Pressure-Pain Threshold Algometric Measurement in Patients With Greater Trochanteric Pain After Total Hip Arthroplasty

A Closer Look at Localized and Distant Pressure Pain Hypersensitivity in People With Lower Extremity Overuse Soft-Tissue Painful Conditions: A Systematic Review and Meta-Analysis

OBJECTIVE

The nociceptive pain processing of soft-tissue overuse conditions is under debate because no consensus currently exists. The purpose of this meta-analysis was to compare pressure pain thresholds (PPTs) in symptomatic and distant pain-free areas in 2 groups: participants with symptomatic lower extremity overuse soft-tissue conditions and controls who were pain free.

METHODS

Five databases were searched from inception to December 1, 2021, for case-control studies comparing PPTs between individuals presenting with symptomatic lower extremity tendinopathy/overuse injury and controls who were pain free. Data extraction included population, diagnosis, sample size, outcome, type of algometer, and results. The methodological quality (Newcastle-Ottawa Quality Assessment Scale) and evidence level (Grading of Recommendations Assessment, Development, and Evaluation) were assessed. Meta-analyses of symptomatic, segmental related, and distant pain-free areas were compared.

RESULTS

After screening 730 titles and abstracts, a total of 19 studies evaluating lower extremity overuse conditions (Achilles or patellar tendinopathy, greater trochanteric pain syndrome, plantar fasciitis, and iliotibial band syndrome) were included. The methodological quality ranged from fair (32%) to good (68%). Participants with lower extremity overuse injury had lower PPTs in both the painful and nonpainful areas, mirrored test-site, compared with controls (affected side: mean difference [MD] = -262.92 kPa, 95% CI = 323.78 to -202.05 kPa; nonaffected side: MD = -216.47 kPa, 95% CI = -304.99 to -127.95 kPa). Furthermore, people with plantar fasciitis showed reduced PPTs in the affected and nonaffected sides at segmental-related (MD = -176.39 kPa, 95% CI = -306.11 to -46.68 kPa) and distant pain-free (MD = -97.27 kPa, 95% CI = 133.21 to -61.33 kPa) areas compared with controls.

CONCLUSION

Low- to moderate-quality evidence suggests a reduction of PPTs at the symptomatic area and a contralateral/mirror side in lower extremity tendinopathies and overuse conditions compared with pain-free controls, particularly in plantar fasciitis and greater trochanteric pain syndrome. Participants with plantar fasciitis showed a reduction of PPTs on the affected and non-affected sides at a segmental-related area (very low-quality evidence) and at a remote asymptomatic area (moderate-quality evidence).

IMPACT

Some overuse peripheral pain conditions may be more associated with pressure pain sensitivity than others. Accordingly, examination and identification of conditions more peripherally, centrally, or mixed mediated could potentially lead to more specific and different treatment strategies.

A Design Study of Orthotic Shoe Based on Pain Pressure Measurement Using Algometer for Calcaneal Spur Patients

The pressure pain threshold (PPT) is a useful tool for evaluating mechanical sensitivity in individuals suffering from various musculoskeletal disorders. The aim of this study is to investigate PPT at the heel area in order to assist in the design of orthotic shoes for sufferers of heel pain due to a calcaneal spur. The size and location of the calcaneal spur was determined by x-ray images, with PPT data measured around the spur at five points by using algometer FDIX 25. The pain test experiment was conducted by pressing each point to obtain the pain minimum compressive pressure (PMCP) and its location. The information of shoe size, spur location and dimensions, and the PMCP location for each individual is used to obtain the exact point location for applying a softer material to the shoe in-sole, in order to reduce heel pain. The results are significant as it can be used by designers to design appropriate shoe in-soles for individuals suffering from heel pain.

