Conserved patterns and locomotor-related evolutionary constraints in the hominoid vertebral column

The evolution of the hominoid lineage is characterized by pervasive homoplasy, notably in regions such as the vertebral column, which plays a central role in body support and locomotion. Few isolated and fewer associated vertebrae are known for most fossil hominoid taxa, but identified specimens indicate potentially high levels of convergence in terms of both form and number. Homoplasy thus complicates attempts to identify the anatomy of the last common ancestor of hominins and other taxa and stymies reconstructions of evolutionary scenarios. One way to clarify the role of homoplasy is by investigating constraints via phenotypic integration, which assesses covariation among traits, shapes evolutionary pathways, and itself evolves in response to selection. We assessed phenotypic integration and evolvability across the subaxial (cervical, thoracic, lumbar, sacral) vertebral column of macaques (n = 96), gibbons (n = 77), chimpanzees (n = 92), and modern humans (n = 151). We found a mid-cervical cluster that may have shifted cranially in hominoids, a persistent thoracic cluster that is most marked in chimpanzees, and an expanded lumbosacral cluster in hominoids that is most expanded in gibbons. Our results highlight the highly conserved nature of the vertebral column. Taxa appear to exploit existing patterns of integration and ontogenetic processes to shift, expand, or reduce cluster boundaries. Gibbons appear to be the most highly derived taxon in our sample, possibly in response to their highly specialized locomotion.

Evaluation of the Interrater Reliability of Sonographic Measurements of Muscle Thickness of 38 Piriformis Muscles in 19 Patients with Piriformis Syndrome

BACKGROUND The piriformis muscle is a flat superficial muscle of the deep gluteal muscles that externally rotates the hip. Ultrasound is widely used to identify the piriformis muscle, especially for guidance of the needle during injections; however, its diagnostic use has recently gained popularity. The operator-dependent nature of ultrasound requires demonstration of reliability between operators. This study aimed to evaluate interrater reliability of sonographic measurements of muscle thickness of 38 piriformis muscles in 19 patients with piriformis syndrome. MATERIAL AND METHODS An ultrasound transducer was placed transversely on the sacral spinous process and moved caudo-laterally until the piriformis muscle was visualized under the gluteus maximus while patients were lying in prone position. The thickness of piriformis muscle was measured with a 2 to 5-MHz broadband curvilinear transducer in 3 regions (thickest regions of muscle over the ilium, near the greater trochanter, and near the sacrum). The interrater reliability of measurements of 2 examiners who were blinded to each other's measurements was assessed by intraclass correlation coefficient. RESULTS In total, 114 samples from 38 piriformis muscles of 19 patients with a diagnosis of piriformis syndrome were evaluated by 2 raters in this study. The median (interquartile range) patient age was 41 (15) years. Intraclass correlation coefficient value for overall thickness measurements of piriformis muscle was 0.836. Intraclass correlation coefficient values for 3 different regions were over the ilium, near the greater trochanter, and near the sacrum were 0.777, 0.883, and 0.811, respectively. CONCLUSIONS Ultrasound measurement of piriformis muscle thickness has good interrater reliability.

Incidence and risk factors of proximal junctional kyphosis in adolescent idiopathic scoliosis after correction surgery: a meta-analysis and systematic review

AIM

To analyze the risk factors of proximal junctional kyphosis (PJK) after correction surgery in patients with adolescent idiopathic scoliosis (AIS).

METHODS

PubMed, Medline, Embase, Cochrane Library, Web of Science, CNKI, and EMCC databases were searched for retrospective studies utilizing all AIS patients with PJK after corrective surgery to collect preoperative, postoperative, and follow-up imaging parameters, including thoracic kyphosis (TK), lumbar lordosis (LL), proximal junctional angle (PJA), the sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), pelvic incidence-lumbar lordosis (PI-LL), sacral slope (SS), rod contour angle (RCA) and upper instrumented vertebra (UIV).

RESULTS

Nineteen retrospective studies were included in this meta-analysis, including 550 patients in the intervention group and 3456 patients in the control group. Overall, sex (OR 1.40, 95% CI (1.08, 1.83), P = 0.01), larger preoperative TK (WMD 6.82, 95% CI (5.48, 8.16), P < 0.00001), larger follow-up TK (WMD 8.96, 95% CI (5.62, 12.30), P < 0.00001), larger postoperative LL (WMD 2.31, 95% CI (0.91, 3.71), P = 0.001), larger follow-up LL (WMD 2.51, 95% CI (1.19, 3.84), P = 0.0002), great change in LL (WMD - 2.72, 95% CI (- 4.69, - 0.76), P = 0.006), larger postoperative PJA (WMD 4.94, 95% CI (3.62, 6.26), P < 0.00001), larger follow-up PJA (WMD 13.39, 95% CI (11.09, 15.69), P < 0.00001), larger postoperative PI-LL (WMD - 9.57, 95% CI (- 17.42, - 1.71), P = 0.02), larger follow-up PI-LL (WMD - 12.62, 95% CI (- 17.62, - 7.62), P < 0.00001), larger preoperative SVA (WMD 0.73, 95% CI (0.26, 1.19), P = 0.002), larger preoperative SS (WMD - 3.43, 95% CI (- 4.71, - 2.14), P < 0.00001), RCA (WMD 1.66, 95% CI (0.48, 2.84), P = 0.006) were identified as risk factors for PJK in patients with AIS. For patients with Lenke 5 AIS, larger preoperative TK (WMD 7.85, 95% CI (5.69, 10.00), P < 0.00001), larger postoperative TK (WMD 9.66, 95% CI (1.06, 18.26), P = 0.03, larger follow-up TK (WMD 11.92, 95% CI (6.99, 16.86), P < 0.00001, larger preoperative PJA (WMD 0.72, 95% CI (0.03, 1.41), P = 0.04, larger postoperative PJA (WMD 5.54, 95% CI (3.57, 7.52), P < 0.00001), larger follow-up PJA (WMD 12.42, 95% CI 9.24, 15.60), P < 0.00001, larger follow-up SVA (WMD 0.07, 95% CI (- 0.46, 0.60), P = 0.04), larger preoperative PT (WMD - 3.04, 95% CI (- 5.27, - 0.81), P = 0.008, larger follow-up PT (WMD - 3.69, 95% CI (- 6.66, - 0.72), P = 0.02) were identified as risk factors for PJK.

CONCLUSION

Following corrective surgery, 19% of AIS patients experienced PJK, with Lenke 5 contributing to 25%. Prior and post-op measurements play significant roles in predicting PJK occurrence; thus, meticulous, personalized preoperative planning is crucial. This includes considering individualized treatments based on the Lenke classification as our future evaluation standard.

Iatrogenic vertebral fracture in ankylosed spine during liver transplantation: a case report and biomechanical study using finite element method

PURPOSE

The occurrence of an iatrogenic vertebral fracture during non-spinal digestive surgery is an exceptional event that has not been previously documented. Our study aims to explain the occurrence of this fracture from a biomechanical perspective, given its rarity. Using a finite element model of the spine, we will evaluate the strength required to induce a vertebral fracture through a hyperextension mechanism, considering the structure of the patient's spine, whether it is ossified or healthy.

METHODS

A 70-year-old patient was diagnosed T12 fracture during a liver transplantation on ankylosed spine. We use a finite element model of the spine. Different mechanical properties were applied to the spine model: first to a healthy spine, the second to a osteoporotic ossified spine. The displacement and force imposed at the Sacrum, the time and location of fractures initiation were recorded and compared between the two spine conditions.

RESULTS

A surgical treatment is done associating decompression with posterior fixation. After biomechanical study, we found that the fracture initiation occurred for the ossified spine after a sacrum displacement of 29 mm corresponding to an applied force of 65 N. For the healthy spine it occurred at a sacrum displacement of 52 mm corresponding to an applied force of 350 N.

CONCLUSION

The force required to produce a type B fracture in an ankylosed spine is 5 times less than in a healthy spine. These data enable us to propose several points of management to avoid unexpected complications with ankylosed spines during surgical procedures.

LEVEL OF EVIDENCE

IV.

Exploring body morphology, sacral skin microclimate and pressure injury development and risk among patients admitted to an intensive care unit: A prospective, observational study

OBJECTIVE

To determine the association between body morphology, sacral skin microclimate and their impact on the development and risk of pressure injuries among patients in an intensive care unit.

METHODOLOGY

A prospective observational exploratory study was conducted over 30 weeks. Repeat study observations occurred multiple times a week for 28 days or until discharge. Participant inclusion criteria were ≥ 18 years of age, expected intensive care length of stay > 24 h and intact skin over the sacrum region.

SETTING

The study was conducted in a 36-bed intensive care unit of a major metropolitan public hospital in Queensland, Australia.

OUTCOME MEASURES

Pressure injuries were staged and independently verified according to the international pressure injury classification system. Pressure injury risk was determined by the Braden scale score and subepidermal oedema, using a subepidermal moisture scanner at the sacrum.

RESULTS

Of the 93 participants recruited, an inverted triangle body shape (p =.049), a BMI > 25 kg/m2 (p =.008), a standard foam mattress type (p =.017) and increased length of stay (p <.001) were associated with an increased pressure injury risk according to subepidermal oedema. Participants with increased sacral skin temperature (p <.001), mechanical ventilation (p <.001), vasoactive drugs administered (p =.003), increased sequential organ failure assessment score (p =.047), neurovascular diagnosis (p =.031) and increased length of stay (p =.027) were associated with increased pressure injury risk according to the Braden scale score.

CONCLUSION

Body morphology and skin microclimate are associated with pressure injury risk during critical illness.

IMPLICATIONS FOR CLINICAL PRACTICE

Subepidermal oedema was associated with a patient's shape, body mass index and mattress type, factors that directly influence the pressure loading and the skin, whereas the Braden scale was associated with sacral temperature and clinical measures of critical illness. Consideration of body morphology and skin microclimate in pressure injury risk assessment could lead to more specific prevention strategies targeting high risk patients.

Correlation between sagittal parameters and disability of patients with nonspecific chronic low back pain: a cross-sectional study of 435 subjects

BACKGROUND CONTEXT

Sagittal parameters are significantly correlated with health-related quality of life (HRQoL) in adult spinal deformity patients. Their association with HRQoL in patients with nonspecific chronic low back pain (NSCLBP) is unclear.

PURPOSE

To analyze the correlation between sagittal parameters and disability in NSCLBP patients.

DESIGN

A cross-sectional study.

PATIENT SAMPLE

Subjects included 435 patients with NSCLBP divided into low disability and high disability groups.

OUTCOME MEASURES

Function was measured using the Oswestry Disability Index (ODI). Pain intensity was measured using the Numeric Rating Scale (NRS) and HRQoL was measured using 36-item Short Form Health Survey (SF-36).

METHODS

Sagittal parameters, demographic data, ODI, SF-36 eight-dimensional scores and NRS scores of patients with NSCLBP were collected. Taking ODI=20 as the cut-off value, patients were divided into low disability group (ODI≤20) and high disability group (ODI>20), and ODI were converted to Ranked ODI (RODI) accordingly. Univariate analysis of the correlation among age, gender, body mass index (BMI), sagittal parameters, RODI, SF-36 eight-dimensional scores, NRS scores were then conducted. The variables related to RODI were analyzed by logistic regression to discover their independent influence on RODI. p<.05 was considered to indicate statistical significance.

RESULTS

A total of 435 patients with NSCLBP were included. Univariate correlation analysis showed that the correlation coefficients between age, sacral slope-pelvic tilt (SS-PT), spinosacral angle (SSA) and RODI were (r=0.126, p<.01), (r=-0.115, p<.05), (r=-0.116, p<.05), respectively. The logistic regression analysis indicated that the regression coefficients of age and SSA were 0.030 (p=.001), -0.044 (p=.002), respectively, and the odds ratio and 95% confidence interval (CI) were 1.031 (1.012, 1.050), 0.957 (0.930, 0.985).

