Spinopelvic Alignment: Importance in Spinal Pathologies and Realignment Strategies

Sagittal spinal malalignment can lead to pain, decreased function, dynamic imbalance, and compromise of patient-reported health status. The goal of reconstructive spine surgery is to restore spinal alignment parameters, and an understanding of appropriate patient-specific alignment is important for surgical planning and approaches. Radiographic spinopelvic parameters are strongly correlated with pain and function. The relationship between spinopelvic parameters and disability in adult spinal deformity patients is well-established, and optimal correction of sagittal alignment results in improved outcomes regarding patient health status and mechanical complications of surgery.

In closed wedge distal femur osteotomies for correction of valgus malalignment overcorrection of mLDFA should be avoided

PURPOSE

The purpose of the study was to investigate the influence of the mLDFA (mechanical lateral distal femur angle) as a parameter in varus realignment osteotomies for valgus deformities of the knee. We hypothesized that joint line obliquity with mLDFA > 90° after distal femur osteotomy (DFO) is associated with inferior clinical outcome.

METHODS

In a retrospective study, a total of 52 patients with isolated femoral valgus deformities were included in the study. The mean postoperative follow-up was 70.5 (SD 33.3) months (standard deviation SD±33.3). In all patients, a distal femur osteotomy was performed. A clinical examination and survey of questionnaires was conducted with the HSS (Hospital for Special Surgery), LG (Lysholm-Gilquist), and KOOS (Knee Injury and Osteoarthritis Outcome Score) scores. Several radiological parameters were assessed on long-standing x-rays: mechanical tibio-femoral angle (mTFA), mLDFA, mechanical medial proximal tibia angle (mMPTA), joint-line convergence angle (JLCA). The t test was used for normally distributed data. The Mann-Whitney U test was performed in non-normally distributed data.

RESULTS

The mLDFA was 84.9° (SD±2.3) preop and changed to 91.9° (SD±3, 22.9) postop. The mTFA (mechanical tibio-femoral angle) was 5.2° (SD±2.9°) preop and - 1.8° (SD±2.9) postop demonstrating a difference of 6.7°. For analysis, the data was divided into two groups based on postop mLDFA. Group 1: mLDFA ≤ 90°; Group 2: > 90°. Postoperatively, a mean mLDFA of 88.6° (SD±1.4°) was measured in group 1 and 93.9° (SD±2.1) in group 2. The change in mLDFA was 4.7° (SD±1.6) in group 1 and 8.4° (SD±2.8) in group 2. Preoperatively, the mTFA was 4.8° (SD±1.9) in group 1 and 5.5° (SD±3.3) in group 2. Postoperatively, the mTFA decreased in group 1 by 4.8° (SD±2.3) to - 0.1° (SD±2.1). In group 2, the mTFA decreased by 8.2° (SD±3.8) to - 2.8° (SD±2.9). Regarding the HSS, group 1 showed a 10.4 points better score than group 2 (p<0.01). Also, regarding the Lysholm, a significant difference of 16.9 points was found (p<0.01).

CONCLUSION

Correction of valgus knees using closed wedge DFO leads to good clinical results. A postoperative mLDFA of 85-90° results in superior clinical outcome compared to mLDFA > 90°. Joint-line obliquity should be avoided using double level osteotomy, if needed.

LEVEL OF EVIDENCE

III.

Supramalleolar osteotomy for the treatment of ankle osteoarthritis leads to favourable outcomes and low complication rates at mid-term follow-up: a systematic review

PURPOSE

The purpose of this systematic review was to evaluate both the clinical and radiographic outcomes following supramalleolar osteotomy (SMO) in patients with ankle osteoarthritis, and to analyse the level of evidence (LOE) and quality of evidence (QOE) of the included studies.

METHODS

A systematic review of the MEDLINE, EMBASE, and Cochrane Library databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting clinical data following SMO for the treatment of ankle osteoarthritis were included and assessed. The level and quality of evidence of the included studies were also evaluated.

