Standardized Quantitative Sensory Testing to assess insufficient recovery of touch discrimination in free flap surgery in extremity reconstruction

Abstract

Background: With major advances in microsurgical techniques, free tissue transfer has become a widely adopted approach to treat complex soft-tissue defects. However, sensory recovery is poor, leaving the anesthetic skin prone to injuries. Methods: Twenty-eight patients with 22 anterior lateral thigh flaps and six latissimus dorsi flaps on their extremities participated in the study. Quantitative sensory testing and two-point discrimination was performed in three test areas and one control on the contralateral unaffected extremity. Physical disability, mental health, quality of life, and characteristics of pain were assessed by the painDetect, Disabilities of the Arm, Shoulder, and Hand, Lower Extremity Functional Scale, and 12-Item Short Form questionnaires, respectively. Results: Somatosensory profiles of all flaps were characterized by an overall loss of nerve function. Small-fiber function was mostly recovered, whereas large-fiber function, and thus touch discrimination, was severely impaired. Mechanical detection thresholds improved over time and from center to the periphery. Reported pain was mild to moderate and correlated with decreased physical function. Conclusions: Standardized quantitative sensory testing provides a useful tool kit to assess the sensory regeneration after surgical treatment of soft-tissue defects. After free tissue transfer, small-fiber function recovers with nerve ingrowth in a centripetal direction from the flap margins to the center, likely by way of collateral axonal sprouting from the undamaged nerves surrounding the flap. Myelinated fibers recover slowly and inefficiently. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Advancing Fingertip Regeneration: Outcomes from a New Conservative Treatment Protocol

“…However, its inclusion in this study was impractical given the highly specialized nature of the procedure and the significantly lower number of eligible patients, making it unfeasible to create a control group for this technique. Another important limitation is the lack of objective sensory recovery assessments, such as the two-point discrimination test, which could have provided a more comprehensive evaluation of sensory outcomes [39]. Additionally, the relatively short follow-up period restricts the ability to fully assess the long-term durability and efficacy of the treatment.…”