Mesenchymal stem cells for chronic knee pain secondary to osteoarthritis: a systematic review and meta-analysis of randomized trials

OBJECTIVE

To assess the effectiveness of mesenchymal stem cells (MSCs) for chronic knee pain secondary to osteoarthritis (OA).

METHODS

We searched MEDLINE, EMBASE, CINAHL, and Cochrane Central to September 2023 for trials that: (1) enrolled patients with chronic pain associated with knee OA, and (2) randomized them to MSC therapy vs. placebo or usual care. We performed random-effects meta-analysis for all patient-important outcomes and used GRADE to assess the certainty of evidence.

RESULTS

We included 16 trials (807 participants). At 3-6 months, when restricted to low risk of bias studies, MSC therapy probably results in little to no difference in pain relief (weighted mean difference [WMD] -0.74cm on a 10cm visual analogue scale [VAS], 95%CI -1.16 to -0.33; minimally important difference [MID] 1.5cm) or physical functioning (WMD 2.23 points on 100-point SF-36 physical functioning subscale, 95%CI -0.97 to 5.43; MID 10-points; both moderate certainty). At 12-months, injection of MSCs probably results in little to no difference in pain (WMD -0.73 cm on a 10cm VAS, 95%CI -1.69 to 0.24; moderate certainty, restricted to low risk of bias studies) and may improve physical functioning (WMD 19.36 points on 100-point SF-36 PF subscale, 95%CI -0.19 to 38.9; low certainty). MSC therapy may increase risk of any adverse events (RR 2.67, 95%CI 1.19 to 5.99; low certainty) and pain and swelling of the knee joint (RR 1.58, 95%CI 1.04 to 2.38; low certainty).

CONCLUSIONS

When restricted to moderate certainty evidence, compared to placebo, intra-articular injection of MSCs for chronic knee pain associated with OA probably provides little to no improvement in pain or physical function.

The Effect of Knee Height Asymmetry on Gait Biomechanics

BACKGROUND

Though the primary goal for limb length discrepancy (LLD) management is to equalize the leg lengths, symmetry between corresponding long bones is usually not achieved, leading to knee height asymmetry (KHA). To date, there is minimal information on what effect KHA has on gait biomechanics and joint loading. Thus, the purpose of this study is to determine the impact of KHA on gait biomechanics.

METHODS

Seventeen subjects with KHA after limb equalizing surgery and 10 healthy controls were enrolled. Subjects participated in 3D gait analysis collected using self-selected speed. Lower extremity kinematics, kinetics, work generated/absorbed, and total work were calculated. Standing lower limb x-rays and scanograms were used to measure LLD and calculate the tibia-to-femur (TF) ratio for each limb. Two sample t tests were used to compare differences in standing LLD, TF ratio, and work between groups. Bivariate correlation using Pearson correlation coefficients was conducted between TF ratio and total mechanical work, as well as between knee height asymmetry indices and total work asymmetry (α=0.05).

RESULTS

Among participants, there were no differences between LLD; however, there were differences between TF ratio and knee height asymmetry. We found a nonsignificant relationship between TF ratio and total mechanical work for individual lower extremities. Therefore, the length of individual bones (TF ratio) relative to each other within the individual lower extremity was not associated with the amount of work produced. However, when a difference exists between sides (asymmetry, ie, TF ratio asymmetry), there were associated differences in work (work asymmetry) produced between sides (r=0.54, P=0.003). In other words, greater knee height asymmetry between limbs resulted in more asymmetrical mechanical work during walking.

CONCLUSIONS

These findings may have implications for the management of LLD. Asymmetrical total mechanical work could lead to atypical joint loading during gait. Surgeons may want to consider prioritizing achieving knee height symmetry as a postoperative goal when correcting limb length discrepancy.

LEVEL OF EVIDENCE

Level III, Case Control Study.

Derivation of a clinical decision rule for a bone marrow aspirate concentrate injection in knee osteoarthritis

Aim: To develop a simple clinical decision rule (CDR) to identify people with knee osteoarthritis who are likely or unlikely to benefit from bone marrow aspirate concentrate (BMAC) injection. Materials & methods: A total of 92 people with clinical and radiographic evidence of refractory knee osteoarthritis received a single intra-articular (IA) BMAC injection. Multiple logistic regression analysis was used to determine which combination of risk factors predicted BMAC responsiveness. A responder was defined as a person whose knee pain improved more than 15% from baseline 6 months post procedure. Results: The CDR demonstrated that those with lower pain levels, or high pain levels with previous surgery, could be predicted to benefit from a single IA BMAC injection. Conclusion: A simple CDR containing three variables predicted responsiveness to a single IA knee BMAC injection with high accuracy. Further validation of the CDR is required prior to routine use in clinical practice.

Outcomes of Total Knee and Hip Arthroplasty in Patients With Perioperative Thrombocytopenia

BACKGROUND

Thrombocytopenia is an abnormally low level of blood platelets (less than 150,000/mL) resulting in an increased risk for bleeding. Typically, patients with platelet levels below 50,000/mL should delay arthroplasty or be transfused with platelets before surgery. However, existing studies are mixed regarding the effects of more moderate thrombocytopenia in terms of total knee and hip arthroplasty outcomes.

METHODS

This level III retrospective chart review examined the effects of different severities of preoperative thrombocytopenia on length of hospitalization, readmission, and transfusion rates in 5,617 primary total knee and hip arthroplasties at one tertiary academic medical center. Preoperative platelet levels were sectioned into clinically relevant groups and compared with clinical outcomes using univariable and multivariable models.

RESULTS

On univariate analysis, having platelet levels of <100,000/mL and 100 to 149,000/mL was associated with a longer length of stay. However, after controlling individual demographics, there was no association between platelet levels and length of stay, nor with 30-day readmission. Finally, on univariate analysis, patients with platelet levels of <100,000/mL and 100 to 149,000/mL were more likely to have a blood transfusion, which remained true for those with <100,000/mL after controlling for individual demographics.

CONCLUSIONS

Total hip and total knee arthroplasty are safe in patients with varying platelet levels and not associated with increased length of stay or 30-day readmission. However, patients with more severe thrombocytopenia are more likely to receive red blood cell transfusions than patients with milder thrombocytopenia.

