Moderate evidence supports nerve block as an intervention to reduce acute pain after hip fracture, and pre-operative traction doesn't seem to help; however the sparse data available for other interventions are inadequate to allow robust conclusions to be drawn, according to a comparative effectiveness review from the US Agency for Healthcare Research and Quality..

Effective pain management is important in patients with hip fracture, as those who experience greater pain are at higher risk for delirium, slow mobilisation, longer hospitalisation, and poorer quality of life. They are also at increased risk of other adverse health events. The authors of this systematic review aimed to summarise the best evidence for effectiveness and safety of pharmacologic and non-pharmacologic techniques for managing pain in older adults after acute hip fracture compared with usual care or other interventions. They carried out a very comprehensive literature search for randomised, controlled trials (RCT); non-randomised, controlled trials (non-RCT); and cohort studies of pain management techniques in older adults after acute hip fracture. No language restrictions were applied; however only research published since 1990 was included as management of these patients has changed substantially since then. Results were pooled if appropriate: odds ratios (OR) were calculated for dichotomous outcomes, and mean difference (MD) or standardised mean difference (SMD) for continuous outcomes.

There were 9,357 articles identified in the original search, and 620 reviewed in full after screening and removal of duplicates. Of these, 522 were excluded (mostly because they did not meet the eligibility criteria) leaving 83 unique studies for analysis: 64 RCTs, 5 non-RCTs, and 14 cohort studies. Interventions studied were nerve blockade (n = 32), spinal anaesthesia (n = 30), systemic analgesia (n = 3), traction (n = 11), multimodal pain management (n = 2), neurostimulation (n = 2), rehabilitation (n = 1), and complementary and alternative medicine (n = 2).

Nerve blockade was shown by moderate quality evidence to be effective in reducing acute pain and delirium, but the results for other outcomes were not significant. Low level evidence suggested that pre-operative traction was ineffective in reducing pain, however the evidence on most other interventions was insufficient to allow firm conclusions to be drawn on efficacy or safety.

The authors conclude that the evidence on managing pain after hip fracture is limited, and more trials are needed. Most interventions appeared to reduce short term pain, however only nerve block had moderate evidence for benefit over standard care. There was a surprising lack of recent trials involving opioids or NSAIDs; they suggest that while there may have been earlier studies on these, the changes in management over the past decades are likely to render older research less relevant to current practice. All the studies were short term and none examined outcomes beyond 30 days.