A systematic review of the psychometric properties of pressure pain detection threshold in evaluating mechanical pain threshold in people with hand or wrist injuries.

PURPOSE: The aim of this study was to conduct a systematic review of the psychometric properties of Pressure Pain Detection Threshold (PPDT) measures in people with hand or wrist injuries. STUDY DESIGN AND METHODS: MEDLINE, Embase, and CINAHL databases were searched to identify eligible studies evaluating psychometric properties of PPDT in samples composed of at least 50% of people with hand or wrist injury. The Consensus-based Standards for the Measurement of Health Instruments' risk of bias checklist was used to critically appraise the included studies, and qualitative synthesis was performed by pooling the results of all studies that presented the same measurement property using Grading of Recommendations, Assessment, Development, and Evaluation. RESULTS: From 415 studies, 11 relevant studies were identified. Of the 11 studies, four hand or wrist injuries were represented; carpal tunnel syndrome, distal radius fractures, osteoarthritis, and complex regional pain syndrome. Intra-rater reliability was considered sufficient (intraclass correlation coefficient 0.64-0.94), with small reported standard error of the mean values (5.3-39.2 kPa). Results of validity and responsiveness could not be synthesized due to heterogeneity. Risk of bias for reliability and measurement error was assessed as very good or adequate, whereas validity and responsiveness were doubtful or inadequate. Overall quality of evidence was low or very low for all measurement properties. CONCLUSIONS: Inconsistent results and low quality evidence provide little confidence in the overall measurement properties of PPDT in a hand or wrist injury population. No criterion standard for pain further highlights complexities around pain measurement such that the results obtained from PPDT measures in clinical practice cannot be compared to a gold standard measure.

How does computed tomography inform our understanding of shoulder kinematics? A structured review.

The objective of this structured review was to review how computed tomography (CT) scanning has been used to measure the kinematics of the shoulder. A literature search was conducted using Evidence-based Medicine Reviews (Embase) and PubMed. In total, 29 articles were included in the data extraction process. Forty percent of the studies evaluated healthy participants' shoulder kinematics. The glenohumeral joint was the most studied, followed by the scapulothoracic, acromioclavicular, and sternoclavicular joints. Three-dimensional computed tomography (3DCT) and 3DCT with biplane fluoroscopy are the two primary imaging techniques that have been used to measure shoulder joints' motion under different conditions. Finally, many discrepancies in the reporting of the examined motions were found. Different authors used different perspectives and planes to report similar motions, which results in confusion and misunderstanding of the actual examined motion. The use of 3DCT has been widely used in the examination of shoulder kinematics in a variety of populations with varying methods employed. Future work is needed to extend these methodologies to include more diverse populations, to examine the shoulder complex as a whole, and to standardize their reporting of motion examined to make study to study comparisons possible.

Are people good prognosticators of their own pain? An exploration of the relationship between sex-specific pain beliefs and clinical pain evaluation.

BACKGROUND: Under-explored to date are the interacting influences of patient sex on multi-modal evaluation techniques that tap different domains of the pain experience. OBJECTIVES: The primary aim of Study 1 was to explore the accuracy of sex-specific personal pain beliefs in relation to quantitative pain indicators within sexes, and the secondary objective was to compare the accuracy of sex-specific personal pain beliefs in relation to quantitative pain indicators between sexes. The primary objective of Study 2 was to explore the accuracy of sex-specific personal pain beliefs and self-rated pain severity within sexes, and the secondary objective was to compare sex-specific personal pain beliefs and pain severity ratings between sexes. METHODS: A cross-sectional analysis on two datasets was performed (Study 1, n = 50; Study 2, n = 111). For both studies, independent samples t-tests were used to identify differences in clinical pain evaluations based on sex-specific pain beliefs. Receiver Operating Characteristic (ROC) curves were used to compare the predictive accuracy of males and females clinical pain evaluations based on their ability to handle pain. RESULTS: There were no statistically significant differences in clinical pain evaluations based on self-rated pain beliefs in either study. In Study 2, males were descriptively more accurate predictors of their clinical pain evaluations than were females, though none of the between sex comparisons were statistically significant. CONCLUSION: This work highlights the importance of considering all available clinical pain evaluations as one technique is unlikely to represent the patients pain experience.

