Target Alignment Research Articles

Clinical outcomes and proximal junctional failure in adult spinal deformity patients corrected to normative alignment versus functional alignment.

The objective of this study was to explore the rate of proximal junctional failure (PJF) and functional outcomes of normative alignment goals compared with alignment targets based on age-appropriate physical function. Baseline relationships between age, pelvic incidence (PI), and a component of the T1 pelvic angle (TPA) within the fusion were analyzed in adult spinal deformity (ASD) patients and compared with those of asymptomatic patients. Linear regression modeling was used to determine alignment based on PI and age in asymptomatic patients (normative alignment), and in ASD patients, alignment corresponding to age-appropriate functional status (functional alignment). A cohort of 288 ASD patients was split into two groups based on whether the patient was closer to their normative or functional alignment goal at their 6-week postoperative radiographic follow-up. The rates of proximal junctional kyphosis (PJK) and PJF were determined for each cohort. In the 288 ASD patients included in this pre- to postoperative analysis, there was no difference in baseline alignment or health-related quality of life (HRQOL) between the normative alignment and functional alignment groups. At 6 weeks, patients with normative alignment had a smaller TPA (4.45° vs 14.1°) and PI minus lumbar lordosis (-7.24° vs 7.4°) (both p < 0.0001) and higher PJK (40% vs 27.2%, p = 0.03) and PJF (17% vs 6.8%, p = 0.008) rates than patients with functional alignment. Correction in ASD patients to normative alignment resulted in higher rates of PJK and PJF without improvements in HRQOL. Correction in ASD patients to functional alignment that mirrors the physical function of their age-matched asymptomatic peers is recommended.

High degree of alignment precision associated with total knee arthroplasty performed using a surgical robot or handheld navigation.

The purpose of this study was to compare the precision of bony resections during total knee arthroplasty (TKA) performed using different computer-assisted technologies. Patients who underwent a primary TKA using an imageless accelerometer-based handheld navigation system (KneeAlign2®, OrthAlign Inc.) or computed tomography-based large-console surgical robot (Mako®, Stryker Corp.) from 2017 to 2020 were retrospectively reviewed. Templated alignment targets and demographic data were collected. Coronal plane alignment of the femoral and tibial components and tibial slope were measured on postoperative radiographs. Patients with excessive flexion or rotation preventing accurate measurement were excluded. A total of 240 patients who underwent TKA using either a handheld (n = 120) or robotic (n = 120) system were included. There were no statistically significant differences in age, sex, and BMI between groups. A small but statistically significant difference in the precision of the distal femoral resection was observed between the handheld and robotic cohorts (1.5° vs. 1.1° difference between templated and measured alignments, p = 0.024), though this is likely clinically insignificant. There were no significant differences in the precision of the tibial resection between the handheld and robotic groups (coronal plane 0.9° vs. 1.0°, n.s.; sagittal plane 1.2° vs. 1.1°, n.s.). There were no significant differences in the rate of overall precision between cohorts (n.s.). A high degree of component alignment precision was observed for both imageless handheld navigation and CT-based robotic cohorts. Surgeons considering options for computer-assisted TKA should take other important factors, including surgical principles, templating software, ligament balancing, intraoperative adjustability, equipment logistics, and cost, into account. III.

The Accuracy of a Portable Accelerometer-Based Navigation System for Tibial Alignment Can be Reliable during Total Knee Arthroplasty for Obese Patients.

