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.

Systematic active environmental surveillance successfully identified and controlled the Legionella contamination in the hospital.

INTRODUCTION: Legionella disease can manifest as severe respiratory tract infection with a high mortality rate and is sometimes associated with a hospital outbreak by a contaminated water supply. A patient with breast cancer admitted about a month before. High fever was observed 18 days after admission and the Legionella antigen test showed the positive result. METHODS: Due to the incidence of Legionella infection, we demonstrated the active surveillance of Legionella contamination in the entire hospital. RESULTS: Cultures of her environmental samples revealed that hot water in two bathrooms were contaminated with Legionella. In our hospital, the hot water is heated and pumped up on the roof and distributed to each room. The contaminated bathrooms were related to the same plumbing. Therefore, we further collected samples throughout the hot water system. Legionella was not detected in the central part of the system. However, we detected Legionella in the hot water sampled from other five rooms, which were also associated with the same plumbing of the two bathrooms. The temperature and chlorine concentration of the hot water were not high enough to inactivate Legionella at the end of the plumbing. After the adjustment of the water temperature and chlorine concentration, Legionella became undetectable. Our prompt and active surveillance successfully identified the plumbing of the hot water system as the source of Legionella contamination and took precautions against future outbreaks. CONCLUSIONS: Monitoring of water temperature and chloride concentration at the end of the hot water circulation is important to prevent nosocomial Legionella disease.

Usefulness of Bridging External Fixation for Prevention a Collapse in the Case of Osteoid Osteoma in the Lunate.

Introduction: We report a patient with osteoid osteoma that developed in the lunate. Case Report: The patient was a healthy 28-year-old male who had the right wrist joint pain and osteosclerosis of the lunate was noted on plain radiography. Kienböck's disease was considered at the first examination, but a nidus was observed on computed tomography, suggesting osteoid osteoma in the lunate. The resection of the bone lesion and bridging external fixation to prevent post-operative collapse of the lunate was performed. Histopathological diagnosis was also osteoid osteoma in the lunate. At 3 years after surgery, no recurrence of the lesion or progression of collapse of the lunate has occurred. Conclusion: As the development of osteoid osteoma in the lunate is a markedly rare pathology and there are many differential diseases, the time to diagnosis may be prolonged. Moreover, it may be useful to attach bridging external fixation to prevent a collapse of the lunate.

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.

Influence of Smoking in the Clinical Outcomes of Distal Radius Fractures.

Introduction There are various studies that reviewed the effect of cigarette smoking in fracture healing process. Nonunion, delayed union, and residual pain are the significant risk factors associated with smoking and fracture healing. Little has been known about the impact of smoking in distal radius fracture healing. We intend to explore in brief the effect of smoking in distal radius fracture healing and comparing it with nonsmokers having the same fracture fixation and analyze the outcomes with respect to fracture healing and return of function. Materials and Methods Of the total 186 patients, 92 were included in the study with ( n = male: 31, female: 61) mean age of 60.2 years. They were divided into two groups: smoking ( n = 43) and nonsmoking ( n = 49). All had surgical fixation of the distal radius with volar locking plate and started on early mobilization. The range of motion of the wrist, grip, visual analog scale, quick disabilities of the arm and shoulder and hand score, Mayo wrist score, and bone healing period were noted between these two groups and compared with statistical analysis. Results The mean follow-up period was 8.7 months. There was a significant association of young age and male patients having distal radius fractures in the smoking group ( p < 0.05). All fractures healed well in both groups without complications. There was no significant difference between these two groups in terms of range of motion, grasp, bone healing period, and functional outcomes. Conclusion Despite the well-known fact that, smoking has negative implications in the fracture healing process, we found group of patients (smoking and nonsmoking) with distal radius fractures treated by volar locking plates healed well with good radiological union and excellent functional outcome There is no significant influence of smoking in distal radius fracture fixation.

Outcomes of conservative treatment for bony mallet fingers.