CONCLUSIONS

Age and SSA are independent factors for disability of NSCLBP. SSA can comprehensively reflect the sagittal balance of the spine of patients with NSCLBP. Decreased SSA represents poor sagittal balance, which will increase the disability of NSCLBP.

Changes in Spinopelvic Parameters Between Standing and Sitting Postures: A Systematic Review and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To report the ratio-of-differences between standing and sitting. To understand how sex and age influence these differences.

SUMMARY OF BACKGROUND DATA

Currently, spinal deformity surgery aims to realign the sagittal profile of the spine with-reference-to the standing posture resulting in overcorrection. New studies report significant disparities between standing and sitting spinal alignment.

METHODS

A comprehensive search and review of the published literature was performed on 4 platforms in accordance with the PRISMA 2009 checklist by 2 authors independently.

RESULTS

From 753 abstracts extracted from the databases, 38 papers involving 5423 patients were identified. sagittal vertical axis was more positive in sitting, with a pooled mean difference of 29.5 mm (95% CI: 17.9-41.0). Pelvic tilt (PT) was larger in sitting, with a pooled mean difference of 16.7 degrees (95% CI: 12.5-20.9), and a pooled odds ratio of 1.2(95% CI:1.1-1.3. P =0.001). Sacral Slope (SS) was smaller and lumbar lordosis (LL) was less lordotic in sitting, with a pooled mean difference of 15.0 degrees (95% CI: 11.918.1) and 21.1 degrees (95% CI:14.5-27.8), respectively, and a pooled odds ratio of 0.7 (95% CI: 0.6-0.8. P <0.001) and 0.7 (95% CI:0.6-0.7, P <0.001), respectively. Pelvic incidence and thoracic kyphosis was similar in sitting. Subgroup meta-analysis comparing odd ratio of standing to sitting showed: Among younger patients (age younger than 50), the PT and LL pooled odds-ratios were 1.4 and 0.7, respectively. Among older patients (age older than or equal to 50), the PT and LL pooled odds-ratios were 1.1 and 0.8, respectively. Among female patients, the SS pooled odds ratio was 0.6. Among male patients, the SS pooled odds ratio was 0.7.

CONCLUSION

When comparing sitting to standing, it gives a more positive sagittal vertical axis, a smaller SS and LL, and a larger PT. pelvic incidence and thoracic kyphosis remained similar. Younger and female patients have pronounced differences in SS, PT, and LL, suggesting the existence of age and sex variations, and its role to be considered when planning for spinal realignment surgeries. Clinical outcome studies are required to ascertain the impact of these findings.

Assessment of Spinal and Pelvic Kinematics Using Inertial Measurement Units in Clinical Subgroups of Persistent Non-Specific Low Back Pain

Inertial measurement units (IMUs) offer a portable and quantitative solution for clinical movement analysis. However, their application in non-specific low back pain (NSLBP) remains underexplored. This study compared the spine and pelvis kinematics obtained from IMUs between individuals with and without NSLBP and across clinical subgroups of NSLBP. A total of 81 participants with NSLBP with flexion (FP; n = 38) and extension (EP; n = 43) motor control impairment and 26 controls (No-NSLBP) completed 10 repetitions of spine movements (flexion, extension, lateral flexion). IMUs were placed on the sacrum, fourth and second lumbar vertebrae, and seventh cervical vertebra to measure inclination at the pelvis, lower (LLx) and upper (ULx) lumbar spine, and lower cervical spine (LCx), respectively. At each location, the range of movement (ROM) was quantified as the range of IMU orientation in the primary plane of movement. The ROM was compared between NSLBP and No-NSLBP using unpaired t-tests and across FP-NSLBP, EP-NSLBP, and No-NSLBP subgroups using one-way ANOVA. Individuals with NSLBP exhibited a smaller ROM at the ULx (p = 0.005), LLx (p = 0.003) and LCx (p = 0.01) during forward flexion, smaller ROM at the LLx during extension (p = 0.03), and a smaller ROM at the pelvis during lateral flexion (p = 0.003). Those in the EP-NSLBP group had smaller ROM than those in the No-NSLBP group at LLx during forward flexion (Bonferroni-corrected p = 0.005), extension (p = 0.013), and lateral flexion (p = 0.038), and a smaller ROM at the pelvis during lateral flexion (p = 0.005). Those in the FP-NSLBP subgroup had smaller ROM than those in the No-NSLBP group at the ULx during forward flexion (p = 0.024). IMUs detected variations in kinematics at the trunk, lumbar spine, and pelvis among individuals with and without NSLBP and across clinical NSLBP subgroups during flexion, extension, and lateral flexion. These findings consistently point to reduced ROM in NSLBP. The identified subgroup differences highlight the potential of IMU for assessing spinal and pelvic kinematics in these clinically verified subgroups of NSLBP.

Relationship between sacral-abdominal wall distance, movement performance, and spinal alignment in osteoporosis: a retrospective study

BACKGROUND

Aging is associated with muscle atrophy, as typified by sarcopenia. Loss of abdominal muscle strength can cause abdominal wall laxity. The purpose of this study was to investigate the relationship between the sacral vertebra-abdominal wall distance (SAD) and movement performance using a simple lateral spine X-ray image for measuring the SAD.

METHODS

In this retrospective study, we included women aged ≥ 65 years who were attending the outpatient clinic for osteoporosis at our hospital. A total of 287 patients (mean age ± SD, 76.8 ± 7.1 years) with measured SAD were included in the analysis. Patients were divided into two groups based on SAD cutoff (160 mm) and age (75 years), respectively. The patients were examined using the two-foot 20 cm rise test, 3 m Timed Up and Go (TUG) test, two-step test, open-eyed one-leg standing time, and spinal alignment. Normally distributed data are expressed as means (standard deviations) and non-normally distributed data as medians (interquartile range), depending on the results of the Kolmogorov-Smirnov test. Student's t-test and χ2 test were used for between-group comparisons. Regression analysis was performed with SAD as the objective variable. A two-sided p < 0.05 was considered statistically significant.

RESULTS

The shorter SAD group performed better in the two-step test, TUG test, and open-eyed one-leg standing time (p < 0.001) as well as in the two-foot 20 cm rise test (p < 0.01) compared to the longer SAD group. Spinal alignment was better in the shorter SAD group than in the longer SAD group, with a shorter sagittal vertical axis (p < 0.001), smaller pelvic tilt (p < 0.001), and greater sacral slope (p < 0.05).

CONCLUSION

SAD was associated with posterior pelvic tilt and movement performance parameters. In addition to testing for osteoporosis, movement performance parameters should be evaluated in women with osteoporosis who are aged ≥ 65 and have greater SAD (≥ 160 mm in this study). The SAD is a new assessment method, and further research is required to verify its validity and reproducibility. This is the first attempt to determine how age and SAD affect movement performance in older adults.

Comparing Impact of Overactive Bladder Therapies on Nocturia

IMPORTANCE

Nocturia is a significant symptom in overactive bladder with little data regarding the impact of overactive bladder treatments on nocturia.

OBJECTIVES

Compare the effect of anticholinergic (AC) medication, onabotulinum toxin A (BTX), and sacral neuromodulation (SNM) on nocturia.

STUDY DESIGN

Secondary analysis of the ABC and ROSETTA trials using data from the National Institutes of Health Data and Specimen Hub database. Patients reporting mean ≥2 voids/night on 3-day diary were included and divided into cohorts by treatment: the ABC trial: (1) AC and (2) BTX 100 units, and the ROSETTA trial: (3) BTX 200 units and (4) SNM. Primary outcome was change in mean voids/night on 3-day diary from baseline to 6 months assessed by mixed-effects models for repeated-measures data with interaction between treatment cohort and time included in model.

RESULTS

A total of 197 patients were included: 43 (22%) AC, 37 (19%) BTX 100 U, 63 (32%) BTX 200 U, and 54 (27%) SNM. There were no significant differences in baseline voids/night, demographics, or urodynamic values except for younger age in AC and BTX 100 U cohorts (P = 0.04). At 6 months, all cohorts demonstrated a mean 41% decrease in mean voids/night (2.7 ± 0.4 at baseline to 1.6 ± 0.5 at 6 months; P < 0.001), with no significant difference in change in mean voids/night between treatment cohorts (decrease of 44% in AC, 46% in 100 U BTX, 32% 200 in U BTX, and 33% in SNM; P > 0.05).

CONCLUSION

For women with nocturia ≥2/night, treatment with AC, BTX 100 or 200 units, or SNM led to a significant decrease in voids/night at 6 months.

Sacral Neuromodulation in Patients With Low Anterior Resection Syndrome: The SANLARS Randomized Clinical Trial

BACKGROUND

Sacral neuromodulation might be effective to palliate low anterior resection syndrome after rectal cancer surgery, but robust evidence is not available.

OBJECTIVE

To assess the impact of sacral neuromodulation on low anterior resection syndrome symptoms as measured by validated scores and bowel diaries.

DESIGN

Randomized, double-blind, 2-phased, controlled, multicenter crossover trial (NCT02517853).

SETTINGS

Three tertiary hospitals.

PATIENTS

Patients with major low anterior resection syndrome 12 months after transit reconstruction after rectal resection who had failed conservative treatment.

INTERVENTIONS

Patients underwent an advanced test phase by stimulation for 3 weeks and received the pulse generator implant if a 50% reduction in low anterior resection syndrome score was achieved. These patients entered the randomized phase in which the generator was left active or inactive for 4 weeks. After a 2-week washout, the sequence was changed. After the crossover, all generators were left activated.

MAIN OUTCOME MEASURES

The primary outcome was low anterior resection syndrome score reduction. Secondary outcomes included continence and bowel symptoms.

RESULTS

After testing, 35 of 46 patients (78%) had a 50% or greater reduction in low anterior resection syndrome score. During the crossover phase, all patients showed a reduction in scores and improved symptoms, with better performance if the generator was active. At 6- and 12-month follow-up, the mean reduction in low anterior resection syndrome score was -6.2 (95% CI -8.97 to -3.43; p < 0.001) and -6.97 (95% CI -9.74 to -4.2; p < 0.001), with St. Mark's continence score -7.57 (95% CI -9.19 to -5.95, p < 0.001) and -8.29 (95% CI -9.91 to -6.66; p < 0.001). Urgency, bowel emptiness sensation, and clustering episodes decreased in association with quality-of-life improvement at 6- and 12-month follow-up.

LIMITATIONS

The decrease in low anterior resection syndrome score with neuromodulation was underestimated because of an unspecific measuring instrument. There was a possible carryover effect in sham stimulation sequence.

CONCLUSIONS

Neuromodulation provides symptoms and quality-of-life amelioration, supporting its use in low anterior resection syndrome. See Video Abstract .

