Asymmetric loading strategies during squats following anterior cruciate ligament reconstruction: A longitudinal investigation with curve analyses throughout and after rehabilitation

Investigations of kinetic asymmetries during bilateral squats following anterior cruciate ligament reconstruction (ACLR) are limited to mainly cross-sectional studies and discrete value data extracted at specific knee angles. We assessed loading asymmetries during squats longitudinally throughout rehabilitation using curve analysis and compared patient-reported outcome measures (PROMs) between those with and without asymmetry. Bodyweight squats were performed by 24 individuals (13 females) post-ACLR on three occasions: (1) Early 2.9 (1.1) months; (2) Mid 8.8 (3.1) months; (3) at Return to Sport (RTS) 13.1 (3.6) months; and 29 asymptomatic controls (22 females) once. Time-normalized between-leg asymmetry curves of sagittal plane hip, knee, and ankle moments and vertical ground reaction forces were compared using functional data analysis methods. Individual asymmetrical loading for ACLR was classified when exceeding the 95% confidence interval of controls during ≥50% of the squat. At Early, ACLR had greater asymmetry than controls for knee (15%-100% eccentric phase; 0%-100% concentric) and ankle flexion moments (56%-65% concentric). At Mid, ACLR had greater asymmetry for knee (41%-72% eccentric) and ankle flexion moments (56%-69% concentric). No between-group differences were found at RTS. From Early to RTS, ACLR reduced asymmetry for hip (21%-46% eccentric), knee (27%-58% concentric), and ankle flexion moments (21%-57% eccentric). At Early, 11/24 underloaded their ACLR knee and 1 overloaded compared with controls. At RTS, 4 underloaded and 6 overloaded. No differences in PROMs were found based on loading asymmetry. Beyond the early phase of rehabilitation from ACLR, individual-level analyses are required to reveal differing loading strategies during bilateral squats.

Right hemisphere brain lateralization for knee proprioception among right-limb dominant individuals

Introduction

Studies indicate that brain response during proprioceptive tasks predominates in the right hemisphere. A right hemisphere lateralization for proprioception may help to explain findings that right-limb dominant individuals perform position matching tasks better with the non-dominant left side. Evidence for proprioception-related brain response and side preference is, however, limited and based mainly on studies of the upper limbs. Establishing brain response associated with proprioceptive acuity for the lower limbs in asymptomatic individuals could be useful for understanding the influence of neurological pathologies on proprioception and locomotion.

Methods

We assessed brain response during an active unilateral knee joint position sense (JPS) test for both legs of 19 right-limb dominant asymptomatic individuals (females/males = 12/7; mean ± SD age = 27.1 ± 4.6 years). Functional magnetic resonance imaging (fMRI) mapped brain response and simultaneous motion capture provided real-time instructions based on kinematics, accurate JPS errors and facilitated extraction of only relevant brain images.

Results

Significantly greater absolute (but not constant nor variable) errors were seen for the dominant right knee (5.22° ± 2.02°) compared with the non-dominant left knee (4.39° ± 1.79°) (P = 0.02). When limbs were pooled for analysis, significantly greater responses were observed mainly in the right hemisphere for, e.g., the precentral gyrus and insula compared with a similar movement without position matching. Significant response was also observed in the left hemisphere for the inferior frontal gyrus pars triangularis. When limbs were assessed independently, common response was observed in the right precentral gyrus and superior frontal gyrus. For the right leg, additional response was found in the right middle frontal gyrus. For the left leg, additional response was observed in the right rolandic operculum. Significant positive correlations were found between mean JPS absolute errors for the right knee and simultaneous brain response in the right supramarginal gyrus (r = 0.464, P = 0.040).

Discussion

Our findings support a general right brain hemisphere lateralization for proprioception (knee JPS) of the lower limbs regardless of which limb is active. Better proprioceptive acuity for the non-dominant left compared with the dominant right knee indicates that right hemisphere lateralization may have meaningful implications for motor control.

Textile electromyography electrodes reveal differences in lower limb muscle activation during loaded squats when comparing fixed and free barbell movement paths

INTRODUCTION

Traditional recordings of muscle activation often involve time-consuming application of surface electrodes affixed to the skin in laboratory environments. The development of textile electromyography (EMG) electrodes now allows fast and unobtrusive assessment of muscle activation in ecologically valid environments. In this study, textile EMG shorts were used to assess whether performing squats with the barbell resting freely on the shoulders or using a Smith machine for a fixed barbell movement path is preferable for maximizing lower limb muscle activation.

