Knee

The knee joint is the largest – and most complicated – joint in the human body. This hinge joint connects the thigh bone (femur) with the shin bone (tibia) and enables us to extend and bend our legs. The knee also permits a certain degree of sideways rotation of the foot and shin bone. These movements are limited by the inner and outer lateral ligaments. The two cruciate ligaments also play a central role. They provide stability at the front and back of the knee.

Between the surfaces of the upper and lower leg bones there is a layer of meniscal tissue. It acts as a buffer and plays a key role in the transmission of force. Like cartilage, the inner and outer meniscus can be damaged. For example, if it slips between the joints during fast rotary movements it can tear or even separate from the bone.

The kneecap, which you can easily feel and move with your fingers, is connected to the femur. The force from the thigh muscles is transmitted via the kneecap to the lower leg.

The knee capsule surrounds the entire knee joint. When the leg is fully extended (straight), the capsule is taut and stable. The tendons are protected by various bursae, which are positioned in places subjected to large amounts of friction.  

Here are some of the common problems and diseases that can affect the knees.

This is not a comprehensive list.

• Osteoarthritis of the knee
• Dislocated kneecap (luxating patella)
• Torn cruciate ligament

Osteoarthritis of the knee

Osteoarthritis of the knee refers to signs of wear and tear in the knee joint, particularly on the cartilage. The treatment depends on the severity of the pain and includes everything from resting the joint to cortisone injections and surgery.

Dislocated kneecap (luxating patella)

If the kneecap becomes dislocated from its usual position, this is known as a luxating patella. Often it moves back into place by itself. However, the more frequently the knee becomes dislocated, the more harm it does – because each time the cartilage gets slightly damaged. And damaged cartilage can later lead to osteoarthritis. A dislocated kneecap can be caused by a fall or a congenital defect. Women are more frequently affected by a luxating patella than men, because women tend to have less pronounced muscles that stabilise the knee joint and hold the kneecap in place. Weak connective tissue can also increase the risk of a dislocated kneecap.

Strengthening specific muscle groups through physiotherapy can help to increase the stability of the joint. If a person has suffered from multiple dislocations then it is worth considering surgery, such as an operation to tighten the ligaments that hold the kneecap securely in its channel of movement.

Torn cruciate ligament

When the knee twists or buckles, the front or rear cruciate ligaments can tear. Although the cruciate ligaments play an important role in stabilising the knee joint, a torn cruciate ligament does not always require surgery. Depending on the injury and the patient’s needs, sometimes physiotherapy exercises [link] may be enough to sufficiently stabilise the knee joint. Often it takes a while before the patient and the orthopaedic specialist can establish whether the knee joint will remain stable during everyday activities and sport and meet the patient’s individual needs.

If the patient is also suffering from related injuries, such as a pinched meniscus or other ligament injury, then it is usually advisable to undergo surgery – particularly to prevent additional damage to the joint cartilage. Top athletes often get their cruciate ligaments reconstructed using plastic surgery in order to regain full use of the joint.

1)- Partial and total knee replacement:

There are many conditions which require a knee replacement surgery / knee arthroplasty surgery. The most common is osteoarthritis. This means that the cartilage of the knee has been worn out, resulting in the top of the shin bone (tibia) and the bottom of the thigh bone (femur) rubbing together. This is very painful and stops you being able to move your knee as once you did.

Knee replacement can be total or partial. In partial knee replacement surgery only one side of the knee joint is replaced. Since there is less bone replacement, the procedure and recovery period is also short.

In total knee surgery, there is complete replacement of both sides of knee joint. It is one of the most common procedures. The surgery is replacing the joint with prosthesis which is either metal alloy or high density plastic.

At Mediclinic City Hospital Bone and Joint department, we have a busy joint replacement service whereby we offer both partial as well as total knee replacement in the cases of severe osteoarthritis, rheumatoid arthritis or post injury arthritis. We also pioneered robotic total knee replacement surgery in the region to improve the accuracy and precision of implant positioning.

To learn more about this surgery, click here. Click here to learn about the robotic knee surgery procedure which is performed only at Mediclinic City Hospital.

2)- Revision knee replacement:

Due to multiple factors, at times patients need to undergo a revision of knee replacement. Factors such as wear and tear of implant/prosthesis, bone loss, injury etc. may cause discomfort and require revision surgery to improve mobility and relieve pain.

Your orthopaedic surgeon will diagnose the source of your discomfort and will design your treatment plan.  Revisional surgery, which may require cleaning or removal of the implant, may take longer than your initial replacement surgery  

3)- Osteotomies of knee:

The word osteotomy means “cutting of the bone”. In knee osteotomy, either the tibia (shin bone) or femur (thigh bone) is cut and reshaped, in order to relieve the pressure on patient’s knee joint.

