Wiwat Wajanavisit

Lumbopelvic alignment on standing lateral radiograph of adult volunteers and the classification in the sagittal alignment of lumbar spine

The analysis of the sagittal balance is important for the understanding of the lumbopelvic biomechanics. Results from previous studies documented the correlation between sacro-pelvic orientation and lumbar lordosis and a uniqueness of spino-pelvic alignment in an individual person. This study was subjected to determine the lumbopelvic orientation using pelvic radius measurement technique. The standing lateral radiographs in a standardized standing position were taken from 100 healthy volunteers. The measurements which included hip axis (HA), pelvic radius (PR), pelvic angle (PA), pelvic morphology (PR-S1), sacral translation distance (HA-S1), total lumbosacral lordosis (T12-S1), total lumbopelvic lordosis (PR-T12) and regional lumbopelvic lordosis angles (PR-L2, PR-L4 and PR-L5) were carried out with two independent observers. The relationships between the parameters were as follows. PR-S1 demonstrated positive correlation to regional lumbopelvic lordosis and revealed negative correlation to T12-S1. PA showed negative correlation to PR-S1 and regional lumbopelvic lordosis, but revealed positive correlation to HA-S1. T12-S1 was significantly increased when PR-S1 was lesser than average (35°–45°) and was significantly decreased when PR-S1 was above the average. PR-L4 and PR-L5 were significantly reduced when PR-S1 was smaller than average and only PR-L5 was significantly increased when PR-S1 was above the average. In conclusion, this present study supports that lumbar spine and pelvis work together in order to maintain lumbopelvic balance.

A genetic association study between growth differentiation factor 5 (GDF 5) polymorphism and knee osteoarthritis in Thai population

ObjectiveOsteoarthritis (OA) is a multi-factorial disease and genetic factor is one of the important etiologic risk factors. Various genetic polymorphisms have been elucidated that they might be associated with OA. Recently, several studies have shown an association between Growth Differentiation Factor 5(GDF5) polymorphism and knee OA. However, the role of genetic predisposing factor in each ethnic group cannot be replicated to all, with conflicting data in the literatures. Therefore, the aim of this study was to investigate the association between GDF5 polymorphism and knee OA in Thai population.Materials and MethodsOne hundred and ninety three patients aged 54-88 years who attended Ramathibodi Hospital were enrolled. Ninety cases with knee OA according to American College of Rheumatology criteria and one hundred and three cases in control group gave informed consent. Blood sample (5 ml) were collected for identification of GDF5 (rs143383) single nucleotide polymorphism by PCR/RFLP according to a standard protocol. This study protocol was approved by the Ethics Committee on human experimentation of Ramathibodi Hospital Faculty of Medicine, Mahidol University. Odds ratios (OR) and 95% confidence intervals were calculated for the risk of knee OA by genotype (TT, TC and CC) and allele (T/C) analyses.ResultsThe baseline characteristics between two groups including job, smoking and activity were not different, except age and BMI. The entire cases and controls were in Hardy-Weinberg equilibrium (p > 0.05). The OA knee group (n = 90) had genotypic figure which has shown by TT 42.2% (n = 38), TC 45.6% (n = 41) and CC 12% (n = 11), whereas the control group (n = 103) revealed TT 32% (n = 33), TC 45.6% (n = 47), and CC 22.3% (n = 23), respectively. Genotypic TT increased risk of knee OA as compared to CC [OR = 2.41 (P = 0.04, 95%CI = 1.02-5.67)]. In the allele analysis, the T allele was found to be significantly associated with knee OA [OR = 1.53 (P = 0.043, 95%CI = 1.01-2.30)].ConclusionThese data suggested that GDF5 polymorphism has an association with knee OA in Thai ethnic. This finding also supports the hypothesis that OA has an important genetic component in its etiology, and GDF5 protein might play important role in the pathophysiology of the disease.

