Aim

In severe cases of postoperative spinal implant infections (PSII) multiple revision surgeries may be needed. Little is known if changes of the microbiological spectrum and antibiotic resistance pattern occur between revision surgeries. Therefore, the aim of this study was to analyze the microbiological spectrum and antibiotic resistance pattern in patients with multiple revision surgeries for the treatment of PSII. Furthermore, changes of the microbiological spectrum, distribution of mono vs. polymicrobial infections, and changes of the antimicrobial resistance profile in persistent microorganisms were evaluated.

Introduction: The skeleton is the most common location for metastases, with life-time prevalences of 15% and 70% during autopsies. The Vienna Bone and Soft Tissue Tumor Registry has been established in 1965 and is collecting data on primary and secondary malignancies of the musculoskeletal apparatus ever since. The objective of this study was to review the epidemiology and survival of patients undergoing spinal stabilization, including an analysis of trends over time.

Methods: Data on patients operated on between 1980 and 2007 were available from the Tumor registry. Information on location of metastases, number of metastases within and outside the spine, primary tumor, as well as complications and recurrences after treatment were extracted. Survival after surgery was assessed using the Kaplan-Meier method, adjusting for patient age by Lexis expansion. Furthermore, the dataset was expanded on calendar time to test changes in epidemiology and survival during the observed 28 years. The effect of the abovementioned variables on survival was assessed in a Cox regression model using patient age and calendar time as time frame.

Results: Data on 254 patients could be ed. The most common primary diagnoses were hypernephroma (26.4%), breast cancer (19.75), and lung cancer (12.2%), mostly metastasizing to thoracic and lumbosacral spine (40% both). 104 patients (47.9%) had multiple spinal and 41 (16.1%) other osseous non-spinal metastases. 14.6% had complications in the immediate postoperative follow-up, 4.3% suffered from recurrences postoperatively. Average survival after surgery was 0.9 years (95%CI 0.7 to 1.0) with an average patient age of 60.4 years (95%CI 58.8 to 62.0). In the regression model location of metastases (p=0.008), primary malignancy (p< 0.001), and recurrences (p=0.008) were associated with decreases in survival. There was no association between survival time and the decade during which patients were treated (p=0.157). However, there were significantly less complications in patients treated in later decades, demonstrating the patient’s benefit of being referred to a specialized centre (p=0.015).

Discussion: For our study, we are able to draw from experience of 28 years with stabilization due to spinal metastases. Analyzing the data from 254 patients we observed that spinal metastases stem from a similar pattern of primary malignancies. The average survival in our cohort was less than a year, with a very narrow confidence interval. While survival was not associated with later periods of follow-up, number of complications was, supporting the recommendation to refer cancer patients to specialized centers with appropriate experience. The external validity of our findings, however, is confined by the source of our patients, which comprises mostly central and eastern European patients, and few cases referred from more remote areas.

Autologous chondrocyte transplantation is technically feasible and biologically relevant to repairing disc damage and retarding disc degeneration in animal models. Prospective clinical trials with open discectomy, cultivation of disc cells and transplantation by a minimally invasive procedure are ongoing (co.don chondro-transplant DISC).

We used the decompressor (Stryker) for percutaneous lumbar discectomy to harvest disc cells for cultivation. A cannula was placed in the degenerated disc. The 1,5mm decompressor was introduced through the cannula. 0,5–1,5 millilitres of disc material was aspirated. In the laboratory the material was cultured using the patients serum. The cells were expandable. The capacity of the cells to produce matrix molecules was proven in vitro.

The percutaneous discectomy of contained discs with signes of early degeneration, the expansion and the transplantation of autologous chondrocytes to the disc might be a possibility of repairing disc damage and retarding disc degeneration.

Aim: The purpose of this study was to describe the prevalence, recurrence rate and disease-free interval of aneurysmal and juvenile bone. Methods: A analysis of 141 cases of cystic bone lesions recorded in the Vienna Bone Tumor Registry between 1970 and 2000 was performed. 73 aneurysmal and 68 juvenile bone cysts were registered. 128 (92%) cases were managed by intralesional curettage and adjunctive chemical cautery with phenol followed by bone grafting. Seven cases (4%) were treated by single curettage, in four cases (2.8%) a marginal enbloc resection was performed and two (1.2%) cases were treated by intracystic injections of methylprednisolone acetate. All patients were followed up for a mean of 36 months (range, seven to 144 months) with frequent clinical and radiological examination. Results: The annual prevalence of aneurysmal bone cyst was between 0 and 1.238 per 105 individuals and for juvenile bone cyst between 0 and 0.963. The median age was 11.1 years (range 1– 19.7 years) with a male to female ratio of 1:1.81 for aneurysmal bone cyst and 10.4 years (range 0.5–19.9 years) and a rate of 1:1.96 for juvenile bone cyst. The cumulative probability of a survival without months after surgery was 0.83 (95% confidence interval, 0.77 to 0.90) for aneurysmal bone cyst and 0.79 (95% confidence interval, 0.69 to 0.90) for juvenile bone cyst. Conclusion: We think that the intralesional curettage with additional phenol induced cautery followed by bone grafting provides excellent results and is a successful and sufficient procedure in the therapy of these non-neoplastic bone lesions.