NEUROMODULACIN SACRA EN PACIENTES CON SNDROME DE RESECCIN ANTERIOR BAJA ENSAYO CLNICO ALEATORIZADO SANLARS

ANTECEDENTES:La neuromodulación sacra podría ser eficaz para paliar el síndrome de resección anterior baja después de la cirugía de cáncer de recto, pero no hay pruebas sólidas disponibles.OBJETIVO:Evaluar el impacto de la neuromodulación sacra en los síntomas del síndrome de resección anterior baja, medido mediante puntuaciones validadas y diarios intestinales.DISEÑO:Ensayo cruzado multicéntrico, controlado, aleatorizado, doble ciego, de dos fases (NCT02517853).LUGARES:Tres hospitales terciarios.PACIENTES:Pacientes con puntuación de resección anterior baja importante, 12 meses después de la reconstrucción del tránsito después de la resección rectal en quienes había fracasado el tratamiento conservador.INTERVENCIONES:Los pacientes se sometieron a una fase de prueba avanzada mediante estimulación durante tres semanas y se les implantó el generador de impulsos si se lograba una reducción del 50% en la puntuación del síndrome de resección anterior baja, ingresando a la fase aleatorizada en la que el generador se dejaba activo o inactivo durante cuatro semanas. Después de observar por 2 semanas, se cambió la secuencia. Después del cruce, todos los generadores quedaron activados.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la reducción de la puntuación del síndrome de resección anterior baja. Los resultados secundarios incluyeron continencia y síntomas intestinales.RESULTADOS:Después de las pruebas, 35 de 46 pacientes (78%) tuvieron una reducción ≥50% en la puntuación del síndrome de resección anterior baja. Durante el cruce, todos los pacientes mostraron una reducción en las puntuaciones y una mejora de los síntomas, con un mejor rendimiento si el generador estaba activo. A los 6 y 12 meses de seguimiento, la reducción media en la puntuación del síndrome de resección anterior baja fue -6,2 (-8,97; -3,43; p < 0,001) y -6,97 (-9,74; -4,2; p < 0,001), con Puntuación de continencia de St. Mark's -7,57 (-9,19; -5,95, p < 0,001) y -8,29 (-9,91; -6,66; p < 0,001). La urgencia, la sensación de vacío intestinal y los episodios de agrupamiento disminuyeron en asociación con una mejora en la calidad de vida a los 6 y 12 meses de seguimiento.LIMITACIONES:La disminución en la puntuación del síndrome de resección anterior baja con neuromodulación se subestimó debido a un instrumento de medición no específico. Posible efecto de arrastre en la secuencia de estimulación simulada.CONCLUSIONES:La neuromodulación mejora los síntomas y la calidad de vida, lo que respalda su uso en el síndrome de resección anterior baja. (Traducción-Dr. Mauricio Santamaria ).

Predictors of Rod Length Gain and Sagittal Alignment Change After Magnetically Controlled Growing Rod Lengthening

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

There are preoperative characteristics that predict rod lengthening of magnetically controlled growing rods (MCGR). The lengthening of MCGR will lead to increased kyphosis.

SUMMARY OF BACKGROUND DATA

The amount of length gained by MCGR is variable, and predictors are lacking. Similarly, sagittal plane changes over the MCGR lengthening period have not been investigated.

MATERIALS AND METHODS

Patients with MCGR and a minimum 2-year follow-up were identified and those with previous spine surgery were excluded. Preimplantation, postimplantation, and last follow-up postlengthening radiographs were examined. Multiple linear regression analyses were used for rod length gain predictors.

RESULTS

Fifty-six patients with early-onset scoliosis met inclusion criteria: nine idiopathic, five congenital, 14 neuromuscular, 20 syndromic, and eight skeletal dysplasia patients. No difference was seen between subtypes of early-onset scoliosis for rod length gain ( P =0.62). Shorter preoperative T1-T12 height and higher curve correction rate after implantation were significant predictors for rod length gain ( P <0.001). Preoperative major curve magnitude and kyphosis were not significant predictors. Flattening of the spine around the actuator and compensative increase in T1-T5 kyphosis were seen secondarily after MCGR implantation. Maximum sagittal kyphosis, T1-T5 kyphosis, and T5-T12 kyphosis did not change during lengthening. Lumbar lordosis significantly decreased postimplantation (first erect) but then increased during lengthening. Pelvic incidence and sacral slope both increased during lengthening, but this may be age related.

CONCLUSION

Patients who gained the most rod length with MCGR were those with an initially shorter T1-T12 height and better initial curve correction at implantation, likely representing that implants work best in small patients with flexible curves. Diagnosis, preoperative curve magnitude, and thoracic kyphosis were not related to rod length gain. Thoracic kyphosis did not deteriorate over the lengthening phase.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Radiation exposure during sacral neuromodulation lead placement: Multi-institutional descriptive study

OBJECTIVES

Fluoroscopy has significantly improved lead placement and decreased surgical time for implantable sacral neuromodulation (SNM). There is a paucity of data regarding radiation and safety of fluoroscopy during SNM procedures. Our study aims to characterize fluoroscopy time and dose used during SNM surgery across multiple institutions and assess for predictors of increased fluoroscopy time and radiation dose.

METHODS

Electronic medical records were queried for SNM procedures (Stage 1 and full implant) from 2016 to 2021 at four academic institutions. Demographic, clinical, and intraoperative data were collected, including fluoroscopy time and radiation dose in milligray (mGy). The data were entered into a centralized REDCap database. Univariate and multivariate analysis were performed to assess for predictive factors using STATA/BE 17.0.

RESULTS

A total of 664 procedures were performed across four institutions. Of these, 363 (54.6%) procedures had complete fluoroscopy details recorded. Mean surgical time was 58.8 min. Of all procedures, 79.6% were performed by Female Pelvic Medicine and Reconstructive Surgery specialists. There was significant variability in fluoroscopy time and dose based on surgical specialty and institution. Most surgeons (76.4%) were considered "low volume" implanters. In a multivariate analysis, bilateral finder needle testing, surgical indication, surgeon volume, and institution significantly predicted increased fluoroscopy time and radiation dose (p < 0.05).

CONCLUSIONS

There is significant variability in fluoroscopy time and radiation dose utilized during SNM procedures, with differences across institutions, surgeons, and subspecialties. Increased radiation exposure can have harmful impacts on the surgical team and patient. These findings demonstrate the need for standardized fluoroscopy use during SNM procedures.

Effectiveness, safety and cost-effectiveness of sacral neuromodulation for idiopathic slow-transit constipation: a systematic review

AIM

Sacral neuromodulation (SNM) is a minimally invasive treatment option for functional constipation. Evidence regarding its effectiveness is contradictory, driven by heterogeneous study populations and designs. The aim of this study was to assess the effectiveness, safety and cost-effectiveness of SNM in children and adults with refractory idiopathic slow-transit constipation (STC).

METHOD

OVID Medline, OVID Embase, Cochrane Library, the KSR Evidence Database, the NHS Economic Evaluation Database and the International HTA Database were searched up to 25 May 2023. For effectiveness outcomes, randomized controlled trials (RCTs) were selected. For safety outcomes, all study designs were selected. For cost-effectiveness outcomes, trial- and model-based economic evaluations were selected for review. Study selection, risk of bias and quality assessment, and data extraction were independently performed by two reviewers. For the intervention 'sacral neuromodulation' effectiveness outcomes included defaecation frequency and constipation severity. Safety and cost-effectiveness outcomes were, respectively, adverse events and incremental cost-effectiveness ratios.

RESULTS

Of 1390 records reviewed, 67 studies were selected for full-text screening. For effectiveness, one cross-over and one parallel-group RCT was included, showing contradictory results. Eleven studies on safety were included (four RCTs, three prospective cohort studies and four retrospective cohort studies). Overall infection rates varied between 0% and 22%, whereas reoperation rates varied between 0% and 29%. One trial-based economic evaluation was included, which concluded that SNM was not cost-effective compared with personalized conservative treatment at a time horizon of 6 months. The review findings are limited by the small number of available studies and the heterogeneity in terms of study populations, definitions of refractory idiopathic STC and study designs.

CONCLUSION

Evidence for the (cost-)effectiveness of SNM in children and adults with refractory idiopathic STC is inconclusive. Reoperation rates of up to 29% were reported.

Does choice of anesthesia during stage 1 sacral neuromodulation testing influence outcomes?

INTRODUCTION

Staged sacral neuromodulation (SNM) testing has been shown to have a high rate of progression to permanent implantation for the management of voiding dysfunction. Stage 1 lead placement (SNM-I) can be performed under monitored anesthesia care (MAC) or general anesthesia (GA). MAC allows for interpretation of sensory and motor responses to optimize lead placement while GA only permits for motor assessment. However, patient discomfort and movement can make lead placement challenging during MAC. Herein we evaluate whether the anesthesia type impacts the progression rate to permanent implantation (SNM-II).

MATERIALS AND METHODS

A retrospective chart review was performed for patients who underwent SNM-I in the operating room for wet overactive bladder between 2005 and 2023. Patients were divided into two groups based on the type of anesthesia used, MAC or GA. Clinical variables and progression to SNM-II were compared between cohorts. Progression to SNM-II was based on ≥50% symptomatic improvement during a 1-2 week trial period following SNM-I.

RESULTS

Of 121 patients included in the study, 95 (79%) underwent MAC and 26 (21%) GA for SNM-I. No difference in the progression rate to SNM-II was noted between groups (MAC, 68/95 patients, 72%; GA, 19/26, 73%; p = 0.39). We also found no difference when comparing the GA group to the 26 most recent MAC patients (MAC, 20/26 patients, 77%; GA, 19/26, 73%; p = 0.48).

CONCLUSION

Types of anesthesia for SNM-I did not affect rate of progression to SNM-II. The result lends support to the reliance on motor responses alone for lead placement during SNM-I.

The correlation between sub-epidermal moisture measurement and other early indicators of pressure ulcer development-A prospective cohort observational study. Part 1. The correlation between sub-epidermal moisture measurement and ultrasound

The correlation between sub-epidermal moisture (SEM) and other early indicators of pressure ulcer (PU) development is yet to be determined. This three-part series aims to bridge this knowledge gap, through investigating SEM and its correlation with evidence-based technologies and assessments. This article focuses on the correlation between SEM and ultrasound. A prospective cohort observational study was undertaken between February and November 2021. Patients undergoing three surgery types were consecutively enrolled to the study following informed consent. Assessments were performed prior to and following surgery for 3 days at the sacrum, both heels and a control site, using a SEM scanner and high-frequency ultrasound scanner (5-15 MHz). Spearman's rank (rs ) explored the correlation between SEM and ultrasound. A total of 60 participants were included; 50% were male with a mean age of 58 years (±13.46). A statistically significant low to moderately positive correlation was observed between SEM and ultrasound across all anatomical sites (rs range = 0.39-0.54, p < 0.05). The only exception was a correlation between SEM and ultrasound on day 0 at the right heel (rs  = 0.23, p = 0.09). These results indicate that SEM and ultrasound agreed in the presence of injury; however, SEM was able to identify abnormalities before ultrasound.

Restoring the ideal Roussouly sagittal alignment in Lenke 5 adolescent idiopathic scoliosis patients: a method for decreasing the risk of proximal junctional kyphosis

PURPOSE

Although the Roussouly classification has been widely used in surgical planning for adult scoliosis patients, little is known about whether it can be used to guide sagittal correction for adolescent idiopathic scoliosis (AIS) patients. The purpose of this study was to explore whether the Roussouly classification could be used to help surgeons restore the ideal sagittal alignment for AIS patients to avoid the development of proximal junctional kyphosis (PJK).

METHODS

In this retrospective cohort study, eighty-seven patients with Lenke 5 AIS who underwent surgery from January 2010 to August 2020 were enrolled and divided into two groups: the PJK group and the non-PJK group. All patients were classified into "current types" and "ideal types" according to two versions of the Roussouly classification, and the mismatch rate was evaluated in terms of the consistency between their current type and ideal type. Student's t test, Mann‒Whitney U test, Pearson's Chi-square test, and others were used to compare the two groups regarding patient demographic characteristics (age, sex, Risser sign, etc.) and radiographic parameters (sagittal vertical axis [SVA]; thoracic kyphosis [TK]; thoracolumbar junctional kyphosis [TLK]; lumbar lordosis [LL]; pelvic incidence [PI]; pelvic tilt [PT]; sacral slope [SS]; upper instrumented vertebra [UIV]; lower instrumented vertebra [LIV]; etc.). Multivariate logistic regression with backwards stepwise selection was performed to identify the risk factors for PJK.

