Levels of free thyroxine are higher in displaced pediatric supracondylar humerus fractures compared with non­displaced fractures.

Relationships between bone metabolic biomarkers and fracture displacement have been reported in the elderly. However, factors related to bone metabolism that predict fracture displacement remain unclear in children. The present study investigated bone metabolic biomarkers associated with the displacement of pediatric supracondylar humerus fractures. A total of 19 patients (7 male and 12 female patients; mean age, 6.3 years) with pediatric supracondylar humerus fractures who underwent surgical treatment at Juntendo University Hospital (Tokyo, Japan) between December 2020 and September 2022 were included. They were divided into two groups according to the Gartland classification: 14 type II patients (6 male and 8 female patients; mean age, 6.3±3.0 years) and 5 type III patients (1 male and 4 female patients; mean age, 6.4±4.0 years). The following bone metabolic biomarkers were examined: 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH), calcium, phosphate, thyroid-stimulating hormone, free triiodothyronine and free thyroxine (FT4). These markers were also compared between the two groups. A total of 16 out of 19 patients (84%) had insufficient serum 25(OH)D levels. Although iPTH levels were elevated, other bone metabolic biomarkers were within normal ranges. When the serum levels of bone metabolic biomarkers were compared, FT4 levels were significantly higher in type III patients than in type II patients (P=0.009). No significant differences were observed in other bone metabolic biomarkers between the two groups. The present results suggest that high FT4 levels are associated with the displacement of pediatric supracondylar humerus fractures.

Factors that interfere with immediate return to activity following volar locking plate fixation for distal radius fractures.

In the present study, the clinical findings that interfere with the immediate return to activity following volar locking plate (VLP) fixation for distal radius fractures were investigated. A total of 95 patients who underwent VLP fixation for distal radius fracture between July, 2014 and January, 2022 were divided into a good group (good score and outcome; n=86; 22 males and 64 females; median age, 61 years) and a poor group (poor score and outcome; n=8; 8 females; median age, 63.6 years) according to the quartiles of the disabilities of the arm, shoulder and hand (Q-DASH) score, at 1 month following VLP fixation. The duration from injury to surgery, the direction of fracture dislocation and radiographic parameters [radial inclination (RI), volar tilt (VT) and ulnar variance (UV)] at the time of injury were examined. Radiographic parameters (RI, VT and UV), the range of motion of the wrist joint, grip strength ratio and visual analog scale (VAS) at 1 month following VLP fixation were also examined. These parameters were compared among both groups. Moreover, logistic regression analysis was performed to determine whether these factors were independently associated with a poor Q-DASH score at 1 month following VLP fixation. At the time of injury, fracture displacement was significantly higher in the poor group (VT, -23.8˚; UV, 4.2 mm) than the good group (VT, -6.5˚; P=0.02; UV, 1.3 mm; P=0.01). No differences in the other parameters were observed between the groups. At 1 month following VLP fixation, the grip strength ratio (17.2%) in the poor group was significantly lower than that in the good group (43.8%, P<0.001), while the VAS score (5.6) in the poor group was significantly higher than that in the good group (2.4, P<0.001). Logistic regression analysis revealed that VT and UV at injury (P<0.05), grip strength ratio (P<0.001) and pain (VAS score) (P<0.001) were all independently associated with a poor Q-DASH score. On the whole, the present study suggests that large amounts of fracture displacement, weakness of grip strength and post-operative pain can be factors interfering with the return to activity immediately following VLP fixation.

Comparison of Conventional Incision and 10 mm Approach for Volar Locking Plates in Dorsal Displaced Distal Radius Fractures.

Introduction: The aim of this study was to investigate whether surgery with a 10 mm approach for volar locking plate fixation provides equivalent early post-operative outcomes to conventional incision surgery for distal radius fractures. Materials and Methods: The subjects were divided into a conventional incision group (mean age: 59.1 years, 8 males and 23 females) and a 10 mm approach group (mean age: 59.9 years of age, 6 males and 20 females). The wrist range of motion; grip strength; visual analog scale (VAS); quick disabilities of the arm, shoulder, and hand (Q-DASH) score; and modified Mayo score were assessed at 3 months after surgery. In addition, radial inclination, ulnar variance, and volar tilt were evaluated on post-operative radiography. Results: There was no significant difference between the groups in the wrist range of motion, grip strength, VAS, Q-DASH score, modified Mayo wrist score, and three parameters of post-operative radiography. All patients in both groups had no complications during the perioperative period. Conclusion: We found that a 10 mm approach obtained early post-operative outcomes and alignment comparable to conventional incision surgery for patients with dorsal displaced distal radius fractures.

Age­related differences for expression of the nerve­specific proteins after peripheral nerve injury.

The effects of aging on axon regeneration currently remain unclear. In addition, the up-regulated expression of neurotrophic factors that occurs within one week of peripheral nerve injury has been shown to play an important role in the axon regeneration. To investigate the effects of aging on axon regeneration, the expression of nerve-specific proteins immediately after peripheral nerve injury were compared between young and aged mice. A mouse peripheral nerve injury model was prepared using the sciatic nerve compression method. In each group, Luxol fast blue staining and immunofluorescence staining were performed to assess the degree of Wallerian degeneration in the sciatic nerve, and to evaluate the expression of repressor element 1-silencing transcription factor (REST)/neuron-restrictive silencer factor (NRSF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT3), nerve growth factor (NGF), and semaphorin 3A (Sema3A) in the dorsal root ganglion, respectively. Wallerian degeneration was observed in both young and aged mice after peripheral nerve injury. Significant increases were observed in the expression of REST/NRSF (P<0.0001), NT3 (P=0.0279), and Sema3A (P=0.0175) following peripheral nerve injury in young mice, while that of BDNF (P=0.5583) and NGF (P=0.9769) remained unchanged. On the other hand, no significant differences were noted in the expression of these nerve-specific proteins in aged mice. Based on the results of the present study, compensatory changes induced by peripheral nerve injury were initiated by the up-regulated expression of REST/NRSF in young mice, but not in aged mice.