Degenerative Lumbosacral Disease Research Articles

Low profile posterior lumbar-sacral interbody fusion for lumbosacral degenerative diseases: a technical note

BackgroundThe purpose of this study was to report our surgical experience in patients with lumbosacral degenerative diseases who underwent posterior decompression and interbody fusion fixed with cortical bone trajectory screw and sacral alar screw, which is known as low-profile posterior lumbosacral interbody fusion (LP-PLSIF).MethodsPatients with lumbosacral degenerative disease who underwent LP-PLSIF and traditional PLSIF (control group) internally fixed with pedicle screws were included retrospectively. Patients’ demographic data, operative parameters, and perioperative complications were recorded and analyzed.ResultsA total of 18 patients were enrolled in this study, which included 9 patients (5 male and 4 female) who underwent LP-PLSIF, and 9 patients (4 male and 5 female) who underwent traditional PLSIF. There wasn’t a significant difference in the average age between the two groups, 56.78 ± 10.92 years in the LP-PLSIF group and 60.22 ± 8.21 years in the PLSIF group (p = 0.460). The bone mineral density (BMD) of the two groups of patients were -2.00 ± 0.26 T and -2.13 ± 0.19 T, respectively (P = 0.239). The mean postoperative follow-up time was 12.7 months (range, 12–14 months). The mean operation time was 142.78 ± 11.21 min and 156.11 ± 13.41 min in the LP-PLSIF group and PLSIF group respectively (P < 0.05). The average blood loss was 137.78 ± 37.09 ml in the LP-PLSIF group, and 150.00 ± 27.84 ml in the PLSIF group (P = 0.441). The average postoperative drainage was 85.56 ± 37.45 ml and 122.22 ± 22.24 ml in the LP-PLSIF group and control group respectively (P < 0.05). Patients in the LP-PLSIF group had shorter incision length compared with the control group, 61.44 ± 10.56 mm vs. 74.56 ± 10.22 mm (P < 0.05). The average length of hospitalization of 11.33 ± 2.92 days in the LP-PLSIF group, and 11.11 ± 1.62 days in the PLSIF group (p = 0.844). All patients had significant improvement in VAS pain score, ODI, and JOA evaluation. However, patients in the LP-PLSIF group had better improvement in terms of VAS back pain and ODI in the short term after the operation. There were no neurological complications or wound infection. The fusion rate at the last follow-up was 100% (9 of 9) in the LP-PLSIF group, and 88.89% (8 of 9) in the control group based on CT scans. 1 patient in the control group had asymptomatic sacral pedicle screw loosening.ConclusionsLP-PLSIF is a safe and effective surgical technique for patients with lumbosacral degenerative disease, which has the potential strength of less invasive and better clinical improvement.

ULTRASONOGRAPHY AS AN INTRAOPERATIVE TOOL FOR LOCALIZATION OF THE ANATOMICAL LEVEL IN LUMBOSACRAL SPINE SURGERIES

Aims and Objectives: The aims and objectives of the study are to find the effectiveness of ultrasound as a pre-operative adjunct to localize the anatomical intervertebral level of interest and study its accuracy by comparing it with the gold standard intra-operative fluoroscopy and to study factors affecting localization of anatomical vertebral level by ultrasound. Methods: This was a prospective study conducted in the Department of Neurology Department of Neurosurgery and Neuroimaging and Interventional Radiology, NIMHANS Hospital, Bengaluru, over a period of 1 year. 50 cases of lumbosacral degenerative diseases were included in this study on the basis of pre-defined inclusion and exclusion criteria. All patients underwent ultrasonography of the lumbosacral spine followed by pre-operative X-ray of the lumbosacral spine using the C-ARM. The accuracy of good localization of the desired level of the lumbosacral spine by ultrasound as compared to X-ray was determined. p&lt;0.05 was taken as statistically significant. Results: There were 22 (44%) males and 28 (56%) females with a M: F ratio of 1:1.27. The mean age was 46.7±13.5 years. 46 (92%) cases were diagnosed with prolapsed intervertebral disc (PIVD) and 4 (8%) cases with Grade II spondylolisthesis radiologically. Good localization which constitutes exact localization, close upper, and close lower localization added up to 82% of the cases (41/50) and the rest 18% were tagged as poor localization (9/50). The accuracy of good localization in both the groups of PIVD and spondylolisthesis (listhesis) was 82.6% and 75%, respectively. Conclusion: Ultrasound can be used as an exceptionally good and accurate method of localizing the anatomical intervertebral level for patients undergoing various lumbosacral spinal surgeries.

