Intracapsular fracture of the proximal femur in a bilateral above-knee amputee: A case report with technical tips for intraoperative positioning and literature review

Intracapsular fractures of the proximal femur are one of the most common fractures of the lower limbs. Most cases require osteosynthesis with suitable implants, and intraoperative positioning of the patient on the fracture table is a prerequisite to facilitate fracture manipulation, traction, reduction and fluoroscopy assessment. However, positioning the limbs of bilateral above-knee amputees for internal fixation of related proximal femoral fractures is a difficult task, which requires customized inventory for effective limb positioning and fracture manipulation. This study reported a rare case following a crush injury of bilateral lower limb in a road traffic accident, and described some technical tips of acute femoral neck fractures in bilateral above-knee amputation. The patient was managed with immediate guillotine amputation and later secondary wound closure followed by internal fixation of the right-sided femoral neck fracture with multiple cancellous cannulated screws.

Intent Pattern Recognition of Lower-limb Motion Based on Mechanical Sensors

Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.

Hemorrhagic shock due to ruptured lower limb vascular malformation in a neurofibromatosis type 1 patient:A case report

BACKGROUND Neurofibromatosis type 1(NF-1)is a common autosomal dominant genetic disorder.It is characterized by café-au-lait spots and cutaneous neurofibromas.Although NF-1 typically involves the skin,nerves,bones,and eyes,vascular manifestation in the form of devastating hemorrhage can occur rarely.CASE SUMMARY We present the case of a 47-year-old female with NF-1 who had a ruptured right lower limb arterial malformation.She presented with sudden right lower limb swelling for two hours and symptoms of hemorrhagic shock on admission.The physical examination revealed a right lower limb presenting as elephantiasis and visible dark-brown pigmentation over a large area.Computed tomography angiography showed right lower limb arteriovenous malformation.Therefore,the patient underwent emergency right lower limb digital subtraction angiography(DSA)and vascular embolization after blood transfusions.However,after DSA,vascular embolization,and repeated blood transfusions,the anemia and right lower limb swelling and tenderness did not improve.As a result,the patient underwent right lower extremity above-knee amputation.After amputation,the patient's hemoglobin level improved significantly without blood transfusion,and she was discharged from the hospital after the incision healed.Postoperative pathological examination suggested neurogenic tumors.No other complications had occurred 1-year follow-up.CONCLUSION Vascular malformation and rupture are fatal complications of NF-1.Embolization may not provide complete relief,the patient might need to undergo neurofibroma resection or amputation.