Biomedical subjects

P Vanderschot

Publications and source records attributed to P Vanderschot.

13 recordsLinked to original sources

PubMed2002

A newly designed vertebral replacement implant to reconstruct the thoracolumbar spine anteriorly.

Calcium phosphate compounds are becoming of increasingly great importance in the field of biomaterials and, in particular, as bone substitutes. In this way donor-side morbidity can be avoided. A type A lesion of the vertebral body can be the reason of a neurological deficit, requiring a corpectomy by means of an anterior approach, tricortical bone grafting and internal stabilization to get a fusion over time. It is our aim to introduce in this study a newly designed vertebral replacement device, tested in an animal model, using domestic pigs. Two biomaterials, Cementek and Biobon were primarily macroscopically and microscopically evaluated, using a critically sized bone defect of a vertebral body and compared with autologous bone grafts. The final tests consisted of two groups of four animals. A corpectomy at the level of L4 was created and stabilized by means of the newly designed vertebral replacement implant. Autologous bone grafts were applied in one group of animals and Cementek in the other to fill the remaining space. Fusion was studied using anteroposterior and lateral radiographs, followed by a computer tomography. The biocompatibility of the biomaterials and autologous bone grafts were in order of: Cementek > autologous bone grafts > Biobon. In the final tests after a six months period, a fusion was diagnosed in four cases, two delayed unions, and two obvious non-unions. An analysis of the failures in this animal study can possibly clarify the shortcomings of this concept. Perhaps, subtle changes of the design combined with other synthetic bone substitutes can possibly improve the fusion rate in the near future.

Animals↗

PubMed2001

The use of 'hybrid' allografts in the treatment of fractures of the thoracolumbar spine: first experience.

Harvesting autogenous bone grafts of the iliac crest carries complications and lengthens operative times. Allografts are preferred to avoid these problems. Fusion after using allogenic bone grafts has been well studied, by examining trabeculations and remodelling on anteroposterior and lateral radiographs. However, the question remains whether one can rely on radiographs alone to determine fusion. 'Hybrid' fresh-frozen allografts from the femur or tibia were used in 11 adult patients with a mean age of 56.4 years (range: 30-78 years) to stabilize the thoracolumbar spine after anterior decompression for trauma. In one case two adjacent levels were fractured, in another case two fractures occurred at different levels. Fresh-frozen allografts of the femur (in ten cases) and tibia (one case), filled with autogenous cancellous bone graft or pieces of rib, were used to reconstruct the anterior column of the spine. Stabilization was performed by means of a Kaneda device. Anteroposterior and lateral radiographs and, additionally, computed tomography (CT) examinations with reconstructions were used to study fusion. One patient died 1 month after surgery. At follow-up in ten patients, after a mean time of 30.2 months (range: 18-42 months), ten allografts showed a grade I fusion and one a grade III fusion. Additional data from the CT examination with reconstructions, however, showed cross-trabeculations in all cases, and a partially united allograft in the patient with a grade III fusion. Cross-trabeculations between the allograft and vertebral body was observed at 6 months, with remodelling occurring at approximately 2 years. Mean loss of correction was minimal, at 3.6 degrees (range 0 degree-16 degrees). Fresh-frozen femoral or tibial allografts worked effectively to maintain correction after trauma when combined with anterior instrumentation. CT examinations with sagittal and coronal reconstructions were more effective for evaluation of fusion compared with anteroposterior and lateral radiographs. The high fusion rate and the low morbidity achieved using allografts in this way supports the exclusive use of allografts in the anterior thoracic and lumbar spine in the future.

Bone Remodeling↗

PubMed2001

Trans iliac-sacral-iliac bar stabilisation to treat bilateral lesions of the sacro-iliac joint or sacrum: anatomical considerations and clinical experience.