Effect of a common exercise programme with an individualised progression criterion based on the measurement of neuromuscular capacity versus current best practice for lower limb tendinopathies (MaLaGa trial): a protocol for a randomised clinical trial

INTRODUCTION

High-load resistance training has shown positive effects in pain and function in lower limb tendinopathies. However, some authors suggest that current exercise programmes produce an increase in tolerance to load and exercise in general but without fixing some existing issues in tendinopathy. This may indicate the need to include training aspects not currently taken into account in the current programmes. The main objective of this study will be to compare the effect of a common exercise protocol for the three predominant lower limb tendinopathies (Achilles, patellar and gluteal), based on an individualised control of the dose and training of specific aspects of the neuromuscular system versus the current best practice for each location.

METHODS AND ANALYSIS

This study will be conducted among people with mid-portion Achilles, patellar or gluteal tendinopathy. The participants allocated to the experimental group will perform a 14-week innovative common therapeutic exercise programme. Participants allocated to the control group will carry out a 14-week exercise programme based on the best current practice for each of the studied locations. The Victorian Institute of Sports Assessment questionnaire will be considered the primary outcome. Pain, central sensitisation, fear avoidance behaviour, quality of life, treatment satisfaction, lower-limb strength and function, and high-density electromyography profile will be evaluated as secondary outcomes. Outcomes will be assessed at baseline, 7 weeks, after the intervention (week 14), 26 weeks and 52 weeks.

ETHICS AND DISSEMINATION

The study has been approved by the Portal de Ética de la Investigación Biomédica de Andalucía Ethics Committee (1221-N-19). All participants will be informed about the purpose and content of the study and written informed consent will be completed. The results of this study will be published in a peer-reviewed journal and will be disseminated electronically and in print.

TRIAL REGISTRATION NUMBER

NCT03853122; Pre-results.

Test Procedures to Assess Somatosensory Abnormalities in Individuals with Peripheral Joint Pain: A Systematic Review of Psychometric Properties

BACKGROUND

Test procedures that were developed to assess somatosensory abnormalities should possess optimal psychometric properties (PMPs) to be used in clinical practice. The aim of this systematic review was to evaluate the literature to assess the level of evidence for PMPs of test procedures investigated in individuals with peripheral joint pain (PJP).

METHODS

A comprehensive electronic literature search was conducted in 7 databases from inception to March 2016. The Quality Appraisal for Reliability Studies (QAREL) checklist and the Consensus-based Standards for the Selection of Health Status Measurement Instruments (COSMIN) tool were used to assess risk for bias of the included studies. Level of evidence was evaluated based on the methodological quality and the quality of the measurement properties.

RESULTS

Forty-one studies related to PJP were included. The majority of included studies were considered to be of insufficient methodological quality, and the level of evidence for PMPs varied across different test procedures. The level of evidence for PMPs varied across different test procedures in different types of PJP. Hand-held pressure algometry is the only test procedure that showed moderate positive evidence of intrarater reliability, agreement, and responsiveness, simultaneously, when it was investigated in patients with chronic knee osteoarthritis.

CONCLUSIONS

This systematic review identified that the level of evidence for PMPs varied across different testing procedures to assess somatosensory abnormalities for different PJP populations. Further research with standardized protocols is recommended to further investigate the predictive ability and responsiveness of reported test procedures in order to warrant their extended utility in clinical practice.

Concurrent validation of a pressure pain threshold scale for individuals with myofascial pain syndrome and fibromyalgia

Background

Manual pressure palpation is an examination technique used in the classification of myofascial pain syndrome (MPS) and fibromyalgia (FM). Currently, there are no validated systems for classifying results. A valid and reliable pressure pain threshold scale (PPTS) may provide a means for clinicians to grade, document, and report findings. The purpose of this investigation was to validate a PPTS in individuals diagnosed with MPS and FM. Intra-rater reliability, concurrent validity, minimum cut-off value, and patient responses were evaluated.

