Ulnar variance in distal radial fractures: assessment and interpretation

We explored patterns of shortening of the distal radius and investigated the effect of displacement on ‘ulnar variance’ in 250 patients with distal radial fractures. A small number of patients (5%) had a fracture that resulted in true shortening. Thirty-two per cent had fractures that appeared short, but lateral radiographs revealed that the articular surface was tilted, with either the anterior or dorsal rim of the articular surface being proximal to the distal ulna but the other rim was distal to it. We recommend initial assessment of variance on lateral radiographs. If the anterior and dorsal rims of the distal radial articular surface are proximal to the distal ulna, then true shortening is present and lengthening and stabilization, to hold the radius distracted, should be considered. If only one rim is proximal to the distal ulna, then correction of the tilt will lessen the apparent positive variance. Level of evidence: IV

Normal Values of Distal Radioulnar Joint Kinematics during a Dynamic Press Test

Background Measurement of in vivo distal radioulnar joint (DRUJ) pathomechanics during simple activities can represent the disability experienced by patients and may be useful in diagnostics of DRUJ instability. A first step is to describe the physiological normal limits for DRUJ kinematics in a reproducible and precise test setup, which was the aim of this study. Methods DRUJ kinematics were evaluated in 33 participants with dynamic radiostereometry (RSA) while performing a standardized press test examination. AutoRSA software was used for image analyses. Computed tomography (CT) forearm bone models were generated, and standardized anatomical axes were applied to estimate kinematic outcomes including, DRUJ translation, DRUJ position ratio, and changes in ulnar variance. Repeatability of dynamic RSA press test double examinations was evaluated to estimate the precision and intraclass correlation coefficient (ICC) test–retest agreement. Results The maximum force during the press test was 6.0 kg (95% confidence interval [CI]: 5.1–6.9), which resulted in 4.7 mm (95% CI: 4.2–5.1) DRUJ translation, DRUJ position ratio of 0.40 (95% CI: 0.33–0.44), and increase in ulnar variance of 1.1 mm (95% CI: 1.0–1.2). The mean maximum DRUJ translation leveled off after a 5 kg force application. The DRUJ translation ICC coefficient was 0.93 within a prediction interval of ± 0.53mm. Conclusions This clinical study demonstrates the normal values of DRUJ kinematics and reports excellent agreement and high precision of the press tests examination using an automated noninvasive dynamic RSA imaging method based on patient-specific CT bone models. The next step is the application of the method in patients with arthroscopic verified triangular fibrocartilage complex injuries. Level of Evidence This is a Level IV, case series study.

Arthroscopic Anatomy of the TFCC with Relevance to Function and Pathology

Introduction The authors present a new comprehensive arthroscopic anatomical description of the fibrocartilage complex “TFCC” which is related to the current TFCC functional and pathological knowledge. Methods Our description of the TFCC is based on an arthroscopic view from the 3-4 portal as observed in more than 100 wrist arthroscopies in fresh cadavers and more than 1000 diagnostic and/or therapeutic wrist arthroscopies. Results TFCC is considered as a 3-D-3-part box-like structure (Reins, Wall and Disc). The first TFCC component (“R”) corresponds to 2 strong radio-ulnar ligamentous Reins, one dorsal (DRUL) and one palmar (PRUL). This “V-shaped” RUL reins diverge from the fovea and ulnar styloid to the volar and dorsal edges of the sigmoid notch. It is a main stabilizer of the DRUJ. The second TFCC component (“W”) is a continuous, radially concave Peripheral Capsular Wall attached and perpendicular to the RUL reins. It surrounds the ulnar aspect of the ulno-carpal interval while attaching to the RUL reins proximally and to the medial carpus distally. Along with the radiocarpal ligaments, the TFCC peripheral capsular wall contributes to the stability of the carpus with respect to the radius-ulna entity. This is especially true for the thick volar TFCC capsular wall. The third TFCC component (“D”) is the disc proper which is a static and dynamic shock absorber intercalated between the ulnar head and the medial proximal row in the coronal/sagittal planes and between the two strands of the RUL in the axial plane. Its pathology is influenced and related to the ulnar variance. Discussion This new arthroscopic description of the TFCC provides a comprehensive anatomical, functional ant pathological background for TFCC disorders analysis and treatment. Currently known disorders are included as “R 1,2,3,4”, “W 1, 2, 3, 4”, and “D 1, 2”. Combined TFCC disorders and further new pathology descriptions may be included in this open classification.

