Correction Of Sagittal Deformity Research Articles

Guiding significance of intra-articular sagittal reduction in the treatment of tibial plateau fractures

Tibial plateau fracture is a fracture involving the proximal articular surface of the tibia, and its injury mechanism is complex, the fracture morphology is different, and it is often accompanied by different degrees of soft tissue injury, which is difficult to diagnose and treat. In recent years, the research hotspot has focused on solving the reduction and fixation of the posterior lateral column of the tibial plateau, because it has been clinically found that the residual sagittal plane after tibial plateau fracture is insufficient reduction or loss of reduction leads to knee joint dysfunction. The posterior inclination angle of the tibial plateau is an important parameter to describe the sagittal alignment of the tibia. In the natural state, the posterior tibial slope(PTS) is altered to involve the soft tissues around the knee joint such as anterior cruciate ligament(ACL) and posterior cruciate ligament(PCL), which affects the stability of the knee joint. In total knee arthroplasty(TKA), choosing the appropriate PTS can effectively increase the prosthesis survival rate, improve the flexion and extension knee efficacy, which is beneficial to knee joint stability. In the field of orthopedic trauma, correction of sagittal deformity is equally important, following the principle of "reverse mechanism of injury". Quantitative evaluation of postoperative sagittal realignment of tibial plateau fractures and investigation of the effect of sagittal realignment on long-term outcomes and complications are still poorly understood and require further clinical and biomechanical studies.

Initial Experience With VELYS Robot-Assisted Total Knee Replacement: Coronal Plane Accuracy and Effect of Robotic Training on Outcomes.

The use of robots for arthroplasty is gaining momentum inrecent times to provide accuracy in bony cuts and alignment. We aimed to study the efficacy of coronal plane correction with a new robotic system (VELYS™Robotic-Assisted Surgery) and also the effect of the learning curve of robot-assisted total knee arthroplasty (RATKA) on outcomes. We hypothesize that the benefits of RATKA are not limited to only surgeons having specific training in robotic knee replacement. A total of 101 RATKAs were performed between November 1, 2022, andDecember 1, 2022, by a surgeon and all the cases were included in this study. The first 50 consecutive knees were considered as 'Cohort I' and the next 51 consecutive knees as 'Cohort II'. The intraoperative robotic registration data and tourniquet time were recorded. On three months follow‑up, Oxford Knee Score and lower limb scannogram were recorded. All the 101 cases achieved the desired coronal plane alignment within 3 degrees from neutral. There was a significant difference in the tourniquet time between the two groups. There was no significant difference in the mean three months post-operative values of coronal and sagittal deformity correction, range of flexion, and Oxford Knee Score between the two groups. The VELYS™​​​​​​​robot-assisted system produces an accurate correction of coronal alignment. As the surgeon's experience increases with the system, there is a reduction in tourniquet time; however, the degree of deformity correction is comparable to that when he had no experience. Hence the benefits of RATKA are not limited to only surgeons having specific training in robotic-assisted knee replacement.

Contemporary utilization of three-column osteotomy techniques in a prospective complex spinal deformity multicenter database: implications on full-body alignment and perioperative course.

Research has focused on the increased correction from a three-column osteotomy (3CO) during adult spinal deformity (ASD) surgery. However, an in-depth analysis on the performance of a 3CO in a cohort of complex spinal deformity cases has not been described. This is a retrospective study on a prospectively enrolled, complex ASD database. This study aimed to determine if three-column osteotomies demonstrate superior benefit in correction of complex sagittal deformity at the cost of increased perioperative complications. Surgical complex adult spinal deformity patients were included and grouped into thoracolumbar 3COs compared to those who did not have a 3CO (No 3CO) (remaining cohort). Rigid deformity was defined as ΔLL less than 33% from standing to supine. Severe deformity was defined as global (SVA > 70mm) or C7-PL > 70mm, or lumbopelvic (PI-LL > 30°). Means comparison tests assessed correction by 3CO grade/location. Multivariate analysis controlling for baseline deformity evaluated outcomes up to six weeks compared to No 3CO. 648 patients were included (Mean age 61 ± 14.6years, BMI 27.55 ± 5.8kg/m2, levels fused: 12.6 ± 3.8). 126 underwent 3CO, a 20% higher usage than historical cohorts. 3COs were older, frail, and more likely to undergo revision (OR 5.2, 95% CI [2.6-10.6]; p < .001). 3COs were more likely to present with both severe global/lumbopelvic deformity (OR 4), 62.4% being rigid. 3COs had greater use of secondary rods (OR 4st) and incurred 4 times greater risk for: massive blood loss (> 3500mL), longer LOS, SICU admission, perioperative wound and spine-related complications, and neurologic complications when performed below L3. 3COs had similar HRQL benefit, but higher perioperative opioid use. Mean segmental correction increased by grade (G3-21; G4-24; G5-27) and was 4 × greater than low-grade osteotomies, especially below L3 (OR 12). 3COs achieved 2 × greater spinopelvic correction. Higher grades properly distributed lordosis 50% of the time except L5. Pelvic compensation and non-response were relieved more often with increasing grade, with greater correction in all lower extremity parameters (p < .01). Due to the increased rate of complications, 3COs trended toward higher perioperative cost ($42,806 vs. $40,046, p = .086). Three-column osteotomy usage in contemporary complex spinal deformities is generally limited to more disabled individuals undergoing the most severe sagittal and coronal realignment procedures. While there is an increased perioperative cost and prolongation of length of stay with usage, these techniques represent the most powerful realignment techniques available with a dramatic impact on normalization at operative levels and reciprocal changes.

