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. 2023 Feb 27;2023(2):CD010003. doi: 10.1002/14651858.CD010003.pub2

Wu 2017.

Study characteristics
Methods Study design: prospective, single‐blinded, RCT
Setting: Tri‐Service General Hospital, Taiwan
Participants Details of sampling frame:
Total n assessed for eligibility = 80
Total n excluded pre‐randomisation = 20
Total n randomised = 60
Total n available for follow‐up = 60
Total n analysed = 60
Intervention group 1 (splint) n = 30
Intervention group 2 (platelet‐rich plasma (PRP)) n = 30
Gender distribution:
Intervention group 1 (splint): 5 males; 25 females
Intervention group 2 (PRP): 3 males; 27 females
Mean ± SD age:
Intervention group 1 (splint): 54.27 ± 7.34
Intervention group 2 (PRP): 57.87 ± 8.27
Mean ± SD duration of CTS symptoms (months):
Intervention group 1 (splint): 30.70 ± 33.0
Intervention group 2 (PRP): 34.43 ± 31.1
Inclusion criteria:
Paraesthesia or dysaesthesia, painful swelling with clumsy weakness of the hand exacerbated by sleep or repetitive use of the wrist, and relieved by shaking the hand with postural change,
AND 1 or more of the following:

  1. Sensory loss with numbness in the median nerve‐innervated regions of the hand

  2. Weakness with atrophy of the median nerve‐innervated thenar muscles

  3. Positive Phalen’s test and Tinel’s sign, or both


Participants diagnosed with mild‐to‐moderate unilateral CTS with clinical symptoms for at least 3 months undergoing electrophysiological study and ultrasonography were enrolled.
Exclusion criteria:

  1. History of wrist surgery, polyneuropathy, brachial plexopathy, or thoracic outlet syndrome

  2. History of thrombocytopenia, platelet dysfunction, systematic infection, pregnancy, and rheumatologic disorders

  3. Previous steroid injection for CTS


CTS diagnostic criteria (case definition):
The cut‐off points or normal range of the electrophysiological study for CTS in this study were as follows:

  1. upper limit of the median nerve SDL is ≤ 3.6 ms at a distance 14 cm away from the active recording

  2. difference in SDL between the ulnar and median nerve is < 0.4 ms and

  3. upper limit of DML of the median nerve is < 4.3 ms at a distance 8 cm away from the thenar muscle belly


Participants with mild and moderate CTS were categorised by the electrophysiological classification of CTS by Padua and colleagues (Padua 1997): mild: only abnormal digit/wrist SNCV with normal DML; moderate: abnormal digit/wrist SNCV and abnormal DML; or severe: absence of SNCV and abnormal DML.
CTS severity: 
Mild‐to‐moderate CTS
Interventions Group 1 ‐ received a night splint through the study period: The splint was applied in a neutral position to restrict the wrist as previously described. The controls were instructed to put on the splint overnight for at least 8 hours daily throughout the study period.
Group 2 ‐ PRP group: participants were injected with one dose of 3 mL of PRP using ultrasound guidance. Ten mL of blood sample were drawn from the antecubital vein using RegentKit‐THT‐1 (RegenLab SA, Mont‐sur‐Lausanne, Switzerland) followed by centrifugation at 3400 rpm for 15 minutes at room temperature using Regen Lab PRP Centri, yielding 3.5 mL of PRP. The RegentKit‐THT‐1 has sodium citrate solution as an anticoagulant, and autologous thrombin as an activator to advance platelet activation and conversion of fibrinogen to fibrin. For quality tests, 0.5 mL of the PRP sample was sent to the laboratory and 3 mL was used for the ultrasound‐guided injection. The concentration of platelets and leukocytes in the PRP was approximately 2.7 ± 0.4 times and 1.2 ± 0.4 times that in whole blood, respectively.
The ultrasound‐guided PRP injection was performed by the same physiatrist, using ultrasonography (MyLab™ 25Gold, Esaote, Genova, Italy). With the palm facing upwards and the wrist slightly extended, the median nerve was identified at the inlet of the proximal carpal tunnel (pisiform level). The ultrasound‐guided injection was conducted using the in‐plane ulnar approach. The ulnar artery was identified using Doppler imaging, and a 25‐gauge needle was passed from the ulnar side of the wrist toward the median nerve. After placing the needle tip on the median nerve, 2 mL of PRP was injected to peel the nerve off the flexor retinaculum via hydrodissection. An additional 1 mL of PRP was delivered to the inferior part of the median nerve and the median nerve was peeled from the underlying subsynovial connective tissue. After this, the entire carpal tunnel was scanned to ensure that the PRP had spread throughout the proximal‐to‐distal area of the carpal tunnel.
Both groups: All participants were instructed to refrain from any other management approaches, such as analgesics, steroid injections, or physical therapy, for CTS symptoms from 2 weeks before and throughout the study period, and were requested to report receiving any of these therapies.
Outcomes Outcomes were assessed before intervention and at months 1, 3, and 6 after treatment

  1. BCTQ Symptom Severity Score (1 to 5; higher is worse)

  2. BCTQ Functional Status Score (1 to 5; higher is worse)

  3. Pain severity and paraesthesia, VAS (0 to 10; higher is worse)

  4. Cross sectional area median nerve (mm2)

  5. SNCV (m/s; higher is better)

  6. DML (ms; lower is better)

  7. Finger pinch strength (kg; higher is better)

  8. Adverse events
Funding The study is supported by the Ministry of Science and Technology, Taiwan, Republic of China (grant no. MOST 105‐2314‐B‐016‐046).
COI The authors declared that they had no competing interests.
Notes Results from BCTQ not reported in scale 1 to 5. We assumed that the total sum was reported and divided the symptom score by 11 and functional score by 8 (as per instructions of the scale).
Authors reported standard error (SE) for age and duration of symptoms, but we calculated SD (SE * SQRT n).
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Quote: "The enrolled patients were block randomized in a 1:1 ratio into two groups, control and PRP groups, by an independent researcher via computer‐generated randomization of study numbers (Microsoft Excel, Microsoft Inc., Redmond, WA, USA)."
Allocation concealment (selection bias) Unclear risk Comment: The method of allocation concealment not described
Blinding of participants and personnel (performance bias)
All outcomes High risk Comment: Blinding of participants not attempted
Blinding of outcome assessment (detection bias)
All outcomes High risk Quote: "One physiatrist (Dr. Ke) with 5 years’ experience in musculoskeletal ultrasonography and electrophysiological study, who was blinded to the patients’ randomization, performed all the measurements in all patients of both groups before intervention and at months 1, 3, and 6 after treatment."
Comment: However, as the participants were likely aware of which treatment they were allocated to, we rated the risk as high.
Incomplete outcome data (attrition bias)
3 months or less Low risk Comment: No loss to follow‐up
Incomplete outcome data (attrition bias)
After 3 months Low risk Comment: No loss to follow‐up
Selective reporting (reporting bias) Unclear risk Comment: According to the protocol, outcomes were assessed at 1, 2, 4, 8, 12, 16 and 24 weeks. Results reported at 1, 3 and 6 months. Unclear if this was related to the nature of the findings
Other bias Low risk Comment: No other sources of bias identified