DOI:
Original papers
Effects of ultrasound-guided suprascapular nerve pulsed radiofrequency on chronic shoulder pain
Tolga Ergönenç
1, Serbülent Gökhan Beyaz
21Sakarya University Education and Research Hospital, Department of Anesthesiology and Reanimation,
2Sakarya University, Faculty of Medicine, Department of Anesthesiology and Algology, Sakarya, Turkey
Received 20.05.2018 Accepted 10.10.2018 Med Ultrason
2018, Vol. 20, No 4, 461-466
Corresponding author: Tolga Ergönenç
Sakarya University Education and Research Hospital, Department of Anesthesiology and Reanimation, Sakarya, Turkey
E-mail: [email protected] Phone: +90 532 4859840 Fax: +90 2642553292
Introduction
Shoulder pain is the second most common musculo- skeletal disease in adults, and it often becomes chronic [1,2] due to treatment difficulties. Rotator cuff disease, shoulder impingement syndrome, adhesive capsulitis, tendinitis and degenerative disease may cause chronic shoulder pain [3], which can negatively affect upper extremity joint function and life quality by limiting the
range of motion of the joint. The treatment of shoulder pain requires an all-around approach, including nonin- vasive methods (nonsteroidal anti-inflammatory drugs, physical therapy and rehabilitation), minimally invasive methods (intraarticular steroid injections and suprascap- ular nerve procedures) and surgical procedures [4-6].
The suprascapular nerve (SSN) provides 70% of the sensory innervation of the shoulder joint; therefore, SSN procedures (selective nerve blocks, steroid injections and radiofrequency applications) have been reported to be effective in the treatment of acute and chronic shoulder pain [7-9]. Although rapid pain control can be provided with a SSN block, its short duration of action limits its use in treatment [8]. Longer pain control can be achieved with a neurolysis or neurectomy, but these methods may cause irreversible paralysis in the supraspinatus and in- fraspinatus muscles. Pulsed radiofrequency (PRF) ther- apy has become increasingly popular in the treatment of chronic shoulder pain due to its long duration of action Abstract
Aim: Pulsed radiofrequency (PRF) therapy has become increasingly popular in the treatment of chronic shoulder pain due to its long duration of action and non-destructive method. The aim of the study was to reveal the effects of PRF therapy of the suprascapular nerve (SSN) under ultrasound guidance (UG) in patients with chronic shoulder pain on both shoulder pain and function. Material and methods: This study included 74 patients diagnosed with at least one of the following: adhesive capsulitis, rotator cuff syndrome and impingement syndrome of shoulder. The PRF therapy of the SSN under UG was per- formed in those patients with a reduction of 50% or more Visual Analog Scale (VAS) score and those that reported healing in the active range of motion (AROM) in the diagnostic SSN block. The resting, motion and sleeping shoulder pain assessments of the patients were done with VAS score. The shoulder joint function was assessed with the Shoulder Pain and Disability Index (SPADI) questionnaire and the AROM of the joint was measured using a goniometer. Results: In 70 of the 74 patients a 50% or more reduction was found in the VAS score with diagnostic SSN block. After the PRF therapy of the SSN, the 15th day, 1st month, 3rd month, and 6th month follow-up VAS averages, SPADI averages and the flexion, internal rotation, external rotation, and abduction values were statistically significantly lower than the baseline values (p<0.05). Conclusion: This study is the largest series in the literature evaluating the efficacy of PRF therapy of the SSN under UG and has shown that pain can be controlled quickly, for a long period of time, using ultrasound guided PRF therapy of the SSN in chronic shoulder pain.
Keywords: impingement syndrome; chronic shoulder pain; suprascapular nerve; pulsed radiofrequency DOI: 10.11152/mu-1543
and the lack of any damage to the targeted and surround- ing tissue, thereby reducing the risk of neural damage and neuritis [10].
In this study, we aimed to reveal the effects of PRF therapy of the SSN under ultrasound guidance (UG) in patients with chronic shoulder pain on both shoulder pain and function.
Materials and methods Patient selection
This cross-sectional observational study was con- ducted after approval by the University Ethical Commit- tee and written informed consent was obtained from all patients included in study. Patients over 18 years-old di- agnosed with at least one of the following: adhesive cap- sulitis, rotator cuff syndrome or impingement syndrome of shoulder were included. Additionally, the patients had to have minimum Visual Analog Scale (VAS) score 4 and minimum Shoulder Pain and Disability Index (SPADI) score 60 despite a 3 months nonsteroidal anti-inflamma- tory oral analgesics and physical therapy (initial passive range of motion, followed by advanced strengthening ex- ercise). Patients with chronic pain due to other diseases, with surgery on the same shoulder, allergy history from local anesthesia, abnormal coagulation tests, cardiac pacemakers, neuropathic pain associated with cervical disc disorder, malignancy, stroke or complications of diabetes were excluded.