Correction of Sagittal Deformity with Bone Resection and Soft Tissue Releases.

Fixed flexion deformities (FFDs) present several unique challenges in total knee arthroplasty (TKA) and require careful consideration to achieve optimal outcomes. FFD alters normal knee biomechanics and increases energy expenditure. They may be attributed to both bony deformities and fibrosed soft tissues, which must be addressed in stepwise fashion at the time of surgery. A literature review was conducted utilizing keywords "fixed flexion deformity TKA." This review article aims to discuss the anatomy and pathology, preoperative evaluation, classification system, surgical techniques for addressing deformity, implant selection considerations, postoperative protocols, clinical outcomes, and potential complications associated with correcting FFD. By comprehensively addressing these aspects, surgeons can optimize surgical planning and improve outcomes in patients with FFD undergoing TKA.

Unilateral Minimally Invasive Across-Midline Vertebral Column Resection Partially Corrects Thoracolumbar Kyphosis – A Case Series

The goal of this study was to describe the indirect and partial correction of spine kyphotic deformities (secondary to various pathologies) achieved by minimally invasive posterolateral extracavitary approach (MIS-PLECA) for corpectomy. The authors retrospectively reviewed a consecutive case series of 12 patients undergoing MIS PLECA in a single institution. Perioperative data were collected and follow-up CTs and radiographs were reviewed to assess for interbody arthrodesis. The mean age was 60.7 ± 20.8 years (58.4% males). The etiologies of deformity included pathological fracture (41.6%), acute trauma (30%), and infection. An expandable cage was used in 66.7% of patients for anterior reconstruction. The mean total EBL was 764.1 ± 332.9 ml. The mean operative time was 413.3 ± 98.8 min. The average length of hospital stay was 5.8 ± 2.5 days. A consistent degree of focal correction of sagittal alignment was seen in all patients with a mean correction of sagittal angle of 7.4 ± 4.3 degrees (P<.0001). The mean duration of rehabilitation was 8.5 ± 6.7 days. All patients remained neurologically stable at the last follow-up with a mean follow-up period of 20.1 ± 12.8 months. Successful fusion was achieved in 91.7% at the last follow-up. MIS PLECA for corpectomy appears to be a feasible, safe, and effective MIS technique for select patients, particularly those who cannot tolerate the traditional open approach. Additionally, a focal sagittal deformity correction can be achieved using MIS corpectomy.

Does the Amount of Correction of Sagittal Deformity Really Promote Proximal Junctional Kyphosis? Multivariate Analyses According to Uppermost Instrumented Vertebra Levels

The present study assumed that the effects of deformity correction amounts on proximal junctional kyphosis (PJK) development after long deformity surgery would vary according to uppermost instrumented vertebrae (UIV) levels. Our study was to reveal the association between the amount of correction and PJK according to UIV levels. Adult spinal deformity patients aged >50years who underwent thoracolumbar fusion (≥4 levels) were included. PJK was defined by proximal junctional angles ≥15°. Presumed demographic and radiographic risk factors for PJK were evaluated including parameters regarding the correction amount such as postoperative change in lumbar lordosis and postoperative offset grouping, the value associated with age-adjusted pelvic incidence-lumbar lordosis mismatch. The patients were divided according to UIV levels of T10 or above (group A) and T11 or below (group B). Multivariate analyses were performed separately for both groups. The present study included 241 patients (74 for group A and 167 for group B). PJK developed in approximately half of all patients within an average of 5 years of follow-up. For group A, only body mass index (P= 0.002) was associated with PJK. No radiographic parameters were correlated. For group B, postoperative change in lumbar lordosis (P= 0.009) and offset value (P= 0.030) were significant risk factors for PJK development. The correction amount of sagittal deformity increased the risk of PJK only in patients with UIV at or below T11. However, it was not associated with PJK development in patients with UIV at or above T10.

