Biomedical subjects

H Wassmann

Publications and source records attributed to H Wassmann.

At least 19 recordsLinked to original sources

PubMed2007

PMMA versus titanium cage after anterior cervical discectomy - a prospective randomized trial.

INTRODUCTION: Nonautologous interbody fusion materials are utilised in increasing numbers after anterior cervical disc surgery to overcome the problem of donor site morbidity of autologous bone grafts. This study investigates the performance of two nonautologous materials, the bone cement Polymethylmethacrylate (PMMA) and titanium cages. This prospective randomised trial, with assessment of the results by an independent observer, evaluates whether a Polymethylmethacrylate (PMMA) spacer or a titanium cage provides a better fusion rate around the implant and a better clinical outcome. PATIENTS/MATERIAL AND METHODS: Between 2000 and 2002, 115 patients with monoradicular cervical nerve root compression syndrome caused by soft cervical disc herniation were eligible for this study. Myelopathy, excessive osteophyte formation, and adjacent level degeneration were exclusion criteria. A block-restricted randomisation was applied. The 2-year clinical outcome served as the primary endpoint of the study. Clinical outcome was assessed according to the Odom scale by an independent observer at the follow-up examination. Preoperative, postoperative, and follow-up radiographs were taken. RESULTS: The study was completed by 107 patients (53 with PMMA and 54 with titanium cage). No significant difference between the two groups could be established with respect to the clinical outcome. In each group, 26 patients scored excellent. Good results were found in 19 PMMA patients and 16 titanium cage patients; satisfactory results were found in 8 PMMA patients and 9 titanium cage patients; bad results were found in 3 titanium cage patients. In 47 titanium cage cases (87%), fusion occurred radiologically as bony bridging around the implant. The fusion rate was significantly lower (p=0.011) in the PMMA group, with 35 cases (66%) united at follow-up. CONCLUSION: The radiological result of the titanium cage is superior to that of PMMA with respect to the fusion rate. Although the titanium cage achieves a better fusion rate, there is no difference between titanium cages and PMMA with respect to the clinical outcome.

Adolescent↗

PubMed2006

Mechanical response of cervical vertebral endplates to axial loading.

OBJECTIVE: After anterior cervical discectomy the implantation of a spacer is common practice. The majority of these spacers are trapezoid titanium cages. During the development of a height-adjustable cervical implant we needed to establish the testing limits for this device. A known phenomenon is subsidence of the cage into the vertebral endplates, which leads to a decrease in height and/or angulation of the cervical spinal segment. In contrast to the thoracic and lumbar spines, there are only limited data concerning the load-bearing ability of cervical endplates. The aim of our investigation was to obtain these data. METHODS: Bone density of 16 cervical vertebrae was estimated by quantitative computed tomography. After embedding of the vertebrae into PMMA, each endplate was slowly compressed until failure using a metal indenter resembling the form of a newly developed cervical implant. A fixed protocol with increasing loading cycles was followed. Endpoint was breakage of the endplate as established by failure to resist the increasing loading forces produced by the testing machine. RESULTS: The mean bone density of the 16 cervical vertebrae was 204 with a standard deviation of 52 mg Ca-HA/mL (range 130-281). The endplates failed with a mean loading of 1084 N +/- 314 (range 340-1550 N). The maximum load correlates with the bone density (R2 = 0.7347). With the 97.79 mm2 load bearing surface of the cage we calculate a mean cervical endplate break strength of 10.47 MPa and a 95 % confidence interval of 12.66-9.51 MPa. An initial settling produced by resting of the anchoring teeth in the cervical endplates was observed in 8 vertebrae at a load of 113 N (range 50-250 N). CONCLUSIONS: In contrast to the thoracic and lumbar spines, cervical endplates show a lower resistance against axial forces. The data are important to understand postoperative cage subsidence and to establish testing limits for the development of new implant designs.

Biomechanical Phenomena↗

PubMed2006

Virtual simulation of neuroendoscopic procedures: early clinical experience with ventricular lesions.

