Long-Term Outcomes of High-Flexion Design Total Knee Arthroplasty with a Short Posterior Flange.

Background: The purpose of this study was to evaluate the clinical and radiological outcomes of high-flexion total knee arthroplasty (TKA) using Vega Knee System (B. Braun, Aesculap) at a long-term follow-up and to analyze the implant survivorship. Methods: We enrolled 165 patients (232 knees) with a minimum 7-year follow-up after TKA (VEGA Knee System). For clinical assessment, range of motion (ROM), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) were used. For radiologic assessment, hip-knee-ankle angle, component position, and the existence of radiolucent lines and loosening were used. Survival analysis was conducted using the Kaplan-Meier method. Results: The mean follow-up period was 9.8 years. The mean ROM increased from 124.4° to 131.4° at the final follow-up. The WOMAC score decreased from 38.5 to 17.4 at the final follow-up (p < 0.001). All 5 subscales of the KOOS improved at the final follow-up (all subscales, p < 0.001). Revision TKA was performed in 10 cases (4.3%), which included 9 cases of aseptic loosing and 1 case of periprostatic joint infection. Of the 9 aseptic loosening cases (3.9%), 8 cases (3.4%) were loosening of the femoral component and 1 case (0.4%) was loosening of the tibial component. When revision for any reason was considered an endpoint, the 10-year survivorship was 96.2% (95% confidence interval [CI], 93.9%-98.5%). On the other hand, when revision for aseptic loosening was considered the endpoint, the 10-year survivorship was 96.6% (95% CI, 94.4%-98.8%). Conclusions: The Vega Knee System provided good clinical results in the long-term follow-up period. Although the VEGA Knee System showed acceptable implant survivorship, loosening of the femoral component occurred in about 3.4% of the patients. For more accurate evaluation of the survivorship of high-flexion design TKA with a short posterior flange, it is necessary to conduct more long-term follow-up studies targeting diverse races, especially Asians who frequently perform high-flexion activities.

[Imaging of Sequestered Lumbar Discs]. / 요추 분리추간판의 영상 소견.

Intervertebral disc herniation is frequently encountered in radiological practice. Sequestered disc herniation occurs when the disc material undergoes degeneration and completely loses continuity with the parent nucleus pulposus. Sequestered discs can reside within and outside the spinal canal, exerting a mass effect on adjacent structures, compressing nerve pathways, and eliciting a range of clinical symptoms. In particular, sequestered discs within the dura cannot be identified without durotomy. Therefore, precise preoperative localization is crucial for surgical planning. On MRI, the signal intensity of the sequestered disc may vary due to independent degeneration processes. Additionally, most sequestered disc fragments show varying degrees of peripheral enhancement depending on the degree of angiogenesis and granulation around the isolated tissue. In this article, we review various imaging findings and the location of the sequestered disc to provide patients with an accurate diagnosis and appropriate treatment direction.

Patterns of Anterior Inferior Tibiofibular Ligament Avulsion Fracture Accompanied by Ankle Fracture.

The anterior inferior tibiofibular ligament (AITFL) avulsion fracture accompanying an ankle fracture can compromise ankle stability, necessitating accurate evaluation and a clear understanding of its pathophysiology.. The aim of this study was to investigate the association between AITFL avulsion fracture and Lauge-Hansen, Wagstaffe classification. A retro-prospective study was conducted at a university-affiliated tertiary care medical center. We selected 128 patients who underwent surgery at our institution between January 2013 and July 2017 and analyzed the association between AITFL avulsion fracture and the foot position. According to the modified Wagstaffe classification system, there were 39 cases of type II, followed by 9 cases of type III and 8 cases of type IV. Of the7 pronation-abduction fractures, 3 were AITFL avulsion fracture (43%), while of the 21 pronation-external rotation fractures, 9 were AITFL avulsion fracture (43%). Of the 95 supination-external rotation fractures, there were 56 cases (59%) of AITFL avulsion fractures. Of the pronation fractures, 0% were fibular avulsion fractures and 43% were tibial avulsion fractures. Of the supination fractures, 44% were fibular avulsion fractures and 16% were tibial avulsion fracture. The difference in the ratio of fibular to tibial avulsion fractures between pronation and supination fractures was significant (p < .001). These results suggest that tibial avulsion fractures of type IV in the modified Wagstaffe classification and pronation fractures occur due to collision with the anterolateral corners of the distal bone when the talus externally rotates. Moreover, in cases of pronation fractures, a new type of AITFL avulsion fracture has been observed.