Comparison of finger kinematics between patients with hand osteoarthritis and healthy participants with and without joint protection programs.

STUDY DESIGN: This is a cross-sectional, clinical observational study. BACKGROUND: Finger range of motion (ROM) and functional performance are critical in many daily activities. Hand osteoarthritis (H-OA) is a prevalent disease that impairs both variables. Little quantitative research has been performed on finger kinematics during activities of daily living (ADLs) across health status and method of performance (with or without joint protection programs). PURPOSE: The purpose of this research is to examine the effects of H-OA and method of performance on ROM in the thumb, index, and middle digits (flexion/extension and abduction/adduction) during ADLs. METHODS: This study was conducted using 10 healthy participants (mean age: 28 years) and nine participants with H-OA (mean age: 72 years). All participants performed baseline ROM movements followed by 9 activities of daily living. These activities involved prehension type grasps and were performed with and without the recommended joint protection procedures specific to each task. Thumb IP and MCP, index distal interphalengeal (DIP) and proximal interphalengeal (PIP), and middle DIP and PIP joints were continuously recorded using an electromagnetic tracking system for ROM analysis. RESULTS: Participants with H-OA had a statistically significant decrease in ROM when comparing values measured in the healthy cohort during active ROM (25° decrease) and ADL ROM (25° decrease) in the flex/ext direction. Similarly, following joint protection instruction, a statistically significant decrease in ROM was found during tasks in the flex/ext direction (healthy participant decrease in ROM: 17°, H-OA decrease in ROM:10°) CONCLUSIONS: This study demonstrated that people with hand arthritis move through a smaller arc of motion when performing some functional tasks as compared with the controls, and that with instruction on joint protection techniques, participants made significant changes in the amount of movement used to perform tasks, which supports a proof of principle of joint protection.

Four-Dimensional Computed Tomography to measure distal radial-ulnar and radio-carpal joint congruency following distal radius fractures.

Four-dimensional computed tomography (4DCT) allows for the assessment of the wrist contact mechanics and kinematics during motion. The purpose of this study was to employ 4DCT to measure the differences in joint surface area (JSA) (3D joint space) at the radioscaphoid, radiolunate, and distal radioulnar joints between a cohort of participants with a distal radius fracture (DRF) and an age-matched cohort of healthy participants. Our results indicated that following a DRF, there was a 20% decrease in JSA at the DRUJ when compared to the healthy (control) cohort. This study demonstrated the use of a non-invasive tool to examine wrist contact mechanics.

Joint Protection Programmes for People with Osteoarthritis and Rheumatoid Arthritis of the Hand: An Overview of Systematic Reviews.

Purpose: Joint protection has been introduced as a self-management strategy for people with rheumatoid arthritis (RA) and osteoarthritis (OA) of the hand. The purpose of this study was to conduct an overview of systematic reviews (SRs) and critically appraise the evidence to establish the current effectiveness of joint protection for people with hand RA and OA. Method: A comprehensive search was conducted of six databases from January 2008 to May 2018. SRs that evaluated the effectiveness of joint protection for people with hand arthritis were eligible for inclusion. The A MeaSurement Tool to Assess systematic Reviews (AMSTAR) 2 checklist was used to assess the methodological quality of each SR. Results: Nine SRs were included: two were rated as high quality, and seven were rated as low quality. Seven of the nine did not take into account risk of bias when interpreting or discussing their findings, six did not assess publication bias, and five did not register their protocol. The high-quality reviews found no clinically important benefit of joint protection for pain, hand function, and grip strength levels. The low-quality reviews reported improvements in function, pain, grip strength, fatigue, depression, self-efficacy, joint protection behaviours, and disease symptoms in people with RA. Conclusions: High-quality evidence from high-quality reviews found a lack of any clinically important benefit of joint protection programmes for pain, hand function, and grip strength outcomes, whereas low-quality evidence from low-quality reviews found improvements in these outcomes.

