Effects of underwater treadmill training on leg strength,balance, and walking performance in adults with incomplete spinal cord injury

Objective

To document the effects of underwater treadmill training (UTT) on leg strength, balance, and walking performance in adults with incomplete spinal cord injury (iSCI).

Design

Pre-test and post-test design.

Setting

Exercise physiology laboratory.

Participants

Adult volunteers with iSCI (n = 11).

Intervention

Participants completed 8 weeks (3 × /week) of UTT. Each training session consisted of three walks performed at a personalized speed, with adequate rest between walks. Body weight support remained constant for each participant and ranged from 29 to 47% of land body weight. Increases in walking speed and duration were staggered and imposed in a gradual and systematic fashion.

Outcome measures

Lower-extremity strength (LS), balance (BL), preferred and rapid walking speeds (PWS and RWS), 6-minute walk distance (6MWD), and daily step activity (DSA).

Results

Significant (P < 0.05) increases were observed in LS (13.1 ± 3.1 to 20.6 ± 5.1 N·kg⁻¹), BL (23 ± 11 to 32 ± 13), PWS (0.41 ± 0.27 to 0.55 ± 0.28 m·s⁻¹), RWS (0.44 ± 0.31 to 0.71 ± 0.40 m·s⁻¹), 6MWD (97 ± 80 to 177 ± 122 m), and DSA (593 ± 782 to 1310 ± 1258 steps) following UTT.

Conclusion

Physical function and walking ability were improved in adults with iSCI following a structured program of UTT featuring individualized levels of body weight support and carefully staged increases in speed and duration. From a clinical perspective, these findings highlight the potential of UTT in persons with physical disabilities and diseases that would benefit from weight-supported exercise.     

Volume and Contact Surface Area Analysis of Bony Tunnels in Single and Double Bundle Anterior Cruciate Ligament Reconstruction Using Autograft Tendons: In Vivo Three-Dimensional Imaging Analysis

Background

Regarding reconstruction surgery of the anterior cruciate ligament (ACL), there is still a debate whether to perform a single bundle (SB) or double bundle (DB) reconstruction. The purpose of this study was to analyze and compare the volume and surface area of femoral and tibial tunnels during transtibial SB versus transportal DB ACL reconstruction.

Methods

A consecutive series of 26 patients who underwent trantibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft from January 2010 to October 2010 were included in this study. Three-dimensional computed tomography (3D-CT) was taken within one week after operation. The CT bone images were segmented with use of Mimics software v14.0. The obtained digital images were then imported in the commercial package Geomagic Studio v10.0 and SketchUp Pro v8.0 for processing. The femoral and tibial tunnel lengths, diameters, volumes and surface areas were evaluated. A comparison between the two groups was performed using the independent-samples t-test. A p-value less than the significance value of 5% (p < 0.05) was considered statistically significant.

Results

Regarding femur tunnels, a significant difference was not found between the tunnel volume for SB technique (1,496.51 ± 396.72 mm³) and the total tunnel volume for DB technique (1,593.81 ± 469.42 mm³; p = 0.366). However, the total surface area for femoral tunnels was larger in DB technique (919.65 ± 201.79 mm²) compared to SB technique (810.02 ± 117.98 mm²; p = 0.004). For tibia tunnels, there was a significant difference between tunnel volume for the SB technique (2,070.43 ± 565.07 mm³) and the total tunnel volume for the DB technique (2,681.93 ± 668.09 mm³; p ≤ 0.001). The tibial tunnel surface area for the SB technique (958.84 ± 147.50 mm²) was smaller than the total tunnel surface area for the DB technique (1,493.31 ± 220.79 mm²; p ≤ 0.001).

Conclusions

Although the total femoral tunnel volume was similar between two techniques, the total surface area was larger in the DB technique. For the tibia, both total tunnel volume and the surface area were larger in DB technique.     

Underestimation of Bone Loss of the Spine With Posterior-Anterior Dual-Energy X-Ray Absorptiometry in Patients With Spinal Cord Injury

Background:

Bone mineral density (BMD) of the lumbar spine (L-spine) has been reported to be normal by routine posterior-anterior (PA) bone density imaging in patients with chronic spinal cord injury (SCI).

Objective:

To determine BMD of the L-spine by PA and lateral (LAT) dual-energy radiographic absorptiometry (DXA) in patients with chronic SCI.

Design:

Prospective study.

Setting:

Veterans Affairs Medical Center and a private rehabilitation facility.