Risk of Infection After Septic and Aseptic Revision Total Knee Arthroplasty: A Systematic Review.

BACKGROUND: The causes of primary total knee arthroplasty (TKA) failure can be divided into septic and aseptic etiologies. It is unclear whether the etiology affects the infection rate after revision TKA. This systematic review was conducted to evaluate whether there is a difference in infection rates between septic and aseptic revision TKA. We hypothesized that infection rates would be higher after septic revision TKA. METHODS: The PubMed and Embase databases and the Cochrane Library were searched to find studies evaluating infection rates following septic and aseptic revision TKA. We included studies that compared the postoperative infection rates of a group that received revision TKA for aseptic failure and a group that received 1- or 2-stage revision TKA for septic failure. Studies on re-revision TKA and on revision surgery after partial knee arthroplasty were excluded, as were studies of debridement, antibiotics, and implant retention (DAIR). RESULTS: Twelve studies were included in this systematic review. In studies in which 1- or 2-stage revision TKA was performed for septic failure, septic revision TKA had a significantly higher infection rate than aseptic revision TKA (odds ratio [OR], 6.83; 95% confidence interval [CI], 1.54 to 30.33; p = 0.01). Similarly, in studies in which 2-stage revision TKA was performed for septic failure, septic revision TKA had a significantly higher infection rate than aseptic revision TKA (OR, 4.14; 95% CI, 2.33 to 7.36; p < 0.00001). In the comparison of revision TKA for aseptic loosening and septic revision TKA, septic revision TKA had a higher infection rate than aseptic revision TKA (OR, 4.45; 95% CI, 2.28 to 8.70; p < 0.0001). CONCLUSIONS: Overall, septic revision TKA had a higher infection rate than aseptic revision TKA. Even when 2-stage revision TKA was performed for septic failure, the infection rate was higher after septic revision TKA than after aseptic revision. Surgeons should explain the relatively high infection rates to patients undergoing revision TKA for septic failure of their primary joint replacement. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Image quality and lesion detectability of deep learning-accelerated T2-weighted Dixon imaging of the cervical spine.

OBJECTIVES: To validate the subjective image quality and lesion detectability of deep learning-accelerated Dixon (DL-Dixon) imaging of the cervical spine compared with routine Dixon imaging. MATERIALS AND METHODS: A total of 50 patients underwent sagittal routine Dixon and DL-Dixon imaging of the cervical spine. Acquisition parameters were compared and non-uniformity (NU) values were calculated. Two radiologists independently assessed the two imaging methods for subjective image quality and lesion detectability. Interreader and intermethod agreements were estimated with weighted kappa values. RESULTS: Compared with the routine Dixon imaging, the DL-Dixon imaging reduced the acquisition time by 23.76%. The NU value is slightly higher in DL-Dixon imaging (p value: 0.015). DL-Dixon imaging showed superior visibility of all four anatomical structures (spinal cord, disc margin, dorsal root ganglion, and facet joint) for both readers (p value: < 0.001 ~ 0.002). The motion artifact scores were slightly higher in the DL-Dixon images than in routine Dixon images (p value = 0.785). Intermethod agreements were almost perfect for disc herniation, facet osteoarthritis, uncovertebral arthritis, central canal stenosis (κ range: 0.830 ~ 0.980, all p values < 0.001) and substantial to almost perfect for foraminal stenosis (κ = 0.955, 0.705 for each reader). There was an improvement in the interreader agreement of foraminal stenosis by DL-Dixon images, from moderate to substantial agreement. CONCLUSION: The DLR sequence can substantially decrease the acquisition time of the Dixon sequence with subjective image quality at least as good as the conventional sequence. And no significant differences in lesion detectability were observed between the two sequence types.

Biomechanical Comparative Study for Osteosynthesis of Pauwels Type III Femoral Neck Fractures: Conventional Devices versus Novel Fixed Angle Devices.

