Knee is modified hinge joint. It is the most complex and largest joint in human body .It is most susceptible to injuries. The four main components of knee are:
Bones –Tibia articulates with femur and forms Tibiofemoral component. Patella articulates with femur to form Patellofemoral component.
Articular cartilage – There are two types of cartilage in knee joint:
- Fibrous cartilage (menisci)-Two C shaped cartilage, called as Medial menisci and Lateral menisci, act as shock absorbers.
- Hyaline cartilage -covers surface along the joints for smooth movement.
- Intracapsular ligaments – Cruciate ligaments (Anterior and Posterior cruciate ligaments), Transverse ligaments, Meniscofemoral ligaments(Anterior and Posterior),Meniscotibial ligaments.
- Extracapsular ligaments- Collateral ligament (Medial and Lateral Collateral ligaments), Anterolateral ligament, Patellar ligament, Oblique Popliteal ligament, Arcuate Popliteal ligament.
Tendons and muscles
Muscles are attached to bones by tendons.
Classification of knee pain :
Anterior knee pain
Pain in the anterior aspect of knee . The possible causes are:
- Patellar subluxation or dislocation
- Singing-Larsen-Johansson lesion (Patellar apophysitis)
- Osgood-Schlatter lesion (Tibial apophysitis)
- Jumper’s knee (Patellar tendinitis)
- Patellofemoral pain syndrome
Posterior knee pain
Pain in the posterior aspect of knee . The possible causes are:
- Baker’s cyst (Popliteal cyst)
- Posterior cruciate ligament injury
- Posterolateral corner injury
- Distal hamstrings injury
- Proximal gastrocnemius injury
Medial knee pain
Pain on the medial aspect of knee . The possible causes are:
- Medial articular cartilage lesion
- Tibial (Medial) collateral ligament sprain
- Medial meniscal tear
- Medial plica syndrome
- Pes anserine bursitis
Lateral knee pain
Pain on the lateral aspect of knee . The possible causes are:
- Lateral meniscal tear
- Fibular (Lateral) collateral ligament sprain
- Lateral articular cartilage lesion
- Iliotibial band syndrome
Other Knee related diseases
- Deep vein thrombosis
- Neurovascular compromise
- Septic arthritis
- Referred pain from hip pathology
- Peripheral nerve entrapment
- Lumbar radiculopathy
Knee Joint Tendons
- Above Patella- Quadriceps Tendon
- Below Patella- Patellar Tendon
- Medial Side Of Knee Joint-Vastus Medialis
- Lateral Side Of Knee Joint-Vastus Lateralis,Iliotibial Band
- Back of Knee Joint-Biceps Femoris ,Semi-Membranous ,Semitendinous ,Gracialis, Plantaris.
- Traumatic injuries- turn or twist, direct blow, violent movement of knee joint.
- Microtrauma – Repetitive action in activities like cycling, running, driving etc.
- Vibration and overuse leads to inflammation of tendon.
- Chronic knee joint pain.
Types of Tendonitis
- Tendon laceration
- Partial tear
- Complete tear
- Pain – Pain usually occurs with the movement of knee joint. Sometimes patient experiences pain even at rest. Location of pain depends upon the type of tendonitis. Radiating pain in lower leg can also be seen in few cases.
- Tenderness – when pressure is applied on the affected tendon, tenderness is present.
- ROM (Range Of Motion) -Joint ROM is restricted. Stiffness persists in the knee joint.
- Skin over the affected tendon feels warm.
- Muscle spasm or atrophy can be usually associated with tendonitis.
To relieve pain and inflammation, anti inflammatory and analgesic drugs are given, like ibuprofen , naproxen etc.
Steroid Injections on the area having tenderness and pain
- Rest and support should be given to the affected joint. Avoid those activities and positions which increase pain.
- Taping – relieves pain by supporting the tendon. Stress and load on the tendon decreases.
- Ice packs-Ice will help in reducing pain and inflammation.
- Ultrasound – it will reduce pain and inflammation.
When pain and inflammation reduces, progressive exercises to restore strength and flexibility of the joint should be started.
Aim of exercise therapy
- To increase the ROM of knee joint.
- To increase the strength of knee joint .
- Retrain the lower extremity and improve movement mechanics of knee joint .
Techniques to achieve desired aims are:
Manual Therapeutic Technique (MTT ) - to increase joint ROM and mobility.
- Soft tissue manipulation
- Stretching – The muscles to be stretched are :Calf muscles, Hamstring, Quadriceps
Therapeutic Exercise (TE)- to regain joint ROM and strength and reduce stress on affected joint.
- Flexibility exercises
- Strengthening-Straight Leg Raising , Leg press , Eccentric Single Leg Decline Squats etc.
Neuromuscular Re-education (NMR) - Retrain the lower extremity and improve movement, mechanics of joint .It will also restore stability.
- Improve movement techniques.
Overall rehabilitation of tendon injuries can be divided into four parts:
Educate- explain the patient what a tendon injury is. Activity modifications should be explained to the patient.
Unload-as tendon inflammation occurs, activity of affected joint should be decreased or minimized as it will help in healing of inflamed tendon. At the same time, isometric exercises can be done to prevent atrophy of muscles. Pain and inflammation can be reduced by cryotherapy or other electrotherapy modalities.
Reload- When pain and inflammation reduces and knee symptoms are under control, progressive exercises to restore strength and flexibility of the joint should be started.
Prevention-In order to prevent recurrence:
- Strengthen muscles involved , so that stress on the tendon can be handled.
- Improve technique
- Always keep a close watch on any change in biomechanics of joints of lower limb.
- If you experience pain during activities, refrain from that activity.
First conservative treatment is given. Surgery is an indicated when conservative measures fail .Different surgical procedures are performed depending on the severity of problem.