Aims. Closed suction subfascial drainage is widely used after instrumented posterior spinal fusion in patients with a spinal deformity. The aim of this study was to determine the effect of this wound drainage on the outcomes in patients with adolescent idiopathic scoliosis (AIS). This was a further analysis of a randomized, multicentre clinical trial reporting on patients after posterior spinal fusion using segmental pedicle screw instrumentation. In this study the incidence of deep surgical site infection (SSI) and chronic postoperative pain at two years’ follow-up are reported. Methods. We conducted a randomized, multicentre clinical trial on adolescents undergoing posterior spinal fusion for AIS using segmental pedicle screw instrumentation. A total of 90 consecutive patients were randomized into a ‘drain’ or ‘no drain’ group at the time of wound closure, using the sealed envelope technique (1:1). The primary outcomes in the initial study were the change in the level of haemoglobin in the blood postoperatively and total blood loss. A secondary outcome was the opioid consumption immediately after surgery. The aim of this further study was to report the rate of deep SSI and persistent postoperative pain, at two years' follow-up. Results. As previously reported, the mean 48-hour opioid consumption was significantly higher in the no drain group (2.0 mg/kg (SD 0.8) vs 1.4 mg/kg (SD 0.7); p = 0.005). There were no delayed deep SSIs. At two years’ follow-up, the mean Scoliosis Research Society 24-item questionnaire (SRS-24) total score did not differ between the groups (4.11 (SD 0.47) vs 4.16 (SD 0.33); p = 0.910). The mean SRS-24 pain score was 4.28 (SD 0.48) in the no drain group compared with 4.33 (SD 0.66) in the drain group (p = 0.245). Seven patients (19%) in the no drain group and six in the drain group (14%) reported moderate to severe pain (numerical rating scale ≥ 4) at two years’ follow-up (p = 0.484). The general self-image domain score was significantly higher in the no drain group compared with the drain group (4.02 (SD 0.74) vs 4.59 (SD 0.54); p < 0.001). Conclusion. The main finding in this study was that more severe pain immediately after surgery did not result in a higher incidence of chronic pain in the no drain group compared with the drain group. Back pain and health-related quality of life at two years’ follow-up did not differ between the groups. The patient-reported self-image domain was significantly better in the no drain group compared with the drain group. Cite this article: Bone Joint J 2024;106-B(10):1176–1181

Aims. The aim of this study was to describe the prevalence and patterns of neuropathic pain over one year in a cohort of patients with chronic post-surgical pain at three months following total knee arthroplasty (TKA). Methods. Between 2016 and 2019, 363 patients with troublesome pain, defined as a score of ≤ 14 on the Oxford Knee Score pain subscale, three months after TKA from eight UK NHS hospitals, were recruited into the Support and Treatment After Replacement (STAR) clinical trial. Self-reported neuropathic pain and postoperative pain was assessed at three, nine, and 15 months after surgery using the painDETECT and Douleur Neuropathique 4 (DN4) questionnaires collected by postal survey. Results. Symptoms of neuropathic pain were common among patients reporting chronic pain at three months post-TKA, with half reporting neuropathic pain on painDETECT (191/363; 53%) and 74% (267/359) on DN4. Of those with neuropathic pain at three months, half continued to have symptoms over the next 12 months (148/262; 56%), one-quarter had improved (67/262; 26%), and for one-tenth their neuropathic symptoms fluctuated over time (24/262; 9%). However, a subgroup of participants reported new, late onset neuropathic symptoms (23/262; 9%). Prevalence of neuropathic symptoms was similar between the screening tools when the lower cut-off painDETECT score (≥ 13) was applied. Overall, mean neuropathic pain scores improved between three and 15 months after TKA. Conclusion. Neuropathic pain is common in patients with chronic pain at three months after TKA. Although neuropathic symptoms improved over time, up to half continued to report painful neuropathic symptoms at 15 months after TKA. Postoperative care should include screening, assessment, and treatment of neuropathic pain in patients with early chronic postoperative pain after TKA. Cite this article: Bone Joint J 2024;106-B(6):582–588

