The aim of this study was to investigate surgeons’ reported change of treatment preference in response to the results and conclusion from a randomized controlled trial (RCT) and to study patterns of change between subspecialties and nationalities. Two questionnaires were developed through the Delphi process for this cross-sectional survey of surgical preference. The first questionnaire was sent out before the publication of a RCT and the second questionnaire was sent out after publication. The RCT investigated repair or non-repair of the pronator quadratus (PQ) muscle during volar locked plating of distal radial fractures (DRFs). Overall, 380 orthopaedic surgeons were invited to participate in the first questionnaire, of whom 115 replied. One hundred surgeons were invited to participate in the second questionnaire. The primary outcome was the proportion of surgeons for whom a treatment change was warranted, who then reported a change of treatment preference following the RCT. Secondary outcomes included the reasons for repair or non-repair, reasons for and against following the RCT results, and difference of preferred treatment of the PQ muscle between surgeons of different nationalities, qualifications, years of training, and number of procedures performed per year. Of the 100 surgeons invited for the second questionnaire, 74 replied. For the primary outcome, 6 of 32 surgeons (19%), who usually repaired the PQ muscle and therefore a change of treatment preference was warranted, reported a change of treatment preference based on the RCT publication. Of the secondary outcomes, restoring anatomy was the most common response for repairing the PQ muscle. The majority of the orthopaedic surgeons, where a change of treatment preference was warranted based on the results and conclusion of a RCT, did not report willingness to change their treatment preference

Aims. The aim of this study was to investigate surgeons’ reported change of treatment preference in response to the results and conclusion from a randomized contolled trial (RCT) and to study patterns of change between subspecialties and nationalities. Methods. Two questionnaires were developed through the Delphi process for this cross-sectional survey of surgical preference. The first questionnaire was sent out before the publication of a RCT and the second questionnaire was sent out after publication. The RCT investigated repair or non-repair of the pronator quadratus (PQ) muscle during volar locked plating of distal radial fractures (DRFs). Overall, 380 orthopaedic surgeons were invited to participate in the first questionnaire, of whom 115 replied. One hundred surgeons were invited to participate in the second questionnaire. The primary outcome was the proportion of surgeons for whom a treatment change was warranted, who then reported a change of treatment preference following the RCT. Secondary outcomes included the reasons for repair or non-repair, reasons for and against following the RCT results, and difference of preferred treatment of the PQ muscle between surgeons of different nationalities, qualifications, years of training, and number of procedures performed per year. Results. Of the 100 surgeons invited for the second questionnaire, 74 replied. For the primary outcome, six of 32 surgeons (19%), who usually repaired the PQ muscle and therefore a change of treatment preference was warranted, reported a change of treatment preference based on the RCT publication. Of the secondary outcomes, restoring anatomy was the most common response for repairing the PQ muscle. Conclusion. The majority of the orthopaedic surgeons, where a change of treatment preference was warranted based on the results and conclusion of a RCT, did not report willingness to change their treatment preference. Cite this article: Bone Joint Open 2020;1-9:549–555

Introduction: Distal radius metaphyseal fractures in children are not uncommon, but when they occur proximal to the insertion of the pronator quadratus muscle, reduction and maintenance of reduction can be challenging. The deforming forces at the fracture site result in pronation and shortening of the distal fragment. Manual manipulation of this fracture often results in tearing of the dorsal periosteum and hence renders this fracture highly unstable. Aim: We present a novel easily reproducible mini-open surgical technique and functionally and radiologically evaluate a series of eleven patients who have undergone this technique. Materials and Methods: The surgical technique consists of a mini-open intrafocal image intensifier guided reduction technique with percutaneous k-wiring fixation. Five males and six females with an average age of 8.8 years (range 5 to 13 years), who sustained a pronator quadratus distal radius fracture and subsequently underwent this surgical technique from 2005 to 2007, were evaluated both radiologically in terms of radial length, radial tilt and volar tilt compared with the contralateral limb and functionally using the Mayo Modified wrist score and the patient related wrist evaluation questionnaire. Results: Patients were followed up for an average of 18 months (range 2–31 months). All patients achieved clinical and radiological union. No patient required remanipulation for loss of reduction. Radiological outcome measures similar to contralateral limb with good functional scores. No complications were noted. All patients returned to preoperative level of function. Conclusion: This minimally invasive technique has been shown to be technically easy, reliable and reproducible with excellent results and low risk of displacement compared to other techniques used to treat this potentially challenging fracture

