CaV α2δ Autoimmune Encephalitis: A Novel Antibody and its Characteristics.

OBJECTIVE: Discovery of a novel antibody would enable diagnosis and early treatment of autoimmune encephalitis. The aim was to discover a novel antibody targeting a synaptic receptor and characterize the pathogenic mechanism. METHOD: We screened for unknown antibodies in serum and cerebrospinal fluid samples from autoimmune encephalitis patients. Samples with reactivity to rat brain sections and no reactivity to conventional antibody tests underwent further processing for antibody discovery, using immunoprecipitation to primary neuronal cells, mass-spectrometry analysis, an antigen-binding assay on an antigen-overexpressing cell line, and an electrophysiological assay with cultured hippocampal neurons. RESULTS: Two patients had a novel antibody against CaV α2δ (voltage-gated calcium channel alpha-2/delta subunit). The patient samples stained neuropils of the hippocampus, basal ganglia, and cortex in rat brain sections and bound to a CaV α2δ-overexpressing cell line. Knockdown of CaV α2δ expression in cultured neurons turned off the immunoreactivity of the antibody from the patients to the neurons. The patients were associated with preceding meningitis or neuroendocrine carcinoma and responded to immunotherapy. In cultured neurons, the antibody reduced neurotransmitter release from presynaptic nerve terminals by interfering with tight coupling of calcium channels and exocytosis. INTERPRETATION: Here, we discovered a novel autoimmune encephalitis associated with anti-CaV α2δ antibody. Further analysis of the antibody in autoimmune encephalitis might promote early diagnosis and treatment. ANN NEUROL 2021;89:740-752.

Comparison of Cable Method and Miniaci Method Using Picture Archiving and Communication System in Preoperative Planning for Open Wedge High Tibial Osteotomy.

PURPOSE: The purpose was to compare the accuracy of Miniaci method using picture archiving and communication system (PACS) with a cable method in high tibial osteotomy (HTO). MATERIALS AND METHODS: This study analyzed 47 patients (52 knees) with varus deformity and medial osteoarthritis. From 2007 to 2013, patients underwent HTO using either a cable method (20 knees) or Miniaci method based on a PACS image (32 knees). In the cable method, the 62.5% point of the mediolateral tibial plateau width was located using an electrocautery cord under fluoroscopy (cable group). The Miniaci method used preoperative radiographs to shift the weight bearing axis (PACS group). Full-length lower limb radiographs obtained preoperatively and at the sixth postoperative week were used to compare the percentage of crossing point of the weight bearing line on the tibial plateau with respect to the medial border. RESULTS: The weight bearing line on the tibial plateau was corrected from a preoperative 11.0±7.0% to a postoperative 47.2±7.4% in the cable group and from 12.7±4.9% to 59.5±5.3% in the PACS group. The mechanical femorotibial angle was corrected from varus 8.9±3.7° to valgus 0.3±4.0° in the cable group and from varus 9.0±3.3° to valgus 2.9±2.6° in the PACS group. CONCLUSIONS: In HTO, correction based on the Miniaci method using a PACS was more accurate than correction using the cable method.

Two-Stage Revision for Infected Total Knee Arthroplasty: Based on Autoclaving the Recycled Femoral Component and Intraoperative Molding Using Antibiotic-Impregnated Cement on the Tibial Side.

BACKGROUND: The purpose of this study was to determine the degree of infection control and postoperative function for new articulating metal-on-cement spacer. METHODS: A retrospective study of 19 patients (20 cases), who underwent a two-stage revision arthroplasty using mobile cement prosthesis, were followed for a minimum of 2 years. This series consisted of 16 women and 3 men, having an overall mean age of 71 years. During the first stage of revision, the femoral implant and all the adherent cement was removed, after which it was autoclaved before replacement. The tibial component was removed and a doughy state, antibiotic-impregnated cement was inserted on the tibial side. To achieve joint congruency, intraoperative molding was performed by flexing and extending the knee joint. Each patient was evaluated clinically and radiologically. The clinical assessments included range of motion, and the patients were scored as per the Hospital for Special Surgery (HSS) and Knee Society (KS) criteria. RESULTS: The mean range of knee joint motion was 70° prior to the first stage operation and 72° prior to the second stage revision arthroplasty; following revision arthroplasty, it was 113° at the final follow-up. The mean HSS score and KS knee and function scores were 86, 82, and 54, respectively, at the final follow-up. The success rate in terms of infection eradication was 95% (19/20 knees). No patient experienced soft tissue contracture requiring a quadriceps snip. CONCLUSIONS: This novel technique provides excellent radiological and clinical outcomes. It offers a high surface area of antibiotic-impregnated cement, a good range of motion between first and second stage revision surgery for the treatment of chronic infection after total knee arthroplasty, and is of a reasonable cost.

