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J Lammens

Publications and source records attributed to J Lammens.

35 records · Page 2Linked to original sources
PubMed1994

[Correction of severe deformities of the foot, using Ilizarov's equipment].

MATERIAL AND METHODS: 38 feet in 36 patients who underwent a progressive foot correction without osteotomies, with an Ilizarov frame have been reviewed. There were 23 equinovarus, 2 equinovalgus, 13 equinus deformities. In 20 patients, the deformity had relapsed after one to four previous operations. The mean follow-up was 22 (12-35) months. The mean age was 17 years (6-68). There were 15 females and 21 males. RESULTS: All but 4 patients were satisfied with the result, although 15 still had pain during daily activities. The shape of the feet was distinctly improved in all patients, although residual equinus was found in 6 patients, residual varus in 2 and forefoot problems in 6. Pintract infections were encountered in half of the patients, all settled with local treatment, adjustement of the tension of the wires and antibiotics. Three specific complications were encountered: talus subluxations (7), toe contractures (6), relapse of equinus (4). DISCUSSION: Few alternatives are available to correct severe foot deformities. Soft tissue releases and/or wedge osteotomies are technically demanding, cause shortening of the foot, correct only one predominant component, are contraindicated in patients with infections or a poor vascular or skin condition. Progressive correction by the Ilizarov method is a valuable alternative, although we would like to stress the importance of some details in order to avoid the specific complications. Progressive correction of foot deformities by the Ilizarov frame is demanding for patient and surgeon. It should be reserved for the indications mentioned earlier and also for foot deformities combined with shortening or axial deviations.

Adolescent↗
PubMed1994

Pin removal after in-situ pinning for slipped capital femoral epiphysis.

We retrospectively reviewed 28 pin-removal procedures in 20 patients with slipped capital femoral epiphysis, who were all treated by in-situ pinning with Kowles pins. Failure to extract the pins occurred in 8 cases (28.6%), and in another 8 cases (28.68%), pin retrieval was only possible after major excavation of the lateral femoral cortex. In view of these data we do not recommend routine removal of Knowles pins used for in-situ pinning of slipped capital femoral epiphysis.

Adolescent↗
PubMed1993

The relation between resonant frequencies and torsional stiffness of long bones in vitro. Validation of a simple beam model.

The results of vibration analysis experiments and impact torsion tests performed on excised animal long bones were used to validate a simple beam model for the prediction of torsional stiffness from resonant frequencies. Resonant frequency data on two mutually perpendicular bending vibration modes of 142 excised long bones were evaluated. Torsional stiffness of the same bones had been determined by an impact torsion test. Using a simple beam model, a theoretical relation between resonant frequencies and torsional stiffness was derived. If total bone mass and bone length are known, the formula thus derived allows one to calculate torsional stiffness from resonant frequencies. Linear regression analysis shows a strong correlation between the measured and the calculated torsional stiffness for sheep femora (r2 = 0.63, n = 24), dog femora (r2 = 0.94, n = 34), dog tibiae (r2 = 0.79, n = 18) and monkey radii (r2 = 0.77, n = 66). It was found that this linear relation was valid not within one bone type alone. Linear regression analysis on the combined data of all bones demonstrated that all bones obeyed the same global linear relation between measured and the calculated torsional stiffness (r2 = 0.98, n = 142). This implies that one and the same beam model is valid for the different bone types investigated. The calculation of stiffness from resonant frequencies, however, requires total bone mass, m, and length to be known. In view of in vivo applications, the feasibility of using total bone mineral content (TBMC) as a measure for m was investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Resection of a periosteal osteosarcoma and reconstruction using the Ilizarov technique of segmental transport.

The reconstruction of a large diaphyseal bone defect is a surgical challenge. Autologous bone grafts are usually insufficient to bridge the gap and allografts are prone to infection and may pose problems with internal fixation. Another solution is presented for the reconstruction of a large ulnar defect due to tumour resection, using the Ilizarov technique of segmental transport.

Adolescent↗
PubMed1993

Derotation osteotomy to correct rotational deformities of the lower extremities in children. A comparison of three methods.

