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Biomedical subjects

J Bellemans

Publications and source records attributed to J Bellemans.

At least 37 records · Page 2Linked to original sources
PubMed1998

Machining and accuracy studies for a tibial knee implant using a force-controlled robot.

Total knee arthroplasty requires accurate preparation of the bone surfaces to maximize bone implant contact area in cementless surgery and to obtain proper joint kinematics and ligament balancing. Robots can make the cuts with the necessary high precision. The purpose of this article is threefold: to propose an alternative method for intraoperative registration using an intramedullary rod and an alternative method for force control using the hybrid force-velocity control scheme; to demonstrate that the accuracy and the surface flatness of the cuts machined by a robot are better than in a conventional operation; and to monitor the machining process and to try to derive some information about the local bone quality from it. The results of the laboratory study are promising: the surface flatness of the tibial plateau, calculated using a least squares method, is 0.1-0.2 mm, which is significantly better than in conventional surgery; and the high angular accuracy of the robot allows the bone cuts to be located precisely. Further, an exponential relation between milling forces and local bone density was established, so measurements of the milling forces can provide the surgeon with on-line information about the local bone quality.

Animals↗
PubMed1998

Synovial chondromatosis: clonal chromosome changes provide further evidence for a neoplastic disorder.

Synovial chondromatosis is a rare lesion, which is still believed by most authors to be reactive rather than neoplastic. We report on a case of synovial chondromatosis with clonal chromosomal changes [43,XX,der (1) t (1;13) (p21-22;q21),-6,-13,-14, add(21) (q21)]. The presence of clonal chromosomal changes in this and in three previously reported cases suggests that synovial chondromatosis is a true neoplastic lesion.

Adult↗
PubMed1997

Open versus arthroscopic subacromial decompression: analysis of one-year results.

The results of open subacromial decompression (OSD) were compared with arthroscopic subacromial decompression (ASD) after 1 year in 32 subjects (4 bilateral), and the correlation between the two shoulder rating scales for impingement was documented. Patients were evaluated clinically on the modified University of California at Los Angeles (UCLA) shoulder rating scale, and Constant scale. Scapular position and rotation were evaluated as well as a rotation and abduction shoulder strength test using the Cybex II dynamometer. No parameters revealed significant differences between the groups, except for the UCLA score which indicated an advantage for the ASD group (p = 0.046). The OSD group scored 24.5 (5.45) on the UCLA scale and 73.8 (18.9) on the Constant scale, whereas the ASD group scored 28.3 (5.6) and 80.8 (16.4). To study the correlation between both scales, the Pearson correlation product-moment coefficient was calculated and a high correlation (r = 0.81) obtained. Less mobility was found in the operated arm for all parameters, with the exception of glenohumeral abduction in both groups and passive elevation in the OSD group. Only in the OSD group did the scapula in the operated extremity show more abduction of the inferior angle of the scapula. Weaker abduction strength in the operated side was found in the ASD group, whereas in the OSD group there was significantly less adduction and external rotation strength at 180 degrees/s en 240 degrees/s. We conclude that after one year the open group tends to catch up with the arthroscopic patients and that the main benefits after arthroscopic surgery as described in literature are more evident in the shorter period.

Adult↗
PubMed1997

Graft selection in anterior cruciate ligament reconstruction--prospective analysis of patellar tendon autografts compared with allografts.

A prospective study of 73 arthroscopic anterior cruciate ligament reconstructions using either a patellar tendon autograft or an allograft was made to assess any difference in clinical outcome. Allocation was by availability of an allograft. There were 48 autografts and 25 allografts. Evaluation was by clinical examination and physical tests. At follow-up 2 years after operation, there were no statistically significant differences between the two groups in mobility or in physical tests, but KT-1000 evaluation showed a slightly greater anterior translation in the autografts at 6 months and one year, although at 2 years the allografts developed greater anterior laxity. Cybex testing showed greater quadriceps strength at 6 months and one year in the allografts, but at 2 years the strength was greater in the autografts. Re-rupture occurred in 3 allografts. ACL reconstruction with a patellar tendon allograft does not produce a significant functional deficit. Full quadriceps recovery takes 2 years. Allografts are not recommended as stability deteriorates with time.

Adolescent↗
PubMed1997

Total knee arthroplasty in the young rheumatoid patient.

