Using Proximal Hooks as a Soft-Landing Strategy to Prevent Proximal Junctional Kyphosis in the Surgical Treatment of Scheuermann's Kyphosis.

AIM: To evaluate the occurrence of proximal junctional kyphosis (PJK) as well as both the clinical and radiologic outcomes of patients who underwent surgery for Scheuermann?s Kyphosis (SK) using either exclusively pedicle screws or a combination of proximal hooks and pedicle screws constructs. MATERIAL AND METHODS: Surgically treated 37 patients with the diagnosis of SK were evaluated retrospectively. The patients were divided into two groups based on the type of instrumentation employed. The first group contained 22 patients with only pedicle screws (PP) while the second group consisted of 15 patients with mixed constructs that were proximal hooks and pedicle screws (HP) at the rest of the levels. The clinical and radiological data were compared in patients who were followed up for a minimum of 2 years. RESULTS: The average duration of follow-up for the PP group was approximately 94.7 ± 53.1 months, whereas the HP group had an average follow-up period of around 103 ± 64.4 months. After conducting the analyses, no statistically significant findings were identified in the measurements taken for the SRS-22 scores in preoperative, postoperative, and the most recent follow-up radiographs (p > 0.05). It is worth noting that among patients who exclusively utilized pedicle screws, both the proximal (p=0.045) and distal (p=0.030) junctional kyphosis angles experienced more pronounced increases compared to hybrid structures. CONCLUSION: While no notable distinction was observed between the two groups, patients with pedicle screws fixation had a higher PJK angle. Conversely, the use of hooks at the upper end seems to be a preventive measure against the development of PJK.

The effect of brace on apical vertebral derotation in adolescent idiopathic scoliosis.

PURPOSE: The current study aims to evaluate the effect of Boston brace treatment on apical vertebral derotation in adolescent idiopathic scoliosis (AIS) patients receiving conservative treatment. METHODS: The study included 51 AIS patients, consisting of 8 males and 43 females, with Cobb angles between 25° and 45° and Risser's findings ranging from 0 to 4. The mean age of the participants was 12.20 ± 1.34 years. All patients were treated with the Boston brace for a minimum of 2 years and evaluated before the brace, during early brace use, and at the last follow-up. Radiographs were assessed to measure apical vertebral rotation (AVR) and vertebral translation (AVT). The SRS-22 questionnaire was used to evaluate patient outcomes. RESULTS: The radiographs of patients were evaluated over a mean follow-up period of 32.42 ± 8.65 months. Before the brace, the mean AVR was 2.1 ± 0.6, while it was 1.1 ± 0.5 with the brace. At the last follow-up, the mean AVR was 1.3 ± 0.5 (p < 0.001). Before the brace, the mean AVT was 36.4 ± 9.6 mm, which decreased to 16.7 ± 7.3 mm with the brace (p < 0.001). At the last follow-up, the mean AVT was 19.8 ± 8.1 mm (p < 0.001). The use of the brace had a significant corrective effect on thoracolumbar and lumbar curvatures compared to before the brace (p < 0.001). CONCLUSION: The findings of the current study suggest that the use of a Boston brace in the conservative treatment of AIS is effective in correcting the coronal and sagittal plane deformities, including thoracic, thoracolumbar, and lumbar curvatures, and in reducing apical vertebral rotation and translation.

Intermittent pedicle screw application provides better kyphosis restoration in adolescent idiopathic scoliosis for Lenke type 1 and type 2 curves.

PURPOSE: There is still no consensus on the optimum pedicle screw density required for the desired thoracic kyphosis restoration in adolescent idiopathic surgery (AIS). The aim of this study to evaluate the effect of pedicle screw density on thoracic kyphosis restoration in AIS surgery. METHODS: The data of 106 patients from two centers that operated for Lenke type 1 and 2 AIS were retrospectively reviewed. Two groups were constituted according to the pedicle screw density: intermittent pedicle screw constructs (IPSC) (n = 52 patients) and consecutive pedicle screw construct (CPSC) (n = 54 patients) groups. The preoperative and at least 24-month follow-up radiographs and SRS-22 scores were evaluated. The Cobb angle of the main and concomitant curves in the coronal plane and the sagittal plane were measured and compared. RESULTS: The mean follow-up period for the IPSC and CPSC groups was 72.3 ± 37.2 and 62.9 ± 28.8 months, respectively. In the SRS-22 questionnaire, there was no significant difference between the two groups in terms of self-image/appearance domain scores (p = 0.466), but better results were obtained in the IPSC group in terms of treatment satisfaction domain scores (p = 0.010) and better thoracic kyphosis restoration was achieved in IPSC group radiologically for Lenke type 1 curves with - 81.4 ± 81.4% in the IPSC group and 6.8 ± 83.8% in the CPSC group (p < 0.001). CONCLUSION: It was considered that better thoracic kyphosis restoration could be achieved with the less lordotic effect of IPSC in Lenke type 1 curves. Although the current situation had a significant impact on radiological outcomes, its effect on SRS-22 scores was limited.

