Morphologic change of nerve and symptom relief are similar after mini-incision and endoscopic carpal tunnel release: a randomized trial

Abstract

BackgroundThe symptoms in carpal tunnel syndrome (CTS) can be ameliorated by open and endoscopic release of the transverse carpal ligament. It is unknown whether a mini-incision or endoscopic carpal tunnel release more effectively reverses the pathological changes that are observed in the median nerve in patients with CTS and these morphologic changes correlates with the subjective outcomes after carpal tunnel release. We hypothesized that (1) at 24 weeks after surgery, the subjective outcomes of mini-incision release and endoscopic release would not differ in patients with CTS; and (2) the ultrasonographic (US) morphology of the median nerve reverses similarly after mini-incision and endoscopic release; (3) the subjective outcomes correlates with these morphologic changes.MethodsBetween November 2011 and January 2013, 67 patients with CTS in their dominant wrist were randomized to either mini-incision (n = 32) or endoscopic (n = 35) release. Each patient was assessed by both the Boston Carpal Tunnel Questionnaire (BCTQ) and the Disabilities of the Arm, Shoulder, and Hand (DASH) pre-operatively and 24 weeks’ post-operation. An US examination was conducted at both time points to measure the cross-sectional area (CSA) at the inlet, middle, and outlet (CSA-I, CSA-M and CSA-O) and the flattening ratio (FR) at the middle and outlet (FR-M and FR-O) of the median nerve.ResultsThe post-operative mean BCTQ and DASH scores were improved significantly from the pre-operative scores in both groups (p < 0.001). The mean CSA-I decreased and CSA-M and CSA-O increased similarly in both groups (by 3.3, 3.0, and 3.8 mm2 in the mini-incision group and 2.9, 3.1. and 2.7 mm2 in the endoscopic group. The mean FR-M/FR-O decreased similarly from 3.6/4.2 to 3.2/3.0 in the mini-incision group and 3.8/4.3 to 3.2/2.9 in the endoscopic group. There were no significant differences in the subjective outcome scores or median nerve measures between the two groups. Improvement in the BCTQ-S only was significantly correlated with changes in the CSA at the inlet.ConclusionsMini-incision and endoscopic release both similarly relieved subjective symptoms and functions along with the pathological changes in the median nerve morphology along the carpal tunnel in patients with idiopathic CTS. Symptom relief after surgical decompression seems to correlate with reduced nerve swelling at carpal inlet and reversed nerve flattening inside carpal tunnel.Trial registrationThis study was retrospectively registered in “ClinicalTrials.gov” at Oct 18th, 2013, and the registration number was NCT01972165.

Ultrasound (US) Changes in the Median Nerve Cross‐Sectional Area After Microinvasive US‐Guided Carpal Tunnel Release

“…Kim et al found no correlation between proximal CSA changes and BCTQ changes after open CTR. Oh et al found a significant correlation between a reduced proximal CSA and improved BCTQ‐SS scores after open/endoscopic CTR ( r = 0.38). Tran et al observed a strong correlation ( r = 0.61) between a reduced proximal CSA and improved BCTQ‐FS scores after open CTR but only a weak correlation with improved BCTQ‐SS scores ( r = 0.26).…”

“…Several studies have attempted to correlate clinical outcomes with changes in the nerve CSA after CTR, producing mixed results. 14,15,46,47 Although correlating changes in the nerve CSA with clinical outcomes was not a primary goal of our current investigation, we did attempt to identify correlations between median nerve CSA changes and BCTQ score changes. As shown in Table 4, there were no statistically significant correlations between nerve CSA changes and BCTQ score changes.…”

The comparison of limited-incision versus standard-incision in treatment of carpal tunnel syndrome

“…[4] Although the standard carpal tunnel release has proven effective and safe, the limited method offer better appearance and minor wound complications compared with the standard open method. [12] Also, the limited technology provides an early return to activities, an early recovery of grip strength and pinch strength. [9] A meta-analysis with a large sample size may be necessary to detect such complications and differences in other outcome measures.…”

Morphologic Analysis of the Carpal Tunnel and Median Nerve Following Open and Endoscopic Carpal Tunnel Release

“…Various studies have defined the outcomes of ECTR and OCTR as clinically equivalent for subjective symptom relief and morphologic changes of the median nerve and carpal canal. 9,12,17 Other studies have reported that ECTR is a superior method to OCTR, as endoscopic technique results in a shorter recovery time than OCTR. 3,18 As discussed previously, prior studies have been unable to obtain clearly reproducible results regarding the mechanism by which decompression of the median nerve occurs.…”