Long-term efficacy and safety of neridronate treatment in patients with complex regional pain syndrome type 1: a pre-specified, open-label, extension study

Conservative treatments of bone marrow lesions

Purpose

Bone marrow lesions (BMLs) of the knee are a common magnetic resonance imaging finding and are present in a wide range of pathologies, including traumatic contusions and fractures, following cartilage surgery alterations, osteoarthritis, transient BMLs syndromes, subchondral insufficiency fractures of the knee and spontaneous osteonecrosis of the knee. Regardless of their aetiology, clinical management may prove challenging. This review focuses on the conservative treatment approaches to manage patients affected by knee BML, thanks to the contribution of field experts.

Methods

Experts from around the globe were involved in performing a review on the most used conservative treatment strategies to address BMLs, trying to summarize the available evidence from the most popular first-line treatments while documenting their applications and results for the different BML aetiologies.

Results

Positive results were documented for unloading knee braces, external shockwave therapy, hyperbaric oxygen therapy, pulsed electromagnetic fields therapy and bisphosphonates. Nonetheless, the analysis of the scientific literature documented a scarce number of publications specifically addressing the knee joint, with even less evidence when it comes to the results for the different aetiologies of BMLs.

Conclusion

The management of BMLs is challenging, and many factors influence clinical and radiological outcomes. This paper summarized the evidence on conservative treatments for knee BMLs. Although showing promising results, conservative options still need to be fully investigated. Open questions to be addressed concern treatment duration, BML stage and overlapping with concomitant therapies. Further studies are needed to identify the best first-line conservative approach or treatment combination based on each BML aetiology.

Level of Evidence

Level V: expert opinion.

10. Complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) is a clinical disorder that can develop following surgery or trauma. Based on the most prominent underlying pathophysiological mechanisms, CRPS can be classified into different subtypes, namely inflammatory, nociplastic/neuropathic, vasomotor, and motor. Depending on the subtype, personalized treatment can be applied. If conservative treatments are insufficient or ineffective, more invasive treatments may be recommended. This article provides an overview of the most recent insights into CRPS and discusses the most common invasive treatments.

METHODS

The literature regarding interventional treatments for CRPS has been systematically reviewed and summarized.

RESULTS

Bisphosphonates are effective in treating the inflammatory subtype, while ketamine can provide pain relief for the nociplastic/neuropathic subtype. Sympathetic blocks are effective in addressing vasomotor disturbances. For patients with refractory symptoms, neurostimulation is a viable option due to its multimechanistic properties for all subtypes. End-of-line motor disturbances may benefit from intrathecal baclofen.

CONCLUSIONS

CRPS is a debilitating condition with an unpredictable course. The effectiveness of treatment varies from patient to patient. When conservative approaches prove insufficient, gradual progression to invasive treatments based on the underlying subtype is recommended.

Benign Evolution of Complex Regional Pain Syndrome (CRPS) Type 1 in Patients Treated with Intravenous Neridronate: A Single-Center Real-Life Experience

OBJECTIVE

To investigate the long-term effects of intravenous neridronate treatment in patients with complex regional pain syndrome type 1 (CRPS) in a real-life setting.

METHODS

We conducted a retrospective study on consecutive CRPS patients treated at our hospital from February 2018 to July 2023. All were treated within three months of the onset of CRPS symptoms. The Patient-Reported Outcomes Measurement Information System 29-Item Health Profile (PROMIS-29) version 2.1 was administered. The main outcome of interest was the evolution of the PROMIS-29 scores from baseline to the last follow-up visit. Patients were categorized as "complete responders" or "non-complete responders". The association of clinical and demographic variables with a complete response was analyzed using chi-square tests and univariate logistic regression.

RESULTS

Thirty-six patients were included, with a median follow-up time of 4.8 years. A significant improvement was noted in the mean numerical pain rating scale (from 6.4 ± 1.9 to 3.1 ± 2.4, p < 0.001), as well as across all PROMIS-29 domains. Physical function improved from 34.2 ± 4.9 to 49.2 ± 9.9, p < 0.001; anxiety from 58.0 ± 6.7 to 49.6 ± 6.9, p < 0.001; depression from 55.3 ± 6.3 to 47.7 ± 6.6, p < 0.001; fatigue from 55.7 ± 7.7 to 50.9 ± 8.7, p < 0.001; sleep disturbance from 53.8 ± 6.8 to 51.3 ± 6.6, p = 0.034; social roles and activities from 41.8 ± 5.2 to 51.8 ± 8.9, p < 0.001; and pain interference from 64.1 ± 5.9 to 52.4 ± 9.9, p < 0.001. The likelihood of achieving a complete response was associated with the male sex, foot or ankle injuries (compared to hand and wrist injuries), and a younger age. No association was found with the type of inciting event or with the body mass index.

CONCLUSIONS

Our real-life data indicate that early treatment with neridronate leads to substantial benefits in patients affected by CRPS type 1. The strongest responses are seen in young patients, males, and those with lower limb involvement.

Is CRPS-1 a Chronic Disabling Disease? A Long-term, Real-Life Study on Patients Treated With Neridronate

Background

Complex Regional Pain Syndrome type 1 (CRPS-1) is severely debilitating and painful disease that is difficult to treat.