Objectif : la protection articulaire est présentée comme une stratégie d'autogestion pour les personnes atteintes d'arthrite rhumatoïde (AR) et d'arthrose de la main. La présente étude visait à survoler les analyses systématiques (AS) et à procéder à une évaluation critique des données probantes afin d'établir l'efficacité actuelle de la protection articulaire pour les personnes ayant une AR et une arthrose de la main. Méthodologie : les chercheurs ont procédé à une recherche exhaustive de six basses de données entre janvier 2008 et mai 2018. Ils ont extrait les AS qui évaluaient l'efficacité de la protection articulaire des personnes atteintes d'arthrite de la main. Ils ont ensuite utilisé la liste AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews) pour évaluer la qualité méthodologique de chaque AS. Résultats : neuf AS ont été incluses : deux ont été classées comme de haute qualité et sept, de faible qualité. Sept des neuf ne tenaient pas compte du risque de biais au moment d'interpréter ou de présenter les résultats, six n'ont pas évalué les biais de publication et cinq n'ont pas enregistré leur protocole. Les analyses de qualité n'ont constaté aucun avantage d'importance clinique à la protection articulaire pour atténuer la douleur et préserver la fonction de la main et la force de préhension. Les analyses de basse qualité rendaient compte d'améliorations à la fonction, à la douleur, à la force de préhension, à la fatigue, à la dépression, à l'autoefficacité, aux comportements de protection articulaire et aux symptômes de maladie chez les personnes ayant une AR. Conclusions : selon les données de qualité d'analyses de qualité, les programmes de protection articulaire n'apportaient pas d'avantages importants sur le plan clinique en matière de douleur, de fonction de la main et de force de préhension, mais les données de faible qualité provenant d'analyses de faible qualité constataient des améliorations à l'égard de tous ces résultats.

The Effect of Distal Radius Fractures on 3-Dimensional Joint Congruency.

PURPOSE: Whereas the goal of distal radius fracture treatment is anatomical restoration, controversy exists as to whether it is the severity of the disruption of joint alignment at the time of fracture or residual malalignment after healing that determines outcome. The objective of this study was to compare joint contact mechanics bilaterally a minimum of 3 years following a distal radius fracture. Our hypothesis was that 3-dimensional joint space would be reduced in individuals following wrist fracture and that these changes in joint load lead to the development of degenerative arthritis. To test the hypothesis, an interbone spacing algorithm was used to determine whether 3-dimensional joint space and contact mechanics were altered in the distal radioulnar (DRUJ) and radiocarpal joints following a wrist fracture. METHODS: In 16 subjects with previous unilateral wrist fractures, 3-dimensional interbone distance (joint space), a measure of joint congruency and 3-dimensional alignment, was quantified from reconstructed computed tomography bone models of the distal radius, ulna, scaphoid, and lunate. RESULTS: At an average of 8 years following fracture, joint interbone spacing area was reduced in the radiolunate joint of the injured wrist in comparison with the uninjured wrist. The joint interbone spacing area was decreased in the DRUJ and radioscaphoid joint of the injured wrist compared with the uninjured wrist but this difference was not statistically significant. CONCLUSIONS: This study demonstrates the use of a noninvasive tool that can be used to examine joint loading and suggests that further investigation into the association between altered joint loading and the development of posttraumatic arthritis is needed, especially in the radiocarpal joints. CLINICAL RELEVANCE: This paper provides a noninvasive image-based framework that can be used to examine joint contact area over time and provides preliminary data examining the effect of a distal radius fracture on the joint congruency of the DRUJ and radiocarpal joints.

Evaluation of the content validity index of the Australian/Canadian osteoarthritis hand index, the patient-rated wrist/hand evaluation and the thumb disability exam in people with hand arthritis.

