Ultrasound-Guided Injection for the Treatment of Carpal Tunnel Syndrome

Local corticosteroid injection versus placebo for carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is a very common clinical syndrome manifested by signs and symptoms of irritation of the median nerve at the carpal tunnel in the wrist. Direct and indirect costs of CTS are substantial, with estimated costs of two billion US dollars for CTS surgery in the USA in 1995 alone. Local corticosteroid injection has been used as a non-surgical treatment for CTS many years, but its effectiveness is still debated.

OBJECTIVES

To evaluate the benefits and harms of corticosteroids injected in or around the carpal tunnel for the treatment of carpal tunnel syndrome compared to no treatment or a placebo injection.

SEARCH METHODS

We used standard, extensive Cochrane search Methods. The searches were 7 June 2020 and 26 May 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-randomised trials of adults with CTS that included at least one comparison group of local injection of corticosteroid (LCI) into the wrist and one group that received a placebo or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was 1. improvement in symptoms at up to three months of follow-up. Our secondary outcomes were 2. functional improvement, 3. improvement in symptoms at greater than three months of follow-up, 4. improvement in neurophysiological parameters, 5. improvement in imaging parameters, 6. requirement for carpal tunnel surgery, 7. improvement in quality of life and 8.

ADVERSE EVENTS

We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 14 trials with 994 participants/hands with CTS. Only nine studies (639 participants/hands) had useable data quantitatively and in general, these studies were at low risk of bias except for one quite high-risk study. The trials were conducted in hospital-based clinics across North America, Europe, Asia and the Middle East. All trials used participant-reported outcome measures for symptoms, function and quality of life. There is probably an improvement in symptoms measured at up to three months of follow-up favouring LCI (standardised mean difference (SMD) -0.77, 95% confidence interval (CI) -0.94 to -0.59; 8 RCTs, 579 participants; moderate-certainty evidence). Up to six months this was still evident favouring LCI (SMD -0.58, 95% CI -0.89 to -0.28; 4 RCTs, 234 participants/hands; moderate-certainty evidence). There is probably an improvement in function measured at up to three months favouring LCI (SMD -0.62, 95% CI -0.87 to -0.38; 7 RCTs, 499 participants; moderate-certainty evidence). We are uncertain if there is a difference in median nerve DML at up to three months of follow-up (mean difference (MD) -0.37 ms, 95% CI -0.75 to 0.02; 6 RCTs, 359 participants/hands; very low-certainty evidence). The requirement for surgery probably reduces slightly in the LCI group at one year (risk ratio 0.84, 95% CI 0.72 to 0.98; 1 RCT, 111 participants, moderate-certainty evidence). Quality of life, measured at up to three months of follow-up using the Short-Form 6 Dimensions questionnaire (scale from 0.29 to 1.0; higher is better) probably improved slightly in the LCI group (MD 0.07, 95% CI 0.02 to 0.12; 1 RCT, 111 participants; moderate-certainty evidence). Adverse events were uncommon (low-certainty evidence). One study reported 2/364 injections resulted in severe pain which resolved over "several weeks" and 1/364 injections caused a "sympathetic reaction" with a cool, pale hand that completely resolved in 20 minutes. One study (111 participants) reported no serious adverse events, but 65% of LCI-injected and 16% of the placebo-injected participants experienced mild-to-moderate pain lasting less than two weeks. About 9% of participants experienced localised swelling lasting less than two weeks. Four studies (229 participants) reported that they experienced no adverse events in their studies. Three studies (220 participants) did not specifically report adverse events.

AUTHORS' CONCLUSIONS

Local corticosteroid injection is effective for the treatment of mild and moderate CTS with benefits lasting up to six months and a reduced need for surgery up to 12 months. Where serious adverse events were reported, they were rare.

