| 제목 |
ULTRASONOGRPAHIC EVALUATION OF PRONATOR QUADRATUS AND SAFE WINDOW FOR NEEDLE EMG WITH VOLAR APPOACH |
| 소속 |
Korea University College of Medicine, Department of Physical Medicine & Rehabilitation1 |
| 저자 |
Seok Jun Lee1*, In Yae Cheong1, Ki Hoon Kim1, Byung Kyu Park1, Dong Hwee Kim1† |
Objective: To determine the proper needle electrode insertion point for volar approach of pronator quadratusmuscle (PQ) based onthe anatomic property of PQ and safety window to avoid neurovascular damage using ultrasonography.
Methods: Total 28 healthy people with 56 arms (6 men and 22 women, mean age=38.07±13.13, mean BMI=22.62±2.91) were examined. Using ultrasonography, the distance from each vertex of origin and insertion point of PQ to ulnar styloid process tip extending line(U line) and the distance between U line and the center of PQ (PQ_M) were measured, followed by the assessment of relative distance and angle of median nerve(MN) and ulnar artery(UA) from the ulnar margin of palmaris longus tendon(uPL), respectively. By measuring vertical depth of MN and UA, we could identify the distance between uPL and vertical surface point of each median nerve(MN’) and ulnar artery (UA’) through Pythagoras Theorem. And, the depth of PQ from the volar aspect and muscle thickness were measured.
Results: From the level of ulnar styloid process tip, the PQ_M was located at a mean 2.15±0.33cm proximally(male 2.36±0.33cm and female 2.09±0.31cm, p<0.05). The safety window for the volar approach was 1.17±0.24cm in radial and 1.72±0.28cm in ulnar side from uPL. The PQ was a mean 1.33±0.14cm deep from the skin and had a mean thickness of 1.24±0.16 cm at the level of PQ_M. The distance between U line and the proximal edge of PQ of male was greater than female [dist_B(p=0.00), dist_D(p=0.01)], as well as the midpoint of PQ(p=0.02). There was no meaningful difference in value of PQ between dominant and non-dominant side.
Conclusions: Based on anatomic landmarks of PQ, volar approach for the needle electromyographic examination to pronator quadratus could be performed precisely and safely.
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Table 1. Participants characteristic and PQ data summary
Figure 1. Anatomic property of pronator quadratus and measured methods
Figure 2. Ultrasonographic measurement for evaluating the volar approach
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