The combined use of carbon nanotubes with synthetic ceramics enhances posterolateral fusion: an experimental study in a rat spinal fusion model.

PURPOSE: The aim of the present study was to evaluate the effectiveness of carbon nanotubes (CNTs)/ HA-tricalcium phosphate (TCP) composite in a posterolateral spinal fusion model. METHODS: At first, CNTs and CNTs/HA-TCP composites were prepared. Twenty adult male Sprague Dawley rats were randomized into four groups with five rats in each group. Decortication was carried out in standard manner in all animals. Group 1 (only decortication), group 2 (CNTs), group 3 (HA-TCP) and group 4 (CNTs/HA-TCP) were formed. Eight weeks later, all animals were killed and obtained fusion segments were evaluated by manual palpation, histomorphometry and micro-computed tomography (mCT). RESULTS: In all evaluations, highest fusion values were obtained in Group 4. In mCT investigations, bone volume/ tissue volume (BV/TV) ratio was found to be significantly higher in composite group (group 4) only compared to ceramic group (group 3) (p < 0.001). Although in Group 2, in which only CNTs were used, the ratio was found to be statistically significantly higher than group 1(p < 0.001), the difference was not considered as significant in terms of fusion and in addition in group 2, CNTs were completely surrounded by fibrous tissue, i.e., no bone formation was observed. CONCLUSIONS: The CNTs/HA-TCP composite is a promising synthetic bone graft substitute for spinal fusion. Although CNTs are inadequate in producing spinal fusion when they are used alone, due to their high biocompatibility due to their high biocompatibility, and multiple effect on bone regeneration, they seem to increase fusion rates significantly when they are used in combination with ceramic-based synthetic grafts.

Evaluation of Blended Online Learning in Three Spinal Surgery Educational Courses.

COVID-19 pandemic created a need to improvise and redefine blended learning to be executed fully online. Background information on the effectiveness of fully online blended learning activities, especially for surgical disciplines is limited. This study describes a fully online blended learning course format on spinal surgery and aims to provide data regarding it effectiveness. Fully online blended courses on three topics of spinal surgery designed as six-week asynchronous and followed by 3-day live parts. Learning gaps (LGs) were identified with a survey at the beginning of asynchronous part, at its end, and at the end of the live part. The effectiveness of the asynchronous and live parts was assessed by LGs and a quiz, login statistics of learners and faculty and a post-course survey. Participants' LGs decreased in all courses, statistically significant in two. Faculty and learner login rates significantly correlated with each other. Faculty and learner satisfaction was very high. A fully online blended learning course can be delivered effectively on spine surgery with a high participant and faculty satisfaction rate. The asynchronous part contributes to learning significantly.

The validity and reliability study of the Turkish version of the spinal appearance questionnaire for congenital scoliosis patients over 10 years old.

PURPOSE: In this study, we aimed to evaluate the validity and the reliability of the Turkish version of the SAQ (Tr-SAQ) in congenital scoliosis patients. METHODS: Applied to 52 patients with congenital scoliosis (38 female), the Tr-SAQ was applied to the same patients for the second time with an average interval of 14.9 ± 0.9 days. Construct validity was evaluated using factor analysis. SRS-22 was used to test the convergent validity of Tr-SAQ. Internal consistency analysis and test-retest reliability were evaluated to show the reliability of Tr-SAQ. RESULTS: A two-factor structure with eigenvalues greater than one, namely "6.1" and "2.6" belonging to the Tr- SAQ, was obtained. The total variance of the factors is 62.1%. The factor load of each item in the first factor 'Appearance' domain varies between 0.7 and 0.8. The second factor 'Expectations' consists of four items. The factor load of each item varies between 0.7 and 0.8. A significant negative correlation was found between the Tr-SAQ appearance score and the self-image/appearance score of SRS-22 (r = - 0.5; p < 0.001). Cronbach alpha for Tr-SAQ was found to be 0.9. The intraclass correlation coefficient (ICC) calculated for test-retest reliability was 0.991 CONCLUSION: Previous validity and reliability studies of SAQ have been performed in idiopathic scoliosis patients. This is the first study containing patients diagnosed with congenital scoliosis. In this piece of work, the 2-factor structure of the Tr-SAQ consisting of 14 items was found to be valid and reliable in patients over 10 years of age with a diagnosis of congenital scoliosis. LEVEL OF EVIDENCE: Level I.