Radiofrequency Ablation of the Infrapatellar Branch of the Saphenous Nerve for the Treatment of Chronic Anterior Inferomedial Knee Pain

INTRO

Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment for chronic knee pain related to osteoarthritis. It is often utilized when conservative management has failed and patients wish to avoid arthroplasty, are poor surgical candidates due to comorbid medical conditions, or in those suffering from persistent pain after arthroplasty. The classic targets for GNRFA include the superior lateral genicular nerve, superior medial genicular nerve, and inferior medial genicular nerve but multiple anatomic studies have demonstrated additional sensory innervation to the knee.

OBJECTIVE

In this research article, we propose an image-guided technique that can safely target the infrapatellar branch of the saphenous nerve which also provides sensory innervation to the anterior capsule.

PROPOSAL

The proposed technique includes variations for conventional bipolar radiofrequency ablation, cooled radiofrequency ablation, dual-tined bipolar radiofrequency ablation, and monopolar radiofrequency ablation using a long axis approach. The described technique is based on updated anatomic studies and takes into account safety concerns such as thermal risk to the skin and/or pes anserine tendons and breaching of the synovial cavity.

CONCLUSION

Future clinical research should be performed to confirm the safety and effectiveness of this specific approach.

Artificial intelligence accurately identifies total hip arthroplasty implants: a tool for revision surgery

BACKGROUND

A critical part in preoperative planning for revision arthroplasty surgery involves the identification of the failed implant. Using a predictive artificial neural network (ANN) model, the objectives of this study were: (1) to develop a machine-learning algorithm using operative big data to identify an implant from a radiograph; and (2) to compare algorithms that optimise accuracy in a timely fashion.

METHODS

Using 2116 postoperative anteroposterior (AP) hip radiographs of total hip arthroplasties from 2002 to 2019, 10 artificial neural networks were modeled and trained to classify the radiograph according to the femoral stem implanted. Stem brand and model was confirmed with 1594 operative reports. Model performance was determined by classification accuracy toward a random 706 AP hip radiographs, and again on a consecutive series of 324 radiographs prospectively collected over 2019.

RESULTS

The Dense-Net 201 architecture outperformed all others with 100.00% accuracy in training data, 95.15% accuracy on validation data, and 91.16% accuracy in the unique prospective series of patients. This outperformed all other models on the validation (p < 0.0001) and novel series (p < 0.0001). The convolutional neural network also displayed the probability (confidence) of the femoral stem classification for any input radiograph. This neural network averaged a runtime of 0.96 (SD 0.02) seconds for an iPhone 6 to calculate from a given radiograph when converted to an application.

CONCLUSIONS

Neural networks offer a useful adjunct to the surgeon in preoperative identification of the prior implant.

Prospective Within Subject Comparison of Fluoroscopically Guided Lumbosacral Facet Joint Radiofrequency Ablation Using a Multi-Tined (Trident) Versus Conventional Monopolar Cannula

BACKGROUND

Radiofrequency ablation (RFA) for the lumbar facet joints has demonstrated efficacy in the management of chronic low back pain. The traditional technique uses a conventional monopolar (CM) cannula placed parallel to the putative nerve to produce a thermal lesion resulting in pain relief of the facet joints. A new multi-tined (MT) cannula has come onto the market that allows targeting the putative nerve using a perpendicular to the nerve approach.

OBJECTIVES

This study describes the technique using the MT cannula and compares its efficacy and procedural characteristics to the CM cannula.

STUDY DESIGN

This is a pre-post crossover observational study.

METHODS

Fifty-one patients were recruited between June 2015 and March 2020. Each patient underwent 2 fluoroscopic guided lumbosacral RFA procedures on 2 separate occasions at the same facet joints, using the CM and MT cannula consecutively. The primary outcome measure was change in pain on the 11-point numeric rating scale (NRS). Secondary outcome measures included change in Pain Disability Quality of Life Questionnaire (PDQQ) score, duration and magnitude of pain relief, local anesthetic use, adverse events, procedural and fluoroscopy exposure time, and radiation dose.

RESULTS

There were no statistically significant difference between CM versus MT canula in terms of absolute (4.0 versus 4.3) and relative (52% versus 57%) change in NRS (P = 0.99) and PDQQ (22 versus 22, P = 0.61) at 3 months, or overall pain magnitude (71% versus 72%, P = 0.96) and duration of relief (8.7 months versus 8.4 months, P = 0.68). The procedures using the MT cannula were completed faster (37.6 minutes versus 31.1 minutes, P < 0.001) and required less local anesthetic (15.8 mL versus 11.0 mL, P < 0.001) and radiation dose (41.5 mGy versus 30.2 mGy, P = 0.05). No adverse events were observed with either cannula.

LIMITATIONS

This was an observational study at a single center with the proceduralist not blinded to the intervention.

CONCLUSION

This study demonstrated that the outcomes in terms of pain, disability, quality of life, adverse events, and fluoroscopy exposure time were equivalent between the 2 cannulae. However, RFA using the MT cannula was faster to perform and involved less local anesthetic and radiation.

Evaluation of an Ultrasound-Assisted Longitudinal Axis Lateral Crest Approach to Radiofrequency Ablation of the Sacroiliac Joint

OBJECTIVE

The aim of the study was to evaluate the effectiveness and procedural characteristics of a novel, ultrasound/fluoroscopically guided technique (longitudinal axis sacroiliac joint radiofrequency ablation) for sacroiliac joint denervation.

DESIGN

A single-arm cohort with historical cohort comparison was used in this study.

METHODS

Thirty-seven participants underwent longitudinal axis sacroiliac joint radiofrequency ablation after 50% or more pain reduction after diagnostic dual-block criterion. Outcomes were the proportion of participants with 50% or more pain reduction and mean Pain Disability Quality of Life Questionnaire change. Subanalysis included longitudinal axis sacroiliac joint radiofrequency ablation procedural and fluoroscopy times compared with participants previously treated with palisade radiofrequency ablation technique.

