Tatton-Brown-Rahman syndrome: Novel pathogenic variants and new neuroimaging findings.

Tatton-Brown-Rahman syndrome (TBRS) or DNMT3A-overgrowth syndrome is characterized by overgrowth and intellectual disability associated with minor dysmorphic features, obesity, and behavioral problems. It is caused by variants of the DNMT3A gene. We report four patients with this syndrome due to de novo DNMT3A pathogenic variants, contributing to a deeper understanding of the genetic basis and pathophysiology of this autosomal dominant syndrome. Clinical and magnetic resonance imaging assessments were also performed. All patients showed corpus callosum anomalies, small posterior fossa, and a deep left Sylvian fissure; as well as asymmetry of the uncinate and arcuate fascicles and marked increased cortical thickness. These results suggest that structural neuroimaging anomalies have been previously overlooked, where corpus callosum and brain tract alterations might be unrecognized neuroimaging traits of TBRS syndrome caused by DNMT3A variants.

Vertebral bone quality score as a novel predictor of proximal junctional kyphosis after thoracic adolescent idiopathic scoliosis surgery.

INTRODUCTION: Proximal junctional kyphosis (PJK) is one of the most common complications after thoracic AIS surgery. Previous studies reported that the etiology of PJK was associated with osteopenia and meanwhile the AIS patients were found osteopenia which could persist into adulthood. Recently, an MRI-based vertebral bone quality score (VBQ) was reported to be a promising tool which can assess preoperative bone quality. OBJECTIVE: This study aims to evaluate the utility of VBQ score in predicting PJK after corrective surgery for thoracic AIS (Lenke 1 and 2). METHODS: We conducted a retrospective study to identify the predictive efficiency of VBQ score for PJK in thoracic AIS patients. Demographic, radiographic parameters, and surgical variables were collected. VBQ score was calculated using preoperative T1-weighted MRI. Univariate analysis, linear regression, and multivariate logistic regression were performed to determine potential risk factors of PJK and correlation between other parameters and VBQ score. Receiver operating characteristic analysis and area under the curve values were utilized to evaluate the predictive efficiency of VBQ score for PJK. RESULTS: A total of 206 patients (aged 14.4 ± 2.3 years) were included, of which 33 (16.0%) developed PJK. VBQ scores were significantly different between the PJK and non-PJK groups (2.8 ± 0.2 vs 2.5 ± 0.2, P < 0.01). A significant positive correlation was found between VBQ score and PJA (R2 = 0.1728, P < 0.01).On multivariate analysis, VBQ score was the only significant predictor of PJK (odds ratio = 2.178, 95% CI = 1.644-2.885, P < 0.001), with a predictive accuracy of 83%. CONCLUSION: Higher VBQ scores were independently associated with PJK occurrence after corrective surgery for thoracic AIS. Preoperative measurement of VBQ score on MRI may serve as a valuable tool in planning thoracic AIS surgery.

Sensory processing in Sotos syndrome and Tatton-Brown-Rahman Syndrome.

Sotos syndrome (Sotos) and Tatton-Brown-Rahman Syndrome (TBRS) are two of the most common overgrowth disorders associated with intellectual disability. Individuals with these syndromes tend to have similar cognitive profiles and high likelihood of autism symptomatology. However, whether and how sensory processing is affected is currently unknown. Parents/caregivers of 36 children with Sotos and 20 children with TBRS completed the Child Sensory Profile-2 (CSP-2) and the Sensory Behavior Questionnaire (SBQ) along with other standardized questionnaires assessing autistic traits (Social Responsiveness Scale, Second Edition, SRS-2), attention deficit hyperactivity disorder (ADHD) traits (Conners 3), anxiety (Spence Children's Anxiety Scale, Parent Version, SCAS-P), and adaptive behavior (Vineland Adaptive Behavior Scales Third Edition). Sensory processing differences were clearly evident in both syndromes, though there was significant variation in both cohorts. SBQ data indicated that both the frequency and impact of sensory behavior were more severe when compared to neurotypicals, with levels of sensory behavior impact and frequency being similar to autistic children. CSP-2 data indicated 77% of children with Sotos and 85% children with TBRS displayed clear differences in sensory Registration (missing sensory input). Clear differences relating to Body Position (proprioceptive response to joint and muscle position; 79% Sotos; 90% TBRS) and Touch (somatosensory response to touch on skin; 56% Sotos; 60% TBRS) were also particularly prevalent. Correlation analyses demonstrated that in both syndromes sensory processing differences tend to be associated with difficulties relating to autistic traits, anxiety, and some domains of ADHD. In Sotos, sensory processing differences were also associated with lower adaptive behavior skills. This first detailed assessment of sensory processing, alongside other clinical features, in relatively large cohorts of children with Sotos and TBRS, demonstrates that sensory processing differences have a profound impact on everyday life. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Distal junctional kyphosis in adult cervical deformity patients: where does it occur?

