Bone mineral density differences between femurs of scoliotic patients undergoing quantitative computed tomography analysis.

PURPOSE: Scoliosis is a cause of loading imbalance between the lower limbs, which can result in BMD differences between the two femurs. We investigated the discrepancy in BMD values assessed by quantitative computed tomography (QCT) between femurs in patients with and without scoliosis, also assessing if this difference can be related to spine convexity. METHODS: Abdominal CT examinations were retrospectively reviewed. An ''asynchronous'' calibration of CT images was performed to obtain BMD values from QCT. Scoliosis was evaluated on the antero-posterior CT localizer to calculate the Cobb angle. Differences between aBMD and vBMD of femurs were assessed in both scoliotic and non-scoliotic subjects. RESULTS: Final study cohort consisted of 263 subjects, 225 of them without scoliosis (85.6%) and 38 with scoliosis (14.4%). No significant differences were found in the general population without scoliosis, except for vBMD at the neck. Comparison of femurs in scoliotic patients showed statistically significant differences at neck aBMD -0.028 g/cm2, p = 0.004), total femur aBMD (--0.032 g/cm2, p = 0.008) and total femur vBMD (--8.9 mg/cm3, p = 0.011), with lower BMD values on the convexity side. In 10 cases (26%) a change in the final T-score diagnosis was observed. CONCLUSION: QCT analysis demonstrated a difference in both areal and volumetric BMD between the two femurs of scoliotic patients, in relation to the side of the scoliotic curve. If these data will be confirmed by larger studies, bilateral femoral DXA acquisition may be proposed for these patients.

Is posteromedial translation with sublaminar bands effective in correcting axial rotation in adolescent idiopathic scoliosis surgery? A 3D reconstruction study.

PURPOSE: Hybrid constructs with sublaminar bands have recently regained popularity as an alternative to all-screw construct for correction of adolescent idiopathic scoliosis (AIS). The aim of this study is to evaluate the ability of hybrid constructs with sublaminar bands to achieve a tridimensional correction of the scoliotic deformity. Our hypothesis is that hybrid construct with sublaminar bands are able to achieve a substantial derotation of the apical vertebrae, while preserving the thoracic kyphosis. METHODS: A prospective evaluation of 50 consecutive cases (41 F, 9 M, mean age 14.7 ± 2 years) of AIS correction with hybrid construct was performed. In all cases, sublaminar bands were used at the apex of the main curve on concave side. All patients underwent pre and postoperative X-rays with EOS System, with full 3D reconstruction. Spinopelvic parameters and axial rotation of the vertebrae were measured pre and postoperatively. RESULTS: 2.7 ± 0.9 mean sublaminar bands were used per patient. Mean correction of deformity was 50 ± 9.5%. on the coronal plane. The mean axial rotation of the apical vertebra went from 18° ± 11.5° preoperatively to 9.4° ± 7.2° postoperatively (p < 0.001) with a mean derotation of 47.7%. Thoracic kyphosis went from 32.1° ± 18° preoperatively to 37.3° ± 13.1° postoperatively (p < 0.05). No intraoperative complications due to sublaminar bands were recorded. CONCLUSIONS: Hybrid construct with sublaminar band have been showed to be safe and effective in deformity correction and in maintaining or restoring thoracic kyphosis. This study showed that with sublaminar bands applied at the curve apex a substantial derotation of the apical vertebrae can be achieved.

MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor of the extremities.

PURPOSE: To determine diagnostic performance of MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor (ALT) of the extremities. MATERIAL AND METHODS: This retrospective study was performed at three tertiary sarcoma centers and included 150 patients with surgically treated and histology-proven lesions. The training-validation cohort consisted of 114 patients from centers 1 and 2 (n = 64 lipoma, n = 50 ALT). The external test cohort consisted of 36 patients from center 3 (n = 24 lipoma, n = 12 ALT). 3D segmentation was manually performed on T1- and T2-weighted MRI. After extraction and selection of radiomic features, three machine learning classifiers were trained and validated using nested fivefold cross-validation. The best-performing classifier according to previous analysis was evaluated and compared to an experienced musculoskeletal radiologist in the external test cohort. RESULTS: Eight features passed feature selection and were incorporated into the machine learning models. After training and validation (74% ROC-AUC), the best-performing classifier (Random Forest) showed 92% sensitivity and 33% specificity in the external test cohort with no statistical difference compared to the radiologist (p = 0.474). CONCLUSION: MRI radiomics-based machine learning may classify deep-seated lipoma and ALT of the extremities with high sensitivity and negative predictive value, thus potentially serving as a non-invasive screening tool to reduce unnecessary referral to tertiary tumor centers.

