Anti-AQP(4) antibody in idiopathic acute transverse myelitis with recurrent clinical course: frequency of positivity and influence in prognosis

Background

The anti-aquaporin4 (anti-AQP4) antibody is specific for neuromyelitis optica (NMO), but is also found in limited forms. The presence of this antibody in acute transverse myelitis (ATM) has been associated with recurrence and conversion to NMO, but the influence on disability has not yet been described.

Objective

To describe the frequency of anti-AQP4 in ATM and analyze the influence in long-term prognosis.

Design

Cross-sectional and retrospective study.

Methods

Consecutive ATM cases in a multiple sclerosis center in Rio de Janeiro, Brazil, from 2000 through 2009 were reviewed. Recurrent cases tested for anti-AQP4 were selected. ATM with magnetic resonance imaging spinal cord lesions extending over three or more vertebral segments was classified as longitudinally extensive transverse myelitis (LETM); Kurtzke scale was applied at last evaluation.

Outcome measures

Frequency of anti-AQP4; severity of spinal cord dysfunction at last follow-up.

Results

Twenty six patients (21 female:5 male; 17 white:9 African descent) were studied. The first ATM occurred at 38.04 ± 12.7 years. The interval between the first and the second ATM was eight months (1–150) and the number of ATM varied from two to seven. After 40.5 months (12–192) of disease, the median Expanded Disability Status Scale (EDSS) score was three (0–9). Anti-AQP4 antibody was positive in 26.9%. LETM was found in 65.4%. LETM presented later onset, higher disability and higher positivity to anti-AQP4 (LETM 41.2% versus no-LETM 0%, P = 0.024). Dysfunction at long-term follow-up was similar in anti-AQP4 positive and negative cases.

Conclusion

The frequency of anti-AQP4 in recurrent ATM was 26.9%, increasing to 41.2% among LETM. Presence of the antibody had no influence on morbidity.     

Recurrent longitudinal extensive transverse myelitis in a neuro-Beh?et syndrome treated with infliximab

Background

Spinal cord involvement is not common, but can be seen in neuro-Behçet''s syndrome (NBS). The major site of involvement is the cervical spinal cord with the myelitis-like inflammatory lesions continuing more than two segments, and extending to the brainstem.

Case

A 30-year-old male patient who has been followed with a diagnosis of Behçet''s syndrome admitted to our neurology department clinically and radiologically suggestive of recurrent and extensive longitudinal myelitis. His anti-aquaporine antibody was negative. Because of insufficient effect of azathioprine, cyclophosphamide, and corticosteroids, infliximab was started. His clinical and radiological status is stationary for 3 years under infliximab treatment.

Discussion

Myelitis such as that occurring in our patient may have a similar presentation like neuromyelitis optica (NMO), which should therefore be included in differential diagnosis. Myelitis observed in both NMO and NBS shows spinal cord lesions longer than three or more vertebrae. Anti-aquaporine antibody must be evaluated in all patients presenting with longitudinal myelitis. Anti-tumor necrosis factor agent infliximab might be an alternative treatment in severe form of NBS such as myelitis.

Conclusion

In our case, successful treatment of recurrent and extensive longitudinal transverse myelitis in NBS with infliximab was demonstrated.     

Effects of compression stockings on sympathetic activity and heart rate variability in individuals with spinal cord injury

Objective

To investigate whether wearing graduated compression stockings (GCS) could affect the sympatho-adrenergic and heart rate variability (HRV) responses at rest and after a strenuous wheelchair exercise in individuals with spinal cord injury (SCI).

Design

Crossover trial.

Setting

Department of Physical Medicine and Rehabilitation, Saint Etienne, France.

Participants

Nine men with SCI (five with low paraplegia: LP, four with high paraplegia: HP).

Interventions

Two maximal wheelchair exercise tests: with and without GCS (21 mmHg).

Main outcome measures

HRV measurements: high frequency (HF), low frequency (LF), and LF/HF ratio. Norepinephrine (NOR) and epinephrine (EPI), at rest and post-exercise. Secondary measures were: blood pressure, heart rate, maximal power output, oxygen uptake, stroke volume, cardiac output, at rest, during and after exercise.

Results

When wearing GCS: LFnu_wavelet-post significantly increased and HFnu_wavelet-post significantly decreased (P < 0.05) in SCI subjects, leading to an enhance ratio of LF_wavelet/HF_wavelet and a significantly increased in NOR_rest (P < 0.05).

