A 53-year-old housewife presented to the outpatient clinic complaining of right thumb pain, especially at the base, and recurring locking episodes that had been present for 1 month. The patient experienced pain gradually while clutching, writing, and squeezing.
The doctor initially recommended analgesics for 15 days, but they were ineffective in controlling the pain and disability, and the discomfort became severe. It eventually resulted in the inability of the individual to perform basic duties.
It took around 2–3 min with the other hand to unlock the thumb. This issue started a year prior, with no history of locking and only mild pain that was neglected. There had been no history of trauma, injury, unhealthy habits, etc. The patient had a history of diabetes and hypothyroidism, but no hypertension, and had been taking medications for all of the aforementioned issues for 10 years.
Examination and differential diagnostic findings
On examination, the palmar fascia was found to be tight, and a nodule was identified at the base of the thumb. Profound tenderness grade 4 was reported near the base, with a pain scale of 7–8 on the NPRS. Trigger points developed at the transverse head of the adductor longus and the base of the third ray as a result of forearm fascial tightness. Palpation exhibited mild discomfort at the extensor pollicis brevis and abductor pollicis longus, but the Finkelstein test was negative. The patient was assessed for Dupuytren’s contracture, RA, and tendon damage. The patient’s four-digit range of motion was normal, with the exception of a hard tightness at the terminal range. A significant reduction in range of motion (ROM) in the first interphalangeal joint (25–5°) and the metacarpophalangeal (MCP) joint (40–5°).
Intervention and outcome measures
The intervention was started after explaining the potential benefits and risks associated with shockwave therapy to the patient.
The primary outcome measure, grip strength, was assessed using a hand dynamometer. Similarly, the secondary outcome measures, the pain intensity, thumb disability, trigger point sensitivity, and range of motion (ROM), were assessed using NPRS, modified Quinnell scale, algometer, and the hand goniometer, respectively.
A verbal and written consent was obtained from the patient before the intervention. The NPRS is an 11-point scale representing along the line from “0” to “10”. “0” represents no pain, and “10” indicates the worst pain. The patient was instructed to choose a number along the line which best indicates their pain levels including none, mild, moderate, and severe. Patient NPRS Score scale between 7 and 8 comes under the severe category [9].
Disability of the thumb was evaluated by a modified Quinnell thumb disability scale based on a system that helps to determine the severity of triggering and stages of stenosing tenosynovitis ranging from “0” to “6”. Zero signifies no triggering episodes whereas “6” indicates full locking and flexion deformity of the thumb. The grades include stage 1= normal; stage 2= uneven motion of tendon; stage 3= triggering, clicking, and catching; stage 4= locking of thumb in extension and flexion unlock by active motion; stage 5= locking of thumb in extension and flexion unlock by passive motion; and stage 6= thumb locked in flexion and extension. As per, the Quinnell scale patient falls between stage 4 and stage 5, the patient sometimes unlocks the thumb by active extension through flexion position, and few incidences need the assistance of another hand for extension of the thumb from flexion position [10].
Algometer is a device used to measure pain pressure threshold (PPT) which is defined as the sensitivity felt on the tissue by applying mechanical pressure with equipment results from a change of pressure feeling into a feeling of pressure and pain. The pressure was applied to the patient’s tender areas at the base of the thumb, and the midpoint of the adductor longus was gradually increased with a pressure of 1kg/cm2 until the patient was instructed to “stop.” The pressure increased at the first spot at the base of the thumb was found to be sensitive at 0.3kg/cm2 and mid-point at 2nd spot adductor longus sensitive at 0.8k/cm2 [11]. A digital ABS hand dynamometer device was used to assess the grip strength of the patient bilaterally to compare the difference in strength (Figs. 1 and 2).
On observation, the grip strength of the right hand (dominant) and left hand (non-dominant) was 4 and 14 kg, respectively [12]. The range of motion which was severely restricted at the interphalangeal (IP) joint varies (25-5°), and the metacarpophalangeal (MCP) joint 40-5° was measured with a hand goniometer [13]. Roles and Maudsley scores were used to determine the functional outcomes of the trigger thumb. It has 4 functional scales varying from points 1 to 4. “1” indicates the excellent recovery with no pain, full movement, and activity, and “4” indicates poor recovery with a pain-limiting activity. “Fair” with a score of 3 and “poor” score 4 results are considered as “failure” of treatment.
The patient was treated with an electro-medical system (EMS) device, the Swiss dolocast master version (Figs. 3 and 4). In order to carry out the rESWT procedure, the patient was instructed to assume a position that would allow them to be as relaxed as is humanly possible. Since the participant felt more at ease sitting with their elbows extended, the experiment was carried out while the participant was in this position.
A total of 6 sessions for 6 days were administered to a patient in a week kept 1000 impulses with baric pressure of 2 bar and frequency of 15–10HZ for less painful areas and 300–500 impulses kept 1.5 bar pressure with a frequency of 5–7HZ directly over the nodule with the more painful area was administered.
Aside from extracorporeal shock therapy (ESWT), a patient was instructed to perform stretching, eccentric, and range of motion exercises at home twice a day for the bilateral hands to maintain the soft tissue properties and ROM attained with the use of rESWT. Furthermore, the patient did not report any adverse therapeutic effects following the session. The whole time spent on therapy was 30–40 min. The patient was followed up on 2 months following the treatment.
Treatment outcomes
Table 1 depicts the features of all the symptoms that were significantly reduced after the first three sessions. NPRS came down from 8 to 3 and 0 at the end of the 6th session of treatment. Modified Quinnell scale assessment shows a significant improvement from stage=4 to stage=3 on the 3rd day of treatment and stage=1 at the end of treatment on the 6th day [9]. Pain pressure holds improved significantly from 0.5 to 1 kg/cm2 on site of nodule at the base of the thumb, whereas PPT of the adductor pollicis and along the 3rd ray was improved from 0.8 to 2kg/cm2. Hand strength showed a significant improvement in terms of grip force from 4 to 13.2kg on the affected side. The range of motion at the interphalangeal joint and metacarpophalangeal joint improved at the end of the 6th session. Maudsley functional score showed improvement in pain, movement, and activity. During the follow-up session 2 months later, the patient shows consistent improvement and recorded the same as on the last session of treatment.