Subsequent Pain Relief Research Articles

Patterns of glenoid bone loss in revision of anatomic shoulder arthroplasty: the impact of prior glenoid resurfacing

BackgroundHistorically, glenoid resurfacing has been avoided in the young patient due to a perceived risk of early glenoid loosening and destructive bone loss. As a result, many young patients with end-stage arthritis undergo humeral-based hemiarthroplasty with subsequent incomplete pain relief. The aim of this study was to determine the status of glenoid bone stock in patients undergoing revision of a painful hemiarthroplasty versus anatomic total shoulder arthroplasty (aTSA). MethodsUsing an institutional shoulder arthroplasty revision database, all patients undergoing revision for aseptic glenoid-based pain after hemiarthroplasty or glenoid loosening of aTSA were identified. Patient demographics, implant longevity prior to revision, and implanted construct at revision were collected for each patient. Based upon preoperative plain films, computed tomography when available, and intraoperative documentation, the status of the glenoid bone stock was described. ResultsA total of 39 patients (14 aTSA and 25 hemiarthroplasty) met the inclusion criteria. No statistically significant difference in age at the time of index arthroplasty (56.4 vs. 52.4 years; P = .18), age at time of revision (64.5 vs. 59.0 years; P = .07), proportion of males (64.2% vs. 56.0%; P = .74), or longevity of the revised implant (110.9 vs. 79.2 months; P = .08) were identified between the aTSA and hemiarthroplasty cohorts, respectively. Patients undergoing revision of aTSA were more likely to receive a reverse total shoulder arthroplasty at revision (85.7% vs. 48%; P = .04). Peripheral wear alone was noted in 40% (10/25) of hemiarthroplasty revisions and central defect alone was noted in 79% (11/14) of aTSA revisions. Combined defects (central and peripheral bone loss) were noted in three patients undergoing revision of an aTSA (21.4%) and five undergoing revision of a hemiarthroplasty (20%; P = 1.0). The number of cases with medialization at or beyond the coracoid (Kocsis Grade 2; 42.9% vs. 40%) and at or beyond the spinoglenoid notch (Kocsis Grade 3; 14% vs. 12%) was not different between groups (P = 1.0). Structural bone graft or augmented glenoid components were used at the time of revision in 29% (4/14) and 32% (8/25) of failed aTSA and hemiarthroplasty, respectively (P = 1.0). ConclusionDespite variability in the cohorts, this study demonstrates no significant improvement in residual glenoid bone stock by deferring glenoid resurfacing at the time of shoulder arthroplasty. At the time of glenoid-based failure, glenoid resurfacing results in central bone loss while hemiarthroplasty results in peripheral/eccentric bone loss.

Serial ganglion impar blocks in a patient with nutcracker syndrome refractory to left renal vein transposition: a case report

BackgroundNutcracker syndrome is a rare disorder caused by compression of the left renal vein, usually between the aorta and the superior mesenteric artery. It typically presents with left-sided abdominal pain and hematuria. Left renal vein transposition is the most commonly employed surgical technique to alleviate the compression.Case presentationA 22-year-old Caucasian man with a known diagnosis of nutcracker syndrome had undergone left renal vein transposition 1 year before presentation without any subsequent pain relief. In addition, his surgery was complicated by massive blood loss and a 1-week-long stay in an intensive care unit (ICU); as such, he was not amenable to further surgical intervention or stenting to treat his underlying pathology. His symptoms included constant sharp left-sided flank, perineal, and testicular pain. A series of ganglion impar blocks were performed every 3–4 months over the course of 5 years with substantial pain relief achieved.ConclusionsOur case report highlights a treatment option that has not yet been described for patients with pain secondary to nutcracker syndrome refractory to surgical intervention.

