Knee: Overview of complaints, causes and treatment

Anatomy of the knee – the interaction of many structures

The knee connects the thigh bone (femur) and shinbone (tibia). The kneecap (patella) lies in front, embedded in the quadriceps tendon. Articular surfaces are covered with hyaline cartilage and are enclosed by the joint capsule with synovial membrane (joint mucosa). Two crescent-shaped menisci (medial and lateral) act as shock absorbers and force distributors. The anterior and posterior cruciate ligaments as well as the inner and outer collateral ligaments ensure stability. Tendons, bursa and the surrounding muscles (especially quadriceps, hamstrings, hip and calf muscles) control function and load transfer.

• Joint partners: femur – tibia – patella
• Buffers: inner and outer meniscus
• Stabilizers: anterior/posterior cruciate ligament, medial and lateral ligament
• Leadership: capsule, synovium, retinacula, patellar tendon
• Dynamics: quadriceps, hamstrings, hip abductors
• Protective structures: bursa (e.g. prepatellar, pes anserinus)

The function of the knee does not only depend on the joint itself. Axial position (X-leg/bow-leg), foot/ankle joint, hip, trunk control and neuromuscular coordination significantly influence strain and pain sensation. That's why we always look at the leg in the entire chain.

Typical symptoms of knee problems

Knee problems manifest themselves in very different ways. The decisive factors are the location, quality and course of pain as well as accompanying symptoms such as swelling, instability or blockage.

• Anterior knee pain: often patellofemoral syndrome, chondropathy, quadriceps/patellar tendon overload.
• Internal or external pain: meniscus irritation/tear, collateral ligament irritation, overloading of the pes anserinus, ITB syndrome (runner's knee).
• Deep joint pain/start-up pain: cartilage damage, beginning osteoarthritis, synovitis.
• Acute swelling/effusion: irritation, inflammation, recent injury (e.g. meniscus, cruciate ligament) – clarification recommended.
• Feeling of instability, buckling: ligament lesions (cruciate ligament/collateral ligaments), muscular deficits.
• Snapping/blockage: possible meniscus lesion or loose joint bodies – orthopedic examination makes sense.

Accompanying signs such as redness, overheating, fever or sudden, severe pain without trauma should be examined by a doctor promptly to rule out rare but serious causes (e.g. infection, acute crystal arthropathy).

Common knee diseases and symptoms

Knee problems arise from overuse, wear and tear, misalignment, sporting stress or accidents. Below is an orientation – detailed information can be found on our subpages.

• Muscles, tendons, ligaments: tendinopathy of the patellar or quadriceps tendon, pes anserinus syndrome, ITB syndrome (runner's knee), strains, irritation of the collateral ligaments.
• Joint, cartilage, synovium: softening of cartilage (chondromalacia), focal cartilage damage, osteoarthritis (gonarthrosis), plica syndrome, synovitis/effusion.
• Meniscus: degenerative tears, traumatic longitudinal/canopy tears, meniscus degeneration with stress and rotation pain.
• Cruciate ligaments and instability: partial or torn anterior/posterior cruciate ligament, functional instability following ligament injuries.
• Patella / patellofemoral system: patellar maltracking, lateral retinaculum shortening, patellofemoral pain, patellar luxation/instability.
• Bone/Structure: Bone marrow edema, stress reactions, fractures, osteochondrosis dissecans; Axial misalignments (varus/valgus) as a risk factor.
• Trauma / Acute Injuries: Distortion, contusion, ligament injuries, meniscus tears, patellar luxation.
• Systemic/inflammatory causes: rheumatoid arthritis, psoriatic arthritis, gout/crystal arthropathy, reactive arthritis, infections (rare but urgent).
• Functional/chronic pain syndromes: patellofemoral pain without structural damage, myofascial causes, central sensitization.

Diagnostics: structured, targeted and gentle

A good diagnosis begins with listening. We record the course, stress and previous illnesses, examine the knee thoroughly and check the entire leg axis. Imaging is added depending on the question - not every knee needs an MRI immediately.

Urgent warning signs include severe pain at rest with fever, a significantly red and overheated knee or a pronounced, painful restriction of movement after an injury. This should be clarified by a doctor as soon as possible.

Therapy: conservative first – combined individually

The aim is to reduce pain, regain resilience and sustainably improve function. In many cases this can be achieved with conservative measures. We combine active therapy, education and – if necessary – temporary help.