Twenty-one supracondylar femoral and 11 tibial derotation osteotomies were performed in 17 patients to correct rotational deformities. Three different methods were used to fix the fragments after derotation: pins incorporated in plaster, plate and screws, and the Ilizarov external fixator. A retrospective review showed no difference in accuracy of derotation between the three methods. However, we recommend the use of the external fixator because it gives less malunion and permits early mobilization and (partial) weight bearing.

Adolescent↗
PubMed1993

Carpo-tarsal osteolysis. Case report and review of the literature.

A hereditary form of multicentric osteolysis is described in an 11-year-old girl whose father is also affected. The results after corrective surgery on the foot with the Ilizarov fixator and the findings during arthroscopy of the knee are discussed. The literature is reviewed.

Carpal Bones↗
PubMed1992

Reconstruction of bony defects using the Ilizarov "bone transport" technique. A preliminary report.

Ilizarov's method of percutaneous transosseous osteosynthesis allows management of complex skeletal deformities using elastic external fixation, atraumatic corticotomy and gradual adaptations between bony fragments. One particular application, useful in the reconstruction of bony defects, is the "lift" or "bone transport" technique, in which in fact internal lengthening is carried out. Using some of their first cases as illustrations, the authors describe the technique and its potential problems.

Adult↗
PubMed1986

Acoustic simulation experiments with preprocessed speech for an 8-channel cochlear implant.

A speech processor for simulation of preprocessed speech in cochlear implantation has been developed. An acoustic simulation of spectrally reduced speech was presented to 169 normally hearing subjects. Several perceptual tests with 9 different filter conditions were carried out. The intelligibility of sentences and the discrimination of phonemes in nonsense syllables were measured. It was established that even within one test session, an important learning effect occurred.

Cochlear Implants↗
PubMedDate not supplied

Iatrogenic pseudoaneurysm in the upper arm: treatment by transcatheter embolization.

A 32-year-old woman presented with a pulsatile, painful mass in her left upper arm, originating several days after removal of an Ilizarov external fixation. The diagnosis of a pseudoaneurysm was made by medical history and by physical and ultrasonographic examination of the mass. Angiography confirmed the presence of the pseudoaneurysm, originating from a branch of the arteria profunda brachii, and definitive treatment was performed by transcatheter embolization. Clinical follow-up showed absence of pulsation and pain in the upper arm and a gradual volume decrease of the mass lesion.

Adult↗
PubMedDate not supplied

Treatment of congenital pseudarthrosis with the Ilizarov technique.

Four patients with congenital pseudarthrosis in neurofibromatosis were treated with percutaneous transosseous fixation according to the Ilizarov method. Three tibias were first treated unsuccessfully with a Sofield procedure. After application of the Ilizarov fixator, consolidation was obtained in two cases after 6 and 19 months, respectively. A fourth case consisted of a congenital pseudarthrosis of the ulna, primarily treated with the Ilizarov system, which showed advanced consolidation after 4 months.

Child↗
PubMedDate not supplied

Kinematic and kinetic asymmetry in patients with leg-length discrepancy.

The symmetry index (SI), as one of methods to evaluate gait pattern in patients with leg-length discrepancy (LLD), helps to estimate the acceptable range of inequality and to determine symmetry in the kinematic and kinetic data before and after a heel lift, although this parameter has a large standard deviation that undermines its accuracy. Thirty patients with LLD were studied by a motion-analysis system and a force plate. Joint motion of the lower extremity in the sagittal plane, back movement in the coronal plane, and three-dimensional ground-reaction forces (GRFs) were registered. From a linear-regression analysis, a mean value of inequality of 2.33 cm (range, 2.12-2.54) was found to correspond to an acceptable gait symmetry. After a heel lift, the SI of the pelvic tilt at midstance and of the vertical GRF at initial contact increases significantly, but the SI of the medial GRF at terminal stance decreases. Patients with an inequality of a mean value of 0.51 cm determined by palpating bilaterally the top of the iliac crest (the TIC1 subgroup) showed a lesser value of the SI of the center of pressure in the forward direction during stance compared with the group with a mean value of inequality of 1.39 cm (the TIC2 subgroup). As a result of our findings, we conclude that the effect of the amount of correction by a heel lift on gait symmetry is unpredictable.

Adolescent↗