Posterior Spinal Fixation Research Articles

Transverse process osteotomy for surgical drainage of primary iliopsoas abscess and secondary cases combined with spondylodiscitis.

It is a prospective study done between 2015 and 2018. The study included 28 patients with confirmed diagnosis of iliopsoas abscess. Laboratory investigations included CBC, ESR, and C-reactive protein that were done for all patients. MRI with contrast enhancement was gold standard for diagnosis. Ten patients underwent surgical psoas abscess drainage by transverse process osteotomy via Wiltse approach without any other spine intervention. Eighteen patients had posterior spine fixation and interbody fusion together with transverse process osteotomy and abscess drainage as treatment for spondylodiscitis. The patients were followed up for clinical improvement, and functional assessment was done by Oswestry disability index. ESR and CRP were used for laboratory follow-up of infection subsidence. Follow-up of abscess size and resolution was done by pelvic-abdominal ultrasonography. The mean maximum width of the abscesses in MRI axial views was 38.8 mm. Patients were divided into two groups. Group (1) included ten patients who underwent drainage only while group (2) included 18 patients who underwent spine fusion for treatment of spondylodiscitis. The amount of pus drained intra-operatively was of average 234 cc in group 1 and 191.6 in group 2. The drain was removed in average 58.6 hours post-operatively in group 1 with mean of 168.4 cc of drained fluid and in average of 74.3 hours for group 2 with mean of 350.5 cc of drained fluid. The ODI and inflammatory markers improved in all patients. The follow-up period was of average 26.7 months. The organism was isolated from 19 patients (5 patients were tuberculous and 14 patients were different pyogenic pathogens). No fluid recollection was observed in pelvic-abdominal ultrasound during follow-up in our series. Transverse process osteotomy is a safe and effective approach for drainage of psoas abscess. It can be done alone or combined with posterior spine fusion for treatment of spondylodiscitis.

Skipping Cross Links in Posterior Spine Surgery: A Review

Background and Aim: Given the conflicting and unreliable evidence for using cross-links in posterior spine surgery, this review was conducted to highlight the different features and usefulness of these augmentation devices in spine surgeries. Methods and Materials/Patients: After searching databases using specific keywords, the relevant articles were ultimately selected and evaluated. Results: Biomechanically investigating the use of cross-links has not resulted in unanimous explanations for their effect. The site and direction of cross-links have been rarely investigated in the literature. Some studies recommended eliminating their application from clinical practice; nevertheless, these studies do not necessarily yield clinical benefits. Posterior spinal fixation with pedicle screws and without cross-links offers stability in all the planes in most clinical conditions. Conclusion: Excluding the cross-links in posterior spine surgery may shorten the operation time and reduce hospital costs. Researchers have reported other problems for cross-links such as late pain, device failure, infections, device prominence, and pseudarthrosis which may be obliterated through the avoidance of their combination in a spinal construct; nevertheless, the results of animal models of the application of special cross-links in a degenerative disorder or deformity suggest that diagonal cross-links provide the highest stability of the construct if they are matched with a rodonly system or with transverse cross-link constructs resulting in a rectangular configuration.

Correction of marked sagittal deformity with circumferential minimally invasive surgery using oblique lateral interbody fusion in adult spinal deformity