RESULTS

Primary outcome worst case analysis demonstrated a responder rate of 64.9% (95% confidence interval = 48.8%-78.2%) and 59.5% (95% confidence interval = 43.5%-73.7%) at 3 and 6 mos. There was significant decrease in mean Pain Disability Quality of Life Questionnaire at 3 (45.6 ± 9.5 to 21.4 ± 16.0, P < 0.001) and 6 mos (45.6 ± 9.5 to 23.0 ± 16.5, P < 0.001). Longitudinal axis sacroiliac joint radiofrequency ablation required more procedure time than the palisade technique (38.2 ± 7.9 vs. 32.1 ± 6.9 mins, P = 0.031) but less fluoroscopy time (35.0 ± 11.8 vs. 57.6 ± 16.8 secs, P < 0.001).

CONCLUSIONS

Longitudinal axis sacroiliac joint radiofrequency ablation resulted in improvement in pain, disability, and quality of life at 3 and 6 mos. Compared with the palisade technique, longitudinal axis sacroiliac joint radiofrequency ablation required greater procedure time but less fluoroscopy time.

The safety and effectiveness of bone marrow concentrate injection for knee and hip osteoarthritis: a Canadian cohort

Aim: Describe the safety and effectiveness of intra-articular bone marrow concentrate (BMC) injection to treat knee and/or hip osteoarthritis (OA) in a Canadian cohort. Materials & methods: A total of 112 patients with refractory OA received a single intra-articular injection of BMC into their knee(s) and/or hip(s). Pain, disability and quality of life were prospectively assessed prior to and 3, 6 and 12 months post-injection. Results: Outcome scores were significantly improved at all time points post-BMC injection with maximal improvement observed at 3-6 months. Improvements were unrelated to patient age, sex or radiographic OA severity. The complication rate was <2%. Interpretation: In this Canadian cohort, knee/hip OA treated with a single BMC injection resulted in significant improvements in pain, disability and quality of life and a low complication rate.

Medication management of chronic pain: A comparison of 2 care delivery models

BACKGROUND

The prevalence of chronic pain is high and increasing. Medication management is an important component of chronic pain management. There is a shortage of physicians who are available and comfortable providing this service. In Alberta, pharmacists have been granted an advanced scope of practice. Given this empowerment, their availability, training and skill set, pharmacists are well positioned to play an expanded role in the medication management of chronic pain sufferers.

OBJECTIVE

To compare the effectiveness and cost of a physician-only vs a pharmacist-physician team model of medication management for chronic nonmalignant pain sufferers.

METHOD

Data was analyzed for 89 patients who had received exclusively medication management at a rural Alberta multidisciplinary clinic. 56 were managed by a sole physician. 33 were managed by a team (pharmacist + physician). In the team model, the physician did the medical assessment, diagnosis, and established a treatment plan in consultation with the patient and pharmacist. The pharmacist then provided the ongoing follow-up including education, dose titration and side effect management and consulted with the physician as needed. Change in pain (Numerical Rating Scale) and disability (Pain Interference Questionnaire) over the course of treatment were recorded. The treatment duration and number of visits were used to calculate cost of care.

RESULTS

Both models of medication management resulted in significant and comparable improvements in pain, disability and patient perception of medication effectiveness. Patients in the physician-only group were seen more frequently and at a greater cost. The pharmacist-physician team approach was markedly more cost-effective, and patients expressed a high level of satisfaction with their medication management.

CONCLUSIONS

The pharmacist-physician team model of medication management results in significant reductions of pain and disability for chronic nonmalignant pain sufferers at a reduced cost and is well accepted by patients.

Radiofrequency sensory ablation as a treatment for symptomatic unilateral lumbosacral junction pseudarticulation (Bertolotti's syndrome): a case report

OBJECTIVE

Describe the clinical presentation, diagnostic evaluation, and successful treatment of a case of symptomatic unilateral lumbosacral junction pseudarticulation using a novel radiofrequency nerve ablation technique.

CASE

A 56-year-old female patient who had suffered with low back and right upper buttock pain for 16 years experienced incomplete relief with L4/5 facet joint radiofrequency ablation. She was found to have an elongated right L5 transverse process that articulated with the sacral ala (Bertolotti's syndrome). Fluoroscopically guided local anesthetic/corticosteroid injection into the pseudarthrosis eliminated her residual right buttock pain for the duration of the local anesthetic only. Complete pain relief was achieved by injecting local anesthetic circumferentially around the posterior pseudarthrosis articular margin. Accordingly, bipolar radiofrequency strip thermal lesions were created at the same locations. Complete pain relief and full restoration of function was achieved for 16 months postprocedure.

CONCLUSION

This case report describes a novel radiofrequency technique for treating symptomatic lumbosacral junction pseudarticulation that warrants further evaluation.

Multidisciplinary chronic pain management in a rural Canadian setting

INTRODUCTION

Chronic pain is prevalent, complex and most effectively treated by a multidisciplinary team, particularly if psychosocial issues are dominant. The limited access to and high costs of such services are often prohibitive for the rural patient. We describe the development and 18-month outcomes of a small multidisciplinary chronic pain management program run out of a physician's office in rural Alberta.

METHODS

The multidisciplinary team consisted of a family physician, physiatrist, psychologist, physical therapist, kinesiologist, nurse and dietician. The allied health professionals were involved on a part-time basis. The team triaged referral information and patients underwent either a spine or medical care assessment. Based on the findings of the assessment, the team managed the care of patients using 1 of 4 methods: consultation only, interventional spine care, supervised medication management or full multidisciplinary management. We prospectively and serially recorded self-reported measures of pain and disability for the supervised medication management and full multidisciplinary components of the program.

RESULTS

Patients achieved clinically and statistically significant improvements in pain and disability.

CONCLUSION

Successful multidisciplinary chronic pain management services can be provided in a rural setting.

Impact of compensation on work outcome of carpal tunnel syndrome

BACKGROUND

Work-related carpal tunnel syndrome (CTS) is a complex and costly condition. There is some evidence that the employment outcome may be worse in cases of CTS where the condition is being considered for compensation.

AIM

To examine whether workers' compensation status is an important determinant of outcome of CTS.