PURPOSE: To evaluate the impact of the lowest instrumented vertebra (LIV) on Distal Junctional kyphosis (DJK) incidence in adult cervical deformity (ACD) surgery. METHODS: Prospectively collected data from ACD patients undergoing posterior or anterior-posterior reconstruction at 13 US sites was reviewed up to 2-years postoperatively (n = 140). Data was stratified into five groups by level of LIV: C6-C7, T1-T2, T3-Apex, Apex-T10, and T11-L2. DJK was defined as a kyphotic increase > 10° in Cobb angle from LIV to LIV-1. Analysis included DJK-free survival, covariate-controlled cox regression, and DJK incidence at 1-year follow-up. RESULTS: 25/27 cases of DJK developed within 1-year post-op. In patients with a minimum follow-up of 1-year (n = 102), the incidence of DJK by level of LIV was: C6-7 (3/12, 25.00%), T1-T2 (3/29, 10.34%), T3-Apex (7/41, 17.07%), Apex-T10 (8/11, 72.73%), and T11-L2 (4/8, 50.00%) (p < 0.001). DJK incidence was significantly lower in the T1-T2 LIV group (adjusted residual = -2.13), and significantly higher in the Apex-T10 LIV group (adjusted residual = 3.91). In covariate-controlled regression using the T11-L2 LIV group as reference, LIV selected at the T1-T2 level (HR = 0.054, p = 0.008) or T3-Apex level (HR = 0.081, p = 0.010) was associated with significantly lower risk of DJK. However, there was no difference in DJK risk when LIV was selected at the C6-C7 level (HR = 0.239, p = 0.214). CONCLUSION: DJK risk is lower when the LIV is at the upper thoracic segment than the lower cervical segment. DJK incidence is highest with LIV level in the lower thoracic or thoracolumbar junction.