BACKGROUND: Virtual endoscopy (VE) is a new and promising imaging technology. Applied to neuroendoscopy it allows preoperative simulation of a procedure and evaluation of the individual intraventricular anatomy in selected cases. Along with neuronavigation and real time intraoperative imaging, VE is expected to improve the safety and efficacy of neuroendoscopic procedures. PATIENTS AND METHODS: Between April 2003 and February 2004 VE simulation was performed in 13 randomly selected patients subjected to endoscopic procedures. Pathological entities included 4 cases with aqueduct stenosis, 4 with suprasellar arachnoid cysts, 2 tumors of the posterior third ventricle, 1 colloid cyst, 1 hyperplasia of the choroid plexus and 1 case with multiloculated hydrocephalus due to intraventricular septations. In 8 patients VE was accomplished preoperatively, in another 5 it was done after the operation, using data sets from neuronavigation imaging planning in 4 patients, and in one case using postoperative imaging studies. T (1)-weighted 3D image sets were acquired on a 1.5 T GE Genesis SIGNA MR scanner and VE reconstruction was performed using the General Electric Navigator software. The VE images were compared with the real images obtained during the endoscopic procedures and evaluated for their impact on the planning of the operative approach. RESULTS: VE implementation succeeded in all 13 patients. Major neuroanatomic reference structures were easily recognizable in all cases. Membranous structures such as the thinned floor of the third ventricle or cyst walls were identifiable in only 46 % of the cases. In 6 cases (46 %) VE showed anatomical variants and details relevant for the endoscopic procedure that were not identified on conventional MR images. CONCLUSIONS: VE has proved to be an important adjunct to the preoperative planning of neuroendoscopic procedures and its routine application is suggested.

Adolescent↗

PubMed2006

Spinal navigation: an accepted standard of care?

OBJECTIVE: In contrast to cranial neuro-navigation, which has been accepted as a routine intraoperative tool, there is still much debate about spinal navigation as an aid for the insertion of pedicle screws. Opinions range from "not useful at all" to "malpractice if not using it". The aim of our investigation was to obtain data about the availability of spinal navigation and compile a common opinion among German neurosurgeons about its usefulness. The current literature is reviewed. METHODS: We present the results of a survey of the Commission for Technical Standards of the German Neurosurgical Society about the use of intraoperative computerised spinal navigation. RESULTS: Of the 128 neurosurgical departments surveyed, 107 (84 %) responded. 57 (53 %) of the responders are equipped with a spinal navigation device, 12 (11 %) use a spinal navigation equipment together with other departments, and 38 (36 %) do not have spinal navigation. Of the departments not equipped with spinal navigation, 58 % would like to have it but 42 % would not. 52 (49 %) responders held the opinion that spinal navigation enhances safety when introducing pedicle screws; while 40 (37 %) answered in the negative, and 15 (14 %) were not sure. Of the responders, 101 (94 %) disagreed with the statement that spinal navigation should be mandatory for pedicle screw placement, 3 (3 %) agreed, and 3 (3 %) were not sure. Of the responders, 105 (98 %) rejected the statement that insertion of pedicle screws without navigation is medical malpractice, 1 (1 %) upheld the statement, and 1 (1 %) was not sure. CONCLUSION: It is still not generally considered common practice to use spinal navigation as an aid for the implantation of pedicle screws. Most pedicle screws are still inserted conventionally. Although nearly 50 % of German neurosurgeons believe that spinal navigation could enhance safety when placing pedicle screws, they clearly reject efforts to make spinal navigation mandatory. With only one exception, the German neurosurgical community unanimously rejects the idea that placing pedicle screws without spinal navigation is medical malpractice.

Clinical Trials as Topic↗

PubMed2005

O-(2-[18F]fluorethyl)-L-tyrosine PET in the clinical evaluation of primary brain tumours.

PURPOSE: The aim of this study was to evaluate the differential uptake of O-(2-[18F]fluorethyl)-L-tyrosine (FET) in suspected primary brain tumours. METHODS: Positron emission tomography (PET) was performed in 44 patients referred for the evaluation of a suspected brain tumour. Acquisition consisted of four 10-min frames starting upon i.v. injection of FET. Tumour uptake was calculated as the ratio of maximal tumour intensity to mean activity within a reference region (FETmax). RESULTS: FET uptake above the cortical level was observed in 35/44 lesions. All histologically confirmed gliomas and many other lesions showed FET uptake to a variable extent. No uptake was observed in nine lesions (one inflammatory lesion, one dysembryoplastic neuroepithelial tumour, one mature teratoma, six lesions without histological confirmation). An analysis of uptake dynamics was done in the patients with increased FET uptake (22 gliomas, three lymphomas, three non-neoplastic lesions, three lesions with unknown histology and four other primaries). Upon classification of tumours into low (i.e. WHO I and II) and high grade (i.e. WHO III and IV), a significant difference in FETmax between the two categories was observed only in the first image frame (0-10 min p.i.), with FETmax=2.0 in low-grade and 3.2 in high-grade tumours (p<0.05); no significant differences were found in frame 4 (30-40 min p.i.), with FETmax=2.4 vs 2.7. Similar results were obtained when the analysis was applied only to astrocytic tumours (2.0 vs 3.1 in the first frame; 2.4 vs 2.6 in the fourth frame). CONCLUSION: These initial results indicate that FET PET is a useful method to identify malignant brain lesions. It appears that high- and low-grade brain tumours exhibit a different uptake kinetics of FET. A kinetic analysis of FET PET may provide additional information in the differentiation of suspected brain lesions.