METHODS

Cases, with a Workers' Compensation Board (WCB) claim, and referents, in work but without a WCB claim, were identified from the practice of a single specialist physician. Data on history prior to and at the time of diagnosis, and events since diagnosis, were collected from clinical records and by a telephone-administered questionnaire. Prior events, severity, treatment and outcome associated with a WCB claim were assessed by logistic regression.

RESULTS

Interviews were successfully completed for 46 cases and 50 referents. In the model adjusted only for age and gender, claimants had a worse outcome in terms of changing job or stopping work with time loss from work due to CTS [odds ratio (OR) 5.1, 95% confidence interval (CI) 1.9-13.3]. The OR was much influenced by the inclusion of treatment in the model (OR = 9.6, 95% CI 1.6-58.6) with WCB cases more likely to have surgical and physiotherapy treatments. Cases with a WCB claim cost more to treat and reported greater loss in income than those not seeking compensation.

CONCLUSIONS

Although these data are limited, the results are suggestive of poorer outcome among WCB claimants despite greater use of treatment and comparable severity of disease.

Fibrous myopathy as a complication of repeated intramuscular injections for chronic headache

Two cases of fibrous myopathy associated with repeated, long-term intramuscular injections for treatment of chronic temporomandibular joint pain and chronic headache, respectively, are described. Both patients developed severe, function-limiting contractures in upper and lower extremity muscles used as injection sites. In one of the cases, the contractures were painful. Electrophysiological testing, magnetic resonance imaging and muscle biopsy results were all consistent with myopathy and replacement of skeletal muscle with noncontractile fibrous tissue. These cases are presented to increase awareness of fibrous myopathy and to promote surveillance for this serious potential complication of long-term intramuscular injections in chronic headache and other pain patients.

A confidential study of deaths after emergency medical admission: issues relating to quality of care

In this retrospective pilot study we examine the feasibility of establishing a confidential enquiry into why some patients die after emergency admission to hospital. After excluding those who died in the first hour or who were admitted for palliative care, pairs of physicians were able to collect quantitative and qualitative data on 200 consecutive deaths. Both physicians reported shortfalls of care in 14 patients and one of the pair in 25 patients whose deaths would not have been the expected outcome. In 25, the shortfalls of care may have contributed to their deaths. Major problems were delays in seeing doctors, inaccurate diagnoses, delays in investigations and initiation of treatment. They occurred mostly in those admitted at night. It is possible that establishing the correct diagnosis and starting appropriate treatment may have been delayed in 64% of the 200 patients. The headline figures appear worse than some previous external assessment studies but this study did concentrate on those in whom problems were more likely. Nevertheless, the frequency is too high to be overlooked. In this feasibility study we have demonstrated that it is practicable for local staff to collect and assess data in hospitals and that the types of problems identified are relevant to anyone planning how to organise emergency care. A larger definitive study should be performed.

Infrared skin temperature measurement cannot be used to detect myofascial tender spots

OBJECTIVE

To determine the relationship between skin temperature and pressure tolerance in patients with myofascial pain.

DESIGN

Blinded, criterion standard.

SETTING

Community physiatry clinic.

PATIENTS

Sixteen consecutive female patients with myofascial pain or fibromyalgia with shoulder girdle symptoms above the T4 level for at least 3 months. No patient met the exclusion criteria of recent trauma to the area or therapy within 48 hours.

INTERVENTIONS

Skin temperature was measured by using a hand-held infrared thermometer over 36 points arranged in a grid on the upper and midtrapezius. Pressure threshold was then assessed at each point by using a pressure threshold meter. A second, blinded examiner then examined each patient to find any myofascial tender spots and noted within which square on the grid they occurred.

MAIN OUTCOME MEASURES

The correlation between temperature and pressure threshold and the temperature differences between tender and nontender areas.

RESULTS

A nonsignificant correlation of.023 (p =.57) was found between temperature and pressure threshold. The mean temperature of the tender spots was 32.1 degrees C. No significant difference existed between tender spot temperature and temperature of nontender points (32.1 degrees C, p =.653) or contralateral points (32 degrees C, p =.893).

CONCLUSIONS

Skin temperature, measured with a hand-held infrared thermometer, cannot be used to diagnose and follow treatment progress of myofascial tender spots, because skin temperature over tender spots does not correlate with pressure sensitivity.

Quadriceps muscle deoxygenation during functional electrical stimulation in adults with spinal cord injury

STUDY DESIGN

Cross-sectional study comparing healthy subjects with age and gender matched subjects with spinal cord injury (SCI, injury levels from C5 to T12).

OBJECTIVES

To compare the acute cardiorespiratory responses and muscle oxygenation trends during functional electrical stimulation (FES) cycle exercise and recovery in the SCI and healthy subjects exercising on a mechanical cycle ergometer.

SETTING

Seven volunteers in each group participated in one exercise test at the Rick Hansen Center, University of Alberta, Edmonton, Canada.

METHODS

Both groups completed a stagewise incremental test to voluntary fatigue followed by 2 min each of active and passive recovery. Cardiorespiratory responses were continuously monitored using an automated metabolic cart and a wireless heart rate monitor. Tissue absorbency, an index of muscle oxygenation, was monitored non-invasively from the vastus lateralis using near infrared spectroscopy.

RESULTS

The healthy subjects showed significant (P<0.05) increases in the oxygen uptake (VO2), heart rate (HR) and ventilation rate (VE) from rest to maximal exercise. The SCI subjects showed a twofold increase in VO2 (P>0.05), a threefold increase in VE (P<0.05) and a 5 beats/min increase in HR (P>0.05) from the resting value. The SCI subjects demonstrated a lesser degree (P<0.05) of muscle deoxygenation than the healthy subjects during the transition from rest to exercise. Regression analysis indicated that the rate of decline in muscle deoxygenation with respect to the VO2 was significantly (P<0.05) faster in the SCI subjects compared to healthy subjects.

CONCLUSIONS

FES exercise in SCI subjects elicits: (a) modest increases in the cardiorespiratory responses when compared to resting levels; (b) lower degree of muscle deoxygenation during maximal exercise, and (c) faster changes in muscle deoxygenation with respect to the VO2 during exercise when compared to healthy subjects.