Morphometric evaluation of subaxial cervical spine using multi-detector computerized tomography (MD-CT) scan: the consideration for cervical pedicle screws fixation

BackgroundCervical pedicle screw (CPS) insertion is a technically demanding procedure. The quantitative understanding of cervical pedicle morphology, especially the narrowest part of cervical pedicle or isthmus, would minimize the risk of catastrophic damage to surrounding neurovascular structures and improve surgical outcome. The aim of this study was to investigate morphology and quantify cortical thickness of the cervical isthmus by using Multi-detector Computerized Tomography (MD-CT) scan.MethodsThe cervical CT scans were performed in 74 patients (37 males and 37 females) with 1-mm slice thickness and then retro-reconstructed into sagittal and coronal planes to measure various cervical parameters as follows: outer pedicle width (OPW), inner pedicle width (IPW), outer pedicle height (OPH), inner pedicle height (IPH), pedicle cortical thickness, pedicle sagittal angle (PSA), and pedicle transverse angle (PTA).ResultsTotal numbers of 740 pedicles were measured in this present study. The mean OPW and IPW significantly increased from C3 to C7 while the mean OPH and IPH of those showed non-significant difference between any measured levels. The medial-lateral cortical thickness was significantly smaller than the superior-inferior one. PTA in the upper cervical spine was significantly wider than the lower ones. The PSA changed from upward inclination at upper cervical spine to the downward inclination at lower cervical spine.ConclusionsThis study has demonstrated that cervical vertebra has relatively small and narrow inner pedicle canal with thick outer pedicle cortex and also shows a variable in pedicle width and inconsistent transverse angle. To enhance the safety of CPS insertion, the entry point and trajectories should be determined individually by using preoperative MD-CT scan and the inner pedicle width should be a key parameter to determine the screw dimensions.

The correlation between the sagittal lumbopelvic alignments in standing position and the risk factors influencing low back pain

Low back pain (LBP) is the most common health problem. Many factors have been demonstrated to be fundamental risk factors of LBP such as body mass index (BMI), age and sex. However, so far there have been few studies demonstrating the association between lumbo-pelvic alignment (LPA) and these factors. This present study was aimed to clarify the correlation between the LPA and the risk factors contributing to LBP. Standing lateral X-rays were taken from 100 healthy volunteers (70 males and 30 females) with no history of low back pain before their participation. Average age of subjects was 33.3±6.8 years (rang 21–50). Mean body weight was 59.1±7.9kg (range 40–82), mean body height was 163.6±7.2 cm (range 145–178) and mean BMI was 22.1±2.4 kg/m2 (range 18.0–29.3). The LPA was classified into 3 types according to the recently proposed pelvic orientation guidelines. No direct correlation was found between the pelvic orientation and age or BMI. Each LPA type was associated with sex but not BMI and age (P=0.00, 0.71, and 0.36, respectively). The results from this study demonstrated the differences in LPA between male and female, and also confirmed that the sagittal orientation of the pelvis remained constant in adults. The high prevalence of LPA type 1 in males may reduce the occurrence of LBP in obese male individuals.

Outcomes of Fluoroscopically Guided Lumbar Transforaminal Epidural Steroid Injections in Degenerative Lumbar Spondylolisthesis Patients