BackgroundSpinal surgery performed entirely with minimally invasive surgery is referred to as circumferential MIS (cMIS). However, cMIS still has a limited sagittal correction capability for adult spinal deformity (ASD) with a marked sagittal deformity. We investigated the effectiveness of cMIS using oblique lateral interbody fusion (OLIF) and percutaneous posterior spine fixation in correcting marked sagittal deformity.MethodsThis study retrospectively evaluated 23 patients with ASD with marked sagittal deformity who underwent cMIS using OLIF without osteotomy and were followed-up for at least 24 months (whole group). The whole group was divided into the following two groups according to the type of interbody fusion at L5–S1: the OLIF51 group (n = 13) underwent OLIF at L1–L5 and L5–S1 and the TLIF51 group (n = 10) underwent OLIF at L1–L5 and transforaminal lumbar interbody fusion (TLIF) at L5–S1.ResultsSagittal vertebral axis (SVA; 125.7 vs. 29.5 mm, p < 0.001), lumbar lordosis (LL; 18.2° vs. 51.7°, p < 0.001), and pelvic incidence-LL mismatch (PI-LL, 35.5° vs. 5.3°) significantly improved postoperatively in the whole group. The OLIF51 group showed significantly higher postoperative LL than the TLIF51 group (55.5° vs. 46.9°, p < 0.001). OLIF yielded a significantly greater disc angle at L5–S1 than did TLIF (18.4° vs. 6.9°, p < 0.001). Proximal junctional kyphosis occurred significantly earlier in the OLIF51 group than in the TLIF51 group (8.6 vs. 26.3 months, p < 0.001).ConclusionSuccessful sagittal correction in ASD patients with marked sagittal deformity was achieved with cMIS using OLIF. OLIF at L5–S1 showed a synergistic effect in sagittal deformity correction by cMIS.

Posterior spinal fixation using percutaneous pedicle screw for thracolumbar vertebral body fractures in elderly and younger patients

Posterior spinal fixation using percutaneous pedicle screw for thracolumbar vertebral body fractures in elderly and younger patients

Posterior short segment spinal fixation in unstable fractures of the thoraco lumbar spine: radiological and neurological outcome assessment

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; A major dilemma still exists regarding management of unstable fractures of thoraco lumbar region. A posterior short segment spinal fixation without bone grafting improves spinal alignment, early ambulation and subsequent decrease in complications arising out of prolonged bedrest.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; A total of 30 patients presenting at the Accident and Emergency Department meeting the inclusion criteria were recruited for the study. A complete neurological and radiological assessment was done preoperatively, immediate post operatively and after 6 months using Frenkels grade system and Denis pain scale and Denis work scale respectively.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; A statistically significant difference was observed between the initial kyphosis of the injured vertebra as compared to immediate postoperative period (p&amp;lt;0.0001), Improvement in neurological status was statistically significant at 6 month follow up (Z=4.355, p=0.00). Functional assessment revealed that 47% of the subjects experienced a minimal pain with a mean pain score of 1.9 with a mean functional score of 3.83 at the final follow up.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Our study shows that short segment spinal fixation in unstable fractures of the thoraco lumbar spine provides a comparable neurological and functional outcome and is a reliable management option.&lt;/p&gt;

181. Sequential changes in lumbar lordosis and segmental stability following lateral interbody cage placement, Smith-Peterson Osteotomy, and anterior longitudinal ligament release