Objective

The objective was to evaluate the long-term residual disability of patients with CRPS-1 following parenteral neridronate treatment.

Design

This is real-life retrospective observational study.

Methods

Patients affected by CRPS-1 of the upper limb were treated with neridronate infusions (400 mg over 10 days) between February 2017 and December 2021 for whom clinical and demographic information was collected. From November 2022, patients treated ⩾1 year previously were recalled for clinical evaluation. A dedicated instrument (DASH questionnaire, Disabilities of the Arm, Shoulder and Hand) was employed to assess residual disability. Multivariate logistic regression analysis was used to investigate predictors of disability.

Results

Forty-nine patients aged 61.1 ± 11.5 years and 73.5% female with CRPS-1 of the upper limb were included. Disease duration before treatment was 9.9 ± 8.0 weeks, and the mean length of follow-up was 4 years (47.7 ± 22.0 months). The disease had fully resolved in 46 patients (93.9%) for whom the diagnostic criteria were no longer recognized. According to the DASH score, 38 patients (77.6%) resulted free of functional limitations, whereas 11 patients (22.4%) were still suffering from disability. The DASH score was positively correlated with residual visual analogue scale (VAS; Spearman's Rho = 0.61; P < .001). Predictors of residual disability were younger age (odds ratio [OR]: 0.77, 95% CI: 0.63-0.93; P = .012) and delay between disease onset and treatment (OR: 1.45, 95% CI: 1.13-1.96; P = .004).

Conclusions

In this real-life study, neridronate parenteral treatment provided a full recovery of CRPS-1 in over 3 quarters of patients, provided they are treated early.

No Significant Differences between Bisphosphonates and Placebo for the Treatment of Bone Marrow Lesions of the Knee: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives: The purpose of the present systematic review and meta-analysis is to summarize the current evidence on the role of bisphosphonates in the treatment of knee bone marrow lesions (BMLs), to understand whether they are truly effective in improving symptoms and restoring the subchondral bone status at imaging evaluation. Methods: A literature search was carried out on PubMed, Cochrane, and Google Scholar databases in accordance with the PRISMA guidelines. Potential risk of bias was evaluated using the Cochrane Risk of Bias 2 tool for randomized controlled trials (RCTs) and the ROBINS-I tool for non-randomized studies. Results: A total of 15 studies were included in the present systematic review and meta-analysis. Seven studies were RCTs, two were prospective cohort studies, three were retrospective, and three were case series. Our meta-analysis revealed that bisphosphonates did not significantly improve clinical scores or reduce BML size compared to placebo. Accordingly, the rate of adverse events was also non-significantly higher among bisphosphonate users versus placebo users. Conclusions: The main finding of the present meta-analysis and systematic review is that bisphosphonates show neither significant benefits nor significant adverse events when compared to placebo in the treatment of BMLs of the knee. Level of Evidence: Level IV systematic review of level II-III-IV studies. Level I meta-analysis of level I studies.

An update on the pharmacotherapeutic options for complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) is a rare and painful condition that has a wide range of triggering factors, often traumatic, and can present various clinical manifestations. The lack of knowledge about the underlying mechanisms has led to numerous treatment approaches, both conservative and surgical, which work through different mechanisms of action.

AREAS COVERED

In this review, the authors explore the key aspects of CRPS, including definition, diagnostic criteria, pitfalls, pathogenic hypotheses, and treatment strategies with a focus on pharmacotherapy. The review was based on a comprehensive search of the literature using PubMed, while also considering international guidelines for managing CRPS.

EXPERT OPINION

Based on the available evidence, pharmacological interventions appear to be effective in treating CRPS, especially when they target peripheral mechanisms, specifically nociceptive inflammatory pain, and when administered early in the course of the disease. However, there is still a lack of reliable evidence regarding the effects of drugs on central mechanisms of chronic pain in CRPS. In our expert opinion, drug therapy should be initiated as soon as possible, particularly in warm CRPS patient clusters, to prevent significant functional limitations, psychological distress, and negative impacts on individuals' social and economic well-being.

Perspectives on the pharmacological management of complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) is a chronic pain condition that is notoriously difficult to treat. Therapies for CRPS include cognitive behavioral, physical, and occupational therapy, single or multidrug pharmacotherapy, and a variety of interventional techniques. Unfortunately, randomized clinical trials of these therapies are limited. The large number of potential pharmacologic options can be overwhelming for providers in their attempts to develop a treatment plan.

AREAS COVERED

This article will review the literature on the pharmacologic management of CRPS. It is based on a systematic search of PubMed using keywords, followed by evaluation of the bibliographies for relevant articles.

EXPERT OPINION

No single drug has amassed enough evidence to suggest clear efficacy, but a handful of agents with at least modest evidence are commonly used, including gabapentinoids, bisphosphonates, ketamine, and pulsed dose steroids. Meanwhile, other agents that lack significant evidence specifically in CRPS but have evidence in other neuropathic conditions are commonly prescribed, including tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SNRIs). In our opinion, careful selection and prompt initiation of appropriate pharmacotherapy may optimize pain relief and improve functionality in patients burdened with this debilitating condition.