Calcium Pyrophosphate Dihydrate Crystal Deposition Disease of the Sternoclavicular Joint

[Chondrocalcinosis: idiopathic or manifestation of rare metabolic diseases?]

Calcification in hyaline and fibrocartilage is caused by the deposition of calcium pyrophosphate dehydrate, commonly referred to as chondrocalcinosis. Clinically, this can lead to arthritis symptoms similar to a gout attack -"pseudogout". Nonetheless, also chronic or asymptomatic disease courses are possible. The prevalence of chondrocalcinosis increases with age. The diagnostic workup of degenerative joint disease, therefore, often reveals calcifications of articular cartilage as harmless incidental findings. However, particularly in patients younger than 60 years of age, chondrocalcinosis can be the symptom of an underlying metabolic disease. This review article highlights these rare diseases and presents unusual manifestations of chondrocalcinosis.

Bilateral septic arthritis of the sternoclavicular joint complicating infective endocarditis: a case report

BACKGROUND

Septic arthritis is an infectious disease that commonly affects weight-bearing or proximal joints such as the knee and the hip. The sternoclavicular joint is an unusual site of this entity. It usually occurs in patients with diabetes mellitus, intravenous drug abusers, or those with rheumatoid arthritis. Analysis of the previous literature showed few articles and these described essentially cases of unilateral presentation.

CASE PRESENTATION

We report a rare case of a bilateral septic arthritis of the sternoclavicular joint sustained by a 71-year-old Tunisian woman whose medical history was significant for methicillin-resistant Staphylococcus aureus infective endocarditis 6 months ago. Imaging investigations revealed destruction of the medial extremities of her two clavicles and bilateral collections in the soft tissues around her sternoclavicular joints. She was treated successfully by needle aspiration drainage combined with a 12-week antibiotherapy.

CONCLUSIONS

Bilateral septic arthritis of the sternoclavicular joint is an extremely rare entity, with a paucity of literature. Only early diagnosis, which is obtained from the culture of the joint fluid using needle aspiration, allows satisfactory functional outcome and a good prognosis. Osteoarticular infections should be considered in patients with recent infective endocarditis in cases of fever recurrence.

Histopathological evaluation and expression of the pluripotent mesenchymal stem cell-like markers CD105 and CD44 in the synovial membrane of patients with primary versus secondary hip osteoarthritis

To present the morphological changes of classic primary versus rapidly progressive and secondary hip osteoarthritis (HO) and to examine the expression of two pluripotent mesenchymal stem cell-like markers in the synovial membrane. A prospective observational study was conducted in 57 consecutive cases of radiologically confirmed HO in which total hip arthroplasty was performed. Based on the radiological and clinicopathological features, the cases were divided into three categories: classic primary HO (group A; n=16), rapidly destructive HO (group B; n=24), and HO secondary to avascular osteonecrosis of the femoral head (group C; n=17). Immunostains were performed using the markers CD44 and CD105. The cases from group A were mainly characterized by a marked perivascular inflammatory infiltrate and simple synovial hyperplasia. In group B, the papillary type of synovial hyperplasia was found and presence of chondromatosis, ossification, and ectopic follicles with germinal centers in the subsynovial layer was characteristic, whereas marked calcification and/or ossification were seen in group C. Focal expression of the CD105 and CD44 was noted in the hyperplastic synovial cells and subsynovial layer in cases from group A, whereas synovial cells from group B were diffusely positive for both CD44 and CD105. In secondary HO, CD44 marked the inflammatory cells. Mobilization of the CD44/CD105 positive synovial cells seems to play a role in the genesis of HO. The number of the pluripotent mesenchymal stem cell-like cells derived from the hyperplastic synovial cells might be related to the severity of possible immune-mediated rapidly destructive HO.