This study quantified the joint reaction forces in the distal radioulnar joint using an instrumented ulnar head replacement implant. Muscle activity was simulated in-vitro to determine the effects on joint reaction force. Forces were found to linearly increase with simulated muscle load in all forearm positions for the biceps and pronator teres muscles. However, this did not occur for simulations of the supinator and pronator quadratus muscles, likely due to their broader insertion, smaller size and non-linear lines-of-action. This work has important implications in forearm biomechanical modelling, implant design, fixation and rehabilitation protocols following arthroplasty. To determine the relationship between forearm muscle activity and joint reaction force (JRF) in the distal radioulnar joint (DRUJ). The DRUJ reaction force is linearly related to the muscle activity of the PT and biceps, but not necessarily to the activity of the supinator and PQ. This work has implications for biomechanical modelling, implant design, fixation and rehabilitation protocols following DRUJ arthroplasty. JRFs were found to increase linearly with muscle load for all muscles simulated (biceps, pronator teres (PT), pronator quadratus (PQ), supinator) in all forearm positions tested (supination, neutral and pronation) (correlation coefficient r> 0.85, p< 0.01) with two exceptions; simulation of the PQ in the neutral position (r=−0.65, p=0.2), and the supinator in the pronated position (r=0.72, p=0.2). Biceps simulation generated larger JRF magnitudes in all positions compared to other muscles (p< 0.001), and the PQ generated larger JRF magnitudes compared to the supinator (p=0.05). Ulnar head arthroplasty was performed with a replacement ulnar head implant instrumented with strain gauges to allow measurement of the DRUJ reaction force. An upper extremity joint simulator applied muscle loads in seven fresh frozen cadaveric upper extremities through computer-controlled pneumatic actuators. Load was varied in 10N increments from 10-80N (biceps and PT) and from 10-50N (PQ and supinator). A hand clamp was used to restrain the forearm in varying positions. The results illustrate that broad insertion and non-linear muscles may not be linearly correlated to joint reaction force in the DRUJ. Please contact author for diagrams and graphs

The influence of the supinator and pronator quadratus (PQ) muscles on distal radioulnar joint stability were evaluated using a joint simulator capable of producing forearm rotation, before and after ulnar head excision. Multiple pronation trials were conducted with incremental loading of the PQ relative to the pronator teres; supination trials were similarly conducted with the supinator and biceps. Incremental supinator muscle loading did not alter forearm kinematics. Increased PQ loading did not affect intact kinematics, but did alter joint motion following ulnar head excision. PQ activation will likely aggravate forearm instability following ulnar head excision; suggesting rehabilitation should incorporate immobilization in supination. The purpose of this study was to study the effect of pronator quadratus (PQ) and supinator loads on forearm kinematics in both an intact distal radioulnar joint (DRUJ) and following ulnar head excision. The PQ muscle appears to aggravate instability of the DRUJ following ulnar head excision, while incremental loading of the supinator muscle had no effect. Patients with DRUJ instability and/or who have undergone surgical removal of the ulnar head should be rehabilitated in supination to limit the influence of the PQ muscle. Eight cadaveric upper extremities were tested in a custom joint simulator employing motion and load-controlled tendon loading to produce forearm rotation. Pronation was achieved via loading of the pronator teres and PQ muscles. Repeated trials were conducted in which the ratio of the PQ load was increased incrementally relative to the pronator teres load. Supination trials were similarly conducted using the biceps and supinator muscles. Testing was conducted in the intact forearm and following ulnar head excision. An electromagnetic tracking device was used to record motion of the radius and ulna. Kinematic data was analyzed with a planar analysis that measured dorsal palmar displacements and diastasis of the DRUJ. Greater diastasis and dorsal translation of the radius relative to the ulna were noted under increased PQ loading following ulnar head excision (p< 0.05). Increased supinator load had no effect on kinematics before or after ulnar head excision. This effect is likely due to the location of the two muscles. The effect of PQ muscle loading was only noted in neutral to full pronation. These results suggest that rehabilitation of the forearm following ulnar head excision should be conducted with the forearm in supination to minimize joint instability. Funding: Natural Sciences and Engineering Research Council of Canada, The Arthritis Society (Canada)