Methods

Eighty-four participants who met the inclusion criteria were placed into three groups of 28 (N = 84): MPS, FM, and asymptomatic controls. All participants underwent a two-part testing session using the American College of Rheumatology criteria for classifying FM. Part-1 consisted of manual palpation with a digital pressure sensor for pressure consistency and part 2 consisted of algometry. For each tender point (18 total), participants graded tenderness using the visual analog scale (VAS) while the examiner concurrently graded response using a five-point PPTS.

Results

The PPTS had good intra-rater reliability (ICC ≥ .88). A moderate to excellent relationship was found between the PPTS and VAS for all groups with the digital pressure sensor and algometer (ρ ≥ .61). A minimum cut-off value of 2 on the PPTS differentiated participants with MPS and FM from asymptomatic controls.

Discussion

The results provide preliminary evidence validating the PPTS for individuals with MPS and FM. Future research should further study the clinimetric properties of the PPTS with other chronic pain and orthopedic conditions.

Levels of Evidence

2c.

Clinical Trial Registration

ClinicalTrials.gov registration No. NCT02802202.

Abductor Muscle Function and Trochanteric Tenderness After Hemiarthroplasty for Femoral Neck Fracture

OBJECTIVES

To compare the abductor muscle function and trochanteric tenderness in patients operated with hemiarthroplasty using the direct lateral (DL) or posterolateral (PL) approach for displaced femoral neck fracture.

DESIGN

Prospective cohort study.

SETTING

A secondary teaching hospital.

PARTICIPANTS

We enrolled 183 hips operated with hemiarthroplasty for displaced femoral neck fracture using the DL or PL approach.

INTERVENTIONS

Preoperatively, we evaluated the Harris hip score (HHS) and European Quality of Life-5 Dimensions (EQ-5D). At 1 year postoperatively, lucid patients were clinically examined to evaluate the Trendelenburg sign, abductor muscle strength with a dynamometer, and trochanteric tenderness with an electronic algometer. The 1-year HHS and EQ-5D were documented.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of postoperative Trendelenburg sign, whereas the secondary outcomes included patients' reported limp, abductor muscle strength, trochanteric tenderness, HHS, and EQ-5D.

RESULTS

There were 48 patients (24 in the DL group and 24 in the PL group) who attended the 1-year clinical follow-up. The 2 groups were comparable (P > 0.05). The DL group showed a higher incidence of the Trendelenburg sign (9/24 vs. 1/24, P = 0.02) and limp (12/24 vs. 2/24, P = 0.004). Further analysis with logistic regression showed the surgical approach to be the only factor that resulted in the increment. No differences regarding HHS, EQ-5D, abductor muscle strength, algometer pressure pain threshold, and radiologic measurements were found (P > 0.05).

CONCLUSIONS

The incidence of the Trendelenburg sign and limp were significantly higher in the DL approach although this seemed not to influence abductor muscle strength or the incidence of trochanteric tenderness or compromise the clinical outcome.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

To predict sufentanil requirement for postoperative pain control using a real-time method: A prospective observational cohort study

Preoperative identification of individual sensitivity to opioid analgesics could improve the quality of postoperative analgesia. We explored the feasibility and utility of a real-time assessment of sufentanil sensitivity in predicting postoperative analgesic requirement.Our primary study included 111 patients who underwent measurements of pressure and quantitative pricking pain thresholds before and 5 minutes after sufentanil infusion. Pain intensity was assessed during the first 24-hour postsurgery, and patients who reported inadequate levels of analgesia were excluded from the study. The sufentanil requirement for patient-controlled analgesia was recorded, and a subsequent exploratory study of 20 patients facilitated the interpretation of the primary study results. In the primary study, experimental pain thresholds increased (P < 0.001) 5 minutes after sufentanil infusion, and the percent change in pricking pain threshold was positively associated with sufentanil requirement at 12 and 24 hours after surgery (β = 0.318, P = 0.001; and β = 0.335, P = 0.001). A receiver-operating characteristic curve analysis showed that patients with a change in pricking pain threshold >188% were >50% likely to require more sufentanil for postoperative pain control. In the exploratory study, experimental pain thresholds significantly decreased after the operation (P < 0.001), and we observed a positive correlation (P < 0.001) between the percent change in pricking pain threshold before and after surgery. Preoperative detection of individual sensitivity to sufentanil via the above described real-time method was effective in predicting postoperative sufentanil requirement. Thus, percent change in pricking pain threshold might be a feasible predictive marker of postoperative analgesia requirement.

