adjustments for multiple comparisons were made. When comparing with the KOOS reference data, the Mann-Whitney test was used, and 95% confidence intervals for the means were calculated. For the SF-36, the 95% confidence intervals for the means obtained in this study were compared with the known confidence intervals for the referents. The influence of 8 potential predictor variables on postoperative knee-related QOL was analyzed by means of linear regression analysis (age, body mass index, preoperative QOL, gender, duration of problems, preinjury activity level, preinjury work level, and cartilage damage). First, the influence of each potential predictor was assessed in simple regression analyses. Those predictors that implied P ⬍ .20 were considered further in a multivariate regression analysis. Backward stepwise elimination was then used to obtain the significant predictors. Model fit was checked by analyzing residuals.25

RESULTS Work Activity Level At postoperative follow-up, 6 patients, compared with 4 patients preoperatively, were not working because of their knee problems. Recreational Activity Level Before arthroscopy, all patients but 2 reported having lowered their physical activity level with regard to work and recreational activities. Of these, all patients but 1 reported that the reason was knee problems. Postoperatively, 36% of the total group, and 40% of the patients with isolated MTs, reported having increased their activity level with regard to work and recreational activities compared with before their arthroscopy.

As expected, when asked about recreational activity level, most patients were not as physically active before arthroscopy as before injury (Table 4). A substantial proportion reported a sedentary lifestyle, 38% compared with 9% before injury. In the patients with isolated MTs, the same trend was seen (Table 4). KOOS As measured by the KOOS, severe affection was seen preoperatively on the subscales sport and recreation function and knee-related QOL. Substantial pain and other symptoms such as grinding and lack of full range of motion were reported. The ADL subscale was the least affected (Table 5). For the patients with isolated MTs, generally better scores were seen than for the group with MT and associated cartilage damage, but the difference was not always statistically significant (Table 5). Postoperatively, significant improvement was seen in all 5 mean KOOS scores for the total group (P ⬍ .001) and for the diagnostic subgroups (with the exceptions of sport and recreation function for the subgroup with MT and associated cartilage damage (P ⫽ .08; Table 5). The improvement was largest for the group with isolated MTs. When comparing the postoperative scores between the subgroups, the patients with associated cartilage damage reported worse scores. Compared with the KOOS reference group, the meniscectomy patients reported significantly worse postoperative scores in all 5 subscales (P ⫽ .002). For the patients with isolated MTs, significant differences were found for pain, sport and recreation, and QOL (Fig 1). SF-36 Preoperative physical health, as measured by the SF-36 subscales physical function, role-physical, and bodily pain, was severely affected. Postoperatively, highly significant improvement (P ⬍ .001) was seen

TABLE 4. Number (percentage) of Patients Reporting Different Recreational Activity Levels Preinjury, Prearthroscopy, and Postoperatively in Total Group and Subgroup With Isolated MTs Total Group

Active in sports (level 5-6) Golf, dancing, hiking (level 4) Heavy household work, walking on even ground (level 3) Sedentary lifestyle (level 0-2)

Isolated MT Group

Preinjury n ⫽ 74

Prearthroscopy n ⫽ 71

Postoperative n ⫽ 63

Preinjury n ⫽ 47

Prearthroscopy n ⫽ 46

Postoperative n ⫽ 40

47 (64) 13 (18)

15 (21) 10 (14)

19 (30) 12 (19)

34 (72) 7 (15)

11 (24) 7 (15)

15 (38) 8 (20)

7 (9) 7 (9)

6 (8) 40 (56)

8 (12) 24 (38)

3 (6) 3 (6)

5 (11) 23 (50)

7 (18) 10 (25)

PATIENT-RELEVANT OUTCOMES OF MENISCECTOMY

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TABLE 5. Preoperative and Postoperative Mean KOOS (SD) for the Total Group and the Subgroups With Isolated MTs and MT With Cartilage Damage (MT-CD). P Values Given for Relevant Comparisons

Preoperative Pain Symptoms ADL Sport/Rec QOL Postoperative Pain P† Symptoms P† ADL P† Sport/Rec P† QOL P†

