Knee pain

Knee pain is a very widespread condition

Knee pain

Knee pain is a very widespread condition

The knee joint is the largest joint in the human body. Every day it is exposed to tremendous stresses. Over time, this can lead to degenerative changes. What's more, our knees are very vulnerable to injury. Thus it comes as no surprise that many people complain of knee pain. Knee pain is a very widespread condition.

Anatomy of the knee joint

Anatomy of the knee joint

The knee

The knee or knee joint is the largest joint in the human body. The knee is a pivotal hinge joint. It permits flexion and extension of the leg as well as slight internal and external rotation when flexed.

Causes of knee pain

Due to the complex anatomy of the knee, knee pain can have many causes. However, these can be divided into knee pain resulting from injuries and knee pain resulting from degenerative changes.

While a knee injury often causes pain in young people (for example during sports), degenerative changes of the knee often lie behind the pain experienced by elderly people. But there are also other factors that can cause knee pain (e.g. overstrain in sports or hereditary factors such as congenital knee deformities). Only a thorough medical examination can pinpoint the exact causes of the knee pain in individual cases.

Knee pain resulting from injuries

Acute knee injuries are caused by the action of external forces (e.g. contusions, kicks or impacts in the case of road traffic accidents or during sports). The following anatomical structures are often affected: 

  • Collateral ligaments (medial or lateral collateral ligament) 
  • Cruciate ligaments (anterior cruciate ligament, posterior cruciate ligament) 
  • Menisci (medial meniscus, lateral meniscus) 
  • Kneecap (e.g. luxation of the patella)
  • Cartilage 
  • Bone

Football, downhill skiing, handball or basketball are particularly high-risk sports for knee injuries. 

Experts recommend proceeding according to the so-called RICE rule after acute knee injuries:

R (REST: rest the knee)
I (ICE: cool the knee quickly to prevent swelling)
C (COMPRESSION: apply pressure dressing or bandages to counteract swelling)
E (ELEVATE: elevate the leg to improve venous return)

Knee pain resulting from degenerative changes

Our knees are exposed to tremendous stresses every day. Over time, this can lead to degenerative changes that are associated with a breakdown of the cartilage layer. The shock absorber function of the cartilage suffers and the joint can feel stiff and painful.

This explains why more and more people suffer from osteoarthritis of the knee (joint degeneration) with increasing age. Osteoarthritis of the knee (gonarthrosis) is a progressive process. In the early stages, the knee pain only occurs occasionally (e.g. on weight-bearing, after longer periods of rest), while in the advanced stage, the cartilage damage is so extensive that the bones practically rub against each other. The pain occurs more often and is more intensive.

Symptoms of knee pain

Knee pain can onset acutely or as a chronic process:

  • Acute knee pain starts suddenly – such as after an injury.
  • Chronic knee pain manifests gradually – initially slight pain, which intensifies with time – as in osteoarthritis of the knee, for example.

Quality of knee pain: how does the pain feel?

  • Dragging, pressure, stabbing, cramp-like pain or a dull continuous pain
  • External signs: effusion, redness, swelling, warm to the touch, restricted freedom of movement

Localisation of knee pain: where does it hurt?

  • On the inside (e.g. injury of the medial collateral ligament, injury of the medial meniscus, bowlegs)
  • On the outside (e.g. injury of the lateral collateral ligament, injury of the lateral meniscus, knock knees)
  • Anterior knee pain (e.g. patella tip syndrome, Osgood-Schlatter disease, patellofemoral pain syndrome due to muscular imbalance)
  • Posterior knee pain (hollow of the knee, e.g. Baker's cyst)

Dependency on the situation: when does it hurt?

  • On weight-bearing (e.g. jogging, going up stairs)
  • After longer periods of rest (e.g. after sitting down for a long time)
  • In the morning (start-up pain)

Treatment of knee pain

The treatment of knee pain depends on the cause. The following conservative therapeutic options are often applied:

  • Anti-inflammatory painkillers and ointments
  • Heat or cold treatment
  • Orthopaedic medical devices (insoles, supports, orthoses, orthopaedic shoes)
  • Physiotherapy
  • Muscle training (strengthening and stretching) 
  • Electrotherapy and ultrasound treatment

However, there are also situations, in which an operation is no longer avoidable. But these days, many operations can be performed almost atraumatically by arthroscopy.

Knee supports and orthoses from medi


1 Klein, Dr Christoph (2014): Orthopaedics for patients. Understanding medicine. Remagen: Published Michels-Klein