Introduction. The regionalisation of major trauma in the UK has significantly improved outcomes for patients with severe, lower limb injuries. Chronic pain after complex lower limb injuries is well documented, but seems to remain a problem despite better clinical and radiological outcomes. We hypothesised that pain was mediated through the saphenous nerve, especially as most tibial injuries affected the soft tissues medially. As a proof of concept, we undertook adductor canal blocks to understand pain aetiology. Materials & Methods. Patients with chronic pain following complex lower limb trauma or congenital deformity correction have been selected and underwent an adductor canal block by one of our trauma anaesthetist that specialises in this procedure. Their outcomes were recorded in their clinical records and patients were contacted by phone to document their experiences. Results. 14 patients with chronic, treatment refractory lower limb pain who were being managed in our orthoplastics clinic following complex, lower limb trauma were identified. Six of those patients had required plastic coverage. Of these 14 patients, all stated their pain completely resolved after the procedure and then returned between 24 hours and 4 weeks after the procedure. Two patients underwent a saphenous nerve diversion after conduction of the blocks, reporting subsequent resolution of their complaints. Conclusions. As a proof of concept, we report that the saphenous nerve underlies chronic pain in patients with complex lower limb injuries. An adductor canal block is an effective diagnostic tool for these patients. Saphenous diversion may offer a permanent solution in patients who respond well to saphenous nerve block. A prospective study is planned to objectively measure pain and quality of life scores after treatment of complex injuries and pre and post adductor canal block

Introduction. There is a lack of evidence-based treatments for patients with chronic pain after total knee arthroplasty (TKA). It is well-established that knee extensor and flexor muscle strength are markedly impaired following TKA, but no studies have examined muscle strength and power in patients with chronic pain after TKA. Therefore, the aim was to investigate if neuromuscular exercises and pain neuroscience education (PNE) were superior to PNE alone for improvement of muscle strength and power in patients with chronic pain after TKA. Method. This report presents the exploratory analysis of a randomized controlled trial (NCT03886259). Participants with chronic moderate-to-severe average daily pain intensity and no signs of prosthesis failure at least one year after primary TKA were included. Participants were randomized to receive either supervised neuromuscular exercise and PNE or the same PNE sessions alone. The outcomes were changes from baseline to 12-months for peak leg extension power and maximum muscle strength, measured during maximal voluntary isometric contractions, for the knee extensors and flexors. Result. Sixty-nine participants (age 62.2±7.2, 40 females) were included. No between-group differences were observed for peak leg extension power (difference 13.6 Watts, 95% CI -22.2 to 49.3), maximum knee extensor muscle strength (difference -20.9 Newtons, 95% CI -65.8 to 24.0) or maximum knee flexor muscle strength (difference 8.6 Newtons, 95% CI -11.9 to 29.1). Peak leg extension power (26.3 Watts, 95% CI 4.3 to 48.3) and maximum knee flexor muscle strength (19.7 Newtons, 95% CI 7.6 to 31.9) improved significantly in the neuromuscular exercise and PNE group with no significant improvements observed in the PNE alone group. Conclusion. Neuromuscular exercise and PNE did not improve muscle strength and power compared to PNE alone in patients with chronic pain after TKA. Acknowledgements. This study was funded by the Danish Rheumatism Association, the Svend Andersen Foundation and Lions Club Denmark

