MRI features of ERSA (exercise-related signal abnormality) lesions in professional soccer players.

OBJECTIVE: This study aims to describe the prevalence, anatomy and morphology of ERSA (exercise-related signal abnormality) lesions, a previously undescribed pattern of muscle signal changes on MRI in professional soccer players with suspected acute thigh muscle injury. METHODS: A multicenter retrospective review was performed of 287 MRIs of professional soccer players referred for suspected acute thigh injury from August 2017 to February 2020. MR images were reviewed for muscle signal abnormalities corresponding to a peritendinous ovoid region or a subfascial ring of faint increased signal on fluid-sensitive MR images. Imaging features including anatomical site, morphology, and craniocaudal length were recorded. Concomitant acute muscle injury was graded in accordance with the British Athletics Muscle Injury Classification (BAMIC). RESULTS: ERSA lesions comprising a peritendinous ovoid region, a subfascial ring, or both, were identified in 40 muscles across 31/287 studies (10.8%). These lesions had a mean length of 15.8 cm and were predominantly located in the proximal or mid-portions of muscles. Affected muscles were rectus femoris (n = 22), adductor longus (n = 11), semitendinosus (n = 6) and biceps femoris (n = 1). 21/31 studies (67.7%) had a BAMIC grade 1-4 injury in a separate muscle, which were largely (81%) in a separate anatomic compartment or contralateral. CONCLUSION: ERSA lesions were evident on MRI in 10.8% of our cohort of professional soccer players referred for suspected acute thigh muscle injury. Characteristic morphology and the longitudinal length (mean 15.8 cm) distinguish ERSA lesions from recognized patterns of acute muscle injury.

MRI findings of tibialis anterior friction syndrome: a mimic of tibial stress injury.

OBJECTIVE: To describe a distinct constellation of MRI demonstrated soft tissue abnormalities centred around the tibialis anterior tendon in a subset of patients presenting as suspected tibial stress injury. MATERIALS AND METHODS: A retrospective review was performed of the clinical and MRI imaging findings from 5 selected patients referred for MRI with suspected tibial stress injury. MRI studies at presentation of each case were systematically reviewed for peritendinous fluid, tibialis anterior tendon change, tibialis anterior muscle and myotendinous junction oedema, periosteal oedema over the tibia and tibial marrow oedema. RESULTS: All 5 cases were athletes (3 soccer players, 2 runners) of between 20 and 40 years of age. On MRI, all 5 cases demonstrated peritendinous fluid around an intact tibialis anterior tendon. This fluid was maximal at the junction of mid and distal thirds of the lower leg, and extended down to the superior extensor retinaculum, with a mean cranio-caudal length of 13 cm (range 8-17 cm). Associated oedema was present in the surrounding subcutaneous tissue, tibial periosteum and distal tibialis anterior musculotendinous junction. CONCLUSION: Peritendinous fluid around an intact tibialis anterior tendon over the mid-to-distal third tibia, with surrounding subcutaneous, periosteal and tibialis anterior myotendinous junction oedema is demonstrable on MRI in a subset of patients presenting as suspected tibial stress injury. A friction syndrome of tibialis anterior between the superior extensor retinaculum and the anterior tibia is proposed as the aetiology of this entity.

A Rare Pattern of Ligamentous Injury of the Ankle: A Case Report and Review of the Literature.

Ankle sprains are the most frequent sport related injuries with involvement of the lateral collateral ligament complex occurring in 85% of cases. Isolated anterior talofibular ligament injury is by far the commonest followed by combined anterior talofibular and calcaneofibular ligament strain. The posterior talofibular ligament is the strongest component of the lateral collateral ligament complex and is injured in severe ankle injury along with the other lateral collateral ligaments. While isolated calcaneofibular ligament strain has been reported, calcaneofibular ligament and posterior talofibular ligament strains with an intact anterior talofibular ligament are rare and reported in cadaveric studies. We present a case of radiologically diagnosed calcaneofibular ligament and posterior talofibular ligament injury and will discuss the anatomy, stress radiography, and magnetic resonance image findings and the mechanism of this particular injury.