Turkish Validity and Reliability Study of Scoliosis Research Society-30 Questionnaire in Adolescent Idiopathic Scoliosis Patients.

STUDY DESIGN: Methodological. OBJECTIVE: Turkish validity and reliability study of Scoliosis Research Society-30 (SRS-30) questionnaire. SUMMARY OF BACKGROUND DATA: SRS-30 is the most current questionnaire of SRS, which is widely used in the evaluation of the treatment of patients with idiopathic scoliosis. There is no validity and reliability study for the Turkish language. METHODS: All translation and cross-cultural adaptation stages of the SRS-30 English version to Turkish were implemented. SRS-30 Turkish and Short Form-36 questionnaires were administered to 96 patients with adolescent idiopathic scoliosis simultaneously. Two weeks later, the SRS-30-Turkish version was applied again. Internal validity was examined using the Rasch model, and external construct validity (convergent validity) was evaluated with the Spearman rho correlation test. Person Separation Index was used for reliability. The internal consistency was analyzed with Cronbach alpha. For test re-test reliability, intraclass correlation coefficient between the two measurements was calculated. RESULTS: As a result of the Rasch analysis, it was observed that the Turkish version of SRS-30 has a multidimensional structure and the disordered threshold problem was observed in some items. Overall fit is provided for each of the four sub-dimensions of SRS-30 Turkish. There was no difference in the functioning of the items in terms of gender and age groups. The lowest Person Separation Index value was obtained with 0.539 in the satisfaction of the treatment sub-dimension. Cronbach alpha values were over 0.70 for all domains. The intraclass correlation coefficient value was found in satisfaction with management dimension (0.463) and above 0.60 in other dimensions. CONCLUSION: It was concluded that the SRS-30 Turkish questionnaire was valid and reliable in evaluating the treatment of patients with adolescent idiopathic scoliosis. Considering the studies related to SRS scales in the literature, especially those applied Rasch analysis, it is seen that the reply categories of the items should be reviewed.Level of Evidence: 2.

Blended Learning Is a Feasible and Effective Tool for Basic Pediatric Spinal Deformity Training.

STUDY DESIGN: Descriptive study. OBJECTIVE: Assessing the applicability of blended learning to specific domains of spine surgery. METHODS: After the needs assessment, a blended pediatric spine deformity course program was designed. A total of 33 participants, including orthopedic and neurosurgeons, registered for the course and all of them completed an online entrance quiz. Thus, they were eligible to have online part of course, which included the theoretical part of the course and also a discussion forum where the discussions about the topics facilitated by faculty. Thirteen of 33 subjects participated second part of the blended pediatric spine deformity course. This face-to-face (F2F) part consisted of case discussions for each topic and discussions facilitated by faculty members. The same quiz was also taken before and after the F2F part. All quiz results were compared statistically. RESULTS: There were 11 lectures within the online part and 6 case discussions in the F2F part. The quiz scores were improved significantly by having a complete blended pediatric deformity course (P < .05). CONCLUSIONS: The current study has demonstrated that blended learning format, including online and F2F, is feasible and effective in training for a domain of spine surgery, pediatric deformity in this specific context.

A simple method for assessing rotational flexibility in adolescent idiopathic scoliosis: modified Adam's forward bending test.