BACKGROUND: The Australian/Canadian Osteoarthritis Hand Index (AUSCAN), the Patient-Rated Wrist/Hand Evaluation (PRWHE) and the Thumb Disability Exam (TDX) are patient-reported outcome measures (PROM) designed to assess pain and hand function in patients with hand arthritis, hand pain and disability, or thumb pathology respectively. This study evaluated the content validity of AUSCAN, PRWHE and TDX in people with hand arthritis. METHODS: This study enrolled participants with hand arthritis to rate the items of all 3 PROM in terms of relevance and clarity. The Content Validity Index (CVI) was computed for each item in each scale (I-CVI) as well as for the overall scale (S-CVI). Kappa was used to determine the inter-rater agreement among the raters. RESULTS: Overall, 64 individuals with hand arthritis (27% with OA, 67% with rheumatoid arthritis and 6% with psoriatic arthritis) participated in the study. The I-CVI for all items and all scales were very high (I-CVI > 0.76) and the modified Kappa agreement among the raters demonstrated excellent agreement (k > 0.76). The S-CVI for all PROMs was very high for relevance (AUSCAN = 0.92, 95% CI 0.90 to 0.94; PRWHE = 0.85, 95% CI 0.82 to 0.88 and TDX = 0.87, 95% CI 0.85 to 0.89) and for clarity (AUSCAN = 0.99, 95% CI 0.98 to 1.00; PRWHE = 0.95, 95% CI 0.93 to 0.97 and TDX = 0.91, 95% CI 0.89 to 0.94), respectively. CONCLUSIONS: This study demonstrated very high content validity indices for the AUSCAN, PRWHE and TDX; with strong consensus across raters. This augments prior studies demonstrating appropriate statistical measurement properties, to provide confidence that all three measures assess important patient concepts of pain and disability.

Analysis of Three-Dimensional Anatomical Variance and Fit of the Distal Radius to Current Volar Locking Plate Designs.

Purpose: Distal radius fractures are the most common upper-extremity fracture and are increasingly being treated surgically with precontoured volar locking plates. It is not currently known whether existing implant designs are anatomically accurate and whether this has clinical implications. The objective of this study was to determine whether anatomic alignment of the distal radius corresponds accurately to modern volar locking plate designs, including any sex-linked differences in morphology of the distal radius. It was hypothesized that the 2 plates examined would show differences in watershed line (WSL) overlap and that female specimens would have a larger overlap compared with males owing to a decrease in plate-WSL border distances. Methods: We used 3-dimensional models of 20 cadaver arms (10 female: mean age, 88.7 ± 4.6 years [range, 82-97 years]; and 10 male: mean age, 86 ± 3.6 years [range, 81-91 years]) to create 3-dimensional computed tomography models of the distal radius. Virtual models of 2 common volar plates were created and were used to place the plate virtually onto the distal radii. Outcome measures included the volar cortical angle of the bone and plate, the definition of the WSL subsequently followed by quantitative distance and overlap measures, and percent contact between the plate and the distal radius. Results: Both sexes showed an decrease (approximately 7°) in average volar cortical angle measure from medial to lateral columns that was statistically significantly smaller on the lateral column (males: 38°; females: 29°) compared with the medial column (males: 45°; females: 36°). Watershed line overlap ranged from 0% to 34.8% with statistically significant differences between sexes. Average border distance for females was 2.7 mm, compared with 3.8 mm for males. Maximum percent contact of 22.0% was observed at a 0.3-mm threshold. Conclusions: Distal radius fractures are common in elderly female patients, yet clinically available plates have important differences in WSL overlap between sexes, and with minimal contact. Female specimens had more WSL overlap than did males. This indicates the need for volar locking plates to be redesigned to factor in anatomical features of individual patients with a particular focus on sex differences. Clinical relevance: New plate designs should focus on providing smaller head sizes that are more accurately tailored to the natural contours of the volar distal radius. It is recommended that future studies incorporate expertise from multiple surgeons to diversify and further understand plate placement strategies.

Comparison of the Short-Term and Long-Term Effects of Surgery and Nonsurgical Intervention in Treating Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis.