Radiofrequency ablation of chondroblastoma: long-term clinical and imaging outcomes.

OBJECTIVES: To investigate the long-term clinical and imaging outcomes of patients with chondroblastoma treated by radiofrequency ablation (RFA). METHODS: Retrospective analysis of 25 consecutive patients treated with RFA from September 2006 to December 2013. Patients were reviewed within one month of the procedure, then every 3-6 months, and yearly for up to three years. Serial magnetic resonance imaging (MRI) was performed at follow-up to monitor recovery. Functional outcome was assessed using the Musculoskeletal Tumour Society Score (MSTS). RESULTS: Pre-procedure MRI confirmed osteolytic lesions (size range 1.0-3.3 cm; mean 2.0 cm). Patients reported continued symptomatic improvement at four months review. Serial MRI confirmed progressive resolution of inflammation with fatty consolidation of cavity. 88 % of patients became asymptomatic during the follow up period. Three patients' (12 %) symptoms returned at 16, 22 and 24 months respectively after RFA. MRI and biopsy confirmed recurrence in these patients. Functional assessment using MSTS score had an average score of 97.5 %. Mean follow up for the study group was 49 months. CONCLUSION: RFA is an effective alternative to surgery in the management of chondroblastoma. We recommend a multi-disciplinary approach and RFA should be considered as a first-line treatment. Long-term follow-up is required for timely detection of recurrences. KEY POINTS: • RFA is a safe and effective technique in the treatment of chondroblastoma. • Positive outcomes in 88 % patients at mean follow-up period of 49 months. • Local recurrences occurred in 12 % cases. • Long-term follow-up is required for timely detection of recurrences. • RFA should be considered as a first-line treatment for chondroblastoma.

Imaging features of osteoid osteoma of the phalanges.

OBJECTIVES: Osteoid osteoma (OO) of the phalanges is regarded as a difficult diagnosis to make, both clinically and radiologically. Our aim was to assess the imaging features of this relatively rare entity to assess for consistent imaging features. MATERIALS AND METHODS: Retrospective analysis of databases at our institutions was performed to identify patients with histologically confirmed OO of the phalanges. Radiographs were assessed for a nidus, surrounding sclerosis, periosteal reaction, cortical erosion and generalised soft tissue swelling. MRI scans were reviewed for visibility of the nidus; reactive marrow oedema; periostitis; and a soft tissue mass associated with the lesion. RESULTS: Ten patients with OO occurring in a phalanx were identified. Nine out of ten patients (90%) were male. The mean age was 20 years (range 11-45). At radiography, a nidus was visible in 100% (10 out of 10) cases. Internal matrix within the nidus was seen in 60% (6 out of 10). Sclerosis surrounding the nidus was present in 90% (9 out of 10). Cortical erosion was identified in 10% (1 out of 10). Generalised swelling of the affected digit was noted in 100% (10 out of 10). Periosteal/cortical sclerosis was seen in 20% (2 out of 10). Of the 8 patients who had an MRI scan, the nidus was visible in 100% (8 out of 8). Reactive marrow oedema within the affected phalanx was present in 100% (8 out of 8). There was a soft tissue mass surrounding the affected phalanx in 75% (6 out of 8). Periosteal oedema was noted in 13% (1 out of 8). CONCLUSION: Phalangeal OO demonstrates similar imaging appearances to OO at other locations in the majority of cases. An inflammatory soft tissue mass often accompanies the nidus at MRI.

Imaging appearances and clinical outcome following sacrectomy and ilio-lumbar reconstruction for sacral neoplasia.

