RESUMEN

BACKGROUND: Although short-segment posterior spinal fixation (SSPSF) has shown promising clinical outcomes in thoracolumbar burst fractures, the treatment may be prone to a relatively high failure rate. This study aimed to assess the effectiveness of machine learning models (MLMs) in predicting factors associated with treatment failure in thoracolumbar burst fractures treated with SSPSF. METHODS: A retrospective review of 332 consecutive patients with traumatic thoracolumbar burst fractures who underwent SSPSF at our institution between May 2016 and May 2023 was conducted. Patients were categorized into two groups based on treatment outcome (failure or non-failure). Potential risk factors for treatment failure were compared between the groups. Four MLMs, including random forest (RF), logistic regression (LR), support vector machine (SVM), and k-nearest neighborhood (k-NN), were employed to predict treatment failure. Additionally, LR and RF models were used to assess factors associated with treatment failure. RESULTS: Of the 332 included patients, 61.4% were male (n = 204), and treatment failure was observed in 44 patients (13.3%). Logistic regression analysis identified Load Sharing Classification (LSC) score, lack of index level instrumentation, and interpedicular distance (IPD) as factors associated with treatment failure (P < 0.05). All models demonstrated satisfactory performance. RF exhibited the highest accuracy in predicting treatment failure (accuracy = 0.948), followed by SVM (0.933), k-NN (0.927), and LR (0.917). Moreover, the RF model outperformed other models in terms of sensitivity and specificity (sensitivity = 0.863, specificity = 0.959). The area under the curve (AUC) for RF, LR, SVM, and k-NN was 0.911, 0.823, 0.844, and 0.877, respectively. CONCLUSIONS: This study demonstrated the utility of machine learning models in predicting treatment failure in thoracolumbar burst fractures treated with SSPSF. The findings support the potential of MLMs to predict treatment failure in this patient population, offering valuable prognostic information for early intervention and cost savings.

Asunto(s)

RESUMEN

PURPOSE: To compare the clinical efficacy of percutaneous functional spinal unit cementoplasty (PFSUP) and posterior spinal fixation combined with vertebroplasty (PSF + VP) for the treatment of symptomatic chronic osteoporotic vertebral fractures (SCOVFs). METHOD: Thirty-one patients with SCOVFs were included in this retrospective study and divided into PFSUP (n = 14) and PSF + VP (n = 17) groups. Visual analog scores (VAS) and Oswestry Disability Index (ODI) were recorded before and after surgery and at the last follow-up. Besides, the local kyphosis angle (LKA) and sagittal vertical axis (SVA) were measured. The operation duration, number of X-ray exposures, amount of blood loss, bed rest duration, hospitalization duration, and presence of complications were recorded. RESULT: The VAS, ODI, LKA, and SVA after surgery and at the last follow-up were significantly improved in both groups compared to preoperative measurements. The PFSUP group experienced shorter operation duration (78.2 ± 13.1 vs. 124.7 ± 14.7, p < 0.001), less blood loss (31.1 ± 8.1 vs. 334.7 ± 70.9, p < 0.001), more X-ray exposures (92.1 ± 14.3 vs. 29.4 ± 5.5, p < 0.001), shorter bed rest duration (12.4 ± 3.8 vs. 43.4 ± 10.0, p < 0.001), shorter hospitalization (6.6 ± 2.4 vs. 10.9 ± 2.7, p < 0.001), lower complication rate (28.5% vs. 64.7%, p < 0.05), and higher cement leakage rate (42.9% vs. 5.8%, p < 0.05) than the PSF + VP group. CONCLUSION: During the treatment of SCOVFs, the combination of PFSUP and PSF + VP can restore spinal stability, improve kyphosis, and relieve pain. PFSUP can reduce blood loss and complications, early mobilization, and shorten the hospital stay, but it is associated with a higher cement leakage rate and more radiation exposure.

