Categories: Abstracts, 2021, Poster

A new clinical test for first ray sagittal instability: the double dorsiflexion test

C. Pasapula, A. Al-Sukaini, I. Liew, J. Goetz, S. Cutts

1Queen Elizabeth Hospital, T&O, Kings Lynn, United Kingdom
2Colchester General Hospital, T&O, Colchester, United Kingdom
3The Queen Elizabeth Hospital, T&O, Kings Lynn, United Kingdom
4James Paget Hospital, T&O, Great Yarmouth, United Kingdom

Introduction: A rigid first ray allows good foot propulsion in stance, taking 60% weight. First, ray instability (FRI) is associated with middle column overload, synovitis, deformity and osteoarthritis. We propose and validate a new clinical test to identify FRI.

Methods: Ten patients who had 8mm or more unilateral dorsal first ray instability as measured with a Klaue Meter were recruited. The maximum passive dorsiflexion of the proximal phalanx at the 1st MTP joint was measured using a video camera and Tracker motion software with and without applying a dorsiflexion force 1st metatarsal head using a Newton meter. SPSS software was used to analyse the data.

Results: The median average dorsal translation for FRI was 11.94mm; interquartile range [IQR], 10.23-13.81. The median average dorsal translation for control feet was 1.77mm; interquartile range [IQR], 1.23-2.96). There was significant difference (P <0.0001) in the percentage of reduction in the 1st MTP joint dorsiflexion ROM when applying the double dorsiflexion test in the FRI group (mean reduction of 67.98%) when compared to control feet (mean reduction of 28.44%). Receiver operating characteristic (ROC) analysis showed that a 50% reduction in dorsiflexion ROM of 1st MTPJ when performing the double dorsiflexion test achieved a specificity of 100% and sensitivity of 90% (AUC =0.990, 95%CI [0.958-1.000], P>0.0001).

Conclusion: The double dorsiflexion (DDF) test is easy to perform in the outpatient setting and can be used in conjunction with other tests in the assessment of FRI.

Next Article Anatomy of the sural nerve in the posterolateral approach to the ankle: a cadaveric study

Documents to download

Click thumbnail below to view poster / thumbnail: