Correlations between ultrasonography findings and surgical findings in patients with refractory symptoms after primary surgical release for carpal tunnel syndrome

Objective: Surgical carpal tunnel release is very effective for symptom relief in carpal tunnel syndrome, and it remains the preferred choice of treatment. However, refractory symptoms following surgical release are not uncommon. We aimed to assess the usefulness of ultrasonography for determining the potential causes of ongoing symptoms following surgical release. Methods: This retrospective study included 34 patients (32 women; mean age, 54.7 }16.65 years; range: 30 to 81 years) with carpal tunnel syndrome who underwent surgical carpal tunnel release. Results: A pathology related to the cause of the ongoing symptoms was detected by ultrasonography in 25 (74.5%) patients. The most common pathological findings were median nerve swelling (70.6%), incomplete transection of the transverse carpal ligament (23.5%) and perineural fibrosis (17.6%). Conclusion: In the majority of the patients the pathology related to the ongoing symptoms was detected by ultrasonography, suggesting that ultrasonography could be used as a complementary imaging method for identifying the causes of failure following surgical carpal tunnel release. Detection of an ongoing pathology might help clinicians in managing persistent disease cases and aid in planning an exploration.