Bone fractures are a major global health issue, with nonunion being a serious complication. While NSAIDs are known to impair bone healing, prompting increased opioid use for pain, the effect of opioids on fracture healing is poorly understood. This article assesses: (1) whether chronic opioid use increases all-bone nonunion risk; (2) whether risk varies by anatomic site; (3) whether duration or NSAID co-use modifies risk; and (4) whether time-to-union is prolonged in opioid users.

A systematic search of PubMed, Embase, Cochrane CENTRAL, and CINAHL was conducted up to January 1, 2026. Included retrospective cohort studies reported opioid exposure and fracture healing outcomes. Study quality was assessed, and adjusted odds ratios (ORs) for nonunion were pooled using quality-effects and random-effects models.

Seven studies, comprising over one million fracture cases, were included. Meta-analysis showed chronic opioid use was associated with higher odds of nonunion across all bone types (OR 5.10, 95% CI: 3.28–7.93). Site-specific analyses revealed elevated odds for the humerus (OR 4.28), radius (OR 4.93), tibia (OR 4.57), and metatarsals (OR 4.81). Concurrent use of opioids and NSAIDs was associated with higher odds compared to opioids alone in limited analyses. One study reported a modestly prolonged time to union in opioid users.

Chronic opioid use is associated with a higher risk of fracture nonunion at multiple skeletal sites. This association appears stronger when opioids are combined with NSAIDs. These findings suggest caution regarding opioid safety in bone healing and highlight the need for cautious prescribing and exploration of multimodal, non-opioid analgesic strategies for fracture pain.

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