A portable accelerometer-based navigation system can be useful for achieving the target alignment. Tibial registration is based on the medial and lateral malleoli; however, the identification of landmarks may be difficult in obese (body mass index [BMI] >30 kg/m2) patients whose bones are not easily palpable from the body surface. This study compared tibial component alignment achieved using a portable accelerometer-based navigation system (Knee Align 2 [KA2]) in obese and control groups and aimed to validate the accuracy of bone cutting in obese patients. A total of 210 knees that underwent primary total knee arthroplasty using the KA2 system were included. After 1:3 propensity score matching, there were 32 and 96 knees in the BMI >30 group (group O) and BMI ≤30 group (group C), respectively. The absolute deviations of the tibial implant from the intended alignment were evaluated in the coronal plane (hip-knee-ankle [HKA] angle and medial proximal tibial angle) and sagittal plane (posterior tibial slope [PTS]). The inlier rate of each cohort, which was defined as tibial component alignment within 2 degrees of the intended alignment, was investigated. In the coronal plane, the absolute deviations of the HKA and MPTA from the intended alignment were 2.2 ± 1.8 degrees and 1.8 ± 1.5 degrees in group C and 1.7 ± 1.5 degrees and 1.7 ± 1.0 degrees in group O (p = 1.26, and p = 0.532). In the sagittal plane, the absolute deviations of the tibial implant were 1.6 ± 1.2 degrees in group C and 1.5 ± 1.1 degrees in group O (p = 0.570). The inlier rate was not significantly different between group C and group O (HKA: 64.6 vs. 71.9%, p = 0.521; MPTA: 67.7 vs. 78.1%, p = 0.372; PTS: 82.2 vs. 77.8%, p = 0.667). The accuracy of tibial bone cutting for the obese group was comparable to that of the control group. An accelerometer-based portable navigation system can be useful when attempting to achieve the target tibial alignment in obese patients. LEVEL OF EVIDENCE: Level IV.

Mechanical complications and patient-reported outcome measures associated with high pelvic incidence and persistent pelvic retroversion: the Roussouly "false type 2" profile.

The objective of this paper was to report mechanical complications and patient-reported outcome measures (PROMs) for adult spinal deformity (ASD) patients with a Roussouly "false type 2" (FT2) profile. ASD patients treated from 2004 to 2014 at a single center were identified. Inclusion criteria were pelvic incidence ≥ 60° and a minimum 2-year follow-up. FT2 was defined as a high postoperative pelvic tilt (PT), as defined by the Global Alignment and Proportion target, and thoracic kyphosis < 30°. Mechanical complications, defined as proximal junctional kyphosis (PJK) and/or instrumentation failure, were determined and compared. Scoliosis Research Society-22r (SRS-22r) scores were compared between groups. Ninety-five patients (normal PT [NPT] group 49, FT2 group 46) who met the inclusion criteria were identified and studied. Most surgeries were revisions (NPT group 30 [61%], FT2 group 30 [65%]), and most were performed via a posterior-only approach (86%) (mean ± SD 9.6 ± 5 levels). Proximal junctional angles increased after surgery in both groups, without differences between groups. Neither rates of radiographic PJK (p = 0.10), revision for PJK (p = 0.45), nor revision for pseudarthrosis (p = 0.66) were different between groups. There were no differences between groups for SRS-22r domain scores or subscores. In this single-center experience, patients with high pelvic incidence fixed with persistent lumbopelvic parameter mismatch and engaged compensatory mechanisms (Roussouly FT2) had mechanical complications and PROMs not different from those with normalized alignment parameters. Compensatory PT may be acceptable in some cases of ASD surgery.

Automatic Classification Method for Oracle Images based on Deep Learning

There are some problems in oracle image classification, such as high image-feature extraction error and low classification accuracy, which leads to low efficiency. Therefore, we designed an automatic classification method for oracle images based on deep learning. The clustering center of an oracle image is determined using k-means algorithm. The obtained oracle image block is used as parallel input to extract a dictionary. The oracle image features are output through a feature mapping function for feature extraction. The CS algorithm is used to reduce the dimension of the oracle image, and the oracle feature compressed sensing signal is sparse under a certain basis for preprocessing of image features. The center of six feature points in the features is used to describe the center of the feature points of the whole oracle image, to determine the position change state of the feature points, and to characterize the key features of the image to achieve the target alignment of oracle image feature points. Based on this, the image feature data are learned using a transfer learning model. The automatic classifier was constructed through a convolution neural network. Experimental results show that the proposed method can effectively reduce the error of image feature extraction and improve the classification accuracy. At the application level, the research results of this paper have brought great improvement to the performance of oracle image classification technology. At the theoretical level, this research introduces k-means and CS algorithms to oracle image classification technology based on deep learning and makes an effective exploration in the direction of this technological progress.