The diagnoses were established after clinical history, physical examination and magnetic resonance imaging (MRI) evaluation. Physical examination of the shoulder included inspection, palpation, evaluation of range of motion (flexion, internal rotation, external rotation, ab- duction) and shoulder provocative tests (Neer’s sign, Ye- rgason test, Hawkins test, Apley scratch test, Drop-arm test, Spurling’s test, “Clunk” sign). The MRI examina- tions were interpreted by radiologists and other physical examination and measurements were performed by an experienced anaesthesiologist and an orthopedic surgeon.
Assessment of pain and functional status
Before and after the SSN block and PRF therapy of the SSN, the resting, motion and sleeping pain assess- ments were completed using a VAS. The shoulder joint function was assessed using the SPADI questionnaire and the active range of motion (AROM) of the joint was measured using a goniometer.
Diagnostic suprascapular nerve block technique Under operating room conditions, a peripheral ve- nous catheter was applied to each patient while the elec- trocardiogram (ECG), noninvasive blood pressure and peripheral oxygen saturation were being monitored. The
diagnostic block of the SSN under UG was applied by a nerve stimulator while the patient was in a sitting po- sition. Following the appropriate skin disinfection, with UG (M5 Color Diagnostic Ultrasound System; Min- dray, Shenzhen, China), a 22 G 80 mm needle (Stimu- plex; B. Braun Melsungen AG, Melsungen, Germany) with a nerve stimulator (Stimuplex HNS 11; B. Braun Melsungen AG, Melsungen, Germany) was pushed for- ward towards the floor of the supraspinous fossa using an in-plane approach (fig 1). A nerve stimulator was set to deliver 0.4 mA current impulses of 0.1 ms duration at a frequency of 2 Hz. The needle was inserted caudally into a sagittal plane until the muscle twitched (external rotation and/or abduction in the shoulder) were observed in synchrony with the stimulation. Then, 4 mL of 0.25%
bupivacaine was released, after confirming that blood was not drawn by intermittent aspiration. The patients received no analgesics after the procedure.
Pulsed radiofrequency application technique The PRF therapy of the SSN was performed in those patients with a reduction of 50% or more VAS score in the diagnostic block of the SSN. The PRF therapy of the SSN was administered under operating room condi- tions while the patient was monitored in a sitting position with UG. An ultrasound-guided 22 G 5-mm active-tip 100-mm radiofrequency needle (SC-K; Top Neuropole, Tokyo, Japan) was pushed forward to the floor of the supraspinous fossa using an in-plane approach. Senso- rial stimulation was given at 50 Hz for 1 ms with a wide pulse. The PRF treatment was applied for 3 cycles at 42
°C, 45 V, 2 Hz, and 20 ms, with a wide wave for 120 s (NeuroTherm, Middleton, MA, USA). This was after obtaining maximal 0.4 V paresthesia in the area of the
Fig 1. Ultrasonographic image of the suprascapular nerve on the floor of the supraspinous fossa. A: Positioning of the trans- ducer and needle; B: Suprascapular fossa sonoanatomy and needle; C: Description of suprascapular fossa sonoanatomy
suprascapular nerve innervation of the shoulder and af- ter monitoring the shoulder abduction and/or external rotation response to the motor stimulus applied at 2 Hz for 1 ms and at least 1 volt. SPADI and AROM assess- ments were conducted postoperatively on the 15th day, 1st month, 3rd month and 6th month follow-ups.
Statistical Analysis
In the data analysis, SPSS for Mac version 23.0 was used. The values were given as the mean±standard de- viation (SD) in the statistical analysis. The normality of distribution of the initial data was assessed using the Kolmogorov-Smirnov test. The demographic variables were compared using a t-test or chi-squared test for the continuous and categorical variables, respectively. The difference between the repeated measurements in the group was assessed using the Repeated Measures-ANO- VA (RM-ANOVA). A p level of <0.05 was accepted for the statistical significance.
Results
In 70 of the 74 patients a 50% or more reduction was found in the VAS score during the diagnostic block of the SSN (94.59%). The four patients without proper response to the diagnostic block were excluded. The demographic
data of the 70 patients are detailed in table I. The aver- age resting, movement, and sleep baseline VAS value of the 70 patients who underwent PRF therapy of the SSN was 4.65±0.85. After the PRF therapy of the SSN, the 15th day, 1st month, 3rd month, and 6th month follow-up VAS averages were statistically significantly lower than the baseline values (p<0.05, Table II).