BACKGROUND: The treatment strategy for bony mallet fingers remains controversial. The outcomes of conservative treatment were investigated in this study. In addition, the time to bone union, and gap between the bone fragment and distal phalanx are discussed. METHODS: The subjects were 26 patients (27 fingers) with bony mallet fingers (20 males and 6 females, mean age: 46.0 years old, the mean limitation of extension of the distal interphalangeal (DIP) joint: - 20.2°). In conservative treatment, splinting was applied for 6 weeks, followed by 2-week taping. The time to bone union, range of motion of the DIP joint, and the Crawford classification on the final follow-up were investigated. In addition, the bone fragment occupation rate was evaluated on plain radiography on the first examination. Furthermore, the gap on the first examination and after splinting. The relationship between the gap and bone union period was also investigated. RESULTS: The mean time from injury to bone union was 170.2 days, the mean range of motion of the DIP joint was - 8.5° in extension and 60.9° in flexion, and the Crawford classification was Excellent for 22 fingers, Good for 2, Fair for 2, and Poor for 1. On the first examination, the mean bone fragment occupation rate was 44.0%. The mean gap on the first examination was 1.1 mm and this was significantly narrowed to 0.8 mm after splinting (p < 0.01). No significant correlation was noted between the time to bone union and gap on the first examination (p = 0.16), however, a significant positive correlation was noted between them after splinting (p < 0.01). CONCLUSIONS: This study suggested that a favorable clinical outcome can be achieved by conservative treatment. Moreover, the bone union period decreased as the gap after splinting decreased, being significantly correlated.

Correction of humpback and DISI deformities by vascularized bone grafting in patients with scaphoid nonunion.

INTRODUCTION: Although vascularized bone grafting (VBG) using 1, 2 intercompartmental supraretinacular artery (1, 2 ICSRA) is effective for scaphoid nonunion, dorsal intercalated segment instability (DISI) deformity persists even after correction of humpback deformity (HD). The purpose of this retrospective study was to evaluate the correction of HD and DISI deformity after 1, 2 ICSRA VBG for scaphoid nonunion. METHODS: We treated 18 patients (mean age: 25.8, 16 males and 2 females) with scaphoid nonunion using a 1, 2-ICSRA VBG between January 2010 and December 2018. The average time from injury to surgery was 20.0 (3-120) months. The nonunions were located at the waist in all patients. The correction of HD and DISI deformity was investigated on the preoperative images and images at the last examination. RESULTS: In all patients, the correction of HD was positively correlated with that of DISI deformity. Moreover, we focused on the time from injury to surgery and evaluated changes in HD and DISI deformity according to the time to surgery. As a result, changes in HD and DISI deformity were positively correlated in patients with a shorter time to surgery but were not correlated when the time to surgery exceeded 5 months. CONCLUSIONS: These results suggest that DISI deformity can be corrected by correcting HD when the time from injury to surgery is short, but that correction is difficult if the time to surgery is prolonged.

Finger shortening for Dupuytren's disease-induced severe PIP joint flexion contracture of the little finger: A report of two cases.

When severe proximal interphalangeal (PIP) joint flexion contracture is induced in the little finger by Dupuytren's disease, it interferes with activities of daily living. To extend the little finger, open fasciectomy is selected as a general treatment method. However, postoperative complications have been frequently reported. To solve these problems, finger shortening was undertaken. In this study, we treated two cases of Dupuytren's disease manifesting severe PIP joint flexion contracture of the little finger with finger shortening by proximodistal interphalangeal (PDIP) fusion in which the middle phalanx is resected and the residual distal and proximal phalanges are fused. For flexion contracture of the MP joint, a percutaneous aponeurotomy using an 18G needle was performed to obtain the extended position of the MP joint. Favorable outcomes with high patient satisfaction, including esthetic aspects of retaining the finger with the nail without complication, were achieved. We report this challenging treatment and its discussion.

Comparison of clinical outcomes with and without volar lunate facet fragments in dorsal displaced distal radius fractures.

