Diffuse idiopathic skeletal hyperostosis (DISH): Increased prevalence in Pacific Islanders.

INTRODUCTION: Diffuse idiopathic skeletal hyperostosis (DISH) is a musculoskeletal disorder in which ligaments and entheses slowly become ossified, leading to decreased mobility and pain. The prevalence is variably reported as between 3% and 25% of the population over 50. In Australasia, the prevalence and severity of DISH has long been thought by radiologists to be high in certain populations, particularly among Pacific Islanders. The purpose of this study is to investigate the prevalence and severity of DISH in a Pacific Islander community. METHODS: Chest radiographs in 459 individuals were retrospectively reviewed to assess for the presence of features consistent with DISH, as per the Resnick Criteria. Each radiograph was also assessed for the number of vertebral bodies involved. The clinical records of these patients were accessed to obtain the patient's ethnicity. RESULTS: The prevalence of DISH in our group overall was 138/459 (30%) with a prevalence of 42/96 (44%) in the Pacific Islanders. The difference compared to the Europeans in the group is highly significant (P < 0.0001). CONCLUSIONS: This study verifies the high prevalence of DISH in Pacific Islanders.

Medial Collateral Ligament Complex of the Ankle: MR Imaging Anatomy and Findings in Medial Instability.

Ankle ligament injuries are among the most common injuries in sports and recreational activities. Injuries of the medial collateral ligament or deltoid ligament complex account for ∼ 15% of ligamentous ankle trauma. They are usually associated with injuries of the lateral collateral ligaments and the tibiofibular syndesmosis, as well as malleolar fractures. The deltoid ligament complex consists of a superficial and a deep layer. The three main components of the superficial layer are the tibionavicular, tibiospring, and tibiocalcaneal ligaments. The deep layer is composed of the anterior and posterior tibiotalar ligaments; the latter is the strongest ligament of the whole complex. In approximately half of patients, injuries of the superficial layer are associated with a lesion of the posterior tibiotalar ligament (pTTL), whereas in contradistinction most injuries to the pTTL are associated with lesions of the superficial layer. The most common location of injuries to the superficial layer is at the tibial periosteal attachment with partial discontinuity, delamination, or a complete tear with or without lesions of the flexor retinaculum. Lesions of the pTTL are often midsubstance. In chronic lesions a distorted and thickened superficial layer at the tibial insertion with periosteal reaction and bony spurs is usually visible. The scarred pTTL shows loss of normal striation. In chronic stages of pTTL lesions, volume loss is typically seen. Associated periosteal spurs and intraligamentous ossicles are common. In late stages, tibiotalar valgus with osteoarthritic changes of the ankle will develop.

Spring Ligament Complex and Posterior Tibial Tendon: MR Anatomy and Findings in Acquired Adult Flatfoot Deformity.

The spring ligament complex is an important stabilizer of the medial ankle, together with the posterior tibial tendon (PTT) and the deltoid ligament complex. Lesions in these stabilizers result in acquired adult flatfoot deformity. The spring ligament complex includes three ligaments: the superomedial calcaneonavicular ligament, the medioplantar oblique calcaneonavicular ligament, and the inferoplantar longitudinal calcaneonavicular ligament. Normal MR imaging anatomy of the spring ligament complex and the PTT are described and illustrated in detail. Isolated lesions of the spring ligament complex are rare. In most cases, spring ligament complex lesions are secondary to PTT dysfunction. The best criteria for an injury of the clinically relevant superomedial calcaneonavicular ligament are increased signal on proton-density or T2-weighted sequences with thickening (> 5 mm), thinning (< 2 mm), or partial or complete discontinuity. A thickened ligament can be simulated by the gliding layer between the PTT and the superomedial calcaneonavicular ligament (thickness: 1-3 mm). The most common location of injury is the superior and distal portion of the superomedial calcaneonavicular ligament. A lesion seen by the orthopedic foot surgeon at the junction between the tibiospring ligament and the superomedial portion of the calcaneonavicular ligament is commonly classified as a spring ligament injury. In addition, an overview of MR imaging findings in different stages of the acquired adult flatfoot deformity is provided.

Functional outcome and the structural integrity of arthroscopic Bankart repair: a prospective trial.