Coronal and Sagittal Component Position in Contemporary Total Knee Arthroplasty: Targeting Native Alignment Optimizes Clinical Outcomes

BackgroundAdvanced technologies, like robotics, provide enhanced precision for implanting total knee arthroplasty components; however, optimal component position and limb alignment remain unknown. This study sought to identify sagittal and coronal alignment targets that correlate with minimal clinically important differences (MCIDs) in patient-reported outcome measures (PROMs). MethodsA total of 1,311 consecutive total knee arthroplasties were retrospectively reviewed. Posterior tibial slope (PTS), femoral flexion (FF), and tibio-femoral alignment (TFA) were measured radiographically. Patients were grouped based on whether they achieved multiple MCIDs for PROM scores. Classification and regression tree machine learning models were utilized to identify optimal alignment zones. The mean follow-up was 2.4 years (range, 1 to 11). ResultsThe change in PTS and postoperative TFA were most predictive for achieving MCIDs in 90% of the models. Approximating native PTS within 4° correlated with MCID achievement and superior PROMs. Preoperative varus and neutral aligned knees were more likely to meet MCIDs and superior PROM scores when not overcorrected into valgus postoperatively (≥7°). Preoperative valgus-aligned knees correlated with MCID achievement when postoperative TFA was not overcorrected into substantial varus (<0°). Albeit less impactful, FF ≤ 7° correlated with MCID achievement and superior PROMs regardless of preoperative alignment. Sagittal and coronal alignment measurements had moderate to strong interactions in 13 of 20 models. ConclusionOptimized PROM MCIDs correlated with approximating native PTS while maintaining similar preoperative TFA and incorporating moderate FF. Study findings demonstrate interactions between sagittal and coronal alignment which may optimize PROMs, highlighting the importance of three-dimensional implant alignment targets. Level of EvidenceIII.

Effect of three-dimensional target and reference data alignment method in an open digital dental communication application on the external surface trueness of CAD-CAM provisional crowns

Effect of three-dimensional target and reference data alignment method in an open digital dental communication application on the external surface trueness of CAD-CAM provisional crowns

Beam-Domain Image Mosaic of Forward-Looking Sonar Using Expression Domain Mapping Model

Since the existing forward-looking sonar (FLS) image mosaic algorithm is completed in the image-domain with reference to the optical image, and the characteristics of FLS imaging are not fully considered, obvious edge-seams and pseudo-target values are prone to generate after mosaic, resulting in poor visual effect and low operation efficiency. To avoid the aforementioned problems, the mosaic operation of beam-domain FLS images is proposed. Combined with the imaging principle of FLS, this study takes advantage of the variation of the sampling beams and sampling points of the same target point during sonar movement to analyze the deformation law of the target in beam-domain which is scanned in image-domain, and then proposes the concept of expression domain mapping model (EDMM). Considering the need of aligning acoustic origin, the target is deformed according to this model in the process of beam-domain mosaic, and the target alignment is completed. Subsequently, the Laplace pyramid (LP) layered algorithm is used for fusion and mosaic, and finally mapped to image-domain for display. Experimental results illustrate that this kind of algorithm can remove the mosaic edge-seams generated during mosaicking in the image-domain because it uses the sonar raw image data for mosaic in the beam-domain and avoids the appearance of sector edges in the image-domain; the actual pixel points sampled by sonar are used for mosaic, which effectively eliminates the pseudo-target value generated by the mosaic of the inter-beam interpolation in the image-domain; moreover, the number of image pixels in the beam-domain is small, and the mosaic time consuming of adjacent frames and continuous frames is more than half shorter than that of the image domain, which significantly improves the mosaic efficiency and has good mosaic performance.

Any technology assisting total knee arthroplasty (TKA) will fail without the correct 3D alignment and balancing target

Any technology assisting total knee arthroplasty (TKA) will fail without the correct 3D alignment and balancing target

Inverse kinematic alignment accommodates native coronal knee alignment better in comparison to adjusted mechanical alignment and restricted kinematic alignment.

