Transcutaneous electrical nerve stimulation for postoperative pain relief after total knee arthroplasty

Complementary Approaches to Postoperative Pain Management: A Review of Non-pharmacological Interventions

Postoperative pain significantly affects many surgical patients. While opioids are crucial for pain management, they come with unwanted side effects. Alternatives like nonsteroidal anti-inflammatory drugs, N-methyl-D-aspartate (NMDA) receptor antagonists, and regional anesthesia techniques such as nerve blocks are utilized, but these also have limitations. This underscores the need for complementary non-pharmacological interventions to enhance postoperative pain control and reduce opioid dependence. This study aimed to synthesize evidence on the efficacy of nondrug approaches for managing postoperative pain. The study examined the effects of non-pharmacological interventions such as preoperative patient education, mind-body modalities, and physical therapies. Findings suggest that these approaches can reduce pain intensity, decrease opioid consumption, and enhance recovery outcomes. The study also highlighted the pivotal role of healthcare professionals in implementing these strategies. However, it identified workload constraints and insufficient training as barriers to effective utilization in clinical practice. Integrating non-pharmacological interventions into multimodal pain management regimens can improve postoperative pain control and reduce reliance on opioids. Further research is crucial to definitively establish the efficacy of individual interventions and optimize their combined use in clinical practice. Additionally, enhanced training programs for nurses and initiatives to facilitate the implementation of these strategies are necessary for their successful adoption.

Effectiveness of Interventions to Reduce Opioid Use After Orthopaedic Surgery: A Systematic Review of Randomised Controlled Trials

BACKGROUND

The prescribing of opioids to patients for postoperative pain can lead to persistent opioid use. This review investigated the effectiveness of interventions aimed at reducing opioid use in patients after orthopaedic surgery.

METHODS

Electronic databases were searched from inception to November 2023. We included randomised controlled trials investigating interventions aimed at reducing opioid use after orthopaedic surgery. Two reviewers conducted the screening and data extraction and assessed the risk of bias (Cochrane Risk of Bias tool) and certainty of evidence (GRADE). The primary outcome was the mean daily dose of opioid analgesic medications in the medium term (1-3 months after randomisation). Results were pooled in a meta-analysis using a random-effects model where appropriate (e.g. I2 < 50%) or summarised narratively.

RESULTS

The search yielded 17,471 records, of which 39 trials were included. High heterogeneity meant that most comparisons could not be pooled. The mean daily dose was lower with multimodal analgesia interventions than with placebo/no intervention/usual care or active control in the medium term. No between-group differences were found between other pharmacological or non-pharmacological interventions and either placebo/no intervention/usual care or active control at the medium-term time point. The certainty of evidence ranged from low to moderate.

CONCLUSIONS

Multimodal analgesic interventions may reduce opioid use compared with placebo/no intervention/usual care or active control in the medium term. However, the high heterogeneity and low certainty of evidence means it is uncertain which interventions are effective in reducing opioid use after orthopaedic surgery.

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

Assessing outcome in postoperative pain trials: are we missing the point? A systematic review of pain-related outcome domains reported in studies early after total knee arthroplasty

ABSTRACT

The management of acute postoperative pain remains suboptimal. Systematic reviews and Cochrane analysis can assist with collating evidence about treatment efficacy, but the results are limited in part by heterogeneity of endpoints in clinical trials. In addition, the chosen endpoints may not be entirely clinically relevant. To investigate the endpoints assessed in perioperative pain trials, we performed a systematic literature review on outcome domains assessing effectiveness of acute pain interventions in trials after total knee arthroplasty. We followed the Cochrane recommendations for systematic reviews, searching PubMed, Cochrane, and Embase, resulting in the screening of 1590 potentially eligible studies. After final inclusion of 295 studies, we identified 11 outcome domains and 45 subdomains/descriptors with the domain "pain"/"pain intensity" most commonly assessed (98.3%), followed by "analgesic consumption" (88.8%) and "side effects" (75.3%). By contrast, "physical function" (53.5%), "satisfaction" (28.8%), and "psychological function" (11.9%) were given much less consideration. The combinations of outcome domains were inhomogeneous throughout the studies, regardless of the type of pain management investigated. In conclusion, we found that there was high variability in outcome domains and inhomogeneous combinations, as well as inconsistent subdomain descriptions and utilization in trials comparing for effectiveness of pain interventions after total knee arthroplasty. This points towards the need for harmonizing outcome domains, eg, by consenting on a core outcome set of domains which are relevant for both stakeholders and patients. Such a core outcome set should include at least 3 domains from 3 different health core areas such as pain intensity, physical function, and one psychological domain.