Cranially Directed Upper Instrumented Vertebrae Screw Angles Are Associated With Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To evaluate the impact of the upper instrumented vertebral (UIV) screw angle in adult spinal deformity (ASD) surgery on: (1) proximal junctional kyphosis/failure (PJK/F), (2) mechanical complications and radiographic measurements, and (3) patient-reported outcome measures (PROMs). SUMMARY OF BACKGROUND DATA: The effect of UIV screw angle in ASD surgery on patient outcomes remains understudied. MATERIALS AND METHODS: A single-institution, retrospective study was undertaken from 2011 to 2017. UIV screw angle was trichotomized into positive: cranially directed screws relative to the superior endplate (2°≤θ), neutral: parallel to the superior endplate (-2°<θ<2°), and negative: caudally directed screws relative to the superior endplate (-2°≥θ). The primary outcome was PJK/F. Secondary outcomes included remaining mechanical complications, reoperation, and PROMs: Oswestry Disability Index, Numeric Rating Scale (NRS) back/leg, and EuroQol. Regression controlled for age, body mass index, postoperative sagittal vertical axis (SVA), and pelvic incidence lumbar-lordosis mismatch. RESULTS: Among 145 patients undergoing ASD surgery, UIV screw angles were 35 (24.1%) cranially directed, 24 (16.6%) neutral, and 86 (59.3%) caudally directed. PJK occurred in 47(32.4%) patients. Positive screws were independently associated with increased PJK [odds ratio (OR)=4.88; 95% CI, 1.85-13.5, P =0.002] and PJF (OR=3.06; 95% CI, 1.32-12.30, P =0.015). Among 108 (74.5%) patients with lower thoracic UIV, PJK occurred in 38 (35.1%). Cranially directed screws were independently associated with an increased odds of PJK (OR=5.56; 95% CI, 1.86-17.90, P =0.003) with a threshold of 0.2° (area under the curve =0.65; 95% CI, 0.54-0.76, P <0.001), above which the risk of PJK significantly increased. No association was found between positive screw angle and PJF (OR=3.13; 95% CI, 0.91-11.40, P =0.073). Because of the low number of patients with an upper thoracic UIV (N=37, 25.5%), no meaningful conclusions could be drawn from this subgroup. There was no association between UIV screw angle and remaining mechanical complications, reoperations, postoperative SVA and T1-pelvic angle, or PROMs. CONCLUSIONS: Cranially directed UIV screw angles increased the odds of PJK in patients with lower thoracic UIV. Meticulous attention should be paid to the lower thoracic UIV screw angle to mitigate the risk of PJK in ASD.

[Effectiveness of trans-intervertebral space osteotomy combined with cage implantation for old thoracolumbar compression fracture with kyphosis].

Objective: To investigate the effectiveness of trans-intervertebral space osteotomy (TIO) combined with cage implantation in treatment of old thoracolumbar compression fracture with kyphosis. Methods: A clinical data of 59 patients with old thoracolumbar compression fracture and kyphosis, who met the selection criteria between January 2010 and August 2020, was retrospectively analyzed. Among them, 20 cases underwent TIO combined with cage implantation (group A), 21 patients underwent TIO (group B), and 18 patients underwent pedicle subtraction osteotomy (PSO; group C). There was no significant difference in gender, age, time from injury to operation, fracture segment, and preoperative Cobb angle, average height of functional spinal unit (FSU), sagittal vertical axis (SVA), visual analogue scale (VAS) score, Japanese Orthopedic Association (JOA) score, and Oswestry disability index (ODI) between groups (P>0.05). The operation time, intraoperative blood loss, and postoperative complications were recorded. Imaging review was performed to observe the fusion of the bone graft. Cobb angle, average height of FSU, and SVA were measured. VAS score, JOA score, and ODI were used to evaluate the degree of low back pain and lumbar function. Frankel grading was used to evaluate neurological function. Results: The operations of 3 groups were successfully completed. The operation time and intraoperative blood loss were significantly lower in groups A and B than in group C (P<0.05); there was no significant difference between group A and group B (P>0.05). All incisions healed by first intention. Patients in all groups were followed up 23-27 months, with an average of 24.8 months. There was no significant difference in follow-up time between groups (P>0.05). At last follow-up, VAS score, JOA score, ODI, and SVA of 3 groups significantly improved when compared with those before operation (P<0.05), there was no significant difference in the differences of pre- and post-operation between groups (P>0.05). The neurological function grading of 3 groups was Frankel grade E. The Cobb angle and the average height of FSU in 3 groups at immediate and last follow-up significantly improved when compared with preoperative ones (P<0.05), there was no significant difference between immediately after operation and last follow-up (P>0.05). And there were significant differences in above indexes between groups at each time point (P<0.05). At last follow-up, the osteotomy site fused without internal fixation failure or pseudarthrosis formation were observed in 3 groups. Conclusion: For patients with old thoracolumbar compression fractures with kyphosis, the effectiveness of TIO combined with cage implantation is satisfactory. Compared with TIO and PSO, it can obtain more deformity correction degree and less invasive.

Establishment of an Individualized Distal Junctional Kyphosis Risk Index following the Surgical Treatment of Adult Cervical Deformities.

