The invention of new anterior spinal instrumentation prototype: a structural analysis of KKU expandable cage.

OBJECTIVE: Report the invention and structural analysis of the new model of anterior spinal instrumentation (KKU expandable cage) that is expandable for space filling after vertebral body resection while simultaneously stabilize the upper vertebra with the lower vertebra, to tolerate the thoracolumbar physiologic load and augment the interbody arthrodesis of the spine. MATERIAL AND METHOD: The new model of expandable anterior spinal instrumentation, named KKU expandable cage, was invented and designed using the computer. The structural property of this instrumentation was tested and analyzed using the computer based structural analysis software. RESULTS: The KKU expandable cage made out of 316L stainless steel is 0.0301044 kg in mass and 3.76305 x 10(-6) m3 for volume. The outer diameter of the device is 23 mm and the height can expand from 20 mm to 35 mm for space filling after thoracolumbar vertebrectomy. The stress in the device after applying the maximal thoracolumbar physiologic compression load (1250N) is between 11692.7 N/m2 to 94.7266 x 10(6) N/m2, less than compression strength of the 316L stainless steel (170 x 10(6) N/m2). CONCLUSION: The stainless steel 316 L KKU expandable cage for anterior spinal instrumentation can withstand the maximal thoracolumbar physiologic compression load without failure whereas its expandable property enable it to fill and fit in the space reaching the height of 35 mm. Therefore, the insertion of this device into a space after thoracolumbar or lumbar corpectomy or vertebrectomy for the vertebral osteomyelitis or vertebral metastasis is appropriate. The device can also stabilize the spine and tolerate the maximal physiologic compression load of the thoracolumbar vertebrae. Therefore, the device helps decrease the need for bone graft or bone substitute in these patients.

KKU knee compression-rotation test for detection of meniscal tears: a comparative study of its diagnostic accuracy with McMurray test.

OBJECTIVE: The purpose of the present study was to compare the sensitivity, specificity and diagnostic accuracy of a new test, named "KKU Knee Compression-Rotation Test", with the most widely used examination, McMurray test. MATERIAL AND METHOD: Sixty-eight patients aged 18 to 39 years old were included in the present study. All of these patients were interviewed for their knee injury histories and examined with both KKU knee compression-rotation and McMurray tests preoperatively. For these clinical examination tests, the sensitivity, specificity, false positive, false negative and diagnostic accuracy rates were calculated and compared with the arthroscopic findings of these patients. RESULTS: The KKU knee compression-rotation test had sensitivity, specificity, and diagnostic accuracy for detection of meniscal tear as 86.27, 88.23, and 86.76% respectively, which superior to McMurray test that was 70.59, 82.35, and 73.53%. In addition, the KKU knee compression-rotation test had false positive and false negative rates of 11.76 and 13.73% less than the 17.65 and 29.41% of McMurray test. The combination of these two tests had diagnostic sensitivity of 90.20% and positive result of both tests suggested torn meniscus with the probability of 97.14%. CONCLUSION: The KKU knee compression-rotation test for detection of torn meniscus had better rates of diagnostic sensitivity, specificity, and accuracy than McMurray test. Therefore, the KKU knee compression-rotation test can be the first line screening examination for detection of torn meniscus. However, if the patient is tested by both the KKU knee compression-rotation and the McMurray tests, it will be a better screening test because a high sensitivity and positive result of both tests suggests a diagnosis of torn meniscus accurately.

Reliability of the medical outcomes study short-form survey version 2.0 (Thai version) for the evaluation of low back pain patients.

OBJECTIVES: To determine the reliability of Thai version of the medical outcomes study short-form survey version 2.0 (SF-36V2) in low back pain patients. MATERIAL AND METHOD: The authors developed the Thai version of the Medical Outcomes Study Short-Form Survey version 2.0 (SF-36V2) and tested it in 100 low back pain patients. Reliability of the Thai version of SF-36V2 was assessed by internal consistency using Chronbach's alpha coefficient and item-scale correlation. RESULTS: The authors demonstrated that the Chronbach's alpha coefficient of the physical health and mental health summary scales were 0.93 and 0.92 respectively. The Chronbach's alpha coefficient of eight scales in the Thai version of the SF-36V2 ranging was 0.72 - 0.94. The Chronbach's alpha coefficient tested in acute or chronic low back pain patients whether they have back pain only or back pain with radiculopathy ranging was 0.72-0.93. The item correlation coefficient for the 35 items within the eight health aspects ranged from 0.43 to 0.8. CONCLUSION: The Thai version of the Medical Outcomes Study Short-Form Survey version 2.0 (SF-36V2) is a reliable tool for assessing functional disability of low back pain in Thai patients.

Reliability of the Roland - Morris Disability Questionnaire (Thai version) for the evaluation of low back pain patients.

OBJECTIVE: To determine the reliability of the Thai version of the Roland - Morris disability questionnaire in low back pain patients. MATERIAL AND METHOD: To develop Thai version of the Roland - Morris disability questionnaire and test it in 120 low back pain patients. Reliability of the Thai version of the Roland - Morris disability questionnaire was assessed by internal consistency using Cronbach's alpha coefficient. RESULTS: The overall Cronbach's alpha coefficient of the scale was 0.83. The Cronbach's alpha coefficient of each question in the Thai version of the Roland - Morris disability questionnaire exceeded 0.7 (range, 0.71- 0.93). The Cronbach's alpha coefficient tested in acute or chronic low back pain patients whether they have back pain only or back pain with radiculopathy which also exceeded 0.7 (range, 0.83-0.87). CONCLUSION: The Thai version of the Roland - Morris disability questionnaire is a reliable tool for assessing functional disability of low back pain in Thai patients.

Treatment of pain after spinal surgery in the recovery room by single dose lornoxicam: a randomized, double blind, placebo-controlled trial.

BACKGROUND: Lornoxicam has been used in microsurgical lumbar discectomy. However, there is no data about controlling pain after open discectomy or laminectomy. OBJECTIVE: To compare the efficacy of a single dose of 16 mg of lornoxicam for the treatment of pain after disectomy or laminectomy with placebo in the PACU. STUDY DESIGN: Randomized, double blind, placebo-controlled trial. MATERIAL AND METHOD: Fifty-six patients who underwent discectomy or laminectomy were randomly allocated to receive 16 mg lornoxicam (Group L), or placebo (Group P) at the beginning of wound closure. Pain scores at rest (using a verbal numeric rating scale: VNRS 0-10), time to first analgesia requirement, morphine consumption during the first 2 hr after surgery and adverse effects were all recorded. The outcomes were assessed on admission to the PACU (T0), then at 1 (T1) and 2 (T2) hr after surgery. RESULTS: Baseline data were comparable between the two groups. The proportion of patients with VNRS > 5 at T0 in both groups were not significantly different (44.4% in group P vs 50.0% in group L, CI of difference: - 32.4%, 21.3%, p = 0.68). The mean VNRS scores, at T0 and T1 were > 5 and at T2 was < 5 in both groups. There was no difference between the two groups. The morphine consumption in both groups was not different (9.0 mg vs 9.3 mg) as well as the time to first analgesia requirement (35 min vs 40 min). Patients in the two groups had no significant difference in the symptoms or degree of nausea/vomiting. The number of patients with excessive sedation and the proportion of patients needing oxygen during transportation to the ward were not different. CONCLUSION: Lornoxicam 16 mg given intravenously before wound closure provides inadequate pain relief immediately after disectomy or laminectomy in the PACU. However, adequate pain relief was demonstrated at 2 hr after surgery, which was similar to the placebo.