Background. Serious traumatic injury is a leading cause of death and disability globally, with the majority of survivors developing chronic pain. Methods. The aims of this study were to describe early predictors of poor long-term outcome for post-trauma pain. We conducted a prospective observational study, recruiting patients admitted to a Major Trauma Centre hospital in England within 14 days of their injuries, and followed them for 12 months. We defined a poor outcome as Chronic Pain Grade ≥ II and measured this at both 6-months and 12-months. A broad range of candidate predictors were used, including surrogates for pain mechanisms, quantitative sensory testing, and psychosocial factors. Univariate models were used to identify the strongest predictors of poor outcome, which were entered into multivariate models. Results. 124 eligible participants were recruited. At 6-months, 19 (23.2%) of 82 respondents reported a good outcome, whereas at 12-months 27 (61.4%) of 44 respondents reported a good outcome. The multivariate model for 6-months produced odds ratios for a unit increase in: number of fractures, 3.179 (0.52 to 19.61); average pain intensity, 1.611 (0.96 to 2.7); pain extent, 1.138 (0.92 to 1.41) and post-traumatic stress symptoms, 1.044 (0.10 to 1.10). At 12-months, equivalent values were: number of fractures, 1.653 (0.77 to 3.55); average pain intensity, 0.967 (0.67 to 1.40); pain extent, 1.062 (0.92 to 1.23) and post-traumatic stress symptoms, 1.025 (0.99 to 1.07). Conclusion. A poor long-term pain outcome from musculoskeletal traumatic injuries can be predicted by measures recorded within days of injury. Conflicts of interest: No conflicts of interest. Sources of funding: This study was funded by the National Institute for Health Research (NIHR) Surgical Reconstruction and Microbiology Research Centre (SRMRC)

Background and aims: The aim of this study is to investigate how people with chronic pain cope with everyday problems. Methods: Subjects (202 men and 323 women) were patients with chronic pain referred to a rehabilitation unit. The Utrecht Coping List (Dutch version of the WCC – ways of coping checklist) was used to measure their coping style at referral. It has 7 factors: approach and avoidance, palliative behaviour, social support, depressive/passive reaction, expressing emotion and comforting cognitions. Results: Men with chronic pain have lower scores on active problem solving behaviour, and higher scores on palliative behaviour and depressive reaction than men without pain (p< .001). Women with chronic pain have also lower scores on active problem solving behaviour than women without pain, but also on social support and expressing emotion. Like the men scores for women are higher on palliative behaviour (p< .001) and depressive reaction (p< .01), but also on avoidant behaviour (p< .01) and comforting cognitions (p< .001). Data shows that women with pain have higher scores than men with pain on all scales, except for expressing emotion. Differences on palliative behaviour, avoidant behaviour, social support and comforting cognitions are significant (p < .001). Conclusions: People – women as well as men – with chronic pain show less active coping behaviour, have a higher score on depressive reaction on problems and use more palliative behaviour in problem situations than people without somatic complaints. It is important to stress the differences between women and men with chronic pain in problem solving behaviour

The superior analgesic effects of minodronate compared with other bisphosphonates has been previously reported. However, to our knowledge, there are no studies analyzing the analgesic effects of bisphosphonates on chronic pain. The purpose of the present study was to evaluate the analgesic effects of minodronate (MIN), alendronate (ALN), and pregabalin (PRG) on chronic pain caused by chronic constriction injury (CCI) of the sciatic nerve. Four-week-old female Wister rats underwent ovariectomy. At 8 weeks old, the left sciatic nerve was ligated to induce the chronic pain model (CCI side), and sham surgery was performed on the right posterior limb as a CCI control (control side). The rats were divided into the following four groups: 1) MIN group, administered with minodronate (0.15 mg/kg/week) (n = 10); 2) ALN group, administered with alendronate (0.15 mg/kg/week) (n = 10); 3) PRG group, administered with pregabalin (10 mg/kg) (n = 9); and 4) Control group, administered with vehicle (n = 10). Treatments were administered subcutaneously every week for 2 weeks immediately after CCI. To quantify the sensitivity to a tactile stimulus, paw withdrawal in response to a tactile stimulus was measured using von Frey filaments at 0, 1, and 2 weeks after CCI. Von Frey filaments were applied to the plantar surface of the hindpaws for 3 s, and this was repeated three times. Paw withdrawal in response to the stimulus was evaluated by scoring as follows: 0, no response; 1, a slow and/ or slight response to the stimulus; 2, a quick withdrawal response; 3, an intense withdrawal response away from the stimulus. The mean value of the score was adopted as the pain score. After evaluating the response, bilateral femurs were harvested for bone mineral density (BMD) measurements. The pain score of the CCI side was significantly higher than that of the sham side in all groups (p < 0.05) at each time point. The pain score for the MIN group, but not the ALN group, of the CCI side was significantly lower (p = 0.05) at 0 and 1 week after CCI. Total femoral BMD of the CCI side was significantly lower in the PRG and Control groups than those of the MIN and ALN groups (p < 0.05). No significant difference was identified for BMD between the MIN and ALN groups. Minodronate showed a significant analgesic effect on chronic pain and suppressed osteoporotic changes caused by CCI

