Clinical manifestations of the patients with glenohumeral osteoarthritis who underwent shoulder arthroplasty ーa comparison with cuff tear arthropathy

Abstract

Purpose: Mechanisms underlying development and progression of primary glenohumeral osteoarthritis (GHOA) have not been proven conclusively yet. As an anatomical factor, Critical Shoulder Angle (CSA) has been received attention and Bjarnison AO et al. recently reported that CSA < 30 degree was a significant risk factor for developing GHOA. Meanwhile, GHOA is possibly a part of generalized OA affected in multiple joints. The aim of this study was to investigate clinical manifestations of the patients with GHOA who underwent shoulder arthroplasty compared with cuff tear arthropathy (CTA) patients. Methods: In 40 consecutive cases who underwent shoulder arthroplasty (TSA/RSA/Hemiarthroplasty) in our hospital, patients with RA, humeral head necrosis, fracture, hemodialysis, and who underwent contralateral shoulder arthroplasty before were excluded, and remaining 27 cases (20 female), with a mean age of 78 years (64−86) were retrospectively analyzed. Patients were allocated to GHOA group (n=16) and CTA group (n=11) according to preoperative imaging studies. 1) Age, sex, 2) Bilateral CSA, 3) Serum CRP, 4) Detection of calcium pyrophosphate dihydrate (CPPD) crystals in ipsilateral synovial fluid, 5) Motion pain and radiological change in contralateral shoulder, and 6) History of TKA/THA, were assessed and compared between the groups. Mann-Whitney U test and Fisher’s exact test were used for statistical analyses and P<0.05 was considered significant. Results: 1) Age and sex were similar between the groups. 2) CSA was bilaterally smaller in GHOA (Figure 1) and patients with CSA < 30 degree was more frequent in GHOA (13/16) compared with CTA (3/11). 3) Serum CRP was similar between the groups. 4) Positive CPPD shoulder was more frequent in GHOA (10/16) compared with CTA (2/11). 5) Motion pain and radiological change in contralateral shoulder were more frequent in GHOA compared with CTA (Figure 2). 6) History of TKA/THA was more frequent in GHOA (11/16) compared with CTA (3/11). All patients in GHOA group had at least 1 factor in 2), 4), 5), 6). Mean number of these factors was significantly higher in GHOA (2.9) than in CTA (1.0). Conclusions: Both anatomical and systemic factors possibly associate with pathogenesis for developing end stage GHOA, which are completely different from CTA. CSA is an important anatomical factor as reported, however, severe GHOA possibly underlies generalized OA, and CPPD deposition disease would associate with the pathology. Although multicenter study including larger number of patients is warranted, our results would provide better understanding for GHOA development and progression. When clinicians undertake arthroplasty for severe GHOA, it should be careful for contralateral shoulder and other joints to achieve better clinical outcome after the surgery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)