Effect of transcutaneous electrical nerve stimulation on quality of recovery and pain after abdominal hysterectomy

Background and Aims:

Transcutaneous electrical nerve stimulation (TENS) is a noninvasive complementary therapy for postoperative pain management. The effect of TENS on quality of recovery (QoR) and pain treatment in the early postoperative period is not well documented. The aim of this study was to evaluate the effect of TENS on postoperative QoR and pain in patients who had undergone a total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH + BSO).

Material and Methods:

Fifty-two patients were randomized into two groups: control (sham TENS treatment) and TENS (TENS treatment). QoR, dynamic pain, and static pain were evaluated after surgery.

Results:

The QoR score was significantly higher in the TENS group as compared with that in the control group (P = 0.029). Pain scores during coughing (dynamic pain) were significantly less in TENS group compared to control group (P <0.001). However, there was no between-group difference in pain scores at rest (static pain) or total analgesic consumption (P = 0.63 or P = 0.83, respectively).

Conclusion:

TENS may be a valuable tool to improve patients' QoR and dynamic pain scores after TAH + BSO.

Effects of transcutaneous electrical nerve stimulation (TENS) on acute postoperative pain intensity and mobility after hip fracture: A double-blinded, randomized trial

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is a noninvasive modality which may be used to reduce acute postoperative pain. Intense perioperative pain within the first few days after hip fracture surgery is common and is related to negative consequences such as restricted and delayed ambulation.

OBJECTIVE

The objective of the present study was to examine the effect of incorporating TENS treatment on pain intensity, and mobility, with standard rehabilitation care during the acute post-operative phase following Gamma-nail surgical fixation of extracapsular hip fractures.

MATERIALS AND METHODS

Forty-one patients were randomly assigned to a supplement of 30 mins of active TENS or sham TENS. The standard rehabilitation care included five daily 30 mins physical therapy treatments beginning 24 hrs after surgery. Outcome measures were: pain intensity at rest, at night and during ambulation (assessed with the Numeric Rating Scale; Functional Ambulation Classification instrument; time to complete five sit-to-stand tests; and two-minute walk test). Data were analyzed with Wilcoxon score rank tests. Significance was set at p≤0.05.

RESULTS

Significantly greater pain reduction during walking was noted in the active TENS group compared to sham TENS group (differences between the fifth and the second days: 2.55±1.37 vs 1.06± 1.11, respectively; p=0.0011). Additionally, advantage of active TENS was demonstrated in greater increase in walking distance on the fifth day and higher level of mobility compared to the sham TENS group. No additional effects of active TENS were noted on pain intensity at rest and at night and on five times sit-to-stand performance.

CONCLUSION

Addition of TENS to the standard care of elderly patients in the early days following Gamma nail surgical fixation of extracapsular hip fracture is recommended for pain management while walking and functional gait recovery. The effect of TENS on long-term functional outcomes should be explored in future studies.

TRIAL REGISTRATION

The trial was registered at the ISRCTN registry: ID ISRCTN32476360.

The Effects of Transcutaneous Electrical Nerve Stimulation on Post-Episiotomy Pain Severity in Primiparous Women: A Randomized, Controlled, Placebo Clinical Trial

Background:

Episiotomy or cutting the perineum is the most common operation in obstetrics. Perineal pain is the main complication of episiotomy that affects the quality of life and mental health of the mother. Reducing the pain and side effects of the chemical drugs prescribed for pain relief has attracted the attention of both physicians and scientists. This study was conducted to determine the effects of transcutaneous electrical nerve stimulation (TENS), as an alternative method, on post-episiotomy pain severity.

Materials and Methods:

This randomized clinical trial was performed on 120 primiparous women who had referred to Sanandaj Besat Hospital in 2018. The patients were divided randomly into three groups, including the intervention group (TENS-On), the placebo group (TENS-Off), and the control group. TENS electrodes were placed near the episiotomy site in genitofemoral and pudendal nerves. The pain was measured after episiotomy in lying, sitting, and activity positions. The pain severity was measured using a pain measurement instrument (numeral rating score) at four-time points, i.e., before the intervention as well as 30, 60, and 120 minutes after the TENS intervention. For data analysis, Pearson correlation, student’s t-test, Kruskal-Wallis test, ANOVA test, and Mann-Whitney U tests were used.

