Lack of toxicological side-effects in silver-coated megaprostheses in humans

Deep infection of megaprostheses remains a serious complication in orthopedic tumor surgery. Furthermore, reinfection gets a raising problem in revision surgery of patients suffering from infections associated with primary endoprosthetic replacement of the knee and hip joint. These patients will need many revision surgeries and in some cases even an amputation is inevitable. Silver-coated medical devices proved their effectiveness on reducing infections, but toxic side-effects concerning some silver applications have been described as well. Our study reports about a silver-coated megaprosthesis for the first time and can exclude side-effects of silver-coated orthopedic implants in humans. The silver-levels in the blood did not exceed 56.4 parts per billion (ppb) and can be considered as non-toxic. Additionally we could exclude significant changes in liver and kidney functions measured by laboratory values. Histopathologic examination of the periprosthetic environment in two patients showed no signs of foreign body granulomas or chronic inflammation, despite distant effective silver concentrations up to 1626 ppb directly related to the prosthetic surface. In conclusion the silver-coated megaprosthesis allowed a release of silver without showing any local or systemic side-effects.     

The treatment of locally recurrent chondrosarcoma: Is extensive further surgery justified?

The aim of this study was to define the treatment criteria for patients with recurrent chondrosarcoma. We reviewed the data of 77 patients to examine the influence of factors such as the intention of treatment (curative/palliative), extent of surgery, resection margins, status of disease at the time of local recurrence and the grade of the tumour. A total of 70?patients underwent surgery for recurrent chondrosarcoma. In seven patients surgery was not a viable option. Metastatic disease occurred in 41 patients, appearing synchronously with the local recurrence in 56% of cases. For patients without metastasis at the time of local recurrence, the overall survival at a mean follow-up after recurrence of 67 months (0 to 289) was 74% (5 of 27) compared with 19% (13 of 50) for patients with metastasis at or before the development of the recurrence. Neither the type/extent of surgery, site of tumour, nor the resection margins for the recurrent tumour significantly influenced the overall survival. With limited survival for patients with metastatic disease at the time of local recurrence (0% for patients with grade III and de-differentiated chondrosarcoma), palliative treatment, including local radiation therapy and debulking procedures, should be discussed with the patients to avoid long hospitalisation and functional deficits. For patients without metastasis at the time of local recurrence, the overall survival of 74% justifies an aggressive approach including wide resection margins and extensive reconstruction.     

Cartilage tumours of the bone. Diagnosis and therapy

Primary malignant bone tumours are rare. The annual incidence of these tumours is 10 per 1 million. Nearly 30% of the primary malignant bone tumours are malignant cartilage tumours. The frequency of benign cartilage tumours cannot be definitely estimated because these tumours are normally clinically inapparent and therefore often diagnosed as an incidental finding. The cartilage tumours appear as benign lesions (e.g. chondroma), as borderline tumours (proliferative chondroma vs grade I chondrosarcoma) or as highly malignant chondrosarcoma (e.g. dedifferentiated chondrosarcoma). Commensurate with the different clinical and oncological manifestations of the cartilage tumours, there are wide differences in the treatment and clinical course of the individual tumour. This article discusses the problems in the diagnosis and treatment of cartilage tumours from an orthopaedic point of view.     

Giant cell tumor of bone: treatment and outcome of 214 cases

BACKGROUND: Two hundred and fourteen patients with benign giant cell tumor of bone (GCTB), treated from 1980 to 2007 at the Department of Orthopedics of the University of Muenster (Germany), were analyzed in a retrospective study. PATIENTS AND METHODS: The mean age was 33.3 years with a female-to-male ratio of 1.2 : 1. The mean follow up was 59.8 months. The recurrence rate of patients who received first treatment at our institution was 16.6%. The most common primary treatment was curettage (188 patients) usually followed by adjuvant local therapy. The effects of bone cement (PMMA), burring and hydrogen peroxide (H(2)O(2)) were statistically analyzed and the influence of a subchondral bone graft on the recurrence rate was evaluated. RESULTS: PMMA alone (n = 52) reduces the likelihood of recurrence by the factor 8.2, additional high-speed burring (n = 39) by the factor 3.9 (compared to PMMA only). H(2)O(2) (n = 42) seems to have an additional effect comparable to that of phenol although it did not reach statistical significance. CONCLUSION: The combination of all adjuncts (PMMA, burring, H(2)O(2) - n = 42) reduces the likelihood of recurrence by the factor 28.2 compared to curettage only and therefore should be recommended as a standard treatment. If the tumor reaches close to the articulating surface a subchondral bone graft (n = 42) can be performed without risking a higher recurrence rate. We add seven cases of pulmonary metastases and two cases of multicentricity to the literature. Bisphosphonates and interferon alpha may have a beneficial effect.     