STUDY DESIGN: A retrospective review of a multicenter comprehensive cervical deformity (CD) database. OBJECTIVE: To develop a novel risk index specific to each patient to aid in patient counseling and surgical planning to minimize postop distal junctional kyphosis (DJK) occurrence. BACKGROUND: DJK is a radiographic finding identified after patients undergo instrumented spinal fusions which can result in sagittal spinal deformity, pain and disability, and potentially neurological compromise. DJK is considered multifactorial in nature and there is a lack of consensus on the true etiology of DJK. MATERIALS AND METHODS: CD patients with baseline (BL) and at least one-year postoperative radiographic follow-up were included. A patient-specific DJK score was created through use of unstandardized Beta weights of a multivariate regression model predicting DJK (end of fusion construct to the second distal vertebra change in this angle by <-10° from BL to postop). RESULTS: A total of 110 CD patients included (61 yr, 66.4% females, 28.8 kg/m 2 ). In all, 31.8% of these patients developed DJK (16.1% three males, 11.4% six males, 62.9% one-year). At BL, DJK patients were more frail and underwent combined approach more (both P <0.05). Multivariate model regression analysis identified individualized scores through creation of a DJK equation: -0.55+0.009 (BL inclination)-0.078 (preinflection)+5.9×10 -5 (BL lowest instrumented vertebra angle) + 0.43 (combine approach)-0.002 (BL TS-CL)-0.002 (BL pelvic tilt)-0.031 (BL C2 - C7) + 0.02 (∆T4-T12)+ 0.63 (osteoporosis)-0.03 (anterior approach)-0.036 (frail)-0.032 (3 column osteotomy). This equation has a 77.8% accuracy of predicting DJK. A score ≥81 predicted DJK with an accuracy of 89.3%. The BL reference equation correlated with two year outcomes of Numeric Rating Scales of Back percentage ( P =0.003), reoperation ( P =0.04), and minimal clinically importance differences for 5-dimension EuroQol questionnaire ( P =0.04). CONCLUSIONS: This study proposes a novel risk index of DJK development that focuses on potentially modifiable surgical factors as well as established patient-related and radiographic determinants. The reference model created demonstrated strong correlations with relevant two-year outcome measures, including axial pain-related symptoms, occurrence of related reoperations, and the achievement of minimal clinically importance differences for 5-dimension EuroQol questionnaire.

Is lumbosacral transitional vertebra associated with lumbar disc herniation in patients with low back pain?

PURPOSE: To evaluate lumbosacral transitional vertebrae (LSTV) frequency in patients with low back pain and lumbar disc herniation (LDH) and to analyze correlations between LSTV presence and intervertebral disc degeneration. METHODS: This retrospective study included patients with low back pain applying between January 2021 and August 2021. Inclusion criteria were age of 18-65, presence of a standing lumbosacral Xray and a lumbar MRI taken within 2 weeks of the indexed symptoms. Patients with a history of spondylolisthesis, spondylodiscitis, scoliosis and vertebral neoplasia were excluded. A total of 1821 patients met the inclusion criteria. Radiographs and MRIs were evaluated by 2 radiologists. RESULTS: Of all patients, 61.4% were female and the mean age was 43.2 ± 12.2. LDH was detected in 57.7% of patients while a LSTV was present in 43.3%. Sacralization and LSTV were significantly different between the patients with and without an LDH. Patients with LSTV had a higher incidence of a LDH affecting 3 or more intervertebral disc levels (p < 0.001). There was a significant difference in-between LSTV and non-LSTV groups regarding the M1 and M2 intervertebral disc degeneration levels. CONCLUSION: A LDH is more common in the presence of a LSTV. Female sex is highly correlated with herniation. Three or more intervertebral disc levels are affected in the presence of an LSTV. Significantly higher degeneration incurs at the M1 and M2 intervertebral levels. Sacralization is a risk factors for a lumbar disc herniation.

