The role of cannabis on total hip and knee surgeries outcomes: a systematic review and meta-analysis

Cannabis refers to medications derived from the Cannabis plant. Cannabis has long been used to treat a wide range of conditions. The widespread legalization of cannabis has increased its use. This meta-analysis evaluates the effects of preoperative cannabis usage on TKA and THA outcomes and complications.

This review follows CRD Guidance for Undertaking Reviews in Healthcare and PRISMA 2020 guidelines. On October 12, 2023, we extensively searched MEDLINE (PubMed), Scopus, Cochrane Central Register of Controlled Trials, and Web of Science. There were no time, place, or language restrictions. We also examined the references and citations in the included publications to find relevant research.

We found 208 references in PubMed/Medline, Scopus, Web of Science, and other databases. After reviewing all publications, we identified 18 references that match the requirements for further assessment. The odds ratios (ORs) for reoperation and readmission are 1.35 (95% CI: 0.69, 2.66, and p-value = 0.38), and 0.89 (95% CI: 0.41, 1.92, and p-value = 0.76). Inpatient morphine milligram equivalent (MME) and length of stay (LOS) have a mean difference (MD) of -1.71 (95% CI: -13.46, 10.05, and p-value = 0.78), and − 0.13 (95% CI: -0.33, 0.08, and p-value = 0.23). The MD of the VAS pain score 24–72 h after surgery is 0.40 (95% CI: -0.07, 0.87, and p-value = 0.10). The odds ratio for PTE and DVT is 1.54 (95% CI: 0.1, 23.24, and p-value = 0.75), and 1.38 (95% CI: 1.08, 1.77, and p-value = 0.01), respectively.

Cannabis users experienced significantly higher rates of DVT following THA and TKA. Our subgroup analysis found that cannabis users who underwent TKA had considerably higher rates of reoperation (p-value = 0.10) and readmission (p-value ≤ 0.01), while those who underwent THA had significantly lower rates of PTE. These findings highlight the need to include cannabis use as a risk factor in surgical planning and patient care protocols, and further studies are warranted.

This study design and protocol were performed in accordance with the PRISMA Statement. The protocol was registered previously on PROSPERO CRD42024551078.