Effect of concurrent strength and endurance training on skeletal muscle properties and hormone concentrations in humans

The purpose of this study was to investigate the effect of concurrent strength and endurance training on strength, endurance, endocrine status and muscle fibre properties. A total of 45 male and female subjects were randomly assigned to one of four groups; strength training only (S), endurance training only (E), concurrent strength and endurance training (SE), or a control group (C). Groups S and E trained 3 days a week and the SE group trained 6 days a week for 12 weeks. Tests were made before and after 6 and 12 weeks of training. There was a similar increase in maximal oxygen consumption (VO2max) in both groups E and SE (P < 0.05). Leg press and knee extension one repetition maximum (1 RM) was increased in groups S and SE (P < 0.05) but the gains in knee extension 1 RM were greater for group S compared to all other groups (P < 0.05). Types I and II muscle fibre area increased after 6 and 12 weeks of strength training and after 12 weeks of combined training in type II fibres only (P < 0.05). Groups SE and E had an increase in succinate dehydrogenase activity and group E had a decrease in adenosine triphosphatase after 12 weeks of training (P < 0.05). A significant increase in capillary per fibre ratio was noted after 12 weeks of training in group SE. No changes were observed in testosterone, human growth hormone or sex hormone binding globulin concentrations for any group but there was a greater urinary cortisol concentration in the women of group SE and decrease in the men of group E after 12 weeks of training (P < 0.05). These findings would support the contention that combined strength and endurance training can suppress some of the adaptations to strength training and augment some aspects of capillarization in skeletal muscle.

Functional electrical stimulation exercise increases GLUT-1 and GLUT-4 in paralyzed skeletal muscle

The study purpose was to determine the effect of functional electrical stimulation (FES)-leg cycle ergometer training (30 minutes on 3 d/wk for 8 weeks) on the GLUT-1 and GLUT-4 content of paralyzed skeletal muscle. Biopsy samples of vastus lateralis muscle were obtained pre- and post-training from five individuals with motor-complete spinal cord injury ([SCI] four men and one woman aged 31 to 50 years, 3 to 25 years postinjury involving C5-T8). Western blot analysis indicated that GLUT-1 increased by 52% and GLUT-4 increased by 72% with training (P < .05). This coincided with an increase in the muscle oxidative capacity as indicated by a 56% increase in citrate synthase (CS) activity (P < .05) and an improvement in the insulin sensitivity index as determined from oral glucose tolerance tests (P < .05). It is concluded that FES endurance training is effective to increase glucose transporter protein levels in paralyzed skeletal muscle of individuals with SCI.

Histochemical changes in muscle of individuals with spinal cord injury following functional electrical stimulated exercise training

STUDY DESIGN

Longitudinal training.

OBJECTIVES

To determine the effects of functional electrical stimulated (FES) leg cycle ergometer training on muscle histochemical characteristics in individuals with motor-complete spinal cord injury (SCI).

SETTING

University of Alberta, Edmonton, Alberta, Canada.

METHODS

Six individuals with motor-complete SCI (age 31-50 years; 3-25 years post-injury) trained using FES leg cycle ergometry for 30 min, 3 days per week for 8 weeks. Biopsies of the vastus lateralis muscle were obtained pre- and post-training and analyzed for fibre composition, fibre size and capillarization.

RESULTS

The majority of muscle fibres were classified as type 2 pre- and post-training. Average fibre area increased 23% (P<0.05) and capillary number increased 39% (P<0.05) with training. As a result of these proportional increases, capillarization expressed relative to fibre area was unchanged with training.

CONCLUSIONS

FES leg cycle ergometer training results in proportional increases in fibre area and capillary number in individuals with SCI.

The effect of a needle biopsy of the vastus lateralis on isokinetic muscular performance

OBJECTIVE

To determine the acute effects of a needle muscle biopsy of the vastus lateralis on knee extension and flexion strength and endurance.

DESIGN

Pretest-posttest design. Testing order of right or left leg was randomly determined.

SETTING

Research Laboratory, University of Alberta, Edmonton Alberta, Canada.

PARTICIPANTS

The subjects were 8 female and 11 male volunteers who were recreationally active. The mean age, height, and weight were 23 +/- 5 years, 174.6 +/- 9.2 cm, and 73.5 +/- 7.3 kg, respectively.

INTERVENTION

Isokinetic testing for knee extension and flexion was performed on both legs before and after a biopsy of the right vastus lateralis muscle.

MAIN OUTCOME MEASURES

Knee extension and flexion peak torque measured at an angular velocity of 1.05 rad.s-1. Mean torque during 25 consecutive maximal contractions at 3.14 rad.s-1 for knee extension and flexion exercise.

RESULTS

There was a significant decrease in right knee extension peak torque after the biopsy of the vastus lateralis muscle. No other differences were noted.

CONCLUSIONS

These findings demonstrated an acute inhibition of knee extension peak torque but not endurance because of a muscle biopsy of the involved musculature.

The effectiveness of topical diclofenac for lateral epicondylitis

INTRODUCTION

Gastrointestinal upset and local pain commonly limit the use of oral nonsteroidal anti-inflammatory drugs and corticosteroid injection as treatments for lateral epicondylitis. Transdermal administration of an anti-inflammatory drug could avoid these adverse effects.

PURPOSE

To determine the effectiveness of topical diclofenac as a treatment of lateral epicondylitis.

METHODS

A convenience sample of 14 subjects meeting clinical criteria of chronic lateral epicondylitis participated in this randomized, double blind, crossover study. Each subject applied a pluronic lecithin liposomal organo-gel (PLO) over the affected lateral elbow three times daily for I week, followed by a 1-week "washout" period of no gel. A second topical PLO gel was then applied similarly for 1 week. Both gels were identical, but only one gel contained 2% diclofenac. Treatment order was randomized, and both the subject and tester were blinded. Pain and isometric wrist extension strength were measured using a visual analog pain scale (VAS) and a mounted manual muscle testing dynamometer, respectively, at the following time periods: just before application of the first gel, the last day of using the first gel, the last day of the washout week, and the last day of using the second gel. Analysis was performed using repeated measures analysis of variance.