How does the use of quantified gap-balancing affect component positioning and limb alignment in robotic total knee arthroplasty using functional alignment philosophy? A comparison of two robotic platforms

PurposeThis study aimed to compare the effect of an image-based (MAKO) system using a gap-balancing technique with an imageless (OMNIbot) robotic tool utilising a femur-first measured resection technique.MethodsA retrospective cohort study was performed on patients undergoing primary TKA with a functional alignment philosophy performed by a single surgeon using either the MAKO or OMNIbot robotic systems. In all cases, the surgeon’s goal was to create a balanced knee and correct sagittal deformity (eliminate any fixed flexion deformity). Intra-operative data and patient-reported outcomes (PROMS) were compared.ResultsA total of 207 MAKO TKA and 298 OMNIbot TKAs were analysed. MAKO TKA patients were younger (67 vs 69, p=0.002) than OMNIbot patients. There were no other demographic or pre-operative alignment differences. Regarding implant positioning, in MAKO TKAs the femoral component was more externally rotated in relation to the posterior condylar axis (2.3° vs 0.1°, p<0.001), had less valgus femoral cuts (1.6° vs 2.7° valgus, p<0.001) and more varus tibial cuts (2.4° vs 1.9° varus, p<0.001), and had more bone resected compared to OMNIbot TKAs. OMNIbot cases were more likely to require tibial re-cuts than MAKO (15% vs 2%, p<0.001). There were no differences in femur recut rates, soft tissue releases, or rate of achieving target coronal and sagittal leg alignment between robotic systems. A subgroup analysis of 100 MAKO and 100 OMNIbot propensity-matched TKAs with 12-month follow-up showed no significant difference in OKS (42 vs 43, p=0.7) or OKS PASS scores (83% vs 91%, p=0.1). MAKO TKAs reported significantly better symptoms according to their KOOS symptoms score than patients that had OMNIbot TKAs (87 vs 82, p=0.02) with a higher proportion of KOOS PASS rates, at a slightly longer follow-up time (20 months vs 14 months, p<0.001). There were no other differences in PROMS.ConclusionA gap-balanced technique with an image-based robotic system (MAKO) results in different implant positioning and bone resection and reduces tibial recuts compared to a femur-first measured resection technique with an imageless robotic system (OMNIbot). Both systems achieve equal coronal and sagittal deformity correction and good patient outcomes at short-term follow-ups irrespective of these differences.

Defining Cervical Sagittal Plane Deformity - When Are Sagittal Realignment Procedures Necessary in Patients Presenting Primarily With Radiculopathy or Myelopathy?

It remains unclear whether cervical sagittal deformity (CSD) should be defined by radiographic parameters alone versus both clinical and radiographic factors, and whether radiographic malalignment by itself warrants a CSD corrective surgery in patients who present primarily with neurologic symptoms. We administered a survey to a group of expert surgeons to evaluate whether radiographic parameters alone were sufficient to diagnose CSD, and in which scenarios surgeons recommend a CSD realignment procedure versus addressing the neurologic symptoms alone. No single radiographic criteria reached a 50% threshold as being sufficient to establish the diagnosis of CSD. When asymptomatic radiographic malalignment was present, a sagittal deformity correction was more likely to be recommended in patients with myelopathy versus those with radiculopathy alone. The majority of surgeons recommended deformity correction when symptoms of cervical deformity were present in addition to radiographic malalignment (85% with deformity symptoms and radiculopathy, 93% with deformity symptoms and myelopathy). There is no consensus on which radiographic and/or clinical criteria are necessary to define the presence of CSD. We recommend that symptoms of cervical deformity, in addition to radiographic parameters, be considered when deciding whether to perform deformity correction in patients who present primarily with myelopathy or radiculopathy.