Purpose: Osteosynthesis has been recommended for treatment of Pauwels type III femoral neck fractures in young patients. However, no implant of choice has been reported so far. This study was conducted in order to compare the fixation stability of two conventional fixation methods with three different novel fixed angle devices in this type of fracture. Materials and Methods: A total of 25 composite femurs (4th Generation Saw bone; Pacific Research Laboratories, USA) corresponding to human bone were used. Pauwels type III fracture type was uniformly reproduced. Specimens were fixed with a cannulated screw, cannulated screw with cable, and Intertan nail, dynamic hip screw, and IKEY nail. Measurement of failure loads and the rotational change of the femoral head fragment was performed for evaluation of fixation stability. Results: All implants were compared with cannulated screw and dynmaic hip screw. No meaningful improvement was observed for the cannulated screw with cable compared with the cannulated screw and dynamic hip screw. Meaningful improvement in load-to-failure and y-rotation and z-rotation was observed for both the Intertan nail and IKEY nail compared with the cannulated screw. However, compared with the dynamic hip screw, only the IKEY nail showed improvement in the same profile but the Intertan nail did not. Conclusion: Among novel fixed angle devices, meaningful improvement was observed for the IKEY nail compared with conventional implants. Strengths of this implant include biomechanical stability and simplicity of surgical technique, indicating that it may be another good option for osteosynthesis of Pauwels type III femoral neck fractures.

Clinical outcomes of two-stage revision for chronic periprosthetic joint infection of the knee: culture-negative versus culture-positive.

BACKGROUND: The effect of negative culture on the treatment outcomes of chronic periprosthetic joint infection (PJI) is still controversial. The purpose of this study is to evaluate whether the outcomes of two-stage revision in culture-negative chronic PJI differ from those in culture-positive PJI. METHODS: The patients who received two-stage revisions due to chronic PJI during the period between 2007 and 2017 were retrospectively reviewed. The culture-negative and culture-positive PJI group included 57 cases and 79 cases, respectively. The demographic data, as well as reoperation, mortality, reinfection, and failure rates of each group were evaluated. RESULTS: There was a significant difference in reoperation rate between the two groups for the period from the first-stage surgery to the second-stage revision arthroplasty (p = 0.045). The reoperation rate of the culture-positive group was 25.3% (20/79) whereas that of the culture-negative group was 10.5% (6/57). Among the 136 PJI cases, 97 cases (71.3%) received reimplantation surgery (culture-negative group, 43 cases; culture-positive group, 54 cases). No significant difference was noted between the culture-negative and culture-positive groups with respect to the number of cases that did not undergo reimplantation surgery and the reoperation, reinfection, mortality, and failure rates after two-stage surgery (p > 0.05, all parameters). CONCLUSIONS: The culture outcome had no significant effect on the outcome of the two-stage revision in patients with chronic PJI. The reoperation rate after first-stage surgery was significantly higher in the culture-positive group, but the overall failure rate did not significantly differ in both the groups. The presence of a negative culture might be a good prognostic factor for chronic PJI.

Fully automated waist circumference measurement on abdominal CT: Comparison with manual measurements and potential value for identifying overweight and obesity as an adjunct output of CT scan.

OBJECTIVE: Waist circumference (WC) is a widely accepted anthropometric parameter of central obesity. We investigated a fully automated body segmentation algorithm for measuring WC on abdominal computed tomography (CT) in comparison to manual WC measurements (WC-manual) and evaluated the performance of CT-measured WC for identifying overweight/obesity. MATERIALS AND METHODS: This retrospective study included consecutive adults who underwent both abdominal CT scans and manual WC measurements at a health check-up between January 2013 and November 2019. Mid-waist WCs were automatically measured on noncontrast axial CT images using a deep learning-based body segmentation algorithm. The associations between CT-measured WC and WC-manual was assessed by Pearson correlation analysis and their agreement was assessed through Bland-Altman analysis. The performance of these WC measurements for identifying overweight/obesity (i.e., body mass index [BMI] ≥25 kg/m2) was evaluated using receiver operating characteristics (ROC) curve analysis. RESULTS: Among 763 subjects whose abdominal CT scans were analyzed using a fully automated body segmentation algorithm, CT-measured WCs were successfully obtained in 757 adults (326 women; mean age, 54.3 years; 64 women and 182 men with overweight/obesity). CT-measured WC was strongly correlated with WC-manual (r = 0.919, p < 0.001), and showed a mean difference of 6.1 cm with limits of agreement between -1.8 cm and 14.0 cm in comparison to WC-manual. For identifying overweight/obesity, CT-measured WC showed excellent performance, with areas under the ROC curve (AUCs) of 0.960 (95% CI, 0.933-0.979) in women and 0.909 (95% CI, 0.878-0.935) in men, which were comparable to WC-manual (AUCs of 0.965 [95% CI, 0.938-0.982] and 0.916 [95% CI, 0.886-0.941]; p = 0.735 and 0.437, respectively). CONCLUSION: CT-measured WC using a fully automated body segmentation algorithm was closely correlated with manually-measured WC. While radiation issue may limit its general use, it can serve as an adjunctive output of abdominal CT scans to identify overweight/obesity.

