Osteochondritis Dissecans of the Knee. M Lucas Murnaghan MD, MEd, FRCSC

Transcription

1 Osteochondritis Dissecans of the Knee M Lucas Murnaghan MD, MEd, FRCSC

2 Outline 1. Clinical Presentation 2. Investigations 3. Classification 4. Non-operative Treatment 5. Operative Treatment 6. Treatment Algorithm

3 Definition Acquired, potentially reversible idiopathic lesion of subchondral bone resulting in delamination and sequestration with or without articular cartilage involvement and instability

4 Juvenile vs. Adolescent OCD Open Physes Closed Physes Heals De Novo AOCD JOCD AOCD

5 Clinical Presentation History Pain - Non-specific, Aching, Anterior Mechanical symptoms if lesion is loose or loosening Physical Exam Mild tenderness, quad atrophy and pain with ROM Severe lesions or loose body Effusion, Tenderness, Quads Atrophy, Locked Knee Examine both knees Bilateral involvement in 20 30% of cases

6 Osteochondritis Dissecans Classic Location (80%) Medial Femoral Condyle Posterolateral Lateral Condyle (15%) Patella (5%) Femoral Trochlea (1%)

7 Plain Radiographs AP, Lateral, Tunnel and Skyline View

8 MRI Routine part of diagnostic evaluation Better estimate of size of lesion Articular cartilage and subchondral bone Extent of bony edema Appearance of high signal zone beneath fragment Presence of loose bodies

9 MRI PROTOCOL Axial FSE (TSE) T2 with fat saturation Coronal T1 Coronal FSE (TSE) T2 with fat saturation * Sagittal FSE (TSE) T2 with fat saturation * Sagittal FSE (TSE) proton density * Sagittal volumetric gradient echo with fat saturation * * mandatory sequence (minimal protocol) to focus upon juvenile OCD

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11 MRI CRITERIA 1. Lesion location 2. Lesion size 3. Physeal patency 4. Articular surface contour 5. Status of overlying articular cartilage 6. Status of un-ossified epiphyseal cartilage (Omen Sign) 7. Thickness of overlying cartilage 8. Interface between cartilage and bone Oreo Cookie Sign 9. Signal in the Parent Bone 10. Presence of round or oval hyper-intense foci (outside of wafer) 11. Presence of discrete bone fragment within the lesion 12. Interface between bone fragment and rest of epiphysis 13. Marrow edema 14. Joint effusion

12 Non-Operative Management Due to good natural history of stable OCD Non-operative treatment is first line Role of Immobilization Focus on bone no motion treat like fracture Focus on cartilage motion cartilage health Most feel that cartilage defect is subsequent to bone failure so focus on bone healing

13 Non-Operative Management Cast vs. Brace ADLs vs. Compliance Hinged Unloader Brace Balance of protection and motion Push medial lesions into valgus and lateral lesions into varus Best Immobilization is unproven

14 6 mos Unloader Brace Treatment

15 Management Wall et al. JBJS-A knees: 41MFC, 6LFC Age range 8-14 Stable lesions = no breach of cartilage surface on MR Rx: 6/52 in long leg walking cast Repeat xray: if no improvement; 6/52 additional casting Unloader brace, no sports/running/jumping until xray healing Extensive data collection multiple logistic regression At 6 months: 34% not healed Lesion size was strongest prognostic variable (avg non-healing = 2.8cm 2 ) Age was not a predictor We will consider surgical intervention in patients with intact OCD lesions with failure to heal after at least 6 months of non-operative treatment

16 1. Intact Lesion Juvenile/Stable Lesion Drilling: 2 Options Trans-Articular Retrograde Passing through the articular cartilage Retro-Articular Antegrade Through the epiphysis Articular cartilage not breached

17 Transarticular vs. Retroarticular No difference between methods of drilling Healing rate ~ 90% Multicenter Prospective Study with ROCK Group Underway Principal Investigator Ben Heyworth Boston Children s

18 Operative Treatment Goal: Joint congruity and rigid fixation Arthroscopic Classification and Treatment 1. Normal 2. Wrinkle in Rug In Situ Fixation 3. Locked Door In Situ Fixation 4. Trap Door Reduction +/- bone grafting + fixation 5. Manhole Reduction +/- bone grafting + fixation 6. Crater Salvage

19 Locked Door, Trap Door, Manhole Cover If not able to be elevated arthroscopically In situ fixation Able to Elevate Fibrous tissue beneath fragment removed Need to leave subchondral bone intact on cartilage fragment Bone grafting into defect if bone loss

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21 Fixation Metal Cannulated screws? Second surgery to remove Bio-Absorbable pins and screws No need for removal Less Compression Complications Loosening Failure to re-absorb Damage to adjacent cartilage Loose bodies Synovitis

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28 5. Unsalvageable Crater < 10 mm diameter Marrow Stimulation Remove fibrous tissue Microfracture picks vs Wires Check for bleeding Post-op Non-Weight bearing +/- CPM > 20 mm diameter Autograft From NWB area of distal femur Allograft risk of disease transmission failure of integration failure of cartilage cell survival

29 OATS Procedure

30 Autologous Chondrocyte Implantation (ACI)

31 Juvenile OCD Stable Stable Atypical Location Approaching Maturity Unstable: Wrinkle/Locked Door Trap Door Manhole Cover

32 Stable Non-Op Tx (6-9 mos) Healed Not Healed Arthroscopy Drilling

33 Stable Atypical Location Approaching Maturity Worry Non-Op Tx (3-6 mos) Healed Not Healed Arthroscopy Drilling vs. Fixation

34 Unstable Arthroscopy Wrinkle / Locked Door Trap Door Manhole Cover Drilling Fixation Prepare Fixation Arthrotomy Prepare Fixation Excision & Resurface

35 Outline 1. Clinical Presentation 2. Investigations 3. Classification 4. Non-operative Treatment 5. Operative Treatment 6. Treatment Algorithm

36 Take Home Points 1. Important diagnosis to consider 2. Tunnel View 3. MRI is imaging modality of choice 4. JOCD Non-operative drilling fixation 5. AOCD Non-operatve (limited role) Drilling (no role) fixation vs. salvage

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