OBJECTIVE: Sacrectomy and ilio-lumbar reconstruction is an uncommonly performed complex surgical procedure for the treatment of sacral neoplasia. There are many challenges in the post-operative period including the potential for tumor recurrence, infection, and construct failure. We present our experience of this patient cohort and describe the complications and imaging appearances that can be encountered during the follow-up period. MATERIALS AND METHODS: Retrospective review of our Orthopaedic Oncology database was undertaken which has been collected over a 30-year period to identify patients that had undergone sacrectomy and ilio-lumbar reconstruction. Pre and post-operative imaging including radiographs, CT, and MRI was reviewed. These were viewed by two experienced musculoskeletal radiologists with consensus opinion if there was disagreement over the imaging findings. Data regarding patient demographics, tumor type, and dimensions was collected. Serial review of radiographs, CT, and MRI was performed to assess implant position and integrity, strut graft position and union, and for the presence of recurrence within the surgical bed. RESULTS: Five male and two female patients (mean age 36 years, age range 15-54 years) were treated with this procedure. Histological diagnoses included chordoma, chondrosarcoma, osteosarcoma, and spindle cell sarcoma. Mean maximal tumor size on pre-operative imaging was 10.7 cm (range, 6-16 cm). Post-operative follow-up ranged from 10-46 months. A total of 76 imaging studies were reviewed. Commonly identified complications included vertical rod and cross-connector fracture and screw loosening. Fibula strut graft non-union and fracture was also evident on imaging review. Two patients demonstrated disease recurrence during the follow-up period. CONCLUSIONS: This study demonstrates the spectrum and frequency of complications that can occur following sacrectomy and ilio-lumbar reconstruction for sacral neoplasia.

British athletics muscle injury classification: a new grading system.

The commonly used muscle injury grading systems based on three grades of injury, representing minor, moderate and complete injuries to the muscle, are lacking in diagnostic accuracy and provide limited prognostic information to the clinician. In recent years, there have been a number of proposals for alternative grading systems. While there is recent evidence regarding the prognostic features of muscle injuries, this evidence has not often been incorporated into the grading proposals. The British Athletics Muscle Injury Classification proposes a new system, based on the available evidence, which should provide a sound diagnostic base for therapeutic decision-making and prognostication. Injuries are graded 0-4 based on MRI features, with Grades 1-4 including an additional suffix 'a', 'b' or 'c' if the injury is 'myofascial', 'musculo-tendinous' or 'intratendinous'. Retrospective and prospective studies in elite track and field athletes are underway to validate the classification for use in hamstring muscle injury management. It is intended that this grading system can provide a suitable diagnostic framework for enhanced clinical decision-making in the management of muscle injuries and assist with future research to inform the development of improved prevention and management strategies.

Osteoid osteoma of the cuboid managed by percutaneous radiofrequency ablation.

We present details of a case of osteoid osteoma of the tarsal cuboid bone. Osteoid osteoma arising in the foot is not very common, and localization in the cuboid is rare. To our knowledge, this is the first case of osteoid osteoma of the cuboid bone treated successfully by percutaneous radiofrequency ablation.

Measurement Analysis of Ice Ball Size during CT-Guided Cryoablation Procedures for Better Prediction of Final Ice Ball Size and Avoidance of Complications.

Introduction Cryoablation is the destruction of living tissue by the application of extreme freezing temperature. There has been an increase in the use of cryoablation in the management of musculoskeletal lesions, in particular fibromatosis. Aim This study aimed to measure the average and relative increase in size of the cryoablation ice ball after the first (10 minutes) and second freeze cycles (20 minutes) to accurately predict the size of the ice ball between first and second freezes to help prevent any unwanted damage of the nearby skin and neurovascular structures. This is especially important when ablating in relatively small body parts such as in the appendicular skeleton. Material and Methods Eight patients treated with cryoablation over a 12-month period for fibromatosis were, included in the study. The size and volume of the ice ball were measured during the first and second cycle of cryoablation. Results The average patient age of the cohort was 35.6 years old (min 28 and max 43). There was female predominance in the study (3:2, F:M). There was a significant increase (26%) in the linear dimensions and almost doubling in the volume of the ice ball between freeze cycles ( p -value = 0.0037 for dimensions and p -value = 0.0002 for volumes). Conclusion This pilot study is a preliminary attempt to predict the eventual size of the ice ball during cryoablation procedures when treating cases of fibromatosis. This should help in planning cryoablation to ensure decrease morbidity by preventing injury to adjacent critical structures (neurovascular bundle and skin).

