Skip to main content
. 2022 Mar 3;2022(3):CD014328. doi: 10.1002/14651858.CD014328

Yim 2013.

Study characteristics
Methods Study design: single centre, parallel‐group, two‐arm, single‐blinded, randomised controlled trial
Setting: Center for Joint Disease, Chonnam National University Hwasun Hospital, Jeonnam, South Korea
Trial time period: participants were enrolled between January 2007 and July 2009
Interventions: arthroscopic surgery plus home exercise versus non‐operative care with physical therapy plus home exercise
Sample size calculations: the sample size was calculated based on Lysholm Knee Score data obtained from 30 prior cases, where the standard deviation was approximately 18. To test the difference in the minimal clinical relevance of 10 between the 2 groups with 80% power and a significance level of P < 0.05, these values were estimated with 54 participants in each group
Analysis: intention‐to‐treat
Participants Number of participants

  • Number of participants screened: 162 (49 declined to participate, 5 did not meet inclusion criteria)

  • Number of participants at enrolment: 108

  • Number randomised: 108 participants: 54 to the arthroscopic meniscectomy group and 54 to the non‐operative exercise group

  • Number included in analyses: 102 participants: 50 in the arthroscopic meniscectomy group and 52 to the non‐operative exercise group (at 24 months)


Inclusion criteria

  • Participants with a degenerative horizontal tear of the posterior horn of the medial meniscus on magnetic resonance imaging (MRI)

  • Daily knee pain on the medial side with mechanical symptoms affecting daily living activities despite management at a primary clinic during the previous month


Exclusion criteria

  • History of definite trauma

  • Previous knee surgery

  • Ligament deficiency

  • Systemic arthritis

  • Osteonecrosis

  • Participants showing a marked degenerative change with grade 2, according to the Kellgren‐Lawrence classification


Baseline characteristics
Arthroscopic meniscectomy

  • Mean (SD) age: 54.9 (10.3) years

  • No. men/women: 9/41

  • Mean (SD) body‐mass index: 25.0 (2.5)

  • Mean (SD) mechanical axis: ‐0.9 (1.3)

  • Mean (SD) maximal flexion, deg: 139 (6.9)

  • Kellgren–Lawrence grade — no: 0 = 39,1 = 11

  • Mean (SD) VAS score: 5.2 (1.8)

  • Mean (SD) Lysholm score: 64.0 (11.2)

  • Mean (range) duration of symptoms (months): 8.4 (6 weeks‐123 months)


Non‐operative group

  • Mean (SD) age: 57.6 (11.0) years

  • No. men/women: 12/40

  • Mean (SD) body‐mass index: 26.4 (1.9)

  • Mean (SD) mechanical axis: ‐1.1 (1.4)

  • Mean (SD) maximal flexion, deg: 141 (10.3)

  • Kellgren–Lawrence grade — no: 0 = 35,1 = 17

  • Mean (SD) VAS score: 4.9 (1.5)

  • Mean (SD) Lysholm score: 65.2 (10.8)

  • Mean (range) duration of symptoms (months): 8.2 (2‐81 months)


Pre‐treatment group differences: there were no differences in baseline characteristics between the two groups.
Interventions Arthroscopic surgery
Arthroscopic meniscectomy plus home exercises. Arthroscopic meniscectomy was carried out by a single experienced orthopaedic surgeon, using a 5.5‐mm, 30 degree arthroscope and a pressure‐controlled irrigation system. The procedure in each case was limited to resection with limited debridement of the articular surface lesion. Participants who underwent additional procedures, such as curettage, abrasion arthroplasty, or subchondral drilling for any articular lesions, were excluded from this study (n = 3). No participant underwent total meniscectomy or peripheral meniscal repair. All participants were discharged on the day after surgery. Subsequently, participants were permitted to use co‐interventions, such as analgesics or NSAIDs, within 2 weeks. All participants were then provided with a home exercise program, which was conducted unsupervised, using the same protocol as the non‐operative group, for 8 weeks.
Exercise
Non‐operative care with physical therapy plus home exercises. All participants in the non‐operative group were prescribed drugs, such as analgesics, non‐steroidal anti‐inflammatory drugs (NSAIDs), or muscle relaxants, depending on clinical symptoms for the first 2 weeks. In addition, they underwent scheduled physical exercise to improve muscle strength, endurance, and flexibility for 60 minutes per session, 3 times weekly, for 3 weeks under the supervision of a physical therapist. After an early, intensive, supervised rehabilitation program to strengthen muscles during the first 3 weeks, all participants were provided with a home exercise program, which they conducted unsupervised for 8 weeks. The home exercise program consisted of daily isometric and isotonic muscle exercises. This included:
1. Stretching of knee extensors and flexors (0‐8 times per week; 3 times per day; 1min/muscle group);
2. Knee extension in sitting position (0‐8 times per week; 3 times per day; 3 x 10 repetitions);
3. Knee flexion in sitting position (0‐8 times per week; 3 times per day; 3 x 10 repetitions);
4. Stationary bicycling (0‐8 times per week; 3 times per day; gradual increase every 15 minutes);
5. Half squats with < 45 degrees of flexion with weights (5‐8 times per week; 3 times per day; 3 x 10 repetitions);
6. Squats with full flexion with weights (5‐8 times per week; 3 times per day; 3 x 10 repetitions).
Participants were instructed to perform the exercises with some strain but almost pain‐free and not adversely influencing the affected knee.
Post‐intervention
Participants in both groups were permitted to use co‐interventions, such as analgesics, muscle relaxants or NSAIDs, within 2 weeks.
Outcomes Outcomes were assessed at baseline and at 3, 6, 12 and 24 months follow‐up.
Study outcomes

