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Biomedical subjects

P Patka

Publications and source records attributed to P Patka.

At least 73 records · Page 4Linked to original sources
PubMed1991

Macroporous calcium phosphate ceramics for bone substitution: a tracer study on biodegradation with 45Ca tracer.

The value of artificial materials in bone replacement depends highly on their biocompatibility and biostability. Porous calcium phosphate ceramics have a good compatibility with natural bone. To study the biodegradation process of calcium phosphate bioceramics, labelled [45Ca]-beta-whitlockite and [45Ca]-hydroxyapatite were implanted in the femurs of dogs. The effects accompanying the ingrowth of new bone into the pores of these bioceramics and its replacement by natural bone were investigated. In vivo degradation of the implant material by biochemical dissolution processes was observed. The beta-whitlockite implants showed a conspicuous decrease in radioactive calcium, in contrast to the hydroxyapatite implants. 45Ca was absent in adjacent bones and locally newly formed bone in both beta-whitlockite and hydroxyapatite suggesting a restricted availability of the 45Ca liberated in these processes. Indications of minor mechanical degradation of the materials were also found; in the lymph nodes a very small amount of 45Ca with a high specific activity was detectable. Urine, blood or faeces contained no detectable amounts of 45Ca activity.

Animals↗
PubMed1989

[The effect of flurbiprofen in acute ankle distortions].

The efficacy of flurbiprofen was studied by means of a double-blind randomized clinical trial involving 50 patients with an acute lateral ankle distortion (grade I). It could not be demonstrated that the NSAID shortened the duration of convalescence after this injury. Neither the pain nor the swelling showed a statistically significant decrease. Side effects were more frequent in patients treated with flurbiprofen. In view of these findings use of flurbiprofen in the treatment of acute ankle distortions is to be regarded as inadvisable.

Adolescent↗
PubMed1989

Macroporous calcium phosphate bioceramics in dog femora: a histological study of interface and biodegradation.

This study examines the biodegradation behaviour of calcium phosphate macroporous bioceramics consisting of hydroxylapatite or beta-whitlockite implants. The implantations were performed in hard tissue of femora and muscular tissue of dogs for periods of 6 and 12 month. With microradiography and light microscopy, respectively, of ground and thin sections it was shown that hydroxylapatite remained unchanged and beta-whitlockite degraded within 6 month in bone tissue. In the muscular tissue, the biodegradation of beta-whitlockite was slower. In addition, beta-whitlockite gave rise to a cellular response of lymphocytes and plasma cells rather than hydroxylapatite in the soft tissue region. For tissue response hydroxylapatite is more suitable as an implant material than beta-whitlockite.

Animals↗
PubMed1989

Results of dynamic hip-screw osteosynthesis for intracapsular fractures of the femoral neck.

Dynamic hip-screw osteosynthesis was carried out in 121 patients with fractures of the proximal femur and intracapsular fractures of the femoral neck. Five patients died (4%). The mean age of the 121 patients was 66.4 years, in the subcapital fracture group of 48 patients, the mean age was 58 years. In the 48 patients, treated for an intracapsular femoral neck fracture, good functional results were achieved in 36 patients (75%). Partial femoral head necrosis was seen in six patients. Fast and proper anatomic reduction and dynamic fixation with a central positioned hip-screw (sliding nail) for intracapsular femoral neck fractures, result in good fracture healing with a low incidence of segmental femoral head necrosis.

Adolescent↗
PubMed1988

Immediate or delayed operative treatment of fractures of the ankle.

This study presents the results of the treatment of 92 unilateral fractures of the ankle. Of these, 72 patients were operated on immediately after the injury and 20 patients had delayed operations. Both groups are comparable in age, injury, fracture type and treatment. From the results it can be concluded that delayed open reduction and internal fixation 5-8 days after injury will give similarly good functional results. However, postoperative immobilization and the time spent in hospital by patients treated by delayed operation is significantly longer.

Adult↗
PubMed1988

Magnetic resonance imaging of meniscal lesions of the knee.

In a prospective study of 25 patients, magnetic resonance imaging (MRI) was employed to detect meniscal tears in the symptomatic knee. All patients underwent arthroscopy and 21 underwent double contrast arthrography. When correlated with these two diagnostic procedures MRI produced no false negative results. There were, however, six false positive MRI findings all of which related to the posterior horn of the medial meniscus. MRI appears to be reliable in detecting meniscal tears but long examination times continue to limit its clinical usefulness.

Adolescent↗
PubMed1988

Fractures of the sternum.

The records of 71 patients treated for sternal fracture were reviewed: 52 patients sustained isolated sternal fracture, 19 patients had a sternal fracture in combination with multiple other injuries, with in 12 patients only rib fractures. Forty-one patients were involved in a car accident, 29 of them used safety belts. Three patients (3/71, 4%) died, two multitrauma patients, in whom artificial ventilation was necessary, died of multiple organ failure. One patient with a sternal fracture and bilateral multiple rib fractures died of cardiac contusion and myocardial infarction. Three patients (3/71, 4%) showed signs of myocardial contusion. The morbidity in the patients with an isolated sternal fracture was very low. The prognosis of an isolated sternal fracture is good. Cardiac contusion was an uncommon complication of sternal fracture. Clinical observation for only a short period is advised.