Conclusions

GCS induces an enhanced sympathetic activity in individuals with paraplegia, regardless of the level of the injury. Enhanced post-exercise sympathetic activity with GCS may help prevent orthostatic hypotension or post-exercise hypotension.     

Voriconazole Is Cytotoxic at Locally Delivered Concentrations: A Pilot Study

Background

Fungal infections are rare but major problems when they involve orthopaedic implants. Preferred treatment in North America is two-staged: resection and then delayed reconstruction, with local delivery of an antifungal between stages. The effect of voriconazole, a hydrophobic antifungal, on local tissues and wound healing is unclear.

Questions/purposes

We asked: (1) Is voriconazole cytotoxic to fibroblasts or osteoblasts at target concentrations for local delivery? And (2) if cytotoxic, can fibroblasts or osteoblasts resume proliferation after voriconazole is removed?

Methods

We exposed 5000 fibroblasts or osteoblasts/well to voriconazole concentrations of 0, 1, 5, 10, 25, 100, 500, 1000, 5000, 10,000, and 20,000 μg/mL (n = 4 wells/concentration) in 24-well plates. At 3 and 7 days, cell growth was assessed with alamarBlue^® and light microscopy. After Day 7, exposure to voriconazole was stopped and incubation continued for 4 days in medium with no voriconazole. On Day 11, cell growth (recovery) was assessed with alamarBlue^® and light microscopy.

Results

Increasing voriconazole concentration to more than 100 μg/mL decreased osteoblast and fibroblast growth. Cell growth recovered after 7 days’ exposure to 1000 μg/mL or less.

Conclusions

Voriconazole is cytotoxic to osteoblasts and fibroblasts, but cell growth recovers over 4 days after exposure to 1000 μg/mL or less.

Clinical Relevance

Cytotoxicity seen from voriconazole to mouse osteoblasts and fibroblasts occurs at concentrations achievable clinically from local delivery. It may be prudent to limit the dose of voriconazole in antibiotic-loaded bone cement.     

Gallbladder perforation: A rare complication of enteric fever

INTRODUCTION

Gallbladder perforation is a rare complication of acute calculous cholecystitis in adults. Perforation of gallbladder due to enteric fever is extremely rare condition. Pre-operative diagnosis is rarely made and mortality is high.

PRESENTATION OF CASE

We report a case of acalculous gallbladder perforation following enteric fever in a 14-year-old boy, who presented as acute abdomen and responded very well after emergency laparotomy and cholecystectomy.

DISCUSSION

Enteric fever is common in tropics and a common cause of bowel perforation. Acute cholecystitis is a rare complication of typhoid and gallbladder perforation is extremely rare complication. Ultrasound and CT lack specificity to detect gallbladder perforation. Diagnosis is usually made intra-operatively. Cholecystectomy is treatment of choice in such cases and provides good result.

CONCLUSION

Gallbladder perforation secondary to enteric fever requires a high degree of clinical suspicion. In typhoid endemic region, it should be considered as a differential diagnosis in patient presenting with a history of prolonged fever and signs of peritonitis. Early diagnosis and immediate surgical intervention are very important in reducing the morbidity and mortality. Cholecystectomy is the choice with a good outcome.     

Peritonsillar abscess after tonsillectomy: a review of the literature

INTRODUCTION

Peritonsillar abscess (PTA) is a common condition with a complicated aetiology. PTA after tonsillectomy is rare. This literature review of PTA in the absence of tonsil tissue aims to collate experience of these cases and examine the wider implications for understanding the aetiology of PTA formation.

METHODS

A structured literature review was performed using Ovid MEDLINE®. Keywords ‘quinsy’ or ‘peritonsillar abscess’ were combined with ‘tonsillectomy’.

RESULTS

The search resulted in 212 citations and the identification of 11 cases of PTA formation in the absence of tonsil tissue. The most common indication for tonsillectomy was recurrent tonsillitis or PTA. Nine patients had no interval peritonsillar infection (ie a peritonsillar infection after a tonsillectomy) prior to presenting with the PTA. The mean interval between tonsillectomy and PTA was 16 years. All patients were managed either by incision and drainage or by needle aspiration with or without antibiotics.

