Aims. Developmental cervical spinal stenosis (DcSS) is a well-known predisposing factor for degenerative cervical myelopathy (DCM) but there is a lack of consensus on its definition. This study aims to define DcSS based on MRI, and its multilevel characteristics, to assess the prevalence of DcSS in the general population, and to evaluate the presence of DcSS in the prediction of developing DCM. Methods. This cross-sectional study analyzed MRI spine morphological parameters at C3 to C7 (including anteroposterior (AP) diameter of spinal canal, spinal cord, and vertebral body) from DCM patients (n = 95) and individuals recruited from the general population (n = 2,019). Level-specific median AP spinal canal diameter from DCM patients was used to screen for stenotic levels in the population-based cohort. An individual with multilevel (≥ 3 vertebral levels) AP canal diameter smaller than the DCM median values was considered as having DcSS. The most optimal cut-off canal diameter per level for DcSS was determined by receiver operating characteristic analyses, and multivariable logistic regression was performed for the prediction of developing DCM that required surgery. Results. A total of 2,114 individuals aged 64.6 years (SD 11.9) who underwent surgery from March 2009 to December 2016 were studied. The most optimal cut-off canal diameters for DcSS are: C3 < 12.9 mm, C4 < 11.8 mm, C5 < 11.9 mm, C6 < 12.3 mm, and C7 < 13.3 mm. Overall, 13.0% (262 of 2,019) of the population-based cohort had multilevel DcSS. Multilevel DcSS (odds ratio (OR) 6.12 (95% CI 3.97 to 9.42); p < 0.001) and male sex (OR 4.06 (95% CI 2.55 to 6.45); p < 0.001) were predictors of developing DCM. Conclusion. This is the first MRI-based study for defining DcSS with multilevel canal narrowing. Level-specific cut-off canal diameters for DcSS can be used for early identification of individuals at risk of developing DCM. Individuals with DcSS at ≥ three levels and male sex are recommended for close monitoring or early intervention to avoid traumatic spinal cord injuries from stenosis. Cite this article: Bone Joint J 2024;106-B(11):1333–1341

Objectives. Pedicle-lengthening osteotomy is a novel surgery for lumbar spinal stenosis (LSS), which achieves substantial enlargement of the spinal canal by expansion of the bilateral pedicle osteotomy sites. Few studies have evaluated the impact of this new surgery on spinal canal volume (SCV) and neural foramen dimension (NFD) in three different types of LSS patients. Methods. CT scans were performed on 36 LSS patients (12 central canal stenosis (CCS), 12 lateral recess stenosis (LRS), and 12 foraminal stenosis (FS)) at L4-L5, and on 12 normal (control) subjects. Mimics 14.01 workstation was used to reconstruct 3D models of the L4-L5 vertebrae and discs. SCV and NFD were measured after 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm pedicle-lengthening osteotomies at L4 and/or L5. One-way analysis of variance was used to examine between-group differences. Results. In the intact state, SVC and NFD were significantly larger in the control group compared with the LSS groups (P<0.05). After lengthening at L4, the percentage increase in SCV (per millimetre) was LRS>CCS>FS>Control. After lengthening at L5 and L4-L5, the percentage increase in SCV (per millimetre) was LRS>FS>CCS>Control. After lengthening at L4 and L4-L5, the percentage increase in NFD (per millimetre) was FS>CCS>LRS>Control. After lengthening at L5, the percentage increase in NFD (per millimetre) was CCS>LRS>control>FS. Conclusions. LRS patients are the most suitable candidates for treatment with pedicle-lengthening osteotomy. Lengthening L4 pedicles produced larger percentage increases in NFD than lengthening L5 pedicles (p < 0.05). Lengthening L4 pedicles may be the most effective option for relieving foraminal compression in LSS patients. Cite this article: P. Li, L. Qian, W. D. Wu, C. F. Wu, J. Ouyang. Impact of pedicle-lengthening osteotomy on spinal canal volume and neural foramen size in three types of lumbar spinal stenosis. Bone Joint Res 2016;5:239–246. DOI: 10.1302/2046-3758.56.2000469