Second-look arthroscopic findings and clinical outcomes after management of intra-articular lesions in acute ankle fractures with arthroscopy.

BACKGROUND: Anatomically surgical reduction of ankle fractures does not always result in a clinically favorable outcome. Arthroscopic examination combined with treatment of intra-articular lesion may related to clinical outcomes OBJECTIVES: The purpose of the present study was to review initial and second look arthroscopic finding of acute ankle fracture and to evaluate clinical outcomes. RESULTS: Lauge-Hansen classification system of ankle fractures included supination-external rotation type (n = 24), supination-adduction type (n = 3), pronation-external rotation type (n = 7), and pronation-abduction type (n = 6), total 40 ankles. Osteochondral lesions were found in 25 ankles (62%) with an initial arthroscopic finding of acute ankle fracture. Newly discovered chondral lesions in secondary arthroscopy were found in 17 cases. According to the Ferkel and Cheng staging at secondary arthroscopy, 4 of 25 ankles with osteochondral lesions of the talus were deteriorating (more than stage D). In terms of ICRS overall repair grades, 5 ankles (20%) were abnormal (grade III). Diffuse synovitis and arthrofibrosis were found in 12 and 7 ankles, respectively, in secondary arthroscopy, and correlations were found between AOFAS scores, VAS and intra-articular lesions. CONCLUSION: Second-look arthroscopic examination combined with treatment of intra-articular lesion such as arthrofibrosis and osteochondral lesion arising from ankle fracture surgery may consider to improve clinical outcomes.

Clinical outcomes of two-stage total knee arthroplasty using articulating cement spacer in patients with infected arthritic knee: A comparison with arthroscopic surgery.

BACKGROUND: The aim of this study was to compare the functional outcomes and recurrence rate of infection between patients who underwent arthroscopic surgery and two-stage total knee arthroplasty (TKA) for infected arthritic knees. METHODS: A retrospective analysis was conducted on 52 patients (52 knees) with advanced knee joint arthritis who underwent arthroscopic surgery or two-stage TKA using articulating cement spacer (ACS) for knee joint infection between January 2009 and November 2013. Of the 52 patients (52 knees), 38 and 14 patients underwent arthroscopic surgery (AS group) and two-stage TKA using ACS (ACS-TKA group), respectively. Patient-reported outcomes (Knee Injury and Osteoarthritis Outcome Score (KOOS) and EuroQol-Visual Analog Scales (EQ-VAS)); range of motion; and recurrence rate of infection were evaluated. RESULTS: Recurrence of infection was observed in 7/38 patients who underwent arthroscopic surgery, all of whom received two-stage TKA using ACS. Regarding the functional outcomes of the ACS-TKA group obtained before conversion to TKA and those of the AS group obtained six months after arthroscopic surgery, the former group had better outcomes for KOOS pain, KOOS activities of daily living, KOOS quality of life, and EQ-VAS. Regarding the functional outcomes of the ACS-TKA group obtained during the last follow-up and after conversion to TKA and those of the AS group who underwent TKA after arthroscopic surgery, no significant between-group differences were observed. The infection recurrence rate was higher in the AS than in the ACS-TKA group. CONCLUSIONS: Considering infection control and functional outcomes, two-stage TKA using ACS can be an effective alternative treatment for patients with infected arthritic knees.

Second-look arthroscopic findings and clinical outcomes of meniscal repair with concomitant anterior cruciate ligament reconstruction: comparison of suture and meniscus fixation device.

