A rticular cartilage injuries are relatively common in the knee and pose a significant problem due to the poor healing potential and long-term disability associated with these lesions. 7,31 In 2 large-scale studies of more than 25 000 knee arthroscopies, 60% of the operated knees demonstrated articular cartilage lesions. 11,74 Approximately 5% to 27% of patients younger than 45 years of age have articular cartilage lesions identified at arthroscopy, 3,11,31,74 and active individuals may be at even higher risk for articular cartilage injury than the general population. 22 In the short term, these lesions may lead to a loss of function and a significant decline in activity participation. 22,25 Although the T T STUDY DESIGN: Systematic literature review.
T T OBJECTIVE:To systematically review the literature relative to muscle performance, knee joint biomechanics, and performance-based functional outcomes following articular cartilage repair and restoration surgical procedures in the knee.
T T BACKGROUND:Articular cartilage injuries are associated with functional limitations, poor quality of life, and the potential for long-term disability. This review systematically evaluates evidence related to muscle performance, joint biomechanics, and performance-based functional outcomes following articular cartilage procedures, and discusses their implications for rehabilitation.
T T METHODS:The online databases of PubMed (MEDLINE), CINAHL, SPORTDiscus, and Scopus were searched (inception to September 2013). Studies pertaining to muscle performance, knee joint biomechanics, and performance-based measures of function following articular cartilage procedure in the knee were included.
T T RESULTS:Sixteen articles met the specified inclusion criteria. Seven studies evaluated muscle performance, all showing persistent deficits in quadriceps femoris muscle strength for up to 7 years postprocedure. Quadriceps femoris strength deficits of greater than 20% were noted in 33% and 26% of individuals at 1 and 2 years following microfracture and autologous chondrocyte implantation (ACI), respectively. Two studies evaluated knee mechanics post-ACI, showing persistent deficits in knee kinematics and kinetics for up to 12 months postprocedure compared to uninjured individuals. Seven studies showed improved functional capacity (6-minute walk test) over time, and 3 studies showed persistent performance deficits during higher-level activities (single-leg hop test) for up to 6 years postprocedure. Five studies comparing weight-bearing protocols (accelerated versus traditional/current practice) following ACI found few differences between the groups in function and gait mechanics; however, persistent gait alterations were observed in both groups compared to uninjured individuals.
T T CONCLUSION:Significant quadriceps femoris strength deficits, gait deviations, and functional deficits persist for 5 to 7 years following ACI and microfracture surgical procedures. Future research regarding rehabilitation interventions to help mitigate these deficits is...