Thirty-four total knee arthroplasties were performed for severe rheumatoid arthritis in 25 patients younger than 45 years. All patients were available for follow-up evaluation at an average of 7.2 years. According to the Knee Society scoring system, the knee score improved from an average of 21 points preoperatively to 85 points at follow-up (p < 0.001). The average functional score improved from 23 points to 87 points (p < 0.001). Average range of motion improved from 71 degrees to 93 degrees (p < 0.001). Nonprogressive radiolucencies less than 1-mm thick were observed in 6 knees. One knee was revised for severe polyethylene wear; another case was revised for chronic patellar dislocation. Actuarial survivorship analysis estimates a 97% survivorship after 5 years and 90% after after 10 years. In young rheumatoid patients, total knee arthroplasty can therefore be considered as a reliable procedure, with satisfactory results during at least the first 5 to 10 postoperative years.

Actuarial Analysis↗
PubMed1996

Reflex response times of vastus medialis oblique and vastus lateralis in normal subjects and in subjects with patellofemoral pain syndrome.

Various authors have indicated that imbalance of the vastus medialis/vastus lateralis muscles might lead to patellofemoral pain syndrome. However, few reports have been published to substantiate such a hypothesis. The purpose of this study was to attempt to set a scale for the normal reflex response times of the vastus medialis oblique and vastus lateralis muscles after a patellar tendon tap and to determine if patellofemoral pain syndrome patients have an alteration in this firing sequence. A control group of 80 healthy adults was compared with a group of 19 patellofemoral pain syndrome patients. Results indicated that the reflex response time of the vastus medialis oblique was significantly shorter than the reflex response time of the vastus lateralis in the normal subjects (p < or = .01). When comparing these data in the patellofemoral pain syndrome group, a significant earlier firing was obtained from the vastus lateralis in comparison with the vastus medialis oblique (p < or = .01). These findings suggest that a reversal has occurred in the firing pattern of the vastus medialis oblique and vastus lateralis muscles in patellofemoral pain syndrome patients. The results indicate an alteration in the neuromuscular answer of the vastus medialis oblique and vastus lateralis muscles during a patellar tendon tap.

Adolescent↗
PubMed1996

The Judet quadricepsplasty: a retrospective analysis of 16 cases.

Sixteen quadricepsplasties performed for severe extension contractures of the knee were reviewed. Preoperatively all cases showed a severe extension contracture with an average of 23 degrees flexion. Only two patients had more than 30 degrees flexion preoperatively. The average improvement in knee flexion at follow-up was 69 degrees with 11 (68.7%) patients achieving a final flexion of 90 degrees or more. In four cases there was a 15 degrees loss of terminal active extension. In one case a rapid recurrence of the contracture was seen during the initial postoperative weeks. One patient developed a deep infection, and another an acute compartment syndrome.

Adolescent↗
PubMed1996

Ultrasonography of the knee.

Despite the increasing use of MRI in knee disorders, ultrasonography remains the first choice examination technique in para-articular disease. The technique is fast, cheap, easily accessible and usable in the acutely injured patient. The choice of equipment, positioning of the patient and some characteristics of normal anatomy are described. The routine applications of ultrasonography include different types of tendon disease, trauma of the collateral ligaments, bursal pathology, joint effusions and synovitis, evaluation of the popliteal fossa and para-articular swellings. Other possible applications, somewhat more depending on the examiner's experience, are meniscal disease, trauma to the cruciate ligaments and evaluation of the articular cartilage and synovial plicae.

Humans↗
PubMed1996

Slipped capital femoral epiphysis: a long-term follow-up, with special emphasis on the capacities for remodeling.

We reviewed 59 hips in 44 children with slipped capital femoral epiphysis (SCFE), all treated by in situ pinning. The average clinical and radiographic follow-up was 11.4 years. Fifty-three hips (90%) were rated as either excellent or good. Osteonecrosis or chondrolysis developed in five patients. Postoperative remodeling was noted, not only by a process of local resorption and apposition of bone, but also by correction of the disturbed anatomic axes, in proportion to the severity of the slip, together with global thickening of the femoral neck. We believe that the good long-term results after in situ pinning are the consequence of this important remodeling process.

Adolescent↗
PubMed1995

[The Cortel-Dubousset device: prospective study on derotation].

