Post-operative Pain of Endoscopic versus Mini-open Carpal Tunnel Release: A Randomized Controlled Trial

Technical Summary: Post-operative Pain of Endoscopic versus Mini-open Carpal Tunnel Release

Problem Statement
Carpal tunnel syndrome (CTS) is a prevalent peripheral nerve entrapment requiring surgical decompression via transection of the transverse carpal ligament (TCL). While both Endoscopic Carpal Tunnel Release (ECTR) and Mini-open Carpal Tunnel Release (MOCTR) are established minimally invasive alternatives to conventional open release, comparative data regarding high-resolution, daily postoperative pain trajectories and immediate socioeconomic reintegration remain limited. Existing literature often focuses on long-term functional outcomes (6–12 months), leaving a gap in understanding the acute recovery kinetics and early analgesic profiles of these two specific techniques.

Methodology
The authors conducted a prospective, single-center, parallel-group randomized controlled trial (RCT) between 2023 and 2026 involving 54 patients with confirmed idiopathic CTS. Patients were randomly assigned to either the ECTR group ($n=27$) or the MOCTR group ($n=27$).

• Surgical Protocols: All procedures were performed by a single fellowship-trained orthopedic hand surgeon to eliminate inter-operator variability.
  • ECTR: Utilized a single-portal endoscopic assembly under local anesthesia with a 2 cm proximal wrist crease incision. The TCL was divided retrogradely under direct endoscopic visualization.
  • MOCTR: Utilized a 1.5 cm longitudinal palmar incision at Kaplan's cardinal line. The TCL was divided under direct, unmagnified vision using a nasal speculum and tenotomy scissors.
• Blinding and Follow-up: An independent orthopedic resident, blinded to the allocation, conducted all assessments. Patients wore custom long-sleeved garments to obscure scar morphology, ensuring assessor blinding. Follow-up occurred daily for the first week, then at weeks 2, 4, 6, 8, and 12.
• Outcome Measures:
  • Primary: Daily Visual Analog Scale (VAS) pain scores from postoperative day 1 through week 12.
  • Secondary: Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ-SSS), grip/pinch strength, return-to-work interval, patient/scar satisfaction (3-month Likert scale), and complication rates.
• Statistical Analysis: Data were analyzed using mixed-effects linear regression models to account for longitudinal pain trajectories and within-subject correlations. Significance was set at $P < 0.05$.

Key Results

• Pain Trajectories: Both techniques significantly alleviated pain with no complications. However, the ECTR group demonstrated statistically significant lower VAS pain scores compared to MOCTR from postoperative day 1 through week 2.
  • The maximum divergence occurred on Day 1 (ECTR: $1.93 \pm 0.13$ vs. MOCTR: $3.07 \pm 0.21$; mean difference $-1.15$, $P < 0.005$).
  • Significant differences persisted through Day 7 and Week 2. By Week 4, pain scores converged, and no significant differences were observed between groups through Week 12.
• Functional and Socioeconomic Outcomes:
  • Return to Work: The ECTR group returned to work significantly faster ($4.96 \pm 0.30$ days) compared to the MOCTR group ($10.48 \pm 0.24$ days), representing a mean acceleration of 5.5 days ($P < 0.005$).
  • Long-term Function: No significant differences were found between groups in BCTQ-SSS scores, grip strength, or pinch strength at any follow-up point up to 3 months.
  • Satisfaction and Safety: Patient satisfaction and scar cosmesis scores were identical at 3 months (4.89/5.0 for both). Both groups reported a 0% complication rate (no infections, nerve injuries, pillar pain, or reoperations).

Key Contributions
This study provides high-resolution, day-by-day documentation of postoperative pain kinetics in a strictly controlled RCT setting. It specifically isolates the early recovery window (Days 1–14), demonstrating that while long-term functional equivalence exists between ECTR and MOCTR, ECTR offers a distinct, statistically significant advantage in early pain reduction. The research quantifies the socioeconomic impact of this analgesic advantage, linking the reduced pain trajectory directly to a nearly one-week reduction in occupational absenteeism.

Significance and Claims
The authors conclude that while both ECTR and MOCTR are equally safe and effective for mid-term CTS decompression, ECTR provides clinically superior advantages for the immediate postoperative period. The study claims that ECTR minimizes early postoperative morbidity and accelerates occupational reintegration without increasing complication risks.

The paper posits that for active, working-age populations and manual laborers, ECTR should be considered the preferred approach when the primary therapeutic objectives are minimizing acute pain trajectories and reducing occupational absenteeism. The authors note that the accelerated recovery timeline of ECTR may offset its higher initial technical costs through reduced indirect costs associated with sick leave. The findings support ECTR not merely as a cosmetic alternative, but as a strategy that optimizes early convalescence.

Limitations Acknowledged by the Authors
The study acknowledges limitations including a sample size sufficient for primary pain endpoints but potentially underpowered for rare adverse events; the execution by a single high-volume surgeon limiting generalizability to lower-volume settings; a 3-month follow-up duration that does not capture ultra-long-term recurrence or late neurophysiological changes; and the inability to blind patients to incision type, which may introduce response bias in subjective scoring.