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.

Sex Differences in Sarcopenia in Patients Undergoing Total Knee Arthroplasty for Advanced Knee Osteoarthritis.

Background and Objectives: The purpose of this study was to compare sex differences in the incidence of sarcopenia, demographic characteristics, and preoperative sarcopenic parameters in patients undergoing TKA for advanced knee osteoarthritis (OA). Moreover, we sought to compare patient-reported outcome measures (PROMs) and the predisposing factors after TKA in patients with sarcopenia by sex through subgroup analysis. Materials and Methods: From May 2020 to September 2022, a total of 892 patients who were evaluable for sarcopenia before primary TKA were enrolled. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Patients were assessed according to the presence or absence of sarcopenia. After a two-to-one matched-pair analysis for subgroup analysis, 21 knees in men were matched with a corresponding number of knees in women (42), resulting in a total of 63 knees. PROMs were investigated using the Knee Injury and Osteoarthritis Outcome Score, Western Ontario and McMaster Universities Osteoarthritis Index, and the Short Form-12 physical and mental component summary scores. Moreover, the postoperative complications and predisposing factors for male sarcopenia were investigated. Results: The prevalence of sarcopenia was 10.9% (97/892), and the prevalence was higher in men (19.6%, 21/107) than in women (9.7%, 76/785). In subgroup analyses, male patients had significantly inferior PROMs up to 12 months after index surgery. Moreover, there was no significant difference in the systemic complications between the two groups. Multivariate binary logistic regression analysis indicated that alcohol consumption, smoking, and higher modified Charlson Comorbidity Index (mCCI) were predisposing factors for male patients with sarcopenia. The prevalence of sarcopenia was higher in male patients undergoing primary TKA. Conclusions: When compared with the propensity-matched female group, male patients had inferior PROMs up to 12 months postoperatively. Alcohol consumption, current smoker status, and higher mCCI were predisposing factors for sarcopenia in male patients with advanced knee OA.

Comparing outcomes of plate augmentation, nail exchange, and nail exchange with plate augmentation in the treatment of atrophic femoral shaft nonunion after intramedullary nailing: a multicenter retrospective study.

INTRODUCTION: Intramedullary (IM) nailing is the treatment of choice for femoral shaft fractures, but nonunion rates have been reported to be as high as 12%. Surgical interventions for nonunion involve exchange nailing or plate augmentation. Recently, a combined treatment of exchange nailing and plate augmentation has demonstrated good results, but its comparative effectiveness remains unclear. This study aimed to compare the clinical and radiographic outcomes of three different surgical interventions for atrophic femoral shaft nonunion, and investigate the factors that affect bone healing after reoperation. MATERIALS AND METHODS: A retrospective study was conducted at five university hospitals involving 149 patients with aseptic atrophic nonunion after IM nailing. These patients underwent reoperation with plate augmentation, exchange nailing, or combined treatment. Clinical and radiographic outcomes were assessed and compared according to reoperation procedure. Logistic regression analysis was performed to identify factors affecting persistent nonunion after reoperation. RESULTS: Of the cohort, 57 patients underwent plate augmentation, 64 underwent exchange nailing, and 28 received combined treatment. There were no significant differences in patient demographics among the groups. Exchange nailing produced a significantly lower union rate than did the combined treatment (82.8% vs. 100%, p = 0.016), whereas no significant difference was observed in the union rate and time to the union between plate augmentation and the combined treatment. Combined treatment showed the longest operative time and the greatest transfusion requirements. The risk factors for persistent nonunion included age, absence of autogenous bone grafts, and use of an exchange nailing technique. CONCLUSIONS: Exchange nailing as a treatment for atrophic femoral shaft nonunion after IM nailing resulted in a lower union rate. The efficacy of the combined treatment requires further study, and persistent nonunion may be influenced by age, bone grafting, and surgical techniques. A comprehensive approach targeting both biological environment and mechanical stability is crucial in the treatment of atrophic femoral shaft nonunion.

Multidisciplinary approach to sarcopenia: a narrative review.

Sarcopenia is a condition in which muscle mass and strength are decreased and muscle function is impaired. It is an indicator of frailty and loss of independence in older adults. It is also associated with increased physical disability, which increases the risk of falls. As a multifactorial disease, sarcopenia is caused by a combination of factors including aging, hormonal changes, nutritional deficiencies, and physical inactivity. Understanding the underlying pathophysiology of sarcopenia and identifying its different causes is critical to developing effective prevention and treatment strategies. This review summarizes the pathophysiology, consequences, diagnostic methods, and multidisciplinary approaches to sarcopenia.