PURPOSE: This study aimed to evaluate the diagnostic aptitude of a modified Adams forward bending test (MAFBT), which addresses the coupling phenomenon of axial rotation with reference to the side-bending movement. Also, this evaluation was facilitated by the introduction of our rotational flexibility index (RFI). METHODS: Thirty-two female and eight male AIS patients were included in this study from a single institution. In the MAFBT, subjects were asked to bend to the convex side of the curve in the forward bending position. Scoliometric measurements were done during the AFBT and MAFBT. Utilizing anteroposterior standing plain radiographs curve flexibility indices were calculated. The diagnostic aptitude of the MAFBT was evaluated based on the receiver operating characteristic (ROC) curves and area under the curve (AUC). The RFI was also assessed, which considered AFBT and MAFBT parameters as a specified function. RESULTS: Significant correlations were noted between the Cobb angle and AFBT (p = 0.005), fulcrum bending and the MAFBT (p = 0.0001), side-bending and MAFBT (p = 0.0001). There were significant positive correlations between rotational flexibility as based on fulcrum bending radiograph to that of the RFI (r = 0.4, p = 0.036) and side-bending technique (r = 0.4, p = 0.008). Based on ROC analyses (AUC range 0.7-0.8), the MAFBT demonstrated high specificity and sensitivity rates for flexible and rigid curves, respectively. CONCLUSIONS: This is the first study to report that the MAFBT is a simple and reliable test for the clinical assessment of rotational flexibility in AIS patients. The study further noted that the novel RFI has clinical utility in the assessment of AIS.

Reliability and validity of the adapted Turkish version of the Spinal Appearance Questionnaire.

PURPOSE: The Spinal Appearance Questionnaire (SAQ), scoliosis specific quality of life questionnaire, was developed to assess the spinal appearance in adolescent idiopathic scoliosis (AIS) patients. The aim of this study is to evaluate the adaptation, validity, and reliability of the Turkish version of the Spinal Appearance Questionnaire (Tr-SAQ). METHODS: Tr-SAQ and already validated Turkish SRS-22 were applied to 75AIS patients (56 females) twice within a 2-week interval for test-retest reliability. Validity of the Tr-SAQ was assessed with factor analysis, convergent validity, and discriminant validity. Convergent validity was evaluated by calculating Spearman correlation coefficients between Tr-SAQ and SRS-22 self-image domain. Internal consistency and intraclass correlation coefficient (ICC) were evaluated for the determination of reliability. RESULTS: Factor analysis indicated that Tr-SAQ had two factors as appearance (items 1-10) and expectations (items 12-15). Convergent validity test showed a significant negative correlation between the Tr-SAQ appearance score and SRS-22 self-image score (Spearman's r = - 0.6).Test-retest was conducted within a mean of 16.7 (range 14-28) days. Both ICC and Cronbach's α were found to be high (0.98, 0. 91, respectively). The correlations with the major curve magnitude were stronger for the Tr-SAQ Appearance (r = 0.7) and Tr-SAQ Total (r = 0.6) scores than the correlations between the SRS-22 self-image (r = - 0.5) and SRS-22 Total (r = - 0.4) scores. CONCLUSION: The Turkish version of the SAQ was reliable and valid for clinical use for AIS patients who are native speakers of Turkish. LEVEL OF EVIDENCE: Level I- diagnostic studies.

Diverse approaches to scoliosis in young children.

Management of scoliosis in young children needs a comprehensive approach because of its complexity. There are many debatable points; however, only serial casting, growing rods (including traditional and magnetically controlled) and anterior vertebral body tethering will be discussed in this article.Serial casting is a time-gaining method for postponing surgical interventions in early onset scoliosis, despite the fact that it has some adverse effects which should be considered and discussed with the family beforehand.Use of growing rods is a growth-friendly surgical technique for the treatment of early onset spine deformity which allows chest growth and lung development. Magnetically controlled growing rods are effective in selected cases although they sometimes have a high number of unplanned revisions.Anterior vertebral body tethering seems to be a promising novel technique for the treatment of idiopathic scoliosis in immature cases. It provides substantial correction and continuous curve control while maintaining mobility between spinal segments. However, long-term results, adverse effects and their prevention should be clarified by future studies. Cite this article: EFORT Open Rev 2020;5:753-762. DOI: 10.1302/2058-5241.5.190087.

Personalized Three-Dimensional Printing Pedicle Screw Guide Innovation for the Surgical Management of Patients with Adolescent Idiopathic Scoliosis.