RESULTS

Twenty-four studies with 1160 patients (1182 ankles) were included. Overall, 78.8% patients presented with post-traumatic ankle osteoarthritis. The weighted mean AOFAS score improved from 52.6 ± 9.7 (range 33.8-78.4) preoperatively to 78.1 ± 5.7 postoperatively at weighted mean follow-up of 50.4 ± 18.6 months (range 24.5-99.0).  The most frequently utilised radiographic parameter was the tibial anterior surface angle, which improved from a preoperative weighted mean of 86.3° ± 5.6° (range 76.0°-102.0°) to a postoperative weighted mean of 89.9° ± 3.7° (range 84.9°-99.6°). The complication rate was 5.1% with non-union as the most commonly reported complication (1.6%). Secondary procedures were carried out in 28.2% of patients, the most common of which was implant and hardware removal (17.6%). The failure rate was 6.8%. Two studies were LOE II, 3 studies were LOE III, and 19 studies were LOE IV. The mean Modified Coleman Methodology Score was 59.3 ± 6.6 and the mean MINORS criteria score of all the included studies was 9.5 ± 3.7.

CONCLUSION

This systematic review demonstrates good clinical and radiological outcomes, together with a low failure rate at mid-term follow-up following supramalleolar osteotomy in patients with ankle osteoarthritis. However, a moderate reoperation rate (28.2%) was reported. A low failure rate (6.8%) was reported, which must be interpreted in light of the shortcomings of the design of the included studies and a relatively short follow-up period. In addition, there is a low level and quality of evidence in the current literature with inconsistent reporting of data which underscores the need for further higher quality research to be conducted. Our review highlights that SMO may be an effective and safe procedure in the setting of early-to-intermediate-stage ankle osteoarthritis.

LEVEL OF EVIDENCE

IV.

Is frailty responsive to surgical correction of adult spinal deformity? An investigation of sagittal re-alignment and frailty component drivers of postoperative frailty status

PURPOSE

Frailty has been associated with adverse postoperative outcomes. Recently, a novel frailty index for preoperative risk stratification in patients with adult spinal deformity was developed. Components of the ASD-FI utilize patient comorbidity, clinical symptoms, and patient-reported-outcome-measures (PROMS). Our purpose was to investigate components of the Adult Spinal Deformity Frailty Index (ASD-FI) responsive to surgery and drivers of overall frailty.

METHODS

Operative ASD patients ≥ 18 years, undergoing multilevel fusions, with complete baseline, 6 W, 1Y and 2Y ASD-FI scores. Descriptive analysis assessed demographics, radiographic parameters, and surgical details. Pearson bivariate correlations, independent and paired t tests assessed postoperative changes to ASD-FI components, total score, and radiographic parameters. Linear regression models determined the effect of successful surgery (achieving lowest level SRS-Schwab classification modifiers) on change in ASD-FI total scores.

RESULTS

409 6-week, 696 1-year, and 253 2-year operative ASD patients were included. 6-week and 1-year baseline frailty scores were 0.34, 2 years was 0.38. Following surgery, 6-week frailty was 0.36 (p = 0.033), 1 year was 0.25 (p < 0.001), and 2 years was 0.28 (p < 0.001). Of the ASD-FI variables, 17/40 improved at 6 weeks, 21/40 at 1 year, and 18/40 at 2 years. Successful surgery significantly predicted decreases in 1-year frailty scores (R = 0.27, p < 0.001), SRS-Schwab SVA modifier was the greatest predictor (Adjusted Beta: - 0.29, p < 0.001).

CONCLUSIONS

Improvement in sagittal realignment and functional status correlated with improved postoperative frailty. Additional research and deformity sub-group analyses are needed to describe associations between specific functional activities that correlated with frailty improvement as well as evaluation of modifiable and non-modifiable indices.

Joint Preservation Surgery for Varus and Posterior Ankle Arthritis Associated with Flatfoot Deformity

This article introduces novel types of ankle arthritis related to a flatfoot deformity. There has been a long-held belief that severe unmanaged flatfoot deformity leads to valgus ankle arthritis, due to deltoid ligament insufficiency. However, flatfoot deformity can also give rise to varus ankle arthritis as the talus and calcaneus subluxate into opposite directions. Plantarflexion and posterior translation of the talus in the sagittal plane contributes to the eccentric narrowing of the posterior aspect of the tibiotalar joint, which the authors termed posterior ankle arthritis. Subtalar arthrodesis was performed to address the opposing dynamics of the talus and calcaneus, and was combined with a medial longitudinal arch reconstruction in most cases of posterior ankle arthritis and in selected cases of varus ankle arthritis, and satisfactory clinical and radiological results were achieved.

Iatrogenic ischiofemoral impingement due to high tibial osteotomy with overvalgization: a case report

Background

Open wedge high tibial osteotomy is a standard procedure for frontal realignment. It is indicated in varus knee with reduced mechanical medial proximal tibia angle. Overcorrection producing a mechanical medial proximal tibia angle out of the normal range (85–90°) is not recommended because this would lead to unphysiological joint-line orientation. Osteotomies around the knee also influence the adjacent ankle and hip joints. For the hip, it is known that frontal alignment of the leg influences the ischiofemoral space. A decreased ischiofemoral space can lead to painful impingement between the ischial bone and the lesser trochanter.

Case presentation

A 53-year-old German woman presented with severe ischiofemoral impingement symptoms and valgus malalignment of the left leg after open wedge high tibial osteotomy, which was indicated and performed by an orthopedic surgeon with intention to treat medial knee pain due to degenerative arthritis of the medial compartment years after medial meniscectomy. The mechanical medial proximal tibia angle was 100.5°. We performed closed wedge high tibial osteotomy producing a mechanical medial proximal tibia angle of 90.0° and normal joint-line orientation. The hip pain was gone immediately after the surgery, and the patient had no signs of ischiofemoral impingement or hip pain at last follow-up 12 months after closed wedge high tibial osteotomy.

Conclusions

Frontal realignment osteotomy around the knee can create problems at adjacent joints. Overvalgization of the proximal tibia made the patient compensate by hyperadduction of the hip to enable full foot sole contact with the floor. Hyperadduction of the hip decreased the ischiofemoral space, leading to severe impingement. Therefore, meticulous planning of osteotomies is important not to produce unphysiological situations or unwanted negative effects at the level of an adjacent joint.

Frontal knee alignment influences the vertical orientation of the femoral neck in standing position

AIMS

The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck.

METHODS

Long-leg standing radiographs of patients undergoing realignment surgery around the knee were used. The hip-knee-ankle angle (HKA) and the vertical orientation of the femoral neck in relation to the floor were measured, prior to surgery and after osteotomy-site-union. Linear regression was performed to determine the influence of knee alignment on the vertical orientation of the femoral neck.

RESULTS

The cohort included 147 patients who underwent knee realignment-surgery. The mean age was 51.5 years (SD 11). Overall, 106 patients underwent a valgisation-osteotomy, while 41 underwent varisation osteotomy. There was a significant association between the orientation of the knee and the coronal neck-orientation. In the varus group, the median orientation of the femoral neck was 46.5° (interquartile range (IQR) 49.7° to 50.0°), while in the valgus group, the orientation was 52.0° (IQR 46.5° to 56.7°; p < 0.001). Linear regression analysis revealed that HKA demonstrated a direct influence on the coronal neck-orientation (β = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002). Linear regression also showed that realignment surgery was associated with a significant influence on the change in the coronal femoral neck orientation (β = 5.6 (95% CI 1.5 to 9.8); p = 0.008).

CONCLUSION

Varus or valgus knee alignment is associated with either a more horizontal or a more vertical femoral neck orientation in standing position, respectively. Subsequently, osteotomies around the knee alter the vertical orientation of the femoral neck. These aspects are of importance when planning osteotomies around the knee in order to appreciate the effects on the adjacent hip joint. The concept may be of even more relevance in dysplastic hips. Cite this article: Bone Jt Open 2021;2(12):1057-1061.

Fixed (Congenital) Patellar Dislocation

Congenital dislocation of the patella is a rare condition characterized by lateral dislocation of the patella that is irreducible without surgical correction. Although there is no clear inheritance pattern, it is associated with several congenital syndromes. Patients often demonstrate flexion contracture, loss of active knee extension, increased tibial external rotation, and absent patella in the trochlea. Treatment requires surgical management and is comprised of lateral release, medial stabilization, quadriceps lengthening, and distal realignment. Results are generally favorable after treatment; persistent flexion contracture and redislocation are the most common complications. Further study is needed to define the optimal timing and treatment strategy for this uncommon condition.

Osteotomies around the knee lead to corresponding frontal realignment of the ankle

Introduction

Despite the fact that osteotomies around the knee represent well-established treatment options for the redistribution of loads and forces within and around the knee joint, unforeseen effects of these osteotomies on the ankle are still to be better understood. It was therefore the aim of this study to determine the influence of osteotomies around the knee on the coronal alignment of the ankle. We hypothesize that osteotomies around the knee for correction of genu varum or valgum lead to a change of the ankle orientation in the frontal plane by valgisation or varisation.

