Do I need a cartilage specialist or a general orthopaedic surgeon?

Cartilage problems sit across general orthopaedics and a smaller group of surgeons who focus on “joint preservation” (trying to keep the native joint surface working for as long as possible). Both can be appropriate, but they tend to see slightly different patterns of disease and offer different menus of procedures.

What should I ask at my first cartilage appointment?

Pre-surgery discussions tend to work best when they stay practical: whether surgery is actually needed, what the alternatives are, what the main risks and trade-offs look like, what recovery involves, and how experienced the team is with the specific procedure being discussed.

About the diagnosis (what is actually damaged)

• “What structures are involved—cartilage only, or also bone, meniscus, ligaments, or alignment?”
• “Where exactly is the defect (e.g., patella, femoral condyle, talar dome) and what are its measurements on MRI—length/width and surface area?”
• “What grade is it (Outerbridge or ICRS)—in plain English, is this a superficial wear area or a full-thickness defect?”
• “If this is an ankle problem, does it meet the definition of an osteochondral lesion of the talus (cartilage plus underlying bone), and what stage or stability features matter in my case?”

About non-surgical options (and what ‘success’ would mean)

• “What non-operative options are realistic for this specific size and location, and for how long are they usually tried?”
• “What would count as success—pain reduction, return to walking, return to running, or return to pivoting sport?”
• “What features (for example, instability or malalignment) would make non-operative care less likely to work?”

About surgical options (and why one is being recommended)

• “Which joint-preserving procedures are on the table here, and which are not—and why?”
• “Where would techniques such as microfracture/bone-marrow stimulation, OATS/mosaicplasty (osteochondral autograft), osteochondral allograft (OCA), or cell-based repair fit for this lesion size and bone involvement?”
• “If a scaffold is being considered, what problem is it aiming to solve—stabilising the repair clot, filling a defect, or addressing bone loss?”

About experience and set-up (volume and team questions)

• “How many of this specific procedure do you perform each year, and is it routine at this hospital?”
• “If more than one technique is reasonable, what is the team’s experience across those options (e.g., OATS versus OCA for larger defects)?”
• “Which other clinicians are involved—specialist physiotherapy, radiology, or a cartilage/joint-preservation team?”

About outcomes, risks, and rehabilitation timelines

• “What outcomes are typical for lesions like mine (size, grade, and location), and what are the main reasons results fall short?”
• “What are the key risks for this procedure (including donor-site problems with autograft, where relevant)?”
• “What is the rehabilitation plan—weight-bearing milestones, physiotherapy schedule, and when impact sport might be considered?”

How surgeons decide between symptom control, repair, and replacement

Cartilage decisions usually follow a stepwise pathway, because a small focal defect is a very different problem from diffuse “bone-on-bone” arthritis. In practice, the same staging logic is often applied to the ankle as well as the knee, including osteochondral lesions of the talus (OLTs) where cartilage and underlying bone are both involved.

A practical four-stage pathway

First-line care is usually symptom control: structured physiotherapy, activity modification, and simple pain relief. This stage is often the starting point even when imaging shows a defect, particularly after an ankle sprain or fracture where symptoms may settle over time.

The next step, in some pathways, is injection-based or other symptom-focused support to reduce pain and calm inflammation. (These approaches are not the same as restoring a damaged joint surface, and suitability depends on diagnosis and context.)

When symptoms persist and the problem is clearly a focal defect, surgeons consider cartilage restoration procedures. In the ankle, the 2024 DGOU recommendations support debridement plus bone marrow stimulation for OLTs smaller than about 1.0 cm² without a bony defect, and recommend considering adding a scaffold for lesions larger than 1.0 cm²; bigger or cystic defects are more often considered for osteochondral transplantation, with systematic reviews reporting good-to-excellent results in about 87% but donor-site morbidity around 16.9% for autograft approaches.

Finally, when damage is diffuse rather than focal, the decision often shifts away from complex cartilage restoration and toward broader joint-level options (which can include realignment procedures in selected patients, or joint replacement when appropriate).

What shifts someone along the pathway

Severity grading helps structure the discussion: systems such as Outerbridge or ICRS broadly range from softened/superficially worn cartilage to full-thickness loss with exposed bone. Size and depth then narrow the options.

