Justin C. Lee

MRI of the popliteofibular ligament: isotropic 3D WE-DESS versus coronal oblique fat-suppressed T2W MRI

ObjectiveThe objective was to compare isotropic 3D water excitation double-echo steady state (WE-DESS) MRI with coronal oblique fat-suppressed T2-weighted (FS T2W) images in the identification of the popliteofibular ligament (PFL).Materials and methodsA prospective analysis of 122 consecutive knee MRIs was performed in patients referred for knee pain from the orthopaedic clinic. In addition to the standard knee sequences, isotropic WE-DESS volume acquisition through the whole knee and coronal oblique FS T2W fast spin echo sequences through the posterolateral corner were obtained. The presence of the popliteus and biceps femoris tendons, lateral collateral and PFL was documented. Anterior cruciate ligament injury was present in 33 cases and these were excluded from the study because of the risk of associated PFL injury, leaving a total of 89 cases. Of the 42 patients in whom arthroscopic evaluation was subsequently obtained, none were found to have an injury to the PFL.ResultsThe lateral collateral ligament, biceps femoris and popliteus tendon were identified in all cases on all sequences. The PFL was seen in 81 (91.0%; 95% CI 85.1–97.0%) patients using the WE-DESS sequence and 63 (70.8%; 95% CI 61.3–80.2%) patients using the coronal oblique FS T2W sequence, a statistically significant difference (p < 0.00005).ConclusionIsotropic 3D WE-DESS MRI significantly enhances our ability to identify the popliteofibular ligament compared with coronal oblique fat-suppressed T2-weighted images.

Ultrasound-guided treatments for chronic Achilles tendinopathy: an update and current status

Minimally-invasive treatments for chronic Achilles tendinopathy may prevent the need for surgery when conservative methods have failed. Whilst injections have traditionally been used to manage symptoms, recently described therapies may also have disease-modifying potential. Ultrasound provides the ability to guide therapeutic interventions, ensuring that treatment is delivered to the exact site of pathology. Treatments can be broadly categorised according to their intended therapeutic targets, although some may act through several possible mechanisms. In this article, we review the ultrasound-guided techniques currently used to treat chronic Achilles tendinopathy, with reference to the available literature. There is strong pilot-level evidence supporting the use of many of these techniques, although large definitive trials are lacking. An approach towards the management of chronic Achilles tendinopathy is suggested.

Imaging in the Assessment and Management of Achilles Tendinopathy and Paratendinitis

Achilles tendinopathy is a common overuse injury in patients engaged in athletic activities. Tendon degeneration is often accompanied by paratendinitis. Radiologists are frequently asked to use imaging techniques to evaluate patients with problems at or around the Achilles tendon. The main imaging modalities used in the assessment of Achilles tendon disorders are plain radiography, ultrasound, and magnetic resonance imaging. In recent years, ultrasound has also been used to guide minimally invasive local treatments for Achilles tendinopathy, which may prevent the need for surgery if conservative treatments have failed. In this article, we review the imaging features of Achilles tendinopathy and consider the relative strengths and weaknesses of the various imaging techniques. The role of imaging in directing patient management is also discussed, with particular focus on ultrasound-guided treatments.

Ankle and Foot Injuries

Injuries to the foot and ankle are common in elite athletes and may be responsible for prolonged periods of absence from competitive activity. The osseous, articular, ligamentous and tendinous structures of the foot and ankle may be injured in isolation or, more commonly, in combination. Various impingement syndromes of the ankle are described, many of which have characteristic features on imaging. Radiology now plays a crucial role in management of these injuries, not only in diagnosis but increasingly in guiding percutaneous therapies. The plain radiograph still plays a crucial role in diagnosis but is now supplemented with advanced imaging techniques such as ultrasound, computed tomography and magnetic resonance imaging. We present a comprehensive review of the anatomy, biomechanics, imaging and surgical management of foot and ankle injuries and impingement syndromes encountered in the sporting population.

Percutaneous Release Procedures: Trigger Finger and Carpal Tunnel.

Trigger digit and carpal tunnel syndrome are both conditions traditionally treated with open surgery but are potentially amenable to curative treatment using percutaneous techniques. The advantages of minimally invasive techniques are lower risk of wound breakdown and infection, quicker healing, reduced postprocedural pain, reduced complications, and a quicker return to normal activity. The advent of high-resolution ultrasound has allowed percutaneous release procedures for these conditions to be developed and performed with a potential for a reduced risk of complications and an increased likelihood of success. This article reviews the literature as well as our institutional experience in performing ultrasound-guided percutaneous release for trigger digit and carpal tunnel syndrome.

The Broken “Ring of Fire”: A New Radiological Sign as Predictor of Syndesmosis Injury?:

Background: Subcircumferential periosteal edema above the ankle joint is frequently present on magnetic resonance imaging (MRI) with syndesmosis injuries but has not been previously reported. Fluid height within the interosseous membrane also has not previously been shown to be associated with syndesmosis injury severity. Purpose: To investigate whether a new sign on MRI and measurement of the length of fluid within the interosseous membrane above the ankle may be used to enable identification of a syndesmosis injury and allow differentiation from lateral ligament injury. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Three groups of patients (those with an isolated syndesmosis injury [SI group], isolated lateral ligament injury [LLI group], and no injury [NI group]) who had an ankle MRI for another reason were identified from a patient notes database and the MRI scans retrieved. The scans were anonymized and independently assessed by 8 clinicians (surgeons and radiologists) who were blinded to the diagnosis. The maximum length of fluid above the ankle within the intraosseous membrane was measured for each patient. The presence or absence of distal anterior, lateral, and posterior tibial periosteal edema was recorded (broken “ring of fire”). Results: Measurement of the length of fluid above the ankle had excellent intraobserver reliability (intraclass correlation coefficient, 0.97; 95% CI, 0.93-0.99) but poor interobserver reliability. Fluid extended higher in both the LLI group (P = .0043) and SI group (P = .0058) than the NI group, but there was no significant difference between the LLI and SI groups (P = .3735), indicating that this measurement cannot differentiate between the injuries. The presence of the broken “ring of fire” around the distal tibia was significantly more frequent in the SI group when compared with both LLI and NI groups (P < .00001). The sensitivity of this sign is 49%, but when present, this sign has a 98% specificity for syndesmosis injury. Conclusion: The presence of tibial subcircumferential periosteal edema 4 to 6 cm above the ankle joint (the “ring of fire”) is highly suggestive of a syndesmosis injury. This new radiological sign can assist with early identification of such injuries. The measurement of height of fluid above the ankle within the interosseous membrane is variable and cannot differentiate severe ankle sprains from high ankle sprains involving the syndesmosis.