BPOP in early childhood following resection of osteochondroma: report of a case.

The diagnosis of an osteochondroma in the short bones of the extremities is atypical and the presentation in infancy is unusual. A 3-month-old female presented for evaluation of radial deviation of the right index finger present since birth. Radiographs showed a broad-based osseous outgrowth with the usual features of an osteochondroma arising from the base of middle phalanx. Initial corrective surgery at 22 months was followed by recurrence of the lesion. Another resection at 4 years confirmed a final diagnosis of BPOP (bizarre parosteal osteochondromatous proliferation). The subsequent pathologic diagnosis of BPOP appears to support the hypotheses concerning the etiology of BPOP as possibly arising from repeated trauma to the metaphysis.

Patients with advanced chronic kidney disease and vascular calcification have a large hydrodynamic radius of secondary calciprotein particles.

BACKGROUND: The size of secondary calciprotein particles (CPP2) and the speed of transformation (T50) from primary calciprotein particles (CPP1) to CPP2 in serum may be associated with vascular calcification (VC) in patients with chronic kidney disease (CKD). METHODS: We developed a high throughput, microplate-based assay using dynamic light scattering (DLS) to measure the transformation of CPP1 to CPP2, hydrodynamic radius (Rh) of CPP1 and CPP2, T50 and aggregation of CPP2. We used this DLS assay to test the hypothesis that a large Rh of CPP2 and/or a fast T50 are associated with VC in 45 participants with CKD Stages 4-5 (22 without VC and 23 with VC) and 17 healthy volunteers (HV). VC was defined as a Kauppila score >6 or an Adragao score ≥3. RESULTS: CKD participants with VC had larger cumulants Rh of CPP2 {370 nm [interquartile range (IQR) 272-566]} compared with CKD participants without VC [212 nm (IQR 169-315)] and compared with HV [168 nm (IQR 145-352), P < 0.01 for each]. More CPP2 were in aggregates in CKD participants with VC than those without VC (70% versus 36%). The odds of having VC increased by 9% with every 10 nm increase in the Rh of CPP2, after adjusting for age, diabetes, serum calcium and phosphate [odds ratio 1.09, 95% confidence interval (CI) 1.03, 1.16, P = 0.005]. The area under the receiver operating characteristic curve for VC of CPP2 size was 0.75 (95% CI 0.60, 0.90). T50 was similar in CKD participants with and without VC, although both groups had a lower T50 than HV. CONCLUSIONS: Rh of CPP2, but not T50, is independently associated with VC in patients with CKD Stages 4-5.

Unexplained "massive osteolysis of femoral head" (MOFH) after acetabular fracture: occurrence and suggested patho-etiology.

Background We observed cases of extensive osteolysis of the femoral head following acetabular fractures even though the original fracture did not involve the femoral head or neck. This observation has been called massive osteolysis of the femoral head (MOFH). Purpose To evaluate the clinical and imaging features of MOFH to gain a better understanding of its patho-etiology. Material and Methods We retrospectively collected cases of acetabular fractures seen over a period of 10 years and evaluated the clinical features and imaging characteristics. The findings were compared with the features of other complications such as osteonecrosis, rapidly progressive osteoarthritis, or post-traumatic osteolysis. Results Fifteen patients (M:F ratio 9:6; mean age, 61.6 years) out of 244 had MOFH (prevalence: 6.1%). Motor vehicle collision and falls were the most common mechanisms of injury. The time interval for developing MOFH was in the range of 1-18 months after the initial injury. Patterns of femoral head osteolysis varied from eccentric (12 cases) to transcervical (3 cases). Four cases of eccentric osteolysis developed high-degree of osteolysis. MOFH was observed near the surgical hardware in 6/15 cases. One biopsy specimen did not reveal typical features of osteoarthritis or avascular necrosis. Conclusion MOFH appears to be a distinct entity from avascular necrosis or rapidly progressive osteoarthritis. It is suggested that MOFH is a variant of post-traumatic osteolysis that is evident in a subset of patients.

Hip anatomic variants that may mimic abnormalities at MRI: labral variants.