• Load control: relative rest instead of complete rest, early, adapted mobilization.
• Acute measures: PECH rule (break, ice, compression, elevation) in the early phase of overload/injury.
• Medication: short-term anti-inflammatory painkillers after benefit-risk assessment; Consider gastric protection and concomitant illnesses.
• Physiotherapy: joint-friendly activation, quadriceps and hip stabilization, leg axis control, proprioceptive training, gradual increase in load.
• Training therapy: progressive strength and endurance programs tailored to the sport and everyday life; Home exercises with clear dosages.
• Aids: Taping, bandages/orthotics for short-term relief and guidance; Insoles for axle/foot problems after examination.
• Injections (if indicated): e.g. B. low-dose cortisone for severe inflammation - cautious, not repeated and after informed consent.
• Effusion management: Puncture if there is severe pressure pain/limited movement, if medically appropriate.

The specific combination depends on the diagnosis, everyday requirements and goals. We define milestones and closely examine the impact.

Regenerative and minimally invasive options – carefully indicated

In selected situations, additional procedures may be useful. The evidence varies depending on the method and findings. We provide transparent advice about benefits, limitations and alternatives - without any promise of cure.

• Hyaluronic acid injections: option for osteoarthritis for short-term symptom relief; Effect varies from person to person.
• Autologous conditioned plasma (PRP): discussed for tendinopathies or early osteoarthritis; Data situation heterogeneous.
• Arthroscopy: for mechanical problems such as blockage due to an unstable meniscus lesion or free joint body - not for sole osteoarthritis without a mechanical correlate.
• Correction options: If the axis is severely misaligned, surgical adjustment can be discussed in specialized centers; previously exhausting conservative measures.

The decisive factors are the symptoms, structural findings, activity level and individual preferences. We make decisions together and based on evidence.

Self-help in everyday life: what you can do yourself

• Weight and loads: Just a few kilograms less relieves the strain on the knee with every step.
• Exercise instead of a protective posture: cycling, brisk walking, aqua training – gentle on the joints and promoting blood circulation.
• Warmth/cold: cold in acute phases, warm in muscular tension; test individually.
• Ergonomics: Adjust the workplace, change positions frequently, use stairs carefully.
• Footwear/Insoles: Cushioning and guidance to match the axle; Vote after investigation.
• Home exercises 2–3 times/week: strengthen quadriceps and hip abductors, stabilize leg axis, stretches for calves/thighs.
• Stress diary: Document stimuli and reactions in order to control training wisely.

If the pain increases, persistent swelling or instability, you should reduce the strain and seek medical advice.

Prevention and safe training

Depending on the sport, adjustments to footwear, bindings (e.g. when skiing) or running technique can be useful. A professional running or movement analysis helps to understand recurring knee problems.

Special patient groups

• Adolescents: Apophysitis such as Osgood-Schlatter or Sinding-Larsen-Johansson is stress-dependent and can usually be treated conservatively.
• Athletes: Often ligament and meniscus injuries; Return to sport based on objective criteria, not just time.
• Older people: Osteoarthritis and muscle weakness are in the foreground; Fall prevention, strength building and walking aids can provide security.
• Postoperative/chronic courses: structured rehabilitation, progressive stress control and recurrence prevention.

Your path to our practice in Hamburg

In the orthopedics department at Dorotheenstrasse 48, 22301 Hamburg, we accompany you from the initial clarification to sustainable stabilization - always with a conservative focus and clear indications for further measures.

In complex cases, we coordinate on an interdisciplinary basis. Operational options are discussed neutrally and, if necessary, referred to suitable centers.

Undersides to focus on the knee

You can find more in-depth information on structures, diagnostics and therapy of individual clinical pictures on these pages:

• Muscles, tendons, ligaments – strains, tendinopathies, collateral ligament injuries
• Joint, cartilage, synovium – osteoarthritis, cartilage damage, plica, synovitis
• Meniscus – tears, degeneration, conservative options and indications
• Cruciate ligaments and instability – diagnostics, training, stabilization
• Patella/patellofemoral system – anterior knee pain, instability
• Bone/Structure – Bone marrow edema, axles, OCD
• Trauma / acute injuries – first aid, assessment, therapy paths
• Systemic/inflammatory causes – rheumatism, gout, infection
• Functional/chronic pain syndromes – pain management, activation