Adolescent↗

PubMed2005

[Is the Canadian CT head rule for minor head injury applicable for patients in Germany?].

PURPOSE: To evaluate the applicability of the Canadian CT Head Rule (CCHR) on head trauma patients in a German university hospital. METHODS: 122 patients (m = 74; f = 48; 40 +/- 19 years) were examined with cranial CT due to minor head trauma. The need for cranial CT according to the CCHR was evaluated retrospectively. RESULTS: With a sensitivity of 98.9 % and a specificity of 46.6 % all patients with the need for neurosurgical intervention were detected by applying the major criteria of the CCHR. Also, every patient with severe brain injury was detected by the extended criteria with a sensitivity of 99.6 % and a specificity of 34.1 %. This would have led to a reduction in the rate of cranial CT examinations by 45.1 % for the major and 22.1 % for the extended criteria. No patient with severe brain injury would have been missed by application of the criteria. CONCLUSION: The Canadian CT Head Rule for patients with minor head trauma is applicable with a very high sensitivity and the potential of significantly reducing the rate of cranial CT examinations in these patients.

Accidental Falls↗

PubMed2005

Cellular and reticular variants of haemangioblastoma revisited: a clinicopathologic study of 88 cases.

The presence of histological variants of haemangioblastoma is well established, but data on the prognostic implications of histological subtyping are missing. We thus characterized clinical factors associated with histological subtypes, that is, of the cellular and reticular variant of haemangioblastoma, in a series of 88 consecutive primary haemangioblastomas of the central nervous system. Ten haemangioblastomas were classified as 'cellular' according to Cushing and Bailey. As compared to the more common 'reticular' variant (n = 78), the proportion of tumours containing glial fibrillary acidic protein-positive tumour cells (80% vs. 7%), as well as median Ki67 (MIB1) proliferation indices [4% (quartiles: 1-8%) vs. < 1% (<1-2%)], was significantly higher in cellular haemangioblastomas (P < 0.01). Recurrences were more frequent in the cellular variant [2/8 (25%) vs. 4/51 (8%)]. Kaplan-Meier analysis confirmed a significantly higher probability of recurrence in the cellular variant (Log-Rank test P < 0.01). Cox regression analysis not only confirmed the well established association of von Hippel-Lindau disease with tumour recurrence (P < 0.01), but also revealed an independent effect of histological subtype on the probability of recurrence (P < 0.05), whereas no significant influence of age, sex or tumour location was observed. To conclude, the results from this retrospective study suggest that histological subtyping of haemangioblastomas has prognostic implications and might contribute to identify patients at risk for recurrence.

Adolescent↗

PubMed2005

Spontaneous spinal epidural haematoma: a therapeutical challenge? Report of an unusual case.

We report the conservative treatment of a spontaneous spinal epidural haematoma attending with acute extensive neurological deficits, which resolved spontaneously. Spontaneous remission of spontaneous spinal epidural haematoma with severe neurological deficit is rare in the literature. An 80 year old man was admitted to our hospital presenting sciatica followed by rapid development of paraparesis and cauda equina syndrome, which represents a neurosurgical emergency. Magnetic resonance imaging revealed a multilevel epidural haematoma from L1 to L5. During the initial diagnostic procedure the symptoms started to decline unexpectedly, so the surgical intervention could be withdrawn. Twenty four hours after admission the patient was almost free of symptoms, mobile, and continent. Awareness and high index of suspicion, and a willingness to seek the prompt help of the imaging department, are crucial to successful management before the opportunity to treat is lost.

Aged↗

PubMed2004

Revascularization procedures in internal carotid artery pseudo-occlusion.

