Navigation-Assisted Total Knee Arthroplasty for a Valgus Knee Improves Limb and Femoral Component Alignment.

The purpose of this study was to evaluate the influence of navigation-assisted surgery on radiographic and clinical outcomes after total knee arthroplasty (TKA) for a valgus knee. The authors identified all patients who underwent TKA for a valgus knee between January 2005 and December 2015. Among 83 conventional TKA cases and 55 navigation-assisted TKA cases, propensity score matching was performed for age, sex, body mass index, and preoperative lower limb mechanical axis. Fifty knees were matched to 50 knees. Each case was evaluated regarding lower limb mechanical axis, mechanical lateral distal femoral angle, medial proximal tibial angle, patellar tilt angle, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society score, and range of motion. Lower outliers of lower limb mechanical axis (30% vs 8%, P=.008) and mechanical lateral distal femoral angle (24% vs 10%, P=.046) were found in navigation-assisted TKA. However, outliers of medial proximal tibial angle, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society score, and range of motion were similar between the 2 different surgical techniques. Navigation-assisted surgery is correlated with fewer outliers of postoperative lower limb alignment and femoral component position but not tibial component position in TKA for preoperative valgus knee. Clinical outcomes for navigation-assisted TKA were not superior to those for conventional TKA. [Orthopedics. 2019; 42(2):e253-e259.].

Factors affecting femoral rotational angle based on the posterior condylar axis in gap-based navigation-assisted total knee arthroplasty for valgus knee.

BACKGROUND: Achieving proper rotational alignment of the femoral component in total knee arthroplasty (TKA) for valgus knee is challenging because of lateral condylar hypoplasia and lateral cartilage erosion. Gap-based navigation-assisted TKA enables surgeons to determine the angle of femoral component rotation (FCR) based on the posterior condylar axis. This study evaluated the possible factors that affect the rotational alignment of the femoral component based on the posterior condylar axis. MATERIALS AND METHODS: Between 2008 and 2016, 28 knees were enrolled. The dependent variable for this study was FCR based on the posterior condylar axis, which was obtained from the navigation system archives. Multiple regression analysis was conducted to identify factors that might predict FCR, including body mass index (BMI), Kellgren-Lawrence grade (K-L grade), lateral distal femoral angles obtained from the navigation system and radiographs (NaviLDFA, XrayLDFA), hip-knee-ankle (HKA) axis, lateral gap under varus stress (LGVS), medial gap under valgus stress (MGVS), and side-to-side difference (STSD, MGVS - LGVS). RESULTS: The mean FCR was 6.1° ± 2.0°. Of all the potentially predictive factors evaluated in this study, only NaviLDFA (ß = -0.668) and XrayLDFA (ß = -0.714) predicted significantly FCR. CONCLUSIONS: The LDFAs, as determined using radiographs and the navigation system, were both predictive of the rotational alignment of the femoral component based on the posterior condylar axis in gap-based TKA for valgus knee. A 1° increment with NaviLDFA led to a 0.668° decrement in FCR, and a 1° increment with XrayLDFA led to a 0.714° decrement. This suggests that symmetrical lateral condylar hypoplasia of the posterior and distal side occurs in lateral compartment end-stage osteoarthritis with valgus deformity.

Role of procalcitonin in infected diabetic foot ulcer.

AIMS: Procalcitonin (PCT) has been recently accepted as a marker for diagnosing infection. The aim of the present study was to determine whether PCT levels are associated with infection severity of diabetic foot ulcers and whether PCT levels would be helpful to differentiate infected diabetic foot ulcer (IDFU) from IDFU associated with other infectious diseases (IDFU+O). METHODS: We prospectively included 123 diabetic patients hospitalized for IDFU. Infection severity of diabetic foot ulcers was graded according to the Infectious Diseases Society of America-International Working Group on the Diabetic Foot clinical classification of diabetic foot infection. Chest radiograph, urinalysis, urine microscopy, urine culture, and blood cultures (if fever was present) were performed for all patients to diagnose other infectious diseases. Laboratory parameters were measured from blood venous samples. RESULTS: PCT (Spearman's ρ=0.338, P<0.001) and C-reactive protein (Spearman's ρ=0.477, P<0.001) levels were significantly associated with infection severity of diabetic foot ulcers. However, only PCT levels could differentiate patients with associated infectious diseases from patients with no concomitant infection (area under the receiver-operator characteristic curve 0.869, P<0.0001; cut-off value 0.59; sensitivity 94.7; specificity 88.5). CONCLUSION: PCT and CRP levels positively correlated with infection severity of diabetic foot ulcers and PCT levels>0.59ng/mL in patients with IDFU may be associated with other systemic bacterial infection.