ANTHROPOMETRIC ANATOMIZATION OF DISTAL RADIUS USING DIGITAL XRAYS IN SOUTH INDIAN POPULATION

Background: Population specic understanding of distal radius athropometry is indeed an essential factor for managing fractures of distal radius which is most commonly encountered. The primary goal of treatment of distal radius fracture is to obtain an well functioning wrist joint with restored normal anatomy, for which reduction criteria based on western population is being used till now . Hence in this study we analyse the anthropometry of distal end of radius using digital xrays in south Indian population. Hundred pat Materials and Methods: ients with a normal wrist joint attending the Department of Orthopaedics and Traumatology unit of Government Medical College and ESI Hospital, Coimbatore were included in this study. Plain Radiographs were taken to measure the Radial Inclination, Palmer Tilt, Radial Height and Ulnar Variance and the values were compared with data reported in the literature. The mean value of Radial Inclination(22.54 Results: °±2.18°), Palmer Tilt(12.01°±1.88°), Radial Height(11.30mm±0.30mm), and Ulnar Variance(0.44mm±1.03mm) in our study population differed on comparing with data reported in the literature for Western and other Indian population. This study concludes Conclusion: that signicant differences exist between the values observed in our study population and the values reported in the literature for western population and other Indian population, which can be used as a reference criteria in managing the fracture distal radius among south Indian population.

Comparison of extra-articular radiographic parameters of distal radius fractures on plain radiographs and CT scans

The aim of this study was to compare extra-articular radiographic parameters of distal radial fractures measured on plain radiographs and CT scans. Two researchers independently measured four extra-articular radiographic parameters (dorsal tilt, carpal alignment, radial inclination and ulnar variance) on both radiographs and CT scans in 85 patients. Inter-observer reliability for both techniques was assessed, along with the agreement between CT scans and radiographs using the intraclass correlation coefficient and Bland–Altman plots. The results showed that dorsal tilt, carpal alignment, radial inclination and ulnar variance can be measured reliably on both radiographs and CT scans. At a patient level, carpal alignment, radial inclination and ulnar variance CT scan measurements are an acceptable alternative to plain radiograph measurements in the vast majority of patients. In contrast, dorsal tilt CT scan measurements are not comparable with radiographs in 40% of the cases. Therefore, caution should be taken in measuring dorsal tilt on CT scans.

Radius-ulna shaft fracture with distal radioulnar joint instability in a case of ipsilateral malunited colles fracture: a case report

<p class="abstract">Malunion of the distal end of radius is a known consequence of the conservative management. The functional impairment depends on the severity of the deformity and it can be associated with distal radioulnar joint (DRUJ) instability. Subsequent radius ulna fracture in an elderly osteoporotic patient is a challenging task to manage. A 60 year old female patient came with radius ulna shaft fracture with DRUJ instability with ipsilateral malunited distal radius fracture. We managed with open reduction and internal fixation using 3.5 mm locking compression plate (LCP) with ulnar shortening and K wires for DRUJ. At one year, follow-up, patient is having good clinical and radiological outcome without any complications. Radius ulna shaft fracture in cases of malunited colles fracture with positive ulnar variance with DRUJ instability can be managed well with open reduction and internal fixation of radius-ulna shaft which provides stable fixation, ulnar shortening at the fracture site to maintain the neutral/negative ulnar variance and DRUJ fixation using K wires. Use of multiple vicryl sutures to tie the plate to the bone gives additional stability in osteoporotic bones till the fracture unites and prevents implant failure. Combination of the above mentioned procedures helps in getting good functional outcome in elderly osteoporotic patients.</p>

The triangular fibrocartilage complex on high-resolution 3 T MRI in healthy adolescents: the thin line between asymptomatic findings and pathology