The capacity of the lumbar spine canal has direct relation to space-compromising conditions. Primary narrowing of the canal may produce no symptoms, but a slight reduction in capacity as a result of degenerative lesions, age, or disc bulging may result in symptomatic spinal canal stenosis. We studied the dimensions in the adult Greek population in order to find the variability factor in the capacity of the lumbar spinal canal. The dimensions of the lumbar spinal canal were measured in 27 adult men and 42 adult women, all under the age of 50. MRI was used to measure four levels of the spine (L2 through L5). The AP and transverse diameters, as well as the cross section area, were measured at each level. Mean age (sd) of females was 34.8 (6.8) years. Mean age for males was 35.2 (7.3) and was comparable to women (P0.8). Mean age of a third group of 11 males over the age of 50 was 54.5 (2.6). All individuals included in the study were healthy and without any apparent degenerative changes in the lumbar spine or any symptoms related to it. Hotelling’s tests (Anderson, 1958), in terms of multivariate measurements of the spinal canal, were used to compare both genders and the two age levels. Tests for trends in the lumbar levels L2 through L5 were based on the exact binomial distribution for the number of cases exhibiting a complete trend from L2 to L5. The reported significance levels are adjusted for multiplicity of tests. The relation of spinal width to lumbar levels is shown separately for the groups of males and females women under the age of 50 and for the group of males under over the age of 50. In all four lumbar levels, the group of men over 50 years old had a narrower spinal canal compared with men under 50 years old (2=0.005). This was particularly evident in levels L2 and L5 where the spinal canal for older men was narrower by factors of 15.5% and 13.1%, respectively. In the two gender groups of comparable age, spinal width was found to differ between men and women (2< 0.0001). In particular, the females had a wider spinal canal than males in levels L2, L3 and L4 and a narrower canal in level L5. Spinal width was found to exhibit a decreasing trend in lumbar levels L2 through L5. The evidence for this trend was strong for all three groups: females under the age of 50 (P< 0.0001), men under 50 (2< 0.005), and the older men (P< 0.0001). A similar trend was present for the anteroposterior diameter, as well as for the Transverse diameter. A numerical summary (mean, sd) of all spinal measurements is reported. We believe this study to be an important one that provides useful information regarding the capacity of the lumbar spinal canal, thus helping the surgeon to properly evaluate the stenotic patient

A new technique of enlargement of the lumbar spinal canal (ELSC) and neural decompression in the treatment of any uni or multilevel segmental pathology causing stenosis with radicular or dural sac compression was performed by a standard laminectomy, posterior osteophytectomy and radical discectomy, leading to a widening of all the saggital and coronal sizes of the spinal canal, including the foraminal outlet of the root. No damage or excessive excision of facet joints are necessary to achieve the wide neural decompression. The outcome of patients that underwent conventional laminectomy and discectomy (Group A) and ELSC ( Group B) was compared. The only objective parameter used to compare between the groups was only the need for reoperation of the patients. The indications for the first surgery or a second reoperation (revision) were identical for both groups. Conventional laminectomy and discectomy (Group A) was performed in 317 patients between 1977 and 1989. In this group 193 (61%) were females and 124 (39%) males. Mean age 42.5 years (range 13 to 72). In this group reoperation at the same level was necessary in 24 patients (8%). ELSC (Group B) was performed in 231 patients between 1990 and 2002. In this group 133 (58%) were females and 98 (42%) males. Mean age 46.5 years (range 17 to 78). Only 3 patients needed reoperation at the same level in this group (1.3%). Using CT-scan cross sectional area measurements , the spinal canal was seen to be enlarged by 217% in average by using the ELSC surgical technique. The follow up for group A was from 1 to 8 years; group B was 3 to 11 years. All patients underwent the operations by the autor. Generous posterior osteophytectomy, scurving the anterior wall of the foramina in both sides, bypasses the pathway of the root, resulting in release of the overtensed, elongated and compressed nerve root at the encroached site of the foraminal outlet. An optimal enlargement of the lumbar spinal canal was achieved without affecting the spinal stability. No symptoms related to perineural scarring were seen in Group B. The ELSC technique can be aplied together with any kind of spinal instrumentation

Objectives: To evaluate and compare the imaging of lumbar spinal canal stenosis using plain radiographs, CT-Myelogram and MRI. Patients and Methods: Prospective study at Medical College Calicut during 2002-2004. 25 patients of age from 25 to 69 years, with clinical features of lumbar spinal canal stenosis were evaluated. Inter pedicular distance, anteroposterior diameter and thecal sac cross sectional area (IPD, APD and TSCA) were measured using plain radiographs, CT-Myelogram and MRI, in all 25 patients. Results: Soft tissue compression evaluated as disc protrusion and ligamentum flavum hypertrophy detected in 20 patients by CT-myelography and 22 patients by MRI. Thecal sac cross sectional area at stenosed level were assessed and compared with CT- Myelography and MRI, out of 25 patients 10 and 11 patients were detected with significant narrowing by CT-Myelogra-phy and MRI respectively in which 2 cases of severe thecal sac compromise (< 76 mm2) detected by CT-Myelography and 3 cases by MRI. CT–Myelography detected one case of single level absolute stenosis (AP diameter of < 10mm), but none of the cases were detected by MRI or Plain radiography. Relative stenosis (AP diameter of 10-12mm) at single level detected in 6 cases by CT–Myelography, in 4 cases by MRI and in 3 cases by plain radiography. Relative stenosis at multiple level detected in 3 cases by CT–Myelogra-phy, in 4 cases by MRI and in 6 cases by plain radi-ography.4 cases of multilevel absolute stenosis were detected by all 3 modalities. Conclusions: CT- Myelographic measurement are well correlating with clinical symptoms and MRI findings. Bony Canal measurements obtained by CT- myelogra-phy are superior to same measurements obtained by MRI. Thecal-sac cross sectional area measurements obtained by CT-Myelography is comparable with that of MRI, even though soft tissue involvement in lumbar spinal canal stenosis is more clearly detected by MRI. In comparison of AP diameter taken by plain radiograph and CT- Myelography, X-ray measurements shows only 50-60% accuracy. AP diameter in CT- Myelography and MRI were comparable, when the thecal-sac cross sectional area measured by MRI taken as gold standard (using Karl pearsons correlation coefficients). CT-Myelography shows sensitivity of 92% and specificity of more than 96%

