Management and Myths of

Cartilage InjuryCharles J. Gatt, Jr., MD

Chair, Department of Orthopaedic SurgeryRutgers, Robert Wood Johnson Medical School

New Brunswick, NJ

• I have no disclosures.

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Clinical question

• Do current surgical techniques restore normal articular cartilage and prevent post traumatic arthritis of the knee?

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Healthy Cartilage

Articular Cartilage

Cancellous Bone

Calcified Zone

Subchondral Bone

Tidemark

Hyaline cartilage vs fibrocartilageHyaline cartilage consists of:• Proteoglycan aggregate, Collagen

Types: II, IX, XI• Organized collagen fiber

orientation

• Fibrocartilage consists of:• Proteoglycan, Collagen Type I• Unorganized collagen fiber

orientation

Knee Cartilage Pathologies

• Chondral Defects: Damage to otherwise healthy knee cartilage– Also OCD

• Chondral Degeneration: Wear damage to knee cartilage over time– Idiopathic, e.g. OA– Secondary

Natural History• Chondral injury → Osteoarthritis?

– Lack of sufficient scientific evidence– However, thought to be strongly correlated

• Natural history of asymptomatic lesions unknown– Typically only symptomatic lesions come to medical

attention

• Animal studies– Articular incongruity → Progressive chondral loss– Mimics OA

Incidental finding during meniscectomy

17 y/o soccer player with effusion

Diagnostic arthroscopy

Surgical repair

Microfracture

• Popularized by Steadman in late 1990s

• Perforation of subchondral bone for release of marrow elements and a vascular healing response

• Reserved for smaller, <2-3 cm2, defects in the absence of subchondral bone damage

• Creates a fibrocartilage scar– Less resistance to sheer stress– Less durable than hyaline

cartilage

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Best outcomes

good repair cartilage volume

lower body-mass index

shorter preoperative duration of symptoms

Microfracture§ Microfracture deterioration at 18 – 36 months

ú Blevins et al - Orthopaedics 2008ú Bachmann et al - Radiologe 2004ú Buckwalter - CORR 1999ú Gobbi et al - KSSTA 2005ú Kreuz et al - Arthroscopy 2006ú Kreuz et al - Osteoarthritis Cartilage 2006ú Mithoefer et al - JBJS 2005ú Mithoefer et al - AJSM 2006

DURABILITY???

Autologous Chondrocyte Implantation (ACI)

• Introduced in Sweden in 1987• First reported in 1994• 2-stage procedure

– Patient’s own cartilage harvested– Expanded in vitro– Reimplanted into cartilage defect

• Resurfaces with hyaline-like cartilage

• Can get overgrowth/hypertrophy of the graft– Reoperation rates as high as 50%*

*Gillogy SD, Wheeler KS. Autologous Chondrocyte Implantation with collagen membrane. Sports Med Arthrosc Rev.2015;23:118-124

Restorative Techniques§ ACI

ú 300 – 500 mg of cartilage obtained (biopsy)ú Sent to cell-culture lab

  Cartilage minced  Serial washes  Re-suspended in culture medium  Expanded 20 – 50 x original cell count  Ready 2 – 3 weeks after biopsy

ú Re-implanted back into patientú Under periosteal flapú 3-8 weeks later

• JBJS 2003• At 5.6 year f/u

– 91 % G-E objective results– 93% G-E results subjectively– Repair tissue quality 11.2 on 12-point scale

• AJSM 2014• RCT (Level 1)• 144 patients (72 each), 95% completed treatment• Cartilage defect >3 cm2 on MFC/LFC/trochlea• MACI had better KOOS pain/function @ 2 yrs

• No major differences between ACI and microfracture• 30 of 80 were treatment failures• 50% of the remaining patients developed at least eary

osteoarthrits• raise serious concerns regarding the efficacy of these

procedures in delaying osteoarthritis and preventing further surgery in this patient group.

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Osteochondral Autograft Transplantation (OAT)

§ Osteochondral Transplantationú OATs or Mosaicplastyú First reported by Judet –

1908ú Transfer of osteochondral

bone plugs  “Nonweightbearing” area  Transplanted to defect

ú Instant fill with hyaline cartilage

ú Addresses subchondral bone issues

Restorative Techniques

§ JBJS 2003§ Prospective Cohort Study§ 92% good-excellent results at long-term f/u§ Femoral condyle > Plateau > Patellofemoral§ 2nd look arthroscopy

ú Maintenance of transplanted hyaline cartilage

ú Fibrocartilage in interstices

Osteochondral Allograft

• Osteochondral allograft– Requires size-matched donor

• Femoral hemicondyle

– Suitable for large defects– Process similar to OATS (press-

fit bone plug)– Also addresses subchondral

bone pathology– Can correct failed cartilage

restoration attempts

• AJSM 2017 • Systematic review (level 4)• 19 studies, 1036 patients, min 2 yr f/u• 5 year survival 86.7%• 10 year survival 78.6%

• Review of current literature– 80% return to play in professional athletes at 2.5 yrs.

(Krych)– 85% graft survival rate after 10 years– Outcomes positively correlated with young age, post-

traumatic lesions, short duration of symptoms

• Level of evidence - 4

Conclusions• Cartilage injuries are very common• The natural history is incompletely understood• Appropriate patient selection is key• No consensus exists on treatment• Reparative techniques may lack durability• Cell-based techniques show promise• More research is needed

Thank you