RESULTS

When subjects used diclofenac PLO, pain was significantly less than that during the pretreatment, washout, and placebo PLO periods (mean VAS: diclofenac PLO, 2.1; pretreatment, 3.5; washout, 3.4; placebo PLO, 3.6). Average wrist extension strength was significantly greater when subjects used diclofenac PLO (8.4 kg) than it was before treatment (5.9 kg). One subject developed a local rash while using diclofenac PLO.

CONCLUSION

Topical 2% diclofenac in PLO appears to provide effective short-term reduction in elbow pain and wrist extensor weakness associated with chronic lateral epicondylitis.

Multiband generation of mid infrared by use of periodically poled lithium niobate

We report the generation of simultaneous multiband mid-infrared laser output by use of periodically polled lithium niobate pumped by the 1.54-microm output from a KTP optical parametric oscillator. The multiband source is capable of producing three mid-infrared wavelengths ranging from 2.5 to 4microm . In initial experiments we obtained output powers of 542 mW near 2.5microm and 453 mW near 4microm , with power conversion efficiencies of 30% and 25%, respectively. To the best of our knowledge, this is the first demonstration of this kind in the literature.

Unusual causes of stiffness in two hockey players

PURPOSE

To describe two cases of competitive hockey players whose performance was impaired by generalized painless muscle stiffness. They were each found to have a separate type of myotonia.

CASE SUMMARY

The first hockey player experienced stiffness only when initiating activity after a period of inactivity. He had a family history of muscle stiffness, grip myotonia clinically, and electrophysiologic findings of myotonic discharges. He had myotonia congenita. The stiffness in the second case was episodic and occurred during bouts of intense physical activity. The legs, arms, and neck were affected. Myotonia fluctuans was the probable diagnosis. Both cases responded well to Mexiletine.

DISCUSSION

The etiology, classification, and clinical presentation of myotonia are discussed.

RELEVANCE

Because of the musculoskeletal nature of our practice, sport medicine clinicians should be aware of myotonic disorders so they can be recognized and appropriately treated.

Effects of 10-ppm hydrogen sulfide inhalation in exercising men and women. Cardiovascular, metabolic, and biochemical responses

This study examined the acute effects of 10-ppm hydrogen sulfide (H2S) inhalation, a concentration equal to its occupational exposure limit, on the cardiovascular, metabolic, and biochemical responses in healthy volunteers. Fifteen men and 13 women completed two 30-minute exercise sessions at 50% of their maximal oxygen uptake, during which they inhaled medical air or 10 ppm H2S in a blind manner. Arterial and finger-prick blood samples were obtained before and during the final minute of exercise. Muscle biopsies were withdrawn from the right vastus lateralis immediately after exercise. Cardiorespiratory measurements were monitored using an automated metabolic cart interfaced with an electrocardiogram and blood pressure apparatus. A significant decrease in oxygen uptake (VO2), with a concomitant increase in blood lactate, was observed in men and women as a result of H2S exposure. No significant changes were observed in arterial blood parameters and the cardiovascular responses under these conditions. Muscle lactate, as well as the activities of lactate dehydrogenase, citrate synthase, and cytochrome oxidase, were not significantly altered by H2S exposure. However, there was a tendency for muscle lactate to increase and citrate synthase activity to decrease in both genders in the presence of H2S. It appeared that 10-ppm H2S inhalation reduced VO2 during exercise, most likely by inhibiting the aerobic capacity of the exercising muscle. These findings question the scientific validity of the current occupational exposure limit for H2S.

Skeletal muscle fibre type transformation following spinal cord injury

Following spinal cord injury (SCI), upper motor neuron paralysed muscles lose the normal type I (slow) and II (fast) fibre mosaic pattern and become predominantly composed of type II (fast glycolytic) fibres). The majority of the research demonstrating this fibre type shift was based on pH sensitive myofibrillar ATPase staining techniques on muscle from longstanding paraplegics and quadriplegics. The purpose of this study was to describe muscle fibre type changes over a wide time spectrum post SCI using immunofluorescent techniques which may be more sensitive to change. A total of 19 vastus lateralis muscle biopsy specimens were obtained from 12 SCI subjects representing time points of 0.5-219 months post SCI. Fast and slow myosin heavy chain isoform distribution was determined on single muscle fibres for each of the biopsy specimens. Early post SCI (< 1 month) myosin heavy chain (MCH) isoform composition remained relatively stable. A transitional period was seen between 1 and 20 months post SCI wherein there was a progressive drop in the proportion of slow MHC isoform fibres and a rise in the proportion that co-expressed both the fast and slow MHC isoform. By approximately 70 months post SCI a new steady state had been reached characterized by almost exclusively fast MHC isoform expression. This research has demonstrated that post SCI muscle type II transformation occurs in stages and commences earlier than previously appreciated. Interventions aimed at preventing or minimizing the transformation would need to be instituted within weeks post SCI.

Effects of 10-ppm hydrogen sulfide inhalation on pulmonary function in healthy men and women

This study examined the acute effects of oral inhalation of 10-ppm hydrogen sulfide (H2S) inhalation (a concentration equal to its occupational exposure limit) on the pulmonary function in healthy men and women. Nine men and ten women consented to inhale medical air or 10 ppm H2S for 15 minutes each during cycle exercise at 50% of their maximal aerobic power. Routine pulmonary function tests were administered at rest and immediately after the two exposure conditions. The results indicated no significant changes in any of the variables derived from the flow volume loop, maximum ventilation volume, and diffusion capacity of the lung for carbon monoxide in both genders. None of the subjects experienced any signs and symptoms as a result of H2S exposure. It was concluded that oral inhalation of 10 ppm H2S at an elevated metabolic and ventilation rate does not significantly alter pulmonary function in healthy men and women.