Summary Statement. Bilaretal epiphysiodesis of he neurocentral cartilages causes shortening of the sagittal length of the pedicles and a subsequent spinal stenosis at the operated segments, resembling that found in patients with achrondroplasia. Introduction. The introduction of pedicle screws in the immature spine may have implications for the growth of the vertebra. The effect of blocking the growth of neurocentral cartilage (NC) is not yet fully defined. Block hypothetically leads to a bilateral symmetrical alteration of the vertebral growth. Using an experimental animal model, our goal is to analyze if a bilateral epiphysiodesis of the NC using pedicle screws is able to induce narrowing of the spinal canal in the thoracolumbar spine. Experimental animals and Methods. A total of 24 domestic pigs were operated on by bilateral blocking of the NC using pedicle screws. The animals were divided into 4 groups depending on the level of blockage: A, low thoracic levels; B, thoracolumbar transitional hinge; C, upper lumbar spine; and D, blocking of the caudal lumbar level below L5 segment. Different morphological, morphometric and standard radiological parameters were analyzed at the thoracic and lumbar vertebrae of the animals. The deviation from the physiological parameters was established by comparing all parameters obtained in the NC-blocked animals with those acquired in 14 pigs without NC blocking. These animals were considered as the control group. Results. None of the animals that underwent NC epiphysiodesis showed asymmetrical spinal growth inducing deformities in the coronal plane. There was neither rotation nor wedging of the vertebral bodies. Whatever the level involved, NC epiphysiodesis caused shortening of the sagittal length of the pedicles and a subsequent decreasing of the antero-posterior diameter of the spinal canal. These features resulted in a frank spinal stenosis at the operated levels. However, the transverse diameter of the spinal canal was conserved in the coronal plane. In the sagittal plane, blocking of the neurocentral cartilage conditioned a lumbar hyperlordosis with compensatory kyphosis of the upper level to the operated vertebra. Conclusions. Symmetrical growth arresting of neurocentral cartilages induces a narrow spinal canal by decreasing the sagittal diameter similar to that observed in patients with achondroplasia. The most affected structure was the development of the vertebral pedicles

The vertebral canal reaches maturity early in life. The size of the lumbar spinal canal was evaluated to determine normal values for vertebral canal size. For our prospective cross-sectional study 95 women with a singleton pregnancy between 16 and 41 weeks of gestation were recruited during their routine anomaly scan. After defining the region of interest on the 2D ultrasound image, volume scanning was performed and the rendered volume was displayed in three orthogonal planes on the screen. Area and volume of the vertebral canal in L1, L3 and L5 were calculated. Area and volume of the vertebral canal showed a close correlation to gestational age. Advancing gestational age was characterised by a statistically significant increase in all volumetric and conventional 2D measurements. No major differences regarding area and volume measurements could be found between upper and lower spine. Sonographic evaluation of the fetal spine plays an important role in obstetric anomaly scans. Prenatal diagnosis may also lead to interesting aspects concerning back pain in adults. A small vertebral canal is considered to be one of the causes for back pain in later life but these syndromes are multi-factorial. Since interpedicular diameter of the spinal canal at the level of L1-L4 at birth is approximately 70 % of the adult size, any kind of intrauterine growth impairment will affect further development. Further data will show if our normal values will have significance in the early detection of disorders of the vertebral canal