Methods:

Measurements of the PA and LAT L-spine and hip were performed in 15 patients with SCI: 9 with tetraplegia and 6 with paraplegia. The DXA (GE Lunar Advance DXA) images were obtained using standard software. Results are reported as mean ± SD.

Results:

The mean age was 35 ± 15 years (range  =  20–62 years), and the duration of injury was 57 ± 74 months (range  =  3–240 months). T- and Z-scores were lower for the LAT L-spine than those for PA L-spine (T-scores L2: −0.7 ± 1.2 vs 0.0 ± 1.4, P < 0.01; L3: −0.9 ± 1.6 vs 0.3 ± 1.3, P < 0.002; L2-L3: −0.8 ± 1.3 vs 0.2 ± 1.3, P < 0.001; Z-scores L2: −0.3 ± 1.1 vs 0.2 ± 1.2, P < 0.05; L3: −0.6 ± 1.3 vs 0.5 ± 1.3, P < 0.01; L2-L3: −0.4 ± 1.1 vs 0.4 ± 1.2, P < 0.005). The T- and Z-scores for the total hip (−1.1 ± 1.0 and −1.0 ± 1.0, respectively) and L2-L3 LAT L-spine demonstrated remarkable similarity, whereas the L2-L3 PA L-spine scores were not reduced. Bone mineral density of the LAT L-spine, but not the PA L-spine, was significantly reduced with increasing duration of injury.

Conclusions:

Individuals with SCI may have bone loss of the L-spine that is evident on LAT DXA that may be misdiagnosed by PA DXA, underestimating the potential risk of fracture.     

Assessment of passive knee stiffness and viscosity in individuals with spinal cord injury using pendulum test

Objective

Stiffness and viscosity represent passive resistances to joint motion related with the structural properties of the joint tissue and of the musculotendinous complex. Both parameters can be affected in patients with spinal cord injury (SCI). The purpose of this study was to measure passive knee stiffness and viscosity in patients with SCI with paraplegia and healthy subjects using Wartenberg pendulum test.

Design

Non-experimental, cross-sectional, case–control design.

Setting

An outpatient physical therapy clinic, University of social welfare and Rehabilitation Science, Iran.

Patients

A sample of convenience sample of 30 subjects participated in the study. Subjects were categorized into two groups: individuals with paraplegic SCI (n = 15, age: 34.60 ± 9.18 years) and 15 able-bodied individuals as control group (n = 15, age: 30.66 ± 11.13 years).

Interventions

Not applicable.

Main measures

Passive pendulum test of Wartenberg was used to measure passive viscous-elastic parameters of the knee (stiffness, viscosity) in all subjects.

Results

Statistical analysis (independent t-test) revealed significant difference in the joint stiffness between healthy subjects and those with paraplegic SCI (P = 0.01). However, no significant difference was found in the viscosity between two groups (P = 0.17). Except for first peak flexion angle, all other displacement kinematic parameters exhibited no statistically significant difference between normal subjects and subjects with SCI.

Conclusions

Patients with SCI have significantly greater joint stiffness compared to able-bodied subjects.     

Discrepancy between training,competition and laboratory measures of maximum heart rate in NCAA division 2 distance runners

A percentage of either measured or predicted maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate in athletes may be greater during competition or training than during laboratory exercise testing. Thus, the aim of the present investigation was to determine if endurance-trained runners train and compete at or above laboratory measures of ''maximum'' heart rate. Maximum heart rates were measured utilising a treadmill graded exercise test (GXT) in a laboratory setting using 10 female and 10 male National Collegiate Athletic Association (NCAA) division 2 cross-country and distance event track athletes. Maximum training and competition heart rates were measured during a high-intensity interval training day (TR HR) and during competition (COMP HR) at an NCAA meet. TR HR (207 ± 5.0 b·min^-1; means ± SEM) and COMP HR (206 ± 4 b·min^-1) were significantly (p < 0.05) higher than maximum heart rates obtained during the GXT (194 ± 2 b·min^-1). The heart rate at the ventilatory threshold measured in the laboratory occurred at 83.3 ± 2.5% of the heart rate at VO₂ max with no differences between the men and women. However, the heart rate at the ventilatory threshold measured in the laboratory was only 77% of the maximal COMP HR or TR HR. In order to optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate obtained either during training or during competition.

Key points

• A percentage of maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate may be greater during competition or training than during laboratory exercise testing.
• Heart rates during training and competition were significantly higher than maximum heart rates obtained during laboratory exercise testing.
• To optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate measure obtained either during training or during competition.

