7 Arthroscopic lavage and debridement A "cleaning up" procedureIs not considered an articular cartilage repair procedure but rather a palliative treatmentReduce pain, mechanical restriction and inflammation.Removes degenerative cartilage flaps and fibrous tissue.The main target group are patientsVery small defects of the articular cartilage.Significant ‘painless’ defects , diagnosed incidentally
8 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 cellsThe blood clot converts to ‘fibrous tissue’ about 8 weeksOver 4 months fibrous tissue becomes ‘fibrocartilage’.
9 Does these work? Mixed results in atheletes Brian Cole et al 75-80% good results with proper pt selection and proper rehabPoor outcomesPoor shear resistance of fibrocartilageElderly, obese,>2.5cm defectsBrian Cole et al839 patients ( )60% improved in 4-6 months25% no improvement15% improved immediately!!!30% revised at 1yrBest outcome in first 2yrs
10 Make them work? Achieve vertical walls Remove calcified cartilage healthy cartilage at the rim better shoulder the load and makes the lesion less clinically relevantRemove calcified cartilageallows better fit and fill by fibrocartilage which is more tenacious and histologically superior.Holes 2-3 mm apartCorrect malalignment/ instabilityCompliance with rehabSMALL defects in high demand patients (<2 sqcm)Larger defects in low demand patients (<4-5 sqcm)
11 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 sqcmOne RCT at 24 months – clinically no significant difference/ radiologically inferior surface and integration
12 Osteochondral Autografts (OATS) OATS > MosaicplastyFew large plugs > Many small plugsTransfer cartilage+bone from non wt bearing area to wt bearing dome.Often 2nd line of TxHigh demand young ptDefects 2-5 sqcmLIMITATIONSDefect sizeAge/ osteoporosisArthrosis
13 Does Oats work? 2 yr/5yr/10yr FU study OATS vs MF (RCT, level 1 evidence)Better pain reliefBetter histologyBetter radiology6wk OATSRomanowski-GiemsaSafranin OMasson trichrome
14 Osteochondral Allografts Cryopreserved < 14 days ( < 28 days)Proteoglycan synthesis / cell viability <14 daysLong 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 graftSubchondral bone necrosis and stabilisation – behaves different to bone grafts, bone allografts and there is no creeping substitution.6 month retrieval study
15 ACIBIOPSY 200mgm of cartilage Culture Of isolated chondrocytes for 6 wk to upto 1 lakh cells TRANSPLANT Under periosteal or biomembrane cover
17 ACI – Future? Arthrofibrosis Symptomatic hypertrophy Disturbed fusion DelaminationGraft failureKnutsen 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 outcomeMinas et al. - clinical outcome in a cohort study of 321 patientsDefects treated by ACI, which had a prior treatment with as microfracture, were three times more likely to fail than for defects treated by primary ACIMarrow stimulating techniques should be employed judiciously in larger cartilage defects that may require future treatment with ACI.