Artificial Intelligence Accurately Detects Traumatic Thoracolumbar Fractures on Sagittal Radiographs.

Background and Objectives: Commonly being the first step in trauma routine imaging, up to 67% fractures are missed on plain radiographs of the thoracolumbar (TL) spine. The aim of this study was to develop a deep learning model that detects traumatic fractures on sagittal radiographs of the TL spine. Identifying vertebral fractures in simple radiographic projections would have a significant clinical and financial impact, especially for low- and middle-income countries where computed tomography (CT) and magnetic resonance imaging (MRI) are not readily available and could help select patients that need second level imaging, thus improving the cost-effectiveness. Materials and Methods: Imaging studies (radiographs, CT, and/or MRI) of 151 patients were used. An expert group of three spinal surgeons reviewed all available images to confirm presence and type of fractures. In total, 630 single vertebra images were extracted from the sagittal radiographs of the 151 patients-302 exhibiting a vertebral body fracture, and 328 exhibiting no fracture. Following augmentation, these single vertebra images were used to train, validate, and comparatively test two deep learning convolutional neural network models, namely ResNet18 and VGG16. A heatmap analysis was then conducted to better understand the predictions of each model. Results: ResNet18 demonstrated a better performance, achieving higher sensitivity (91%), specificity (89%), and accuracy (88%) compared to VGG16 (90%, 83%, 86%). In 81% of the cases, the "warm zone" in the heatmaps correlated with the findings, suggestive of fracture within the vertebral body seen in the imaging studies. Vertebras T12 to L2 were the most frequently involved, accounting for 48% of the fractures. A4, A3, and A1 were the most frequent fracture types according to the AO Spine Classification. Conclusions: ResNet18 could accurately identify the traumatic vertebral fractures on the TL sagittal radiographs. In most cases, the model based its prediction on the same areas that human expert classifiers used to determine the presence of a fracture.

Classification of endplate lesions in the lumbar spine and association with risk factors, biochemistry, and genetics.

PURPOSE: To detect the associations between the degree of the endplate (EP) lesions with the presence of risk factors, biochemical and genetic markers previously observed in low back pain (LBP) patients with EP defects in comparison with hernia/discopathy patients and healthy controls. METHODS: In this observational retrospective study, T2-weighted sagittal MRI images (n = 223 LBP patients) were scored for EP lesions by two independent observers. Total MRI score and number of affected levels (L1/L2-L5/S1) have been considered for the correlation with demographic, behavioral, clinical, biochemical (25(OH)D, CTx-I and CTx-II levels, n = 69 males) and VDR variables. RESULTS: Males showed higher BMI and total MRI score than females. Patients bearing TT compared to tt VDR genotypes showed significant higher total MRI scores. Among males (n = 125), TT, bb and aa genotypes showed increased total MRI scores. Higher total MRI score directly correlates with higher levels of CTx-I and CTx-II (n = 69 males). CONCLUSIONS: The markers previously identified as associated with the presence of EP lesions have been confirmed as related to their severity and could be used to follow the pathology progression.

Innovative sacropelvic fixation using iliac screws and triangular titanium implants.