The purpose was to determine the proportion of native non-arthritic knees that fit within the target zones of adjusted mechanical alignment (aMA), restricted kinematic alignment (rKA), and inverse kinematic alignment (iKA), and to estimate adjustments in native coronal alignment to bring outlier knees within the respective target zones. The hypothesis was that the target zone of iKA, compared to the target zones of aMA and rKA, accommodates a higher proportion of native non-arthritic knees. The study used measurements obtained from a computed tomography (CT) scan database (SOMA, Stryker) of 972 healthy knees (Caucasian, 586; Asian, 386). Hip knee ankle (HKA) angle, medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA) were used to estimate the proportions of knees within the patient-specific alignment target zones; and to estimate theoretical adjustments of MPTA, LDFA and soft tissue balance (HKA) to bring outlier knees within target zones. Theoretical adjustments to bring outlier knees within the alignment target zones of aMA, rKA and iKA were calculated by subtracting the native coronal alignment angles (MPTAnative, LDFAnative and HKAnative) from angles on the nearest target zone border (MPTAtarget, LDFAtarget and HKAtarget). Patients were aged 59.8 ± 15.8years with a BMI of 25.0 ± 4.4kg/m2. The HKA angles were between 168° and 186°, MPTA between 78° and 98° and LDFA between 79° and 93°. Of the 972 knees, 81 (8%) were in the aMA target zone, 530 (55%) were in the rKA target zone, and 721 (74%) were in the iKA target zone. Adjustments of MPTA, LDFA and HKA angle to bring outlier knees within the target zones, were, respectively, 90, 91 and 28% for aMA, 45, 28 and 25% for rKA, and 25, 23 and 7% for iKA. There is considerable variability in native knee coronal alignment that corresponds to different proportions of the restricted patient-specific alignment target zones for TKA. Although extension of the MPTA and LDFA target zones with rKA accommodate native knee alignment better than aMA, up to 25% would require adjustment of native HKA angle. By also extending the HKA angle target zone into varus, iKA accommodates a greater proportion (93%) of native limb alignment. IV.

Alignment options and robotics in total knee arthroplasty.

Total knee arthroplasty is one of the most widely performed surgical procedures today. Its widespread popularity has helped drive innovation and improvement in the field. Different schools of thought have developed regarding the best way to perform this operation. Specifically, there are controversaries regarding the best alignment philosophy for the femoral and tibial components to optimize implant stability and longevity. Traditionally, neutral mechanical alignment has been the preferred alignment target. More recently, some surgeons advocate for alignment matching the patient's pre-arthritic anatomic alignment ("physiologic" varus or valgus), which has been described as kinematic alignment. Functional alignment is a hybrid technique that focuses on the coronal plane minimizing soft tissue releases. To date, there is no evidence demonstrating superiority of one method over another. There is growing popularity of robotic surgical techniques to improve accuracy of implant position and alignment. The choice of alignment philosophy is an important aspect of robotic assisted TKA surgery and has the potential to clarify the optimal alignment technique.

SiamSTC: Updatable Siamese tracking network via Spatio-Temporal Context

To adapt to the target appearance, some trackers focus only on learning the target model online with the spatial context or only on learning an adaptive template with the temporal context. However, these trackers do not fully utilize spatial and temporal contexts and therefore cannot robustly adapt to sharp appearance variations in challenging situations, such as deformation, rotation, out-of-view, and background clutter. To address the above problem, we propose a novel online updatable Siamese tracker (SiamSTC) that takes advantage of the spatiotemporal context to be aware of the appearance variations in the target to improve the accuracy and robustness of tracking. Specifically, we build a memory bank to collect the spatial and temporal contexts of the target, and design a template update module to learn an adaptive target template using the historical knowledge in memory. We propose a novel update mechanism to ensure that high-quality samples are utilized to update the memory bank. In addition, we propose a target alignment module to explore the fine-grained relationships between the adaptive template and the search image, and locate discriminative regions for tracking based on fine-grained relationships. The proposed method achieves state-of-the-art tracking performance on seven challenging benchmarks, including OTB100, LaSOT, TC128, GOT10k, VOT2016, VOT2018, and VOT2019.

