Arthroscopic lavage and debridement A "cleaning up" procedure Is not considered an articular cartilage repair procedure but rather a palliative treatment Reduce pain, mechanical restriction and inflammation. Removes degenerative cartilage flaps and fibrous tissue. The main target group are patients Very small defects of the articular cartilage. Significant ‘painless’ defects, diagnosed incidentally
Marrow stimulation – Microfracture Dr Richard Steadman, 1980s The subchondral bone is perforated to generate a ‘blood clot’ within the defect ( drilling, microfracture, abrasion) Blood clot contains pluripotent stem cells The blood clot converts to ‘fibrous tissue’ about 8 weeks Over 4 months fibrous tissue becomes ‘fibrocartilage’.
Does these work? Brian Cole et al 839 patients (1998-2007) 60% improved in 4-6 months 25% no improvement 15% improved immediately!!! 30% revised at 1yr Best outcome in first 2yrs Mixed results in atheletes 75-80% good results with proper pt selection and proper rehab Poor outcomes Poor shear resistance of fibrocartilage Elderly, obese, >2.5cm defects
Make them work? Achieve vertical walls healthy cartilage at the rim better shoulder the load and makes the lesion less clinically relevant Remove calcified cartilage allows better fit and fill by fibrocartilage which is more tenacious and histologically superior. Holes 2-3 mm apart Correct malalignment/ instability Compliance with rehab SMALL defects in high demand patients (<2 sqcm) Larger defects in low demand patients (<4-5 sqcm)
Marrow stimulation - Microfracture + AMIC Evolvement of the microfracture technique - Implantation of a collagen membrane onto the site of the micro-fracture - Autologous Matrix Induced Chondrogenesis – AMIC (2003) Collagen membrane provides an environment where cells can adhere, proliferate and produce repair tissue in a protected setting – improved ‘fibrocartilage’ quality. Outcome studies: Coming from propounders – significantly better/ longer lasting benefit/ large defects <8 sqcm One RCT at 24 months – clinically no significant difference/ radiologically inferior surface and integration
Osteochondral Autografts (OATS) OATS > Mosaicplasty Few large plugs > Many small plugs Transfer cartilage+bone from non wt bearing area to wt bearing dome. Often 2 nd line of Tx High demand young pt Defects 2-5 sqcm LIMITATIONS Defect size Age/ osteoporosis Arthrosis
Does Oats work? 2 yr/5yr/10yr FU study OATS vs MF (RCT, level 1 evidence) Better pain relief Better histology Better radiology 6wk OATS Romanowski-Giemsa Safranin OMasson trichrome
Osteochondral Allografts Cryopreserved < 14 days ( < 28 days) Proteoglycan synthesis / cell viability <14 days Long term retrieval study (Jamali, JBJS, 2007, 30yrs/ Maury, JBJS, 2007, 25yrs) Donor chondrocytes survive, donor host margin indistinct – host chondrocytes do not re -populate the graft Subchondral bone necrosis and stabilisation – behaves different to bone grafts, bone allografts and there is no creeping substitution. 6 month retrieval study
ACI BIOPSY 200mgm of cartilage Culture Of isolated chondrocytes for 6 wk to upto 1 lakh cells TRANSPLANT Under periosteal or biomembrane cover
MACI ( Matrix Induced ACI) 2-10 sq.cm <5-6mm deep Failed primary treatment Best results in PF articulation
ACI – Future? Arthrofibrosis Symptomatic hypertrophy Disturbed fusion Delamination Graft failure Knutsen et al - FU results in patients randomized for ACI or microfracture. At 2 yrs FU: "Both methods had acceptable short-term clinical results. There was no significant difference in macroscopic or histological results no association between the histological findings and the clinical outcome." At 5 yrs : "Both methods provided satisfactory results in 77% of the patients at five years. There was no significant difference in the clinical and radiographic results between the two treatment groups and no correlation between the histological findings and the clinical outcome Minas et al. - clinical outcome in a cohort study of 321 patients Defects treated by ACI, which had a prior treatment with as microfracture, were three times more likely to fail than for defects treated by primary ACI Marrow stimulating techniques should be employed judiciously in larger cartilage defects that may require future treatment with ACI.