Alice S. Ha

Update on Talar Fracture Patterns: A Large Level I Trauma Center Study

OBJECTIVE Prior studies of talar fracture patterns are dated and based on radiography only. The purpose of our study was to describe talar fracture patterns and associated injuries in a modern large level 1 trauma center setting using both radiography and CT. MATERIALS AND METHODS The radiolog and clinical data of patients with acute talar fractures diagnosed over an 18-month period were retrospectively reviewed. Data analysis included descriptive statistics for injury mechanisms and associated injuries. RESULTS Over the study period, a total of 132 talar fractures were detected in 122 patients. The most common talar fracture location was the body (61%). The most common body fractures were dome compression (26%), lateral process (24%), and posterior tubercle (21%). Of the 132 fractures, 62% were comminuted and 21 (16%) were vertical neck fractures compatible with the Hawkins-Canale classification. Both radiography and CT were used in 91% of cases, with CT providing additional information in 112 (93%) cases. By use of CT as the reference standard, the sensitivity of radiography for detecting talar fractures was 74%. The most common fracture missed by radiography was talar dome compression (31% not seen on radiography) Talar fractures were associated with adjacent joint subluxation or dislocation in more than 66% of the cases and adjacent fracture in more than 72% of the cases. CONCLUSION In our study, the most common site of talar fracture was the body. Current classification systems do not apply to most talar fractures. Talar fracture patterns cannot be characterized with radiography alone. CT is a critical tool for the detection and characterization of talar fractures. There is a high incidence of adjacent fracture and dislocation with acute traumatic talar fractures.

Digital Tomosynthesis to Evaluate Fracture Healing: Prospective Comparison With Radiography and CT

OBJECTIVE Radiography, currently the standard for postoperative fracture imaging, is limited by overlapping bone and hardware. Tomosynthesis has the benefit of level-by-level imaging without the disadvantages of metal artifacts, increased radiation, and higher costs of CT, the current problem-solving tool. The purpose of this study was to compare tomosynthesis with radiography for evaluating fracture healing. SUBJECTS AND METHODS In a prospective study, patients within 1 year of wrist hardware fixation underwent radiography, tomosynthesis, and CT, and the images were interpreted by three readers. The diagnostic accuracy of radiology and tomosynthesis was assessed with ROC curves, and interreader agreement was assessed with Cohen kappa. Fracture scores were correlated with Disabilities of the Arm, Shoulder, and Hand (DASH) and pain scores. RESULTS The study participants were 49 patients with 51 fractures. The most common fracture sites were distal radius (43%), scaphoid (18%), and metacarpals (18%). Rates of cortex obscuration by hardware were 2% for CT, 8% for tomosynthesis, and 15% for radiography (p < 0.01 between one modality and another). Detection of cortical fracture lines was significantly better with tomosynthesis than with radiography (AUC, 0.84 vs 0.76, p = 0.01). Inter-reader agreement was moderate for both radiography and tomosynthesis (κ = 0.44 vs 0.55, p = 0.051). There was no significant correlation between fracture scores and DASH scores. There was significant correlation between reported pain levels and both tomosynthesis (r = 0.28, p = 0.03) and CT (r = 0.29, p = 0.04) fracture scores. CONCLUSION Tomosynthesis provides diagnostic information superior to that of ra diography in postoperative evaluation of wrist fractures with lower cost and radiation than CT and should be considered in fracture follow-up imaging of other bones.

Arthroplasty of the Hand: Radiographic Outcomes of Pyrolytic Carbon Proximal Interphalangeal and Metacarpophalangeal Joint Replacements

OBJECTIVE The purpose of this study was to describe the radiographic outcomes of pyrolytic carbon implants in the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints, determine the most common complications, and assess risk factors associated with complications. MATERIALS AND METHODS Retrospective review over a 10-year period was performed to identify patients with pyrolytic carbon implants of the PIP or MCP joint. All available radiographs were reviewed and correlated with clinical information. Statistical analysis included calculation of the complication rate, Phi coefficient for variable association with a complication, and Kaplan-Meier survival. RESULTS Forty-seven implants in 43 patients were reviewed. There were 30 PIP and 17 MCP implants. The mean age of the patients was 56 years. The mean radiographic follow-up was 17.2 months (range, 1-82 months). The indication for arthroplasty included osteoarthritis (55.3%), trauma (27.7%), rheumatoid arthritis (12.8%), and benign neoplasm (4.26%). Fourteen second surgeries were performed: four for retrieval and 10 for revision. Radiographic abnormalities included subsidence (31.9%); loosening with dorsal or volar tilt of the stem (34.1%); loosening without tilt (6.38%); periprosthetic fracture (8.51%); and ulnar subluxation of joint (4.26%). There was no statistical association (r < 0.001) between 1 mm or less of symmetric lucency around the distal implant with future complications. The sensitivity of radiography for the clinical failure of the implant was 28.6% and specificity, 30.3%. CONCLUSION Of the 47 pyrolytic carbon PIP and MCP implants, 14 (29.8%) required surgical revision or retrieval, mostly for extensor tendon contractures. Compared with the clinical survival of the implant, radiographic survival was poorer and did not correlate with clinical survival. Tilt of the proximal stem and subsidence were the more common radiographic complications.