RESULTS

PJK was observed in 16 out of 87 patients (18.4%) until the final follow-up. The incidence of PJK was significantly higher in the patients not matching their ideal type than in those who did after surgery (60.9% vs. 3.1%, p = 0.000). The patients with ideal Type 1 had the highest incidence of PJK, while the lowest incidence was observed in patients with ideal Type 2 (50.0% vs. 5.1%, p = 0.000). The PJK group had greater TK, LL, and PI-LL than the non-PJK group before and after surgery. The postoperative PJA in the PJK group was also larger than that in the non-PJK group. Multivariate logistic regression revealed that postoperative Roussouly type mismatch was significantly associated with the occurrence of PJK (OR = 64.2, CI = 9.6-407.1, p = 0.000).

CONCLUSIONS

The Roussouly classification could serve as a prognostic tool for PJK in Lenke 5 AIS patients. Corrective surgery should restore sagittal alignment with respect to the patient's ideal sagittal profile (according to the Roussouly classification based on the PI) to decrease the incidence of PJK in AIS patients.

Fusion to the sacrum or pelvis increases survival in patients with Duchenne muscular dystrophy

This commentary is on the original article by Arshad and Tsirikos on pages 187–194 of this issue.

The differences in the anatomy of the thoracolumbar and sacral autonomic outflow are quantitative

PURPOSE

We have re-evaluated the anatomical arguments that underlie the division of the spinal visceral outflow into sympathetic and parasympathetic divisions.

METHODOLOGY

Using a systematic literature search, we mapped the location of catecholaminergic neurons throughout the mammalian peripheral nervous system. Subsequently, a narrative method was employed to characterize segment-dependent differences in the location of preganglionic cell bodies and the composition of white and gray rami communicantes.

RESULTS AND CONCLUSION

One hundred seventy studies were included in the systematic review, providing information on 389 anatomical structures. Catecholaminergic nerve fibers are present in most spinal and all cranial nerves and ganglia, including those that are known for their parasympathetic function. Along the entire spinal autonomic outflow pathways, proximal and distal catecholaminergic cell bodies are common in the head, thoracic, and abdominal and pelvic region, which invalidates the "short-versus-long preganglionic neuron" argument. Contrary to the classically confined outflow levels T1-L2 and S2-S4, preganglionic neurons have been found in the resulting lumbar gap. Preganglionic cell bodies that are located in the intermediolateral zone of the thoracolumbar spinal cord gradually nest more ventrally within the ventral motor nuclei at the lumbar and sacral levels, and their fibers bypass the white ramus communicans and sympathetic trunk to emerge directly from the spinal roots. Bypassing the sympathetic trunk, therefore, is not exclusive for the sacral outflow. We conclude that the autonomic outflow displays a conserved architecture along the entire spinal axis, and that the perceived differences in the anatomy of the autonomic thoracolumbar and sacral outflow are quantitative.

Three-column osteotomy in long constructs has lower rates of proximal junctional kyphosis and better restoration of lumbar lordosis than anterior column realignment

PURPOSE

Three-column osteotomies (TCOs) and minimally invasive techniques such as anterior column realignment (ACR) are powerful tools used to restore lumbar lordosis and sagittal alignment. We aimed to appraise the differences in construct and global spinal stability between TCOs and ACRs in long constructs.

METHODS

We identified consecutive patients who underwent a long construct lumbar or thoracolumbar fusion between January 2016 and November 2021. "Long construct" was any construct where the uppermost instrumented vertebra (UIV) was L2 or higher and the lowermost instrumented vertebra (LIV) was in the sacrum or ileum.

RESULTS

We identified 69 patients; 14 (20.3%) developed PJK throughout follow-up (mean 838 days). Female patients were less likely to suffer PJK (p = 0.009). TCO was more associated with open (versus minimally invasive) screw/rod placement, greater number of levels, higher UIV, greater rate of instrumentation to the ilium, and posterior (versus anterior) L5-S1 interbody placement versus the ACR cohort (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.005, respectively). Patients who developed PJK were more likely to have undergone ACR (12 (32.4%) versus 2 (6.3%, p = 0.007)). The TCO cohort had better improvement of lumbar lordosis despite similar preoperative measurements (ACR: 16.8 ± 3.78°, TCO: 23.0 ± 5.02°, p = 0.046). Pelvic incidence-lumbar lordosis mismatch had greater improvement after TCO (ACR: 14.8 ± 4.02°, TCO: 21.5 ± 5.10°, p = 0.042). By multivariate analysis, ACR increased odds of PJK by 6.1-times (95% confidence interval: 1.20-31.2, p = 0.29).

CONCLUSION

In patients with long constructs who undergo ACR or TCO, we experienced a 20% rate of PJK. TCO decreased PJK 6.1-times compared to ACR. TCO demonstrated greater improvement of some spinopelvic parameters.

Sacrum and Coccyx Shape Changes During Pregnancy and After Delivery

Remodeling of the sacrum and coccyx to accommodate pregnancy and delivery has been hypothesized but not directly quantified. This study aimed to quantify the remodeling of the sacrum and coccyx by comparing midsagittal lengths, angles, curvature, and shape between nulliparous, pregnant, and parous women using both 2 and 3 dimensional measures. Ninety pelvic magnetic resonance images of the pelvis were retrospectively collected and segmented. Twelve length, angle, and curvature measurements were made using definitions from previous literature on the midsagittal plane to define the sacrum, coccyx, and combined sacrum-coccyx shape. These measures were followed by a statistical shape analysis, which returned modes of variation and principal component scores. A separate MANCOVA analysis was conducted for both the 2D and 3D measures. The 2D and 3D analyses agreed that pregnant women had a significantly straighter coccyx and combined sacrum/coccyx than nulliparous (9.1% and 5.6%, respectively) and parous (7.5% and 2.7%, respectively) subjects. All comparisons showed that, on average, a pregnant woman's sacrum and coccyx were significantly straighter than their nulliparous counterparts. Then after delivery, the sacrum/coccyx returned, but not completely back to a more curved configuration.

Assessment of a fully-parametric thoraco-lumbar spine model generator with articulated ribcage

The present paper describes a novel user-friendly fully-parametric thoraco-lumbar spine CAD model generator including the ribcage, based on 22 independent parameters (1 posterior vertebral body height per vertebra + 4 sagittal alignment parameters, namely pelvic incidence, sacral slope, L1-L5 lumbar lordosis, and T1-T12 thoracic kyphosis). Reliable third-order polynomial regression equations were implemented in Solidworks to analytically calculate 56 morphological dependent parameters and to automatically generate the spine CAD model based on primitive geometrical features. A standard spine CAD model, representing the case-study of an average healthy adult, was then created and positively assessed in terms of spinal anatomy, ribcage morphology, and sagittal profile. The immediate translation from CAD to FEM for relevant biomechanical analyses was successfully demonstrated, first, importing the CAD model into Abaqus, and then, iteratively calibrating the constitutive parameters of one lumbar and three thoracic FSUs, with particular interest on the hyperelastic material properties of the IVD, and the spinal and costo-vertebral ligaments. The credibility of the resulting lumbo-sacral and thoracic spine FEM with/without ribcage were assessed and validated throughout comparison with extensive in vitro and in vivo data both in terms of kinematics (range of motion) and dynamics (intradiscal pressure) either collected under pure bending moments and complex loading conditions (bending moments + axial compressive force).

Greater pelvic obliquity in adolescent idiopathic scoliosis combined with hip dysplasia

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is a spinal deformity that affects adolescents and poses a challenging public health problem. Compared to the general population, adolescents with AIS have a higher prevalence of hip dysplasia. However, the mechanisms underlying the impact of hip dysplasia on the coronal balance of the spine remain poorly understood. We hypothesized that the combination of AIS with hip dysplasia would exacerbate coronal imbalance.

METHODS

We retrospectively analyzed the medical records and radiographs of adolescents diagnosed with AIS between 2015 and 2020. Participants were divided into two groups: those with hip dysplasia and those without. We recorded parameters related to the coronal deformity of the spine, sacral and pelvic obliquity, and center edge angle (CEA). We investigated differences in these parameters in those with and without hip dysplasia and analyzed their relationships in those with combined AIS and hip dysplasia.

RESULTS

A total of 103 adolescents were included, 36 with hip dysplasia and 67 without. Those with hip dysplasia had significantly higher sacroiliac discrepancy (SID) compared to those without (t = - 2.438, P = 0.017). In adolescents with hip dysplasia, only iliac obliquity angle (IOA) was significantly correlated with SID (r = - 0.803, P < 0.001), with a linear relationship between them (r2 = 0.645, P < 0.001).

CONCLUSIONS

The incidence of hip dysplasia is higher in the AIS population. In adolescents with combined AIS and hip dysplasia, pelvic obliquity is greater, potentially contributing to the increased prevalence of low back pain.

Pelvic Incidence as a Predictor of Proximal Junctional Failure in Patients Undergoing Anterior Column Realignment with Anterior Longitudinal Ligament Release to Restore Lordosis in Adult Spinal Deformity: A Retrospective Cohort Study

OBJECTIVE

To identify variables that may contribute to the development of proximal junctional failure (PJF) in patients with long lumbo-sacral and thoraco-lumbo-pelvic constructs undergoing anterior column realignment (ACR) with anterior longitudinal ligament release (ALLR).

METHODS

Data of patients with adult spinal deformity who underwent ACR with ALLR at L3-4 were collected retrospectively from medical records and a prospectively maintained spine research database between 2016 and 2022.

RESULTS

Eleven (41%) developed PJF at a mean of 24 ± 21 months from the index surgery. The cohort was then divided into 2 groups for analysis, 13 subjects in the high pelvic incidence (PI) group (defined as PI ≥ 55°) and 14 subjects in the low PI group (defined as PI < 55°). Visual Analog Scale for back pain and Oswestry Disability Index decreased from 9.5 to 2.1 and 61 to 10 in the high PI group, and from 8.9 to 2.4 and 60.9 to 10.3 in the low PI group, respectively. PI (P = 0.004), sacral slope (P = 0.005), and postoperative PI-lumbar lordosis mismatch (P = 0.02) were found to be significant predictors of PJF. The receiver operator curve revealed a cutoff PI value ≤ 53° (95% confidence interval: 52°-64°), below which the risk of PJF becomes significantly higher in patients undergoing ACR with ALLR at L3-4.

CONCLUSIONS

PI may be a predictor of PJF and highly correlates with ACR-ALLR levels. In patients undergoing L3-4 ACR-ALLR, a PI value of ≤53° is associated with a significantly elevated risk of PJF. Preoperative planning of ACR-ALLR level based on normal sagittal alignment in otherwise healthy individuals may mitigate the risk of PJF development in patients with adult spinal deformity treated with ACR-ALLR.