OBJECTIVE: Normal anatomic variants of the acetabular labrum are observed on MR images and include labral variants, several sublabral sulci, and perilabral sulcus. Because variants can be misidentified as labral abnormalities such as labral tears, the radiologist needs to avoid the pitfall of mistaking variants as abnormalities. CONCLUSION: The hip has multiple anatomic variants that can mimic abnormalities at hip MRI. The labrum has several anatomic variants that can be confused with true labral tears.

Hip anatomic variants that may mimic pathologic entities on MRI: nonlabral variants.

OBJECTIVE: The hip has several anatomic variants that may be mistaken for pathologic abnormalities. The radiologist needs to be able to distinguish these variants from true abnormalities. In this review, we present nonlabral variants of the hip that can be seen on MRI. CONCLUSION: The hip has multiple anatomic variants that may mimic disease on hip MRI. Like labral variants, nonlabral variants can be confused for true abnormalities.

Near-Infrared Imaging of Indocyanine Green Identifies Novel Routes of Lymphatic Drainage from Metacarpophalangeal Joints in Healthy Human Hands.

Background: Collecting lymphatic vessel (CLV) dysfunction has been implicated in various diseases, including rheumatoid arthritis (RA). RA patients with active hand arthritis exhibit significantly reduced lymphatic clearance of the web spaces adjacent to the metacarpophalangeal (MCP) joints and a reduction in total and basilic-associated CLVs on the dorsal surface of the hand by near-infrared (NIR) imaging of indocyanine green (ICG). In this pilot study, we assessed direct lymphatic drainage from MCP joints and aimed to visualize the total lymphatic anatomy using novel dual-agent relaxation contrast magnetic resonance lymphography (DARC-MRL) in the upper extremity of healthy human subjects. Methods and Results: Two healthy male subjects >18 years old participated in the study. We performed NIR imaging along with conventional- or DARC-MRL following intradermal web space and intra-articular MCP joint injections. ICG (NIR) or gadolinium (Gd) (MRL) was administered to visualize the CLV anatomy of the upper extremity. Web space draining CLVs were associated with the cephalic side of the antecubital fossa, while MCP draining CLVs were localized to the basilic side of the forearm by near-infrared indocyanine green imaging. The DARC-MRL methods used in this study did not adequately nullify the contrast in the blood vessels, and limited Gd-filled CLVs were identified. Conclusion: MCP joints predominantly drain into basilic CLVs in the forearm, which may explain the reduction in basilic-associated CLVs in the hands of RA patients. Current DARC-MRL techniques show limited identification of healthy lymphatic structures, and further refinement in this technique is necessary. Clinical trial registration number: NCT04046146.

Relationship Between Lymph Node Volume and Pain Following Certolizumab Therapy for Rheumatoid Arthritis Flare: A Pilot Study.

OBJECTIVES: The mechanisms that trigger flare in rheumatoid arthritis (RA) are unknown. In murine arthritis models, dysfunctional lymph node (LN) drainage is associated with joint flare. To examine if LN alterations are associated with RA flare, we analyzed the change in LN volume via contrast-enhanced magnetic resonance imaging (CE-MRI) in patients with active joint flare at baseline and 16 weeks after certolizumab pegol (CZP) therapy. We also assessed the changes in popliteal or epitrochlear LN volumes versus the Rheumatoid and Arthritis Outcome Score (RAOS) (knee), or the Michigan Hand Questionnaire (MHQ; wrist/hand), and Disease Activity Score 28 (DAS28), at baseline and 16 weeks. RESULTS: Total LN volume in 7 of 10 patients with measurable LN on CE-MRI significantly decreased 16 weeks after CZP therapy (mean decrease 37%; P = 0.0019). Improvement in knee pain measured by the RAOS (P = 0.03) inversely correlated with a decrease in total popliteal LN volume (R2 = 0.94). All patients demonstrated significant improvement in DAS28 (mean decrease 1.48; P = 0.0002). For flare in the hand, significant improvement in activities of daily living (ADL) as measured by the MHQ was observed (left hand mean improvement 20%; P = 0.02; right hand mean improvement 37%; P = 0.03). CONCLUSION: RA patients with the smallest change in LN volume during anti-tumor necrosis factor (anti-TNF) therapy experienced the greatest pain relief in symptomatic knee joints. Moreover, the remarkably linear inverse correlation between LN volume and joint pain observed in this small clinical pilot provides initial evidence to support the concept that dynamic changes in draining LN volume are a biomarker of clinical response to therapy in RA.