Ulnar Styloid Research Articles

Sonoanatomy of sensory branches of the ulnar nerve below the elbow in healthy subjects.

We identify sensory branches of the ulnar nerve-palmar ulnar cutaneous nerve (PUCN), dorsal ulnar cutaneous nerve (DUCN), and superficial sensory branch-using ultrasonography. In 60 forearms of 30 healthy adult volunteers, the origin and size of the PUCN, DUCN, and superficial sensory branch were measured by ultrasonography. The relative pathway of the DUCN to the ulnar styloid process was also investigated. The PUCN was observed in 47 forearms (78%), and the DUCN was observed in all forearms. Average distances from the pisiform to the origin of the PUCN and DUCN were 11.9 ± 1.4 and 7.0 ± 1.0 cm, respectively. Superficial and deep divisions split 0.9 ± 0.3 cm distal to the pisiform. Cross-sectional areas of the PUCN, DUCN, and superficial sensory branch were 0.3 ± 0.1, 1.5 ± 0.5, and 3.9 ± 1.0 mm2 , respectively. Sensory branches of the ulnar nerve can be visualized by ultrasonography, helping to differentiate ulnar nerve injury originating at either wrist or elbow. Muscle Nerve 57: 569-573, 2018.

Functional outcomes of distal radius fractures with and without ulnar styloid fractures: a meta-analysis.

The aim of this meta-analysis was to compare the functional outcomes of patients with a distal radius fracture with and without a concomitant fracture of the ulnar styloid process. A systematic literature search was performed to identify all studies comparing patients with a distal radius fracture with and without an ulnar styloid process fracture. The initial search revealed 511 articles, of which 12 articles with a total of 2243 patients were included; 1196 patients with and 1047 patients without an ulnar styloid process fracture. A statistically significant mean difference of 3.40 points (95% CI 1.33–5.48) in the Disability of the Arm, Shoulder, and Hand score was found in favour of patients without an ulnar styloid process fracture. This difference is less than 10 and therefore not clinically important. No significant difference was found in Patient-Rated Wrist Evaluation scores, range of motion, grip strength, visual analogue scale pain scores, ulnar-sided wrist pain and distal radio-ulnar joint instability between patients with and without an ulnar styloid process fracture after 1 year of follow-up. Moreover, no significant differences were found between ulnar styloid base and nonbase fractures.Level of evidence: I

Does concomitant ulnar styloid fracture and distal radius fracture portend poorer outcomes? A meta-analysis of comparative studies

PurposeAn ulnar styloid fracture often occur in association with a distal radial fracture. Whether an ulnar styloid fracture interfere with the results of a distal radial fracture still remains controversial. The aim of this study was to analyse the effects of an accompanying ulnar styloid fracture on clinical outcomes in patients with distal radial fractures. MethodsA meta-analysis of published studies comparing outcomes of distal radial fractures with an ulnar styloid fracture versus isolated distal radial fractures was performed. Outcomes of function results, radiological evaluation, and patient reported scores were analyzed. ResultsTen studies including 1403 distal radius fractures were identified fitting inclusion criteria. There was no significant difference in wrist motion, grip strength, radial height, volar angle, ulnar variance, pain score, PRWE score, or SF-36 score for distal radial fractures associated with an ulnar styloid fracture versus isolated distal radial fractures. In final follow up, patients with associated an ulnar styloid fracture had lower radial inclination and higher DASH scores. But there was no significant clinical difference. In addition, we found there was no significant difference of outcomes between union and non-union ulnar styloid fractures. ConclusionsBased on this meta-analysis, we suggest that an associated ulnar styloid fracture does not affect the outcomes of a distal radial fracture and clinicians should be caution in electing operative treatment for patients with an ulnar styloid fracture.