BACKGROUND CONTEXT Interbody cage systems can be used in isolation to achieve lumbar lordosis correction, but can also be deployed using techniques to shorten the posterior or lengthen the anterior spinal column to yield even larger corrections. The Thomasen pedicle subtraction osteotomy (PSO) yields ∼30° of correction but with high degree of difficulty and surgical complication rates. A lateral lordotic cage with Smith-Petersen Osteotomy (SPO), a hyper-lordotic lateral cage with anterior longitudinal ligament (ALL) release, or a lateral cage with combined techniques show potential for substantial lordosis correction. The removal or release of local spinal anatomy, however, can increase segmental motion and may inhibit fusion. The objective of this biomechanical cadaver study was to identify the lordosis correction and resulting segmental stability achieved with implantation of lateral lordotic cages of increasing angle coupled with either or both minimally invasive surgical techniques of ALL release and SPO. We hypothesize that a combination of lordotic interbody cage placement, ALL release and SPO will yield more lordosis at a single level than with either of these interventions in isolation, and the biomechanical stability of the construct will be sufficiently rigid to promote fusion. METHODS Cadaveric lumbar spines (n=6) were divided into L1-L2 and L3-L4 segments, potted in plaster with pedicles exposed and randomly distributed to treatment groups (n=6 segments/group) consisting of eight interventions. Native lordosis and range of motion (ROM) were recorded prior to intervention. Within each treatment group, lateral cages of 8°, 20°, and 30° were placed and backed up with posterior spinal fixation, a 1-hole modular fixation plate was added with ALL release, and was replaced by a 2-hole plate at the last intervention. Treatment groups were designed to test procedure order; in Group 1, SPO with an 8° cage preceded ALL release with a 20° cage, and in Group 2, ALL release with a 20° cage preceded SPO with a 30° cage. Sagittal fluoroscopic images for lordosis angle measurement and ROM data were collected after each intervention. 7.5Nm pure moments were applied to segments in flexion-extension (FE), lateral bending (LB), and axial rotation (AR), while optical motion capture recorded ROM. Linear mixed models with repeated measures provided statistical comparisons at α=0.05 within each group for each metric (angle, FE-, LB-, AR-ROM); data reported as percent of native. RESULTS The combination of SPO with ALL release yielded the largest lordotic angle regardless of procedure order (correction angle: 28.5°±7.3°), but also greatest ROM in all planes (FE: 61.5%±48.4%, LB: 42.2%±42.0%, AR: 162.8%±178.3%). A 30° cage provided no additional gain in lordotic angle and increased ROM in FE and AR with ALL release and SPO (FE: 36.8%±27.1%, AR: 144.3%±138.6%). An 8° lordotic cage with SPO achieved the largest angle correction (10.1°±6.8°) while reducing ROM in all planes. Addition of a 2-hole plate does not decrease correction and tends to reduce ROM in all planes compared to the 1-hole plate. CONCLUSIONS Lordosis >15° is possible through minimally invasive techniques of SPO and ALL release and performing a SPO without ALL release yields substantial correction without compromising stability. Performing a SPO after ALL release increases segment ROM in FE, LB, AR, thus a 2-hole plate is recommended to aid in stability with ALL release. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

LLIF as a Less Invasive Adjunct for Deformity Surgery

Adult spinal deformity is a complex spectrum of disorders that commonly results in symptomatic spinal stenosis and decreased quality of life in patients over 60. Correction of severe deformity remains a challenge for even the most experienced surgeons. This challenge is amplified in patients over 60, where traditional open approaches are associated with significant intraoperative blood loss and postoperative complications. Newer, minimally invasive techniques for interbody fusion and posterior spinal fixation have sought to decrease these complications. Lateral lumbar interbody fusion (LLIF) utilizes a lateral, retroperitoneal corridor to access the intervertebral disk spaces of the lumbar spine. This approach allows for placement of large diameter interbody cages and indirect decompression of neural elements without the associated risks of open anterior and posterior approaches. However, LLIF is not without its own unique complications secondary to violation of the psoas muscle during the approach, and anatomical variations in vascular and neural structures make the approach dangerous in some patients. Despite these challenges, LLIF remains a promising adjunct to posterior spinal fixation. This review will focus on the surgical technique, outcomes, and complication rates of LLIF in adult spinal deformity, as well as compare these parameters to alternative techniques including anterior lumbar interbody fusion, posterior lumbar interbody fusion, and stand-alone posterior spinal fixation.

Posterior Thoracolumbar Instrumented Fusion for Burst Fractures: A Meta-analysis.

This was a meta-analysis study. To compare different posterior spine fixation methods for burst fracture fixation. This study was performed to elucidate if the current body of literature supports one posterior spinal fusion fixation method for burst fracture to minimize the rate of implant failure and progression of posttraumatic kyphosis. An extensive electronic search was conducted using PubMed for pertinent articles. The articles were examined against the inclusion and exclusion criteria. Data pertaining to kyphosis angle, Frankel score, vertebral level, blood loss, operation time, hospital stay, postoperative bracing, instrument failure, complications, and follow-up were collected. A random effects model was chosen due to variation among the individual studies' patient populations and surgical methods. A total of 23 publications were eventually deemed eligible according to the criteria and included into this study. The group with 2 levels above and 1 below with intermediate screws had the greatest maintenance of spine kyphosis and lowest implant failure at final follow-up (P<0.001). There was no difference between the periods of hospital stay (P=0.788) and blood loss (P=0.154) among different tiers. A fixation method consisting of 2 levels above and 1 below with intermediate screws for the thoracolumbar burst fractures showed the highest correction of kyphosis angle both at immediate and final follow-up and also the lowest implant failure at final follow-up.