PURPOSE: Sacropelvic fixation is frequently used in combination with thoracolumbar instrumentation for the correction of severe spinal deformities. The purpose of this study was to explore the effects of the triangular titanium implants on the iliac screw fixation. Our hypothesis was that the use of triangular titanium implants can increase the stability of the iliac screw fixation. METHODS: Three T10-pelvis instrumented models were created: pedicle screws and rods in T10-S1, and bilateral iliac screws (IL); posterior fixation and bilateral iliac screws and triangular implants inserted bilaterally in a sacro-alar-iliac trajectory (IL-Tri-SAI); posterior fixation and bilateral iliac screws and two bilateral triangular titanium implants inserted in a lateral trajectory (IL-Tri-Lat). Outputs of these models, such as hardware stresses, were compared against a model with pedicle screws and rods in T10-S1 (PED). RESULTS: Sacropelvic fixation decreased the L5-S1 motion by 75-90%. The motion of the SIJ was reduced by 55-80% after iliac fixation; the addition of triangular titanium implants further reduced it. IL, IL-Tri-SAI and IL-Tri-Lat demonstrated lower S1 pedicle stresses with respect to PED. Triangular implants had a protective effect on the iliac screw stresses. CONCLUSION: Sacropelvic fixation decreased L5-S1 range of motion suggesting increased stability of the joint. The combination of triangular titanium implants and iliac screws reduced the residual flexibility of the sacroiliac joint, and resulted in a protective effect on the S1 pedicle screws and iliac screws themselves. Clinical studies may be performed to demonstrate applicability of these FEA results to patient outcomes.

Biomechanics of sacropelvic fixation: a comprehensive finite element comparison of three techniques.

PURPOSE: Sacropelvic fixation is frequently used in combination with thoracolumbar instrumentation for complex deformity correction and is commonly associated with pseudoarthrosis, implant failure and loosening. This study compared pedicle screw fixation (PED) with three different sacropelvic fixation techniques, namely iliac screws (IL), S2 alar-iliac screws (S2AI) and laterally placed triangular titanium implants (SI), all in combination with lumbosacral instrumentation, accounting for implant micromotion. METHODS: Existing finite element models of pelvis-L5 of three patients including lumbopelvic instrumentation were utilized. Moments of 7.5 Nm in the three directions combined with a 500 N compressive load were simulated. Measured metrics included flexibility, instrumentation stresses and bone-implant interface loads. RESULTS: Fixation effectively reduced the sacroiliac flexibility. Compared to PED, IL and S2AI induced a reduction in peak stresses in the S1 pedicle screws. Rod stresses were mostly unaffected by S2AI and SI, but IL demonstrated a stress increase. In comparison with a previous work depicting full osteointegration, SI was found to have similar instrumentation stresses as those due to PED. CONCLUSIONS: Fixation with triangular implants did not result in stress increase on the lumbosacral instrumentation, likely due to the lack of connection with the posterior rods. IL and S2AI had a mild protective effect on S1 pedicle screws in terms of stresses and bone-implant loads. IL resulted in an increase in the rod stresses. A comparison between this study and previous work incorporating full osteointegration demonstrates how these results may be applied clinically to better understand the effects of different treatments on patient outcomes. These slides can be retrieved under Electronic Supplementary Material.

What Is the Impact of a Previous Femoral Osteotomy on THA? A Systematic Review.