Materials and methods

Long-leg standing radiographs of 154 consecutive patients undergoing valgisation or varisation osteotomy around the knee in 2017 were obtained and utilized for the purpose of this study. Postoperative radiographs were obtained after union at the osteotomy site. The hip knee ankle angle (HKA), the mechanical lateral distal femur angle (mLDFA), the mechanical medial proximal tibia angle (mMPTA) and five angles around the ankle were measured. Comparison between means was performed using the Wilcoxon-Mann–Whitney test.

Results

One hundred fifty-four patients (96 males, 58 females) underwent osteotomies around the knee for coronal realignment. The mean age was 51 ± 11 years. Correction osteotomies consisted of 73 HTO, 54 DFOs, and 27 double level osteotomies. Of all osteotomies, 118 were for valgisation and 36 for varisation. For valgisation osteotomies, the mean HKA changed from 5.8° ± 2.9° preoperatively to − 0.9° ± 2.5° postoperatively, whereas the mMPTA changed from 85.9° ± 2.7° to 90.7° ± 3.1° and the malleolar-horizontal-orientation-angle (MHA) changed from 16.4° ± 4.2° to 10.9° ± 4.2°. For varisation osteotomies, the mean HKA changed from − 4.3° ± 3.7° to 1.1° ± 2.2° postoperatively, whereas the mLDFA changed from 85.7° ± 2.2° to 89.3° ± 2.3° and the MHA changed from 8.8° ± 5.1° to 11.2° ± 3.2°.

Conclusion

Osteotomies around the knee for correction of coronal limb alignment not only lead to lateralization or medialization of the weight-bearing line at the knee but also lead to a coronal reorientation of the ankle. This can be measured at the ankle using the MHA. When planning an osteotomy around the knee for correction of genu varum or valgum, the ankle should also be appreciated—especially in patients with preexisting deformities, ligament instabilities, or joint degeneration around the ankle.

Supracondylar rotation osteotomy of the femur influences the coronal alignment of the ankle

Purpose

Osteotomies represent well-established treatment-options for the redistribution of loads and forces within and around the knee-joint. Effects of these osteotomies on the remaining planes and adjacent joints are not fully understood. The aim of this study was to determine the influence of a distal-femoral-rotation-osteotomy on the coronal alignment of the ankle. It was hypothesized that supracondylar-external-rotation-osteotomy of the distal femur leads to a change in the coronal orientation of the ankle joint.

Methods

Long-leg standing radiographs and CT-based torsional measurements of 27 patients undergoing supracondylar-rotational-osteotomy of the femur between 2012 and 2019 were obtained and utilized for the purpose of this study. Postoperative radiographs were obtained after union at the osteotomy-site. The hip-knee-ankle-angle (HKA), the mechanical-lateral-distal-femur-angle (mLDFA), and Tibia-Plafond-Horizontal-Orientation-Angle (TPHA) around the ankle were measured. Comparison between means was performed using the Wilcoxon-Mann–Whitney test.

Results

Twenty-seven patients with high femoral antetorsion (31.3° ± 4.0°) underwent supracondylar-external-rotation-osteotomy. The osteotomy led to a reduced antetorsion (17.4 ± 5.1; p < 0.001) and to a valgisation of the overall limb-alignment. The HKA decreased by 2.4° ± 1.4° (p < 0.001). The TPHA decreased by 2.6° (p < 0.001).

Conclusions

Supracondylar external rotation osteotomy of the femur leads to lateralization of the weight bearing line at the knee and ankle due to valgisation of the coronal limb alignment. The mobile subtalar joint has to compensate (inversion) for the resulting valgus orientation of the ankle to ensure contact between the foot and the floor. When planning a rotational osteotomy of the lower limb, this should be appreciated – especially in patients with a preexisting valgus alignment of the lower extremities or restricted mobility in the subtalar joint.

Evolution to Pedicle Reformation Technique in Surgical Management of Hangman's Fracture

BACKGROUND

Opinions vary regarding optimal treatment of unstable hangman's fractures. Recent technological advances have allowed short segment, motion preserving fixation, even in complex cases. The aim of the study was to demonstrate C1-C2 motion-preserving short-segment fusion in hangman's fracture and the evolution of technique from pedicle realignment to pedicle reformation in complex fractures with resorbed/destroyed C2 pedicles.

METHODS

This was a retrospective study. Patients operated by a single surgeon at a tertiary level center from 2012 to 2018 were included. The type of fracture, operating time, and blood loss was recorded. Neurologic deficits were recorded using the American Spinal Injury Association scale with regular clinicoradiologic follow-up.

