Reliability of the pronator quadratus fat pad sign to predict the severity of distal radius fractures

AIM To evaluate the reliability of pronator quadratus fat pad sign to detect distal radius fracture and to predict its severity.METHODS Retrospectively we identified 89 consecutive patients(41 female, mean age 49 ± 18 years) who had X-ray(CR) and computed tomography(CT) within 24 h following distal forearm trauma. Thickness of pronator quadratus fat pad complex(PQC) was measured using lateral views(CR) and sagittal reconstructions(CT). Pearson's test was used to determine the correlation of the PQC thickness in CR and CT. A positive pronator quadratus sign(PQS) was defined as a PQC > 8.0 mm(female) or > 9.0 mm(male). Frykman classification was utilized to assess the severity of fractures.RESULTS Forty-four/89 patients(49%) had a distal radius fracture(Frykman Ⅰ n = 3, Ⅱ n = 0, Ⅲ n = 10, Ⅳ n = 5, Ⅴ n = 2, Ⅵ n = 2, Ⅶ n = 9, Ⅷ n = 13). Mean thickness of the PQC thickness can reliably be measured on X-ray views and was 7.5 ± 2.8 mm in lateral views(CR), respectively 9.4 ± 3.0 mm in sagittal reconstructions(CT), resulting in a significant correlation coefficientof 0.795. A positive PQS at CR was present in 21/44 patients(48%) with distal radius fracture and in 2/45 patients(4%) without distal radius fracture, resulting in a specificity of 96% and a sensitivity of 48% for the detection of distal radius fractures. There was no correlation between thickness of the PQC and severity of distal radius fractures.CONCLUSION A positive PQS shows high specificity but low sensitivity for detection of distal radius fractures. The PQC thickness cannot predict the severity of distal radius fractures.

Sleeve bridging of the rhesus monkey ulnar nerve with muscular branches of the pronator teres: multiple amplification of axonal regeneration

Multiple-bud regeneration, i.e., multiple amplification, has been shown to exist in peripheral nerve regeneration. Multiple buds grow towards the distal nerve stump during proximal nerve fiber regeneration. Our previous studies have verified the limit and validity of multiple ampli- fication of peripheral nerve regeneration using small gap sleeve bridging of small donor nerves to repair large receptor nerves in rodents. The present study sought to observe multiple ampli- fication of myelinated nerve fiber regeneration in the primate peripheral nerve. Rhesus monkey models of distal ulnar nerve defects were established and repaired using muscular branches of the right forearm pronator teres. Proximal muscular branches of the pronator teres were su- tured into the distal ulnar nerve using the small gap sleeve bridging method. At 6 months after suture, two-finger flexion and mild wrist flexion were restored in the ulnar-sided injured limbs of rhesus monkey. Neurophysiological examination showed that motor nerve conduction veloc- ity reached 22.63 _＋ 6.34 m/s on the affected side of rhesus monkey. Osmium tetroxide staining demonstrated that the number of myelinated nerve fibers was 1,657 ＋ 652 in the branches of pronator teres of donor, and 2,661 ~ 843 in the repaired ulnar nerve. The rate of multiple amplification of regenerating myelinated nerve fibers was 1.61. These data showed that when muscular branches of the pronator teres were used to repair ulnar nerve in primates, effective regeneration was observed in regenerating nerve fibers, and functions of the injured ulnar nerve were restored to a certain extent. Moreover, multiple amplification was subsequently detected in ulnar nerve axons.

Effect of fixing distal radius fracture with volar locking palmar plates while preserving pronator quadratus

Background L-shaped incision of pronator quadratus （PQ） muscle along its radial and distal borders was always taken for distal radius fractures reduction and internal fixation.Repair of the PQ muscle was always recommended at the end of operation for some instructive reasons.But repair of PQ is not satisfied because of poor quality of muscle and fascial tissues which may cause pain or impede forearm pronation and supination for post-operative scarring around PQ.Inserting the locking palmar plate to pass under the pronator quadratus muscle and the locking screws are inserted through miniincisions in pronator quadratus in some patients with distal radius fractures is a reasonable technique which can preserve the pronator quadratus.The purpose of this study was to evaluate and compare the clinical effects after volar plating of the distal radius fractures while preserving the pronator quadratus and pronator quadratus repair.Methods Between September 2010 and April 2012,65 patients （42 males and 23 females; aged 20-68 years and a mean age of 42.5 years） with distal radius fracture underwent open reduction and internal fixation using the volar locking palmar plates （Depuy or Smith companies）.The patients were classified as 23A-2 through 23C-3 according to the Orthopaedic Trauma Association （OTA） classifications.All surgeries were completed by the same trained team.The volar locking palmar plates of distal radius performed with preserving pronator quadratus group involved 30 patients including 19 males and 11 females and performed with pronator quadratus repair group involved 35 patients including 23 males and 12 females.We compared the two groups for wrist pain,forearm range of motion,grip strength,pedoperative complications and wrist functional recovery score.Results The minimum follow-up for the whole cohort was one year.The differences between the two groups were significant with regard to wrist pain,forearm range of motion,grip strength and wrist function at 1,2,and 6 weeks postoperatively,but insignificant at 6 and 12 months postoperatively.No significant differences were found in the pedoperative complications and radiographs postoperatively.Conclusions Preservation of the pronator quadratus muscle is a satisfactory method for the treatment of majority of the fractures of the distal radius with volar locking palmar plates,as this technique can yield better early wrist function and shorten the rehabilitation.