BACKGROUND: Surgical treatment of patients with suspected internal carotid artery (ICA) pseudo-occlusion and reduced cerebrovascular reactivity (CVR) is still uncertain regarding the diagnostic procedures, the risks and the optimal timing as well as performance of revascularization. METHOD: From 1983-2001, 781 patients with symptomatic ICA stenosis were treated surgically. In 53 patients, a final diagnosis of extracranial ICA pseudo-occlusion was established by repeating Digital Subtraction Angiography (DSA). Angiographical findings were anterograde "string-like" filling of ICA beyond the carotid bifurcation or retrograde filling of the proximal, so called "occluded" extracranial ICA, extending up to the skull base. The CVR was reduced. All patients underwent direct surgery of extracranial carotid artery. Diagnostic parameters, peri-operative risks and postoperative course of these patients were evaluated. FINDINGS: In 40 patients (75.5%) a successful revascularization of ICA was possible. ICA pseudo-occlusion was in all cases of atheromatous origin, moreover in 8 patients combined with a floating thrombus, distal to the stenosis. Thrombectomy was done by means of Fogarty catheter. In 13 patients (24.5%), a surgical re-opening of the ICA lumen was not possible. Five of these patients showed in DSA an anterograde "string sign", eight presented retrograde filling of ICA reaching the skull base. Peri-operative mortality was 1.9%, peri-operative morbidity was 7.5%. After a 4 years (mean) follow-up, 95% of the reopened ICA remained patent. CONCLUSION: In patients with explicit carotid artery occlusion signs, careful selective DSA should be compulsory with a late series to detect ICA pseudo-occlusion. There is a chance for extracranial reopening ICA, even with compromised CVR, if anterograde "string like" or retrograde filling of proximal so called "occluded" ICA as far as the skull base is angiographically identified.

Adult↗

PubMed2004

Treatment strategy of pineal tumors in consideration of their pathomorphology.

BACKGROUND: Tumors of the pineal gland are rare pathology. This paper reports on therapeutical considerations of histologically heterogeneous pineal tumors in a group of 15 patients and is presenting a special case of neuroaxial seeding. METHODS: Surgery and/or additional therapeutic procedures were performed in 13 of our 15 patients ("youngster" and "adults") in respect of pathomorphology. Details are reported concerning a 52-year-old man suffering from pineocytoma (WHO grade II), who underwent different kinds of therapy within 10 years follow-up. RESULTS: In the six "youngster" the histological assessment revealed two teratomas, one mixed pineocytoma/pineoblastoma, one astrocytoma and one epidermoid cyst. All neoplasms were treated surgically with good results. Additional radio-/chemotherapy was used in a case of teratoma and pineocytoma/pineoblastoma. From five successfully surgically treated "adults" (germinoma, pineoblastoma, pineocytoma, two cystic formations) in two of them (germinoma, pineoblastoma) additional radiotherapy was needed, another two patients (cystic formations) were healed after stereotactic puncture. The patient with pineocytoma showed recurrent neuroaxial seeding within 10 years in spite of repeated radiotherapy, though his neurological status remained stable (Karnofsky performance score of 100). CONCLUSION: Precise histopathological assessment of pineal tumors is essential to guide optimal modern therapy modalities in order to assure a local tumor control. (Fig. 3, Ref. 18.).

Adolescent↗

PubMed2003

Inflammatory thromboembolic complication after craniopharyngioma surgery?

Aside from endocrine or visual disturbances an appearance of other complications after craniopharyngioma surgery is rare. We report a case of delayed brain infarction in the postoperative period of craniopharyngioma resection. A 30-year-old man presented with visual impairment and diabetes insipidus. Imaging revealed a partly cystic, partly contrast enhancing intra-/suprasellar mass lesion. The patient underwent craniotomy with resection of the tumour. Histological examination revealed an adamantinomatous craniopharyngioma. Early postoperative an aseptic meningitis, which was diagnosed clinically as well as by laboratory and CSF analysis, resolved spontaneously. One week later a cerebral incident with infarction in the peripheral territory of MCA on the left side occurred. For this unusual event with a review of the literature a thromboembolic origin is suggested on the basis of inflammatory vascular involvement after an attack of aseptic meningitis.

Acute Disease↗

PubMed2003

Plasma cell granuloma involving the brain and the lung.

