Far cortical locking constructs for fixation of distal femur fractures in an Asian population: A prospective observational study.

BACKGROUND: The stiffness of locked plates suppresses healing process, prompting the introduction of far cortical locking to address this issue. This study aimed to demonstrate the clinical efficacy of far cortical locking constructs in treating distal femoral fractures in an Asian population. METHODS: This multicenter prospective observational study was conducted at four university hospitals between February 2018 and February 2021. Demographic data, the presence of metaphyseal comminution, and surgical fixation details were recorded. Clinical outcomes, including single-leg standing, EQ-5D, and EQ-VAS scores, and radiologic outcomes, including the RUST score of each cortex, were evaluated and compared according to the presence of metaphyseal comminution. RESULTS: There were 37 patients (14 men and 23 women) with a mean age of 67.3 ± 11.8 years. Twenty-two patients had metaphyseal comminution (59%), and 15 presented simple fractures in metaphyseal areas. Four patients (13%) could stand on one leg >10s at 6 weeks, and 24 patients (92%) at 1 year. EQ-5D increased from 0.022 ± 0.388 to 0.692 ± 0.347, and the mean EQ-VAS 51.1 ± 13.1 to 74.1 ± 24.1 between discharge (n = 37) and post-operative 1 year (n = 33), respectively. RUST score presented increment for time, from 6.2 ± 1.8 at 6 week to 11.6 ± 1.1 at 1 year. Radiological healing demonstrated rapid increase from week 6 (16/28, 43%) to month 3 (27/31, 87%), with no obvious increase was observed in 6 months (23/26, 89%) or 12 months (25/28, 89%). Simple metaphyseal fractures presented significantly higher RUST scores at 6 weeks and 3 months, but there was no difference in RUST scores at 6 months or 1 year according to metaphyseal comminution. CONCLUSIONS: Plate constructs with far cortical locking screws provided safe and effective fixation for distal femoral fractures, with consistent radiological and clinical results, regardless of metaphyseal comminution.

Accuracy of planar anteversion measurements using anteroposterior radiographs.

BACKGROUND: Several methods using simple anteroposterior (AP) radiographs have been suggested for the measurement of anteversion of the cup component after total hip arthroplasty. Herein, we compared six widely used anteversion measurement methods using two different types of AP radiograph, the conventional pelvis AP and hip-centered AP radiographs, to identify the measurement method and the type of radiograph that would provide the highest accuracy and reliability. METHODS: We developed two custom-made bi-planar anteversion measurement models for the validation test. The models were designed for pelvis AP and hip-centered AP radiographs, respectively. The radiographs were acquired using the inclination angles of both models, changing from 10° to 70° at 10° increments. For each inclination angle, anteversion was changed from 0° to 30° at 5° increments. The measurements were obtained independently by two orthopedic surgeons blinded from each other's measurements, using the methods of 1) Pradhan et al., 2) Lewinnek et al., 3) Widmer et al., 4) Liaw et al., 5) Hassan et al., and 6) Ackland et al. The measurements were repeated after 2 months. The accuracy, compared with that of the reference angle, and intra-observer and inter-observer reliabilities of each method were calculated. RESULTS: The highest accuracy was found when the method of Liaw et al. was used with hip-centered AP radiographs, which showed a difference of 1.37° ± 1.73 from the reference angle. Moreover, regardless of the type of radiograph, the methods by Pradhan et al., Lewinnek et al., and Liaw et al. showed excellent correlations with the reference anteversion. However, substantial differences were found when the methods by Widmer et al., Hassan et al., and Ackland et al. were used, regardless of the type of radiograph used. When anteversion was measured in an inclination between 30° and 50°, the method of Pradhan et al., when used with pelvis AP radiographs, showed the highest accuracy (1.23° ± 0.92°). We also found no significant difference in anteversions between the measurements made on pelvic and hip-centered AP radiographs. Both interobserver and intraobserver reliabilities were high for all the measurements tested. CONCLUSIONS: The methods by Pradhan et al., Liaw et al., and Lewinnek et al. may provide relatively accurate anteversion measurements with high reliability, regardless of the type of radiograph.

Modified Outside-In Plus Suture Technique for Repair of the Anterior and Middle Segments of the Meniscus: Technical Note.