OBJECTIVE: To assess the safety and efficacy of patient-specific three-dimensional (3D) rapid-prototype printing technology for pedicle screw insertion in patients with adolescent idiopathic scoliosis (AIS). METHODS: The 3D pedicle screw guides were produced after selecting the fixation points for all individual levels to be used intraoperatively. Preoperative computed tomography images recreated 3D bone models of each vertebra specific to each patient. Safe pedicle trajectories were determined in all 3 planes on these models. 3D printed guides were modeled according to these trajectories and manufactured with a biocompatible material. Postoperatively, all screws were evaluated and scored with computed tomography as class 1 (accurate), class 2 (inaccurate), or class 3 (deviated). The mean angle between the inserted pedicle screw and the intended trajectory, and the mean distance between the central longitudinal axis of a screw and pedicle were also measured. RESULTS: A total of 134 screws were inserted. On the concave and convex sides, the mean medial malposition was 0.5 ± 0.8 and 0.4 ± 0.6 mm, the mean lateral malposition was 1.4 ± 2.3 and 0.8 ± 1.3 mm, angle between the inserted pedicle screw and the intended trajectory was 4.2 ± 4.6 and 4.3° ± 6.0°, and distance between the central longitudinal axis of a screw and pedicle was 1.5 ± 2.1 and 0.9 ± 1.2 mm, respectively. A total of 117 screws were regarded as class 1, 14 as class 2, and 3 as class 3. Of all screws inserted, 92.5% achieved positional accuracy. There were no screw-related complications. CONCLUSIONS: This is one of the initial reports to note the novel design and implementation of patient-specific 3D pedicle screw guides for adolescent idiopathic scoliosis surgery. Our pilot study shows that the use of these low-cost personalized 3D guides is completely safe and effective in both convex and concave sides of the curves.

The implant density does not change the correction rate of the main and the accompanying curves: A comparison between consecutive and intermittent pedicle screw constructs.

OBJECTIVE: The aim of this study was to evaluate the clinical outcomes and the coronal correction rate of the main and accompanying curves of adolescent idiopathic scoliosis (AIS) corrected with pedicle screws inserted consecutively or intermittently. METHODS: The prospectively collected data of 60 patients (8 men and 52 women; mean age: 14.6±2.5 years) who underwent corrective surgery for AIS between January 2010 and December 2015 were reviewed retrospectively. Two groups were constituted according to the pedicle screw construct type: consecutive pedicle screw construct (CPSC) and intermittent pedicle screw construct (IPSC) groups. The preoperative, early postoperative, and 24-month follow-up radiographs and the Scoliosis Research Society-22 (SRS-22) scores were reevaluated. The Cobb angle of the main and accompanying curves, the correction rate, and the flexibility of the curves were calculated. RESULTS: The mean preoperative Cobb angles were 57.03° and 57.46°, the mean postoperative Cobb angles were 14.93° and 14.4°, and the mean correction rates were 76.22% and 75.31% in IPSC and CPSC groups, respectively (p>0.05). The preoperative and postoperative accompanying curve magnitudes and correction rates were similar (p>0.05). These radiographic outcomes were also consistent with the SRS-22 scores. CONCLUSION: Both the pedicle screw constructs had satisfactory outcomes following the surgery, which were confirmed by both the SRS-22 scores and radiographs taken perioperatively and at follow-ups. The IPSC and CPSC groups did not demonstrate a significant change in the correction rate of the main and minor or major accompanying structural and nonstructural curves, and also in the SRS-22 scores. LEVEL OF EVIDENCE: Level III, Retrospective comparative study.

3D printing and spine surgery.

Rapid prototyping (RP), also known as three-dimensional printing (3DP), allows the rapid conversion of anatomical images into physical components by the use of special printers. This novel technology has also become a promising innovation for spine surgery. As a result of the developments in 3DP technology, production speeds have increased, and costs have decreased. This technological development can be used extensively in different parts of spine surgery such as preoperative planning, surgical simulations, patient-clinician communication, education, intraoperative guidance, and even implantable devices. However, similar to other emerging technologies, the usage of RP in spine surgery has various drawbacks that are needed to be addressed through further studies.

Strategies of management of deep spinal infection: from irrigation and debridement to vacuum-assisted closure treatment.

Postoperative surgical site problems (PSSPs) following spinal surgery may lead to patient mortality, increased treatment costs and possible recurrent medical interventions. Despite efforts to reduce spinal surgery-related infection rates, complications are common and significantly increased by patient comorbidities. Since PSSPs occur regardless of deterrent measures, it is essential to distinguish the related risk factors. Different treatment conventions for PSSPs, for example, antibiotic treatment, debridement, soft tissue care and removal of implants have been prescribed with blended outcomes. The utilization of the wound vacuum-assisted closure (VAC) system has gained increasing popularity in the management of deep wound infections after deformity surgery.