Lumbopelvic Fixation in Unstable Traumatic Spinopelvic Sacral Fractures: Clinical and Radiological Outcome

Background Data: Although most sacral fractures can be treated conservatively, several surgical options are available for highly unstable fractures. Surgery aims to provide sacral realignment, fixation, and maybe neural decompression with subsequent pain relief and early mobilization. Surgical options are variable depending on the type of fractures and surgeon’s experience. Spinopelvic fixation is one of the famous surgical procedures. Purpose: To evaluate the safety and efficacy of lumbopelvic fixation for the treatment of unstable traumatic spinopelvic sacral fractures. Study Design: Prospective cohort study. Patients and Methods: All patients with unstable spinopelvic sacral fractures excluding those with other types of sacral fractures were recruited for this study. All patients were submitted to lumbopelvic fixation. Patients were evaluated clinically and radiologically, including full lumbar and pelvis X-Ray and 3D MSCT scan at the pre- and postoperative period. Clinical parameters included a full neurological examination, VAS, ODI, and modified Rankin scale. Results: A total of 15 patients including 7 males and 8 females with mean age of 28±8.11 years were recruited for this study. All patients were suffering from unstable traumatic spinopelvic type C sacral fractures according to AO Spine sacral fractures classification system. Four patients suffered from type C0, 2 from C1, 4 from C2, and 5 from C3. Neural insults were reported in 13 patients. The mean follow-up period was 19.2±8.6 (range, 6–36) months. The mean preoperative VAS improved from 8.13±1.25 to 2.6±1.01 postoperatively, while the mean preoperative ODI improved from 88.53±2.24 to 16.8±3.16 postoperatively. According to the modified Rankin scale for functional recovery, 14 (93.3%) of the patients were categorized as excellent and good, while only one patient (6.6%) was categorized as fair outcome. Complete fractures’ healing was reported in all patients and none required any revision procedure. Deformity correction was incomplete in 40% without clinical effects on patients. Surgical site infection was reported in 3 patients and one of them necessitated debridement. Conclusion: Lumbopelvic fixation is a safe and effective procedure in the treatment of unstable traumatic spinopelvic sacral fractures. (2019ESJ196)

Targeted cyclooxygenase-2 inhibiting nanomedicine results in pain-relief and differential expression of the RNA transcriptome in the dorsal root ganglia of injured male rats.

Chronic constriction injury of the sciatic nerve in rats causes peripheral neuropathy leading to pain-like behaviors commonly seen in humans. Neuropathy is a leading cause of neuropathic pain, which involves a complex cellular and molecular response in the peripheral nervous system with interactions between neurons, glia, and infiltrating immune cells. In this study, we utilize a nonsteroidal anti-inflammatory drug -loaded nanoemulsion to deliver the cyclooxygenase-2 inhibitor, Celecoxib, directly to circulating monocytes following nerve injury, which provides long-lasting pain relief. However, it is not fully understood how cyclooxygenase-2 inhibition in a macrophage traveling to the site of injury impacts gene expression in the dorsal root ganglia. To elucidate aspects of the molecular mechanisms underlying pain-like behavior in chronic constriction injury, as well as subsequent pain relief with treatment, we employ RNAseq transcriptome profiling of the dorsal root ganglia associated with the injured sciatic nerve in rats. Using high throughput RNA sequencing in this way provides insight into the molecular mechanisms involved in this neuroinflammatory response. We compare the transcriptome from the dorsal root ganglias of the following study groups: chronic constriction injury animals administered with cyclooxygenase-2 inhibiting celecoxib-loaded nanoemulsion, chronic constriction injury animals administered with vehicle treatment, a drug-free nanoemulsion, and a group of naïve, unoperated and untreated rats. The results show an extensive differential expression of 115 genes. Using the protein annotation through evolutionary relationship classification system, we have revealed pain-related signaling pathways and underlying biological mechanisms involved in the neuroinflammatory response. Quantitative polymerase chain reaction validation confirms expression changes for several genes. This study shows that by directly inhibiting cyclooxygenase-2 activity in infiltrating macrophages at the injured sciatic nerve, there is an associated change in the transcriptome in the cell bodies of the dorsal root ganglia.

MRI and CT Guided Cryoablation for Intracranial Extension of Malignancies along the Trigeminal Nerve.

Objectives To describe the technical aspects and early clinical outcomes of patients undergoing percutaneous magnetic resonance imaging (MRI)-guided tumor cryoablation along the intracranial trigeminal nerve. Design This study is a retrospective case review. Setting Large academic tertiary care hospital. Participants Patients who underwent MRI-guided cryoablation of perineural tumor along the intracranial trigeminal nerve. Main Outcome Measures Technical success, pain relief, local control. Results Percutaneous MRI-guided cryoablation of tumor spread along the intracranial portion of the trigeminal nerve was performed in two patients without complication, with subsequent pain relief, and with local control in the patient with follow-up imaging. Conclusions Percutaneous MRI-guided cryoablation is a feasible treatment option for malignancies tracking intracranially along the trigeminal nerve.