CONCLUSIONS

PTA in the absence of tonsil tissue is rare. Potential sources of infection include congenital branchial fistulas, Weber''s glands and dental disease. These alternatives should also be considered in patients presenting with PTA formation in the absence of concurrent tonsillitis and may influence management decisions.     

Effectiveness of local cooling for enhancing tissue ischemia tolerance in people with spinal cord injury

Objective

To investigate the effects of localized cooling and cooling rate on pressure-induced ischemia for people with and without neurological deficits.

Design

A 2 × 3 mixed factorial design with two groups: (1) people with spinal cord injury (SCI) and (2) people without neurological deficits (control), and three test conditions: (1) pressure only, (2) pressure with fast cooling (−4°C/min), and (3) pressure with slow cooling (−0.33°C/min).

Setting

University laboratory.

Participants

Fourteen controls and 14 individuals with SCI.

Interventions

Pressure on the sacrum was 0.4 kPa for 5 minutes, then 8 kPa for 20 minutes, and finally 0.4 kPa for 15 minutes. Fast and slow cooling to 25°C applied during 8 kPa of pressure.

Outcome measures

Reactive hyperemia and its spectral densities in the metabolic, neurogenic, and myogenic frequency ranges.

Results

In controls, reactive hyperemia was greater in pressure only as compared with both cooling conditions. No change was noted in all spectral densities in both cooling conditions, and only neurogenic spectral density increased without cooling. In subjects with SCI, no difference was noted in reactive hyperemia among conditions. However, metabolic and myogenic spectral densities increased without cooling and all spectral densities increased with slow cooling. No change was noted in all spectral densities with fast cooling.

Conclusion

Local cooling reduced the severity of ischemia in controls. This protective effect may be masked in subjects with SCI due to chronic microvascular changes; however, spectral analysis suggested local cooling may reduce metabolic vasodilation. These findings provide evidence towards the development of support surfaces with temperature control for weight-bearing soft tissues.     

Minimally invasive technique for release of Dupuytren��s contracture: segmental fasciectomy through multiple transverse incisions

Background

A multitude of operative approaches have been described for treatment of Dupuytren’s contracture. A less-invasive technique of segmental fasciectomies performed through multiple small transverse incisions is presented.

Methods

Seventy-three digits in 37 patients were treated with segmental fasciectomies. The results of 34 digits in 14 patients are described with subsequent follow-up longer than 2 years.

Results

Metacarpophalangeal joint extension improved from a mean of 32.5° to 2.2°, while proximal interphalangeal joint extension improved from 22.9° to 4.1°. Patients subjectively rated their surgical outcomes as excellent or good in 91.2% of cases. No recurrence of the disease was noted, though extension of the disease to adjacent digits was observed in three patients.

Conclusions

Though this approach is technically demanding and requires the help of a skilled assistant, this preliminary study supports our contention that this less-extensive procedure allows excellent correction of contractures; results in mild postoperative pain; and permits a rapid return of finger flexion with satisfactory long-term results so far at 2-years follow-up.     

Voriconazole Is Delivered From Antifungal-Loaded Bone Cement

Background

Local delivery of antifungals is an important modality in managing orthopaedic fungal infection. Voriconazole is a powder antifungal suitable for addition to bone cement that is released from bone cement but the mechanical properties of antimicrobial-loaded bone cement (ALBC) made with voriconazole are unknown.

Questions/Purposes

(1) Is voriconazole release dose-dependent? (2) Is released voriconazole active? (3) Is the loss of ALBC’s compressive strength caused by voriconazole dose- and elution-dependent?

Methods

Sixty standard test cylinders were fabricated with ALBC: 300 or 600 mg voriconazole per batch eluted for 30 days in deionized water. Voriconizole concentration in the eluate was measured using high-performance liquid chromatography. Cumulative-released voriconizole was calculated. Biologic activity was tested. Compressive strength was measured before and after elution. The effect of dose and time on release and compressive strength were analyzed using repeated-measure analysis of variance.

Results

Fifty-seven percent and 63% of the loaded voriconazole were released by Day 30 for the 300-mg and 600-mg formulations, respectively. The released voriconazole was active on bioassay. Compressive strength was reduced from 79 MPa to 53 MPa and 69 MPa to 31 MPa by 30 days for the 300-mg and 600-mg formulations, respectively.

Conclusions

Voriconazole release from ALBC increases with dose and is bioactive. Loss in compressive strength is greater after elution and with higher dose.

