Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 10036650

Computer-assisted bone segment navigation.

R Marmulla·H Niederdellmann
View original source ↗Export metadata ↓

Abstract

Computer-assisted bone segment navigation is defined as the precise 3-D positioning of geometrically mapped and mathematically described skeletal segments. These bone segments are osteotomized, fractured or prefabricated according to a surgical plan. The high-precision positioning should have an accuracy of 1 mm or better. Segment navigation should be prepared with plain computed tomography (CT) without the implantation of registration markers before CT in order to reduce the number of CTs and operations. The Surgical Segment Navigator (SSN) was developed at the University of Regensburg with the support of Carl Zeiss. This is the first system to meet these criteria. The SSN is based on an infrared positioning device which is connected to a Hewlett Packard LD Pro Workstation. Infrared transmitters are connected to individual templates which are fixed to the bone segment by osteosynthesis screws. Intraoperative correlation between surgical planning and surgical site is achieved by use of a surface-pattern of the bone segment which fits equally well to the laboratory model and the conditions encountered in the patient. The concept of the SSN was submitted by Carl Zeiss as German Patent DE 19747427 A1 in 1997. The SSN system presented here has already been applied clinically and its precision has been evaluated by bone segment navigation in human cadavers.

Explore related subjects

Bone and BonesDental ArticulatorsEquipment DesignHumansModels, AnatomicOral Surgical ProceduresPatient Care PlanningTherapy, Computer-AssistedTomography, X-Ray ComputedJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R Marmulla, H Niederdellmann. 1998. Computer-assisted bone segment navigation.. https://doi.org/10.1016/s1010-5182(98)80067-x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2000

The eye injury of King Philip II and the skeletal evidence from the royal tomb II at Vergina.

The Royal Tomb II was discovered in Vergina, Greece, in 1977. It contained a male skeleton and a rich array of grave goods. Evidence of trauma supposedly in the orbital bones of the skull has been thought to correspond to an eye injury that King Philip II is historically known to have suffered. However, reexamination of the orbital morphology showed no evidence of such pathology. Therefore, the skeleton does not belong to Philip II. New skeletal evidence shows that the skeleton belongs to King Philip III Arrhidaeus. In this case, the tomb may well contain some of the paraphernalia of Alexander the Great.

Bone and Bones↗
PubMed2000

Evaluation of prostate cancer patients receiving multiple staging tests, including ProstaScint scintiscans.

BACKGROUND: Multiple serum tests were performed on archival samples from patients who participated in trials to assess the ProstaScint scan staging ability. Traditional statistical analysis as well as artificial neural network (ANN) analysis were employed to evaluate individual patients and the group as a whole. The results were evaluated so that each factor was tested for prognostic value. METHODS: Data obtained from serum tests, bone scans, and ProstaScint scans were evaluated by traditional statistical methods and ANN to determine the individual value in clinical staging of prostate cancer. RESULTS: Two hundred seventy-five patients (180 postprostatectomy, 95 intact prostate) with prostate cancer (14 with distant metastases) were available for analysis. Data available included: clinical state (remission or progression), most recent clinical TNM stage, bone scan, and ProstaScint scan. Serum was tested for prostate-specific membrane antigen(PSMA), prostate-specific antigen(PSA), free PSA (fPSA), and complexed PSA (cPSA). Additional calculations included percent free PSA, and percent complexed PSA. Spearman individual statistical assessment for traditional group evaluation revealed no significant factors for T-stage. The free PSA and complex PSA had a significant association with node (N)-status. The distant metastases (M) stage correlated well with the bone scan and clinical stage. ANN analysis revealed no significant T-stage factors. N-stage factors showed a 95% sensitivity and 49% specificity. These factors included the presence or absence of a prostate, PSA serum levels, bone scan, and ProstaScint scans as major associated indicators. ANN analysis of the important variables for M-stage included ProstaScint scan score, and PSA levels (total, percent complexed, percent free, and fPSA). These factors were associated with a 95% sensitivity and 15% specificity level. CONCLUSIONS: Two hundred seventy-five patients receiving treatment for prostate cancer were evaluated by ANN and traditional statistical analysis for factors related to stage of disease. ANN revealed that PSA levels, determined by a variety of ways, ProstaScint scan, and bone scan, were significant variables that had prognostic value in determining the likelihood of nodal disease, or distant disease in prostate cancer patients.

Bone and Bones↗
PubMed2000

Sequential labelling of microdamage in bone using chelating agents.

Basic fuchsin labels microcracks, but a series of stains is required to differentiate between preexisting and test-induced microcracks and to label their growth in vitro. Basic fuchsin and five chelating agents-alizarin complexone, calcein, calcein blue, oxytetracycline, and xylenol orange-were randomly assigned to label microcracks in sequential rib sections from 10 donors. The density, length, and location of the microcracks did not differ significantly between the six stains, suggesting that each was equally effective in detecting microcracks. Paired specimens of trabecular bone were machined from bovine tibiae, stained with oxytetracycline, and fatigued in compression. One specimen from each pair was then stained with xylenol orange. Preexisting microdamage was stained with oxytetracycline, propagating microcracks with both stains and new, test-initiated damage with xylenol orange. Chelating agents are site-specific markers of the initiation and growth of microcracks.

Bone and Bones↗