The Effect of a Subsequent Pregnancy After Ovarian Vein Embolization in Patients with Infertility Caused by Pelvic Congestion Syndrome

To report the effect of pregnancy on patients who have undergone pelvic vein embolization with pelvic congestion syndrome, which was suspected to be the only cause of infertility. Data from a total of 12 women (mean age: 36.5 ± 4.3 years, range: 29-45 years) were collected between May 2013 and June 2016. Transvenous embolization with fibre platinum coils combined with anhydrous alcohol was performed in unilateral or bilateral ovarian veins after the diagnosis of venous varices confirmed by transvaginal ultrasound or pelvic venography. The follow-up time was 2-3 years. The primary outcomes of this study were the technical procedure and clinical effect, especially the pregnancy rate and complications. The successful embolization rate was 100% with no significant complications during or after embolization. Ovarian vein embolization was performed unilaterally (7/12, 58.3%) or bilaterally (5/12, 41.7%). A total of 66.7% (8/12) of women had a subsequent pregnancy and complete pelvic pain relief, and 33.3% (4/12) of patients had partial pain relief. The numeric pain perception scores improved from 6.7 ± 1.1 to 2.7 ± 1.2 (p < 0.001). Ovarian varices may be associated with infertility in some patients, and embolization of ovarian varices is a safe and effective method for those trying to become pregnant.

Does Immediate Pain Relief After an Injection into the Sacroiliac Joint with Anesthetic and Corticosteroid Predict Subsequent Pain Relief?

To determine if immediate pain response following an injection with local anesthetic and corticosteroid predicts subsequent relief. Prospective observational cohort. An institutional review board-approved prospective study from a single academic medical center. Patients with clinical diagnosis of sacroiliac (SIJ) pain and referred for SIJ injection were enrolled; 1 cc of 2% lidocaine and 1 cc of triamcinolone 40 mg/mL were injected into the SIJ. Pain score on 0-10 numeric rating scale (NRS) during provocation maneuvers was recorded immediately before injection, immediately after injection, and at two and four weeks of follow-up. Oswestry Disability Index (ODI) was also recorded. Various cutoffs were identified to establish positive anesthetic response and successful outcomes at follow-up. These were used to calculated likelihood ratios. Of those with 100% anesthetic response, six of 11 (54.5%, 95% confidence interval [CI]+/-29.4%, +LR 2.6, 95% CI = 1.1-5.9) demonstrated 50% or greater pain relief at follow-up, and four of 11 (36.5%, 95% CI+/-28.4%, +LR 3.00, 95% CI = 1.4-5.1) had 100% relief at two to four weeks. Fourteen of 14 (100%, 95% CI+/-21.5%, -LR 0.0, 95% CI = 0.0-2.1) with an initial negative block failed to achieve 100% relief at follow-up. Patients who fail to achieve initial relief after SIJ injection with anesthetic and steroid are very unlikely to achieve significant pain relief at follow-up; negative likelihood ratios (LR) in this study, based on how success is defined, range between 0 and 0.9. Clinically significant positive likelihood ratios of anesthetic response to SIJ injection are more limited and less robust, but are valuable in predicting 50% relief or 100% relief at two to four weeks.

Heart rate variability during treatment of breakthrough pain in patients with advanced cancer: a pilot study.

BackgroundDecisions on the intensity of analgesic therapy and judgments regarding its efficacy are difficult at the end of life, when many patients are not fully conscious and pain is a very common symptom. In healthy individuals and in postoperative settings, nociception and subsequent pain relief have been shown to induce changes in the autonomic nervous system (ANS), which can be detected by measuring heart rate variability (HRV).ObjectivesThe changes in the ANS were studied by measuring HRV during opioid therapy for cancer breakthrough pain (CBTP) in palliative-care patients with cancer and compared these changes with patient-reported pain levels on a numeric rating scale (NRS).Patients and methodsThe study included ten patients with advanced cancer and baseline opioid therapy. In each patient, a 24-hour peak-to-peak HRV measurement with a sampling rate of 4,000 Hz was performed. High frequency (HF), low frequency (LF), total power, pNN50 (indicating parasympathetic activity), and log LF/HF were obtained in two intervals prior to therapy and in four intervals thereafter. Intensity of CBTP was recorded using a patient-reported NRS prior to therapy and 30 minutes afterward.ResultsCBTP occurred in seven patients (three males and four females; mean age: 62 ± 5.2 years) and was treated with opioids. A highly significant positive correlation was found between opioid-induced reduction in patient-reported pain intensity based on NRS and changes in log LF/HF (r > 0.700; p < 0.05). Log LF/HF decreased in patients who had a reduction in pain of >2 points on the NRS but remained unchanged in the other patients.ConclusionOur data suggest that log LF/HF may be a useful surrogate marker for alleviation of CBTP in patients with advanced cancer and might allow detection of pain without active contribution from patients.