Современные аспекты предоперационного планирования и выбора хирургической методики ревизионной реконструкции передней крестообразной связки

Introduction Reconstruction of the anterior cruciate ligament (ACL) is one of the most common surgical procedures around the knee. Despite good long-term outcomes in general, thousands of revisions after ACL reconstruction are performed annually in the world due to graft failures, repeated injuries, technical errors, disorders in ligamentization process or inadequate rehabilitation. The aim of the study was to evaluate the current evidence and describe the relevant clinical features of planning and performing revision ACL reconstruction. Materials and methods A search was conducted for English- and Russian-language publications in the electronic databases PubMed and e-LIBRARY for the period from 2000 to 2020 using the keywords: anterior cruciate ligament, ACL, revision, re-reconstruction, re-rupture. Among 572 publications, 107 corresponded to the study topic. Based on the inclusion criteria (more than 50 reported cases; follow-up more than 2 years; homogeneous groups of patients; assessment with knee function scores; application of various imaging options), 31 articles were included in this review. There were no Russian studies that met the above-mentioned criteria. Results and discussion The analysis of the literature identified four clinically relevant features in the treatment of patients with failures of ACL reconstruction: criteria and principles for the implementation of a one- or two-stage approach; additional features of the revision ACL reconstruction; determination of the optimal graft type. Conclusion Most of the revision ACL reconstructions can be performed at one stage, combined with bone grafting if needed. For a successful treatment outcome, in some cases, correction of frontal and sagittal deformity of the lower limb, management of the injury to other knee joint stabilizers, to cartilage or menisci is required. Surgeons’ preferences in the choice of plastic material has shifted to autografts with bone blocks, or allografts, especially if reconstruction of several stabilizers is necessary.

Improved Surgical Correction Relative to Patient-Specific Ideal Spinopelvic Alignment Reduces Pelvic Nonresponse for Severely Malaligned Adult Spinal Deformity Patients.

Persistent pelvic compensation following adult spinal deformity (ASD) corrective surgery may impair quality of life and result in persistent pathologic lower extremity compensation. Ideal age-specific alignment targets have been proposed to improve surgical outcomes, though it is unclear whether reaching these ideal targets reduces rates of pelvic nonresponse following surgery. Our aim was to assess the relationship between pelvic nonresponse, age-specific alignment, and lower-limb compensation following surgery for ASD. Single-center retrospective cohort study. ASD patients were grouped: those who did not improve in Scoliosis Research Society-Schwab pelvic tilt (PT) modifier (pelvic nonresponders [PNR]), and those who improved (pelvic responders [PR]). Groups were propensity score matched for preoperative PT and assessed for differences in spinal and lower extremity alignment. Rates of pelvic nonresponse were compared across patient groups who were undercorrected, overcorrected, or matched age-specific postoperative alignment targets. A total of 146 surgical ASD patients, 47.9% of whom showed pelvic nonresponse following surgery, were included. After propensity score matching, PNR (N = 29) and PR (N = 29) patients did not differ in demographics, preoperative alignment, or levels fused; however, PNR patients have less preoperative knee flexion (9° vs 14°, P = 0.043). PNR patients had inferior postoperative pelvic incidence and lumbar lordosis (PI-LL) alignment (17° vs 3°) and greater pelvic shift (53 vs 31 mm). PNR and PR patients did not differ in rates of reaching ideal age-specific postoperative alignment for sagittal vertical axis (SVA) or PI-LL, though patients who matched ideal PT had lower rates of PNR (25.0% vs 75.0%). For patients with moderate and severe preoperative SVA, more aggressive correction relative to either ideal postoperative PT or PI-LL was associated with significantly lower rates of pelvic nonresponse (all P < 0.05). For patients with moderate to severe baseline truncal inclination, more aggressive surgical correction relative to ideal age-specific PI-LL was associated with lower rates of pelvic nonresponse. Postoperative alignment targets may need to be adjusted to optimize alignment outcomes for patients with substantial preoperative sagittal deformity. These findings increase our understanding of the poor outcomes that occur despite ideal realignment. Surgical correction of severe global sagittal deformity should be prioritized to mitigate these occurrences.

Ponte osteotomies increase risk of intraoperative neuromonitoring alerts in adolescent idiopathic scoliosis surgery.

