A new compression design that increases proximal locking screw bending resistance in femur compression nails.

The aim is to present our new method of compression, a compression tube instead of conventional compression screw and to investigate the difference of proximal locking screw bending resistance between compression screw application (6 mm wide contact) and compression tube (two contact points with 13 mm gap) application. We formed six groups each consisting of 10 proximal locking screws. On metal cylinder representing lesser trochanter level, we performed 3-point bending tests with compression screw and with compression tube. We determined the yield points of the screws in 3-point bending tests using an axial compression testing machine. We determined the yield point of 5 mm screws as 1963±53 N (mean±SD) with compression screw, and as 2929±140 N with compression tubes. We found 51% more locking screw bending resistance with compression tube than with compression screw (p=0,000). Therefore compression tubes instead of compression screw must be preferred at femur compression nails.

Treatment of posttraumatic cubitus varus with corrective supracondylar humeral osteotomies using the methyl methacrylate external fixator.

BACKGROUND: In upper and lower extremity fractures and osteotomy fixation, the use of methyl methacrylate (MM) as an external fixator presents an alternative method. The primary aim of this retrospective study was to evaluate the midterm outcome of pediatric patients who underwent corrective humeral supracondylar lateral closing-wedge osteotomy, with the external fixation system composed of MM and multiplane K-wires. METHODS: Fourteen consecutive cases with cubitus varus, who underwent corrective osteotomy with a limited lateral approach stabilized with MM and the multiplane K-wires external fixator system between January 2006 and May 2010, were retrospectively evaluated. Time of union, preoperative and postoperative elbow range of motion, and humeroulnar angle were measured. Results were rated as excellent, good, or poor, according to Bellemore criteria. RESULTS: There were a total of 6 female patients and 8 male patients with a mean age of 5.7 years (range, 3 to 9 y). The mean follow-up period was 28.2 months (range, 24 to 48 mo). The mean humeroulnar angle was (-) 18.6 degrees preoperatively, and (+) 16.3 degrees at the final follow-up. Thirteen patients were evaluated as excellent and 1 patient as good, according to Bellemore criteria. Union was seen in all patients at mean 7 weeks (range, 6 to 8 wk). Pin tract infection was observed in 1 patient and treated with oral antibiotics. Loss of correction was not observed in any patient during follow-up. CONCLUSIONS: External fixation of corrective supracondylar humeral osteotomy with MM and multiplane K-wires is a practical, effective, reliable, and cheap alternative method that can be applied. LEVEL OF EVIDENCE: Level IV. Retrospective study.

The Effects of Electrocautery on Peripheral Nerve: An Experimental Study.

BACKGROUND The aim of this study was to assess the usability of an electrocautery device as nerve stimulator and to investigate histopathologically the adverse effects of electrocautery at low power on rat sciatic nerves. METHODS A total of 36 female Sprague-Dawley albino rats were divided into six groups according to the power applied to their sciatic nerves (1, 2, 3, 4, 5 and 6 W, respectively). Pathologic changes were studied by microscopic examination and scored (no change = 0, mild = 1, moderate = 2, severe = 3). Multiple comparisons were provided for all groups by the Bonferroni test (one-way analysis of variance). A p value < 0.05 was accepted as statistically significant. RESULTS The average scores were 2.66 ± 0.51, 3.66 ± 0.51, 5.83 ± 1.83, 10.0 ± 1.78, 11.0 ± 1.54, and 13.8 ± 0.89 in groups 1 to 6, respectively. Significant differences were found between all groups (p < 0.01), except between groups 1 and 2, groups 2 and 3, and groups 4 and 5 (p > 0.05) Variable motor responses and foot deformities were observed at the different power levels. CONCLUSION Although electrocautery devices provoke motor responses if getting in contact with peripheral nerves as do nerve stimulators, their use induces histopathologically adverse effects even at the lowest power. Their use around peripheral nerves should be avoided.

Wrist tourniquet: the most patient-friendly way of bloodless hand surgery.

BACKGROUND: The literature is scarce on wrist tourniquets. In this study, three well-established locations of tourniquet setting including upper arm, proximal forearm, and wrist were compared on the same limb using both clinical as well as biochemical variables in paramedical volunteers. METHODS: Twenty unmedicated, healthy, paramedical, right-hand dominant volunteers participated in the study. The left upper arms were used for monitoring. Blood pressures and heart rates were monitored and recorded before (baseline) and immediately after the application of the tourniquet, every 5 minutes, and at the time the patient requested deflation. An intravenous cannula (22 G) was placed on the right hand to obtain samples, which were taken at baseline and immediately after deflation of the tourniquet to evaluate the levels of pO2, pCO2, O2 saturation, pH, bicarbonate, blood sugar, lactate, hematocrit, and electrolytes. The tourniquets were applied to the right upper arm, forearm, and wrist of each subject with 5-day intervals between each trial. Subjective discomfort and tourniquet pain levels were recorded. For each trial, tourniquet tolerance and details of discomfort were recorded. Statistical analysis was performed as appropriate. RESULTS: Twenty volunteers aged 20 to 44 years were included. For each trial, in the first 10 minutes after inflation of the tourniquet, the heart rate and systolic blood pressure were increased compared with baseline values. Diastolic blood pressure was elevated immediately after inflation and remained so until deflation in each trial. Diastolic blood pressure values were higher in the upper-arm tourniquet group compared with wrist. Then pH, pO2, and O2 saturation values were decreased and pCO2 and lactate levels were increased compared with baseline values in each trial. Blood sugar was decreased significantly in the arm group. The decrease in pH, pO2, O2 saturation, and blood sugar in the upper arm group was significantly higher compared with wrist and forearm groups. The lactate value was higher in the upper arm group compared with wrist. Visual analog scale and numerical rating scores were lower in the wrist group compared with others at all times. The longest tourniquet tolerance was in the wrist group. In the wrist group, curling was observed in all subjects but the fingers could easily be extended. CONCLUSION: The wrist tourniquet is the most comfortable technique of bloodless surgery for procedures limited to the hand region.