METHODS

Sixteen athletes performed free and fixed barbell squats in a gym with external loads equivalent to their body mass. Quadriceps, hamstrings and gluteus maximus activation was measured bilaterally with textile EMG electrodes embedded in shorts.

RESULTS

Mean quadriceps activation was greater for the free compared with the fixed movement path for the right (mean difference [MD] 14μV, p = 0.04, ηp 2 = 0.28) and left leg (MD 15μV, p = 0.01, ηp 2 = 0.39) over the entire squat and specifically during the first half of the eccentric phase for the left leg (MD 7μV, p = 0.04, d = 0.56), second half of the eccentric phase for both legs (right leg MD 21μV, p = 0.05, d = 0.54; left leg MD 23μV, p = 0.04, d = 0.52) and the first half of the concentric phase for both legs (right leg MD 24μV, p = 0.04, d = 0.56; left leg MD 15μV, p = 0.01, d = 0.72). Greater hamstrings activation for the free path was seen for the second half of the eccentric phase (left leg MD 4μV, p = 0.03, d = 0.58) and first half of the concentric phase (right leg MD 5μV, p = 0.02, d = 0.72). No significant differences were found for gluteus maximus.

DISCUSSION

Textile EMG electrodes embedded in shorts revealed that to maximize thigh muscle activity during loaded squats, a free barbell movement path is preferable to a fixed barbell movement path.

Brain Response to a Knee Proprioception Task Among Persons With Anterior Cruciate Ligament Reconstruction and Controls

Knee proprioception deficits and neuroplasticity have been indicated following injury to the anterior cruciate ligament (ACL). Evidence is, however, scarce regarding brain response to knee proprioception tasks and the impact of ACL injury. This study aimed to identify brain regions associated with the proprioceptive sense of joint position at the knee and whether the related brain response of individuals with ACL reconstruction differed from that of asymptomatic controls. Twenty-one persons with unilateral ACL reconstruction (mean 23 months post-surgery) of either the right (n = 10) or left (n = 11) knee, as well as 19 controls (CTRL) matched for sex, age, height, weight and current activity level, performed a knee joint position sense (JPS) test during simultaneous functional magnetic resonance imaging (fMRI). Integrated motion capture provided real-time knee kinematics to activate test instructions, as well as accurate knee angles for JPS outcomes. Recruited brain regions during knee angle reproduction included somatosensory cortices, prefrontal cortex and insula. Neither brain response nor JPS errors differed between groups, but across groups significant correlations revealed that greater errors were associated with greater ipsilateral response in the anterior cingulate (r = 0.476, P = 0.009), supramarginal gyrus (r = 0.395, P = 0.034) and insula (r = 0.474, P = 0.008). This is the first study to capture brain response using fMRI in relation to quantifiable knee JPS. Activated brain regions have previously been associated with sensorimotor processes, body schema and interoception. Our innovative paradigm can help to guide future research investigating brain response to lower limb proprioception.

Properties of tests for knee joint threshold to detect passive motion following anterior cruciate ligament injury: a systematic review and meta-analysis

BACKGROUND

Threshold to detect passive motion (TTDPM) tests of the knee joint are commonly implemented among individuals with anterior cruciate ligament (ACL) injury to assess proprioceptive acuity. Their psychometric properties (PMPs), i.e. reliability, validity and responsiveness, are however unclear. This systematic review aimed to establish the PMPs of existing knee joint TTDPM tests among individuals with ACL injury.

METHODS

The databases PubMed, AMED, CINAHL, SPORTDiscus, Web of Science, Scopus, CENTRAL and ProQuest were searched to identify studies that assessed the properties of knee joint TTDPM tests in individuals with ACL injury. The risk of bias for each included study was assessed at the outcome level for each test. Overall quality and levels of evidence for each property were rated according to established criteria. Meta-analyses with mean differences were conducted using random-effects models when adequate data were available.

RESULTS

Fifty-one studies covering 108 TTDPM tests and 1632 individuals with unilateral ACL injury were included. A moderate-to-strong level of evidence indicated insufficient quality for all of the following: convergent validity, known-groups validity, discriminative validity, responsiveness between subgroups, and responsiveness to intervention. Subgroup meta-analyses for known-groups validity did however find that a starting angle of 15° resulted in significantly worse TTDPM for knees with ACL injury compared to those of asymptomatic persons (mean difference 0.28°; 95% CI 0.03 to 0.53; P = 0.03), albeit based on only three studies. Due to the lack of evidence, it was not possible to estimate the quality of reliability, measurement error, and criterion validity, nor responsiveness from a criterion and construct approach.

