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Biomedical subjects

J Y Dupont

Publications and source records attributed to J Y Dupont.

At least 19 recordsLinked to original sources
PubMed2002

Comparison of three standard radiologic techniques for screening of patellar subluxations.

The presence of many "abnormal" types of PF joints in asymptomatic cases and the frequent unilateral complaints in morphologically symmetric joints indicate that emphasis must be placed on factors that cause "abnormal" PF joints to decompensate, rendering them symptomatic. These factors include hyperlaxity, puberty, overuse, or athletic activities. It is our conviction that full understanding of PF problems needs dynamic, three-dimensional motion analysis of patellofemoral relationships. At the present time these imaging techniques do not exist, as they require more powerful computer capacities. The absence of strict and reliable relationships between radiographic anomalies and clinical symptoms brings two reflections about the treatments in symptomatic cases: It is common sense to treat PPS by conservative methods first. Our study indicates that the goal should be to turn the symptomatic patella into an asymptomatic one, rather than correcting maltracking by vastus medialis training. The high failure rates at long-term follow-up of patellar maltracking correction by surgical methods such as lateral release and tibial tubercle transfer show us that correction of part or all of the anomalies does not always make the symptoms disappear. A nice lesson in humility for the orthopedist.

Female↗
PubMed2001

[The origin of femoral trochlear dysplasia: comparative anatomy, evolution, and growth of the patellofemoral joint].

We performed a comparative analysis of the femoropatellar morphology examining the evolutionary aspects to search for the origin of trochelar dysplasia. Trochlear dysplasia is frequent in the human population and, when associated with morphological and positional abnormalities of the patella, can lead to patellar pain syndrome in minor cases or patellar dislocation in severe cases. There is no strict relationship between the observed anomalies and clinical expression. The shape of the articular surfaces is variable in mammals depending on their type of locomotion: unguligrade, digitigrade, plantigrade. In greater apes, the femoral diaphysis is straight and the trochlea is flat and symmetrical. The patella does not tend to dislocate laterally since the knee under load is always flexed. In human adults, the femoral diaphysis has a valgus obliquity angle of 8 degrees to 10 degrees. Consequently, the trochlea has a deepened sulcus and an elevated lateral lip, avoiding lateral patellar dislocation, especially during initial knee flexion. In the human newborn, the femoral diaphysis is vertical. As the child starts walking, the femoral obliquity angle develops between 1 and 7 years of age, inducing a secondary valgus of the extensor apparatus. This obliquity does not develop in non-walking children. Fossil femurs of australopithecus demonstrate that a high obliquity angle had appeared more than 3 million years ago, but also exhibit a poorly deepened trochlea and a slight elevation of the lateral facet. At 1.8 million years, the fossils have the oblique diaphysis, the strongly deepened sulcus and the strongly elevated lateral facet. The obliquity angle of the femoral diaphysis is the leading feature which initiated the later modifications of the patellofemoral joint that over 3 million years were never inscribed in the human genoma. Lateral trochleal lip and deep sulcus are features that were first acquired, then once selected, genetically assimilated, and now appear on the fetal cartilaginous epiphysis.

Adult↗
PubMed1998

[Patellofemoral pain].

A variable combination of patellar lateral subluxation, patellofemoral dysplasia, patella alta and secondary chondromalacia is the major cause of patellofemoral pain. Specific pathology such as medial plica syndrome or patellar tendinitis are less frequent, but their treatment is easier. A strict radiological protocol most often demonstrates the abnormalities. A CT-scan combined with an arthrogram is another imaging option. The goal of conservative treatment is to bring pain relief. The surgical correction of patellar maltracking can be proposed if conservative treatment fails, but has a high failure rate.

Diagnostic Imaging↗
PubMed1997

Synovial plicae of the knee. Controversies and review.