Treatment and outcome of giant cell tumors of the pelvis: 20 cases followed for 1 to 11 years

Background and purpose Giant cell tumors (GCTs) of bone rarely affect the pelvis. We report on 20 cases that have been treated at our institution during the last 20 years.Methods 20 patients with histologically benign GCT of the pelvis were included in this study. 9 tumors were primarily located in the iliosacral area, 6 in the acetabular area, and 5 in the ischiopubic area. 8 patients were treated by intralesional curettage and 6 by intralesional resection with additional curettage of the margins. 3 patients with iliacal tumors were treated by wide resection. 2 patients were treated by a combination of external beam irradiation and surgery, and 1 patient solely by irradiation. In addition, 9 patients received selective arterial embolization one day before surgery. Of the 6 patients with acetabular tumors, 1 secondarily received an endoprosthesis and 1 was primarily treated by hip transposition. The patients were followed for a median time of 3 (1–11) years.Results 1 patient with a pubic tumor developed a local recurrence 1 year after intralesional resection and additional curettage of the margins. The recurrence presented as a small soft tissue mass within the scar tissue of the gluteal muscles and was treated by resection. No secondary sarcoma was detected and none of the patients developed pulmonary metastases or multicentricity. No major complication occurred during surgery.Interpretation We conclude that most GCTs of the pelvis can be treated by intralesional procedures. For tumors of the iliac wing, wide resection can be an alternative. Surgical treatment of tumors affecting the acetabular region often results in functional impairment. Pre-surgical selective arterial embolization appears to be a safe procedure that may reduce the risk of local recurrence.     

Benigne Knorpeltumoren

Background

The majority of benign bone tumors are cartilage tumors. Most common are enchondroma and osteochondroma. Often they represent incidental findings in radiological diagnostics. Thus, the incidence of cartilage tumors is unknown, as most of them are never diagnosed due to the absence of any symptoms.

Objectives

This article describes the diagnostic and therapeutic approach of benign cartilage tumors, focusing on incidental findings.

Methods

The current knowledge and our own experience in the diagnostics and treatment of benign condroid tumors are presented.

Results

As enchondroma represent most often the classic incidental finding without any symptoms or clinical findings, osteochondroma are often diagnosed in young patients by clinical examination showing a painless swelling that can increase in size according to skeletal growth. Most of these asymptomatic enchondroma and osteochondroma are so called “leave me alone lesions” and do not need any treatment, while other benign tumors (e.g., atypical cartilage tumors, chondroblastoma, chondromyxoidfibroma or osteochondroma with a cartilage cap of over 2 cm) need surgical treatment. These active or local aggressive tumors must be differentiated from the “leave me alone lesions”. Additionally, patients with syndromes like Ollier disease (enchondromatosis), Maffucci syndrome or hereditary multiple exostosis must be examined and checked carefully as malignant degradation is possible.

Conclusion

As most cartilage tumors are benign and remain benign, inappropriate diagnostics or operative treatment just to provide security is obsolete. Plain X-ray is often enough for follow-up and other modalities only become necessary when symptoms occur.     

Knorpelbildende Knochentumore

Primary malignant bone tumours are rare. The annual incidence of these tumours is 10 per 1 million. Nearly 30% of the primary malignant bone tumours are malignant cartilage tumours. The frequency of benign cartilage tumours cannot be definitely estimated because these tumours are normally clinically inapparent and therefore often diagnosed as an incidental finding. The cartilage tumours appear as benign lesions (e.g. chondroma), as borderline tumours (proliferative chondroma vs grade I chondrosarcoma) or as highly malignant chondrosarcoma (e.g. dedifferentiated chondrosarcoma). Commensurate with the different clinical and oncological manifestations of the cartilage tumours, there are wide differences in the treatment and clinical course of the individual tumour. This article discusses the problems in the diagnosis and treatment of cartilage tumours from an orthopaedic point of view.