In patients with os trigonum, the posterior fibers of the PTFL were inserted herein. In the case of an os trigonum signal alterations of ligaments were more common, which may reflect chronic instability.

Background Loose bodies are one of the most frequently seen pathological processes observed in the knee joint. Just as loose bodies may settle within the knee joint cavity, they may also be localized within recesses and bursae. Purpose To determine in which anatomic localizations and at what frequencies loose bodies were located in recesses and bursae within the knee joint. It was also aimed to review the radiological anatomy of the common and unusual knee joint synovial recesses and bursae including arthroscopic blind spots on MRI. Material and Methods A total of 145 loose bodies in 104 knees evaluated by MRI were identified. The locations of loose bodies around the knee joint were divided into 11 groups and some of these groups were divided into specific subgroups on MRI. The anatomic localizations, the number, and dimensions of loose bodies were determined. Results There were 145 loose bodies and 45 patients had one, 19 patients had two, and 40 patients had three or more loose bodies in different locations. The average size of loose bodies was 9.3 mm (range = 9–23 mm). Posterior cruciate ligament recess was the most frequent location; the subpopliteal recess was the second and posterior femoral recess was the third most common location for the loose bodies. Conclusion The correct identification, the number, size, and anatomic localization of loose bodies on MRI is critical in the determination of the appropriate treatment and, thus, the development of osteoarthritis can be prevented. Loose bodies were mostly localized in the posterior, primarily in the posterior cruciate ligament recess, most were multiple and < 1 cm.

Background It is vital to know the anatomical variations of the wrist to avoid iatrogenic injuries during carpal tunnel (CT) surgery. Purpose To determine the anatomical variations of the median nerve (MN) and the prevalence of persistent median artery (PMA) on wrist magnetic resonance imaging (MRI). Material and Methods A total of 300 wrists evaluated by MRI during 2013–2015 were retrospectively identified. While branching of the MN distal to the CT is accepted as the normal anatomy, proximal to the tunnel and within the tunnel were considered as variations. The prevalence of PMA was also evaluated. The patients were assigned to groups according to age, gender, and wrist side and compared to determine whether there was any significant difference in terms of these variations. All evaluations were assessed with the shared decision of a musculoskeletal radiologist and a radiology resident. Results Of the 300 wrists, 38 (12.7%) and 34 (11.3%) had a bifid MN proximal to the CT and within the CT, respectively. Only one nerve trifurcation was seen within the CT. The MN exhibited branching distal to the CT in 227 (76%) patients. PMA was observed in 44 (14.7%) patients. Of the 44 PMA cases, 28 (63.6%) also had a coexisting MN variation. There was no significant difference in the prevalence of MN variations and PMA in the subgroups ( P > 0.05). Conclusion Nearly one in four patients (24.4%) have MN variations and 14.8% had PMA. Preoperative evaluation of these common anatomical variations with MRI will be protective against postoperative complications of CT surgery.

Osteomas are the most frequently observed benign bone tumors of paranasal sinuses. Although they are generally detected by chance during radiological analyses, they may create severe complications after intracranial extension. While computed tomography findings play a key role to differentiate osteoma from other osseous lesions of paranasal sinus, magnetic resonance imaging identifies extension to surrounding structures and possible complications. Osteoma was detected in a 28-year-old female patient who admitted with complaints of headache and difficulty in breathing. Patient was operated after diagnosis; however, we were unable to remove the mass totally due to its location and size. In this article, we report, to our knowledge, the largest defined osteoma case in the literature to date, with ethmoid sinus origin, orbital, nasal cavity and intracranial extension, accompanied with distinctive computed tomography and magnetic resonance imaging findings.

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