Computed Tomographic Study of Occipital Thickness in Ethnic Malays

@#Introduction: Occipitocervical fusion is performed to address craniocervical and atlantoaxial instability. A screw of at least 8mm is needed for biomechanical stability. Occipital thickness of Malay ethnicity is unknown, and this study presents the optimal screw placement positions for occiput screw in this population. This was a retrospective crosssectional study of 100 Malays who underwent computed tomography (CT) scan for brain assessment. To measure the occipital bone thickness of Malay ethnicity at the area of common screw placement for occipitocervical fusion. The subject’s data was obtained from the institutional database with consent from the administrations and the patients. None of the patients had any head and neck pathology. Materials and methods: The subject’s data was obtained from the institutional database with consent from the administrations and the patients. None of the patients had any head and neck pathology. Computed tomography (CT) of 100 Malay patients who underwent head and neck CT were analysed, based on our inclusion and exclusion criteria. Measurements were taken using a specialised viewer software where 55 points were measured, followed a grid with 10mm distance using external occipital protuberance (EOP) as the reference point. Results: There were 57 males and 43 females of Malay ethnicity with a mean age of 36.7 years analysed in this study. The EOP was the thickest bone of the occiput which measured 16.15mm. There was an area of at least 8mm thickness up to 20mm on either side of the EOP, and at level 10mm inferior to the EOP. There is thickness of at least 8mm, up to 30mm inferior to the EOP at the midline. The males have significantly thicker bone especially along the midline compared to females. Conclusion: Screws of at least 8mm can be safely inserted in the Malay population at 20mm on either side of the EOP at the level 10mm inferior to the EOP and up to 30mm inferior to the EOP at the midline.

Lumbar Spinal Stenosis: The Reliability, Sensitivity and Specificity of the Nerve Root Sedimentation Sign

@#sensitivity and specificity of nerve root sedimentation sign(NRS) in our populations. The NRS is a radiological sign todiagnose lumbar spinal stenosis (LSS). It is claimed to bereliable with high sensitivity and specificity. MaterialsandMethods:A total of 82 MRI images from 43patients in Group A (LSS) and 39 patients in Group B (nonLSS) were analysed and compared for the presence of theNRS sign. Two assessors were used to evaluate intra andinter-assessor reliability of this sign based on 56 (33 patients,Group A and 23 patients, Group B). The findings werestatistically analysed using SPSS software. Results:There was a significant association between spinalclaudication and leg numbness with LSS (p<0.001 andKappa=0.857, p<0.001). The inter-assessor reliability wasalso good (Kappa of 0.786, p<0.001).Conclusion:The NRS sign has high sensitivity andspecificity for diagnosing LSS. The sign also has good intraand inter-assessor reliability.

The Relationship amongst Intervertebral Disc Vertical Diameter, Lateral Foramen Diameter and Nerve Root Impingement in Lumbar Vertebra

@#Introduction: The vertical diameter of the foramen isdependent upon the vertical diameter of the correspondingintervertebral disc. A decrease in disc vertical diameter hasdirect anatomic consequences to the foraminal diameter andarea available for the nerve root passing through it. Thisstudy is to establish the relationship amongst theintervertebral disc vertical diameter, lateral foramendiameters and nerve root compression in the lumbarvertebra.Materials and Methods: Measurements of the studyparameters were performed using sagittal MRI images. Theparameters studied were: intervertebral disc verticaldiameter (DVD), foraminal vertical diameter (FVD),foraminal transverse diameter (FTD) and nerve root diameter(NRD) of both sides. The relationship between the measuredparameters were then analyzed.Results: A total of 62 MRI images were available for thisstudy. Statistical analysis showed moderate to strongcorrelation between DVD and FVD at all the lumbar levelsexcept at left L23 and L5S1 and right L3L4 and L4L5.Correlation between DVD and FTD were not significant atall lumbar levels. Regression analysis showed that a decreaseof 1mm of DVD was associated with 1.3, 1.7, 3.3, 3.3 and1.3mm reduction of FVD at L1L2, L2L3, L3L4, L4L5 andL5S1 respectively.Conclusion: Reduction of DVD was associated withreduction of FVD. However, FVD was relatively wide forthe nerve root even with complete loss of DVD. FTD wasmuch narrower than the FVD making it more likely to causenerve root compression at the exit foramina. Theseanatomical details should be given consideration in treatingpatients with lateral canal stenosis.