This procedure is performed for patients who are experiencing early stage osteoarthritis which is impacting one side of the knee joint.  This can be cut to straighten it into normal position. 

4)- Knee ligament surgery:

The knee is stabilised by belts consisting of collagen fibres and is embedded in soft tissues called ligaments. There are four major ligaments in the knee that connect to the thighbone (femur) to the shin bone (tibia).  When any of them are damaged, this can cause the knee joint to become instable, limiting its movement. Surgery is considered an effective option if other medical treatments are not delivering the right result.

a)- Arthroscopic primary and revision ACL & PCL reconstruction surgery (paediatric as well as adult)

The function of the anterior cruciate ligament (ACL) is mainly as a stabiliser of the knee in frontal and backward directions but also in rotation. Typically, the lesion happens a during sudden twist movement or torsion during sports activities. The patient usually mentioned that they heard or felt a ‘crack’ in the knee, which can later rapidly swell. After clinical examination and MRI, the treatment plan is decided which is either conservative if no instability complaints are predominant, otherwise surgery is considered.

To learn more about this surgery click here

The posterior cruciate ligament (PCL) is one of the major ligaments of the knee that is located at the back. Unlike the ACL (anterior cruciate ligament), the PCL very strong because it twice the size of the ACL, meaning PCL injuries are very rare and caused by direct impact such a car accidents or football tackles. Treatment is based on the severity of injury to the PCL.

For reconstruction, arthroscopic surgery is performed which is a minimally invasive procedure using a special camera and surgical tools which help the surgeon assess and repair the injury without needing to perform open surgery.

b)- Knee multi-ligament reconstruction for complex ligament injuries including LCL / MCL / MPFL

In multi-ligament knee injuries, two or more ligaments are injured which is due to high impact/ force such as falling from a height or sports activities. In such injuries, often other problems also surface such as a dislocated kneecap or a fracture which requires special attention by an orthopaedic surgeon to perform reconstruction surgery to rebuild the damaged ligaments and prevent further complication caused by unstable knee such premature osteoarthiritis.

5)- Patello-femoral stabilising surgery including osteotomies and trochloeplasty

Patello-femoral pain is pain around the front of the knee and kneecap. Stabilising surgery is performed on patients who constantly face patella (knee cap) dislocation even with minimum activity, if physiotherapy is not effective.

Based on the age and condition, surgeries are tailored for the patient and may involve both bone and soft tissue procedures. Procedures include osteotomies (commonly performed tibial tubercle osteotomies) and trochloeplasty which is a procedure that reshapes the groove where knee cap glides. These surgeries are performed to stabilise the knee and avoid future complications.

6)- Arthoscopic meniscus surgery - repair and replacement

Each knee contains two C-shaped discs of cartilage called menisci that connect thighbone to shinbone. The menisci provide three basic functions to the knee:  distribution of pressure, sliding and stability. 

If a person sustains a severe injury, surgery might be considered. Common surgeries performed are arthroscopic repair where through small incision, in which the surgeon will stitch the tear, guided by a camera. Other common surgeries are partial, where a piece of meniscus is removed for the knee to function better, synthetic meniscus and meniscal transplant.

To learn more about the surgery: click here 

7)- Cartilage preservation surgery including osteochondral injuries  ( ACI / MACI)

Cartilage preservation surgery is a treatment option for knee pain which is caused by damage to articular cartilage, a smooth surface that caps the ends of bones and allows joints to glide smoothly. Injuries such as an osteochondral injury which range from a small crack to bone breaking off inside the joint may require preservation surgery.

The most common preservation surgery performed is autologous chondrocyte implantation (ACI) and now its newer version, MACI, which is the newest generation of cartilage transplantation that can preserve a patient’s knee cartilage by harvesting new cartilage cells in defective cartilage. 

8)- Joint injection therapy

Joint infiltration or joint injection is the injection of therapeutic substances directly into a joint. The substances administered are usually pain-killers, local anaesthetics and anti-inflammatory agents such as cortisone.

Inflammation and degeneration of the joints (osteoarthritis) often cause pain. Joint infiltration is an option for injecting drugs directly into an inflamed or damaged joint. In principle, this can be done in any joint. However, it is most commonly used for problems with the hip and knee joints and in the shoulder joint.

The three types of joint injection are: 

• Stem cell therapy
• Plasma rich protein therapy (PRP)
• Visco-supplementation therapy