Objective The objective of the study is to provide a reference for morphology, homogeneity, and signal intensity of triangular fibrocartilage complex (TFCC) and TFCC-related MRI features in adolescents. Materials and methods Prospectively collected data on asymptomatic participants aged 12–18 years, between June 2015 and November 2017, were retrospectively analyzed. A radiograph was performed in all participants to determine skeletal age and ulnar variance. A 3-T MRI followed to assess TFCC components and TFCC-related features. A standardized scoring form, based on MRI definitions used in literature on adults, was used for individual assessment of all participants by four observers. Results per item were expressed as frequencies (percentages) of observations by all observers for all participants combined (n = 92). Inter-observer agreement was determined by the unweighted Fleiss’ kappa with 95% confidence intervals (95% CI). Results The cohort consisted of 23 asymptomatic adolescents (12 girls and 11 boys). Median age was 13.5 years (range 12.0–17.0). Median ulnar variance was −0.7 mm (range − 2.7–1.4). Median triangular fibrocartilage (TFC) thickness was 1.4 mm (range 0.1–2.9). Diffuse increased TFC signal intensity not reaching the articular surface was observed in 30 (33%) observations and a vertical linear increased signal intensity with TFC discontinuation in 19 (20%) observations. Discontinuation between the volar radioulnar ligament and the TFC in the sagittal plane was seen in 23 (25%) observations. The extensor carpi ulnaris was completely dislocated in 10 (11%) observations, more frequent in supinated wrists (p = 0.031). Inter-observer agreement ranged from poor to fair for scoring items on the individual TFCC components. Conclusion MRI findings, whether normal variation or asymptomatic abnormality, can be observed in TFCC and TFCC-related features of asymptomatic adolescents. The rather low inter-observer agreement underscores the challenges in interpreting these small structures on MRI. This should be taken into consideration when interpreting clinical MRIs and deciding upon arthroscopy.

The effect of forearm rotation on radiographic measurements of the wrist: an experimental study using radiostereometric analyses on cadavers

Background Although dorsal/palmar tilt, radial inclination (RI), and ulnar variance (UV) are measurements commonly performed in wrist radiographs, the impact of forearm rotation on those measurements during the radiographic procedure is uncertain. Our aim was to determine the impact of supination and pronation on the reliability of measurements of tilt, RI, and UV. Methods Tantalum markers were inserted into the distal radius of 21 unfractured cadaver forearms. The forearms were radiographed in different degrees of supination and pronation. The exact degree of rotation was calculated with radiostereometric analyses. Tilt, RI, and UV were measured by two independent readers in a random and anonymised fashion. Association between forearm rotation and radiographic measurements was examined using linear regression. Results Forearm rotation significantly impacted the radiographically measured tilt. One degree of supination and pronation respectively increased and decreased palmar tilt with 0.68° and 0.44°, observers 1 and 2, respectively. As opposed to observer 1, observer 2 found that RI was significantly impacted by rotation with a slope of 0.08. Ulnar variance was not significantly impacted by rotation with linear regression slopes of 0.01° (95% confidence interval [CI] − 0.02–0.05, p = 0.490) and 0.02° (95% CI − 0.02–0.07; p = 0.288), observer 1 and observer 2, respectively. Conclusion In unfractured forearms, the radiographically measured tilt was significantly affected by rotation. Palmar tilt increased with supination and decreased with pronation. Rotation significantly affected radial inclination, although of a magnitude that is probably not clinically relevant. No significant impact on UV was found.

Simplifying the Volar Distraction Osteotomy for Distal Radius Malunion Repair

Background Extra-articular fractures of the distal radius are often treated with a trial of nonoperative management if radiographic parameters are within an acceptable range, especially in the elderly population. Unfortunately, some malunions become symptomatic or become grossly misaligned during nonoperative management which require corrective surgery to restore the normal osseous anatomy and restore function. Description of Technique We describe correction of a distal radius malunion utilizing a distraction-type volar osteotomy, a volar plate specific distraction device, and a novel resorbable calcium phosphate bone cement (Trabexus) designed to withstand compressive loads. Patients and Methods Twelve patients with 13 distal radius fractures were included in this study. The average patient age was 60.9 years and average time from injury to corrective osteotomy was 96.3 days. Radiographic measures (radial inclination, volar tilt, and ulnar variance) and clinical assessment (wrist/forearm range of motion and grip strength) were done pre- and postoperatively and compared. Results The average time from corrective surgical osteotomy to final clinical follow-up was 375.8 days. After surgical intervention, there was a statistically significant improvement in mean volar tilt (−19.8 vs. +0.5 degrees) and mean ulnar variance (+2.8 vs. −0.4 mm). Improvements were also seen in grip strength (1.7 vs. 43.6 lb), wrist flexion (30.5 vs. 48.3 degrees), wrist extension (33.3 vs. 53.8 degrees), forearm pronation (75.0 vs. 88.8 degrees), and forearm supination (53.8 vs. 81.3 degrees). On average, 56.0% of Trabexus bone substitute remained on final clinical radiographs. Conclusion This simplified technique of distraction corrective osteotomy after distal radius malunion results in improved clinical and radiographic outcomes for patients.