  • Mean pain related to specific activities (e.g. stair climbing, squatting, and standing up and sitting down). Measured using 10‐point visual analogue scale (VAS) scale (horizontal line that was 10 cm in length)

  • Pain relief ‐ measured using 10‐point VAS scale. Scores categorised as ‘‘complete relief’’ (0 or 1 point on scale), ‘‘improved’’ (> 2‐point decrease), or ‘‘persistent’’ (changes within 2 points)

  • Lysholm Knee Score ‐ scores range from 0 to 100 with lower scores reflecting more severe symptoms

  • Tegner activity scale ‐ scores range from 0 to 100 with lower scores reflecting more severe symptoms

  • Participant satisfaction with management, based on knee joint condition and degree of interference with everyday life ‐ rated as ‘‘very satisfied’’ (treatment met participant expectations), ‘‘satisfied’’ (treatment helped, and participant would undergo this treatment option), or ‘‘dissatisfied’’ (participant was the same or worse than before).

  • Osteoarthritic changes, observed by roentgenography (anteroposterior, lateral, and Merchant views), were graded using the Kellgren‐Lawrence classification (grade 1 (doubtful): doubtful joint space narrowing and possible osteophytic lipping; grade 2 (minimal): definite osteophytes and possible joint space narrowing; grade 3 (moderate): moderate multiple osteophytes, definite narrowing of joint space and some sclerosis and possible deformity of bone ends; grade 4 (severe): large osteophytes, marked narrowing of joint space, severe sclerosis and definite deformity of bone ends). Participants with grade ≥ 2 arthritis (definite osteophytes or definite narrowing of the joint space on plain radiography) with clear osteophytes were defined as having OA.


Outcomes used in this review at 3, 6 and 24 months

  • Pain ‐ mean knee pain during activity, measured on a 10‐point VAS scale (endpoint score), lower score = less pain

  • Function ‐ Lysholm Knee Score, higher score = better outcome with fewer symptoms and disability

  • Participant‐reported treatment success ‐ satisfaction with management at 24 months, measured as number of participants reporting 'very satisfied' or 'satisfied'

  • Progression of knee OA
Notes Funding: not reported
Trial registration: not registered
Adverse events: unclear if measured; not reported
Knee surgery (replacement or osteotomy): not reported
Progression of knee OA: 2/50 (4.0%) participants in the meniscectomy group and 3/52 (5.8%) in the non‐operative group at 2‐year follow‐up
Withdrawals: 4/54 (7.4%) in the meniscectomy group and 2/54 (3.7%) in the non‐operative group
Data imputations: SDs for VAS pain and Lysholm Knee Function Score not reported at follow‐up and not provided by authors on request. We used Yim 2013 baseline SDs in analyses Analysis 2.1; Analysis 2.2; Analysis 13.1; and Analysis 13.2.
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk No description of sequence generation process provided
Allocation concealment (selection bias) Unclear risk Allocation concealment unclear. "Closed‐envelope technique" reported
Blinding of participants and personnel (performance bias)
All outcomes High risk Blinding of participants and study personnel not done
Blinding of outcome assessor
Self‐reported outcomes High risk Participants were aware of treatment allocation; thus, there is risk of bias in measurements of pain, knee function and activity and participant satisfaction with treatment
Blinding of outcome assessor
Assessor‐reported outcome (knee replacement) Low risk Outcome assessors for progression of knee OA probably blinded: "Clinical outcome measures and physical examinations were conducted by independent authors not involved in the treatment"
Incomplete outcome data (attrition bias)
All outcomes Low risk 4/54 (7.4%) (not meeting inclusion criteria = 3, loss to follow‐up = 1) in the arthroscopic meniscectomy group and 2/54 (3.7%) (cross‐over to the other group = 1, loss to follow‐up = 1) in the non‐operative exercise group were excluded from the analysis at 24 months
Selective reporting (reporting bias) High risk Trial registration not done and protocol not available. The authors reported mean and range for study outcomes but standard deviations and confidence intervals were not reported. Adverse events were not reported
Other bias Unclear risk An unspecified number of participants in the arthroscopic surgery group were not prescribed exercise

ACR: American College of Rheumatology; ADL: activities of daily living; AIMS: Arthritis Impact Measurement Scale; AIMS2‐P: pain subscale of the Arthritis Impact Measurement Scale; BMI: body mass index; cc: cubic centimetres; DVT: deep vein (venous) thrombosis; EQ‐5D 3L: EuroQoL 5‐dimension 3‐level quality of life questionnaire; IQR: interquartile range; ITT: intention‐to‐treat; KL grade: Kellgren‐Lawrence classification grade; KOOS: Knee injury and Osteoarthritis Outcome Score; KOOS 4/5: derived from 4 or 5 KOOS subscale scores; MI: myocardial infarction; MRI: magnetic resonance imaging; NSAIDS: non‐steroidal anti‐inflammatory drugs; OA: osteoarthritis; OARSI: Osteoarthritis Research Society International; PT: physical therapy; QoL/QOL: quality of life; ROM: range of motion; SD: standard deviation; SMD: standardised mean difference; VAS: visual analogue scale; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; WOMET: Western Ontario Meniscal Evaluation Tool