8.7 Surgical repair options

8.7.1 Microfracture - 2 years

Bedi et al. J Bone Jt Surg Am 2010. @Geeslin2016Cartilage

  • Microfracture
    • Results in fibrocartilage repair

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.2 Microfracture - 2 years

The Surgical Procedure: Microfracture

“The microfracture procedure is done arthroscopically. The surgeon visually assesses the defect and performs the procedure using special instruments that are inserted through three small incisions on the knee. After assessing the cartilage damage, any unstable cartilage is removed from the exposed bone. The surrounding rim of remaining articular cartilage is also checked for loose or marginally attached cartilage. This loose cartilage is also removed so that there is a stable edge of cartilage surrounding the defect. The process of thoroughly cleaning and preparing the defect is essential for optimum results.”

“Multiple holes, or microfractures, are then made in the exposed bone about 3 to 4mm apart. Bone marrow cells and blood from the holes combine to form a "super clot" that completely covers the damaged area. This marrow-rich clot is the basis for the new tissue formation. The microfracture technique produces a rough bone surface that the clot adheres to more easily. This clot eventually matures into firm repair tissue that becomes smooth and durable. Since this maturing process is gradual, it usually takes two to six months after the procedure for the patient to experience improvement in the pain and function of the knee. Improvement is likely to continue for about 2 to 3 years.”

Source (last access 2020)

8.7.3 Microfracture FAQ

  • “Is the new tissue that forms after the microfracture identical to the original articular cartilage?”
    • “No, the new tissue is a”hybrid" of articular-like cartilage plus fibrocartilage. Experience shows that this hybrid repair tissue is durable and functions similarly to articular cartilage."

Source (last access 2020)

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.4 Autologous Osteochondral Transplantation

Bedi et al. J Bone Jt Surg Am 2010. Source

  • Harvest of viable hyaline cartilage from non- weight bearing surface, transfer to defect

8.7.5 Fresh frozen allograph

@Geeslin2016Cartilage

  • Fresh frozen allograph (cadaver, with viable chondrocytes)
  • MRI demonstrates incorporation, isointense cartilage signal

Bedi et al. J Bone Jt Surg Am 2010.

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.6 Evidence based medicine

Grades of Recommendation for Cartilage Repair Procedures

*A = good evidence (Level-l studies with consistent findings) for or against recommending intervention, B = fair evidence (Level II or III studies with consistent findings) for or against recommending intervention, C = poor-quality evidence (Level-IV or V studies with consistent findings) for or against recommending intervention, and 1 = there is insufficient or conflicting evidence not allowing a recommendation for or against intervention.

Bedi et al. J Bone Jt Surg Am 2010.

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.7 Future directions in cartilage repair

  • Chondral scaffolds
  • Osteochondral scaffolds
  • Platelet rich plasma, mix of growth factors
  • Mesenchymal stem cells
  • Isolated growth factors
  • Quantitative MRI

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.8 Chondral scaffolds

@Geeslin2016Cartilage

  • Chondral scaffolds

    • E.g. juvenile, adult
    • Fibrin glue

  • Autologous chondrocyte implantation

    • Ex vivo expansion
    • Implantation under periosteal patch or other matrix

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.9 Scaffold methods

  • Biocartilage (Arthrex) (Hirahara Sports Med Arthrosc 2015)

“…dehydrated allograft cartilage ECM scaffold and can stimulate autologous cellular interactions. The ECM is made up of type II collagen, proteoglycans, and cartilaginous growth factors, which are components of native cartilage”

  • DeNovo (Zimmer) (Farr AJSM 2014; Farr Cartilage 2011)

“…consists of allograft articular cartilage from donors younger than 13 years old that has been cut into approximately 1-mm cubes. It is applied to cartilage lesions in a monolayer and held in place with the use of fibrin sealant” (particulated juvenile allograft)

  • Neocart (Histogenics) (DeBerardino Sports Med Arthrosc 2015)

“3-dimensional type-I collagen scaffold seeded with autologous chondrocytes”

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.10 Osteochondral scaffolds

@Geeslin2016Cartilage

[ ( slide credit: @Geeslin2016Cartilage ) ]

8.7.11 Biologics

  • Platelet rich plasma, mix of growth factors
  • Mesenchymal stem cells
  • Isolated growth factors

@Geeslin2016Cartilage

[ ( slide credit: @Geeslin2016Cartilage ) ]