P262 Contraceptive implant induced ulnar neuropathy

Significant complications from subdermal insertion of a contraceptive implant in the medial upper arm are rare; a UK Government drug safety update indicating the risk of intravascular insertion was published in 2016.We report the introduction of an implant into the ulnar nerve sheath. Introduction of a contraceptive implant into the medial aspect of the distal left upper arm was followed 5 min later by the patient reporting pins and needles in the arm and tips of the left ring and little fingers. The implant was not palpable. 2 h later loss of sensation was apparent in these fingers; clinical review was unrevealing. Ultrasound suggested the implant was lying between the ulnar nerve and blood vessel in the medial upper arm. At surgery the implant was found within the left ulnar nerve sheath and removed.3 months post surgery the numbness in the little finger had resolved but reduced sensation was still evident over the dorso-ulnar hand and distal forearm with hypersensitivity over the ulnar styloid, weakness was not apparent. Nerve conduction studies revealed the left dorsal ulnar sensory NAP was small when compared to the right side (13 vs. 31 microvolts).The left digit 5 sensory NAP was normal amplitude. Motor studies showed mild slowing in the left ulnar nerve around the elbow. While publications and warnings have highlighted the rare occurrence of intravascular insertion, the neurovascular bundle is at risk hence drug company advice to avoid the sulcus between biceps and triceps. This case indicates fascicular damage to the ulnar nerve.

Hot Off the Press: Which Febrile Children With Sickle Cell Disease Need a Chest X-ray?

Hot Off the Press: Which Febrile Children With Sickle Cell Disease Need a Chest X-ray?

Point-of-Care US and Nonangulated Forearm Fractures

Research Article| August 01 2017 Point-of-Care US and Nonangulated Forearm Fractures AAP Grand Rounds (2017) 38 (2): 17. https://doi.org/10.1542/gr.38-2-17 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Point-of-Care US and Nonangulated Forearm Fractures. AAP Grand Rounds August 2017; 38 (2): 17. https://doi.org/10.1542/gr.38-2-17 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: diagnostic radiologic examination, forearm fractures, point-of-care ultrasonography, pain Source: Poonai N, Myslik F, Joubert G, et al. Point-of-care ultrasound for nonangulated distal forearm fractures in children: test performance characteristics and patient-centered outcomes. Acad Emerg Med. 2017; 24(5): 607– 616; doi: https://doi.org/10.1111/acem.13146Google Scholar Researchers from multiple Canadian institutions conducted a cross-sectional study to determine the utility of point-of-care ultrasonography (POCUS) in children with suspected nonangulated distal forearm fractures. Children were eligible if they were 4–17 years old and presented to the study emergency department (ED) with a suspected nonangulated distal forearm fracture, defined as maximal pain and tenderness at the distal third of the forearm after an acute fall on an outstretched hand. Each participant underwent radiography and POCUS of the distal ulna and radius. POCUS was performed and interpreted by 4 POCUS-certified pediatric ED physicians with at least 2 years of POCUS experience who were not involved in the patient’s care. POCUS evaluators were blinded to the radiographs, and radiography technicians and radiologists were blinded to POCUS interpretations. Each study child was classified as having a fracture or not on the basis of a radiologist’s interpretation of the patient’s radiographs. The primary outcome was the sensitivity and specificity of the POCUS evaluation by the ED physician (fracture or no fracture) when compared to radiograph interpretation. Secondary outcomes included (a) patient self-reported pain immediately after radiography and POCUS by using Faces Pain Scale–Revised scores, (b) caregiver satisfaction with each imaging procedure by using a single-item question and a 5-point Likert scale, and (c) duration of POCUS and radiography procedures. Of 169 children enrolled, 76 had a fracture on radiographs. The most common type was a buckle fracture (80%). The sensitivity and specificity of POCUS were 94.7% (95% confidence interval [CI], 89.7%–99.8%) and 93.5% (95% CI, 88.6%–98.5%), respectively. There were 4 fractures missed with POCUS (1 distal radius buckle fracture and 3 ulnar styloid factures). There were 6 nonfractures that were interpreted as fractures at POCUS. POCUS was associated with a significantly lower median pain score when compared with radiography. There was no significant difference in median caregiver satisfaction scores with POCUS and radiographic procedures. POCUS was associated with a significantly lower median procedure duration than radiography (1.5 vs 27 minutes, respectively; P < .001). The researchers conclude that using POCUS to assess distal forearm injuries in children is accurate, timely, and associated with low levels of pain. Dr Stevenson has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device. POCUS is a useful tool in the pediatric ED setting. The current study is 1 of several published in recent years to evaluate its use in forearm fractures in children. A recent meta-analysis of these studies supports the high sensitivity and specificity reported in the present study,1 which excluded children with obvious forearm deformities and thereby reduced the potential for inflated test performance. Few prior studies have been conducted to evaluate pain... You do not currently have access to this content.