The baseline SPADI average of the patients was 64.95±8.21. After the PRF therapy of the SSN, the 15th day, 1st month, 3rd month, and 6th month follow-up SPADI averages of the patients were statistically sig- nificantly lower than the baseline values (p<0.05, Table III).
Table I. Demographic characteristics of the patients n = 70
Age (years) 50.97±10.57
Sex (Male/Female) 32/38
Side (Right/Left) 36/34
Medical diagnosis
Adhesive capsulitis 17(24.29)
Rotator cuff syndrome 22(31.43) Shoulder impingement syndrome 31(44.29) Data are given by mean±standard deviation and percentiles.
Table II. Visual Analog Scale (VAS) values before and after pulsed radiofrequency therapy
VAS Basal 15th day 1st month 3rd month 6th month p
Resting 1.49 ±0.79† 1.29±0.76** 1.03±0.78 0.79±0.72 † 0.73±0.70 0.48
Movement 6.44±1.20 2.80±1.21 2.20±1.31 1.77±1.17† 1.80±1.12 0.07
Sleep 6.03±1.57 2.41±1.57 1.47±1.44† 0.86±0.82† 1.00±1.02 0.12
Mean score 4.65±0.85 2.17±0.82 1.57±0.73 1.14±0.49† 1.18±0.53 0.00*
*Differences compared with basal value (p<0.05); **There were no differences compared with basal value (p>0.05); †There were no dif- ferences compared with 6rd month (p>0.05).
Table III. The Shoulder Pain and Disability Index score values before and after pulsed radiofrequency therapy
SPADI Basal 15th day 1st month 3rd month 6th month p
Pain 66.70±11.72 44.77±12.92† 42.99±13.66† 41.83±14.26 44.17±13.94 0.28
Disability 63.20±12.05 39.77±13.80 38.73±13.88 35.23±14.53 34.60±14.59 0.00*
Mean score 64.95±8.21 42.27±9.62 40.86±10.09 38.53±10.63 39.39±10.64 0.00*
SPADI: Shoulder Pain and Disability Index; *Differences compared with basal value (p<0.05); †There were no differences compared with 6rd month (p>0.05).
Table IV. The active range of motion values before and after pulsed radiofrequency therapy
AROM Basal 15th day 1st month 3rd month 6th month p
Flexion 152.69±4.67 170.94±5.82 172.87±6.11†† 173.63±6.59 166.47±7.07 0.12
Internal rotation 60.44±4.46 69.37±3.16 71.07±2.89 80.21±1.48 75.17±5.95 0.00* External rotation 65.99±7.08 70.64±7.18 74.33±7.46† 76.29±8.39 74.29±8.73 0.18 Abduction 97.10±15.19 140.44±14.37 155.06±12.47 161.27±11.98 159.37±11.76 0.00* AROM: Active range of motion’*Differences compared with basal value (p<0.05); †There were no differences compared with 6rd month (p>0.05); ††There were no differences compared with 3rd month (p>0.05).
Regarding the basal AROM averages of the patients after the PRF therapy of the SSN, at the 15th day, 1st month, 3rd month, and 6th month follow-ups, the aver- age flexion, internal rotation, external rotation, and ab- duction values were statistically significantly higher than the baseline values (p<0.05, Table IV).
No early and late complications were observed in any patient.
Discussions
In this study we determined that applying PRF ther- apy of the SSN in 3 cycles at 120 s each to patients with chronic shoulder pain (due to adhesive capsulitis, rotator cuff syndrome, or shoulder impingement syndrome) is effective for reducing shoulder pain, improving shoulder joint movement, and improving comfort. These positive effects lasted at least 6 months.
Chronic shoulder pain is caused most often by the structures in the shoulder [2,11], and shoulder impinge- ment syndrome is the most common role in its etiology.
Medical treatment for shoulder pain is often difficult and unsuccessful. Interventional procedures maybe used in patients who do not benefit from conservative treatment [12]. After unsuccessful conservative treatment, it should be decided whether surgery is necessary to resolve the underlying causes of the complaints.
The SSN provide sensorial innervation of the pos- terior capsule of the glenohumeral joint, as well as the acromioclavicular joint, subacromial bursa and coraco- clavicular ligament [13]. Therefore, the SSN is the focal point of many interventional procedures, including the SSN block, which is an effective method for controlling chronic shoulder pain [8,14-16]. However, the short du- ration of pain control provided by an SSN block limits its treatment uses [8].
