Imaging of the lesions in the lateral muscle compartment of the forearm, alias mobile wad of Henry: Demographics, radiological anatomy and surgical relevance.

INTRODUCTION: Mobile wad of Henry (MOH) is a preferred surgical term used to describe the lateral compartment muscles of the forearm consisting of brachioradialis, extensor carpi radialis longus and brevis. The lesions in this compartment are uncommon. In this paper, we describe the largest series of the MOH lesions including their demographics, imaging appearances and importance of surgical anatomy whilst managing MOH lesions via radiological or surgical interventions. METHODS: A retrospective search of oncology database for lesions in MOH at our tertiary orthopaedic oncology institute was performed for the last 12 years (2007-2019) after obtaining institutional review board approval. We further analyse data to obtain further clarity of various neoplasms occurring at this particular anatomical site. RESULTS: We identified 28 patients with MOH lesions with an age range of 8 to 84 years and a male predominance. Imaging-wise, majority of lesions were benign following characteristics of lipomatous tumours, lipomas being the commonest. Other relatively uncommon benign lesions were nodular fasciitis, myositis ossificans and brachioradialis muscle injury; whereas aggressive MOH soft tissue neoplasms included synovial sarcoma and fibrohistiocytoma. CONCLUSION: Although majority of MOH lesions are benign, one needs to be aware of spectrum containing uncommon benign and aggressive MOH lesions. When posed with dilemma, the MOH lesions require multidisciplinary approach with close collaboration of the radiologist, the surgeon and the pathologist to decide further management.

How Are Indeterminate Pulmonary Nodules at Diagnosis Associated with Survival in Patients with High-Grade Osteosarcoma?

BACKGROUND: Pulmonary metastases are a poor prognostic factor in patients with osteosarcoma; however, the clinical significance of subcentimeter lung nodules and whether they represent a tumor is not fully known. Because the clinician is faced with decisions regarding biopsy, resection, or observation of lung nodules and the potential impact they have on decisions about resection of the primary tumor, this remains an area of uncertainty in patient treatment. Surgical management of the primary tumor is tailored to prognosis, and it is unclear how aggressively patients with indeterminate pulmonary nodules (IPNs), defined as nodules smaller than 1 cm at presentation, should be treated. There is a clear need to better understand the clinical importance of these nodules. QUESTIONS/PURPOSES: (1) What percentage of patients with high-grade osteosarcoma and spindle cell sarcoma of bone have IPNs at diagnosis? (2) Are IPNs at diagnosis associated with worse metastasis-free and overall survival? (3) Are there any clinical or radiologic factors associated with worse overall survival in patients with IPN? METHODS: Between 2008 and 2016, 484 patients with a first presentation of osteosarcoma or spindle cell sarcoma of bone were retrospectively identified from an institutional database. Patients with the following were excluded: treatment at another institution (6%, 27 of 484), death related to complications of neoadjuvant chemotherapy (1%, 3 of 484), Grade 1 or 2 on final pathology (4%, 21 of 484) and lack of staging chest CT available for review (0.4%, 2 of 484). All patients with abnormalities on their staging chest CT underwent imaging re-review by a senior radiology consultant and were divided into three groups for comparison: no metastases (70%, 302 of 431), IPN (16%, 68 of 431), and metastases (14%, 61 of 431) at the time of diagnosis. A random subset of CT scans was reviewed by a senior radiology registrar and there was very good agreement between the two reviewers (κ = 0.88). Demographic and oncologic variables as well as treatment details and clinical course were gleaned from a longitudinally maintained institutional database. The three groups did not differ with regard to age, gender, subtype, presence of pathological fracture, tumor site, or chemotherapy-induced necrosis. They differed according to local control strategy and tumor size, with a larger proportion of patients in the metastases group presenting with larger tumor size and undergoing nonoperative treatment. There was no differential loss to follow-up among the three groups. Two percent (6 of 302) of patients with no metastases, no patients with IPN, and 2% (1 of 61) of patients with metastases were lost to follow-up at 1 year postdiagnosis but were not known to have died. Individual treatment decisions were determined as part of a multidisciplinary conference, but in general, patients without obvious metastases received (neo)adjuvant chemotherapy and surgical resection for local control. Patients in the no metastases and IPN groups did not differ in local control strategy. For patients in the IPN group, staging CT images were inspected for IPN characteristics including number, distribution, size, location, presence of mineralization, and shape. Subsequent chest CT images were examined by the same radiologist to reevaluate known nodules for interval change in size and to identify the presence of new nodules. A random subset of chest CT scans were re-reviewed by a senior radiology resident (κ = 0.62). The association of demographic and oncologic variables with metastasis-free and overall survival was first explored using the Kaplan-Meier method (log-rank test) in univariable analyses. All variables that were statistically significant (p < 0.05) in univariable analyses were entered into Cox regression multivariable analyses. RESULTS: Following re-review of staging chest CTs, IPNs were found in 16% (68 of 431) of patients, while an additional 14% (61 of 431) of patients had lung metastases (parenchymal nodules 10 mm or larger). After controlling for potential confounding variables like local control strategy, tumor size, and chemotherapy-induced necrosis, we found that the presence of an IPN was associated with worse overall survival and a higher incidence of metastases (hazard ratio 1.9 [95% CI 1.3 to 2.8]; p = 0.001 and HR 3.6 [95% CI 2.5 to 5.2]; p < 0.001, respectively). Two-year overall survival for patients with no metastases, IPN, or metastases was 83% [95% CI 78 to 87], 65% [95% CI 52 to 75] and 45% [95% CI 32 to 57], respectively (p = 0.001). In 74% (50 of 68) of patients with IPNs, it became apparent that they were true metastatic lesions at a median of 5.3 months. Eighty-six percent (43 of 50) of these patients had disease progression by 2 years after diagnosis. In multivariable analysis, local control strategy and tumor subtype correlated with overall survival for patients with IPNs. Patients who were treated nonoperatively and who had a secondary sarcoma had worse outcomes (HR 3.6 [95% CI 1.5 to 8.3]; p = 0.003 and HR 3.4 [95% CI 1.1 to 10.0]; p = 0.03). The presence of nodule mineralization was associated with improved overall survival in the univariable analysis (87% [95% CI 39 to 98] versus 57% [95% CI 43 to 69]; p = 0.008), however, because we could not control for other factors in a multivariable analysis, the relationship between mineralization and survival could not be determined. We were unable to detect an association between any other nodule radiologic features and survival. CONCLUSION: The findings show that the presence of IPNs at diagnosis is associated with poorer survival of affected patients compared with those with normal staging chest CTs. IPNs noted at presentation in patients with high-grade osteosarcoma and spindle cell sarcoma of bone should be discussed with the patient and be considered when making treatment decisions. Further work is required to elucidate how the nodules should be managed. LEVEL OF EVIDENCE: Level III, prognostic study.

