General Information About the Operation

• Duration: arthroscopic microfracture / debridement 30–60 minutes; mosaicplasty (with a medial malleolar osteotomy) 90–120 minutes; allograft transplantation or ACI 90–120 minutes
• Anaesthesia: regional block, spinal/epidural or general anaesthesia
• Hospital stay: 1 day for arthroscopic cases; 1–2 days for open and complex cases
• Radiographs, MRI and, where required, CT are reviewed for preoperative planning; prophylactic antibiotics are given

Surgical Approaches

• Arthroscopic anterior approach: anteromedial and anterolateral portals; visualisation of the anterior cartilage surface
• Arthroscopic posterior approach: posteromedial and posterolateral portals; particularly for posterior medial talar dome lesions
• Medial malleolar osteotomy (open): the most commonly used open approach for access to the posterior part of the medial talar dome; the osteotomy is fixed back with screws
• Lateral malleolar osteotomy / temporary removal of the fibula: for the lateral talar dome (rarely)
• Anterior arthrotomy: for some anterior lesions and for allograft placement
• Hybrid approaches: arthroscopic assessment plus a limited open procedure

Arthroscopic Debridement and Removal of Loose Bodies

• This is the first step in every case. Free cartilage or bone fragments within the joint (loose bodies) are removed with a grasper or small instruments
• Unstable or unattached cartilage fragments are cleared
• A partial synovectomy is added where there is associated synovitis

Microfracture / Drilling / Nanofracture

This is the most commonly used bone marrow stimulation technique. Indication: small lesions (<1–1.5 cm²) with intact subchondral bone support.

• The edges of the lesion are debrided back to stable hyaline cartilage (creating vertical walls)
• Fine holes (1–2 mm) are made in the subchondral bone with an awl (microfracture), a K-wire (drilling) or dedicated nanofracture instruments, approximately 3–4 mm apart
• The mesenchymal stem cells in the blood that seeps from these holes lead to the formation of fibrocartilage
• Advantages: minimally invasive, no additional implants required, short operative time

Retrograde Drilling

• Preferred in stable lesions where the overlying cartilage is intact and there is only oedema or a small cyst in the subchondral bone
• A tunnel is drilled towards the lesion under fluoroscopic guidance from the lateral or medial surface of the talus, through the sinus tarsi or by a transmalleolar approach
• The tunnel may be filled with bone graft or a substitute
• Advantage: healing is stimulated without breaching the intact cartilage surface

In Situ Fragment Fixation

• Stage II–III stable but detached cartilage-bone fragments are repositioned and fixed
• Bioabsorbable screws or pins, small metal screws or headless compression screws are used
• This has the advantage of preserving hyaline cartilage
• Indication: a young patient, an acute displaced fragment, and good fragment quality

AMIC (Matrix-Assisted Microfracture)

• A collagen or hyaluronic membrane is placed over the lesion after microfracture to retain the mesenchymal stem cells at the site
• This is a single-stage method that does not require cell culture
• It may be preferred in medium-sized lesions (1–3 cm²) where microfracture alone is insufficient
• It can be performed arthroscopically or open, and is more practical than ACI

Mosaicplasty / OAT (Osteochondral Autograft Transfer)

True hyaline cartilage and subchondral bone are transferred together as a unit. Indication: medium to large lesions (1–3 cm²), particularly where subchondral bone support is compromised.

• Donor site: one or more cylindrical bone-cartilage grafts 4–10 mm in diameter are harvested from the knee on the same side (the non-weight-bearing part of the medial femoral condyle or the trochlear ridge)
• Recipient site: cylindrical tunnels of the same diameter are drilled into the base of the lesion in the talus
• The grafts are inserted into the tunnels by press-fit; the cartilage surfaces are set flush with the surrounding intact cartilage
• A medial malleolar osteotomy is usually required for medial talar dome lesions; it is fixed back with two or three cannulated screws at the end of the operation
• Advantage: transfer of hyaline cartilage, biomechanically superior to fibrocartilage

Osteochondral Allograft Transplantation (OCA)

• The lesion is reconstructed with a fresh talar or femoral allograft from a donor
• It is usually inserted through an anterior arthrotomy; a medial or lateral malleolar osteotomy may be required
• Indication: large (>3 cm²) and deep cystic lesions; failed previous treatment; an alternative to arthrodesis or arthroplasty in young patients
• Advantage: near-complete reconstruction of the joint surface is possible in very large lesions
• Disadvantages: limited tissue availability, slow allograft integration, and a (low) risk of immune response

Autologous Chondrocyte Implantation (ACI / MACI)

This is a two-stage (classic ACI) or single-stage (matrix-based MACI) cellular treatment. Indication: medium to large lesions (>2 cm²), particularly after failed microfracture.