Changes in coronal alignment of the ankle joint after high tibial osteotomy.

PURPOSE: The purpose of this study was to investigate changes in coronal alignment of the ankle joint after HTO. Our hypothesis was that ankle joint orientation may become more parallel or less parallel to the ground after HTO, and this change may affect ankle symptoms. METHODS: Eighty-six knees were retrospectively analysed after HTO for varus osteoarthritis. Preoperative and follow-up whole-leg radiographs were taken. The hip-knee-ankle (HKA) angle and medial proximal tibial angle (MPTA) were measured to evaluate coronal alignment of the knee. Tibial plafond inclination (TPI), talar inclination (TI), talar tilt (TT), and lateral distal tibial angle (LDTA) were measured to evaluate coronal alignment of the ankle. Patients were divided into two groups: those who exhibited a decrease in the absolute value of TPI and TI after HTO (group A) and those who exhibited an increase in the absolute value of TPI or TI after HTO (group B). Clinical outcomes of the knee and ankle were evaluated pre- and postoperatively. RESULTS: Mean TPI and TI changed from 6.9° ± 3.6° and 8.0° ± 3.8° to 2.8° ± 3.1° and 3.9° ± 3.0° in group A (P < 0.001 for both) and from -1.3° ± 3.7° and 0.6° ± 4.5° to -6.0° ± 4.2° and -4.6° ± 5.9° in group B (P = 0.018 for both). VAS for ankle pain did not change significantly after HTO (n.s.) in group A, whereas those of group B increased significantly after HTO (P = 0.014). CONCLUSION: Ankle joint orientation becomes more parallel or less parallel to the ground after HTO. Smaller preoperative HKA and LDTA result in a more valgus ankle joint orientation after HTO. Ankle symptoms were affected by coronal alignment changes of the ankle after HTO. LEVEL OF EVIDENCE: III.

A Novel Medial Soft Tissue Release Method for Varus Deformity during Total Knee Arthroplasty: Femoral Origin Release of the Medial Collateral Ligament.

INTRODUCTION: Numerous methods of medial soft tissue release for severe varus deformity during total knee arthroplasty (TKA) have been reported. These include tibial stripping of the superficial medial collateral ligament (MCL), pie-crusting technique, and medial epicondylar osteotomy. However, there are inherent disadvantages in these techniques. Authors hereby present a novel quantitative method: femoral origin release of the medial collateral ligament (FORM). SURGICAL TECHNIQUE: For medial tightness remaining even after the release of the deep MCL and semimembranosus, the FORM is initiated with identification of the femoral insertion area of the MCL with the knee in flexion. Starting from the most posterior part of the femoral insertion, one third of the MCL femoral insertion is released from its attachment. If necessary, further sequential medial release is performed. MATERIALS AND METHODS: Seventeen knees that underwent the FORM were evaluated for radiological and clinical outcomes. RESULTS: Regardless of the extent of the FORM, no knees showed residual valgus instability at 24 weeks after surgery. CONCLUSIONS: As the FORM is performed in a stepwise manner, fine adjustment during medial release might be beneficial to prevent inadvertent over-release of the medial structures of the knee.

Comparison of the Modified McBride Procedure and the Distal Chevron Osteotomy for Mild to Moderate Hallux Valgus.