Predictive Power of Distal Radial Metaphyseal Tenderness for Diagnosing Occult Fracture

To correlate the physical examination finding of distal radial metaphyseal tenderness with plain radiographic and magnetic resonance imaging after acute wrist injury to diagnose occult distal radius fractures. We hypothesized that persistent distal radial metaphyseal tenderness 2 weeks after acute injuries is predictive of an occult fracture. Twenty-nine adult patients presented, after acute trauma, with distal radial metaphyseal tenderness and initial plain radiographs and/or fluoroscopic images that did not show a distal radius fracture. Patients were reevaluated clinically and radiographically at approximately 2 weeks after initial presentation. Patients with persistent distal radial tenderness and negative radiographs underwent magnetic resonance imaging to definitively diagnose an occult distal radius fracture. We calculated the sensitivity and positive predictive value for persistent distal radial metaphyseal tenderness using a 95% confidence interval and standard formulas. Both radiographs and magnetic resonance imaging were used as our endpoint diagnosis for a distal radius fracture. We diagnosed 28 occult distal radius fractures, 8 by follow-up radiograph and 20 by magnetic resonance imaging. The positive predictive value for patients who completed the protocol was 96%. One patient who did not have an occult distal radius fracture had a fracture of the ulnar styloid. Tenderness of the distal radial metaphysis after wrist injury is strongly suggestive of a distal radius fracture despite both normal plain radiographs and fluoroscopic images. Diagnostic III.

Safety Window for the Volar Needle Approach for Examination of the Pronator Quadratus Using Ultrasonography

ObjectivesTo investigate pronator quadratus (PQ) anatomy and determine the proper volar needle insertion point based on landmarks, the tip of the ulnar styloid (an imaginary vertical line passing the tip of the ulnar styloid process [U line]), and the ulnar margin of the palmaris longus tendon (uPL) using ultrasonography. DesignDescriptive study. SettingDepartment of physical medicine and rehabilitation. ParticipantsParticipants between 20 and 60 years without any diseases. (N=25; 13 men, 12 women; 50 forearms). InterventionsUltrasonography. Main Outcome MeasuresThe proximal and distal volar surface points of origin, the proximal and distal insertion sites, and the midpoint of the PQ (PQ_M) were determined. The distance of each of the PQ surface indices from the U line was measured, and the probe was positioned at the level of PQ_M parallel to the U line. The relative distances from the vertical surface points of the median nerve and ulnar artery to the uPL were measured. ResultsThe mean age and body mass index were 32.7±10.4 years and 21.98±2.83kg/m2. The PQ_M was located at a mean distance of 2.63±0.35cm proximal from the U line (men 2.79±0.37cm and women 2.45±0.21cm; P<.05). The mean safety window for the volar approach was 0.72±1.8cm toward the radial side and 1.51±0.30cm toward the ulnar side from the uPL. The PQ was at a mean depth of 1.30±0.19cm from the skin and had a mean thickness of 1.19±0.24cm at the level of PQ_M. The distance between the U line and the proximal edge of the PQ, as well as the PQ thickness, was greater in men than in women. ConclusionsThe volar approach for needle electromyographic examination of the PQ can be performed precisely and safely.