CONCLUSIONS

Among persons with ACL injury, existing tests of knee joint TTDPM lack either sufficient quality or evidence for their reliability, validity and responsiveness. Significantly worse thresholds for ACL-injured knees compared to those of asymptomatic controls from a 15° starting angle and trends towards significance for some validity measures nevertheless encourage the development of standardised tests. Further research investigating the influence of modifiable test components (e.g. starting angle and motion direction) on the PMPs of knee joint TTDPM tests following ACL injury is warranted.

An obstacle clearance test for evaluating sensorimotor control after anterior cruciate ligament injury: A kinematic analysis

Sensorimotor deficits, particularly proprioceptive, are often reported following rupture of the anterior cruciate ligament (ACL). High secondary injury rates and long-term negative consequences suggest that these deficits are not properly identified using current assessment methods. We explored a novel obstacle clearance test to evaluate sensorimotor control in individuals following ACL reconstruction (ACLR) and rehabilitation. Thirty-seven post-ACLR individuals, 23 nonathletic asymptomatic controls (CTRL), and 18 elite athletes stepped over a hurdle-shaped obstacle, downward vision occluded, aiming for minimal clearance. Kinematic outcomes (3D motion capture) for the leading and trailing legs, for two unpredictably presented obstacle heights, were categorized into Accuracy: vertical foot clearance and minimal distance from the obstacle; Variability: end-point and hip/knee trajectory; and Symmetry: trunk/hip/knee crossing angles, hip-knee-ankle movement, and velocity curves. Accuracy was worse for CTRL compared with both other groups. ACLR had less leading and trailing vertical foot clearance with their injured compared with their noninjured leg. ACLR and athletes had less crossing knee flexion in their injured/nondominant legs compared with their contralateral leg, both leading and trailing. ACLR showed greater trunk flexion when crossing with their injured leg, both leading and trailing. For the leading leg, ACLR showed greater asymmetry for the hip-knee-ankle velocity curve compared with elite athletes. Trailing leg trajectory variability was lower for ACLR compared with CTRL and athletes for higher obstacles. Clinical significance: Sensorimotor deficits in individuals post-ACLR were reflected by greater asymmetry and less variable (more stereotypical) trajectories rather than limb positioning ability. This consideration should be addressed in clinical evaluations.

Robotic versus laparoscopic median arcuate ligament (MAL) release: a retrospective comparative study

BACKGROUND

Multiple retrospective studies have demonstrated the safety and feasibility of laparoscopic median arcuate ligament division with celiac neurolysis for the definitive management of median arcuate ligament syndrome (MALS). This study queries the clinical equipoise of robotic (RMALR) versus laparoscopic MAL release (LMALR) at a high-volume center.

METHODS

A retrospective analysis of consecutive 26 RMALR and 24 LMALR between March 2018 and August 2019 by a single surgeon at a quaternary academic institution was completed. Primary endpoint was postoperative decrease in celiac trunk expiratory peak systolic velocities (PSVs) measured by mesenteric duplex ultrasonography. Secondary outcomes included reported improvement in MALS-related clinical symptoms, distribution of first assistant seniority level, and involvement of second assistants in RMALR versus LMALR.

RESULTS

Mean operative times for LMALR and RMALR were 86 and 134 min, respectively (p < 0.0001). There were no open conversions and mean length of hospital stay was 1 day for both cohorts. Both groups provided an equally effective decrease in postoperative peak systolic velocities (PSVs) (LMALR p = 0.0011; RMALR p = 0.0022; LMALR vs. RMALR p = 0.7772). While RMALR had significantly higher reduction of chronic abdominal pain postoperatively, there were no significant differences in other postoperative symptom relief between groups. However, RMALR patients reported significant relief of postprandial abdominal pain (p < 0.0001) and chronic nausea (p = 0.0002). RMALR had significantly more junior first assistants (p = 0.0001) and less frequently required second assistants compared to LMALR (p = 0.0381).

CONCLUSIONS

In this study comparing RMALR to LMALR, postoperative chronic abdominal pain relief was significantly less in the former while other outcomes were equivalent. In comparison with LMALR, RMALR cases were associated with more junior first assistants, fewer second assistants, and longer operative times. Both approaches are safe and feasible for well-selected patients in experienced centers.