Radial Head Arthroplasty: A Radiologic Outcome Study

OBJECTIVE The purpose of this study is to provide a radiographic outcome assessment of radial head arthroplasty in correlation with clinical outcomes and to determine whether there is an association between certain patient factors and clinical and radiographic outcomes. MATERIALS AND METHODS A 10-year retrospective review was performed to identify patients with metal radial head arthroplasty. At least two follow-up radiographs were reviewed for each patient and were correlated with clinical information. Statistical analysis included calculation of complication rates, phi coefficient for variable association with complications, and Kaplan-Meier survival. RESULTS A total of 258 radial head implants in 244 patients were reviewed. The mean patient age was 46 years, with mean follow-up time of 12.8 months. Two hundred nineteen (84.9%) implants were unipolar in design, whereas 39 implants were bipolar. The most common indication for arthroplasty was trauma (94% acute and 2% failed internal fixation). Radiographic abnormalities included nonbridging heterotopic ossification (38.0%), secondary radiocapitellar joint osteoarthritis (27.9%), loosening (19.8%), bridging heterotopic ossification (8.9%), fracture (2.3%), and hardware dislocation (2.7%). Overall, there were 62 second surgeries for either revision or removal. Reasons for second surgery included heterotopic ossification (53.2%), synovectomy or capsulectomy (43.5%), and infection (3.2%). There was a statistically significant association between radiographic complications and the presence of patient symptoms (p < 0.05). There was no association between radiographic or clinical complications with age, sex, side, or type of arthroplasty (R < 0.001). CONCLUSION There is a positive association between radiographic findings and patient symptoms for postoperative complications after radial head arthroplasty. By 9 months, 50% of implants showed radiographic complications.

Imaging of Adverse Reactions to Metal Debris

Hip replacements with metal-on-metal components can cause a spectrum of adverse tissue reactions-from benign localized fibrosis and chronic inflammation to delayed hypersensitivity response. In addition to history, physical examination, and relevant laboratory data, imaging plays a critical role in the evaluation of hip arthroplasties. Imaging assessment begins with radiographs and may be followed by ultrasound, computed tomography, or MRI. MRI optimized for metal artifact reduction is the most sensitive and specific imaging modality and is essential in assessing the spectrum of metal-related adverse tissue reactions. In this article, we discuss the history, pathophysiology, and imaging findings of adverse reactions to metal debris.

Current Concepts of Shoulder Arthroplasty for Radiologists: Part 1???Epidemiology, History, Preoperative Imaging, and Hemiarthroplasty

OBJECTIVE The purpose of this article is to provide a review of indications for shoulder arthroplasty, describe preoperative imaging assessment, present new and modified designs of shoulder arthroplasty, illustrate normal and abnormal postoperative imaging findings, and review key radiographic measurements. CONCLUSION Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing shoulder prostheses.

Fracture of the distal radius: epidemiology and premanagement radiographic characterization.

OBJECTIVE Fractures of the distal radius are common and frequently encountered by the radiologist. We review the epidemiology, classification, as well as the concept of instability. Salient qualitative and quantitative features of the distal radius fracture identifiable on the routine radiography series are highlighted. We conclude with a synopsis of descriptors that are of greatest utility to the clinician for treatment planning and that should be addressed in the radiology report. CONCLUSION A detailed understanding of the intricacies of the distal radius fracture is necessary for the radiologist to provide a clinically relevant description.

Current Concepts of Shoulder Arthroplasty for Radiologists: Part 2???Anatomic and Reverse Total Shoulder Replacement and Nonprosthetic Resurfacing

OBJECTIVE The purpose of this article is to provide a review of the indications for shoulder arthroplasty, describe preoperative imaging assessment, present new and modified designs of shoulder arthroplasty, illustrate normal and abnormal postoperative imaging findings, and review key radiographic measurements. CONCLUSION Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing shoulder prostheses.

Acromioclavicular joint: the other joint in the shoulder.

OBJECTIVE The purpose of this article is to provide a review of acromioclavicular joint anatomy, describe common pathologies at the joint, and present normal and abnormal postoperative imaging findings after surgical treatments. CONCLUSION Knowledge of anatomy with related pathologies, orthopedic trends, imaging findings, and complications, is important in assessing the acromioclavicular joint.

Radiographic pitfalls in lower extremity trauma.

OBJECTIVE Radiography remains the imaging standard for fracture detection after trauma. However, fractures continue to be the most common type of missed injuries. In this article, we describe common radiographic pitfalls in lower extremity trauma and describe strategies for dealing with them. CONCLUSION Pitfalls include insufficient views, improperly positioned or technically imperfect radiographs, nondisplaced fractures, commonly missed locations, small avulsions portending large injury, sesamoid injuries, satisfaction of search, incomplete or faulty reasoning, and periprosthetic fractures.