BACKGROUND: Femoral osteotomies have been widely used to treat a wide range of developmental and degenerative hip diseases. For this purpose, different types of proximal femur osteotomies were developed: at the neck as well as at the trochanteric, intertrochanteric, or subtrochanteric levels. Few studies have evaluated the impact of a previous femoral osteotomy on a THA; thus, whether and how a previous femoral osteotomy affects the outcome of THA remains controversial. QUESTIONS/PURPOSES: In this systematic review, we asked: (1) What are the most common complications after THA in patients who have undergone femoral osteotomy, and how frequently do those complications occur? (2) What is the survival of THA after previous femoral osteotomy? (3) Is the timing of hardware removal associated with THA complications and survivorship? METHODS: A systematic review was carried out on PubMed, the Cochrane Systematic Reviews Database, Scopus, and Embase databases with the following keywords: "THA", "total hip arthroplasty", and "total hip replacement" combined with at least one of "femoral osteotomy" or "intertrochanteric osteotomy" to achieve the maximum sensitivity of the search strategy. Identified studies were included if they met the following criteria: (1) reported data on THAs performed after femoral osteotomy; (2) recorded THA followup; (3) patients who underwent THA after femoral osteotomy constituted either the experimental group or a control group; (4) described the surgical and clinical complications and survivorship of the THA. The database search retrieved 383 studies, on which we performed a primary evaluation. After removing duplicates and completing a full-text evaluation for the inclusion criteria, 15 studies (seven historically controlled, eight case series) were included in the final review. Specific information was retrieved from each study included in the final analysis. The quality of each study was evaluated with the Methodological Index for Non-randomized Studies (MINORS) questionnaire. The mean MINORS score for the historically controlled studies was 14 of 24 (range, 10-17), whereas for the case series, it was 8.1 of 16 (range, 5-10). RESULTS: The proportion of patients who experienced intraoperative complications during THA ranged from 0% to 17%. The most common intraoperative complication was femoral fracture; other intraoperative complications were difficulties in hardware removal and nerve palsy; 15 studies reported on complications. The survivorship of THA after femoral osteotomy in the 13 studies that answered this question ranged from 43.7% to 100% in studies that had a range of followup from 2 to 20 years. The timing of hardware removal was described in five studies, three of which detailed more complications with hardware removal at the time of THA. CONCLUSIONS: This systematic review demonstrated that THA after femoral osteotomy is technically more demanding and may carry a higher risk of complications than one might expect after straightforward THA. Staged hardware removal may reduce the higher risk of intraoperative fracture and infection, but there is no clear evidence in support of this contention. Although survivorship of THA after femoral osteotomy was generally high, the studies that evaluated it were generally retrospective case series, with substantial biases, including selection bias and transfer bias (loss to followup), and so it is possible that survivorship of THA in the setting of prior femoral osteotomy may be lower than reported. LEVEL OF EVIDENCE: Level III, therapeutic study.

Multicentric, multifocal, and recurrent osteoid osteoma of the hip: first case report.

BACKGROUND: Osteoid osteoma is a benign bone-forming tumour, which very unfrequently has multifocal or multicentric presentation. We report the first known case of a multicentric, multifocal and recurrent osteoid osteoma treated using radiofrequency ablation. CASE PRESENTATION: A 39-year-old man with two-year history of left hip pain was admitted at our Institution. The pain was more intense during the night and partially relieved by salicylates. Pelvis CT demonstrated two lytic lesions (8 and 7 mm, respectively) with surrounding sclerotic reactive bone, both with a central focal area of high attenuation, located in the femoral neck and along the anterior portion of the acetabulum, respectively. Both lesions had clinical and imaging findings consistent with multicentric osteoid osteoma. Thus, the two lesions were biopsied - with pathologic confirmation of osteoid osteoma - and treated using radiofrequency ablation. Hip pain decreased but did not disappear, actually increasing a few months after treatment. CT and MRI were performed showing a smaller lesion (5 mm) with the same imaging features, surrounded by marrow oedema, along the posterior column of the acetabulum. The lesion was considered suspicious for osteoid osteoma, overlooked on previous examinations. Therefore, a diagnosis of multicentric and multifocal osteoid osteoma was established. The new lesion was again treated with radiofrequency ablation with symptom disappearance. However, hip pain relapsed after 18 months, and CT and MRI showed an osteoid osteoma recurrence on the posterior column of the acetabulum, which was biopsied and successfully treated using radiofrequency ablation. CONCLUSIONS: To our knowledge, this is the first reported case of multicentric, multifocal, recurrent osteoid osteoma. Our case report highlights the importance of considering a diagnosis of multifocal osteoid osteoma when dealing with multifocal lytic lesions of the bone and with pain persistence after treatment. It also emphasises the combined role of CT and MRI in this setting.

Two-stage cementless hip revision for peri-prosthetic infection with an antibacterial hydrogel coating: results of a comparative series.

PURPOSE: The aim of this study was to investigate the hypothesis that a two-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, may provide better infection cure rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic hip infection. METHODS: In this case-control study, 27 patients, treated with a two-stage procedure, using cementless implants coated with an antibiotic-loaded hydrogel (DAC®, "Defensive Antibacterial Coating"), were compared with 27 matched controls, treated with a two-stage cementless revision procedure, without the coating. RESULTS: At a mean follow-up of 2.7 (minimum 2.1-maximum 3.5) years, no evidence of infection, implant loosening, or adverse events were observed in the DAC-treated group, compared to four cases of infection recurrence in the control group. CONCLUSIONS: Although in a relatively limited series of patients our data show that cementless two-stage hip revision, performed with an antibacterial hydrogel coating, may provide better infection control than two-stage without the coating, with reduced hospitalization time, these findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections.

