Anterior cruciate ligament injury : factors affecting selection of treatment and intermediate outcome

Aim: The aim of this comprehensive study was to evaluate whether anterior cruciate ligament (ACL) injured patients choosing non-operative treatment differ from those choosing ACL reconstruction regarding age, gender, personality, activity level prior to injury, anterior-posterior knee joint laxity and outcome as evaluated using the Knee Osteoarthritis Outcome Score (KOOS) five weeks following the ACL injury. Furthermore the reasons for choosing reconstruction were studied to determine whether patients who choose reconstructive surgery early do so for the same reasons as patients who choose reconstruction later. The aim was also to identify factors, such as gender, personality and subsequent knee trauma, affecting the outcome six years after the injury as well as to study the effects of a functional knee brace on ACL-deficient patients early in the rehabilitation process.

Material and methods: The subjects participating in this comprehensive study were between 18 and 50 years and had sustained a unilateral ACL tear within the past five weeks. At the time of inclusion the subjects completed the Swedish universities Scales of Personality (SSP). The subjects were continuously evaluated with the KOOS, the Cincinnati knee score, the Tegner score, the Visual Analogue Scale (VAS) 0-10, the KT-1 000 arthrometer and the Biodex System 3. Subjects who chose to undergo ACL reconstruction were asked to report the reasons relevant for their decision. At the six years follow-up the subjects completed the KOOS, the Tegner score and a questionnaire to determine ACL reconstruction and subsequent knee trauma. Medical records were reviewed.

Results: The subjects who chose non-operative treatment had a lower pre-injury activity level and were older than those who chose to undergo ACL reconstruction. Further, they displayed less irritability and less aggression at the time of entry into the study than the subjects who later chose reconstructive surgery. Neither outcome, as evaluated using the KOOS within five weeks after the ACL injury, sagital knee joint laxity nor gender did correlate with treatment selection.

The decision to undergo early reconstruction was in 15/20 (75 %) subjects based on concerns about future knee problems and not on their experience of knee dysfunction. Fourteen of the sixteen (88 %) subjects who chose delayed reconstructive surgery, based their decision on their experience of knee dysfunction.

At the six years follow-up the subjects who had sustained additional knee trauma after their ACL injury had a significantly worse outcome according to the KOOS than the other subjects. There were no significant differences in the KOOS between the subjects who had undergone ACL reconstruction and those who were treated non-operatively. Furthermore neither age, gender, pre-injury activity level, personality nor history of meniscus and/or articular cartilage injury seemed to have an effect on the outcome at follow-up.

When using the brace the subjects in the brace group reported significantly less knee instability as measured with the VAS than the control group. There was no difference between the groups with respect to pain, discomfort, ability to walk on even ground, stair climbing or ability to perform preinjury physical activities as measured with the VAS. Furthermore, bracing had no effect on any of the variables in the KOOS or the Cincinnati knee score and no effect on quadriceps or hamstring muscle peak torque. However, a vast majority of the subjects in the brace group noted that they experienced improved stability and a positive effect on rehabilitation when using the brace.

List of scientific papers

I. Swirtun LR, Eriksson K, Renstrom P (2006). Who chooses anterior cruciate ligament reconstruction and why? A 2-year prospective study. Scand J Med Sci Sports. 16(6): 441-6.
https://pubmed.ncbi.nlm.nih.gov/17121647

II. Swirtun LR, Edman G, Renström P (2006). Patient´s personality affects the choice of treatment after ACL injury - a prospective study. [Submitted]

III. Swirtun LR, Renström P (2006). Factors affecting outcome after ACL injury - a prospective study with six years follow-up. [Submitted]

IV. Swirtun LR, Jansson A, Renstrom P (2005). The effects of a functional knee brace during early treatment of patients with a nonoperated acute anterior cruciate ligament tear: a prospective randomized study. Clin J Sport Med. 15(5): 299-304.
https://pubmed.ncbi.nlm.nih.gov/16162987