Key words: Competition, heart rate, laboratory, performance, running, training     

Oxygen Cost During Treadmill Walking with Hip and Knee Immobilised

The aim of this study was to determine the effect of immobilising the knee and hip on the oxygen cost (ml·kg^-1·min^-1) to velocity relationship during treadmill walking. The study was a prospective experimental conducted in a Rehabilitation centre. Ten healthy individuals, five men and five women, with no gait abnormality participated. Following familiarisation five men and five women walked on a treadmill and selected their own, free “comfortable walking velocity ”(SSWS). Subjects then performed an incremental test at -60 to +60% of SSWS. Individuals later repeated the test with the knee and hip of one limb immobilised. Samples of expired air were measured at each velocity and the oxygen cost (ml·kg^-1·min^-1) to Froude number (Fr) relationship plotted (where calculation of Fr normalizes for subjects of differing leg length and acts as an index of velocity). There was a higher oxygen cost, and lower Fr at SSWS during immobilised (0.21 ± 0.03 ml·kg^-1·min^-1; Fr = 0.12 ± 0. 03) compared with free walking (0.16 ± 0.02 ml·kg^-1·min^-1; Fr = 0.18 ± 0.04) (p < 0. 01). Statistical analysis demonstrated that during immobilised walking an inverse fit (y = β₀ + β₁/x) and for free walking a cubic fit (y = β₀ + β₁x + β₂x² + β₃x³) best fitted the data. Hip and knee immobilisation increased the oxygen cost at SSWS and altered the oxygen cost to Fr relationship. The results have implications in selecting optimal walking velocities in individuals with impairments affecting mobility such as hemiplegic gait.

Key Points

• Walking with one limb immobilised requires greater energy cost than normal free walking.
• This has clinical implications when developing rehabilitation strategies for patients who mobility problems such as those with hemi paretic gait.

Key words: Froude number, oxygen cost, immobilisation, hip, knee, walking, hemiplegic gait     

Pressure support-ventilation versus spontaneous breathing with "T-Tube" for interrupting the ventilation after cardiac operations

Objective

To compare pressure-support ventilation with spontaneous breathing through a T-tube for interrupting invasive mechanical ventilation in patients undergoing cardiac surgery with cardiopulmonary bypass.

Methods

Adults of both genders were randomly allocated to 30 minutes of either pressure-support ventilation or spontaneous ventilation with "T-tube" before extubation. Manovacuometry, ventilometry and clinical evaluation were performed before the operation, immediately before and after extubation, 1h and 12h after extubation.

Results

Twenty-eight patients were studied. There were no deaths or pulmonary complications. The mean aortic clamping time in the pressure support ventilation group was 62 ± 35 minutes and 68 ± 36 minutes in the T-tube group (P=0.651). The mean cardiopulmonary bypass duration in the pressure-support ventilation group was 89 ± 44 minutes and 82 ± 42 minutes in the T-tube group (P=0.75). The mean Tobin index in the pressure support ventilation group was 51 ± 25 and 64.5 ± 23 in the T-tube group (P=0.153). The duration of intensive care unit stay for the pressure support ventilation group was 2.1 ± 0.36 days and 2.3 ± 0.61 days in the T-tube group (P=0.581). The atelectasis score in the T-tube group was 0.6 ± 0.8 and 0.5 ± 0.6 (P=0.979) in the pressure support ventilation group. The study groups did not differ significantly in manovacuometric and ventilometric parameters and hospital evolution.

Conclusion

The two trial methods evaluated for interruption of mechanical ventilation did not affect the postoperative course of patients who underwent cardiac operations with cardiopulmonary bypass.     

Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Using a Gracilis Autograft without Bone Tunnel

Background

Several tendon graft and fixation methods have been introduced in medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation. The purpose of this study was to evaluate the results of MPFL reconstruction using a gracilis autograft fixation without bone tunnel in patients with recurrent patellar instability.

Methods

Nine patients (four males and five females) diagnosed with recurrent patellar instability from July 2009 to January 2013 and had MPFL reconstruction using a gracilis autograft were included. The average age of the patients was 24.6 years (range, 13 to 48 years), and the average follow-up period was 19.3 months (range, 12 to 30 months). For every patient, femoral attachment was fixed using suture anchors securing the patella by suturing the periosteum and surrounding soft tissue. Clinical evaluation included the Kujala, Lysholm, and Tegner scores; in addition, patients were examined for any complication including recurrent dislocation. The congruence angle and patella alta were assessed radiologically before and after surgery.

