GH Joint Osteoarthritis

Abstract

Glenohumeral OA describes a painful multifactorial joint disease with lesions and degeneration of the hyaline cartilage and subsequent osteophyte development.

Osteoarthritis in the shoulder joint usually has a cause. But typically, no single cause but rather a mix of different underlying pathologies, such as systemic diseases, instability, cuff tear arthropathy or trauma can be held responsible in developing osteoarthritis.

Diagnosis is made by x-ray imaging, where the severity of the disease is measured by size of osteophytes.

Treatment consists of administration of NSAID, glenohumeral injections and physical therapy. In severe cases, arthroplasty may be required.

General considerations

Definition

Glenohumeral osteoarthritis (GHOA) is a painful multifactorial degenerative joint disease, which affects the cartilage and the bones and has typical radiological findings.

Aetiology

Generally, aetiologies can be divided into primary and secondary osteoarthritis. In primary osteoarthritis no specific underlying cause can be found [1]. In contrast, secondary GHOA is a result of different pathologies such as [1]:

  • Trauma to the shoulder

    • Humeral Fracture

    • Dislocation or subluxation

  • GH instability

      • Traumatic

      • Atraumatic

  • Rotator cuff tears

  • Glenohumeral Chondrolysis

  • Glenoid dysplasia

  • Inflammatory arthritis

  • Avascular necrosis

  • Crystal deposition diseases (e.g. CPPD, gout)

Epidemiology

GHOA is more commonly seen in women and the risk of developing manifest OA rises with age, with exponential increase after the age of 50 [2]. Although, compared to other joints of the body, the glenohumeral joint is not affected as much as it is not a weight-supporting joint, typical radiographic findings have been found in 17% of patients with shoulder pain [3]. It should also be noted that secondary OA was only found in 1.3%-1.7%, making primary OA 10 times more common [3]. However, in patients below the age of 50, secondary OA is more common [3].

Clinical presentation

Patients complain about slowly progredient pain deep in or to the posterior aspect of the shoulder, especially after activity. As arthritis progresses, pain during the night and limitations in range of motion become apparent [4]. Additionally, in later stages, symptoms like catching, locking and crepitus become apparent [3]. Clinical presentation of secondary OA of the glenohumeral joint might not be as clear, as concomitant pathologies could mask symptoms of OA.

Diagnosis

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].

Top: x-ray in ap-view of patient with osteoarthritis, inferiomedial humeral osteophyte spur; Bottom: x-ray in ap-view, no pathological findings

Treatment

First line of therapy consists of physical therapy and the use of NSAID regardless of the severity of GHOA as these measurements are also shown to improve postoperative prognosis as well [2]. If patients are irresponsive to first-line therapy or OA is acutely exacerbated, administration of an intra-articular corticosteroid, PRP or hyaluronic acid injection can be attempted, although data on the benefit in glenohumeral OA of this method remains inconclusive [2].

If these measurements do not alleviate any of the symptoms, arthroplasty can be considered. Total- or hemiarthroplasty is indicated especially in senior patients with severe GHOA and functional limitations in their everyday life. In patients with severe posterior erosion and posterior subluxation, the implantation of a reverse shoulder arthroplasty is indicated. In younger patients with severe OA, due to longetivity of the implant, hemiarthroplasty is preferred to prevent early loosening of the glenoid [4]. However, the AAOS changed their recommendation for the use of total shoulder arthroplasty (TSA) over hemiarthroplasty to strong, as TSA was shown to have advantages regarding pain, range of motion, patient satisfaction, patient reported outcomes and lower complication rates [5].

Prognosis and progressive course of disease

As is the case with any other osteoarthritis, glenohumeral osteoarthritis is a progredient disease, especially if left untreated

References

  1. J. Mehl, A. B. Imhoff, K. Beitzel (2018). Omarthrose: Pathogenese, Diagnostik und konservative Therapieoptionen. Der Orthopäde, 47(5), pp.368-376.

  2. Salvador Israel Macías-Hernández, Juan Daniel Morones-Alba, Antonio Miranda-Duarte, Roberto Coronado-Zarco, María de los Angeles Soria-Bastida, Tania NavaBringas, Eva Cruz-Medina, Andrea Olascoaga-Gómez, Laura Verónica Tallabs-Almazan & Chanell Palencia (2017) Glenohumeral osteoarthritis: overview, therapy, and rehabilitation, Disability and Rehabilitation, 39:16, pp.1674-1682, DOI: 10.1080/09638288.2016.1207206

  3. Ibounig, T., T. Simons, A. Launonen, and M. Paavola. 2020. "Glenohumeral Osteoarthritis: An Overview Of Etiology And Diagnostics". Scandinavian Journal Of Surgery, 145749692093501. doi:10.1177/1457496920935018.

  4. Ansok, C. and Muh, S., 2018. Optimal management of glenohumeral osteoarthritis. Orthopedic Research and Reviews, Volume 10, pp.9-18.

  5. Khazzam, Michael, Albert O. Gee, and Michael Pearl. 2020. "Management Of Glenohumeral Joint Osteoarthritis". Journal Of The American Academy Of Orthopaedic Surgeons 28 (19): 781-789. doi:10.5435/jaaos-d-20-00404.