Background: The objective of the study is to examine the short-term and long-term efficacy of surgical treatment of carpal tunnel syndrome (CTS) compared with conservative treatment (ie, splint, steroid injection, or physical therapy). Methods: Two reviewers searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and PEDro up to September 2017. Quality appraisal and data extraction were performed in duplicate. Patient self-reported functional and symptom changes, as well as improvement of electrophysiological studies, were assessed as outcomes. Meta-analyses were performed in RevMan. Results: From 1438 studies identified after searching, 10 remained for analysis after exclusion criteria were applied. Moderate-quality evidence indicated that surgical interventions were superior to splint or steroid injection at 6 months with a weighted mean difference of 0.25 (95% confidence interval [CI], 0.07-0.44) for functional status and 0.64 (95% CI, 0.07-1.21) for symptom severity. The surgical group had better nerve conduction outcomes at 6 months (0.57 [95% CI, 0.05-0.50] ms). No significant differences were observed at 3 or 12 months. Conclusions: Both surgical and conservative interventions provide treatment benefits in CTS. Further studies on long-term outcome are needed.

The effectiveness of joint-protection programs on pain, hand function, and grip strength levels in patients with hand arthritis: A systematic review and meta-analysis.

STUDY DESIGN: Systematic review with meta-analysis. INTRODUCTION: Joint protection (JP) has been developed as a self-management intervention to assist people with hand arthritis to improve occupational performance and minimize joint deterioration over time. PURPOSE OF THE STUDY: We examined the effectiveness between JP and usual care/control on pain, hand function, and grip strength levels for people with hand osteoarthritis and rheumatoid arthritis. METHODS: A search was performed in 5 databases from January 1990 to February 2017. Two independent assessors applied Cochrane's risk of bias tool, and a Grading of Recommendations Assessement, Development and Evaluation (GRADE) approach was adopted. RESULTS: For pain levels at short term, we found similar effects between JP and control standardized mean difference (SMD; -0.00, 95% confidence interval [CI]: -0.42 to 0.42, I2 = 49%), and at midterm and long-term follow-up, JP was favored over usual care SMD (-0.32, 95% CI: -0.53 to -0.11, I2 = 0) and SMD (-0.27, 95% CI: -0.41 to -0.12, I2 = 9%), respectively. For function levels at midterm and long-term follow-up, JP was favored over usual care SMD (-0.49, 95% CI: -0.75 to -0.22, I2 = 34%) and SMD (-0.31, 95% CI: -0.50 to -0.11, I2 = 56%), respectively. For grip strength levels, at long term, JP was inferior over usual care mean difference (0.93, 95% CI: -0.74 to 2.61, I2 = 0%). CONCLUSIONS: Evidence of very low to low quality indicates that the effects of JP programs compared with usual care/control on pain and hand function are too small to be clinically important at short-, intermediate-, and long-term follow-ups for people with hand arthritis.

The Effect of Dorsally Angulated Distal Radius Deformities on Carpal Kinematics: An In Vitro Biomechanical Study.

PURPOSE: The purpose was to quantify the effect of distal radius dorsal angulation (DA) on carpal kinematics and the relative roles of the radiocarpal and midcarpal joints during wrist motion. METHODS: Six cadaveric specimens (69 ± 17 y) were mounted at 90° elbow flexion in a custom wrist motion simulator. The wrist was guided through planar passive flexion and extension motion trials (∼ 5°/s). A custom modular distal radius implant was used to simulate native alignment and 3 distal radius DA deformities (10°, 20°, 30°). An optical tracking system captured carpal bone motion, from which radiocarpal and midcarpal joint motion was determined. RESULTS: The radiocarpal joint made a greater contribution to wrist motion than the midcarpal joint in flexion, and the midcarpal joint made a greater contribution to motion than the radiocarpal joint in wrist extension. Increasing DA caused the radiocarpal joint contribution to increase throughout the motion arc, with the effect being more pronounced in wrist flexion. Conversely, as DA increased, the midcarpal joint contributed less rotation to the total wrist motion and its overall motion arc decreased; the magnitude of effect was greater in wrist extension. Dorsal angulation resulted in increased lunate flexion with respect to the distal radius. CONCLUSIONS: Our findings agree with current literature that suggests that, in an uninjured wrist, the radiocarpal joint predominates flexion, and the midcarpal joint predominates extension. In addition, the radiocarpal joint has an amplified contribution in wrist flexion with greater DA malunion. CLINICAL RELEVANCE: The altered contributions of the radiocarpal and midcarpal joints may contribute to pain, stiffness, and the development of arthritis, which is commonly seen at the radiocarpal joint after malunion of the distal radius.

