Although the recurrence rate of giant cell tumors of bone (GCTB) is relatively high exact data on treatment options for the recurrent cases is lacking. The possible surgical procedures range from repeated intralesional curettage to wide resection.

214 patients with histologically certified GCTB have been treated at the authors department from 1980 to 2007. 67 patients with at least one local recurrence were included in this study. The mean follow-up was 77.3 months. The data was evaluated according the re-recurrence rate with regard to the surgical procedure for the recurrence.

The mean time until the first local recurrence was 22.0 months; the mean number of recurrences per patient was 1.4. The recurrence occurred in 69.7 % (46 out of 66 patients) within the first two years. If after intralesional procedures (curettage or intralesional resection) no adjunct was used the re-recurrence rate was 58.8 % (10 out of 17 patients) and decreased to 21.7 % (5 out of 23 patients) if a combination of all adjuncts (PMMA + burring) was used. The likelihood of re-recurrence was reduced by the factor 5.508 which was clearly significant (p = 0.016). In case of wide resection no re-recurrence occurred. Seven patients (10.5 %) developed pulmonary metastases. Fourteen patients (20.9 %) finally received an endoprosthesis; 12 due to tumor recurrence, 2 due to secondary arthritis.

Recurrent GCTB can be treated by further curettage with additional burring and cementing with an acceptable re-recurrence rate of 21.7 %. The rate of patients finally needing an endoprosthesis is 20.9 %. Due to the high rate of pulmonary metastases recurrent GCTB may be considered as a severe disease.

The development of local recurrence after multimodal treatment of osteosarcoma is associated with a very poor prognosis. The importance of clear surgical margins has been demonstrated in multiple studies, however up to date there are no studies defining which margin width is safe from an oncological perspective. The purpose of this retrospective analysis was to evaluate whether margin width or other surgical and tumour-related factors influence the development of local recurrence in osteosarcoma patients.

The files of 1867 consecutive patients with high-grade central osteosarcoma of the extremities, the pelvic bones and the shoulder girdle, who had achieved a complete surgical remission during combined-modality therapy on neoadjuvant Cooperative Osteosarcoma Study Group (COSS) protocols between 1986 and 2005, were reviewed. Of those, the data required were available for 1369 patients, who were the subject of this analysis. Eighty of these patients developed a local recurrence during the course of their illness.

The median surgical margin width amounted to 45 mm (range, 0 to 140 mm) in the local recurrence (LR) group and 50 mm (range, 0 to 350 mm) in the non-local recurrence (NLR) group (p=0.106). No statistically significant difference between the two groups was found regarding tumour size (mean, 10.38 cm and 9.53 cm respectively, p=0.169), T-status (p=0.225) and presence of pathological fracture (p=0.231). However infiltration of the soft tissue beyond the periosteum was documented in 58.8% of the patients with local recurrence and only in 36.9% of the rest (p=0.003). Furthermore, in 50% of the LR group the biopsy had been performed in a centre other than the one performing the definitive tumour resection, compared to 30.2% of the NRL group (p=0.001).

In conclusion, the absolute metric width of surgical margins does not define oncological safety. Local recurrence is more likely to develop in patients with soft tissue infiltration beyond the periosteum or those biopsied in a centre other than the one performing the tumour resection.

78 patients (41 male and 37 female) with a revision total knee or hip arthroplasty were enrolled in this prospective study to evaluate the role of new laboratory markers in the diagnostic of deep implant infection.

The average age at the time of surgery was 64 years. Based on intraoperative cultures, 21 patients had a septic and 57 patients had an aseptic revision total joint arthroplasty. White blood cell counts, erythrocyte sedimentation rate, C-reactive protein levels, interleukin-6, procalcito-nin and TNF-alpha were measured in preoperative blood samples. Diagnostic cut of values were determined by Receiver Operating Characteristic curve analysis.

If patients with rheumatoid arthritis and other concomitant infections are excluded the C-reactive protein (> 3.2md/dl) and interleukin 6 (> 12 pg/ml) have the highest sensitivity (0.95). Interleukin 6 is less specific than the C-reactive protein (0.87 versus 0.96). Combining C-reactive protein and interleukin identifies all patients with deep implant infection. Procalcitonin (> 0.3 ng/ml) and TNF-alpha (> 40 ng/ml) are very specific (0.98 versus 0.94)) but have a low sensitivity (0.33 versus 0.43).

The combination of C-reactive protein and interleu-kin 6 is an excellent screening tests for deep implant infection. Highly specific marker like procalcitoninn as well as preoperative joint aspiration might be useful to identify patients with true positive CRP and/or interleu-kin 6 levels.