Patient specific pointer tool for corrective osteotomy: Quality of symmetry based planning and case study of ulnar reconstruction surgery

Malunion after forearm fractures are described to appear in 2% to 10% of cases. Reconstructive surgeries ensure adequate anatomical repositioning. Their importance derives from the fact that malunion can often lead to severe pain as well as deformities causing loss of function and aesthetic issues not only in the forearm, but also the wrist and elbow joint.In this paper a clinical case will be presented using a Patient Specific Instrument (PSI) as navigational aid for reconstructive surgery after malunion of a proximal ulnar fracture combined with allograft surgery of the radial head and radial condyle due to chronic traumatic radial head luxation (Monteggia fracture). A planning method based on symmetry is described and evaluated on twelve Computed Tomographic (CT) data sets of intact forearms. The absolute point to point deviation at distal end of the ulnar styloid process was used as a characteristic value for accuracy evaluation. It is 7.9±4.9mm when using only the proximal end of the ulna for registration. The simulated change of ulnar variance is −1.4±1.9mm. Design and concept of the PSI are proven in a clinical trial

Topographical Anatomy of the Distal Ulna Attachment of the Radioulnar Ligament

The deep component of the distal radioulnar ligament provides translational stability and rotational guidance to the forearm. However, controversy exists regarding the importance of this structure as well as the nature of its attachment to the distal ulna. We aimed to evaluate the topographic anatomy of the distal ulna attachment of both the superficial and the deep components of the radioulnar ligament and to assess the relationship between its internal and its external morphometry. Thirteen human distal ulnae attached by ulnar part of the distal radioulnar ligament were scanned using micro-computed tomography and reconstructed in 3 dimensions. In addition, the distal radioulnar ligaments were examined under polarized light microscopy to determine the histological characteristics of collagen contained within the ligaments. The deep limbs have broad marginal insertions at the fovea, whereas the superficial limbs have a circular and condensed insertion to the ulnar styloid. The center of the deep limb was separated from the base of the ulnar styloid by a mean of 2.0 ± 0.76 mm, and this distance was positively correlated with the width of the ulnar styloid. The mean distance between the center of the ulnar head and the center of the fovea was 2.4 ± 0.58 mm. The proportion of collagen type I was lower in the deep limb than in the superficial limb. This new observation of the footprint of the radioulnar ligament in the distal ulna indicates that the deep limb may serve as an internal capsular ligament of the distal radioulnar joint, whereas the superficial limb as the external ligament. Knowledge of the topographic anatomy of the radioulnar ligament's attachment to the distal ulna may provide a better understanding of distal radioulnar ligament-related pathologies.

Functional Outcome after Surgical Stabilization of Fractures of Distal End of Radius with or Without Ulnar Styloid Fractures- A Comparative Study

Functional Outcome after Surgical Stabilization of Fractures of Distal End of Radius with or Without Ulnar Styloid Fractures- A Comparative Study

Carpal tunnel release: Safe and simple identification of the flexor retinaculum based on superficial anatomical landmarks.

The aim of our study was to project the borders of the flexor retinaculum (FR) onto superficial landmarks since its insufficient splitting is the most common reason for persistence of symptoms after carpal tunnel release. In 60 hands the radial and ulnar styloid processes were linked by a horizontal line and a longitudinal line was laid through the ring finger's radial side. These were intersected resulting in the reference point "A" on the forearm. As the second basing point "B", the radial margin of the ring finger at the palmar digital crease was chosen. Measurement of the FR was carried out with regard to the reference points. The proximal margin of the FR was located at 4% of the reference line A-B starting from point A and extended up to 52% of this total length. Results indicate that splitting alongside the proximal half of line A-B divides the FR completely. Clin. Anat. 30:512-516, 2017. © 2017 Wiley Periodicals, Inc.

