Achilles tendon assessment on quantitative MRI: Sources of variability and relationships to tendinopathy.

Quantitative MRI (qMRI) measures are useful in assessing musculoskeletal tissues, but application to tendon has been limited. The purposes of this study were to optimize, identify sources of variability, and establish reproducibility of qMRI to assess Achilles tendon. Additionally, preliminarily estimates of effect of tendon pathology on qMRI metrics and structure-function relationships between qMRI measures and ankle performance were examined. T1, T1ρ, T2, and T2* maps of the Achilles tendon were obtained using a 3T MRI scanner. In participants with asymptomatic tendons (n = 21), MRI procedures were repeated twice, and region of interest selection was performed by three raters. Variance decomposition and reproducibility statistics were completed. To estimate the effect of pathology, qMRI measures from individuals with asymptomatic tendons were compared to qMRI measures from a pilot group of individuals with Achilles tendinopathy (n = 7). Relationships between qMRI and ankle performance measures were assessed. Between-participant variation accounted for the majority of variability (46.7%-64.0%) in all qMRI measures except T2*. ICCs met or exceeded 0.7 for all qMRI measures when averaged across raters or scans. Relaxation times were significantly longer in tendinopathic tendons (mean (SD) T1: 977.8 (208.6) ms, T1ρ: 35.4 (7.1) ms, T2: 42.8 (7.9) ms, T2*: 14.1 (7.6) ms, n = 7) compared to asymptomatic control tendons (T1: 691.7 (32.4) ms, T1ρ: 24.0 (3.6) ms, T2: 24.4 (7.5) ms, T2*: 9.5 (3.4) ms, n = 21) (p < 0.011 for all comparisons). T1 related to functional performance measures in symptomatic and asymptomatic groups. Study findings suggest that qMRI is reliable to assess the Achilles tendon. qMRI quantitatively assesses the presence of tendon pathology and relates to functional performance outcomes, supporting the utility of incorporating qMRI in research and clinic.

Unique Case of Accelerated Bone Growth Precipitating a One-Stage Masquelet: A Case Report.

Introduction: The masquelet technique is a two-stage procedure used by orthopedic surgeons to treat large segmental bone defects secondary to infection, trauma, and tumor resection. This technique characteristically requires the placement of a temporary cement spacer and subsequent bone grafting for complete reconstruction. We describe a unique case of segmental bone loss reconstruction in which a patient successfully achieved fracture union after the first step of the masquelet technique without bone grafting. Case Report: This is a case of a 21-year-old male who presented with an open femur fracture with 10 cm of segmental bone loss after a motorcycle collision. An antibiotic cement spacer was inserted according to the first stage of the masquelet technique. Due to considerable callus formation around the spacer, normal alignment, and pain-free ambulation at follow-up, further surgical intervention was not pursued, and the poly-methyl-methacrylate spacer was left in place. The fracture healed without infection, and the patient remained weight-bearing without pain. Conclusion: This case identifies a unique instance of successful fracture union of a 10 cm segmental bone defect despite the completion of only the first step in the masquelet procedure. While the masquelet technique is believed to be a mandatory two-step procedure, this unique case of rapid bone growth and fracture union warrants further research on the possibilities of masquelet-induced regeneration without bone grafting.

Extraskeletal Myxoid Chondrosarcoma Identified in a Traumatic Fracture of the Toe: A Case Report.

Introduction: Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft-tissue sarcoma that typically presents in the proximal lower extremity and limb-girdle. It can be easily misdiagnosed, especially when located in atypical locations like the foot. Case Report: We present the case of an 80-year-old Caucasian female with a left 3rd toe pain and swelling that was initially misdiagnosed as a traumatic fracture on radiographs but later determined to be an indolent EMC based on histology. She was successfully treated with amputation of the toe. Conclusion: EMC should be considered in the differential of osseous and soft-tissue abnormalities on radiographic imaging of the extremities. As reported in the literature, it can present in atypical locations with minimal symptoms and successful treatments include resection. Future cases presenting similarly should be evaluated for EMC and, if present, reported along with their applied treatment protocols to allow for further assessment of current therapeutic guidelines.

Infection of Baker's Cyst without Bacteremia, Sepsis, or Extraneous Source: A Case Report.

Introduction: Baker's cysts are benign fluid-filled cysts that commonly form around knee joints which typically resolve spontaneously. Infection of baker's cysts is uncommon, but most often associated with septic arthritis or bacteremia. We describe a unique case of an infected Baker's cyst that presented without bacteremia, septic knee, or external source of infection. This is a rare manifestation that has not been described in the current literature. Case Report: This is a case of a 46 year-old woman who developed an infected Baker's cyst without bacteremia or septic arthritis. She initially presented with the right knee pain, swelling, and limited range of motion. Blood work and synovial fluid aspiration of her right knee showed no source of infection. The patient subsequently developed erythema and tenderness over her right knee. This prompted MRI imaging that demonstrated a complex Baker's cyst. The patient later developed a fever, tachycardia, and worsening anion-gap metabolic-acidosis. Aspiration of the fluid collection was performed and revealed purulent fluid which grew pansensitive Methicillin-Sensitive Staphylococcus aureus, blood and knee aspiration cultures remained negative. The patient was treated with antibiotics and debridement procedures and her symptoms/infection resolved. Conclusion: Given that isolated infections of Baker's cysts are rare, the localized aspect of this infection makes this case quite unique. Development of an infected Baker's cyst after negative aspiration cultures, combined with the presence of systemic symptoms including fever, without evidence of systemic spread, has not been seen before in the literature to our knowledge. The unique presentation of this case is important for future analysis of Baker's cysts as it introduces the possibility of localized cyst infections as a possible diagnosis for physicians to consider.