Results

The Kujala score improved from an average of 42.7 ± 8.4 before surgery to 79.6 ± 13.6 (p = 0.008) at final follow-up; the Lysholm score improved from 45.8 ± 5.7 to 82.0 ± 10.5 (p = 0.008); and the Tegner score improved from 2.8 ± 0.8 to 5.6 ± 1.5 (p = 0.007). The Insall-Salvati ratio changed from 1.16 ± 0.1 (range, 0.94 to 1.35) before surgery to 1.14 ± 0.1 (range, 0.96 to 1.29; p = 0.233) at the final follow-up without significance. The congruence angle significantly improved from 26.5° ± 10.6° (range, 12° to 43°) before surgery to -4.0° ± 4.3° (range, -12° to 5°; p = 0.008) at final follow-up. Subluxation was observed in one patient and hemarthrosis occurred in another patient 2 years after surgery, but these patients were asymptomatic.

Conclusions

We achieved good results with a patellar fixation technique in MPFL reconstruction using a gracilis autograft employing soft tissue suturing in patients with recurrent patellar dislocation.     

How Do Different Anterior Tibial Tendon Transfer Techniques Influence Forefoot and Hindfoot Motion?

Background

Idiopathic clubfoot correction is commonly performed using the Ponseti method and is widely reported to provide reliable results. However, a relapsed deformity may occur and often is treated in children older than 2.5 years with repeat casting, followed by an anterior tibial tendon transfer. Several techniques have been described, including a whole tendon transfer using a two-incision technique or a three-incision technique, and a split transfer, but little is known regarding the biomechanical effects of these transfers on forefoot and hindfoot motion.

Questions/purpose

We used a cadaveric foot model to test the effects of three tibialis anterior tendon transfer techniques on forefoot positioning and production of hindfoot valgus.

Methods

Ten fresh-frozen cadaveric lower legs were used. We applied 150 N tension to the anterior tibial tendon, causing the ankle to dorsiflex. Three-dimensional motions of the first metatarsal, calcaneus, and talus relative to the tibia were measured in intact specimens, and then repeated after each of the three surgical techniques.

Results

Under maximum dorsiflexion, the intact specimens showed 6° (95% CI, 2.2°–9.4°) forefoot supination and less than 3° (95% CI, 0.4°–5.3°) hindfoot valgus motion. All three transfers provided increased forefoot pronation and hindfoot valgus motion compared with intact specimens: the three-incision whole transfer provided 38° (95% CI, 33°–43°; p < 0.01) forefoot pronation and 10° (95% CI, 8.5°–12°; p < 0.01) hindfoot valgus; the split transfer, 28° (95% CI, 24°–32°; p < 0.01) pronation, 9° (95% CI, 7.5°–11°; p < 0.01) valgus; and the two-incision transfer, 25° (95% CI, 20°–31°; p < 0.01) pronation, 6° (95% CI, 4.2°–7.8°; p < 0.01) valgus.

Conclusion

All three techniques may be useful and deliver varying degrees of increased forefoot pronation, with the three-incision whole transfer providing the most forefoot pronation. Changes in hindfoot motion were small.

Clinical Relevance

Our study results show that the amount of forefoot pronation varied for different transfer methods. Supple dynamic forefoot supination may be treated with a whole transfer using a two-incision technique to avoid overcorrection, while a three-incision technique or a split transfer may be useful for more resistant feet. Confirmation of these findings awaits further clinical trials.     

Effect of N-acetylcysteine in hearts of rats submitted to controlled hemorrhagic shock

Introduction

Pharmacological therapy is a strategy for the prevention of complications associated with ischemia and reperfusion injury that occurs after volume replacement in the treatment of hemorrhagic shock.

Objective

The aim of this study was to evaluate the effect of N-acetylcysteine associated with fluid resuscitation in cardiac injury in a rat hemorrhagic shock model.

Methods

Mice Wister male rats were randomly and subjected to controlled hemorrhagic shock for 60 min. and then, subjected to resuscitation with Ringer lactate. In a group of six animals, 150mg/kg of N-acetylcysteine were added to fluid volume replacement. The animals were observed for 120 min and after this period, were euthanized and cardiac tissue was collected for histopathological analysis and measurement of thiobarbituric acid reactive substances and pro-and anti-inflammatory interleukin.

Results

Cardiac tissue of the group treated with N-acetylcysteine showed lower concentrations of thiobarbituric acid reactive substances (0.20±0.05 vs. 0.27±0.05, P=0.014) and reduced histopathological damage and edema when compared to the group whose volume replacement occurred only with Ringer lactate. There was no difference in the expression of cytokines interleukin 6 (2,138.29±316.89 vs. 1,870.16±303.68, P=0.091) and interleukin 10 (1.019,83±262,50 vs. 848.60±106.5, P=0.169) between the treated groups.