Results:

Intragroup evaluation results for placebo and control groups demonstrated no significant difference in the pain score (P>0.05). A significant difference was observed between the mean pain severity of the intervention group and that of the group with walking activities (P=0.04). In terms of the intergroup evaluation, there was a significant difference observed between the mean pain severity of the lying position and that of the control group (P=0.008). Regarding the sitting position, no significant difference was observed between its mean pain severity and that of the other two groups (P=0.04).

Conclusion:

TENS is an effective and safe method for post-episiotomy pain relief and a routine method used in the obstetrics and gynecology ward.

Effects of Electroacupuncture on Local Anaesthesia for Inguinal Hernia Repair: A Randomised Placebo-Controlled Trial

Objective

To assess the effect of electroacupuncture (EA), akin to percutaneous electroneurostimulation, on pain and biochemical measures during and after inguinal hernia repair.

Methods

Thirty-three patients were randomised to EA (n=16) or sham transcutaneous electrical nerve stimulation (TENS) control (n=17). EA was applied at different frequencies, through needles inserted around the incision, over selected peripheral nerve branches and in the ear, from 30 min before surgery until the end of surgery, when needles were removed. All patients also received routine sedation and local anaesthesia.

Results

There was no difference between the pain scores in the groups receiving EA and sham TENS in the immediate postoperative period, which may be owing to adequate levels of analgesia from conventional techniques. On the fourth and seventh postoperative days, less pain and lower consumption of analgesic drugs were reported in the treatment group. Seroma occurred more frequently in the control group, which also had higher glucose blood levels in the immediate postoperative surgery period. The single case of chronic postoperative pain occurred in the control group.

Conclusions

The sample size was too small to draw any conclusions about the effect of EA on pain and other parameters following inguinal hernia surgery, but our observations suggest that future studies in this area are justified.

Systematic Review of Three Electrical Stimulation Techniques for Rehabilitation After Total Knee Arthroplasty

BACKGROUND

The comparative effectiveness of neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and electroacupuncture (EA) for improving patient rehabilitation following total knee arthroplasty (TKA) is controversial. Therefore we conducted this systematic review to assess the available evidence.

METHODS

The PubMed, OVID, and ScienceDirect databases were comprehensively searched and studies were selected and analyzed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Data were extracted and qualitatively synthesized for several outcomes.

RESULTS

Data were analyzed from 17 randomized controlled trials involving 1285 procedures: 8 NMES studies (608 procedures), 7 TENS studies (560 procedures), and 2 EA studies (117 procedures). Qualitative analysis suggested that NMES was associated with higher quadriceps strength and functional recovery after TKA. Recovery benefits were maximal when the stimulation was performed once or twice a day for 4-6 weeks at an intensity of 100-120 mA and frequency of 30-100 Hz. The electrode should be sufficiently large (100-200 cm²) to reduce discomfort. TENS at an intensity of 15-40 mA and frequency of 70-150 Hz provided effective analgesia after TKA. EA at an intensity of 2 mA and frequency of 2 Hz may also provide postoperative analgesia of TKA.

CONCLUSION

As adjunct modalities, NMES and TENS can effectively improve rehabilitation after TKA without triggering significant intolerance, and maximal benefits depend on optimized parameters and intervention protocols. EA may be an effective adjunct modality for analgesia after TKA.

Transcutaneous electrical nerve stimulation for postoperative pain control after total knee arthroplasty: A meta-analysis of randomized controlled trials

BACKGROUND

This meta-analysis aimed to evaluate the efficiency and safety of transcutaneous electrical nerve stimulation (TENS) for pain control after total knee arthroplasty.

METHODS

A systematic search was performed in Medline (1966 to June 2017), PubMed (1966 to June 2017), Embase (1980 to June 2017), ScienceDirect (1985 to June 2017), and the Cochrane Library. Only randomized controlled trial (RCT) was included. The fixed/random effect model was used according to the heterogeneity tested by I statistic. Meta-analysis was performed using Stata 11.0 software.

