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Background: Patellar instability is the most common disorder of the knee during childhood and adolescence. Surgical treatment significantly reduces the rate of redislocation, but the underlying pathologies and pattern of instability may affect the results. We aimed to report the clinical and functional outcomes of the three-in-one procedure for patellar realignment in a cohort of skeletally immature patients with or without syndromes and various patterns of chronic patellar instability. Methods: We retrospectively investigated 126 skeletally immature patients (168 knees) affected by idiopathic or syndromic patellar instability, who underwent patella realignment through a three-in-one procedure. We classified the instability according to the score proposed by Parikh and Lykissas. Results: Patellar dislocation was idiopathic in 71 patients (94 knees; 56.0%) and syndromic in 55 (74 knees; 44.0%). The mean age at surgery was 11.5 years (range 4–18) and was significantly lower in syndromic patients. Syndromic patients also exhibited more severe clinical pattern at presentation, based on the Parikh and Lykissas score. The mean follow-up was 5.3 years (range 1.0–15.4). Redislocation occurred in 19 cases, with 10 cases requiring further realignment. The Parikh and Lykissas score and the presence of congenital ligamentous laxity were independent predictors of failure. A total of 22 knees in 18 patients required additional surgical procedures. The post-operative Kujala score was significantly lower in patients with syndromic patellar instability. Conclusions: The type of instability and the presence of underlying syndromes negatively affect the rate of redislocation and the clinical and functional outcome following patellar realignment through the three-in-one procedure. We recommend the consideration of alternative surgical strategies, especially in children with severe syndromic patellar dislocation.

(1) Background: The application of computer-aided planning in the surgical treatment of post-traumatic forearm deformities has been increasingly widening the range of techniques over the last two decades. We present the “flipping-wedge osteotomy”, a promising geometrical approach to correct uniapical deformities defined during our experience with virtual surgical planning (VSP); (2) Methods: a case of post-traumatic distal radius deformity (magnitude 43°) treated with a flipping-wedge osteotomy in an 11-year-old girl is reported, presenting the planning rationale, its geometrical demonstration, and the outcome of the procedure; (3) Results: surgery achieved correction of both the angular and rotational deformities with a neutral ulnar variance; (4) Conclusions: flipping-wedge osteotomy may be a viable option to achieve correction in forearm deformities, and it deserves further clinical investigation.

Complex deformities of lower limbs are frequent in children with genetic or metabolic skeletal disorders. Early correction is frequently required, but it is technically difficult and burdened by complications and recurrence. Herein, we described the case of a 7-year-old girl affected by severe bilateral genu varum due to spondyloepiphyseal dysplasia. The patient was treated by patient-specific osteotomies and customized structural wedge allograft using Virtual Surgical Planning (VSP) and 3D-printed patient-specific instrumentation (PSI). The entire process was performed through an in-hospital 3D-printing Point-of-Care (POC). VSP and 3D-printing applied to pediatric orthopedic surgery may allow personalization of corrective osteotomies and customization of structural allografts by using low-cost in-hospital POC. However, optimal and definitive alignment is rarely achieved in such severe deformities in growing skeleton through a single operation.

Joint fractures of the knee include epiphyseal detachments of the distal femur and proximal tibia (types 3 and 4 according to Salter-Harris). Extra-articular fractures include: avulsion of the tibial spines, detachment of the anterior tuberosity and patellar fractures. Fractures involving the distal femoral and proximal tibial epiphysis are relatively infrequent but may lead to long-term complications owing to the formation of post-traumatic bone bridges. Unless the fracture is composed, surgical treatment is always indicated. Avulsion fractures of the tibial spines occur as a result of a chondro-epiphyseal detachment of the insertion of the cruciate ligaments (predominantly the anterior one). They are infrequent injuries (3 per 100,000 cases per year, 2% of all knee injuries). Accurate diagnosis and appropriate treatment prevent unfortunate outcomes. Adolescent tibial tubercle fractures are uncommon, high-energy injuries sometimes combined with patellar tendon rupture; they represent a frequently missed diagnosis. Open reduction/internal fixation is generally required. Patellar fractures are caused by direct trauma (primary osseous fractures) or by an eccentric load during extension of the knee (sleeve and avulsion fractures). Most fractures require open reduction/internal fixation. The complication rate is low but late reconstruction of missed injuries may result in an extensor deficit.

Silicon MEMS microphones show competitive advantages to portable consumer electronics with tiny device size, high sound quality, reliability and affordability. The application of MEMS analog/digital microphones can now be found in smart phones, hearing aids, tablets, and automotive voice recognition systems. A double backplate (DB) MEMS transducer brings higher sensitivity and lower distortion compared to a single backplate MEMS. In this paper, we first show an attractive DB MEMS analog microphone where two sufficiently high positive DC voltages are required to bias top and bottom backplates, respectively. As a solution, a fully integrated dual-output high-voltage (HV) positive charge pump is proposed, and the layout area saving is about 40%. To verify the design, an analog readout ASIC is fabricated in a standard 0.18 um CMOS process, and the ASIC includes the proposed HV charge pump, clock generation, and other circuit blocks. In silicon validation, two voltages 12.42 V and 12.40 V with no ripples are generated successfully, and the settling time is well within 5 mS. The two voltages can be perfectly applied to the DB MEMS.