BACKGROUND: Symptomatic plasma cell granulomas (PCG) of the central nervous system (CNS) are a rare entity, especially in association with an extracranial manifestation. CLINICAL PRESENTATION: A 13 years old boy was operated on for a symptomatic plasma cell granuloma of the lower lobe of the left lung. Four years later, he suffered his first generalized seizure. CT and MRI scans revealed a small hyperdense lesion, which was located in the right frontal lobe, adjacent to the motor strip. Intervention. Stereotactic guided surgery was performed. A plasma cell granuloma was found, which histopathologically resembled the intrapulmonary lesion, which had been removed four years ago. CONCLUSION: Histological findings, differential diagnosis and specific treatment are reviewed and discussed. Patients with PCG should be radiologically staged. Long term prognosis of PCG is good in cases surgically resectable. Nevertheless, patients require lifelong follow up.

Adolescent↗

PubMed2003

Complications of halo treatment for cervical spine injuries in patients with ankylosing spondylitis--report of three cases.

BACKGROUND: Patients suffering from ankylosing spondylitis are prone to injuries of the cervical spine even with minor trauma. Although the fractures are markedly unstable, nonsurgical treatment using a halo-thoracic plaster or jacket is a common approach. METHODS: We present three patients with cervicothoracic fractures of the ankylosed spine to describe problems and complications inherent in this type of treatment. In two, pin track infections and pin protrusion through the skull occurred, leading in one case to an intracerebral hemorrhage. In the third patient, the halo had to be removed after 8 months, just early enough to prevent the pins from cutting through. RESULTS: One patient required craniotomy. The second one could be resolved by local revision. In the third case, the fracture eventually united after using a stiff collar for 2 years. CONCLUSION: Halo treatment for cervical spine fracture in patients with ankylosing spondylitis is a challenging task for orthopedic surgeons and neurosurgeons.

Aged↗

PubMed2003

Salmonella enteritidis causing brain abscess and coxitis following intracranial surgery.

We report the case of a 46-year-old woman who underwent surgery for an adamantinous craniopharyngeoma (WHO grade I). The postoperative course, during which the patient received 16 mg/day of dexamethasone, was initially uneventful. After a fortnight the patient developed infectious signs and an intracranial abscess at the operation site with simultaneous purulent coxitis. Both the intracranial abscess and the coxitis were evacuated and drained. In tissue samples and pus obtained during re-craniotomy and during surgery on the hip, Salmonella enteritidis was detected by cultivation. Salmonella enteritidis was also isolated from several stool specimens. There was no known salmonellosis in the patient's medical history. She recovered as a result of antibiotic treatment with ciprofloxacin and chloramphenicol. The intracranial abscess healed without leaving any neurological deficit. Unfortunately the left hip subsequently required further surgery, culminating in removal of the entire femoral head. Prosthetic replacement could not yet be performed due to the recurrent septic course of the hip. Our case illustrates a serious complication with presumed haematogenous spread of the infection from a pre-existing asymptomatic and unknown colon infection. The immunosuppressive effect of corticosteroids in the treatment of the brain neoplasm might have been a contributing factor to the sudden exacerbation of the latent infection.

Adrenal Cortex Hormones↗

PubMed2003

No evidence of tumour cells in blood of patients with glioma.

BACKGROUND: Although clinically apparent systemic metastases of gliomas are very rare, reports of gliomas developing in recipient's transplanted organs have suggested that haematogenous spread might be more common. METHODS: This report describes a newly developed, sensitive real time quantitative reverse transcription polymerase chain reaction assay for the detection of mRNA encoding glial fibrillary acidic protein (GFAP). Blood from 10 patients with astrocytoma and 10 patients with glioblastoma was analysed. RESULTS: No GFAP mRNA was detected. CONCLUSIONS: These results suggest that even subclinical metastases are very rare and are probably restricted to distinct subsets of glioma.

Biomarkers, Tumor↗

PubMed2001

High uptake of L-3-[123I]iodo-alpha-methyl tyrosine in pilocytic astrocytomas.