Quadrupole deformation signatures in elastic electron scattering from oriented odd-A nuclei

Elastic electron scattering from oriented odd-A axially deformed nuclei is studied in the plane-wave Born approximation. The nuclear structure is described within a microscopic selfconsistent Skyrme deformed Hartree-Fock approximation with pairing correlations. The interference form factors between monopole and quadrupole Coulomb terms that characterize the nuclear response with aligned nuclear targets are shown to increase or decrease the unpolarized cross-section, depending on the sign of the quadrupole deformation. This feature provides valuable information on the nuclear deformation that can be used as a signature of the oblate or prolate character of the nuclear shape. Some selected cases of nuclei with different spins are presented that exemplify the scope of the method.

The Association of Patient and Procedural Factors on Improved Outcomes: A Cluster Analysis on 853 Total Knee Arthroplasty Patients.

Many studies involving robotic-assisted total knee arthroplasty (RATKA) have demonstrated superiority regarding soft tissue balance and consistency with alignment target achievement. However, studies investigating whether RATKA is associated with improved patient outcomes regarding physical function and pain are also important. Therefore, we performed a cluster analysis and examined factors that contributed to differences in patient-reported outcome measures (PROMs). Specifically, we analyzed: (1) reduced WOMAC (rWOMAC) scores regarding pain and function; (2) usage of RATKA; (3) common patient comorbidities; as well as (4) patient demographic factors. The rWOMAC score is an abbreviated PROM that includes pain and physical function domains. This study analyzed 853 patients (95 conventional and 758 robotic-assisted) who had completed preoperative, 6-month, and 1-year postoperative rWOMAC surveys. Two clusters were constructed using rWOMAC pain and function scores at 1 year. Cluster 1 included 753 patients who had better outcomes at 1 year (mean rWOMAC pain = 0.9, mean rWOMAC function = 1.4), and cluster 2 included 100 patients who had worse outcomes at 1 year (mean rWOMAC pain = 7.7, mean rWOMAC function = 10.4). The clusters were compared to determine (1) how scores improved and (2) what patient characteristics were significantly different between clusters. Cluster 1 demonstrated greater improvement from preoperative to 6 months or 1 year (p = 0.0013 for pain preoperative to 6 months, p< 0.0001 for other measures) and 6 months to 1 year (p< 0.0001). Comparisons demonstrated that cluster 1 had older patients (67 vs. 65 years, p = 0.0479) who had lower body mass index or BMIs (31.8 vs. 33.9 kg/m2, p = 0.0042) and no significant differences in sex (p = 0.7849). Cluster 1 also had a significantly higher percentage of RATKA patients (90 vs. 79%, p< 0.001). Cluster analyses provided differentiating factors which were associated with improved postoperative rWOMAC pain and function scores at 1 year. Patients undergoing robotic-assisted TKA were associated with better rWOMAC pain and function scores from preoperative to 6 months and 1 year.

Enhanced Mid-Resection Workflow Technique for Severe Varus Deformity Correction Using Robotic-Arm Assisted Total Knee Arthroplasty.

Robotic technology in total knee arthroplasty has been proven to improve accuracy of component positioning, achieve alignment targets, and balance the knee objectively. However, the utility of robotics in correction of severe varus deformities of the knee has not been investigated in detail. The aim of this paper was to establish the utility and describe the technique of robotic-arm assisted total knee arthroplasty (RA-TKA) in achieving pre-balance in severe varus deformities of the knee. Among the existing Mako (Stryker, Kalamazoo, Michigan) RA-TKA workflows, pre-resection workflow is limited to knees which can be pre-balanced by component positioning according to functional alignment. Mid-resection workflow (distal femur/tibia first) is reserved for complex cases, whereby the extension gap is balanced first. In our experience, both workflows could not achieve pre-balance in severe varus deformities, necessitating the need to develop a novel technique. The ability of the robot to execute precise bone cuts allows for a provisional postero-medial femoral bone cut in flexion, giving access to remove large inaccessible posterior osteophytes and the tight posterior capsule, thus balancing the knee in extension. The flexion gap is subsequently matched to the extension gap by alterations in axial component positioning. This novel "enhanced mid-resection workflow" technique establishes the utility of the RA-TKA in balancing severe varus deformities of the knee. We also propose an algorithm which simplifies and helps surgeons choose between the three workflows to pre-balance knees irrespective of the severity of the varus deformity.

