Joint structures of the shoulder: cartilage and capsule

Anatomy: What are the joint structures?

The actual shoulder joint (glenohumeral joint) is formed by the head of the upper arm (humeral head) and the very flat socket of the shoulder blade (glenoid). In order for this ball joint to be guided despite its great mobility, several structures work together.

• Hyaline articular cartilage: smooth coating on humeral head and glenoid; reduces friction and distributes loads.
• Labrum glenoidale: fibrocartilaginous articular lip around the socket; increases the contact area, serves as the attachment of the capsule and the biceps tendon (above).
• Joint capsule: fibrous covering around the joint; contains straps that secure the end positions; Inside lies the synovial membrane.
• Synovial membrane (joint lining): produces synovial fluid to nourish cartilage and as a lubricant; can become inflamed (synovitis).
• AC joint (acromioclavicular joint): small joint between the clavicle and acromion; Cartilage-covered, often affected by arthritic changes.
• Surrounding soft tissues: Rotator cuff, biceps tendon and capsular ligament apparatus work functionally together with the joint structures.

Function: guidance, cushioning, stability

The cartilage, labrum and capsule ensure that the head of the humerus remains centered in the flat socket and that movements occur smoothly. Cartilage surfaces distribute forces and minimize friction. The labrum deepens the socket and acts as a sealing and suction cup mechanism. The capsule limits end positions, provides proprioception (sense of movement and position) and protects the interior of the joint. The synovial membrane nourishes the avascular cartilage and is sensitive to irritation or crystals.

• Shock absorption and load distribution for everyday and sports loads
• Centering and stability in movement (especially overhead)
• Lubrication through synovial fluid
• Protection against entrapment through intact capsule tension

Common problems with cartilage, labrum and capsule – overview

Below you will find the most important diseases and injuries to the shoulder joint structures. Each diagnosis has typical triggers, symptoms and different treatment options. On the linked subpages you can read details about causes, diagnostics and therapy.

• Shoulder joint arthrosis (omarthrosis): Wear and tear of the articular cartilage on the head and socket. The main symptoms are initial stiffness, stress-dependent pain, later pain at rest and restriction of movement.
• AC joint arthrosis: Wear and tear in the acromioclavicular joint, often due to overhead strain. Local pain at the top of the shoulder, tenderness, pain when crossing the arm.
• SLAP lesion: tear of the superior labrum at the insertion of the biceps tendon. Complaints v. a. during throwing and overhead sports with snapping/clicking and deep joint pain.
• Bankart lesion: avulsion of the anterior-inferior labrum after shoulder dislocation; leads to a feeling of instability and recurring dislocations.
• Hill-Sachs lesion: dent on the humeral head after dislocation; can affect stability, especially with larger defects.
• Cartilage damage in the glenoid: Circumscribed defects of the socket or head, traumatic or degenerative; often stress- and movement-dependent pain.
• Frozen shoulder (adhesive capsulitis): Inflammation and shrinkage of the joint capsule with painful progressive stiffness; typically proceeds in phases.
• Synovitis/irritant effusion: Inflammation of the joint mucosa with swelling, warmth and pain when moving; There are many causes (overload, crystals, rheumatic diseases).
• Capsular hyperexpansion or capsular shortening: After trauma, instability or immobilization; leads to hypermobility or restricted movement and pain.

Typical symptoms: How do you recognize problems?

• Pain deep in the joint or at the top of the AC joint, often dependent on stress
• Clicking, snapping or blocking sensation during rotational and overhead movements
• Feeling of instability or “slipping” of the arm
• Start-up pain and morning stiffness, later pain at rest and night pain
• Swelling/warmth in synovitis, often with restricted movement

Warning signs that should be quickly clarified by a doctor: acute misalignment after trauma, pronounced pain at rest with fever, rapidly increasing redness/swelling, sensory disturbances or significant loss of strength.

Diagnostics: Thorough and gradual

At the beginning there is a detailed discussion about medical history, sport, job and previous illnesses. This is followed by a physical examination with movement analysis, capsular tension tests and tested interaction of the shoulder blades.

• Specific tests depending on suspicion: Apprehension/Jobe relocation (instability), O’Brien/Speed ​​(SLAP/bicep anchor), cross-body adduction (AC joint), impingement tests.
• Imaging: Ultrasound for soft tissue diagnosis and effusion assessment; X-ray for joint space, osteophytes, Hill-Sachs; MRI, if labrum is suspected, MR arthrography if necessary.
• Diagnostic infiltration: targeted local anesthetic injection to assign the source of pain (e.g. AC joint vs. glenohumeral).
• Laboratory if inflammation/infection or underlying rheumatological disease is suspected.

The result is an individual treatment strategy. Not every MRI change requires treatment - the combination of findings and symptoms is crucial.