The Impact of Upper Instrumented Vertebra Orientation on Proximal Junctional Kyphosis: A Novel and Fixed Parameter, Fused Spinopelvic Angle.

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate the impact of upper instrumented vertebra (UIV) orientation including the fused spinopelvic angle (FSPA) on proximal junctional kyphosis (PJK). SUMMARY OF BACKGROUND DATA: PJK is a challenging complication after adult spinal deformity (ASD) surgery. Some studies proposed UIV orientation act as a risk factor of PJK, but there remain debates because UIV orientation is changed by position. Therefore, we investigated the relationship between the FSPA, a novel parameter for the relationship between UIV and pelvis which did not change by position, and PJK. MATERIALS AND METHODS: ASD patients who underwent long-segment fusion to the pelvis and followed up for more than two years were included. Comparative analysis was performed on spinopelvic parameters including UIV orientation parameters (UIV slope angle and FSPA) between PJK and non-PJK group. Binary regression analysis was conducted to find out the risk factors for PJK. And correlation analysis was conducted to find out the parameters that affect the FSPA. RESULTS: A total of 190 patients were included. PJK incidence was 13.2% (25/190). PJK group showed a significantly greater postoperative UIV slope (21.3° vs. 18.8°, P =0.041) and significantly lesser postoperative FSPA (-0.9° vs. 4.5°, P <0.001). In binary regression analysis, only FSPA acted as a risk factor of PJK (odds ratio=0.920, P =0.004). The FSPA has strong positive correlation with pelvic incidence (PI)-lumbar lordosis (LL) ( r =0.666, P <0.001) and negative correlation with lordosis distribution index (LDI) ( r =-0.228, P =0.004). CONCLUSION: The FSPA is a fixed parameter which is not dependent on position. A reduction of the FSPA increases the risk for PJK. The FSPA can be adjusted through PI-LL and LDI. Thus, surgeons should increase the FSPA by adjusting the PI-LL and LDI during ASD surgery to prevent PJK.

Further characterization of Borjeson-Forssman-Lehmann syndrome in females due to de novo variants in PHF6.

While inherited hemizygous variants in PHF6 cause X-linked recessive Borjeson-Forssman-Lehmann syndrome (BFLS) in males, de novo heterozygous variants in females are associated with an overlapping but distinct phenotype, including moderate to severe intellectual disability, characteristic facial dysmorphism, dental, finger and toe anomalies, and linear skin pigmentation. By personal communication with colleagues, we assembled 11 additional females with BFLS due to variants in PHF6. We confirm the distinct phenotype to include variable intellectual disability, recognizable facial dysmorphism and other anomalies. We observed skewed X-inactivation in blood and streaky skin pigmentation compatible with functional mosaicism. Variants occurred de novo in 10 individuals, of whom one was only mildly affected and transmitted it to her more severely affected daughter. The mutational spectrum comprises a two-exon deletion, five truncating, one splice-site and three missense variants, the latter all located in the PHD2 domain and predicted to severely destabilize the domain structure. This observation supports the hypothesis of more severe variants in females contributing to gender-specific phenotypes in addition to or in combination with effects of X-inactivation and functional mosaicism. Therefore, our findings further delineate the clinical and mutational spectrum of female BFLS and provide further insights into possible genotype-phenotype correlations between females and males.

Vertebral column resection (VCR) at the subapical vertebra for correction of angular kyphosis associated with neurofibromatosis type 1(NF1): a case report.