Is bone scintigraphy necessary in the initial surgical staging of chondrosarcoma of bone?

OBJECTIVE: To assess the value of whole-body bone scintigraphy in the initial surgical staging of chondrosarcoma of bone. METHODS: A retrospective review was conducted of the bone scintigraphy reports of a large series of patients with peripheral or central chondrosarcoma of bone treated in a specialist orthopaedic oncology unit over a 13-year period. Abnormal findings were correlated against other imaging, histological grade and the impact on surgical staging. RESULTS: A total of 195 chondrosarcomas were identified in 188 patients. In 120 (63.8%) patients the reports of bone scintigraphy noted increased activity at the site of one or more chondrosarcomas. In one patient the tumour was outside the field-of-view of the scan, and in the remaining 67 (35.6%) cases, there was increased activity at the site of the chondrosarcoma and further abnormal activity in other areas of the skeleton. Causes of these additional areas of activity included degenerative joint disease, Paget's disease and in one case a previously undiagnosed melanoma metastasis. No cases of skeletal metastases from the chondrosarcoma were found in this series. Multifocal chondrosarcomas were identified in three cases. In two it was considered that all the tumours would have been adequately revealed on the initial MR imaging staging studies. In only the third multifocal case was an unsuspected, further presumed low-grade, central chondrosarcoma identified in the opposite asymptomatic femur. Although this case revealed an unexpected finding the impact on surgical staging was limited as it was decided to employ a watch-and-wait policy for this tumour. CONCLUSION: There is little role for the routine use of whole-body bone scintigraphy in the initial surgical staging in patients with chondrosarcoma of bone irrespective of the histological grade.

Profunda femoris pseudoaneurysm following Birmingham hip resurfacing: an important differential diagnosis for a periarticular cystic mass.

Vascular injury following hip resurfacing arthroplasty is rare: we present a case of profunda femoris pseudoaneurysm complicating hip resurfacing arthroplasty performed via an anterolateral approach. Over recent years, it has been recognized that an adverse reaction to metal debris from metal-on-metal arthroplasties can also result in the development of cystic masses around the hip. This case highlights a potential rare differential diagnosis that needs to be considered when imaging cystic mass lesions around the postoperative hip. Imaging can provide a definitive diagnosis if this entity is considered and its appearances recognized, resulting in appropriate management of this potentially limb- and life-threatening complication.

Musculoskeletal imaging: current and future trends.

Advances in imaging technology and the increasing role of interventional procedures in musculoskeletal imaging have continued to stimulate research over recent years. This review summarises some recent articles on musculoskeletal radiology topics and looks forward to potential future developments in this exciting sub-speciality.

Imaging in the diagnosis, prognostication, and management of lower limb muscle injury.

Muscle injuries of the lower extremity are extremely common among athletes leading to significant morbidity and time out from competition. Furthermore, increasing athletic activity in the general population has resulted in lower limb muscle injuries becoming commonplace. It is therefore vital for the musculoskeletal radiologist to be familiar with the imaging findings of lower limb muscle injuries and to be aware of the role of imaging in the prognostication and management of these injuries. The most commonly injured lower limb muscles are the quadriceps, the hamstring complex, and the gastrocnemius muscles. This article reviews the biomechanical and imaging features of common acute muscle injuries of the lower extremity and evaluates the role of imaging in the prognosis of these sport injuries.

