Pectus excavatum with delayed diagnosis of implant tear on MRI apparently causing recurrent postoperative seromas: A case report.

Seroma formation is the most common early postoperative complication after pectus excavatum repair, but later seromas are rare. While many seromas eventually resorb or decrease in size after aspiration, our case demonstrates recurrent seroma formation as a late complication of pectus excavatum repair in a patient with an implant tear. Postoperative seromas can result in prolonged chest wall pain, large chest wall masses, and increased mass effect on the heart with potential risk for resultant right ventricular outflow obstruction. This case report illustrates a solid silicone implant tear. Though rare, early recognition may help to decrease the likelihood of recurrent postoperative seromas.

Use of multi-detector computed tomography for the detection of periprosthetic osteolysis in total knee arthroplasty.

This study determined the accuracy of plain radiography in detecting osteolytic lesions around total knee prostheses compared to multi-detector computed tomography (CT). Thirty-one patients diagnosed with periprosthetic osteolysis by multi-detector CT after total knee arthroplasty (TKA) were studied. Computed tomography for each patient was retrospectively reviewed in a blinded fashion. The plain radiographs for each patient that had been obtained prior to CT were reviewed in the same manner. The results of the CT were compared with the results of the radiographs. The number, size, and location of the lesions were compared. The multi-detector CT detected 48 lesions in 31 knees: 40 tibial lesions, 4 femoral lesions, and 4 patellar lesions. Radiographic diagnosis was made in 6 of the 40 tibial lesions, 2 of the 4 femoral lesions, and 0 of the 4 patellar lesions. Plain radiographs are inadequate for evaluating periprosthetic osteolysis in TKA with only 8 (17%) of 48 lesions detected by multi-detector CT visible on the standard radiographs. Multi-detector CT provides the surgeon with a diagnostic and preoperative planning tool when osteolysis is suspected.

Complications of abdominal and pelvic procedures: computed tomographic diagnosis.

The postprocedural period is a critical time in which serious complications can manifest. Localization of suspected complications following abdominal and pelvic procedures can be difficult on clinical evaluation alone. For example, abdominal pain after a colonoscopy may vary in etiology and can result from simple colonic spasm to colonic perforation, hemoperitoneum, or even splenic rupture. Vague abdominal pain following a renal biopsy may be due to minimal postprocedural bleeding into and around the kidney or may be due to potentially life-threatening hemorrhage. In such patients, computed tomography can play a crucial role in the rapid identification of complications as well guidance of subsequent patient management. The purpose of this article is to demonstrate the benefit of computed tomography-assisted diagnosis of complications associated with routine procedures performed on or throughout the abdomen and pelvis, including cardiac catheterization, colonoscopy, endoscopy, percutaneous biopsy, and interventional radiology procedures.

Imaging of Musculoskeletal Infection.

Diagnostic imaging plays a crucial role in confirming the diagnosis of musculoskeletal (MSK) infection and determining the severity and extent of disease. The clinical diagnosis may be challenging due to the nonspecific presentation of pain and swelling. There are certain features that are pathognomonic for infection. Pre-existing conditions an make diagnosing infection difficult. Prior surgery can create artifacts on advanced imaging modalities such as computed tomography and MRI, obscuring the tissues immediately around the hardware. Recent technological advances have improved physicians' ability to diagnose MSK infection with greater sensitivity, specificity, and accuracy.

Imaging of total knee arthroplasty.

Painful total knee arthroplasty (TKA) represents a diagnostic challenge for the clinician and radiologist, as there is a wide variety of potential etiologies, with a broad range of clinical presentations, and the abnormalities on imaging studies are often subtle, absent, or nonspecific. Imaging findings of normal TKA are reviewed, in addition to a variety of complications such as loosening, infection, instability, osteolysis, heterotopic ossification, extensor mechanism disruption, and fracture. Although imaging evaluation of painful TKA is usually limited to conventional radiographs and nuclear imaging, examples of the utility of computed tomography are also illustrated, and suggested imaging strategies and algorithms are discussed.

Polyethylene post failure in posterior stabilized total knee arthroplasty.

Posterior-stabilized (PS) prostheses have been used extensively in total knee arthroplasty (TKA), with excellent long-term results. The key feature of these prostheses is the femoral cam and tibial post mechanism that limits posterior displacement and produces femoral rollback. Although articular-surface polyethylene wear of the tibial component has not been a significant clinical problem, tibial post wear has been reported. In distinction to chronic post wear, little information exists about catastrophic post failure. We present the case of a 56-year-old woman who presented 63 months after TKA with a PS prosthesis with acute fracture of the polyethylene post. The evaluation and treatment of this patient, including the previously unreported use of computed tomography arthrography to diagnose this rare problem, is reviewed.

Anatomic risk of peroneal nerve injury with the "pie crust" technique for valgus release in total knee arthroplasty.

Peroneal nerve damage can occur during total knee arthroplasty because of indirect or direct injury. The potential for direct laceration injury exists when performing the "pie crust" lateral soft-tissue release in a valgus knee. To assess this risk, the axial, magnetic resonance images of 60 adult knees were evaluated. The distance from the peroneal nerve to the tibia was measured at the level of the standard tibial resection. At this level, the lateral gastrocnemius muscle is interposed between the capsule and the nerve. The mean nerve to bone distance was 1.49 cm (0.91-2.18 cm). These results suggest that the peroneal nerve is adequately protected at the posterolateral corner of the knee but that the "pie crust" release should be performed carefully.