The coronal hypomochlion: a tipping point of clinical relevance when planning valgus producing high tibial osteotomies.

AIMS: In patients undergoing medial opening wedge high tibial osteotomy (MOWHTO), soft tissue opening on the medial side of the knee is difficult to predict. When the load bearing axis is corrected beyond a certain point, the knee joint tilts open on the medial side. We therefore hypothesised that there is a tipping point and defined this as the coronal hypomochlion. PATIENTS AND METHODS: In this prospective study of 150 navigated MOWHTOs (144 consecutive patients), data were collected before surgery and at three months post-operatively. In order to calculate the hypomochlion, we compared the respective changes to the joint line convergence angle (JLCA) with the post-operative axis of the leg. The change to the medial proximal tibial angle accounts for only about 80% of the change to the femorotibial angle; 20% of the correction can therefore be attributed to non-osseous, soft-tissue changes. RESULTS: We were able to demonstrate a linear change of JLCA in a range of 0° to 5° of valgus which started when the post-operative long-leg axis was corrected beyond 2° of valgus. CONCLUSION: We found that the coronal hypomochlion occurs at 2° of valgus. TAKE HOME MESSAGE: It is recommended to plan realignment for medial open wedge high tibial osteotomy at a maximum of 2° valgus. Cite this article: Bone Joint J 2016;98-B:628-33.

Severe intoxication with the veterinary tranquilizer xylazine in humans.

Xylazine (Rompun, Proxylaz) is a veterinary tranquilizing agent. A case of self-injection of 1.5 g xylazine by a 27-year-old farmer is reported. He subsequently became comatose, hypotensive, bradycardic, and mildly glycemic. An intensive supportive therapy including intubation and ventilation was required. The patient made a full recovery over the next 30 h. The largest concentrations measured were 4.6 mg/L in plasma, 446 mg/L in gastric fluid, and 194 mg/L in urine. The calculated plasma half-life was 4.9 h. Kinetic data correlated with clinical symptoms. Qualitative and quantitative analyses of xylazine were done by thin-layer chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. These methods allow the detection of small amounts substance in stomach, plasma, and urine. Liquid-liquid extraction was used for the isolation of drug. The sensitvity is high, and with these methods, a rapid analysis is possible. Xylazine intoxications in humans are rare. We describe the management of acute poisoning and present a review of xylazine toxicity in humans.

Importance of the renin-angiotensin system in the regulation of arterial blood pressure in conscious mice and rats.

AIM: The present experiments were designed to determine the mechanism(s) for increased sensitivity to blockade of the renin-angiotensin system in mice in comparison with rats. METHODS: Mice and rats, with indwelling femoral arterial and venous catheters, were chronically administered angiotensin II or pharmacological inhibitors of the renin-angiotensin system as sodium intake was altered. RESULTS: Increasing sodium intake led to suppression of circulating renin, angiotensin II, and aldosterone in rats and mice in the absence of alterations in arterial blood pressure. Additional experiments demonstrated that continuous intravenous infusion of angiotensin II (20 ng kg(-1) min(-1)) significantly increased arterial blood pressure by approximately 35 mmHg in conscious rats at all levels of sodium intake (n = 6). In contrast, arterial pressure was unaffected by angiotensin II infusion in conscious mice under conditions of low sodium intake, although arterial pressure was increased by 16 mmHg when mice were administered a high sodium intake while infused with angiotensin II (n = 6). In comparison, blockade of the endogenous renin-angiotensin system led to significantly greater effects on arterial pressure in mice than rats. Continuous infusion of captopril (30 microg kg(-1) min(-1)) or losartan (100 microg kg(-1) min(-1)) resulted in a 55-90% greater fall in blood pressure in conscious mice in comparison with conscious rats. CONCLUSION: The present studies indicate that arterial pressure in mice is more dependent upon the endogenous renin-angiotensin system than it is in rats, but mice are more resistant to the hypertensive effects of exogenous angiotensin II.

Perceptions of quality in long-term care: a satisfaction survey.

At a 387-bed geriatric hospital in Montreal, Canada, a cross-sectional satisfaction survey was conducted on random samples of patients, families, families of deceased patients, and nursing staff. Using the same pretested structured questionnaire, the subjects were asked to rank (assign importance to) and rate (assign a rate of success to) 15 indicators of quality care. Significant differences both between and within the four groups were found on the perceived importance and rate of success of many of the indicators, supporting the primary hypotheses. Ethnicity and several sociodemographic covariates influenced the importance and rate of success assigned to the key indicators. The article discusses survey methodology issues as well as the integration of a satisfaction survey into an overall quality improvement program.