RESULTS

Nine patients (8 male), with a mean age of 36 ± 16.9 years were included. In the initial 7 patients, C2 pedicle screw, C3-C4 lateral mass screw, and rod fixation was done. The last 2 patients were complex neglected injuries, with 1 having severe angulation and displacement and the other having spondyloptosis with C2 body placed anterior to C4 body. In both these patients, direct C2 body screw were placed and pedicle reconstruction was done. Mean follow up was 41.4 ± 29.8 months. All 5 patients with preoperative neurologic deficits had improvement in power. C1-C2 joint motion was preserved in all. All patients had bony fusion.

CONCLUSIONS

Preservation of motion at the C1-C2 joint should be the goal in all surgically managed hangman's fracture patients. The technique of C2 pedicle reconstruction can be utilized for the same in old neglected hangman's fractures.

Tibial and femoral osteotomies in varus deformities - radiological and clinical outcome

BACKGROUND

Varus deformities of the knee are frequently corrected by osteotomies, which should be performed at the level of origin. But in contrast to high tibial osteotomies (HTO), little data exists for distal femoral osteotomies (DFO). This study evaluates radiological and clinical outcomes after valgisation osteotomies in the proximal tibia and distal femur.

METHODS

We used an observational cohort study design and prospectively performed preoperative long standing radiographs (LSR), lateral x-rays and clinical questionnaires (SF-36, Lysholm score, VAS). Postoperative LSR and lateral x-rays were obtained on average 18 months postoperative and postoperative clinical questionnaires at final visit (mean follow up 46 months). A subgroup analysis of the different surgical techniques (oHTO vs. cDFO) was performed, with regards to radiological and clinical outcomes.

RESULTS

Finally 28 osteotomies with medial tibial opening (oHTO) or lateral femoral closing (cDFO) wedge osteotomies in 25 consecutive patients (mean age 40 years) were identified. There were 17 tibal and 11 femoral procedures. All osteotomies were performed at the origin of deformity, which was of different etiology. The average deviation of the final HKA compared to the preoperative planning was 2.4° ± 0.4°. Overall, there was a significant improvement in all clinical scores (SF-36: 61.8 to 79.4, p < 0.001; Lysholm-score: 72.7 to 90.4, p < 0.001; VAS: 3 to 1, p < 0.001). There was no significant correlation between surgical accuracy and outcome scores.

CONCLUSION

Valgisation osteotomies lead to a significant improvement in all clinical scores with the demonstrated treatment protocol. An appreciable proportion of varus deformities are of femoral origin. Since cDFO provides comparable radiological and clinical results as oHTO, this is an important treatment option for varus deformities of femoral origin.

Clinical mid- to long-term outcome after autologous chondrocyte implantation for patellar cartilage lesions and its correlation with the geometry of the femoral trochlea

BACKGROUND

The aim was to investigate the clinical results after autologous chondrocyte implantation (ACI) at the patella in a mid- to long-term course, and whether trochlear dysplasia has an influence on the outcome.

METHODS

Inclusion criteria were ACI for focal patella cartilage defects and preoperative magnetic resonance imaging (MRI). Patients with previous trochleoplasty or osteotomy have been excluded. Trochlea morphology was evaluated by sulcus depth, sulcus angle, lateral condyle index (LCI) and Dejour's classification for trochlea dysplasia. The clinical outcome was evaluated by a questionnaire including the Kujala- and IKDC-Scores. Survival of the ACI was analysed by the Kaplan-Meier method. A correlation analysis between morphologic parameters and clinical scores was performed.

RESULTS

Seventy-eight patients (mean age 33.2 ± 10.7 years) were included (mean follow-up 6.5 ± 3.4 years). The mean sulcus depth was 5.0 ± 1.6 mm (normal value ≥5 mm), the mean sulcus angle was 153.4 ± 9.0° (normal value ≤145°) and the mean LCI was 84.9 ± 7.5% (normal value ≥90%). Major trochlea dysplasia (grades B-D) was seen in 29 patients (36.7%). Five-year survival rate was 98%, satisfaction-rate was 78.9% and the mean clinical scores were 67.6 ± 20.2 for the Kujala-Score and 64.7 ± 20.2 for the IKDC-Score. A lower LCI showed significant correlation with a lower IKDC score (r = 0.25; p = 0.037).