Effects of perceived and exerted pain control on neural activity during pain relief in experimental heat hyperalgesia: A fMRI study

Perceived control over pain can attenuate pain perception by mechanisms of endogenous pain control and emotional reappraisal irrespective of whether this control is exerted or only perceived. Self-initiated termination of pain elicits different expectations of subsequent pain relief as compared to perceived pain control. It is unknown whether and how this perceived vs. exerted control on pain differs and affects subsequent pain relief. Using fMRI, we studied two factors of pain control on pain relief: the (i) sense of control (perceived control but no execution) and (ii) the execution of control (exerted control). To account for the impact of factual execution of pain control on pain relief we applied bearable short and hardly bearable long contact-heat stimuli which were applied either controllable or not. Using controllability as factor, there was dissociable neural activity during pain relief: following the perceived control condition neural activity was found in the orbitofrontal and mediofrontal cortex and, following the exerted control condition, in the anterolateral and dorsolateral prefrontal cortex and posterior parietal cortex. We conclude that (i) pain controllability has an impact on pain relief and (ii) the prefrontal cortex shows dissociable neural activity during pain relief following exerted vs. perceived pain control. This might reflect the higher grade of uncertainty during pain relief following perceived pain control mediated by the orbitofrontal and medial prefrontal cortex and processes of working memory and updating expectations during pain relief following exerted control mediated by the lateral prefrontal cortex.

Evaluation of ultrasound-guided diagnostic local anaesthetic hip joint injection for osteoarthritis

The diagnosis of hip osteoarthritis is often complicated by co-existing pathology in the knee and spine, and mismatch between clinical and radiological signs. Temporary pain relief from a local anaesthetic injection into the hip joint has been reported to help localise symptoms, reducing the risk of unnecessary surgery being performed. We hypothesize that good surgical outcome is predicted by good analgesia following diagnostic injection, and that alternative pathology is present when there is no response to injection. Data were analysed from a prospective database of 163 consecutive patients who underwent diagnostic hip injection for possible osteoarthritis. We recorded result of injection and whether hip arthroplasty was performed. A good outcome to surgery was defined as subsequent pain relief without significant residual symptoms. A total of 138 patients were suitable for inclusion in the study. Fifty-eight patients had hip arthroplasty following a good response to diagnostic injection. Of these 54 had a good outcome following surgery (93%). There was also a quantitative improvement in pain and function in these patients as measured by 1year post-operative and pre-operative Harris hip scores (P < 0.0001). A total of 44/49 patients had no surgery following no response to injection. A clear alternative diagnosis to hip osteoarthritis was made in 40 of these patients (91%). Diagnostic ultrasound-guided local anaesthetic injection of the hip joint is a useful test in confirming hip pathology. Complete relief of hip pain following intracapsular injection of local anaesthetic is associated with good surgical outcome following joint replacement.

Safety and acceptability of suprascapular nerve block in rheumatology patients

Suprascapular nerve block (SSNB) is a popular treatment for shoulder pain. To date, studies undertaken mainly describe the methods of performing the technique or are trials examining its efficacy. As a result, the numbers of blocks reported are small and therefore confidence in the safety of the procedure must be limited. Furthermore, although most studies report pain reduction using visual analogue scales, there are no reports of patient satisfaction with the subsequent pain relief. This study aimed (1) to determine the safety of SSNB in a population of patients presenting in rheumatology practice and (2) to determine the patient satisfaction with the pain relief. From 2003 to 2009, 1,005 SSNBs were undertaken by rheumatologists in several centres in South Australia. All patients who had at least one SSNB performed were identified. Case notes were examined and patients were contacted to identify any side effects from the procedure. Patients were also asked to report their satisfaction with the pain relief. Of the 1,005 nerve blocks performed, there were a total of six side effects. They were three episodes of transient dizziness, two episodes of transient arm weakness and one episode of facial flushing. There were no serious side effects reported. Patient satisfaction with the pain relief was high, with over 80% of respondents being satisfied or very satisfied with the result. SSNB is a very safe procedure in the outpatient setting, even among frail, elderly patients. Patients rate the satisfaction with the pain relief highly.