Conservative therapy first: evidence-based and relevant to everyday life

The aim of conservative orthopedics is to relieve pain, calm inflammation, improve the centering of the joint and ensure the ability to perform everyday activities and sports. The approach depends on the diagnosis, stage and life goals.

• Education and activity control: temporarily adjusting strained movements, ergonomic advice (workplace, hobbies).
• Physiotherapy: scapulothoracic control, strengthening rotator cuff and shoulder muscles, capsular stretching programs (e.g. for frozen shoulder) or stabilization (for instability).
• Drug pain therapy: temporary use of anti-inflammatory medications as needed and tolerated.
• Infiltrations: if specifically indicated, cortisone preparations intra- or periarticularly, e.g. B. in the AC joint or subacromial; not too often and with information about the risks.
• Hyaluronic acid: option for osteoarthritis symptoms; Study situation heterogeneous, effect individual – joint decision-making.
• Physical measures: cold/heat, electrotherapy, shock wave for calcification-related complaints (not aimed at cartilage).
• Tape/Orthoses: short-term for relief or proprioception.

Regenerative procedures: Autologous blood (PRP) can be used in selected patients with mild to moderate symptoms, e.g. B. in omarthrosis or persistent synovitis without structural instability. The evidence is growing, but is not consistent across all indications. We discuss opportunities, limits and costs transparently.

Operational options – when do they make sense?

Operations are considered if consistent conservative measures do not help sufficiently or if there are structural instabilities or larger defects. The decision is made individually and after exhausting the non-surgical options, if the situation allows it.

• Labrum refixation (Bankart/SLAP) arthroscopically for persistent instability or stressful tears, especially. a. for those who are physically active.
• Treatment of the Hill-Sachs lesion: depending on size and risk of entrapment, e.g. B. Remplissage in combination with stabilization.
• Cartilage surgery: arthroscopic debridement/smoothing, microfracture for localized defects; Procedures such as shoulder chondrocyte transplantation are case-by-case decisions with limited evidence.
• Arthrolysis/capsule solution for treatment-refractory frozen shoulder after a long conservative phase.
• Shoulder endoprosthetics (anatomical or reverse) for advanced arthrosis with significant reduction in quality of life.

Thorough information about the benefits, risks, alternatives and expected rehabilitation is mandatory. The aim is to manage realistic expectations, not guarantees.

Rehabilitation and course: Patience pays off

The shoulder reacts sensitively to changes in load. Rehab therefore means measured, steady progression instead of short-term overload. The time periods vary depending on the diagnosis: a frozen shoulder can take 6-18 months in phases, while after a labrum refixation, a return to sport is often only possible after 4-6 months at the earliest - depending on the course.

• Pain-adapted training with clear homework from physiotherapy
• Focus on scapula control and rotator cuff for better centering
• Early everyday functional goals (e.g. washing hair, putting on a jacket), later sport-specific
• Regular re-evaluation of the plan in practice

Prevention and self-help in everyday life

• Dose your load wisely: breaks and technique training for overhead sports (throwing, tennis, functional training).
• Ergonomics: screen height, armrest, mouse guidance; Carry loads close to your body.
• Basic exercises 3–4 times per week: external rotation with band, scapula setting, pectoral muscle stretch.
• Warmth before mobilization, cold after exercise in irritable conditions.
• Address risk factors: metabolism, smoking, body weight, sleep.

Self-exercises do not replace medical diagnosis. If the symptoms persist or worsen, have the shoulder specifically examined.

Further subpages on cartilage, labrum and capsule

You can find more detailed information on individual clinical pictures on these pages in our shoulder section:

• Shoulder joint arthrosis (omarthrosis): causes, stages, conservative options, prosthetics at a glance.
• AC joint arthrosis: diagnosis and treatment of local shoulder pain.
• SLAP Lesion: Biceps Anchor, Imaging and Conservative vs. Surgical - for Throwing and Overhead Athletes.
• Bankart lesion: Stability concepts after dislocation, from tape and training to refixation.
• Hill-Sachs lesion: significance of defect size and combined procedures.
• Cartilage damage in the glenoid: focal defects, microfracture and rehabilitation.
• Frozen Shoulder: phase model, pain management and mobilization programs.
• Synovitis/irritable effusion: variety of causes and targeted calming of the inflammation.
• Capsular overstretching or shortening: Diagnosis of capsular tension and therapeutic pathways.
• Muscles, tendons, ligaments: how soft tissues relieve the strain on joint structures.
• Instabilities / dislocations: overview and decision-making for therapy.

Your shoulder in good hands – in Hamburg

As an orthopedic specialist practice in Winterhude (Dorotheenstrasse 48, 22301 Hamburg), we value understandable information, structured diagnostics and conservative, everyday therapy planning. If special examinations or surgical partners make sense, we coordinate these in a coordinated treatment path.