Properties of Knee Joint Position Sense Tests for Anterior Cruciate Ligament Injury: A Systematic Review and Meta-analysis

Background:

Knee proprioception is believed to be deficient after anterior cruciate ligament (ACL) injury. Tests of joint position sense (JPS) are commonly used to assess knee proprioception, but their psychometric properties (PMPs) are largely unknown.

Purpose:

To evaluate the PMPs (reliability, validity, and responsiveness) of existing knee JPS tests targeting individuals with ACL injury.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

PubMed, Allied and Complementary Medicine, CINAHL, SPORTDiscus, Web of Science, Scopus, CENTRAL, and ProQuest databases were searched to identify studies that assessed PMPs of knee JPS tests in individuals with ACL injury. The risk of bias for each included study was assessed and rated at the outcome level for each knee JPS test. Overall quality and levels of evidence for each PMP were rated according to established criteria. Meta-analyses with mean differences were conducted using random effects models when adequate data were available.

Results:

Included were 80 studies covering 119 versions of knee JPS tests. Meta-analyses indicated sufficient quality for known-groups and discriminative validity (ACL-injured knees vs knees of asymptomatic controls and contralateral noninjured knees, respectively), owing to significantly greater absolute errors for ACL-injured knees based on a strong level of evidence. A meta-analysis showed insufficient quality for responsiveness, which was attributed to a lack of significant change over time after diverse interventions with a moderate level of evidence. Statistical heterogeneity (I² > 40%) was evident in the majority of meta-analyses. All remaining PMPs (reliability, measurement error, criterion validity, convergent validity, and other PMPs related to responsiveness) were assessed qualitatively, and they failed to achieve a sufficient quality rating. This was a result of either the study outcomes not agreeing with the statistical cutoff values/hypotheses or the level of evidence being rated as conflicting/unknown or based on only a single study.

Conclusion:

Knee JPS tests appear to have sufficient validity in differentiating ACL-injured knees from asymptomatic knees. Further evidence of high methodologic quality is required to ascertain the reliability, responsiveness, and other types of validity assessed here. We recommend investigations that compare the modifiable methodologic components of knee JPS tests on their PMPs to develop standardized evidence-based tests.

Influence of visual feedback, hand dominance and sex on individuated finger movements

The ability to perform individual finger movements, highly important in daily activities, involves visual monitoring and proprioception. We investigated the influence of vision on the spatial and temporal control of independent finger movements, for the dominant and non-dominant hand and in relation to sex. Twenty-six healthy middle-aged to old adults (M age = 61 years; range 46–79 years; females n = 13) participated. Participants performed cyclic flexion–extension movements at the metacarpophalangeal joint of one finger at a time while keeping the other fingers as still as possible. Movements were recorded using 3D optoelectronic motion technique (120 Hz). The movement trajectory distance; speed peaks (movement smoothness); Individuation Index (II; the degree a finger can move in isolation from the other fingers) and Stationarity Index (SI; how still a finger remains while the other fingers move) were extracted. The main findings were: (1) vision only improved the II and SI marginally; (2) longer trajectories were evident in the no-vision condition for the fingers of the dominant hand in the female group; (3) longer trajectories were specifically evident for the middle and ring fingers within the female group; (4) females had marginally higher II and SI compared with males; and (5) females had fewer speed peaks than males, particularly for the ring finger. Our results suggest that visual monitoring of finger movements marginally improves performance of our non-manipulative finger movement task. A consistent finding was that females showed greater independent finger control compared with males.

Spontaneous Chest Wall Herniation in Centrally Obese Patients: A Single-Center Experience of a Rare Problem

BACKGROUND

Spontaneous rib fractures, especially in association with chest wall herniation, represent an uncommon pathology. As such, there are little data analyzing approaches to treatment or regarding the success of intervention. The goal of this study was to analyze our cumulative experience with this unusual condition.

METHODS

A case series of 12 patients was gathered from a single institution based on outpatient visits between February 2015 and October 2018. Each chart was retrospectively reviewed with particular attention to age, gender, BMI, area of injury, and smoking history. Patients presented with complaints of dyspnea or pain related to rib fractures with or without intercostal neuralgia. Each of these patients was noted to have rib fractures with lung herniation either on imaging, outside hospital records, or physical exam. A thorough medical history was obtained with attempts to find common predisposing factors as well as data regarding any previous surgical intervention for their herniation.