Isolated Complete Distal Biceps Femoris Tendon Tears: Case Series and Literature Review.

The Biceps femoris is a vital component of the posterolateral corner of the knee. We report two cases of isolated rupture of the biceps femoris, discuss the possible mechanism of injury, and review the literature.

Association of the British Athletic Muscle Injury Classification and anatomic location with return to full training and reinjury following hamstring injury in elite football.

BACKGROUND: The relationship between hamstring muscle injuries (HMIs) that involve the intramuscular tendon and prolonged recovery time and increased reinjury rate remains unclear in elite footballers. OBJECTIVE: To determine the association of time to return to full training (TRFT) and reinjury of HMIs using the British Athletic Muscle Injury Classification (BAMIC) and specific anatomical injury location in elite-level football players. METHODS: The electronic medical records of all players at an English Premier League club were reviewed over eight consecutive seasons. All players who sustained an acute HMI were included. Two experienced musculoskeletal radiologists independently graded each muscle using the BAMIC, categorised each injury location area (proximal vs middle vs distal third and proximal vs distal tendon) and reported second muscle involvement. TRFT and reinjury were recorded. RESULTS: Out of 61 HMIs, the intramuscular tendon (BAMIC 'c') was involved in 13 (21.3%). HMI involving the intramuscular tendon ('c') had a mean rank TRFT of 36 days compared with 24 days without involvement (p=0.013). There were 10 (16.4%) reinjuries with a significant difference of 38.5% reinjury rate in the group with intramuscular tendon injury ('c') and 12.5% in the group without (p=0.031). TRFT and reinjury involving a second muscle was statistically significantly higher than without. Most of the HMIs to the biceps femoris with reinjury (5 out of 9) were in the distal third section related to the distal tendon site involving both the long and short head. CONCLUSION: TRFT in HMI involving the intramuscular tendon ('c') of the Biceps femoris is significantly longer with significantly higher reinjury rate compared with injuries without, in elite football players. The finding that most reinjures of the biceps femoris occurring in the distal third muscle at the distal tendon site, involving both the long and short head, merits further investigation.

Soft tissue tumors with muscle differentiation.

The working group of the World Health Organization (WHO) updated its classification of soft tissue and bone tumors in 2002, and modifications were made primarily to the nomenclature for soft tissue neoplasms. This review presents the imaging features, patient demographics, and clinicopathological findings for benign and malignant skeletal and smooth muscle tumors using the current WHO classification system.

Proximity of the femoral neurovascular bundle during hip resurfacing.

A standard posterior approach was performed in 5 fresh frozen cadaveric limbs. An anterior incision was then used to measure the distance of the femoral neurovascular structures to the anterior capsule. Magnetic resonance imaging (MRI) of 11 hips was also analyzed to validate our cadaveric method. Cadaveric results demonstrated that before dislocation the femoral artery and vein were closest to the anterior capsule (mean distance, 21 mm), and the femoral nerve was the furthest away (mean distance, 25 mm). These results were not significantly different from the MRI findings. When the hip was dislocated, these distances significantly increased. This study suggests that the neurovascular structures are relatively well protected during an anterior capsulotomy performed during hip resurfacing. The procedure may be safer if the capsulotomy is performed with the hip dislocated and in a flexed position while cutting the anterosuperior aspect and in an extended position while cutting the anteroinferior aspect.

Technical report: dynamic assessment of plantar fasciitis and plantar fascia tears utilising dorsiflexion of the great toe.

Discrimination between plantar fasciitis and partial tears of the plantar fascia can be difficult on ultrasound given laxity of the plantar fascia in the region of its calcaneal insertion and anisotropy. Dynamic assessment with great toe dorsiflexion can improve visualisation of the proximal portion of the plantar fascia on ultrasound, by straightening the plantar fascia due to the windlass mechanism. This article describes the technique and its anatomical basis.