INTRODUCTION: Although many clinical studies about distal radius fracture (DRF) accompanied by volar lunate facet fragments (VLFF) have recently been reported, none focus on the direction of displacement of distal fragments. Many previous cases with difficulty in treating DRF with VLFF were volar-displaced fractures. Thus, the postoperative risk for re-displacement is different between volar- and dorsal-displaced fractures with VLFF. The aim of this study is to compare the outcome of dorsal-displaced fractures treated using proximal volar locking plates (PVLP) between those with VLFF and those without, in order to reconsider the indications of distal volar locking plates (DVLP) and investigate the possibility of treating dorsal-displaced DRF with VLFF using PVLP. METHODS: The subjects were 122 patients with dorsal-displaced DRFs treated using PVLP (42 males and 80 females, mean age: 59.2 years old). The patients were divided into 13 patients with VLFF group and 109 patients without VLFF group, and the clinical outcomes at 12 months after surgery were compared. RESULTS: No significant difference was noted on any evaluation between the groups. In addition, no postoperative re-displacement of VLFF was observed and bone union was confirmed. Furthermore, no osteoarthritic change was noted in all patients. CONCLUSIONS: We confirmed that surgical treatment for dorsal-displaced DRF using PVLP is possible even in cases of DRF with VLFF. In addition, DVLP is an implant with a high complication risk; therefore, it may be necessary to reconsider the use of DVLP for dorsal-displaced DRF with VLFF treatable by PVLP.

Influence of aging on the peripheral nerve repair process using an artificial nerve conduit.

The influence of aging on the induction of nerve regeneration in artificial nerve conduits has yet to be clarified. In the present study, artificial nerve conduit transplantation and histological analysis using the sciatic nerve of young and elderly mice were performed. Using 20 male C57BL/6 mice, an artificial nerve conduit was transplanted to the sciatic nerve at 8 weeks (Young group) or 70 weeks of age (Aged group), and the sciatic nerve was evaluated histologically at 1, 4 and 12 weeks after surgery. Using hematoxylin and eosin staining, the state of induction of nerve regeneration in the artificial nerve conduit was evaluated. Additionally, immunohistochemical staining was used to investigate an angiogenic marker [vascular endothelial growth factor A (VEGFA)], Schwann cell markers [sex determining region Y-box 10 (SOX10) and S100 calcium-binding protein ß (S100ß)] and a nerve damage marker [nerve growth factor (NGF)]. The results revealed that the induction of nerve regeneration was significantly higher in the Young group than in the Aged group. In addition, VEGFA and SOX10 expression at 1 week, SOX10 expression at 4 weeks and SOX10, S100ß and NGF expression at 12 weeks in the proximal stump were significantly higher in the Young group than in the Aged group. At the center of the artificial nerve conduit, S100ß and NGF expression at 4 weeks, and VEGFA, SOX10, S100ß and NGF expression at 12 weeks were significantly higher in the Young group than in the Aged group. In the distal stump, no significant difference was noted in immunostaining at any week between the two groups. The present study suggested that the nerve regeneration-inducing functions decrease due to aging.

Clinical Outcomes in Distal Radius Fractures Accompanied by Volar Lunate Facet Fragments: A Comparison between Dorsal and Volar Displaced Fractures.

Background: The treatment strategy for distal radius fractures accompanied by volar lunate facet fragment is controversial. In most cases, only the bone fragment size was discussed and a plate for distal placement is selected due to the accompanying volar lunate facet fragment regardless of the direction of bone fragment displacement. In this study, we divided distal radius fractures accompanied by volar lunate facet fragment into dorsal and volar displaced fractures, and treated these surgically based on different treatment strategies. Methods: The subjects were 25 patients with distal radius fractures accompanied by volar lunate facet fragment treated by reduction and fixation using a volar locking plate (VLP) (male: 14, female: 11, mean age: 57.8 years old). A proximal VLP (PVLP) was selected for 13 dorsal displaced fractures and a distal VLP (DVLP) was selected for 12 volar displaced fractures. The range of motion, VAS, Q-DASH, and Mayo score were evaluated at 12 months after surgery, and compared. Results: No significant difference due to the difference in the direction of displacement was noted in the range of motion, VAS, Q-DASH, or Mayo score at 12 months after surgery and there were no perioperative complications. In addition, no re-displacement of volar lunate facet fragment was noted after surgery in any patient and bone fusion was observed. Conclusions: Reduction and fixation with a PVLP are possible even for dorsal displaced distal radius fractures accompanied by volar lunate facet fragment. For the volar displaced distal radius fractures, a favorable postoperative outcome is possible by applying a DVLP to the distal ulnar.