Conclusion

The association of N-acetylcysteine on volume replacement attenuates oxidative stress in the heart, as well myocardial damage and edema, but does not modify the expression of inflammatory cytokines.     

Does Vitamin E-blended UHMWPE Prevent Biofilm Formation?

Background

Biofilm-related periprosthetic infections are catastrophic to patients and clinicians. Data suggest the addition of vitamin E to UHMWPE may have the ability to reduce biofilm formation on the surface of UHMWPE; however, previous studies were performed using stagnant broth solutions that may not have simulated a physiologic environment. In addition, the observed differences in levels of bacterial attachment, though statistically significant, may not be clinically significant.

Questions/purposes

We blended vitamin E with UHMWPE material and tested it for the ability to resist biofilm formation using a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA). Three additional materials were tested for comparison: highly crosslinked UHMWPE, compression-molded UHMWPE, and polyetheretherketone. We also determined whether the surface roughness of these materials facilitated biofilm formation.

Methods

Using a flow cell system, samples of each material type were placed into separate chambers. A 10% solution of brain-heart infusion broth containing 10⁵ colony-forming units (CFUs)/mL was flowed through the flow cell over 48 hours. The number of bacteria that adhered to the surface was quantified and biofilm formation was observed qualitatively using scanning electron microscopy. Optical profilometry was used to determine the surface roughness of each material type.

Results

Vitamin E-blended UHMWPE did not reduce biofilm formation of a clinically relevant strain of MRSA compared to materials that did not have vitamin E. More specifically, vitamin E-blended materials had similar amounts of biofilm formation (~ 8 log₁₀ CFUs/cm²) compared to materials not containing vitamin E (~ 8.1 log₁₀ CFUs/cm²) (p > 0.4). The roughness of vitamin E-blended material surfaces (mean ± SD: 1.85 ± 0.46 µm) compared to that of materials without vitamin E (2.06 ± 1.24 µm) did not appear to influence biofilm formation.

Conclusions

Under physiologically relevant conditions, vitamin E-blended UHMWPE did not have the ability to reduce the formation of biofilms by MRSA.

Clinical Relevance

These data indicate that the addition of vitamin E to UHMWPE may not reduce clinically relevant rates of biofilm-related periprosthetic infections of total joint arthroplasty devices.     

Bioburden Increases Heterotopic Ossification Formation in an Established Rat Model

Background

Heterotopic ossification (HO) develops in a majority of combat-related amputations wherein early bacterial colonization has been considered a potential early risk factor. Our group has recently developed a small animal model of trauma-induced HO that incorporates many of the multifaceted injury patterns of combat trauma in the absence of bacterial contamination and subsequent wound colonization.

Questions/purposes

We sought to determine if (1) the presence of bioburden (Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus [MRSA]) increases the magnitude of ectopic bone formation in traumatized muscle after amputation; and (2) what persistent effects bacterial contamination has on late microbial flora within the amputation site.

Methods

Using a blast-related HO model, we exposed 48 rats to blast overpressure, femur fracture, crush injury, and subsequent immediate transfemoral amputation through the zone of injury. Control injured rats (n = 8) were inoculated beneath the myodesis with phosphate-buffered saline not containing bacteria (vehicle) and treatment rats were inoculated with 1 × 10⁶ colony-forming units of A baumannii (n = 20) or MRSA (n = 20). All animals formed HO. Heterotopic ossification was determined by quantitative volumetric measurements of ectopic bone at 12-weeks postinjury using micro-CT and qualitative histomorphometry for assessment of new bone formation in the residual limb. Bone marrow and muscle tissue biopsies were collected from the residual limb at 12 weeks to quantitatively measure the bioburden load and to qualitatively determine the species-level identification of the bacterial flora.