Total Group

MT

MT-CD

n ⫽ 74 58 (16) 60 (19) 70 (18) 29 (24) 34 (17) n ⫽ 63 78 (20) ⬍.001 75 (21) ⬍.001 84 (17) ⬍.001 50 (30) ⬍.001 53 (24) ⬍.001

n ⫽ 47 64 63 74 32 36 n ⫽ 40 84 ⬍.001 82 ⬍.001 91 ⬍.001 58 ⬍.001 60 ⬍.001

n ⫽ 27 50 53 62 24 29 n ⫽ 23 66 .003 64 .05 71 .006 35 .08 41 .006

MT Versus MT-CD P* ⬍.001 .04 .005 .22 .09 .001 .004 ⬍.001 .004 .003

*P value for Mann-Whitney when comparing patients with isolated MTs with patients with MT-CD. †P value for Wilcoxon test when comparing preoperative and postoperative scores of corresponding subscales.

for these 3 subscales. Significant improvement was also seen for the subscales vitality (P ⫽ .002) and mental health (P ⫽ .005) (Fig 2). When compared with a referent sample from the Swedish population, the meniscectomy patients reported significantly worse physical function, more bodily pain, and problems with work or recreational activities because of declined physical health (rolephysical) (Fig 2). The patients with isolated MTs

FIGURE 1. KOOS data. Postoperative data for the group with isolated MT (E, n ⫽ 40) and the group with MT and cartilage damage (䊐, n ⫽ 23). Reference data from 50 subjects (F) obtained in a previous study21 (mean age, 53 years; range, 37-79; with no clinical signs of injury to the menisci or ACL and no radiographic signs of osteoarthritis) were used for comparison. 95% confidence intervals for the means are given.

reported significantly worse function and problems with work or recreational activities because of declined physical health (role-physical) compared with the referent group. Lysholm Score Preoperatively, a total Lysholm score could only be calculated for 84% (62 of 74 patients) because of

FIGURE 2. SF-36 data. Preoperative data for the total group (‚, n ⫽ 74) and postoperative data for the total group (E, n ⫽ 63). The reference group (F, n ⫽ 8,930) is the norm for the general Swedish population (mean age, 43 years; range, 15-93). 95% confidence intervals for the means are given. Abbreviations: PF, physical function; RP, role-physical; BP, bodily pain; GH, general health; VT, vitality; SF, social functioning; RE, role-emotional; MH, mental health.

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items left out. The mean preoperative Lysholm score for 62 patients was 61 (standard deviation, 16), 6% having a score of ⱖ84, a limit for satisfactory score suggested by others.26,27 The patients with scores of ⱖ84 all had isolated MTs. Because of left-out items in the postoperative assessment of the Lysholm Knee Scoring Scale, a postoperative score could only be calculated for 79% (50 patients) and a preoperative to postoperative difference could only be calculated for 65% (41 of 63 patients). The mean postoperative score for 41 patients was 74 (standard deviation, 19), 22 (54%) having a satisfactory score of ⱖ84. The mean postoperative score for the patients with MT but no cartilage damage was 81 (standard deviation, 13), 18 (56%) having a satisfactory score of 84. The mean score difference for 41 patients was 12 (P ⬍ .001). Predictors of Worse Postoperative Outcome Injury to the lateral meniscus was not associated with more residual pain (P ⫽ .48), symptoms (P ⫽ .12), worse ADL (P ⫽ .54), sport and recreation (P ⫽ .21), or QOL (P ⫽ .17). Associated grade III-IV cartilage damage and worse preoperative knee-related QOL were predictors of worse postoperative kneerelated QOL (Table 6). Age, gender, body mass index,

high preinjury work level, and longer duration of problems were not associated with worse knee-related QOL. Being active in sports before injury was the predictor last eliminated, and these patients tended to have a higher postoperative QOL. The 2 predictors included produced a model, which explained 26% of the total variance in postoperative knee-related QOL. DISCUSSION The most commonly performed orthopaedic intervention is arthroscopic partial meniscectomy.28,29 However, compared with reconstruction of the ACL, meniscectomy has received little attention with respect to functional outcome, in particular from the patient’s perspective.19,30,31 To our knowledge, this is the first prospective study using validated questionnaires to assess patient-relevant outcomes after arthroscopic partial meniscectomy. We found that, despite significant improvement and minor symptoms postoperatively, substantial disability, reduced QOL, and reduced activity levels were evident 14 weeks after arthroscopic partial meniscectomy. The findings indicate that, although the procedure has been successful in alleviating pain, swelling, and other symptoms, patients have difficulties with