Introduction: The principal aim of total knee replacement (TKR) surgery is to relieve chronic knee pain. However, following recuperation from surgery, 10–30% of patients report chronic pain in the replaced joint. There has been little research investigating the impact of this continuing pain on patients’ lives or exploring the way in which individuals adjust to this pain. Therefore, the aim of this study is to explore, from their own perspectives, patients’ experiences of chronic pain following this end-stage treatment of TKR. Participants and Methods: Participants were twenty-eight patients who had undergone a TKR with the National Health Service at Bristol, Southwest UK, and who reported chronic pain in the replaced knee joint at least one year post-operatively. Purposive sampling was used in order to recruit participants both of a range of ages and with moderate to severe chronic pain. In-depth, semi-structured interviews were conducted with participants. Interviews explored individuals’ perceptions of the identity of their condition, its cause, duration and consequences and whether they had any control over it. Data was analysed using thematic analysis. Results: Analysis revealed that, while all participants experienced chronic pain which necessitated the use of pain relief medication, there was great variation among individuals in terms of their adjustment to their condition: while some were well adjusted and accepting of their pain, for others the pain constituted a source of ongoing distress. Regardless of their expectations concerning level of pain following TKR, those participants who perceived an improvement in pain as a result of their TKR were less likely to expect a cure for their residual pain and were either very well or reasonably well adjusted to the pain. Nevertheless, those who had moderate expectations of outcome were more likely to perceive an improvement than those with high expectations. Those individuals who reported having held high expectations of TKR outcome and subsequently experienced increased pain were likely to experience distress in relation to their pain; those who also felt that a cure for their current pain may be possible experienced particularly high levels of distress. Discussion: The findings show the significance of cognitions, beliefs and expectations to individuals’ adjustment to chronic pain following TKR. They highlight a group of patients for whom adjustment may be problematic, which could indicate the need for assessment and intervention. There could be potential for surgeons to influence their patients’ adjustment positively by attempting to instil realistic expectations both prior to surgery and when chronic pain is experienced after recovery from TKR

We conducted a community survey of the prevalence, health impact and location of chronic pain. We explored the relationship and patterns of chronic pain that commonly occur, with a view to understanding why some treatment approaches may be more appropriate than others for particular patterns of pain. In 2002, 2504 randomly sampled patients from 16 General Practices in the South East of England responded to a postal questionnaire about chronic pain. Those with chronic pain completed a pain drawing. We calculated descriptive statistics, relative risk and correlations to identify the associations and risks of having linked pain. The highest prevalences were low back (23%), shoulder (20%) and knee (18%) pain. The number of pain sites experienced was age related in men but less so in women. Lower body pain was more age related than upper body and non musculoskeletal pain. Multi site pain was more common than single site pain. Of those with low back, knee and shoulder pain, 14%, 4.5 % and 1.9% had only low back, knee and shoulder pain respectively. Correlations and minimum spanning trees showed that chronic upper and lower body pain are distinct and axial pain link the two. Chronic pain is more likely to be multi site, especially at middle age. Research, physical treatments and approaches to managing chronic pain are often site specific, therefore specialising treatment to one area eg low back pain often negates the bigger issue. This may help explain the self perpetuating problem of persistent chronic pain