Can Discharge Radiographs Predict Junctional Complications? A Decision Tree Analysis.

Retrospective cohort study. To determine if standing pre-discharge radiographs can predict the development of junctional complications. Adult spinal deformity patients who underwent fusion of the lumbar spine (≥5 levels, LIV pelvis) were included. All patients underwent full-length standing radiographs before hospital discharge. Outcomes of interest included 2-year radiographic PJK and proximal junctional failure (PJF). Patients were stratified into 3 exclusive groups: No PJK, PJK, and PJF. Chi-square automatic interaction detection (CHAID) decision tree analysis was utilized to identify pre-discharge proximal junctional angle (PJA) thresholds associated with increased risk of PJK or PJF. The 117 study patients had a mean age 65.8 ± 8.5, BMI 27.2 ± 4.9, PI-LL 23.3 ± 17.4, TPA 27.2 ± 11.5. Sample was stratified into 64 (54.7%) No PJK, 39 (33.3%) PJK, 14 (12.0%) PJF. No differences were detected between cohorts in discharge alignment, preop-discharge change, or offset from age-adjusted alignment targets (P > .005). Decision tree analysis showed that the first branch point depended on the UIV, as most patients with an UT UIV did not develop PJK or PJF (no PJK, 67.4%). For patients with an LT UIV, a second branch point occurred based on the ΔPJA. 89.5% of LT patients with a ΔPJA < 4.3° were free of radiographic PJK and PJF. The third branch point occurred based on the PJA at discharge. Thus, the highest risk group was comprised of ΔPJA ≥4.3° and PJA > 15.5°, as 57.1% of developed PJF and 28.6% PJK. Most patients with a lower thoracic UIV, preop-discharge ΔPJA ≥4.3°, and discharge PJA > 15.5° develop PJF.

End-to-end kernel learning via generative random Fourier features

Random Fourier features (RFFs) provide a promising way for kernel learning in a spectral case. Current RFFs-based kernel learning methods usually work in a two-stage way. In the first-stage process, learning an optimal feature map is often formulated as a target alignment problem, which aims to align the learned kernel with a pre-defined target kernel (usually the ideal kernel). In the second-stage process, a linear learner is conducted with respect to the mapped random features. Nevertheless, the pre-defined kernel in target alignment is not necessarily optimal for the generalization of the linear learner. Instead, in this paper, we consider a one-stage process that incorporates the kernel learning and linear learner into a unifying framework. To be specific, a generative network via RFFs is devised to implicitly learn the kernel, followed by a linear classifier parameterized as a full-connected layer. Then the generative network and the classifier are jointly trained by solving an empirical risk minimization (ERM) problem to reach a one-stage solution. This end-to-end scheme naturally allows deeper features, in correspondence to a multi-layer structure, and shows superior generalization performance over the classical two-stage, RFFs-based methods in real-world classification tasks. Moreover, inspired by the randomized resampling mechanism of the proposed method, its enhanced adversarial robustness is investigated and experimentally verified.

Comparison of local and regional radiographic outcomes in minimally invasive and open TLIF: a propensity score-matched cohort.

