603 Evaluation the First Ray Instability Using the Double Dorsiflexion Test: A Prospective Observational Case-Controlled Study

Abstract First-Ray (FR) stability allows for foot propulsion in-stance, taking 60% weight. First-ray instability (FRI) is associated with middle column overload, synovitis, deformity, and osteoarthritis. Clinical detection can still be challenging. We propose to develop a clinical test that helps identify FRI using two simple manual manoeuvres. 10 patients unilateral were recruited. Stringent exclusion criteria applied including hallux MTP pain, laxity, inflammatory arthropathy. A Klauemeter directly measured the sagittal plane dorsal first metatarsal head translation of affected vs unaffected feet. Maximum passive proximal phalanx 1st joint dorsiflexion was Tracker motion software analysis without applying force at Newton meter. P-value <0.05 considered significant. feet had greater than 8mm (median, 11.94; interquartile range [IQR], 10.23–13.81) 1.77 control 1.77; 1.23–2.96) Klauemeter. The percentage reduction in ROM when double (mean 67.98%) compared 28.44%)(P<0.01). Receiver operating characteristic (ROC) showed 50% MTPJ performing achieved specificity 100% sensitivity 90% (AUC =0.990, 95%CI [0.958–1.000], P>0.0001). (DDF) easy perform manoeuvres avoid complex instrumented radiation-based assessment. decrease has an over identifying FRI.