RESULTS

Nine of the 12 patients reviewed had recent or prior surgical intervention. Every patient seen in the clinic with a spontaneous fracture and herniation incidentally had a BMI >30 and was therefore classified as obese. Additionally, every patient who had a recurrence after their first surgical attempt at repair had a BMI greater than or equal to 35. All 12 patients seen at our institution were males. The failure rate of operative intervention was 66%.

CONCLUSIONS

Obesity was a prevalent comorbidity in the patient population we reviewed. Given the role obesity plays in abdominal and hiatal hernia repair success rates, it should be considered that obesity is a significant contributor to chest wall herniation if rib fractures occur. With 66% chest wall repair failure, patient selection is critical in the success of surgical intervention. Perhaps additional patient optimization, especially weight loss, should be considered prior to surgery.

One-leg rise performance and associated knee kinematics in ACL-deficient and ACL-reconstructed persons 23 years post-injury

BACKGROUND

Research indicates reduced knee function and stability decades after anterior cruciate ligament (ACL) injury. Assessment requires reliable functional tests that discriminate such outcomes from asymptomatic knees, while providing suitable loading for different populations. The One-leg rise (OLR) test is common in clinics and research but lacks scientific evidence for its implementation. Our cross-sectional study compared performance including knee kinematics of the OLR between ACL-injured persons in the very long term to controls and between legs within these groups, and assessed the within-session reliability of the kinematics.

METHODS

Seventy ACL-injured individuals (mean age 46.9 ± 5.4 years) treated with either reconstructive surgery and physiotherapy (ACL_R; n = 33) or physiotherapy alone (ACL_PT; n = 37), on average 23 years post-injury, and 33 age- and sex-matched controls (CTRL) attempted the OLR. Participants completed as many repetitions as possible to a maximum of 50 while recorded by motion capture. We compared between all groups and between legs within groups for total repetitions and decomposed the OLR into movement phases to compare phase completion times, maximum and range of knee abduction and adduction angles, and mediolateral knee control in up to 10 repetitions per participant.

RESULTS

ACL_PT performed significantly fewer OLR repetitions with their injured leg compared to the CTRL non-dominant leg (medians 15 and 32, respectively) and showed significantly greater knee abduction than ACL_R and CTRL (average 2.56°-3.69° depending on phase and leg). Distribution of repetitions differed between groups, revealing 59% of ACL_PT unable to complete more than 20 repetitions on their injured leg compared to 33% ACL_R and 36% CTRL for their injured and non-dominant leg, respectively. Within-session reliability of all kinematic variables for all groups and legs was high (ICC 3,10 0.97-1.00, 95% CI 0.95-1.00, SEM 0.93-1.95°).

CONCLUSIONS

Negative outcomes of OLR performance, particularly among ACL_PT, confirm the need to address aberrant knee function and stability even decades post-ACL injury. Knee kinematics derived from the OLR were reliable for asymptomatic and ACL-injured knees. Development of the OLR protocol and analysis methods may improve its discriminative ability in identifying reduced knee function and stability among a range of clinical populations.

Psychometric properties of knee proprioception tests targeting healthy individuals and those with anterior cruciate ligament injury managed with or without reconstruction: a systematic review protocol

INTRODUCTION

An anterior cruciate ligament (ACL) injury affects knee proprioception and sensorimotor control and might contribute to an increased risk of a second ACL injury and secondary knee osteoarthritis. Therefore, there is a growing need for valid, reliable and responsive knee proprioception tests. No previous study has comprehensively reviewed all the relevant psychometric properties (PMPs) of these tests together. The aim of this review protocol is to narrate the steps involved in synthesising the evidence for the PMPs of specific knee proprioception tests among individuals with an ACL injury and knee-healthy controls.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses will be followed to report the review. A combination of four conceptual groups of terms-(1) construct (knee proprioception), (2) target population (healthy individuals and those with an ACL injury managed conservatively or with a surgical reconstruction), (3) measurement instrument (specific knee proprioception tests) and (4) PMPs (reliability, validity and responsiveness)-will be used for electronic databases search. PubMed, AMED, CINAHL, SPORTDiscus, Web of Science, Scopus, the Cochrane Central Register of Controlled Trials and ProQuest will be searched from their inception to November 2018. Two reviewers will independently screen titles, abstracts and full text articles, extract data and perform risk of bias assessment using the updated COnsensus-based Standards for the selection of health Measurement INstruments risk of bias checklist for the eligible studies. A narrative synthesis of the findings and a meta-analysis will be attempted as appropriate. Each PMP of knee proprioception tests will be classified as 'sufficient', 'indeterminate' or 'insufficient'. The overall level of evidence will be ascertained using an established set of criteria.

