There are several ways injecting steroids to treat carpal tunnel syndrome (CTS). one of which is an ultrasound-guided steroid injection method. Steroid injection is an effective therapeutic option but can be dangerous if performed improperly.

Steroid injection is a simple and easy therapeutic modality. Steroid injection in carpal tunnel syndrome treatment is generally performed locally, intracarpally, with reference to the longus palmar tendon's anatomical location. This procedure can be very effective if performed properly.

However, this procedure also carries the risk of tendon damage, nerve damage, minimal therapeutic effects. It requires repeated injections within a short period of time, especially if performed with an invisible anatomical estimate (blinded).

The use of ultrasonography to guide steroid injection in carpal tunnel syndrome is considered to improve accuracy. The effectiveness of therapy is better and can reduce the risk of side effects due to action.

Carpal tunnel syndrome is caused by median nerve mononeuropathy due to increased intracanal carpal pressure, compression of the median nerve's connective tissue, nerve damage that triggers the accumulation of inflammatory cells, synovial tissue hypertrophy. Carpal tunnel syndrome is characterized by pain, burning, paresthesia, and decreased hand function that interferes with the sufferer's activity and life quality. 

Carpal Tunnel Syndrome Treatment using Ultrasound Guided Steroid injection
Carpal Tunnel Syndrome Treatment using Ultrasound-Guided Steroid injection
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Carpal Tunnel Syndrome Treatments

Until now, there is no therapeutic modality that can definitively treat carpal tunnel syndrome. The risk of recurrence or subtle reduction in symptoms is common.

Therapy options that can be given are:
  • First line: Immobilization of the wrist with splinting and oral steroids
  • Second line: Steroid injection
  • Third line: Surgery

The choice of treatment modality determines the patient's prognosis. Successful therapy can relieve symptoms and restore the patient's motor function and stop disease progression.

Of all the therapeutic modalities, steroid administration is the more effective option. Immobilization and oral prednisolone 20 mg/day for two weeks, followed by 10 mg/day for two weeks, can improve carpal tunnel syndrome symptoms. If there is no improvement, then the steroid injection is given twice.

Steroid Injection to treat Carpal Tunnel Syndrome

This steroid injection has been shown to effectively reduce carpal tunnel syndrome symptoms over a longer time, and its recurrence is less frequent. Studies have also shown that local steroid injections are superior to systemic and oral steroid injections and other therapeutic modalities such as anti-inflammatory and splinting.

A double-blind randomized controlled study showed that injection of methylprednisolone 15 mg and oral placebo for ten days was more effective than oral methylprednisolone 25 mg and injection of placebo in lowering the global symptom score (GSS) at 12 weeks.

Other studies have shown that 80 mg and 40 mg methylprednisolone injections effectively reduce the need for carpal tunnel syndrome surgery after one year (73% and 81%) compared to placebo (92%). This study was conducted with 37 patients for each therapy and control group. Patients were less likely to need surgery with 80 mg and 40 mg methylprednisolone. 1 in 9 people who get 40 mg of methylprednisolone and 1 in 5 who get 80 mg of methylprednisolone do not need surgery.

The 15 mg injection of local triamcinolone and oral placebo was also better at lowering GSS scores and improving nerve conduction than oral triamcinolone and placebo injection. Long-acting and short-acting steroid injections effectively reduce symptoms after six weeks, but higher doses of short-acting steroids are required.

Steroid injection is also as effective as surgery to improve nocturnal paraesthesia symptoms by more than 20% at 2-year follow-up, but surgery provides a 2-year longer remission time. Nonetheless, steroid injections are easier to perform, less invasive, and more cost-effective than surgery. Steroid injection in carpal tunnel syndrome treatment can be performed under approximate anatomical location (blinded) or injection with ultrasound guidance.

Ultrasound-Guided Steroid Injection

The intracarpal injection has many possible side effects, but this therapy is relatively safe to do. The study showed that out of 9515 injections, only 4 cases had serious complications, while side effects occurred in 33% of cases. The most common side effect was local pain in 13% of cases after six weeks, which disappeared for 3 weeks.

The use of ultrasound in the injection procedure provides better visualization of anatomical structures, increasing precision, reducing the risk of tissue damage around the median nerve, reducing the likelihood of side effects, increasing therapeutic effectiveness, and reducing the need for further action.

A meta-analysis of three randomized controlled trials with a total of 181 steroid injections showed that ultrasound-guided intracarpal injection was more effective than injection than landmark-guided injection in improving Symptom Severity Score (SSS) with differences in means. Difference -0.46.

Studies in Egypt comparing blinded and intracarpal steroid injection without ultrasound also showed similar results. This study found that steroid injection by ultrasonography (100%) resulted in better nerve conduction improvement than blinded injection (73%) as indicated by improved flattening ratio and decreased cross-sectional area of ​​the median nerve. Both methods showed improvement; however, ultrasonography injection showed fewer side effects after injection (13%) than blinded injection (73%).

A study of 234 patients showed that ultrasound-guided steroid injection reduced the likelihood of needing repeat therapy within one year by 55% compared to blinded injection.

Several approaches can also carry out the use of ultrasonography in the intracarpal injection. Studies have shown that the in-plane approach of the ulnar nerve is superior to the out-plane approach. However, both methods are still superior to blinded intracarpal steroid injection. Another study said no clinically significant difference in improvement at 6 and 12 weeks between injection above and below the median nerve assisted by ultrasonography.

Steroid administration is a second-line treatment for carpal tunnel syndrome. Steroids are more effective given by local injection than other modalities of administration. The injection can be given using methylprednisolone 40 mg / 80 mg.