Table 1

Baseline characteristics of participants allocated to exercise therapy or arthroscopic partial meniscectomy. Values are means (standard deviations) unless stated otherwise

CharacteristicsExercise groupMeniscectomy group
Demographics:n=70n=70
 No (%) men43 (61)43 (61)
 No (%) right knee41 (59)41 (59)
 Age (years)50.2 (6.2)48.9 (6.1)
 Body mass index (weight (kg)/(height (m)2))26.4 (4.3)26.0 (3.7)
 No (%) smokers3 (4.2)10 (14.3)
 No (%) use analgesics daily3 (4.2)3 (4.2)
 No (%) primary school education only3 (4.2)2 (2.9)
 No (%) education at university level37 (53)36 (51)
Severity of radiographic knee osteoarthritis*:n=70n=70
 Grade 049 (70)51 (73)
 Grade 118 (26)16 (23)
 Grade 22 (3)3 (4)
 Grade 31 (1)0
Magnetic resonance imaging†: n=69n=70
 Meniscal degeneration‡
  No (%) grade 1-26 (9)6 (9)
  No (%) grade 3a-3b63 (91)64 (91)
 Meniscal extrusion§
  No (%) no extrusion24 (35)35 (50)
  No (%) extrusion45 (65)35 (50)
Pain:n=70n=69
 Duration (months)17.3 (21.5)12.0 (15.7)
Knee function:n=67n=63
 Visual analogue scale (0-100, worse to best)57.9 (21.5)63.8 (18.9)
KOOS scores (0-100, worst to best):n=70n=70
 KOOS454.3 (18.2)59.6 (13.8)
 Pain63.4 (20.8)67.6 (14.9)
 Symptoms69.8 (16.7)77.4 (14.6)
 Activities of daily living75.0 (21.5)79.6 (16.1)
 Function in sport and recreation44.0 (25.8)47.8 (23.4)
 Knee related quality of life40.0 (17.5)45.6 (15.5)
SF-36 points (0-100, worst to best):n=70n=70
 Physical component summary45.4 (8.4)47.4 (6.1)
 Mental component summary55.0 (9.2)56.0 (6.3)
Muscle strength (higher is better):n=70n=70
 Peak torque extension (Nm)157.5 (48.7)163.1 (53.2)
 Total work extension (J)772.9 (245.1)790.8 (254.8)
 Peak torque flexion (Nm)81.9 (27.2)88.5 (25.7)
 Total work flexion (J)448.3 (187.8)492.9 (158.7)
Performance tests:n=69n=69
 One leg hop test (cm) (higher is better)76.6 (32.8)83.2 (35.5)
 6 m timed hop test (sec) (lower is better)3.1 (1.7)2.7 (1.2)
 Knee bends 30 sec test (No) (higher is better)28.2 (10.6)¶29.3 (10.6)

KOOS=knee injury and osteoarthritis outcome score; SF-36=36 item short form; Nm=Newtonmetre; J=Joule.

*Kellgren-Lawrence classification.

†Although inclusion was based on clinical readings of baseline magnetic resonance images by several radiologists and orthopaedic surgeons, the data presented here originate from post hoc reading by one radiologist blinded to group allocation and study outcome.

‡Graded according to Crues et al.19

§Evaluated on coronal sequence images, with largest tibial spine volume, defined as meniscal subluxation crossing a vertical line on the medial margin of tibia without osteophytes.

¶n=70 participants.