Anatomical and clinical study of internal fixation for distal radius fractures with pronator quadratus preserved / 中华创伤骨科杂志

ABSTRACT

Objective To explore the anatomic basis for and clinical outcomes of the internal fixation which preserves the pronator quadratus (PQ) for distal radius fractures.Methods Twenty cadaveric specimens of adult upper extremity were used for this study (14 males and 6 females).The radial and ulnar lengths of PQ,the distal and proximal widths of PQ,the distances from the distal end of PQ to the articular surface of the distal radius and to the transverse line of the wrist,and the width of the bony tunnel of PQ were dissected and measured to study the anatomical features of PQ.A retrospective study was conducted of the 18 distal radius fractures which had been treated from March 2015 to March 2017 by internal fixation with T-shaped anatomic locking compression plate (LCP) with PQ preserved.They were 8 males and 10 females,with an average age of 52.7 years (range,from 28 to 65 years).According to the AO classification,there were 8 cases of type 23-A,5 ones of type 23-B and 5 ones of type 23-C1.The functional outcomes of the wrist were assessed using the Cooney scoring system at the last follow-ups.Results The PQ muscle was flat and like a right angle trapezoid with rich blood vessels.The radial and ulnar lengths of PQ were about 4.60 cm and 4.46 cm;the distal and proximal widths of PQ were about 4.41 cm and 4.48 cm;the distance from the distal end of PQ to the transverse line of the wrist was about 3.61 cm;the widths of the distal and proximal bony tunnels were about 3.08 cm and 1.91 cm.The 18 patients were followed up for 6 to 36 months (average,11.5 months).Bone union was achieved in all the patients after a mean time of 2.5 months (range,from 2 to 3 months).The mean Cooney score for the wrist function was 97.7 (range,from 95 to 100) at the last follow-up,yielding an excellent rate of 100％.Conclusions The transverse line of the distal radius fracture is located between 1/4 and 1/2 of the distal PQ.The bony tunnel of PQ is wide enough.It is feasible to preserve the distal PQ muscle in the internal fixation of distal radius fractures of types 23-A,23-B and 23-C1,because it may lead to rapid recovery of the patients and satisfactory wrist function.