Abstract. Introduction. Approximately 15–20% of patients report chronic pain three months after total knee replacement (TKR). The STAR care pathway is a clinically important and cost-effective personalised intervention for patients with pain 3 months after TKR. The pathway comprises screening, assesment, onward referral for treatment and follow-up over one year. In a multicentre randomised controlled trial comparing the pathway with usual care, the pathway improved pain at 6 and 12 months. This study examined the longer-term clinical and cost-effectiveness of the STAR care pathway. Methodology. STAR trial participants were followed-up at a median of 4 years post-randomisation. Co-primary outcomes were self-reported pain severity and interference in the replaced knee, assessed with the Brief Pain Inventory (BPI). Resource use from electronic hospital records was valued with UK reference costs. Results. Of the 337 participants active at trial completion, 326 had confirmed vital status, and 226 (69%) provided outcome data at a median of 4 years. The between-group difference in mean BPI severity score was −0.42 (95% CI −1.07, 0.23; p=0.20) and for BPI interference was −0.64 (95% CI −1.41, 0.12; p=0.10), favouring the intervention. Multiple imputation analyses led to attenuations of about 0.2 points. Mean hospital admission costs over four years were £2461.49 (95% CI £1354.42, £3568.57) in the intervention arm and £3791.68 (95% CI £2095.12, to £5488.24) in usual care. Conclusion. These data are consistent with sustained benefits from the STAR care pathway at 4 years, albeit attenuated and with wider confidence intervals, in part attributable to attrition after 1 year

Background. Chronic pain after joint replacement is common, affecting approximately 10% of patients after total hip replacement (THR) and 20% of patients after total knee replacement (TKR). Heightened generalised sensitivity to nociceptive input could be a risk factor for the development of this pain. The primary aim of this study was to investigate whether preoperative widespread pain sensitivity was associated with chronic pain after joint replacement. Methods. Data were analysed from 254 patients receiving THR and 239 patients receiving. TKR. Pain was assessed preoperatively and at 12 months after surgery using the Western Ontario and McMaster Universities Osteoarthritis Pain Scale. Preoperative widespread pain sensitivity was assessed through measurement of pressure pain thresholds (PPTs) at the forearm using an algometer. Statistical analysis was conducted using linear regression and linear mixed models, and adjustments were made for confounding variables. Results. In both the THR and TKR cohort, lower PPTs (heightened widespread pain. sensitivity) were significantly associated with higher preoperative pain severity. Lower PPTs were also significantly associated with higher pain severity at 12 months after surgery in the THR cohort. However, PPTs were not associated with the change in pain severity from preoperative to 12 months postoperative in either the TKR or THR cohort. Conclusions. These findings suggest that although preoperative widespread pressure pain sensitivity is associated with pain severity before and after joint replacement, it is not a predictor of the amount of pain relief that patients gain from joint replacement surgery, independent of preoperative pain severity. Level of Evidence. 2. Approvals. The APEX trials were registered as an International Standardised Randomised Controlled Trial (96095682), approved by Southampton and South West Hampshire Research Ethics Committee(09/H0504/94) and all participants provided informed written consent

Due to limitations of existing pharmacological therapies for the management of chronic pain in osteoarthritis (OA), surgical interventions remain a major component of current standard of care, with total joint replacements (TJRs) considered for people who have not responded adequately to conservative treatment. This study aimed to quantify the economic burden of moderate-to-severe chronic pain in patients with OA in England prior to TJR. A retrospective, longitudinal cohort design was employed using Clinical Practice Research Datalink GOLD primary care data linked to Hospital Episode Statistics secondary care data in England. Patients (age ≥18 years) with an existing OA diagnosis of any anatomical site (Read/ICD-10) were indexed (Dec-2009 to Nov-2017) on a moderate-to-severe pain event (which included TJR) occurring within an episode of chronic pain. 5-year TJR rates from indexing were assessed via Kaplan-Meier estimates. All-cause healthcare resource utilisation and direct medical costs were evaluated in the 1–12 and 13–24 months prior to the first TJR experienced after index. Statistical significance was assessed via paired t-tests. The study cohort comprised 5,931 eligible patients (57.9% aged ≥65 years, 59.2% female). 2,176 (36.7%) underwent TJR (knee: 54.4%; hip: 42.8%; other: 2.8%). The 5-year TJR rate was 45.4% (knee: 24.3%; hip: 17.5%; other: 6.8%). Patients experienced more general practitioner consultations in 1–12 months pre-TJR compared with 13–24 months pre-TJR (means: 12.13 vs. 9.61; p<0.0001), more outpatient visits (6.68 vs. 3.77; p<0.0001), more hospitalisations (0.74 vs. 0.62; p=0.0032), and more emergency department visits (0.29 vs. 0.25, p=0.0190). Total time (days) spent as an inpatient was higher in 1–12 months pre-TJR (1.86 vs. 1.07; p<0.0001). Mean total per-patient cost pre-TJR increased from £1,771 (13–24 months) to £2,621 (1–12 months) (p<0.0001). Resource-use and costs incurred were substantially greater in the 12 months immediately prior to TJR, compared with 13–24 months prior. Reasons for increased healthcare and economic burden in the pre-TJR period deserve further exploration as potential targets for efforts to improve patient experience and efficiency of care