High-resolution MRI of the ulnar and radial collateral ligaments of the wrist.

Background Accurate diagnosis of injuries to the collateral ligaments of the wrist is technically challenging on MRI. Purpose To investigate usefulness of high-resolution two-dimensional (2D) and isotropic three-dimensional (3D) magnetic resonance imaging (MRI) for identifying and classifying the morphology of the ulnar and radial collateral ligaments (UCL and RCL) of the wrist. Material and Methods Thirty-seven participants were evaluated using 3T coronal 2D and isotropic 3D images by two radiologists independently. The UCL was classified into four types: 1a, narrow attachment to the tip of the ulnar styloid (Tip); 1b, broad attachment to the Tip; 2a, narrow attachment to the medial base of the ulnar styloid (Base); and 2b, broad attachment to the Base. The RCL was also classified into four types: 1a, separate radioscaphoid and scaphotrapezial ligaments (RS + ST) with narrow scaphoid attachment; 1b, RS + ST with broad scaphoid attachment; 2a, continuous radio-scapho-trapezial ligaments (RST) with narrow scaphoid attachment; and 2b, RST with broad scaphoid attachment. The inter-observer reliability of these classifications was calculated. Results Type 1a was the most common of both collateral ligaments. Of UCL classifications, 31.4% were revised after additional review of multiplanar reconstruction (MPR) images from isotropic data. The inter-observer reliability of UCL classification was substantial (k = 0.62) without MPR, and almost perfect (k = 0.84) with MPR. The inter-observer reliability of RCL classification was almost perfect (k = 0.89). Anatomic delineation between the two sequences was not statistically different. Conclusion The UCL and RCL were each identified on high-resolution 2D and isotropic 3D MRI equally well. MPR allows accurate identification of the UCL attachment to the ulnar styloid.

Treatment of traumatic ulnar styloid impaction syndrome by Sauvé-Kapandji procedure

To evaluate the effectiveness of Sauvé-Kapandji procedure in the treatment of traumatic ulnar styloid impaction syndrome. Between June 2010 and January 2013, 12 patients with traumatic ulnar styloid impaction syndrome were treated by Sauvé-Kapandji procedure. There were 4 men and 8 women, with an average age of 58.9 years (range, 50-69 years). The disease was caused by traffic accident in 1 case, and by falling from height in 11 cases. All patients had dislocation of the distal radioulnar joint, and 7 patients also had old fractures of the distal radius. The main clinical symptoms were pain and limited activity of the wrist joint, and the disease duration was 2-4 months (mean, 3.5 months). The visual analogue scale (VAS) was 6.2±1.4. The clinical outcomes were assessed by VAS, range of motion (ROM) of the wrist, grip strength, Evans score, and X-ray film of wrist joint during follow-up. All patients obtained healing of incision by first intention and were followed up 37-73 months (mean, 58.4 months); no complication of infection, blood vessel injury, or nerves injury occurred. VAS was 1.2±1.0 at the final follow-up, showing significant difference when compared with preoperative one ( t=9.950, P=0.000). The ROM of the affected wrist joint in flexion, extension, ulnar deviation, forearm pronation and supination were improved, but the ROM of the affected side were significantly less than those of normal side ( P<0.05). No significant difference was found in the grip strength and Evans score between the affected side and normal side ( t=-0.885, P=0.386; t=-1.969, P=0.062). According to Evans scores, the results were excellent in 8 cases, good in 3 cases, and fair in 1 case, with an excellent and good rate of 91.7%. Postoperative radiographs showed bony healing in all patients, with the average healing time of 3.5 months (range, 3-6 months). The instability of proximal ulna occurred in 3 cases. Sauvé-Kapandji procedure is a reliable remedy method for traumatic ulnar styloid impaction syndrome, with favorable improvement in wrist pain and forearm rotation. However, the surgical indications for Sauvé-Kapandji procedure should be strictly controlled.