Traditionally, an outside-in suture technique is appropriate to repair longitudinal tears of the anterior and middle segments of the meniscus. However, it has a fundamental weakness of not creating a vertical mattress-type suture. To overcome this weakness, the modified outside-in technique was developed using a suture hook to create a vertical mattress-type suture in the inner fragment. However, it still has the disadvantage of requiring an open skin incision to prevent neurovascular damage during knot tying. Thus, we developed the modified outside-in plus technique to make a vertical mattress suture without an open skin incision in the knee joint. With this technique, the use of both vertical and horizontal mattress sutures is possible. Although this technique is similar to the modified outside-in technique, a suture knot is made inside the knee joint. Therefore, it compensates for the disadvantage of the outside-in technique. The modified outside-in plus technique is able to achieve good reduction and sufficient stability through a vertical mattress suture technique without additional skin incisions.

Optimization of the clinically approved mg-Zn alloy system through the addition of ca.

BACKGROUND: Although several studies on the Mg-Zn-Ca system have focused on alloy compositions that are restricted to solid solutions, the influence of the solid solution component of Ca on Mg-Zn alloys is unknown. Therefore, to broaden its utility in orthopedic applications, studies on the influence of the addition of Ca on the microstructural, mechanical, and corrosion properties of Mg-Zn alloys should be conducted. In this study, an in-depth investigation of the effect of Ca on the mechanical and bio-corrosion characteristics of the Mg-Zn alloy was performed for the optimization of a clinically approved Mg alloy system comprising Ca and Zn. METHODS: The Mg alloy was fabricated by gravitational melting of high purity Mg, Ca, and Zn metal grains under an Ar gas environment. The surface and cross-section were observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to analyze their crystallographic structures. Electrochemical and immersion tests in Hank's balanced salt solution were used to analyze their corrosion resistance. Tensile testing was performed with universal testing equipment to investigate the impact of Ca addition. The examination of cytotoxicity for biometric determination was in line with the ISO10993 standard. RESULTS: In this study, the 0.1% Ca alloy had significantly retarded grain growth due to the formation of the tiny and well-dispersed Ca2Mg6Zn3 phase. In addition, the yield strength and elongation of the 0.1% Ca alloy were more than 50% greater than the 2% Zn alloy. The limited cell viability of the 0.3% Ca alloy could be attributed to its high corrosion rate, whereas the 0.1% Ca alloy demonstrated cell viability of greater than 80% during the entire experimental period. CONCLUSION: The effect of the addition of Ca on the microstructure, mechanical, and corrosion characteristics of Mg-Zn alloys was analyzed in this work. The findings imply that the Mg-Zn alloy system could be optimized by adding a small amount of Ca, improving mechanical properties while maintaining corrosion rate, thus opening the door to a wide range of applications in orthopedic surgery.

Is the popliteus tendon always inserted antero-inferiorly 18.5 mm from the lateral collateral ligament of the femur? Magnetic resonance imaging and cadaveric evaluations.

BACKGROUND: The aim of this study was to analyze the locations of the femoral attachments of the popliteus tendon (PT) and lateral collateral ligament (LCL) via magnetic resonance imaging (MRI) and cadaveric dissection in a Korean population and compare with literature standards to determine whether variability exists. METHODS: We retrospectively analyzed knee MRIs from 87 cases selected from January 2017 to December 2018. The relationship between the femoral attachment of PT and LCL was analyzed by MRI using PACS and Image J. In addition, the femoral attachments of each structure were identified and marked in 14 unpaired human cadaveric knees. Three-dimensional models were reconstructed, and the surface area, location and distances were analyzed. RESULTS: On MRI, the femoral attachment of PT was located at mean distances of 0.89 mm posterior and 9.35 mm inferior to the LCL femoral attachment. We identified three groups of PT locations relative to the LCL on MRI evaluation: parallel (63%), posterior (29%), and anterior (8%). On cadaveric evaluation, the femoral attachment of the PT was located at mean distances of 0.77 mm posterior and 8.90 mm inferior to the LCL femoral attachment. We also identified three groups of PT locations relative to the LCL on cadaveric evaluation: parallel (43%), posterior (36%), and anterior (21%). CONCLUSIONS: Based on both MRI and cadaveric evaluations in a Korean population, the femoral attachment of the PT is located just distal to and posterior to the LCL. The differences between the centroids of the femoral attachments of the two structures was approximately 9.7 mm, suggesting that racially based anatomical differences of the posterolateral corner may exist.