ETHICS AND DISSEMINATION

Ethical approval or patient consent is not required for a systematic review. The review findings will be submitted as a series of manuscripts for peer-review and publication in scientific journals.

PROSPERO REGISTRATION NUMBER

CRD42018108014.

GALPROP cosmic-ray propagation code: recent results and updates

Information on cosmic-ray (CR) composition comes from direct CR measurements while their distribution in the Galaxy is evaluated from observations of their associated diffuse emission in the range from radio to gamma rays. Even though the main interaction processes are identified, more and more precise observations provide an opportunity to study more subtle effects and pose a challenge to the propagation models. GALPROP is a sophisticated CR propagation code that is being developed for about 20 years. It provides a unified framework for interpretations of data from many different types of experiments. It is used for a description of direct CR measurements and associated interstellar emissions (radio to gamma rays), thereby providing important information about CR injection and propagation in the interstellar medium. By accounting for all relevant observables at a time, the GALPROP code brings together theoretical predictions, interpretation of the most recent observations, and helps to reveal the signatures of new phenomena. In this paper we review latest applications of GALPROP and address ongoing and near future improvements. We are discussing effects of different propagation models, and of the transition from cylindrically symmetrical models to a proper 3D description of the components of the interstellar medium and the source distribution.

Curve analyses reveal altered knee, hip, and trunk kinematics during drop-jumps long after anterior cruciate ligament rupture

BACKGROUND

Anterior cruciate ligament (ACL) ruptures may lead to knee dysfunctions later in life. Single-leg tasks are often evaluated, but bilateral movements may also be compromised. Our aim was to use curve analyses to examine double-leg drop-jump kinematics in ACL-reconstructed, ACL-deficient, and healthy-knee cohorts.

METHODS

Subjects with unilateral ACL ruptures treated more than two decades ago (17-28years) conservatively with physiotherapy (ACL_PT, n=26) or in combination with reconstructive surgery (ACL_R, n=28) and healthy-knee controls (n=25) performed 40-cm drop-jumps. Three-dimensional knee, hip, and trunk kinematics were analyzed during Rebound, Flight, and Landing phases. Curves were time-normalized and compared between groups (injured and non-injured legs of ACL_PT and ACL_R vs. non-dominant and dominant legs of controls) and within groups (between legs) using functional analysis of variance methods.

RESULTS

Compared to controls, ACL groups exhibited less knee and hip flexion on both legs during Rebound and greater knee external rotation on their injured leg at the start of Rebound and Landing. ACL_R also showed less trunk flexion during Rebound. Between-leg differences were observed in ACL_R only, with the injured leg more internally rotated at the hip. Overall, kinematic curves were similar between ACL_R and ACL_PT. However, compared to controls, deviations spanned a greater proportion of the drop-jump movement at the hip in ACL_R and at the knee in ACL_PT.

CONCLUSIONS

Trunk and bilateral leg kinematics during double-leg drop-jumps are still compromised long after ACL-rupture care, independent of treatment. Curve analyses indicate the presence of distinct compensatory mechanisms in ACL_PT and ACL_R compared to controls.

Metronidazole Toxicity in Cockayne Syndrome: A Case Series

Cockayne syndrome (CS) is a rare genetic disorder characterized by small stature, intellectual disability, and accelerated pathologic aging. Through the Cockayne Syndrome Natural History Study, we have identified 8 cases of acute hepatic failure after metronidazole administration (8% of our cohort), 3 of which were fatal. The interval between initial administration and death was 6 to 11 days. Two of these patients also experienced acute neurologic deficit. Both hepatotoxicity and acute neurologic deficit have been reported previously as extremely rare adverse events after metronidazole administration. However, we have not identified any patients with CS who have received metronidazole without serious adverse effects. We recommend that a diagnosis of CS be considered an absolute contraindication to the use of metronidazole.

VERTEPORFIN THERAPY OF SUBFOVEAL CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION

PURPOSE

We sought to evaluate the detailed safety profile of photodynamic therapy with verteporfin in patients with subfoveal choroidal neovascularization (CNV) caused by age-related macular degeneration (ARMD) from the combined analysis of three multicenter, double-masked, placebo-controlled, randomized 24-month clinical trials of similar design (TAP Investigation Studies A and B and the VIP ARMD Trial), and to clarify the adverse reaction information in the current verteporfin product prescription information approved in the United States.