Distal metatarsal osteotomy and the modified McBride procedure have each been used for the treatment of mild to moderate hallux valgus. However, few studies have compared the results of these 2 procedures for mild to moderate hallux valgus. The purpose of the present study was to compare the results of distal chevron osteotomy and the modified McBride procedure for treatment of mild to moderate hallux valgus according to the severity of the deformity. We analyzed the data from 45 patients (49.5%; 48 feet [49.0%]), who had undergone an isolated modified McBride procedure (McBride group), and 46 patients (50.5%; 50 feet [51.0%]), who had a distal chevron osteotomy (chevron group). We subdivided each group into those with mild and moderate deformity and compared the clinical and radiologic outcomes between the groups in relation to the severity of the deformity. The improvements in the American Orthopaedic Foot and Ankle Society scale score and the visual analog scale for pain were significantly better for the chevron group for both mild and moderate deformity. The chevron group experienced significantly greater correction in the hallux valgus angle and intermetatarsal angle for both mild and moderate deformity. The chevron group experienced a significantly greater decrease in the grade of sesamoid displacement for patients with moderate deformity. The McBride group had a greater risk of recurrence than did the chevron group for moderate deformity (odds ratio 14.00, 95% confidence interval 3.91 to 50.06, p < .001). The results of the present study have demonstrated the superiority of the distal chevron osteotomy over the modified McBride procedure for mild to moderate deformity. For patients with moderate deformity, the McBride group had a greater risk of hallux valgus recurrence than did the distal chevron group. Therefore, we recommend distal chevron osteotomy rather than a modified McBride procedure for the treatment of mild and moderate hallux valgus.

Use of auxiliary locking plates for the treatment of unstable pertrochanteric femur fractures.

Pertrochanteric femur fractures are successfully treated by orthopedic surgeons worldwide, but maintaining the reduction status or fixation of the greater trochanter is sometimes difficult in unstable cases in elderly patients. Several biomechanical advantages have been reported in locking plates when compared with conventional plates; locking plates provide angular and axial stability, better rigidity, and no toggling, and they preserve periosteal blood supply. The authors describe the use of auxiliary locking plates in unstable pertrochanteric femur fractures in elderly patients. Mini locking plates are simple, straightforward, and versatile enough to be used in elderly patients.

Attitudes and reactions to a healthcare robot.

OBJECTIVE: The use of robots in healthcare is a new concept. The public's perception and acceptance is not well understood. The objective was to investigate the perceptions and emotions toward the utilization of healthcare robots among individuals over 40 years of age, investigate factors contributing to acceptance, and evaluate differences in blood pressure checks taken by a robot and a medical student. MATERIALS AND METHODS: Fifty-seven (n = 57) adults aged over 40 years and recruited from local general practitioner or gerontology group lists participated in two cross-sectional studies. The first was an open-ended questionnaire assessing perceptions of robots. In the second study, participants had their blood pressure taken by a medical student and by a robot. Patient comfort with each encounter, perceived accuracy of each measurement, and the quality of the patient interaction were studied in each case. Readings were compared by independent t-tests and regression analyses were conducted to predict quality ratings. RESULTS: Participants' perceptions about robots were influenced by their prior exposure to robots in literature or entertainment media. Participants saw many benefits and applications for healthcare robots, including simple medical procedures and physical assistance, but had some concerns about reliability, safety, and the loss of personal care. Blood pressure readings did not differ between the medical student and robot, but participants felt more comfortable with the medical student and saw the robot as less accurate. Although age and sex were not significant predictors, individuals who held more positive initial attitudes and emotions toward robots rated the robot interaction more favorably. CONCLUSIONS: Many people see robots as having benefits and applications in healthcare but some have concerns. Individual attitudes and emotions regarding robots in general are likely to influence future acceptance of their introduction into healthcare processes.

Bio-information scanning technology using an optical pick-up head.

We have developed a low cost and a highly compact bio-chip detection technology by modifying a commercially available optical pick-up head for CD/DVD. The highly parallel and miniaturized hybridization assays are addressed by the fluorescence emitted by the DNA-chip using the optical pick-up head. The gap between the objective lens and the bio-chip is regulated by the focus servo during the detection of the fluorescence signal. High-resolution and high-speed scanning is effectively realized by this simple scanning system instead of utilizing high-precision mechanism. Regardless of achievement of effective detection mechanism, the technique of fluorescence detection can prove to be disadvantageous because of the low stability of the dyes with low S/N ratio and an expensive setup such as a PMT detector is always required for fluorescence detection. We propose, for the first time, a novel scanning scheme based on metal nanoparticles in combination with a bio-chip substrate having a phase change recording layer. We found that the phase change process is highly affected by the existence of the densely condensed metal nanoparticles on the phase change layer during the writing process of the pick-up head.