Comparative Radiographic Analyses and Clinical Outcomes Between O-Arm Navigated and Fluoroscopic-Guided Minimally Invasive Transforaminal Lumbar Interbody Fusion.

The differences in clinical and radiographic outcomes between 3-dimensional computer navigation (NAV) and fluoroscopic-guided (FLUO) minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) are currently unclear, with different studies showing different advantages of each technique. This study aimed to compare the clinical and radiographic outcomes of NAV and FLUO MIS-TLIF. Furthermore, we determined the correlation between radiographic findings and predictable clinical outcomes. Between January 2016 and October 2018, 97 consecutive patients who had undergone MIS-TLIF with the lumbosacral degenerative disease in our institute were retrospectively reviewed. Radiographic outcomes (angle of screw convergence, screw-to-pedicle diameter ratio, %screw depth, screw penetration, %fusion, and facet joint violation) were analyzed by 2 independent orthopedists using thin-slice computed tomography. Clinical outcomes were assessed with Oswestry Disability Index (ODI), visual analog scale (VAS), and satisfaction score. The association between radiographic and clinical outcomes was then analyzed to determine the predictable variable outcomes. Sixty-one patients (270 screws) in the FLUO group and 36 patients (172 screws) in the NAV group were compared. The NAV group showed a significantly higher %screw depth (89.04% ± 6.07% vs 85.18% ± 7.54%; P = 0.011), larger angle of screw convergence (27.7° ± 3.93° vs 18.44° ± 7.54°; P < 0.001), lower incidence of pedicle penetration (0% vs 3.7%; P = 0.016), and less facet joint violation (1.0% vs 8.1%; P = 0.003). The clinical results revealed a significantly better VAS and ODI in the NAV group at 6 and 12 months. The %screw depth correlated with the VAS back pain score at the 1-year follow-up. NAV MIS-TLIF showed superior screw placement accuracy, better screw convergence and depth, and lower cranial facet joint violation than FLUO MIS-TLIF. Furthermore, better clinical scores were revealed in the NAV group at the 6-month and 1-year follow-up.

Clinical application of sacral alar screw fixation in surgical treatment of lumbosacral degenerative disease

Objective: To verify the safety and feasibility of sacral alar screw fixation and fusion surgery in lumbosacral area. Methods: The clinical and radiological data of patients receiving L5/S1 single-level cortical bone trajectory screw combined with sacral alar screw decompression fixation and fusion in Beijing Chaoyang Hospital due to lumbar spinal stenosis from January 2019 to January 2020 were retrospectively analyzed. The clinical data included operation duration, intraoperative blood loss, postoperative drainage, pain and function scores during follow-up. The radiological data included preoperative and postoperative follow-up X-rays and three-dimensional reconstruction of lumbar spine CT. The fusion status and complication of internal fixation, such as screw loosening and fixation failure were evaluated by the radiological examination. Results: According to the inclusion and exclusion criteria, a total of 16 patients (7 males and 9 females) were included, with an average age of (69.6±5.2) years. The patients were followed-up for (16.2±1.7) months. The average operation duration was (144±21) min, the intraoperative blood loss was (103±20) ml, and the postoperative drainage was (80±34) ml. The patient's low back pain visual analogue scale (VAS) score was 6.8±1.0 before surgery, and it was improved to 0.9±0.7 at the last follow-up; leg pain VAS score was 6.1±0.9 before the operation and it improved to 0.9±0.7 at the last follow-up; Oswestry disability index (ODI) function score was 66.2%±8.0% before the surgery and it decreased to 26.6%±7.2% at the last follow-up. No neurological complications, surgical site infection, screw loosening, internal fixation failure or cage displacement were observed during the follow-up. The fusion rate was 68.8% (11/16) at 6 months post operation. Conclusion: It is safe, feasible and effective to apply cortical screws combined with sacral alar screws in short-segment decompression, fixation and fusion surgery on the lumbosacral region to treat lumbosacral spinal stenosis.

Tethered spinal cord syndrome in adults in the MRI era: recognition, pathology, and long-term objective outcomes.