The immediate effects of thoracic transverse mobilization in patients with the primary complaint of mechanical neck pain: a pilot study

OBJECTIVE

Posterior-to-anterior (PA) vertebral mobilization to the thoracic spine has been studied as an intervention for neck pain. Our purpose was to explore effects of a different mobilization technique, transverse vertebral pressure, on cervical range of motion (ROM) and pain when applied to the thoracic spine among participants with neck pain.

METHODS

A single-blinded quasi-experimental study with a one-group pretest-posttest design. A transverse group consisted of 21 participants whose neck pain increased with active movements. A non-intervention group of 20 asymptomatic participants was included simply to ensure rater blinding. The treatment group received Grades IV to IV+ transverse mobilizations at T1 through T4 bilaterally. Measurements taken immediately after intervention included pre/post cervical ROM, distant pressure pain threshold (PPT), and a numerical pain rating scale (NPRS). Analysis utilized t-tests and ordinal counterparts.

RESULTS

The transverse group demonstrated significant gains in extension and bilateral rotation (P≤0.005) but not flexion or side-bend. A total of 57% of mobilized participants reported clinically meaningful decreased pain (P<0.001). Seven participants exceeded the PPT MDC95 of 0.36 kg/cm(2). The non-intervention group had no significant changes in ROM or NPRS scores.

DISCUSSION

After 8 minutes of transverse mobilization to the upper thoracic spine, significant gains in cervical extension and bilateral rotation, and decreased pain scores were found. There were no adverse effects. Unlike other mobilization studies, PPT changes at a remote site were statistically but not clinically meaningful. Findings suggest that transverse mobilization would be a productive topic for controlled clinical trials.

Postoperative analgesia after low-frequency electroacupuncture as adjunctive treatment in inguinal hernia surgery with abdominal wall mesh reconstruction

OBJECTIVE

To determine whether an electroacupuncture (EA) technique that was developed for a surgical population under general anaesthesia reduces pain after mesh inguinal hernia open repair.

METHODS

A total of 54 patients with right or left inguinal hernia were randomised to group I (preoperative, intraoperative, postoperative EA), group II (preoperative, postoperative EA), or a sham control group (group III; preoperative and postoperative placement of needles, but without skin penetration). The Visual Analogue Scale (VAS) (primary outcome) and the State-Trait Anxiety Spielberger Inventory were evaluated preoperatively and at 30 min, 90 min, 10 h and 24 h after surgery. Pain threshold and tolerance were evaluated using an algometer at these same time points and preoperatively before and after EA. Levels of the stress hormones cortisol, corticotrophin and prolactin were determined at 30 min, 90 min and 10 h after surgery and preoperatively before and after EA.

RESULTS

The results showed significant differences between the true EA and control groups. The true EA groups (I and II) showed statistically significantly greater improvements in the primary (VAS pain, p<0.05) and secondary outcome measures (Anxiety scale; algometer measurements, p<0.05 and stress hormones, p<0.01) compared to the control group. There were no statistically significant differences between groups I and II.

CONCLUSIONS

Electroacupuncture reduces postoperative pain after mesh inguinal hernia repair and decreases stress hormone levels and anxiety during the postoperative period.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier NCT01722253.

