Carpal tunnel procedure-long term (1)

988080 HANXXX10.1177/1558944720988080HANDLeiby et al

research-article2021

Surgery Article

Long-term Clinical Results of Carpal Tunnel Release Using Ultrasound Guidance

Braeden M. Leiby1 , John P. Beckman2 ,

and Anthony E. Joseph1,3

Abstract

HAND

1–8

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Background: The purpose of this study was to determine the long-term safety and efficacy of carpal tunnel release (CTR) using ultrasound guidance in a group of patients treated by a single physician. Methods: The study group consisted of 76 consecutive CTRs performed on 47 patients between June 2017 and April 2019 for whom 1-year follow-up was available. All procedures were performed by the same operator using a single CTR technique. Outcomes included complications; Boston Carpal Tunnel Questionnaire symptom severity (BCTQ-SSS) and functional status (BCTQ-FSS) scores; Quick Disabilities of the Arm, Shoulder, and Hand (QDASH) scores; and a 5-point global satisfaction score (4 = satisfied, 5 =

very satisfied). Results: The 47 patients included 27 females and 20 males (ages 31-91 years). Twenty-five patients (50 hands) had simultaneous bilateral CTRs, 4 patients (8 hands) had staged bilateral CTRs, and 18 patients had unilateral CTRs. No complications occurred. Statistically and clinically significant reductions in BCTQ-SSS, BCTQ-FSS, and QDASH scores occurred by 1 to 2 weeks post-CTR and persisted at 1-year (mean 1-year changes vs. pre-CTR -2.11, -1.70, and -44.99, respectively; P < .001 for all). The mean global satisfaction score at 1-year was 4.63. Conclusions: CTR using ultrasound (US) guidance is a safe and effective procedure that produces statistically and clinically significant improvements within 1 to 2 weeks postprocedure that persist to 1 year. Furthermore, simultaneous bilateral CTRs using US guidance are feasible and may be advantageous for patients who are candidates for bilateral CTR.

Keywords: carpal tunnel syndrome, nerve, diagnosis, outcomes, research & health outcomes, treatment, surgery, specialty, nerve compression, hand, anatomy, wrist

Introduction

Carpal tunnel syndrome (CTS) is the most common entrap ment neuropathy and affects 3.1% to 3.7% of the general population1 and up to 8% of workers.2 In severe or refrac tory cases, carpal tunnel release (CTR) provides good or excellent outcomes for 80% to 100% of patients with a low complication rate.3,4 Over 600,000 CTRs are performed annually in the United States, 70% to 80% of which use the traditional “open” technique.4 Over time, there has been a trend to reduce incision size with the goals of minimizing surgical morbidity and improving outcomes.3,5,6 Although a smaller incision may facilitate recovery following CTR, some authors have expressed concern regarding the reduced visualization of the carpal tunnel contents provided by smaller incisions.5,6

In recent years, multiple publications have demonstrated the feasibility of using ultrasound (US) to facilitate CTR through smaller incisions while maintaining or even improving visualization of the carpal tunnel region and its

neurovascular structures.7-12 Although the safety and effi cacy of CTR using US guidance has been well-documented in the short- and intermediate-term, few studies have reported long-term clinical results of 1-year or more. There fore, the durability of clinical improvement following CTR using US guidance warrants further investigation, particu larly given concerns with respect to persistent or early recurrent symptoms when performing CTR through smaller incisions.13 Consequently, the primary purpose of this study was to determine the 1-year clinical results of CTR using US guidance in a cohort of patients treated within a single practice. We hypothesized that CTR using US guidance

1OrthoIdaho, Pocatello, ID, USA

2Sonex Health, Inc., Eagan, MN, USA

3Idaho State University, Pocatello, ID, USA

Corresponding Author:

Anthony E. Joseph, OrthoIdaho, 2240 E. Center Street, Pocatello, ID 83201, USA.

Email: joseanth@isu.edu

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Figure 1. Patient flowchart defining current study group.

Note. CTR = carpal tunnel release; TSZ = transverse safe zone.

would be safe and result in significant improvements in patient-reported outcomes (PROs) that would persist at 1-year follow-up.