Clinical Relevance

Three hundred milligrams of voriconazole in ALBC would be expected to deliver meaningful amounts of active drug in vivo. The compressive strength of ALBC with 600 mg voriconazole is less than expected compared to commonly used antibacterials.     

Cementless modular intramedullary nail without bone-on-bone fusion as a salvage procedure in chronically infected total knee prosthesis: long-term results

Purpose

Our purpose was to evaluate long-term results of two-stage cementless intramedullary nailing without achieving bone-to-bone fusion for treating chronically infected total knee arthroplasty (TKA).

Methods

Thirty-eight patients treated according to the same protocol were retrospectively evaluated for clinical, functional, laboratory and radiological outcomes.

Results

Spacer exchange was necessary for infection persistence in one case. At a minimum two year follow-up, 34 patients (89.5 %) showed no infection recurrence; among these 34 patients, 29 (85.3 %) reported no or moderate pain [visual analogue scale (VAS) ≤3]; mild to moderate handicap (Lequesne Algofunctional Index < 7.5) was observed in 18 patients (52.9 %). No patient underwent revision for aseptic loosening, and no nail breakage was observed.

Conclusions

Two-stage cementless intramedullary nailing without achieving bone-to-bone fusion is a viable option for treating chronically infected TKA in selected, complex cases.     

Accuracy of Individualized Custom Tibial Cutting Guides in UKA

Background

Component malposition is one of the major reasons for early failure of unicompartmental knee arthroplasty (UKA).

Questions/Purposes

It was investigated how reproducibly patient-specific instrumentation (PSI) achieved preoperatively planned placement of the tibial component in UKA specifically assessing coronal alignment, slope and flexion of the components and axial rotation.

Patients and Methods

Based on computer tomography models of ten cadaver legs, PSI jigs were generated to guide cuts perpendicular to the tibial axis in the coronal and sagittal planes and in neutral axial rotation. Deviation ≥3° from the designed orientation in a postoperative CT was defined as outside the range of acceptable alignment.

Results

Mean coronal alignment was 0.4 ± 3.2° varus with two outliers. Mean slope was 2.8 ± 3.9° with six components in excessive flexion. It was noted that the implants were put in a mean of 1.7 ± 8.0° of external rotation with seven outliers

Conclusions

PSI helped achieve the planned coronal orientation of the component. The guides were less accurate in setting optimal tray rotation and slope.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9410-z) contains supplementary material, which is available to authorized users.     

Analysis of lumbar pedicle morphology in degenerative spines using multiplanar reconstruction computed tomography: what can be the reliable index for optimal pedicle screw diameter?

Purpose

The measurement of transverse pedicle width is still recommended for selecting a screw diameter despite being weakly correlated with the minimum pedicle diameter, except in the upper lumbar spine. The purpose of this study was to reveal the difference between the minimum pedicle diameter and conventional transverse or sagittal pedicle width in degenerative lumbar spines.

Methods

A total of 50 patients with degenerative lumbar disorders without spondylolysis or lumbar scoliosis of >10° who preoperatively underwent helical CT scans were included. The DICOM data of the scans were reconstructed by imaging software, and the transverse pedicle width (TPW), sagittal pedicle width (SPW), minimum pedicle diameter (MPD), and the cephalocaudal inclination of the pedicles were measured.

Results

The mean TPW/SPW/MPD values were 5.46/11.89/5.09 mm at L1, 5.76/10.44/5.39 mm at L2, 7.25/10.23/6.52 mm at L3, 9.01/9.36/6.83 mm at L4, and 12.86/8.95/7.36 mm at L5. There were significant differences between the TPW and MPD at L3, L4, and L5 (p < 0.01) and between the SPW and MPD at all levels (p < 0.01).

Conclusions

The MPD was significantly smaller than the TPW and SPW at L3, L4, and L5. The actual measurements of the TPW were not appropriate for use as a direct index for the optimal pedicle screw diameter at these levels. Surgeons should be careful in determining pedicle screw diameter based on plain CT scans especially in the lower lumbar spine.     

Body composition modifications in people with chronic spinal cord injury after supervised physical activity

Background

Quantification of body composition variables is important for planning of better activities in relation to individuals with spinal cord injury (SCI).

Objectives

(1) To evaluate changes in body composition in patients with SCI after a supervised physical activity process; (2) To correlate total body fat with time since injury.

Design

Pre-post intervention.