Hormonal responses to graded-resistance, FES-assisted strength training in spinal cord-injured

Functional electrical stimulation (FES) assisted resistance training has been effective in increasing muscular strength and endurance in spinal cord injured men and women in preparation for FES-assisted cycle programs and for FES-assisted standing and walking. Increases in blood pressure and a concomitant bradycardia suggestive of autonomic dysreflexia have been reported during FES-assisted resistance training. Self-induced autonomic dysreflexia in athletes who use wheelchairs suppressed the normal exercise induced serum testosterone increase. We, therefore, examined the changes in hematocrit and circulating levels of testosterone, sex hormone binding globulin (SHBG), cortisol, prolactin, norepinephrine and epinephrine during FES assisted resistance exercise in five high spinal cord injured men (SCI) and comparable maximal exercise in five able bodied controls (AB). Mean serum testosterone levels significantly increased with FES-assisted resistance training in SCI and maximal resistance exercise in AB with no significant change in hematocrit or SHBG. Prolactin, cortisol and epinephrine levels were unchanged while norepinephrine levels were significantly increased in SCI and AB. These findings suggest that there is no concern over inadequate physiological androgen response to an exercise stimulus in SCI. The data do not support the previous findings that elevated levels of norepinephrine in autonomic dysreflexia suppress testosterone response to exercise.

Effects of 5 ppm hydrogen sulfide inhalation on biochemical properties of skeletal muscle in exercising men and women

This study compared the acute effects of 5 ppm hydrogen sulfide (H2S) inhalation (50 % of its occupational exposure limit) on the biochemical properties of skeletal muscle in exercising men and women. Twenty-five healthy volunteers, 13 men and 12 women, completed two 30-minute submaximal tests at 50% of their predetermined maximal aerobic power (VO2max) while breathing 0 ppm (control) or 5 ppm H2S from a specially designed flow system in a single-blind manner. Immediately after exercise, biopsies were obtained from the vastus lateralis muscle under local anaesthesia. They were subsequently analyzed for concentrations of the following markers of anaerobic and aerobic metabolism: lactate (La), lactate dehydrogenase (LDH), citrate synthase (CS), and cytochrome oxidase (CytOx). Repeated measures analysis of variance indicated that in men, the CS concentration decreased significantly (p = 0.006) as a result of H2S exposure. There was also a tendency for their La and LDH concentrations to increase and CytOx concentration to decrease in the presence of H2S, but these changes were not significant (p > 0.05). In women no significant changes were observed in any of these biochemical properties. These results suggest that (1) exposure to H2S at 50% of its OEL might inhibit aerobic metabolism during exercise in healthy men, thereby increasing their dependency on anaerobic metabolism; and (2) there could be a significant gender difference in the acute response to sub-OEL exposures of H2S.

Efficacy of rowing, backward wheeling and isolated scapular retractor exercise as remedial strength activities for wheelchair users: application of electromyography

Shoulder dysfunction due to regular wheelchair use is a common problem among people with spinal cord injuries. As a remedial measure, strengthening of the scapular retractor muscles has been suggested. Electromyographical analysis was utilized to examine scapular retraction muscle use during rowing, backward wheeling and a standardized scapular retraction exercise in seven people with spinal cord injuries and seven able bodied subjects. In addition, a pilot study using indwelling electrodes was completed to validate the use and placement of surface electrodes. Both rowing and the standardized scapular retraction exercise recruited higher levels of retractor involvement than backward wheeling. We suggest that rowing, because of its value as a cardiovascular exercise and high level of retractor recruitment, is an appropriate and effective means of remediating scapular retractor weakness.

Comparative physiological responses of exercising men and women to 5 ppm hydrogen sulfide exposure

A study compared the effects of inhalation of 5 ppm hydrogen sulfide (50% of its occupational exposure limit) on the physiological and hematological responses of healthy men and women during exercise. Subjects were 13 men (mean +/- SD for age, height, and weight = 24.7 +/- 4.6 yr, 173 +/- 6.6 cm, 73.1 +/- 8.1 kg, respectively) and 12 women (mean +/- SD for age, height, and weight = 22.0 +/- 2.1 yr, 165 +/- 8.2 cm, 63.4 +/- 8.6 kg, respectively). Subjects completed two 30-minute exercise tests on a cycle ergometer at 50% of their predetermined maximal aerobic power while breathing medical air or 5 ppm H2S from a specially designed flow system. The results indicated that there were no significant differences between the two exposures for the metabolic (oxygen uptake, carbon dioxide production, respiratory exchange ratio), cardiovascular (heart rate, blood pressure, rate pressure product), arterial blood (oxygen and carbon dioxide tensions, pH), and perceptual (rating of perceived exertion) responses in either sex. None of the subjects reported any adverse health effects subsequent to the H2S exposure. These results suggest that healthy men and women can safely perform moderate intensity work in environments contaminated with 5 ppm H2S.

Acute median nerve dysfunction from wheelchair propulsion: the development of a model and study of the effect of hand protection

Carpal tunnel syndrome is prevalent among individuals who are wheelchair dependent. Maximal electrophysiologic median nerve dysfunction has been isolated to the proximal part of the carpal tunnel--the site of hand-wheel interface during wheeling. The objective of this study was to determine if measurable median nerve dysfunction (conduction slowing or block) results from a single session of vigorous wheeling and, if so, if protection for the hand with a glove (padded over the region of the carpal tunnel) could minimize the dysfunction. Thirty-five subjects (16 wheelchair dependent; 19 able-bodied) propelled a roller-mounted wheelchair at maximal rate of 2,000 hand strikes. A protective glove was worn on 1 hand only. Immediately before and after the wheeling, hand surface temperatures and bilateral median motor and sensory conductions were performed, and across-carpal tunnel conduction velocity and conduction block were calculated. Another group of 11 able-bodied subjects underwent similar electrodiagnostic testing before and after one half hour of vigorous stationary cycling (no hand trauma). Results were analyzed using a three-way analysis of covariance for repeated measures and demonstrated that (1) significant increases (5.2% to 8.5%) in across carpal tunnel conduction block occurred as a result of wheelchair propulsion but not cycling; (2) the wheeling-induced conduction block was not altered by using a protective glove. This study has demonstrated a model for measuring acute median nerve dysfunction resultant from wheeling but raises doubts regarding the protective effect of glove use on median nerve function.

