Role of remote ischaemic conditioning in fracture healing and orthopaedic surgery-a systematic review and narrative synthesis.

INTRODUCTION

Remote ischaemic conditioning (RIC) involves the use of controlled and transient ischemia and reperfusion cycles, commonly of the upper or lower limb, to mitigate cellular damage from ischaemic events. Studies have demonstrated that RIC may have anti-inflammatory and cardiovascular protective effects and thus could represent a novel therapeutic strategy to improve outcomes following orthopaedic surgery. This review aimed to comprehensively describe the current pre-clinical and clinical evidence for RIC in orthopaedics.

METHODS

MEDLINE and EMBASE via OVID (1966-March 2024) were searched using a systematic search strategy for randomised controlled trials (RCTs) investigating the effects of RIC on fracture, bone healing, and orthopaedics. Both pre-clinical and clinical RCTs were included.

RESULTS

Three pre-clinical RCTs (comprising of 198 rats in models of experimental fracture) met the inclusion criteria. These showed that RIC was associated with enhanced callus formation (volume and biomechanical strength) post-fracture, reduced oxidative stress and upregulated osteoblastic activity. Sixteen clinical RCTs, involving 628 patients, investigated RIC in 6 different elective orthopaedic procedures (knee, lower limb, cervical, shoulder, general, hip fracture). RIC protocols varied in cycle frequency, duration, and pressure, but all were given as a single dose at induction of anaesthesia. Significant results included reductions in oxidative stress, improved cerebral and peripheral oxygenation, and reduced pain scores and analgesia use. Only 1 study (n = 648) evaluated RIC in acute hip fracture and demonstrated an early cardioprotective effect.

CONCLUSION

The potential therapeutic effects of RIC in orthopaedic surgery is supported by preliminary evidence from pre-clinical and clinical studies. Trials to date are largely small but warrant investigation in well-powered multicentre RCTs. There are still many unanswered questions about the optimal RIC parameters (cuff pressure, frequency and duration) in orthopaedic surgery and determining which patients may benefit most from this therapy.