“Milwaukee shoulder”—association of microspheroids containing hydroxyapatite crystals, active collagenase, and neutral protease with rotator cuff defects. i. clinical aspects

Abstract

Four women, aged 63 to 90 years old, presented with mildly painful shoulders of decreased mobility or stability. Radiographic evidence of a complete tear of the fibrous rotator cuff was present in 7 of 8 shoulder joints. Microspheroids containing hydroxyapatite crystals were seen by scanning electronmicroscopy in 12 of 13 synovial fluid samples. All synovial fluids showed activated collagenase and neutral protease activity. This constellation of findings represents a heretofore undescribed syndrome which we have designated "Milwaukee shoulder."The shoulder is the most mobile joint in the human body. The glenohumeral joint contributes most to this remarkable range of motion (1). Such mobility has been achieved at the sacrifice of joint stability, which depends largely on the integrity of the fibrous conjoint tendons of the surrounding muscles+ommonly called the rotator cuff (1).

Destructive Spondylarthropathy in Hemodialyzed Patients

“…Sections were collected on a copper grid, which is responsible for the additional peaks. strengthened by McCarty et al who observed destructive arthropathy of the shoulders associated with the presence of microspheroids containing hydroxyapatite crystals, active collagenase, and neutral protease in the synovial fluid (28). Moreover, these authors showed that the synovial lining cells could phagocytize hydroxyapatite crystals (29) and that apatite crystals stimulated the secretion of collagenase and neutral protease by synovial cells in culture (30).…”

Adenosine triphosphate pyrophosphohydrolase and neutral inorganic pyrophosphatase in pathologic joint fluids. Elevated pyrophosphohydrolase in calcium pyrophosphate dihydrate crystal deposition disease

“…As noted by Silcox and McCarty (4), the PPi concentrations in CPPD deposition are lower during attacks of pseudogout. The "miscellaneous" group ( Table 2) included 1 patient with Milwaukee shoulder syndrome (25) who had the second highest PPi concentration recorded in this study. A correlation between synovial PPi concentration and ATPPPH activity was observed ( P < 0.01; r = 0.71) for all 37 patients studied ( Figure 2).…”

Partial characterization of synovial fluid nucleotide pyrophosphohydrolase

“…Patients were selected by the staff of the Medical College of Wisconsin rheumatology clinic and the consulting staff at the time of diagnostic or therapeutic arthrocentesis, whenever at least 5 ml of SF could be obtained. Joint fluid was obtained from 41 patients: 8 with definite or classic RA, 3 with crystal-proven gout, 4 with primary OA, 12 with chondrocalcinosk (CPPD deposition disease) and with chronic noninflammatory effusions, 2 with pseudogout, 2 with OA secondary to trauma, 3 with Milwaukee shoulder syndrome (18), I with basic calcium phosphate deposition (191, 2 with renal disease treated by hemodialysis, 1 with postseptic arthritis, 1 with systemic lupus erythematosus (SLE), and 2 with undifferentiated chronic arthritis. Thirty-one of the patients were included in a previous study (10).…”