Commentary Why was this article selected as a classic orthopaedic reference? This article, published almost thirty years ago, describes a classification that is still used for this fracture. It is very difficult to manage fractures of the odontoid process, particularly those that occur at the base of the odontoid process (type II). This article is important because many other classifications do not relate to treatment or prognosis and, hence, may not be very useful. The classification proposed by Anderson and D’Alonzo has a direct relation to the treatment as well as the prognosis of this type of fracture. Not only these authors, but many subsequent authors, including Clark and White—whose multicenter study under the auspices of the Cervical Spine Research Society was published by The Journal in 1985—have used this classification and have found that both treatment and prognosis are indeed affected by the level of the injury. How has the information in the article withstood the “test of time”? This article is still quoted in major textbooks and is the basic classification system used in the upcoming edition of The Cervical Spine, a textbook published by the Cervical Spine Research Society. Recently, at the annual meeting of the Cervical Spine Research Society, I was involved in a debate that dealt with the management of type-II fractures of the odontoid process according to the classification system of Anderson and D’Alonzo. The debate was very lively, providing further proof that this article has indeed withstood the test of time.

https://militaryhealth.bmj.com/content/jramc/59/5/371.full.pdf

Fracture of the Odontoid Process of the Axis

The Persistent Sciatic Artery

Object Cervical pedicle screw (PS) misplacement leads to injury of the spinal cord, nerve root, and vertebral artery. Recently, several investigators reported on the usefulness of a spinal navigation system that improves the accuracy of PS insertion. In this study, the authors assessed the accuracy of cervical pedicle, lateral mass, and odontoid screw insertions placed using a 3D fluoroscopy navigation system, the Iso-C3D unit. Methods In this prospective analysis of the authors' initial 50 cases of 3D fluoroscopy–assisted cervical screw insertion, the authors inserted 176 PSs, 58 lateral mass screws, and 5 odontoid screws into the C1–7 vertebrae. They placed screws using intraoperative acquisition of data by the isocentric C-arm fluoroscope and a computer navigation system. They obtained postoperative fine-cut CT scans in all patients and assessed the accuracy of screw insertion. Results A PS (≥ 3.5 mm) could be inserted into 24 (63%) of 38 pedicles at the level of C-3, 18 (53%) of 34 pedicles at C-4, 30...

Clinical accuracy of 3D fluoroscopy-assisted cervical pedicle screw insertion.

Joining of carbon fibre reinforced polymer (CFRP) composites and aluminium alloys – A review Part A Applied science and manufacturing

Over the past decade, the minimally disruptive lateral transpsoas approach for lumbar interbody fusion (MI-LIF) is increasingly being used as an alternative to conventional surgical approaches. The purpose of this review was to evaluate four primary questions as they relate to MI-LIF: (1) Is there an anatomical justification for MI-LIF at L4–5? (2) What are the complication and outcome profiles of MI-LIF and are they acceptable with respect to conventional approaches? (3) Given technical and neuromonitoring differences between various MI-LIF procedures, are there any published clinical differences? And, (4) are modern minimally disruptive procedures (e.g., MI-LIF) economically viable? Through a MEDLINE and Google Scholar search, a total of 237 articles that discussed MI-LIF were identified. Of those, topical areas included anatomy (22), biomechanics/testing (17), technical descriptions (11), case reports (40), complications (30), clinical and radiographic outcomes (43), deformity (23), trauma or thoracic applications (10), and review articles (41). In answer to the questions posed, (1) there is a high strength of evidence showing MI-LIF to be anatomically justified at all levels of the lumbar spine from L1–2 to L4–5. The evidence also supports the use of advanced neuromonitoring modalities. (2) There is moderate strength evidence in support of reproducible and reasonable complication, side effect, and outcome profiles following MI-LIF which may be technique dependent. (3) There is low-strength evidence that shows elevated neural complication rates in non-traditional (e.g., shallow-docking approaches and/or those without specialized neuromonitoring) MI-LIF, and (4) there is low- to moderate-strength evidence that modern minimally disruptive surgical approaches are cost-effective. There is considerable published evidence to support MI-LIF in spinal fusion and advanced applications, though the results of some reports, especially concerning complications, vary greatly depending on technique and instrumentation used. Additional cost-effectiveness analyses would assist in fully understanding the long-term implications of MI-LIF.