Methods

Study Participants

All patients treated with CTR using US guidance by the senior author between June 2017 and April 2019 were pro spectively followed for 12 months. One hundred forty-six hands/92 patients were potential candidates for CTR during this time period. General indications for CTR using US guid ance included: (1) clinical CTS; (2) at least 6 months of non surgical management including splinting and corticosteroid injections; and (3) US evidence of median nerve enlargement (cross-sectional area ≥ 10 mm2 or a wrist-pronator cross sectional area [CSA] difference of greater than 2 mm2 for a non-bifid median nerve or greater than 4 mm2 for a bifid median nerve).14 Electrodiagnostic testing was not routinely

obtained. Thirty hands/21 patients were not operated on for various reasons (Figure 1). Thus, 116 hands/71 patients were treated with CTR using US guidance and followed prospec tively. All procedures were performed following a mutual decision-making process including discussion of alternative non-surgical and surgical treatment options.

Patient records were reviewed to identify patients with 1-year follow-up. Of the 116 hands/71 patients treated with CTR using US guidance between June 2017 and April 2019, 1-year follow-up was available on 76 hands/47 patients. Follow-up was also available on 91% of the 76 hands at 1 to 2 weeks, 96% at 1 month, 91% at 3 months, and 82% at 6 months. The short-term (3 months) clinical results of a sub

set of this cohort consisting of 31 hands/19 patients have been previously reported.15

Procedural Description

All procedures were completed by the senior author in either a hospital operating room or ambulatory surgery center

Leiby et al 3

using a small incision and US guidance to divide the trans

verse carpal ligament (TCL) using a retrograde cutting knife.

One of 2 US machines was used in all cases (X-Porte with a

6-15 MHz linear transducer, SonoSite Corporation, Bothell,

Washington, or HS60 with a 4-18 MHz linear transducer,

Samsung Medison America, Inc., Cypress, California). At

the time of the study, the senior author had 14 years of expe

rience in diagnostic and interventional US and had per

formed over 200 CTRs using US guidance.

The procedural details have been described elsewhere.15

In brief, all procedures were performed using US guidance

and local anesthesia, with midazolam administered for anx

iolysis per patient preference. Sterile technique was uti

lized, including a sterile US probe cover and sterile US gel.

The forearm was immobilized with the wrist slightly extended. The carpal tunnel was scanned to identify the rel evant anatomy, including the transverse safe zone (TSZ) between the median nerve and the hook of the hamate or ulnar artery (whichever was closer); the median, palmar cutaneous, thenar motor, and digital nerves; the ulnar artery and superficial palmar arterial arch; and the TCL, including its distal portion. Local anesthesia was obtained by inject ing 10 mL of 1% lidocaine with epinephrine subcutane ously and into the carpal tunnel, including hydrodissection of the synovium from the undersurface of the TCL. A #11 scalpel was used to create a small longitudinal incision (typ ically < 5 mm; Figure 2) in the region of the proximal wrist crease, followed by passing a blunt elevator into the tunnel to complete additional synovial dissection. CTR was per formed with a commercially available device designed to create space in the carpal tunnel and divide the TCL using a retrograde knife (SX-One MicroKnife, Sonex Health, Inc., Eagan, Minnesota). The device was advanced into the TSZ (Figure 3a) and positioned to engage the distal TCL. After checking the device position relative to the TCL and sur rounding neurovascular structures, the balloons were deployed, and the device position was rechecked (Figure 3b). The cutting knife was then activated to transect the ligament distal to proximal (Figures 3b and 4). Following transection, the blade was replaced into its recessed posi tion, the balloons deflated, the device removed, and the ligament probed using US visualization to ensure a com plete release. Ultrasound guidance was then used to inject 5 mL of 0.5% bupivacaine around the median nerve for post operative comfort.

Wounds were generally dressed with sterile adhesive wound closure strips, although sutures were used in both hands of a single patient due to the size of the incisions. Fol lowing closure, wounds were covered with sterile gauze and a sterile film dressing and wrapped with a compression wrap. Patients were instructed in edema control and counseled to use non-steroidal anti-inflammatories or acetaminophen for pain control. Opioids were only prescribed upon patient request. Only 3 patients requested narcotics specifically for

Figure 2. Typical incision for carpal tunnel release with ultrasound guidance (length = 3 mm).

Figure 3. Transverse ultrasound views of the carpal tunnel at the level of the hook of HH.