Long locking plate combined with locking attachment plate in patients with periprosthetic femoral fracture around ipsilateral stem after total knee arthroplasty.

BACKGROUND: The purpose of this study was to introduce the surgical technique using long locking plate and locking attachment plate (LAP) in patient with periprosthetic femoral fracture around ipsilateral stem after total knee arthroplasty (TKA). Moreover, we sought to investigate the outcomes of this fixation technique and to propose a new subtype in the existing classification of periprosthetic femoral fractures. METHODS: From January 2013 to January 2022, thirty-four consecutive periprosthetic femoral fractures around ipsilateral stem following TKA with minimum 1-year follow-up were enrolled in this study. Most cases were fixed with long-locking plate and LAP using the MIPO technique. For subgroup analysis, we classified patients with stemmed hip implant (group H) and stemmed knee implant (group K). Bone union, American Knee Society Score (AKSS) scale, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Western Ontario and McMaster Universities Osteoarthritis Index for pain and function, and range of motion were investigated. RESULTS: The number of group H and K were 24 patients (70.6%) and 10 patients (29.4%), respectively. The mean age at operation was 71.5 years (range, 65‒85 years), and the mean follow-up period was 27.5 months (range, 12‒72 months). Bone union was confirmed radiographically in all patients, and the mean union time was 4.9 months (range, 3.5‒6 months). There were no significant differences in radiographic and clinical outcomes between the groups. CONCLUSIONS: Long-locking plate combined with LAP showed favorable radiographic and clinical outcomes in patients with periprosthetic femoral fracture around ipsilateral stem after TKA. LEVEL OF EVIDENCE: Level IV, Retrospective Case Series.

Clinical Efficacy and Safety of the Intra-articular Injection of Autologous Adipose-Derived Mesenchymal Stem Cells for Knee Osteoarthritis: A Phase III, Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Intra-articular injection of autologous culture-expanded adipose-derived mesenchymal stem cells (ADMSCs) has introduced a promising treatment option for knee osteoarthritis. Although the clinical efficacy and safety of ADMSCs have been reported, the treatment remains controversial owing to the small sample sizes and heterogeneous osteoarthritis grades in previous studies. PURPOSE: To assess the efficacy and safety of intra-articular injection of ADMSCs as compared with placebo in alleviating pain and improving functional capacity in a large sample of patients with knee osteoarthritis of Kellgren-Lawrence (K-L) grade 3. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: This phase III multicenter clinical trial was a double-blind randomized controlled study that included 261 patients with K-L grade 3 symptomatic knee osteoarthritis who were administered a single injection of autologous culture-expanded ADMSCs or placebo. Clinical data were assessed at baseline and at 3 and 6 months after the injection. The primary endpoints were improvements in 100-mm visual analog scale (VAS) for pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for function at 6 months after the injection. The secondary endpoints included clinical and radiologic examinations and safety after injection. The changes in cartilage defects after injection were assessed by magnetic resonance imaging at 6 months. RESULTS: The ADMSC and control groups included 125 and 127 patients available for follow-up, respectively. At 6 months, the ADMSC group showed significantly better improvements in 100-mm VAS (ADMSC vs control, 25.2 vs 15.5; P = .004) and total WOMAC score (21.7 vs 14.3; P = .002) as compared with the control group. The linear mixed model analysis indicated significantly better improvements in all clinical outcomes in the ADMSC group after 6 months. At 6 months, the ADMSC group achieved significantly higher proportions of patients above the minimal clinically important difference in 100-mm VAS and WOMAC score. Radiologic outcomes and adverse events did not demonstrate significant differences between the groups. No serious treatment-related adverse events were observed. Magnetic resonance imaging revealed no significant difference in change of cartilage defects between the groups at 6 months. CONCLUSION: Intra-articular injection of autologous culture-expanded ADMSCs provided significant pain relief and functional improvements in patients with K-L grade 3 osteoarthritis. Long-term results are needed to determine the disease-modifying effects of ADMSCs, such as structural changes, and the duration of effect of intra-articular injection of ADMSCs in knee osteoarthritis. REGISTRATION: NCT03990805 (ClinicalTrials.gov identifier).

