title: Examination of the pronator quadratus muscle during hardware removal procedures after volar plating for distal radius fractures.
abstract: BACKGROUND
  It is not clear whether the pronator quadratus (PQ) muscle actually heals and provides a meaningful pronation force after volar plating for distal radius fractures (DRFs). We aimed to determine whether the length of the PQ muscle, which is dissected and then repaired during volar plating for a DRF, affects the forearm rotation strength and clinical outcomes.
  
  
  METHODS
  We examined 41 patients who requested hardware removal after volar plating. We measured the isokinetic forearm rotation strength and clinical outcomes including grip strength, wrist range of motion, and disabilities of the arm, shoulder and hand (DASH) scores at 6 months after fracture fixation. During the hardware removal surgery, which was performed at an average of 9 months (range, 8.3 to 11.5 months) after fracture fixation, we measured the PQ muscle length.
  
  
  RESULTS
  The average PQ muscle length was 68% of the normal muscle length, and no significant relationship was found between the PQ muscle length and the outcomes including isokinetic forearm rotation strength, grip strength, wrist range of motion, and DASH scores.
  
  
  CONCLUSIONS
  This study demonstrates that the length of the healed PQ muscle does not affect isokinetic forearm rotation strength and clinical outcomes after volar plating for DRFs. The results of this study support our current practice of loose repair of the PQ that is performed by most of the surgeons to prevent tendon irritation over the plate, and suggest that tight repair of the PQ is not necessary for achieving improved forearm function.
authors.affiliation: Department of Orthopedic Surgery, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Jae-Hwi
authors.initials: JH
authors.lastname: Nho
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyun Sik
authors.initials: HS
authors.lastname: Gong
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Cheol Ho
authors.initials: CH
authors.lastname: Song
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung Myung
authors.initials: SM
authors.lastname: Wi
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Goo Hyun
authors.initials: GH
authors.lastname: Baek
mesh_terms: D000328:Adult; D000368:Aged; D001860:Bone Plates; D020878:Device Removal; D005260:Female; D005542:Forearm / Q000503:physiopathology / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000379:methods*; D018737:Hand Strength; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000503:physiopathology / Q000601:surgery*; D011859:Radiography; D011885:Radius Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D016059:Range of Motion, Articular; D014945:Wound Healing; D055815:Young Adult
keywords: Distal radius fracture; Isokinetic strength; Pronator quadratus; Volar plating