RESULTS

Five RCTs including 472 patients met the inclusion criteria. The present meta-analysis indicated that there were significant differences between groups in terms of visual analogue scale score at 12 hours (average: 3.58 vs 4.34, SMD = -0.260, 95% CI: -0.442 to -0.078, P = .005), 24 hours (average: 3.18 vs 3.52, SMD = -0.244, 95% CI: -0.426 to -0.063, P = .008), and 48 hours (average: 2.70 vs 2.96, SMD = -0.214, 95% CI: -0.395 to -0.033, P = .021) after total knee arthroplasty. Significant differences were found regarding opioid consumption at 12 hours (average: 14.44 vs 18.54, SMD = -0.503, 95% CI: -0.687 to -0.319, P = .000), 24 hours (average: 16.10 vs 18.40, SMD = -0.262, 95% CI: -0.443 to -0.080, P = .005), and 48 hours (average: 12.92 vs 15.12, SMD = -0.183, 95% CI: -0.364 to -0.002, P = .048).

CONCLUSION

TENS could significantly reduce pain and opioid consumption after total knee arthroplasty. In addition, there were fewer adverse effects in the TENS groups. Higher quality RCTs are required for further research.

Transcutaneous electrical nerve stimulation for the control of pain during rehabilitation after total knee arthroplasty: A randomized, blinded, placebo-controlled trial

This study evaluated the efficacy of transcutaneous electrical nerve stimulation (TENS) in reducing pain and hyperalgesia and increasing function after total knee arthroplasty (TKA). We hypothesized that participants using TENS during rehabilitation exercises would report significantly lower pain during range-of-motion (ROM) activity and fast walking but not at rest, would have less hyperalgesia, and would have better function than participants receiving placebo-TENS or standard care. We also hypothesized that change in ROM pain would differ based on psychological characteristics (trait anxiety, pain catastrophizing, and depression) and treatment group. This prospective, randomized study used intent-to-treat analyses in 317 participants after primary, unilateral TKA. Assessors, blinded to treatment allocation, measured pain, function (ROM and gait speed), and hyperalgesia (quantitative sensory tests) postoperatively and 6 weeks after surgery. Analgesic intake, anxiety, depression, and pain catastrophizing were also assessed. TENS participants used it 1 to 2 times per day at 42 mA (on average) and had less pain postoperatively during active knee extension (P=.019) and fast walking (P=.006) than standard care participants. TENS and placebo-TENS were not significantly different. TENS participants who scored low on anxiety and pain catastrophizing had a greater reduction in ROM pain at 6 weeks than those who scored high on these factors (P=.002 and P=.03). Both TENS and placebo-TENS participants had less postoperative mechanical hyperalgesia (P=.03-.01) than standard care participants. Supplementing pharmacologic analgesia with TENS during rehabilitation exercises reduces movement pain postoperatively, but a placebo influence exists and the effect is gone by 6 weeks. Patients with low anxiety and pain catastrophizing may benefit most from TENS.

Postoperative pain management after total knee arthroplasty in elderly patients: treatment options

Total knee arthroplasty (TKA) is a common surgical procedure in the elderly and is associated with severe pain after surgery and a high incidence of chronic pain. Several factors are associated with severe acute pain after surgery, including psychological factors and severe preoperative pain. Good acute pain control can be provided with multimodal analgesia, including regional anesthesia techniques. Studies have demonstrated that poor acute pain control after TKA is strongly associated with development of chronic pain, and this emphasizes the importance of attention to good acute pain control after TKA. Pain after discharge from hospital after TKA is currently poorly managed, and this is an area where increased resources need to be focused to improve early pain control. This is particularly as patients are often discharged home within 4-5 days after surgery. Chronic pain after TKA in the elderly can be managed with both pharmacological and non-pharmacological techniques. After excluding treatable causes of pain, the simplest approach is with the use of acetaminophen combined with a short course of non-steroidal anti-inflammatory drugs (NSAIDs). Careful titration of opioid analgesics can also be helpful with other adjuvants such as the antidepressants or antiepileptic medications used especially for patients with neuropathic pain. Topical agents may provide benefit and are associated with fewer systemic side effects than oral administration. Complementary or psychological therapies may be beneficial for those patients who have failed other options or have depression associated with chronic pain.

A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty

OBJECTIVE

To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used.

DATA SOURCES

PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain.

REVIEW METHODS

Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings.

RESULTS

A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them.

CONCLUSION

This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality.

