Correction of clawed hallux deformity: comparison of the Jones procedure and FHL transfer in a cadaver model.

BACKGROUND: A clawed hallux is defined as extension of the first metatarsophalangeal (MTP) joint combined with flexion of the interphalangeal (IP) joint. Two operative procedures, the modified Jones procedure and flexor hallucis longus (FHL) transfer, are indicated for correction. The purpose of this study were to evaluate the overall effectiveness of these two procedures in correcting both the clawed hallux deformity and its mechanical consequences and to compare their effect on postoperative plantar pressures. METHODS: The modified Jones procedure and FHL transfer were done on cadaver specimens that were tested before and after surgery in a specialized foot-loading frame. We quantified the angular correction of the MTP and the IP joints, as well as the plantar pressures under the head of the first metatarsal and the hallux. RESULTS: Both surgeries were equally effective in correcting the angular deformity at the MTP and IP joints (p = 0.037 and 0.0020, respectively). A significant reduction in the plantar pressure (p = 0.015) beneath the first metatarsal was observed with both the modified Jones procedure and the FHL transfer. Overall, there was no significant difference between preoperative and postoperative pressures beneath the hallux (p = 0.5); however, for the FHL overpull group there was significantly less pressure beneath the hallux after surgery (p = 0.014). CONCLUSIONS: The two surgeries produced similar results, but the FHL transfer does not require fusion of the hallux, which is considered an undesirable co-morbidity of the modified Jones procedure.

Evaluation of urinary methoxyphenols as biomarkers of woodsmoke exposure.

Urinary methoxyphenols have been proposed as biomarkers for woodsmoke exposure, but the relationship between exposure and urinary methoxyphenol concentrations has not been characterized. We collected personal particulate matter2.5 and urine samples from 9 adults experimentally exposed to smoke from an open wood fire to characterize this relationship. Personal exposures (PM2.5 mean 1500 microg/ m3) varied 3.5-fold. Twenty-two methoxyphenols, levoglucosan, and 17 polynuclear hydrocarbons were quantified by gas chromatography/mass spectrometry assays for personal filter samples and urine samples. Most methoxyphenols had measurable preexposure levels. Propylguaiacol, syringol, methylsyringol, ethylsyringol, and propylsyringol had peak urinary concentrations after the woodsmoke exposure. Eight subjects had peak urinary elimination of methoxyphenols within 6 h (t1/2 3-5 h), whereas one had delayed elimination. Several metrics for urinary excretion were evaluated. Analyte concentration was greatly affected by diuresis. Excretion rate and analyte concentrations normalized by creatinine gave a clearer signal and were equivalent in predictive ability. Twelve-hour average creatinine-normalized concentrations of each of the 5 methoxyphenols gave a Pearson correlation > or = 0.8 with their particle-phase concentration. The sum of urinary concentrations for the 5 methoxyphenols versus levoglucosan on personal filters gave a regression coefficient of 0.75. This sum versus PM2.5 gave a regression coefficient of 0.79. The intercept of this regression suggests that the threshold for detection of an acute exposure event would be approximately 760 microg/m3 particulate matter from woodsmoke. The signal-to-noise (12-h postexposure average/preexposure average) ranged from 1.1 to 8 for the 5 methoxyphenols. Analysis of multiple compounds provided assurance that elevations were not artifactual due to food or other products.