We investigated the response of chronic neck and shoulder pain to decompression of the carpal tunnel in 38 patients with whiplash injury. We also determined the plasma levels of substance P (SP) and calcitonin gene-related peptide (CGRP), which are inflammatory peptides that sensitise nociceptors. Compared with normal control subjects, the mean concentrations of SP (220 v 28 ng/l; p < 0.0001) and CGRP (400 v 85 ng/l; p < 0.0005) were high in patients with chronic shoulder and neck pain before surgery. After operation their levels fell to normal. There was resolution of neurological symptoms with improvement of pain in 90% of patients. Only two of the 30 with chronic neck and shoulder pain who had been treated conservatively showed improvement when followed up at two years. In spite of having neuropathic pain arising from the median nerve, all these patients had normal electromyographic and nerve-conduction studies. Chronic pain in whiplash injury may be caused by ‘atypical’ carpal tunnel syndrome and responds favourably to surgery which is indicated in patients with neck, shoulder and arm pain but not in those with mild symptoms in the hand. Previously, the presence of persistent neurological symptoms has been accepted as a sign of a poor outcome after a whiplash injury, but our study suggests that it may be possible to treat chronic pain by carpal tunnel decompression

Introduction: Chronic joint pain is the primary reason for individuals electing to undergo TKR and therefore pain relief is an extremely important outcome after surgery. Although the literature suggests that TKR produces excellent pain relief, the prevalence of chronic pain after TKR is often masked in the reporting of mean pain scores. The aim of this study was to explore the prevalence, impact and onset of pain at 1-year after TKR. Methods: 243 patients (251 knees) were recruited into a multi-centre randomised controlled trial comparing the outcomes of the Kinemax Plus fixed-bearing and mobile-bearing implant. Patients were assessed pre-operatively and then 3 months, 1-year and 2-years post-operatively. At each assessment time patients completed the WOMAC, KOOS quality of life scale, SF-12, American Knee Society Score, Satisfaction Scale for Joint Replacement Arthroplasty and a clinical examination. As part of the clinical assessment patients were asked to rate the pain in their knee as none, mild, occasionally moderate, continually moderate or severe. Results: To date, 240 knees have reached their 1-year follow-up. Complete data regarding pain ratings was available for 198 patients. The mean age of patients was 68 years (range 40–81) and 52% were male. At 1-year after TKR, 13% of patients had occasionally moderate pain, 6% had continually moderate pain and 6% of patients had severe pain. In total, 25% patients reported moderate-severe pain at 1-year after TKR. 60% patients with pain at 1-year post-operative also experienced moderate-severe pain at 3 months post-operative. Using a Mann-Whitney U test, patients with moderate-severe pain at 1-year after TKR had significantly worse physical function (p< 0.001), knee-related quality of life (p< 0.001) and mental health scores (p< 0.05) than those patients with no-mild pain. Conclusion: This study suggests the prevalence of pain after TKR is high, with 25% of patients reporting moderate-severe pain at 1-year after TKR. Pain experienced at 1-year post-operative was most frequently preceded by pain at 3-months post-operative, suggesting that for many patients a pain-free period after surgery is not experienced. The pain present at 1-year after TKR affected several domains of life, including functional ability, quality of life and mental health. Future research will focus on developing a pre-operative screening protocol to identify patients at risk of chronic pain after TKR. This research was supported by funding from Stryker UK