Do Impairments Predict Hand Dexterity After Distal Radius Fractures? A 6-Month Prospective Cohort Study.

BACKGROUND: The relationship of routinely measured grip and motion measures may be related to hand dexterity. This has not yet been thoroughly examined following a distal radius fracture (DRF). The purpose of this study was to investigate if impairments in range of motion (ROM) and grip strength predict hand dexterity 6 months following a DRF. METHODS: Patients with DRFs were recruited from a specialized hand clinic. Hand grip was assessed with a J-Tech dynamometer; ROM was measured using standard landmarks and a manual goniometer. Multiple regression analyses were performed to identify whether potential predictors (grip, ROM, age, hand dominance, and sex) were associated with 3-month or 6-month outcomes in large- and small-object subtests of the NK dexterity test in the affected hand. RESULTS: Age, sex, and arc motion for radial-ulnar deviation were significant predictors of large-object hand dexterity explaining the 23% of the variation. For small-object hand dexterity, age and flexion-extension arc motion were significant predictors explaining 11% of the variation at 3 month after the fracture (n = 391). At 6 months post injury (n = 319), grip strength, arc motion for flexion-extension, and age were found to be significant predictors of large-object dexterity explaining 34% of the variance. For the small objects, age, grip strength, sex, and arc motion of radial-ulnar deviation explained 25% of the variation. CONCLUSIONS: Although this confirms that the impairments in ROM and grip that occur after a DRF can explain almost one-third of the variation in hand dexterity, it also suggests the need for dexterity testing to provide more accurate assessment.

Recovery, age, and gender effects on hand dexterity after a distal radius fracture. A 1-year prospective cohort study.

STUDY DESIGN: A prospective cohort study. INTRODUCTION: Physical factors that predict hand dexterity and the recovery of hand dexterity after a distal radius fracture (DRF) have not yet been examined. PURPOSE OF THE STUDY: The first objective was to evaluate the recovery of hand dexterity comparing the injured and uninjured hands during the year after a DRF. The second objective was to determine the effect of age and sex on hand dexterity of the injured hand. METHODS: Hand dexterity was examined bilaterally for the manipulation of 3 different sized objects (small, medium, and large) using the NK hand dexterity test. The measurements took place at 3, 6, and 12 months after DRF. Generalized linear modeling was performed, with age and sex as covariates, to assess changes over time, and between sides. RESULTS: Overall, 242 patients with DRF (45 males and 197 females) with a mean age of 60.2 years with SD of 11.26, participated in the study. Statistical differences in hand dexterity were found between the injured and uninjured hands across all time intervals (P < .001). The effect size for the deficit between the injured and uninjured hands decreased across the time intervals and ranged from 0.19 to 0.38 for large objects, from 0.17 to 0.25 for medium objects, and from 0.11 to 0.32 for small objects. For each 1-year increase in age, hand dexterity scores were 0.3-0.4 seconds slower. Sex had much less effect, with annual increases of 0.1 seconds in hand dexterity scores. CONCLUSIONS: Scores on the NK dexterity test improved between 3 and 6 months and then worsened between 6 and 12 months; at no point did dexterity equal the uninjured side. Greater attention to measuring and treating dexterity may be needed to provide a complete recovery after DRF. Scores will be affected by age and sex. LEVEL OF EVIDENCE: Prognosis, 2a.

Design of Anatomical Population-Based and Patient-Specific Radial Head Implants.

