What a chondral lesion in the hip actually is

Being told you have a chondral lesion in the hip can sound alarming, but understanding what it actually means helps clarify the options available to you.

The hip is a ball-and-socket joint where the rounded femoral head sits inside the cup-shaped acetabulum of the pelvis. Both surfaces are covered in hyaline articular cartilage — a smooth, glassy tissue a few millimetres thick that allows the joint to glide with minimal friction and absorbs load during walking, climbing stairs, and impact activities. A chondral lesion is a focal area of damage confined to this cartilage layer, most commonly affecting the acetabulum. Crucially, it does not penetrate the underlying bone — that would be an osteochondral lesion, a distinct and more complex problem.

Hyaline cartilage contains no blood vessels and no nerve supply. This absence of vascularity means that, unlike skin or muscle, it cannot mount a healing response on its own. Without blood-borne repair cells reaching the damaged area, focal lesions do not resolve — and evidence suggests they tend to enlarge over time if left unmanaged.

This matters clinically because a focal chondral lesion and widespread osteoarthritis are not the same thing. Generalised cartilage thinning across the whole joint surface — the hallmark of osteoarthritis — calls for a different management pathway. A focal lesion, by contrast, is a discrete defect in an otherwise functioning joint, and that distinction is what makes joint-preservation techniques a realistic consideration for many patients.

Why chondral lesions develop in the hip

Several distinct mechanical processes can produce a focal chondral lesion, and identifying which one applies matters as much as characterising the lesion itself.

Femoroacetabular impingement (FAI) is the most common structural driver. In cam-type FAI, an abnormal bony prominence at the femoral head–neck junction repeatedly grinds against the acetabular rim during flexion and rotation, typically shearing cartilage from the anterosuperior acetabulum — often producing a Grade IV delamination pattern alongside a concurrent labral tear. Pincer-type FAI, where the socket rim over-covers the femoral head, creates a different injury pattern: so-called contre-coup damage to the posterior acetabular cartilage as the femoral head levers against it. Most symptomatic patients have elements of both.

Acute trauma can damage cartilage in a single event. A posterior hip dislocation, a high-impact fall, or a collision in contact sport can shear cartilage directly from the subchondral bone — damage that may not be apparent on initial plain radiographs.

Repetitive mechanical loading — common in distance runners, cyclists, and workers performing sustained squatting or lifting — can exceed the cartilage's tolerance gradually, producing focal breakdown before any generalised joint-space narrowing develops. The same process can occur in patients with mild hip dysplasia or other structural variants that concentrate load unevenly across the joint surface.

The practical implication is straightforward: treating a chondral lesion without correcting the mechanical cause is unlikely to produce a durable result. Where FAI is present, surgical correction of the impingement is typically planned alongside cartilage repair — addressing the root cause and the resulting damage in the same pathway.

How chondral lesions are graded

Clinicians use the Outerbridge Classification as the standard framework for describing how serious a chondral lesion is — four grades that map directly onto treatment decisions.

• Grade 1 — the cartilage surface remains intact but has softened and may show blistering. Symptoms can be present even though no structural breach has occurred.
• Grade 2 — partial-thickness fissuring or fragmentation affecting less than 50% of the cartilage depth, with a defect smaller than 1.5 cm in diameter.
• Grade 3 — deeper fissuring penetrating more than 50% of cartilage depth, diameter greater than 1.5 cm, but the subchondral bone beneath remains covered.
• Grade 4 — full-thickness cartilage loss with exposed subchondral bone. This is the most severe pattern and is the grade most commonly associated with cam-type FAI damage at the anterosuperior acetabulum.

Why lesion size matters as much as grade

Grade alone does not determine treatment. A Grade 3 defect measuring 1.5 cm² and a Grade 3 defect measuring 5 cm² will not follow the same surgical pathway. The widely used thresholds are roughly under 2 cm², 2–4 cm², and above 4 cm²: marrow-stimulation techniques are generally considered appropriate only for smaller defects, while regenerative procedures such as AMIC and MACI are indicated for the mid-size and larger range respectively. Larger or post-traumatic defects involving underlying bone may require osteochondral grafting.

In practice, the acetabulum — the socket — is the most frequently affected site, and an MRI scan or diagnostic arthroscopy will establish both the grade and the approximate defect size. Knowing these two figures before a consultation gives patients the information they need to have a meaningful conversation about which restoration pathway is most appropriate for them.

Symptoms and diagnosis

Deep groin pain that worsens with activity — walking, stair-climbing, or pivoting — is usually what brings patients to a consultation. The discomfort tends to sit in the groin crease or front of the hip rather than the outer hip, and may be accompanied by clicking, clunking, or a catching sensation during movement. Stiffness after rest that eases with gentle activity is common, and some patients describe an occasional feeling of locking or giving way, particularly after sustained sitting.

These symptoms overlap considerably with those of FAI, labral tears, and hip bursitis — conditions that frequently coexist with a chondral lesion rather than occurring in isolation. Clinical examination, conducted in standing, supine, prone, and lateral positions, provides useful information but cannot reliably distinguish between these diagnoses on its own. Imaging is generally required to reach a firm conclusion.