Novel Motor-Sparing Ultrasound-Guided Neural Injection in Severe Carpal Tunnel Syndrome: A Comparison of Four Injectates

Nerve hydrodissection uses fluid injection under pressure to selectively separate nerves from areas of suspected entrapment; this procedure is increasingly viewed as potentially useful in treating carpal tunnel syndrome (CTS). The usage of normal saline (NS), 5% dextrose water (D5W), platelet-rich plasma (PRP), and hyaluronic acid (HA) as primary injectates for hydrodissection without an anesthetic can limit anesthetic-related toxicity and preserve the motor functions of the median nerve. Here, we describe a novel motor-sparing neural injection and compare the effect of these four injectates for severe CTS. We retrospectively reviewed the outcomes of 61 severe CTS cases after a single neural injection with NS, D5W, PRP, or HA. Outcomes were evaluated on the 1st and 6th months postinjection, including the Boston Carpal Tunnel Questionnaire (BCTQ) scores and the nerve cross-sectional area (CSA). The results revealed that PRP, D5W, and HA were more efficient than NS at all measured time points ( $p<0.05$ ), except for CSA at the 1st month between the NS and D5W groups. Single-injections of PRP and D5W seemed more effective than that of HA within 6 months postinjection for symptom and functional improvement (6th-month BCTQ-symptom, D5W vs. HA, $p=0.047$ ; 1st-month BCTQ-symptom, PRP vs. HA, $p=0.018$ ; 1st- and 6th-month BCTQ-function, D5W vs. HA, $p=0.002$ and 0.016, respectively; 1st-month BCTQ-function, PRP vs. HA, $p<0.001$ ). For reducing CSA, PRP and HA seemed more effective than D5W ( $\text{HA}>\text{PRP}>\text{D}5\text{W}$ on the 1st month and HA vs. D5W, $p=0.001$ ; $\text{PRP}>\text{HA}>\text{D}5\text{W}$ on the 6th month and PRP vs. D5W, $p=0.012$ ).

Comparison of short- and long-axis nerve hydrodissection for carpal tunnel syndrome: A prospective randomized, single-blind trial

Background: This study is to compare the efficacy of short-axis hydrodissection with long-axis hydrodissection for patients with mild-to-moderate carpal tunnel syndrome (CTS). Methods: Forty-seven patients with mild-to-moderate CTS were enrolled in a prospective, randomized, single-blinded, controlled trial (6 months follow-up). With ultrasound guidance, patients in both groups (short-axis or long-axis groups) were injected with normal saline (5 mL per session). Assessments were performed before and 2 weeks after the injection, as well as at 1, 3, and 6 months post-intervention. The primary outcome measure was the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) score and secondary outcomes included the cross-sectional area of the median nerve and electrophysiological studies. Results: Forty-four patients (21 wrists in the short-axis group and 23 wrists in the long-axis group) completed the study. Compared with the baseline, both groups showed improved BCTQ and cross-sectional area at all follow-up assessments (p<0.05). The short-axis group was not more effective except significant improvements in BCTQ-severity and BCTQ-function 1 month post-injection compared to the long-axis group (p = 0.031 and p = 0.023, respectively). Conclusions: Both short- and long-axis hydrodissection were effective for patients with mild-to-moderate CTS and the short-axis approach was not more effective than long-axis injection. Further studies with larger sample sizes, multiple injections, and larger injection volume are encouraged in the future.

Accuracy of Carpal Tunnel Injection: A Prospective Evaluation of 756 Patients

Background: Corticosteroid injection into the carpal tunnel is both a diagnostic test and a therapeutic modality in the treatment of carpal tunnel syndrome. Many injection techniques are described in the literature. Improper placement of injection may result in damage to neurovascular structures in the carpal canal or decrease efficacy of the test and/or therapy. The purpose of this study is to determine if carpal tunnel injection using anatomic landmarks is reproducible and safe. A review of the senior author's injection technique is presented. Methods: Over 8 years, there were 756 attempted placements of a 25-gauge needle into the carpal tunnel in a simulated carpal tunnel injection prior to open carpal tunnel release. The needle was inserted at the wrist crease, just ulnar to palmaris longus. Open carpal tunnel release was subsequently performed, and position of the needle was recorded. Results: In 572 patients (75.7%), the needle was found to be in the carpal tunnel without penetration of contents. The needle was in the carpal tunnel but piercing the median nerve in 66 attempts (8.7%). The carpal tunnel was missed in 118 attempts (15.6%). Conclusions: This is the largest study looking at accuracy of carpal tunnel injection using anatomic landmarks. Our injection accuracy (75.7%) is less than reported in previous studies, which note 82% to 100% accuracy using the same injection technique. This may indicate that carpal tunnel injection is less reliable than previously thought. Safety of carpal tunnel injection remains an important concern. The median nerve was penetrated in 8.7% of attempts.