Do we really need to repair the pronator quadratus after distal radius plating?

Purpose:Fractures of distal radius are one of the common orthopaedic injuries.Placing the plate on volar surface requires release of underlying pronator quadratus(PQ)muscle.No consensus is present in the literature about the repair or not of the PQ.The purpose of this study was to evaluate the influence of PQ repair on functional outcome and complications.Methods:Retrospectively 83 patients of distal radius fractures managed with volar plating between 2014 and 2016 were evaluated.Demographic data,operative notes and physical therapy records were retrieved.Patients were divided into group A where PQ repair was done and group B where no repair was done.Functional data such as range of motion(ROM),grip strength,visual analogue scale(VAS)score and disabilities of arm,shoulder and hand(DASH)score at 4 weeks,3 months,6 months and finial follow-up were retrieved.Results:Totally 63 patients(n=29 in group A and n=34 in group B)with the mean age of 51.64 years were examined.Patients were followed up for a mean of 35.2 months(range 27.2-47.1 months)in group A and 38.6 months(range 28.6-51.0 months)in group B.Though functional outcome of the affected limb was not significantly different between two groups after 3 months,PQ repair did affect the recovery at an early stage.Repair group had significantly better ROM(p=0.0383)and VAS score at 4 weeks(p=0.017)while grip strength(p=0.014)was significantly better at 3 months.Conclusions:Repair of PQ may provide pain relief and increased ROM in early postoperative period and hence every attempt should be made to achieve the repair.

Techniques in Hand &Upper Extremity Surgery

The use of tendon transfer to restore functions of extremities was initially recognised in the 19th century, and its advancement was further amplified by the polio epidemic towards the turn of that century. Tendon transfer surgery extended to the use for traumatic reconstructive surgery during World War I, with key surgical pioneers, including Mayer, Sterling Bunnell, Guy Pulvertaft and Joseph Boyes. In 1921, Robert Jones first described the transfer of pronator teres (PT) to the wrist extensors for irreparable radial nerve paralysis in infantile hemiplegia. Although, a detailed description of its indication and surgical outcomes were not published until 1959 and 1970 by Stelling and Meyer, and Keats, respectively. Pronator teres is often the tendon of choice for reconstructing wrist extensors, and used in a multiple of pathologies, including radial nerve palsy, cerebral palsy, and tetraplegia. Reconstruction of finger extensors are less straightforward and options include flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), and flexor digitorum superficialis (FDS). Our article describes the techniques and outcomes of 25 patients that undergone pronator teres transfer. A good understanding of the pronator teres anatomical location and potential variations, aids efficient harvesting and limits unnecessary tissue dissection. Pronator teres tendon harvest is best performed through a systematic and anatomic approach.

Rare pattern of Maisonneuve fracture:A case report

BACKGROUND Maisonneuve fracture is a special type of ankle fracture that consists of proximal fibular fracture,a lesion of the inferior tibiofibular syndesmotic complex(interosseous ligament,anterior inferior tibiofibular ligament and posterior inferior tibiofibular ligament),and injury of the medial structure of the ankle(deltoid ligament tear or medial malleolar fracture).The accepted mechanism of Maisonneuve fracture is pronation external rotation according to the Lauge-Hansen classification.In this paper,we report a rare pattern of Maisonneuve fracture,which has the characteristics of both pronation external rotation ankle fracture and supination adduction ankle fracture.CASE SUMMARY A 31-year-old female patient accidentally sprained her right ankle while walking 5 d before hospitalization in our hospital.The patient was initially missed in other hospitals and later rediagnosed in our outpatient department.Full-length radiographs of the lower leg revealed proximal fibula fracture,inferior tibiofibular joint separation,and medial malleolar fracture involving the posterior malleolus,which was also revealed on computed tomography scans.Magnetic resonance imaging revealed rupture of the anterior inferior tibiofibular ligament and anterior talofibular ligament.We diagnosed a rare pattern of Maisonneuve fracture with proximal fibular fracture,inferior tibiofibular joint separation,medial malleolar fracture and ruptures of the anterior inferior tibiofibular ligament and anterior talofibular ligament.The patient underwent open reduction and internal fixation in our hospital.A 6-mo postoperative follow-up confirmed a good clinical outcome.CONCLUSION To our knowledge,this rare pattern of Maisonneuve fracture has not been previously described.The possible mechanism of injury is supination adduction combined with pronation external rotation.Careful analysis of the injury mechanism of Maisonneuve fracture is of great clinical significance and can better guide clinical treatment.