Investigating concurrent validity of inertial sensors to evaluate multiplanar spine movement

Inertial measurement units (IMUs) offer a portable and inexpensive alternative to traditional optical motion capture systems, and have potential to support clinical diagnosis and treatment of low back pain; however, due to a lack of confidence regarding the validity of IMU-derived metrics, their uptake and acceptance remain a challenge. The objective of this work was to assess the concurrent validity of the Xsens DOT IMUs for tracking multiplanar spine movement, and to evaluate concurrent validity and reliability for estimating clinically relevant metrics relative to gold-standard optical motion capture equipment. Ten healthy controls performed spine range of motion (ROM) tasks, while data were simultaneously tracked from IMUs and optical marker clusters placed over the C7, T12, and S1 vertebrae. Root mean square error (RMSE), mean absolute error (MAE), and intraclass correlation coefficients (ICC2,1) were calculated to assess validity and reliability of absolute (abs; C7, T12, and S1 sensors) and relative joint (rel; intersegmental thoracic, lumbar, and total) motion. Overall RMSEabs = 1.33°, MAEabs = 0.74° ± 0.69, and ICC2,1,abs = 0.953 across all movements, sensors, and planes. Results were slightly better for uniplanar movements when evaluating the primary rotation axis (prim) absolute ROM (MAEabs,prim = 0.56° ± 0.49; ICC2,1,abs,prim = 0.999). Similarly, when evaluating relative intersegmental motion, overall RMSErel = 2.39°, MAErel = 1.10° ± 0.96, and ICC2,1,rel = 0.950, and relative primary rotation axis achieved MAErel,prim = 0.87° ± 0.77, and ICC2,1,rel,prim = 0.994. Findings from this study suggest that these IMUs can be considered valid for tracking multiplanar spine movement, and may be used to objectively assess spine movement and neuromuscular control in clinics.

Effects of alternating pressure patterns on sacral skin blood flow responses in people with spinal cord injury

Alternating pressure support surface (APSS) is a common support surface for treating pressure injury in individuals with spinal cord injury (SCI). However, conflicting results on the effectiveness of APSS have been reported and may be associated with inappropriate configurations of APSS. The objectives of this study were to compare the different pressure amplitudes (75/5 mmHg [alternating between 75 and 5 mmHg] vs. 65/15 mmHg) and cycle periods (5 min [4 cycles] vs. 2.5 min [8 cycles]) of alternating pressure on sacral skin blood flow responses in 10 individuals with SCI. Sacral skin blood flow during and after loading of four alternating pressure protocols was assessed using laser Doppler flowmetry and was normalised to the value before loading (10-min baseline, 20-min loading and 10-min recovery). The results demonstrated that during the high-pressure phase, there was a significant difference between the 75/5 and 65/15 mmHg protocols (0.3658 ± 0.0688 for 75/5 mmHg and 0.1702 ± 0.0389 for 65/15 mmHg, p < 0.05); and during the low-pressure phase, there was a significant difference between the 75/5 and 65/15 mmHg protocols (1.7184 ± 0.262 for 75/5 mmHg and 0.5916 ± 0.1378 for 65/15 mmHg, p < 0.05). There were no differences between cycle periods in skin blood flow responses. No adverse events were reported. Our finding indicates that the pressure amplitude of alternating pressure is a significant factor affecting sacral skin blood flow responses. An appropriate configuration of alternating pressure is needed to effectively increase skin blood flow and tissue viability in individuals with SCI.

CT-Guided Trans-osseous Biopsy: Experience in 24 Patients

PURPOSE

The objective of this study is to assess the effectiveness of computed tomography-guided trans-osseous biopsies in deep-seated lesions and report encountered complications.

MATERIALS AND METHODS

A retrospective cohort study was performed which included twenty-four patients with pathologic medical history and lesions non-accessible by common approaches. Exclusion criteria include patients who could be biopsied without trans-osseous access, as for example procedures aided with hydro- or pneumo-dissection. The population studied included 13 females (54.2%) and the overall average age was 64.5 (IIQ 43-69). The procedures were carried out through the following bones: sternum (n = 6), vertebral (n = 5), iliac (n = 5), scapula (n = 3), rib (n = 2), sacral (n = 2), and pubis (n = 1).

RESULTS

The efficiency for these procedures was 87.5%, while 8.33% of them were non-diagnostic and 4.17% were inconclusive due to vital risk during the procedure.

CONCLUSION

Computed tomography-guided trans-osseous biopsy resulted in a safe and effective technique for those lesions blocked by vital structures or apparently directly inaccessible.

Investigating sagittal spinopelvic alignment and equivalent stress on the femoral head in patients with rapidly destructive coxarthrosis

PURPOSE

Rapidly destructive coxarthrosis (RDC) is a rare syndrome of unknown etiology. This study evaluated sagittal spinopelvic alignment (SSPA) in patients with RDC and compared it with that in patients with hip osteoarthritis (HOA). In addition, finite element analysis (FEA) was performed to investigate the distribution of stress on the femoral head in RDC versus HOA.

METHODS

This retrospective study included patients who had undergone primary total hip arthroplasty for RDC (n = 33) and HOA (n = 99; age- and sex-matched to patients with RDC) at three hospitals from June 2014 to September 2020. Preoperative SSPA parameters and inflammatory blood markers were compared between the two groups. FEA on the computed tomography data was performed for four patients from each group with similar pelvic tilt (PT) and lateral center-edge angle (LCEA). The distribution of Drucker-Prager equivalent stress was assessed at the loaded area of the femoral head.

RESULTS

Patients with RDC had significantly higher PT, lower sacral slope, decreased lumbar lordosis (LL), higher sagittal vertical axis, and higher pelvic incidence minus LL than patients with HOA, indicating sagittal spinal imbalance. Blood test revealed patients with RDC had higher levels of inflammation markers than patients with HOA. FEA revealed no statistically significant difference in the degree of stress concentration or the maximum equivalent stress between the two groups when PT and LCEA were comparable.

CONCLUSION

Patients with RDC tend to have sagittally imbalanced spine. Decreased acetabular coverage of the femoral head may heighten mechanical load of the hip joint in patients with RDC.

Angiographic challenges of spinal dural and epidural arteriovenous fistulas: report on 45 cases

PURPOSE

The localization of the fistula level in spinal dural arteriovenous fistulas (dAVFs) and epidural arteriovenous fistulas (edAVFs) remains a diagnostic challenge.

METHODS

Consecutive patients with spinal dAVFs and edAVFs in the thoracic, lumbar, and sacral regions were included. The primary endpoint was to describe the characteristics of patients who required angiography with multiple catheterizations of segmental arteries (10 or more).

RESULTS

Forty-five patients (median age 69 years; male 89%; dAVFs, n = 31; edAVFs, n = 14) were included. Spinal dAVFs commonly developed in the thoracic region and edAVFs in the lumbosacral region. Fistulas were predicted at the correct level or plus/minus 2 level in less invasive examinations using multi-detector CT angiography (n = 28/36, 78%) and/or contrast-enhanced MR angiography (n = 9/14, 64%). We encountered diagnostic challenges in the localization of fistulas in 6 patients. They underwent angiography a median of 2 times. In each patient, spinal levels were examined at a median of 25 levels with a median radiation exposure of 3971 mGy and 257 ml of contrast. Fistulas were finally localized at the high thoracic region (T4-6) in 3 patients, the sacral region (S1-2) in 2, and the lumbar region (L3) in 1. Four patients were diagnosed with edAVFs and 2 with dAVFs. The correlation coefficient between the fistula level and the rostral end of the intramedullary T2 high-signal intensity on MRI was interpreted as none.

CONCLUSION

In patients in whom less invasive examinations failed for fistula localization, high thoracic or sacral AVFs need to be considered.

A new mathematical model for evaluating surface changes in the mid-abdominal sagittal plane after two-level pedicle reduction osteotomy in patients with ankylosing spondylitis

BACKGROUND

The purpose of this study was to create a mathematical model to precalculate the acreage change in the abdominal median sagittal plane (ac-AMSP) of patients with ankylosing spondylitis (AS) for whom two-level pedicle subtraction osteotomy (PSO) was planned.

METHODS

A single-centre retrospective review of prospectively collected data was conducted among 11 adults with AS. Acreage of the abdominal median sagittal plane (a-AMSP) was performed. The distances and angles between the osteotomy apexes, anterosuperior edge of T12, xiphoid process, superior edge of the pubis, and anterosuperior corner of the sacrum were measured on preoperative thoracolumbar computed tomography. A mathematical model was created using basic trigonometric functions in accordance with the abdominal parameters. Planned osteotomized vertebra angles (POVAs) were substituted into the mathematical model, and the predictive ac-AMSP (P-AC) was obtained. A paired sample t test was performed to determine the differences between the P-AC and actual ac-AMSP (A-AC) and between the predictive acreage change rate (P-CR) and actual acreage change rate (A-CR).

RESULTS

The mean age and GK were 44.4 ± 8.99 years and 102.9° ± 19.17°, respectively. No significant difference exists between A-CR and P-CR via mathematical modeling (p > 0.05). No statistically significant difference existed between POVA and actual osteotomized vertebra angles (AOVA) (p > 0.05). A statistically significant difference was observed between preoperative and postoperative measurements of LL, SVA, and GK variables (p < 0.001).

CONCLUSIONS

The novel mathematical model was reliable in predicting the ac-AMSP in AS patients undergoing two-level PSO.

Assessment of the sacroiliac joint with computed tomography motion analysis: a diagnostic study of 12 patients

BACKGROUND AND PURPOSE

Pain in the sacroiliac joint may be caused by abnormal joint motion. Diagnosis is mainly based on clinical tests. The aims of this study were to examine whether low-dose computed tomography with provocation of the hip could detect sacroiliac joint motion, and to study whether provocation of the hip results in greater sacroiliac joint motion in the ipsilateral than in the contralateral sacroiliac joint.

PATIENTS AND METHODS

12 patients with sacroiliac joint pain were examined with low-dose computed tomography scans of the sacroiliac joint, one with the hips in the neutral position, and one each in provocation with the left or the right hip in a figure-of-4 position. Accuracy was tested by comparing internal rotation of the sacrum with internal rotation in the sacroiliac joint. Motion in the sacroiliac joint was assessed by comparing the position of each of the ilia with the reference, the sacrum. Data is shown as mean with 95% confidence interval (CI).

RESULTS

We observed greater motion in the sacroiliac joint than internally in the sacrum, i.e., 0.57° (CI 0.43-0.71) vs. 0.20° (CI 0.11-0.28). The motion of the geometric center of the moving object for the sacroiliac joint was larger on the provoked side; mean difference 0.17 mm (CI 0.01-0.33), P = 0.04. Corresponding figures for rotation were mean difference 0.19° (CI 0.10-0.28), P < 0.001. Compared with the sacrum, the largest motion was seen at the anterior superior iliac spine; mean difference 0.38 mm (CI 0.10-0.66), P = 0.001.

CONCLUSION

Provocation in the figure-of-4 position of the hip results in sacroiliac joint motion measurable with computed tomography motion analysis. Provocation of the hip induces larger motion on the ipsilateral than on the contralateral sacroiliac joint.

The Long-term Outcomes of Sacral Neuromodulation for Fecal Incontinence: A Single-Center Experience

BACKGROUND

Sacral neuromodulation is an effective treatment for fecal incontinence.

OBJECTIVE

To assess the long-term outcomes of sacral neuromodulation and establish the outcomes of patients with inactive devices.

DESIGN

This is an observational study of patients treated for >5 years. A positive outcome was defined as a more than 50% reduction in fecal incontinence episodes or improvement in a symptom severity score. Data were reviewed from a prospectively managed database.

SETTINGS

This study was conducted at a single tertiary referral center.

PATIENTS

Data from 74 patients (72 women) were available at long-term follow-up.

MAIN OUTCOME MEASURES

Bowel diary, St. Mark's incontinence score, and Manchester Health Questionnaire data were prospectively recorded at baseline, after percutaneous nerve evaluation, and at last follow-up.

RESULTS

Patients were analyzed in cohorts based on time since sacral neuromodulation implantation: group 1: 5 to 10 years (n = 20), group 2: >10 years (n = 35), and group 3: inactive sacral neuromodulation devices (n = 19). Median St. Mark's incontinence score and Manchester Health Questionnaire improved from baseline to last follow-up in group 1 ( p ≤ 0.05) and group 2 ( p ≤ 0.05), but in group 3, results returned to baseline levels at the last follow-up. Similarly, weekly fecal incontinence episodes improved in both active device groups at the last follow-up. However, in group 3, incontinence episodes were no different from baseline ( p = 0.722). Despite active devices, fecal urgency episodes increased at the last follow-up after >10 years since percutaneous nerve evaluation ( p ≤ 0.05). Complete continence was reported by 44% of patients, and at least a 50% improvement was seen in 77% of patients with active devices.