Asunto(s)

RESUMEN

BACKGROUND: The treatment of thoracolumbar burst fractures continues to pose challenges. Although short-segment posterior spinal fixation (SSPSF) has shown satisfactory clinical outcomes, it is accompanied by a relatively high rate of treatment failure. This study aimed to assess factors associated with treatment failure in thoracolumbar burst fractures treated with SSPSF. METHODS: The clinical data of 241 consecutive patients with a traumatic thoracolumbar burst fracture who underwent SSPSF at our center between Apr 2016 and Apr 2021 were retrospectively reviewed. Patients were divided into two groups (failure of the treatment group and non-failure of the treatment group). We compared potential risk factors for the failure of treatment including age, gender, body mass index, smoking, diabetes, vertebral body compression rate, use of crosslinks, percentage of anterior height compression, presence of index level instrumentation, Cobb angle, interpedicular distance (IPD), canal compromise, Load Sharing Classification (LSC) score, use of posterolateral fusion, and pain intensity between the two groups. RESULTS: A sum of 137 (56.8%) males and 104 (43.2%) females were enrolled where the mean age and follow-up of the participants were 48.34 ± 10.23 years and 18.67 ± 5.23 months, respectively. Treatment failure was observed in 34 cases (14.1%). The results of the binary logistic regression analysis revealed that the lack of index level instrumentation (OR 2.21; 95% CI 1.78-3.04; P = 0.014), LSC score (odds ratio [OR] 2.64; 95% confidence interval [95% CI], 1.34-3.77; P = 0.007), and IPD (OR 1.77; 95% CI 1.51-2.67; P = 0.023) were independently associated with a higher rate of failure of treatment. CONCLUSIONS: The findings of this study revealed that increased rates of treatment failure in thoracolumbar burst fractures treated with SSPSF were associated with factors such as the absence of index level instrumentation, higher LSC scores, and larger IPD. These findings could be helpful in the proper management of patients with unstable thoracolumbar burst fractures.

Asunto(s)

RESUMEN

INTRODUCTION: This is a retrospective study of consecutive patients undergoing transforaminal lumbar interbody fusion (TLIF) at a single institution. The objective of this study was to compare the long-term results associated with cortical bone trajectory (CBT) and traditional pedicle screw (TPS) via posterolateral approach in TLIF. METHODS: Consecutive patients treated from November 2014 to March 2019 were included in the CBT TLIF group, while consecutive patients treated from October 2010 to August 2017 were included in the TPS TLIF group. Inclusion criteria comprised single-level or two-level TLIF for degenerative spondylolisthesis with stenosis and at least one year of clinical and radiographic follow-up. Variables of interest included pertinent preoperative, perioperative, and postoperative data. Non-parametric evaluation was performed using the Wilcoxon test. Fisher's exact test was used to assess group differences for nominal data. RESULTS: Overall, 140 patients met the inclusion criteria; 69 patients had CBT instrumentation (mean follow-up 526 days) and 71 patients underwent instrumentation placement via TPS (mean follow-up 825 days). Examination of perioperative and postoperative outcomes demonstrate comparable results between the groups with perioperative complications, length of stay, discharge destination, surgical revision rate, and fusion rates all being similar between groups (p = 0.1; p = 0.53; p = 0.091; p = 0.61; p = 0.665, respectively). CONCLUSIONS: CBT in the setting of TLIF offer equivalent outcomes to TPS with TLIF at both short- and long-term intervals of care.

RESUMEN

Background: Modular pedicle screws have a separate head that can be intraoperatively assembled to the inserted shank. The aim of this study was to report associated intra- and post-operative complications and reoperation rates of posterior spinal fixations with modular pedicle screws at a single center. Methods: A retrospective, institutional chart review was performed on 285 patients who underwent posterior thoracolumbar spinal fusion with modular pedicle screw fixation between January 1, 2017, and December 31, 2019. The primary outcome was failure of the modular screw component. Other measures recorded were length of follow-up, other complications, and need for additional procedures. Results: There were 1,872 modular pedicle screws (average 6.6 per case). There were no (0.0%) screw head dissociations at the rod screw junction. There was 20.8% overall complication rate (59/285) with 25 reoperations: 6 due to non-union and rod breakage, 5 for screw loosening, 7 for adjacent segment disease, 1 for acute postoperative radiculopathy, 1 for epidural hematoma, 2 for deep surgical-site infections, and 3 for superficial surgical-site infections. Other complications included superficial wound dehiscence [8], dural tears [6], non-unions not requiring reoperation [2], lumbar radiculopathies [3], and perioperative medical complications [5]. Conclusions: This study demonstrates that modular pedicle screw fixation has reoperation rates similar to those previously reported for standard pedicle screws. There was no failure at the screw-head junction, and no increases in other complications. Modular pedicle screws present an excellent option to allow surgeons to place pedicle screws without the risk of extra complications.