Background: Ponte osteotomies (PO) are commonly used in adolescent idiopathic scoliosis (AIS) surgeries to improve the coronal and sagittal deformity correction. Here, we compared the incidence of perioperative neurologic complications for patients undergoing AIS with versus without PO.Methods: In a retrospective cohort study of 80 consecutive AIS patients undergoing scoliosis correction, 40 underwent PO, while 40 did not. All operations were performed by one surgeon at one tertiary care center. Patients’ demographics, Lenke classifications, surgical data, and deformity characteristics were comparable in both groups. Perioperative neurologic complications, defined as spinal cord or nerve root injuries identified by the surgeon, were tracked for those undergoing AIS surgery with or without PO being performed.Results: The risk of IOM alerts was significantly higher in the PO patients (12.5%: 5 patients) versus those in the No-PO group (0%, P = 0.021). Despite these changes, no patient incurred an increased postoperative deficit. Nevertheless, PO group patients demonstrated a higher coronal deformity correction rate (PO: 71% ± 10.9 vs. NoPO: 64.2% ± 11.5, P = 0.008) and a greater kyphosis Cobb angle (PO: 25.2 ± 6 vs. No-PO: 17.5 ± 9.4, P = 0.0001) on postoperative follow-up.Conclusion: While PO improved 3D correction of AIS, it increased the risk of IOM alerts in 12.5% of cases.

Study of Functional Outcome of Posterior Lumbar Interbody Fusion Technique with Implant in Degenerative Spondylolisthesis at L4 and L5 Level

Background: Lumbar interbody fusion is the most reliable fusion technique currently available for the lumbar spine as these constructs are biomechanically stronger, provide axial support with less graft subsidence or collapse comparing to those with posterolateral arthrodesis, and produce a better biologic fusion in lordotic alignment1, 2. Aims and Objectives: To study functional outcome of posterior lumbar interbody fusion technique with implant in degenerative spondylolisthesis at L4 and L5 level. Materials and Methods: The study was carried on 34 patients enlisting in the casualty or inpatient department of orthopaedics at a medical college and tertiary health care centre. Only those patients satisfying the inclusion and exclusion criteria were included in the study. All the patients were explained about the surgical procedure, the purpose of the study and Informed consent was taken. Results: As per Japanese Orthopaedic Association score, Normal results were observed in none of the cases while grade I, II and III was observed in 73.5%, 20.6% and 5.9% cases. Post-op results were observed as normal in 64.7% while Grade I, II and III was observed in 32.4% and 2.9% cases respectively (p&lt;0.01). Conclusion: Present study concluded that although, long-term role of deformity correction and restoration of lumbar spinal balance in cases of spondylolisthesis is yet to be determined, the current study appears to indicate that satisfactory radiological correction of degenerative focal sagittal deformity can be achieved with the insert and-rotate PLIF technique. There appeared to be high levels of patient satisfaction in this relatively short-term study and low levels of complications. Longer-term and comparative clinical outcome studies are required.

Quality metrics in adult spinal deformity surgery over the last decade: a combined analysis of the largest prospective multicenter data sets.

The reported rate of complications and cost of adult spinal deformity (ASD) surgery, associated with an exponential increase in the number of surgeries, cause alarm among healthcare payers and providers worldwide. The authors conjointly analyzed the largest prospective available ASD data sets to define trends in quality-of-care indicators (complications, reinterventions, and health-related quality of life [HRQOL] outcomes) since 2010. This is an observational prospective longitudinal cohort study. Patients underwent surgery between January 2010 and December 2016, with > 2 years of follow-up data. Demographic, surgical, radiological, and HRQOL (i.e., Oswestry Disability Index, SF-36, Scoliosis Research Society-22r) data obtained preoperatively and at 3, 6, 12, and 24 months after surgery were evaluated. Trends and changes in indicators were analyzed using local regression (i.e., locally estimated scatterplot smoothing [LOESS]) and adjusted odds ratio (OR). Of the 2286 patients included in the 2 registries, 1520 underwent surgery between 2010 and 2016. A total of 1151 (75.7%) patients who were treated surgically at 23 centers in 5 countries met inclusion criteria. Patient recruitment increased progressively (2010-2011 vs 2015-2016: OR 1.64, p < 0.01), whereas baseline clinical characteristics (age, American Society of Anesthesiologists class, HRQOL scores, sagittal deformity) did not change. Since 2010 there has been a sustained reduction in major and minor postoperative complications observed at 90 days (major: OR 0.59; minor: OR 0.65; p < 0.01); at 1 year (major: OR 0.52; minor: 0.75; p < 0.01); and at 2 years of follow-up (major: OR 0.4; minor: 0.80; p < 0.01) as well as in the 2-year reintervention rate (OR 0.41, p < 0.01). Simultaneously, there has been a slight improvement in the correction of sagittal deformity (i.e., pelvic incidence-lumbar lordosis mismatch: OR 1.11, p = 0.19) and a greater gain in quality of life (i.e., Oswestry Disability Index 26% vs 40%, p = 0.02; Scoliosis Research Society-22r, self-image domain OR 1.16, p = 0.13), and these are associated with a progressive reduction of surgical aggressiveness (number of fused segments: OR 0.81, p < 0.01; percent pelvic fixation: OR 0.66, p < 0.01; percent 3-column osteotomies: OR 0.63, p < 0.01). The best available data show a robust global improvement in quality metrics in ASD surgery over the last decade. Surgical complications and reoperations have been reduced by half, while improvement in disability increased and correction rates were maintained, in patients with similar baseline characteristics.