LIMITATIONS

This study is retrospective with some gaps in the available data at the last follow-up.

CONCLUSIONS

Sacral neuromodulation is an effective treatment for fecal incontinence in the long term, but all outcomes are adversely affected by device inactivity. Therefore, ongoing stimulation is required for continued benefit. See Video Abstract.

RESULTADOS A LARGO PLAZO DE LA NEUROMODULACIN SACRA PARA LA INCONTINENCIA FECAL EXPERIENCIA DE UN SOLO CENTRO

ANTECEDENTES:La neuromodulación sacra es un tratamiento eficaz para la incontinencia fecal.OBJETIVO:Este estudio tuvo como objetivo evaluar los resultados a largo plazo de la neuromodulación sacra y establecer los resultados de los pacientes con dispositivos inactivos.DISEÑO:Este es un estudio observacional de pacientes tratados durante más de 5 años. Un resultado positivo se definió como una reducción >50 % en los episodios de incontinencia fecal o una mejoría en la puntuación de gravedad de los síntomas. Los datos se revisaron a partir de una base de datos administrada prospectivamente.ENTERNO CLINICO:Este estudio se realizó en un solo centro de referencia terciario.PACIENTES:Los datos de 74 pacientes (72 mujeres) estaban disponibles en el seguimiento a largo plazo.PRINCIPALES MEDIDAS DE RESULTADO:Diario intestinal, puntuación de incontinencia de St. Mark y datos del Cuestionario de salud de Manchester se registraron prospectivamente al inicio, después de la evaluación de nervio periférico y en el último seguimiento.RESULTADOS:Los pacientes se analizaron en cohortes según el tiempo transcurrido desde la implantación de la neuromodulación sacra: Grupo 1: 5-10 años (n = 20), Grupo 2: >10 años (n = 35) y Grupo 3: dispositivos SNM inactivos (n = 19). La mediana de la puntuación de incontinencia de St. Mark y Questionnaire Cuestionario de salud de Manchester mejoraron desde el inicio hasta el último seguimiento en el Grupo 1 (p = < 0,05) y el Grupo 2 (p = < 0,05), pero en el Grupo 3 los resultados volvieron a los niveles iniciales en el último seguimiento. arriba. De manera similar, los episodios semanales de incontinencia fecal mejoraron en ambos grupos de dispositivos activos en el último seguimiento. Sin embargo, en el Grupo 3 los episodios de incontinencia no fueron diferentes de los basales (p = 0,722). A pesar de los dispositivos activos, los episodios de urgencia fecal aumentaron en el último seguimiento después de más de 10 años desde la evaluación del nervio periférico (p = < 0,05). Continencia completa se reportó en el 44 % de los pacientes, y al menos una mejora del 50 % en el 77 % con dispositivos activos.LIMITACIONES:Este estudio es retrospectivo con algunas vacíos en los datos disponibles en el último seguimiento.CONCLUSIONES:La neuromodulación sacra es un tratamiento eficaz para la incontinencia fecal a largo plazo, pero todos los resultados se ven afectados negativamente por la inactividad del dispositivo. Por lo tanto, se requiere estimulación continua para un beneficio continuo. (Traducción- Dr. Francisco M. Abarca-Rendon ).

The difference in the relationship of spinal sagittal alignment between individuals with flat lumbar and normal lordosis posture based on global and regional angles

BACKGROUND

According to previous studies, the relationship between lumbar lordosis and thoracic kyphosis or that between pelvic parameters and thoracic kyphosis have been inconsistent.

OBJECTIVE

The purpose of this study was to investigate spinal sagittal alignment and its relationship to global and regional lumbar and thoracic angles, pelvic and sway angles, and C7-S1 distance measurements, followed by a detailed subgroup analysis using an inertial measurement unit system.

METHODS

A total of 51 asymptomatic volunteers stood in a comfortable posture with inertial measurement units attached to the T1, T7, T12, L3, and S2 vertebrae. T1, T7, T12, L3, and S2 sagittal angles were acquired during standing posture using the Eulerian angle coordinate system. All angles are reported as the mean of three 5-s measurements. Following the measurement of lumbar lordosis angles (T12 relative S2), participants were divided into the flat lumbar and normal lordosis groups.

RESULTS

There were different correlation patterns between groups because of spinal sagittal imbalance, which was greater in the flat lumbar group than in the normal lordosis group. In addition, sacral inclination proved the ideal parameter to evaluate reciprocal balance in lumbar lordosis, showing a stronger correlation with lower than with upper lumbar lordosis. T1 was the key element in assessing thoracic kyphosis, which showed a stronger correlation with upper than with lower thoracic kyphosis.

CONCLUSION

We suggest that when assessing posture, it is necessary to identify the global and regional angles and it is useful to classify spinal sagittal alignment into subgroups according to lumbar lordosis and evaluate the groups separately.

Management of Tarlov cysts: an uncommon but potentially serious spinal column disease-review of the literature and experience with over 1000 referrals

Tarlov cysts were thought to be anatomic variants of uncertain etiology and clinical significance when initially described over 80 years ago. They are often detected in routine lumbosacral imaging and generally not reported in a differential diagnosis. There is increasing evidence that at least some Tarlov cysts are symptomatic and can have a significant adverse impact on patients' health and well-being. Women are disproportionately affected with this condition, often presenting with long-standing pain and neurological dysfunctions. Significant gender bias has been a concern in the management of these patients. Unfortunately, there is no consensus on patient selection or management approaches for symptomatic Tarlov cysts. This review article updates information on the prevalence, diagnosis, clinical significance, and treatments of these cysts. Based on these findings and experience with over 1000 patient referrals, a treatment decision algorithm for symptomatic Tarlov cysts was constructed to provide guidance for appropriate management of patients with these complex cysts.

Longitudinal Fluctuations in Treatment Response After OnabotulinumToxinA and Sacral Neuromodulation for Refractory Urgency Incontinence

PURPOSE

We compared fluctuations in treatment response after onabotulinumtoxinA and sacral neuromodulation for urgency incontinence using Markov models.

MATERIALS AND METHODS

We fit data from a randomized trial to Markov models to compare transitions of success/failure over 6 months between 200 U onabotulinumtoxinA and sacral neuromodulation. Objective failure was <50% reduction in urgency incontinence episodes from baseline; subjective failure "strongly disagree" to "neutral" to the Patient Global Symptom Control questionnaire.

RESULTS

Of the 357 participants (median baseline daily urgency incontinence episodes 4.7 [IQR 3.7-6.0]) 61% vs 51% and 3.2% vs 6.1% reported persistent states of objective success and failure over 6 months after onabotulinumtoxinA vs sacral neuromodulation. Participants receiving onabotulinumtoxinA vs sacral neuromodulation had lower 30-day transition probabilities from objective and subjective success to failure (10% vs 14%, ratio 0.75 [95% CI 0.55-0.95]; 14% vs 21%, ratio 0.70 [95% CI 0.51-0.89]). The 30-day transition probability from objective and subjective failure to success did not differ between onabotulinumtoxinA and sacral neuromodulation (40% vs 36%, ratio 1.11 [95% CI 0.73-1.50]; 18% vs 17%, ratio 1.14 [95% CI 0.65-1.64]).

CONCLUSIONS

Over 6 months after treatment, 2 in 5 women's symptoms fluctuate. Within these initial 6 months, women receiving onabotulinumtoxinA transitioned from success to failure over 30 days less often than sacral neuromodulation. For both treatments, there was an almost 20%-40% probability over 30 days that women returned to subjective and objective success after failure. Markov models add important information to longitudinal models on how symptoms fluctuate after urgency incontinence treatment.

Association of radiological severity of hip involvement with clinical characteristics and sagittal spinopelvic balance in patients with ankylosing spondylitis

INTRODUCTION

This is the first study to analyze the associations between the radiological severity of hip involvement with clinical characteristics and sagittal spinopelvic balance in patients with ankylosing spondylitis (AS).

METHOD

We evaluated 182 patients with AS who were referred to outpatient clinics. Patient demographic data and clinical and radiographic parameters were collected. Patients were divided into three groups based on the Bath Ankylosing Spondylitis Radiology Hip Index. Clinical characteristics and spinopelvic parameters acquired by a low-dose biplanar imaging system were evaluated among these groups.

RESULTS

Patients with more severe hip involvement were older and had longer disease duration and diagnostic delay, with lower Harris Hip Score (p < 0.001) and 12-item Short Form Health Survey Physical Component Score (p < 0.001) and higher Bath Ankylosing Spondylitis Disease Activity Index (p = 0.030) and Functional Index (p < 0.001). Patients with more severe hip involvement had significantly higher sacroiliac grade (p < 0.001) and higher modified Stoke Ankylosing Spondylitis Spinal Score (p < 0.001). Patients with moderate and severe hip involvement had similar lumbar lordosis and spino-sacral angle, whereas patients with severe hip involvement had lower pelvic tilt, pelvic femoral angle, higher sacral slope, and sagittal vertical axis.

CONCLUSIONS

The severity of hip involvement is associated with physical function and is not consistent with the severity of spinal involvement. Severe hip involvement impairs the ability to retrovert the pelvis to accommodate the sagittal deformity, and spinopelvic parameters should be concretely evaluated in preoperative counseling of patients with AS waiting for total hip arthroplasty. Key Points • The severity of hip involvement in patients with AS is associated with physical function. • Severe hip involvement impairs the ability to retrovert the pelvis to accommodate the sagittal deformity.

Effects of vibration-based biofeedback on multifidus muscle activity and pelvic tilt angle in subjects with hip flexion limitation

BACKGROUND

Sedentary work may lead to low back pain. In particular, a slumped sitting position may exacerbate low back pain because of tissue damage caused by excessive lumbar flexion and posterior pelvic tilting. Subjects with low back pain may have excessive changes in the lumbopelvic posture and back muscle activity in the sitting position.

OBJECTIVE

The purpose of this study was to compare the effects of vibration-based biofeedback using a motion sensor belt and no biofeedback on multifidus (MF) muscle activity and pelvic tilt angle during typing.

METHODS

Thirty subjects with low back pain accompanied by hip flexion limitation (15 each in the biofeedback and non-biofeedback groups) were enrolled. Electromyography was used to investigate MF muscle activity before and after typing for 30 min. Pelvic tilt was measured after typing in a sitting position for 30 min. Independent t-tests were used to compare MF muscle activity, and pelvic and second sacrum tilt angles, between the biofeedback and non-biofeedback groups.

RESULTS

After typing for 30 min, changes in MF muscle activity (11.45% and -7.19% for the biofeedback and nonbiofeedback groups, respectively) and pelvic and second sacrum tilt angles (3.15∘ and 4.12∘ for the biofeedback group and -11.05∘ and -18.16∘ for the non-biofeedback group, respectively) were significantly smaller in the biofeedback than non-biofeedback group (p< 0.05).

CONCLUSION

Vibration-based biofeedback minimizes the reduction in MF muscle activity and changes in pelvic and second sacrum tilt angles during typing in individuals with low back pain accompanied by hip flexion limitation.