PURPOSE: To describe the process and outcome of vertebral column resection (VCR) at the subapical vertebra for correction of angular kyphosis associated with neurofibromatosis type 1(NF1). METHODS: A review and summary of the medical history, radiographs, operative procedure, and complications of a 16-year-old male presenting with severe angular kyphosis associated with NF1 with dyspnea. RESULTS: A 16-year-old male presented with severe angular kyphosis associated with NF1 with dyspnea. Preoperative radiographs demonstrated multiple vertebrae were rotated in the vicinity of the apical vertebra, with a wedge-shaped deformity, dysplasia, T10-T12 kyphotic angle of 160°, and T2-L2 kyphotic angle of 95°. VCR at the L1 vertebra (distal end of the apical vertebra) with bone grafting and internal fixation was performed. Postoperative imaging revealed that the T2-L2 Cobb angle was 20°, denoting a correction rate of 79%. The patient's height increased from 130 to 150 cm. The position of internal fixation was not displaced, and the correction angle was maintained at 2-year follow-up. CONCLUSIONS: The novel strategy of performing VCR at the subapical vertebra, with posterior displacement of the distal end, and remodeling of the spinal canal is potentially a safe and efficacious option to correct sharp angular kyphosis.

Posterior-only Resection of Single Hemivertebrae With 2-Level Versus >2-Level Fusion: Can We Improve Outcomes?

BACKGROUND: The outcomes of congenital scoliosis (CS) patients undergoing hemivertebra (HV) resection surgery with a 2-level fusion versus a >2-level fusion are unclear. We hypothesized that CS patients undergoing HV resection and a >2-level fusion have decreased curve progression and reoperation rates compared with 2-level fusions. METHODS: Retrospective review of prospectively collected data from a multicenter scoliosis database. Fifty-three CS patients (average age 4.5, range 1.2 to 10.9 y) at index surgery were included. Radiographic and surgical parameters, complications, as well as revision surgery rates were tracked at a minimum of 2-year follow-up. RESULTS: Twenty-six patients had a 2-level fusion while 27 patients had a >2-level fusion with similar age and body mass index between groups. The HV was located in the lumbar spine for 69% (18/26) 2-level fusions and 30% (8/27) >2-level fusions ( P =0.006). Segmental HV scoliosis curve was smaller in 2-level fusions compared to >2-level fusions preoperatively (38 vs. 50 degrees, P =0.016) and at follow-up (25 vs. 34 degrees, P =0.038). Preoperative T2-T12 (28 vs. 41 degrees, P =0.013) and segmental kyphosis (11 vs. 23 degrees, P =0.046) were smaller in 2-level fusions, but did not differ significantly at postoperative follow-up (32 vs. 39 degrees, P =0.22; 13 vs. 11 degrees, P =0.64, respectively). Furthermore, the 2 groups did not significantly differ in terms of surgical complications (27% vs. 22%, P =0.69; 2-level fusion vs. >2-level fusion, respectively), unplanned revision surgery rate (23% vs. 22%, 0.94), growing rod placement or extension of spinal fusion (15% vs. 15%, P =0.95), or health-related quality of life per the EOS-Questionnaire 24 (EOSQ-24). Comparison of patients with or without the need for growing rod placement or posterior spinal fusion revealed no significant differences in all parameters analyzed. CONCLUSIONS: Two-level and >2-level fusions can control congenital curves successfully. No differences existed in curve correction, proximal junctional kyphosis or complications between short and long-level fusion after HV resection. Both short and long level fusions are viable options and generate similar risk of revision. The decision should be individualized by patient and surgeon.

Accelerated anterior vertebral growth resulting in kyphosis correction following posterior spinal instrumented fusion.

