Biomedical subjects
C Villas
Publications and source records attributed to C Villas.
Preliminary CT study of C1-C2 rotational mobility in normal subjects.
A CT study of normal atlanto-axial (C1-C2) rotary mobility was carried out on ten normal immature subjects. In order to determine the limits of normality, the ten children underwent clinical and radiological examination. The clinical study included checking for objective signs of joint laxity and measurement of rotational neck mobility. The radiological study included standard lateral radiographs in neutral and maximal flexion positions and a CT scan taken in maximal left and right side rotation at the C1-C2 articular processes joint. The superpositioning of the images taken in every rotational direction showed, in all ten children, a wide contact loss between the C1-C2 corresponding facets, ranging from 74 to 85% of the total articular surface. The report on these images, carried out by three independent radiologists, concluded that there was a rotary subluxation in all cases. In the ten children studied, there were no significant differences with regard to neck mobility or laxity signs in clinical or standard X-ray examination. Our results lead us to conclude that, except for complete C1-C2 rotational dislocation with facet interlocking, a CT scan showing a wide - but incomplete - rotational facet displacement is not sufficient to define a status of subluxation. This leads us to perceive that there is a risk of overdiagnosis when evaluating upper cervical spine rotational problems in children. The concept of both rotary C1-C2 fixation and subluxation should be revised.
Congenital absence of the pedicles and the neural arch of L2.
Congenital pedicle abnormalities are rare. Unilateral aplastic and hypoplastic lumbar pedicles have been reported, but these were usually discovered incidentally and did not need surgical treatment. We present a case of absence of both pedicles and the neural arch of L2, with associated kyphoscoliosis with neurological involvement, that needed a two-stage corrective surgery. An L1-L4 fusion was achieved with relief of the symptoms.
Lumbosacral arthrodesis using pedicular screws and ringed rods.
Sixty-one patients who had lumbar instability and chronic low back pain or deformity from nontraumatic lumbar pathologies were studied. In all of them a posterior lumbosacral fusion with CUN (Clinic of the University of Navarre) pedicle rod fixation was used. The mean follow-up period was 36 months (range 26-46 months). The consolidation rate was evaluated according to plain and functional radiographs, and a clinical evaluation was made using an analogue pain scale. The rate of fusion was 93.5%. Neurological complications occurred in 3.3%. The incidence of screw failure was 2.3% of all the screws. No other implant failure occurred. The patients rated their clinical results as 'excellent' in 33.8% of the cases, 'good' in 42.2%, 'fair' in 16.9% and 'poor' in 6.7%. CUN instrumentation is a versatile internal fixation system that has been shown to provide satisfactory stability. Furthermore, the clinical results are comparable to those reported in studies in which the most common hardwares were used.
Apical hemifacetectomy of the first sacral vertebra in the treatment of an osteoid osteoma.
We present the surgical technique of apical hemifacetectomy, which is useful for performing selective resection of lesions located in the upper articular processes avoiding facet joint instability. This surgical technique was used in a 20-year-old patient to remove an osteoid osteoma deeply located in the S1 articular process.
Ewing's tumor of the spine: report on seven cases including one with a 10-year follow-up.
This study analyzed the cases of seven patients who completed the Treatment Protocol of the University Clinic of Navarre for Ewing's tumor of the spine between 1982 and 1993. The surgical procedures aimed at gaining local control and recovering the neurological deficit are discussed. Poor results in the survival rate can be expected, as shown by the clinical study. Only two patients are alive, including one who is free of disease more than 10 years after surgery.
Adhesive capsulitis. Is it possible in childhood?
Adhesive capsulitis affecting shoulders has been extensively studied by orthopedic surgeons, but few reports have been published on this condition when it affects other joints (hips, ankles). To our knowledge no pediatric cases have been reported. As its treatment requires prolonged physiotherapy and sometimes manipulation, a correct diagnosis is essential. We would like to emphasize the importance of having this condition in mind when one is regarding a differential diagnosis, also in children.
Lumbosacral arthrodesis with louis technique. Review of 186 cases.
A retrospective study was carried out of 186 patients surgically treated by lumbosacral arthrodesis using Louis plates from 1981 to 1989 with an average follow-up of 7.2 years (range 3-11). The average age of the patients was 42.2 years (range 11-71). The indication for surgery was a herniated disc and segmentary instability in 29% (54 patients), spondylolysis or spondylolisthesis in 26.3% (49 patients), arthrosis in 11.3% (21 patients), instability (narrowing of the disc space and zygapophyseal hypertrophy) and stenosis in 5.9% (11 patients), tumour in 5.4% (10 patients), fractures in 0.5% (1 patient) and combinations of the above in 21.5% (40 patients who mainly had a herniated disc and associated spinal stenosis). Iliac crest autograft was used in 33 cases (17.7%), bank allograft in 5 (2.6%), and in the other 148 patients the graft was obtained from the arthrodesis bed. After follow-up we observed loosening of the screws in 20 patients and screw rupture in 10. We only documented 2 cases of pseudarthrosis using dynamic X-radiography. We conclude that the Louis plate is a simple method that leads to lumbosacral arthrodesis with a low rate of pseudoarthrosis.
Union after multiple anterior cervical fusion. 21 cases followed for 1-6 years.
With a mean follow-up of 3 (1-6) years, we report on 21 patients who underwent multiple level cervical fusion, using autologous iliac crest grafts. Dissectomies were performed in 14 patients and corpectomies in another 7. Instrumentation was used in all patients with corpectomies and in 2 patients who underwent 2-level and 3-level dissectomies. Non-union occurred in 1 patient at 1 level. Graft displacement requiring reoperation was observed in 2 patients with massive corpectomies, in 1 of them as a consequence of trauma. In both patients complete bony fusion was obtained after reoperation and no other complications were observed. We conclude that the success rate with multiple-level fusion is comparable to that of single-level fusion when adequate fixation is achieved.