• Stage 1: a small biopsy is taken arthroscopically from a non-weight-bearing area of cartilage; the cells are cultured in the laboratory for 4–6 weeks
• Stage 2: the lesion is prepared through an open procedure; the cultured chondrocytes are placed beneath a periosteal flap (classic ACI) or a collagen membrane (MACI)
• Advantage: formation of hyaline-like cartilage; long-term results are promising

Open ORIF and Bone Grafting

• Open ORIF (in situ fixation): for large, acute, displaced stage III–IV fragments. The lesion is reached through a medial malleolar osteotomy or an anterior arthrotomy; the bed beneath the fragment is debrided, bone graft is added and the fragment is fixed with cannulated or bioabsorbable screws
• Open bone grafting (cystic lesions): for large subchondral cysts the cyst is curetted and filled with autologous (iliac crest) or allogeneic bone graft or a bone substitute. The overlying cartilage surface is preserved or reconstructed

Ankle Arthrodesis (Salvage Surgery)

• Performed for advanced arthritis that develops after several failed OCD treatments
• The joint surfaces are removed and the tibia is fused to the talus (with screws or a plate)
• Joint movement is permanently lost; however, pain is reduced dramatically

Implant Options

• Bioabsorbable screws / pins — for in situ fragment fixation
• Headless compression screws (Herbert, Acutrak) — countersunk beneath the cartilage surface
• Cannulated screws — to fix a medial malleolar osteotomy (3.5–4.5 mm)
• Collagen / hyaluronic membranes — for AMIC and MACI
• Autologous bone graft (iliac crest, distal tibia) — for cystic lesions
• Allogeneic bone graft or a synthetic bone substitute — for cystic lesions
• Mosaicplasty instrumentation (osteochondral transfer systems)

Discharge Information and Weight-Bearing Protocol

Arthroscopic cases are usually discharged the same day; a stay of 1–2 days may be required after open surgery or a medial malleolar osteotomy. After surgery the ankle is generally immobilised in a short leg cast, a walker boot or a volar splint. The weight-bearing protocol varies according to the procedure performed:

• Arthroscopic debridement / removal of a loose body: weight bearing as tolerated (in a walker boot)
• Microfracture / nanofracture: non-weight bearing for 4–6 weeks, then graduated
• Retrograde drilling: non-weight bearing for 4–6 weeks (this may be shorter if the cartilage surface is intact)
• In situ fragment fixation: non-weight bearing for 6–8 weeks
• Mosaicplasty / OAT: non-weight bearing for 6–8 weeks
• Allograft transplantation: non-weight bearing for 8–12 weeks
• ACI / MACI: non-weight bearing for 6–8 weeks
• Medial malleolar osteotomy: the osteotomy healing protocol is followed (usually 6 weeks non-weight bearing)
• Ice for 15–20 minutes three to four times a day and elevation are recommended. Analgesics, anti-inflammatories, gastric protection and anticoagulation (until weight bearing) are prescribed. Sutures are removed on day 10–14

Early Postoperative Period (First 3 Weeks)

The aims during this period are wound healing, control of swelling, pain management, maintaining movement of the toes and of the hip and knee, minimising muscle atrophy and continuing thromboprophylaxis.

• Wound monitoring: discharge, marked redness, increased warmth or wound edge separation are monitored. It is important not to wet the wound for the first 10–14 days
• Control of swelling: keeping the leg above the level of the heart (elevation), ice and compression stockings reduce oedema
• Weight-bearing protocol: strict compliance with the programme set for the procedure performed is critical. Early weight bearing increases the risk of graft failure and revision
• Early passive movement: after microfracture, mosaicplasty, ACI/MACI and AMIC, early passive and active-assisted ankle movement exercises support cartilage healing. A CPM machine or manual passive exercises are recommended
• Toe, hip and knee movement: performed three to four times a day within the splint or boot; this reduces swelling and prevents stiffness in the more distant joints
• Pain: once the regional block has worn off, prescribed medication, ice and elevation control the pain
• Thromboprophylaxis: the risk increases during the non-weight-bearing period. Anticoagulation, compression stockings, toe movement and hip and knee exercises are used together
• Nerve monitoring: the superficial peroneal, sural and saphenous nerves lie close to the portals and open incisions; report any numbness or tingling in the toes

Follow-up

• Days 10–14: suture removal and check radiograph
• Weeks 4–6: decision on weight bearing and, where required, a check radiograph of the osteotomy
• Month 3: rehabilitation review and, where required, MRI
• Month 6 and one-year review

After Arthroscopic Microfracture / Nanofracture

• Weeks 0–2: Non-weight bearing with crutches. A walker boot or short leg cast. Early passive and active-assisted ankle movement exercises (with a CPM machine or manually, 4–6 hours a day). Toe, hip and knee exercises. Ice and elevation.
• Weeks 2–6: Non-weight bearing continues. Active movement exercises (flexion, extension, gentle inversion and eversion). Quadriceps and calf isometric exercises. Stationary cycling (with light resistance).
• Weeks 6–8: Graduated weight bearing (partial → full). Transition from the walker boot to a normal shoe. Calf and intrinsic foot strengthening.
• Months 2–4: Full weight bearing; gait normalises. Strengthening with a resistance band. Balance and proprioception exercises. Swimming.
• Months 4–6: Beginning light running in a straight line (with the surgeon's approval). Graduated introduction of sport-specific drills.
• Months 6–12: Full return to sport and high-impact activity with the surgeon's approval. Maturation of the fibrocartilage takes 12 months.