Mid-Term Results after Lateral Transfibular Approach Total Ankle Arthroplasty

Category:Ankle Arthritis; AnkleIntroduction/Purpose:Continued improvements in total ankle arthroplasty (TAA) implant design have led to promising clinical outcomes. The lateral transfibular approach TAA allows for excellent visualization of the center of rotation of the ankle and allows for correction of rotational and sagittal deformity by shortening or lengthening of the fibula. Furthermore, the curved implant design allows for minimal bony resection. The purpose of this study is to report the medium-term clinical and radiographic results for consecutive patients who underwent the lateral approach TAA.Methods:IRB approval was obtained for this study. Consecutive patients who underwent lateral approach TAA for tibiotalar arthritis by a single surgeon were enrolled on a prospective basis from January 2013 to June 2015. This time period represented the initial case series of TAA performed by the surgeon. Patient reported outcomes (PROs) were collected including the Ankle Osteoarthritis Scale (AOS), 12-item short-form survey (SF-12), and Visual Analogue Pain Scale (VAS). The need for subsequent procedures was recorded. Radiographs were evaluated for preoperative and postoperative alignment using the lateral distal tibial angle (LDTA), tibiotalar surface angle (TTS), anterior distal tibia angle (ADTA), and the lateral talar station (LTS). Radiographs were also evaluated for the development of peri-implant lucency and subsidence. Data was tested for normality. T-tests were used to determine differences between preoperative data and postoperative data. A p<0.05 was considered significant.Results:53 patients who underwent 59 TAA procedures were included. Average follow-up was 5.7 +/- 0.9 years. Average age was 53 +/- 7.0. Comorbidities included smoking (11/53), diabetes (6/53), and prior procedures (33/53). Sixteen ankles (27%) underwent one or more subsequent procedures including gutter debridement (7/59), debridement for periprosthetic infection (3/59), and removal of hardware (7/59). All fibular osteotomies healed. Four ankles had asymptomatic peri-implant lucency or cysts (4/59). No patients had subsidence or required revision of the tibial or talar components. Coronal and sagittal alignment were significantly improved for all measures (p<0.05). VAS scores improved from a mean of 7.5 preoperatively to 1 at final follow- up (p<0.0001). SF-12 physical component scores improved from 34 to 41.5 (p=0.0227). AOS scores improved from 54.8 to 19.1 (p<0.0001).Conclusion:At medium term follow-up, patient reported outcomes remain significantly improved in patients after lateral approach TAA. There were very few radiographic findings of lucency and cyst formation, and all of these were asymptomatic. No revision of metal implants was required. Excellent deformity correction was achieved. The rate of subsequent procedures was high, although the rate of actual component revision was 0%. Lateral approach TAA appears to have overall good outcomes at medium term follow-up.

