Total ankle arthroplasty: a radiographic outcome study.

OBJECTIVE: Total ankle arthroplasty (TAA) is becoming a popular alternative to arthrodesis for patients with end-stage ankle arthrosis. Prior outcome studies have primarily focused on surgical findings. Our purpose is to determine the radiographic outcome of TAA and to correlate it with clinical outcome. MATERIALS AND METHODS: In a 9-year retrospective review of patients with TAA, all available ankle radiographs and clinical data were reviewed. Data analysis included descriptive statistics, Fisher exact test, and Kaplan-Meier survival curves for radiographic and clinical survival. RESULTS: Two hundred sixty-two TAAs in 260 patients were reviewed; 55% were in women, and the mean patient age was 61.5 years. The mean radiographic follow-up was 142 weeks, with an average of six radiographs per patient. One hundred sixty-three patients (62.2% of TAAs) developed one or more radiographic complications, including periprosthetic lucency (34.0%), hardware subsidence (24.4%), perihardware fracture (11.1%), syndesmotic screw loosening (10.3%), and screw fracture (6.5%). One hundred nineteen patients (45.4% of TAAs) developed symptoms of ankle pain or instability, and 71 patients (27.1% of TAAs) underwent at least one reoperation. In patients with radiographic complications, 41.7% developed ankle pain and 5.1% developed ankle instability, compared with 23.7% and 2.2%, respectively, of patients with no radiologic complications (p < 0.05). Of the patients with radiographic complications, 33.1% had at least one additional surgery compared with 17.1% of patients without radiographic complications (p < 0.05). CONCLUSION: Radiographic complications are common in patients after total ankle arthroplasty. There is a strong positive association between postoperative radiographic findings and clinical outcome. Knowledge of common postoperative radiographic findings is important for the practicing radiologist.

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 features of superficial and deep fibromatoses in the adult population.

The fibromatoses are a group of benign fibroblastic proliferations that vary from benign to intermediate in biological behavior. This article will discuss imaging characteristics and patient demographics of the adult type superficial (fascial) and deep (musculoaponeurotic) fibromatoses. The imaging appearance of these lesions can be characteristic (particularly when using magnetic resonance imaging). Palmar fibromatosis demonstrates multiple nodular or band-like soft tissue masses arising from the proximal palmar aponeurosis and extending along the subcutaneous tissues of the finger in parallel to the flexor tendons. T1 and T2-weighted signal intensity can vary from low (higher collagen) to intermediate (higher cellularity), similar to the other fibromatoses. Plantar fibromatosis manifests as superficial lesions along the deep plantar aponeurosis, which typically blend with the adjacent plantar musculature. Linear tails of extension ("fascial tail sign") along the aponeurosis are frequent. Extraabdominal and abdominal wall fibromatosis often appear as a heterogeneous lesion with low signal intensity bands on all pulse sequences and linear fascial extensions ("fascial tail" sign) with MR imaging. Mesenteric fibromatosis usually demonstrates a soft tissue density on CT with radiating strands projecting into the adjacent mesenteric fat. When imaging is combined with patient demographics, a diagnosis can frequently be obtained.

Radiologic review of total elbow, radial head, and capitellar resurfacing arthroplasty.

The use of metal and pyrolytic carbon radial head implants, capitellar resurfacing, and total elbow arthroplasty has become common in contemporary orthopedic surgery practice. The goal of total elbow arthroplasty is to decrease pain and restore an acceptable range of motion to the elbow joint. Rheumatoid arthritis is the primary indication for total elbow arthroplasty; newer indications include primary or posttraumatic osteoarthritis, fracture nonunion, acute comminuted fractures of the elbow, and postoperative resection of a neoplasm. Unlike total elbow arthroplasty, radial head replacement is most commonly performed in patients with trauma. Radial head fractures account for 33% of all elbow fractures in adults and are often associated with ligament disruption and valgus instability at the elbow. The goals of capitellar resurfacing arthroplasty include prevention of secondary osteoarthritis of the radiocapitellar joint and erosion in patients with radial head arthroplasty. Effective postoperative radiologic assessment of these different types of elbow reconstructions requires an understanding of their basic component design, physiologic purpose, and normal postoperative appearance, as well as the appearance of complications. Radiologists may have little training and experience with these new orthopedic devices.

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.

Verification bias: an under-recognized source of error in assessing the efficacy of MRI of the meniscii.