The use of trans iliac-sacral-iliac bars is an alternative to sacro-iliac screws in the treatment of bilateral lesions of the posterior pelvic ring, and the same biomechanical principles can be applied. Of 20 patients, ten men and ten women, a CT-scan of the pelvis was performed to study the individual and common safe area at the level of S1 and S2. The location and maximal diameter of the individual safe area were studied using a computer-navigation system, displaying images in sagittal, coronal and axial anatomic planes together with a 3-D reconstruction. The common safe area was studied using three points: upper- (UA) and lower anterior corner (DA) of S1 and S2, and the centre of the safe area. It would have been possible to place an iliac-sacral-iliac bar (5 mm or more) in S1 and S2 in all the men, but in the women a bar could only have been inserted in only five in S1 and eight in S2. A statistically significant difference between men and women was found at S1 (P=0.033) but not at S2 (P=0.211). No significant correlation was found between the diameter of the safe area at both levels in men and women and age, height, and weight. Furthermore, no common safe area of 5 mm or more was measured at the same levels.Four patients were treated using trans iliac-sacral-iliac bars. Three were placed under fluoroscopic control in combination with a frame, and in one patient an image-guided system was used. A postoperative CT confirmed the correct position of the bars in each patient. The complexity and individual variability of the sacrum makes complex preoperative planning of the iliac-sacral-iliac path mandatory.

Adult↗

PubMed1998

Surgical treatment of post-traumatic pelvic deformities.

Two patients with nonunion and malunion of an unstable pelvic fracture, presenting with pain and gait abnormality, were successfully treated with a pelvic reconstruction. The surgical repair consisted of a three staged procedure to perform the osteotomy, the reduction and the internal fixation. Both patients were satisfied with their outcome and experienced no complications.

Adult↗

PubMed1997

[Preparation and technique for surgical treatment of 225 acetabulum fractures. 2 year results of 175 cases].

Between December 1986 and November 1995, 222 patients with 225 acetabular fractures were treated operatively by three surgeons in the Department of Traumatology and Emergency Surgery of the University Hospitals of the Catholic University of Leuven. Indications for surgery were unstable fracture, displaced fracture through the acetabular dome and fracture with intra-acetabular fracture fragments. There were 37.3% A-fractures, 49.7% B-fractures, and 13% C fractures according to the AO Classification. In 16.4% of fractures there were primary neurological deficits. Patients were treated operatively after an average of 5.0 days. The Kocher-Langenbeck approach was used in 56.9% of cases, the ilio-inguinal approach in 27.1% and the extended iliofemoral approach in 4%. In 7.1% of patients, a primary total hip endoprosthesis was implanted. There was no intra- oder perioperative mortality. The average hospital stay was 26.1 days. In 7.1% of patients, we noted secondary neurological problems. Deep infections were present in 1.3%. In 11.1% of patients a second operative procedure was necessary. We were able to review 175 patients after an average of 2 years. Signs of arthrosis and periarticular ossification were noted on the x-rays: walking distance, hip mobility and pain intensity were asked about and recorded after the clinical examination. In 76% of patients an excellent or good result on the Merle-d'Aubigne scale was obtained. T-fractures and posterior wall fractures were followed by the worst results. During this 9-year period, changes have been made to the preoperative radiological examination carried out, the choice of operative approach and our policy on prevention of thrombosis prophylaxis and postoperative ossification. After thorough preoperative diagnosis and with a meticulous operative technique, it is possible to stabilise the vast majority of acetabular fractures through the three classical approaches. Because the fractures are relatively rare, their diagnosis complex and their surgical treatment difficult, specific training is essential for every acetabular surgeon.

Acetabulum↗

PubMed1995

A review on 161 subtrochanteric fractures--risk factors influencing outcome: age, fracture pattern and fracture level.

The results obtained in 161 subtrochanteric fractures of the femur following treatment with a 95 degrees condylar blade plate or a dynamic condylar screw or a gamma nail were retrospectively analyzed. A 95 degrees angular blade plate was used in 107 cases, a dynamic condylar screw in 25, and a gamma nail in 29. There were 114 patients who were admitted after a simple fall and 47 who had sustained a high-energy trauma. In the type of trauma, associated lesions, ISS, pre-existing diseases and finally age we found statistically significant difference (P < 0.001) between patients admitted after a simple fall and patients admitted after a high-energy trauma. The mean operating times for the 95 degrees angled blade plate, the dynamic condylar screw and the gamma nail were 86, 85 and 74 min, respectively. Of the 161 patients, 18 required a revision operation. Of these 18 patients, 8 were initially treated using a 95 degrees condylar blade plate, 2 with a dynamic condylar screw and finally 8 with insertion of a gamma nail; 5 of these patients were less than 70 years old, while the other 13 were older than 70 years (P = 0.025; Fisher's exact test P = 0.042). The post-injury roentgenogram showed a fracture at the level of the lesser trochanter in 11 of the patients older than 50 years (P = 0.017; Fisher exact P = 0.053). Among the 18 patients who underwent revision operations, the post-injury roentgenograms showed 6 type IIIA fractures and 5 type V fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Multiple trauma in elderly patients. Factors influencing outcome: importance of aggressive care.

