Indications and Surgical Treatment of Osteochondritis Dissecans of the Knee

Mark Hazel MD Financial Disclosure

I have no financial interests, relationships, or potential conflicts of interest relative to this presentation Osteochondritis Dissecans (OCD) of the Knee ❑ Definition

❑ Locations

❑ Healing Potential

❑ Non operative treatment

❑ Operative treatment OCD Definition ➢ ROCK (research in osteochondritis dissecans of the Knee) ➢ A focal idiopathic alteration of sub-chondral bone with risk for instability and disruption of adjacent articular cartilage that may result in premature osteoarthritis

➢ Clinical problem-some heal, some don’t

➢ Can result in osteoarthritis in young patients OCD-(in laymen’s terms)

• OCD is a condition in which the bone that supports the cartilage inside a joint undergoes softening. This softening is caused by an interruption in the blood flow to that portion of the bone. Over time, if left untreated, this can lead to damage to the overlying cartilage of the joint. Loose pieces of bone and cartilage can even break off into the joint. Long term ramifications may even include arthritis. 2 forms of OCD Juvenile/Adult Juvenile ▪ Open physis (5-15 years old)

▪ Better prognosis, with complete healing in many, but not all cases

Adult ▪ Closing/closed physis (16-50 years old)

• Greater likelihood of failing non-operative treatment and worse overall prognosis Clinical Presentation ➢ Most children and adolescents with OCD present with stable lesions

➢ Complaints I. Non-specific II. Aching and activity related pain Physical Exam ➢ Unstable lesions ▪ More pronounced mechanical symptoms ▪ Antalgic gait is common ▪ Usually-knee effusion ▪ Possibly crepitus

Check both knees as it may be bilateral in up to 30% of cases.

Plain Radiographs ❑ AP

❑ Lateral

❑ Tunnel or Notch

❑ Merchant or Sunrise views Plain Radiographs

Diagnostic/Imaging Studies ➢ Goals I. Characterize the lesion II. Determine prognosis for healing with non-operative management Imaging ❑ No imaging protocol predicts the success of non-operative management in all cases

❑ Emphasis upon evaluation of lesion stability and potential for healing

❑ MRI better at predicting for older teenagers and for adults Lesion Stability and Healing ➢ Radiographs-”loose” fragments, incongruent fragment, clear boundary between parent and progeny bone

➢ MRI-stability features

➢ Arthroscopy ▪ Gold standard for stability ▪ Stable or immobile lesion ▪ Unstable or mobile lesions Classification ➢ Stable or immobile lesion

➢ Unstable or mobile lesions Clinical Staging Summary I – abnormality of subchondral bone

II – demarcation, clear margins, no fluid

III – demarcation, sclerosis, fluid

IV – detached fragment in situ, surrounded by fluid

V – displaced fragment, empty defect, loose body MRI Stability, Healing Prediction ❑ Stable ❑ Stages with MRI (Guhl) I – thickening of cartilage, low signal II – cartilage breached, low signal ❑ Unstable III – high signal (fluid) behind the fragment IV – loose body MRI based staging

Who may heal with non-operative treatment ➢Young, skeletally immature Treatment of stable OCD lesions in skeletally immature patients Non-operative treatment – 66% healed after 6-month protocol, knee immobilizer, cast or brace and activity restrictions ▪ Predictors for not healing – larger lesions, swelling, mechanical symptoms ▪ Consider surgical treatment if not healed by 6 months Indications for fixation of OCD lesions in the knee Stable/immobile OCD lesions • Usually treated with subchondral bone drilling

Unstable, salvageable OCD lesion • Drilling with screw fixation • Bone grafting • Repair, fixation of cartilage lesion Operative treatment ➢ Drilling – antegrade or retrograde

➢ Fixation

➢ Autograft – OATS, Mosaicplasty

➢ Autologous Chondrocyte implantation (ACI) or MACI ▪ MACI (autologous cultured chondrocytes on porcine collagen membrane

➢ Allograft

➢ Fragment removal-with or without microfracture Drilling

❑ Antegrade

❑ Retrograde Drilling

❑ Antegrade Drilling

❑ Retrograde Arthroscopic Repair of the Osteochondritis Dissecans of Medial Femoral Condyle

Click link below

Arthroscopic Repair of the Osteochondritis Dissecans of the Medial Femoral Condyle Fixation ▪ K-wire (no compression)

▪ Metal screws – both headless and regular, need to remove later??

