1.Clinical and radiological outcomes of selective fusion for rotatory olisthesis in degenerative lumbar scoliosis: a retrospective cohort study
Guodong WANG ; Keith DK LUK ; Yang LI ; Chenggui ZHANG ; Jianmin SUN
Asian Spine Journal 2024;18(3):346-353
Methods:
A cohort of 54 consecutive patients with DLS and RO was included in the study. All the included patients underwent selective RO fusion and at least 2 years of follow-up. They were divided into two groups: group 1 with a curve <30° and group 2 with a curve ≥30°. The clinical outcomes were evaluated by the Oswestry Disability Index (ODI) and Numerical Rating Scale. The radiological assessment included RO location, offset and subluxated-disc orientation, Cobb angle, and coronal as well as sagittal alignments.
Results:
The offset value was greater in group 2 than in group 1 (13.4±4.7 mm vs. 9.3±3.5 mm, p<0.001). The subluxated disc was mainly oriented to the concave side in group 2 (15/21) but to the convex side in group 1 (20/33) (p =0.022). Group 2 had a higher rate of postoperative adjacent RO than group 1 (14/21 vs. 1/33, p<0.001). The ODI was comparable between both groups preoperatively but higher at the final follow-up in group 2 (34.9±9.5) than in group 1 (24.4±6.2). In the multiple logistic regression analysis, the thoracolumbar/lumbar curve was identified as the risk factor for postoperative adjacent RO (odds ratio, 1.400; p=0.007). The receiver operating characteristic analysis verified it with an area under the curve of 0.960 (p<0.001).
Conclusions
The clinical and radiological outcomes were maintained well in group 1 but not in group 2. Selective RO fusion in DLS with a lumbar curve <30° is a rational option. However, it should be avoided in those with a lumbar curve >30° because of a higher complication rate and a worse clinical outcome at the final follow-up.
2.Relationship between Fusion Mass Shift and Postoperative Distal Adding-on in Lenke 1 Adolescent Idiopathic Scoliosis after Selective Thoracic Fusion
Yang LI ; Jianlong LI ; Keith D. K. LUK ; Chenggui ZHANG ; Jianmin SUN ; Guodong WANG
Asian Spine Journal 2023;17(6):1117-1124
Methods:
This study included 60 patients with Lenke 1 AIS who underwent selective thoracic fusion surgery. Coronal spinal alignment parameters were analyzed preoperatively, postoperatively, and at the final follow-up. The postoperative FMS was divided into two groups: the balanced group (FMS ≤20 mm) and the unbalanced group (FMS >20 mm). An independent t-test was used to compare quantitative data between groups, and a chi-square test was used for qualitative data. Furthermore, binary logistic regression and receiver operating characteristics curve analyses were used to identify the risk factors for postoperative distal adding-on in AIS.
Results:
At 2-year follow-up, the unbalanced group was more likely to have adding-on (17 of 24 patients) than the balanced group (six of 36 patients; p<0.001). Twenty-three patients with distal adding-on had significantly greater preoperative and postoperative lower instrumented vertebrae (LIV) rotation, FMS, and FMS angle (FMSA) than those without postoperative distal adding-on. Binary logistic regression analysis selected three independent risk factors for adding-on incidence after surgery: FMS (odds ratio [OR], 1.115; 95% confidence interval [CI], 1.049–1.185; p<0.001), FMSA (OR, 1.590; 95% CI, 1.225–2.064; p<0.001), and postoperative LIV rotation (OR, 6.581; 95% CI, 2.280–19.000; p<0.001).
Conclusions
Achieving a balanced fusion mass intraoperatively is important to avoid postoperative distal adding-on, with FMS of <20 mm and FMS angle of <4.5°. Furthermore, correcting LIV rotation helps to decrease the incidence of postoperative distal addingon.
3.The Concept of Lamina–Pedicle Perpendicularity: Part 1. Lumbar Spine
Tarek Anwar ELFIKY ; Nirmal Dhananjay PATIL ; Keith DK LUK ; Mohamed Esam FAHEEM ; Dino SAMARTZIS
Asian Spine Journal 2021;15(1):81-88
Methods:
This was a retrospective study on normal lumbar spine lateral radiographs of patients who presented with low back pain and were reviewed by two observers. Different inclination angles were constructed to estimate the safety zones of the pedicle screws’ sagittal inclination.
Results:
Radiographs of 30 consecutive patients, 25 females and five males, with a mean age of 39.43±11.18 years, were studied. The mean angle of the interlaminar line and the pedicle axis was almost orthogonal at all the levels, with a range of 89.16°–94.63°, which was not affected by the lumbar sagittal profile. The safety zones of the pedicle screws were measured, and they revealed a safe sagittal range of 19.73°–24.40° if the screw was inserted from the pedicle axis, 21.03°–22.59° if inserted from the most cephalic part, and 13.31°–17.03° if inserted from the most caudal part.
