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Biomedical subjects

H J Helling

Publications and source records attributed to H J Helling.

32 records · Page 2Linked to original sources
PubMed1999

The vascularization of the os calcaneum and the clinical consequences.

This study was conducted to analyze extraosseous and intraosseous vascularization of the os calcaneum and to elucidate possible clinical manifestations. The arteries of 13 lower leg and foot specimens of human cadavers were injected with a polymer and subjected to maceration or were embedded in plastic. The examination revealed that 45% of the bone is vascularized via medial arteries and 45% via lateral arteries, whereas the remaining 10% is supplied by the sinus tarsi artery. From the medial side, two or three vessels branch off the posterior tibial artery, penetrate the calcaneus below the sustentaculum, and supply the medial part of the posterior joint. The lateral calcaneal artery normally is a branch from the posterior tibial artery. In two of 13 specimens, this lateral supply comes from the peroneal artery. The medial and lateral intraosseous arterial supply for the calcaneus is equal. Inside the bone there is a water-shed zone where the medial and lateral arterial supply meet in the midline. Only 10% of the blood flow is supplied by vessels in the sinus tarsi. Clinically, interruption of the lateral calcaneal artery during the conventional lateral surgical approach for a calcaneus fracture may result in ischemic bone necrosis. The lateral calcaneal artery could supply a local microvascular flap to cover soft tissue defects of the heel. A compartment syndrome after a calcaneus fracture may be caused by bleeding from the medial calcaneal arteries into the quadratus plantae compartment.

Adult↗
PubMed1998

The lateral calcaneal artery.

An anatomic study of the lateral extraosseous and intraosseous arterial supply of the calcaneus and the lateral soft tissue was carried out on 10 fresh lower adult cadaver legs using different anatomic and radiologic procedures (plastination, modified Spalteholz clearing technique, digital subtraction and rotational angiography and computed tomographic angiography). Consistent patterns of extraosseous and intraosseous lateral calcaneal vascular anatomy were demonstrated. The lateral calcaneal artery is a branch of the anterior tibial artery which crosses over the calcaneal tuberosity and forms a large lateral arch with the lateral tarsal artery which is a branch of the dorsalis pedis artery. The intraosseous circulation is supplied laterally by the lateral calcanear artery, medially via the short branches of the lateral plantar artery. Comparing magnet resonance images after fresh calcaneal fractures the lateral calcanear artery may be interrupted by the impacted lateral bulge, by the conventional lateral surgical approach, or by applying a lateral osteosynthesis plate. This may cause avascular bone necrosis. Furthermore the lateral calcanear artery can clinically serve as a vascular pedicle for a local rotational skin flap to cover soft tissue defects of the heel.

Adult↗
PubMed1997

[Local foreign body reactions to biodegradable implants. A classification].

Biodegradable implants are increasingly used in orthopedic and trauma surgery. Many different implants consisting of different biodegradable polymers are currently available. Different factors contribute to the biocompatibility of these implants, and local foreign-body reactions remain a matter of concern. Therefore, it is mandatory to document and compare the tissue reactions caused by various biodegradable implants in experimental or clinical studies. We have developed a standardized system of classification based on our previous experimental and clinical observations. Foreign-body reactions are differentiated into osteolysis (0-0 to 0-4), extra-articular (EA-0 to EA-4) and intraarticular (IA-0 to A-4) soft-tissue reactions.

Animals↗
PubMed1997

Post-traumatic costochondritis caused by Candida albicans. Aetiology, diagnosis and treatment.

Candida costochondritis is a rare disease of complex aetiology. Pathogenetic factors range from postoperative and posttraumatic complications to haematogenous dissemination in intravenous drug addicts. In addition to clinical examination, possible diagnostic procedures include scintiscan and magnetic resonance imaging. The treatment of choice is extensive debridement and resection of the structures affected by the inflammatory process. The long-term prognosis is good.

Abdominal Injuries↗
PubMed1997

[New developments in the application of resorbable implants].