Short-oblique lumbar spine fracture in ankylosing spondylitis patient

Ankylosing spondylitis (AS) is a chronic inflammatory joint disease that mainly causes fusion of the intervertebral discs and facet joints by involving the axial skeleton that typically leads to kyphotic bamboo spine. Demineralization of vertebral bodies in AS raises the risk of spinal fracture even after a simple trauma. During the progression of the disease, the spine becomes more prone to injury, even after minor trauma. Patients with AS have a higher fracture risk during their lifetime by four times compared to the normal population. A 61-year-old male, a known case of AS, came to the emergency room complaining of back pain. His neurological examination was normal, and the images showed transverse/oblique fracture involving L2 vertebral body associated with small retropulsed fragments and bone debris. Posterior spinal fixation and fusion with a bone graft from T10 to S1 was decided to stabilize the fracture. On the 2nd postoperative day, the radiograph showed good alignment and fixation. One-year follow up showed a normal neurological exam with a stable and fused spine. In this case, we present a rare lumbar spine fracture orientation in a patient with AS, with a good outcome with 1-year follow-up. Up to our knowledge, this is the first report to presenting a short-oblique fracture in a patient with AS disease.

Anterior versus posterior instrumentation for treatment of thoracolumbar tuberculosis : Ameta-analysis.

To compare clinical and functional outcomes of anterior versus posterior debridement and spinal fixation for surgical treatment of thoracolumbar tuberculosis. Acomputer-based online search of the Cochrane Library, PubMed, EMBase, Wanfang, VIP, and the CNKI database was performed. The methodological quality of included studies was evaluated, and data analyses were performed using RevMan5.0 software (The Nordic Cochrane Centre, The Cochrane Collaboration Copenhagen, Denmark). Eleven trials were studied, with eight performed in China, two in Egypt, and one in India. The results showed significant differences between the two operative approaches in terms of correction of kyphotic angle and intraoperative blood loss, but not in terms of operation time, hospital stay, fusion time, and loss of correction at the final follow-up. The anterior and posterior approaches are equally good methods for treatment of thoracolumbar tuberculosis. The anterior approach results in less blood loss, whereas posterior instrumentation is better suited for correction of kyphotic angle.

Vacuum-assisted closure combined with a closed suction irrigation system for treating postoperative wound infections following posterior spinal internal fixation

BackgroundWound infections after posterior spinal surgery are a troublesome complication; patients are occasionally forced to remove the internal fixation device, which can lead to instability of the spine and injury to the spinal cord. The purpose of this study was to evaluate the efficacy of modified vacuum-assisted closure (VAC) for treating an early postoperative spinal wound infection.MethodsWe conducted a retrospective study of 18 patients with wound infections after posterior spinal surgery from 2014 to 2017 at a single tertiary center. All patients included in the study received modified VAC treatment (VAC combined with a closed suction irrigation system, CSIS) until the wound satisfied the secondary closure conditions. Detailed information was obtained from the medical records.ResultsWound size decreased significantly after 1 week of the modified VAC treatment. Three patients were treated with VAC three times and one patient received the VAC treatment four times; the remaining patients received the VAC treatment twice. The patients had excellent wound beds after an average of 8 days. The wound healed completely after an average of 17 days, and the average hospital stay was 33 days. There was no recurrence of infection at the 1-year follow-up.ConclusionsThis study demonstrates that VAC combined with a CSIS is a safe, reliable, and effective method to treat a wound infection after spinal surgery. This improved VAC procedure provides an excellent wound bed to facilitate wound healing and shorten the hospital stay.

上位胸椎部の化膿性脊椎炎により両下肢麻痺を生じた症例にHook and rod systemによる後方固定術を施行した2例

上位胸椎部の化膿性脊椎炎により両下肢麻痺を生じた症例にHook and rod systemによる後方固定術を施行した2例

Residual Stresses in Titanium Spinal Rods: Effects of Two Contouring Methods and Material Plastic Properties.