Correction to: Anterior versus posterior spinal fusion for Lenke type 5 adolescent idiopathic scoliosis: a systematic review and meta-analysis of comparative studies

PURPOSE To review and compare clinical and radiologic outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) for the treatment of Lenke type 5 adolescent idiopathic scoliosis (AIS). METHODS A systematic review was performed according to Preferred reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. All level I-III evidence studies investigating the clinical and radiologic outcomes of ASF and PSF for the treatment of Lenke type 5 AIS were included. RESULTS Nine studies (285 ASF patients, 298 PSF patients) were included. ASF was associated with a significantly lower number of levels fused compared with PSF (p < 0.01) with similar immediate and long-term coronal deformity correction (p = 0.16; p = 0.12, respectively). PSF achieved a better correction of thoracic hypokyphosis in one study and lumbar hypolordosis in three studies. PSF was associated with a significant shorter length of stay (LOS) compared with ASF (p < 0.01). One long-term study demonstrated a significantly higher rate of proximal junctional kyphosis (PJK) with PSF compared with ASF. There were no significant differences in major complication or re-operation rates. CONCLUSION For the treatment of Lenke type 5 AIS, there is moderate evidence to suggest that ASF requires a lower number of instrumented levels to achieve similar immediate and long-term coronal deformity correction compared with PSF. There is some evidence to suggest that PSF may achieve better thoracic and lumbar sagittal deformity correction compared with ASF. There is some evidence to suggest a higher incidence of PJK at long-term follow-up with PSF compared with ASF. ASF is associated with a longer post-operative LOS compared with PSF.

Maximizing mechanical advantage: surgical technique increases stiffness in spinal instrumentation.

While there has been a great improvement in the treatment of adolescent idiopathic scoliosis, sagittal deformity correction has remained challenging. Increased rod stiffness has been shown to reduce thoracic flattening. We propose that the surgical technique can increase rod stiffness. A mechanical study was created to quantify the effect this has on construct stiffness. The sagittal bending stiffness of a constrained over contoured rod was measured using four different commonly used instrumentation systems. Pedicle screws were secured into custom printed blocks. One block was completely immobilized, while the other block was subject to four levels of constraint. This includes no constraint, mild constraint, moderate constraint, and maximal constraint with both blocks immobilized. The rod apex was loaded until 1cm of displacement occurred. The stiffness was then calculated and compared between groups. All four rod types showed increased bending stiffness as the construct became more constrained. The moderately constrained and the maximally constrained groups had a significantly higher stiffness compared to the unconstrained groups in all rod types (p < 0.05). The 6.0mm titanium circular rods showed the highest increase in stiffness between maximal and no constraint, which became 3.02 × stiffer. Rod stiffness is not only determined by size, shape, and metal alloy, but also by surgical technique. Constraining the spinal instrumentation by first locking the rod to the proximal and distal anchors significantly increases the sagittal bending stiffness. In a mechanical model this technique increases rod bending stiffness regardless of the material or shape.

Anterior versus posterior spinal fusion for Lenke type 5 adolescent idiopathic scoliosis: a systematic review and meta-analysis of comparative studies.

To review and compare clinical and radiologic outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) for the treatment of Lenke type 5 adolescent idiopathic scoliosis (AIS). A systematic review was performed according to Preferred reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. All level I-III evidence studies investigating the clinical and radiologic outcomes of ASF and PSF for the treatment of Lenke type 5 AIS were included. Nine studies (285 ASF patients, 298 PSF patients) were included. ASF was associated with a significantly lower number of levels fused compared with PSF (p < 0.01) with similar immediate and long-term coronal deformity correction (p = 0.16; p = 0.12, respectively). PSF achieved a better correction of thoracic hypokyphosis in one study and lumbar hypolordosis in three studies. PSF was associated with a significant shorter length of stay (LOS) compared with ASF (p < 0.01). One long-term study demonstrated a significantly higher rate of proximal junctional kyphosis (PJK) with PSF compared with ASF. There were no significant differences in major complication or re-operation rates. For the treatment of Lenke type 5 AIS, there is moderate evidence to suggest that ASF requires a lower number of instrumented levels to achieve similar immediate and long-term coronal deformity correction compared with PSF. There is some evidence to suggest that PSF may achieve better thoracic and lumbar sagittal deformity correction compared with ASF. There is some evidence to suggest a higher incidence of PJK at long-term follow-up with PSF compared with ASF. ASF is associated with a longer post-operative LOS compared with PSF.