PURPOSE OF THE STUDY: CD instrumentation has been presented as a system which is able to achieve a 3-dimensional correction of idiopathic scoliose. We performed a prospective study about the apex derotation following CD instrumentation. MATERIALS AND METHODS: 24 consecutive patients with idiopathic scoliosis were included in this study. On pre- and postoperative CT scans the rotation angle relative to the sagittal plane according to Aaro and Dahiborn (RA sag) were measured the pre- and postoperative changes were evaluated with paired T-tests together with the significance. Kruskal Wallis tests were performed to correlate the mean values of those calculated changes with the number of instrumented levels and with the different King types of scoliosis. RESULTS: There was no statistical significant increase or decrease of the rotation if we consider the sag without taking into account the type of curve. DISCUSSION: The different ways to measure rotation in scoliosis are presented. The limits of the method we used (RA sag) are also discussed. We reviewed the literature concerning derotation with CD instrumentation to compare it with our results. CONCLUSION: The evaluation of rotation in scoliosis is not easy. The CT scan seems to be the best method. Nevertheless, the postoperative changes of the morphology of the patient can be a factor of error in rotational measurement.

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

Os trigonum and soleus tertius anomaly.

A case of both an os trigonum and a soleus tertius anomaly is presented in a patient with chronic posteromedial ankle pain. A resection of the os trigonum was performed, with complete relief of symptoms. The diagnosis and therapy are discussed, and the literature is reviewed.

Adult↗
PubMedDate not supplied

DNA analysis of a transplanted cryopreserved meniscal allograft.

SUMMARY: Meniscal transplantation is frequently performed in young patients with a single meniscal-deficient compartment as a result of previous total meniscectomy. Indications, operative techniques, and preservation of meniscal allografts have been studied extensively. In this study we compared the DNA profile of a meniscal allograft with that of the human recipient 1 year after transplantation. Applying techniques routinely used in forensic analysis, we were able to show that the DNA profile of the meniscal allograft was 95% identical to that of the human recipient. These findings indicate that 1 year after transplantation the meniscal allograft is nearly completely repopulated by host cells.

Adult↗
PubMedDate not supplied

Intrinsic risk factors for the development of anterior knee pain in an athletic population. A two-year prospective study.

Many variables have retrospectively been associated with the presence of anterior knee pain. Very few prospective data exist, however, to determine which of these variables will lead to the development of anterior knee pain. It was our purpose in this study to determine the intrinsic risk factors for the development of anterior knee pain in an athletic population over a 2-year period. Before the start of training, 282 male and female students enrolled in physical education classes were evaluated for anthropometric variables, motor performance, general joint laxity, lower leg alignment characteristics, muscle length and strength, static and dynamic patellofemoral characteristics, and psychological parameters. During this 2-year follow-up study, 24 of the 282 students developed patellofemoral pain. Statistical analyses revealed a significant difference between those subjects who developed patellofemoral pain and those who did not concerning quadriceps and gastrocnemius muscle flexibility, explosive strength, thumb-forearm mobility, reflex response time of the vastus medialis obliquus and vastus lateralis muscles, and the psychological parameter of seeking social support. However, only a shortened quadriceps muscle, an altered vastus medialis obliquus muscle reflex response time, a decreased explosive strength, and a hypermobile patella had a significant correlation with the incidence of patellofemoral pain. We concluded that the latter four parameters play a dominant role in the genesis of anterior knee pain and we therefore deem them to be risk factors for this syndrome.

Adolescent↗
PubMedDate not supplied

Open versus closed kinetic chain exercises for patellofemoral pain. A prospective, randomized study.

The goal of this prospective study was to evaluate the efficacy of open versus closed kinetic chain exercises in the nonoperative management of patellofemoral pain. Sixty patients were randomized into a 5-week program that consisted of only closed kinetic chain exercises or only open kinetic chain exercises. Muscle characteristics, subjective symptoms, and functional performance were evaluated in this study at the time of the initial physical examination, at the end of the treatment period, and 3 months later. Both groups experienced a statistically significant decrease in pain and an increase in functional performance. This study shows that both open and closed kinetic chain exercise programs lead to an improved subjective and clinical outcome in patients with anterior knee pain. The few significantly better functional results for some of the tested parameters in the closed kinetic chain group suggest that this type of treatment is a little more effective than the open kinetic chain program in the treatment of these patients.

Adolescent↗