Plicae are some of the normal synovial structures of the knee joint cavity. They are remnants of the mesenchymal tissue that occupies the space between the distal femoral and proximal tibial epiphyses in the 8-week-old embryo. The incomplete resorption leaves synovial pleats in most of the knee. The superior and the inferior plicae are the most common (50% to 65%) but have extremely little clinical relevance. Each may be of many various morphological types. The lateral plica is rare (1% to 3%). The medial plica is present at autopsies in one of every three or four knees. It also is of various types, wide and thick in one of every fifteen knees. Arthrography, ultrasonography, CT scan with arthrography, and MR imaging can demonstrate their presence and measure their size with good accuracy. Arthroscopy allows a very precise assessment of the plica, including dynamic examination. It looks for medial impingement against the patellofemoral articular surfaces and secondary (localized chondromalacia) as well as incidentally associated other knee pathologic conditions. Rarely, the medial plica becomes symptomatic, circumstances such as a history of blunt trauma, or more often, overuse of the knee can cause symptoms. Sometimes no special condition is necessary. The plica causes symptoms such as pain, crepitus, snapping or popping, or effusion related to patellofemoral joint motion. The clinical picture mimics a torn medial meniscus or a maltracking patella. Clinical examination is extremely helpful if the snapping plica is palpated at the medial edge of the patella, reproducing the patient's symptoms. If chronic, these symptoms may be treated with nonsteroidal anti-inflammatory drugs, physiotherapy, electrophoresis, or local injection. Surgical treatment is indicated if conservative therapy fails. Arthroscopic complete resection of the plica cures the symptoms in a few days, therefore confirming the correct diagnosis and the effectiveness of the treatment. Histologic examination often confirms the chronic conflict between the plica and the femoral condyle. No morphologic character allows the assessment of the pathologic aspect of the plica. A medial plica is or is not symptomatic. The incidence of this syndrome is probably one out of ten medial plicae and 3% of arthroscopies at most. Associated lesions are very common. They often make the evaluation of the plica's responsibility in symptoms difficult to analyze, leading to unsatisfactory results.

Arthroscopy↗
PubMed1995

[Patellar subluxation: where are we in 1995?].

In 1995 orthopedic surgeons cope daily with problems related to patellofemoral pathology. The lack of a true relation between the anomalies and the clinical signs is only one of the misleading factors. In spite of the abundant literature on the subject, misunderstanding remains the rule, starting with lack of consensus about the value of words and what they mean. Solutions will come only from a rigorous and scientific approach, in which imaging techniques will probably play a major role. This will be the only way to get rid of one of the last important myths of knee pathology: "the patellar pain syndrome".

Arthrography↗
PubMed1989

Lateral discoid menisci in children.

In children, the snapping-knee syndrome is strongly suggestive of a diagnosis of discoid menisci; alternatively, the loss of physiological hyperextension of the knee suggests a diagnosis of a torn lateral discoid meniscus. We used arthroscopic meniscectomy to treat 19 lateral discoid menisci in 16 children (average age, 10.5 years). Excellent results were achieved in 18 of 19 cases, with disappearance of the snapping with knee flexion (maximum follow-up, 3 years).

Arthroscopy↗
PubMed1988

[The jerk-test in external rotation in rupture of the anterior cruciate ligament. Description and significance].

The authors describe a dynamic test of anterior subluxation of the tibia in lateral rotation in ruptures of the anterior cruciate ligament. This jerk-test in lateral rotation indicates general anterior laxity, including the posteromedial and posterolateral capsular structures. It is only present in lesions of the anterior cruciate ligament, and is only positive in 60 per cent. Its presence is a contra-indication to an isolated lateral extra-articular ligamentoplasty and an indication for intra-articular ligamentoplasty of the anterior cruciate ligament. This test must be distinguished from the Jacob reverse pivot shift test, which indicates posterolateral laxity.

Evaluation Studies as Topic↗
PubMed1985

[Role of synovial plicae in pathology of the knee].

Medial synovial plicae are a cause of internal derangement of the knee in less than 3 p. 100 of cases. The diagnosis of a symptomatic plica is made on clinical and arthroscopic findings. Superior plicae are generally not pathological. When associated with another cause of internal derangement, a medial plica is generally not pathological.

Humans↗
PubMed1983

[Arthroscopic meniscectomies. Short- and median-term results].

