Aim

When a prosthetic joint infection (PJI) is suspected, guidelines recommend performing periprosthetic samples, at least one for histopathological examination and 3 to 6 for microbiological culture. The diagnosis of infection is based on the presence of neutrophil granulocytes whose number and morphology can be variable, resulting in definition of “acute” inflammation. The acute inflammation of periprosthetic tissue is supportive of infection. Since 2007, in our hospital, for all patients with suspected PJI who underwent surgery, from each sample taken by the surgeon, one part has been sent to the pathologist and the other one to the microbiologist. Our aim was to compare histopathological to microbiological results from samples taken intraoperatively at the same site.

Aim and purpose

The clinical management of osteosarcoma differs significantly from that of chondrosarcoma;

Therefore it is extremely important to diagnose these two types of bone tumour accurately. In the absence of a specific marker, differential diagnosis by histochemistry is sometimes impossible, especially between chondroblastic osteosarcoma and conventional chondrosarcoma. The aim of the study was to find an useful diagnostic marker, simple to use for distinguishes chondroblastic osteosarcoma from conventional chondrosarcoma.

Purpose of the study: Propionibacterium acnes (PBA) is an anaerobic Gram-positive commensal bacillus of human skin which can cause bone and joint infections (Lutz 2005, Zeller 200, Levy 2008). The purpose of this work was to evaluate over a given period the frequency of PBA infections and the reality of its role as a pathogenic organism.

Material and methods: A retrospective survey of activity from 2006 to 2008 using bacteriology laboratory data identified 34 patients (22 male and 12 female) with at least one sample collected during an orthopaedic or traumatology surgical procedure that was positive for PBA. The mean number of positive samples was 3.6; 17 from the thoracic limb, 17 from the pelvic limb, involving 16 arthroplasties (4 hips, 6 knees, 5 shoulders, 1 elbow), 13 osteosynthesis procedures, 3 cuff repairs and 1 acromioclavicular procedure. Six of 20 histology samples showed a septic granuloma.

Results: The PBA was the only germ isolated in 18 cases; it was associated with other bacteria in 16 cases. Other blood tests were abnormal (WBC 6800 leukocytes, CRP 25mg/L en average). According to the Lutz classification, three groups of infection could be identified: certain infection with clinical signs and at least two positive samples (n=12), possible with clinical signs but only one positive sample (n=5), and probable without clinical signs and one or more positive samples (n=17). Of the 12 patients in the first group, eight had material (three shoulder prostheses, three hips, one knee and one femoral nail), which had to be removed for six with use of a cemented spacer in four. Mean duration of antibiotics was five weeks. Four patients in this group have not yet achieved cure. In the second group, all samples were taken from a thoracic limb and had another germ in four cases; all patients have achieved cure. In the third group, the samples were systematic (two shoulder arthroplasties, two repeated cuff repairs, five revision prostheses, four nonunions and four material removal); only one sample was positive in ten cases and only five patients were given antibiotics; all achieve cure.

Discussion: This series is in agreement with the literature: frequent localization on a thoracic limb, association with another germ, questionable attribution to PBA. Patients meeting the criteria of the first group should be treated. If a PBA infection is suspected, samples should be repeated, with prolonged culture; this attitude should be validated prospectively.

Purpose of the study: The proximal humerus is a common localization for solitary endchondroma. Levy (Clin Orthop2004, 431) emphasized the frequency of associated muscle and tendon disease. Treatment is generally curettage-autograft filling. Use of calcium phosphate bone substitute has been validated (A. Uchida et al. J Bone Joint Surg (Br) 90, F. Gouin Rev Chir Orthop 95, R. Mirzayan J Bone Joint Surg (Am) 2001). This retrospective analysis was conducted to determine the signs and symptoms and report the results of surgical treatment obtained in a consecutive series of 15 patients with metaphyseal enchondroma treated in the same unit.

Material and methods: This series included twelve women and three men, mean age 48.2 years (range 38–73). All complained of pain. Two also had signs of calcification and six presented a cuff tendinopathy. Eight had had one or more joint injections. On average, the enchondromas measured 3.1 cm on the ap view and 3.6 cm on the lateral view. Magnetic resonance imaging (MRI) demonstrated the presence of a subacromial effusion in 13/16 shoulders, supraspinatus tendinopathy in six, calcifications in three, and acromioclavicular arthropathy in three. Curettage was followed by filling with biphased tricalcium phosphate (SBM, Lourdes) associated in nine shoulders with acromioplasty-bursectomy and in two with resection of a calcification.

Results: There were no postoperative complications. Mean follow-up was six months. All patients recovered joint motion, seven were pain free, six complained of pain at exercise and two had episodic pain. There were no local signs of substitute intolerance. Follow-up was greater than one year in 12 patients and greater than two years in eight: seven shoulders were pain free, three presented pain at exercise, and two required analgesic drugs. Radiographically, the limit between the bone substitute and the cancellous bone was imprecise; the bone substitute could not be readily visualized in four shoulders, had faded out in three, and was visible in five.

Discussion: The association of enchondroma and a rotator cuff pathology is common suggesting the tumor could affect disease expression. Imaging provides strong arguments favoring a benign disease. Use of bone substitute for filling is reliable and avoids the need for an iliac graft.

Conclusion: A fortuitously discovered or painful enchondroma of the humerus should be treated by curettage-filling with bone substitute as soon as the nature of the tumor has been clearly identified and/or strong uptake on scintigraphy visualized. This is a supplementary operative argument suggesting an associated cuff pathology.