One-stage exchange with antibacterial hydrogel coated implants provides similar results to two-stage revision, without the coating, for the treatment of peri-prosthetic infection.

PURPOSE: Aim of this study was to verify the hypothesis that a one-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, provides similar infection recurrence rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic joint infection (PJI). METHODS: In this two-center case-control, study, 22 patients, treated with a one-stage procedure, using implants coated with an antibiotic-loaded hydrogel [defensive antibacterial coating (DAC)], were compared with 22 retrospective matched controls, treated with a two-stage revision procedure, without the coating. RESULTS: At a mean follow-up of 29.3 ± 5.0 months, two patients (9.1%) in the DAC group showed an infection recurrence, compared to three patients (13.6%) in the two-stage group. Clinical scores were similar between groups, while average hospital stay and antibiotic treatment duration were significantly reduced after one-stage, compared to two-stage (18.9 ± 2.9 versus 35.8 ± 3.4 and 23.5 ± 3.3 versus 53.7 ± 5.6 days, respectively). CONCLUSIONS: Although in a relatively limited series of patients, our data shows similar infection recurrence rate after one-stage exchange with DAC-coated implants, compared to two-stage revision without coating, with reduced overall hospitalization time and antibiotic treatment duration. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections. LEVEL OF EVIDENCE: III.

Animal Models of Implant-Related Low-Grade Infections. A Twenty-Year Review.

The demand for joint replacement and surgical treatment is continuously increasing, thus representing a clinical burden and a cost for the healthcare system. Among several pathogens involved in implant-related infections, staphylococci account for the two-thirds of clinically isolated bacteria. Despite most of them are highly virulent microorganisms (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa), low virulent bacteria (Staphylococcus epidermidis, Propionibacterium acnes) are responsible for delayed, low-grade infections without specific clinical signs and hardly distinguishable from aseptic prosthetic failure. Therefore, there is a real need to study the pathogenesis of orthopedic infections through in vivo animal models. The present review of the literature provides a 20-year overview of animal models of acute, subclinical or chronic orthopedic infections according to the pathogen virulence and inocula. Through this analysis, a great variety of conditions in terms of bacterial strains and inocula emerged, thus encouraging the development of more reproducible in vivo studies to provide relevant information for a translational approach to humans.

Never tell me the odds: Investigating pro-hoc explanations in medical decision making.

This paper examines a kind of explainable AI, centered around what we term pro-hoc explanations, that is a form of support that consists of offering alternative explanations (one for each possible outcome) instead of a specific post-hoc explanation following specific advice. Specifically, our support mechanism utilizes explanations by examples, featuring analogous cases for each category in a binary setting. Pro-hoc explanations are an instance of what we called frictional AI, a general class of decision support aimed at achieving a useful compromise between the increase of decision effectiveness and the mitigation of cognitive risks, such as over-reliance, automation bias and deskilling. To illustrate an instance of frictional AI, we conducted an empirical user study to investigate its impact on the task of radiological detection of vertebral fractures in x-rays. Our study engaged 16 orthopedists in a 'human-first, second-opinion' interaction protocol. In this protocol, clinicians first made initial assessments of the x-rays without AI assistance and then provided their final diagnosis after considering the pro-hoc explanations. Our findings indicate that physicians, particularly those with less experience, perceived pro-hoc XAI support as significantly beneficial, even though it did not notably enhance their diagnostic accuracy. However, their increased confidence in final diagnoses suggests a positive overall impact. Given the promisingly high effect size observed, our results advocate for further research into pro-hoc explanations specifically, and into the broader concept of frictional AI.

Evidence-based XAI: An empirical approach to design more effective and explainable decision support systems.