Introduction. There is an unresolved controversy in the published work about the effect of screws crossing the neuro-central cartilage (NCC) on spinal canal dimension in very young children and in animals. Anterior vertebral body screws with fusion can invade and damage the NCC, especially at the site of screw insertion; however, this finding has never been studied. Methods. This study is a retrospective, clinical and radiological analysis of seven consecutive children aged 1–2 years treated with anterior vertebral instrumentation and fusion by downsized rod screw systems. The mean age at time of surgery was 2 years 4 months (range 1 year 9 months to 2 years 10 months). The average follow-up period was 3 years 3 months (2 years 6 months to 4 years 5 months). 16 screws inserted anteriorely were evaluated by a follow-up CT scan. Spinal canals were divided with known anatomical landmarks into right and left hemicanals. The relation of the anterior screws to the NCC and the spinal canal dimension were studied. All clinical and radiological complications were recorded. Results. Only 11 screws were suitable for measurement. There was a difference of 10–20% between the surface areas of the two hemicanals in six levels in which the screw heads were passing through or encroaching on the NCC; the canal was smaller ipsilateral to the affected NCC. The hemicanals were almost symmetrical in five levels in which the screw heads were away from the NCC, except in one in which it was touching the NCC. For the 16 screws evaluated there were no recorded complications apart from one screw breaching the adjacent end plate. Conclusions. Anterior vertebral body screws with fusion can encroach on the NCC when inserted in very young children, which seems to decrease the ipsilateral canal dimension between 10% and 20%. Apart from this finding, anterior instrumentation is safe when used in very young children aged 1–2 years. Canal asymmetry had no clinical effect in childhood; however, long-term follow-up of these children is needed to measure its clinical significance. Change of screw position with time is a frequent occurrence in the distal pedicle screws with single growing rods. There are two different types identified. With growing rods some degree of distal pedicle screw migration in this paediatric age group may not be regarded as a complication of treatment

Posterior approach to the lumbar spine necessarily induces structural damage of paravertebral muscles. In order to avoid these changes, we have started to utilize a microscopic decompression of the spinal canal via an unilateral approach since 1998. The purpose of this study was to evaluate the results of this operative procedure for lumbar spinal canal stenosis. A total of 18 patients, 13 men and five women, were reviewed. The age at the time of surgery ranged from 53years to 78years with a mean of 69.0years. Follow up period averaged 12.3months ranging from one to 32months. As for operative procedure, unilateral paravertebral muscle was retracted laterally and lam-inotomy in the approached side was performed. Following complete decompression of a nerve root in the approached side, microscope was tilted and the inner aspect of lamina in the contralateral side was resected using high-speed drill with a guard of yellow ligament to dural sac and nerve root. Following the procedure, yellow ligament was resected and nerve root in the contralateral side was decompressed. Results: In operation time, blood loss and recovery rate of JOA score, there were no statistical differences compared with ordinal laminotomy cases. Dural sac was well decompressed not only in the hemilaminec-tomy side but also in the contralateral side. All cases showed intensity change of paravertebral muscle in the approached side on T2 weighted MRI. Conclusion: The procedure described here was definitely effective because paravertebral muscle in the contralateral side and midline structure of the lumbar spine could be completely preserved

Introduction: We report the outcome two years following Dynesys for the treatment of Spinal Canal Stenosis. In both the FDA trial and the European multicentre study, stenosis was invariably combined with decompression, invalidating conclusions on the results of Dynesys alone. Method: Eighteen patients had symptomatic Spinal Canal Stenosis with root claudication sufficient to justify surgical intervention. Average age of patients was 68 with a range between 44–86 years. Dynesys was applied for the treatment of a single level in 4, two levels in 8, and more than two levels in 6. Patients were evaluated preoperatively using ODI, SF36, VAS, plain x-ray, MRI scanning & discography. Questionnaires were evaluated at the first and second years. Results: 2 patients had undergone previous spinal decompression, and decompression at the time of Dynesys surgery in 7. In the remaining 9 cases, no decompression was used, relying on distraction alone as in the X stop system. In this latter group, stenotic symptoms failed to resolve. Removal of Dynesys was indicated in 3 (16.6%). Discussion & Conclusions: Dynesys alone is not recommended as a treatment for symptomatic spinal stenosis. A separate study is required to address the question of whether Dynesys adjunct improves the back pain outcome compared with decompression alone

Purpose: There are a wide variety of operative procedures for lumbar spinal canal stenosis. Bilateral fenestration, preserving the continuity of the lamina and spinous processes, has widely been employed in our department and its affiliated hospitals. The following questions are raised: Are decompressive effects of fenestration and spinal stability maintained without spinal fusion or instrumentation? In order to answer the questions, we compared the rates of revision after fenestration with those after laminectomy alone and decompressive surgery with spinal fusion. Materials and methods: The registry of spinal surgeries of our university and affiliated hospitals from 1988 to 1997 was consulted. During the first 5-years period 1159 patients underwent decompressive surgery. 908 of them had spondylosis and 251 had degenerative spondylolisthesis (DO) as a contributing factors of neural compression. Fenestration was done in 740 (81%) of patients with spondylosis and in 176 (70%) of patients with DO. Results: Regarding the whole series 31 out of 1159 patients had a revision. The revision rate was 2.7%. 15 out of 908 patients (1.7%) with spondylosis and 16 out of 251 patients (6.4%) with DO underwent revisions. 11 out of 740 (1.5%) with spondylosis and 11 out of 176 (6.3%) with DO underwent revisions after fenestration. No significant differences were found among the revision rate of fenestration, laminectomy and decompressive surgery with spinal fusion. Conclusion: The decompressive effect of fenestration was maintained long enough, even for degenerative spondylolisthesis. As a first operation spinal fusion is not necessarily indicated for lumbar canal stenosis

