No abstract

A 30-year-old woman presented with swelling in her right thumb of 3-month duration which was slow-growing in nature without a history of trauma. On examination, firm non-tender swelling with ill-defined border over the dorsomedial aspect of the first metacarpal was noted. The swelling was mobile only in the vertical plane with restricted adduction and abduction. Plain X-ray revealed mild erosion of the first metacarpal head. Diagnostic ultrasound confirmed the lesion to arise from the extensor tendon sheath of diffuse type without any bony involvement. A wide local excision biopsy of the swelling was planned. Intraoperatively, a 3×2 cm greyish-white mass, bony hard in consistency with lobulated surface was found arising from the tendon sheath of the extensor tendon of the thumb; it was completely excised with a wide margin. Histopathological examination revealed polyhedral cells admixed with osteoclastic type giant cells. Biopsy from the first metatarsal was normal. The patient is on follow-up for the last 5 years with no evidence of recurrence.

No abstract

A comparison was made between Mg alloy and A3 steel on weight, bending, sound absorption, and vibration conditions. In this study, a swivel plate, which is used in rotating car seats, is to be taken into consideration for finding bending, natural frequency, and frequency under static loading conditions. The swivel plate is generally made up of A3 steel plate; instead, we have replaced that with Mg alloy (AZ91D) plate. Stiffness, flexural strength, natural frequency, frequency under different static loading conditions, and sound absorption capacity were obtained through experimental methods. Finally, it was concluded that the damping capacity of Mg alloy of swivel plate is higher, has better stiffness, and incurred weight reduction by 26.58% less than that of the A3 steel. Also, the Mg alloy material exhibits better specific flexural strength, and specific flexural modulus and sound absorption coefficient are 11.76% and 25% higher than those of A3 steel at higher frequency level (2000 Hz) and at lower frequency level (100 Hz).