A cadaveric study for the volar needle approach to the pronator quadratus using the palmaris longus tendon landmark

A new diagnostic morphological parameter for the Carpal tunnel syndrome: The palmaris longus tendon cross-sectional area

Carpal tunnel syndrome (CTS) is correlated with increased intracarpal canal pressure (ICP). The effect of palmaris longus tendon (PLT) loading on ICP is documented in previous researches. PLT loading induces the greatest absolute increase in ICP. Therefore, to analyze the connection between the PLT and CTS, we newly made the measurement of the PLT cross-sectional area (PLTCSA). We assumed that PLTCSA is a reliable diagnostic parameter in the CTS. PLTCSA measurement data were acquired from 21 patients with CTS, and from 21 normal subjects who underwent wrist magnetic resonance imaging (W-MRI). We measured the PLTCSA at the level of pisiform on W-MRI. The PLTCSA was measured on the outlining of PLT. The two different cutoff values in the analysis were determined using receiver operating characteristic (ROC) analysis. The mean PLTCSA was 2.34 ± 0.82 mm2 in the normal group and 3.97 ± 1.18 mm2 in the CTS group. ROC curve analysis concluded that the best cutoff point for the PLTCSA was 2.81 mm2, with 76.2% sensitivity, 71.4% specificity, and area under the curve of 0.88 (95% CI, 0.78-0.98). PLTCSA is a sensitive, new, objective morphological parameter for evaluating CTS.

Dorsal dry needling to the pronator quadratus muscle is a safe and valid technique: A cadaveric study

BACKGROUND

The pronator quadratus (PQ) muscle is an important stabilizer of the distal radio-ulnar joint and its pain referral pattern can mimic median or ulnar neuropathy. Research on treatment safety and efficacy with dry needling is scarce.

OBJECTIVE

To determine if a solid filiform needle accurately and safely penetrates the PQ during simulated clinical application of dry needling.

METHODS

A cadaveric descriptive study was conducted. Needling insertion of PQ was performed in 10 cryopreserved forearms with a 30*0.32 mm solid filiform needle. With the forearm pronated, the needle was inserted 3 cm proximal to the ulnar styloid in an anterior direction toward the muscle. The needle was advanced into the PQ based upon clinician judgment. Safety was assessed by calculating the distance from the needle to the surrounding neurovascular bundles.

RESULTS

Accurate needle penetration of the PQ was observed in 90% of the cadavers (needle penetration: 19.8 ± 4.0 mm, 95%CI 17.0 to 22.6 mm). No neurovascular bundle was pierced during needling in any specimen forearms. The distance from the tip of the needle was 15.1 ± 4.8 mm (95%CI 11.7 to 18.5 mm) to the ulnar nerve, 15.6 ± 7.6 mm (95%CI 10.0 to 21 mm) to the ulnar artery, 11.2 ± 3.3 mm (95%CI 8.8 to 13.6 mm) to the median nerve, and 4.9 ± 1.4 mm (95%CI 3.9 to 5.9 mm) to the anterior interosseous neurovascular bundle.

CONCLUSION

The results from this cadaveric study support the assumption that needling of the PQ by the dorsal aspect of the forearm can be accurately and safely conducted by an experienced clinician. Studies investigating the clinical safety and effectiveness of this interventions are needed.