This study reports on postoperative changes of intra and epidural space of both degenerative lumbar spinal canal stenosis(DLSCS) and degenerative spondylolisthesis(DO)on MRI. 48cases(DLSCS:20cases, DO:28cases)were investigated in this study. All cases performed bilateral wide fenestration. The average age of these patients was 65 years and average follow-up period was 60 months. The average improvement ratio(%) of JOA score was 68% at the last follow-up. Symptomes had deteriorated in 8 cases, according to an increase in the volume of the postlaminectomy membrane, at the last follow-up. There were 8 cases(29%)in DO. showing an increase of % slip on X-ray at the last follow-up, accompanied with both a slight decreasing of the cross-sectional area(CSA)of dural sac and a slight deterioration of clinical results. Discussion: Symptomes in around 17% of the cases deteriorated, and there were three factors on MRI ; a poor expansion of the dural sac, a grouping of the cauda equina, and a decrease in the CSA of the dural sac

Study design: Retrospective, descriptive study. Objectives: To describe the characteristics and outcomes of patients with spinal canal stenosis who suffer significant spinal cord injury (SCI) due to hyperextension injury of the cervical spine. To compare their characteristics and outcomes with all patients suffering traumatic cervical SCI and with the total cohort of patients admitted to a Spinal Injuries Unit for rehabilitation. Setting: Spinal Injuries Unit (SIU), Princess Alexandra Hospital, Brisbane. Methods: Demographic, injury and outcome data were obtained from an existing database and by review of the medical records of 575 patients admitted to and discharged from the SIU between July 1st, 1995 and July 1st 2002. Main outcome measures were: change in American Spinal Injury Association (ASIA) scale category, change in ASIA motor score, discharge Functional Independence Measure (FIM) score and change in FIM score, length of stay (LOS), primary means of mobility at discharge and discharge destination. Standard statistical methods were used to compare groups. Results: A total of 18 (3%) of the 575 patients were found to have cervical canal stenosis and hyperextension injury (the CCS/HI group). This represents 8% of the total group suffering traumatic injury to the cervical spinal cord (the total cervical trauma: TCT group, n = 225). This CCS/HI group was found to have a mean age at injury of 55.1 years compared to 37.1 and 37.8 years respectively for the TCT and total groups. Ninety-four percent of patients were found to have a neurological level at admission at C1–3 or C4–5 compared to 75.6% of the TCT group and only 5.6% of patients had an ASIA Impairment Category A lesion at admission compared to 38.7% of the TCT group. Falls (55.6%) was the most common cause of injury in the CCS/HI group with motor vehicle accidents (33.8%) most common in the TCT group. The mean change in ASIA motor score between admission and discharge was 34.7 compared to 20.4 for the TCT group. Degree of impairment (measured by a change in ASIA Category) improved in 28% of patients and mean change in total FIM score was 41.3. There was no difference seen with the TCT group. LOS was shorter for these patients (111.1 days vs. 161.6 days). The primary means of mobility at discharge was “walking” for 50% of this group (compared to 28.4% for the TCT group) while the next most common means of mobility was “power wheelchair” at 28% (17% of TCT group). Most patients (55.4%) were discharged to their previous home following rehabilitation and 22.3% were discharged to another rehabilitation unit or acute hospital. Conclusions: Patients with cervical spinal canal stenosis who suffer hyperextension injury constitute a distinct subgroup with the total group of traumatic cervical spinal cord injuries. This study suggests that they are older at the time of injury, have more rostral cervical injuries, are more likely to have incomplete injuries and that falls is the most common cause of injury. They have greater improvement in motor function but this does not appear to result in greater function at discharge as measured by the FIM. There appears to be a dichotomy with results for mobility at discharge with patients either being able to walk or requiring a power wheelchair. LOS in the SIU is shorter but a higher percentage are discharged to another hospital or rehabilitation unit