This paper proposes a user study aimed at evaluating the impact of Class Activation Maps (CAMs) as an eXplainable AI (XAI) method in a radiological diagnostic task, the detection of thoracolumbar (TL) fractures from vertebral X-rays. In particular, we focus on two oft-neglected features of CAMs, that is granularity and coloring, in terms of what features, lower-level vs higher-level, should the maps highlight and adopting which coloring scheme, to bring better impact to the decision-making process, both in terms of diagnostic accuracy (that is effectiveness) and of user-centered dimensions, such as perceived confidence and utility (that is satisfaction), depending on case complexity, AI accuracy, and user expertise. Our findings show that lower-level features CAMs, which highlight more focused anatomical landmarks, are associated with higher diagnostic accuracy than higher-level features CAMs, particularly among experienced physicians. Moreover, despite the intuitive appeal of semantic CAMs, traditionally colored CAMs consistently yielded higher diagnostic accuracy across all groups. Our results challenge some prevalent assumptions in the XAI field and emphasize the importance of adopting an evidence-based and human-centered approach to design and evaluate AI- and XAI-assisted diagnostic tools. To this aim, the paper also proposes a hierarchy of evidence framework to help designers and practitioners choose the XAI solutions that optimize performance and satisfaction on the basis of the strongest evidence available or to focus on the gaps in the literature that need to be filled to move from opinionated and eminence-based research to one more based on empirical evidence and end-user work and preferences.

Does the anterior column realignment technique influences the stresses on posterior instrumentation in sagittal imbalance correction? A biomechanical, finite-element analysis of L5-S1 ALIF and L3-4 lateral ACR.

STUDY DESIGN: Biomechanical finite-element study. OBJECTIVE: To directly compare the biomechanical effects of two different techniques for sagittal plane correction of adult spine deformity based on the anterior longitudinal ligament (ALL) resection and use of hyperlordotic cages, namely, the anterior column realignment (ACR) in L3-4, and ALIF in L5-S1 in terms of primary stability and rod stresses using finite-element models. METHODS: A finite-element model of the thoracolumbar spine was used to perform the analysis. Starting from this "intact" model, three further models were constructed through the insertion of spinal instrumentation, i.e., pedicle screws, rods and cages: 1) posterior instrumentation between T9 and S1 (referred to as "T9-S1"); 2) posterior instrumentation T9-S1 + Hyperlordotic (26°) ALIF cage in L5-S1 ("ALIF"); 3) posterior instrumentation T9-S1 + Hyperlordotic (30°) ACR cage in L3-4 ("ACR"). These models were studied by simulations applying, alternately, a pure moment of 7.5 Nm between the three planes of motion (flexion, extension, lateral bending, and bilateral axial rotation), uniformly distributed over the upper surface of the T9 thoracic vertebra. A total of 24 simulations were performed (6 per models). RESULTS: All models presented a significant reduced ROM when compared to the intact model; the ROM reduction was higher both at L3-4 in the ACR model and at L5-S1 in the ALIF model. At L3-4, the ACR model had, in all cases, the lowest maximum values of Von Mises stresses on the rods, especially in flexion-extension. At L4-5, the ALIF model had the lowest stresses during flexion-extension and axial rotation, while the ACR model had the lowest stresses during lateral bending. At L5-S1, the ALIF model had, in all cases, the lowest stresses on the rods. CONCLUSIONS: This finite-element study showed how both ACR at L3-4 and ALIF-ACR at L5-S1 are effective in restoring lumbar lordosis (LL), stabilizing the spine and reducing stress on posterior rods at the index level when compared to a simple fixation model. Interestingly, ALIF-ACR reduces rod stress even at L4-5 in flexion-extension and axial rotation, possibly due to a better distribution of LL, especially on the lower arch, while ACR reduces the stress at L4-5 in lateral bending, possibly thanks to the larger footprint of the cage that increases the area of contact with the lateral side of the endplates.

Paraparesis and congenital severe hyperkyphosis in Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome: A rare deformity management during the Sars-Cov-2 pandemic.

