PROSPERO systematic review protocol registration number CRD4201400882 2.

Objective. To determine the prevalence and factors associated with knee osteoarthritis (OA) defined by magnetic resonance imaging (MRI) and specific OA features on MRI 1 year after anterior cruciate ligament reconstruction (ACLR).Methods. Conclusion. OA 1 year following ACLR was more common than previously recognized, while being absent in uninjured control knees. The patellofemoral compartment seems to be at particular risk for early OA after ACLR, especially in men. The association with meniscectomy and BMI demonstrates the construct validity of MRI criteria.

Patellofemoral joint (PFJ) osteoarthritis (OA) is a prevalent disease capable of being a potent source of knee symptoms. Although anterior cruciate ligament (ACL) injury and reconstruction (ACLR) are well-established risk factors for the development of tibiofemoral joint OA, PFJ OA after ACL reconstruction has gone largely unrecognised. This is despite the high prevalence of anterior knee pain after ACLR, which can reduce the capacity for physical activity and quality of life. The susceptibility of the PFJ to degenerative change after ACLR may have implications for current rehabilitation strategies. This review summarises the evidence describing the prevalence of PFJ OA after ACLR and examines why this compartment may be at increased risk of early onset OA after ACLR. Strategies that address the modifiable factors for risk of PFJ OA may aid in alleviating joint loads and symptoms for people after ACLR.

Summary estimates of MRI osteoarthritis feature prevalence among asymptomatic uninjured knees were 4%-14% in adults aged <40 years to 19%-43% in adults ≥40 years. These imaging findings should be interpreted in the context of clinical presentations and considered in clinical decision-making.

Objectives To evaluate the compartmental distribution of knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR), to determine if patellofemoral or tibiofemoral OA is more strongly associated with knee symptoms and function, and to evaluate the contribution of associated injuries and surgical delay to the development of OA. Methods This cross-sectional study recruited 70 participants who underwent hamstring tendon (HT) ACLR 5-10 years previously. Radiographic OA was assessed according to the Osteoarthritis Research Society International (OARSI) criteria. Knee symptoms were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Anterior Knee Pain Scale (AKPS), while function was assessed with three lower limb tasks (hop-for-distance, one-leg rise and side-hop). Multivariate and binary logistic regression analyses were performed to assess the relationship between OA and symptomatic/functional outcomes and associated injuries/ surgical delay, respectively. Results Radiographic OA was observed in the patellofemoral (47%) and tibiofemoral joints (31%). Pain, symptoms and quality of life on the KOOS and the AKPS were associated with severity of patellofemoral OA (standardised regression coefficient (β)=−0.3 to −0.5, p=0.001-0.042), whereas only the KOOS-pain subscale was associated with tibiofemoral OA (β=−0.3, p=0.037). For each functional task, greater patellofemoral OA severity was associated with worse performance, independent of tibiofemoral OA severity (β=−0.3 to −0.4, p=0.001-0.026). Medial meniscal and patellofemoral chondral lesions at surgery were associated with tibiofemoral and patellofemoral OA development at follow-up, respectively, while a longer surgery delay was associated with patellofemoral OA. Conclusions Patellofemoral OA is common following HT ACLR and is associated with worse knee-related symptoms, including anterior knee pain, and decreased functional performance.

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Meta-analysis showed that lower knee extensor strength is associated with an increased risk of symptomatic and functional deterioration, but not tibiofemoral JSN. The risk of patellofemoral deterioration in the presence of knee extensor strength deficits is inconclusive.

logistic regressions to determine if an incident knee injury was associated with the outcome of rapid KOA or non-rapid KOA after adjusting for age, sex, body mass index (BMI), presence of static knee malalignment, and systolic blood pressure. We also conducted a secondary analysis by replicating these analyses with 71 additional individuals who had rapid KOA but their contralateral knee had prevalent OA at baseline. This permitted us to test our hypothesis in a larger sample size. Results: Individuals with rapid KOA (n ¼ 54) tended to be older and have greater baseline BMI and systolic blood pressure (Table). Individuals with rapid KOA had a higher incidence of knee injuries, particularly within the 12 months prior to presenting with KL Grade ¼ 3 or 4. An incident knee injury between baseline and meeting our study definition was associated with rapid KOA (odds ratio [OR] ¼ 3.14, 95% confidence interval [CI] ¼ 1.61 to 6.13) but not non-rapid KOA (OR ¼ 1.08, 95% CI ¼ 0.65 to 1.81) after adjusting for sex, baseline age, body mass index, presence of static knee malalignment, and systolic blood pressure. Furthermore, an incident knee injury within the year prior to meeting the study definition was associated with rapid KOA (OR ¼ 8.46, 95% CI ¼ 3.93 to 18.21) and non-rapid KOA (OR ¼ 3.12, 95% CI ¼ 1.65 to 5.89) even after adjustments. Our secondary analyses supported our primary findings. Conclusions: Recent knee injuries are associated with rapid KOA. Most concerning is that certain injuries may initiate a rapid cascade towards joint failure in less than one year. It will be important to determine which injuries increase the risk of non-rapid and rapid KOA.