STUDY DESIGN: Retrospective, descriptive study. OBJECTIVES: To describe the characteristics and outcomes of patients with spinal canal stenosis who suffer significant spinal cord injury (SCI) due to hyperextension injury of the cervical spine. To compare their characteristics and outcomes with all patients suffering traumatic cervical SCI and with the total cohort of patients admitted to a Spinal Injuries Unit for rehabilitation. SETTING: Spinal Injuries Unit (SIU), Princess Alexandra Hospital, Brisbane. METHODS: Demographic, injury and outcome data were obtained from an existing database and by review of the medical records of 575 patients admitted to and discharged from the SIU between July 1st, 1995 and July 1st 2002. Main outcome measures were: change in American Spinal Injury Association (ASIA) scale category, change in ASIA motor score, discharge Functional Independence Measure (FIM) score and change in FIM score, length of stay (LOS), primary means of mobility at discharge and discharge destination. Standard statistical methods were used to compare groups. RESULTS: A total of 18 (3%) of the 575 patients were found to have cervical canal stenosis and hyperextension injury (the CCS/HI group). This represents 8% of the total group suffering traumatic injury to the cervical spinal cord (the total cervical trauma: TCT group, n = 225). This CCS/HI group was found to have a mean age at injury of 55.1 years compared to 37.1 and 37.8 years respectively for the TCT and total groups. Ninety-four percent of patients were found to have a neurological level at admission at C1-3 or C4-5 compared to 75.6% of the TCT group and only 5.6% of patients had an ASIA Impairment Category A lesion at admission compared to 38.7% of the TCT group. Falls (55.6%) was the most common cause of injury in the CCS/HI group with motor vehicle accidents (33.8%) most common in the TCT group. The mean change in ASIA motor score between admission and discharge was 34.7 compared to 20.4 for the TCT group. Degree of impairment (measured by a change in ASIA Category) improved in 28% of patients and mean change in total FIM score was 41.3. There was no difference seen with the TCT group. LOS was shorter for these patients (111.1 days vs. 161.6 days). The primary means of mobility at discharge was “walking” for 50% of this group (compared to 28.4% for the TCT group) while the next most common means of mobility was “power wheelchair” at 28% (17% of TCT group). Most patients (55.4%) were discharged to their previous home following rehabilitation and 22.3% were discharged to another rehabilitation unit or acute hospital. CONCLUSIONS: Patients with cervical spinal canal stenosis who suffer hyperextension injury constitute a distinct subgroup with the total group of traumatic cervical spinal cord injuries. This study suggests that they are older at the time of injury, have more rostral cervical injuries, are more likely to have incomplete injuries and that falls is the most common cause of injury. They have greater improvement in motor function but this does not appear to result in greater function at discharge as measured by the FIM. There appears to be a dichotomy with results for mobility at discharge with patients either being able to walk or requiring a power wheelchair. LOS in the SIU is shorter but a higher percentage are discharged to another hospital or rehabilitation unit

Lumbar disc herniations are quite common pathology in orthopedics. Percutaneous discectomy remains somewhat controvercial. It has limited indications and has not proven to be as effective as conventional or microscopic discectomy. Smith and Foley developed a new minimum invasive procedure for lumbar disc disease, Microendoscopic Discectomy (MED) in 1995. We started MED from October 1998. Besides, we started the clinical application of MED for lumbar spinal canal stenosis from February 2000. The purpose of the presentations are to present operative technique, early clinical results and complications. A) We operated upon 40 patients of MED from October 1998 to July 2000 for lumbar disc herniations. Male were 25, female were 15, and mean age was 38 years (15~64). In one patient, operated disc level was L2/3, in 21, L4/5, in 16, L5/S, and in two L4/5/S. Methods: We investigated: period of hospital stay, period of hospital stay postoperation, period to return to normal temperature, frequency of postop. NSAID, operation time, blood loss, period to begin to walk, JOA score, period to return to work or school, and complications. Results: The mean hospital stay was 17.9 days, the mean hospital stay postop. 9.7 days, period to return to normal temperature 1.3 days, frequency of postop. NSAID 1.1 times. The mean operation time was 105 ± 42 minutes, (65–180 min). The mean blood loss was 9.7 ± 18.5 Gm. (uncountable~ 120Gm.). All patients began to walk one day postoperatively. Mean JOA score was improved from 10.7 ± 3.8 preop. to 27.6 ± 0.9 4w. postop, to 28.1 ± 0.7 12w. postop., to 28.7 ± 0.6, 24w. postop. The mean period to return to work or school was 22.3 days. In one case, we had liquorrhea, and the damaged dura had to be repaired. B)We operated upon five patients of decompression by MED for lumbar spinal canal stenosis from February 2000 to July 2000. Male were one, female were four, and mean age was 72 years (65–77). In four patient, operated disc level was L4/5, in one, L5/S. We will show the operative procedures by videotape. We investigated – operation time, blood loss, period to begin to walk, JOA score, and complications. Results: The mean operation time was 128+−31 minutes, (85m–170m.). The mean blood loss was 25 ± 29 Gm. (uncountable – 70Gm.). All patients began to walk one day postoperatively. Mean JOA score was improved from 15.7 ± 3.3preop. to 27.5 ± 0.5 4w. postop, to 28.0 ± 0.7 12w. postop.. There was no complication. Discussion: The advantages of MED are small skin incision, less invasion to paravertebral muscles, short bed rest, and rapid return to work. The disadvantages are loss of deep perception and technical demands. To overcome the disadvantages, we are developping the 3D MED, and we are organizing live pig seminar biannually. Conclusion: MED has several advantages i,e, small skin incision, less invasion to paravertebral muscles, short bed rest, and rapid return to work. We need proper knowledge and technique about endoscopic surgery, and laboratory training by live pig and cadaver. MED can be applied to the decompression surgery for lumbar spinal canal stenosis

