Pedicle screw instrumentation has superior biomechanical as well as clinical outcome. Thoracic pedicles show great variation in different population groups, particularly in Asians who have been shown to have smaller pedicle dimensions. Although plain radiographs are widely performed prior to spine surgery, no studies have been done so far to investigate whether the thoracic pedicle profile on plain radiographs affect thoracic pedicle screw insertion. Therefore, this is a cadaveric study aimed to determine the relationship between plain radiographic thoracic pedicle profile in Asians and the outcome of pedicle screw insertion in the thoracic spine.
A cross sectional study of thoracic pedicle morphometry in the immature spine of Malaysian population using reformatted computed tomographic (CT) images.
Pedicle screw system has increasingly been used for correction of thoracic scoliosis. It offers several biomechanical advantages over hook system as it controls all three-column of the spine with enhanced stability. Of many techniques of pedicle screw placement in the thoracic spine, the funnel technique has been used in Sarawak General Hospital since 2002. This prospective study aims to assess the accuracy of the placement of thoracic pedicle screws using the funnel technique in the corrective surgery of idiopathic scoliosis. A total of 88 thoracic pedicle screws were inserted into the T4 to T12 vertebrae of 11 patients. Post-operative CT-scan was performed to evaluate the position of the pedicle screw. Seventy six (86.4%) screws were noted to be totally within the pedicle. There was no screw with medial violation of the pedicle, 8 (9.1%) screws breeching the lateral wall of the pedicle and 4 (4.5%) screws with anterior and lateral penetration of the vertebral body. No clinical sequel with the mal-positioned screws was noted. In conclusion, the funnel technique enabled simple, accurate and reliable insertion of pedicle screw even in the scoliotic thoracic spine without the need of any imaging guidance. It is however imperative for the surgeon to have a thorough knowledge of the thoracic spine anatomy, and to be familiar with the technique to insert these screws diligently.
Patients with upper airway obstruction from malignant disease are difficult to manage. A 62 year old patient presented with stridor and was found to have an upper tracheal tumour. Bronchoscopy, dilatation and stenting were performed successfully. The techniques and indications for the use of dynamic airway stent are discussed.
Recent evidences suggest functional thoracic hyperkyphosis (FTH) could be a different approach in the management of subacromial impingement syndrome (SIS). This case study aims firstly with the development of evidence informed FTH model for SIS. Secondly this study aimed to develop well defined multimodal physical therapy intervention for FTH and its related mechanical consequences in elderly patient with chronic SIS. As a result, Level IV positive evidence was found in both the short and long-term pain and disability of chronic SIS, using FTH model with 26 months of follow-up.
Severe, persistent back pain following back surgery is often referred to as Failed Back Surgery Syndrome (FBSS). Conservative measures such as physiotherapy, back strengthening exercises, transcutaneous electrical nerve stimulation and epidural steroids may be inadequate to alleviate pain. Spinal Cord Stimulators were implanted into two patients suffering from FBSS. Both patients responded successfully to spinal cord stimulation with reduction of pain and disability.
Percutaneous placement of pedicle screws is a well-established technique, however, no studies have compared percutaneous and open placement of screws in the thoracic spine. The aim of this cadaveric study was to compare the accuracy and safety of these techniques at the thoracic spinal level. A total of 288 screws were inserted in 16 (eight cadavers, 144 screws in percutaneous and eight cadavers, 144 screws in open). Pedicle perforations and fractures were documented subsequent to wide laminectomy followed by skeletalisation of the vertebrae. The perforations were classified as grade 0: no perforation, grade 1: < 2 mm perforation, grade 2: 2 mm to 4 mm perforation and grade 3: > 4 mm perforation. In the percutaneous group, the perforation rate was 11.1% with 15 (10.4%) grade 1 and one (0.7%) grade 2 perforations. In the open group, the perforation rate was 8.3% (12 screws) and all were grade 1. This difference was not significant (p = 0.45). There were 19 (13.2%) pedicle fractures in the percutaneous group and 21 (14.6%) in the open group (p = 0.73). In summary, the safety of percutaneous fluoroscopy-guided pedicle screw placement in the thoracic spine between T4 and T12 is similar to that of the conventional open technique.
The objective of this cadaveric study is to determine the safety and outcome of thoracic pedicle screw placement in Asians using the funnel technique. Pedicle screws have superior biomechanical as well as clinical data when compared to other methods of instrumentation. However, misplacement in the thoracic spine can result in major neurological implications. There is great variability of the thoracic pedicle morphometry between the Western and the Asian population. The feasibility of thoracic pedicle screw insertion in Asians has not been fully elucidated yet. A pre-insertion radiograph was performed and surgeons were blinded to the morphometry of the thoracic pedicles. 240 pedicle screws were inserted in ten Asian cadavers from T1 to T12 using the funnel technique. 5.0 mm screws were used from T1 to T6 while 6.0 mm screws were used from T7 to T12. Perforations were detected by direct visualization via a wide laminectomy. The narrowest pedicles are found between T3 and T6. T5 pedicle width is smallest measuring 4.1 +/- 1.3 mm. There were 24 (10.0%) Grade 1 perforations and only 1 (0.4%) Grade 2 perforation. Grade 2 or worse perforation is considered significant perforation which would threaten the neural structures. There were twice as many lateral and inferior perforations compared to medial perforations. 48.0% of the perforations occurred at T1, T2 and T3 pedicles. Pedicle fracture occurred in 10.4% of pedicles. Intra-operatively, the absence of funnel was found in 24.5% of pedicles. In conclusion, thoracic pedicle screws using 5.0 mm at T1-T6 and 6.0 mm at T7-T12 can be inserted safely in Asian cadavers using the funnel technique despite having smaller thoracic pedicle morphometry.