Tethered cord syndrome (TCS) has been well described in pediatric patients. Many recent reports of TCS in adult patients have grouped retethering patients with newly diagnosed ones without separately analyzing each entity and outcome. The authors reviewed their experience of newly diagnosed adult TCS patients to identify and explore TCS misdiagnosis, recognition, subtype pathology, and individual objective outcomes. This study included 24 adult patients (20 female and 4 male) who fit the criteria of being newly diagnosed and aged 20 years and older (age range 20-77 years). Preexisting dermal sinus was present in 6 patients, hypertrichosis in 5, skin tag/cleft/dimple and fatty subcutaneous masses in 5, scoliosis in 2, and neurological abnormalities in 4 patients. The pathology consisted of TCS with taut filum in 8 patients, conus lipoma with TCS in 7, diastematomyelia in 7, and cervical cord tethering in 2 patients. Of the 24 study patients, nondermatomal low-back or perineal pain occurred in 19 patients, bladder dysfunction in 21, and motor, sensory, and reflex abnormalities in 21 patients. Aggravating factors were repeated stretching, multiple pregnancies, heavy lifting, and repeated bending. Urological evaluation included bladder capacity, emptying, postvoid residuals, detrusor function, pelvic floor electromyography (EMG), bladder sensitivity, and sphincter EMG, which were repeated at 6 months and 1 year postoperatively. The follow-up was 1 to 30 years. Detailed postoperative neurological findings and separate patient outcome evaluations were recorded. Four of the 24 patients did not have an operation. Resolution of pain occurred in 16 of the 19 patients reporting low-back or perineal pain. Motor and sensory complaints resolved in 17 of 20 patients. Regarding bladder dysfunction, in the 20 patients with available data, bladder function returned to normal in 12 patients, improved in 3 patients, and was unchanged in 5 patients. If the symptom duration was less than 6-8 months, there was recovery of all parameters of pain, bladder dysfunction, and neurological deficit, and recovery from hyperreflexia matched that from neurological deficit. Fifteen patients were employed preoperatively and returned to work, and an additional 3 others who were unable to work preoperatively were able to do so postoperatively. Most adults with newly diagnosed TCS have unrecognized neurocutaneous abnormalities and neurological deficits. The triad of nondermatomal sacral or perineal pain, bladder dysfunction, and neurological deficit should not be confused with hip or degenerative lumbosacral disease. Addressing the primary pathology often leads to successful results.

Association of Lower Lumbar Facet Joint Osteoarthritis With Demographic Factors And Intervertebral Disc Degeneration In Patients With Low Back Pain

Background: Facet joint osteoarthritis (FJO) is an important element of lumbosacral degenerative disease. However, its association with other possible risk factors is still controversial. This study was conducted to investigate the association of FJO with risk factors and with presence of lumbar intervertebral disc degeneration (IVDD).&#x0D; Patient and method: Lumbosacral magnetic resonance imaging (MRI) examinations of 100 patients (36 male and 64 female) with low back pain (LBP) were reviewed in this cross-sectional retrospective study for the presence of FJO. The overall prevalence of FJO as well as the number of levels affected was correlated with the age, gender, body weight, height, BMI, female parity. FJO was also correlated with presence of corresponding IVDD.&#x0D; Results: Overall prevalence of FJO was 23%. The prevalence of FJO was significantly associated with advancing age (p=0.018). Females were more affected than males but without statistical significance (p value = 0.79). Similarly, FJO were more frequent in women with advanced multiparity but the association was statistically not significant (p value 0.1) there was statistically significant association between BMI and number of levels affected by FJO (p value 0.037). IVDD was significantly associated with higher prevalence of FJO especially at L3/4 and L4/5 levels (p values P&lt;0.0001 and 0.04 respectively).&#x0D; Conclusion: Age was the single most important factor significantly associated with both overall higher prevalence of FJO and higher number of involved levels. BMI was statistically associated with increasing number of level affected. IVDD was significantly associated with presence of FJO at L3/4 &amp; L4/5 levels.

The cement leakage in cement-augmented pedicle screw instrumentation in degenerative lumbosacral diseases: a retrospective analysis of 202 cases and 950 augmented pedicle screws.