Conclusions
Our results confirmed the perpendicularity of the interlaminar line with the pedicle axis in the lumbar spine at all the levels. The interlaminar line is a useful guide for pedicle screw sagittal inclination.
4.The Concept of Lamina–Pedicle Perpendicularity: Part 2: Thoracic Spine
Tarek Anwar ELFIKY ; Nirmal Dhananjay PATIL ; Keith DK LUK ; Mohamed Esam FAHEEM ; Dino SAMARTZIS
Asian Spine Journal 2021;15(2):252-260
Methods:
This was a retrospective study on the computed tomography (CT) chest scans of patients with no spinal pathologies. The ILL–PA, superior and inferior safe angles of the pedicle screw trajectories, and the exit zone of the screw perpendicular to the ILL were reviewed by two observers via three-dimensional multiplanar reconstruction mode of the Horos DICOM software (https:// horosproject.org/).
Results:
The CT chest images of 30 consecutive patients (20 males and 10 females) with a mean age of 49.87±15.48 years (range, 24–74 years) were evaluated. The mean ILL–PA angle was almost orthogonal for all levels. This angle ranged between 86.21°±3.01° at D5 and 90.59°±2.72° at D10. The safety zones of the sagittal inclination of the pedicle screws were demonstrated. The results revealed that the least safe angle was when the screw was directed cranially along the middle part of the pedicle between 4.43°±0.75° at D8 and 6.94°±1.19° at D11.
Conclusions
The results of this study confirmed the ILL–PA angle perpendicularity in the thoracic spine at all levels. The ILL is a useful guide for pedicle screw sagittal inclination.
5.The Concept of Lamina–Pedicle Perpendicularity: Part 2: Thoracic Spine
Tarek Anwar ELFIKY ; Nirmal Dhananjay PATIL ; Keith DK LUK ; Mohamed Esam FAHEEM ; Dino SAMARTZIS
Asian Spine Journal 2021;15(2):252-260
Methods:
This was a retrospective study on the computed tomography (CT) chest scans of patients with no spinal pathologies. The ILL–PA, superior and inferior safe angles of the pedicle screw trajectories, and the exit zone of the screw perpendicular to the ILL were reviewed by two observers via three-dimensional multiplanar reconstruction mode of the Horos DICOM software (https:// horosproject.org/).
Results:
The CT chest images of 30 consecutive patients (20 males and 10 females) with a mean age of 49.87±15.48 years (range, 24–74 years) were evaluated. The mean ILL–PA angle was almost orthogonal for all levels. This angle ranged between 86.21°±3.01° at D5 and 90.59°±2.72° at D10. The safety zones of the sagittal inclination of the pedicle screws were demonstrated. The results revealed that the least safe angle was when the screw was directed cranially along the middle part of the pedicle between 4.43°±0.75° at D8 and 6.94°±1.19° at D11.
Conclusions
The results of this study confirmed the ILL–PA angle perpendicularity in the thoracic spine at all levels. The ILL is a useful guide for pedicle screw sagittal inclination.
6.Managing the Pediatric Spine: Growth Assessment.
Jason Pui Yin CHEUNG ; Keith Dip Kei LUK
Asian Spine Journal 2017;11(5):804-816
Management of pediatric spinal deformities requires an accurate prediction of growth spurts to allow for timely initiation of treatment and prevention of curve progression. Determining remaining growth potential is also important for avoiding prolonged unnecessary treatment, e.g. bracing for patients nearing skeletal maturity. Many clinical and radiological growth parameters have been developed to aid clinicians in growth prediction. Of these, several commonly used measures such as height and arm span growth trends, timing of menarche, and the Risser sign are mostly retrospective and lack strong predictive utility. Bone age assessments, such as digital skeletal age and the distal radius and ulna classification, are more accurate parameters, but further research is required to determine interethnic variations and develop their role in management decisions.
Arm
;
Braces
;
Classification
;
Congenital Abnormalities
;
Female
;
Humans
;
Menarche
;
Radius
;
Retrospective Studies
;
Spine*
;
Ulna
7.Decompression without Fusion for Low-Grade Degenerative Spondylolisthesis.