A new real-time method for detecting the effect of fentanyl using the preoperative pressure pain threshold and Narcotrend index: a randomized study in female surgery patients

Individual variability in the effects of opioid analgesics such as fentanyl remains a major challenge for tailored pharmacological treatment including postoperative analgesia. This study aimed to establish a new real-time method for detecting the effects of fentanyl and their individual differences in the preoperative period, using the pressure pain threshold (PPT) and Narcotrend index (NTI) test.Eighty women undergoing elective surgery under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study to receive either intravenous fentanyl (Group F) or saline (Group S). Before (T1) and 5 (T2) and 10 min (T3) after intravenous injection, the PPT, NTI, respiratory rate, heart rate, blood pressure, and pulse oxygen saturation were measured. The initial time at which the Narcotrend index showed a decline was also recorded.In total, 40 patients in Group S and 38 patients in Group F were included in the final analysis. At 5 min and 10 min after intravenous fentanyl administration, the analgesic effect was determined by measuring the PPT, which was significantly increased (P < 0.001), and the sedative effect was detected using the NTI, which was significantly decreased (P < 0.001). The distribution of percentage changes of the PPT and NTI showed individual differences. At T2 and T3, the absolute changes in NTI and PPT were positively correlated (r = 0.444 at T2, P = 0.005; r = 0.332 at T3, P = 0.042).Through the PPT and NTI, it was feasible to easily detect the effects of fentanyl and their individual differences in real time before induction of anesthesia in the operation room. This method could potentially be applied to preoperatively determine patients' sensitivity to fentanyl.

Treatment of reducible unstable fractures of the distal radius: randomized clinical study comparing the locked volar plate and external fixator methods: study protocol

BACKGROUND

Various treatments are available for reducible unstable fractures of the distal radius, such as closed reduction combined with fixation by external fixator (EF), and rigid internal fixation using a locked volar plate (VP). Although there are studies comparing these methods, there is no conclusive evidence indicating which treatment is best. The hypothesis of this study is that surgical treatment with a VP is more effective than EF from the standpoint of functional outcome (patient-reported).

METHODS/DESIGN

The study is randomized clinical trial with parallel groups and a blinded evaluator and involves the surgical interventions EF and VP. Patients will be randomly assigned (assignment ratio 1:1) using sealed opaque envelopes. This trial will include consecutive adult patients with an acute (up to 15 days) displaced, unstable fracture of the distal end of the radius of type A2, A3, C1, C2 or C3 by the Arbeitsgemeinschaft für Osteosynthesefragen-Association for the Study of Internal Fixation classification and type II or type III by the IDEAL32 classification, without previous surgical treatments of the wrist. The surgical intervention assigned will be performed by three surgical specialists familiar with the techniques described. Evaluations will be performed at 2, and 8 weeks, 3, 6 and 12 months, with the primary outcomes being measured by the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and measurement of pain (Visual Analog Pain Scale and digital algometer). Secondary outcomes will include radiographic parameters, objective functional evaluation (goniometry and dynamometry), and the rate of complications and method failure according to the intention-to-treat principle. Final postoperative evaluations (6 and 12 months) will be performed by independent blinded evaluators. For the Student's t-test, a difference of 10 points in the DASH score, with a 95% confidence interval, a statistical power of 80%, and 20% sampling error results in 36 patients per group.

DISCUSSION

Results from this study protocol will improve the current evidence regarding to the surgical treatment these fractures.

TRIAL REGISTRATION

ISCRTN09599740.

An improvement of mechanical pain sensitivity measurement method: the smaller sized probes may detect heterogeneous sensory threshold in healthy male subjects

OBJECTIVE

On the basis of our experience in the application of the mechanical algometer and a number of pilot experiments, we speculated that 0.1- and 0.01-cm(2) probes might improve the measurement of mechanical pain sensitivity relative to the conventional 1-cm(2) probe. Here, we examined the accuracy, feasibility, and applicability of these probes in detecting the mechanical pain sensitivity.

DESIGN

Mechanical pain threshold and tolerance tests were performed on subjects using the three probes of 1, 0.1, and 0.01 cm(2) in random order. We compared the application of these probes.

SETTING

The study was set at the Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

SUBJECTS

Fifty healthy male Han Chinese subjects were recruited.