To evaluate the incidence, type and risk factors of cement leakage (CL) with cement-augmented pedicle screw instrumentation (CAPSI) in degenerative lumbosacral disease. Two hundred and two patients using a total of 950 cement-augmented screws were enrolled. CL was classified into three types: type S: leakage via segmental veins; type B: leakage via basivertebral veins; and type I: leakage via pedicle screw instrumentation to paravertebral soft tissue. The age, gender, operation stage (primary or later stage), body mass index, bone mineral density, the number and type of augmented screw, the position of the tip of screw (lateral or internal part of vertebral body), the position of screw (left or right side), the volume of bone cement, location of the augmented vertebra (lumbar or sacrum), the type of CL and complications were recorded. Binary logistic regression correlation was used to analyze risk factors of veins leakage (type S and type B). The CL was observed in 165 patients (81.68%) and 335 screws (35.26%), leakage types of S, B and I were seen in 255 (76.12%), 77 (22.99%), and 30 (8.96%) of screws, respectively. Besides, double or multiple routes of leakage were seen in 27 screws. Number of augmented screw was a risk factor for vein leakage (OR 0.58; 95% CI 0.44-0.77; P = 0.000). Furthermore, the doses of cement (OR 0.79; 95% CI 0.61-0.99; P = 0.038) and the position of screw (OR 0.39; 95% CI 0.29-0.53; P = 0.000) were identified as risk factors for type S, and the doses of bone cement (OR 0.37; 95% CI 0.25-0.54; P = 0.000) and the position of the tip of screw (OR 0.07; 95% CI 0.04-0.13; P = 0.000) were risk factors for type B. CAPSI bears a high risk of asymptomatic CL, with a higher rate of leakage into segmental veins and basivertebral veins. As is known, more augmented screws and larger doses of cement are risk factors for veins leakage (type S and type B), while the tip of screw approaching to the midline of the vertebral body is another risk factor to type B. Thus, the CL could be reduced by the amelioration of operative techniques and procedures. These slides can be retrieved under Electronic Supplementary Material.

Surgical Treatment of Lumbosacral Discospondylitis with Gentamicin-Impregnated Polymethylmethacrylate Cement and Omentalization

Objective The aim of this study was to describe a novel technique using a gentamicin-impregnated polymethylmethacrylate (PMMA) plug for the surgical treatment of lumbosacral discospondylitis with concomitant instability. Clinical Report A 7-year-old male German Shepherd dog with lumbosacral (LS) discospondylitis and previously diagnosed with degenerative lumbosacral disease underwent ventral slot and distraction of the L7 to S1 intervertebral space with a gentamicin-impregnated PMMA plug. The lumbosacral joint was accessed via the abdomen. Samples were collected for bacterial culture and sensitivity, fungal culture and histopathological examination. The surgical site was omentalized. Long-term oral antimicrobials were administered. Results Clinical improvement was seen immediately after surgery. Complete return to previous activity level was observed 12 months after surgery. Follow-up radiographs 18 months after the procedure revealed no implant migration. Clinical Significance The gentamicin-impregnated PMMA plug in addition to the surgical debridement seemed to be an effective way for short-term distraction, potentially contributing, along with the appropriate antimicrobial therapy and analgesia, to alleviation of pain immediately after surgery and providing for a good short-term outcome, in this clinical case. The use of cement plugs as sole devices in the LS joint warrants further study.

The Effect and Safety of Polymethylmethacrylate-Augmented Sacral Pedicle Screws Applied in Osteoporotic Spine with Lumbosacral Degenerative Disease: A 2-Year Follow-up of 25 Patients

A high rate of instrumentation failure is frequently seen in osteoporotic spines, especially at the sacral segment because of the great shear stress. Several techniques of sacral pedicle screw placement, such as bicortical and tricortical fixation, have been developed; however, the problems of loosening and pulling out of the screws are still a concern. Recently, the polymethylmethacrylate (PMMA)-augmented pedicle screws have been shown to strengthen the purchase in osteoporotic spine, but there are few reports on the effect of S1 pedicle screw with PMMA augmentation. Seventy-five patients receiving cement-augmented pedicle screws at lumbosacral vertebra were enrolled and divided into 3 groups by different patterns of S1 pedicle screw placement: S1 pedicle screw with PMMA augmentation (group A, 25 patients), S1 bicortical pedicle screw fixation (group B, 25 patients), and S1 tricortical pedicle screw fixation (group C, 25 patients). The Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) scores were assessed preoperatively and at the last follow-up. Besides, the complications, loosening rate, and fusion rate were recorded. The VAS and ODI scores at the last follow-up were significantly improved in the 3 groups compared with preoperative results. Better pain relief and functional improvement at the last follow-up was seen in group A compared with the other 2 groups; however, no significant difference was detected between groups B and C. Although the lowest screws loosening rates and the highest fusion rate were found in group A, no significant difference among these 3 groups. Furthermore, longer fusion segments and larger postoperative pelvic incidence-lumbar lordosis (PL-LL) were found as risks related to S1 screw loosening without cement augmentation. The S1 pedicle screws with PMMA augmentation achieved better stability with less screw loosening in the osteoporotic spine with lumbosacral degenerative diseases compared with bicortical/tricortical fixation at S1. This procedure is especially recommended for patients with long segment fixation and large postoperative PI-LL, but there is also a risk of bone cement leakage and a learning curve.

Cortical bone trajectory screws for circumferential arthrodesis in lumbar degenerative spine: clinical and radiological outcomes of 101 cases.