Testosterone, cortisol and catecholamine responses to exercise stress and autonomic dysreflexia in elite quadriplegic athletes

Episodes of short high intensity exercise are associated with an increase in circulating total testosterone (T) in men. Mechanisms may include hemoconcentration, decreased metabolic clearance and/or increased synthesis. Beta-blockade abolishes the T response suggesting a direct beta-adrenergic effect on the testes. Some spinal cord injured (SCI) athletes deliberately induce autonomic dysreflexia (boosting) to enhance performance. Associated with this practice are elevated catecholamine (CA) levels and exaggerated responses to serum catecholamine levels. Since basal T levels are reported to be normal in the SCI male, the T response to acute high intensity exercise might be expected to be exaggerated by boosting and associated elevated CA levels. The acute exercise T response has not been examined in SCI men to date. To determine whether the increased CA values associated with boosting enhanced the exercise-induced T elevation we measured circulating levels of T, cortisol (C), norepinephrine (NE) and epinephrine (E) before and after maximal exertion and a simulated 7.5 km race with and without boosting in eight elite quadriplegic athletes. Maximal incremental exercise and a simulated 7.5 km race resulted in a rise in T similar to able bodied men under normal exercise conditions. Under boosted conditions the rise in T was eliminated while NE levels were significantly elevated above unboosted levels. The data may suggest an inhibitory role for CA on T production or release under conditions of extreme stress. Other possible mechanisms include C induced suppression, impaired gonadotropin stimulation of the Leydig cell and CA mediated alterations in gonadal blood supply.

Nature and standards of gastrointestinal and liver services in the United Kingdom

1. Purpose of the working party: 1.1 To describe the scope of major digestive and liver disorders and identify changes in patterns of disease. 1.2 To identify diagnostic and therapeutic services required to manage these disorders in the United Kingdom. 1.3 To describe the facilities and staffing required to provide these services. 1.4 To examine the training requirements for medical, nursing, and other support staff. 1.5 To define the part that audit and research should play in the provision and maintenance of high quality gastrointestinal and liver services.

Evidence of autonomic dysreflexia during functional electrical stimulation in individuals with spinal cord injuries

The purpose of the investigation was to examine the safety and efficacy of functional electrical stimulation (FES)-assisted hydraulic resistance training in improving cardiovascular fitness in persons with spinal cord injuries. The cardiopulmonary responses of 10 high spinal cord injured (SCI) and five able bodied (AB) subjects were assessed during three bouts of FES-assisted leg extension exercise. The protocol involved three 30-minute tests: (1) unloaded leg extension, (2) hydraulically-resisted leg extension (loaded), and (3) a reproduction of the unloaded and loaded protocols to measure cardiac output (Q). Pre-measurements were made of body mass, mean limb weight, maximal force output and maximal oxygen uptake (incremental arm ergometry). Oxygen uptake (VO2), minute ventilation (Ve), respiratory exchange ratio (RER), heart rate (HR), blood pressure (BP) were recorded before, during and after tests. There was a significant difference in VO2 max between SCI and AB subjects. Cardiac output significantly increased between the loaded and unloaded tests. The significant increases from rest to unloaded and loaded exercise pointed to the potential value of adding resistance to a leg extension training regime. Heart rate and BP of the participants with SCI consistently demonstrated a response suggestive of autonomic dysreflexia. Upon stimulation an immediate increase in (predominantly systolic) BP was observed, followed by a fall in HR. On cessation of stimulation HR exhibited a substantial rebound effect and BP returned to normal levels. This response was highly reproducible and suggests caution be exercised in the use of FES for people with SCI with lesion levels above the major splanchnic outflow (T6).

Electrical stimulation-assisted rowing exercise in spinal cord injured people. A pilot study

Recently a FES (functional electrical stimulation)-assisted rowing machine was developed to enhance cardiovascular training in people with spinal cord injuries. The machine was assessed in terms of its efficacy as a training tool. Six patients who were quadriplegic (C6-T1) and 2 who were paraplegic (T3-6) completed a series of three tests in succession: (1) leg stimulation only (quadriceps and hamstring groups)--'Stim', (2) arm row only--'Row' and (3) simultaneous row and stimulation--'R & S'. Measurements recorded included oxygen uptake (VO2), minute ventilation (Ve), respiratory exchange ratio (RER), heart rate (HR) and blood pressure (BP). In addition, 6 out of the 8 subjects took part in a qualitative assessment comprising a guided interview exploring the subject's perception of the machine and test. Significant increases in VO2 were demonstrated between the three tests with R & S producing mean steady-state values of 16.34 nm (+/- 0.74) ml/kg/min (83% of maximum). These values represented a 12% increase over Row alone. Of interest was the qualitative assessment which revealed that subjects perceived R & S to be easier than Row despite the higher levels of VO2 observed. The results suggest that the rowing machine represents a potentially valuable hybrid training device that may significantly reduce risk factors for cardiovascular disease and improve the quality of life of people with SCI.

The effects of a reduced exercise duration taper programme on performance and muscle enzymes of endurance cyclists

The influence of tapering on the metabolic and performance parameters in endurance cyclists was investigated. Cyclists (n = 25) trained 5 days.week-1, 60 min.day-1, at 75-85% maximal oxygen consumption (VO2max) for 8 weeks and were then randomly assigned to a taper group: 4D (4 days; n = 7), 8D (8 days; n = 6), CON (control, 4 days rest; n = 6), NOTAPER (non-taper, continued training; n = 6). Muscle biopsy specimens taken before and after training and tapering were analysed for carnitine palmityltransferase (CPT), citrate synthase, beta-hydroxyacyl CoA dehydrogenase (HOAD), cytochrome oxidase (CYTOX), lactate dehydrogenase, glycogen and protein. Significant increases in VO2max (6%), a 60-min endurance cycle test (34.5%), oxidative enzymes (77-178%), glycogen (35%) and protein (34%) occurred following training. After the taper, HOAD and CPT decreased 25% (P less than 0.05) and 26% respectively, in the CON. Post-taper CYTOX values were different (P less than 0.05) for 4D and 8D compared with CON. Muscle glycogen levels were increased (P less than 0.05) after tapering in the 4D, 8D and CON, but decreased in NOTAPER. Similarly, power output at ventilation threshold was significantly increased in the 4D (27.4 W) and 8D (27 W) groups, but decreased (22 W) in the NOTAPER. These findings suggest that tapering elicited a physiological adaptation by altering oxidative enzymes and muscle glycogen levels. Such an adaptation may influence endurance cycling during a laboratory performance test.