Drug Disease Interactions: Role of Inflammatory Mediators in Pain and Variability in Analgesic Drug Response

Pain has both physical and emotional components. Physical noxious stimuli activate peripheral sensory neurons that, in turn, relay signals to the spinal and supraspinal nuclei. Subsequently, these signals activate areas within the brain associated with pain. Despite considerable knowledge in this area, analgesics may provide pain complete relief in only one out of five patients. Failure to manage pain may be due to a lack of understanding of the neurobiological processing of pain. Factors such as anticipation, anxiety and pain history play roles in the perception of pain. Non-neuronal cells such as those of the immune system influence perception and modulation of pain by the nervous system. In post-dental surgery patients, the severity of the pain and the relief following administration of anti-inflammatory analgesics has been linked to the time course of inflammatory mediators. Similarly, the relief of post-operative pain after abdominal surgery is also associated with a reduction in expression of pro-inflammatory mediators. Administration of anti-cytokines to sciatica patients and subsequent pain relief further emphasizes the role of pro-inflammatory mediators in modulation of pain. Increased expression of inflammatory mediators may also alter response to analgesia. For example, rheumatoid patients with temporal mandibular joint disease with increased expression of interleukins prior to treatment demonstrate inadequate pain relief after administration of anti-TNF-. In addition, pain or its trauma impairs absorption of oral analgesics causing therapeutic failure. Improved analgesic pharmacotherapy may require a better understanding of the involvement of the inflammatory pathways.

Combined percutaneous transpedicular tumor debulking and kyphoplasty for pathological compression fractures

Percutaneous balloon kyphoplasty has become a widely adopted treatment option for patients with pain due to pathological compression fractures. One potential risk of the procedure is the displacement of tumor into the spinal canal and resulting spinal cord or cauda equina injury during inflation of the balloon prior to polymethylmethacrylate (PMMA) placement. In addition, the presence of any remaining tumor between the PMMA and the fractured cortical bone can lead to suboptimal improvement in stabilization and subsequent pain relief. The authors describe a technique to remove tumor from within the vertebral body (VB) through a percutaneous working channel prior to kyphoplasty balloon inflation and augmentation. The technique was successfully used in all three patients who had presented with pain, and the pain improved in all three cases. There was no extravasation of PMMA into the spinal canal in any case. A combined VB tumor debulking and kyphoplasty technique offers the ability to improve the placement of PMMA within the diseased vertebral body, potentially leading to increased safety as well as clinical effectiveness for stabilization of these fractures.

The effect of injection of two vs 10 mL saline on the subsequent spread and quality of epidural analgesia in parturients

Objective To determine whether two vs 10 mL of saline injected into the epidural space affects the subsequent spread and quality of epidural analgesia in parturients. Design Randomized, double-blinded, placebo-controlled study. Setting Delivery room. Patients 105 ASA physical status I and II parturients requesting epidural analgesia. Interventions After identification of the epidural space by the loss-of-resistance technique using normal saline, two mL of saline was then injected into the epidural space in the 2-mL group (n = 53) and 10 mL in the 10-mL group (n = 52). Five minutes after the test dose, patients received 10 mL of bupivacaine (0.1%) with fentanyl two μg mL −1. Measurements 25 minutes after the initial bolus of bupivacaine and fentanyl, spread of block, subsequent pain relief, and influence of the volume of the injected saline on the ease of epidural catheter insertion and on the incidence of blood vessel trauma and paresthesia were evaluated. Results The total number of dermatomes blocked for cold and pinprick sensation in the 10-mL group was significantly more than in the 2-mL group (19 [6-29] vs 15 [4-27] for cold sensation, P = 0.000; and 15 [3-29] vs 11.5 [3-26] for pinprick sensation, P = 0.001). However, the visual analog pain scale and need for supplemental analgesia were similar between the two groups. The epidural catheter was easily inserted in 94.2% of the 2-mL group and 100% of the 10-mL group. The incidence of blood vessel trauma was low and the incidence of paresthesia was high without any significant difference between the two groups. Conclusions 10 mL saline was associated with a higher total number of dermatomes blocked for both cold and pinprick sensation than the two mL saline. However, the pain relief was adequate in both groups, and two mL saline was as effective as the 10 mL in the ease of catheter insertion and prevention of intravascular cannulation.