Evolution of sagittal spinal shape for the development of thoracic ossification of ligamentum flavum

Thoracic ossification of the ligamentum flavum (TOLF) is a rare pathology for which limited research exists. While it is known that mechanical factors play a role in the development of TOLF, little is currently understood about the sagittal alignment and related mechanical stress involved in its development. This study aims to describe the sagittal alignment of patients with TOLF based on the pathologic evolution of the Roussouly classification. The current study evaluated the preoperative Roussouly type in consecutive patients who underwent posterior decompressive laminectomy with or without posterior screw fixation for TOLF between January 2015 and December 2021. The post-evolution sagittal alignments were analyzed using the classic Roussouly classification based on sacral slope (SS). To determine the pre-evolution Roussouly type, the patients were retrospectively classified using their individual PI and PT values. Lumbopelvic parameters and morphological index including inflection point (IP), lumbar apex (LA), and lordosis distribution index (LDI) were also evaluated. Forty-three patients (21 women and 22 men) were included; their mean age was 64.21 ± 11.01 years (range 43-81). The most affected level was T10-11 (48.83%). The mean PI was 50.81 ± 9.56°, the mean SS was 33.11 ± 8.61°and the mean PT was 17.69 ± 7.89°. According to the post-evolution Roussouly classification, type 2 shape was the most frequently observed type (n = 23, 53.5%) in the post-evolution classification while type 3 was the most common type observed in the pre-evolution classification (n = 22, 51.5% and P = .00). The level of IP and LA in type 3 moved caudally (around L2 and L4/5 level, respectively) and the LDI increased (77.98 ± 8.08%) than the normal standard value. The authors found that the majority of the patients had a false type 2 spine, which had evolved pathologically from Roussouly type 3 and exhibited increased LDI, a lowered level of IP, and a lowered level of LA. These changes of spinal shape, including the transition to long hypolordosis and increased length of the thoracic kyphosis, may have accentuated tensile stress at the lower thoracic spine and contributed to the development of TOLF.

Evaluation of the efficacy of sacral neuromodulation in the treatment of voiding dysfunction after endometriosis surgery

Pelvic surgery for endometriosis is associated with a risk of bladder and digestive sequelae. Sacral neuromodulation (SNM) has been shown to be effective in the treatment of overactive bladder (OAB) and voiding dysfunction (VD). This study aimed to evaluate the efficacy of sacral neuromodulation (SNM) in treating voiding dysfunction (VD) following endometriosis surgery. A retrospective analysis was conducted on data from women who underwent SNM testing for persistent VD after endometriosis surgery. The study included 21 patients from a French tertiary referral center. Patient characteristics, lower urinary tract symptoms, urodynamic findings, SNM procedures, and outcomes were assessed. The primary outcome was the success of SNM treatment for VD. After a median follow-up of 55 months, 60% of patients achieved successful outcomes, with significant improvements of VD and quality of life. Moreover, more than half of patients who required clean intermittent self-catheterization (CISC) before SNM were able to wean off CISC. Complications such as infections and paraesthesia were observed, but overall, SNM was found to be effective and well tolerated. Age and the interval between endometriosis surgery and SNM testing were associated with treatment success. This study adds to the limited existing literature on SNM for VD after endometriosis surgery and suggests that SNM can be a valuable therapeutic option for these patients. Further research is needed to identify predictive factors and mechanisms underlying the effectiveness of SNM in this context. MRI-compatible and rechargeable devices, has improved the feasibility of SNM for these patients. In conclusion, SNM offers promise as a treatment option for persistent VD after endometriosis surgery, warranting further investigation. LEVEL OF EVIDENCE: 4.

How Sagittal Spinal Parameters Predict Anterolateral Spinal Ossification Severity: A Study Based on CT Classification

STUDY DESIGN

Retrospective observational study.

OBJECTIVE

The purpose of this study was to establish a CT classification system of anterolateral spinal ossification and analyze the effects of sagittal spinal parameters on ossification.

SUMMARY OF BACKGROUND DATA

Patients with diffuse idiopathic skeletal hyperostosis often present with anterolateral ossification of the spine. Few reports consider anterolateral spinal ossification at each spinal level or explore the influence of sagittal alignment.

MATERIALS AND METHOD

One hundred and twenty patients (79 males and 41 females) over 60 years old who underwent whole spinal CT scans from October 2018 to November 2021 were analyzed. Volume rendering technique images were used to assess the degree of anterolateral spinal ossification in each intervertebral space, and a classification system was established. Sagittal parameters, such as thoracic kyphosis, lumbar lordosis (LL), cervical lordosis, sacral slope, and thoracolumbar junction angle of the patients were measured. Multifactor stepwise linear regression analysis and ordered logistic regression analysis were used to study the effects of the sagittal parameters on ossification grades.

RESULTS

The median age of the study population was 67 years (63-72 IQR). The new classification system classifies the severity of anterolateral spinal ossification in each intervertebral space into grades 0 to 3 with an intra-observer intraclass correlation coefficient value of 0.909 and inter-observer intraclass correlation coefficient value of 0.900. Multivariate stepwise linear regression analysis showed that age (OR=1.30, P <0.001), weight (OR=1.23, P =0.013), and cervical lordosis (OR=1.19, P <0.001) were significantly correlated with total ossification grade. Multifactor ordered logistic regression analysis showed that there was a statistically significant correlation between cervical lordosis and the ossification grades of each intervertebral space of T1~T4 ( P ≤0.005), between thoracic kyphosis and each intervertebral space in T4~T12 ( P ≤0.019), and between thoracolumbar junction angle and each intervertebral space in T10~L3 ( P ≤0.025). LL was significantly and positively correlated with the ossification grades of each intervertebral space in T7~T11 ( P ≤0.041). LL and sacral slope were significantly negatively correlated with the ossification grades of each intervertebral space in L3~S1 ( P ≤0.047).

CONCLUSION

Our new classification scheme demonstrated good accuracy and reliability for the evaluation of the severity of anterolateral spinal ossification. The effect of sagittal parameters on anterolateral spinal ossification was position-specific. The greater the kyphosis or the smaller the lordosis of a spinal region, the more severe the degree of ossification in the corresponding region.

LEVEL OF EVIDENCE

3.

Engineering the perfect mattress: The influence of substrate mechanics on deep tissue stresses in supine

BACKGROUND

With increasing global interest in sleep hygiene, sleep ergonomics is an area that has been largely understudied. During sleep individuals turn over during the night to restore blood flow in occluded blood vessels, indicating that control of local tissue pressure may play a role in improving sleep comfort. This study investigates the influence of mattress stiffness on tissue compressive stresses during supine lying.

METHODS

A subject-specific 3D finite element (FE) model of the pelvis area has been developed to simulate supine lying on substrates of varying firmness. Constitutive parameters for the adipose-skin tissue and muscle-organ tissue were calibrated using a novel application of the inverse finite element method.

FINDINGS

The compressive stress was consistently greatest in the muscle interfacing the sacrum at 18.5 kPa on the soft foam, and 30.9 kPa on the firm foam. From soft to firm, the compressive stress increased by 67% at the sacrum, 20% at the ischium, 42% at the lesser trochanter, and 50% at the skin.

INTERPRETATION

The non-linearity of the foam substrate had a pressure distributing effect, relieving the peak compressive stresses at the sacrum, indicating that it may be possible to design arrays of foam substrates that can provide most efficient pressure relief.

Over 50% of Studies Report Low-Back Pain Is Associated With Worse Outcomes After Hip Arthroscopy When Compared With a Control Group: A Systematic Review

PURPOSE

To review outcomes of patients with low-back pathology undergoing primary hip arthroscopy for the treatment of femoroacetabular impingement (FAI) syndrome.

METHODS

The PubMed, Cochrane Trials, and Scopus databases were queried in June 2022 to conduct this systematic review using the following terms: ("hip" OR "femoroacetabular impingement") AND ("arthroscopy" OR "arthroscopic") AND ("spine" OR "lumbar" OR "sacral" OR "hip-spine" OR "back") AND ("outcomes"). Articles were included if they reported on patient-reported outcomes (PROs) and/or clinical benefit of patients undergoing hip arthroscopy with concomitant low-back pathology. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria. Case reports, opinion articles, review articles, and technique articles were excluded from this study. Forest plots were created to analyze preoperative and postoperative outcomes among patients with low-back pathology.

RESULTS

Fourteen studies were included in the review. There were 750 hips with low-back pathology and FAI (hip-spine syndrome) and 1,800 hips with only FAI (no hip-spine syndrome). All 14 studies reported PROs. In 4 studies in the group with hip-spine syndrome and 8 studies in the group with FAI without low-back pathology, the respective cohorts were reported to achieve the minimal clinically important difference in at least 1 PRO at a rate of 80%. Eight studies reported that patients with low-back pathology were associated with inferior outcomes or clinical benefit compared with patients without low-back pathology.

CONCLUSIONS

Patients undergoing primary hip arthroscopy with concomitant low-back pathology can expect favorable outcomes, but outcomes are superior in patients undergoing hip arthroscopy for FAI alone compared with FAI with concomitant low-back pathology.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to Level IV studies.

Infection Rate of a Prolonged Sacral Neuromodulation Test: A Large Retrospective Study

OBJECTIVES

It is estimated that 3.8% to 12.5% of patients develop a device infection during the two to four weeks of the sacral neuromodulation (SNM) test, leading to removal of the entire system. It is possible to prolong the test phase up to the clinician's decision, particularly when benefits are unclear. The aim of our study is to assess the device infection rate in a prolonged SNM test.

MATERIALS AND METHODS

We retrospectively enrolled patients who performed a prolonged SNM test (at least eight weeks) in the last five years (2017-2021). All procedures were performed using a standardized technique and the same prophylactic antibiotic protocol. In case of a clinical suspicion of infection, all components were explanted. Patient information (age at implantation, medical history of diabetes, metabolic syndrome, immunologic diseases, or chronic immunosuppressive therapy), surgical data (operative time, intraoperative complications), and infection data (timing of onset, symptoms reported, wound culture results) were recorded.

RESULTS

We enrolled 232 patients who underwent a prolonged SNM test (mean duration 65.5 days). A local infection that led to the removal of the entire system occurred in six patients (2.6%). The gluteal pocket was always involved, and in two cases, infection was also extended to the exit point of the extension wire. No significant correlations with clinical data were found. Infection occurred beyond four weeks in two cases, between three and four weeks in three cases, and within two weeks in one case. Intraoperative wound culture was performed in five of six patients, and Staphylococcus aureus (S aureus) was isolated in four cases. One culture test gave negative bacterial growth results.

CONCLUSIONS

The infection rate of a prolonged eight-week SNM test is low and does not differ from that reported in the literature for a two-to-four-week SNM test. S aureus remains the most frequent bacterium involved.

Effects of flexible sacrum position at birth on maternal and neonatal outcomes: A retrospective cohort study

OBJECTIVE

To examine the differences in both maternal and neonatal outcomes between flexible and non-flexible sacrum positions at birth.

METHODS

A descriptive, cross-sectional, retrospective study was carried out on a sample of low-risk pregnant women. Univariate and multivariate logistic regressions and multivariate linear regressions were conducted to estimate the association between our discrete or continuous variables of interest. Maternal outcomes were perineal tear, maternal blood loss, second stage length; neonatal outcomes were Apgar scores and neonatal asphyxia. Results were adjusted for maternal age, neonatal birth weight, and epidural analgesia.

RESULTS

We considered for final analysis 2198 women. In primiparous women, women giving birth in the all-fours position were significantly more likely to have an intact perineum (P = 0.011) and a shorter length of the second stage of labor (P = 0.022). Maternal age (P = 0.005) and neonatal weight (P = 0.013) significantly increased perineal tearing; maternal age (P = 0.004) and neonatal birth weight (P < 0.001) were significantly associated with a higher amount of blood loss. Maternal age (P = 0.002) and neonatal weight (P < 0.001) significantly increased the length of the second stage of labor. For multiparous women, the side-lying position was significantly correlated with an intact perineum (P = 0.031); maternal age and intact perineum were statistically inversely associated. Epidural analgesia significantly increased the length of the second stage of labor in both nulliparous (P < 0.001) and pluriparous women (P < 0.001). No significant differences were found in neonatal outcomes.

