Establishing the indications for temporising knee-spanning external fixation: A modified Delphi study of the International Knee Dislocation Study Group

Knee dislocations (KDs) can be limb-threatening injuries that may require a temporising knee-spanning external fixator (KSEF) for stabilisation. Precise indications for this commonly utilised invasive immobilisation technique remain controversial and poorly defined. The purpose of this study was to establish consensus-driven indications for temporising KSEF use in the initial management of KDs. A working group of fellowship-trained orthopaedic surgeons generated clinical scenarios reflecting commonly debated indications for temporising KSEF application. Utilising a modified Delphi technique, 23 surgeons from the International Knee Dislocation Study Group completed two anonymous online survey rounds. Consensus was defined a priori as ≥70% agreement or disagreement. Response rates were 100% for Round 1 and 96% for Round 2. Four scenarios achieved unanimous consensus: (1) KD without post-reduction instability (100% disagreement), (2) inability to maintain tibiofemoral reduction in the sagittal/coronal plane with non-invasive knee immobilisation (NIKI) after initial reduction (i.e., redislocation/subluxation) (100% agreement), (3) tibial plateau fracture-dislocation with post-reduction subluxation (100% agreement), and (4) in bilateral closed KDs where one limb is indicated and the other is NOT, span ONLY the indicated limb (100% agreement). Two scenarios achieved strong positive consensus (90%-99.9% agreement): (1) morbid obesity (BMI ≥ 40) without NIKI of sufficient size (91.3% agreement), and (2) extensor mechanism injury with post-reduction subluxation (91.3% agreement). Four and one additional scenarios achieved positive and negative consensus, respectively. This modified Delphi study established consensus-driven indications for temporising KSEF application in the initial management of KDs, which advocate for more selective use than what is demonstrated in the literature. Level V.