From 1978 to 1991, 126 multiply-injured patients of 65 years and over were admitted to the Department of Traumatology and Emergency Surgery of the University Hospitals of Leuven. The seriousness of the injury was evaluated using the Injury Severity Score (ISS) and the Glasgow Coma Scale (GCS). Traffic accident (57 per cent) and a simple fall at home (30 per cent) were the main causes of injury. The overall mortality rate within 6 months was 17 per cent. Multiple system organ failure (MSOF) was responsible for the fatal outcome in 48 per cent of the cases and in 71 per cent of the deaths more than 7 days after trauma. Of the survivors still living at home before injury, 78 per cent were able to go back to their normal surroundings. Survivors were compared with non-survivors. There was no significant difference in age or in ISS, nor in pre-existing diseases. On the other hand, the GCS was of important prognostic value, both for survival and functional recovery (P < 0.001). Also, the need for early intubation and continued ventilation were predictive of survival (P < 0.001). Nevertheless, this need for respiratory assistance was not an indication for withdrawing support as 9 per cent of the survivors also required endotracheal intubation for 5 days or longer. In our opinion, aggressive trauma care for the elderly is justified.

Accidental Falls↗

PubMed1993

Surgical treatment of metastatic fracture of the femur improvement of quality of life.

Radiotherapy and chemotherapy will result in an increase in the number of pathological fractures that occur, principally as a consequence of metastatic disease. Especially at the level of the femur, these lesions are painful and are apt to make the patient invalid. Aggressive surgery is often the only possible treatment for such patients, who in many cases may live on for several weeks, months or years. Contra-indications, however are: a survival expectancy of less than 4 weeks, a poor general condition that is an obstacle to a safe operation, or complete mental deterioration. If possible, internal fixation should be performed prophylactically before the real fracture occurs. From January 1980 to December 1990, 65 patients (53 women and 12 men) with 77 pathological fractures of the femur were operated on in the department of traumatology and emergency surgery of the Leuven University Hospital. The average age was 65 years. Metastatic spread from breast cancer was by far the most frequent pathology (75%). Sixty fractures out of the 77 (78%) occurred at the level of the proximal end of the femur in 29 cases (38%) the fracture was in the subtrochanteric region. In 6 cases a "prophylactic" osteosynthesis was performed because of an impending fracture. Endoprosthetic surgery was performed in 36 cases (47%). In 41 cases we performed osteosynthesis: 34 times a compound double-plate fixation, 5 times a gamma nail, 2 times an interlocking nail. Fourty-six patients (71%) obtained very reasonable functional results: they were able to walk again independently or with the help of sticks and crutches.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

PubMed1993

Splenic function after splenic rupture treated with an absorbable mesh.

Overwhelming postsplenectomy sepsis remains a problem despite the introduction of a vaccine and antimicrobial prophylaxis. Removal of the spleen increases the risk of death from overwhelming sepsis to approximately 50 times that in healthy persons. The morbidity and mortality due to infection increase with the extent of associated injuries. Between 1987 and 1991, 24 patients were admitted at the Katholieke Universiteit Leuven for a splenic injury and treated with an absorbable vicryl mesh (woven polyglycolic acid mesh; Polyglactine 910). The injuries to the spleen were classified according to Barrett. Three patients died of severe craniocerebral trauma. A splenectomy was performed in one polytraumatized patient because of rebleeding. The spleen was evaluated in 20 patients after a mean of 20 weeks using 99mTc-denaturated erythrocyte scintigraphy together with tomographies. A type IV injury is a contraindication. All abnormalities on scintigraphy are mainly seen in type III lesions and less in type II and type I lesions. In type IV injury splenectomy and autotransplantation are indicated. Except for type IV lesions, we conclude that a ruptured spleen can be safely treated with a vicryl mesh without great loss of function.

Adolescent↗

PubMed1993

[Internal hemorrhages associated with fractures of the pelvic girdle. Importance of early stabilization using an external fixator].

