Management of radial tunnel syndrome: a therapist's clinical perspective

Establishing the diagnosis of radial tunnel syndrome: a systematic review of published clinical series

PURPOSE

Radial tunnel syndrome (RTS) is a controversial diagnosis due to non-specific exam findings and frequent absence of positive electromyography (EMG) and nerve conduction study (NCS) findings. The purpose of this study was to identify the methods used to diagnose RTS in the literature.

METHODS

We queried PubMed, Embase, Web of Science, and Cochrane databases per PRISMA guidelines. Extracted data included article and patient characteristics, diagnostic assessments utilized and their respective findings, and treatments. Objective data were summarized descriptively. The relationship between reported diagnostic findings (i.e., physical exam and diagnostic tests) and treatments was assessed via a descriptive synthesis.

RESULTS

Our review included 13 studies and 391 upper extremities. All studies utilized physical exam in diagnosing RTS; most commonly, patients had tenderness over the radial tunnel (381/391, 97%). Preoperative EMG/NCS was reported by 11/13 studies, with abnormal findings in 8.9% (29/327) of upper extremities. Steroid and/or lidocaine injection for presumed lateral epicondylitis was reported by 9/13 studies (46/295 upper extremities, 16%), with RTS being diagnosed after patients received little to no relief. It was also common to inject the radial tunnel to make the diagnosis (218/295, 74%). The most common reported intraoperative finding was narrowing of the PIN (38/137, 28%). The intraoperative compressive site most commonly reported was the arcade of Frohse (142/306, 46%).

CONCLUSIONS

There is substantial heterogeneity in modalities used to diagnose RTS and the reported definition of RTS. This, in conjunction with many patients having concomitant lateral epicondylitis, makes it difficult to compare treatment outcomes for RTS.

LEVEL OF EVIDENCE

Level III. Systematic review of retrospective and prospective cohort studies.

Radial Tunnel Syndrome: Review and Best Evidence

Radial tunnel syndrome (RTS) is caused by compression of the posterior interosseous nerve and consists of a constellation of symptoms that have previously been characterized as aspects of other disease processes, as opposed to a distinct diagnosis. First described in the mid-20th century as "radial pronator syndrome," knowledge regarding the anatomy and presentation of RTS has advanced markedly over the past several decades. However, there remains notable controversy and ongoing research regarding diagnostic imaging, nonsurgical treatment options, and indications for surgical intervention. In this review, we will discuss the anatomic considerations of RTS, relevant physical examination findings, potential diagnostic modalities, and outcomes of several treatment options.

Ultrasound-Guided Hydrodissection Provides Complete Symptom Resolution in Radial Tunnel Syndrome: A Case Series and Scoping Review on Hydrodissection for Radial Nerve Pathology

ABSTRACT

This study analyzes the effectiveness of ultrasound-guided hydrodissection (HD) perineural as a treatment for radial tunnel syndrome (RTS). A literature search was performed along with retrospective analysis of local cases to assess outcomes and safety of this procedure. In the case series, surgical candidates, defined as cases with over 80% but temporary relief after diagnostic injection, were treated with ultrasound-guided HD. Of 22 patients who received ultrasound-guided diagnostic injections, 11 proceeded to HD. All HD patients experienced complete and lasting symptom resolution for a minimum of 2 years, and none required surgery. Thorough literature review provided seven studies, which fulfilled inclusion criteria. Sixty-one patients are represented in the literature. All studies reported significant benefit to pain symptoms with HD of radial nerve, with five specifying over 90% improvement. No adverse effects from HD were noted in any study. Ultrasound-guided HD of the radial tunnel has potential to be a surgery sparing treatment for RTS.

Nerve entrapment around elbow

Entrapment neuropathy around elbow is a common cause of disability across all age groups. The major nerves that traverse the elbow are ulnar, median and radial nerves and their branches. Cubital tunnel syndrome leading to ulnar nerve compression can often present with significant pain, paresthesia or weakness. Median and Radial nerve compression around the elbow, albeit less frequent, can also lead to significant morbidity and must be kept in the differential diagnosis when dealing with patients complaining of persistent pain around the elbow and weakness of forearm/hand muscles. Electrodiagnostic studies can be a useful adjunct to clinical examination, to help localize the site and quantify the grade of compression. Management should involve a trial of conservative treatment and failing that, surgical treatment should be considered. We hereby provide an overview of nerve entrapments around the elbow including their applied anatomy, etiology, clinical assessment and overview of the current concepts in surgical treatment.