Results

At 12 weeks, we observed a greater volume of HO in rats infected with MRSA (68.9 ± 8.6 mm³; 95% confidence interval [CI], 50.52–85.55) when compared with A baumannii (20.9 ± 3.7 mm³; 95% CI, 13.61–28.14; p < 0.001) or vehicle (16.3 ± 3.2 mm³; 95% CI, 10.06–22.47; p < 0.001). Soft tissue and marrow from the residual limb of rats inoculated with A baumannii tested negative for A baumannii infection but were positive for other strains of bacteria (1.33 × 10² ± 0.89 × 10²; 95% CI, −0.42 × 10²–3.08 × 10² and 1.25 × 10⁶ ± 0.69 × 10⁶; 95% CI, −0.13 × 10⁶–2.60 × 10⁶ colony-forming units in bone marrow and muscle tissue, respectively), whereas tissue from MRSA-infected rats contained MRSA only (4.84 × 10¹ ± 3.22 × 10¹; 95% CI, −1.47 × 10¹–11.1 × 10¹ and 2.80 × 10⁷ ± 1.73 × 10⁷; 95% CI, −0.60 × 10⁷–6.20 × 10⁷ in bone marrow and muscle tissue, respectively).

Conclusions

Our findings demonstrate that persistent infection with MRSA results in a greater volume of ectopic bone formation, which may be the result of chronic soft tissue inflammation, and that early wound colonization may be a key risk factor.

Clinical Relevance

Interventions that mitigate wound contamination and inflammation (such as early débridement, systemic and local antibiotics) may also have a beneficial effect with regard to the mitigation of HO formation and should be evaluated with that potential in mind in future preclinical studies.     

Randomized controlled trial of pharmacological replacement of melatonin for sleep disruption in individuals with tetraplegia

Objective

To determine the effectiveness of a melatonin agonist for treating sleep disturbances in individuals with tetraplegia.

Design

Placebo-controlled, double-blind, crossover, randomized control trial.

Setting

At home.

Participants

Eight individuals with tetraplegia, having an absence of endogenous melatonin production and the presence of a sleep disorder.

Interventions

Three weeks of 8 mg of ramelteon (melatonin agonist) and 3 weeks of placebo (crossover, randomized order) with 2 weeks of baseline prior to and 2 weeks of washout between active conditions.

Outcome

Change in objective and subjective sleep.

Measures

Wrist actigraphy, post-sleep questionnaire, Stanford sleepiness scale, SF-36.

Results

We observed no consistent changes in either subjective or objective measures of sleep, including subjective sleep latency (P = 0.55, Friedman test), number of awakenings (P = 0.17, Friedman test), subjective total sleep time (P = 0.45, Friedman test), subjective morning alertness (P = 0.35, Friedman test), objective wake after sleep onset (P = 0.70, Friedman test), or objective sleep efficiency (P = 0.78, Friedman test). There were significant increases in both objective total sleep time (P < 0.05, Friedman test), subjective time in bed (P < 0.05, Friedman test), and subjective sleep quality (P < 0.05, Friedman test), although these occurred in both arms. There were no significant changes in any of the nine SF-36 subscale scores (Friedman test, Ps >Bonferroni adjusted α of 0.005).

Conclusion

In this pilot study, we were unable to show effectiveness of pharmacological replacement of melatonin for the treatment of self-reported sleep problems in individuals with tetraplegia.

Trial Registration

ClinicalTrials.gov # {"type":"clinical-trial","attrs":{"text":"NCT00507546","term_id":"NCT00507546"}}NCT00507546.     

Goal-directed fluid therapy for microvascular free flap reconstruction following mastectomy: A pilot study

BACKGROUND:

Fluid management of the surgical patient has undergone a paradigm shift over the past decade. A change from ‘wet’ to ‘dry’ to a ‘goal-directed’ approach has been witnessed. The fluid management of patients undergoing free flap reconstruction is particularly challenging. This is typically a long operation with minimal surgical stimulation, and hypotension often ensues. The use of vasopressors in these cases is contraindicated to maintain adequate flow to the flap. Hypotension is often treated with intravenous fluid boluses. However, aggressive fluid administration to maintain adequate blood pressure can result in flap edema, venous engorgement and, ultimately, flap loss.

OBJECTIVE:

The primary objective of the present study was to determine whether goal-directed fluid therapy, titrated to maintain stroke volume variation ≤13%, with the use of an arterial pulse contour device results in improved postoperative cardiac index (CI) and stroke volume index (SVI) with reduced amounts of intravenous fluid. The primary end points studied were CI, SVI and cumulative crystalloid/colloid administration.

METHODS:

Twenty female patients undergoing simultaneous microvascular free flap reconstruction immediately following mastectomy were studied. Preoperative and intraoperative care were standardized. Each patient received intra-arterial blood pressure monitoring. In all patients, cardiac output measurement occurred throughout the intraoperative period using the arterial pulse contour device. Control patients had their fluid administered at the discretion of the anesthesiologist (blinded to results from the cardiac output device). Patients in the intervention group had a baseline crystalloid infusion of 5 mL/kg/h, with intravenous colloid boluses to maintain a stroke volume variation ≤13%.