[Effects of two methods of heat therapy on the acute vascular response and hemodynamics in healthy subjects]

OBJECTIVE

Recently, non-pharmacological resources to relieve pain like hot packs and ultrasound (US) have become common in clinical practice. However, little experimental evidence is available about the possible mechanisms through which these methods bring about pain relief. We aimed to determine the effects of hot packs and US on the acute vascular response and on hemodynamic parameters in healthy subjects.

MATERIALS AND METHODS

We conducted an experimental study in 20 healthy subjects (10 men and 10 women; mean age, 22.54±1.70 years). The two interventions were randomly applied: a) hot packs (n=10): 15min at 60°C and b) US (n=10): 15min at 1Mhz. Before and after each intervention, the following vascular parameters were measured in the brachial artery using Doppler ultrasonography with a 7MHz probe: arterial compliance, elastic modulus, beta stiffness index, systolic and diastolic arterial diameters, systolic flow velocity and diastolic flow velocity, systolic/diastolic ratio, resistance index, and pulsatility index. The following hemodynamic parameters were monitored: heart rate and blood pressure (systolic, diastolic, and mean).

RESULTS

After the application of hot packs, we observed changes in diastolic flow velocity and in the pulsatility index (P<05). After the application of US, we observed changes in diastolic flow velocity, systolic/diastolic ratio, resistance index, and arterial compliance (P<05). No changes in hemodynamic parameters were observed after either intervention.

CONCLUSIONS

Applying hot packs or US modifies the physiology of the vascular system but does not affect hemodynamic parameters in healthy subjects.

Non-invasive interactive neurostimulation (InterX™) reduces acute pain in patients following total knee replacement surgery: a randomised, controlled trial

Background

Adequate post-operative pain relief following total knee replacement (TKR) is very important to optimal post-operative recovery. Faster mobilisation and rehabilitation ultimately results in optimum recovery outcomes, but pain is often the limiting factor. This study evaluates the potential clinical benefit of the InterX neurostimulation device on pain reduction and rehabilitative outcome.

Methods

A clinical trial under the Hywel Dda Clinical Audit Committee to validate the clinical benefit of Non-invasive Interactive Neurostimulation (NIN) therapy using the InterX device was performed in patients undergoing TKR. 61 patients were randomised to treatment groups in blocks of two from the Theatre Operation List. The control group received the standard hospital course of pain medication and rehabilitation twice daily for 3 post-op days. The experimental group received 8 sessions of NIN therapy over 3 post-op days in addition to the standard course received by the Control group. Pain and range of motion were collected as the primary study measures.

Results

Sixty one subjects were enrolled and randomised, but 2 subjects (one/group) were excluded due to missing data at Baseline/Final; one subject in the InterX group was excluded due to pre-existing rheumatoid pain conditions confounding the analysis.

The experimental group pre- to post-session Verbal Rating Scale for pain (VRS) showed that NIN therapy consistently reduced the pain scores by a mean of 2.3 points (SE 0.11). The NIN pre-treatment score at Final was used for the primary ANCOVA comparison, demonstrating a significantly greater cumulative treatment effect of a mean 2.2 (SE 0.49) points pain reduction (p = 0.002). Control subjects only experienced a mean 0.34 (SE 0.49) point decrease in pain. Ninety degrees ROM was required to discharge the patient and this was attained as an average despite the greater Baseline deficit in the InterX group. Eight control patients and three experimental patients did not achieve this ROM.

Conclusions

The results clearly demonstrated the clinical benefit of NIN therapy as a supplement to the standard rehabilitation protocol. The subjects receiving InterX fared significantly better clinically. Within a relatively short 3-day period of time, patients in the experimental group obtained the necessary ROM for discharge and did it experiencing lower levels of pain than those in the control group.

Three-armed trials including placebo and no-treatment groups may be subject to publication bias: systematic review

Background

It has been argued that placebos may not have important clinical impacts in general. However, there is increasing evidence of a publication bias among trials published in journals. Therefore, we explored the potential for publication bias in randomized trials with active treatment, placebo, and no-treatment groups.

Methods

Three-armed randomized trials of acupuncture, acupoint stimulation, and transcutaneous electrical stimulation were obtained from electronic databases. Effect sizes between treatment and placebo groups were calculated for treatment effect, and effect sizes between placebo and no-treatment groups were calculated for placebo effect. All data were then analyzed for publication bias.