INTRODUCTION: The purpose of this study was to evaluate the healing rate of repaired meniscus and functional outcomes of patients who received all-inside meniscal repair using sutures or devices with concomitant arthroscopic anterior cruciate ligament (ACL) reconstruction. MATERIALS AND METHODS: Among the patients who have ACL tear and posterior horn tear of medial or lateral meniscus, 61 knees who received all-inside repair using sutures (suture group, n = 28) or meniscal fixation devices (device group, n = 33) with concomitant ACL reconstruction during the period from January 2012 to December 2015, followed by second-look arthroscopy, were retrospectively reviewed. Healing status of the repair site was assessed by second-look arthroscopy. Through the clinical assessment, clinical success (negative medial joint line tenderness, no history of locking or recurrent effusion, and negative McMurray test) rate of the repaired meniscus and functional outcomes (International Knee Documentation Committee subjective score and Lysholm knee score) was evaluated. RESULTS: In a comparison of healing status of repaired meniscus evaluated by second-look arthroscopy, suture group had 23 cases of complete healing (82.1%), 4 cases of incomplete healing (14.3%), and 1 case of failure (3.6%). Device group had 18 cases of complete healing (54.5%), 4 cases of incomplete healing (24.2%), and 7 cases of failure (21.2%) (p = 0.048). Clinical success rate of the meniscal repair was 89.3% (25 cases) and 81.8% (27 cases) in suture group and device group, respectively (p = 0.488). No significant difference of functional outcomes was observed between the two groups (p > 0.05, both parameters). CONCLUSIONS: Among the patients who received meniscal repair with concomitant ACL reconstruction, suture group showed better healing status of repaired meniscus based on the second-look arthroscopy than device group. However, no significant between-group difference of clinical success rate and functional outcomes was observed.

Intraoperative fluoroscopy reduces the variability in femoral tunnel placement during single-bundle anterior cruciate ligament reconstruction.

PURPOSE: To evaluate the effect of using intraoperative fluoroscopy on femoral and tibial tunnel positioning variability in single-bundle anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 80 consecutive patients with single-bundle ACL reconstruction between 2014 and 2016 were retrospectively reviewed. Among them, 40 underwent ACL reconstruction without fluoroscopy (non-fluoroscopy group) and 40 underwent fluoroscopy-assisted ACL reconstruction (fluoroscopy group). Femoral and tibial tunnel locations were evaluated using a standardized grid system with three-dimensional computed tomography images. Femoral and tibial tunnel location variability was compared between the groups. RESULTS: The operation time was longer in the fluoroscopy group than in the non-fluoroscopy group (61.3 ± 5.2 min vs. 55.5 ± 4.5 min, p < 0.001). In the fluoroscopy group, a guide pin was repositioned in 16 (40%) cases on the femoral side and 2 (5%) cases on the tibial side. No significant difference in the femoral tunnel location was observed between the fluoroscopy and non-fluoroscopy groups (anterior-posterior plane, 29.0% ± 3.2% vs. 30.0% ± 6.1%; proximal-distal plane, 30.8% ± 4.8% vs. 29.4% ± 8.3%; all parameters, n.s.); variability was significantly lower in the fluoroscopy group (p < 0.001 for both anterior-posterior and proximal-distal planes). No significant difference in the tibial tunnel location and variability was observed between the fluoroscopy and non-fluoroscopy groups (medial-lateral plane, 45.8% ± 2.0% vs. 46.6% ± 2.4%; anterior-posterior plane, 31.2% ± 4.0% vs. 31.0% ± 5.4%) (all parameters, n.s.). CONCLUSIONS: Tunnel positioning with fluoroscopic assistance is feasible and effective in achieving consistency in femoral tunnel placement despite a slightly longer operation time. Intraoperative fluoroscopy can be helpful in cases wherein identifying anatomical landmarks on arthroscopy was difficult or for surgeons with less experience who performed ACL reconstruction. LEVEL OF EVIDENCE: IV.

Clinical and Radiologic Outcomes of Patients With Lax Healing After Medial Meniscal Root Repair: Comparison With Subtotal Meniscectomy.