PURPOSE: The objective of this study was to characterize the morphology of the radial head and design population-based anatomical and patient-specific radial head implants. METHODS: Computed tomography (CT) images of 50 normal cadaveric upper extremities (34 male, 16 female) were obtained using a 64-slice CT scanner. Surface models were ellipse-fitted and characterized. Using an intersurface distance mapping approach, the surface geometry of the population-based anatomical design (PB-An), 3 distinct patient-specific designs, and an existing axisymmetrical implant (Com-Axi) were compared with the native radial head and the overall surface mismatch was measured. RESULTS: Morphological analysis indicated that the diameters of the outer and rim ellipses were correlated. The mean mismatch for the existing commercially available axisymmetrical implants was 0.5 ± 0.1 mm.The PB-An implants showed significantly reduced surface mismatch (0.4 ± 0.2 mm). The PS-An implant using 82 parameters in its design (0.1 ± 0.0 mm), had the lowest mean surface mismatch of any of the implants investigated. CONCLUSIONS: The mean surface mismatch of radial head implants may be reduced using reverse engineering techniques to determine the required parameters for both population-based and patient-specific implant designs. Whether there is a significant clinical advantage of a more anatomically shaped radial head implant requires additional study. More anatomical implant shapes rely on a surgical technique to accurately position these implants during surgery. It is unclear if this can be achieved clinically using conventional techniques or whether computer-assisted surgery will be required to realize the potential advantages of a more anatomical implant. CLINICAL RELEVANCE: This study characterized the morphology of the radial head with implications for population-based anatomical implants and patient-specific implants. The overall design of each implant was quantitatively compared with the native radial head. This study has implications for the design of patient-specific/anatomical implants and compares their use with commercially available generic implants.

Effect of Radial Head Implant Shape on Radiocapitellar Joint Congruency.

PURPOSE: Radial head arthroplasty is indicated in displaced fractures in which comminution precludes successful internal fixation. Many types of radial head implants have been developed varying in material, methods of fixation, and degrees of modularity and geometry. The purpose of this study was to investigate the effect of radial head implant shape on radiocapitellar joint congruency. METHODS: Joint congruency was quantified in 7 cadaveric specimens employing a registration and inter-surface distance algorithm and 3-dimensional models obtained using computed tomography. Forearm rotation was simulated after computer-guided implantation of an axisymmetric radial head, a population-based quasi-anatomic radial head implant, and a reverse-engineered anatomic radial head implant. Inter-surface distances were measured to investigate the relative position of the radial head implant and displayed on 3-dimensional color-contour maps. Surface area was measured for inter-surface distances (1.5 mm) and compared for each radial head geometry. RESULTS: There were no statistical differences in the contact surface area between radial head implants during active or passive forearm rotation. The joint was more congruent (larger contact surface area) during active forearm rotation compared with passive forearm rotation. CONCLUSIONS: This study investigated the effect of implant geometry on the radiocapitellar joint contact mechanics by examining a commercially available radial head system (axisymmetric), a quasi-anatomic design, and an anatomic reverse-engineered radial head implant. We found no statistical differences in radiocapitellar joint contact mechanics as measured by 3-dimensional joint congruency in cadaveric specimens undergoing continuous simulated forearm rotation. CLINICAL RELEVANCE: The importance of choosing an implant that matches the general size of the native radial head is recognized, but the degree to which it is necessary to create an implant that replicates the native anatomy to restore elbow stability and prevent cartilage degenerative changes remains unclear. This study concluded that the geometry of the implant did not have a statistically significant effect on joint contact mechanics; therefore, future work is needed to examine additional factors related to implant design, such as material choice and implant positioning to investigate their influence on joint contact mechanics.

Impact of Radius Malunion on Wrist Contact Mechanics.

The patient was a 15-year-old adolescent girl with a chief complaint of intermittent pain and clicking at her right distal radioulnar joint, after having fractured her forearm 5 months previously. Radiographs of the patient's forearm indicated a midshaft radial deformity. Given the patient's pain and limited range of motion, computed tomography imaging was requested to assess whether the midshaft malunion resulted in distal radioulnar joint instability and to plan the corrective osteotomy. J Orthop Sports Phys Ther 2016;46(5):399. doi:10.2519/jospt.2016.0406.

A structured review addressing the use of radiographic measures of alignment and the definition of acceptability in patients with distal radius fractures.