RESULTS:

There was no difference in heart rate or mean arterial pressure between groups at the end of the operation. However, at the end of the operation, the intervention group had significantly higher mean (± SD) CI (3.8±0.8 L/min/m² versus 3.0±0.5 L/min/m²; P=0.02) and SVI (51.4±2.4 mL/m² versus 43.3±2.3 mL/m²; P=0.03). This improved CI and SVI was achieved with similar amounts of administered intraoperative fluid (5.8±0.5 mL/kg/h versus 5.0±0.7 mL/kg/h, control versus intervention). The intervention group required less postoperative fluid resuscitation during the early postoperative period (total fluid administered from end of operation to midnight of the operative day, 6.4±1.9 mL/kg/h versus 10.2±3.3 mL/kg/h, intervention versus control, respectively, P<0.01).

DISCUSSION:

Goal-directed fluid therapy using minimally invasive cardiac output monitoring resulted in improved end-operative hemodynamics, with less ‘rescue’ fluid administration during the perioperative period.     

The lifetime risk of pneumonia in patients with neuromuscular scoliosis at a mean age of 21?years: the role of spinal deformity surgery

Background

Patients with neuromuscular disorders often have an increased risk of pneumonia and decreased lung function, which may further be compromised by scoliosis. Scoliosis surgery may improve pulmonary function in otherwise healthy patients, but no study has evaluated its effect on the risk of pneumonia in patients with neuromuscular scoliosis (NMS).

Methods

The patient charts of 42 patients (mean age 14.6 years) who had undergone surgery for severe NMS (mean scoliosis 86°) were retrospectively reviewed from birth to a mean of 6.1 years (range 2.8–9.5) after scoliosis surgery. The main outcome was radiographically confirmed pneumonia as a primary cause for hospitalization. We excluded postoperative (3 months) pneumonia from the analyses.

Results

The lifetime annual incidence of pneumonia was 8.0/100 before and 13.4/100 after scoliosis surgery (p > 0.10). The mean number of hospital days per year due to pneumonia were 0.59 (SD 2.3) before scoliosis surgery and 2.24 (SD 6.9) after surgery (p > 0.10). Multivariate analysis demonstrated that lifetime risk factors for pneumonia were epilepsy (RR 15.2, 95 % CI 1.3–176.8, p = 0.027), non-cerebral palsy (CP) etiology (RR = 10.2, 95 % CI 3.2–32.7, p < 0.001) and major scoliosis (main curve >70°; RR = 11.3, 95 % CI 1.8–70.7, p = 0.01).

Conclusions

Epilepsy, non-CP etiology and major scoliosis are significant risk factors for pneumonia in patients with NMS. Scoliosis surgery does not decrease the incidence of pneumonia in patients with severe NMS.

Level of Evidence

Retrospective comparative study, Level III.

Electronic supplementary material

The online version of this article (doi:10.1007/s11832-015-0682-8) contains supplementary material, which is available to authorized users.     

Late outcome analysis of the Braile Biomédica? pericardial valve in the aortic position

Objective

Aortic valve replacement with Braile bovine pericardial prosthesis has been routinely done at the Heart Institute of the Universidade de São Paulo Medical School since 2006. The objective of this study is to analyze the results of Braile Biomédica^® aortic bioprosthesis in patients with aortic valve disease.

Methods

We retrospectively evaluated 196 patients with aortic valve disease submitted to aortic valve replacement with Braile Biomédica^® bovine pericardial prosthesis, between 2006 and 2010. Mean age was 59.41±16.34 years and 67.3% were male. Before surgery, 73.4% of patients were in NYHA functional class III or IV.

Results

Hospital mortality was 8.16% (16 patients). Linearized rates of mortality, endocarditis, reintervention, and structural dysfunction were 1.065%, 0.91%, 0.68% and 0.075% patients/year, respectively. Actuarial survival was 90.59±2.56% in 88 months. Freedom from reintervention, endocarditis and structural dysfunction was respectively 91.38±2.79%, 89.84±2.92% and 98.57±0.72% in 88 months.

Conclusion

The Braile Biomédica^® pericardial aortic valve prosthesis demonstrated actuarial survival and durability similar to that described in the literature, but further follow up is required to assess the incidence of prosthetic valve endocarditis and structural dysfunction in the future.     