Local and regional radiographic outcomes following minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) versus open TLIF remain unclear. The purpose of this study was to provide a comprehensive assessment of local and regional radiographic parameters following MI-TLIF and open TLIF. The authors hypothesized that open TLIF provides greater segmental and global lordosis correction than MI-TLIF. A single-center retrospective cohort study of consecutive patients undergoing MI- or open TLIF for grade I degenerative spondylolisthesis was performed. One-to-one nearest-neighbor propensity score matching (PSM) was used to match patients who underwent open TLIF to those who underwent MI-TLIF. Sagittal segmental radiographic measures included segmental lordosis (SL), anterior disc height (ADH), posterior disc height (PDH), foraminal height (FH), percent spondylolisthesis, and cage position. Lumbopelvic radiographic parameters included overall lumbar lordosis (LL), pelvic incidence (PI)-lumbar lordosis (PI-LL) mismatch, sacral slope (SS), and pelvic tilt (PT). Change in segmental or overall lordosis after surgery was considered "lordosing" if the change was > 0° and "kyphosing" if it was ≤ 0°. Student t-tests or Wilcoxon rank-sum tests were used to compare outcomes between MI-TLIF and open-TLIF groups. A total of 267 patients were included in the study, 114 (43%) who underwent MI-TLIF and 153 (57%) who underwent open TLIF, with an average follow-up of 56.6 weeks (SD 23.5 weeks). After PSM, there were 75 patients in each group. At the latest follow-up both MI- and open-TLIF patients experienced significant improvements in assessment scores obtained with the Oswestry Disability Index (ODI) and the numeric rating scale for low-back pain (NRS-BP), without significant differences between groups (p > 0.05). Both MI- and open-TLIF patients experienced significant improvements in SL, ADH, and percent corrected spondylolisthesis compared to baseline (p < 0.001). However, the MI-TLIF group experienced significantly larger magnitudes of correction with respect to these metrics (ΔSL 4.14° ± 4.35° vs 1.15° ± 3.88°, p < 0.001; ΔADH 4.25 ± 3.68 vs 1.41 ± 3.77 mm, p < 0.001; percent corrected spondylolisthesis: -10.82% ± 6.47% vs -5.87% ± 8.32%, p < 0.001). In the MI-TLIF group, LL improved in 44% (0.3° ± 8.5°) of the cases, compared to 48% (0.9° ± 6.4°) of the cases in the open-TLIF group (p > 0.05). Stratification by operative technique (unilateral vs bilateral facetectomy) and by interbody device (static vs expandable) did not yield statistically significant differences (p > 0.05). Both MI- and open-TLIF patients experienced significant improvements in patient-reported outcome (PRO) measures and local radiographic parameters, with neutral effects on regional alignment. Surprisingly, in our cohort, change in SL was significantly greater in MI-TLIF patients, perhaps reflecting the effect of operative techniques, technological innovations, and the preservation of the posterior tension band. Taking these results together, no significant overall differences in LL between groups were demonstrated, which suggests that MI-TLIF is comparable to open approaches in providing radiographic correction after surgery. These findings suggest that alignment targets can be achieved by either MI- or open-TLIF approaches, highlighting the importance of surgeon attention to these variables.

Clinical and Radiological Outcome in a Series of Patients Treated by Anterior Cervical Discectomy and Fusion: Retrospective Controlled Study With 2 Different Stand-Alone Cages.

Cervical spine balance and alignment targets after cervical spine surgery are poorly established in patients with cervical spine degenerative disease surgically treated by anterior cervical discectomy and fusion (ACDF). The objective of the study is to determine the correlation between radiological and clinical outcomes in patients surgically treated by ACDF with 2 different stand-alone cervical cages. Clinical outcomes were evaluated using visual analog scale (VAS), Neck Disability Index (NDI), Nurick Scale, and Japanese Orthopedic Association score for myelopathy. Radiological evaluation included cervical and segmental Cobb angles, cervical sagittal vertical axis (cSVA), T1 slope (T1s), C0-C2 angle, fusion rates, adjacent segment degeneration, and cage subsidence. A total of 80 patients were included with an average age of 53 years. There was a statistically significant improvement in both clinical and radiological evaluations. There was a statistical significant correlation between cervical pain on cervical VAS and cSVA. There was a significant correlation between postoperative T1s and cSVA, related to the improvement in cervical angles. There was no significant difference in rates of fusion, adjacent segment changes, or reoperation between both cervical cages, and there was a higher rate of subsidence in the Aleutian group. There were significant differences between both groups on postoperative NDI and VAS, but this difference is not maintained during follow-up. Cervical sagittal balance is directly related to clinical outcome in patients with cervical spine degenerative disease. Both cervical implants analyzed were comparable in clinical and radiological outcomes. There are important clinical and radiological parameters that should be taken into account for the analysis of the surgical outcome of patients treated by ACDF; this is one of the few studies that report the results with 2 different cervical cage designs.

P63. Assessing the effects of prehabilitation protocols on postoperative outcomes in adult cervical deformity surgery: does early optimization lead to optimal clinical outcomes?

