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. 2016 Apr 3;2016(4):CD011166. doi: 10.1002/14651858.CD011166.pub2

Frobell 2010b.

Methods Randomised controlled trial
Number of centres: 2
Dates of enrolment: February 2002 to June 2006
Follow‐up: 2 and 5 years
Participants 141 participants were randomised; 121 were included in the main analysis.
Assigned: 69/72 (ACL reconstruction/conservative treatment)
Assessed: 62/59 (ACL reconstruction/conservative treatment)
Inclusion criteria:

  • Young adults aged 18 to 35 years presenting to the emergency department with recent knee trauma;

  • Rotational trauma to a previously uninjured knee within the preceding 4 weeks;

  • ACL insufficiency as determined by clinical examination;

  • A score of 5 to 9 on the Tegner Activity Scale‐ (TAS) 12 before the injury (scores range from 1 to 10, with a score of 5 indicating participation in recreational sports, and a score of 9 indicating participation in competitive sports on a nonprofessional level).


Exclusion criteria:

  • Earlier major knee injury to index knee;

  • Previous knee surgery (other than diagnostic arthroscopy);

  • Associated PCL injury or MCL injury Grade III;

  • Concomitant severe injury to contra‐lateral knee;

  • Injury to lateral/posterolateral ligament complex;

  • Pregnancy;

  • History of deep vein thrombosis (DVT);

  • Claustrophobia;

  • General systemic disease affecting physical function;

  • Systemic medication/abuse of steroids.


Post‐randomisation exclusion criteria:
If one of the following associated injuries to the index knee were visualised on MRI, arthroscopy or both:

  • A total collateral ligament rupture;

  • Full‐thickness cartilage lesion;

  • Bi‐compartmental extensive meniscus resections or unstable longitudinal meniscus tear that required repair and specified postoperative treatment (i.e. bracing and limited ROM).
Interventions Group 1: ACL reconstruction followed by structured rehabilitation. Early ACL reconstruction was defined as surgery performed within 10 weeks after the injury.
Group 2: Conservative treatment comprising structured rehabilitation alone. Built into the study design was a formal option for subsequent (delayed) ACL reconstruction in the conservative treatment group, if chosen by the participant reporting instability and if pre‐specified criteria were met.
Outcomes Primary:

  • Subjective knee scores. "The primary outcome was the change from baseline to 2 years in the average score on four subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS) — pain, symptoms, function in sports and recreation, and knee‐related quality of life (KOOS‐4; range of scores, 0 [worst] to 100 [best])" (Frobell 2010b). Also measured as final mean KOOS‐4 score at 5 years;

  • Adverse events (classified as serious and non‐serious);

  • Treatment failure (re‐operation (for surgery) or subsequent operation (for conservative treatment)).


Secondary:

  • General health‐related quality of life, measured using the SF‐36 physical and mental components;

  • Return to activity or level of sport participation, measured using the Tegner Activity Scale;

  • Knee stability, measured using a knee ligament testing device KT 100, Lachman test and pivot shift test.
Notes The study was supported by grants from the Swedish Research Council and the Medical Faculty of Lund University, the Skåne Regional Council, the Thelma Zoegas Fund, the Stig and Ragna Gorthon Research Foundation, the Swedish National Center for Research in Sports, and Pfizer Global Research.
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Quote: "..they [patients] were randomly assigned by computer‐generated random numbers in permuted blocks of 20".
Allocation concealment (selection bias) Low risk Quote: "An investigator who was not involved in the randomisation procedure prepared all sequentially numbered, opaque, sealed envelopes containing the assigned interventions to ensure that the sequence was concealed."
Blinding of participants and personnel (performance bias) 
 All outcomes High risk Due to the nature of the interventions, it was impossible to blind the participants or personnel.
Blinding of outcome assessment (detection bias) 
 Subjective knee score High risk Quote: ".. assessments were performed by one or two experienced clinicians, both of whom were aware of the treatment assignments".
Incomplete outcome data (attrition bias) 
 All outcomes Unclear risk Of 20 (14% of 141) post‐randomisation exclusions, 12 were excluded because of MRI findings and 8 because of findings at surgery. There was some imbalance in the losses in the two groups (7/69 = 10% in the surgery group; 13/72 = 18% in the conservative group) and there is some question whether it was appropriate to exclude for findings, usually resulting in extensive meniscal fixation (2 versus 5), at surgery. However, there was clear comparability between the two groups in the baseline characteristics of the 121 kept in the trial.
Selective reporting (reporting bias) Low risk Outcomes pre‐specified in the clinical trial register (ISRCTN 84752559) are reported in the results.
Other bias Low risk No additional potential sources of bias were identified.

ACL: Anterior cruciate ligament
 MCL: Medial collateral ligament
 PCL: Posterior cruciate ligament