Arthroscopic assisted tendon reconstruction for triangular fibrocartilage complex irreparable tears.

IV.

Ulnar Styloid Base Fractures Cause Distal Radioulnar Joint Instability in a Cadaveric Model.

The deep portion of the distal radioulnar ligaments (DRUL) inserts on the ulnar fovea and is the most important stabilizer of the distal radioulnar joint (DRUJ). Ulnar styloid base fractures that include the ulnar fovea may cause DRUJ instability. DRUJ stability in pronosupination was evaluated in 12 fresh-frozen upper extremities (4 female) aged 52 to 68 years (mean: 58.8 years) using a custom fixture, which allowed free rotation of the radius around the fixed ulna. Optical motion capture was used to record rotation of the radius with respect to the ulna. Each specimen was subjected to 3 N m of torque in both supination and pronation under 4 conditions: intact, ulnar styloid osteotomy with disruption of the foveal insertion of the DRUL, ulnar styloid fixation, and DRUL transection. Group differences were compared using a 1-way repeated-measures analysis of variance and Tukey multiple comparison post hoc tests. When compared with the intact condition, both ulnar styloid osteotomy and DRUL transection significantly increased mean pronation (by 9.40° and 15.21°, respectively) and supination (by 9.05° and 17.42°, respectively) of the forearm. Screw fixation only significantly reduced pronation compared with osteotomy (by 2.62°). Screw fixation did not significantly affect supination. Ulnar styloid fractures that disrupt the fovea cause instability of the DRUJ in pronation and supination under 3 N m of torque in a cadaveric model. Screw fixation of ulnar styloid base fractures achieves anatomic reduction; however, it only partially returns rotational stability acutely to the DRUJ and only during pronation.

Updates on Ulnar Impaction Syndrome

Ulnar impaction syndrome is one of the common causes of ulnar-sided wrist pain. The pain is usually aggravated by ulnar deviation during a power grip, especially when the forearm is in a pronated position. The most common predisposing factor of ulnar impaction syndrome is ulnar positive variance, which is an increased ulnar length relative to the radius of the radiocarpal joint. However, it can also occur in patients with ulnar neutral or negative variance because ulnar variance can increase during functional activities, including pronation and power gripping. In these patients, the triangular fibrocartilage complex (TFCC) may be thickened. If conservative treatments-lifestyle modification, medication, or wrist splinting-are unsuccessful, surgical treatments, such as wafer procedure or ulnar shortening osteotomy can be considered. The wafer procedure is an effective treatment for ulnar impaction syndrome. It removes the distal 2 to 4 mm of the ulnar head, while preserving the ulnar styloid process from fracturing via a limited open or an arthroscopic approach. The advantages of the wafer procedure are that it does not require bone healing or internal fixation and provides direct access to TFCC. However, it is a technically demanding procedure and is contraindicated in patients with distal radio-ulnar joint (DRUJ) instability, lunotriquetral instability, ulnar minus variance, and with an ulnar positive variance of more than 4 mm. Ulnar shortening osteotomy is the most popular method for the treatment of ulnar impaction syndrome. It can effectively relieve ulnar impaction symptoms and stabilize DRUJ. However, an excessive amount of shortening may increase the peak pressure at DRUJ, which results in DRUJ arthritis. There is also a possibility of delayed union or nonunion in the osteotomy site. To prevent delayed union or nonunion, we should make an effort to decrease the gap in the osteotomy site during surgery. A serial follow-up is also recommended to evaluate the occurrence of arthritis in DRUJ after ulnar shortening.

Clinical and functional outcome of open primary repair of triangular fibrocartilage complex tears associated with distal radius fractures.