PURPOSE: To compare radiologic and clinical outcomes between patients who underwent medial meniscus posterior root tear (MMPRT) repair and were subsequently classified as having lax healing based on second-look arthroscopy and patients who underwent subtotal meniscectomy for an MMPRT. METHODS: The patients who received pullout repair or subtotal meniscectomy due to MMPRT between January 2011 and December 2014 were retrospectively reviewed. Among the patients who underwent MMPRT repair, those whose lax healing of the repair site was confirmed by second-look arthroscopy (repair/lax healing group) and among the patients who received subtotal meniscectomy, those who have varus deformity of <5° and a Kellgren-Lawrence grade of ≤2 (meniscectomy group) were included in the study population. Medial joint space width, Kellgren-Lawrence grade, International Knee Documentation Committee Subjective Knee Evaluation Form score, and Lysholm Knee score were used for radiologic and clinical assessment. RESULTS: The meniscectomy group included 24 patients (average follow-up, 37.2 months), and the repair/lax healing group included 21 patients (average follow-up, 39.2 months). The 2 groups showed improved patient-reported outcomes postoperatively (P < .001). However, medial joint space width (P < .001) became narrow and Kellgren-Lawrence grade (P = .002 and P = .005, respectively) worsened. Comparison of the radiologic outcomes between the 2 groups revealed that the repair/lax healing group had less Kellgren-Lawrence grade progression than the meniscectomy group (P = .014). The grade progressed by ≥2 grades in 4 patients (16.7%) and 0 patients in the meniscectomy and repair/lax healing groups, respectively (P < .001). CONCLUSIONS: Although the repair/lax healing group showed improved functional outcomes on short-term follow-up, arthritic change progressed radiologically. Nevertheless, the repair/lax healing group showed better radiologic outcomes than the meniscectomy group, despite lax healing of the repair site. However, because of the small number of cases in this study, the results of this study could be associated with potential for type II or ß errors. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Genetic diversity and population structure of Perilla frutescens collected from Korea and China based on simple sequence repeats (SSRs).

BACKGROUND: Perilla frutescens (L.) Britt. is divided into two varieties based on morphology and use. One is P. frutescens var. frutescens, which is used both as a leafy vegetable and as an oil obtained from the seeds. The other variety is P. frutescens var. crispa, a Chinese medicine or spice vegetable crop. In addition, weedy types of var. frutescens and var. crispa are occasionally grown as relict forms and are easy to find on roadsides, in waste areas and around farmers' fields or farmhouses. SSR markers have been successfully used to examine the genetic diversity and relationships of cultivated and weedy types of Perilla in many regions. OBJECTIVES: In this study, we used 25 simple sequence repeat (SSR) markers were used to assess the genetic diversity and population structure of 90 Perilla accessions from Korea and China. METHODS: A total of 90 accessions of Perilla were collected in Korea and China included 45 accessions from each of Korea and China. We selected 25 SSR markers representing the polymorphism of and adequately amplifying all the Perilla accessions. RESULTS: A total of 153 alleles were identified, with an average of 6.12 alleles per locus. The GD level and PIC value for cultivated and weedy types of P. frutescens from China were higher than those for accessions from Korea. Weedy accessions had higher GD and PIC values than cultivated accessions. In the population structure analysis using the model-based method, the 90 Perilla accessions were divided into two main group and an admixed group based on a membership probability threshold of 0.8. Based on the distance-based unweighted pair group method with the arithmetic mean (UPGMA), all accessions were classified into four major groups with a genetic similarity of 32.8%. CONCLUSION: Finally, the findings of this study will provide useful theoretical knowledge for further study of the population structure and genetic diversity of Perilla species and benefit Perilla crop breeding and germplasm conservation in Korea and China.

Construction of genetic linkage map and identification of QTLs related to agronomic traits in DH population of maize (Zea mays L.) using SSR markers.

BACKGROUND: In this study, we used phenotypic and genetic analysis to investigate Double haploid (DH) lines derived from normal corn parents (HF1 and 11S6169). DH technology offers an array of advantages in maize genetics and breeding as follows: first, it significantly shortens the breeding cycle by development of completely homozygous lines in two or three generations; and second, it simplifies logistics, including requiring less time, labor, and financial resources for developing new DH lines compared with the conventional RIL population development process. OBJECTIVES: In our study, we constructed a maize genetic linkage map using SSR markers and a DH population derived from a cross of normal corn (HF1) and normal corn (11S6169). METHODS: The DH population used in this study was developed by the following methods: we crossed normal corn (HF1) and normal corn (11S6169), which are parent lines of a normal corn cultivar, in 2014; and the next year, the F1 hybrids were crossed with a tropicalized haploid inducer line (TAIL), which is homozygous for the dominant marker gene R1-nj (Nanda and Chase in Crop Sci 6:213-215, 1966), and we harvested seeds of the haploid lines. RESULTS: A total of 200 SSR markers were assigned to 10 linkage groups that spanned 1145.4 cM with an average genetic distance between markers of 5.7 cM. 68 SSR markers showed Mendelian segregation ratios in the DH population at a 5% significance threshold. A total of 15 quantitative trait loci (QTLs) for plant height (PH), ear height (EH), ear height ratio (ER), leaf length (LL), ear length (EL), set ear length (SEL), set ear ratio (SER), ear width (EW), 100 kernel weight (100 KW), and cob color (CC) were found in the 121 lines in the DH population. CONCLUSION: The results of this study may help to improve the detection and characterization of agronomic traits and provide great opportunities for maize breeders and researchers using a DH population in maize breeding programs.