Introduction: Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) syndrome can be classified into two types: type I (isolated) without extragenital abnormalities; type II (associated) with the presence of extragenital dimorphisms. Skeletal abnormalities are the second most frequent extragenital manifestations. Research question: Association between MRKH and congenital scoliosis has been described; on the contrary, hyperkyphosis is very rare and sparsely described in the medical literature. Here we report our experience in the management of thoracolumbar hyperkyphosis in 16-year-old patient diagnosed with MRKH syndrome with an acute neurological impairment due to T11-T12 disc herniation. Material and methods: Clinical and radiological images of the case were retrieved from the medical notes, operative records and imaging system. Results: Posterior surgical correction was proposed to treat the severe spinal deformity; however, surgery was delayed because of SARS-CoV2 pandemic outbreak. During the pandemic, the patient had a major clinical and radiological deterioration with development of paraparesis. Complete clinical resolution of the paraparesis and restoration of balance was achieved with a two stage surgical approach, with a first anterior stage followed by a delayed posterior approach aimed at deformity correction. Discussion: Congenital kyphosis are rare deformities that can progress rapidly leading to severe neurological deficits and worsening of the deformity. When patient has neurological deficit the surgical strategy to address the neurological problem first and plan the more complex and demanding corrective surgery remains a valid strategy that must be consider. Conclusion: This is the first reported case of hyperkyphosis in Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) syndrome surgically treated.

What Is the Role of Traction Test Radiographs in the Preoperative Planning of Adolescent Idiopathic Scoliosis?

Lower instrumented vertebra (LIV) selection is critical to avoid complications like adding-on. This study aims to determine the usefulness of the traction test (TR) in selecting the LIV during surgery for adolescent idiopathic scoliosis (AIS). We analyzed 42 AIS patients with Lenke 1 curves who had preoperative, postoperative, and at least 12-month follow-up X-rays, as well as preoperative side bending (SB) and TR radiograms. Neutral vertebra (NV), stable vertebra (SV), lower instrumented vertebra (LIV), and Cobb angles were identified and compared on all radiographic images. In 23 cases, the TR resulted in SV proximalization compared to the preoperative X-rays, while in 8 cases, SV-TR was more distal. This distalization occurred in 50% of Lenke 1C curves, where a greater correction of the distal curve was found. NV-TR was proximal to NV-preop in 9 cases, while NV-SB was proximal in 22 cases. LIV was proximal to SV-TR in 8 cases, while it was proximal to SV-preop in 22. One patient with LIV proximal to SV-TR developed adding-on. In conclusion, the TR is crucial in AIS preoperative planning as it provides information distinct from that of standard X-rays and SB: (1) it better assesses gravitational stability than rotational stability; and (2) choosing LIV equal to or proximal to SV-TR may prevent adding-on, except in 'flexible' Lenke 1C curves where LIV should be equal or distal to SV-preop.

Relationship between lumbar lordosis, pelvic parameters, PI-LL mismatch and outcome after short fusion surgery for lumbar degenerative disease. Literature review, rational and presentation of public study protocol: RELApSE study (registry for evaluation of lumbar artrodesis sagittal alignEment).

Background: Vertebral arthrodesis for degenerative pathology of the lumbar spine still remains burdened by clinical problems with significant negative results. The introduction of the sagittal balance assessment with the evaluation of the meaning of pelvic parameters and spinopelvic (PI-LL) mismatch offered new evaluation criteria for this widespread pathology, but there is a lack of consistent evidence on long-term outcome. Methods: The authors performed an extensive systematic review of literature, with the aim to identify all potentially relevant studies about the role and usefulness of the restoration or the assessment of Sagittal balance in lumbar degenerative disease. They present the study protocol RELApSE (NCT05448092 ID) and discuss the rationale through a comprehensive literature review. Results: From the 237 papers on this topic, a total of 176 articles were selected in this review. The analysis of these literature data shows sparse and variable evidence. There are no observations or guidelines about the value of lordosis restoration or PI-LL mismatch. Most of the works in the literature are retrospective, monocentric, based on small populations, and often address the topic evaluation partially. Conclusions: The RELApSE study is based on the possibility of comparing a heterogeneous population by pathology and different surgical technical options on some homogeneous clinical and anatomic-radiological measures aiming to understanding the value that global lumbar and segmental lordosis, distribution of lordosis, pelvic tilt, and PI-LL mismatch may have on clinical outcome in lumbar degenerative pathology and on the occurrence of adjacent segment disease.