After In Situ Fragment Fixation

• Weeks 0–6: Non-weight bearing with crutches. A walker boot or cast. Early passive movement exercises. Toe, hip and knee exercises.
• Weeks 6–8: The position of the fragment is confirmed on a check radiograph; graduated weight bearing begins. Active movement exercises.
• Months 2–4: Full weight bearing. Strengthening and proprioception. Swimming and stationary cycling.
• Months 4–9: Graduated return to sport; high-impact activity at months 9–12.

After Mosaicplasty / OAT

• Weeks 0–6/8: Non-weight bearing with crutches. Early passive movement exercises are critical. Rehabilitation of the donor site (the knee) proceeds in parallel (quadriceps strengthening, knee movement).
• Weeks 8–12: Graduated weight bearing. Active movement exercises. Light strengthening. Stationary cycling and swimming.
• Months 3–6: Full weight bearing; gait normalises. Strengthening and proprioception intensify. Beginning light running in a straight line (around months 4–5).
• Months 6–9: Graduated return to sport-specific drills.
• Months 9–12: Full return to contact and high-impact activity with the surgeon's approval.

After Allograft Transplantation

• Weeks 0–8/12: Non-weight bearing (graft integration takes longer). Early passive movement exercises. Quadriceps and hip exercises.
• Weeks 12–16: Graduated weight bearing. Active movement exercises.
• Months 4–9: Strengthening and proprioception. Return to low-impact activity.
• Months 9–12: Graduated return to sport; full high-impact activity at months 12–18.

After ACI / MACI

• Weeks 0–6: Non-weight bearing; a CPM machine is recommended. Early movement exercises are critical for cartilage maturation. Toe and distant joint exercises.
• Weeks 6–12: Graduated weight bearing. Active movement exercises. Light strengthening.
• Months 3–6: Full weight bearing; return to low-impact activity.
• Months 6–12: Graduated return to sport.
• Months 12–18: Complete maturation of the cartilage; full return to high-impact activity.

Special Notes for Cases with a Medial Malleolar Osteotomy

• The osteotomy takes 6 weeks to heal; the weight-bearing protocol is set taking both the OCD and the osteotomy into account
• Screw removal at the osteotomy site is usually not required; if it causes pain, it is considered after months 9–12
• Active inversion (turning the foot inwards) is limited for the first 6 weeks

Criteria for Return to Sport and Activity

• Full, pain-free ankle range of motion
• Calf muscle strength reaching at least 85–90% of the other leg
• At least 25 repetitions on the single-leg heel rise test
• Single-leg balance tests (30 seconds with the eyes closed)
• 90% symmetry on single-leg hop tests
• No swelling or pain after activity
• Pain-free completion of sport-specific drills
• Approval of the surgeon and physiotherapist (with a check MRI where required)

Recommended Activities

• Stationary cycling and the elliptical trainer (non-weight-bearing cardiovascular activity)
• Swimming (once the wound has healed)
• Low-impact strengthening exercises
• Pilates and yoga (with the surgeon's approval)
• Running in a straight line (from months 4–6, with the surgeon's approval)

To Be Avoided in the First 6–9 Months

• Jumping and high-impact activities
• Running on uneven ground
• Sports involving pivoting and cutting movements
• Heavy lifting
• Contact sports

Lifestyle and Recovery Advice

• Perform your home exercise programme every day; the passive movement exercises in particular are critical for cartilage healing
• Do not smoke (it seriously impairs cartilage and bone healing and markedly increases the risk of failure)
• Maintain tight blood glucose control if you have diabetes
• Healthy weight: every excess kilogram places additional load on the ankle and the repair site
• Strict compliance with the weight-bearing programme (early weight bearing causes the graft to collapse)
• Take care to keep the leg above the level of the heart (particularly for the first 3 months)
• Use ice and compression stockings regularly for 3–6 months
• Where there is associated ankle instability, physiotherapy and, if required, ligament repair; where there is malalignment, an osteotomy should be considered
• Attend your regular follow-up appointments (weeks 4–6, month 3, month 6, one year, and MRI where required)

Expected Outcomes

Recovery after talar OCD surgery varies with the procedure performed and the size of the lesion. Return to daily activities is possible at 4–6 months after arthroscopic microfracture, with return to sport at months 6–9. Recovery after mosaicplasty / OAT takes longer (6–9 months to daily activities and 9–12 months to sport). After allograft and ACI / MACI, complete recovery may take 12–18 months.

Mild stiffness, swelling and pain after activity may continue for 6–12 months; this is expected and settles with time. Patient and disciplined rehabilitation, correction of any associated pathology and stopping smoking are the fundamental determinants of success. Most patients report a marked improvement in quality of life compared with before surgery.