TABLE 6. Linear Regression Performed to Determine Predictors of Worse Knee-Related QOL Univariate Analysis

Multivariate Analysis㛳

Predictor Variable

N*

C†

(95% CI)

P‡

R2adj§

Age (yr) BMI (kg/m2) Preop QOL (0-100) Gender 0: female 1: male Duration of problem 0: ⱕ1 yr 1: ⬎1 yr Preinjury recreational activity level 0: not active in sports 1: active in sports Preinjury work level 0: moderate, light, or sedentary 1: heavy or moderately heavy Cartilage damage 0: no 1: yes

63 60 63 63 23 40 61 36 25 63 21 42 60 36 24 63 40 23

⫺0.61 ⫺1.32 0.69 10.6

(⫺1.07, ⫺0.14) (⫺3.47, 0.82) (0.34, 1.03) (⫺2.05, 23.3)

.01 .22 ⬍.001 .10

9% 1% 20% 3%

.8

0%

No

Included

10%

No

Included

0%

No

Included

13%

⫺14.4

(⫺25.8, ⫺3.2)

0.97

17.4 ⫺6.54 ⫺19.2

(⫺12.1, 14.1)

(4.92, 29.8)

.007

(⫺19.5, 6.38)

.3

(⫺31.2, ⫺7.3)

.002

C†

(95% CI)

No No 0.58 No

Included Included (0.24, 0.92) Included

*Number of patients included. †Estimated change of postoperative QOL per unit change of predictor variable; 95% confidence interval (CI) within parenthesis. ‡P value for effect of predictor variable. §Fraction of postoperative QOL variance explained by each predictor (adjusted value). 㛳For the 2 predictors included in the multivariate model: R2adj ⫽ 26%.

P‡

.001

.01

PATIENT-RELEVANT OUTCOMES OF MENISCECTOMY functional activities, such as running, jumping, kneeling, and squatting, and they lack confidence in their knee, resulting in reduction of physical activity and lifestyle changes. We evaluated consecutive patients having MTs with or without cartilage damage, a sample thought to reflect the average patient having arthroscopic partial meniscectomy. To enhance interpretation of the results, patients with a concomitant injury to the ACL injury were excluded and results from patients with and without associated cartilage damage were, when appropriate, reported separately. The patients studied had a wide age span from 14 to 75 years. However, older age was not associated with worse postoperative knee-related QOL, neither were any of the other demographic variables examined (body mass index, gender, duration of problems, or preinjury work level). There was a trend that subjects who were active in sports at least on a recreational level before the onset of symptoms reported a more favorable outcome, pointing to a possibility that patients in other studies where a more favorable outcome has been reported may have been more physically active. However, 45% in our study reported being active in recreational sports and 19% in competitive sports before onset of symptoms. The only factor, of those previously reported, that predicted postoperative QOL was cartilage damage. However, this measure of impairment accounted for only 13% of the variance. This finding confirms that objective measures of impairment are not closely related to subjective measures of disability and handicap. The most plausible explanation for the discrepancy in results between this study and prior studies is, together with patient selection, the use of patientrelevant outcome measures. If the results of arthroscopic partial meniscectomy were based on relief of symptoms such as pain, swelling, and mechanical problems, the patients in our study would be characterized as having improved substantially and having only minor remaining problems. However, this and other studies show that to fully assess the outcome of surgery, functional assessment and QOL need to be included.10,13,31 Similar results were achieved by all 3 outcome measures used. However, they differed with regard to sensitivity, responsiveness, and suitability for selfadministration. We choose KOOS as our primary disease-specific outcome measure because of its validity for the subjects, known reliability and responsiveness, and its 5 subscales measuring outcomes separately at impairment, disability, and handicap levels.19-21 Using a questionnaire that has also been validated for ACL