A Sonographically Guided In-Plane Distal-to-Proximal Transligamentous Approach to Carpal Tunnel Injections

BACKGROUND

Several sonographically guided injection methods have been described to treat carpal tunnel syndrome. In most cases, the medication diffuses through the carpal tunnel to the site of maximum compression of the nerve after being injected proximally. In this article, we describe a novel method of sonographically guided carpal tunnel injection that utilizes a distal-to-proximal, in-plane, and transligamentous approach. This novel method may provide ergonomic as well as safety advantages to both clinicians and patients, and should be considered by those performing carpal tunnel injections.

METHODS

A distal-to-proximal transligamentous approach is taken, utilizing high-resolution ultrasound guidance. Once the median nerve is sonographically visualized longitudinally within the carpal tunnel, an ulnar shift is made with the transducer. With the median nerve out of view, the needle is inserted in-line and distal to the transducer on the palmar side of the hand, at the ulnar portion of Kaplan's cardinal line. Following a trajectory that is nearly parallel to the median nerve, the needle is sonographically guided to the site of maximum nerve compression.

CONCLUSIONS

This novel method provides an alternative to previous carpal tunnel injections. The use of ultrasound guidance allows the clinician to visualize and avoid the neurovascular structures near the median nerve and guide the needle to the site of maximum nerve compression. It is possible that this parallel trajectory with the median nerve will provide a lower risk of damage to the nerve.

Comparison of the Clinical Effectiveness of Ultrasound-Guided Corticosteroid Injection with and without Needle Release of the Transverse Carpal Ligament in Carpal Tunnel Syndrome

BACKGROUND

To compare the clinical effectiveness of ultrasound-guided corticosteroid injection with and without needle release of the transverse carpal ligament (TCL) in carpal tunnel syndrome (CTS).

METHODS

Between May 2014 and June 2016, 52 patients (56 wrists) with CTS were included in this study. Among these patients, 28 wrists were treated with ultrasound-guided corticosteroid injection plus needle release of the TCL (group A) and 28 wrists were treated with a single ultrasound-guided corticosteroids injection (group B). The following parameters were assessed and compared including postoperative results of procedure based on relief of symptoms, electrophysiological parameters (distal motor latency, sensory conduction velocity, and sensory nerve action potential of median nerve), and ultrasound parameters (anteroposterior diameter and cross-sectional area of the median nerve at the levels of pisiform and hamate bone, and the thicknesses of TCL on the cross-section at the level of hamate bone).

RESULTS

The overall excellent and good rate regarding the postoperative results of procedure based on the relief of symptoms at 1 month postoperatively was 82.1% in group A and 46.4% in group B (p = 0.004). There was significant difference in the above electrophysiological and ultrasound parameters between the preoperative and postoperative values in both groups (all p < 0.05). Furthermore, a significant difference was also observed in the postoperative values of the above-mentioned electrophysiological and ultrasound parameters in the 2 groups (all p < 0.05).

CONCLUSIONS

Both approaches had treatment benefit in CTS. Ultrasound-guided corticosteroid injection in combination with needle release of the TCL is superior to the single ultrasound-guided corticosteroids injection.

Update in Musculoskeletal Ultrasound Research

CONTEXT

Musculoskeletal ultrasound (US) research is expanding due to increased clinical utility of sonography.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Ultrasound is widely applied in musculoskeletal imaging and sports medicine. The real-time capabilities and favorable cost profile of US make it ideal for use in diagnosis of musculoskeletal conditions. The enthusiasm for the use of US in musculoskeletal imaging has led to an increase in US research to broaden its applications.

CONCLUSION

Several recent advances have been made in conventional and novel US imaging techniques, quantitative US imaging, and US-guided interventions.

STRENGTH OF RECOMMENDATIONS TAXONOMY SORT

C.

Ultrasound-Guided Peripheral Nerve Injection Techniques

OBJECTIVE

Peripheral nerves are well seen using ultrasound (US) imaging, making US an ideal modality for image-guided nerve injections. This article provides a technical guide for common upper and lower extremity peripheral nerve injections, including the median, ulnar, and radial nerves in the upper extremity and the lateral femoral cutaneous, sciatic, common peroneal, tibial, and sural nerves in the lower extremity.

CONCLUSION

US is an effective modality for use in common upper and lower extremity peripheral nerve injections. With correct technique, peripheral nerve injections can be performed safely and are useful for both diagnostic evaluation of and therapy for peripheral neuropathy.