Long-Term Sensation in the Medial Plantar Flap

Introduction: The glabrous plantar skin found on the foot and ankle is unique and perfectly adapted to weight bearing, limiting options for like-for-like tissue reconstruction in this region. Soft-tissue reconstruction of foot and ankle defects must be durable [1] and provide sensation to prevent future injury. [2] A sensate medial plantar flap can be raised from the non-weight bearing aspect of the sole and used to repair these defects, providing like-for-like tissue reconstruction whilst limiting donor site morbidity. [3] This study aims to quantify sensation return when this versatile flap is used to repair foot and ankle defects.

Methods: Two-point discrimination in millimetres (2PD) was assessed in both flap and normal tissue of the contralateral foot in patients who had received a medial plantar flap over a year previously. The mean two-point discrimination in both flap and normal tissue was calculated and a paired T-test was used to assess for a significant difference between flap and normal tissue.

Results: 12 patients were eligible. 4 were excluded due to either 2PD in the normal tissue being larger than the flap (3 patients) or because testing was impossible due to hypersensitivity in the flap (1 patient). In the remaining 8, mean 2PD in the contralateral foot was 29mm (SD: 11.9) and mean 2PD in the flap was 33mm (SD: 9.97). No statistically significant difference in 2PD was found between flap and contralateral foot (two tailed p value: 0.1898). Mean age was 53.2 years (range 15-84). There was no statistically significant correlation between age and 2PD on the flap tissue (r=0.6, p=0.15) suggesting no worsening of sensation when this flap is utilised in older age groups.

Conclusions: To the best of our knowledge this is the first case series to quantify long-term sensation return in medial plantar flaps used to repair foot and ankle defects. Our results suggest that after a year, sensation in the medial plantar flap can return to near normal. This demonstrates the important role the medial plantar flap plays in soft tissue reconstruction in this region.