Aims. To identify the prevalence of neuropathic pain after lower limb fracture surgery, assess associations with pain severity, quality of life and disability, and determine baseline predictors of chronic neuropathic pain at three and at six months post-injury. Methods. Secondary analysis of a UK multicentre randomized controlled trial (Wound Healing in Surgery for Trauma; WHiST) dataset including adults aged 16 years or over following surgery for lower limb major trauma. The trial recruited 1,547 participants from 24 trauma centres. Neuropathic pain was measured at three and six months using the Doleur Neuropathique Questionnaire (DN4); 701 participants provided a DN4 score at three months and 781 at six months. Overall, 933 participants provided DN4 for at least one time point. Physical disability (Disability Rating Index (DRI) 0 to 100) and health-related quality-of-life (EuroQol five-dimension five-level; EQ-5D-5L) were measured. Candidate predictors of neuropathic pain included sex, age, BMI, injury mechanism, concurrent injury, diabetes, smoking, alcohol, analgaesia use pre-injury, index surgery location, fixation type, Injury Severity Score, open injury, and wound care. Results. The median age of the participants was 51 years (interquartile range 35 to 64). At three and six months post-injury respectively, 32% (222/702) and 30% (234/787) had neuropathic pain, 56% (396/702) and 53% (413/787) had chronic pain without neuropathic characteristics, and the remainder were pain-free. Pain severity was higher among those with neuropathic pain. Linear regression analyses found that those with neuropathic pain at six months post-injury had more physical disability (DRI adjusted mean difference 11.49 (95% confidence interval (CI) 7.84 to 15.14; p < 0.001) and poorer quality of life (EQ-5D utility -0.15 (95% CI -0.19 to -0.11); p < 0.001) compared to those without neuropathic characteristics. Logistic regression identified that prognostic factors of younger age, current smoker, below knee fracture, concurrent injuries, and regular analgaesia pre-injury were associated with higher odds of post-injury neuropathic pain. Conclusion. Pain with neuropathic characteristics is common after lower limb fracture surgery and persists to six months post-injury. Persistent neuropathic pain is associated with substantially poorer recovery. Further attention to identify neuropathic pain post-lower limb injury, predicting patients at risk, and targeting interventions, is indicated. Cite this article: Bone Joint J 2021;103-B(6):1047–1054

There have been no studies assessing the acceptability of opioid tapering in the pre-arthroplasty setting. This qualitative study aimed to (1) explore barriers and facilitators to opioid tapering amongst patients with chronic non-cancer pain (CNCP), and (2) explore the similarities and differences in acceptability of opioid tapering between pre-arthroplasty patients and those participating in a biopsychosocial pain management program. From January 2021, adult participants diagnosed with CNCP and taking opioids daily (any dose at time of screening for a period of 3 months) were recruited from either Fairfield Orthopaedic Hip and Knee Service (FOHKS) or Liverpool Hospital Pain Clinic (LHPC). Semi-structured interviews underwent thematic analysis using the framework method. 17 participants were recruited (FOHKS, n=9, mean age 67, female 77%, LHPC, n=8, mean age 54, female 63%). Both groups had participants who; (i) were reluctant to use opioid medications and used them out of “necessity”, (ii) were reluctant to taper due to concerns of worsening pain, quality of life, (iii) believed opioids were “toxins” causing bodily harm. Some FOHKS participants believed tapering should be a post-operative focus, whilst others believed tapering opioids pre-operatively will assist in post-op pain management. Few LHPC participants felt dependent/addicted to opioids, thus driving their intention to taper opioids. The belief of tapering opioids causing worse pain was based on either previous experiences or concerns alone. Some FOHKS participants were more inclined to taper opioids if they were educated on the chronic and peri-operative risks associated with using opioids at time of arthroplasty. Opioid users recognise the harms associated with chronic opioid use and believe they are used out of desperation for adequate analgesia, function, and quality of life. Tapering opioids in the pre-arthroplasty context may need coupling with patient education highlighting the importance of opioid tapering pre-operatively