Ultrasound-Guided Hydraulic Release Associated With Corticosteroids in Radial Tunnel Syndrome: Description of Technique and Preliminary Clinical Results

The aim of this study was to describe a perineural ultrasound-guided infiltration technique for management of radial tunnel syndrome and to report its preliminary results in 54 patients. A mixture of a saline solution, a local anesthetic, and a corticosteroid solution was infiltrated in the perineural region at the arcade of Frohse. Pain was reported in 100% of patients before the procedure versus 1.9% after the procedure. Scratch collapse and Cozen test results were positive in 98.1% and 66.7% of patients before infiltration, respectively, versus 5.6% and 9.2% after infiltration. All variables had statistically significant differences between preprocedure and postprocedure evaluations (P < .01).

Effect of dry needling on radial tunnel syndrome: A case report

This case report describes a 45-year-old male who presented with chronic right lateral elbow pain managed unsuccessfully with conservative treatment that included anti-inflammatory medication, injection, massage, exercise, bracing, taping, electro-physical agents, and manual therapy. Diagnosis of radial tunnel syndrome (RTS) was based on palpatory findings, range of motion testing, resisted isometrics, and a positive upper limb neural tension test 2b (radial nerve bias). Conventionally, the intervention for this entrapment has been surgical decompression, with successful outcomes. This is potentially a first-time report, describing the successful management of RTS with dry needling (DN) using a recently published DN grading system. Immediate improvements were noted in all the outcome measures after the first treatment, with complete pain-resolution maintained at a 6-month follow-up. A model is proposed describing the mechanism by which DN could be used to intervene for nerve entrapment interfaces.

Effects of Pulsed Ultrasound Therapy on Sensory Nerve Conduction Parameters and the Pain Threshold Perceptions in Humans

BACKGROUND

Therapeutic ultrasound is an often-used clinical modality in the nonsurgical treatment of entrapment neuropathies. To date, the possible mechanism of action of pulsed ultrasound therapy on the peripheral nerve in the treatment of entrapment neuropathies is unclear.

OBJECTIVE

To examine the effects of pulsed ultrasound therapy on peripheral nerve conduction parameters.

DESIGN

A prospective, randomized, single blind, crossover study.

SETTING

Outpatient clinic of a university department of physical medicine and rehabilitation.

PARTICIPANTS

Twelve healthy volunteers between 22 and 38 years of age (8 male, 4 female).

METHODS

Each patient (blinded) received ultrasound therapy (1W/cm², pulsed: 1:5; over the course of the superficial branch of the radial nerve of the nondominant arm) and placebo (intensity: zero). The interval between the individual interventions was 1 week.

MAIN OUTCOME MEASUREMENT

The sensory nerve conduction velocity, sensory nerve action potential, supramaximal stimulation intensity of the sensory fibers of the radial nerve, and the pressure pain threshold in the sensory area of the radial nerve before and after an ultrasound-therapy and placebo intervention. To compare the results of the intervention with placebo, a paired-samples t test was applied.

RESULTS

Compared with placebo, a significant increase after pulsed ultrasound therapy was found for the supramaximal stimulation intensity (P = .02). For the other primary outcome parameters, a significant difference was not found.

CONCLUSIONS

The immediate effect of pulsed ultrasound therapy on a sensory nerve is minimal. Therefore, the previously reported benefit of pulsed ultrasound therapy in entrapment neuropathies might be not due to its effect on the sensory nerve.

LEVEL OF EVIDENCE

I.

Assessing the Reliability of Ultrasound Imaging to Examine Radial Nerve Excursion

Ultrasound imaging allows cost effective in vivo analysis for quantifying peripheral nerve excursion. This study used ultrasound imaging to quantify longitudinal radial nerve excursion during various active and passive wrist movements in healthy participants. Frame-by-frame cross-correlation software allowed calculation of nerve excursion from video sequences. The reliability of ultrasound measurement of longitudinal radial nerve excursion was moderate to high (intraclass correlation coefficient range = 0.63-0.86, standard error of measurement 0.19-0.48). Radial nerve excursion ranged from 0.41 to 4.03 mm induced by wrist flexion and 0.28 to 2.91 mm induced by wrist ulnar deviation. No significant difference was seen in radial nerve excursion during either wrist movement (p > 0.05). Wrist movements performed in forearm supination produced larger overall nerve excursion (1.41 ± 0.32 mm) compared with those performed in forearm pronation (1.06 ± 0.31 mm) (p < 0.01). Real-time ultrasound is a reliable, cost-effective, in vivo method for analysis of radial nerve excursion.

Radial tunnel syndrome

Radial tunnel syndrome is a pain syndrome resulting from compression of the posterior interosseous nerve at the proximal forearm. It has no specific radiologic or electrodiagnostic findings. Treatment should be started conservatively; if not successful, surgical treatment is indicated. The posterior interosseous nerve may be explored through dorsal or anterior approaches. All the potential sites of entrapment should be released, including complete release of the superficial head of the supinator muscle. Surgical treatment is generally successful, but patients who have associated lateral epicondylitis or those who are involved in workers' compensation claims have less successful outcomes.