Note. (a) The device is in the transverse safe zone between MN radially and the hook of the hamate and UA ulnarly, just deep to the transverse carpal ligament (asterisks). The balloons of the device are not yet deployed and the blade is not exposed. (b) The 2 balloons have been deployed to create space within the transverse safe zone, separating the MN radially from the UA and HH ulnarly. The retrograde cutting blade (circled) is engaged and superior to the transverse carpal ligament (asterisks). The transection of the transverse carpal ligament proceeds distal to proximal. ThM = thenar muscles; FT = flexor tendons; Top = superficial; HH= hamate; MN = median nerve; UA= ulnar artery.

pain control after the procedure. No splinting or postopera tive therapy was prescribed. All patients resumed normal daily activities as tolerated. Patients performing heavy or

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the mean (SEM). Preoperative versus postoperative differ

ences in BCTQ-SSS, BCTQ-FSS, and QDASH scores were

calculated for each hand and summarized via means and

SEMs. The significance of these differences was assessed

via a 2-tailed Wilcoxon signed-rank test. Analyses were

conducted using JMP 14.3.0 (SAS Institute Inc, Cary, North

Carolina). P < .05 was considered statistically significant.

Minimal clinically important differences (MCIDs) were

considered to be 1.14 for BCTQ-SSS, 0.74 for BCTQ-FSS,

and 15 for QDASH.23-25

Figure 4. Longitudinal ultrasound image showing the device

directly under the TCL (asterisks) with the cutting blade engaged to transect the TCL distal to proximal.

Note. The blade arises 4 mm proximal to the distal device tip, safely proximal to the SPA. TCL = transverse carpal ligament; SPA = superficial palmar arterial arch.

repetitive work activities were advised to take the first week off, return to partial duties on week 2, and thereafter resume normal job duties. Patients returned for in-person follow-up at 1 to 2 weeks and 4 to 6 weeks postprocedure.

Patient-Reported Outcomes

Clinical outcomes included complications, Boston Carpal Tunnel Questionnaire symptom severity and functional sta tus scores (BCTQ-SSS, BCTQ-FSS), Quick form of the Dis abilities of the Arm, Shoulder, and Hand (QDASH) score, and a global satisfaction score (GSS; 5-point scale from 1 = very dissatisfied to 5 = very satisfied). Data were collected via paper questionnaires administered to patients in-person at the preoperative and 1 to 2 week postoperative time-points. At 1 month, 3 months, 6 months, and 1 year postoperatively, data were typically collected via paper questionnaires sent to patients via postal mail and returned the same way. Boston carpal tunnel questionnaire scores and a QDASH score were collected pre- and postoperatively for each treated hand. Postoperative global satisfaction scores were assessed once per patient at each time point for simultaneous bilateral pro cedures and separately for each hand at each time point for staged bilateral procedures. The BCTQ is a commonly used, validated, disease-specific PRO measure for CTS consisting of an 11-item symptom severity scale with each item graded as 1 (normal) to 5 (very serious) and an 8-item functional status scale with each item graded as 1 (no difficulty) to 5 (cannot perform the activity).16-19 Each item is graded on a 1 (better) to 5 (worse) scale. The QDASH an 11-item region specific PRO that has been validated for CTS and provides a score from 0 (no symptoms or disability) to 100 (severe symptoms or disability).20-22

Statistical Analysis

At each time-point, BCTQ-SSS, BCTQ-FSS, QDASH, and GSS data were summarized via mean and standard error of

Results

One-year follow-up was available on 76 hands among 47 patients ages 31 to 91 years (mean 58.4 years), including 27 females and 20 males with a mean body mass index of 31.51 kg/m2 (21.63-42.91 kg/m2). Fifty-four releases (71% of all releases) were performed in patients having at least one of the following comorbidities: diabetes mellitus (19 hands, 25%), hypertension (37 hands, 49%), hypothy

roidism (23 hands, 30%), and rheumatoid arthritis (2 hands, 3%). Fifty hands/25 patients were treated as simul taneous bilateral releases, 8 hands/4 patients as staged bilateral releases, and 18 hands/18 patients as unilateral releases. The dominant hand was released in 89% of patients claiming to have a dominant hand (1 patient was ambidextrous). The median nerve cross-sectional area at the carpal tunnel entrance was 15.74 ± 3.49 mm2 (mean ± SD; normal < 10 mm2). Although electrodiagnostic test ing was not routinely obtained, 32 hands/21 patients had electrodiagnostic testing performed prior to referral or as part of their clinical evaluation by the senior author. Of these, 10 hands (31.3%) were graded as severe, 15 (46.9%) as moderate, and 4 (12.5%) as mild with respect to median neuropathy at the wrist. In the remaining 3 hands, the tests had been performed elsewhere, and the results were unable to be obtained.

Local anesthesia only (i.e., Wide Awake Local Anesthesia No Tourniquet) was used in 55% (42/76) of hands and in 45% (34/76) of hands midazolam anxiolysis was used at patient request. Sixty-six hands (87%) required only one pass to divide the TCL and the average procedure time (inci

sion to closure) was 16 minutes and 45 seconds. Incisions were typically 4 to 5 mm in length. No procedures were dis continued due to patient discomfort or poor visualization.

