Cannabis for pain in orthopedics: a systematic review focusing on study methodology

Cannabis for pain in orthopedics: a systematic review focusing on study methodology

Can J Surg 2019;62(6):369-380 | PDF | Appendix

Kim Madden, PhD; Annie George, BHSc; Niek J. van der Hoek, MD; Felipe Moreira Borim, MD; George Mammen, PhD; Mohit Bhandari, MD, PhD

Abstract

Background: Medical cannabis use is an emerging topic of interest in orthopedics. Although there is a large amount of literature on medical cannabis use for managing various types of pain, few studies have focused on orthopedic conditions. There is little high-quality evidence in core orthopedic areas. The objective of this study was to summarize the literature on the efficacy of cannabis use for pain related to orthopedic conditions.

Methods: We conducted a systematic review of the literature on the use of cannabinoids for pain management in core orthopedic conditions. Two independent reviewers extracted information on reporting quality, risk of bias, drugs, population, control, duration of study, pain outcomes and the authors’ conclusions regarding efficacy for pain outcomes.

Results: We identified 33 orthopedic studies, including 21 primary studies and 12 reviews. Study quality was generally low to moderate. Six of the included studies had a control group and 15 were noncontrolled studies. Methodologies, drugs and protocols of administration varied greatly across studies. Study conclusions were generally positive in noncontrolled studies and mixed in controlled studies. Studies using higher doses tended to conclude that cannabis use was effective, but the potential for harmful effects may also be increased with higher doses.

Conclusion: Variability in the methodologies used in cannabis research makes it challenging to draw conclusions about dosing, routes and frequency of administration. Most of the existing evidence suggests that medical cannabis use is effective, but this efficacy has been demonstrated only when either there is no comparator or cannabis is compared with placebo. Studies using an active comparator have not demonstrated efficacy. Future research should focus on improving study reporting and methodologic quality so that protocols that optimize pain control while minimizing harmful effects can be determined.

Résumé

Contexte : La consommation de cannabis à des fins médicales est un sujet d’intérêt émergent en orthopédie. Malgré l’existence d’un important corpus de littérature médicale sur l’utilisation du cannabis pour traiter divers types de douleurs, peu d’études ont porté sur les problèmes orthopédiques. On dispose de peu de données probantes de grande qualité relatives aux principaux domaines de l’orthopédie. L’objectif de cette étude était de résumer la littérature sur l’efficacité du cannabis à soulager les douleurs orthopédiques.

Méthodes : Nous avons réalisé une revue systématique de la littérature sur l’utilisation des cannabinoïdes pour la prise en charge de la douleur associée aux principaux problèmes orthopédiques. Deux examinateurs indépendants ont extrait l’information sur la qualité des rapports, le risque de biais, les médicaments, les populations et groupes témoins, la durée des études, les scores de douleur et les conclusions des auteurs quant à l’efficacité au plan des scores de douleur.

Résultats : Nous avons recensé 33 études orthopédiques, dont 21 études primaires et 12 revues. La qualité des études était généralement de faible à moyenne. Six des études incluses étaient contrôlées et 15 ne l’étaient pas. Les méthodologies, les médicaments et les protocoles d’administration variaient grandement d’une étude à l’autre. Les conclusions étaient généralement positives dans les études non contrôlées, et mixtes dans les études contrôlées. Les études qui utilisaient des doses plus fortes avaient tendance à conclure que le cannabis était efficace, mais le risque d’effets négatifs pouvait également être proportionnel à la dose.

Conclusion : En raison de la variabilité des méthodologies utilisées dans la recherche sur le cannabis, il est difficile de tirer des conclusions sur la posologie, les voies et la fréquence d’administration. La plupart des preuves disponibles donnent à penser que le cannabis médical est efficace, mais cette efficacité n’a été démontrée que s’il n’y avait pas de comparateur ou si le cannabis était comparé à un placebo. Les études ayant utilisé un comparateur actif n’ont pas fait état d’efficacité. La recherche future devrait veiller à améliorer les rapports et la qualité méthodologique des études afin de déterminer quels protocoles améliorent la maîtrise de la douleur tout en réduisant les effets négatifs.


Accepted Feb. 13, 2019; published online Sept. 23, 2019

Acknowledgements: The authors thank Ms. Tristiana Dalchand, Ms. Simrun Chona, Mr. Joshua George and Dr. Hassan Baldawi for their assistance with article screening.

Affiliations: From the Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ont. (Madden, Bhandari); the Department of Surgery, McMaster University, Hamilton, Ont. (George, Bhandari); the Department of Medicine, University of Groningen, Groningen, the Netherlands (van der Hoek); the Department of Orthopaedic Surgery, Vall d’Hebron University Hospital, Barcelona, Spain (Borim); and Beleave Inc., Dundas, Ont. (Mammen).

Funding: K. Madden is funded by a Canadian Institutes of Health Research (CIHR) doctoral award (GSD-134929). M. Bhandari is funded in part by a Canada Research Chair. Funding for this program of research was provided by Beleave Inc. (a licensed cannabis producer). The funders played no role in the design or execution of the study or in the analysis or interpretation of the findings.

Competing interests: A. George and N. van der Hoek declare no competing interests. K. Madden received an honorarium to prepare this review from OrthoEvidence Inc., an orthopedics knowledge translation company. At the time of this study, G. Mammen was employed as a clinical research and collaboration liaison for Beleave Inc. (a licensed cannabis producer) for 6 months to develop consumer-focused educational content; his compensation was not tied in any way to the findings of this study. M. Bhandari received a grant from Beleave Inc. during the conduct of this study.

Contributors: K. Madden and M. Bhandari designed the study. K. Madden, A. George, N. van der Hoek and F. Borim acquired the data, which K. Madden, A. George, G. Mammen and M. Bhandari analyzed. K. Madden, A. George, N. van der Hoek and M. Bhandari wrote the article, which K. Madden, A. George, F. Borim, G. Mammen and M. Bhandari reviewed. All authors approved the article for publication and agreed to be accountable for all aspects of the work.

DOI: 10.1503/cjs.001018

Correspondence to: K. Madden, McMaster University, 293 Wellington St N Suite 110, Hamilton ON L8L 8E7, maddenk@mcmaster.ca