Molekulare Grundlagen zur schmerzvermittelnden Wirkung extrakorporaler Sto�wellen

The biologic action of extracorporeal shock wave application on the musculoskeletal system is understood poorly. To prove the hypothesis that alterations of tissue concentrations of substance P and prostaglandin E(2) are involved in the biologic action of shock waves, extracorporeal shock waves with energy flux density of 0.9 mJ/mm(2 )(1500 pulses at 1/s) were applied in vivo to the distal femur of rabbits. The concentrations of substance P and prostaglandin E(2) eluated from the periosteum of the femur were measured. Compared with the untreated contralateral hindlimbs, substance P release from the periosteum from the femur was increased 6 and 24 h after extracorporeal shock wave application, but was decreased 6 weeks after extracorporeal shock wave application. By contrast, extracorporeal shock wave application did not result in altered prostaglandin E(2) release from the periosteum from the femur. Remarkably, there was a close relationship between the time course of substance P release found here, and the well-known clinical time course of initial pain occurrence and subsequent pain relief after extracorporeal shock wave application to tendon diseases. Accordingly, substance P might be involved in the biologic action of extracorporeal shock wave application on tissue of the musculoskeletal system. This is the first study providing insights into the molecular mechanisms of extracorporeal shock wave application to the musculoskeletal system.

MULTIDISCIPLINARY PAIN ABSTRACTS: 4 . Anesthesia (4)

In this study the authors investigated the duration of labor analgesia produced by a small dose of spinal bupivacaine/fentanyl alone or in combination with a small dose of morphine. Sixty parturients were enrolled in this placebo‐controlled, double‐blinded, randomized trial. All women received a spinal injection of 12.5 μg of fentanyl with 2 mg of bupivacaine. The morphine group (MBF) also received 125 μg of morphine; the placebo group (BF) received saline. Pain scores were &lt;3 of 10 within 10 minutes of the injection. The median duration of analgesia was similar between groups (89 minutes versus 84 minutes), and only 20% of the MBF group experienced prolonged analgesia. During subsequent epidural analgesia, the MBF group had a significantly lesser rate of breakthrough pain (0.15 ± 0.14 episodes per hour versus 0.26 ± 0.18 episodes per hour). Also, during the first 24 hours postpartum, the MBF group required significantly fewer medications (3.3 ± 3.7 doses versus 4.7 ± 3.5 doses). Intrathecal injection of this small dose of bupivacaine/fentanyl produced a rapid onset of labor analgesia; the addition of a small dose of morphine did not significantly prolong analgesia, but it improved subsequent pain relief, as measured by the rate of breakthrough pain and postpartum medication requirements. This may provide a clinically useful means of improving intrapartum and postpartum pain relief. A small dose of intrathecal fentanyl 12.5 μg and bupivacaine 2 mg produces effective labor analgesia lasting for approximately 85 minutes. The addition of a small 125‐ μg dose of morphine improves pain control during subsequent epidural analgesia and reduces the requirements for postpartum pain medications.

Substance P and prostaglandin E2 release after shock wave application to the rabbit femur.

The biologic action of extracorporeal shock wave application on the musculoskeletal system is poorly understood. To prove the hypothesis that alterations of tissue concentrations of substance P and prostaglandin E(2) are involved in the biologic action of shock waves, extracorporeal shock waves with energy flux density of 0.9 mJ/mm2 (1500 pulses at 1/second) were applied in vivo to the distal femur of rabbits. The concentrations of substance P and prostaglandin E(2) eluted from the periosteum of the femur were measured. Compared with the untreated contralateral hindlimbs, substance P release from the periosteum from the femur was increased 6 hours and 24 hours after extracorporeal shock wave application, but was decreased 6 weeks after extracorporeal shock wave application. By contrast, extracorporeal shock wave application did not result in altered prostaglandin E(2) release from the periosteum from the femur. Remarkably, there was a close relationship between the time course of substance P release found here, and the well-known clinical time course of initial pain occurrence and subsequent pain relief after extracorporeal shock wave application to tendon diseases. Accordingly, substance P might be involved in the biologic action of extracorporeal shock wave application on tissue of the musculoskeletal system. This is the first study providing insights into the molecular mechanisms of extracorporeal shock wave application to the musculoskeletal system.