There were no intra-operative or postoperative compli cations. During the 1-year follow-up period, no hand experienced recurrent symptoms and no re-operations occurred. Mean BCTQ-SSS, BCTQ-FSS, and QDASH scores at each time-point are presented in Table 1 and Figures 5 and 6. Statistically significant improvements in BCTQ-SSS, BCTQ-FSS, and QDASH scores (P < .001) occurred by 1 to 2 weeks postprocedure and persisted throughout the 1-year follow-up period (Table 1). In

Leiby et al 5 Table 1. Patient Reported Outcomes at up to 1 Year Following Carpal Tunnel Release (CTR) With Ultrasound Guidance.

Time period Pre-CTR

1-2 weeks post-CTR

1 month post-CTR

3 months post-CTR

6 months

post-CTR 1 year post-CTR

Mean (standard error) BCTQ-SSS 3.46 (0.09) 2.01 (0.09) 1.62 (0.07) 1.51 (0.06) 1.41 (0.08) 1.34 (0.06) BCTQ-FSS 3.05 (0.10) 2.15 (0.11) 1.59 (0.07) 1.38 (0.06) 1.27 (0.05) 1.35 (0.06) QDASH 55.41 (2.19) 36.02 (2.88) 17.78 (1.92) 12.40 (1.55) 10.10 (1.86) 10.43 (1.66) Global Satisfaction N/A 4.59 (0.10) 4.55 (0.11) 4.50 (0.12) 4.58 (0.10) 4.63 (0.09)

Mean individual change from pre-CTR

(standard error)*

BCTQ-SSS N/A −1.46 (0.10) −1.83 (0.10) −2.00 (0.10) −2.04 (0.11) −2.11 (0.10) BCTQ-FSS N/A −0.96 (0.11) −1.50 (0.09) −1.72 (0.09) −1.72 (0.10) −1.70 (0.10) QDASH N/A −20.43 (2.74) −38.63 (2.15) −44.14 (2.24) −45.15 (2.35) −44.99 (2.47)

Note. BCTQ-SSS = Boston Carpal Tunnel Symptom Severity Score; BCTQ-FSS = Boston Carpal Tunnel Functional Status Score; QDASH = Quick form of the Disabilities of the Arm, Shoulder, and Hand score; Global Satisfaction = 5-point scale from 1 = very dissatisfied to 5 = very satisfied. *P < .001 in all cases.

addition, improvements exceeded previously published

MCIDs for BCTQ-SSS, BCTQ-FSS, and QDASH

throughout the follow-up period.23-26 Mean patient subjec

tive global satisfaction scores were ≥ 4.5 at all postopera

tive follow-up periods, with 4 being “satisfied” and 5

being “very satisfied” (Table 1). Given the high proportion

of patients treated with simultaneous bilateral releases,

further analysis was performed to determine whether out

comes from these procedures differed from unilateral or

staged bilateral releases. As assessed using a mean differ

ence F-test, there were no statistically significant differ

ences in preoperative versus postoperative improvement

in BCTQ-SSS, BCTQ-FSS, or QDASH at any postopera

Figure 5. BCTQ-SSS and BCTQ-FSS scores (mean ± SEM) for 76 hands with 1-year follow-up.

Note. BCTQ-SSS = Boston Carpal Tunnel Symptom Severity Score; BCTQ-FSS = Boston Carpal Tunnel Functional Status Score; CTR = carpal tunnel release. At all postoperative time-points, mean BCTQ-SSS and BCTQ-FSS scores were significantly reduced compared to pre-CTR (P < .001).

Figure 6. QDASH scores (mean ± SEM) for 76 hands with 1-year follow-up.

Note. CTR = carpal tunnel release; QDASH = Quick form of the Disabilities of the Arm, Shoulder, and Hand score. At all postoperative time-points, mean QDASH scores were significantly reduced compared to pre-CTR (P < .001).

tive time-point between unilateral, simultaneous bilateral, and staged bilateral releases (P ≥ .11).

Discussion

The most important finding of the current investigation is that CTR using US guidance is safe and resulted in statis tically and clinically significant improvements in PROs that persisted at 1-year follow-up. There were no intra- or peri-operative complications, and during the 1-year fol low-up period, no wrists experienced recurrent symptoms and no re-operations occurred. Finally, patients reported a high degree of satisfaction with the procedure at 1-year postrelease.