PURPOSE: To discuss the effect of posterior instrumented deformity correction and fusion on the progressive endochondral ossification of anterior vertebral body in a patient with congenital kyphosis secondary to type 1 vertebral anomaly. METHODS: A 15-year-old male patient presented with a progressively worsening congenital TL kyphosis of 52° magnitude secondary to a posterior hemivertebra. His pre-operative antero-posterior vertebral height ratio (APVHR) and anterior vertebral body defect ratio (AVBDR) on CT were 38% and 49%, respectively. He underwent posterior instrumented deformity correction with multilevel type 1 Schwab osteotomies and fusion. RESULTS: Over the next 3 years, his serial imaging revealed progressive endochondral ossification and gradual increase in the dimensions of the vertebral body. At the final follow-up, there was a significant restoration of the deficient anterior vertebral body, and the final APVHR and AVBDR were 81% and 90%, respectively. CONCLUSIONS: Restitution of posterior column integrity through stabilization can mitigate the compressive stresses across anterior column. Over a period of time, forces restraining the growth of anterior vertebral apophysis are alleviated, and the vertebra can potentially re-grow to near-normal dimensions in pediatric population. This phenomenon could be well-demonstrated in our patient during follow-up. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Evolution of Proximal Junctional Kyphosis and Proximal Junctional Failure Rates Over 10 Years of Enrollment in a Prospective Multicenter Adult Spinal Deformity Database.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to investigate the evolution of proximal junctional kyphosis (PJK) rate over 10-year enrollment period within a prospective database. SUMMARY OF BACKGROUND DATA: PJK is a common complication following adult spinal deformity (ASD) surgery and has been intensively studied over the last decade. METHODS: Patients with instrumentation extended to the pelvis and minimum 2-year follow-up were included. To investigate evolution of PJK/proximal junctional failure (PJF) rate, a moving average of 321 patients was calculated across the enrollment period. Logistic regression was used to investigate the association between the date of surgery (DOS) and PJK and/or PJF. Comparison of PJK/PJF rates, demographics, and surgical strategies was performed between the first and second half of the cohort. RESULTS: A total of 641 patients met inclusion criteria (age: 64±10 years, 78.2% female, body mass index: 28.3±5.7). The overall rate of radiographic PJK at 2 years was 47.9%; 12.9% of the patients developed PJF, with 31.3% being revised within 2-year follow-up. Stratification by DOS produced two halves. Between these two periods, rate of PJK and PJF demonstrated nonsignificant decrease (50.3%-45.5%, P =0.22) and (15.0%-10.9%, P =0.12), respectively. Linear interpolation suggested a decrease of 1.2% PJK per year and 1.0% for PJF. Patients enrolled later in the study were older and more likely to be classified as pure sagittal deformity ( P <0.001). There was a significant reduction in the use of three-column osteotomies ( P <0.001), an increase in anterior longitudinal ligament release ( P <0.001), and an increase in the use of PJK prophylaxis (31.3% vs 55.1%). Logistical regression demonstrated no significant association between DOS and radiographic PJK ( P =0.19) or PJF ( P =0.39). CONCLUSION: Despite extensive research examining risk factors for PJK/PJF and increasing utilization of intraoperative PJK prophylaxis techniques, the rate of radiographic PJK and/or PJF did not significantly decrease across the 10-year enrollment period of this ASD database.

Does pelvic incidence tell us the risk of proximal junctional kyphosis in adult spinal deformity surgery?

PURPOSE: To investigate the relationship between pelvic incidence (PI) and proximal junctional kyphosis (PJK) in patients treated surgically for adult spinal deformity (ASD) with fusion from thoracolumbar junction to sacrum. METHODS: A consecutive series of ASD patients who underwent fusion from the thoracolumbar junction to the sacrum with a minimum of 2-year follow-up was studied. Patients were divided into low PI (≤ 50°) and high PI (> 50°) groups. We compared radiographic parameters and the rates of PJK, between the two groups. A sub-analysis was performed on patients with a postoperative PI minus lumbar lordosis mismatch between - 10° and 10° (i.e., ideally corrected). RESULTS: Sixty-three patients were included: 19 low PI and 44 high PI. Median follow-up was 34 months (range 24-103). Overall PJK rate was 38%. PJK was observed in 16% of low PI and 48% of high PI patients (p = 0.02). The odds ratio for developing PJK with a high PI compared to a low PI was 4.9 (p = 0.03). There were 32 ideally corrected patients. Eleven of these were in the low PI group, and 21 patients were in the high PI group. The incidence of PJK was 25% for ideally corrected patients. PJK occurred in none of these patients in the low PI group and 38% of patients in the high PI group (p = 0.03). CONCLUSION: When the upper-instrumented vertebra includes the thoracolumbar junction, patients with a PI > 50° are at a significantly higher risk of developing PJK compared to patients with a PI ≤ 50°.