VASECTOMY REVERSAL FOR THE POST-VASECTOMY PAIN SYNDROME: : A CLINICAL AND HISTOLOGICAL EVALUATION

The cause of the post-vasectomy pain syndrome is unclear. Some postulated etiologies include epididymal congestion, tender sperm granuloma and/or nerve entrapment at the vasectomy site. To our knowledge nerve proliferation has not been evaluated previously as a cause of pain. Vasectomy reversal is reportedly successful for relieving pain in some patients. We report our experience and correlate histological findings in resected vasal segments with outcome to explain the mechanism of pain in these patients. We retrospectively reviewed the records of 13 men who underwent vasectomy reversal for the post-vasectomy pain syndrome. We compared blinded histological evaluations of the vasal ends excised at vasectomy reversal in these patients with those of pain-free controls who underwent vasectomy reversal to reestablish fertility. Controls were matched to patients for the interval since vasectomy. Histological features were graded according to the degree of severity of vasitis nodosum, chronic inflammation and nerve proliferation. Mean time to pain onset after vasectomy was 2 years. Presenting symptoms included testicular pain in 9 cases, epididymal pain in 2, pain at ejaculation in 4 and pain during intercourse in 8. Physical examination demonstrated tender epididymides in 6 men, full epididymides in 6, a tender vasectomy site in 4 and a palpable nodule in 4. No patient had testicular tenderness on palpation. Unilateral and bilateral vasovasostomy was performed in 3 and 10 of the 13 patients, respectively. Postoperatively 9 of the 13 men (69%) became completely pain-free. Mean followup was 1.5 years. We observed no differences in vasectomy site histological features in patients with the post-vasectomy pain syndrome and matched controls, and no difference in histological findings in patients with the post-vasectomy pain syndrome who did and did not become pain-free postoperatively. No histological features aid in identifying a cause of pain or provide prognostic value for subsequent pain relief. Vasectomy reversal appeared to be beneficial for relieving pain in the majority of select patients with the post-vasectomy pain syndrome.

Comparative Study of Self-rating Pain Scales in Osteoarthritis Patients

SummaryAlthough progress has been made in the clinical metrology of pain in osteoarthritis, much further work remains. The preferred methods of measurement remain debatable. In this longitudinal, open study, a comparison of eight self-rating pain scales has been conducted. A total of 333 patients entered the four-week study after completing a 3-7 day NSAID-free washout period. Patients were assigned to treatment with oxaprozin 1200 mg p.o. once daily with titration permitted between 600 mg and 1800 mg. Rescue analgesia with acetaminophen (paracetamol) 325 mg (maximum 2600 mg) was allowed. At the end of the washout and the treatment period, patients completed eight self-administered pain scales.All pain measures detected clinically important and statistically significant improvements in pain. The pain scales differed in their degree of responsiveness. The Likert and visual analogue scales and their primary variations (continuous chromatic analogue and numerical scales) were more responsive than more complex measures. A positive correlation between initial pain rating and subsequent pain relief was confirmed in this study.We conclude that, while pain is a subjective sensory phenomenon, its perceived severity can be evaluated using a variety of self-administered pain scales, all of which are capable of detecting improvements in health status following effective pharmacological intervention.

Lumbar Epidural Blockade for Management of Pain in Interstitial Cystitis

Thirteen patients with interstitial cystitis (IC), whose predominant symptom was pelvic or urethral pain, were treated with a series of lumbar epidural local anaesthetic blocks over an 18-month period. Response was evaluated by interview and with voiding diaries and visual analogue scales (VAS) for pain. Of the 55 injections given, immediate pain relief (lasting longer than 24 h) was obtained from 41 (75%). The duration of subsequent pain relief varied considerably, ranging from 2 to 75 days (mean 15.1). Pain relief was accompanied by significant improvement in sleep habit and quality of life. A good correlation was noted between verbally expressed pain and the recorded VAS pain scores. Urinary frequency and average voided volumes were unaffected by treatment. Two patients failed to obtain any relief. Apart from minor transient backache at the injection site, there were no complications from the procedure. Lumbar sympathetic epidural blockade is an excellent means of providing pain relief in interstitial cystitis.