[Measuring vibration sense in childhood. Normal values and initial experiences in polyneuropathies]. / Messung des Vibrationssinns im Kindesalter. Normwerte und erste Erfahrungen bei Polyneuropathien.

BACKGROUND: We have attempted to obtain normal values for vibration thresholds in children and to evaluate their application in polyneuropathies. METHODS: Vibration thresholds determinations were made by means of a handheld vibrameter (Fa Somedic AB Sweden): Within a constant frequency (100 Hz) and a calibrated pressure (450 g) the amplitude ranged variably from 0.01 to 399 microns. Measurements were made at three sites (carpal, tibial and tarsal). Vibration threshold (VT) was determined by the average of Vibration Perception Threshold (VPT) and Vibration Disappearance Threshold (VDT). RESULTS: Reference values obtained from 106 children and adolescents (control group), 5.5 to 19 years of age, correlated with age but not with sex. The amplitude of VT-values ranged from 0.4 microns (carpal at 6 years), to 1.10 microns (tarsal at 18 years). Patients with Friedreich's ataxia (n = 7) or hereditary motosensory neuropathy (n = 11) showed strongly increased thresholds at all sites up to a factor of 100. CONCLUSIONS: The examination by means of a vibrameter took at least 10 min, the shorter examination by tuning fork however showed to be less sensitive and rather inexact. An examination with a vibrameter is, as rule, reliably possible in children older than 5 years.

[Functional capacity after peripheral nerve lesion: significance of pain syndromes]. / Begutachtung peripherer Nervenschäden. Wertigkeit von Schmerzsyndromen.

INTRODUCTION: The loss of functional capacity by peripheral nerve lesion is easy to be estimated: A certain neurologic dysfunction results in a characteristic reduction of the former individual capacity. In contrast, the effect of accompanying pain to every-day life and working ability is not known exactly. In this study, we compared the results of judgement in nerve lesions under the circumstances of additional pain syndromes. METHODS: From January 1994 until December 1998 we saw 57 patients with peripheral nerve lesions, part of them with an additional pain syndrome. Beside conventional neurological examination a detailed pain analysis has been done. RESULTS: Lesions of the median or ulnar nerves showed regularly disturbances in neurological functions (10/14 for the median nerve, 13/16 for the ulnar nerve). Astonishing is the fact, that serious pain after nerve lesion only occurs in cases of partial nerve lesion. We saw neuralgias in 6 patients with ulnar neuropathy, in three cases of median nerve lesions we could see severe neuralgia (causalgia we found in 3 cases of ulnar neuropathy, in 6 cases after Median Nerve lesion). Patients with a lesion of the central plexus brachialis showed in 10 of 11 cases an additional pain syndrome. Other nerves have been affected more rarely. For the judgement of the loss of earning capacity we saw an additional pain related diminuition of at least 10% compared to those patients without pain problems. CONCLUSIONS: The common grading scales for peripheral nerve lesions are not suitable in cases accompanied by an additional pain syndrome. Beside a functional deficit the effect of severe pain in these patients has to be estimated. On an average, patients with additional pain-problems get a 10% extended loss of earning capacity, even more in particular cases.

[Secondary deformities after section of primary bone tumors of the spine in children and adolescents]. / Sekundäre Deformitäten nach Resektion primärer Knochentumoren der Wirbelsäule bei Kindern und Jugendlichen.

Primary bone tumors and tumor-like lesions of the vertebral column are rare in children. After operative tumor resection, 25 children under the age of 17 could be reviewed in a retrospective analysis. Malignant bone tumors occurred only twice in the region of the vertebral body. No deformity was registered in 9 of 16 cases after local tumor resection with and without laminectomy on one level. In contrast, after resection of one or both facets in combination with laminectomy cranial to L4 or thoracal, progressive kyphosis was found within 6-22 months postoperatively in four cases. This required a secondary fusion. After primary fusion and instrumentation, no deformity was registered. In nine cases with a location of the tumor in the vertebral body, only two patients developed a secondary instability of the spine. Both cases had no primary fusion. The other seven patients with initial fusion and instrumentation showed no deformity within 24 up to 127 months postoperatively. These results are compared with data from the current literature.

Capillary gas chromatographic determination of terbutryn and its degradation products in sorghum grain and confirmation of the compounds by mass spectrometry.

An analytical method with a limit of detection 0.05 mg kg-1 is described for the determination of the herbicide terbutryn and its three degradation products, GS-26575, GS-11355 and GS-26831 in sorghum grains using fused silica capillary gas chromatography. Electron impact and methane chemical ionization mass spectra are reported to confirm the characterization of the compounds. No residues of these chemicals were found in sorghum harvested 14 weeks following terbutryn treatment at 0-4.5 kg ha-1.