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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

Triple arthrodesis in neuromuscular disorders.

Triple arthrodesis, consisting of a fusion of the calcaneo-cuboid, talonavicular, and talocalcaneal joints, is used to correct deformity and replace braces. Indications depend on symptoms. For good results, patients should be at least 12 years old. A review of 25 cases shows that a varus deformity usually does not give good results, a pseudarthrosis always had a poor outcome, and patients are usually more satisfied than the surgeon with the result.

Adolescent

Treatment of nonunion using pulsed electromagnetic fields: a retrospective follow-up study.

Pulsed electromagnetic fields (PEMF) are a useful means of treating cases of fracture nonunion. In 67.7% of nonunions with a disability time of at least 24 months, complete consolidation was obtained. This success rate is increased to 76.6% if we exclude nonunion, that presented contraindications for treatment with PEMF. The disability time had no effect on the success rate. Lesions of the humerus and atrophic nonunion had an unfavorable prognosis.

Adolescent

A new system to produce intraoperatively custom femoral prosthesis from measurements taken during the surgical procedure.

A system has been developed that allows the surgeon to match a prosthesis to any femoral cavity. The surgeon may choose how and where it will preferentially fit. The surgeon does not have to create a cavity to suit a premade prosthesis. The system is based on a novel technique for making a mold of the prepared femoral cavity. This is accurately and thoroughly measured using a laser. An implant is designed and manufactured while the operation is in progress using state-of-the-art computer and machining techniques. All important parameters such as neck length, offset, and anteversion are fully variable intraoperatively. To date, more than 800 consecutive procedures have been carried out. In a limited trial, no subjective difference was found with a cemented Charnley total hip arthroplasty at one year. It currently takes about 40 minutes to manufacture the implant and make it available in the operating room, and this time is being continually reduced. Using a femur first approach, operating time is not greatly extended. In the future, perhaps the operating time will not be extended at all. All data including cavity geometry are centrally recorded for analysis.

Adult

Treatment of chronic osteomyelitis with ciprofloxacin.

The results of the treatment of twenty-one patients (age 22-66 years) with chronic bone or joint infections with ciprofloxacin were evaluated. The osteomyelitis was secondary to trauma in 12 patients, joint replacement in six, previous acute hematogenous infection in two and osteotomy in one. Stafylococcus aureus (11 times) and Pseudomonas aeruginosa (9 times) were most frequently cultured. The duration of ciprofloxacin therapy averaged 76 days. Concomitant antimicrobial drugs were used in one patient only. Fifteen patients were operated during treatment; in most cases the surgical procedure consisted of a thorough debridement. Nineteen patients could be evaluated. The bacteriological results were as follows: eradication 27; marked reduction 1; eradication with recurrence 1. Contamination occurred in five patients and superinfection in two, without much influence on the final outcome. The investigator's assessment at the end of the therapy was as follows: complete success in 14 patients and partial success in seven. During the follow-up (3-13 months) the therapy was judged completely successful in 16, partially successful in four and unsuccessful in one. Two patients had minor gastric complaints during therapy and one showed a temporary slight increase in the liver transaminases.

Adult

Long-term study of the peroperative infection rate in 1007 total hip replacements using prophylactic cefamandole and other precautions.

Of 1824 primary total hip replacements performed between April 1, 1979, and December 31, 1983, 1007 were reviewed at regular interval and provided sufficiently complete data with special emphasis on pre- and postoperative bacteriological examination and pre- and postoperative determination of the erythrocyte sedimentation rate. All patients with known superficial and deep infections were included. In all cases 2 g of cefamandole q.i.d. were administered within a 24-h period starting with the induction of the anesthesia. All procedures were performed in operating rooms equipped with a vertical laminar air flow. Other precautions included the use of Charnley gowns with a body exhaust system, special draping of the patient, and preoperative culture of the urine. As of June, 1981, gentamicin-loaded polymethylmetacrylate was used routinely. When positive cultures were found in the swabs taken from the tissues during the surgical procedure, appropriate antibiotics were started if the patient was still hospitalized. Follow-up showed two deep (0.2%) and four superficial infections (0.4%). Host factors may play a more important role than suspected, since one patient with a deep infection suffered from severe rheumatoid arthritis and the other from diabetes. Both these patients underwent bilateral hip replacement, the second intervention following the first within 5 weeks. In these two patients the deep infection became apparent 5 and 9 months after the second procedure. Only one of these patients developed a sinus (Staphylococcus aureus).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

In vitro experiments with an injection technique for cup fixation in total hip arthroplasty.

A new technique has been developed to position the cup rigidly into the acetabulum during total hip joint replacement. After positioning the flanged cup on the acetabulum by means of screws, a low-viscosity cement is injected through a hole in the rim of the cup. A comparison with the standard cementing technique was made on the basis of in vitro experiments. For this purpose a mold was constructed to produce castings simulating the human acetabulum. The distribution of the cement, the pressure developed in the acetabulum, and the penetration of the cement are compared for the two cementing techniques.

Acetabulum

Partial arthroscopic meniscectomy versus total open meniscectomy.

One hundred sixteen patients who had undergone partial arthroscopic meniscectomy were reviewed in a short-term follow-up study (mean follow-up: 16 months). Their results were compared with those of a group of 402 patients who had been treated previously by conventional open meniscectomy in the same hospital. Average age in the arthroscopic group was 40 years, in the open group 34. Average sick leave was 4 weeks in the arthroscopic group, 10 weeks in the arthrotomy group. In the endoscopic group, there was virtually no sick leave for self-employed people, but 7 weeks if the lesion was sustained at work. Top-class sportsmen resumed competition 5 weeks after arthroscopy, 8 weeks after conventional meniscectomy. Still, most of them complained of prolonged synovial reaction resulting in a period of poor physical condition and performance. Of the patients treated by arthroscopy, 7.5% presented minor problems related to the approach (anteromedial-transpatellar), while 21.5% had similar problems after routine anteromedial incision in the open meniscectomy group. The overall results after arthroscopy were excellent in 49 cases (41.5%), good in 51 (43%), fair in 14 (12%), and poor in four (3.5%). These short-term results are comparable to those of the open meniscectomy group. The short-term results in the older patients confirm our belief that (partial) meniscectomy is useful for the older patient with a history of mechanical meniscal problems, with or without cartilage degeneration, provided one is not dealing with frank osteoarthrosis and secondary varus or valgus deformity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Mechanical behaviour of femoral bones in bending loading.

A series of 33 human femoral bones have been subjected to a four point bending test at high strain rates. Two different failure modes were recognized. A Y shaped fracture at the middle region induced by a pure bending moment yielded a zone of non-linearity at the load vs deformation curve and a higher bending force, more deformation of the structure and higher strain energy to fracture compared with the less frequently occurring oblique fracture at the distal third of the structure resulting in a failure without a 'plastic' portion at the load-deformation curve. Estimated values of bending modulus and maximum bending moment based upon a simple uniform beam model showed high correlation coefficients with the experimentally determined values. Scanning electron microscopic examination of the Y fracture showed distortion and void formation of the material at the structural level. This could explain the extensive non-elastic deformation prior to failure.

Aged

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

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

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

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