Aim: Life quality is decreased due to pain and the consequences of kyphosis after osteoporotic vertebral fractures. Injections of bone cement (PMMA) are known to stabilise fractured vertebral bodies avoiding major surgeries. The balloon kyphoplasty was introduced for reduction of the local kyphosis. We wanted to observe the range of time in which a correction of the deformity might be possible. Methods: A needle is introduced via a transpedicular or extrapedicular approach into the vertebral body. Then a balloon is inserted and inßated to elevate the endplates and to decrease the local kyphosis. After removal of the balloon PMMA is þlled into the cavity for stabilisation. We performed this procedure in 64 vertebral bodies in 40 patients. Results: The method was mainly used in deformities of vertebral bodies after stable fracture of the endplates due to osteoporosis but also in non-unions within the vertebral bodies. In these cases no signs of ongoing bone remodelling were found within the horizontal fracture gaps in the magnetic resonance imaging despite of the long lasting history of pain. In functional x-rays the instability within the vertebral body was observed. Only the dorsal wall of the vertebral body and the spinal canal had been proven to be intact. A distinct decrease in pain and disability was found in the patients during the time of follow up. The vertebral bodies showed a partial restoration of height and reduction of the local kyphosis even after a period of 3months. The non-unions were stabilised. However the fracture rate of adjacent segments was twice compared to other segments. Conclusion: We conclude that the balloon kyphoplasty is a save procedure in the hand of spine surgeons and sufþcient to reduce pain and improve the mechanical properties of the spine.

Ten year results of 100 primary lower limb reconstruction prostheses implanted between 1982 and 1989 were analysed. In a Kaplan-Meier estimate there was a 85% three years, a 79% five years and 71% ten years survival rate. Most common reason for implant failure was aseptic loosening in 27% of patients (11 patients; range 10–121 months) after initial operation. Other reasons for revision surgery were implant failure (4) and infection (4). Early repair of prostheses-related minor complications, was polyethylene bushings destruction. After a median followup of 127.5 months after the initial surgery, 51 patients had died and eight patients were lost to followup. Forty-one patients were evaluated clinically and radiologically using the MTS score and the radiologic implant evaluation system of the International Symposium on Limb Salvage. 41 patients had a mean of 80% (range, 40%–100%) of the normal functional capability.

We investigated prospectively the bone mineral density (BMD) of the proximal femur after implantation of a tapered rectangular cementless stem in 100 patients with a mean age of 60 years (16 to 87). It was determined using dual energy x-ray absorptiometry, performed one week after surgery and then every six months until the end-point of five years.

The BMD increased significantly in Gruen zones 2, 4 and 5 by 11%, 3% and 11% respectively, and decreased significantly in Gruen zones 1, 6 and 7 by 3%, 6% and 14% respectively, over the five-year period. The net mean BMD did not change over this time period. The changes in the BMD were not confined to the first 12 months after surgery. This investigation revealed no change in the overall periprosthetic BMD, but demonstrated a regional redistribution of bone mass from the proximal to distal zones.

We studied the bone mineral density (BMD) of 48 long-term survivors of highly malignant osteosarcoma who had been treated according to the chemotherapy protocols of the German- Swiss-Austrian Co-operative Osteosarcoma Study Group which include high-dose methotrexate. The mean age of the patients was 31 ± 4.2 years and the mean follow-up 16 ± 2.2 years. The BMD of the lumbar spine and of the proximal femur of the non-operated side was measured by dual- energy x-ray absorptiometry. A questionnaire was given to determine life-style factors, medical history and medication. Ten patients were osteoporotic, 21 osteopenic and 17 normal according to the WHO definition.

Eighteen patients suffered fractures after receiving chemotherapy and all had significantly lower levels of BMD for all the sites measured.

Primary malignant tumours should be resected with wide margins. This may be difficult to apply to lesions of the spine. We undertook total vertebrectomy on seven patients, four males and three females with a mean age at operation of 26.5 years (6.3 to 45.8). The mean follow-up was 52.3 months. Histological examination revealed a Ewing’s sarcoma in two patients and osteosarcoma, leiomyosarcoma, spindle-cell sarcoma, chondrosarcoma and malignant schwannoma in one each. In five patients, histological examination showed that a wide resection had been achieved. At follow-up there was no infection and a permanent neurological deficit was only seen in those patients in whom the surgical procedure had required resection of nerve roots. Despite the high demands placed on the surgeon and anaesthetist and the length of postoperative care we consider total vertebrectomy to be an appropriate procedure for the operative treatment of primary malignant lesions of the spine.

In 251 patients over a period of 15 years an uncemented Kotz modular femoral and tibial reconstruction mega prosthesis was implanted after resection of a malignant tumour of the lower limb. Twenty-one patients (8.4%) underwent revision for aseptic loosening, again using an uncemented prosthesis, and five of these required a further revision procedure. The median follow-up time from the first revision was 60 months (11 to 168) and after a second revision, 33 months (2 to 50). The probability of a patient avoiding aseptic loosening for ten years was 96% for a proximal femoral, 76% for a distal femoral and 85% for a proximal tibial implant.

At the time of follow-up all radiographs were assessed according to the International Symposium of Limb Salvage criteria. The first radiological signs of aseptic loosening were always seen at the most proximal or distal part of the anchorage stem at a mean of 12 months (4 to 23) after the first implantation. Using the Musculoskeletal Tumor Society score for evaluation, the clinical results showed a mean of 88% of normal function.

Scoliosis seen in the chicken after pinealectomy resembles adolescent idiopathic scoliosis in man. It has been suggested that in both species, deficiency of the pineal hormone, melatonin, is responsible for this phenomenon.

In nine patients with adolescent idiopathic scoliosis and in ten age- and gender-matched controls, the circadian levels of serum melatonin and the excretion of urinary 6-hydroxy-melatonin-sulphate, the principal metabolite of melatonin, were determined. There were no statistically significant differences in the secretion of serum melatonin or the excretion of urinary 6-hydroxy-melatonin-sulphate between the patients and the control group. The hypothesis of melatonin deficiency as a causative factor in the aetiology of adolescent idiopathic scoliosis cannot be supported by our data.