Comparison of the Effects of Normal Saline, Hypertonic Saline, and Hyaluronidase on Patients with Postoperative Relapse of Carpal Tunnel Syndrome: A Randomized Controlled Trial.

BACKGROUND

Recurrent carpal tunnel syndrome affects up to 25% of patients following surgical decompression, causing significant therapeutic challenges. Hydrodissection, a minimally invasive technique that alleviates perineural adhesions, has shown promise for symptom relief. However, optimal injectable agents for hydrodissection in postoperative relapse of carpal tunnel syndrome remain under investigation.

OBJECTIVES

Our study aimed to compare the clinical efficacy of 3 injectable treatments-normal saline, hypertonic saline, and hyaluronidase-in ultrasound-guided hydrodissection for patients with postoperative relapse of carpal tunnel syndrome.

STUDY

DESIGN

A randomized controlled trial with a 12-month follow-up.

SETTING

Our study was conducted at Imam Hospital Center in Sari, Islamic Republic of Iran.

METHODS

Ninety patients aged 18-60 years, experiencing carpal tunnel syndrome relapse within 6 months postsurgery, were randomly assigned to 3 equal groups (n = 30) to receive ultrasound-guided hydrodissection with either hyaluronidase (300 IU) combined with methylprednisolone, bupivacaine, and normal saline; hypertonic saline (5%) with methylprednisolone and bupivacaine; or normal saline with methylprednisolone and bupivacaine. Patients were followed at postinjection months 3, 6, and 12. Assessed outcomes included the Visual Analog Scale (VAS) for pain, Symptom Severity Scale, patient satisfaction, and the number of required reinjections.

RESULTS

All 3 groups had statistically significant improvements in pain and function (P < 0.05). However, the hyaluronidase group had statistically significant greater reductions in VAS and Symptom Severity Scale scores at all follow-up points compared to the other 2 groups (P < 0.01). Additionally, this group required fewer reinjections and reported the highest satisfaction rates throughout the study period. There were no statistically significant differences between the hypertonic and normal saline groups in terms of pain, function, satisfaction, or reinjection frequency.

LIMITATIONS: Including methylprednisolone in all injection treatments may have confounded the independent effects of the tested agents. The single-center design limits generalizability, and objective imaging or electrophysiological evaluations were not used. The follow-up period was limited to 12 months, leaving long-term outcomes unexplored.

CONCLUSIONS

Ultrasound-guided hydrodissection using hyaluronidase statistically significantly improves pain, symptom severity, and patient satisfaction in cases of postoperative relapse of carpal tunnel syndrome and reduces the need for reinjections compared to hypertonic or normal saline. Hyaluronidase appears to be a superior adjunct in hydrodissection procedures and may offer a cost-effective and clinically advantageous approach for managing postoperative relapse of carpal tunnel syndrome.