Correlation between meniscal extrusion and symptom duration, alignment, and arthritic changes in medial meniscus posterior root tear: research article.

BACKGROUND: Medial meniscus posterior root tear can result in medial meniscus extrusion. However, the severity of medial meniscus extrusion is different in each root tear patient. The purpose of this study was to identify the factors that contribute to the severity of medial meniscus extrusion with medial meniscus posterior root tear, such as duration of disease, the degree of arthritis-chondral wear, subchondral edema, osteophyte size, and Kellgren-Lawrence (K/L) grade-and mechanical alignment for appropriate treatment method. METHODS: From January 2009 to August 2014, we retrospectively analyzed magnetic resonance imaging (MRI) and simple x-ray of 99 patients with medial meniscus posterior root tear. The duration of the disease was identified through retrospective chart review. The severity of medial meniscus extrusion, the presence of subchondral edema, the degree of chondral wear, and the size of the osteophyte were measured on MRI. K/L grade was confirmed on simple x-ray, and the mechanical axis was measured on whole extremity radiographs. Statistical analysis was performed by using bivariate correlation analysis and one-way analysis of variance. RESULTS: The mean medial meniscus extrusion was 4.61 mm, and the mean duration of the disease was 15.52 months. The mean degree of chondral wear was 25.8%, and 63 out of 99 cases showed subchondral edema. The average alignment was 4.30 degrees, and the average size of the osteophyte was 1.48 mm. There were 40 cases (40.4%) with K/L grade I, 48 cases (48.5%) with grade II, 11 cases (11.1%) with grade III, and no cases with grade IV. In the group mean analysis between the K/L grade and the severity of medial meniscus extrusion, the average medial meniscus extrusions were 3.97 mm in grade I, 4.93 mm in grade II, and 5.59 mm in grade III. There was a statistical significance between the size of the osteophyte and the severity of medial meniscus extrusion (P = 0.000), K/L grade, and the severity of medial meniscus extrusion (P = 0.001). CONCLUSIONS: The severity of medial meniscus extrusion with medial meniscus posterior horn root tear is associated with the size of the osteophyte and K/L grade.

Work-related factors of knee osteoarthritis in Korean farmers: a cross-sectional study.

BACKGROUND: Several studies have reported a high prevalence of osteoarthritis (OA) of the knee among agricultural workers. We investigated work-related factors that increase the risk of knee OA among Korean farmers. METHODS: Data were extracted from the Jeonnam Center for Farmer's Safety and Health survey, conducted between 2013 and 2015. The sample included 489 farmers (man 240, woman 249). We defined knee OA as radiographic knee OA (≥ Kellgren-Lawrence grade 2) with symptoms (≥ Western Ontario and McMaster Universities Osteoarthritis, Korean version score 29.5). We considered covariates such as cumulative squatting working time (CSWT), cumulative heavy lifting working time (CLWT), body mass index (BMI), and history of knee injury. Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated for knee OA and adjusted for relevant covariates. RESULTS: The results of multivariate logistic regression analysis indicated that knee OA was correlated by factors such as sex, age, BMI, history of knee injury, CSWT, and CLWT. Particularly, CSWT > 20,000 hours (OR: 2.83; 95% CI: 1.35-5.92; reference < 10,000 hours) and CLWT > 5,000 hours (OR: 2.62; 95% CI: 1.14-6.06; reference < 2,000 hours) were associated with an increased risk of knee OA after adjustment for covariates. CONCLUSIONS: Squatting posture and heavy lifting associated with farm work might increase the risk of knee OA among Korean farmers.

Comparison of Blood Loss between Neutral Drainage with Tranexamic Acid and Negative Pressure Drainage without Tranexamic Acid Following Primary Total Knee Arthroplasty.

