Current Concepts of Articular Repair

Matthew P. Melander, DO Sports Medicine and Arthroscopic Surgery

Articular Cartilage Homeostasis in the environment

Mechanical Properties- frictionless environment

Relatively devoid of blood vessels, lymph and nervous tissue

Although its composition, structure and performance is surprisingly complex, its relative metabolic inactivity and lack of blood supply per- mit for only a very limited response to injury Normal Articular Cartilage WHO IS THE IDEAL CANDIDATE FOR CARTILAGE REPAIR ?

Patient Specific Lesion Specific • Age • Mechanical environment • Activity Level • Malignment • BMI • Joint laxity • Co-morbidities • Meniscal injury • Leg alignment • Associated injuries Treatment algorithm for focal cartilage defects in the Femoral <2 cm2 Femoral Condyle<2 cm2 Marrow Stimulation Chondrocyte Implantation OsteoarticularAutograft OsteoarticularAutograft Synthetic Scaffold Synthetic Scaffold Treatment algorithm for focal cartilage defects in the knee Femoral Condyle>2 cm2 Femoral Condyle>2 cm2 Debridement Implantation Marrow Stimulation Osteoarticular Allograft Treatment algorithm for focal cartilage defects in the knee PFJ/Tibia <2cm2 PFJ/Tibia <2cm2 Marrow Stimulation Chondrocyte Implantation Chondrocyte Implantation OsteoarticularAutograft Treatment algorithm for focal cartilage defects in the knee PFJ/Tibia >2cm2 PFJ/Tibia >2cm2

Debridement Chondrocyte Implantation Marrow Stimulation Osteoarticular Allograft Chondrocyte Implantation Abrasion arthroplasty

• Less focal, more widespread defects • DJD • Arthroscopic burr • 60-70% symptomatic relief 3-5 yrs • <2.5 cm2 MARROW STIMULATION MARROW STIMULATION Microfracture MARROW STIMULATION

• Local inflammatory • Microfracture- response Steadman technique • Proliferation of • Best outcomes, young mesenchymal stem cells pts., < 4cm2 lesions • Subchondral plate blood supply • 75% satisfactory, good short term (3-5 yr) relief • - Type I resists tension v. compression • Transcortical drilling MARROW STIMULATION

Hyaline Cartilage Fibrocartilage Autologous Matrix Induced Chondrogenesis • Combination with microfracture • Cell-free collagen matrix • No definitive advantage REPLACEMENT TECHNIQUES OsteochondralAutograft (OATS) Synthetic resorbable scaffolds • Trufit- SN NWB harvest • Biomatrix- Arthrex • 2.5-10mm/ 12-15 mm • Cylinders engineered to mimic the composition of human and • Surface congruity cartilage • 6-18 mo resorption • Backfill synthetics • The temporary matrix allows mesenchymal stem cells to impregnate the pores of the scaffold • Preclinical studies have shown restora- tion of hyaline-like cartilage in a goat model with subchondral bony incorporation at 12 months Synthetic Resorbable Scaffolds CELL BASED REPAIR TECHNIQUES

• AutologousChondrocyte Implantation (ACI) • Lars Peterson, 1994 • The treatment aims at the regeneration of hyaline or hyaline-like cartilage rich in collagen typeII, thereby restoring normal joint function • Femoral trochlea and • Microfracture and mosaic- plasty have shown to deteriorate with time, whist chondrocyte implantation have demonstrated time dependent long-term improvements ACIis a two-stage procedure

• 5 mm “chips” 1-300 mg sample • Cultured 4-6 wks • 250,000-20 million cells ACI Matrix Autologous Chondrocyte implanta- tion method (MACI® Genzyme, Cambridge, USA) purified and cell-free porcine collagen membraneand Novocart® 3D, a bovine based bi-phasic foam composed of collagen and chodroitin- sulphate. Study results of these cell based 3rd generation techniques have been promising and are at least equivalent to those achieved with ACi, with report- ed good clinical medium-term results Partial re-surfacing arthroplasty

• Hemi-cap • Focal condylar defects • The procedure is intended to bridge the gap between biologic procedures and conventional joint replacement Partial re-surfacing arthroplasty Although the technique of partial surface replacement has been available for some time no comparative or medium-term out-come studies are yet available to verify its clinical performance. These implants should hence be used with utmost caution. POST-OPERATIVE REHABILITATION Following marrow stimulation & structural grafting Following cell based cartilage repair • NWB 6 wks, PWB 2 wks • Similar protocols • CPM “reshaping” • Immobilization • 8 wk strengthening • Verify cartilage integrity by • 6 mos RTP obtaining MRIscans at 6-12 months Natural Tissue Grafts

DeNovo NT Benefits • DeNovo® NT Natural Tissue Graft (Fig. 1) is an off-the-shelf human tissue, • Single stage consisting of viable, juvenile hyaline DeNovo cartilage pieces and is intended for the • The NT Graft repair of articular cartilage defects in a surgical technique mitigates single-stage procedure. The DeNovo NT Graft surgical technique mitigates the the need for harvesting and need for harvesting and suturing of suturing of a periosteal flap, unlike autologous chondrocyte implantation (ACI), as it a periosteal flap, unlike employs a fibrin sealant to secure the autologous chondrocyte minced tissue pieces into the defect. • DeNovo® NT Natural Tissue Graft implantation (ACI), as it is an off-the-shelf human tissue, employs a fibrin sealant to consisting of viable, juvenile hyaline cartilage pieces and is intended for the secure the minced tissue repair of articular cartilage defects in a single-stage procedure.. pieces into the defect. DeNovo NT On the Horizon Thank you

References

• Adams MR, Gehrmann RM, Bibbo C et al. in vivo assessment of incorporation of bone graft substitute plugs in osteoarticular autograft transplant surgery. Presented at the Annual Meeting of the American Orthopaedic Society for Sports Medicine, Providence, Rhode island, 2010. • Alford JW, Cole BJ. Cartilage restoration, part 1 : basic science, historical perspective, patient evaluation, and treatment options. Am J Sports Med 2005 ; 33 : 295-306. • Bartlett W, Skinner JA, Gooding CR et al. Autologous chondrocyte implantation versus matrix- induced autolo- gous chondrocyte implantation for osteochondral defects of the knee : a prospective randomised study. J Bone Joint Surg 2005 ; 87-B : 640-645. • Behrens P, Bitter T, Kurz B, Russlies M. Matrix-associ- ated autologous chondrocyte transplantation/implantation (MACT/MACi) 5-year follow-up. Knee 2006 ; 13 : 194-202. • Peterson L, Minas T, Brittberg M et al. Two- to 9-yearoutcome after autologous chondrocyte transplantation of the knee. Clin Orthop Relat Res 2000 ; 374 : 212-234. • Steadman JR, Briggs KK, Rodrigo JJ et al. Outcomes of microfracture for traumatic chondral defects of the knee : average 11-year follow-up. Arthroscopy 2003 ; 19 : 477-484.