RATIONALE AND OBJECTIVES: The sensitivity and specificity of magnetic resonance imaging (MRI) for diagnosis of meniscal tears has been studied extensively, with tears usually verified by surgery. However, surgically unverified cases are often not considered in these studies, leading to verification bias, which can falsely increase the sensitivity and decrease the specificity estimates. Our study suggests that such bias may be very common in the meniscal MRI literature, and illustrates techniques to detect and correct for such bias. MATERIALS AND METHODS: PubMed was searched for articles estimating sensitivity and specificity of MRI for meniscal tears. These were assessed for verification bias, deemed potentially present if a study included any patients whose MRI findings were not surgically verified. Retrospective global sensitivity analysis (GSA) was performed when possible. RESULTS: Thirty-nine of the 314 studies retrieved from PubMed specifically dealt with meniscal tears. All 39 included unverified patients, and hence, potential verification bias. Only seven articles included sufficient information to perform GSA. Of these, one showed definite verification bias, two showed no bias, and four others showed bias within certain ranges of disease prevalence. Only 9 of 39 acknowledged the possibility of verification bias. CONCLUSION: Verification bias is underrecognized and potentially common in published estimates of the sensitivity and specificity of MRI for the diagnosis of meniscal tears. When possible, it should be avoided by proper study design. If unavoidable, it should be acknowledged. Investigators should tabulate unverified as well as verified data. Finally, verification bias should be estimated; if present, corrected estimates of sensitivity and specificity should be used. Our online web-based calculator makes this process relatively easy.

Primary chordoid meningioma of the lung.

We present a case of primary chordoid meningioma of the lung in a 21-year-old patient with Diamond-Blackfan anemia. The neoplasm was incidentally discovered as a new right upper lobe mass on admission chest radiograph. Computed tomography examination showed a round mass with peripheral nodular enhancement. Pathologic diagnosis was conclusive for the rare entity of chordoid meningioma. To our knowledge, this is the first case showing the radiographic features of an extraskeletal and extracranially located chordoid meningioma.

Madura foot masquerading as a hemangioma.

Mycetoma, also known as Madura foot, is a rare soft-tissue granulomatous infection caused by Actinomyces or true fungi. The MRI "dot-in-circle" sign has been described as a characteristic finding of mycetoma. This sign represents spherical T2 bright masses containing central and intervening low-signal-intensity foci. However, other soft-tissue masses can have similar appearances. We present a case of a Madura foot that was erroneously given the imaging diagnosis of soft-tissue hemangioma due to the presence of serpiginous enhancing masses with the "dot-in-circle" sign (believed to be due to phleboliths).

Cerebellopontine angle meningioma presenting with hearing loss.

We present the case of a 48-year-old woman with a cerebellopontine angle meningioma who presented with sensorineural hearing loss. The lesion was nearly 4 cm in maximum dimension and extended into the internal auditory canal. Hearing loss resulting from cerebellopontine angle tumor is most commonly caused by vestibular schwannomas, which arise directly from the sheath of the vestibular nerve (VIII) in the internal auditory canal. Our case provides a review of magnetic resonance imaging features that aid in differentiation of enhancing cerebellopontine angle masses that can have similar clinical presentations.

Acute sensorineural hearing loss resulting from cerebellopontine angle arachnoid cyst.

We present the case of a 49-year-old woman who presented with acute, nonprogressive left sensorineural hearing loss and benign positional vertigo that was associated with an arachnoid cyst of the cerebellopontine angle. The presence of the lesion was documented by MRI examinations that were obtained 7 years apart. Arachnoid cysts at the cerebellopontine angle are usually found incidentally on MRI performed for unrelated reasons. However, if the arachnoid cyst displaces or compresses adjacent cranial nerves, symptoms may result. We review the salient imaging features of arachnoid cysts that allow their differentiation from other lesions of the cerebellopontine angle.

Tumoral calcinosis mimicking recurrent osteosarcoma.

We report a case of a tumoral calcinosis mimicking the appearance of recurrent osteosarcoma of the left femur and tibia in a 29-year-old woman with a history of osteosarcoma and chronic renal failure. Both processes can appear radiographically and histologically similar. Due to loosening of the orthopedic hardware, our patient underwent surgical revision and biopsy. We review the imaging appearances of both entities as well as the underlying mechanism of tumoral calcinosis secondary to renal disease. We also discuss how PET and CT imaging can aid in differentiation of these processes and possibly prevent surgical biopsy in other cases.