The use of cortical bone trajectory (CBT) pedicle screws for circumferential interbody fusion represents a viable alternative for single-level procedure with reduced invasiveness and less tissue destruction than the traditional technique. In addition, CBT screws have a potentially stronger pullout strength because of the greater amount of cortical bone intercepted. Only few series exist evaluating clinical and radiological outcomes of CBT screws. This is a retrospective cohort study. All patients that underwent circumferential lumbar interbody fusion with CBT screws in our institution from 2014 to 2017 were reviewed. Patient demographics, clinical outcome with visual analogue scale (VAS) and Oswestry Disability Index (ODI), radiological data such as fusion, lordosis and muscle trauma, operative blood loss, hospital stay and use of fluoroscopy were evaluated. A total of 101 patients undergoing CBT-arthrodesis for degenerative lumbo-sacral disease were reviewed. Mean procedural time was 187min. The mean operative blood loss and X-ray dose per procedure was 383ml and 1.60mgcm2, respectively. The mean hospital stay was 3.47days. The mean follow-up was 18.23months. Mean lordosis increment at the treated level was 4.2°. When the follow-up was longer than 12 months (53% of patients), fusion was obtained in 94% of cases. Mean ODI and VAS index improved with statistical significance. This is to our knowledge that the largest available study regarding CBT for circumferential arthrodesis. Results underlined the safety of this technique and the promising clinical and radiological outcomes that will need a longer follow-up. These slides can be retrieved under Electronic Supplementary material.

The morphological relationship between lumbosacral transitional vertebrae and lumbosacral pedicle asymmetry.

Introduction The clinical significance of lumbosacral transitional vertebrae (LSTV) has been reported. However, the association between LSTV and lumbosacral pedicle anatomical anomaly has not been investigated. We hypothesized that LSTV might be associated with lumbosacral anatomical anomaly. The purpose of this study was to examine the morphological association between LSTV and lumbosacral pedicle asymmetry (PA) using computed tomography (CT). Methods A retrospective review of CT images of 347 lumbosacral degenerative disease patients was performed. We divided the subjects into two groups: the normal and LSTV groups. LSTV was classified based on Castellvi's classification. PA was defined as a difference of more than 20° between the right and left angles of the pedicle. Results Seventy out of 347 lumbosacral degenerative disease patients (20.17%) were diagnosed with LSTV. In the normal group, only a 0.54% incidence of PA was seen; however, with respect to the LSTV group, a 9.29% incidence of PA was seen. A significant difference in PA incidence was observed between the groups (p < 0.001). Type IIIa and Type IV in the LSTV group showed a statistically significant PA incidence rate (p = 0.004 and p = 0.039, respectively). Conclusions Our study demonstrated that there was a significant difference in the incidence of PA between LSTV subjects and normal subjects. Moreover, the incidence of PA was significantly higher in LSTV subjects with severe anomaly. These results suggested that lumbosacral spine anomaly might have a close relationship with the incidence of PA and lumbosacral nerve root asymmetry. Therefore, morphological evaluation of the pedicle is important for preoperative surgical management, especially in cases using pedicle screws. This information could lower the incidence of pedicle screw malposition when pedicle screws are inserted at the lumbosacral spine.

Kinematic behavior of a novel pedicle screw-rod fixation system for the canine lumbosacral joint.

To determine the biomechanical behavior of a novel distraction-stabilization system, consisting of an intervertebral distraction bolt, polyaxial screws, and connecting rods, in the canine lumbosacral spine. Biomechanical study. Cadaveric canine lumbosacral spines (L4-Cd3) (N = 8). Cadaveric lumbosacral spines were harvested, stripped of musculature, mounted on a 4-point bending jig, and tested in extension, flexion, and lateral bending using nondestructive compressive axial loads (0-150 N). Angular displacement was recorded from reflective optical trackers rigidly secured to L6, L7, and S1. Data for primary and coupled motion were collected from intact spines, after destabilization at L7-S1, and following surgical stabilization with the new implant system. As compared with the intact spine, laminectomy resulted in a modest increase in angular displacement at L6-L7 and a marked increase at L7-S1. Instrumentation significantly reduced motion at the operated level (L7-S1) with a concomitant increase at the adjacent level (L6-L7). The combination of a polyaxial pedicle screw-rod system and intervertebral spacer provides a versatile solution of surgical stabilization of the lumbosacral joint following surgical decompression in the canine lumbosacral spine. The increase in motion at L6-L7 may suggest the potential for adjacent level effects and clinical trials should be designed to address this question. These results support the feasibility of using this new implant system for the management of degenerative lumbosacral disease in dogs. The increase in motion at L6-L7 may suggest the potential for adjacent level effects and clinical trials should be designed to address this question.