Jason Pui Yin CHEUNG ; Prudence Wing Hang CHEUNG ; Kenneth Man Chee CHEUNG ; Keith Dip Kei LUK
Asian Spine Journal 2016;10(1):75-84
STUDY DESIGN: Retrospective series. PURPOSE: Assess results of decompression-only surgery for low-grade degenerative spondylolisthesis with consideration of instability. OVERVIEW OF LITERATURE: There is no consensus on whether fusion or decompression-only surgery leads to better outcomes for patients with low-grade degenerative spondylolisthesis. Current trends support fusion but many studies are flawed due to over-generalization without consideration of radiological instability and their variable presentations and natural history. METHODS: Patients with surgically treated degenerative spondylolisthesis from 1990-2013 were included. Clinical and radiological instability measures were included. Any residual or recurrence of symptoms, revision surgery performed and functional outcome scores including the numerical global rate of change scale, visual analogue scale, and modified Barthel index were measured. Follow-up periods for patients were divided into short-term (<5 years), mid-term (5-10 years) and long-term (>10 years). RESULTS: A total of 64 patients were recruited. Mechanical low back pain was noted in 48 patients and most (85.4%) had relief of back pain postoperatively. Radiological instability was noted in 4 subjects by flexion-extension radiographs and 12 subjects with prone traction radiographs by increased disc height and reduction of olisthesis and slip angle. From the results of the short-term, mid-term and long-term follow-up, reoperation only occurred within the first 5-year follow-up period. All functional scores improved from preoperative to postoperative 1-year follow-up. CONCLUSIONS: Decompression-only for low-grade degenerative spondylolisthesis has good long-term results despite instability. Further higher-level studies should be performed on this patient group with radiological instability to suggest the superior surgical option.
Back Pain
;
Consensus
;
Decompression*
;
Follow-Up Studies
;
Humans
;
Low Back Pain
;
Natural History
;
Recurrence
;
Reoperation
;
Retrospective Studies
;
Spondylolisthesis*
;
Traction
8.Complications of Anterior and Posterior Cervical Spine Surgery.
Jason Pui Yin CHEUNG ; Keith Dip Kei LUK
Asian Spine Journal 2016;10(2):385-400
Cervical spine surgery performed for the correct indications yields good results. However, surgeons need to be mindful of the many possible pitfalls. Complications may occur starting from the anaesthestic procedure and patient positioning to dura exposure and instrumentation. This review examines specific complications related to anterior and posterior cervical spine surgery, discusses their causes and considers methods to prevent or treat them. In general, avoiding complications is best achieved with meticulous preoperative analysis of the pathology, good patient selection for a specific procedure and careful execution of the surgery. Cervical spine surgery is usually effective in treating most pathologies and only a reasonable complication rate exists.
Pathology
;
Patient Positioning
;
Patient Selection
;
Spine*
9.A Lethal Sequelae of Spinal Infection Complicating Surgery and Radiotherapy for Head and Neck Cancer.
Jason Pui Yin CHEUNG ; Kin Cheung MAK ; Helen Hoi Lun TSANG ; Keith Dip Kei LUK
Asian Spine Journal 2015;9(4):617-620
Patients who have undergone neck dissection and radiotherapy are at risk of cervical spine infections. Furthermore, previous radiotherapy and cervical spine infections can lead to fistula formation to the subarachnoid space and intracranial infection. This report discusses the serious consequences of a missed cervical spine infection including cerebrospinal fluid fistula formation and persistent central nervous system infection, and serves as a reminder to clinicians of the possible association between cervical spine infections and prior head and neck surgery and radiotherapy. In all such cases, the posterior pharyngeal wall should be inspected during follow-up. Despite the appearance of an intracranial infection, the cervical spine should be investigated, especially if the response to appropriate antibiotics is suboptimal.
Anti-Bacterial Agents
;
Central Nervous System Infections
;
Cerebrospinal Fluid
;
Discitis
;
Fistula
;
Follow-Up Studies
;
Head
;
Head and Neck Neoplasms*
;
Humans
;
Neck
;
Neck Dissection
;
Radiotherapy*
;
Spine
;
Subarachnoid Space
10.Classification and management of the tandem ossification of the posterior longitudinal ligament and flaval ligament.
Jiong-jiong GUO ; Hui-lin YANG ; Kenneth M C CHEUNG ; Tian-si TANG ; Keith D K LUK
Chinese Medical Journal 2009;122(2):219-224
OBJECTIVETo provide appropriate guidelines for treatment of tandem ossification of the posterior longitudinal ligament (OPLL) and flaval ligament (OFL). Data sources Published articles about OPLL and OFL were selected using Medline and Embase electronic databases. Study selection An English literature search from January 1980 to December 2006 was conducted. Because many reported cases were incorporated in OFL studies, the key words for search were OFL or OFL and OPLL. The first step revealed 93 studies of which 13 reports of tandem OPLL and OFL (tandem ossification) were selected.
RESULTSAll studies were case series or case report and advocated that the primary therapy for tandem ossification should be operative. The clinical outcomes of surgery were evaluated in most reports, predominantly using the JOA scores. Gender is the only factor which has prognostic value. A higher proportion of women was found in the failure group. A two-stage classification of tandem ossification was developed to relate diagnosis to outcome.
CONCLUSIONSAll patients with suspected ossification of the spinal ligaments should undergo routine MRI screening of the whole spine. The correlation of the classification with surgical treatments needs further studies to validate its usefulness.
Female ; Humans ; Ligamentum Flavum ; pathology ; Male ; Ossification of Posterior Longitudinal Ligament ; classification ; pathology ; Ossification, Heterotopic ; classification ; pathology

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