Co-Authors:
Milford H. Marchant Jr., M.D.; Steven Anderson, M.D.; M.D.; Mark E. Easley, M.D.; James A. Nunley II., M.D.
History
- Konig in 1888 described “Osteochondritis Dissecans” in the knee
- Distinct lesion with detachment of articular cartilage from subchondral bone forming a loose body
- Kappis in 1922 described similar process in talus
- 1959 Berndt and Harty provided great insight into the pathoanatomy and pathophysiology
Talus - Anatomy Review
- Receives forces 5 – 10 times the body weight during normal ambulation
- 3/5 of surface is covered by articular cartilage
- Articular Cartilage is 1 – 2 mm thick
- No Muscular Attachments
- Delicate Blood Supply
Etiology
- Primary Cause = Trauma
- Controversial
- Berndt and Harty through cadaveric studies showed that the OLT was likely a result of trauma
- Transchondral Fracture of Talar Dome
- Medial Lesions were created when the posteromedial talar dome impacted
the tibial articular surface during combined plantar-flexion, inversion and external rotation
- Lateral Lesions generated when the anterolateral talar dome impacted
the fibula during inversion and dorsiflexion
- Other Causes
- Ischemic Necrosis
- Embolic phenomenon
- Ossification Defects
- Predisposing Factors
- Endocrine Disorders
- Peripheral vascular disease
- Genetic Predisposition?
- 10-25% Bilateral Lesions
Prevalence
- Average Age Ranges 20 – 35 years
- Male 70% : Female 30%
- 6% of pts with any hx of Ankle Sprains, have OLTs
- 38% of pts w/ SER-IV ankle injuries, have OLTs
- 16 – 23% of pts undergoing lateral ligament reconstruction, have OLTs
Evaluation
- Presentation
- Acute inversion injury
- Chronic Ankle pain
+/- history of trauma
+/- instability
- Known History of OLT +/- prior treatment
- Symptoms
- Pain
- Catching, grinding
- Feelings of instability and give-way episodes
Diagnosis and Staging
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Radiography
- X-ray – initial evaluation
- MRI – modality of choice for suspected lesions
- CT-Scan – modality of choice for known lesions
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Arthroscopy
- Gold standard for diagnosis and determining optimal treatment modality
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Staging
- Radiographic (Berndt and Harty)
1. Trabecular compression fracture of subchondral bone
2. Partially detached osteochondral fragment
3. Completely detached, non-displaced fragment
4. Detached and displaced fragment
- Arthroscopic Staging (Pritsch et al. JBJS-Am. 1986)
1. Intact, firm, shiny cartilage
2. Intact, soft cartilage
3. Frayed Cartilage
- Radiographic and Arthroscopic findings did not always correlate.
- Many are now using Berndt & Harty Staging with arthroscopic evaluation
- Advanced Radiographic modalities are also helpful
- CT Staging (Ferkel et al. Orthop Trans. 1990)
Stage 1 – Cystic Lesion within the Talar dome
Stage 2a – Cystic lesion with communication to the Talar dome
Stage 2b – Open articular surface lesion with overlying non-displaced fragment
Stage 3 – Non-displaced lesion with lucency
Stage 4 – Displaced fragment
- Magnetic Resonance Staging (Hepple et al. Foot & Ankle Int.
1999)
1. Articular Cartilage Damage only
2. Cartilage injury with underlying fracture
a. Surrounding bony edema
b. Without edema
3. Detached but non-displaced fragment
4. Detached and displaced fragment
5. Subchondral cyst
Mintz et al.
Arthroscopy.
2003.
- Compared MRI with Arthroscopic findings for the purpose of grading
- 92 patients with persistent ankle pain & swelling
- 100% specificity in identification and localization of lesions.
- Accurate Grading in 83% of cases
- 95% sensitive and 100% specific in
Disease positive (grade 0 – 1) vs. Disease negative (grade 2 – 5) analysis
Classic Lesions
- Anterolateral
- Shallow
- Traumatic
- Posteromedial
- Deep
- Central lesions have also been described
Treatment Planning
- Acute vs. Chronic symptoms along with Radiographic Staging / Severity of Lesion dictate treatment
- Acute Injuries
- Initial management if no radiographic evidence of fx or OLT
- Activity Restrictions
- Ice
- Trial of Immobilization
- Compression
- Elevation
- Chronic Injuries
- Essential to define the severity of the lesion
- Low-Grade:
Operative vs. Non-operative
- Condition of articular cartilage in question
- With MRI Grade I – II lesions most attempt a 4 – 6 month trial of conservative therapy +/- immobilization
- Immobilization for 4 – 8 weeks
- Persistent symptoms after conservative therapy = Arthroscopy
- High Grade:
Operative Management
- Lesion stability during arthroscopic evaluation
- With MRI Grade III – V injuries = arthroscopic intervention
- Depending on the location, size, and character of the lesion various reconstructions may be performed
- Other Factors
- Location of the Lesion
- Quality of Subchondral Bone
- Ankle Instability
- Prior Interventions
Treatment Modalities
- Non-Tissue Transplantation
- Internal Fixation
- Arthroscopy
- Excision
- Curettage / Abrasion
- Drilling
- Micro-fracture
Robinson et al (JBJS 2003)
- 65 patients
- Improvement seen with arthroscopic treatment in MRI grade I – IV.
- Grade V cystic lesions had high incidence of poor outcome (53%).
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- Tissue Transplantation
- Modalities
- Autologous Bone Grafting
- Autologous Chondrocyte Transplantation
- Osteochondral Autograft Transplantation (OATs)
- Single Osteochondral Plug
- Mosaicplasty
- Osteochondral Allograft Transplantation
- Benefits
- Provides the ability to fill in a larger defect
Osteochondral Autograft Transplantation
- Benefits
- Non-immunogenic graft
- No increase in disease transmission
- Provides an articulating surface
- Prevents excessive weight bearing loads on the remaining portion of the talus which would accelerate ankle joint arthritis
- Structural Limitations
- Lesion size = Limited “extra” cartilage
- Only Carticel can fill irregular shaped lesions
- Flat surface required
- Attempts at angular repairs have been challenging
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Osteochondral Lesions of Talus - Allograft Transplantation:
- Allograft Transplantation is proving to be beneficial for large osteochondral defects
where duplication of the anatomy would be difficult with autologous tissue.
- Talus allograft is size matched = Custom fit
- Able to treat the “shoulder lesion” (See Figure)
- Defect involving more than one articulating plane
- Benefits
- In Fresh Allografts, Viable Chondrocytes are present within
an intact Hyaline Cartilage Structure
- Arthroscopy and Mosaicplasty rely on fibrocartilage ingrowth
- Shorter procedure
- No second operative site for harvest
- Compared to OATs or Mosaicplasty
- Single surgical procedure
- Compared to Autologous Chondrocyte Transplants (Carticel)
- Risks
- Transmission of Disease
- Immune Response
- Resorption and fragmentation of the graft
- Procedure-based risk
- Osteotomy Non-union
- Post-op Arthritis