Two hundred and forty arthroscopic meniscectomies have been performed between 1980 and 1982. One hundred and ninety-eight cases have been reviewed with a follow up of between 3 and 6 months and 101 cases were reviewed with a follow up of between 6 months and 2 years. On eight occasions the arthroscopy had to be completed by an arthrotomy and one of these became septic. No sepsis was observed in the absence of arthrotomy. Three cases of phlebitis and one haemarthrosis were seen. Social and functional rehabilitation was very rapid. The stay in hospital was 2 days and resumption of sport and work was 2 or 3 times more rapid than after meniscectomy by arthrotomy. The results were excellent or good in 85 p. 100 of cases, slightly better than after arthrotomy. The prognosis was worse when there were patellar or tibio-femoral chondral lesions, and the results were not as good in lateral meniscus lesions, and particularly when there was an associated lesion of the anterior cruciate ligament. However, two patients out of three with this condition were noticeably improved. The remainder will possibly have a secondary repair of the anterior cruciate ligament. The present follow up is not sufficient to evaluate long-term results but the fact that meniscectomy was partial in 3 cases out of 4 supports the hope that the results will be stable. It is only later that it will be possible to evaluate the unobserved lesions or the incidence of recurrence.

Adolescent↗
PubMed1979

[Recurrent fractures of both bones of the forearm in children].

Repeated fractures are not unusual in the course of forearm fractures in children. 49 cases were reviewed in this work. Some of them result from insufficient duration of the plaster. Other fractures are due to the weakness of the forearm bones after the fractures especially when there is a residual malalignment. The findings of this work emphasize the importance of the reduction even when the displacement is moderate. Open reduction and internal fixation is reserved in only rare cases.

Bony Callus↗
PubMedDate not supplied

Value and limits of arthrography in the study of pathological mediopatellar plicae of the knee; a comparison with arthroscopy.

The results from arthroscopy and arthrography were compared in a prospective study of the mediopatellar plicae in 100 knees with internal disorders. With reference to arthroscopy, the sensitivity and specificity of arthrography for the detection of mediopatellar plicae were, respectively, 83.6 and 88.8%. The arthrographic signs of pathological plicae were: a thick plica, thicker than the internal condylar cartilage (sensitivity: 72%; specificity: 84%) and an interposed plica (sensitivity: 85%; specificity: 81.8%). Statistically the arthrographic signs agreed with the arthroscopic signs. The two methods did not differ significantly in their contribution to the diagnosis of pathological plicae.

Adolescent↗
PubMedDate not supplied

Axial and lateral radiographs in evaluating patellofemoral malalignment.

This is a prospective study of 431 patients (862 knees) with patellofemoral pain, patellar dislocation, or other abnormalities of the knee joint. There were 217 asymptomatic knees with no contralateral problems for comparison. All patients had a history and physical and radiographic examination of both knees. The radiographs included standard anteroposterior views, axial views at 30 degrees of knee flexion, and standing lateral views at 0 degree and 30 degrees of flexion. The presence of patellar tilt or subluxation was noted on the axial view. The lateral view of the patella, with precise overlap of the posterior femoral condyles, allowed determination of relationships between the patella's medial edge, median ridge, and lateral edge to assess patellar tilt. Sixty-two percent of patients with patellar dislocations demonstrated subluxation on the axial view, while 98% demonstrated an abnormal lateral view. Eighteen percent of the control knees revealed evidence of subluxation on the axial view while 35% demonstrated subluxation on the extended lateral view. The axial view demonstrated 62% sensitivity for dislocation, while the lateral view taken in full extension demonstrated 98% sensitivity. The specificity for previous dislocation was 82% for the axial view and 93% for the lateral flexed view. Given the high sensitivity of the lateral view for detecting prior patellar dislocation, a normal result on this view can virtually eliminate the question of previous dislocation. Also, with the high specificity of the axial view and lateral view with knee flexion, the two views combined can confirm a clinical impression of patellofemoral malalignment.

Adolescent↗
PubMedDate not supplied

[Severe fractures of the lower end of the humerus in adults (author's transl)].

The authors have treated sixty six cases of severe comminuted fracture of the lower end of the humerus. Five main types have been distinguished: 1. Supracondylar fractures. 2. T-shaped fractures. 3. Trans-condylar fractures in which the fracture line is distal, detaching only the articular surfaces. 4. Diaphyso-epiphysial fractures. 5. Trans-columnar fractures similar to transcondylar fractures but with additional fractures detaching a fragment of lateral or medial epicondyle and a fracture through the trochlea separating the articular surface into two parts. Fifty-four patients were operated on to apply internal fixation. Analysis of the results based on critical criteria shows 53 p. 100 of satisfactory results. The authors emphasise the frequency and severity of damage to the ulnar nerve. They conclude that the results are better after surgical treatment than with conservative treatment which should be reserved for distal and comminuted fractures. A new type of plate has been designed to be applied and fixed to the lateral aspect of the bone.

Adolescent↗