Characteristics of sagittal spine alignment in female patients with distal radius fractures due to fall.

OBJECTIVES: Distal radius fractures occur due to reflex clasp when falling. Recently, attention has been focused on the strong relationship between sagittal spine alignment and falls. Therefore, we investigated the parameters of sagittal spinal alignment in distal radius fractures in female patients. PATIENTS AND METHODS: The subjects were group D: 28 female patients with distal radius fractures aged 50 years or older (mean age: 69.3 years), and group C: 26 healthy female patients without a history of fragility fractures (mean age: 70.5 years). Height, body weight, and body mass index (BMI) were measured as physical indices. As parameters of sagittal spinal alignment, the sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumber lordosis (LL), and thoracic kyphosis (TK) were measured on lateral whole-spine plain radiographs in a standing position. The measured physical indices and sagittal spinal alignment parameters were compared between groups. RESULTS: Height, weight, and BMI did not differ significantly between the two groups. Among the sagittal spinal alignment parameters, PT, PI, SS, LL, and TK did not differ significantly between groups, whereas SVA was significantly higher in group D than in group C (P < 0.05). CONCLUSION: In this study, SVA was significantly higher in group D than in group C. As SVA increased, the center of gravity of the body shifts forward, which can cause the body to lose balance and fall. This study suggested that an increase in SVA is associated with distal radius fractures.

Robot-assisted Intercostal Nerve Harvesting: A Technical Note about the First Case in Japan.

Recently, surgical robotic systems have been used to perform microsurgery. Surgical robots have certain properties that make them well suited to microsurgery; for example, they possess 3-dimensional vision, which can be magnified up to 25 times; their movements are up to 5 times more precise than those of surgeons; they possess 7 degrees of wrist articulation; they do not suffer from physiologic tremors; and they can achieve ergonomic surgical positions. The purpose of this study was to report the feasibility of robot-assisted intercostal nerve harvesting in a clinical case. A healthy 57-year-old man suffered a left plexus injury. On diagnosis of clavicular brachial plexus injury, the intercostal nerve transfer to the muscular cutaneous nerve to restore elbow flexion was performed with Da Vinci Xi robot. The harvesting of intercostal nerves using the conventional open approach involves significant surgical exposure, which can lead to perioperative complications. Robot-assisted intercostal nerve harvesting might reduce postoperative pain, shorten patients' hospital stays, lower complication rates, and produce better quality-of-life outcomes. There are many issues to be solved when performing robotic surgery on peripheral nerves in Japan. However, robot-assisted intercostal nerve harvesting was a feasible surgical procedure, and patient satisfaction was high.

Evaluation of Patient-Reported and Clinician-Reported Outcomes of Volar Locking Plate Fixation for Distal Radius Fractures.

