Focal resurfacing implants to treat articular cartilage damage in the knee

The condition

2.1 Cartilage covers the end of the bones comprising the knee joint. There are 2 types of cartilage in the knee – articular (or chondral) and meniscal. Damage because of injury or disease to a focal area of articular cartilage, particularly in the main weightbearing areas, can cause pain, stiffness, and reduced mobility. Cartilage tissue has very limited self-healing potential and, if left untreated, cartilage damage can progress to osteoarthritis.

Current treatments

2.2 Treatment for people with focal articular cartilage damage typically involves arthroplasty or biological treatment. Arthroplasties include total, bicompartmental, unicompartmental, and patellofemoral knee arthroplasties. Biological treatments include microfracture, osteochondral autograft transfer system, and autologous chondrocyte implantation.

The procedure

2.3 Focal articular resurfacing is aimed at people for whom biological treatments and arthroplasty may not be suitable due to age or other factors.

2.4 Before surgery, the articular cartilage damage is assessed using a pre-planned MRI, an arthroscopy, or both. Then, either the implant is custom-adapted to fit the damaged area, or an implant is selected from a catalogue to closely match the damaged area. Various implant brands, designs, and materials are used for the procedure. The procedure is done under regional (spinal) or general anaesthesia. An incision is made to access the damage site. The damaged area is prepared by removing the damaged bone and cartilage, and drilling a hole for the stem of the implant. The implant is then press-fitted into the damaged area with or without the use of bone cement. The surface of the implant is slightly recessed below the surrounding articular cartilage.

2.5 Rehabilitation after surgery depends on the person and implant. It typically includes either an immediate (as tolerated) or gradual return to full weight bearing and range of motion.