The application of biodegradable implants is combined with advantages and disadvantages. They offer a great deal of innovative ideas. Best evaluation has been done with pins for the fixation of low loaded osteochondral fractures. When using 2.7 mm Polypin primary mechanical stability of distal radius fractures is comparable with the fixation by 1.8 mm K-wires. A prospective and randomised study with two years follow up, including 183 radial head fractures, showed no significant difference in results and complications in metal and polyactide implants. For this localisation and other comparable indications the implant can be recommended. Despite the more extensive degradable device overall costs can be reduced with the polymer implant. Orientruded polyactide screws showed good clinical results, newetheless resorption was extremely late within 5 to 7 years.

Adolescent↗
PubMed1996

[Partial median sternotomy in resection of metastases of the upper thoracic spine].

A modified method of access to the upper thoracic spine is presented based on a case report. The third and fourth thoracic vertebral bodies can be reached by partial upper sternotomy. This approach takes the local anatomic situation into account, thus avoiding the typical complications of complete sternotomy and reducing the postoperative pain. Closure was done using biodegradable sutures, achieving satisfactory stabilisation and a low rate of complications. In only 4 of 130 cases (3%) did a superficial wound infection occur. There was no case of deep infection, osteomyelitis or dehiscence of the sternum.

Aged↗
PubMed1996

Foreign-body reaction and the course of osteolysis after polyglycolide implants for fracture fixation: experimental study in sheep.

Foreign-body reaction to polyglycolide (PGA) implants has been described in man. Many animal experiments have verified the mechanical properties of fixation devices made from PGA, but a significant foreign-body reaction has not been described. We studied the effect of PGA rods in 12 sheep with standardised osteochondral fractures of the medial femoral condyle fixed with uncoloured, self-reinforced PGA rods (Biofix). Radiographs were taken at intervals ranging from two weeks to two years, and the sheep were killed at intervals ranging from six to 24 months. All knees were examined histologically. Eleven of the 12 fractures healed radiologically and histologically. Moderate to severe osteolysis was seen at four to six weeks with maximum changes at 12 weeks in ten animals. Six knees showed fistula-like connections between the implant site and the joint space. Three developed synovitis, one with inflammatory changes involving the whole cartilage and one with destruction of the medial condyle. Although in our study osteochondral fractures fixed with PGA rods healed reliably, there were frequent, significant foreign-body reactions. Caution is needed when considering the use of PGA fixation devices in vulnerable regions such as the knee.

Animals↗
PubMed1996

[Trauma in the last trimester of pregnancy].

Although accidents during pregnancy are fairly rare, besides endangering the mother, they nearly always mean a vital threat to the fetus: lethality rates are up to 8% for the mother and up to 34% for the fetus. Besides depression of the circulatory system in the mother, coupled with fetal hypoxy, injury to the placenta and uterus is also possible. Moreover, the unborn child may be injured by direct trauma. If the fetus sustains a direct injury, the head of the child is affected in the majority of instances. In addition, the risk of an intrauterine death is very high. If the injured baby survives after a section, permanent damage must be taken into account. Pregnant women who are injured in an accident should quickly be checked by sonography and cardiotocography. If no danger is expected for the child, the usual therapeutic rules that apply for traumatology should be followed. If the mother and child are endangered, a cesarean section must be undertaken along with simultaneous accident-related surgery on the mother. Case reports are presented on three cases in our clinic last year, and the current literature is discussed. All three mothers and newborns survived because of the cooperation between surgeons, gynecologists and pediatricians.

Adult↗
PubMed1994

Membrane versus bubble oxygenator in hyperthermic regional perfusion: a prospective randomized clinical study.

In a prospective randomized clinical study a routinely used bubble oxygenator (Bentley-5) was compared with a hollow fiber membrane oxygenator (D 701 Masterflo 34) during hyperthermic isolated extremity perfusion. This was done to find out whether there were differences between the two oxygenators in hemolysis, cellular damage, oxygenation and temperature achieved during extremity perfusion. In 30 perfusions blood samples were obtained at defined times: plasma hemoglobin (Hb), serum lactate dehydrogenase (s-LDH), number of erythrocytes, mean corpuscular volume (MCV), hemoglobin and bilirubin were determined for hemolysis, leukocyte count (neutrophils, lymphocytes, monocytes) and platelets as a check for cellular damage, and PO2, PCO2, O2 saturation and pH to define blood oxygenation and CO2 elimination. Maximal increase in temperature after 30 min and perfusion time until maximum tissue temperature were also recorded. The membrane oxygenator yielded better results from the aspect of hemolysis: s-LDH and plasma Hb were significantly different (p < 0.001). Cellular damage was less with the membrane oxygenator: platelet differences were significant (p < 0.01). Oxygenation and hyperthermia were obtained more quickly and were better controllable in membrane oxygenator. Further advantages for the patient were the smaller volume of blood needed for priming in a membrane oxygenator (750 vs. 1,200 ml) and improved safety resulting from a 'closed' perfusion system. On the basis of the clinical prospective randomized trial conducted, we conclude that membrane oxygenators must be adopted as the new standard in isolated hyperthermic extremity perfusion.