Posterior spinal fixation based on long spinal rods is the clinical gold standard for the treatment of severe deformities. Rods need to be contoured prior to implantation to fit the natural curvature of the spine. The contouring processes is known to introduce residual stresses and strains which affect the static and fatigue mechanical response of the implant, as determined through time- and cost-consuming experimental tests. Finite element (FE) models promise to provide an immediate understanding on residual stresses and strains within a contoured spinal rods and a further insight on their complex distribution. This study aims at investigating two rod contouring strategies, French bender (FB) contouring (clinical gold standard), and uniform contouring, through validated FE models. A careful characterization of the elastoplastic material response of commercial implants is led. Compared to uniform contouring, FB induces highly localized plasticizations in compression under the contouring pin with extensive lateral sections undergoing tensile residual stresses. The sensitivity analysis highlighted that the assumed postyielding properties significantly affect the numerical predictions; therefore, an accurate material characterization is recommended.

Magnetic resonance imaging evaluation of intervertebral disc injuries can predict kyphotic deformity after posterior fixation of unstable thoracolumbar spine injuries.

The aim of the present study is to identify factors correlated with kyphotic deformity after thoracolumbar spine injuries. We performed a retrospective case–control study with data from thoracolumbar spine fracture patients who were treated with posterior spinal fixation. Patients with a follow-up period shorter than 6 months and who experienced low-energy trauma were excluded. Intervertebral disc injuries (IDIs) were graded from 0 to 3 upon admission in accordance with Sander's classification of traumatic intervertebral disc lesions. Vertebral wedge angles (VWAs) and local kyphosis angles (LKAs) were also measured. Patients were allocated to kyphosis and control groups if they had LKA correction losses of ≥10° and <10°, respectively. Forty-eight patients followed over a median period of 25 months were included. The median correction loss at the site of the injured vertebral body was 2.0°. The median LKA correction loss was 9.0°. Twenty-three and 25 patients were allocated to the kyphosis and control groups, respectively. Univariate analysis revealed that the median age was significantly lower in the kyphosis (35 years) than control group (56 years). The level of injury and IDI severity also significantly differed between groups, with a significantly greater proportion of more severe IDI cases in the kyphosis than control group. Finally, significantly more patients in kyphosis group underwent fusion (kyphosis, 19 vs control, 13) and implant removals (kyphosis, 19 vs control, 10). Multiple regression analysis revealed that IDI severity according to Sander's classification (P = .005; odds ratio, 5.263; 95% confidence interval [CI], 1.637–16.927) and implant removal (P = .011; odds ratio, 7.980; 95% CI, 1.603–39.728) were significantly associated with kyphotic deformity. IDI severity at initial magnetic resonance imaging (MRI) evaluation and implant removal are associated with kyphotic deformity after posterior fixation of thoracolumbar spine injuries. Thus, initial MRI evaluation of IDIs could be used to predict of recurrent kyphosis.

Management of postoperative Complications after posterior lumber spinal fixation

Background: For increasing safety and reducing complications that may occur with Trans-Pedicular Scre Placement, different ways have been reported including application of C-arm X-ray view, application of axial computed tomography scan (CTS), frameless stereotactically guided screw placement and different guidance devices. However, the application of all these devices and techniques are not so easy and even in many operating rooms such kinds of instruments are not available. A posterior approach to anterior and middle column reconstruction is often preferred in the lumbar spine for two reasons, the first is that the morbidity associated with an anterior approach is significant and delays recovery, the second is that pedicle screws and rods or plates can be placed before dural retraction and dissection of the intervertebral disk. Aim of the Work: The aim of this work was to evaluate the postoperative Complications. In posterior lumber transpedicular fixation and their management. Patients and Methods: Retrospective and prospective study for evaluating the history, clinical state, laboratory investigations, radiological findings and way of management in 25 cases of postoperative Complications after posterior lumber spinal fixation. Results: 25 patients operated upon for posterior lumbar fixation were included in the present work, In the current work we divided complications of posterior lumbar fixation into intraoperative complications and postoperative complications, Among the 25 patients of our work we had 5 cases of intraoperative complications (20 %) and 20 cases of postoperative complications (80%), Dural tear was the most common intraoperative complications (8%), instrument failure was the most common postoperative complications 12 cases (48%). Conclusion: According to medical history smoking was statistically significant risk factor for intraoperative complications; significant epidural bleeding and dural tear. Hypertension was statistically significant risk factor for intraoperative complications; inappropriate screw insertion and fracture pedicle. Also, smoking was Statistically significant risk factor for development of postoperative complications; infection, C.S.F leak, infection, nerve root injury and pseudoarthrosis.