Across both knee and ankle, choice of stage is also strongly shaped by the whole-joint context—age, activity demands, limb alignment, meniscus and ligament status, defect location, and whether the joint is otherwise “healthy” or already showing broader degeneration. That is why cartilage clinics and textbooks emphasise detailed, joint-preservation-style assessment rather than picking a procedure from MRI measurements alone.

Where microfracture fits now

Microfracture (a bone marrow stimulation technique) remains best supported for relatively small OLTs and is included among established joint-preserving options for focal defects. Even so, published outcomes are not uniformly strong across all stages: a 2025 retrospective series across 97 OLT operations reported complete symptom resolution in 56% and partial improvement in 25%, with worse results in stage IV lesions and only moderate success rates for bone marrow stimulation. This helps explain why many specialist centres reserve microfracture for carefully selected, smaller defects—especially when there is concern that a larger, deeper, or recurrent lesion will need a more structural solution such as grafting.

How osteochondral lesions of the talus are assessed and treated

An osteochondral lesion of the talus (OLT) refers to a focal area of damage on the talar dome (the top of the ankle bone) that involves both the joint cartilage surface and the underlying subchondral bone.

Symptoms are often described as deep ankle pain with swelling and reduced range of motion, sometimes with mechanical features such as catching or locking, and difficulty returning to impact activities like running. In clinical practice, this presentation may follow an injury initially labelled a “simple sprain”, with symptoms persisting beyond the expected recovery window for soft-tissue sprain alone.

Assessment typically combines the history of a specific sprain or fracture with imaging that clarifies lesion size, depth and stability. Plain X-rays can identify some lesions and related bone changes, but MRI is commonly used to assess the cartilage surface, bone oedema, and whether a fragment appears unstable. CT may be added in certain cases to define bony architecture (for example, a cystic defect) when surgical planning is being considered.

Formal staging systems are used to guide decisions, but the practical elements are usually the same across systems: whether the defect is stable or unstable, how large it is (surface area), and how much bone is involved (for example, a contained defect versus a cyst or void). Arthroscopic grading systems (including ICRS grades) are often referenced when describing full-thickness cartilage loss and the condition of the surrounding rim, while radiographic and MRI-based classifications focus on fragment stability and subchondral bone involvement.

Treatment is generally organised as a stepwise ladder rather than a single “best” operation for every lesion. The 2024 DGOU recommendations provide a practical threshold-based example: debridement plus bone marrow stimulation for lesions smaller than about 1.0 cm² without a bony defect, and consideration of adding a scaffold for lesions larger than 1.0 cm². For bigger or cystic defects, DGOU summarises systematic-review evidence reporting good-to-excellent clinical results in roughly 87% after osteochondral transplantation, alongside recognised donor-site morbidity approaching 16.9% for autograft approaches.

These size-and-bone-based steps set up the main “beyond microfracture” decision point: when a lesion is too large, too deep, or too structurally complex for marrow stimulation alone, surgeons typically weigh osteochondral grafting (autograft or allograft) against other reconstructive strategies in carefully selected cases.

Where OATS, OCA and MACI fit for ankle cartilage repair

Once an OLT becomes too large, too cystic, or too recurrent for marrow-stimulation alone, the discussion often shifts to “structural” repairs that bring new cartilage and bone into the defect, or to scaffold-and-cell approaches aimed at forming a more durable surface. In most ankle pathways this step comes after persistent symptoms despite nonoperative care and, in many cases, after prior debridement and bone marrow stimulation (microfracture/drilling). For context, the 2024 DGOU recommendations place debridement plus bone marrow stimulation in lesions smaller than about 1.0 cm² (when there is no bony defect), with scaffold augmentation considered as lesions get larger—so OATS and fresh osteochondral allograft generally sit beyond that simpler end of the spectrum.

OATS / mosaicplasty (autograft osteochondral transplantation)

OATS aims to replace the damaged talar surface with one or more cylindrical “plugs” of living cartilage attached to supporting bone, taken from the patient (autograft) and press-fitted into the prepared defect.

The trade-off is that autograft has a donor site. The DGOU 2024 evidence summary reports good-to-excellent clinical results in roughly 87% of patients after osteochondral transplantation, but also highlights donor-site morbidity reaching 16.9%—a meaningful consideration when choosing between autograft and other approaches.