The Usefulness of a Simplified Navigation-Based Instrumentation for a Novice Surgeon in Primary Total Knee Arthroplasty: A Retrospective Analysis of a Randomized Controlled Trial.

Background: A novel simplified navigation-based instrumentation system has been developed. It simplifies the existing navigation system and facilitates convenient bone cutting by positioning the tracker on an existing cutting block without additional pin fixation. This study aimed to compare the outcomes of this newly developed simplified navigation-based instrumentation system in primary total knee arthroplasty (TKA) performed by a novice surgeon with those of conventional surgical techniques. Methods: From January 2020 to July 2020, 67 knees that underwent primary TKA using the ExactechGPS TKA Plus (group A) were compared to 68 knees that underwent primary TKA using a conventional technique (group B). All patients had a minimum follow-up of 24 months. The operative details such as tourniquet time were investigated. Postoperative hip-knee-ankle (HKA) angle and component position angles in the coronal and sagittal planes (α, ß, γ, and δ angles) were evaluated. The outlier rates were compared between the groups as those lying outside ± 3°. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Western Ontario and McMaster Universities Osteoarthritis Index for pain and function, and range of motion were compared. Results: There was no statistically significant difference in average tourniquet time between the groups (74.3 vs. 70.3 minutes, p = 0.061). Outlier rates for HKA angle (7.5% vs. 23.5%, p = 0.010) and ß angle (1.5% vs. 22.1%, p < 0.001) in group A were significantly lower than those in group B. There were no significant differences in clinical outcomes between the groups. Conclusions: Primary TKA performed by a novice surgeon using a simplified navigation-based instrumentation system did not significantly increase the operation time, and more accurate lower extremity mechanical alignment and tibial component alignment in the coronal plane could be obtained.

Particulated Costal Hyaline Cartilage Allograft With Subchondral Drilling Improves Joint Space Width and Second-Look Macroscopic Articular Cartilage Scores Compared With Subchondral Drilling Alone in Medial Open-Wedge High Tibial Osteotomy.

PURPOSE: To compare the articular cartilage regeneration based on second-look arthroscopy in patients who underwent medial open-wedge high tibial osteotomy (MOWHTO) combined with particulated costal hyaline cartilage allograft (PCHCA) implantation with those who underwent MOWHTO and subchondral drilling (SD). Moreover, we compared the clinical and radiographic outcomes between the groups. METHODS: From January 2014 to November 2020, patients with full-thickness cartilage defect on the medial femoral condyle who underwent MOWHTO combined with PCHCA (group A) or SD (group B) were reviewed. Fifty-one knees were matched after propensity score matching. The status of regenerated cartilage was classified according to the International Cartilage Repair Society-Cartilage Repair Assessment (ICRS-CRA) grading system and Koshino staging system, based on second-look arthroscopic findings. Clinically, the Knee Injury and Osteoarthritis Outcome Score, the Western Ontario and McMaster Universities Osteoarthritis Index, and range of motion were compared. Radiographically, we compared the differences in the minimum joint space width (JSW) and change in JSW. RESULTS: The average age was 55.5 years (range, 42-64 years), and the average follow-up period was 27.1 months (range, 24-48 months). Group A showed a significantly better cartilage status than group B based on the ICRS-CRA grading system and Koshino staging system (P < .001 and <.001, respectively). There were no significant differences in clinical and radiographic outcomes between groups. In group A, the minimum JSW at the last follow-up was significantly increased than that before surgery (P = .013), and a significantly greater increase in JSW was observed in group A (P = .025). CONCLUSIONS: When performed with MOWHTO, the combination of SD and PCHCA was associated with superior articular cartilage regeneration on the ICRS-CRA grading and Koshino staging on second-look arthroscopy performed at a minimum of 2 years follow-up than SD alone. However, there was no difference in clinical outcomes. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Does Sarcopenia Accompanying End-Stage Knee Osteoarthritis Affect the Outcomes following Total Knee Arthroplasty?