Introduction. Pain is an expected and appropriate experience following traumatic musculoskeletal injury. By contrast, chronic pain and disability are unhelpful yet common sequelae of trauma-related injuries. Presently, the mechanisms that underlie the transition from acute to chronic disabling post-traumatic pain are not fully understood. The aim of this study is to identify prognostic factors for risk of developing chronic pain and disability following acute musculoskeletal trauma. Methods. A prospective observational study will recruit two temporally staggered cohorts (n=250 each cohort; 10 cases per candidate predictor) of consecutive acute musculoskeletal trauma patients aged ≥16 years, who are emergency admissions into a Major Trauma Centre in the United Kingdom, with an episode inception defined as the traumatic event. The first cohort will identify prognostic factors to develop a screening tool to predict development of chronic and disabling pain, and the second will allow evaluation of the predictive performance of the tool (validation). The outcome being predicted is an individual's absolute risk of poor outcome measured at 6-months follow-up using the Chronic Pain Grade Scale (poor outcome ≥Grade II). Candidate predictors encompass the four primary mechanisms of pain: nociceptive (e.g. injury characteristics), neuropathic (e.g. painDETECT), inflammatory (biomarkers), and central hypersensitivity (e.g. quantitative sensory testing). Concurrently, patient-reported outcome measures will assess general health and psychosocial factors. Risk of poor outcome will be calculated using multiple variable regression analysis. Conclusion. A prognostic screening tool for post-trauma pain will inform precision rehabilitation, targeting interventions to individual patients to improve clinical and cost effectiveness. Conflicts of interest: None. Sources of funding: NIHR Surgical Reconstruction and Microbiology Research Centre

Background. There is growing evidence for an important role of central sensitization (CS) in the development and maintenance of chronic pain. Consequently, alleviation of CS might be helpful, as was demonstrated for pregabalin. For tapentadol this is unknown. Tapentadol is a drug with a dual mechanism: 1) it acts on the mu-opioid receptor (µ-OR) and 2) it inhibits the reuptake of noradrenalin in the central nervous system3. The noradrenergic effect might involve a modulation of descending pain pathways and thereby reduce or alleviate CS. Aim. The aim of the present study is to determine the alterations in CS parameters by tapentadol in patients with chronic visceral (endometriosis) pain and deep somatic (low back) pain, using pregabalin as comparator. Hypothesis. In both visceral and deep somatic pain when using tapentadol or pregabalin a decrease in pain (NRS) correlates to a decrease in CS. Method/design. Prospective, open label 2×2 randomized cross-over study in 30 patients with proven endometriosis and 30 patients with chronic (>3 months) low back pain radiating to the leg (CLBPr). Each group of patients will start with either pregabalin of tapentadol for 8 weeks, followed by a wash out period of one week, after which the second drug is used for 8 weeks. Discussion. The rationale for this study is to provide more insights about the affect tapentadol has on CS parameters in comparison to pregabalin in patients suffering from chronic pain that has a visceral or deep somatic origin. No conflict of interest. Sources of funding: Grünenthal

This edition of the Cochrane Corner looks at the three reviews that were published in the second half of 2023: surgical versus non-surgical interventions for displaced intra-articular calcaneal fractures; cryotherapy following total knee arthroplasty; and physical activity and education about physical activity for chronic musculoskeletal pain in children and adolescents

Background. Chronic pain is a significant burden and represents a major issue for world healthcare systems. Interventions include medication, surgery, pain management programmes, and social support through peer support groups. These groups are often informal, providing informational, emotional, and social support to members. The aim of this project is to co-produce guidance on how to establish a peer support programme for people living with chronic, non-cancer pain that is informed by evidence, theory, and stakeholder experience. Methods. This project is using Steps 1–4 of the Intervention Mapping (IM) approach to inform the research. Online workshops consisting of people living with chronic pain, third sector representatives, healthcare professionals, and researchers are being used to co-produce the guidance. Results. To date, 2 of the 4 planned workshops have been conducted. These have identified the needs of people living with chronic pain, goals for the peer support programme, and expectations of how a peer support programme should be executed. Topics for inclusion in the programme and their content have been identified, with further workshops to refine this planned. The final stage of this project will identify methods of delivery, specific resources that should be developed, and the training to be provided to peer support volunteers. Conclusion. The project has identified the diverse needs of people living with chronic pain and how these may be addressed by a peer support programme. It has identified flexible options that can be recommended to those who want to set up a programme and a variety content that may be included. Conflicts of Interest. None. Sources of Funding. Robert Gordon University