Biplanar Open Wedge High Tibial Osteotomy in the Medial Compartment Osteoarthritis of the Knee Joint: Comparison between the Aescula and TomoFix Plate.

BACKGROUND: The purpose of this study was to compare the results of Aescula and TomoFix plates used for biplanar open wedge high tibial osteotomy in medial osteoarthritis of the knee joint with varus deformity. METHODS: A consecutive series of 50 cases of biplanar open wedge high tibial osteotomy were evaluated retrospectively. Group A contained 25 cases treated by using the Aescula plate, and group T contained 25 cases treated by using the TomoFix plate. Full weight-bearing was permitted at 6 weeks after surgery in group A and at 2 weeks in group T. Clinical evaluations were performed at the final follow-up by using postoperative knee scores and functional scores. Radiographic analysis included postoperative mechanical femur-tibia angle, change in posterior tibial slope angle, and complications related to implants. The mean follow-up periods were 30 months in group A and 26 months in group T. RESULTS: The knee and functional scores were improved at the final follow-up in both groups (p < 0.05), but no differences were observed between the two groups (p > 0.05). An acceptable correction angle was obtained in 52% of group A and in 84% of group T (p = 0.015). Change in posterior tibial slope angle was larger in group A than in group T (p < 0.001), showing better maintenance of posterior tibial slope in group T. In group A, there were 3 cases of screw loosening and 4 cases of delayed union. In addition, there were residual varus deformities in 7 cases (6 in group A and 1 in group T). CONCLUSIONS: This study shows that firm fixation using a TomoFix plate for open wedge high tibial osteotomy produces better radiologic results and a low complication rate than those of the Aescula spacer plate.

Prognostic Factors of Arthroscopic Extensor Carpi Radialis Brevis Release for Lateral Epicondylitis.

PURPOSE: The purpose of this study was to analyze factors affecting the treatment outcomes and prognoses of arthroscopic debridement for refractory lateral epicondylitis. METHODS: We included 45 patients who had undergone arthroscopic extensor carpi radialis brevis release for chronic refractory lateral epicondylitis between October 2008 and December 2012. Demographic data, magnetic resonance imaging studies, and arthroscopic findings were examined and analyzed. RESULTS: The mean age of the enrolled patients (23 men and 22 women) was 45.9 ± 7.8 years, and the mean follow-up duration was 26.9 ± 9.0 months. All the patients showed significant clinical improvement on all parameters assessed using the visual analog scale (6.9 preoperatively to 0.9 postoperatively), the Upper Extremity Functional Scale (34.8 to 66.7), and the Mayo Elbow Score (63.5 to 92.3) (P < .05). There were no reports of serious surgical complications. At final follow-up, 37 patients (82.2%) were satisfied with their outcomes whereas 8 patients (17.8%) were dissatisfied. In terms of demographic factors, female sex was significantly different between the 2 groups. On preoperative magnetic resonance imaging, 7 patients in the satisfied group (18.9%) had a definite tendon lesion (grade III defect, ≥6 mm) whereas 6 patients in the dissatisfied group (75%) had a grade III defect (P = .016). CONCLUSIONS: Overall, clinical outcome scores showed improvement after arthroscopic extensor carpi radialis brevis release for refractory lateral epicondylitis. However, preoperative tendon status and sex were associated with dissatisfaction and poor postoperative outcomes after the arthroscopic release procedure. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Comparison of results between hook plate fixation and ligament reconstruction for acute unstable acromioclavicular joint dislocation.

BACKGROUND: In the present study, we aimed to compare clinical and radiographic outcomes between hook plate fixation and coracoclavicular (CC) ligament reconstruction for the treatment of acute unstable acromioclavicular (AC) joint dislocation. METHODS: Forty-two patients who underwent surgery for an unstable acute dislocation of the AC joint were included. We divided them into two groups according to the treatment modality: internal fixation with a hook plate (group I, 24 cases) or CC ligament reconstruction (group II, 18 cases). We evaluated the clinical outcomes using a visual analog scale (VAS) for pain and Constant-Murley score, and assessed the radiographic outcomes based on the reduction and loss of CC distance on preoperative, postoperative, and final follow-up plain radiographs. RESULTS: The mean VAS scores at the final follow-up were 1.6 ± 1.5 and 1.3 ± 1.3 in groups I and II, respectively, which were not significantly different. The mean Constant-Murley scores were 90.2 ± 9.9 and 89.2 ± 3.5 in groups I and II, respectively, which were also not significantly different. The AC joints were well reduced in both groups, whereas CC distance improved from a mean of 215.7% ± 50.9% preoperatively to 106.1% ± 10.2% at the final follow-up in group I, and from 239.9% ± 59.2% preoperatively to 133.6% ± 36.7% at the final follow-up in group II. The improvement in group I was significantly superior to that in group II (p < 0.001). Furthermore, subluxation was not observed in any case in group I, but was noted in six cases (33%) in group II. Erosions of the acromion undersurface were observed in 9 cases in group I. CONCLUSIONS: In cases of acute unstable AC joint dislocation, hook plate fixation and CC ligament reconstruction yield comparable satisfactory clinical outcomes. However, radiographic outcomes based on the maintenance of reduction indicate that hook plate fixation is a better treatment option.

Single-Bundle Anterior Cruciate Ligament Reconstruction with Semitendinosus Tendon Using the PINN-ACL CrossPin System: Minimum 4-Year Follow-up.

PURPOSE: This study evaluated mid-term results of anterior cruciate ligament (ACL) reconstruction using the PINN-ACL CrossPin system that allowed for short graft fixation. MATERIALS AND METHODS: Forty-three patients underwent single-bundle ACL reconstruction with a 4-strand semitendinosus tendon graft using the PINN-ACL CrossPin system. Femoral fixation was done using the PINN-ACL CrossPin system, and the tibial side was fixed with post-tie and a bioabsorbable interference screw. The mean follow-up period was 50 months. Evaluation was done using the Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC) score and grade. Anterior displacement was assessed. RESULTS: There was improvement in the Lachman test and pivot-shift test at final follow-up, form grade II (n=40) or III (n=3) to grade I (n=3) or 0 (n=40) and from grade I (n=20) or II (n=10) to grade I (n=8) or 0 (n=22), respectively. The mean IKDC score was 88.7, and grade A and B were 93.0% at final follow-up. Side-to-side difference was improved from 6.7 mm to 2.1 mm at final follow-up. Complications occurred in 3 patients, a re-ruptured due to trauma at 2 years after surgery and a deep infection and a superficial infection. CONCLUSIONS: The mid-term follow-up results of ACL reconstruction with the PINN-ACL CrossPin system were satisfactory. The PINN-ACL CrossPin can be considered as a useful instrument for short graft fixation.

Biomechanical analysis of operative methods in the treatment of extra-articular fracture of the proximal tibia.

BACKGROUND: To determine relative fixation strengths of a single lateral locking plate, a double construct of a locking plate, and a tibial nail used in treatment of proximal tibial extra-articular fractures. METHODS: Three groups of composite tibial synthetic bones consisting of 5 specimens per group were included: lateral plating (LP) using a locking compression plate-proximal lateral tibia (LCP-PLT), double plating (DP) using a LCP-PLT and a locking compression plate-medial proximal tibia, and intramedullary nailing (IN) using an expert tibial nail. To simulate a comminuted fracture model, a gap osteotomy measuring 1 cm was created 8 cm below the knee joint. For each tibia, a minimal preload of 100 N was applied before loading to failure. A vertical load was applied at 25 mm/min until tibial failure. RESULTS: Under axial loading, fixation strength of DP (14,387.3 N; standard deviation [SD], 1,852.1) was 17.5% greater than that of LP (12,249.3 N; SD, 1,371.6), and 60% less than that of IN (22,879.6 N; SD, 1,578.8; p < 0.001, Kruskal-Wallis test). For ultimate displacement under axial loading, similar results were observed for LP (5.74 mm; SD, 1.01) and DP (4.45 mm; SD, 0.96), with a larger displacement for IN (5.84 mm; SD, 0.99). The median stiffness values were 2,308.7 N/mm (range, 2,147.5 to 2,521.4 N/mm; SD, 165.42) for the LP group, 4,128.2 N/mm (range, 3,028.1 to 4,831.0 N/mm; SD, 832.88) for the DP group, and 5,517.5 N/mm (range, 3,933.1 to 7,078.2 N/mm; SD, 1,296.19) for the IN group. CONCLUSIONS: During biomechanical testing of a simulated comminuted proximal tibial fracture model, the DP proved to be stronger than the LP in terms of ultimate strength. IN proved to be the strongest; however, for minimally invasive osteosynthesis, which may be technically difficult to perform using a nail, the performance of the DP construct may lend credence to the additional use of a medial locking plate.

The incidence and the risk factors of venous thromboembolism in Korean patients with pelvic or acetabular fractures.

BACKGROUND: Pelvic ring and acetabular fractures are the results of high energy trauma, but there is a paucity of information available regarding the incidence and risk factors of venous thromboembolism (VTE) after these injuries in Asians. This study was undertaken to evaluate the incidence of VTE after a pelvic or an acetabular fracture and to identify predictive factors. METHODS: A prospective evaluation was performed by indirect computed tomography (CT) venography in patients with pelvic or acetabular fractures. Ninety-five patients were examined by indirect CT venography. Fifty-five patients suffered from a pelvic ring injury (anteroposterior compression 5, lateral compression 25, vertical shear 25), and the remaining 40 from acetabular fractures (simple 18, complex 22). Indirect CT venography was performed within 1-2 weeks of initial trauma. Relationships between VTE and sex, age, fracture pattern, body mass index, injury severity score, period of immobilization, and need for surgical treatment were analyzed. Deep vein thrombosis (DVT) in a more proximal to popliteal vein and the existence of PE were considered clinically significant. RESULTS: Thirty-two patients (33.7 %) were found to have VTE at an average of 11 days after initial injury. Clinically significant DVT was found 20 cases (21.1 %). No statistical difference was found between pelvic ring injuries and acetabular fractures with respect to the development of VTE. For those with pelvic ring injury, the incidence of VTE in those with a vertical shear injury (52 %) was significantly greater than in others with a pelvic ring injury (p = 0.014). Patients with an age >50 were found to be at greater risk of VTE (p = 0.032). CONCLUSION: Our findings demonstrate that Korean patients with pelvic or acetabular fractures have a higher risk of VTE than is generally believed, and caution should be taken to prevent and treat VTE, especially in high energy pelvic ring injury and elderly patients.

Midterm results of primary total hip arthroplasty using highly cross-linked polyethylene: minimum 7-year follow-up study.

The purpose of this study was to investigate the results of 113 total hip arthroplasties in 109 patients using highly cross-linked polyethylene (HXLPE) after midterm (minimum 7 years) follow-up retrospectively. The mean age at the time of operation was 57 years. Preoperative diagnosis was osteonecrosis in 81 hips and other diagnosis in 32 hips. There was no component loosening. Acetabular osteolysis was found in 12 hips (10.6 %). Mean linear HXLPE wear rate was 0.031 ± 0.012 mm/y. We analyzed the relationship between HXLPE wear rate and several variables influencing HXLPE wear. Only the cup position was related with wear rate of HXLPE significantly (P < .05). The results of total hip arthroplasties using HXLPE showed excellent results with decreased wear rate and low incidence of osteolysis after midterm follow-up.