The PRF therapy of the SSN has been increasingly used in the treatment of chronic shoulder pain due to its longer duration of pain control and the fact that it is non- destructive [10]. Unlike conventional radiofrequency, PRF does not cause any damage to the targeted and sur- rounding tissue, thereby reducing the risk of neural dam- age and neuritis [17-19]. Jang et al [20] observed that with a 240-pulse 50-V PRF therapy of the SSN applied to 11 patients with chronic persistent shoulder pain, at least 9 months of recovery was achieved in 10 of the patients.
Lüleci et al [21] reported that they provided 6 months of pain control in 45 (78.9%) of 57 patients using PRF treat- ment of the SSN, which they performed for 480 s. In our study, we found that the 360 s ultrasound guidance PRF relieved pain, improved joint movement, and improved life quality for at least 6 months.
The PRF treatment of the SSN was performed by Jang et al [20] via C-arm fluoroscopy, while Lüleci et al [21] performed it blindly according to the anatomical landmarks. We performed the PRF therapy of the SSN under UG, due to its safety in experienced hands, thus reducing the complications (pneumothorax and intra- vascular injection), not including the radiation. In con- trast to the other radiological imaging techniques, there was a higher success rate and a shorter treatment time [22].
There are a total of three publications in the literature, two of which were case reports, on PRF treatment of the SSN application via UG. Huang et al [23] described two patients diagnosed with frozen shoulders and Kim et al [24] described one patient with calcific tendinitis. Both of these reports described successful pain control for ap- proximately 6 months with the PRF treatment of the SSN under UG. However, the first and only UG PRF treat- ment of the SSN study in the literature was conducted by Wu et al [25]. They reported that SSN PRF applied to 21 adhesive capsulitis patients, 12 weeks before physi- otherapy, was more effective in improving joint function and pain control than in those patients treated with only physiotherapy for 12 weeks. Our research has provided the largest series in the literature on ultrasound-guided PRF therapy of the SSN with at least 6 months of recov- ery and pain control (similar to the time reported by Wu et al [25]).
In 32 disease cases in which the short-term and long- term efficacy of PRF on SSN were assessed by Keskin- boraet al [10], decreased shoulder pain and increased shoulder joint movement at the 3rd week and 6th month were reported. In our study, we observed decreases in the VAS and SPADI values and increases in the AROM throughout the follow-up period, with short and long- term results compatible with those from Keskinbora et al study [10]. The remaining pain control at the 6th month follow-up after the PRF therapy of the SSN is important, since it indicates that PRF has a long-acting effect on no- ciceptive pain.
Gurbet et al [26] reported that they applied PRF on SSN twice for 120 seconds each to 8 patients with shoul- der pain who had no response to medical treatment or physiotherapy. It provided an improvement in both pain control and range of motion for 3 months. Although there is insufficient data in the literature suggesting that ap- plying 360 s of PRF therapy of the SSN may provide a longer duration of pain control comparing with 240 s, it has been shown that the antiallodynic activity increas- es with an increased duration of PRF from 2 minutes to 6 minutes [27]. We applied PRF on SSN 3 times for 120 s.
Physiotherapy has an important role in the treatment of shoulder pain, but physiotherapy related pain can re- duce patient compliance. Wu et al [25] reported that PRF therapy of the SSN treatments before physiotherapy im- proved the patient’s compliance and tolerance. We found that at the 15th day after PRF therapy of the SSN, there was a significant decrease in the VAS score and increase in the AROM values, with healed shoulder joint function being provided. Physiotherapy can begin earlier thanks to PRF therapy of the SSN, which provides rapid pain control. A painless physiotherapy process can increase patient compliance and prevent chronic pain; neverthe- less, there is insufficient evidence in the literature to rec- ommend PRF therapy of the SSN routinely before physi- otherapy.
There are several limitations of our study. Applying an invasive pseudo interventional procedure was an ethi- cal problem to the control group. Therefore, the lack of a control group was a major limitation of our study. Sec- ond, the passive range of motion was not assessed in our study. In addition, although psychological factors may contribute to perception of pain they were not evaluated in this study.
Conclusion
Our study has shown that pain can be controlled quickly, for a long period of time, using ultrasound- guided PRF therapy of the SSN in chronic shoulder pain.
There was significant recovery in the AROM in addition to this pain relief, along with a significant improvement in shoulder joint function. In chronic shoulder pain, PRF therapy of the SSN under UG can be applied safely as a nondestructive method, and that it can be repeated, if necessary. In order to verify our results additional large series, long-running, randomized controlled trials need to be conducted.
Conflict of interest: none
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