CONCLUSIONS

The present study reports an excellent survival rate and a good satisfaction rate in a mid- to long-term course after patella ACI. The clinical scores show a high variance and there is evidence that a pathologic trochlea correlates with inferior results.

[11C]SCH23390 binding to the D1-dopamine receptor in the human brain-a comparison of manual and automated methods for image analysis

Background

The D₁-dopamine receptor radioligand [¹¹C]SCH23390 has been frequently used in PET studies. In drug-naïve patients with schizophrenia, the findings have been inconsistent, with decreases, increases, and no change in the frontal cortex D₁-dopamine receptors. While these discrepancies are likely primarily due to a lack of statistical power in these studies, we speculated that an additional explanation may be the differences due to methods of image analysis between studies, affecting reliability as well as bias between groups.

Methods

Fifteen healthy subjects underwent two PET measurements with [¹¹C]SCH23390 on the same day. The binding potential (BP_ND) was compared using a 95% confidence interval following manual and automated delineation of a region of interest (ROI) as well as with and without frame-by-frame realignment.

Results

Automated target region delineation produced lower BP_ND values, while automated delineation of the reference region yielded higher BP_ND values. However, no significant differences were observed for repeatability using automated and manual delineation methods. Frame-by-frame realignment generated higher BP_ND values and improved repeatability.

Conclusions

The results suggest that the choice of ROI delineation method is not an important factor for reliability, whereas the improved results following movement correction confirm its importance in PET image analysis. Realignment is therefore especially important for measurements in patient populations such as schizophrenia or Parkinson’s disease, where motion artifacts may be more prevalent.

Electronic supplementary material

The online version of this article (10.1186/s13550-018-0416-2) contains supplementary material, which is available to authorized users.

Metabolic Plasticity Enables Circadian Adaptation to Acute Hypoxia in Zebrafish Cells

BACKGROUND/AIMS

Reduced oxygen availability, hypoxia, is frequently encountered by organisms, tissues and cells, in aquatic environments as well as in high altitude or under pathological conditions such as infarct, stroke or cancer. The hypoxic signaling pathway was found to be mutually intertwined with circadian timekeeping in vertebrates and, as reported recently, also in mammals. However, the impact of hypoxia on intracellular metabolic oscillations is still unknown.

METHODS

For determination of metabolites we used Multilabel Reader based fluorescence and luminescence assays, circadian levels of Hypoxia Inducible Factor 1 alpha and oxidized peroxiredoxins were semi quantified by Western blotting and ratiometric quantification of cytosolic and mitochondrial H2O2 was achieved with stable transfections of a redox sensitive green fluorescent protein sensor into zebrafish fibroblasts. Circadian oscillations of core clock gene mRNA´s were assessed using realtime qPCR with subsequent cosine wave fit analysis.

RESULTS

Here we show that under normoxia primary metabolic activity of cells predominately occurs during day time and that after acute hypoxia of two hours, administrated immediately before each sampling point, steady state concentrations of glycolytic key metabolites such as glucose and lactate reveal to be highly rhythmic, following a circadian pattern with highest levels during the night periods and reflecting the circadian variation of the cellular response to hypoxia. Remarkably, rhythms in glycolysis are transferred to cellular energy states under normoxic conditions, so that ADP/ATP ratios oscillate as well, which is the first evidence for cycling ADP/ATP pools in a metazoan cell line to our knowledge. Furthermore, the hypoxia induced alterations in rhythms of glycolysis lead to the alignment of three major cellular redox systems, namely the circadian oscillations of NAD+/NADH and NADP+/NADPH ratios and of increased nocturnal levels of oxidized peroxiredoxins, resulting in a highly oxidized nocturnal cellular environment. Of note, circadian rhythms of cytosolic H2O2 remain unaltered, while the transcriptional clock is already attenuated, as it is known to occur also under chronic hypoxia.

CONCLUSION

We therefor propose that the realignment of metabolic redox oscillations might initiate the observed hypoxia induced attenuation of the transcriptional clock, based on the reduced binding affinity of the CLOCK/BMAL complex to the DNA in an oxidized environment.