Results

For the treatment effect, small trials with fewer than 100 patients per arm showed more benefits than large trials with at least 100 patients per arm in acupuncture and acupoint stimulation. For the placebo effect, no differences were found between large and small trials. Further analyses showed that the treatment effect in acupuncture and acupoint stimulation may be subject to publication bias because study design and any known factors of heterogeneity were not associated with the small study effects. In the simulation, the magnitude of the placebo effect was smaller than that calculated after considering publication bias.

Conclusions

Randomized three-armed trials, which are necessary for estimating the placebo effect, may be subject to publication bias. If the magnitude of the placebo effect is assessed in an intervention, the potential for publication bias should be investigated using data related to the treatment effect.

Transcutaneous electrical nerve stimulation (TENS) for chronic pain

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is a popular pain treatment modality but its effectiveness in chronic pain management is unknown. This review is an update of the original Cochrane review published in Issue 3, 2001.

OBJECTIVES

To evaluate the effectiveness of TENS in chronic pain.

SEARCH STRATEGY

The Cochrane Library, EMBASE, MEDLINE and CINAHL were searched. Reference lists from retrieved reports and reviews were examined. Date of the most recent search: April 2008.

SELECTION CRITERIA

RCTs were eligible if they compared active TENS versus sham TENS controls; active TENS versus 'no treatment' controls; or active TENS versus active TENS controls (e.g. High Frequency TENS (HFTENS) versus Low Frequency TENS (LFTENS)). Studies of chronic pain for three months or more which included subjective outcome measures for pain intensity or relief were eligible for evaluation. No restrictions were made to language or sample size. Abstracts, letters, or unpublished studies, and studies of TENS in angina, headache, migraine, dysmenorrhoea and cancer-related pain were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted and summarised on the following items: patients and details of pain condition, treatments, study duration, design, methods, subjective pain outcome measures, methodological quality, results for pain outcome measures and adverse effects, and conclusions by authors of the studies. Extracted data and methodological quality of studies were confirmed by the review authors.

MAIN RESULTS

Of 124 studies identified from the searches, 99 did not fulfil pre-defined entry criteria. Twenty-five RCTs involving 1281 participants were evaluated. Included studies varied in design, analgesic outcomes, chronic pain conditions, TENS treatments and methodological quality. The reporting of methods and results for analgesic outcomes were inconsistent across studies and generally poor. Meta-analysis was not possible. Overall in 13 of 22 inactive control studies, there was a positive analgesic outcome in favour of active TENS treatments. For multiple dose treatment comparison studies, eight of fifteen were considered to be in favour of the active TENS treatments. Seven of the nine active controlled studies found no difference in analgesic efficacy between High Frequency (HF) TENS and Low Frequency (LF) TENS.

AUTHORS' CONCLUSIONS

Since the last version of this review, new relevant studies have not provided additional information to change the conclusions. Published literature on the subject lacks the methodological rigour or robust reporting needed to make confident assessments of the role of TENS in chronic pain management. Large multi-centre RCTs of TENS in chronic pain are still needed.

Multidisciplinary rehabilitation programmes following joint replacement at the hip and knee in chronic arthropathy

BACKGROUND

Joint replacements are common procedures and treatment of choice for those with intractable joint pain and disability arising from arthropathy of the hip or knee. Multidisciplinary rehabilitation is considered integral to the outcome of joint replacement.

OBJECTIVES

To assess the evidence for effectiveness of multidisciplinary rehabilitation on activity and participation in adults following hip or knee joint replacement for chronic arthropathy.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Group Trials Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and CINAHL up to September 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared organised multidisciplinary rehabilitation with routine services following hip or knee replacement, and included outcome measures of activity and participation in accordance with the International Classification of Functioning, Health and Disability (ICF).

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data and assessed methodological quality of included trials.

MAIN RESULTS

Five trials (619 participants) met the inclusion criteria; two addressed inpatient rehabilitation (261 participants) and three (358 participants) home-based settings. There were no trials addressing outpatient centre-based programmes. Pooling of data was not possible due to differences in study design and outcomes used. Methodological assessment showed all trials were of low quality. For inpatient settings early commencement of rehabilitation and clinical pathways led to more rapid attainment of functional milestones (disability) (Functional Independence Measure (FIM) transfer WMD 0.5, 95% CI 0.15, 0.85, number needed to treat to benefit (NNTB) = 6, FIM ambulation WMD 1.55 (95%CI 0.96, 2.14), NNTB = 3), shorter hospital stay, fewer post-operative complications and reduced costs in the first three to four months. Home-based multidisciplinary care improved functional gain (Oxford Hip Score (OHS) WMD at 6 months -7.00 (95%CI -10.36, -3.64), NNT = 2 and quality of life (QoL) and reduced hospital stay in the medium term (six months). No trials addressed longer-term outcomes following hip replacement only.