RESUMEN

The present study used triggered electromyographic (EMG) testing as a tool to determine the safety of pedicle screw placement. In this Institutional Review Board exempt review, data from 151 consecutive patients (100 robotic; 51 non-robotic) who had undergone instrumented spinal fusion surgery of the thoracic, lumbar, or sacral regions were analyzed. The sizes of implanted pedicle screws and EMG threshold data were compared between screws that were placed immediately before and after adoption of the robotic technique. The robotic group had significantly larger screws inserted that were wider (7 ± 0.7 vs 6.5 ± 0.3 mm; p < 0.001) and longer (47.8 ± 6.4 vs 45.7 ± 4.3 mm; p < 0.001). The robotic group also had significantly higher stimulation thresholds (34.0 ± 11.9 vs 30.2 ± 9.8 mA; p = 0.002) of the inserted screws. The robotic group stayed in the hospital postoperatively for fewer days (2.3 ± 1.2 vs 2.9 ± 2 days; p = 0.04), but had longer surgery times (174 ± 37.8 vs 146 ± 41.5 min; p < 0.001). This study demonstrated that the use of navigated, robot-assisted surgery allowed for placement of larger pedicle screws without compromising safety, as determined by pedicle screw stimulation thresholds. Future studies should investigate whether these effects become even stronger in a later cohort after surgeons have more experience with the robotic technique. It should also be evaluated whether the larger screw sizes allowed by the robotic technology actually translate into improved long-term clinical outcomes.

Asunto(s)

RESUMEN

Background: A downward penetrating endplate screw (PES) technique combined with caudal anchor screws inserted in the upward direction under O-arm navigation (i.e., crossing screw technique) avoided screw backout and proximal junctional kyphosis (PJK) in three patients with osteoporotic vertebral body fractures and diffuse idiopathic skeletal hyperostosis (DISH). Methods: The PES techniques were utilized for patients with T12 (one patient) and L1 (two patients) spontaneous fusion across the targeted vertebrae, with minimal damage to the involved endplates/intervertebral discs. The average number of instrumented vertebrae was 5.3. Results: There were no perioperative complications over the mean follow-up period of 28.7 months; no screw loosening, and no PJK. Conclusion: The PES technique prevented screw backout, and PJK in three patients with lumbar osteoporotic vertebral fractures and DISH.

RESUMEN

Background: The thoracolumbar junction (TLJ) represents a transition zone of the spine that leads to a high incidence of fractures. The treatment of burst fractures remains controversial regarding the ideal management. This study assessed the postoperative radiological outcome of TLJ fixation in patients with TLJ injuries who underwent surgery. Methods: All traumatic patients with TLJ injuries who were referred to the Khatam hospital of Zahedan between 2015 and 2020, with their thoracolumbar injury classification and severity score (TLICS) of four or more and who underwent surgery, were included in this study. The patients who entered the study were called for a follow-up examination. The degree of kyphosis, proximal junctional kyphosis, and fusion were assessed in these patients. Results: Among 273 patients, the average age was 43.5 ± 12.3 (21-73) years. One hundred and ninety-eight patients (72.5%) had no neurological symptoms at admission. Based on the above criteria, the kyphosis angle of these patients was calculated before surgery, which in 46 patients (16.8%), the kyphosis angle was more than 25°. Preoperation kyphosis was significantly associated with follow-up kyphosis (P < 0.001). Evidence of no fusion was also observed in 22 patients (8.1%). According to the Chi-square test, no association was observed between preoperative kyphosis and postoperative complications, including PJK and fusion (P > 0.05). Conclusion: According to our study, the posterior spinal fixation procedure is a low-complication method with an acceptable radiological outcome. Although kyphosis before surgery is a factor in developing long-term kyphosis, it is not associated with nonfusion and PJK.