Tarsal tunnel syndrome secondary to accessory or variant muscles: a clinical and anatomical systematic review.

PURPOSE: Many etiologies are known to lead to a tarsal tunnel syndrome (TTS). One rare cause is mass-occupying lesions, and particularly accessory or variant muscles (AVM). This study aimed to systematically collect published clinical cases of TTS caused by AVM. METHODS: An electronic literature search was conducted from inception to April 2021. The diagnosis of AVM should be reported in one of the following methods: ultrasonography, magnetic resonance imaging (MRI), or per-operatively. Data extraction included types and prevalence of accessory muscles, clinical presentation and diagnosis, and treatment modalities. Twenty-five studies were identified with a total 39 patients (47 ankles). RESULTS: The prevalence of TTS was reported in only two studies (9%). Forty-nine AVM were identified with the accessory flexor digitorum longus being the most common (52%). The most common sign/symptoms were tenderness (78.7%), pain (82.9%), dysesthesia (57.4%), Tinel sign (44.6%), and a swelling (25.5%). Decompression and excision were the most commonly performed procedures. Four accessory/variant muscles in the ankle have the potential to induce a tarsal tunnel syndrome. CONCLUSION: This review highlights the clinical and imagery specificities of TTS secondary to accessory or variant muscles. Mass-occupying etiology should be included in the list of differential diagnoses whenever a posterior tibial nerve compression is suspected.

Case Report of Angular Post-Tuberculotic Kyphosis Corrected Through Pedicle Subtraction Osteotomy Above C7.

BACKGROUND AND IMPORTANCE: Angular cervical kyphosis and its association with syringomyelia were rarely described. Correcting this kind of deformity from the front is extremely difficult or even impossible. Meanwhile, no study has made a report about correcting angular cervical kyphosis through pedicle subtraction osteotomy (PSO) above C7 because of the special anatomy of the vertebral artery. This is the first case of cervical deformity correction through PSO above C7. CLINICAL PRESENTATION: We present the case of a 52-yr-old man who previously underwent debridement, decompression, and skull traction for cervical tuberculosis at age 6 yr. The sequelae of right-hand weakness occurred after surgery, and cervical kyphosis formed gradually. The patient recently started to complain of a severe neck pain. X-rays showed a cervical sagittal malalignment due to the angular kyphosis. Computed tomography scans revealed a fused angular kyphosis at C6-7, and MRI showed a long syringomyelia distal to the kyphosis. The definite diagnosis of the patient was post-tuberculotic cervical angular kyphosis, and because of the extremely narrow surgery corridor from the front, we decided to perform the surgery in a posterior approach. Hence, the patient was treated with the PSO with a long-segment pedicle screw fixation from C3 to T5 and received satisfactory angular kyphosis correction. CONCLUSION: PSO above C7 to correct angular cervical kyphosis is feasible and reasonable when there is no other better solution, and it can achieve a satisfactory kyphotic deformity correction.

Proteus Syndrome: Case Report with Anatomopathological Correlation.

Background: Proteus syndrome is characterized by a progressive segmental or patchy growth of bone, skin, adipose tissue, and central nervous system, associated with a wide range of neoplasms, pulmonary pathology, and thrombotic risk. The main histological findings are diffuse patchy overgrowth of skin and subcutaneous tissue, plantar cerebriform connective tissue nevus, and ossification defects. Case report: We present a patient that met the clinical and histological criteria necessary for the diagnosis of the disease. He required multiple surgical interventions, including amputation of the right foot. Genetic evaluation confirmed an AKT1 mutation. Discussion: CLOVES syndrome, neurofibromatosis 1 or PTEN hamartoma tumor syndrome are partially superimposable entities to Proteus syndrome and may generate diagnostic doubt. Although the clinical criteria and histologic findings are indicative, the diagnostic confirmation of this entity is genetic.