Incidence and prognostic factors of knee extension deficits following anterior cruciate ligament reconstruction: A systematic review and meta-analysis of randomised controlled trials

Abstract

Background and aimsKnee extension deficits complicate recovery from ACL injury and reconstruction, however the incidence of knee extension loss is not well defined. The aim of this review was to identify the incidence of loss of extension (LOE) following ACL rupture and reconstruction, explore the definitions of knee extension deficits reported and identify prognostic factors affecting LOE incidence.Methods and analysisA systematic search was conducted in Medline, Cochrane Library and PEDro for studies in publication up to September 2019, with no restrictions on publication year. References were screened and assessed for inclusion using predetermined eligibility criteria. Randomised controlled trials (RCTs) that quantified knee angle, loss of extension or incidence of extension deficit were included for quality assessment and data extraction. Statistical summaries were generated and meta-analyses performed in two parts to examine: (i) the probability of a datapoint being zero incidence compared to a non-zero incidence, and (ii) the relationship between the predictors and non-zero LOE incidence.ResultsA sample of 8594 papers were retrieved using the search criteria, with 48 studies meeting eligibility criteria. Pooled results from 4065 participants were included for analysis, with 3965 participants who had undergone ACLR. The proportion of included studies judged at an overall low risk of bias was small (6%). The analysis revealed median LOE incidence of 15.9% (IQR 1.4 - 46.5) at a median follow up from treatment of 4.9 months (IQR 1.9 - 24). Median LOE incidence was 23 % (IQR 8.4 - 50.0) for the subset of studies reporting up to 12 months of follow up. The observed group and study were the most important predictors for whether a datapoint reported an incidence of extension deficit. Time to follow up (P < 0.001) and graft type (P = 0.02) were found to have a significant influence on non-zero LOE incidence (%).ConclusionsThis review examined the definitions for the measurement and interpretation of postoperative knee extension, and established the trajectory of knee extension deficit after ACL injury and reconstruction. While factors associated with loss of extension were identified, the trajectory of knee extension deficits were difficult to infer due to discrepancies in measurement techniques and patient variation. Clinicians should expect up to 1 in 3 patients to present postoperatively with loss of extension of at least 3 degrees, which may partially resolve over time. Future work should focus on the development of a standardised framework for postoperative measurement and reporting of LOE.

The effect of short-graft preparation with tape suspension and screw fixation on loss of knee extension following anterior cruciate ligament reconstruction: A retrospective cross-sectional analysis of public hospital cases from 2015 - 2017

“…Non-inferiority was declared if the upper limit of the one-sided 97.5% confidence interval for the marginal estimate of LOE Incidence in the SGTS group did not exceed a relative difference of 30% from the baseline incidence of the non-SGTS group (risk-ratio 1.3), equivalent to a one-sided test with an alpha of 0.025 [28]. The non-inferiority margin was derived from a related systematic review [10] which identified a median baseline incidence of LOE 0.16 at a median of 4.9 months post ACLR. A 10% absolute increase in patients presenting with LOE given the new technique above the rate seen with the existing techniques was deemed clinically acceptable.…”

Imageless navigation system (Naviswiss) provides accurate component position in total hip arthroplasty with lateral decubitus position for end-stage hip osteoarthritis: A prospective cohort study with CT-validation

“…A trial protocol was developed to assess the validity of this new and unique hip navigation system in measuring acetabular cup inclination, acetabular cup version, femoral offset and leg length discrepancy (Ektas, Scholes, Harrison-Brown, et al, 2020). This study reports the accuracy of the device by comparing intraoperative component positioning to postoperative CT measurements, specifically in patients undergoing THA using an anterolateral approach in the lateral decubitus position.…”