The Hip: Preservation, Replacement and Revision

Microfracture Technique for Knee Injuries

- Discussion: - see management of osteochondral injuries and cartilage menu
       - microfracture is a knee surgery that involves the creation of multiple perforations (microfractures in the subchondral bone) in areas that are cartilage deficient.
       - theory behind this type of technique is that simple abrasion arthroplasty may not allow a sustained reparative response (no more than 2 weeks of healing) where as the micro-fracture technique (which penetrates the subchondral bone) allows a better and more sustained healing process.
       - microfracture is often chosen as the benchmark for which to compare to other cartilage repair procedures.
       - much of the healing will be manifested as fibrocartilage
       - ref: Cartilage repair approach and treatment characteristics across the knee joint: a European survey 
- Surgical Technique: 
        - an arthroscopic awl is used to make multiple perforations (microfractures) in the subchondral bone; 
        - theory behind this type of technique is that simple abrasion arthroplasty may not allow a sustained reparative response (no more than 2 weeks of healing) where as the micro-fracture technique (which penetrates the subchondral bone) allows a better and more sustained healing process; 
        - removal of the calcified cartilage layer:
                 - curet is then used to remove the calcified cartilage layer from the base of the lesion; (see articular cartilage)
                 - calcified cartilage layer: (see articular cartilage defects)
                            - thin layer between the deep zone of the cartilage and the subchondral bone
                            - can increase in thickness with age
                            - removal of the calcified cartilage may improve the bonding of the repair tissue to the subchondral bone after microfracture;
                            - references:
                                     - Arthroscopic subchondral bone plate microfracture technique augments healing of large chondral defects in the radial carpal bone and medial femoral condyle of horses.
                                     - Effects of calcified cartilage on healing of chondral defects treated with microfracture in horses.
        - bone perforations:
                 - bone is perforated every 4-5 mm to a depth of 3-4 mm (some evidence for 6 mm depth)
                 - classic teaching is to use an awl, but recent evidence supports deep drilling;
                 - references:
                          - Drilling and microfracture lead to different bone structure and necrosis during bone-marrow stimulation for cartilage repair.
                          - Complete vs. Central Hole Placement to Improve Percentage Fill after Microfracture.  
                          - Depth of subchondral perforation influences the outcome of bone marrow stimulation cartilage repair
                          - Characterization of Subchondral Bone Repair for Marrow-Stimulated Chondral Defects and Its Relationship to Articular Cartilage Resurfacing

        - adjunctive measures:
                 - Concentrated Bone Marrow Aspirate Improves Full-Thickness Cartilage Repair Compared with Microfracture in the Equine Model
        - post op care and rehab:
                 - patients are kept on CPM 8 hours per day and non wt bearing for 6-8 weeks, although this too has been questioned;
                          - Arthroscopic microfracture of chondral defects of the knee: a comparison of two postoperative treatments.
                          - Rehabilitation following microfracture for chondral injury in the knee.
        - references:
                          - The surgical treatment of knee injuries in skiers.   
                          - Treatment of articular cartilage defects in athletes: An analysis of functional outcome and lesion appearance.  
                          - Early events in cartilage repair after subchondral bone microfracture.
                          - Chondral Defect Repair After the Microfracture Procedure.  A Nonhuman Primate Model. 
                          - The microfracture technique for the treatment of articular cartilage lesions in the knee. A prospective cohort study. 
                          - A Randomized Trial Comparing Autologous Chondrocyte Implantation with Microfracture. Findings at Five Years
                          - Healing of canine articular cartilage defects treated with microfracture, a type-II collagen matrix, or cultured autologous chondrocytes.
                          - Results after microfracture of full-thickness chondral defects in different compartments in the knee

- Role Microfracture in Degenerative Arthritis in the Knee (see osteoarthritis and arthroscopy of the degenerative knee)
        - references:
                  - The Treatment of Articular Cartilage. Defects Using the Microfracture Technique 
                  - Orthopaedic Surgeon Performs Innovative Microfracture Procedure On Arthritic Knees Avoiding Knee Replacement Surgery 
                  - Microfracture Surgery Recovery: Slow Down for Best Results
                  - Steadman Hawkins Research Foundation 
                  - Microfracture Surgery for Cartilage Regeneration in Degenerative Arthritis of the Knee. 
                  - Knee Microfracture Surgery: New York Times Health Guide
                  - Knee microfracture surgery
                  - What is New in the Treatment of Focal Chondral Injuries of the Knee?
                  - Microfracture success depends not only on the operation but rehabilitation as well
                  - Treatment of Osteoarthritis of the Knee with Microfracture and Rehabilitation
                  - Cartilage healing after microfracture in osteoarthritic knees
                  - Patient satisfaction and outcome after microfracture of the degenerative knee.
                  - Articular cartilage regeneration with microfracture and hyaluronic acid
                  - [Early results of medial opening wedge osteotomy in varus gonarthrosis]
                  - Benefit of microfracture, implant for cartilage defects seen in early studies

Enhanced Microfracture with Autologous Hamstring Resurfacing Arthroplasty

Articular cartilage regeneration with microfracture and hyaluronic acid

Microfracture techniques in the treatment of osteochondral injuries.

The Use of Continuous Passive Motion Following Knee Cartilage Defect Surgery: A Systematic Review

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, January 11, 2013 2:48 pm