PubMed Health⌕ Search

Biomedical subjects

H J Kreder

Publications and source records attributed to H J Kreder.

27 records · Page 2Linked to original sources
PubMed1996

X-ray film measurements for healed distal radius fractures.

In order to understand the effect of malunion on functional outcome, it is essential that deformity be measured in a consistent manner. A standardized method of measuring eight anatomic parameters at the distal radius was developed. By this method, six x-ray films of healed distal radius fractures were subsequently measured by 16 raters. Rater agreement was quantified by using the intraclass correlation coefficient. Tolerance limits were developed in order to estimate the expected margin of error for each parameter. Parameters measured with high rater agreement include ulnar variance, palmar tilt, and radial shift; however, even experienced clinicians did not readily agree on the size of step and gap deformity. Using the method of tolerance limits, one would expect that two randomly chosen clinicians measuring step and gap deformity on a random x-ray film will differ by more than 3 mm at least 10% of the time. Similarly, repeat step or gap measurements by the same observer are expected to differ by more than 2 mm at least 10% of the time. In view of our inability to measure deformity more accurately, the concept of a specific relationship between a given degree of deformity and outcome must be questioned. Prospective research is needed in order to improve our understanding of the precise relationship between malunion and functional outcome.

Fracture Healing↗
PubMed1996

Total hip arthroplasty complicated by tuberculous infection.

The case of a 66-year-old woman with tuberculous infection complicating a total hip arthroplasty that had been performed 4 years previously for degenerative arthritis is reported. The patient had no prior history of exposure to tuberculosis and no evidence of skeletal or nonskeletal tuberculous infection. The need for a high index of suspicion when dealing with unexpected arthroplasty failure is emphasized. Tuberculous cultures are recommended in these cases prior to revision surgery.

Aged↗
PubMed1996

Non-union of the scaphoid. Treatment with cannulated screws compared with treatment with Herbert screws.

We retrospectively reviewed the results for thirty-four patients in whom a non-union of the scaphoid had been treated with bone-grafting and internal fixation with use of one of two types of screws as well as the temporary placement of Kirschner wires parallel to the screw to prevent rotation. The patients were divided into two groups: Group 1 contained sixteen patients who had been managed with a Herbert screw from 1986 through 1989 and Group 2, eighteen patients who had been managed with a 3.5-millimeter cannulated AO/ASIF screw from 1990 through 1992. There were no clinical or radiographic differences between the two groups. The time to union, confirmed with tomography, was 7.6 +/- 3.6 months for Group 1 and 3.6 +/- 1.2 months for Group 2. This difference was significant (p < 0.01). Both screws significantly improved the alignment of the scaphoid and decreased carpal collapse (p < 0.05). Regardless of the type of screw used, the time to union was significantly shorter when the screw had been placed in the central one-third of the scaphoid (p < 0.05). Seventeen of the eighteen cannulated screws had been placed centrally, compared with seven of the sixteen Herbert screws (p < 0.01).

Adolescent↗
PubMed1996

Consistency of AO fracture classification for the distal radius.

We sought to quantify agreement by different assessors of the AO classification for distal fractures of the radius. Thirty radiographs of acute distal radial fractures were evaluated by 36 assessors of varying clinical experience. Our findings suggest that AO 'type' and the presence or absence of articular displacement are measured with high consistency when classification of distal radial fractures is undertaken by experienced observers. Assessors at all experience levels had difficulty agreeing on AO 'group' and especially AO 'subgroup'. To categorize distal radial fractures according to joint displacement and AO type is simple and reproducible. Our study examined only whether distal radial fractures could be consistently classified according to the AO system. Validation of the classification as a predictor of outcome will require a prospective clinical study.

Acute Disease↗
PubMed1994

Biologic resurfacing of a major joint defect with cryopreserved allogeneic periosteum under the influence of continuous passive motion in a rabbit model.

