Thermal Radiofrequency Ablation of the Articular Branch of the Lateral Pectoral Nerve: A Case Report and Novel Technique

Cryoanalgesia for shoulder pain: a motor-sparing approach to rotator cuff disease

Introduction

Rotator cuff disease is a common cause of musculoskeletal pain and disability, and the management can be challenging. Joint denervation emerges as a new technique, but the literature on shoulder neural ablation procedure is largely limited to pulsed radiofrequency due to the concern of motor impairment. We described a novel motor-sparing approach of cryoablation for the management of shoulder pain based on the recent literature on the innervation of shoulder.

Methods

Four patients with a history of rotator cuff disease refractory to conservative therapy and not amenable to surgery underwent a ultrasound-guided cryoablation of the capsular branches of the shoulder joint after a positive diagnostic injection. The target articular branches were based on the anatomical landmarks described in recent publication. They were the acromial, superior and inferior branches of the suprascapular nerve, the anterior branch of the axillary nerve, the nerve to the subscapularis, which were all located around the superior, posterior and anterior glenoid. The lateral pectoral nerve articular branch was targeted at the coracoclavicular space.

Results

All four patients experienced at least 60% pain relief with improvement in function for 6–12 months following the procedure without any clinical evidence of motor impairment. No adverse effect was observed.

Discussion

Based on the current understanding of the glenohumeral joint articular branches and their relationship to the bony landmark, targeting the articular branches only was feasible and led to good outcomes. Further large prospective cohort study is needed.

Ultrasound-guided continuous radiofrequency ablation of the suprascapular nerve for chronic shoulder pain secondary to osteoarthritis: a retrospective cohort study

OBJECTIVES

The objective of this study is to retrospectively evaluate the use of ultrasound-guided continuous radiofrequency (CRF) lesioning of the suprascapular nerve for treating chronic shoulder pain, due to osteoarthritis. We describe a modified distal and selective ablation technique in the spinoglenoid notch, with motor and sensory stimulation, which protects the motor branch of the nerve from ablation.

METHODS

A retrospective analysis was performed of patients, who underwent ultrasound-guided CRF lesioning of the suprascapular nerve from October 2013 to January 2020. During the procedure, the CRF electrode is placed in the spinoglenoid notch, at the distal suprascapular nerve capsular branch. Motor and sensory stimulations are used to confirm the position. CRF lesioning is applied up to three times, at 3 different points, for 1 min each time, at 80^° C.

RESULTS

In total, 127 first CRF suprascapular nerve lesioning procedures were performed on 101 patients with chronic shoulder pain secondary to osteoarthritis. One hundred nineteen diagnostic ultrasound-guided suprascapular nerve corticosteroid injections were performed prior to ablation. Mean pre-injection Visual Analogue Scale pain score (VAS) was 8.3, with post-injection VAS score of 4.4 at 24 h and 4.5 at 2 weeks. Mean pre-CRF lesioning VAS pain score was 7.7 with post-CRF lesioning VAS score of 4.4 at 24 h and 4.5 at 2 weeks.

CONCLUSIONS

Ultrasound-guided CRF lesioning of the suprascapular nerve in the spinoglenoid notch is a safe treatment for chronic osteoarthritic shoulder pain, with repeat treatments infrequently required. It is associated with significant improvement in VAS pain scores.

KEY POINTS

• Ultrasound-guided continuous radiofrequency lesioning of the suprascapular nerve in the spinoglenoid notch is a safe treatment for chronic shoulder pain in degenerative disease, with repeat treatments infrequently required. • The procedure is performed under ultrasound guidance, without the use of ionising radiation.

Multimodal nerve injection provides noninferior analgesic efficacy compared with interscalene nerve block after arthroscopic rotator cuff repair

PURPOSE

This randomized noninferiority trial aimed to evaluate whether combined suprascapular, axillary nerve, and the articular branch of lateral pectoral nerve block (3NB) is noninferior to interscalene nerve block (ISB) for pain control after arthroscopic rotator cuff repair (ASRCR).

MATERIALS AND METHODS

Eighty-five patients undergoing ASRCR were randomized to either 3NB (n = 43) or ISB (n = 42) group. We used 5 and 15 ml of 0.2% ropivacaine for each nerve in the 3NB and ISB groups, respectively. The primary outcome was the visual analog scale (VAS) pain score at 4 h postoperatively measured assessed on an 11-point scale (ranging from 0 = no pain to 10 = worst pain) that was analyzed using noninferiority testing. The secondary outcome was VAS pain scores in the recovery room and at 8, 12, 24, 36, 48, and 72 h postoperatively. Rebound pain, IV-PCA usage during 48 h, dyspnea, muscle weakness, and satisfaction were evaluated.

RESULTS

Regarding the primary outcome, the mean difference in VAS pain scores between the 3NB (2.5 ± 1.6) and ISB (2.2 ± 2.3) groups at 4 h postoperatively was 0.3, with a 95% confidence interval (CI) of -0.56 to 1.11. The upper limit of 95% CI is lower than the noninferiority margin of 1.3 (p < 0.001). At all other time points, except in the recovery room, 3NB showed noninferior to ISB. Rebound pain, IV-PCA usage during the second 24 h, and muscle weakness were lower in the 3NB group (all p < 0.005). The satisfaction was similar in both groups (p = 0.815).

CONCLUSION

Combined 3NB is noninferior to ISB in terms of pain control after ASRCR; and is associated with low levels of rebound pain, IV-PCA usage, and muscle weakness.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I.

