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Biomedical subjects

J C Mulier

Publications and source records attributed to J C Mulier.

At least 19 recordsLinked to original sources
PubMed1979

Short term bonding behaviour of bioglass coatings on metal substrate.

Bioglass specimens were implanted in 11 dogs for periods ranging between two and twelve weeks in order to study the short term bonding behaviour of bioglass coated on metal. Metal fibre porous coated specimens without bone growth inducive microlayer were implanted as controls. The conclusions reached pertain to the validity of push out test results, bioglass short term bonding and the effect of the dipping procedure to coat bioglass on metal: 1. It is impossible to compare the bonding effectiveness of bonding materials tested under slightly differing circumstances, and a fortiori at different laboratories, 2. there is no sufficient evidence to establish a difference in bone bonding strength with regard to trabecular bone of bioglass and metal fibre porous coated specimens at 2 and 4 weeks; at 12 weeks, however, a higher interfacial failure shear strength is obtained with the control porous specimens, 3. bone bonding may be hampered by compositional differences arising as a result of the processing of a bioglass on metal coating. Technologically it is, however, possible to exclude this problem.

Animals↗
PubMed1979

Clinical study on internal fixation of femoral neck fractures.

A clinical study on the results of internal fixation of femoral neck fractures treated by multiple Knowles pinning was undertaken and correlated with the results of an experimental study. Experimentally, failures were produced by downwards migration of the Knowles pins. This phenomenon accounts for the settling of the femoral head on the neck and the frequency of non-union or malunion in patients with subcapital fractures. The type of fracture, type of reduction and age correlate with failure rate. This has to be explained by biomechanical considerations based upon the mode of failure of the internal fixation. A Garden stage III and IV, a varus or anatomical reduction of the fracture and an old age predispose to failure of the internal fixation and consequent non-union.

Age Factors↗
PubMed1979

Experimental study on internal fixation of femoral neck fractures.

The relative strength and the failure mode of internal fixation by multiple pinning and nailing was investigated on 35 specimens. Internal fixation consisted of 3, 5 and 7 Knowles pins, a Smith-Petersen nail or a sliding nail plate. The strength of a specimen with a triflanged nail is only half of that with multiple Knowles pins. There is no significant difference in strength of 3, 5, or 7 pin specimens. The strength of an internal fixation with a sliding nail plate is not superior to the strength of multiple pinning. The mode of failure for the different types of internal fixation is primarily a crush fracture of the supporting trabecular bone at the femoral neck with downward and outward migration of the pins or nail. Except with the fixation with 3 pins where an initial bending could be observed, failure is not a plastic deformation of the internal fixation device.

Bone Nails↗
PubMed1978

In vitro cultivation of human tumor tissues. II. Morphological and virological characterization of three cell lines.

Nineteen human tumors, mostly of sarcomatous nature, were cultured in vitro. Three cell lines were isolated and further characterized: MG-57 derived from a giant cell tumor, MG-63 derived from an osteosarcoma and MG-72 derived from a xanthohistiocytoma. The cell lines varied in morphology and growth pattern. An abnormal karyotype with marker chromosomes was present in Mg-63 and MG-72. None of the cell lines spontaneously produced detectable C-type virus particles. Stimulation with IUDR and dexamethasone also failed to induce detectable particle release.

Animals↗
PubMed1977

Microscopic fracture aspects of impact tested human bones.

The fracture aspects of impact twisted human femurs and tibias have been studied in their wet condition. The main tool used to correlate fracture behaviour with bone structure was the scanning electron microscope. Supplementary data were obtained from macroscopic fracture pattern analyses and stress coat experiments on slowly tested dried bone. The interest of the data reported concerns two major points. Firstly the analysis of the fractographic results leads to the conclusion that the fracture has presumably been initiated by shearing parallel with the torsion axis. The fracture propagates along so called spiral and oblique fracture lines. Secondly, the correlation of the macroscopic fracture pattern with microscopic fracture aspects indicates that the fracture is initiated along the cement lines, which can be considered as the weak matrix in an osteon-cement lining composite. The fracture propagates along the cement lines as well as through osteons and lamellae. Throughout the impact fracture surfaces ductile and brittle fracture aspects were observed, although the brittle fracture mode was predominant during propagation.

Bone and Bones↗
PubMed1976

Haematogenous osteomyelitis of the patella. Report of three cases.

Three cases of osteomyelitis of the patella are reported. One presented as an acute septic arthritis and another developed a sterile arthritis despite antibiotics. The clinical signs, diagnosis and treatment are discussed. Treatment with rest and antibiotics failed to cure the disease. In all three cases a sequestrectomy was carried out resulting in healing of the affected patella and recovery of knee mobility.

Acute Disease↗
PubMed1976

Experimental study on the electrical impedance of bone and the effect of direct current on the healing of fractures.

An experimental study of the electrical impedance of cortical bone and medullary cavity and on the effect of a D.C. or a periodically interrupted D.C. on the healing of fractures in rabbits, suggests that the bone behaves as a capacitance of about 20 muF in parallel with a high D.C. resistance. Also a 10 muA periodically interrupted D.C. current stimulates osteogenesis.

Animals↗
PubMed1975

Fatigue fractures of the femoral component of Charnley and Charnley-Müller type total hip prostheses.

A survey is given of the mechanical failures of the femoral component of Charnley and Charnley-Müller type total hip prostheses. Fractographic analysis reveals that all the prostheses have broken by metal fatigue. A review of the clinical data has been combined with a metallurgical and a mechanical study in order to assess the reasons of the mechanical failures. The following conclusions have been reached. The prosthesis should be inserted in varus position with regard to the axis of the intramedullary canal, and the prosthesis should be made of an alloy with appreciably higher yield stress and fatigue strength than the alloys of the investigated broken Charnley and Charnley-Müller type prostheses.

Alloys↗
PubMedDate not supplied

Treatment of clubfoot by posterior capsulectomy.

Posterior capsulectomy is a complete excision of the posterior tibiotalar and talocalcaneal capsule with a release of the distal tibiofibular connection. The operation is proposed for a resistant or relapsed clubfoot, where remaining equinus is the major problem. A follow-up of 29 operations showed that the average talocalcaneal angle became normal in the AP and lateral views. The best results were obtained with long postoperative cast immobilization, i.e. 6 months.

Achilles Tendon↗
PubMedDate not supplied

Patellar tendinitis (jumper's knee).

A jumper's knee is an overload lesion of patellar or quadriceps tendon near its insertion at the lower or upper pole of the patella. If conservative treatment fails, an operation can be performed in Phase 3 where disabling symptoms, are present. The necrotic tissue in the patellar tendon is excised. The early results of this surgery are encouraging.

Humans↗