Treatment of posterior urethral distractions defects following pelvic fracture

Posterior urethral injuries typically arise in the context of a pelvic fracture. Retrograde urethrography is the preferred diagnostic test in trauma patients with pelvic fracture where a posterior urethral rupture is suspected. Pelvic fractures however preclude the adequate positioning of the patient on the X-ray table on admission and computed tomography scan with intravenous contrast and delayed films generally performed first. Suprapubic bladder catheter placement under ultrasound guidance should be performed whenever a posterior urethral disruption is suspected. Early diagnosis and proper acute management decrease the associated complications, such as strictures, urinary incontinence and erectile dysfunction. The correct and appropriate initial treatment of associated urethral rupture is critical to the proper healing of the injury. Placing of a suprapubic cystostomy on admission and delayed anastomotic urethroplasty after 3–6 months continues to be the gold standard of treatment. In this paper, we provide a comprehensive review of the literature with a special emphasis on the various treatments available: Open or endoscopic primary realignment, immediate or delayed urethroplasty after suprapubic cystostomy, and delayed optical urethrotomy.

Cost-effective management of pelvic fracture urethral injuries

PURPOSE

To compare the cost-effectiveness of various treatment strategies in the management of pelvic fracture urethral injuries using decision analysis.

METHODS

Five strategies were modeled from the time of injury to resolution of obstructed voiding or progression to urethroplasty. Management consisted of immediate suprapubic tube (SPT) placement and delayed urethroplasty; primary endoscopic realignment (PER) followed by urethroplasty in failed patients; or PER followed by 1-3 direct vision internal urethrotomies (DVIU), followed by urethroplasty. Success rates were obtained from the literature. Total medical costs were estimated and incremental cost-effectiveness ratios (ICERs) were generated over a 2-year follow-up period.

RESULTS

PER was preferred over SPT placement in all iterations of the model. PER followed by a single DVIU and urethroplasty in cases of failure was least costly and used as the referent approach with an average cost-effectiveness of $17,493 per unobstructed voider. The ICER of a second DVIU prior to urethroplasty was $86,280 per unobstructed voider, while the ICER of a third DVIU was $172,205. The model was sensitive to changes in the success rate of the first DVIU, where when the probability of DVIU success is expected to be less than 32% immediate urethroplasty after failed PER is favored.

CONCLUSIONS

Management of pelvic fracture urethral injuries with PER is the preferred management strategy according to the current model. For those who fail PER, a single DVIU may be attempted if the presumed success rate is >32%. In all other cases, urethroplasty following PER is the preferred approach.

Surgical Treatment of the Twisted Nose

The twisted nose is a challenging procedure in rhinoplasty. The goal of surgery is to realign the nasal skeleton to create symmetry in the face and restore nasal patency. Key in the surgical procedure is that all structures of the nasal skeleton be dissected free, mobilized, repositioned, and stabilized. Important surgical steps are intermediate osteotomies on the contralateral side of the deviation for the upper nasal third; for the mid nasal third, a unilateral spreader graft or splint on the nondeviated side, and for the lower nasal third, fixation of the caudal septum to the anterior nasal spine.

Technique for direct posterior reduction in irreducible atlantoaxial dislocation: multi-planar realignment of C1-2

OBJECTIVE

Apart from the commonly seen antero-posterior subluxation of C1 over C2, the dislocation may occur in vertical, lateral or rotational plane. Desired C1-2 realignment can be achieved by corrrecting its dislocation in all planes. We describe a technique for the same.

MATERIAL AND METHODS

The clinical and radiological features of 16 patients (4 – traumatic and 12 – congenital) with irreducible atlantoaxial dislocation (AAD) admitted in the last 1.5 years were studied. Specific attention was paid to vertical dislocation with lateral and rotational components, apart from anterior-posterior subluxation. They were operated through direct posterior approach. The technique using a long rod holder as lever and screw head (tulip) as fulcrum was employed to achieve C1-2 realignment in all planes. The postoperative clinical and radiological data was analyzed and compared with preoperative data.

RESULTS

Patients presented with progressive myelopathy and/or progressive worsening of neck pain. Vertical dislocation was seen in 11 patients with congenital AAD in addition to the antero-posterior subluxation seen in all. Three patients with traumatic AAD and 8 with congenital AAD had additional lateral dislocation or lateral tilt. Three patients with traumatic AAD and 7 with congenital AAD showed rotational component. Postoperatively, all patients showed clinical improvement.

CONCLUSIONS

The antero-posterior and vertical realignment could be achieved in all except one. Similarly, rotational and lateral components could be completely corrected in 8 out of 10 patients. The technique appears to realign the C1-2 in all planes and provides good anatomical restoration.