Study Design: Thirty-four patients who were operated for spinal deformities with the Spine System Evolution (SSE) were retrospectively reviewed. Objectives: To evaluate the efficiency of SSE to correct spinal deformities. Summary of Background Data: Since the end of the Harrington rods era, several instrumentation were introduced for correction of spinal deformities. Most of these instrumentations are evolution of he CD instrumentation and are based on combination of translation, distraction/compression and possible some rotation forces. Cord injuries were informed to be more frequent with the new instruments and are related both to ischemic injuries and to mechanical insults to the cord by the supralaminar and the infralaminar hooks. Correction by the SSE is based on pedicle screws and pedicular-transverse locks. No hook is inserted into the spinal canal. Methods: All charts, radiographs, and images of the patients operated for spinal deformities with the SSE were reviewed. Thirty-four patients were found. For the purpose of this study they were evaluated for the amount of correction achieved, balance of the spine, subjective satisfaction of the cosmetic appearance and the surgical complications. Results: The mean age of the operated patients was 19.5 years. Twenty-one were operated for idiopathic scoliosis and were found to have 61% correction of the major curves. Five patients were operated for neuromuscular scoliosis with 69% of correction in average, four were operated for thoracic hyperkyphosis with reduction of the curves to physiologic range in all of them and four were operated for adult scoliosis with 38% of correction. Twenty-eight patients were satisfied from the results and the same number of patients were found to be balanced in the range of up to one-centimeter shift from the mid-line. No patient was found to have any major neurologic complication and no deep wound infections was registered. One patient had postoperative bronchopneumonia, another one had pneumothorax, one had superficial wound infection and another girl was troubled with her body image. Conclusions: SSE instrumentation was found friendly to use and relatively safe for correction of spinal deformities

To assess radiological fusion rates in posterolateral fusions using SiS-CaP. Retrospective, radiological follow-up study. Single surgeon series of 76 consecutive patients were evaluated, in a regional spinal unit. All patients had clinical and radiological (MRI) spinal canal stenosis secondary to degenerative spondylosis or spondylolisthesis. Surgery consisted of instrumentation, decompression and meticulous preparation of the posterolateral graft bed by removal of all soft tissues posterior to the inter-transverse membrane and decortication of transverse processes (TPs). SiS-CaP putty was injected into this gutter and moulded around the instrumentation. Good quality, well prepared bone chips from the posterior decompression were seeded into the putty. Patient radiographs were reviewed at 3-6 months, 1 year and 2 years. Radiographs were assessed using a protocol to examine granularity, bone formation and evidence of pseudarthrosis, based upon previously reported literature . 1. and our personal experience. Of the 76 patients, 26 were excluded. M:F was 21:29. Mean age was 58yrs. Average number of motion segments fused per case was 2.2. There was one pseudarthrosis with metalwork fracture, and thus a total fusion rate of 98%. In addition, one patient had scanty bridging of TPs, and one patient had lucency around the S1 screws. SiS-CaP, as a bone graft substitute in posterolateral instrumented fusions, gives comparable results to published fusion rates using autologous iliac crest grafting and/or Bone Morphogenic Protein . 2. Moreover, it avoids the associated morbidity of iliac bone harvest

Aims. Lumbar spinal stenosis (LSS) is a common skeletal system disease that has been partly attributed to genetic variation. However, the correlation between genetic variation and pathological changes in LSS is insufficient, and it is difficult to provide a reference for the early diagnosis and treatment of the disease. Methods. We conducted a transcriptome-wide association study (TWAS) of spinal canal stenosis by integrating genome-wide association study summary statistics (including 661 cases and 178,065 controls) derived from Biobank Japan, and pre-computed gene expression weights of skeletal muscle and whole blood implemented in FUSION software. To verify the TWAS results, the candidate genes were furthered compared with messenger RNA (mRNA) expression profiles of LSS to screen for common genes. Finally, Metascape software was used to perform enrichment analysis of the candidate genes and common genes. Results. TWAS identified 295 genes with permutation p-values < 0.05 for skeletal muscle and 79 genes associated for the whole blood, such as RCHY1 (PTWAS = 0.001). Those genes were enriched in 112 gene ontology (GO) terms and five Kyoto Encyclopedia of Genes and Genomes pathways, such as ‘chemical carcinogenesis - reactive oxygen species’ (LogP value = −2.139). Further comparing the TWAS significant genes with the differentially expressed genes identified by mRNA expression profiles of LSS found 18 overlapped genes, such as interleukin 15 receptor subunit alpha (IL15RA) (PTWAS = 0.040, PmRNA = 0.010). Moreover, 71 common GO terms were detected for the enrichment results of TWAS and mRNA expression profiles, such as negative regulation of cell differentiation (LogP value = −2.811). Conclusion. This study revealed the genetic mechanism behind the pathological changes in LSS, and may provide novel insights for the early diagnosis and intervention of LSS. Cite this article: Bone Joint Res 2023;12(6):387–396