OUTCOME MEASURES

We compared the qualities of stimulus-evoked pain, test stability, the measuring time, the subjects' acceptance level of the procedure, the validity of pain measurement, and the arduousness of the task for the investigator among the three different size probes.

RESULTS

Compared with the conventional 1-cm(2) probe, the 0.01- and 0.1-cm(2) probes resulted in the subjects responding to stimulus-evoked pain more quickly, accurately, and consistently, and also made the measurement more comfortable for investigators. Up to 80% of the subjects reported the pain quality as a pricking sensation when the 0.01-cm(2) probe was used.

CONCLUSION

The use of the 0.1-cm(2) probe might be more suitable as an optimized method for the detection of pressure pain sensitivity in clinical studies. In addition, the 0.01-cm(2) probe could potentially serve as an alternative to the weighted needle pinprick, providing continuous quantizing detection for pricking pain sensitivity.

A single-nucleotide polymorphism in SCN9A may decrease postoperative pain sensitivity in the general population

BACKGROUND

This study aimed to explore the role of a nonsynonymous single-nucleotide polymorphism, 3312G>T, in SCN9A, which was identified in probands with congenital indifference to pain, but which is also present in normal controls, in the prediction of individual baseline pain perception, and postoperative pain sensitivity in the general population.

METHODS

Preoperative pressure pain thresholds and tolerance were measured in 200 patients undergoing pancreatectomy, and the postoperative pain sensitivity and analgesic demand were recorded. These variables were compared according to the SCN9A 3312G>T alleles. Logistic regression analysis was used to test the role of preoperative variables in the prediction of postoperative inadequate analgesia.

RESULTS

The 3312Tallele was present in 22 individuals, and the 3312Tallele frequency was 5.5% (22/200). The average patient-controlled analgesia pressing frequency and opioid consumption in 3312G patients was significantly higher than those in 3312T patients (2.70 [SD: 0.84] vs. 2.05 [SD: 0.43], P < 0.001; 100.8 [SD: 40.7] vs. 74.8 [SD: 20.8] ml, P = 0.006). The incidence of inadequate analgesia in 3312G patients was significantly higher than that of patients carrying the 3312Tallele (29.2% vs. 4.5%; P = 0.013). Carrying the 3312Tallele and having a higher pressure pain threshold predicted a lower risk of postoperative inadequate analgesia, with an odds ratio of 0.10 (95% CI: 0.01 to 0.76, P = 0.026) and 0.32 (95% CI: 0.13 to 0.82, P = 0.018), respectively.

CONCLUSION

Patients carrying the SCN9A 3312Tallele presented with lower postoperative pain sensitivity in the presence of a similar surgical pain stimulus, and had a lower likelihood of developing inadequate analgesia than those carrying the 3312Gallele.

Pain assessment in patellar tendinopathy using pain pressure threshold algometry: an observational study

OBJECTIVE

Assessing pain in patellar tendinopathy (PT) is difficult to perform in a standardized way. With this study, we measured pain in athletes with PT by means of pain pressure threshold (PPT) algometry in a standardized manner. Subsequently, the goal of this study is to determine normative values for clinical use.

DESIGN

Observational study.

SETTING

Patients and healthy subjects were recruited from an outpatient clinic of a university medical center and at different sports clubs in northern Netherlands.

SUBJECTS

A total of 234 athletes, 114 diagnosed with PT and 120 healthy controls, were included.

OUTCOME MEASURES

PPT, Victorian Institute of Sport Assessment-Patellar tendinopathy questionnaire, and visual analog scale-pain.

RESULTS

PPT scores of PT athletes with tendinopathy were significantly lower compared with healthy athletes (Mann-Whitney U-test; U = 293.5; P < 0.001). With a receiver operating characteristic (ROC) curve, the optimal cut-off point to distinguish between healthy athletes and PT athletes was calculated at 36.8 N. The area under the ROC curve was 0.98 (95% CI: 0.96-1.0). There was a positive predictive value of 96.5% that athletes with a PPT below 36.8 N. had PT.