MIS lateral spine surgery: a systematic literature review of complications, outcomes, and economics

Study design The cervical pedicle diameter size differs between Asians and non-Asians. The authors studied the transverse pedicle diameter of the C2-C7 of the cervical spine in a Malaysian population using computerized tomography (CT) measurements. The transverse diameter of the pedicle is the determinant of the feasibility of this technique because the sagittal diameter of the pedicle has been wider than the transverse pedicle diameter. Objectives To study the average transverse pedicle diameter of the cervical spine in a Malaysian population, and evaluate the feasibility and safety of pedicle screw fixation in these patients. Summary of background data Cervical transpedicular screw fixation has been safe and is most probably going to be the gold standard for cervical spine fixation. However, its use in the Asian population should be considered cautiously because our cervical pedicle diameter may not be adequate to accommodate the standard pedicle screw size, which can be dangerous because there are vital structures located adjacent to the pedicles. Methods The measurements of the cervical pedicles were performed on CT images using its measurement tools. CT cutting was made at 2.5-mm intervals. The pedicle transverse diameters were defined as the most outer diameter of the pedicle, taken perpendicular to the axis of the pedicle and measured in millimeters up to 0.1 mm. Results The mean transverse diameters of the cervical pedicle of C2, C3, C4, C5, C6, and C7 in males were 5.4, 5.2, 5.1, 5.2, 5.5, and 6.5 mm, respectively, and ranged between 5.1 and 6.5 mm. In females, the mean transverse diameter of the cervical pedicle of C2, C3, C4, C5, C6, and C7 were 5.0, 4.6, 4.7, 4.9, 5.2, and 5.6 mm, respectively, and ranged between 4.6 and 5.6 mm. If the minimum transverse diameter required is 5.0 mm for 3.5-mm screw insertion, about 4.2% to 54.2% (male) of pedicles at different levels and 6.7% to 73.3% (females) of patients cannot have fixation with a 3.5-mm screw using this technique. Conclusion Transpedicular screw fixation for the cervical spine must not be attempted in the Malaysian population before the exact pedicle diameters are known.Therefore, preoperative CT evaluation is a must before transpedicular fixation is performed, especially in female patients. Because the margin for mistake is very narrow, it is best avoided in upper cervical spines.

Computerized tomographic measurement of the cervical pedicles diameter in a Malaysian population and the feasibility for transpedicular fixation.

Study design A cross-sectional study of thoracic pedicle morphometry (T1-T12) of 180 Malaysian Malay patients obtained from computed tomographic scan. Objectives To determine the safety margin in the placement of thoracic transpedicular screw in the Malay population. Summary of the background data Previous studies have shown a significantly smaller thoracic pedicular parameters in Asians compared with whites. The safety margin in the placement of thoracic transpedicular screw in our population therefore needs to be defined. Methods T1-T12 vertebral pedicles were studied in 180 Malay ethnic patients (age range, 18-80 years). The following parameters were studied: transverse outer pedicle diameter, transverse inner pedicle diameter, transverse pedicle angle, chord length, pedicle length, and pedicle cortical thickness. The data obtained were statistically analyzed using Student's t test and ANOVA test. Results Female patients have significantly smaller dimensions in most of the parameters measured compared with male patients. However, no significant difference was found between age groups. Transverse outer pedicle diameter were widest at T1 (male, 8.42 mm; female, 7.56 mm) and narrowest at T4 (male, 4.56 mm; female, 3.95 mm). Pedicle diameters of less than 5.5 mm were commonly seen at T4 followed by T5, T6, T7, T8, and T9. A significant percentage of patients have an outer diameter of less than 4.5 mm from T4-T7. The medial cortices were 50% thicker than the lateral cortices at most levels. Chord lengths were maximum at T8 and minimum at T1. Transverse pedicle angle were widest at T1 and less than 5 degrees from T7-T12. Conclusions The results suggest that the current pedicle screw system is not suitable for the majority of Malay population, especially at midthoracic level. The smaller pedicle measurements in Malays may be attributed to their shorter body built compared with whites.

Computed tomographic morphometry of thoracic pedicles: safety margin of transpedicular screw fixation in malaysian malay population.