Imaging options

Plain X-rays are the necessary starting point, establishing joint-space narrowing and any bony features associated with FAI, but cartilage itself is not visible on radiographs. MR arthrography (gadolinium-enhanced MRI) is the current gold standard for visualising hip chondral lesions: injected contrast distends the joint capsule, improving resolution and allowing lesion location, depth, and approximate size to be characterised before any treatment is planned.

Where standard MRI is poorly tolerated or produces clinically ambiguous images, dynamic or open MRI can offer a practical alternative, allowing assessment in more natural joint positions and accommodating patients who find conventional closed-bore scanners difficult.

Arthroscopy as the definitive step

MR arthrography is highly informative, but the grade estimated on imaging may understate the true extent of damage seen directly at surgery. Diagnostic arthroscopy remains the definitive method for confirming lesion grade, extent, and the condition of surrounding tissue — with the added practical advantage that treatment can begin within the same procedure rather than as a separate step.

Treatment pathways from conservative care to cartilage repair

Matching the right intervention to a specific lesion grade, defect size, and patient profile is the central task of hip cartilage management. The pathway moves from least to most invasive, and for most patients several steps are considered before surgery is discussed.

Conservative care

For Grade 1–2 lesions, or where surgical candidacy is limited by age or general health, guided physiotherapy remains the starting point — targeting hip muscle strength and biomechanical load distribution to reduce repetitive stress on the damaged area. Activity modification, weight management, and short-course NSAIDs support symptom control. Intra-articular injections such as platelet-rich plasma (PRP) may be used as adjuncts to reduce inflammation and support the local healing environment, though in cartilage-repair pathways they are supportive rather than restorative.

Chondroplasty (arthroscopic debridement)

Arthroscopic smoothing of frayed cartilage edges — chondroplasty — can reduce mechanical symptoms such as catching and locking. It provides symptomatic management, not cartilage restoration, and is best understood as a step that buys time or accompanies other procedures rather than a standalone repair.

Microfracture

For small defects historically under 2 cm², microfracture — drilling tiny holes into subchondral bone to recruit marrow stem cells — was the standard first surgical choice for over two decades. Current evidence shows a meaningful limitation: the fibrocartilage it produces tends to break down within two to three years, and the technique can damage the subchondral bone plate in ways that complicate any subsequent repair attempt. Microfracture is no longer considered a first-line modern choice for most patients.

AMIC

Autologous matrix-induced chondrogenesis (AMIC) addresses microfracture's shortcomings by covering the marrow-stimulation site with a protective collagen scaffold membrane. This single-stage approach is currently considered a first-line surgical technique in UK practice for Grade 3–4 defects approximately 2–4 cm² in patients aged 18–55. The scaffold guides new tissue formation and may produce more durable repair tissue than microfracture alone.

MACI

For larger defects — typically in the 2–10 cm² range — matrix-induced autologous chondrocyte implantation (MACI) is a two-stage option: the patient's own cartilage cells are harvested at a first procedure, cultured in a laboratory, and reimplanted on a collagen membrane at a second. Published five-year RCT data show superior pain and function scores over microfracture for defects of 3 cm² or above, though it is worth noting that most long-term evidence originates from other joints and is extrapolated to the hip specifically.

ChondroFiller injection

For suitable patients with focal defects, a ChondroFiller injection offers a regenerative route that does not require a theatre procedure. Delivered as an ultrasound-guided outpatient injectable collagen scaffold, it works by recruiting the patient's own progenitor cells into the matrix — a mechanism described as matrix-induced chondrogenesis. Published hip outcomes report modified Harris Hip Score improvements of approximately 30 points in studied patients. It is a distinct pathway from AMIC or MACI and appropriate for different indications.

OATS and osteochondral allograft

For smaller contained defects of 1–2 cm², osteochondral autograft transfer (OATS or mosaicplasty) transplants cylindrical plugs of bone and cartilage from low-load areas of the same joint. Where defects are larger, post-traumatic, or involve underlying bone loss, fresh osteochondral allograft (OCA) transplantation from a donor is an option — though availability and timing constraints apply.

FAI correction and end-stage considerations

Whichever cartilage restoration technique is selected, any underlying structural cause — most often FAI — is typically addressed at the same time to prevent the lesion progressing again. Where damage is diffuse, high-grade, or associated with advanced osteoarthritis that has not responded to joint-preserving measures, hip replacement remains the appropriate end-stage pathway. Individual suitability across this full range requires consultant assessment.

Getting a hip cartilage assessment in Lincolnshire

Across this article, one principle threads through every section: the right treatment depends on knowing the lesion grade, its size, the underlying cause, and what the patient needs from their hip — and that combination of information can only be assembled through a proper specialist assessment.

If you have been told you have a chondral lesion, FAI, or unexplained hip pain that is limiting your activity, a specialist hip assessment is the appropriate next step. That assessment brings together clinical examination, imaging review, and a structured conversation about grade, defect size, and your activity goals — the same factors that determine where any individual patient sits within the treatment pathway described above.

Lincolnshire Hip has consulting clinics in Sleaford and Grantham, serving patients across Lincolnshire and the wider East Midlands. Lincolnshire Hip is part of the MSK Doctors group and accepts patients without referral for hip assessment.