METHODS

Nine hundred forty-eight patients were randomly assigned to verteporfin or placebo. Treatment was administered as described in previous reports. All general entry criteria were similar, so systemic safety results were combined for this analysis. Entry criteria for CNV lesion composition and visual acuity in the two TAP Investigation trials was different from those used in the VIP ARMD trial, so ocular safety results for the treated eye were not combined.

RESULTS

The percentage of patients who experienced at least one ocular or nonocular adverse event, regardless of relationship to therapy, was similar between the verteporfin and placebo groups (92.3 and 89.1%, respectively, P = 0.114). The overall incidence of study eye adverse events was not significantly different between verteporfin and placebo. The only clinically relevant ocular adverse events reported with higher incidence after verteporfin compared with placebo were visual disturbances (22.1 versus 15.5% in TAP [P = 0.054] and 41.7 and 22.8% in VIP [P < 0.001]). Acute severe visual acuity decrease (defined as a visual acuity letter score decrease of at least 20, equivalent to at least four-line decrease, within 7 days of therapy) occurred in 3 patients treated with verteporfin in the TAP Investigation (0.7%) and 11 in the VIP ARMD trial (4.9%). Systemic adverse events with increased incidence after verteporfin compared with placebo, most of which were transient and mild or moderate, were injection site reactions (13.1 versus 5.6%; P < 0.001), photosensitivity reactions (2.4 versus 0.3%; P = 0.016), and infusion-related back pain (2.4 versus 0%; P = 0.004). No clinically relevant difference was observed between the verteporfin and placebo groups in any other adverse event.

CONCLUSION

In 948 ARMD patients, verteporfin therapy had an overall safety profile similar to that for placebo, with a few exceptions. Visual disturbances, including acute severe visual acuity decrease, did not affect the net vision outcome benefits associated with treatment that has been reported previously. This detailed safety profile of verteporfin therapy clarifies the adverse reaction information in the current verteporfin product prescription information.

Verteporfin therapy for subfoveal choroidal neovascularization in age-related macular degeneration: three-year results of an open-label extension of 2 randomized clinical trials--TAP Report no. 5

OBJECTIVE

To report vision and safety outcomes from an extension of a 2-year investigation evaluating verteporfin photodynamic therapy in patients with age-related macular degeneration with subfoveal choroidal neovascularization (CNV).

DESIGN AND SETTING

Open-label extension of selected patients from 2 multicenter, double-masked, placebo-controlled, randomized clinical trials, the Treatment of Age-Related Macular Degeneration With Photodynamic Therapy (TAP) Investigation, at 22 ophthalmology practices in Europe and North America.

PARTICIPANTS

Patients enrolled in the TAP Investigation and followed up for at least 24 months in whom verteporfin therapy to CNV might reduce the risk of further vision loss.

METHODS

Before receiving verteporfin therapy in the extension, eligible patients signed a written informed consent form accompanied by an oral consent process approved by local institutional review boards. Methods were similar to those described for 1- and 2-year results, with follow-up examinations beyond 2 years continuing at 3-month intervals with a few exceptions, including that extension patients with fluorescein leakage from CNV were to receive open-label verteporfin therapy irrespective of their original treatment assignment.

RESULTS

Of 402 patients in the verteporfin group, 351 (87.3%) completed the month 24 examination; 320 (91.2%) of these enrolled in the extension study. The enrolled participants included 124 (78.0%) of the 159 verteporfin-treated patients with lesions composed of predominantly classic CNV at baseline, of whom 105 (84.7%) completed the month 36 examination. Verteporfin-treated patients with this lesion composition at baseline who participated in the extension study, with or without a month 36 examination, appeared more likely to have a younger age, better level of visual acuity, absence of fluorescein leakage from classic CNV, or no progression of classic CNV beyond the baseline boundaries of the lesion at the month 24 examination compared with those who did not enroll in the extension. For the 105 patients with a predominantly classic baseline lesion composition who completed the month 36 examination, an average of 1.3 treatments were given from the month 24 examination up to, but not including, the month 36 examination. A letter score loss in the study eye of at least 15 from baseline for these patients occurred in 39 (37.5%) at the month 24 examination compared with 44 (41.9%) of these patients at the month 36 examination. Visual acuity changed little from the month 24 examination (mean, -1.9 lines) to the month 36 examination (mean, -2.0 lines) for these eyes. Verteporfin-treated patients had little change in the mean visual acuity lost and few or no additional instances of infusion-related back pain or photosensitivity reactions from month 24 to month 36. Two patients originally assigned to placebo had acute severe vision decrease within 7 days after verteporfin treatment during the extension. One patient originally assigned to verteporfin had acute severe vision decrease after verteporfin treatment of the fellow eye during the extension.