AUTHORS' CONCLUSIONS

Based on the heterogeneity and the low quality of the included trials that precluded pooled meta-analysis, there is silver level evidence that following hip or knee joint replacement, early multidisciplinary rehabilitation can improve outcomes at the level of activity and participation. The optimal intensity, frequency and effects of rehabilitation over a longer period and associated social costs need further study. Future research should focus on improving methodological and scientific rigour of clinical trials, and use of standardised outcome measures, so that results can be pooled for statistical analysis.

Combined continuous "3-in-1" and sciatic nerve blocks provide improved postoperative analgesia with no correlation to catheter tip location after unilateral total knee arthroplasty

This study assessed the efficacy and duration of postoperative analgesia after continuous sciatic nerve block with and without continuous "3-in-1" block with bupivacaine after unilateral total knee arthroplasty and determined catheter tip correlation with analgesia. Thirty patients were randomized into 2 groups. Results suggested significantly reduced pain and rescue analgesic requirement in combined sciatic and 3-in-1 (group TS) compared to 3-in-1 group alone (group T). The postoperative pain-free interval and satisfaction score was significantly higher in the combined group (P < .05). The percentage of catheters in the ideal position was 53.3% for 3-in-1 and 93.3% for sciatic nerve. In conclusion, continuous sciatic nerve block when added to continuous 3-in-1 block provides a better quality of analgesia with lesser requirements of rescue analgesics without the need for routine radiographic conformation.

Microcurrent skin patches for postoperative pain control in total knee arthroplasty: a pilot study

Pain control following painful orthopaedic procedures such as total knee arthroplasty (TKA) is an ongoing challenge, as current pain management techniques often result in under-medication and/or complications. In a study designed to test the effect of the micro-current skin patch (MCT) on pain relief in patients following TKA, we followed 24 patients, randomly divided into two groups, one group receiving MCT plus tramadol hydrochloride (tramadol) for pain relief and a control group receiving only tramadol, for 10 days postoperatively. Tramadol was given intramuscularly in increment doses of 100 mg, as needed, for the duration of the study period. Pain was assessed daily using a visual analogue score (VAS). Other parameters, including the effect of MCT on the dose of tramadol needed for pain relief, the degree of wound healing measured at the end of the follow-up period, category of the wound 10 days postoperatively (1, 2 or 3) and total drain fluid volume, were also assessed. During the 10-day postoperative period there was a progressive decrease in pain in patients of both groups, however the patients of the MCT group showed a consistently lower VAS throughout the observation period, most markedly on those follow-up days with the highest pain scores in patients of the control group. This effect was monitored on the basis of the average dose of tramadol administered per day: 200.0+/-7.0 mg/day in the control group and 63.3+/-15.8 mg/day in the MCT group. Wound healing was better with the application of the MCT patch: grade 1 wounds were observed in 50% of the patients of the MCT group as compared to 8.3% in control group. The total drain volume was lower in patients of the MCT group compared to the controls (1020.8+/-211.6 and 1170.8+/-243.5 ml, respectively). None of the patients indicated that they wished to discontinue MCT therapy. This pilot study shows that MCT therapy led to better pain control with a markedly lower need for tramadol as compared to the control group. This better pain control was accompanied by a better healing of the wound and a lower drain volume.

Autologous chondrocyte implantation postoperative care and rehabilitation: science and practice

Autologous chondrocyte implantation is an advanced, cell-based orthobiological technology used for the treatment of chondral defects of the knee. It has been in clinical use since 1987 and has been performed on 12 000 patients internationally; but despite having been in clinical use for more than 15 years, the evidence base for rehabilitation after autologous chondrocyte implantation is notably deficient. The authors review current clinical practice and present an overview of the principles behind autologous chondrocyte implantation rehabilitation practices. They examine the main rehabilitation components and discuss their practical applications within the overall treatment program, with the aim of facilitating the formulation of appropriate, individualized patient rehabilitation protocols for autologous chondrocyte implantation.

Endogenous opiates and behavior: 2004

This paper is the 27th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over 30 years of research. It summarizes papers published during 2004 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.