GH Joint Osteoarthritis

History

The medical histroy of GHOA should contain the following topics [4]:

• Evaluation of nature of pain

  • Site

  • Onset

  • Character

  • Radiation

  • Associations

  • Time course

  • Exacerbating / Relieving factors

  • Severity

  • Examples for GHOA:

    • Worsens gradually until patients might have trouble to sleep

    • Activity related

    • Felt deep in the joint or to the posterior aspect of the shoulder

    • Night and rest pain

• Degree of functionality of the joint

• Triggering mechanisms

• Surgical and/or traumatic history

• Repetitive motions in the past (work or sports-related)

Disease specific diagnosis

Physical examination of the shoulder starts with palpation of the anterior and posterior shoulder regions. Patients with GHOA experience pain as the swollen synovia and osteophytes are palpated [2]. The patient’s range of motion might be limited in all directions, as the directions often coincide with the swollen synovia. However, external rotation is affected the most [3]. It is important to note that both active and passive motions are limited and painful. If only active motions are affected, other diagnosis such as tendinosis, rotator cuff tears and bursitis are to be considered [2].

There are no specific tests, the examiner can perform in order to rule out or rule in GHOA. That is why radiological imaging plays a crucial role in diagnosing GHOA with x-ray imaging being by far the most important modality. At least three images should be made one in each true anteroposterior, lateral (Y-view) and axillary view [3]. Typical radiological findings such as: joint space narrowing, subchondral sclerosis, osteophytes, and subchondral cysts can be found [3]. An early sign of OA in the glenohumeral joint is a inferomedial humeral osteophyte spur ("goat-beard"), whereas findings in later stages are humeral head deformities with loss of concentricity and posterior subluxation of the humeral head in axial views [3]. Examples can be found on Radiopedia. According to a specific classification by Samilson-Prieto, GHOA can be divided into three different groups [2]. The classification takes the before mentioned inferomedial osteophyte size into consideration.

• Grade I: inferior humeral osteophyte <3 mm

• Grade II: inferior humeral osteophyte 3-7 mm

• Grade III: inferior humeral osteophyte >7 mm

Walch has also found a classification system, where the joints are classified by the morphology of the respective glenoid:

• Type A: central humeral head position in the glenoid (55%)

  • • A1: minor central glenoid erosion

    • A2: major central glenoid erosion, humeral head protruding into the glenoid cavity

• Type B: posteriorly subluxated humeral head, asymmetric wear (40%)

  • • B1: posterior glenoid erosion with retroversion of the glenoid >10°

    • B2: biconcave posterior glenoid deformity

• Type C: Pprimary dysplastic glenoid retroverstion >25° (5%)

Another classification by Kellgren-Lawrence similar to other joints in the body is as followed [2]:

• Grade 0: no radiographic signs of OA

• Grade 1: uncertain joint space narrowing and possible presence of osteophytes

• Grade 2: definitive osteophytes and narrowing of the joint space

• Grade 3: osteophytes, severe joint space narrowing, subchondral sclerosis and possible bony deformation

• Grade 4: multiple osteophytes, marked narrowing of the joint-space, severe sclerosis, and definitive bony deformation

It should be noted that neither of these classifications are recognised by associations, although they might help visualising the course of disease.

Differential Diagnosis

It is difficult to distinguish OA from possible underlying causes of OA, since most of these pathologies can coexist. Primary differential diagnosis is adhesive capsulitis, as it is one of the only pathologies with a limited passive range of motion [3].

• Adhesive capsulitis

• Tendinosis of the long head of the biceps

• Rotator cuff tears

• Bursitis

• Subacromial impingement

• Cervicalgia