CONCLUSIONS

Vision outcomes for verteporfin-treated patients with predominantly classic lesions at baseline remained relatively stable from month 24 to month 36, although only approximately one third of the verteporfin-treated patients originally enrolled with this lesion composition had a month 36 examination. From these results, the TAP Study Group identified no safety concerns to preclude repeating photodynamic therapy with verteporfin. Additional treatment was judged likely to reduce the risk of further vision loss. Caution appears warranted in the absence of comparison with an untreated group during the extension and since not all patients in the TAP Investigation participated in the TAP Extension.

Clinical pharmacokinetics of verteporfin

Verteporfin, a benzoporphyrin derivative, is the first photo-sensitive (light-activated) drug to be proven effective in treating certain types of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). The pharmacokinetics of light-activated drugs are central to their safety and efficacy. Forty healthy Caucasian volunteers, 24 healthy Japanese volunteers, 9 patients with mild hepatic dysfunction, 69 patients with CNV due to AMD, and 21 patients with skin cancer were infused with verteporfin 3 to 20 mg/m2 of body surface area over 1.5 to 45 minutes. Verteporfin regioisomers and the metabolite benzoporphyrin derivative diacid (BPD-DA) were quantified by validated methods of liquid chromatography and capillary electrophoresis with laser-induced fluorescence. Cmax of verteporfin occurred at the end of the infusion and was proportional to the dose and rate of infusion. The extent of formation of the metabolite BPD-DA was less than 10%, based on the AUC ratio. Renal elimination was minimal (< 0.01% of the dose). All groups studied had similar pharmacokinetics, which were biexponential with distribution in the first 1 to 3 hours and elimination t(1/2) of 5 to 6 hours. No significant differences were observed between Japanese and Caucasian volunteers or between men and women. Patients older than 65 years had a slightly higher average Cmax than patients younger than 65 years (1.14 vs. 1.03 microg/ml, p = 0.066), but the ranges of the two age groups overlapped. Verteporfin has a short half-life and is rapidly eliminated in the bile, mainly as unchanged drug. Based on pharmacokinetic data, dose adjustments are not required for age, gender, race, or mild hepatic or renal impairment. The rapid elimination of verteporfin shows that the period of skin photosensitivity is unlikely to persist after 24 to 48 hours.

Machine perfusion for kidneys: how to do it at minimal cost

Due to a shortage of organs for transplantation, many centres use marginal grafts to increase their donor pool. As kidneys from non-heart-beating donors (NHBD) have sustained initial ischaemic damage, their viability is difficult to predict. Hypothermic pulsatile perfusion has not only been used to improve the condition of such grafts, but also allows viability assessment. Suitable systems are becoming more readily available, but they are expensive. We have used existing dialysis equipment with modified sterilised inserts to create a pulsatile hypothermic perfusion system. With this system, 41 NHBD kidneys were perfused for up to 8 h; their intravascular renal resistance (IRVR), flow characteristics as well as glutathione S transferase (GST) measurements were performed to assess viability. This hypothermic pulsatile perfusion system is now an integral component of our NHBD programme.

Machine perfusion for kidneys: how to do it at minimal cost

Due to a shortage of organs for transplantation, many centres use marginal grafts to increase their donor pool. As kidneys from non-heart-beating donors (NHBD) have sustained initial ischaemic damage, their viability is difficult to predict. Hypothermic pulsatile perfusion has not only been used to improve the condition of such grafts, but also allows viability assessment. Suitable systems are becoming more readily available, but they are expensive. We have used existing dialysis equipment with modified sterilised inserts to create a pulsatile hypothermic perfusion system. With this system, 41 NHBD kidneys were perfused for up to 8 h; their intravascular renal resistance (IRVR), flow characteristics as well as glutathione S transferase (GST) measurements were performed to assess viability. This hypothermic pulsatile perfusion system is now an integral component of our NHBD programme.