Joint Cartilage Treatment
What Is Articular Cartilage and Why Does It Heal Poorly?
Articular cartilage is the smooth, glossy white tissue that caps the ends of the bones inside a joint. Only a few millimetres thick, it does two jobs: it keeps friction during movement extremely low, and it spreads the load generated by walking, running or lifting the arm so that the bone underneath is protected.
Cartilage has a very limited capacity to repair itself because the tissue contains no blood vessels, no nerves and no lymphatic drainage. Cartilage cells (chondrocytes) are fed by diffusion from the joint fluid and divide very slowly. That is why a skin wound closes within weeks while a cartilage defect does not fill in with tissue of the same quality on its own. When repair tissue does form spontaneously, it is usually fibrocartilage, which is less durable than the original hyaline surface.
The absence of nerve endings inside cartilage also explains why early damage can stay silent. Pain usually appears once the joint lining becomes irritated, fluid accumulates inside the joint, or load starts to reach the bone beneath the cartilage (the subchondral bone). By the time symptoms begin, the damage may already have been present for some time.
How Does Joint Cartilage Get Damaged? Causes and Risk Factors
Cartilage damage is not the result of a single mechanism. Some patients can point to one specific injury, while in others the problem builds up from load accumulated over years. The common causes are:
- Acute trauma: a twisting injury, dislocation, fall from height or a direct blow to the joint. In some cases a fragment of cartilage separates together with the bone beneath it (an osteochondral injury).
- Associated ligament and meniscus injuries: after a meniscus tear or a cruciate ligament tear, load distribution and stability inside the joint are disturbed, and the unprotected cartilage surface wears faster.
- Malalignment and abnormal joint shape: bow legs or knock knees, bony impingement in the hip, and a kneecap that tends to track off centre all concentrate load onto a small area.
- Repetitive overload: jumping and contact sports, occupations involving heavy lifting, and prolonged squatting or kneeling.
- Excess body weight, which markedly increases the pressure carried by cartilage in weight-bearing joints such as the knee and hip.
- Loss of blood supply to the bone beneath the cartilage: osteonecrosis, and osteochondritis dissecans in younger patients, can leave the overlying cartilage without support.
- Inflammatory joint disease and long-standing inflammation inside the joint, together with the age-related decline in the water content and elasticity of cartilage.
Symptoms of Cartilage Damage
Symptoms vary with the size and location of the lesion and with which joint is involved. A small defect may cause no complaints for years, while damage in a weight-bearing area can become obvious early.
- Deep joint pain, usually felt in one specific spot and worse when the joint is loaded.
- Recurrent swelling after activity and a sensation of fullness in the joint.
- Catching, locking or the feeling that something is trapped inside the joint, which becomes more obvious when a loose fragment is present.
- Grinding, clicking or a gritty sensation during movement (crepitus).
- Stiffness after a period of inactivity and a gradual loss of range of motion.
- A sense of giving way or lack of confidence in the joint, particularly when a ligament injury is also present.
None of these findings is specific to cartilage damage on its own. Swelling and redness accompanied by fever, sudden locking of the joint, pain severe enough to prevent weight-bearing, or a visible deformity after trauma are warning signs that need prompt assessment.
Which Joints Are Affected?
Cartilage damage can occur in any weight-bearing joint. The knee is the most common site, with the femoral condyles and the back of the kneecap being typical locations. Knee-specific detail is covered on the knee cartilage injury page.
In the hip, cartilage damage most often accompanies bony impingement and a tear of the labrum at the rim of the socket. In the shoulder, cartilage loss is commonly seen after repeated dislocations or with advanced joint wear. In the ankle, a sprain or a fracture can leave a localised defect on the upper surface of the talus.
Once cartilage loss extends across a wide part of a joint, the picture is no longer a single defect but generalised joint wear, as seen in hip arthritis. The treatment plan is built around that distinction.
How Is Cartilage Damage Diagnosed?
Assessment starts with a detailed history: when the symptoms began, whether there was a specific injury, which movements aggravate them, the demands of work and sport, and any treatment already tried. Examination looks for joint effusion, points of tenderness, range of motion, muscle strength, ligament stability and limb alignment.
Imaging is used to confirm the diagnosis and to define the treatment options:
- X-ray: does not show cartilage directly, but reveals joint space narrowing, bone spurs, malalignment and fractures. In weight-bearing joints, standing films are preferred.
- MRI: the mainstay of cartilage assessment. It shows the location, depth and size of the defect, whether the underlying bone is swollen, and any associated meniscus, ligament or labral problem.
- CT: requested when the bony anatomy, osteochondral fragments or intra-articular fracture lines need to be defined in more detail.
- Arthroscopy: both diagnostic and therapeutic, it allows the cartilage surface to be seen directly and the grade of damage to be established definitively.
Cartilage lesions are classified on grading systems that run from surface softening through to full-thickness loss down to bone. That grade, together with the size and position of the defect, is the main factor determining which treatment is appropriate.
Non-Surgical Management: The First Step
A substantial proportion of patients with cartilage damage bring their symptoms under control without surgery. This approach does not grow cartilage back; the aim is to reduce pain, build the muscle support around the joint, and lower the load reaching the damaged area so that progression is slowed.
- Activity modification: cutting back on impact and twisting movements that provoke pain and spreading load through the day. The joint is not immobilised, because movement is essential to nourish cartilage.
- Weight management: in weight-bearing joints, every kilogram lost reduces the pressure on the joint with each step by a multiple of that amount.
- Physiotherapy and exercise: graded strengthening of the quadriceps, hamstrings, hip abductors and trunk; stretching to maintain range of motion; low-impact activity such as cycling and swimming.