CONCLUSIONS

PPT algometry should be considered by clinicians as a pain assessment tool in patients with PT. The optimal cut-off point for the PPT to distinguish between PT athletes and healthy athletes was 36.8 N.

Quantitative sensory testing in painful osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To systematically review the use of quantitative sensory testing (QST) in pain characterisation (phenotyping) in osteoarthritis (OA).

METHODS

Six bibliographic databases (Medline, Embase, Amed, Cinahl, PubMed, Web of Science) were searched to identify studies published before May 2011. Data were extracted based on the primary site of OA, QST modalities, outcome measures and test sites. Standardised mean difference (SMD) and 95% confidence intervals (CIs) were calculated if possible. Publication bias was determined using funnel plot and Egger's test. Heterogeneity was examined using Cochran Q test and I2 statistic. Random effects model was used to pool the results.

RESULTS

Of 41 studies (2281 participants) included, 23 were case control studies, 15 case only studies, two randomised controlled trials, and one uncontrolled trial. The majority of studies examined pressure pain with smaller numbers using electrical and/or thermal stimuli. QST was more often applied to the affected joint than distal and remote sites. Of 20 studies comparing people with OA and healthy controls, seven provided sufficient information for meta-analysis. Compared with controls, people with OA had lower pressure pain thresholds (PPTs) both at the affected joint (SMD = -1.24, 95% CI -1.54, -0.93) and at remote sites (SMD = -0.88, 95% CI -1.11, -0.65).

CONCLUSION

QST of PPTs demonstrated good ability to differentiate between people with OA and healthy controls. Lower PPTs in people with OA in affected sites may suggest peripheral, and in remote sites central, sensitisation. PPT measurement merits further evaluation as a tool for phenotyping OA pain.

Acupuncture as an adjunctive therapy to pharmacological treatment in patients with chronic pain due to osteoarthritis of the knee: a 3-armed, randomized, placebo-controlled trial

The efficacy of acupuncture as an adjunctive therapy to pharmacological treatment of chronic pain due to knee osteoarthritis was studied with a 3-armed, single-blind, randomized, sham-controlled trial; it compared acupuncture combined with pharmacological treatment, sham acupuncture including pharmacological treatment, and pharmacological treatment alone. A total of 120 patients with knee osteoarthritis were randomly allocated to 3 groups: group I was treated with acupuncture and etoricoxib, group II with sham acupuncture and etoricoxib, and group III with etoricoxib. The primary efficacy variable was the Western Ontario and McMaster Universities (WOMAC) index and its subscales at the end of treatment at week 8. Secondary efficacy variables included the WOMAC index at the end of weeks 4 and 12, a visual analogue scale (VAS) at the end of weeks 4, 8, and 12, and the Short Form 36 version 2 (SF-36v2) health survey at the end of week 8. An algometer was used to determine changes in a predetermined unique fixed trigger point for every patient at the end of weeks 4, 8, and 12. Group I exhibited statistically significant improvements in primary and secondary outcome measures, except for Short Form mental component, compared with the other treatment groups. We conclude that acupuncture with etoricoxib is more effective than sham acupuncture with etoricoxib, or etoricoxib alone for the treatment of knee osteoarthritis.

Experimental pressure-pain assessments: Test-retest reliability, convergence and dimensionality

Introduction

Experimental pain studies can provide unique insight into the dimensions of pain and into individual differences in pain responsiveness by controlling different aspects of pain-eliciting stimuli and pain measures. In experimental pain studies, pain responsiveness can be assessed as pain threshold, pain tolerance or pain ratings. The test-theoretical qualities of these different measures, however, have not yet been completely documented. In the current study, several of these qualities were investigated in a pain experiment applying different algometric techniques. The objective of the study was to investigate the reliability (test–retest) and the convergent validity (correspondence) of the different methods found in the literature of measuring pressure-pain threshold, and the interrelationship between pressure-pain threshold, pressure-pain tolerance, and pressure-pain ratings.