RESUMEN

Horner's syndrome following posterior spinal instrumentation for scoliosis has been rarely reported. We describe the case of a 15-year-old male who presented with right-sided ptosis, miosis, and anhidrosis after scoliosis correction. This is the first reported case of first-order Horner's syndrome developing after scoliosis repair via posterior fixation in a patient known to have asymptomatic syringomyelia. The impression was that Horner's syndrome developed secondary to increased traction of the syringomyelia after scoliosis repair. This is significant as a diagnosis of Horner's syndrome can be distressing to patients and chronic cases cause cosmetic defects that might require surgical correction. We suggest that similar patients should be warned pre-operatively given the psychological distress associated with chronic Horner's syndrome. This case also illustrates the importance of an appropriate workup to rule out other sinister pathologies that can cause Horner's syndrome.

RESUMEN

Thoracolumbosacral pedicle screw systems (TPSSs) are spinal implants commonly utilized to stabilize the spine as an adjunct to fusion for a variety of spinal pathologies. These systems consist of components including pedicle screws, rods, hooks, and various connectors that allow the surgeon to create constructs that can be affixed to a wide range of spinal anatomy. During the development and regulatory clearance process, TPSSs are subjected to mechanical testing such as static and dynamic compression bending per ASTM F1717, axial and torsional grip testing per ASTM F1798, and foam block pullout testing per ASTM F543. In this study, design and mechanical testing data were collected from 200 premarket notification (510(k)) submissions for TPSSs submitted to FDA between 2007 and 2018. Data were aggregated for the most commonly performed mechanical tests, and analyses were conducted to assess differences in performance based on factors such as component type, dimensions, and materials of construction. Rod material had a significant impact on construct stiffness in static compression bending testing with cobalt chromium rods being significantly stiffer than titanium rods of the same diameter. Pedicle screw type had an impact on compression bending yield strength with monoaxial screws having significantly higher yield strength as compared to polyaxial or uniplanar screws. Axial and torsional gripping capacities between components and the rods were significantly lower for cross-connectors than the other component types. The aggregated data presented here can be utilized for comparative purposes to aid in the development of future TPSSs.

Asunto(s)

RESUMEN

BACKGROUND: Incidental durotomy is a well-known complication of spinal surgery. It can lead to persistent cerebrospinal fluid leakage resulting in significant secondary complications. Here, we present a case in which the cauda equina herniated into a pseudomeningocele that penetrated a facet joint, leading to lower extremity radiculopathy warranting surgical correction. CASE DESCRIPTION: One year ago, a 67-year-old male underwent a partial left L4-L5 laminectomy. At surgery, a durotomy was repaired with a nylon suture and reinforced with a fat patch. He subsequently presented with severe left lower extremity radiculopathy and a partial cauda equina syndrome. On MR, the cauda equina had herniated into a pseudomeningocele that penetrated the left facet joint. Once the defect was repaired at surgery, the patient's symptoms improved. CONCLUSION: It is critical to correctly repair an intraoperative durotomy to avoid further neurological deficits that may include cauda equina herniation into pseudomeningoceles penetrating facet joints.

RESUMEN

OBJECTIVE: Spondylodiscitis and vertebral osteomyelitis cause significant morbidity and mortality, and typically occur in patients with multiple comorbidities. The use of minimally invasive spinal surgery in the previous decade has offered the advantages of reduced intraoperative blood loss and postoperative pain for patients. In the present report, we have described our experience with using a hybrid minimally invasive (HMI) technique (combining percutaneous fixation with a mini-open approach for decompression and debridement) for the treatment of thoracolumbar spondylodiscitis, reporting the patient demographics, intraoperative measures, and 12-month outcomes. METHODS: The data from patients presenting to a tertiary referral neurosurgical center with thoracolumbar spondylodiscitis and osteomyelitis who had undergone HMI from 2016 to 2018 were retrospectively evaluated. Patient demographics, intraoperative factors, estimated blood loss, and immediate postoperative complications were recorded. The patient outcomes were evaluated using EuroQOL 5-dimension questionnaire and visual analog scale in the immediate postoperative period and at 12 months postoperatively. RESULTS: A total of 13 patients were included in the present study, 12 with spontaneous infection and 1 with infection secondary to recent microdiscectomy at another institution. All the patients had systemic comorbidities with an American Society of Anesthesiologists class of ≥2. Of the 13 patients, 11 had pyogenic infections and 2 had spinal tuberculosis. The mean estimated blood loss was 546.2 mL. The mean time for patients to sit out of bed was 2.2 days, and the mean time to start mobilizing was 4.5 days. The EuroQOL 5-dimension questionnaire scores showed improvement in all modalities at 12 months postoperatively. CONCLUSIONS: In our cohort, HMI was a safe and effective treatment of thoracolumbar spondylodiscitis, with the potential benefits of reduced blood loss, operative duration, and postoperative pain.