Eosinophilic granuloma of the spine with and without vertebra plana: long-term follow-up of six cases.
Vertebral eosinophilic granuloma is a rare condition frequently associated with vertebra plana. In this paper we present six patients with eosinophilic granuloma of the spine; three were without vertebra plana, which represents a diagnostic problem. The mean follow-up was 9 years, (range 2 to 23) and the mean age was 10.8 years at diagnosis. All complained of pain with no neurological deficit. The lesions were located on the vertebral bodies of C4, T9, T10, L1, L2, and L5, respectively. Histologic confirmation of diagnosis was obtained in all patients, two by puncture and four by open biopsy. The patients with vertebra plana (T10, L1, and L5, respectively) were treated conservatively. Long-term follow-up demonstrated total healing of the vertebral body in two and partial rebuilding 8 years after diagnosis in one. Patients without vertebra plana (C4, T9, and L2, respectively) underwent curettage and bone grafting. In the patient with T9 location, a T8-10 anterior arthrodesis with autogenous rib graft was performed. The outcome was satisfactory in all.
Osteoid osteoma in the lumbar and sacral regions: two cases of difficult diagnosis.
We present two cases of osteoid osteoma affecting a lumbar vertebral body and the sacrum, being both in a very infrequent localization and difficult diagnosis. We found the scintigraphy to be of invaluable assistance in revealing the presence of this small nodular lesion of the spine, and the computed axial tomography (CAT) scan study was likewise useful for its precision in localizing the tumor as a basis for deciding upon a viable surgical approach. Without such techniques, correct diagnosis may be made too late. In our experience, surgical resection of the osteoid osteoma brings about immediate relief of the symptoms.
The neurocentral vertebral cartilage: anatomy, physiology and physiopathology.
The neurocentral cartilage (NCC) described by Schmorl was an intermediate cartilage has aroused discussion among numerous authors as to its role, its age of closure and its possible involvment in the genesis of scoliosis. The authors have attempted to define these problems on the basis of a histologic study of 20 vertebral specimens of different ages and a scanographic study of 25 children. The NCC remains open until adolescence and even beyond, but its maximal activity is probably around 5-6 years. Part of its function is to ensure growth of the posterior arch. Finally, the scanograms of scoliosis show the NCC to be more widely open on the concave side, as if this remained active for a longer period.
Intraoperative radiotherapy in the multidisciplinary management of soft tissue sarcomas.
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Bone lengthening by physial distraction. An experimental study.
Experimental physial distraction was carried out in the distal part of the femur in 45 two-month old lambs in order to study the basic mechanisms of lengthening as well as the viability of the growth cartilage after using this method. The animals were divided into three groups (A, B and C), and each group into three subgroups (1, 2 and 3) according to the rate of distraction used (2 mm/day, 1 mm/day, 0.5 mm/day) and the time of sacrifice. The results obtained show that the basic lengthening mechanisms consists, firstly, in the production of a fracture between the metaphysis and the epiphysis and, secondly, that the lower the distraction speed employed, the greater is the short-term and long-term viability of the growth cartilage. Optimum viability was observed at a distraction rate of 0.5 mm/day. On this basis we conclude that in clinical practice physical distraction could be indicated for children at an early stage of skeletal growth and repeated later provided that the rate of distraction is kept within reasonable limits.
Metacarpophalangeal subluxation: locked finger.
The so-called locked finger is a rarely reported condition that can be easily recognized when its typical picture is borne in mind: painful locking of a finger, making it impossible to fully extend the metacarpophalangeal joint, and a lateral displacement of the extensor tendon at this level. Radiological findings may include abnormal shape of the metacarpal head, free intra-articular bodies, sesamoid bones at the volar plate level and degenerative changes in the metacarpophalangeal joint. There is consistently a previous history of repeated light manual effort. This condition generally affects men, aged 50 or older. Two of the three cases presented (three of the four affected fingers) were successfully treated by means of gentle manipulation under regional nerve blocking. The patient who refused treatment remains with a painless locked finger 1 year later. There has been no recurrence with either of the two manipulated patients (three fingers).
Vertebral eosinophilic granuloma. Long-term evolution of a case.
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Aseptic diaphyseal pseudarthrosis: treatment by rigid internal fixation.
The authors define their concepts with regard to nonunion of fractures and study the possible causes of aseptic diaphyseal pseudarthrosis in the 182 cases in their casuistics. They have found that the indication for osteosynthesis was incorrect in 34% of the cases and when it was correct, the technique was poor in 58%. The authors conclude that the risk of nonunion in fractures and nonconsolidation of pseudarthrosis can be minimished if there is: (1) correct indication with respect to type and level of fracture or pseudarthrosis; (2) choice of an appropriate internal fixation method; and (3) good achievement of the selected osteosynthesis.
New plate for lateral translation in valgus intertrochanteric osteotomy (CUN plate).
A new plate is presented for internal fixation of valgus intertrochanteric osteotomy. This plate enables a controlled translation, permits dynamic compression of the osteotomy line and eludes some of the complications involved in the use of other double-angle plates. The morphological characteristics of the plate as well as its technical and surgical aspects are described. A follow-up study of 63 patients operated on between January 1978 and June 1980 has been carried out, underlining some of the mistakes that can affect the healing time.