Knee surgery: ligament, cartilage and knee replacement operations explained

Knee surgery is carried out by consultant orthopaedic surgeons, many of whom specialise in the knee or in sports injuries, and who work with anaesthetists, specialist nurses, physiotherapists and radiographers. Procedures range from keyhole arthroscopy to ligament reconstruction, cartilage restoration, realignment osteotomy, and partial or total joint replacement.

Many knee problems are managed without surgery. In many areas, you can refer yourself to NHS community musculoskeletal services for physiotherapy without needing a GP referral, according to the NHS.

The NHS lists a range of causes of knee pain, depending on whether there has been an injury, and advises against self-diagnosis.

A surgeon examines the knee for swelling, stability, range of movement and tenderness. X-rays show joint space and arthritis, while MRI shows ligaments, menisci and cartilage and is often used for injuries, and ultrasound can assess tendons and fluid. Arthroscopy is generally used to treat problems already identified on examination and imaging rather than as a first diagnostic step.

For a meniscus tear, the NHS says some tears get better without treatment, and that if damage is severe arthroscopic surgery may be used to repair or remove the damaged cartilage. Repair is preferred where the tear is in a part of the meniscus with a good blood supply, particularly in younger people.

ACL reconstruction replaces a torn anterior cruciate ligament with a graft, usually taken from a tendon, and is usually considered for people with ongoing instability, particularly those wanting to return to pivoting sport. It requires many months of structured rehabilitation. Cartilage procedures such as microfracture, scaffold insertion or cell-based repair are options for focal cartilage damage in suitable patients.

The NHS says alternatives to replacement include osteotomy, where the shape of the shin bone is changed to reduce pressure on the worn part of the knee, as well as arthroscopy, microfracture and scaffold insertion. In a total knee replacement, the ends of the thigh and shin bones are replaced with metal and plastic parts. In a partial knee replacement only the affected half is replaced, with a smaller cut and a quicker recovery.

After a knee replacement you start walking soon after surgery with help from physiotherapists, using crutches or a frame at first. The NHS says stitches or clips are removed after about 10 days, follow-up takes place around 6 weeks after surgery, compression stockings are usually worn for at least 6 weeks, and return to work is usually after about 6 to 12 weeks depending on your job. Kneeling on the new knee should be avoided until your doctor says you can.

Risks include infection, blood clots, stiffness, persistent pain and, over time, wear of the implant. After knee replacement you will be asked if you consent to your details being added to the National Joint Registry, which monitors outcomes. Ligament and cartilage surgery have their own risks, including stiffness, graft failure and the return of symptoms.

On the NHS, a GP or musculoskeletal service assesses you, tries non-surgical options and refers you to an orthopaedic clinic if surgery is being considered. The NHS lists non-surgical treatments such as weight loss, low-impact exercise, strengthening, walking aids, special footwear or insoles, pain relief and steroid injections, which are tried before replacement.

Privately, you may see a consultant knee surgeon directly, usually with an MRI arranged early. Costs depend on the procedure, implants, anaesthesia, hospital and physiotherapy. Ask for a quote that is itemised, and what the surgeon's experience is with your particular operation.

• Ask whether your problem could settle with physiotherapy and exercise before an operation is considered.

• Ask what the operation involves, what the realistic improvement is and how long before you can drive, work and exercise.

• Bring scan reports, a list of medicines and a note of which activities you want to return to.

• Ask which implant or graft will be used and how outcomes are monitored.

• Get an urgent GP appointment or NHS 111 advice if your knee is very painful, hot and swollen, you have a temperature, or you cannot bear weight.

• Go to A&E or call 999 if your knee has moved out of place or changed shape, you have tingling or no feeling in the leg or toes, or you develop sudden breathlessness or chest pain after surgery.