BACKGROUND: Recurrent anterior shoulder dislocations are common in young patients with Bankart lesions. Arthroscopic repair is an established treatment; however, recurrent instability occurs in up to 35% of patients. It is unclear whether recurrence is the result of a failure of the surgical repair to heal or a repeat injury. The aim of the present pilot study was to assess radiographic healing of Bankart lesions 6 months post surgical repair and identify any correlations between radiographic findings and subsequent recurrent dislocations. METHODS: Eighteen patients underwent arthroscopic Bankart repair for recurrent instability. Magnetic resonance (MR) arthrograms were obtained both pre-operatively and 6 months postoperatively. Standard T1 and T2 views were obtained along with an abduction and external rotation (ABER) view. Patients were followed for a minimum of 4 years for the risk of recurrence, and functional outcomes were obtained, including the American Shoulder and Elbow Surgeons Subjective Shoulder Scale, Ontario Shoulder Instability Index, Oxford Shoulder Instability Score and 12-Item Short Form Health Survey. Scores were correlated with pre-operative and postoperative MR findings. RESULTS: Six of 18 patients developed recurrent instability. We could not identify correlations between reconstructed labrum (labral bumper) position, failure at suture sites and ABER findings with recurrent instability or functional outcome. Paradoxically, there was a nonstatistically significant trend for patients with no clefts between the labrum and the glenoid at any points along the repair to have worse outcomes than patients with partial or complete clefts. CONCLUSIONS: In our pilot study, MR arthrogram was used to evaluate the labrum in detail 6 months postoperatively. Despite its proven ability to detect labral lesions, we were unable to demonstrate any features on postoperative MR arthrogram that predicted either functional outcome or recurrent instability. At 6 months post operation, functional recovery and the risk of recurrence may not depend on the anatomical appearance of the labrum alone.

The pitfalls of ultrasonography in the evaluation of soft tissue masses.

INTRODUCTION: Ultrasonography is associated with a high error rate in the evaluation of soft tissue masses. The purposes of this study were to examine the nature of the diagnostic errors and to identify areas in which reporting could be improved. METHODS: Patients who had soft tissue tumours and received ultrasonography during a 10-year period (1999-2009) were identified from a local tumour registry. The sonographic and pathological diagnoses were categorised as either 'benign' or 'non-benign'. The accuracy of ultrasonography was assessed by correlating the sonographic with the pathological diagnostic categories. Recommendations from radiologists, where offered, were assessed for their appropriateness in the context of the pathological diagnosis. RESULTS: One hundred seventy-five patients received ultrasonography, of which 60 had 'non-benign' lesions and 115 had 'benign' lesions. Ultrasonography correctly diagnosed 35 and incorrectly diagnosed seven of the 60 'non-benign' cases, and did not suggest a diagnosis in 18 cases. Most of the diagnostic errors related to misdiagnosing soft tissue tumours as haematomas (four out of seven). Recommendations for further management were offered by the radiologists in 144 cases, of which 52 had 'non-benign' pathology. There were eight 'non-benign' cases where no recommendation was offered, and the sonographic diagnosis was either incorrect or unavailable. CONCLUSIONS: Ultrasonography lacks accuracy in the evaluation of soft tissue masses. Ongoing education is required to improve awareness of the limitations with its use. These limitations should be highlighted to the referrers, especially those who do not have specific training in this area.

Musculoskeletal CPD revision: cases from the New Zealand bone and soft tissue tumour registry.

The following case report was selected from the New Zealand Bone and Soft Tissue Tumour Registry to highlight some key concepts and findings in musculoskeletal imaging with radiological-pathological correlation. The presentation follows a question and answer format followed by clinical information, selected images, diagnosis, discussion and teaching points.

Bilateral flexor carpi radialis brevis and unilateral flexor carpi ulnaris brevis muscle: case report.

We present findings of anomalous musculotendinous anatomy in a patient having exploration of an acute volar wrist laceration. Surgical dissection demonstrated supernumerary flexor carpi radialis brevis and flexor carpi ulnaris brevis muscle bellies crossing the radiocarpal and ulnocarpal joints, in addition to injuries to several normal tendons and nerves. Postoperative magnetic resonance imaging confirmed the presence of a bilateral supernumerary flexor carpi radialis brevis but contralateral absence of flexor carpi ulnaris brevis.

Nontraumatic multidirectional instability of the scaphotrapeziotrapezoid joint: a cause of scaphotrapeziotrapezoid osteoarthritis and static distal intercalated segment instability.

We report a case of bilateral multidirectional instability of the scaphotrapeziotrapezoid joint associated with osteoarthritis of the same joint and static dorsal intercalated segment instability. Because there is no previous trauma it is likely that this is a case of nontraumatic instability at the scaphotrapeziotrapezoid joint causing a dorsal intercalated segment instability deformity of carpal malalignment and secondary scaphotrapeziotrapezoid osteoarthritis.