Study Design A prospective cohort. Purpose To report the short and long term outcomes of fluoroscopically guided lumbar transforaminal epidural steroid injection (TFESI) in degenerative lumbar spondylolisthesis (DLS) patients. Overview of Literature TFESI has been widely used for the treatment of lumbosacral radicular pains. However, to our knowledge, there has been no study which has evaluated the outcomes of TFESI in patients with DLS. Methods The DLS patients received fluoroscopically guided lumbar TFESI with 80 mg of methylprednisolone and 2 mL of 1% lidocaine hydrochloride. Patients were evaluated by an independent observer before the initial injection, at 2 weeks, at 6 weeks, at 3 months, and at 12 months after the injections. Visual analog scale (VAS), Roland 5-point pain scale, standing tolerance, walking tolerance, and patient satisfaction scale were evaluated for outcomes. Results Thirty three DLS patients treated with TFESI, who were completely followed up, were included in this study. The average number of injections per patient was 1.9 (range from 1 to 3 injections per patient). Significant improvements in VAS and Roland 5-point pain scale were observed over the follow up period from 2 weeks to 12 months. However, the standing and walking tolerance were not significantly improved after 2 weeks. At 2 weeks, the patient satisfaction scale was highest, although, these outcomes declined with time. The DLS patients with one level of spinal stenosis showed significantly better outcome than the DLS patients with two levels of spinal stenosis. Five patients (13%) underwent surgical treatment during the 3 to 12 months follow up. Conclusions TFESI provides short term improvements in VAS and Roland 5-point pain scale, standing tolerance, walking tolerance and patient satisfaction scale in DLS patients. In the long term, it improves VAS but limits the improvements in Roland 5-point pain scale, standing tolerance, walking tolerance and patient satisfaction scale.

Prevalence of High-Riding Vertebral Artery and Morphometry of C2 Pedicles Using a Novel Computed Tomography Reconstruction Technique

Study Design Cross-sectional, matched-pair comparative study. Purpose To determine whether a thin-sliced pedicular-oriented computed tomography (TPCT) scan reconstructed from an existing conventional computed tomography (CCT) scan is more accurate for identifying vertebral artery groove (VAG) anomalies than CCT. Overview of Literature Posterior atlantoaxial transarticular screw fixation and C2 pedicle screws can cause vertebral artery (VA) injury. Two anatomic variations of VAG anomalies are associated with VA injury: a high-riding VA (HRVA) and a narrow pedicle of the C2 vertebra. CCT scan is a reliable method used to evaluate VAG anomalies; however, its accuracy level remains debatable. Literature comparing the prevalence of C2 VAG anomalies between CCT and TPCT is limited. Methods A total of 200 computed tomography scans of the upper cervical spine obtained between January 2008 and December 2011 were evaluated for C2 VAG anomalies (HRVA and narrow pedicular width) using CCT and TPCT. The prevalence of C2 VAG anomalies was compared using these two different measurement methods via a McNemars test. Results Of the 200 patients studied, 23 HRVA (6.01%; 95% confidence interval [CI], 3.61%–8.39%) were detected with CCT, whereas 66 HRVA (16.54%; 95% CI, 12.85%–20.23%) were detected with TPCT (p<0.001). Sixty-two narrow pedicles (15.58%; 95% CI, 11.99%–19.15%) were detected with CCT, whereas 90 narrow pedicles (22.83%; 95% CI, 18.58%–26.87%) were detected with TPCT (p<0.001). Conclusions VAG anomalies are commonly observed. A preoperative evaluation using TPCT reconstructed from an existing CCT revealed a significantly higher prevalence of C2 VAG anomalies than did CCT and showed comparable prevalence to previously published studies using more sophisticated and higher risk techniques. Therefore, we propose TPCT as an alternative preoperative evaluation for C2 screw placement and trajectory planning.

Effect of early surgery in high surgical risk geriatric patients with femoral neck fracture and taking antiplatelet agents

AIM To investigate the effect of early surgical intervention on the high surgical risk elderly patients who sustained femoral neck fracture (FNF) and taking concomitant antiplatelet agents. METHODS Between 2010 and 2012, a prospective study was conducted on 49 geriatric patients, who took antiplatelet agents, sustained FNF and underwent surgery within 72 h [early surgery (ES) group], and these were compared with a retrospective consecutive case series of patients with similar characteristics (45 cases) who had delayed surgery (DS group) after 72 h during an earlier 3-year period. Postoperative outcomes were followed for one year and compared. RESULTS There were non-significant differences in perioperative blood loss, blood transfusion, intensive care unit requirement and postoperative mortality (P > 0.05 all). There were 2 patients (4%) in the DS group who died after surgery (P = 0.23). However, the ES group showed a significantly better postoperative outcome in terms of postoperative complications, length of hospital stay, and functional outcome (P < 0.05 all). CONCLUSION Early hip surgery in geriatric hip fracture patients with ongoing antiplatelet treatment was not associated with a significant increase of perioperative blood loss and postoperative mortality. Moreover, ES resulted in a better postoperative surgical outcome. In early hip surgery protocol, the antiplatelet agents are discontinued and the patient is operated on within 72 h after admission, which is safe and effective for the medically fit patients.