Intradural osteogenic sarcoma in the lumbar spine.

To our knowledge, this is the third reported case of spinal intradural osteogenic sarcoma. The two prior reported cases had a history of iophendylate injection whereas this patient did not. Other cases involved the cranial meninges, not the spine. This is the first reported case of intradural osteosarcoma in the absence of iophendylate injection. We report our workup, diagnosis, and treatment. We also include a video demonstrating the intraoperative invasion of tumor and dural erosion.

FACTORS ASSOCIATED WITH VISUAL OUTCOME AFTER MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT SURGERY.

PURPOSE: To evaluate preoperative factors influencing the visual outcome and postoperative factors associated with the changes in visual acuity, after reattachment surgery to treat macula-off rhegmatogenous retinal detachment. METHODS: A total of 180 eyes of 180 patients who underwent reattachment surgery to treat macula-off rhegmatogenous retinal detachment, and who were followed up for more than 12 months, were reviewed retrospectively. Preoperative and postoperative characteristics, including optical coherence tomography findings, were comprehensively analyzed using univariate and multivariate models to evaluate preoperative factors influencing best-corrected visual acuity 12 months after macula-off rhegmatogenous retinal detachment surgery and postoperative factors associated with changes in best-corrected visual acuity after surgery. RESULTS: Preoperatively, the extent of detachment (P = 0.037), macula-off duration (P < 0.001), and integrity of the external limiting membrane (ß = 0.163; P = 0.002) were significantly associated with postoperative visual prognosis. Six factors were associated with changes in visual acuity after surgery: disruption of ellipsoid zone integrity (ß = 0.167; P < 0.001), the Henle's fiber layer and the outer nuclear layer (HFL + ONL)/photoreceptor layer ratio (ß = 0.199; P < 0.001), the photoreceptor outer segment length (ß = -0.020; P < 0.001), the photoreceptor inner segment length/photoreceptor outer segment length ratio (ß = 0.047; P = 0.005), the ratio of photoreceptor layer thickness between the RD eye and fellow eye (ß = -0.126; P = 0.018), and the photoreceptor outer segment length ratio between the RD eye and fellow eye (ß = -0.425; P < 0.001). CONCLUSION: Preoperative factors associated with the visual outcome after macula-off rhegmatogenous retinal detachment surgery were the extent of detachment, macula-off duration, and external limiting membrane integrity. Postoperatively, predictive factors were the outer retinal microstructures, particularly the photoreceptor outer segment layer.

A comparison of responses to intravitreal bevacizumab, ranibizumab, or aflibercept injections for neovascular age-related macular degeneration.

PURPOSE: To compare the responses of intravitreal injections of bevacizumab, ranibizumab, or aflibercept for the treatment of neovascular age-related macular degeneration (nAMD). METHODS: This retrospective study examined 232 eyes of 232 patients who received intravitreal anti-vascular endothelial growth factor (VEGF) injections due to treatment-naïve nAMD. All patients, who were followed-up for at least 1 year, were treated with intravitreal injections monthly until 3 months, and then as needed. We evaluated the effects of intravitreal injections for treatment of nAMD using the central macular thickness (CMT), subretinal fluid (SRF), pigment epithelial detachment (PED) size, and best-corrected visual acuity (BCVA). RESULTS: CMT, SRF, PED size, and BCVA (LogMAR) were significantly decreased after treatment with all three anti-VEGF agents. Overall, the bevacizumab, ranibizumab, and aflibercept treatments showed no significant differences in their responses. However, the aflibercept injections decreased PED size more quickly than bevacizumab injections (P = 0.034). CONCLUSIONS: Bevacizumab, ranibizumab, and aflibercept injections are effective treatments for nAMD and have similar responses, although the number of injections of aflibercept was fewer than other anti-VEGF agents. In addition, aflibercept injections may be a better choice than other anti-VEGF agents for cases of severe increases in PED height.