Osteochondral Allografting of the Knee William Bugbee, MD Director, - - PowerPoint PPT Presentation

Osteochondral Allografting of the Knee

William Bugbee, MD Director, Cartilage Transplantation Program Scripps Clinic, La Jolla CA Professor, University of California, San Diego

Disclosure

• Joint Restoration Foundation

– Consultant, research support

• Arthrex

– consultant

• FDA

– Medical advisory committee: Cellular, tissue and gene therapy

Fundamental Strategies of Cartilage Restoration

• Cell based

– Induce cells to form (chondral) tissue in situ – Marrow stimulation – ACI – Other cell sources

• Whole tissue based

– Restore defect with mature tissue – Osteochondral autograft (OAT) – Osteochondral allograft (OCA) – Processed (acellular) allografts

“Seed vs. Sod”

Subchondral Bone and the Osteochondral Unit

• Integrated organ system
• Interdependent structure-

function relationship

Cartilage is an Ideal Tissue for Transplantation

• Avascular
• Aneural
• Immunoprivileged
• Amenable to storage
• Can be fashioned to fit

recipient

Advantages of Osteochondral Repair

• Mature hyaline cartilage
• Bone healing paradigm
• Replace diseased subchondral

bone

• Faster and simpler

rehabilitation

Nomenclature for Osteochondral Grafts

• Osteochondral autograft transfer

= OAT

• Mosaicplasty = transfer of more

than one plug

• OATS = trademarked name of

surgical instrument set

• Osteochondral allograft

transplant = OCA

• Allograft OATS = ?
• Fresh = never frozen
• Stored/refrigerated
• Fresh-frozen (?)
• Frozen

Osteochondral Allograft Transplantation

• Originally introduced as a joint reconstructive

procedure for trauma, tumor reconstruction

• Now widely used as a cartilage restoration

technique for chondral and osteochondral lesions

• San Diego program began in 1983

Cartilage repair paradigm

• Microfracture
• OAT
• ACI
• OCA

Complex reconstruction paradigm

• OCD
• AVN
• Post-traumatic

Governing Principles for Fresh Allograft Use Cartilage Repair

• Whole tissue transplant
• Viable chondrocytes in mature

hyaline cartilage matrix

• No cell or tissue differentiation

required

• Maximizing and preserving

inherent chondrocyte and matrix properties critical

• Cells within matrix are

Immunoprivileged

• Allograft chondrocytes survive

transplantation and maintain matrix

Governing Principles for Fresh Allograft Use in Cartilage Repair

• Osseous portion is a nonliving scaffold

and interface for attachment and integration

• Minimal volume unless osseous

reconstruction necessary

• Incorporation by creeping substitution
• Potential site for immunologic

response by recipient

• Behavior of osseous component is

important predictor of clinical success

Indications for Osteochondral Allografts

• Osteochondritis dissecans/OLT
• Traumatic

chondral/osteochondral lesions

• Revision of previous cartilage

surgery

• Osteonecrosis/ SONK
• Fracture malunion (tibial plateau)
• Focal degenerative chondral

lesions

• Osteoarthritis

Surgical Techniques

• Dowel or plug
• Focal lesions

– 10-30 mm – Femoral condyle, trochlea, patella, humeral head, femoral head

• Shell graft

– Complex, inaccessible lesions – Femoral condyle, trochlea, tibia, talus

• Small fragment

– Large or deep lesions – Tibia, patella, glenoid

Surgical Technique: Femoral Condyle

Surgical Technique: Femoral Condyle

Large Lesions: Multiple Grafts

Multiple Grafts

Patellar Allograft

Tibial Plateau and Meniscus

Allografting of Other Joints

• Ankle

– OLT – Osteoarthritis – AVN

• Shoulder

– AVN – Chondral or osteochondral lesions

• Hip

– AVN – Trauma

• Small joints

Femoral Head Allograft

Humeral Head Allografting

Clinical Outcomes by Diagnosis

Diagnosis OCA failure Mean IKDC pain Mean IKDC Function Satisfaction* Traumatic chondral injury 2% 3.3 7.3 90% Osteochondritis dissecans 7% 2.1 8.1 96% Fracture 15% 4.4 6.1 80% Degenerative chondral lesion 21% 3.7 6.3 81% Avascular necrosis 25% 2.7 7.1 92% Osteoarthritis 39% 3.5 5.8 79% Among patients with grafts in situ at latest follow-up

*responded either “satisfied” or “extremely satisfied”

Clinical Outcome

Patient Satisfaction at Latest Follow-up

68% 21% 6% 3% 2% 0% 20% 40% 60% 80% 100%

Extremely satisfied Satisfied Somewhat satisfied Somewhat dissatisfied Dissatisfied

68% 21% 6% 3% 2% 0% 20% 40% 60% 80% 100%

Extremely satisfied Satisfied Somewhat satisfied Somewhat dissatisfied Dissatisfied

89% satisfied

Postoperative Rehabilitation

• Depends on graft size, fixation and location
• Concurrent procedures such as ACL, osteotomy, meniscal repair or

transplantation generally guide Rx

• Simple outline

– Protect weight bearing (25%) for 4-6 weeks – No ROM restrictions except occasionally for PF grafts – No routine bracing or CPM – Rule of thumb: treat like a fracture that has been fixed

• Clear advantage of OCA: simple and rapid rehabilitation in spite of

need for arthrotomy

Rapid recovery after OCA

• Tissue maturation not required

– Best quality at time=0 – No ROM restrictions

• Excellent initial graft stability
• Bone healing occurs rapidly

– 4-6 weeks – Protected wt bearing 0-4 weeks

• Functional recovery

– Arthrotomy – Neuromuscular – Between 3-6 months

Returned to sports 75.2% Did not return to sports 24.8% Very strenuous activities 37.2% Strenuous activities 16.3% Moderate activities 25.0% Light activities 19.7% Unable to perform any activities 1.8% Fair function 10.3% Good function 18.6% Very good function 34.4% Excellent function 36.7%

Return to Sports After OCA

75.2% returned to sport 78.5% able to participate in high lev&77el of activity 71.1% very good to excellent function

Variables predicting return to sport

• Males more likely than females
• to return to sport

Gender

• Patients sustaining a sports-related injury more

likely to return to sport

Etiology of injury

• Patients with osteochondritis dissecans more

likely to return to sport than those with a degenerative chondral lesion

Diagnosis

• Patients with unifocal condylar lesions more

likely to return to sport than multifocal or patellar lesions

Anatomical location of graft

• Patients with smaller grafts more likely
• to return to sport

Graft size

p=0.042 p=0.005 p=0.001 p=0.004 p=0.042 Patient age and duration of symptoms not significant

47% 41% 41% 35% 29% 25% 18% 12%

Pain Worried about re-injury Clicking or grinding Stiffness Could not fully bend Other problem with knee Instability Instructed not to participate

0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50%

25% did not return to sport….why?

Knee-related problems

24% 12% 6% 6%

Health issues unrelated to knee Less interest in sports Started a family Changed jobs or career

0% 5% 10% 15% 20% 25%

25% did not return to sport….why?

Lifestyle reasons

Osteochondral Allografts in 2017

• A mainstream treatment option

(more OCA than ACI performed in US)

• Proven safety, efficacy and

versatility

• Addresses the common

subchondral bone disease

• High rate of return to ADLs,

sports and recreation

• High acceptance and patient

satisfaction

Thank You