- Pain management: short courses of analgesic or anti-inflammatory medication under medical supervision, and cold application during flare-ups.
- Assistive measures: walking aids, offloading braces, and suitable footwear or insoles can reduce the load carried by the damaged compartment.
This programme needs weeks of consistency before it pays off. Stopping the exercises as soon as the pain eases is the most common reason symptoms return with the first demanding task.
Injections and Biologic Treatments
Intra-articular injections may be considered when symptoms persist despite exercise and load management. An injection is not a treatment on its own; it is always planned alongside a continuing rehabilitation programme.
A corticosteroid injection can reduce pain in the short term during flare-ups where inflammation inside the joint dominates the picture, but the effect is temporary and frequently repeated injections are avoided. Hyaluronic acid preparations aim to support the quality of the joint fluid and are considered in selected patients.
Platelet-rich plasma (PRP) and stem cell based applications are discussed under biologic treatments. These methods may improve pain and function, but they have not been shown to rebuild damaged cartilage; the available evidence is heterogeneous and preparation protocols differ between centres. Patient selection, a realistic discussion of expectations, and placing the injection within a complete treatment plan are therefore decisive.
Surgical Options: An Overview
Surgery is considered for patients who do not respond to non-surgical management, who have mechanical symptoms such as catching or locking, or who have a well-defined deep defect. The choice of technique depends on the size, depth and location of the defect, the patient's age and activity level, and the condition of the bone beneath the cartilage.
- Debridement and chondroplasty: arthroscopic removal of loose fragments and unstable cartilage edges. It aims to relieve mechanical symptoms such as catching and locking; it does not replace lost cartilage.
- Marrow stimulation (microfracture and related techniques): small openings are made in the bone at the base of the defect so that cells from the marrow can reach the area. The tissue that forms is mostly fibrocartilage, and the technique is generally reserved for small defects with a stable, healthy rim.
- Osteochondral grafting: cartilage is transferred together with its underlying bone. The graft may be taken from a low-load area of the patient's own joint (autograft) or from a donor (allograft); allograft is considered for larger defects.
- Cell-based methods: cartilage cells are harvested at a first procedure, expanded in the laboratory, and implanted into the defect at a second operation. This is a two-stage approach used in selected patients, usually for larger lesions.
- Correcting associated problems: ligament repair or reconstruction, meniscus surgery and realignment osteotomy. If these steps are skipped, the repaired cartilage surface continues to face the same excessive load.
The technical detail of these operations in the knee, together with candidate selection and postoperative protocols, is covered on the knee cartilage restoration page.
What Changes When the Wear Is Widespread?
Cartilage repair and transplantation techniques were developed for focal defects surrounded by healthy cartilage. If a large part of the joint surface is worn, the opposing surface is damaged as well, and the X-ray shows clear joint space narrowing, there is no longer a healthy rim for these techniques to rely on.
In that situation treatment shifts from repairing cartilage to managing the joint: exercise and weight control, an osteotomy to shift load towards the healthier compartment when malalignment is present, and partial or total joint replacement in advanced cases. The management of widespread knee wear is set out in detail on the knee osteoarthritis treatment page.
Recovery and Rehabilitation
Recovery after cartilage surgery demands more patience than most orthopaedic operations, because the repair tissue takes months to mature. The programme is tailored to the technique used, the site of the defect and any procedures performed at the same time.
- Protection phase: the repaired surface must be shielded from pressure, which means a period of restricted weight-bearing with crutches. This period is short after a simple debridement and considerably longer after repair or grafting.
- Early motion: joint movement nourishes cartilage and prevents adhesions. Range-of-motion work begins before full weight-bearing is permitted.
- Graded loading: weight-bearing is advanced once pain and swelling are controlled, followed by closed-chain strengthening and balance work.
- Strength and endurance: the goal is to bring the strength of the muscles around the joint close to that of the other side. Cycling and pool-based work are frequently used at this stage.
- Return to activity: going back to running, jumping and pivoting sport is decided by measurable criteria — pain-free full motion, absence of swelling, and strength and movement-quality testing — rather than by the calendar.
Age, the size of the defect, smoking, body weight, baseline muscle strength and adherence to the programme all influence how quickly recovery progresses. Rather than quoting a fixed number of days, it is safer to wait until the criteria for the next stage have been met.
Joint Protection and Prevention
Protecting cartilage is not about avoiding the joint but about managing load sensibly. The following habits help reduce both the risk of new damage and the rate at which existing damage progresses.
- Keep your body weight within a healthy range; in weight-bearing joints this is the single most effective measure.
- Keep the leg and hip muscles strong as part of your weekly routine, since strong muscles absorb the impact reaching the joint.
- Increase training volume or workload gradually, spreading the change over several weeks and avoiding sudden jumps.
- Pay attention to warm-up, suitable footwear and playing surfaces, and correct faulty technique.
- Do not neglect ligament and meniscus injuries; untreated instability accelerates cartilage wear.
- Do not push through pain in a joint. Swelling and pain are warnings that the load is too high.
When Should You See a Doctor?
Diagnosing cartilage damage early, while the defect is still small and the surrounding surface is intact, keeps more treatment options open. Assessment is advised in the following situations:
- Joint pain has lasted several weeks and does not settle with rest.
- The joint swells repeatedly.
- You have catching, locking or the feeling that something is trapped inside the joint.
- The joint gives way or no longer feels reliable.
- Range of motion has decreased, or everyday movements such as stairs and squatting have become limited.
- After an injury you cannot bear weight on the joint, or there is marked swelling or deformity.
To have your symptoms assessed and a treatment plan defined for you, you can contact Assoc. Prof. Serkan Sürücü, and you may also want to review the other conditions covered under knee surgery.