Analysis of delayed infection of proximal junctional zone after posterior spinal internal fixation and its treatment strategy

To explore the features and treatment strategy of delayed infection of proximal junctional zone after posterior spinal internal fixation. The clinical data of 1325 patients underwent posterior spinal internal fixation were retrospectively analyzed. Delayed infection occurred in 10 patients, among which 4 infections occurred at the proximal junction (non-operative site). And these 4 patients were treated with combined broad-spectrum antibiotics. Their clinical symptoms and signs, lab tests, MRI findings, pathology findings, and clinical effects were analyzed. All four patients were followed up from 6 months to 4 years. No infection recurrence was found. All patients obtained satisfactory results after hospital discharge. No nerve injury was found. One patient developed kyphosis in the proximal junctional zone 2 years after the operation. According to the criteria of N.Nakano and T.Nakano, 3 cases obtained excellent results, while 1 poor. The incidence rate of delayed infections was rare after spinal operation. Delayed infections occurred in proximal junctional zone may be attributed to the stress concentration of adjacent segments after fixation and the degeneration of adjacent segments, thus forming inflammation areas. For refractory lumbar and back pains, an elevated blood sedimentation rate, C-reactive protein level, MRI manifestation and focal pathology would be helpful for establishing a definite diagnosis. Full course of combined broad-spectrum antibiotics in treating the infection can lead to satisfactory clinical results.

Postoperative deep wound infection in posterior spinal fixation surgeries: Does it affect the clinicoradiological outcome? - At a minimum follow-up of 2 years

Background: Incidence of postoperative deep wound infection (PODWI) after lumbar surgery varies from 2.1% to 6.7%.Studies looking into the effect of postoperative infection on functional recovery of the patient have thrown conflicting results. The aim of this study is to evaluate 2-year functional and radiological outcome of patients with PODWI. This was a retrospective, matched cohort study. Materials and Methods: A total of 23 patients developing acute PODWI (

Comparative Analysis of Changes in the Desmal and Chondral Structures of Spinal Motion Segment at Various Methods for Posterior Spine Fixation in Experiment

Purpose:to elaborate the criteria for the assessment of the degree of spinal motion segment degradation at various methods for posterior spine fixation in experiment.Material and methods. The study included mongrel dogs with body mass of 12±1.5 kg aged 21±3 months. Transpedicular lumbar spine fixation was performed with either rigid titanium alloy rods (1st group, n=5) or dynamic nitinol rods (2nd group, n=5). X-ray examination and morphologic study of the structural elements of spinal motion segment (SME) were performed to all animals in 3, 6, 12, 18 and 24 months after surgery.Results. Functional examination showed that in both groups the range of motion made up 18±1.2° preoperatively. In the 1st group of animals the range of motion in the operated SME made up 0±0.03°. In the second group the range of motion was preserved throughout the experiment and averaged 15±1.3° that made up 78.9% of the preoperative range. In both groups the disc height at the fixation level was constant throughout the experiment and made up 0,3±0.003 cm pre- and postoperatively. Obtained roentgenologic and morphologic data indicated that posterior dynamic spine fixation with nitinol rods ensured more balanced distribution of loads on the supportive elements of the construction and enabled prevent the development of the adjacent segments degeneration. Based on the study results the criteria for the assessment of the degree of the facet joints and discs degradation were formulated.