Low back pain is the single most common cause for disability in individuals aged 45 years or younger, it carries tremendous weight in socioeconomic considerations. Degenerative aging of the structural components of the spine can be associated with genetic aspects, lifetime of tissue exposure to mechanical stress & loads and environmental factors. Mechanical consequences of the disc degenerative include loss of disc height, segment instability and increase the load on facets joints. All these can lead to degenerative changes and osteophytes that can narrow the spinal canal. Surgery is indicated in patients with spinal stenosis who have intractable pain, altered quality of life, substantially diminished functional capacity, failed non-surgical treatment and are not candidates for non-surgical treatment. The aim was to determine the reasons for refusal of surgery in patients with established degenerative lumber spine pathology eligible for surgery. All patients meeting the study criteria, patients older than 18 years, patients with both clinical and radiological established symptomatic degenerative lumbar spine pathology and patients eligible for surgery but refusing it were recruited. Questionnaire used to investigate reasons why they are refusing surgery. Results 59 were recruited, fifty-one (86.4 %) females and eight (13.6 %) males. Twenty (33.8 %) were between the age of 51 and 60 years, followed by nineteen (32.2 %) between 61 and 70 years, and fourteen (23.7 %) between 71 and 80 years. 43 (72 %) patients had lumber spondylosis complicated by lumber spine stenosis, followed by nine (15.2 %) with lumbar spine spondylolisthesis and four (6.7 %) had adjacent level disease. 28 (47.4 %) were scared of surgery, fifteen (25.4 %) claimed that they are too old for surgery and nine (15.2 %) were not ready. Findings from this study outlined that patients lack information about the spinal surgery. Patients education about spine surgery is needed

The purpose of the study is to evaluate the outcome of two methods: Posterolateral fusion and instrumentation versus posterolateral fusion, instrumentation and interbody fusion using clinical and radiological criteria in demographically similar groups. This is a prospective cohort study of sixty-four patients randomized to two therapeutic strategies (Level II study). Sixty-four patients were randomized to either instrumented posterolateral fusion (control) or combined instrumented posterolateral and interbody fusion (study) in one level degenerative disorders of the lumbar spine. Demographics of the groups were similar including age, gender and other variables. The demographics of the groups were similar for one level degenerative disorders—disc herniation, spondylolisthesis and spinal stenosis. The primary outcome was measured by the Oswestry Disability Index at two years. There was no statistically significant difference. Secondary outcomes (SF36, VAS, fusion rate, disc height maintenance, maintenance of deformity correction, adjacent segment degeneration) were statistically similar in both groups. In conclusion, no clinical advantage with interbody fusion versus posterolateral fusion alone. Analysis of the correlation between the pedicle shape and the spinal canal anatomy in scoliotic anatomic specimens. S. Parent1, H. Labelle, W. Skalli, J. de Guise,. 13175 Côte Ste-Catherine, Montréal, Québec H3T 1C5. The objective of the present study was to analyze the correlation between the pedicle shape and spinal canal anatomy in scoliotic specimens. Vertebral canal anatomy was evaluated in a series of thirty anatomic scoliotic specimens and compared to thirty normal specimens. Spinal canal enlargement inversely correlated with pedicle width modifications on the concavity of scoliotic curves. These findings suggest that changes in pedicle anatomy are secondary to local changes in spinal cord position. Recent studies have demonstrated the close relationship between the spinal cord and the pedicle on the concavity of the scoliotic curve of patients with scoliotic deformities. The hypothesis of the present study is that changes in spinal canal shape are related to spinal cord position and resulting bone remodeling. This study evaluated the characteristic changes of spinal canal shape in anatomic scoliotic specimens. Posterior elements morphology is closely related to the local spinal cord anatomy and its relationship with the bony architecture. The characteristic posterior element changes seen in scoliosis are likely the result of local bone remodeling. Spinal asymmetry was observed in scoliotic specimens when compared to normal specimens. Spinal canal was enlarged asymmetrically on the concavity of thoracic scoliotic curves (p < 0.01). Overall, canal surface was greater in scoliotic specimens when compared to normal specimens (p < 0.01). These changes were more important at the apex of the curve. Spinal canal characteristic shape was evaluated in thirty scoliotic anatomic specimens and thirty normal anatomic specimens using twelve parameters representing measures of right and left hemi-canal length, width or surface area. The 3-D coordinates of eight points taken at the periphery of each spinal canal were recorded. The results of this study support the hypothesis that spinal canal shape is modified by the spinal cord position and that posterior element changes seen in scoliosis are in part due to bone remodeling in response to local neural anatomy modifications. Funding: Fonds de Recherche en Santé du Québec