Epidermal growth factor enhances spinal fusion: Posterolateral lumbar fusion model on rats.

OBJECTIVE: The aim of this study was to investigate the effects of human recombinant epidermal growth factor (EGF) on posterolateral lumbar fusion in a rat model. METHODS: 36 male Sprague Dawley rats underwent posterolateral fusion at L4-5 level. They were randomly assigned to 3 groups: 1- Sham control group where no local augmentation was made, 2- Local Hydoxyapatite ß-tricalcium phosphate (HA/ß-TCP) augmentation group and 3- Local HA/ß-TCP + EGF augmentation group. Rats were euthanized at 8 weeks post-surgery. 6 rats from each group were selected for manual palpation examination, micro-computed tomography analysis and histologic analysis; and the rest was used for biomechanical analysis. RESULTS: Based on manual palpation, there was no fusion in the sham control group. Fusion rate was 33.3% in the HA/ß-TCP group and 66.7% in the HA/ß-TCP + EGF group (p = 0.085). Micro-CT results revealed that new bone formation was higher in the HA/ß-TCP + EGF group (BV/TV: 40% vs. 65%) (p = 0.004). Histologically newly formed bone tissue was more pronounced in the EGF group and compacted and bridging bone spicules were observed. The median maximum bending moment values were 0.51 Nmm (0.42-0.59), 0.73 Nmm (0.49-0.88) and 0.91 Nmm (0.66-1.03) in the sham control, HA/ß-TCP and HA/ß-TCP + EGF groups, respectively (p = 0.013). The median stiffness values were 1.69 N/mm (1.12-2.18), 1.68 N/mm (1.13-2.74) and 3.10 N/mm (1.66-4.40) as in the previous order (p = 0.087). CONCLUSION: This study demonstrates that EGF enhances posterolateral lumbar fusion in the rat model. EGF in combination with ceramic grafts increased the fusion rates. Our findings may provide insights to further studies, investigating EGF's clinical usage as an alternative fusion enhancer.

Excision and short segment fusion of a double ipsilateral lumbar hemivertebrae associated with a diastematomyelia and fixed pelvic obliquity.

We report the surgical treatment course of a 4-year-old girl with congenital scoliosis, diastematomyelia and double adjacent hemivertebrae. She had a lumbar curve with an apparent pelvic obliquity. Simultaneous excision of double segmented sequential hemivertebra at the L3-L4 level and fusion with short-segment instrumentation was performed via a posterior approach. Intraoperative radiographs revealed satisfactory curve correction and 0° pelvic obliquity. Following the excision of double adjacent hemivertebrae, three adjacent nerve roots were placed in one intervertebral foramen bilaterally. Nevertheless, no neurological deficit was developed, and the patient was able to ambulate with a brace at day one. Pelvic balance and deformity correction were maintained with no implant failure at the fifth year follow-up. Excision of two ipsilateral adjacent hemivertebra and short-segment posterior fusion performed via posterior-only approach simultaneously is an effective, safe, and less invasive technique for the treatment of the described case.

Biomechanical Evaluation of a Novel Apatite-Wollastonite Ceramic Cage Design for Lumbar Interbody Fusion: A Finite Element Model Study.

OBJECTIVES: Cage design and material properties play a crucial role in the long-term results, since interbody fusions using intervertebral cages have become one of the basic procedures in spinal surgery. Our aim is to design a novel Apatite-Wollastonite interbody fusion cage and evaluate its biomechanical behavior in silico in a segmental spinal model. MATERIALS AND METHODS: Mechanical properties for the Apatite-Wollastonite bioceramic cages were obtained by fitting finite element results to the experimental compression behavior of a cage prototype. The prototype was made from hydroxyapatite, pseudowollastonite, and frit by sintering. The elastic modulus of the material was found to be 32 GPa. Three intact lumbar vertebral segments were modelled with the ANSYS 12.0.1 software and this model was modified to simulate a Posterior Lumbar Interbody Fusion. Four cage designs in different geometries were analyzed in silico under axial loading, flexion, extension, and lateral bending. RESULTS: The K2 design had the best overall biomechanical performance for the loads considered. Maximum cage stress recorded was 36.7 MPa in compression after a flexion load, which was within the biomechanical limits of the cage. CONCLUSION: Biomechanical analyses suggest that K2 bioceramic cage is an optimal design and reveals essential material properties for a stable interbody fusion.