Comparative analysis of changes in the desmal and chondral structures of spinal motion segment at various methods for posterior spine fixation in experiment

Purpose: to elaborate the criteria for the assessment of the degree of spinal motion segment degradation at various methods for posterior spine fixation in experiment. Material and methods. The study included mongrel dogs with body mass of 12±1.5 kg aged 21±3 months. Transpedicular lumbar spine fixation was performed with either rigid titanium alloy rods (1st group, n=5) or dynamic nitinol rods (2nd group, n=5). X-ray examination and morphologic study of the structural elements of spinal motion segment (SME) were performed to all animals in 3, 6, 12, 18 and 24 months after surgery. Results. Functional examination showed that in both groups the range of motion made up 18±1.2° preoperatively. In the 1st group of animals the range of motion in the operated SME made up 0±0.03°. In the second group the range of motion was preserved throughout the experiment and averaged 15±1.3° that made up 78.9% of the preoperative range. In both groups the disc height at the fixation level was constant throughout the experiment and made up 0,3±0.003 cm pre- and postoperatively. Obtained roentgenologic and morphologic data indicated that posterior dynamic spine fixation with nitinol rods ensured more balanced distribution of loads on the supportive elements of the construction and enabled prevent the development of the adjacent segments degeneration. Based on the study results the criteria for the assessment of the degree of the facet joints and discs degradation were formulated.

Preliminary results of anterior lumbar interbody fusion, anterior column realignment for the treatment of sagittal malalignment

OBJECTIVE Sagittal malalignment decreases patients' quality of life and may require surgical correction to achieve realignment goals. High-risk posterior-based osteotomy techniques are the current standard treatment for addressing sagittal malalignment. More recently, anterior lumbar interbody fusion, anterior column realignment (ALIF ACR) has been introduced as an alternative for correction of sagittal deformity. The objective of this paper was to report clinical and radiographic results for patients treated using the ALIF-ACR technique. METHODS A retrospective study of 39 patients treated with ALIF ACR was performed. Patient demographics, operative details, radiographic parameters, neurological assessments, outcome measures, and preoperative, postoperative, and mean 1-year follow-up complications were studied. RESULTS The patient population comprised 39 patients (27 females and 12 males) with a mean follow-up of 13.3 ± 4.7 months, mean age of 66.1 ± 11.6 years, and mean body mass index of 27.3 ± 6.2 kg/m2. The mean number of ALIF levels treated was 1.5 ± 0.5. Thirty-three (84.6%) of 39 patients underwent posterior spinal fixation and 33 (84.6%) of 39 underwent posterior column osteotomy, of which 20 (60.6%) of 33 procedures were performed at the level of the ALIF ACR. Pelvic tilt, sacral slope, and pelvic incidence were not statistically significantly different between the preoperative and postoperative periods and between the preoperative and 1-year follow-up periods (except for PT between the preoperative and 1-year follow-up, p = 0.018). Sagittal vertical axis, T-1 spinopelvic inclination, lumbar lordosis, pelvic incidence-lumbar lordosis mismatch, intradiscal angle, and motion segment angle all improved from the preoperative to postoperative period and the preoperative to 1-year follow-up (p < 0.05). The changes in motion segment angle and intradiscal angle achieved in the ALIF-ACR group without osteotomy compared with the ALIF-ACR group with osteotomy at the level of ACR were not statistically significant. Total visual analog score, Oswestry Disability Index, and Scoliosis Research Society-22 scores all improved from preoperative to postoperative and preoperative to 1-year follow-up. Fourteen patients (35.9%) experienced 26 complications (15 major and 11 minor). Eleven patients required reoperation. The most common complication was proximal junctional kyphosis (6/26 complications, 23%) followed by vertebral body/endplate fracture (3/26, 12%). CONCLUSIONS This study showed satisfactory radiographic and clinical outcomes at the 1-year follow-up. Proximal junctional kyphosis was the most common complication followed by fracture, complications that are commonly associated with sagittal realignment surgery and may not be mitigated by the anterior approach.