Lumbar Spinal Fixation with Cortical Bone Trajectory Pedicle Screws in 79 Patients with Degenerative Disease: Perioperative Outcomes and Complications

Biomechanical studies demonstrate that cortical bone trajectory pedicle screws (CBTPS) have greater pullout strength than traditional pedicle screws with a lateral-medial trajectory. CBTPS start on the pars and angulate in a mediolateral-caudocranial direction. To our knowledge, no large series exists evaluating the perioperative outcomes and safety of CBTPS. We retrospectively reviewed all patients who received lumbar CBTPS at our institution. Data were collected regarding patient demographics, use of image guidance, operative blood loss, hospital stay, and postoperative complications. A total of 79 patients undergoing CBTPS fusion for degenerative lumbosacral disease with back pain were included in the analysis (42 female, 37 male; October 2011-January 2015). Twenty patients (25.3%) had previous lumbar spine surgery, 39 (49.4%) had a smoking history, and mean body mass index was 28.7. Mean length of stay was 3.5 days, and mean operative blood loss was 306.3 mL. Image guidance was used in 69 (87.3%) cases. A total of 66 (83.5%) fusions were single level, and 54 (68.4%) fusions were single level without previous surgery. There were 9 complications in 7 (8.9%) patients; these included hardware failure, pseudarthrosis, deep vein thrombosis, pulmonary embolism, epidural hematoma, and wound infection. No complications were caused by misplaced screws. Mean follow-up was 13.2 months. As CBTPS becomes increasingly popular among spine surgeons performing lumbar fusion, this report provides an important evaluation of technique safety and acceptable perioperative outcomes.

Hybrid Surgery Combined with Dynamic Stabilization System and Fusion for the Multilevel Degenerative Disease of the Lumbosacral Spine.

As motion-preserving technique has been developed, the concept of hybrid surgery involves simultaneous application of two different kinds of devices, dynamic stabilization system and fusion technique. In the present study, the application of hybrid surgery for lumbosacral degenerative disease involving two-segments and its long-term outcome were investigated. Fifteen patients with hybrid surgery (Hybrid group) and 10 patients with two-segment fusion (Fusion group) were retrospectively compared. Preoperative grade for disc degeneration was not different between the two groups, and the most common operated segment had the most degenerated disc grade in both groups; L4-5 and L5-S1 in the Hybrid group, and L3-4 and L4-5 in Fusion group. Over 48 months of follow-up, lumbar lordosis and range of motion (ROM) at the T12-S1 global segment were preserved in the Hybrid group, and the segmental ROM at the dynamic stabilized segment maintained at final follow-up. The Fusion group had a significantly decreased global ROM and a decreased segmental ROM with larger angles compared to the Hybrid group. Defining a 2-mm decrease in posterior disc height (PDH) as radiologic adjacent segment pathology (ASP), these changes were observed in 6 and 7 patients in the Hybrid and Fusion group, respectively. However, the last PDH at the above adjacent segment had statistically higher value in Hybrid group. Pain score for back and legs was much reduced in both groups. Functional outcome measured by Oswestry disability index (ODI), however, had better improvement in Hybrid group. Hybrid surgery, combined dynamic stabilization system and fusion, can be effective surgical treatment for multilevel degenerative lumbosacral spinal disease, maintaining lumbar motion and delaying disc degeneration.

Hybrid Circumferential Fixation for Degenerative Lumbosacral Spine Disease

Retrospective study on circumferential hybrid instrumentation with posterior lumbar interbody fusion (PLIF) and the novel posterior Universal Clamp (UC) instrumentation. This study evaluated the roentgenographic and clinical outcome after PLIF with PEEK cage augmented with UC posterior sublaminar fixation without posterior fusion. Although UC has been successfully used in scoliosis surgery, to our knowledge, this is the first report on its use in degenerative lumbosacral disease. Rigid pedicle screw lumbosacral fixation is associated with several intraoperative screw-related complications. The use of sublaminar bands and rods combined with PEEK PLIF should increase fusion rate and avoid screw-related complications. From a total of 295 consecutive patients who experienced degenerative lumbosacral disease and received posterior decompression, implantation of PLIF with PEEK cages and semirigid posterior fixation with sublaminar UC bands-rods without posterolateral fusion, 150 patients were eligible for this study with a follow-up of more than 2 years. Interbody fusion rate and global plus segmental sagittal spinal lordosis restoration were recorded pre- and postoperatively. Visual analogue scale and Oswestry Disability Index were used to assess functional outcome. Hybrid instrumentation expanded over 1 to 5 levels. Surgical time ranged from 45 to 225 minutes. Only 12.6% of the patients were transfused. There was no nerve root lesion or deep wound infection. Laminar fracture occurred intraoperatively in one case during band insertion. Interbody fusion was achieved in 94% of the operated segments. Lumbar lordosis improved from -36 ± 9° preoperatively to -53 ± 6° postoperatively. Segmental lordosis improved in L4-L5 segment from -5 ± 3° preoperatively to -12 ± 2° postoperatively and in L5-S1 from -9 ± 4° to -14 ± 2° postoperation. Oswestry Disability Index score improved from 44.9 preoperatively to 2.2 postoperatively (P < 0.001). No patient required further spinal surgery until the final evaluation. UC, a novel semirigid sublaminar posterior instrumentation, combined with wedge-shaped PEEK PLIF corrected both global and segmental sagittal lumbar alignment and achieved fusion rate similar to that historically reported with pedicle screw-PLIF techniques, however, avoiding intraoperative complications associated with the use of pedicle screws.

