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ACL reconstruction: No increased risk of adverse outcome with early or delayed surgery

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ACL reconstruction: No increased risk of adverse outcome with early or delayed surgery

Vol: 2| Issue: 4| Number:69| ISSN#: 2564-2537
Study Type:Meta analysis
OE Level Evidence:2
Journal Level of Evidence:N/A

The optimal timing for anterior cruciate ligament reconstruction with respect to the risk of postoperative stiffness

Arthroscopy. 2013 Mar;29(3):556-65. doi: 10.1016/j.arthro.2012.09.005. Epub 2013 Jan 12

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Dr. Chris Servant discusses the optimal timing for anterior cruciate ligament reconstruction with respect to the risk of postoperative stiffness.


Eight studies (4 randomized control trials and 4 cohort studies) were included in this analysis which investigated the impact of early versus late surgery on stiffness outcomes of anterior cruciate ligament (ACL) reconstruction. Adverse outcomes of arthrofibrosis, stiffness, or range of motion deficits were reported for a minimum of one year postoperatively in the included studies. The results of the analysis indicated that surgery characterized as either early or delayed did not increase the risk of adverse stiffness outcomes.

Publication Funding Details +
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None disclosed

Risk of Bias


Reporting Criteria


Fragility Index


Were the search methods used to find evidence (original research) on the primary question or questions stated?

Was the search for evidence reasonably comprehensive?

Were the criteria used for deciding which studies to include in the overview reported?

Was the bias in the selection of studies avoided?

Were the criteria used for assessing the validity of the included studies reported?

Was the validity of all of the studies referred to in the text assessed with use of appropriate criteria (either in selecting the studies for inclusion or in analyzing the studies that were cited)?

Were the methods used to combine the findings of the relevant studies (to reach a conclusion) reported?

Were the findings of the relevant studies combined appropriately relative to the primary question that the overview addresses?

Were the conclusions made by the author or authors supported by the data and or analysis reported in the overview?

How would you rate the scientific quality of this evidence?

Yes = 1

Uncertain = 0.5

Not Relevant = 0

No = 0

The Reporting Criteria Assessment evaluates the transparency with which authors report the methodological and trial characteristics of the trial within the publication. The assessment is divided into five categories which are presented below.




Accessing Data


Analysing Data





Detsky AS, Naylor CD, O'Rourke K, McGeer AJ, L'Abbé KA. J Clin Epidemiol. 1992;45:255-65

The Fragility Index is a tool that aids in the interpretation of significant findings, providing a measure of strength for a result. The Fragility Index represents the number of consecutive events that need to be added to a dichotomous outcome to make the finding no longer significant. A small number represents a weaker finding and a large number represents a stronger finding.

Why was this study needed now?

There has been recent interest in the timing of anterior cruciate ligament (ACL) reconstruction following ACL injury, with some advocating that delayed surgery can lead to reduced prevalence of arthrofibrosis and improved postoperative stiffness. Although there has been evidence to support this claim, research has also been undertaken which has found no difference between the early and delayed surgery. Due to these conflicting findings, a synthesis of existing literature was undertaken to determine if there was a significant relationship between the timing of surgery and postoperative stiffness experienced by patients.

What was the principal research question?

Did delaying ACL reconstruction significantly reduce the incidence of postoperative motion loss and knee stiffness compared to early surgery, measured after a minimum of 12 months postoperatively?

Study Characteristics -
Data Source:
A search was conducted of articles from Ovid Medline In-Process & Other Non-Indexed Citations and Ovid Medline (1948-present), Embase (1980-August 2011), and the Cochrane Library. Bibliographies of identified articles after initial screening process were also searched for additional studies.
Index Terms:
Medline search strategy included terms:,,, anterior cruciate ligament, Reconstructive Surgical Procedures/, and Anterior Cruciate Ligament/. Embase search strategy included terms:,,, anterior cruciate ligament, and anterior cruciate ligament reconstruction/. Cochrane Library search strategy included: "(anterior cruciate ligament) OR (anterior cruciate ligament reconstruction) OR (anterior cruciate ligament surgery) OR (anterior cruciate ligament operation) OR (anterior cruciate ligament repair) in Title, Abstract, or Keywords and (timing) OR (timing of surgery) OR (timing of operation) OR (problems) or (complications) or (arthrofibrosis) OR (postoperative complications) in Title, Abstract or Keywords in Cochrane Central Register of Controlled Trials.
Study Selection:
Articles were selected if they were randomized or nonrandomized studies which compared outcomes of range of motion deficits, arthrofibrosis and stiffness between groups of early and delayed reconstruction following ACL injury. Additionally, studies must have featured an accelerated rehabilitation protocol with immediate full weight bearing. Selection process was undertaken independently by two authors, with uncertainty of inclusion decided by a third, senior author.
Data Extraction:
Data extraction on Microsoft Excel was performed by a single author for data on study design, level of evidence, clinical setting, methodology, demographics, and results.
Data Synthesis:
Calculation of risk ratios and pooling of data (random effects model) was performed using Review Manager Software (RevMan v5.1.6). Heterogeneity was assessed using the I-squared statistic, with 30%-60% representing moderate heterogeneity.

What were the important findings?

  • Search strategy concluded with finding four RCTs (3 Level I evidence and 1 Level II evidence) and four cohort studies (all Level II evidence).
  • The three Level I studies were analyzed for risk of adverse outcomes (reduced range of motion, arthrofibrosis, stiffness, extension deficit) associated with variable cutoff points for early surgery (2, 3, and 10 weeks), and indicated there were no significant differences in outcome in any of the studies (2 weeks: RR 1.38 (95%CI 0.10-20.16); 3 weeks: RR 0.34 (95%CI 0.04-3.14); 10 weeks: RR 3.81 (95%CI 0.44-33.08).
  • Analysis of 7 included studies (1 excluded because it did not report poolable outcomes) indicated there was no significant increase in risk of adverse outcome associated with early or delayed surgery when stratified by different cutoff points for early surgery (1, 2, 3, 10, 12, and 20 weeks).
  • A sensitivity analysis considering individual outcomes of arthrofibrosis incidence, extension deficit >3°, and flexion deficit >3° and stratified for different criteria of early surgery observed no clear overall trend.

What should I remember most?

There was no increased risk of adverse outcome, with respect to arthrofibrosis, stiffness and ROM deficit, observed associated with early surgery compared to delayed surgery following ACL injury.

How will this affect the care of my patients?

The results of this analysis suggest that there is no increased risk of arthrofibrosis or range of motion deficit between early and delayed ACL reconstruction, provided a modern surgical technique and an accelerated postoperative rehabilitation protocol is implemented. The overall strength of this evidence is debatable, however, considering the nonuniformity in classification of "early" surgery (1 to 20 weeks), as well as the inclusion of a considerable amount of Level II evidence (primarily cohort studies). Future research should be guided by establishing definitive criteria for early versus late surgery and outcomes should be investigated in randomized controlled trials before any conclusive statements can be made.

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