Highly Crosslinked Polyethylene Improves Wear But Not Surface Damage in Retrieved Acetabular Liners

Background

Highly crosslinked polyethylene (XLPE) is believed to demonstrate better wear resistance than conventional polyethylene (CPE) in total hip arthroplasty.

Questions/purposes

The purpose of this study was to compare visual damage scores and micro-CT measurements of penetration, a surrogate for wear, between matched retrieved XLPE and CPE acetabular liners.

Methods

Thirteen XLPE acetabular liners were matched in terms of implant design (all were of the same design), patient age, sex, liner dimensions, duration of implantation, and reason for revision to a group of CPE liners that were retrieved in the same time period. Penetration resulting from the combination of wear and creep in the two groups of liners was measured with micro-CT. Surface damage was scored by two blinded observers using a surface damage system that considers the seven common damage modes: pitting, scratching, burnishing, abrasions, impingement, embedded debris, and delamination, and wear patterns were documented.

Results

There was no difference (p = 0.32) in total damage score between the XLPE group (14 ± 4) and the CPE group (15 ± 5). However, there was three times greater penetration (odds ratio, 3.1; confidence interval, 2.3–5.1; p < 0.001) in the CPE group (0.18 ± 0.09 mm/year) than in the XLPE group (0.05 ± 0.07 mm/year). There was less volumetric loss in XLPE (82 ± SD 134 mm³) versus the CPE group (350 ± SD 342 mm³; p = 0.017).

Conclusions

XLPE liners undergo less penetration as a result of creep and wear than CPE liners based on quantitative measurements provided by micro-CT, which was not apparent using damage scoring alone. This demonstrates the use of three-dimensional imaging techniques such as micro-CT for quantifying wear in retrieval studies.

Clinical Relevance

In this study, XLPE had less wear but similar damage scores than CPE, allaying concerns that the beneficial wear properties of XLPE might come with a tradeoff arising from the increased brittleness of that material.     

Patients Undergoing Total Shoulder Arthroplasty on the Dominant Extremity Attain Greater Postoperative ROM

Background

Total shoulder arthroplasty (TSA) provides excellent functional outcomes and pain relief in appropriately selected patients. Although it is known to affect other shoulder conditions, the role of hand dominance after TSA has not been reported, to our knowledge.

Questions/Purposes

We asked: (1) Does TSA of the dominant arm result in greater postoperative ROM compared with TSA of the nondominant arm? (2) Does hand dominance affect validated outcome scores after TSA?

Methods

We performed a review of all patients who underwent primary TSAs between 2008 and 2011 with a minimum of 12 months followup. During that time, one surgeon performed 156 primary TSAs. One hundred twenty-seven patients met the minimum followup requirement for this analysis (81%), whereas 29 (19%) were lost to followup. Seven patients were excluded for surgical indications other than glenohumeral osteoarthritis. A total of 58 patients underwent TSA of the dominant upper extremity and 62 underwent TSA of the nondominant upper extremity. Patient demographics, preoperative and postoperative ROM, and preoperative and postoperative outcome scores, were collected from the medical records. Student’s t-tests and chi-square tests were used for analysis. Demographics and preoperative ROM did not differ between patients undergoing TSA on the dominant or the nondominant upper extremity.

Results

Dominant-arm TSAs showed greater postoperative forward elevation and external rotation. Postoperative active forward elevation in the dominant group was 151° versus 141° in the nondominant group (mean difference, 10°; 95% CI, 1°–18°; p = 0.033). Postoperative active external rotation was 61° in the dominant group, versus 51° in the nondominant group (mean difference, 10°; 95% CI, 5°–15°; p < 0.001). Active internal rotation did not differ (dominant, 52°, nondominant, 50°; mean difference, 2°; 95% CI, −3° to 7°; p = 0.419). There were no differences in postoperative VAS (dominant, 0.9, nondominant, 1.4; mean difference, 0.5; 95% CI, −0.1 to 1.1; p = 0.129), simple shoulder test (dominant, 9.8, nondominant, 9.2; mean difference, 0.5; 95% CI, −0.5 to 1.5; p = 0.278), and American Shoulder and Elbow Surgeons scores (dominant, 84, nondominant, 80; mean difference, 4; 95% CI, −2 to 10; p = 0.211).

Conclusions

Patients who underwent TSA of their dominant upper extremity had greater postoperative active forward elevation and active external rotation compared with patients who had TSA of their nondominant upper extremity. This average difference of 10° active forward elevation and active external rotation could be useful for preoperative and postoperative counseling of patients. Regardless of hand dominance, similar functional outcomes were achieved.

Level of Evidence

Level III, therapeutic study.