Background: Postoperative evaluation of wrist joint trauma is divided into patient-reported outcomes (PROs) and clinician-reported outcomes (CROs). We investigated the association of the Q-DASH score as the postoperative PROs and the Mayo wrist score as the postoperative CROs with clinical evaluation in patients with distal radius fractures surgically treated using a volar locking plate (VLP). Moreover, whether PROs and CROs are correlated to the clinical evaluation was investigated. Methods: The subjects were 109 patients surgically treated for distal radius fractures at our hospital between June 2013 and May 2017. Forty-one patients were male, 68 patients were female, and the mean age was 61.4 (19-86) years old. The fracture type was AO classification A type in 30 patients (A2: 25, A3: 5), B type in 5 (B2: 1, B3: 4), and C type in 74 (C1: 50, C2: 11, C3: 13). All patients were surgically treated using VLP. The range of motion of the wrist, grip strength the Visual Analog Scale (VAS), the Q-DASH score (PROs), and the Mayo wrist score (CROs) were investigated. Each evaluation was compared as the clinical outcome between at 3 months after surgery and the final follow-up. In addition, the correlations of the postoperative PROs and CROs with the clinical evaluation were analyzed. Results: Each evaluation was significantly improved compared with that at 3 months after surgery. There was a significant correlation between PROs and CROs at 3 months after surgery and the final follow-up. However, the range of motion of the wrists was not significantly correlated with PROs or CROs at 3 months after surgery or at the final follow-up. Conclusions: On evaluation after surgery for distal radius fractures, PROs and CROs improved early after surgery (3 months after surgery) before the final follow-up, and an inverse correlation was present between these scores.

Locked wires fixator for fractures of the distal third of the radius and ulna in children.

BACKGROUND: Prevention of redisplacement is an issue after the treatment of fractures of the distal third of the radius in children. In this study, we used a locked wires fixator for this type of fracture and achieved favorable treatment outcomes. METHODS: The subjects were 8 children with fractures of the distal third of the radius (male: 7, female: 1, mean age: 9.0 years old) who underwent surgery with locked wires fixators and were able to be evaluated 12 months after surgery. Immobilization was not applied after surgery. The locked wires fixator or K-wire was removed when the bridging callus was observed on plain radiography 4-6 (mean 5.5) weeks after surgery in all patients. The presence of bone union, functional outcomes, and complications were investigated postoperatively. RESULTS: All patients achieved bone union without redisplacement excellent function. The pin site infection was observed in two patients. CONCLUSIONS: The locked wires fixator may be a new useful treatment method for fractures likely to cause postoperative redisplacement.

Protective mechanism against age-associated changes in the peripheral nerves.

AIMS: Senescence is the normal decline in physiological functions due to aging that results in cell dysfunction. However, age-associated changes in peripheral nerves have not been elucidated. We observed histological changes in the sciatic nerves of young and older mice to investigate how peripheral nerves changed with age, and we evaluated protective mechanisms of peripheral nerves against aging. MAIN METHODS: Sciatic nerves were collected from female C57BL/6 mice at the ages of 8 weeks (young group) and 78 weeks (aged group) and examined histologically. Using hematoxylin and eosin staining, the number and density of sciatic nerve axons were evaluated. Through immunofluorescence staining, the expression of nerve-specific proteins, oxidative stress markers, and a neuronal aging marker (REST/NRSF) were investigated, and the intensity of fluorescence was quantified. The differences between the groups were assessed, and age-associated peripheral nerve changes were evaluated. Statistical analysis was performed using the Mann-Whitney U test. KEY FINDINGS: Although the number and density of axons did not differ significantly between the groups, they were lower in the aged group than in the young group. In addition, the fluorescence intensity of each marker did not differ significantly between the groups, but the expression of REST/NRSF alone was significantly higher in the aged group than in the young group (p < 0.05). SIGNIFICANCE: This study suggested that peripheral nerve functions are preserved by the expression of REST/NRSF, which increases with age. Because oxidative stress did not change, the protective effects of REST/NRSF are considered to be related to oxidative stress.

Functional Outcomes in Volar-Displaced Distal Radius Fractures Patients with Marginal Rim Fragment Treated by Volar Distal Locking Plates.