Lesions of the heel fat pad.

OBJECTIVE: The heel fat pad (HFP) is a specialized soft tissue structure formed of adipose tissue that overlies the inferior and posterior aspect of the calcaneus and provides the cushioning effect of the heel. Lesions of the HFP are rare and can be a cause of debilitating heel pain that may often pose a challenge to clinicians. This study provides a series of lesions identified within the HFP. METHODS AND MATERIALS: A retrospective review of heel pad lesions over a 12 year period was conducted at our tertiary orthopaedic oncology centre. All lesions of the heel fat pad were included in the study. Plantar fasciitis was excluded. RESULTS: There were 17 heel pad lesions identified, of which the majority (n = 15) were benign. CONCLUSION: We highlight a wide spectrum of pathologies that can occur in the HFP. Although rare, clinicians should be aware of these lesions, to initiate appropriate management.

Myositis ossificans of mobile wad of Henry-Tennis elbow mimic.

Lateral epicondylitis also known as "tennis elbow" is the most common cause of lateral elbow pain. Several pathologies can mimic symptoms of tennis elbow. We present a case of myositis ossificans within the mobile wad of Henry (MWH), which presented with symptoms of tennis elbow and believe this to be the first reported case in literature.

Gluteus medius muscle pathologies - A case series & pictorial review.

INTRODUCTION: Gluteus medius lesions are rare and can present with lateral hip pain. We present a spectrum of pathologies involving the gluteus medius and discuss the imaging features. MATERIAL AND METHODS: A search of our oncology database at tertiary orthopaedic oncology service was performed. The imaging features of these were analysed. RESULTS: There were nine cases involving the gluteus medius, which included soft tissue sarcomas, lipomas, infection and trauma with an average age of 62 years. CONCLUSION: Gluteus medius lesions are rare and one should be aware of these as these can present as lateral hip pain.

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.