Asunto(s)

RESUMEN

BACKGROUND: Due to its rarity, surgical treatments for a complete fifth lumbar osteoporotic vertebral burst fracture (L5 OVBF) have yet to be well documented as compared to that for osteoporotic vertebral fractures of the thoracolumbar spine. The current case report discusses details of the surgical outcomes following posterior decompression and fusion for a complete L5 OVBF. CASE DESCRIPTION: Three women, ranging in age from 69 years to 82 years, were surgically treated for a complete L5 OVBF. Two of these patients were being treated for rheumatoid arthritis. Surgery was performed using the L5 shortening osteotomy or vertebroplasty, with one- or two-level posterior lumbar interbody fusion, and posterior spinal fixation for the L2 or L3 to the pelvis. Although the spinal alignment parameters, which included lumbar lordosis (LL), pelvic incidence-lumbar lordosis, T1 pelvic angle, and sagittal vertical axis, were better as compared to that observed before the surgery, these worsened at the final follow-up due to clinical fractures that occurred at the adjacent vertebral body and proximal junctional kyphosis. Compared to preoperative Japanese Orthopaedic Association (JOA) scores, postoperative JOA scores were improved and maintained at the final follow-up. CONCLUSION: Posterior surgery of a complete L5 OVBF led to improvement of both the JOA score and spinal alignment after the surgery. Despite a worsening of the spinal alignment parameters, the JOA score was maintained at the final follow-up.

RESUMEN

Coronal imbalance is a type of spinal deformity with deviation from midline in the coronal plane. It is challenging to correct even in the hands of experienced spine surgeons. Many conventional techniques lead to unsuccessful results or complications. However, the incorporation of "kickstand rod" (KR) instrumentation is now understood to provide a more supported coronal correction and improve spinal deformities. Sometimes it can be used to provide additional spinal support in instances where spinal fusion has already occurred. The KR is placed from a posterior approach along the lateral spine from lumbar spine to ilium and exerts distraction forces that counteract misaligned spinal segments. Our objective is to present a clinical case example with a brief review of literature. Herein, we present a case of a 62-year-old male with the development of significant coronal imbalance following his posterior lumbosacral instrumentation and fusion 11 years prior to presentation. KR supplementation to his hardware improved his functional outcome significantly. Further, we provide a literature review of the surgical characteristics, indications, and functional outcomes of KR instrumentation. A term search of "kickstand rod" was performed in PubMed, and relevant English language publications were included. The literature search yielded only six publications. A total of 45 patients across three studies were assessed. A mean postoperative coronal balance magnitude of 26.83 mm was calculated compared to the preoperative coronal magnitude of 64.16 mm. Results also showed only four cases of intraoperative or postoperative complications. Moreover, the presented case reported successful KR implementation without any intraoperative complications. KR instrumentation is a safe and effective technique for coronal imbalance correction. The results show favorable outcomes in terms of coronal adjustment and low complication rates. Nevertheless, we caution the fact that further studies are warranted with long-term follow-ups.

