Muscle strength and functional performance in patients with anterior cruciate ligament injury treated with training and surgical reconstruction or training only: a two to five-year followup.
OBJECTIVE
To study muscle strength and functional performance in patients with anterior cruciate ligament (ACL) injury with or without surgical reconstruction 2 to 5 years after injury. Good muscle function is important in preventing early-onset osteoarthritis (OA), but the role of reconstructive surgery in restoring muscle function is unclear.


METHODS
Of 121 patients with ACL injury included in a randomized controlled trial on training and surgical reconstruction versus training only (the Knee, Anterior cruciate ligament, NON-surgical versus surgical treatment [KANON] study, ISRCTN: 84752559), 54 (mean age at followup 30 years, range 20-39, 28% women) were assessed a mean +/- SD of 3 +/- 0.9 years after injury with reliable, valid, and responsive test batteries for strength (knee extension, knee flexion, leg press) and hop performance (vertical jump, one-leg hop, side hop). The Limb Symmetry Index (LSI; injured leg divided by uninjured and multiplied by 100) value and absolute values were used for comparisons between groups (analysis of variance). An LSI >or=90% was considered normal.


RESULTS
There were no differences between the surgical and nonsurgical treatment groups in muscle strength or functional performance. Between 44% and 89% of subjects had normal muscle function in the single tests, and between 44% and 56% had normal function in the test batteries.


CONCLUSIONS
The lack of differences between patients treated with training and surgical reconstruction or training only indicates that reconstructive surgery is not a prerequisite for restoring muscle function. Abnormal muscle function, found in approximately one-third or more of the patients, may be a predictor of future knee OA.
Ageberg
Eva
E
Clinical Sciences Lund, Lund University, Lund, Sweden. eva.ageberg@med.lu.se
Thomeé
Roland
R
Neeter
Camille
C
Silbernagel
Karin Grävare
KG
Roos
Ewa M
EM
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D010809:Physical Fitness; D014947:Wounds and Injuries / Q000534:rehabilitation