Treatment of acute tuberculous spondylitis by the spinal shortening osteotomy: a technical notes and case illustrations.

Surgical treatment for spinal tuberculosis is necessary in particular cases that a large amount of necrotic tissue is encountered and there is spinal cord compression. A spinal shortening osteotomy procedure has previously been described for the correction of the sagittal balance in a late kyphotic deformity, but there have been no reports on this as a surgical treatment in the acute stage. Thus, the aim of this report is to present the surgical techniques and clinical results of 3 patients who were treated with this procedure. Three patients with tuberculous spondylitis at the thoracic spine were surgically treated with this procedure. All the patients presented with severe progressive back pain, kyphotic deformity and neurological deficit. The patients recovered uneventfully from surgery without further neurological deterioration. Their pain was improved and the patients remained free of pain during the follow-up period. In conclusion, posterior spinal shortening osteotomy is an alternative method for the management of tuberculous spondylitis.

Anatomic Considerations of Intervertebral Disc Perspective in Lumbar Posterolateral Approach via Kambin's Triangle: Cadaveric Study

Study Design Anatomical study. Purpose To evaluate the anatomy of intervertebral disc (IVD) area in the triangular working zone of the lumbar spine based on cadaveric measurements. Overview of Literature The posterolateral percutaneous approach to the lumbar spine has been widely used as a minimally invasive spinal surgery. However, to our knowledge, the actual perspective of disc boundaries and areas through posterolateral endoscopic approach are not well defined. Methods Ninety-six measurements for areas and dimensions of IVD in Kambins triangle on bilateral sides of L1–S1 in 5 fresh human cadavers were studied. Results The trapezoidal IVD area (mean±standard deviation) for true working space was 63.65±14.70 mm2 at L1–2, 70.79±21.88 mm2 at L2–3, 99.03±15.83 mm2 at L3–4, 116.22±20.93 mm2 at L4–5, and 92.18±23.63 mm2 at L5–S1. The average dimension of calculated largest ellipsoidal cannula that could be placed in IVD area was 5.83×11.02 mm at L1–2, 6.97×10.78 mm at L2–3, 9.30×10.67 mm at L3–4, 8.84×13.15 mm at L4–5, and 6.61×14.07 mm at L5–S1. Conclusions The trapezoidal perspective of working zone of IVD in Kambins triangle is important and limited. This should be taken into consideration when developing the tools and instruments for posterolateral endoscopic lumbar spine surgery.

Using a reconstruction locking compression plate as external fixator in infected open clavicle fracture

Open clavicle fracture is an uncommon injury mostly caused by severe direct trauma. It is often associated with multiple organ injuries. Generally, surgical intervention with debridement and fracture repair is always indicated in order to prevent infection, non-union, and malalignment. In situations of bony exposure and significant contamination concomitant with severe soft tissue damage, the external fixation is the treatment of choice because of the possibility it offers of providing stable fixation with minimal local tissue damage resulting in excellent union rates and better soft tissue outcome. Nevertheless, traditional external fixation encountered some potential problems as its bulkiness and sharp edges caused discomfort to the patient. In this study, we present an interesting case of a polytraumatized patient with a gunshot injury with complex open clavicle fracture that was successfully treated with external fixation using reconstruction with a locking compression plate as definitive treatment.