title: Functional outcomes after surgical management of articular cartilage lesions in the knee: a systematic literature review to guide postoperative rehabilitation.
abstract: METHODS
  Systematic literature review.
  
  
  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.
  
  
  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.
  
  
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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 warranted. Level of Evidence Prognosis, level 2a-.
authors: Division of Physical Therapy, School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH.
authors: Laura C
authors: LC
authors: Schmitt
authors: Carmen E
authors: CE
authors: Quatman
authors: Mark V
authors: MV
authors: Paterno
authors: Thomas M
authors: TM
authors: Best
authors: David C
authors: DC
authors: Flanigan
mesh_terms: D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery*; D005684:Gait / Q000502:physiology; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D053580:Muscle Strength / Q000502:physiology; D020127:Recovery of Function; D016474:Weight-Bearing / Q000502:physiology
keywords: autologous chondrocyte implantation; gait; microfracture; strength