As the knee joint ages, the cartilage that cushions the bones may gradually break down, leading to conditions such as knee osteoarthritis. This natural process can result in pain, stiffness, and reduced range of motion, particularly with activities such as climbing stairs or walking for extended periods. Older adults and those with a history of previous knee injuries may be more susceptible to age-related knee changes.

Activities involving jumping, running, or rapid changes in direction are among the more common causes of ACL injuries and meniscus tears. Sports such as football, basketball, and badminton are frequently associated with these injuries.

Repetitive loading of the knee joint over time — often seen in runners, cyclists, and individuals with physically demanding occupations — may contribute to conditions such as patellar tendonitis (Jumper’s Knee) and patellofemoral pain syndrome. These conditions typically develop gradually rather than from a single incident and may worsen if activity levels are not appropriately managed.

Direct trauma to the knee — such as from a fall, road accident, or collision during contact sports — may result in fractures, ligament tears, or cartilage damage. ACL avulsion fractures, in which the ligament pulls away a fragment of bone, may occur following high-energy injuries. Prompt medical assessment is advisable following any significant trauma to the knee.

Inadequate warm-ups, poor landing technique, sudden increases in training intensity, or the use of ill-fitting footwear may place excessive strain on the knee joint. These factors can contribute to ligament sprains, tendon injuries, and stress-related knee conditions. Attention to proper technique and progressive training loads may help reduce injury risk.

Carrying excess body weight may place increased mechanical load on the knee joints during everyday activities such as walking or climbing stairs. Over time, this additional load may contribute to cartilage wear and the development or progression of conditions such as knee osteoarthritis. Weight management through appropriate nutrition and physical activity is generally considered a supportive measure in knee health.

Certain anatomical and inherited factors may influence an individual’s susceptibility to knee conditions. These can include joint alignment, bone structure, and family history of conditions such as osteoarthritis. Individuals with a genetic predisposition to knee problems may benefit from early assessment if they develop symptoms, as well as appropriate preventive strategies where possible.

For many knee conditions, non-surgical treatment approaches may help reduce pain and support functional recovery. The most appropriate option depends on the nature and severity of the injury, as well as individual patient factors. Common non-surgical options include:

• Medications: Where pain is more significant, a doctor may consider prescription medications as part of a broader pain management plan. The appropriate medication will be determined based on individual clinical assessment.
• Activity Modification: Initially, the knee specialist may recommend reducing or altering activities that exacerbate knee pain, such as switching from high-impact to low-impact exercises.
• Corticosteroid Injections: These can provide relief from inflammation and pain. Their use is generally limited due to their potential side effects.
• Viscosupplementation: This approach is commonly used in the management of osteoarthritis and may be considered where appropriate.
• Supportive Devices: Knee braces or shoe inserts can help in stabilising the knee, aligning the leg, and distributing weight more evenly across the joint.
• Cast or Splint: In cases of specific injuries like fractures or ligament tears, immobilising the knee with a cast or splint can facilitate healing by restricting movement.
• Physical Therapy: This involves structured exercise programs to strengthen the muscles supporting the knee, enhancing stability and flexibility. Physical therapy also includes techniques like heat or cold therapy, ultrasound, and electrical nerve stimulation to reduce pain and swelling.

Surgery is typically considered when non-surgical approaches have not adequately restored knee stability, or when the injury is severe enough that reconstruction is clinically indicated — for example, in complete ACL tears, recurrent knee instability, or when associated structures such as the meniscus or cartilage are also affected. The decision to proceed with surgery is made on an individual basis following specialist assessment.

• ACL Reconstruction: As a torn ACL generally cannot be stitched back together, reconstruction involves replacing the damaged ligament with a graft. The graft — which may be taken from the patient’s own patellar tendon, hamstring tendon, or quadriceps tendon, or from a donor (allograft) — acts as a scaffold for a new ligament to develop over time. The procedure is typically performed arthroscopically (keyhole surgery), which involves small incisions and may support a faster recovery compared to open surgery. The graft source and surgical approach are determined by the specialist based on individual clinical factors.
• Knee Arthroscopy: Knee arthroscopy is a minimally invasive surgical procedure in which a small camera (arthroscope) is inserted into the knee joint through a small incision. This allows the surgeon to visualise the internal structures of the knee and address a range of conditions — including cartilage damage, meniscus tears, and loose bodies within the joint — without the need for a large open incision. It is commonly used both as a diagnostic and a therapeutic procedure.
• Meniscus Repair: Where a meniscus tear occurs alongside an ACL injury, surgical repair of the meniscus may be considered at the same time as ACL reconstruction. The suitability for repair depends on the location, pattern, and extent of the tear, as well as the patient’s age and activity level. Not all meniscus tears are suitable for repair; in some cases, partial removal (meniscectomy) may be the more appropriate approach, as determined by the specialist.
• Recovery and rehabilitation after surgery: Recovery following ACL reconstruction typically involves a structured rehabilitation programme, usually commencing shortly after surgery. The timeline for returning to sports or high-demand activities varies depending on individual factors, the nature of the procedure, and adherence to the rehabilitation plan. Patients are generally advised that returning to full sporting activity may take several months, and that this timeline is guided by clinical progress rather than a fixed schedule.