Background Treatment of volar-displaced distal radius fractures (DRF) accompanied by marginal rim fragment has recently been actively discussed. It is difficult to obtain a sufficient buttress effect on this fragment. Therefore, we actively apply a distal volar locking plate (DVLP) to fractures with this fragment. Here, we report the treatment outcomes and caveats of surgery of fractures with this fragment. Materials and Methods The subjects were 32 patients (male: 11, female: 21, and mean age: 59.4 years) with volar dislocated DRF accompanied by the marginal rim fragment treated using DVLP. The fracture type of AO classification was B3 in 6 patients, C1 in 12, C2 in 6, and C3 in 8. Results The mean duration of follow-up was 13.8 (12-30) months. The plate could be covered with the pronator quadratus muscle in surgery in all patients. On the final follow-up, visual analog scale score was 1.4/10, quick disabilities of the arm, shoulder, and hand score was 9.2/100, and the Mayo wrist score was 93.7/100. No complication was observed in the soft tissue, such as the nerves and flexor tendons. Conclusion The factor determining retention of the reduction position of the marginal rim fragment is a sufficient buttress effect, and DVLP is a useful implant in terms of this point.

Surgical Treatment of Distal Radius Fractures under the Ultrasound-Guided Brachial Plexus Block Performed by Surgeons.

Background: The upper limb surgery under the ultrasound-guided brachial plexus block is becoming popular due to its safety, effectiveness, and convenience. However, the uneven distribution of anesthesiologists become a social problem. Ultrasound-guided brachial plexus block by surgeons has been widespread especially in hand surgeons. We report the surgical treatment of distal radius fractures under the ultrasound-guided brachial plexus block performed by surgeons in our hospital. Methods: The subjects were 101 patients (41 males and 60 females, average age 61.6 years) who underwent surgery for distal radius fractures under ultrasound-guided brachial plexus block administered by orthopedists at our university or related facilities between January 2014 and June 2016. Brachial plexus block was administered through the supraclavicular approach. The time from initiation of anesthesia to initiation of surgery, mean operative time, the presence or absence of additional anesthesia (local infiltration anesthesia, intravenous anesthesia, and general anesthesia), and complications were evaluated. Results: The mean time from brachial plexus block to initiation of surgery was 35.7 (20-68) minutes, and the mean operative time was 90.5 (35-217) minutes. Surgery was completed with brachial plexus block alone in 62 patients (61.4%), and additional anesthesia was necessary in 39 patients (38.6%). Furthermore, general anesthesia was employed in 6 patients (5.9%). No serious complications occurred. Conclusions: According to our results, the operation could be completed with brachial plexus block alone and additional local infiltration anesthesia or intravenous anesthesia in 94.1% (95 cases). However, 6 cases (5.9%) shifted to general anesthesia. Although it needs training, we consider that hand surgery including distal radius fractures treatment under the ultrasound-guided brachial plexus block is possible. On the other hand, cooperation or a cooperative system with anesthesiologists is necessary for surgeons to administer this anesthesia.

Anatomical-positional relationship between the bone structure of the distal radius and flexor pollicis longus tendon using ultrasonography.

PURPOSE: In this study, using an ultrasonography, we investigated the positional relationship between the volar bone cortex of distal radius and flexor pollicis longus (FPL) tendon in the distal radius of healthy subjects. METHODS: The subjects were 32 healthy volunteers (56 wrists) (Age 32.9 ± 8.5, 16 males and 16 females). Their wrists were imaged by an ultrasonography. The distances between the watershed line (WS) and FPL (A), between the distal margin of pronator quadratus (DMPQ) and FPL (B), between the FPL and volar radial bone cortex at the maximum muscle belly of the PQ muscle right below the sliding region of the FPL tendon (C), and between the WS and DMPQ (D) were measured. RESULTS: All these parameters showed a normal distribution. When the correlation among the parameters was investigated, a correlation with an index of the physique, BMI, was noted in A (P < 0.01), B (P < 0.01), and C (P < 0.01), but no correlation was noted only in D (P = 0.59). CONCLUSIONS: Our results were suggested that when distal radius fracture is treated with a distal plate placement, the appropriate placement can be achieved by applying about 3 mm additional dissection of soft tissue on the volar bone cortex distal to the DMPQ.