Technical considerations for functional magnetic resonance imaging analysis

Clinical application of functional magnetic resonance imaging (fMRI) based on blood oxygenation level-dependent (BOLD) effect has increased over the past decade because of its ability to map regional blood flow in response to brain stimulation. This mapping is primarily achieved by exploiting the BOLD effect precipitated by changes in the magnetic properties of hemoglobin. BOLD fMRI has utility in neurosurgical planning and mapping neuronal functional connectivity. Conventional echo planar imaging techniques are used to acquire stimulus-driven fMR imaging BOLD data. This article highlights technical aspects of fMRI data analysis to make it more accessible in clinical settings.

Consistency of gait characteristics as determined from acceleration data collected at different trunk locations

Estimates of gait characteristics may suffer from errors due to discrepancies in accelerometer location. This is particularly problematic for gait measurements in daily life settings, where consistent sensor positioning is difficult to achieve. To address this problem, we equipped 21 healthy adults with tri-axial accelerometers (DynaPort MiniMod, McRoberts) at the mid and lower lumbar spine and anterior superior iliac spine (L2, L5 and ASIS) while continuously walking outdoors back and forth (20 times) over a distance of 20 m, including turns. We compared 35 gait characteristics between sensor locations by absolute agreement intra-class correlations (2, 1; ICC). We repeated these analyses after applying a new method for off-line sensor realignment providing a unique definition of the vertical and, by symmetry optimization, the two horizontal axes. Agreement between L2 and L5 after realignment was excellent (ICC>0.9) for stride time and frequency, speed and their corresponding variability and good (ICC>0.7) for stride regularity, movement intensity, gait symmetry and smoothness and for local dynamic stability. ICC values benefited from sensor realignment. Agreement between ASIS and the lumbar locations was less strong, in particular for gait characteristics like symmetry, smoothness, and local dynamic stability (ICC generally<0.7). Unfortunately, this lumbar-ASIS agreement did not benefit consistently from sensor realignment. Our findings show that gait characteristics are robust against limited repositioning error of sensors at the lumbar spine, in particular if our off-line realignment is applied. However, larger positioning differences (from lumbar positions to ASIS) yield less consistent estimates and should hence be avoided.

Posterior realignment of irreducible atlantoaxial dislocation with C1-C2 screw and rod system: a technique of direct reduction and fixation

BACKGROUND CONTEXT

Treatment of chronic and irreducible atlantoaxial dislocation (AAD) with ventral compression is challenging for surgeons. The main procedures are occipitocervical/C1-C2 fusion after transoral odontoidectomy or release of the periodontoid tissues. These surgical procedures, which are performed simultaneously or intermittently, have many disadvantages that may discount their effectiveness. Therefore, a more effective way to achieve surgical reduction and to keep solid stability with only a single procedure is needed.

PURPOSE

We describe a technique to reduce chronic and irreducible AAD with C1 lateral mass and C2 pedicle screw and rod system.

STUDY DESIGN

This was a retrospective case series.

PATIENT SAMPLE

Our sample comprised 26 patients (9 men and 17 women) with irreducible AAD who ranged in age from 15 to 54 years (mean, 35 years).

OUTCOME MEASURES

Patients' neurologic status was evaluated with the Japanese Orthopedic Association (JOA) scale.

METHODS

Twenty-six symptomatic patients underwent posterior realignment and reduction through the C1 lateral mass and C2 pedicle screw and rod system. The proposed mechanism of reduction is that the implanted screws and rods between C1 and C2 acting as a lever system drew C1 backward and pushed C2 downward and forward after removing circumambient obstruction and scars and thoroughly releasing the facet joints. The preoperative and postoperative JOA score, the extent of reduction, and the conditions of C1-C2 bony fusion were examined.

RESULTS

No neurovascular injury occurred during surgery. Follow-up ranged from 6 to 40 months (mean 20.7 months). Radiographic evaluation showed that solid bony fusion was achieved in all patients, and that complete reduction was attained in 18 patients and partial reduction (>60% reduction) in 8 patients. The mean postoperative JOA score at last follow-up was 15.7, compared with the preoperative score of 12.1 (p<.01).

CONCLUSIONS

This C1-C2 screw and rod system provides reliable stability and sufficient reduction of the anatomic malalignment at the craniovertebral junction and meanwhile retains the mobility of atlanto-occipital joints in the treatment of chronic and irreducible AAD. Sophisticated skills, thorough release of the facet joints, and intraoperative protection of the vertebral artery are key points to accomplish this technique.