Management of degenerative lumbosacral disease in cats by dorsal laminectomy and lumbosacral stabilization

In this case series we describe the diagnosis and surgical treatment of five cats affected by clinical cauda equina syndrome as a result of degenerative lumbosacral stenosis. Radiographic and magnetic resonance imaging findings confirmed the suspected diagnosis of disc-associated lumbosacral disease. Cauda equina decompression was achieved by dorsal laminectomy followed by dorsal annulectomy and nuclear extirpation. Dorsal stabilization was achieved using miniature positive-profile pins inserted into the vertebral body of L7 and the wings of S1 with the free ends of the pins being embedded in a bolus of gentamicin-impregnated polymethylmethacrylate. Reassessment two years postoperatively using a previously validated feline specific owner questionnaire indicated satisfactory outcome with complete return to normal activity and resolution of signs of pain in all cases.

A survey of diseases of working farm dogs in New Zealand

AIMS: To record the incidence of specific diseases affecting working farm dogs; identify any apparent breed predispositions; determine the most important causes of loss from death, euthanasia, or retirement of the dog; and identify potential interventions that could reduce the incidence of disease. METHODS: A national questionnaire-based cross-sectional study was conducted to identify the incidence of specific diseases, and circumstances of trauma affecting working farm dogs that presented to rural veterinary practices over a 12-month period, between April 2008 and April 2009. The practices were convenience-sampled on the basis of geography and size. RESULTS: Sixty-six practices were approached, and veterinarians from 30 practices agreed to participate, with representation from all major rural regions of New Zealand. Data were provided on 2,214 presentations, excluding revisits, of which 51% were for Huntaways and 39% Heading dogs. Trauma was identified as a cause of injury in 848 (38%) visits. Huntaways were apparently over-represented in cases of constipation, gastric dilatation-volvulus (GDV), theriogenological problems, laryngitis, hip dysplasia, and degenerative lumbosacral disease. In contrast, Heading dogs were over-represented among cases of multiple ligamentous injury of the stifle, disruption of the gastrocnemius or Achilles tendon, tarsal injuries, and hip luxation. Traumatic injury involved injury by stock (20%), automotive incidents (19%), transit across fence lines (16%), and dog bites (12%). Loss occurred following 10% of visits, of which trauma was known to be involved in 32%. The most important nontraumatic causes of loss were GDV, degenerative joint disease, mammary neoplasia and diseases involving the female reproductive tract, cardiac disease, and poisoning. CLINICAL RELEVANCE: Several important diseases appear amenable to intervention through nutrition, neutering, or behavioural modification, including constipation, GDV, theriogenological problems, dog-bite injuries, and laryngitis. Altering modes of transit across fence lines has the potential to reduce large numbers of serious orthopaedic injuries to working farm dogs.

Clinical and Radiographic Analysis of an Optimized rhBMP-2 Formulation as an Autograft Replacement in Posterolateral Lumbar Spine Arthrodesis