RESUMEN

STUDY DESIGN: A retrospective study of consecutive surgically managed cases of cervical spinal fractures and diffuse idiopathic skeletal hyperostosis (DISH) at our hospital from October 2006 to April 2016. SUMMARY OF BACKGROUND DATA: Prognostic factors have not been determined for cervical fractures in DISH. OBJECTIVES: To assess demographics, surgical techniques, and complications in cervical spinal cord injury with DISH and to evaluate factors affecting neurological prognosis. METHODS: Patients' medical records and radiographs were reviewed and analyzed for demographics, injury characteristics, surgical outcomes, perioperative complications, additional surgeries, and neurological prognosis. Neurological status was assessed by the American Spinal Injury Association (ASIA) grade at admission and discharge. RESULTS: Of 38 patients (mean age 71.9 ± 8.8), 20 had type 1 fractures (through the disc space), 8 had type 2 (through the vertebral body), and 10 had type 3 (through disc and vertebral body). ASIA grades at admission included 14 ASIA-A, 4 ASIA-B, 7 ASIA-C, 8 ASIA-D, and 5 ASIA-E. All patients underwent posterior fusion with an average of 4.5 ± 2.5 instrumented vertebrae (range, 2-7) and six patients required secondary halo-vest fixation. Of 14 ASIA-A patients, 12 developed serious postsurgical pulmonary complications and 4 of these died within 6 months of surgery. Of the 38 patients, 13 improved more than one grade after treatment, 24 did not improve, and 1 deteriorated. In the 18 ASIA-A/B cases (complete motor paralysis), neither fracture type nor injury mechanism (e.g. a ground-level fall or high-energy trauma) correlated with neurological prognosis, but a time of 8 h or less from injury to surgery correlated significantly with an improvement from ASIA A/B to C/D ( p < 0.01, Pearson's χ2 test). CONCLUSION: Patients with complete motor paralysis after a cervical fracture with DISH may recover to partial paralysis if surgically treated within 8 h of injury.

Asunto(s)

RESUMEN

Objective To analyze the biomechanical characteristics of 3 different posterior internal fixation methods for treating thoracolumbar burst fracture by three-dimensional finite element (FE) method. Methods The FE fixation models of normal thoracolumbar, short-segment posterior fixation (SSPF), short-segment posterior fixation with intermediate screws at fractured level (SSPFI) and long-segment posterior fixation (LSPF) were established, respectively. The biomechanical characteristics of L1 centrum and the adjacent intervertebral disc under 6 kinds of motion states (spinal flexion, extension, lateral bending and axial rotation), in normal thoracolumbar model and 3 fixation models were compared by FE analysis. Results L1 centrum equivalent stress distributions in normal thoracolumbar model, SSPF model, SSPFI model, LSPF model were 31.63, 13.41, 110.35, 13.17 MPa, respectively. The maximum equivalent stress of adjacent intervertebral disc in normal thoracolumbar model was 3.84 MPa, which was located in L1-2 intervertebral disc; the maximum equivalent stress of adjacent intervertebral disc in 3 fixation models was 0.41, 0.36, 0.40 MPa, respectively, which was all located in T12-L1 intervertebral disc. Conclusions Fixation in short segment of the fractured vertebrae could lead to an increase of stress in the centrum. The stress of the adjacent intervertebral disc in 3 fixation models was smaller than that in normal spinal model.

RESUMEN

In spine surgery, pedicle screw instrumentation is being used very commonly. However, putting pedicle screws in the right place and direction needs the use of image intensifier in 2 orthogonal planes. This consumes valuable time while moving the image intensifier and operating table multiple times during the surgery and also excess radiation exposure. Here, we present a simple technique to apply surgical pearl to angulate the pedicle screws in cephalocaudal direction using simple instrument available on table. This may help in reducing the usage of image intensifier and expedite the procedure.