PURPOSE: There are many methods to reduce massive bleeding during total knee arthroplasty (TKA). In our study, tranexamic acid and neutral drainage were used to decrease total blood loss. MATERIALS AND METHODS: The study was performed on 97 TKA patients from March 2012 to January 2013. In the study group, tranexamic acid was administered and neutral drainage was applied. The study group had group I (unilateral, n=29) and group III (bilateral, n=17). The control group had group II (unilateral, n=35) and group IV (bilateral, n=16). RESULTS: In group I, the drainage volume on the 1st and 2nd postoperative days and the total drainage decreased with statistical significance (p<0.05). Between group III and group IV, group III had less drainage volume. In group III, the drainage volume on the 1st postoperative day and total drainage volume decreased statistically significantly (p<0.05). Between groups I and II, total blood loss showed no statistically significant difference, whereas between groups III and IV, the value was significantly different. CONCLUSIONS: Intravenous administration of tranexamic acid with neutral drainage for 3 postoperative hours is a recommendable method because it can be helpful in reducing total blood loss in bilateral TKA.

In vitro dynamic degradation behavior of new magnesium alloy for orthopedic applications.

We report on methodologies for use in the design of a biodegradable Mg alloy appropriate for load-bearing but temporary orthopedic implant applications. Comparative studies of Mg-5Ca and Mg-5Ca-1Zn were conducted to explore the effects of a combination of minor alloying and hot extrusion, on the alloy's mechanical properties and corrosion resistance. The extruded Mg-5Ca-1Zn exhibited high ultimate compressive strength of 385 MPa and suffered no significant structural degradation even after immersion in simulated body fluid for 30 days. Mg-5Ca-1Zn alloy showed the mechanical strength and controlled corrosion rate to be considered as an ideal candidate for biodegradable orthopedic implant material.

Acute simultaneous ruptures of the anterior cruciate ligament and patellar tendon.

Acute simultaneous rupture of the anterior cruciate ligament (ACL) and patellar tendon is a rare injury. We present a case report of a 32-year-old male patient with ruptured ACL and ipsilateral patellar tendon rupture sustained while playing baseball. Surgery was performed on the patellar tendon and the ACL simultaneously. The clinical and radiological outcomes of the treatment were successful. We present this case with a review of the literatures.

Popliteal artery pseudoaneurysm after anterior cruciate ligament re-revision using a rigidfix cross pin.

Popliteal artery injury is a very rare complication of anterior cruciate ligament (ACL) reconstruction. The authors experienced a case of popliteal arterial pseudoaneurysm after re-revision of ACL reconstruction using Rigidfix for femoral tunnel fixation. Pseudoaneurysm was detected in knee magnetic resonance imaging, which caused pain, limit of motion, common peroneal nerve palsy, leg swelling and symptoms similar to compartment syndrome. After excision and re-anastomosis of the popliteal artery using a greater saphenous vein graft, all symptoms were resolved within 3 months except for common peroneal nerve palsy. So we report on this case with a review of the literature.

Comparison between Autogenous Bone Graft and Allogenous Cancellous Bone Graft in Medial Open Wedge High Tibial Osteotomy with 2-Year Follow-up.

PURPOSE: To compare the radiographic and clinical results of medial open wedge high tibial osteotomy (OWHTO) using autogenous bone graft and allogenous cancellous bone graft for medial compartment osteoarthritis of the knee with two-year follow-up. MATERIALS AND METHODS: Fifty-one patients (52 knees) who underwent medial OWHTO from October 2007 to April. 2010 were included in the study. The patients were divided into group I (n=29) that received an autogenous tricortical bone graft and group II (n=23) that received an allogenous cancellous bone chip graft. The radiographic parameters (preoperative anatomical and mechanical femorotibial angles, modified tibial bone varus angle, and posterior tibial slope), clinical parameters, bone union period, and complications were evaluated from medical records. RESULTS: The radiographic and clinical outcomes did not show significant difference between two groups. The average bone union period was 11.7 weeks in group I and 12.1 weeks in group II. The visual analog scale score on the first postoperative day was significantly higher in group I than group II. CONCLUSIONS: Medial OWHTO using allogenous cancellous bone graft for medial compartment osteoarthritis of the knee can be considered as an alternative treatment method that provides equivalent radiographic and clinical results of OWHTO using autogenous bone graft and causes less immediate postoperative pain.