Influence of common clinical variables on intraoperative parathyroid hormone monitoring during surgery for primary hyperparathyroidism.

BACKGROUND: Intraoperative monitoring of parathyroid hormone (IOPTH) is a reliable method of predicting the cure of primary hyperparathyroidism (PHPT). The aim of this study is to assess whether common clinical variables (CCV) frequently encountered in patients with PHPT may affect the magnitude of PTH drop or the likelihood of patients meeting the intraoperative cure criterion. DESIGN: Patients who were surgically cured from PHPT caused by single gland disease (SGD) and had full IOPTH protocol (4 measurements) were stratified according to age, gland weight, renal function, vitamin D status and severity of hypercalcemia. The percentage of IOPTH drop and the frequency of patients who had true positive IOPTH test results were compared among groups. RESULTS: 762 patients had surgery for PHPT, of whom 746 were (98%) cured. Of these 746 patients, 511 who had SGD and a full IOPTH protocol were included in this study. The median IOPTH drop was significantly higher among younger patients, those with severe hypercalcaemia at 5, 10, 15 min after gland excision, giant glands (at 5-min only), patients with vitamin D deficiency (at 10, 15 min), and those with normal renal function (at 15 min only). The likelihood of the patients meeting the intraoperative cure criterion was not significantly affected among the groups except in patients with mild hypercalcaemia, who were significantly less likely to have 50% IOPTH drop than those with severe hypercalcaemia at all time points. The frequency of mildly hypercalcaemic patients who met cure criterion was significantly improved by extending measurement to 15 min. CONCLUSIONS: IOPTH monitoring has the ability to mitigate the variability of IOPTH kinetics associated with most clinical variables. Mildly hypercalcemic patients in particular may benefit from waiting for 15-min measurement before any surgical decision is made.

Axially vascularized bone substitutes: a systematic review of literature and presentation of a novel model.

INTRODUCTION: The creation of axially vascularized bone substitutes (AVBS) has been successfully demonstrated in several animal models. One prototypical indication is bone replacement in patients with previously irradiated defect sites, such as in the mandibular region. The downside of current clinical practice, when free fibular or scapular grafts are used, is the creation of significant donor site morbidity. METHODS: Based on our previous experiments, we extended the creation of an arterio-venous loop to generate vascularized bone substitutes to a new defect model in the goat mandibula. In this report, we review the literature regarding different models for axially vascularized bone substitutes and present a novel model demonstrating the feasibility of combining this model with synthetic porous scaffold materials and biological tissue adhesives to grow cells and tissue. RESULTS: We were able to show the principal possibility to generate axially vascularized bony substitutes in vivo in goat mandibular defects harnessing the regenerative capacity of the living organism and completely avoiding donor site morbidity. CONCLUSION: From our findings, we conclude that this novel model may well offer new perspectives for orthopedic and traumatic bone defects that might benefit from the reduction of donor site morbidity.

The treatment of infected non-union of the tibia by compression-distraction techniques using the Ilizarov external fixator.

Circular external fixation using the Ilizarov apparatus combined with compression-distraction techniques was used to treat 11 patients with infected non-union and segmental bone loss of the tibia. The series comprised 8 males and 3 females, with an average age of 27 years (range 17-51 years). The average number of previous failed surgical attempts at union was 2 per patient (range 1 to 4). Three infected non-unions without shortening were treated with complete resection of the site and conversion of the diaphysis into a segmental defect. The functional results were excellent in 5, good in 3, fair in 2 and poor in one patient. No additional procedures were used in any of the patients.