CONCLUSION

Women with a low-risk labor should be free to choose their birth position as flexible sacrum positions are shown to increase maternal well-being and do not affect neonatal health.

Integrating navigation assistance for redirecting freehanded spinal instrumentation: experience and technique

Retrospective review of all spinal fusions > 3 levels involving the thoracolumbar and/or sacroiliac at a single institution, by a single surgeon between 3/12/2020 and 8/13/2021 were reviewed. All screws that were secondarily navigated after identified as misdirected on intraoperative CT scan were included. Neuromonitoring reports were culled for mA threshold to triggered EMG response for all redirected screws. Intraoperative, post-de novo screw placement images (fluoroscopy scout and intraoperative CT) and post-redirection intraoperative scoliosis films and post-operative scoliosis films were independently reviewed by a senior neuroradiologist. Fifty redirected screws in the thoracic, lumbar, sacral, and ilium were identified as misdirected and redirected via navigation. The new trajectory of all screws was confirmed satisfactory by independent review between a senior neuroradiologist and neurosurgeon. Four screws could not be verified by post-operative imaging (4/50, 8%). All triggered EMG stimulated > 15 mA. No screws required return to the operating room for revision. No patients experienced a post-operative deficit. Redirection of misdirected thoracolumbar and sacroiliac screws can be performed using intraoperative CT and navigation as a means to detect and directly visualize appropriate placement.

Pilot study of locomotor asymmetry in horses walking in circles with and without a rider

Background

Horses commonly show asymmetries that manifest as left (L)-right (R) differences in vertical excursion of axial body segments. Moving on a circle confounds inherent individual asymmetries. Our goals were to evaluate individual and group asymmetry patterns and compare objective data with subjective impressions of side preference/laterality in horses walking on L and R circles.

Methods

Fifteen horses walked on L and R circles unridden and ridden on long and short reins. Optical motion capture (150 Hz) tracked skin-fixed markers. Variables were trunk horizontal angle; neck-to-trunk angle; vertical range of motion (ROM) for the head, withers and sacrum; ROM for pelvic roll, pitch, and yaw; mean pelvic pitch; and ROM for hip, stifle and tarsal joints. Differences between inside and outside hind steps were determined for vertical minima and maxima of the head (HMinDiff/HMaxDiff), withers (WMinDiff/WMaxDiff) and sacrum (PMinDiff/PMaxDiff). Subjective laterality was provided by owners. Data analysis used mixed models, first without and then with subjective laterality. Iterative k-means cluster analysis was used to associate biomechanical variables with subjective laterality.

Results

PMaxDiff, PMinDiff and WMaxDiff indicated R limb asymmetry in both directions. WMinDiff indicated L (inside) fore asymmetry for L direction but was close to zero for R direction. Hip ROM was significantly smaller for the inside limb in both directions (L inside/outside: 16.7° vs. 20.6°; R: 17.8° vs. 19.4°). Stifle ROM was significantly larger for the inside limb in both directions (L: 43.1° vs. 39.0°; R: 41.9° vs. 40.4°). Taking the general direction effect into account the R hip and L stifle had larger ROM. Adding laterality to the models (seven horses L- vs. six horses R-hollow), PMaxDiff R hind asymmetry was more obvious for L-hollow horses than for R-hollow horses. L-hollow horses had greater pelvic roll ROM moving in L vs. R direction. L-hollow horses had smaller inside and greater outside hip joint ROM in L vs. R direction. R-hollow horses had a significant difference in HMinDiff between L (0 mm) and R (-14 mm) directions, indicating less head lowering at outside forelimb midstance in R direction, and larger outside tarsal ROM in R (38.6°) vs. L (37.4°) direction (p ≤ 0.05). The variables that agreed most frequently with subjective laterality in cluster analysis were pelvic roll ROM, followed by HMinDiff and PMaxDiff.

Conclusion

Differences between horses walking in L and R directions were found both at group and individual levels, as well as evidence of associations with subjective laterality. Horses maintained more symmetric hip and stifle ROM and withers vertical motion when walking on the R circle. Findings suggest that left and right lateralised horses may not be perfect mirror images. Pelvic roll ROM emerged as a promising variable to determine laterality in walk as perceived by the rider, especially when considered together with other variables.

Prediction Model for Neurogenic Bladder Recovery One Year After Traumatic Spinal Cord Injury

INTRODUCTION

Neurogenic bladder is a common complication after spinal cord injury (SCI) that carries substantial burdens on the inflicted individual. The objective of this study is to build a prediction model for neurogenic bladder recovery 1 year after traumatic SCI.

METHODS

We queried the National Spinal Cord Injury Model Systems database for patients with traumatic SCI who had neurogenic bladder at the time of injury. The primary outcome of interest was the complete recovery of bladder function at 1 year. Multiple imputations were performed to generate replacement values for missing data, and the final imputed data were used for our analysis. A multivariable odds logistic regression model was developed for complete bladder recovery at 1 year.

RESULTS

We identified a total of 2515 patients with abnormal bladder function at baseline who had an annual follow-up. A total of 417 patients (16.6%) recovered bladder function in 1 year. Predictors of complete bladder recovery included the following baseline parameters: sacral sensation, American Spinal Injury Association (ASIA) impairment score, bowel function at baseline, voluntary sphincter contraction, anal sensation, S1 motor scores, and the number of days in the rehabilitation facility. The model performed with a discriminative capacity of 90.5%.

CONCLUSIONS

We developed a prediction model for the probability of complete bladder recovery 1 year after SCI. The model performed with a high discriminative capacity. This prediction model demonstrates potential utility in the counseling, research allocation, and management of individuals with SCI.

The impact of femoral rotation on sacroiliac articulation during pregnancy. Is there evidence to support Farabeuf's hypothesis by finite element modelization?

BACKGROUND

Counter-nutation movement is deemed crucial during the management of the birth process. It is a combination of lateral ilia expansion and backward displacement of the promontory resulting from the external rotations of the femurs producing an enlargement of the pelvic inlet. However, since its description by Farabeuf, this mechanism has never been challenged and analyzed in a dynamic finite element study.

METHODS

Based on a female pelvic mesh and sacroiliac ligaments, we simulated external rotations of both femurs with imposed rotation of the two acetabulum centers. We hypothesize that lateral ilia expansion generates a sacrum movement resulting in a backward displacement of the promontory and a pelvic inlet enlargement.

RESULTS

Finite element simulation confirms our hypothesis and reveals that ilio-sacro-transverse and axile ligaments play an essential role in this mechanism. Indeed, the increase in stiffness (ranging from 500 MPa to 750 MPa) of these ligaments accentuates the counter-nutation movement and the opening of the inlet. Instead of the anatomic congruence between the ilium and the sacrum, the sacroiliac ligaments may explain the counter-nutation. After a 6° of femur rotation, the inlet area increases to 11 cm2 (141 cm2 vs. 130 cm2). This enlargement could be noteworthy in case of obstructed labor or shoulder dystocia. Moreover, the association between external rotation and flexion of the femurs could be more efficient for opening the pelvic inlet.

CONCLUSIONS

Our result did not support the original assumption of Farabeuf. By revealing how postural adjustment increases the bony birth canal, this study provides essential information for the clinical management of the delivery.

Spine Surgery with Electronic Conductivity Device: A Prospectively Multicenter Randomized Clinical Trial and Literature Review

OBJECTIVE

Improving accuracy and safety of pedicle screw placement is of great clinical importance. Electronic conductivity device (ECD) can be a promising technique with features of affordability, portability, and real-time detection capabilities. This study aimed to validate the safety and effectiveness of a modified ECD.

METHODS

The ECD underwent a modification where six lamps of various colors, and it was utilized in a prospectively multicenter randomized controlled clinical trial involving 96 patients across three hospitals from June 2018 to December 2018. The trial incorporated a self-control randomization with an equal distribution of left or right side of vertebral pedicle among two groups: the free-hand group and the ECD group. A total of 496 pedicle screws were inserted, with 248 inserted in each group. The primary outcomes focused on the accuracy of pedicle screw placement and the frequency of intraoperative X-rays. Meanwhile, the secondary indicator measured the time required for pedicle screw placement. Results were presented as means ± SD. Paired samples t-test and χ2 -test were used for comparison. Furthermore, an updated review was conducted, which included studies published from 2006 onwards.

RESULTS

Baseline patient characteristics were recorded. The primary accuracy outcome revealed a 96.77% accuracy rate in the ECD group, compared to a 95.16% accuracy rate in the free-hand group, with no significant differences noted. In contrast, ECD demonstrated a significant reduction in radiation exposure frequency when compared to the free-hand group (1.11 ± 0.32 vs. 1.30 ± 0.53; p < 0.001), resulting in a 14.6% reduction. Moreover, ECD displayed a decrease of 30.38% in insertion time (70.88 ± 30.51 vs. 101.82 ± 54.00 s; p < 0.001). According to the results of the 21 studies, ECD has been utilized in various areas of the spine such as the atlas, thoracic and lumbar spine, as well as sacral 2-alar-iliac. The accuracy of ECD ranged from 85% to 100%.

CONCLUSION

The prospectively randomized trial and the review indicate that the use of ECD presents a secure and precise approach to the placement of pedicle screws, with the added benefit of reducing both procedure time and radiation exposure.

[Pelvic coronal inclination change in adolescent flexible flatfoot surgically treated with arthroereisis]

Objective: To evaluate adolescent pelvic coronal inclination angle change after flatfoot treated with arthroereisis. Method: A case-series study. From June 2018 to September 2020, 25 children with flexible flat foot and pelvic obliquity were included in this retrospective study in Peking University Shenzhen Hospital. There were 17 males and 8 females with a mean age of (11.2±2.2) years (9-15 years). There were 5 cases of unilateral flatfoot and 20 cases of bilateral flatfoot. All of the patients were surgically treated with arthroereisis. Regular follow-up was done in 3 months, 1 and 2 years postoperatively. Weightbearing fluoroscopy of entire lower limb and foot were investigated to measure Meary's angle, calcaneal pitch angle, height difference at ankle and pelvic plane, pelvic inclination and sacrum-iliac distance (F value) on coronal plane. Results: The mean Mearys' angle at 3 month postoperatively was improved when compared with that before the operation (3.1°±1.5° vs 25.9°±4.3°, P<0.001), and it remained at the same level 2 years after the operation (compared with that at 1 year after the operation, P=0.748). The calcaneal pitch angle improved significantly at 3-month follow-up when compared with that before the operation (16.6°±2.4° vs 9.9°±1.5°, P<0.001), and there was no significant change between 1 year and 2 years after operation (P=0.542). The height difference at mortise plane were also reduced at the 3-month follow-up(P<0.001), and it remained at the same level at 1 year and 2 years after the operation (P=0.159). Pelvic height difference decreased dramatically from (12.4±1.7) mm (before operation) to (7.1±1.2) mm(3 month after the operation) (P<0.001), it decreased to (3.6±1.8) mm 1 year after the operation (compared with that at 3 months after the operation, P<0.001), and no further reduction was observed 2 years after the surgery (P=0.483). The pelvic inclination angle and sacrum-iliac distance were also improved at 3-month follow-up when compared with those before the operation (both P<0.001), and they declined further 1 year after the operation(both P<0.05), but the decreasing trend disappeared at the 2-year follow-up (both P>0.05). Conclusion: For adolescent flexible flat foot patients with pelvic obliquity, the coronal inclination and pelvic height discrepancy would partially recovered with correction of flatfoot deformity, but it could not be completely corrected in the mean follow-up period of 2 years after the operation.