We evaluate the clinical and functional outcome of open primary repair of acute TFCC tears in distal radius fracture, when there is gross intraoperative distal radioulnar joint (DRUJ) instability after fixation of the distal radius, in the absence of an ulnar styloid fracture or when the ulnar fracture fragment is too small to be fixed. A retrospective review of our institution's distal radius fracture database over a 4-year period (January 2010 to December 2013). A total of 12 (1.38%) out of 3379 patients had an open TFCC repair in the same setting as fixation of distal radius. Assessment of outcome involved the analysis of objective and subjective clinical and functional outcomes. All patient regained Activities of Daily Living (ADL) independence; eleven out of 12 patients (91.7%) returned to pre-injury function and 8 out of 11 patients (72.7%) returned to their jobs. DRUJ stability was preserved in 10 patients (83.3%) with 10 patients (83.3%) having grip strength of at least 50%, compared to the uninjured hand, and 7 (58.3%) with grip strength of more than or equal to 75%. Complications of surgery identified can be classified into 4 broad categories: infection, neurological complications, persistent DRUJ instability and prolonged pain. The authors believe a primary open repair of the TFCC should be considered when patients present with instability during intra-operative DRUJ ballottement test after distal radius fixation, in the absence of an ulnar styloid fracture or when the ulnar fracture fragment is too small to be fixed.

Optimal Radial Motor Nerve Conduction Study Using Ultrasound in Healthy Adults.

ObjectiveTo obtain reference values, to suggest optimal recording and stimulation site for radial motor nerve conduction study (RmNCS), and to analyze the correlation among RmNCS parameters, demographics and ultrasonography (US) findings.MethodsA total of 55 volunteers participated in this study. We hypothesized that ‘lateral edge of spiral groove (A)’ was the optimal stimulation site, and the ‘largest cross-sectional area (CSA) of extensor indicis proprius (EIP) muscle (B)’ was the optimal recording site. The surface distance between ‘A’ and the lateral epicondyle of the humerus divided by upper arm length, was named the spiral groove ratio. The surface distance between ‘B’ and the ulnar styloid process divided by forearm length, was named the EIP ratio. Using US, we identified these sites, and further conducted RmNCS.ResultsData was collected from 100 arms of the 55 volunteers. Mean amplitude and latency were 5.7±1.1 mV and 5.7±0.5 ms, respectively, at the spiral groove, and velocity between elbow and spiral groove was 73.7±7.0 m/s. RmNCS parameters correlated significantly with height, weight, arm length, and CSA of the EIP muscle. Spiral groove ratio and EIP ratio were 0.338±0.03 and 0.201±0.03, respectively; both values were almost the same, regardless of age, sex and handedness.ConclusionWe established a reference value and standardized method of RmNCS using US. Optimal RmNCS can be conducted by placing the recording electrode 20% (about one-fifth) of forearm length from the ulnar styloid process, and stimulating at 34% (about one-third) of the humeral length from the lateral epicondyle.

Incidence des fractures de l’extrémité distale de l’ulna associées aux fractures de l’extrémité distale du radius (processus styloïde ulnaire). Nos choix thérapeutiques

Fractures of the neck and/or head of the ulna or distal ulna fracture (DUF) other than ulnar styloid fractures can occur in combination with distal radius fractures (DRF). This combination can have a significant influence on the treatment and prognosis since it causes the entire distal forearm to be unstable. In a series of 1279 consecutive unilateral DRFs, we found an associated ulnar neck fracture in 5.9% of cases, ulnar head and neck fracture in 1.6%, and isolated ulnar head fracture in 1.4%. Overall, 9% of cases in this study had a DUF with a DRF. The frequency of extra-articular “A” (11%) and intra-articular “C” (9%) DRFs according to the AO classification was about the same. There were no cases of DUF combined with partial “B” DRF. There was a correlation between combined DUF with DRF and the patient's group in the PAF classification. DUF are more frequently associated with DRF in elderly patients. Specific distal ulnar locking plates were recently introduced and they may be a useful adjunct to distal radius locking plates when treating patients with combined DUF and DRF.