RESUMEN

OBJECTIVE Surgical treatment of adult spinal deformity (ASD) is an effective endeavor that can be accomplished using a variety of surgical strategies. Here, the authors assess and compare radiographic data, complications, and health-related quality-of-life (HRQoL) outcome scores among patients with ASD who underwent a posterior spinal fixation (PSF)-only approach, a posterior approach combined with lateral lumbar interbody fusion (LLIF+PSF), or a posterior approach combined with anterior lumbar interbody fusion (ALIF+PSF). METHODS The medical records of consecutive adults who underwent thoracolumbar fusion for ASD between 2003 and 2013 at a single institution were reviewed. Included were patients who underwent instrumentation from the pelvis to L-1 or above, had a sagittal vertical axis (SVA) of < 10 cm, and underwent a minimum of 2 years' follow-up. Those who underwent a 3-column osteotomy were excluded. Three groups of patients were compared on the basis of the procedure performed, LLIF+PSF, ALIF+PSF, and PSF only. Perioperative spinal deformity parameters, complications, and HRQoL outcome scores (Oswestry Disability Index [ODI], Scoliosis Research Society 22-question Questionnaire [SRS-22], 36-Item Short Form Health Survey [SF-36], visual analog scale [VAS] for back/leg pain) from each group were assessed and compared with each other using ANOVA. The minimal clinically important differences used were -1.2 (VAS back pain), -1.6 (VAS leg pain), -15 (ODI), 0.587/0.375/0.8/0.42 (SRS-22 pain/function/self-image/mental health), and 5.2 (SF-36, physical component summary). RESULTS A total of 221 patients (58 LLIF, 91 ALIF, 72 PSF only) met the inclusion criteria. Average deformities consisted of a SVA of < 10 cm, a pelvic incidence-lumbar lordosis (LL) mismatch of > 10°, a pelvic tilt of > 20°, a lumbar Cobb angle of > 20°, and a thoracic Cobb angle of > 15°. Preoperative SVA, LL, pelvic incidence-LL mismatch, and lumbar and thoracic Cobb angles were similar among the groups. Patients in the PSF-only group had more comorbidities, those in the ALIF+PSF group were, on average, younger and had a lower body mass index than those in the LLIF+PSF group, and patients in the LLIF+PSF group had a significantly higher mean number of interbody fusion levels than those in the ALIF+PSF and PSF-only groups. At final follow-up, all radiographic parameters and the mean numbers of complications were similar among the groups. Patients in the LLIF+PSF group had proximal junctional kyphosis that required revision surgery significantly less often and fewer proximal junctional fractures and vertebral slips. All preoperative HRQoL scores were similar among the groups. After surgery, the LLIF+PSF group had a significantly lower ODI score, higher SRS-22 self-image/total scores, and greater achievement of the minimal clinically important difference for the SRS-22 pain score. CONCLUSIONS Satisfactory radiographic outcomes can be achieved similarly and adequately with these 3 surgical approaches for patients with ASD with mild to moderate sagittal deformity. Compared with patients treated with an ALIF+PSF or PSF-only surgical strategy, patients who underwent LLIF+PSF had lower rates of proximal junctional kyphosis and mechanical failure at the upper instrumented vertebra and less back pain, less disability, and better SRS-22 scores.

Asunto(s)

RESUMEN

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: As CBTPS becomes increasingly popular among spine surgeons performing lumbar fusion, this report provides an important evaluation of technique safety and acceptable perioperative outcomes.

Asunto(s)

RESUMEN

INTRODUCTION: Conventionally, posterior C1-C2 fusion has been performed using a sublaminar wiring technique with a structural bone graft. Subsequent advent of newer fixation devices, such as the C1 lateral mass screw and C1 hook, has achieved more solid fixation with improved surgical outcome; however, in these fixation systems, the protruding end of the metal implant above the level of the atlas may result in a complication due to contact with the surrounding structures. CASE DESCRIPTION: Two men and two women whose ages at the time of surgery ranged from 14 to 72 years. A supralaminar hook was used as a fixation device for C1 in two cases, whereas a lateral mass screw (Tan's method) and an atlas claw hook were employed for one each of the remaining 2 cases. We retrospectively reviewed the clinical features and postoperative course of these patients using the clinical records. Moreover, we measured the protruding height of the instrument above the atlas as well as the Redlund-Johnell (R-J) value on postoperative radiographs. All patients complained of crepitus and/or pain on neck extension. Erosion in the occipital bone was detected on multiplanar reconstruction computed tomography (MPR-CT), whereas plain radiographs failed to reveal the bony change. In those cases, protruding instruments used for C1 fixation contacted the occipital bone resulting in an erosive change at the impingement point. We removed the implant in all four cases after confirmation of solid bony union. DISCUSSION AND EVALUATION: Two of the four patients complained of occipital crepitus alone without pain. The management options for this condition may be controversial; however, progression of bony erosion may result in perforation of the occipital bone. This may possibly be associated with the serious complication of cerebrospinal fluid leakage. Considering this potential sequela, we removed the implants from all our reported cases after confirmation of solid bony union. CONCLUSIONS: We treated four cases that developed erosion in the occipital bone after posterior spinal instrumentation was performed for upper cervical lesions including C1. MPR-CT was useful in detecting the erosive changes in the occipital bone.