In clinical series, outcomes are often reported as sustained improvements in pain and function at mid- to longer-term follow-up. For example, one long-term evaluation of “large cystic” OLTs (>150 mm²) treated with primary OATS reported mean pain scores improving from about 7 to about 3 and AOFAS scores from roughly 67 to roughly 89 at a mean follow-up of about 84 months, with around 80% rating results good/excellent. Another series of lateral OLTs followed for a mean 68.5 months reported large gains in FAOS and FAAM scores and return to pre-injury sport in about 82%. A 2025 prospective comparison study also reported marked improvements after OATS and return to sport of 90% in that cohort.

Indication-wise, OATS is often considered when an OLT is clearly focal but “big enough” to need a mechanically solid repair—particularly when prior bone marrow stimulation has not delivered a durable result. Even when it is single-stage, it is technically demanding, because matching the talar curvature and avoiding a step-off matters to ankle mechanics.

Osteochondral allograft (OCA)

Fresh osteochondral allograft transplantation uses donor osteochondral tissue to resurface the talus in a single operation, replacing both cartilage and bone and aiming to restore the joint contour. A 2025 report of hemitalus allograft transplantation for large OLTs described the procedure as safe and effective with improvements in patient-reported outcome scores, supporting its role as a joint-preservation option in selected large lesions.

MACI and other cell-based repair (where evidence is mixed)

Cell-based cartilage implantation is used in some settings, but guideline summaries for the ankle highlight uncertainty: the 2024 DGOU recommendations report no evidence of any additional benefit from autologous chondrocyte implantation (ACI) for OLTs.

Across all three pathways (OATS, OCA, and cell-based/scaffold-based options), head-to-head superiority trials remain sparse, and results can vary with lesion stage, size and prior surgery. The shared goal is joint preservation—reducing pain and improving function while trying to delay (and in some cases avoid) later procedures such as ankle fusion or replacement—using a technique that matches the defect’s size and bone involvement.

Choosing a surgeon and service for complex cartilage repair

In practice, the biggest differences between cartilage services show up in what they do every week (case volume and technique range) and how they support the months of rehabilitation that follow. This section keeps the focus on practical checks and published guidance, rather than behind-the-scenes reference codes or acronyms alone.

For complex knee cartilage restoration and ankle osteochondral lesion surgery, surgeon “fit” is often clearest when a clinician can describe a joint-preservation plan that matches the defect pattern and the wider joint mechanics—and can also describe what happens if the first operation is not the last.

A simple service-level checklist (relevant in the UK whether NHS or independent) is:

• Clear subspecialty focus documented as knee joint preservation/cartilage restoration or foot and ankle surgery (rather than only general arthroplasty).
• Regular performance of the exact procedures being discussed, such as osteochondral autograft transfer and fresh osteochondral allograft for larger lesions.
• A realistic “plan B” for persistence/recurrence—particularly important in the ankle, where a 2025 retrospective series across 97 OLT operations reported 56% complete symptom resolution and 25% partial improvement, with worse outcomes in stage IV lesions.
• Rehabilitation infrastructure, including named specialist physiotherapy pathways and a clear weight-bearing and return-to-sport plan (even if final timelines vary).
• Access to imaging and interpretation, with MRI review that links measurements and staging to an actual decision pathway.

Consultation questions can be adapted into a centre-comparison set that avoids re-litigating the whole diagnosis:

• “For defects like this (location, size, and bone involvement), which 2–3 techniques are used most often here, and why?”
• “How many osteochondral graft procedures are done in a typical year at this hospital, and what proportion are revision cases?”
• “Which techniques are used less often now (for example, standalone marrow-stimulation in larger lesions), and what has driven that change in practice?”
• “If the first-line repair fails, what is the next step in this service—repeat repair, grafting (autograft vs allograft), or a different salvage pathway?”
• “What are the ‘make-or-break’ parts of rehab for this operation, and how is adherence supported over the first 3–6 months?”

Availability can legitimately shape choices. The 2024 DGOU recommendations for OLTs describe where debridement/bone marrow stimulation, scaffold augmentation, and osteochondral transplantation tend to sit; they also highlight trade-offs such as donor-site morbidity with autograft.

Referrals are often strengthened by a short, concrete packet brought via a GP, physiotherapist or sports doctor: the MRI report (date and key measurements), a symptom timeline from the original injury, prior treatments (including any arthroscopy), and a clear functional goal (for example “running 5 km” or “pivoting sport”).