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.

Osteoarthritis (OA) is the most common form of arthritis worldwide. It is a major cause of disability in the adult population with its prevalence expected to increase dramatically over the next 20 years. Although current therapies can alleviate symptoms and improve function in early course of the disease, OA inevitably progresses to end-stage disease requiring total joint arthroplasty. Mesenchymal stromal cells (MSCs) have emerged as a candidate cell type with great potential for intra-articular (IA) repair therapy. However, there is still a considerable lack of knowledge concerning their behaviour, biology and therapeutic effects. To start addressing this, we explored the secretory profile of bone marrow derived MSCs in early and end-stage knee OA synovial fluid (SF).

Subjects were recruited and categorised into early [Kellgren-Lawrence (KL) grade I and II, n=12] and end-stage (KL grade III and IV, n=11) knee OA groups. The SF proteome of early and end-stage OA was tested before and three days after the addition of bone marrow MSCs (16.5×10^3, single donor) using multiplex ELISA (64 cytokines) and mass spectrometry (302 proteins detected). Non parametric Wilcoxon-signed rank test for paired samples was used to compare the levels of proteins before and after addition of MSCs in early and end-stage knee OA SF. Significant differences were determined after multiple comparisons correction (FDR) with a p<0.05.

Gender distribution and BMI were not statistically different between the two cohorts (p>0.05). However, patients in early knee OA cohort were significantly younger (44.7 years, SD=7.1) than patients in the end-stage cohort (58.6 years, SD=4.4; p<0.05). In both early and end-stage knee OA, MSCs increased the levels of VEGF-A (by 320.24 pg/mL), IL-6 (by 826.78 pg/mL) and IL-8 (by 128.85 pg/mL), factors involved in angiogenesis; CXCL1/2/3 (by 103.35 pg/mL), CCL2 (by 1187.27 pg/mL), CCL3 (by 15.82 pg/mL) and CCL7 (by 10.43 pg/mL), growth factors and chemokines. However, CXCL5 (by 48.61 pg/mL) levels increased only in early knee OA, whereas PDGF-AA (by 15.36 pg/mL) and CXCL12 (by 497.19 pg/mL) levels increased only in end-stage knee OA.

This study demonstrates that bone marrow derived MSCs secrete angiogenic and chemotactic factors both in early and end-stage knee OA. More importantly, MSCs show a differential reaction between early and end-stage OA. Functional assays are required to further understand on how the therapeutic effect of MSCs is modulated when exposed to OA SF.

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: To compare clinical results and MR images of different arthroscopic techniques used in our hospital (mosaic-plasty, microfractures, fixation or excision and curettage).

Materials and methods: This was a retrospective study of 40 cases of knee ostochondritis in adolescent patients operated in our hospital between 1992 and 2005 assessed by location, sex, surgical technique and MRI.

Results: Mean age at surgery was 16 years of age. The most frequent location was the medial condyle. The right knee was involved in 74% of cases. Mosaic-plasty was carried out in 26% of cases, microfractures in 42%, excision and curettage in 26% and fragment osteosynthesis in 6%. Mean follow-up was 7 years and in the microfracture group there were 25% poor results and 75% excellent results. The results were poor in 100% of the group that underwent fragment osteosynthesis. In the excision and curettage group there were 50% good results and 50% excellent results. In the mosaic-plasty group there were excellent results in 100% of the patients. The MRI showed incorporation and a normal profile of the subchondral surface in all the patients of the group that underwent mosaic-plasty. In the group of patients with microfractures there was cartilage in the microfractured area in 75% of the patients. In fragment osteosynthesis there was MRI evidence of non-union in 100% of cases. In the excision and curettage group there was only partial regeneration in 100% of cases.

Conclusions: In comparison with the other techniques described, better outcomes are seen when mosaic-plasty is the treatment used in advanced stages of knee osteochondritis in adolescent patients.

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.

We describe a 46-year-old woman who presented at intervals of seven years with osteonecrosis of the outer end of both clavicles. The clinical, radiological features and the appearances of the bone scans are described. Although the condition may be confused with osteolysis there is a clear histological distinction between the two conditions. If the symptoms fail to respond to conservative treatment, excision of the outer end of the clavicle is recommended.