Persistent sciatic artery is a very uncommon embryological vascular variant. This case report highlights this rare vascular anomaly, diagnostic difficulty, complication and subsequent treatment in a 43-year-old man who presented with sudden onset of right leg pain for a few hours. He was unable to walk because of pain and numbness. Emergency right lower limb angiogram showed a large aneurysm that was initially thought to arise from the right common femoral artery, associated with thrombus formation within the right popliteal artery. A below knee amputation was performed due to worsening ischaemia of the right leg. The persistent right sciatic artery was later obliterated using percutaneous stenting and endovascular grafting, with deployment of two wallstents.

Bilateral persistent sciatic arteries with unilateral complicating aneurysm.

Purpose. To measure the cervical pedicles and assess the feasibility of transpedicular fixation in a Malay population. Methods. 960 computed tomography (CT) scans of bilateral C2 to C7 pedicles of 80 Malays were compared. 22 men and 24 women aged <60 (mean, 37.3; range, 18–56) years were defined as young patients, whereas 18 men and 16 women aged ≥60 (mean, 63.9; range, 60–76) years as elderly patients. An inner diameter of <3.0 mm (85% of a 3.5-mm screw) was defined as ‘unfeasible’ and a medial or lateral wall thickness of <1.0 mm as ‘unsafe’ for cervical pedicle screw fixation. Results. In the respective young versus elderly groups, the inner diameters ranged from 1.94 to 2.80 mm versus 2.51 to 3.37 mm in men, and from 1.52 to 2.31 mm versus 1.64 to 2.46 mm in women. Medial wall thickness ranged from 1.25 to 1.46 mm versus 1.13 to 1.48 mm in men, and from 1.28 to 1.72 mm versus 1.10 to 1.24 mm in women. Lateral wall thickness ranged from 0.80 to 0.90 mm versus 0.66 to 0.88 mm in men, and from 0.85 to 0.99 mm versus 0.59 to 0.86 mm in women. Conclusion. The cervical spine of Malays may not be adequate to accommodate a 3.5-mm pedicle screw for transpedicular fixation, as this procedure may risk adjacent vital structures.

https://journals.sagepub.com/doi/pdf/10.1177/230949900701500213

Computed tomographic measurement of cervical pedicles for transpedicular fixation in a Malay population.

Purpose We sought to present our preliminary experience on the effectiveness and safety of magnetic resonance imaging (MRI)-guided, high-intensity focused ultrasound (HIFU) therapy using a volumetric ablation technique in the treatment of Association of Asian Nations (ASEAN) patients with symptomatic uterine leiomyomas. Methods This study included 33 women who underwent HIFU treatment. Tissue characteristics of leiomyomas were assessed based on T2- and T1-weighted MRI. The immediate nonperfused volume (NPV) ratio and the treatment effectiveness of MRI-guided HIFU on the basis of the degrees of volume reduction and improvement in transformed symptom severity score (SSS) were assessed. Results The median immediate NPV ratio was 89.8%. Additionally, the median acoustic sonication power and HIFU treatment durations were 150 W and 125 min, respectively. At six-month follow-up, the median leiomyoma volume had decreased from 139 mL at baseline to 84 mL and the median transformed SSS had decreased from 56.2 at baseline to 18.8. No major adverse events were observed. Conclusion The preliminary results demonstrated that volumetric MRI-guided HIFU therapy for the treatment of symptomatic leiomyomas in ASEAN patients appears to be clinically acceptable with regard to treatment effectiveness and safety.

/pdf/volumetric-mri-guided-high-intensity-focused-ultrasound-4f70js1iaa.pdf

Mohd Shafie Abdullah

Papers

Computerized tomographic measurement of the cervical pedicles diameter in a Malaysian population and the feasibility for transpedicular fixation.

Computed tomographic morphometry of thoracic pedicles: safety margin of transpedicular screw fixation in malaysian malay population.

Bilateral persistent sciatic arteries with unilateral complicating aneurysm.

Computed tomographic measurement of cervical pedicles for transpedicular fixation in a Malay population.

Volumetric MRI-guided, high-intensity focused ultrasound ablation of uterine leiomyomas: ASEAN preliminary experience