Progression of tibiofemoral (TF) and patellofemoral (PF) osteoarthritis (OA) and changes in knee function more than 15 years after anterior cruciate ligament reconstruction (ACLR) are not well understood. To examine the progression of knee OA and changes in symptoms and function in isolated and combined injuries from 15 to 20 years after ACLR. Cohort study; Level of evidence, 2. A total of 210 subjects with ACLR were prospectively followed. At the 15- and 20-year follow-ups, radiographs were obtained and classified by the Kellgren and Lawrence (K-L) grading system. Symptoms and function were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) as well as isokinetic quadriceps and hamstring muscle strength tests. There were 168 subjects (80%) who returned for the 20-year follow-up, with a mean (±SD) age of 45 ± 9 years, mean body mass index of 27 ± 4, and median Tegner activity level of 4 (range, 0-9). The prevalence of radiographic TF and PF OA at the 20-year follow-up was 42% and 21%, respectively. Patients with ACL injuries and other combined injuries had significantly higher prevalence of radiographic TF OA compared with those who had isolated ACL injury (P < .0001). There was a 13% increase in radiographic TF OA (P = .001) and an 8% increase in PF OA (P = .015) from the 15- to the 20-year follow-up. A significant deterioration in knee symptoms and function was observed on the KOOS subscales (P ≤ .01), with the exception of quality of life (P = .14), as well as a decrease in quadriceps muscle strength and hamstring muscle strength (P < .0001). The prevalence of radiographic TF and PF OA was 42% and 21%, respectively. A significantly higher prevalence of TF OA was found for subjects with combined injuries compared with those who had isolated ACL injury. The majority of the subjects were stable radiographically over the 5 years between follow-ups. A statistically significant deterioration in symptoms and function was noted, but the mean changes were of questionable clinical importance.

We like to think that we are successful in the treatment of individuals with anterior cruciate ligament (ACL) injury, but recent literature reveals that only about 60% of these individuals make a full recovery, less than 60% return to sport, and more than 50% develop knee osteoarthritis (OA) by middle age. Both short- and long-term outcomes after ACL injury and reconstruction need attention and action. We need to implement strategies early after ACL injury to prevent the development and progression of posttraumatic OA, rather than “sit and wait” until posttraumatic knee OA has developed. J Orthop Sports Phys Ther 2016;46(9):710–713. doi:10.2519/jospt.2016.0608

Objectives Critically appraise and summarise the measurement properties of knee muscle strength tests after anterior cruciate ligament (ACL) and/or meniscus injury using the COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist. Design Systematic review with meta-analyses. The modified Grading of Recommendations Assessment, Development and Evaluation-guided assessment of evidence quality. Data sources Medline, Embase, CINAHL and SPORTSDiscus searched from inception to 5 May 2022. Eligibility criteria for selecting studies Studies evaluating knee extensor or flexor strength test reliability, measurement error, validity, responsiveness or interpretability in individuals with ACL and/or meniscus injuries with a mean injury age of ≤30 years. Results Thirty-six studies were included involving 31 different muscle strength tests (mode and equipment) in individuals following an ACL injury and/or an isolated meniscus injury. Strength tests were assessed for reliability (n=8), measurement error (n=7), construct validity (n=27) and criterion validity (n=7). Isokinetic concentric extensor and flexor strength tests were the best rated with sufficient intrarater reliability (very low evidence quality) and construct validity (moderate evidence quality). Isotonic extensor and flexor strength tests showed sufficient criterion validity, while isometric extensor strength tests had insufficient construct and criterion validity (high evidence quality). Conclusion Knee extensor and flexor strength tests of individuals with ACL and/or meniscus injury lack evidence supporting their measurement properties. There is an urgent need for high-quality studies on these measurement properties. Until then, isokinetic concentric strength tests are most recommended, with isotonic strength tests a good alternative.