Osteras 2012.

Study characteristics
Methods	Study design: multicentre, two‐arm, randomised controlled trial Setting: two orthopedic clinics in two hospitals in Norway Trial time period: participants were recruited over a period of one year; however, the exact time frame was not mentioned. Interventions: arthroscopic surgery versus exercise Sample size calculations: based on a pre‐determined difference between treatment groups of 20% change in pain on a 10‐cm visual analogue scale and a standard deviation of 1.5 cm, 10 participants were required in each group to have 80% power to detect the 20% difference as statistically significant at the level of P < 0.05. Analysis: intention‐to‐treat
Participants	Number of participants Number of participants screened: 29 Number of participants at enrolment: 17 Number randomised: 17: 8 in the arthroscopic meniscectomy group and 9 in the medical exercise therapy group Number included in analyses: 17: 8 in the arthroscopic meniscectomy group and 9 in the medical exercise therapy group (at 3 months) Inclusion criteria Aged 35 to 60 years Knee pain for more than 3 months Eligible for an arthroscopic partial meniscectomy MRI showing a degenerative meniscus tear Exclusion criteria Anterior cruciate ligament (ACL) rupture for individuals requiring acute trauma surgeries High‐energy traumas with ligament injuries Osteoarthritis grades 3 to 4 (Kellgren‐Lawrence classification) Haemarthroses and acute cases of locking knee Symptomatic pain in contrary extremities Other musculoskeletal comorbidities severely affecting lower extremity muscle function that override the symptoms from the knee Comorbidities excluding physical activities and exercise Not able to speak or read the language of interest Baseline characteristics Arthroscopic partial meniscectomy Mean (SD) age: 52.7 (7.2) years Mean (SD) body weight: 82.4 (10.9) Mean (SD) duration of symptoms: 2.1 (1.7) Mean (SD) stage of arthritis: 0.9 (1.0) No. (%) of men: 5 (62.5) Mean (SD) VAS: 3.7 (0.9) Mean (SD) 5RM (Repetition Max): 8.6 (5.4) Mean (SD) KOOS: 48.4 (25.6) Mean (SD) Hospital Anxiety and Depression Scale (HADS) Anxiety: 4.0 (2.6) Mean (SD) HADS Depression: 5.0 (2.5) Medical exercise therapy Mean (SD) age: 47.0 (10.4) years Mean (SD) body weight: 79.8 (7.5) Mean (SD) duration of symptoms: 1.6 (1.2) Mean (SD) stage of arthritis: 0.6 (0.7) No. (%) of men: 8 (88.9) Mean (SD) VAS: 3.5 (1.7) Mean (SD) 5RM: 12.4 (6.1) Mean (SD) KOOS: 51.4 (24.4) Mean (SD) HADS Anxiety: 4.5 (3.1) Mean (SD) HADS Depression: 5.0 (2.9) Pre‐treatment group differences: there were no obvious differences in baseline characteristics between the two groups.
Interventions	Arthroscopic surgery Arthroscopic partial meniscectomy. A standard arthroscopic partial meniscectomy was applied as a surgical intervention, which was carried out at two hospitals in Trondheim, Norway, and performed on participants who fulfilled inclusion criteria and were randomised to surgical treatment. Normal procedures for this surgery at the respective hospitals were followed, the protocols did not differ between the hospitals, and there were two surgeons involved. Exercise Supervised (medical) exercise therapy. The exercise program was developed for this particular study, with a focus on co‐ordination and muscle function training, along with pain modification exercise therapy. The program was for 3 months, and participants exercised 3 times per week. Each treatment in the exercise group started with 15 to 20 minutes of aerobic work on a stationary ergometer cycle. After 4 exercises each of 3 sets of 30 repetitions halfway through the exercise program, the subjects cycled for 10 minutes and again after the last 4 exercises, the participants did another 10 minutes on a stationary ergometer cycle.
Outcomes	Outcomes were measured at baseline and at 3 months of follow‐up. Primary outcome Pain in the last week measured with a visual analogue scale (VAS) at rest and recorded on a 0 to 10 cm line (0 = no pain and 10 = maximal pain) Secondary outcomes Knee injury and Osteoarthritis Outcome Score (KOOS) comprising 5 subscales ‐ pain, symptoms, ADL, sports/rec, QoL; scores range from 0 to 100 where 100 indicates good knee function Hospital Anxiety and Depression Scale (HADS), a self‐screening questionnaire for depression and anxiety scores ranged from 0 to 21 for anxiety and 0 to 21 for depression; a lower score indicates a better clinical status. 5RM ‐ dynamic quadriceps muscle strength was measured with a leg extension bench and a protocol in which the participants lifted a weight with a maximum external load using 5 repetitions. Outcomes used in this review at 3 months Pain measured on VAS at rest (0 to 10, lower score = less pain) Function measured on KOOS total score (0 to 100, higher score = better function) (KOOS ADL subscale was not reported separately)
Notes	Funding: no information on funding was provided in this article Trial registration: not reported Adverse events: unclear if measured; not reported Knee surgery (replacement or osteotomy): not reported Progression of knee OA: not reported Withdrawals: unclear; pilot study results published in conference abstract (Osteras 2011, secondary publication of Osteras 2012) includes more participants Conference abstract (n = 22 participants); not reported if same participants as in Osteras 2012
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information on sequence generation process provided
Allocation concealment (selection bias)	Unclear risk	"The randomisation procedure was concealed from the experimenters and treating physiotherapist". There was no information on how the allocation was concealed.
Blinding of participants and personnel (performance bias) All outcomes	High risk	The interventionists were blinded to the group assignment; however, participants were unable to be blinded due to the nature of the intervention (surgery versus physiotherapy).
Blinding of outcome assessor Self‐reported outcomes	High risk	Participants were not blinded and there is risk of bias in the measurement of pain, other symptoms, activities of daily living, functioning in sport and recreation, knee‐related quality of life, depression and anxiety.
Blinding of outcome assessor Assessor‐reported outcome (knee replacement)	High risk	As the outcome assessor was not blinded to the intervention group assignment, there is risk of bias in the measurement of the quadriceps muscle strength tests.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Different numbers of participants were included in two reports (n = 17 versus n = 22). These are likely to be from a single study (trial registration not reported).
Selective reporting (reporting bias)	Unclear risk	Trial registration not done. While outcomes described in methods were reported in the results of the main publication, there is a discrepancy in participant numbers across two reports so the risk of bias is unclear.
Other bias	Unclear risk	Unclear if there was an unplanned interim analysis performed