A Good Short-term Outcome in Delayed Decompression of Cauda Equina Syndrome in Klebsiella pneumoniae Spinal Epidural Abscess: A Case Report

Spinal epidural abscess is a severe, generally pyogenic, infection of the epidural space of spinal cord or cauda equina. The swelling caused by the abscess leads to compression or vascular disruption of neurological structures that requires urgent surgical decompression to avoid significant permanent disability. We share a rare case of Klebsiella pneumoniae spinal epidural abscess secondary to haematogenous spread of previous lung infection that presented late at our centre with cauda equina syndrome that showed good short-term outcome in delayed decompression. A 50-year old female presented with one-week history of persistent low back pain with progressively worsening bilateral lower limb weakness for seven days and urinary retention associated with saddle anesthesia of 2-day duration. Magnetic resonance imaging with contrast of the lumbo-sacral region showed an intramuscular collection of abscess at left gluteus maximus and left multifidus muscle with a L3-L5 posteriorly placed extradural lesion enhancing peripherally on contrast, suggestive of epidural abscess that compressed the cauda equina. The pus was drained using the posterior lumbar approach. Tissue and pus culture revealed Klebsiella pneumoniae, suggestive of bacterial infection. The patient made immediate improvement of muscle power over bilateral lower limbs postoperative followed by ability to control micturition and defecation the 4th post-operative day. A good short-term outcome in delayed decompression of cauda equine syndrome is extremely rare. Aggressive surgical decompression combined with antibiotic therapy led to good short-term outcome in this patient despite delayed decompression of more than 48 hours.

The Morphometric Study of Degenerative Lateral Canal Stenosis at L4-L5 and L5-S1 Using Magnetic Resonance Imaging (MRI): Feasibility Analysis for Posterior Surgical Decompression

This study was to evaluate the morphological features of degenerative spinal stenosis and adequacy of lateral canal stenosis decompression via unilateral and bilateral laminectomy. Measurements of facet joint angulation (FJA), mid facet point (MFP), mid facet point distance (MFPD), the narrowest point of the lateral spinal canal (NPLC) and the narrowest point of the lateral spinal canal distance (NPLCD) were performed. At L4L5 of the right and left side, the mean distance between the lateral border of the dura and MFP was 1.0 ± 0.2 cm and 1.0 ± 0.3cm respectively. The mean NPLC was seen at 0.7 ± 0.3 and 0.7 ± 0.3 cm cm from the dura. At L5S1 of the right and left side, the mean distance between the lateral border of the dura and MFP was 1.2± 0.2 and 1.3 ± 0.2 cm respectively. The mean NPLC was seen at 0.8 ± 0.4 and 0.9 ± 0.5 cm from the dura. Unilateral laminectomy may result in incomplete decompression.

The Effectiveness of Intravenous Morphine Infusion as Preemptive Analgesia in Preventing Phantom Limb Pain Following Lower Limb Amputation

Phantom limb pain may reduce ambulation and mobility in amputees, resulting in diminished quality of life. We conducted a prospective study to compare the perioperative analgesic use of intravenous morphine infusion in 27 patients (Group A) and intramuscular diclofenac sodium in 28 patients (Group B) in patients undergoing lower limb amputation. All patients underwent amputation under spinal anaesthesia and reported a Modified Verbal Numerical Pain Score of less than two prior to the procedure. Presence of phantom pain was assessed on the first, second, third and seventh day as well as at the third month and sixth month post-operatively. Twelve (44 %) patients from group A and 21 patients (75 %) from group B developed phantom limb pain following amputation, a statistically significant difference between groups (p<0.05). We conclude that intravenous morphine infusion is more effective than intramuscular diclofenac sodium in preventing the occurrence of phantom limb pain following amputation.