This paper presents a reconfigurable discrete-time audio Sigma-Delta modulator implemented in 0.18-µm CMOS technology. The 600, µm, ×, 400, µm core area SD modulator is based on a 2, +, 2 MASH architecture, and features several different operating modes in which noise-shaping order, number of output word bits, sampling rate, and bandwidth can be programmed ad hoc. By design, the power consumption is minimized for the selected operating mode. The achieved performance ranges from 99-dB DR with 4th-order noise shaping and full standard audio bandwidth, while consuming 0.97 mW down to 85-dB DR with second order noise shaping over reduced bandwidth for vocal control operation, while consuming 100, µW. The developed device can be used either to read-out different sources (microphones) or to operate in different modes within the same system (i.e. with the same microphone in different scenarios). The trade-off between performance and re-configurability is the key element of this work.

Digital audio sensors have been used in microphone-embedded portable electronics. This paper shows a mixed-signal adaptive readout ASIC for digital audio sensor, which includes a programmable-gain-amplifier, a switched-capacitor sigma-delta modulator, digital signal processing, and power management circuits. The digital part comprises a digital low-pass filter, a digital-gain-compensation and a digital automatic-gain-controller. The clear advantage of this system is to obtain high signal-to-noise ratio (SNR) and wide input range simultaneously. In addition, both a normal operation mode and a sleep mode are realized to address a flexible current budget. The ASIC is fabricated in a 0.18-um CMOS process. Experimental results show the expected adaptive readout function over the input range from 94 to 136Â dB SPL. In the normal mode, a system SNR of 68Â dB (A-weighted) at 1Â kHz 94Â dB SPL input is achieved under 600Â uA. Further, an impressive acoustic overload point (AOP) of 136Â dB SPL is guaranteed. In the standby condition, the sleep mode with current less than 20Â uA is obtained, so that the battery life can be extended. Compared to other existing solutions, this adaptive readout ASIC shows the best combination of achievable SNR, AOP and current budget for digital audio sensors.

Mixed-signal speech processing system has been used in microphone-embedded portable electronics. Speech codec is the core of such a system. In speech codecs, sigma-delta modulator is one key block which converts analog voice signal into pulse density modulation (PDM) output for further digital signal processing. This paper shows the design of a triple-mode switched-capacitor sigma-delta modulator for speech codec. High mode (20 kHz signal bandwidth), low mode (4 kHz signal bandwidth), and sleep mode are implemented by addressing a flexible operation current. In order to realize a fully integrated solution, power management circuits dedicated to the modulator are also implemented, which includes frequency detector, LDO, bandgap and reference voltage buffers. The ASIC is fabricated in a 0.18-um CMOS process. In high mode measurement, an A-weighted signal-to-noise ratio (SNR) of 78 dB with −2.5 dBFS input is achieved under 138 uA. In low mode measurement, an SNR of 78 dB with −2 dBFS is achieved under 100 uA. In the standby condition, a sleep mode with current less than 10 uA is realized, so that the battery life is extended.

Adolescent hallux valgus is a common problem, and there is no agreement about the best surgical technique to use to correct this deformity. Excellent results have been reported with a distal soft tissue procedure and an associated osteotomy at the base of the first metatarsal. The current study reports the early results of using an incomplete osteotomy at the base of the first metatarsal. No hardware was used to fix the osteotomy, and the postoperative immobilization was shorter. The study included 20 feet in 11 female patients. All osteotomies healed primarily without complications. The average preoperative hallux valgus of 31.2 degrees was reduced to 17.8 degrees at a minimum of 2 years follow-up. The average intermetatarsal angle improved from 13.5 degrees in the preoperative period to 11.3 degrees. Using the duPont bunion rating score as an outcome assessment, the authors had 4 excellent and 16 good results.

Silicon MEMS microphones that offer small size, ease of integration with CMOS electronics, and the ability to withstand lead-free solder reflow cycles, are becoming increasingly popular for high-volume consumer electronic products, and are competing in price and performance with traditional electret condenser microphones [1]. The design of a MEMS microphone, consisting of a compliant membrane and a stiff back-plate forming a variable capacitor, is a challenging task with a number of design trade-offs [2]. For cost reasons, a small-area membrane is desired; however, lower acoustical noise is obtained with a larger membrane. In this work, we demonstrate a method to increase the SNR of a microphone system without the need for a complicated and risky MEMS die redesign. An SNR of 66dB is achieved using two microphones (instead of a single one) in a differential configuration, thus doubling the total membrane area.

This paper describes a novel method for trimming a low noise, differential micro-electromechanical system (MEMS) microphone with a state of the art signal to noise ratio (SNR) of 66 dB(A) and a sensitivity of -38 dBV/Pa @ 1 kHz after completing the fabrication process. The method allows compensating the electroacoustic variations caused by process tolerances and reducing specification limits of the microphone sensitivity from ±3 dB to ±0.5 dB. Trimming is done by programming the bias supply voltage of the capacitive membrane-backplate-system and the gain factor of the output pre-amplifier. Microphone sensitivity can be modified within a range of 11.2 dB. Thus the standard deviation of the sensitivity of a production batch could be reduced from 0.97 dB to 0.11 dB. Furthermore the SNR could be increased to 66.5 dB(A).