Persistent knee extension deficits are common after anterior cruciate ligament reconstruction: a systematic review and meta-analysis of randomised controlled trials

Abstract

PurposeKnee 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. MethodsA systematic search was conducted in Medline, Cochrane Library and PEDro for studies in publication up to November 2021, 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 nonzero incidence and (ii) the relationship between the predictors and nonzero LOE incidence. ResultsA sample of 15,494 studies were retrieved using the search criteria, with 53 studies meeting eligibility criteria. The pooled results from 4991 participants were included for analysis, with 4891 participants who had undergone ACLR. The proportion of included studies judged at an overall low risk of bias was small (7.8%). 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 nonzero LOE incidence (%). Covariate adjusted estimates of average LOE indicated 1 in 3 patients presenting with LOE at 12 month follow‐up, reducing to 1 in 4 at 2 years. 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 exact trajectory of knee extension deficits was difficult to infer due to discrepancies in measurement techniques and patient variation. On average, 1 in 3 patients may present with loss of extension of at least 3 degrees at 12‐month follow‐up, decreasing to 1 in 4 at 2 years. These results may be used by clinicians as an upper threshold for acceptable complication rates following ACLR. Future work should focus on LOE as a clinically relevant complication of ACL injury and treatment with appropriate attention to standardisation of definitions, measurements and better understanding of natural history. PROSPERO registration numberCRD42018092295. Level of evidenceLevel I

Inclinometers and Apps Are Better than Goniometers, Measuring Knee Extension Range of Motion in Anterior Cruciate Ligament Patients: Reliability and Minimal Detectable Change for the Three Devices

“…Prior to the pilot study two training and familiarization sessions of 2 hours each were performed by the 2 testers. This pilot investigation showed an ICC (2,1) value of approximately 0.85, 0.90, and 0.90 for the universal goniometer, inclinometer, and smartphone app respectively. The subsequent a priori power analysis (testing the null hypothesis H 0 : p=0.8 ICC versus H 1 : p>0.8 ICC) suggested a minimum of 50 participants were required to have an observed power of 80%, (α=0.05) with 2 measurements per participant 21 .…”

“…Knee range of motion (ROM) is a common clinical measurement used to monitor the progress of patients after an anterior cruciate ligament (ACL) injury as 1 out of 3 patients will experience loss of knee extension ROM at 12-month follow-up after this surgery 1 . This deficit could be attributed to multiple of reasons including, but not limited to, inflammation and swelling, surgical problems (e.g.…”

Postoperative quadriceps weakness and male sex are risk factors for patellofemoral articular cartilage lesions after anatomical anterior cruciate ligament reconstruction

“…Generally, PF OA is correlated with knee extension deficit [ 5 ]. Knee extension deficit early after ACL reconstruction or at the final follow-up was associated with OA changes [ 13 , 24 ]. However, the present study revealed no significant correlation between preoperative and postoperative extension deficit and new PF cartilage lesion.…”

The Effects of Corticosteroid Administration and Treadmill Exercise on Marrow Adipose Tissue and Trabecular Bone after Anterior Cruciate Ligament Reconstruction in Rats

“…Surgical reconstruction is the primary treatment for ACL injury, restoring knee stability [ 7 ]. However, various side effects, including pain and joint contracture, which are triggered by inflammation, are observed after ACL reconstruction surgery [ 11 , 12 , 18 , 29 ]. Steroidal anti-inflammatory drugs (corticosteroids) have been used short-term to alleviate pain and joint contracture after ACL reconstruction, and their effectiveness has been reported [ 18 , 28 ].…”