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Over the past two decades, robots have been increasingly used in biomedical applications such as bone cutting. Traditional automated manufacturing processes are often unable to meet the safety and accuracy requirements for such applications, particularly for cutting inhomogeneous constitutions of bone. In this case, human–robot cooperation may prove to be an effective approach. In this paper, we demonstrate that a hybrid parallel manipulator under cooperative force control can achieve accurate bone cutting with sufficient safety guaranteed. First, a hybrid parallel manipulator was constructed to provide the required rigidity for bone cutting. Then a two-loop controller was designed to implement the human–robot cooperation in bone cutting. The position control loop of adaptive fuzzy control is responsible for achieving high-tracking performance by overcoming varying friction forces from the mechanism. The force control loop of the cooperative force control adjusts the feed rate of the cutter according to the bone slicing conditions and operator's supervisory commands. The experimental results show that the proposed controller can effectively achieve the required accuracy in bone cutting with required safety. [ABSTRACT FROM AUTHOR]

Proximal femoral deformities can occur in children as sequelae of several disorders such as hip joint infection or avascular necrosis of the femoral head. Early surgical correction of deformities promises a good result; however, limited exposure of the surgical field often creates difficulties for surgeons. Application of a rapid prototyping model for proximal femoral corrective osteotomy in children serves not only as a guide for surgical planning but also as a communication tool between physicians and patients. [ABSTRACT FROM AUTHOR]

Although scoliosis is commonly seen in patients with Prader-Willi syndrome, the patterns and extent of the deformity may change along their growth. Increased body weight is another issue in these patients, and its relationship with scoliosis is still controversial. The aim of this study was to evaluate scoliosis in patients with PWS, and its relationship with BMI. This was a retrospective cohort study in which a series of radiographic images and BMI from each patient were collected, and the data were rearranged following the age at which they were recorded. These patients were subsequently labeled as non-Scoliotic (<10°), Moderate (10° - 39°), and Severe (≥40°) according to their final Cobb angle, also as Normal (≤85%), Overweight (86%-95%), and Obese (≥95%) according to final BMI percentage. Thirty-four patients with age from 1 to 20 years old were recruited for this study, and the mean length of follow-up was 6.6 years. The prevalence of scoliosis was 71% (24 patients in Moderate, and 9 patients in Severe), and 65.6% were either overweight (11 patients) or obese (10 patients). The mean BMI percentage in non-scoliotic patients was 93.10 ± 13.84, which was significantly higher than that of the scoliotic groups ( P  = 0.0180). When looking at the longitudinal change, the non-Scoliotic group had high BMI since childhood, and obese patients had less spine deformity also from early childhood. In this study, we found that the prevalence of scoliosis in Taiwanese population with PWS was 71% without gender preference. Not every patient had a high BMI, and obese patients seemed to have significantly less chance to develop scoliosis. Level III., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The optimal treatment for femoral fractures in children is controversial. The purpose of this study was to compare the results of Rush pin fixation with those of conservative treatment, and to evaluate the sequels of growth plate injury by internal fixation., Methods: Eighteen femoral shaft fractures in 17 children who had concomitant head injury or multiple traumas were treated surgically. The mean age at operation was 9 years 3 months (range, 7 years 5 months to 11 years 1 month). One Rush pin was inserted from the tip of the greater trochanter, without reaming, to fix the fracture. Another 20 age-matched children treated by traction and casting were the control subjects., Results: All the fractures united without consequences. In addition to a decrease in hospital stay with the use of the Rush pin (10 days vs. 27 days, p<0.05), fewer leg length discrepancies (4.2 mm vs. 7.1 mm, p<0.05) were also noted, compared with conservative treatment. The growth of the proximal femur after Rush pin fixation was evaluated after an average of 59 months. No femur shortening, coxa valgus, or hip dysplasia was noted., Conclusions: Intramedullary Rush pin fixation for femoral shaft fracture in children older than 7 years is a simple and reliable alternative. One narrow and non-reaming pin inserted from greater trochanter did not demonstrate femoral growth inhibition.

Acute primary infection of the epiphysis is uncommon. We present 2 cases of acute osteomyelitis of the distal femoral epiphysis. They were not diagnosed until 10 days and 3 weeks, respectively, after the onset of symptoms. The epiphyseal infection spread into the knee joint, and surgical debridement was performed. The majority of reported cases in the medical literature are of bacterial etiology, and the most common pathogen is Staphylococcus aureus. We report a rare case which was infected by Salmonella enteritidis. Prompt diagnosis and early treatment are required to prevent further destruction and growth disturbance.