Previous studies have demonstrated the ability of recombinant human bone morphogenetic protein to achieve a solid fusion in anterior lumbar interbody arthrodesis. The purpose of this study was to compare iliac crest bone graft and recombinant human bone morphogenetic protein-2, combined with a carrier consisting of bovine collagen and beta-tricalcium phosphate-hydroxyapatite to create a compression-resistant matrix, for instrumented single-level posterolateral arthrodesis. Four hundred and sixty-three patients with symptomatic single-level lumbosacral degenerative disease with no greater than grade-1 spondylolisthesis were treated with single-level instrumented posterolateral arthrodesis through an open midline approach. Patients were randomly assigned to either the recombinant human bone morphogenetic protein-2 matrix group (239 patients) or the autogenous iliac crest bone-graft group (224 patients). The Oswestry Disability Index, Short Form-36, and back and leg pain scores were determined preoperatively and at 1.5, three, six, twelve, and twenty-four months postoperatively. Radiographs and computed tomography scans were made at six, twelve, and twenty-four months postoperatively to evaluate for fusion. The mean operative time and mean blood loss in the recombinant human bone morphogenetic protein-2 matrix group (2.5 hours and 343.1 mL, respectively) were significantly less than those in the iliac crest bone-graft group (2.9 hours and 448.6 mL). Both groups showed similar improvements in clinical outcomes and reduced pain. At twenty-four months, 60% of the iliac crest bone-graft group reported donor-site pain. At twenty-four months, fusion was evident in 96% of the patients in the recombinant human bone morphogenetic protein-2 matrix group compared with 89% in the iliac crest bone-graft group (p = 0.014). There was a significant difference (p = 0.011) in the rate of failures because of nonunion (eighteen patients with an iliac crest bone graft compared with six patients with the recombinant human bone morphogenetic protein-2 matrix). Also, the number of patients requiring second surgeries was significantly higher in the iliac crest bone-graft group (thirty-six patients) compared with the recombinant human bone morphogenetic protein-2 matrix group (twenty patients) (p = 0.015). The use of recombinant human bone morphogenetic protein-2 in instrumented posterolateral lumbar arthrodesis decreases operative time and blood loss and produces earlier and higher fusion rates than does iliac crest bone graft. Clinical outcomes are similar to those with iliac crest bone graft. Thus, the need for harvesting iliac crest bone is eliminated along with the morbidities associated with the harvest procedure.

A comparison of long-term outcomes of translaminar facet screw fixation and pedicle screw fixation: a prospective study

In this paper, the authors compare the long-term outcomes of translaminar facet screw fixation (TFSF) and pedicle screw fixation (PSF) in the treatment of degenerative lumbosacral disease. This prospective analytical study was performed to compare the long-term outcomes of TFSF and PSF for degenerative lumbosacral disease. Outcomes were defined as the need for reoperation for the development of a nonunion, end-fusion degeneration, or for explantation of hardware. A total of 77 patients were analyzed. Thirty-seven patients underwent PSF and 40 received TFSF. Twenty-three of the 77 patients required a reoperation: 13 (32.5%) of the 40 patients in the TFSF group and 10 (27%) of the 37 the patients in the PSF group. The overall mean time to reoperation (regardless of outcome) was 4.05 years. For patients in the TFSF group the mean time to reoperation was 2.94 years, whereas it was 4.35 years in the PSF group (p = 0.34). Nonunion was noted in seven of the 40 patients in the TFSF group and one of 37 in the PSF group. The mean time to surgery for nonunion for patients in the TFSF group was 3.46 years and for those in the PSF group it was 6.27 years (p = 0.04). Surgery for end-fusion degeneration was performed in two patients in the TFSF group and five in the PSF group (p = 0.43). Explantation of hardware was performed in two patients with TFSF and four patients with PSF. Multivariable analysis revealed a statistically significant difference in the time to surgery for nonunion between PSF and TFSF (p = 0.048), with a hazard ratio of 0.097 (95% confidence interval 0.01-0.98). Findings from the current prospective study suggest that there is an increased risk of requirement for a reoperation for nonunion among TFSF cases compared with PSF cases.

COMPARISON BETWEEN COMPUTED TOMOGRAPHIC AND SURGICAL FINDINGS IN NINE LARGE‐BREED DOGS WITH LUMBOSACRAL STENOSIS

In a three‐year prospective study, computed tomographic (CT) and surgical findings were compared for nine large breed dogs with lumbosacral stenosis. Surgically‐excised tissue was examined histologically in seven dogs and additional necropsy evaluation was performed in one dog. The CT abnormalities observed at sites of confirmed cauda equina compression were: loss of epidural fat, increased soft tissue opacity, bulging of the intervertebral disc margin, spondylosis, thecal sac displacement, narrowed intervertebral foramen, narrowed vertebral canal, thickened articular process, articular process subluxation, articular process osteophyte, and telescoped sacral lamina. The CT characteristics of lumbosacral degenerative disease and discospondylitis were similar to those described in humans. In three dogs, CT findings at the site of cauda equina compression were consistent with congenital or developmental spinal stenosis, but the method of surgical exposure precluded confirmation. Epidural fibrosis (eight dogs) and multi‐level CT abnormalities (six dogs) were identified but the cause(s) and significance were unknown.