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injury and post-traumatic osteoarthritis enabled comparisons with these diagnostic groups. The scores before meniscectomy were equal or worse than scores reported previously in a study on ACL reconstruction.19 Despite the ACL patients in that study being 10 years younger than the meniscectomy patients in this study, this indicates that patients about to undergo meniscectomy experience degrees of impairment, disability, and handicap similar to patients about to undergo reconstruction of the ACL. The SF-36 has previously been used in a retrospective study determining predictors of worse functional outcome of arthroscopic partial meniscectomy,5 and was recommended as an outcome measure for arthroscopic partial meniscectomy by a nominal study group.13 Its appropriateness for arthroscopic partial meniscectomy was confirmed by this study, but it was not as sensitive as the KOOS, implying that both disease-specific and generic questionnaires should be included in the evaluation of meniscectomy. The advantages of using generic instruments include measuring outcomes related to both physical and mental health, and making comparisons of health status between groups of patients and to reference groups possible. A validated Swedish version of the SF-36 was available as well as reference data from the general Swedish population. Compared with the reference group, physical function was still significantly affected 3 months after arthroscopic partial meniscectomy. Reference data of the SF-36 were also available stratified for age and sex. Male patients reported better physical health than did female patients, and younger patients reported better physical health than older, implying even greater differences when comparing our data with more closely matched groups from the reference material. By using the SF-36, it was found that arthroscopic partial meniscectomy not only improves outcomes related to physical health but also vitality and mental health. The Lysholm scale, which has been used most frequently to assess functional outcome of arthroscopic partial meniscectomy, was not considered an ideal outcome measure for this study. It was developed to be completed by an observer and it aggregates symptoms and function, i.e., impairment and disability, into 1 total score. However, the Lysholm scale was included for comparison with previous studies. Unfortunately, Lysholm score change could only be calculated for 65% of the patients due to missing items. This low quality of data together with the difference in administration mode makes comparison with previous studies difficult. To avoid observer bias, the patients filled out the questionnaires themselves in their

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homes. A negative aspect of this data collection mode is that a higher dropout frequency can be expected. In the present study, the follow-up rate was 87%, which is high. Zarins et al.3 pointed out that professional athletes with an early recovery—a small but highly visible fraction of patients—raise the expectations of most patients to unrealistic levels. This may also be true for operating surgeons. The results of our survey among orthopaedic surgeons indicate that unrealistic expectations of recovery time are given in many cases. Three months was not a sufficient time for complete recovery after arthroscopic partial meniscectomy, neither for the patients with MT nor the patients with MT and cartilage damage. From our study, it is not clear whether complete recovery will be achieved after a longer time period, or if interventions like physical therapy improve the outcome. However, prior to this study, no information was available suggesting that a postoperative evaluation later than 3 months would be needed. Prospective studies with longer follow-up should be carried out to add information on the natural course following arthroscopic partial meniscectomy. We recommend that patient-relevant outcomes should be assessed after arthroscopic partial meniscectomy. We also suggest that preoperative information to the meniscectomy patient should include a realistic expected functional outcome. REFERENCES 1. Patel D, Fahmy N, Sakayan A. Isokinetic and functional evaluation of the knee following arthroscopic surgery. Clin Orthop 1982;167:84-91. 2. Hamberg P, Gillquist J. Knee function after arthroscopic meniscectomy. Acta Orthop Scand 1984;55:172-175. 3. Zarins B, Boyle J, Harris BA. Knee rehabilitation following arthroscopic meniscectomy. Clin Orthop 1985;198:36-42. 4. Vander Schilten JL. Improvements in rehabilitation of the postmeniscectomized or meniscal-repaired patient. Clin Orthop 1990;252:73-79. 5. Katz JN, Harris TM, Larson MG, et al. Predictors of functional outcomes after arthroscopic partial meniscectomy. J Rheumatol 1992;19:1938-1942. 6. St. Pierre D. Rehabilitation following arthroscopic meniscectomy. Sports Med 1995;20:338-347. 7. Ferkel RD, Davis JR, Friedman MJ, et al. Arthroscopic partial meniscectomy: An analysis of unsatisfactory results. Arthroscopy 1985;1:44-52. 8. Bolano LE, Grana WA. Isolated arthroscopic partial meniscectomy. Functional radiographic evaluation at five years. Am J Sports Med 1993;21:432-437. 9. WHO. International classification of impairments, disabilities, and handicaps. Geneva: World Health Organization, 1980. 10. Clancy CM, Eisenberg JM. Outcomes research: Measuring the end results of health care. Science 1998;282:245-246.

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