BACKGROUND CONTEXT Previous studies have demonstrated that preoperative rehabilitation (prehab) may be beneficial in adult cervical deformity surgery. Though protocols vary widely, general overlap exists in terms of inclusion of mental and physical modalities in order to optimize patient outcomes. However, there remains a paucity of literature in regards to assessing outcomes in a controlled setting. PURPOSE To assess the effects of prehabilitation on peri- and postoperative outcomes in adult cervical deformity surgery. STUDY DESIGN/SETTING Retrospective review of prospective CD database. PATIENT SAMPLE A total of 290 CD patients. OUTCOME MEASURES Peri- and postoperative complication rates; medication usage; HRQLs. METHODS Operative CD patients 18yrs with complete pre-(BL) and 2-year(2Y) postop radiographic/HRQL data were stratified by enrollment in prehabilitation protocols beginning in 2019, consisting of physical therapy, nutritional counseling and/or psychological counseling. Patients were stratified as having underwent prehabilitation (Prehab+), versus those who did not (Prehab-). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors and complication rates were assessed via means comparison analysis. Costs were calculated using PearlDiver database estimates from Medicare pay-scales. QALY was calculated via NDI mapped to SF6D using validated methods. RESULTS A total of 115 patients were included (56.37±8.90 years, 38% female, 29.84±6.19 kg/m2). Of these patients, 57 (49.6%) were classified as Prehab+. At baseline, groups were comparable in age, gender, BMI, CCI and frailty. In terms of BL HRQLs, Prehab+ significantly lower mJOA scores (p=.047), though were equivalent in NDI and EQ5D scores (both p>.05). Baseline opioid usage was comparable prior to prehab enrollment (p=.093). Surgically, Prehab+ were able to undergo longer procedures (p=.017) with equivalent EBL (p=.627), and shorter SICU stay (p.05) and QALYs gained by 2Y (.43 vs .40, p>.05). CONCLUSIONS This study demonstrates that introducing prehabilitation protocols in adult cervical deformity surgery may aid in improving patient physiological status, enabling them to undergo longer surgeries with lessened risk of peri- and postoperative complications. Though cost-effectiveness of such programs should be further assessed, prehabilitation should be considered for eligible patients to assist in optimizing recovery and reducing complications or reoperations. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Previous studies have demonstrated that preoperative rehabilitation (prehab) may be beneficial in adult cervical deformity surgery. Though protocols vary widely, general overlap exists in terms of inclusion of mental and physical modalities in order to optimize patient outcomes. However, there remains a paucity of literature in regards to assessing outcomes in a controlled setting. To assess the effects of prehabilitation on peri- and postoperative outcomes in adult cervical deformity surgery. Retrospective review of prospective CD database. A total of 290 CD patients. Peri- and postoperative complication rates; medication usage; HRQLs. Operative CD patients 18yrs with complete pre-(BL) and 2-year(2Y) postop radiographic/HRQL data were stratified by enrollment in prehabilitation protocols beginning in 2019, consisting of physical therapy, nutritional counseling and/or psychological counseling. Patients were stratified as having underwent prehabilitation (Prehab+), versus those who did not (Prehab-). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors and complication rates were assessed via means comparison analysis. Costs were calculated using PearlDiver database estimates from Medicare pay-scales. QALY was calculated via NDI mapped to SF6D using validated methods. A total of 115 patients were included (56.37±8.90 years, 38% female, 29.84±6.19 kg/m2). Of these patients, 57 (49.6%) were classified as Prehab+. At baseline, groups were comparable in age, gender, BMI, CCI and frailty. In terms of BL HRQLs, Prehab+ significantly lower mJOA scores (p=.047), though were equivalent in NDI and EQ5D scores (both p>.05). Baseline opioid usage was comparable prior to prehab enrollment (p=.093). Surgically, Prehab+ were able to undergo longer procedures (p=.017) with equivalent EBL (p=.627), and shorter SICU stay (p.05) and QALYs gained by 2Y (.43 vs .40, p>.05). This study demonstrates that introducing prehabilitation protocols in adult cervical deformity surgery may aid in improving patient physiological status, enabling them to undergo longer surgeries with lessened risk of peri- and postoperative complications. Though cost-effectiveness of such programs should be further assessed, prehabilitation should be considered for eligible patients to assist in optimizing recovery and reducing complications or reoperations.