Shoulder Ablation Approaches

The shoulder is structurally and functionally complex. Shoulder pain may be refractory to conventional treatments, such as physical therapy, pharmacotherapy, and corticosteroid injections. In such cases, radiofrequency ablation may serve as an alternative treatment plan. Current literature has demonstrated 4 target nerves for ablative therapy: the suprascapular nerve, axillary nerve, lateral pectoral nerve, and subscapular nerve. Special caution is needed when targeting these nerves in order to avoid motor denervation. This article summarizes the current evidence for radiofrequency ablation as a useful treatment option for chronic shoulder pain as well as the described techniques for performing this promising procedure.

Putting Our Shoulder to the Wheel: Current Understanding and Gaps in Nerve Ablation for Chronic Shoulder Pain

Shoulder pain is prevalent, burdensome, and functionally limiting, with diverse pathology and associated treatments. This narrative review provides a summary of relevant neuroanatomy, proposed ablation targets, safety and efficacy concerns for ablation targets, and current research gaps. Radiofrequency ablation (RFA) of peripheral sensory nerves is a well-established treatment for chronic joint and spine pain, but it is relatively nascent for shoulder pain. Cadaveric studies demonstrate the shoulder joint is innervated by articular branches of the suprascapular nerve, axillary nerve, lateral pectoral nerve, and upper and lower subscapular nerves. Shoulder articular branch RFA appears to be a safe and effective treatment for chronic shoulder pain, but there are currently no widely accepted protocols for ablation targets. There are also no randomized controlled trials (RCT) assessing safety and efficacy of proposed targets or the prognostic value of articular blocks. Future research studies should prioritize categorical data, use appropriate functional measures as primary endpoints, and would ideally include a large-scale RCT.

Diagnostic block and radiofrequency ablation of the acromial branches of the lateral pectoral and suprascapular nerves for shoulder pain: a 3D cadaveric study

BACKGROUND AND OBJECTIVES

Acromial branches of the lateral pectoral and suprascapular nerves have been proposed as targets for diagnostic block and radiofrequency ablation to treat superior shoulder pain; however, the nerve capture rates of these procedures have not been investigated. The objectives of this study were to use dissection and 3D modeling technology to determine the course of these acromial branches, relative to anatomical landmarks, and to evaluate nerve capture rates using ultrasound-guided dye injection and lesion simulation.

METHODS

Ultrasound-guided dye injections, targeting the superior surface of coracoid process and floor of supraspinous fossa, were performed (n=5). Furthermore, needles targeting the superior and posterior surfaces of the coracoid process were placed under ultrasound guidance to simulate needle electrode position (n=5). Specimens were dissected, digitized, and modeled to determine capture rates of acromial branches of lateral pectoral and suprascapular nerves.

RESULTS

The course of acromial branches of lateral pectoral and suprascapular nerves were documented. Dye spread capture rates: acromial branches of lateral pectoral and suprascapular nerves were captured in all specimens. Lesion simulation capture rates: (1) when targeting superior surface of coracoid process, the entire acromial branch of lateral pectoral nerve was captured in all specimens and (2) when targeting posterior surface of coracoid process, the acromioclavicular and bursal branches of acromial branch of suprascapular nerve were captured in all specimens; coracoclavicular branch was captured in 3/5 specimens.

CONCLUSIONS

This study supports the anatomical feasibility of ultrasound-guided targeting of the acromial branches of lateral pectoral and suprascapular nerves. Further clinical investigation is required.

A systematic review and meta-analysis of radiofrequency procedures on innervation to the shoulder joint for relieving chronic pain

BACKGROUND AND OBJECTIVE

Studies have reported relief of chronic shoulder pain with non-ablative pulsed neuromodulatory (pRF) or ablative radiofrequency (aRF) procedures on innervation of the shoulder joint but interpretation of these reports is hampered by inconsistent indications, anatomic targets and follow-up. This systematic review was conducted to synthesize the existing literature on procedures employing pRF or aRF for treating chronic shoulder pain.

DATABASES AND DATA TREATMENT

MEDLINE and other medical literature databases were reviewed up to 31 December 2019 for publications on pRF or aRF procedures on shoulder joint innervation to relieve chronic pain. Data on analgesic and functional outcomes measured at any time point following the interventions were extracted. Existing knowledge on innervation of the shoulder joint with relevance to RF procedures was also synthesized.

RESULTS

In all, 42 publications, 7 randomized controlled trials (RCTs) and 35 observational studies, case series or reports were identified. Thirty-six of these publications were on pRF procedure and 29 of these reported procedures exclusively targeting the suprascapular nerve. A meta-analysis of the seven RCTs evaluating pRF indicated no analgesic benefit or functional improvement with this treatment over conventional medical management. Case series and reports on aRF indicate a potential for analgesic benefit but the quality of this evidence was low.

CONCLUSIONS

RF treatments targeting the sensory innervation of the shoulder joint affected by degenerative conditions have the potential to reduce pain but the current evidence does not suggest analgesic or functional benefit (GRADE certainty of evidence-low). Studies of high methodological quality are required to further investigate the role of these interventions.

SIGNIFICANCE

This is a comprehensive review of literature on pulsed (non-ablative) and ablative radiofrequency (RF) procedures for chronic shoulder pain. The systematic review and meta-analysis of 7 trials found that pulsed RF for chronic shoulder pain provided similar analgesia and functional improvement as conservative medical management at three months after the procedures. The case series and reports on ablative RF for shoulder pain indicate possible analgesic benefit but their quality was low. This review highlights the need for studies of a high quality on ablative RF treatments for chronic shoulder pain.