Accidents, Traffic↗
PubMed1987

Treatment of fractures of the shaft of the humerus accompanied by paralysis of the radial nerve.

This paper reports the results of treatment of 17 patients with fractures of the shaft of the humerus accompanied by paralysis of the radial nerve in a series of 111 patients with fractures of the shaft of the humerus. In early operative explorations in 14 cases the radial nerve appeared undamaged in 13 cases. In cases where spontaneous recovery of the function of the radial nerve failed to occur, no evidence has been found that the delay in exploration influenced eventual motor recovery. The high incidence of undamaged nerves at exploration suggests that a conservative approach by collar and cuff or Sarmiento bracing is justified in such cases of fractures of the shaft of the humerus. Paralysis of the radial nerve associated with fractures of the shaft of the humerus is, in our opinion, not an indication for early operative treatment.

Adolescent↗
PubMed1987

Treatment of complicated or infected pilonidal sinus disease by local application of phenol.

This article reports on the results of conservative treatment of 48 patients with complicated pilonidal sinus disease. The treatment consisted of an injection of phenol 80% into the sinus tract after the patients had undergone depilation and excavation while under local anesthesia. The number of phenol injections in each patient varied from one to nine (mean: two injections). Patients were considered cured if no signs of recurrent pilonidal sinus disease occurred within 1 year after treatment. The mean follow-up period after cure was 3 years (range: 1 to 6 years). The recurrence rate was 6.3% (a 95% confidence interval of 1.3% to 17.2%), which was one of the lowest reported for different methods of treatment for pilonidal sinus disease. The good results in this study justify continuation of conservative treatment of pilonidal sinus disease, especially in view of the low costs and the high degree of patient comfort. Sclerosing therapy with phenol is thus recommended as a successful treatment for complicated pilonidal sinus disease.

Abscess↗
PubMed1987

Shoulder injury caused by electric shock.

Shoulder injury and more in particular bilateral dislocation of the shoulder joint after electric shock is rare. Three patients are presented with dislocation and fracture of the shoulder and serious muscle contraction. After an accident involving electric current potential shoulder injuries should be considered. Early diagnosis improves the functional results of adequate treatment.

Adult↗
PubMed1985

Scintigraphic studies to evaluate stability of ceramics (hydroxyapatite) in bone replacement.

In this study, the suitability of a radionuclide bone imaging technique was examined in cases of hydroxyapatite implants for segmental replacements of long bones. The radionuclide bone imaging technique, using [99mTc]MDP was applied to estimate osseous changes at the sites of the hydroxyapatite implants up to 2 yr after their implantation in an animal experimental model. The results were correlated with histological and radiographical findings at the same time. The radionuclide bone imaging with technetium proved to be a useful method to estimate the intensity of osseous changes after bone replacement by a hydroxyapatite implant. It proved to be more sensitive than radiography. The differences in elasticity of the implanted material and adjacent bone may cause an increase of radionuclide uptake at the site of the implant 2 yr after implantation. These osseous changes cannot be detected by standard histological and radiographical methods but could be detected by radionuclide bone imaging. It is submitted that the radionuclide bone imaging is a noninvasive, sensitive, and useful method for the estimation of osseous changes in sites of long term bone implants.

Animals↗
PubMed1985

Reconstruction of large bone defects with calcium phosphate ceramics--an experimental study.

The aim of the present study is to evaluate the bone-defect-repairing capacity of dense hydroxyapatite compared with 40% macroporous hydroxyapatite in a weight-bearing model. The experiment consisted of the production of a relatively large mid-diaphysary defect in the left femur of 18 mongrel dogs. Cylindrical and semicylindrical hydroxyapatite implants were placed in these bone defects in order to restore continuity. The biocompatibility of implanted material has been studied physiologically, by radiographs and scintigraphs, by histology and finally by biomechanical tests. The normal weight-bearing of the operated limb restored in three weeks time. There were two mechanical failures in dense cylindric implants and two in porous cylindric implants. Radiographically, no evidence was found of degradation of porous or dense implants. Radionuclide bone imaging to assess osseous changes at the site of implants, showed intense radionuclide accumulation in all recordings of porous implants up to two years after implantation, in contrast to dense implant recordings. Histologically, there was no evidence of bioresorption. The implants were in direct contact with normal bone tissue. The pores were filled by calcified bone. There were no differences between porous and dense implants concerning the biocompatibility of hydroxyapatite.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Refractures of the femoral shaft.

A retrospective analysis of refracture in 148 femoral shaft fractures is presented. Nineteen (13%) refractures occurred, mostly after plate fixation. Based on the outcome of this analysis and on the literature, recommendations are given to prevent refracture of the femoral shaft after primary therapy by a plate-osteosynthesis. If possible external compression should be used in the treatment of femoral fractures. Cancellous bone grafting should be carried out in all fractures with medial cortical bone defects, or if there is devascularization of bone fragments. Furthermore, a delayed cancellous bone graft (8-12 weeks after primary surgery) is advocated in some of these fractures.

Adolescent↗