Pelvic ring injuries due to high-energy forces are among the most serious involving the musculoskeletal system. Life-threatening hemorrhage, local and distant associated injuries, deformity, pain and diminished functional capacity are all potential problems for a patient with a disrupted pelvis. There is a clear correlation between total blood loss, incidence of associated injuries, final functional result and the type of pelvic ring injury. Between January 1987 and December 1990, 66 patients with an unstable lesion, type B or type C in Tie's classification, were treated in the University Hospital Gasthusiberg of the Katholieke Universiteit Leuven. In 42 cases, primary stabilization was achieved by means of an external fixator, of the type "Monofixateur". The overall mortality rate was less than 7%, and 53 patients could be seen for follow-up 6 months to 4 years after injury. Our findings confirm that compared to type B lesions there is a higher incidence of pain, permanent deformity and diminished functional capacity in type C lesions (P < 0.05). The external fixator used in the immediate post-injury period provides an effective splint that reduces bleeding from bone and veins but cannot maintain reduction in lesions with rotational and vertical instability. In these cases, a semi-elective internal fixation, after defining the exact pathoanatomy by means of a CT-scan, should be performed in selected centers.

Activities of Daily Living↗

PubMedDate not supplied

The operative treatment of unstable pelvic ring fractures.

Pelvic ring injuries due to high energy forces are among the most serious, involving the musculoskeletal system. Life threatening hemorrhage, local and distant associated injuries, deformity, pain and diminished functional capacity are all potential problems for a patient with a disrupted pelvis. There is a clear correlation between total blood loss, incidence of associated injuries, final functional result and the type of pelvic ring injury. Between January 1987 and July 1989, 44 patients with an unstable lesion, type B or type C in Tile's classification have been treated in the University Hospital Gasthuisberg of the Katholieke Universiteit Leuven. In 28 cases, primary stabilisation was done by means of an external fixator, "Monofixateur" type. The overall mortality rate was less than 7%. Thirty-five patients could be seen for follow-up six months to three years after injury. Our findings confirm that compared to type B lesions there is a higher incidence of pain, permanent deformity and diminished functional capacity in type C lesion (p < 0.05). The external fixator, used in the immediate post injury period provides an effective splint that reduces bleedings from bone and veins but cannot maintain reduction in lesions with rotational and vertical instability. In these cases, a semi-elective internal fixation, after defining the exact patho-anatomy by means of a CT-scan has to be performed in selected areas.

Adult↗

PubMedDate not supplied

[Functional results following the surgical treatment of unstable pelvic girdle fractures].

Unstable pelvic ring fractures, during the first days post-trauma, are potentially life-threatening lesions. In the long term, these lesions can lead to important functional deficits. 44 patients with an unstable pelvic ring fracture were included in this study. 35 of which were reevaluated after an average of 19 months. It is demonstrated that a rapid stabilisation of the pelvic ring fracture decreases the mortality and that after surgical intervention, the M. Tile Fracture Classification is of prognostically significant value with respect to the functional outcome. Type B fractures, which are only rotationally unstable, have a better final functional result compared with the Type C fractures with rotational and vertical instability. There exists a significant difference between the two groups.

Adolescent↗

PubMedDate not supplied

Multiple trauma in patients of 65 and over. Injury patterns. Factors influencing outcome. The importance of an aggressive care.

In a first study of 416 polytrauma patients, 49 were aged 65 years or older. These "old patients" (mean age 72.1) were compared with the remaining 367 "young patients" (mean age 31.3). In a second study concerning 126 polytrauma patients of 65 and over, the survivors and non survivors were profiled and compared. The typical injured old patient was a pedestrian hit by a car or a motorbike or someone who had simply fallen at home. Despite the fact that the mean Injury Severity Score (ISS) was significantly lower in the old patients' groups (33.2 versus 42.1 degrees) (p < 0.0001) the mortality rate was higher (18% versus 7.6%) (p < 0.05). In old trauma victims multiple system organ failure (MSOF) was responsible for the fatal outcome in 48% of the cases and in 71% of the deaths more than 7 days after trauma. Seventy eight percent of the surviving old patients still living at home pre-injury were able to go back to their normal surroundings. In the old patients groups there was no significant difference in age nor in ISS nor in pre-existing diseases between survivors and non-survivors. On the other hand the Glasgow Coma Scale (GCS) was of important prognostic value, as well as to survival as to functional recovery (p < 0.001). Also the need for early intubation and continued ventilation were predictive of survival (p < 0.001). Nevertheless this need for respiratory assistance was not an indication for withdrawing support as also 9% of the survivors required endotracheal intubation for 5 days or longer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