Methods

Sixty-six healthy female subjects were enrolled in the study. All pressure stimuli were applied by a trained investigator, using a digital algometer with a 1 cm2 rubber tip. Pressure-pain thresholds were assessed repeatedly on six different body points (i.e. left and right calf one third of total calf muscle length below the popliteal space), the lower back (5 cm left and right from the L3), and left and right forearm (thickest part of brachioradialis muscle). Next, pressure-pain tolerance was measured on the thumbnail of the non-dominant hand, followed by rating affective and sensory components (on visual analogue scales) of a stimulus at tolerance level. Last, affective and sensory ratings were obtained for two pressure intensities.

Results

With intraclass correlations above .75 for pain responses per body point, test–retest reliability was found to be good. However, values obtained from all first measurements were significantly higher as compared with the two succeeding ones. Convergent validity of pain thresholds across different body points was found to be high for all combinations assessed (Cronbach’s alpha values >.80), but the highest for bilateral similar body parts (>.89). Finally, principal components analysis including measures of threshold, tolerance and pain ratings yielded a three-factor solution that explained 81.9% of the variance: Moderate-level stimulus appraisal & pain tolerance; Pain threshold; Tolerance-level stimulus appraisal.

Conclusion and implications

Findings of the current study were used to formulate recommendations for future algometric pain studies. Concerning pressure-pain threshold, it is recommended to exclude first measurements for every body point from further analyses, as these measurements were found to be consistently higher compared with the following measurements. Further, no more than two consecutive measurements (after the first measurement) are needed for a reliable mean threshold value per body point. When combining threshold values of several body points into one mean-aggregated threshold value, we suggest to combine bilateral similar points, as convergent validity values were highest for these combinations. The three-factor solution that was found with principal components analyses indicates that pressure-pain threshold, subjective ratings of moderate intensity stimuli, and subjective ratings of the maximum (tolerance) intensity are distinct aspects of pain responsiveness. It is therefore recommended to include a measure of each of these three dimensions of pain when assessing pressure pain responsiveness. Some limitations of our study are discussed.

Distal lengthening of ilio-tibial band by Z-plasty for treating refractory greater trochanteric pain after total hip arthroplasty (Pedersen-Noor operation)

INTRODUCTION

The development of greater trochanteric pain (GTP) after total hip arthroplasty (THA) represents a special category. Despite that treatment is mainly conservative, some patients show poor response and surgical intervention should be considered. We propose a new method consisting of distal lengthening of ilio-tibial band (ITB) by Z-plasty.

MATERIAL AND METHODS

Between March 2004 and June 2006, 12 women with refractory GTP after THA were operated on using distal ITB lengthening. The procedure was done under local anaesthesia on an outpatient basis. The patients were followed up 3-4 months postoperatively by phone interview and at 1-3 years by EQ-5D questionnaire and clinical examination including tenderness evaluation with algometer.

RESULTS

All patients improved significantly (EQ-5D = 0.26 preoperatively vs. 0.67 postoperatively; P < 0.005) except one patient who experienced no change in GTP symptoms. No postoperative complications were reported.

CONCLUSION

We believe that treating patients with GTP after THA by the technique described offers a simple, safe and reliable method.

Outcome measures for evaluation of treatments for osteonecrosis

With the advent of cell-based therapies, biologics, and pharmaceuticals for the potential treatment of osteonecrosis, it is important to conduct evaluations using scientifically accepted outcomes measures. For the treatment of osteonecrosis, most studies have focused on pain relief, surgery, or the need for surgery, disease progression (advancing stage), and change in lesion size. Quantification of imaging techniques continue to gain in sophistication but have not yet been validated for use in clinical trials. Despite recent interest in using biomarkers or genetic markers in the diagnosis and analysis of disease progression, more research is needed to determine the sensitivity and specificity of these techniques with respect to osteonecrosis.