Although smaller incisions have been associated with improved cosmesis and more rapid recovery, smaller incisions also reduce visibility, which may compromise outcome.5,6,13 For example, endoscopic carpal tunnel release (ECTR) has been associated with higher rates of both tran

sient neuropraxia and revision for persistent or recurrent symptoms.13,27-29 Ultrasound can also be used to facilitate CTR through smaller incisions while maintaining adequate visualization of the carpal tunnel contents.7-12,15,30-33

Whereas several publications have highlighted the advan tages of CTR performed through relatively small incisions

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using US guidance and surgical knives or blades to cut the TCL, only 4 have reported results at ≥ 1 year.11,31-33 Among the 280 hands/234 patients reported in these 4 publications, there were no neurovascular complications, and only 1 late recurrence was reported > 14 months post-CTR.32 Two of these publications reported the results of prospective, com

parative trials that demonstrated superior short-term out comes (QDASH, pain and patient satisfaction) among patients treated with CTR using US guidance compared to those treated with traditional mini-open CTR.11,33 The results of the current investigation are commensurate with these previously published studies and further support the long-term safety and efficacy of CTR using relatively small incisions and US guidance.

It is noteworthy that 53% of the patients (25/47) in the current study were treated with simultaneous bilateral CTRs. None of the 4 previously mentioned long-term studies spe cifically reported the inclusion of patients treated with simul taneous bilateral releases. The high prevalence of bilateral CTS is well-documented in the literature,34 as are the chal lenges facing patients in the early postoperative period fol lowing bilateral simultaneous CTR with larger incisions.35 In the senior author’s experience, patients tolerate bilateral simultaneous CTRs using the current technique extremely well, an observation supported by the current study, in which most procedures were performed using only local anesthesia, opioids were generally not required for postoperative pain control, and significant improvements in PROs occurred by the first follow-up at 1 to 2 weeks. The ability to offer appro priate patients the option of simultaneous bilateral CTRs can significantly abbreviate the episode of care and could be an advantage of CTR using US guidance.35

The current study has several strengths, including the use of a standardized evaluation and treatment protocol, prospective data collection over a 1-year period using vali dated PROs, and inclusion of a global satisfaction score. However, several study limitations should be considered when interpreting the results of the current investigation. First, all procedures were performed by a single experi enced physician, which may limit the generalizability of the results. However, CTR using US guidance has been suc cessfully performed by clinicians with various levels of experience.8-11,30,36-39 Furthermore, the characteristics of the study group are typical for CTS patients treated with CTR (predominately female, refractory symptoms for ≥ 6 months, 74% with comorbidities, 89% with dominant hand involvement, and a high proportion of hands with moderate or severe disease based on US or electrodiagnostic criteria). Second, the primary purpose of this cohort study was to report clinical results at 1-year post-CTR. Although the cur rent results are similar or superior to previously reported data for CTR, the study design precludes direct comparison between techniques.11,27,31-33,40 Third, although we used val idated PROs as well as a global satisfaction score, we did

not record return to work as part of the current investiga tion. Although the rapid clinical recovery observed in the current investigation might indicate the ability to return to work in the early postoperative period, further study is required in this regard.

In conclusion, CTR using US guidance is a safe and effective procedure that produces statistically and clinically significant improvements within 1 to 2 weeks postprocedure that persist to 1 year. Furthermore, simultaneous bilateral CTRs using US guidance are feasible and may be advanta

geous for patients who are candidates for bilateral CTR.

Ethical Approval

This study was approved and deemed exempt from review by the Idaho State University Human Subjects Committee.

Statement of Human and Animal Rights

All procedures followed in this study were in accordance with the ethical standards of the responsible committee on human experi mentation and with the Helsinki Declaration of 1975, as revised in 2008.

Statement of Informed Consent

Before initiation of chart review and data analysis, this study was reviewed by the Idaho State University Human Subjects Commit tee. It was deemed exempt from review as a retrospective chart review of prospectively collected data. Although we believe this article contains no patient-identifying information, patient consent was nonetheless obtained to publish ultrasound images and a pho tograph of the wrist incision.

Declaration of Conflicting Interests

The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: B.M.L. does not have any relevant conflicts of interest to disclose. J.P.B. is an employee of and owns stock options of Sonex Health, Inc., Eagan, Minnesota. A.E.J. is a consultant for and owns stock in Sonex Health, Inc.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Braeden M. Leiby https://orcid.org/0000-0003-0383-1187 John P. Beckman https://orcid.org/0000-0003-4657-5953 Anthony E. Joseph https://orcid.org/0000-0003-1514-6910

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