Periosteal autografts have been widely used for biologic resurfacing of full-thickness articular cartilage defects in rabbits. This study examined the effect of donor and recipient age on biologic joint resurfacing using fresh and cryopreserved periosteal allografts in a rabbit model. The study also assessed the ability of cryopreserved periosteal allografts to undergo neochondrogenesis. Eighty New Zealand rabbits were divided into six groups receiving combinations of fresh or cryopreserved allografts. After all the grafts were secured with fibrin glue, the animals were subjected to two weeks of continuous passive motion followed by four weeks of cage activity or intermittent active motion. The rabbit knees were analyzed at six weeks by gross examination, histochemical staining, and collagen typing. No significant difference in chondrogenic potential between fresh and cryopreserved periosteal allografts was observed. Grafts obtained from adult donors were much less chondrogenic than those from adolescents, but adults recipients experienced reasonably good results when they received allografts from young donors. No evidence of rejection was found in any of the samples as late as six weeks after transplantation.

Aging↗
PubMed1994

The significance of perioperative cultures in open pediatric lower-extremity fractures.

The value of perioperative cultures in 86 open pediatric lower-extremity fractures was assessed. Thirteen infections were identified, for an incidence of 15%. The predebridement culture was positive in 63% of wounds, and the postdebridement culture was positive in 40%. In the 13 wounds with infection, the infecting pathogen was found among the organisms grown on positive predebridement cultures 29% of the time, and on 60% of post-debridement cultures. Neither culture was of value in predicting the identity of a potential subsequent infecting pathogen. There was no significant difference in the rate of infection for negative cultures versus positive cultures; however, a negative predebridement culture was associated with a 94% chance of avoiding infection, and a negative postdebridement culture correlated with a 79% probability that infection would not occur. A positive culture result was less useful, however, because the infection rate remained low in these instances. Predebridement cultures were highly sensitive (88%) in identifying wounds that developed infection; however, the false positive rate was high, resulting in a specificity of only 43%. Postdebridement cultures, although somewhat more specific (63%), lacked sensitivity (50%). Clearly the routine use of perioperative cultures in open pediatric lower-extremity fractures must be questioned. Further prospective study is needed to confirm the validity and general applicability of the results of this retrospective review.

Bacteria↗
PubMed1993

Cryopreservation of periosteum for transplantation.

The concept of biological joint resurfacing has been widely studied, with encouraging results to date in both animal and human experiments. Most investigators have studied autograft tissue, however, in the clinical setting, situations might arise where autografting would not be suitable. We were therefore interested in developing a method of storing allograft periosteal tissue for biological joint resurfacing. A total of 192 periosteal grafts were harvested from 48 New Zealand White rabbits using sharp dissection (to include the cambium layer of progenitor cells). The free grafts were placed in a culture medium containing the cryopreservative dimethyl sulfoxide, then cooled at a controlled rate in a programmable freezer at rates of -0.5, -1.0, -2.0, or -10.0 degrees C/min. Viability of the grafts was assessed upon thawing after frozen storage for 8 days or 4 months using autoradiography and radioactive isotope uptake into newly synthesized proteins. Fresh, noncryopreserved and killed grafts were used as controls. A rate of cooling of -1.0 degrees C/min yielded viability results that were not significantly different from those of fresh controls. Furthermore, there was no change in viability as measured by radioactive isotope uptake over 4 months of storage. These results indicate that cryopreservation is a simple and efficient means of storing periosteal tissue for up to 4 months.

Animals↗
PubMedDate not supplied

A review of open tibia fractures in children.

Fifty-six open tibia fractures in 55 children were studied retrospectively. The overall case fatality rate was 7% (four patients). The most significant factor affecting death rate was injury to the chest and abdomen. Four amputations were performed in four patients with five injuries. Statistically, the presence of neurovascular compromise was significant, with four of eight compromised extremities (in seven patients) requiring amputation. Infection occurred in eight injuries, for an incidence of 14% overall (50% deep). The most important variables were presence of neurovascular injury and delay in getting the patient to surgery. A delay of > 6 h was correlated with a 25% infection rate compared with a 12% rate for those operated on within 6 h. The average time to union was approximately 5 +/- 4 months (range, 1.5-24.8 months). The most significant factor affecting union time was the age of the patient.

Adolescent↗