Despite a favourable prognosis, pilocytic astrocytomas may exhibit signs of malignancy on various neuroimaging modalities. This retrospective analysis was conducted to determine whether scintigraphic features of malignancy are also found on single-photon emission tomography (SPET) using L-3-[123I]iodo-alpha-methyl tyrosine (IMT) as a tracer. Twenty patients with pilocytic astrocytomas were retrospectively selected from a large series of patients referred for the evaluation of primary or recurrent brain tumours. IMT SPET was performed in 16 patients, positron emission tomography (PET) using 2-[18F]fluoro-2-deoxy-D-glucose (FDG) was available in 10 of the patients and SPET using technetium-99m tetrofosmin or thallium-201 had been performed in 11. Image analysis was performed using standard protocols to determine how many patients exceeded the respective thresholds of malignancy. Features of malignancy were found in 7/16 IMT SPET studies, in 7/10 FDG PET studies and in 7/11 of the residual SPET investigations. A significant correlation of tumour size and IMT uptake in primary pilocytic astrocytomas indicated partial volume effects to partly account for the differential uptake behaviour (n = 10, r = 0.87, P < 0.05). Differences in IMT uptake in primaries (1.7 +/- 0.6, n = 10) and in recurrent tumours (2.3 +/- 0.7, n = 6) did not attain statistical significance. IMT SPET results indicative of malignancy are regularly found in pilocytic astrocytomas, despite their good prognosis. No uptake may be detected in largely cystic or in small tumours.

Adolescent↗

PubMed2001

Pediatric high-grade astrocytomas show chromosomal imbalances distinct from adult cases.

We studied 23 pediatric high-grade astrocytomas by comparative genomic hybridization. Chromosomal imbalances were found in 10 of 10 anaplastic astrocytomas and 11 of 13 glioblastomas and consisted of +1q (43%), +3q (26%), +1p, +2q, +5q (22%), -22q (34%), -6q, -10q (30%), -9q, -11q, -13q, -16q, and -17p (22%). Anaplastic astrocytomas frequently showed +5q (40%), +1q (30%), -22q (50%), -6q, -9q (40%), and -12q (30%); glioblastomas +1q (54%), +3q (38%), +2q, +17q (23%), -6q, -8q, -10q, -13q, and -17p (31%). Minimal common regions mapped to +1q21-41, +3q27-qter, +2q31-32, +5q14-22, -22q12-qter, -10q23-25, -6q25-qter, -9q34.2, -11q14-22, -16q22-qter, and -17p. High-level gains were located on 1q (7 cases), 2q, 7q (4 cases), 3q (3 cases), 9, 17q (2 cases), 4q, 8q, 18, and 20q (1 case). A significantly shorter survival was found for anaplastic astrocytomas showing +1q (P: < 0.05), MIB-1 proliferation index >25% (P: < 0.001) and glioblastomas (P: < 0.05). Compared with adult cases, +1p, +2q, and +21q as well as -6q, -11q, and -16q were more frequent in pediatric malignant astrocytomas. Among the latter +5q, -6q, -9q, -12q, and -22q were characteristic for pediatric anaplastic astrocytomas and +1q, +3q, +16p, -8q, and -17p for pediatric glioblastomas. Our results show that chromosomal aberrations differ between pediatric anaplastic astrocytomas and glioblastomas as well as between pediatric and adult high-grade astrocytomas, supporting the notion of a different genetic pathway. Furthermore, gains of chromosomal material on 1q might be correlated with a worse prognosis in pediatric anaplastic astrocytomas.

Adolescent↗

PubMed2001

[Polymethylmethacrylate (PMMA) in anterior cervical spine surgery - current situation in Germany].

In German speaking countries Polymethylmethacrylate (PMMA) is widely used as spacer material after ventral microdiscectomy of the cervical spine. With the introduction of other materials i.e. titanium, carbon and polyetheretherketone (PEEK) and upcoming reports about long term complications PMMA is currently in discussion. We present the results of an enquiry about the use of PMMA and the complications observed in Germany. - 100 German neurosurgical departments perform annually 8608 anterior cervical discectomies and fusions, 3410 (40%) with PMMA, 2373 (27%) with titanium, 2370 (27%) with bone graft, 407 (5%) with carbon and 48 (1%) without fusion materials. In 47 of the 100 departments PMMA is used on regular base, in 18 occasionally and in 35 never. The use of PMMA is limited to a single cervical segment in 12 departments, 21 are using PMMA in two and 22 in more than two segments. - Fracturing of fusion material was observed in PMMA in 13 cases (0.15% per year), in bone grafts in 33 (0.53% per year) and in carboncages in one case (0.05% per year). Dislocations of PMMA is reported in 66 cases (0.7% per year), of bone grafts in 32 (0.73% per year), of titanium spacers in 20 (0.37% per year) and of carboncages in 4 cases (0.33% per year). - In conclusion PMMA is still the most widely used spacer material after anterior cervical discectomy in Germany. An increased complication rate in comparison with other implants could not be observed.

Biocompatible Materials↗