Chemotherapy, Cancer, Regional Perfusion↗
PubMed1994

[Report of the Biodegradable Implants Study Group].

There is a group for the development and testing of biodegradable implants within the German Section of AO/ASIF-International. After in-vitro screening of various polylactide materials and copolymers a L/DL-polylactide 70/30 was selected. In animal experiments it showed long durability over a period of 9 months and expected degradation afterwards. In clinical experience over more than three years the biodegradable pins with x-ray opaque markers (Polypin) applied for fixation of osteochondral lesions yielded good results and no infections. A multicenter clinical study now includes 57 patients. Polypin is the first biodegradable implant of the AO/ASIF-group.

Animals↗
PubMed1985

[Reduction of postoperative edema following isolated hyperthermic perfusion of the extremities with prophylactic administration of aprotinin. Preliminary results].

Experience from more than 380 operations resulted in the standardisation of isolated hyperthermic perfusion with cytostatic drugs for the treatment of malignancies of the extremities. A side-effect of this procedure is postoperative oedema in varying degrees of severity. The influence of prophylactic intraoperative administration of aprotinin (Trasylol) was investigated under experimental and clinical conditions. In these preliminary studies aprotinin distinctly reduced maximum extent and duration of the postoperative oedema. An investigation concerning interaction of aprotinin with the cytotoxic activity of the drugs used in perfusion showed only minor inhibition which does not limit clinical usefulness.

Animals↗
PubMed1983

Ultrastructural changes in the dog liver cell after isolated liver perfusion with various cytotoxins.

Following isolated liver perfusion with different cytotoxins - 5-fluorouracil (5-FU), methotrexate (MTX), dacarbazine (DTIC) cis-platinum (cis-PT) - liver tissue of dogs was examined with the electron microscope (a) directly after the perfusion and (b) after a survival time of 4 weeks (5-FU and DTIC). Acute disintegration of the granular endoplasmic reticulum and depletion of the glycogen stores occurred after perfusion with 5-FU, MTX, and DTIC, while cis-PT induced disintegration of the granular endoplasmic reticulum accompanied by an accumulation of glycogen. Four weeks after perfusion with DTIC signs of remarkably increased cellular activity were observed, while 4 weeks after perfusion with 5-FU the parenchymal liver cells revealed a well-balanced and moderate recovery of the cellular structures.

Animals↗
PubMedDate not supplied

[CT morphometry for calcaneal fractures and comparison of the Zwipp and Sanders classifications].

AIM: The aim of the study is to correlate the CT-morphological changes of fractured calcaneus and the classifications of Zwipp and Sanders with the clinical outcome. METHOD: In a retrospective clinical study, the preoperative CT scans of 75 calcaneal fractures were analysed. The morphometry of the fractures was determined by measuring height, length diameter and calcaneo-cuboidal angle in comparison to the intact contralateral side. At a mean of 38 months after trauma 44 patients were clinically followed-up. The data of CT image morphometry were correlated with the severity of fracture classified by Zwipp or Sanders as well as with the functional outcome. RESULTS: There was a good correlation between the fracture classifications and the morphometric data. Both fracture classifying systems have a predictive impact for functional outcome. The more exacting and accurate Zwipp classification considers the most important cofactors like involvement of the calcaneo-cuboidal joint, soft tissue damage, additional fractures etc. The Sanders classification is easier to use during clinical routine. CONCLUSION: The Zwipp classification includes more relevant cofactors (fracture of the calcaneo-cuboidal-joint, soft tissue swelling, etc.) and presents a higher correlation to the choice of therapy. Both classification systems present a prognostic impact concerning the clinical outcome.

Adult↗