BACKGROUND: Standard radiographs are routinely used in clinical care to characterize the severity of a distal radius fracture and to monitor patients following a distal radius fracture. The objective of this review was to describe the range and variability of radiographic measures described in the literature in patients following a distal radius fracture. METHODS: A structured literature review was conducted using the Embase and PubMed databases. Inclusion criteria included full-text publications which employed radiographic measures to examine 100 or more participants following a distal radius fracture. A standardized data extraction form was used to identify study design, fracture classification systems, the types of and definitions of radiographic measurements, and acceptability criteria following distal radius fractures. RESULTS: From an initial 263 studies, 31 studies were included in the final data extraction process. A narrative synthesis of the articles included in this review indicated that there was a set of commonly used radiographic measurements examined in patients with a distal radius fracture which included radial inclination, volar/dorsal tilt, intra-articular step/gap, and a measure of ulnar variance/radial shortening. While 52 % of studies referenced or published a standardized measurement technique, there was substantial variability in the actual description of each radiographic measurement performed. CONCLUSIONS: Substantial variability in how radiographic measurements are defined in large clinical studies as seen in this review suggest a need for consensus on the assessment and interpretations of radiographic measures used in patients following a distal radius fracture. Guidelines for radiographic measures should be established to ensure consistency between research and treatment centers.

Evaluation of an Image-Based Tool to Examine the Effect of Fracture Alignment and Joint Congruency on Outcomes after Wrist Fracture.

Some mal-alignment of the wrist occurs in up to 71% of patients following a distal radius fracture. A multiple case study was used to provide proof of principle of an image-based technique to investigate the evolution and impact of post-traumatic joint changes at the distal radioulnar joint. Participants who had a unilateral distal radius fracture who previously participated in a prospective study were recruited from a single tertiary hand center. Long term follow-up measures of pain, disability, range of motion and radiographic alignment were obtained and compared to joint congruency measures. The inter-bone distance, a measure of joint congruency was quantified from reconstructed CT bone models of the distal radius and ulna and the clinical outcome was quantified using the patient rated wrist evaluation. In all four cases, acceptable post-reduction alignment and minimal pain/disability at 1-year suggested good clinical outcomes. However, 10 years following injury, 3 out of 4 patients had radiographic signs of degenerative changes occurring in their injured wrist (distal radioulnar joint/radio-carpal joint). Proximity maps displaying inter-bone distances showed asymmetrical congruency between wrists in these three patients. The 10-year PRWE (patient rated wrist evaluation) varied from 4 to 60, with 3 reporting minimal pain/disability and one experiencing high pain/disability. These illustrative cases demonstrate long-term joint damage post-fracture is common and occurs despite positive short-term clinical outcomes. Imaging and functional outcomes are not necessarily correlated. A novel congruency measure provides an indicator of the overall impact of joint mal-alignment that can be used to determine predictors of post-traumatic arthritis and is viable for clinical or large cohort studies.

Accuracy assessment of 3D bone reconstructions using CT: an intro comparison.

Computed tomography provides high contrast imaging of the joint anatomy and is used routinely to reconstruct 3D models of the osseous and cartilage geometry (CT arthrography) for use in the design of orthopedic implants, for computer assisted surgeries and computational dynamic and structural analysis. The objective of this study was to assess the accuracy of bone and cartilage surface model reconstructions by comparing reconstructed geometries with bone digitizations obtained using an optical tracking system. Bone surface digitizations obtained in this study determined the ground truth measure for the underlying geometry. We evaluated the use of a commercially available reconstruction technique using clinical CT scanning protocols using the elbow joint as an example of a surface with complex geometry. To assess the accuracies of the reconstructed models (8 fresh frozen cadaveric specimens) against the ground truth bony digitization-as defined by this study-proximity mapping was used to calculate residual error. The overall mean error was less than 0.4 mm in the cortical region and 0.3 mm in the subchondral region of the bone. Similarly creating 3D cartilage surface models from CT scans using air contrast had a mean error of less than 0.3 mm. Results from this study indicate that clinical CT scanning protocols and commonly used and commercially available reconstruction algorithms can create models which accurately represent the true geometry.