▪ Bio screws

▪ Bioabsorbable pins – no compression, breakage, loss of fixation, immune reaction Principles of fixation ❑ Restore articular surface

❑ Rigid fixation

❑ Enhance blood supply

❑ Initial early post op ROM Fixation ❑ Screws • retrograde (not as commonly done)

• antegrade (much more common) Fixation-retrograde screw Fixation-antegrade screw Fixation-antegrade screw Autograft Autologous Chondrocyte Implantation (ACI) or MACI ❑ ACI

Is a two-stage procedure, first is the arthroscopy that evaluates the chondral injury and harvests chondrocytes from the patient’s knee for lab growth of more cartilage cells. The second surgery is to repair the cartilage defect. The new chondrocytes, which are grown in a lab, are introduced into the defect. The defect is covered with a membrane that is sewn down and sealed with fibrin glue. Autologous Chondrocyte Implantation (ACI) MACI ❑ Autologous cultured chondrocytes on porcine collagen membrane Allograft Fresh Osteochondral Allograft Transplantation of the Medial Femoral Condyle for the Treatment of OCD

Click link below https://www.vumedi.com/video/fresh- osteochondral-allograft-transplantation-of- the-medial-femoral-condyle-for-the- treatment-of-ost/ Fragment removal ➢ With Microfracture

➢ Without Microfracture

➢ Removal of the fragment ▪ Can relieve symptoms but activity with residual defect may be risky Fragment removal Surgical Treatment Outcome Summary Arthroscopic drilling • Transchondral or retrograde • 82—98% success Surgical fixation • Metallic screws • Bioabsorbable implants • Osteochondral plugs • 66-100% success Open bone grafting • With fixation Surgical Treatment Outcome Summary Fragment excision • 65% “fair to poor” Microfracture • 63% success OATS • 90% success ACI • 90-96% success OCA • 85-100% success Midterm Results of Surgical Treatment of Adult OCD Pascual-Garrido,et al, AJSM 2009 ➢ 48 knees. Mean lesion size 4.5 cm

➢ Multiple treatment modalities • Debridement, drilling, screw fixation, loose body removal, ACI, OCA

➢ Improvement in all outcome measures independent of modality

➢ 14% failure rate Sources

• Current Concepts and Techniques for Fixation and Repair of OCD Lesions, Jason L. Koh MD, Cherry Blossom Seminar 2017 • OCD Treatment Options – Care of Stable Lesions, Kevin Shea MD, CA Orthopaedic Association Meeting 2018 • Management of Pediatric and Adult OCD, William Bugbee MD, Metcalf/AANA Arthroscopy Meeting 2016 • Greenspan,A., Beltran,J, 6th Edition, Orthopedic Imaging A practical Approach New York NY, Wolters Kluwer • Chambers, H. Diagnosis and Treatment of Osteochondritis Dessicans JAAOS, 19(5): May 2011 297-306 • Crawford, D. Osteochondritis Dessicans of the Knee JAAOS, 14(20): February 2006 90-100 • Krych,A. Cartilage Injury in the Knee: Assesment and Treatment Options JAAOS, 28(22): November 2020 914-922 • Cahill,B. Osteochondritis Dessicans of the Knee: Treatment of Juvenile and Adult Forms JAAOS, 3(4): July- August 1995 237-247 • Pascual-Garrido,et al, Midterm Results of Surgical Treatment of Adult OCD AJSM • Wiesel, S. Operative Techniques in Orthopaedic Surgery 2nd edition, volume one Chapter 41 Osteochondritis Dessicans and Avascular Necrosis Thank you!