Setting

Sarah Rehabilitation Hospital Network, Brazil.

Participants

Fifty-three men with SCI aged 18–52 years with duration of injury >3 years.

Interventions

The subjects were divided into three groups: tetraplegia (TT) (C5–C8), high paraplegia (HP) (T1–T6), and low paraplegia (LP) (T7–L2). Body composition was estimated in the first and last weeks of hospitalization.

Outcome measures

Body weight (kg), skinfolds sum (mm), absolute (kg), and relative (%) fat and lean body mass.

Results

Body weight increased in TT and decreased in HP (0.8 kg, 95%CI 0.1–1.5; and −1.0 kg, 95%CI −2.0 to 0.0, respectively; P < 0.05). Skinfolds sum decreased only in HP (−13.1 mm, 95%CI −20.7 to −5.5; P < 0.05). Absolute and relative body fat decreased significantly in the paraplegia groups. Lean body mass (LBM) percentage increased significantly in the paraplegia groups. Absolute LBM increased in TT and LP (0.8 kg, 95%CI 0.3–1.3; and 1.3 kg, 95%CI 0.8 to 1.8, respectively; P < 0.05). There was no correlation between time since injury and skinfolds sum for the three groups (P < 0.05).

Conclusion

TT, HP, and LP demonstrated favorable changes in body composition after 29 days of supervised physical activity. However, these changes were different in direction and magnitude.     

Muscle spasticity associated with reduced whole-leg perfusion in persons with spinal cord injury

Objective

To determine the association between peripheral blood flow and spasticity in individuals with spinal cord injury (SCI).

Design

A cross-sectional study with measurements of muscle spasticity and whole-limb blood flow in individuals with SCI.

Setting

University of Texas at Austin and Brain & Spine Recovery Center, Austin, TX, USA.

Participants

Eighteen individuals (14 males and 4 females) with SCI were classified into high (N = 7), low (N = 6), and no (N = 5) spasticity groups according to the spasticity levels determined by the modified Ashworth scale scores.

Interventions

Whole-limb blood flow was measured in the femoral and brachial arteries using Doppler ultrasound and was normalized to lean limb mass obtained with dual-energy X-ray absorptiometry.

Outcome measures

Limb blood flow and muscle spasticity.

Results

Age, time post-SCI, and the American Spinal Injury Association impairment scale motor and sensory scores were not different among groups with different muscle spasticity. Femoral artery blood flow normalized to lean leg mass was different (P = 0.001) across the three spasticity groups (high 78.9 ± 16.7, low 98.3 ± 39.8, no 142.5 ± 24.3 ml/minute/kg). Total leg muscle spasticity scores were significantly and negatively correlated with femoral artery blood flow (r = −0.59, P < 0.01). There was no significant difference in brachial artery blood flow among the groups.

Conclusions

Whole-leg blood flow was lower in individuals with greater spasticity scores. These results suggest that a reduction in lower-limb perfusion may play a role, at least in part, in the pathogenesis leading to muscle spasticity after SCI.     

Minimizing Electromagnetic Interference from Surgical Instruments on Electromagnetic Surgical Navigation

Background

Electromagnetic computer-assisted surgery (EM-CAS) can be affected by various metallic or ferromagnetic factors.

Questions/purposes

We determined to what extent metals interfere with accuracy and identified measures to prevent interference from occurring.

Methods

Using an EM-CAS system, we made six standard measurements of tibiofemoral position and alignment on a surrogate knee. A stainless steel mallet was positioned 10 cm from the stylus, and then 10 cm from the localizer to create errors attributable to electromagnetic interference. The experiment was repeated with bars of different metals placed 10 cm from the stylus.

Results

The maximum errors recorded with a mallet were: varus/valgus alignment, −2.7° and 2.4°; flexion/extension, −5.8° and 3.0°; lateral resection level, −3.1 and 7.5 mm; and medial resection level, −4.0 and 2.3 mm, respectively. The smallest errors were recorded with cylinders of titanium, cobalt-chrome alloy, and stainless steels. When moved more than 10 cm away from the stylus, errors became negligible.

Conclusions

The accuracy of EM navigation systems is affected substantially by the size, type, proximity, and shape of metal objects.

Clinical Relevance

Stainless steel objects, such as cutting blocks and trial prostheses, should be kept more than 10 cm from EM-CAS instruments to minimize error.