107. Cervical alignment and distal junctional failure in posterior cervical fusion: a multicenter comparison of two surgical approaches

<h3>BACKGROUND CONTEXT</h3> Posterior cervical fusion (PCF) is successfully used to treat cervical spondylotic myelopathy, multilevel cervical stenosis, and cervical deformity. However, limited evidence exists regarding the appropriate level of proximal and distal extension of PCF constructs. Further investigation is required to understand the effects of construct endpoint on fusion rate, junctional failure, and sagittal deformity correction. <h3>PURPOSE</h3> To compare the surgical and radiographic outcomes of patients undergoing posterior cervical fusion (PCF) with constructs extending from C2-T2 to patients with constructs extending from C3-T1. <h3>STUDY DESIGN/SETTING</h3> This was a multicenter retrospective review of two prospective cohorts of patients undergoing PCF from C2-T2 or C3-T1 for subaxial cervical stenosis at two academic institutions from 2012 to 2020. <h3>PATIENT SAMPLE</h3> We identified 106 patients for inclusion in the C2-T2 cohort and 49 patients for inclusion in the C3-T1 cohort. <h3>OUTCOME MEASURES</h3> Pre- and postoperative cervical alignment parameters, distal screw loosening, distal junctional failure, and pseudarthrosis were measured. <h3>Methods</h3> Cervical alignment parameters were measured on both preoperative and postoperative radiographs performed greater than 6 months postoperatively. The cohorts were compared based on preoperative cervical alignment, postoperative cervical alignment, and change in cervical alignment. Postoperative radiographs were also assessed for signs of distal screw loosening, distal junctional failure, and pseudarthrosis. We utilized Student's t-test to compare all means between groups with p<0.05 deemed statistically significant. <h3>Results</h3> A total of 155 patients were included in the study (C2-T2: 106 patients, C3-T1: 49 patients). There were no significant differences in demographics or preoperative symptoms between cohorts. Fusion rates were significantly higher in the C2-T2 (93%) than the C3-T1 (80%, p=0.040) cohort. When comparing the C2-T2 to the C3-T1 cohort, the C3-T1 cohort had a significantly greater rate of proximal junctional failure (2% vs 10%, p=0.006), distal junctional failure (1% vs 20%, p<0.001) and distal screw loosening (4% vs 15%, p=0.02). Although ΔC2-7 Sagittal vertical axis increased significantly in both cohorts (C2-T2: 6.2°, p=0.04; C3-T1: 8.4°, p<0.001), correction did not significantly differ between groups (p=0.32). The C3-T1 cohort had a significantly greater increase in ΔC2 Slope (8.0° vs 3.1°, p=0.03) and ΔC0-C2 Cobb angle (6.4° vs 1.2°, p=0.04) <h3>Conclusions</h3> In patients undergoing PCF, a C2-T2 construct demonstrated lower rates of pseudarthrosis, DJF, PJF, and compensatory upper cervical hyperextension compared to a C3-T1 construct. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Sagittal deformity correction with expandable cages with large endplates for thoracolumbar vertebral body replacement

Sagittal deformity correction with expandable cages with large endplates for thoracolumbar vertebral body replacement

Restoring spinopelvic harmony with lateral lumbar interbody fusion: is it a realistic goal?

The importance of spinopelvic harmony [pelvic incidence (PI) = lumbar lordosis (LL) ±10 degrees] is well established in the literature. We aimed to determine whether lateral lumbar interbody fusion (LLIF) surgery in isolation is successful in restoring spinopelvic harmony, and whether the surgery maintained the relationship in those who present in a balanced state. A retrospective radiographic analysis was performed on patients who underwent LLIF surgery, followed by posterior instrumented fusion, between January 2012 to August 2019 by a single surgeon (AD). Pre- and post-operative X-rays were reviewed by two authors using Surgimap spinal imaging 2.2.15.5. The LL, PI, and PI-LL mismatch, as well as a range of coronal and segmental sagittal radiographic parameters, were recorded. A total of 71 patients with 170 levels treated via LLIF were analysed. A mean pre-operative PI-LL of 14.3 degrees and post-operative value of 13.4 degrees was recorded (P=0.43). Of the 41 patients who were imbalanced pre-operatively, 13 (31.7%) were restored to a LL within 10 degrees of PI post-LLIF procedure. 30 patients presented in spinopelvic harmony, and 25 (83.3%) of those maintained that relationship following LLIF. Mean coronal global Cobb angles (13.7 degrees pre-operatively to 7.7 degrees post-operatively), segmental coronal Cobb angles (3.8 to 0.9 degrees), and anterior (5.2 to 9.8 mm) and posterior (3.2 to 6.7 mm) disc heights all improved significantly post-LLIF surgery (P<0.0001). Although an effective treatment for coronal deformities and providing indirect decompression for degenerative lumbar disc disease, LLIF surgery alone is unlikely to result in correction of sagittal deformity and in particular spinopelvic harmony.