Background and Objectives: This study aimed to investigate the prevalence of sarcopenia in patients undergoing total knee arthroplasty (TKA) for advanced knee osteoarthritis (OA), and to assess whether sarcopenia accompanying OA affects patient-reported outcome measures (PROMs) after TKA. We evaluated which predisposing factors could influence the development of sarcopenia in patients with advanced knee OA. Material and Methods: A total of 445 patients whose body composition, muscle strength, and physical performance could be measured before primary TKA were enrolled. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Patients were categorized into sarcopenia (S, n = 42) and non-sarcopenia groups (NS, n = 403). PROMs were investigated using the Knee Injury and Osteoarthritis Outcome Score and Western Ontario and McMaster Universities Osteoarthritis Index. Additionally, postoperative complications and predisposing factors for sarcopenia were evaluated. Results: The incidence of sarcopenia in the entire sample was 9.4%; the prevalence was higher in men (15.4%) than in women (8.7%), and significantly increased with advancing age (p < 0.001). At the six-month follow-up, PROMs in group S were significantly inferior to those in group NS, except for the pain score; however, at the 12-month follow-up, no significant difference was observed between the groups. Multivariate logistic regression indicated that age, body mass index (BMI), and a higher modified Charlson Comorbidity Index (mCCI) were predisposing factors for sarcopenia. Conclusions: A higher prevalence of sarcopenia was observed in men with progressive knee OA. Up to six months after primary TKA, PROMs in group S were inferior to those in group NS, except for the pain score; however, no significant difference was observed between the groups at 12 months. Age, BMI, and higher mCCI were predisposing factors for sarcopenia in patients with OA.

Safety and effectiveness of intra-articular injection of a highly cross-linked hyaluronic acid, LBSA0103 (Synovian): Results from a post-marketing surveillance study in South Korea.

This study aimed to assess the safety and effectiveness of the highly cross-linked hyaluronic acid-LBSA0103-in patients with knee osteoarthritis (OA) as per the prescribing information (PI) in South Korea. A total of 3,140 subjects aged ≥19 years were enrolled in this post-marketing surveillance (PMS) study from 2013 to 2019. The subjects received one or two injections of LBSA0103. The median duration of follow-up was 308 days. Adverse events (AEs), adverse drug reactions (ADRs), and serious AEs (SAEs) were monitored. Effectiveness was evaluated based on an index of effectiveness in accordance with the guidelines established by the Ministry of Food and Drug Safety and using a 100-mm visual analog scale (VAS) for weight-bearing pain. Overall, 250 subjects (7.96%) experienced 292 AEs and of these, unexpected AEs occurred in 114 subjects (3.63% [95% CI: 3.00-4.35]). Injection site pain was the most frequent AE reported by 81 subjects (2.58% [95% confidence intervals (CI): 2.05-3.20]). One hundred subjects experienced 108 ADRs (3.18% [95% CI: 2.60, 3.86]) and 15 unexpected ADRs were experienced by 13 subjects (0.41% [95% CI: 0.22-0.71]). Seventeen subjects experienced 22 SAEs (0.54% [95% CI: 0.32-0.87]) during the entire PMS period, and all were considered "unlikely" related to the study drug. Most AEs were mild in terms of severity and resolved during the study period. LBSA0103 was also effective in relieving symptomatic pain in knee OA patients. The condition in more than 80% of the subjects was considered to be improved when assessed by the investigators. LBSA0103 resulted in a significant reduction in the mean VAS score at 12 weeks after the first and second injections (24.79 (± 20.55) mm and 17.63 (±12.31) mm, respectively; p<0.0001). In conclusion, LBSA0103, used for the treatment of knee OA in a real-world setting, was well tolerated, with an acceptable safety profile and consistent therapeutic effect.

Preliminary outcomes following revision total knee arthroplasty using a new fixed-bearing revision knee system in Asians: a mean of 3-year follow-up.

PURPOSE: The purpose of this study was to investigate the early outcomes of the new semi-constrained revision total knee arthroplasty (TKA) system by performing subgroup analysis according to the revision cause. MATERIALS AND METHODS: From August 2019 to July 2020, 83 revision TKAs using the fixed-bearing Attune® revision knee system with a minimum follow-up of 2 years were retrospectively reviewed. Clinically, the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Western Ontario and McMaster Universities Osteoarthritis Index, and range of motion (ROM) were evaluated. The incidence of systemic and specific postoperative complications was investigated. Each cohort was divided into septic (group A, 34 patients) and aseptic mode (group B, 41 patients), and compared to assess the outcomes. RESULTS: The mean age at the time of revision was 73.3 years (range 59.0 to 84.0 years), and the follow-up duration was 36.1 months (range 30.0 to 40.0 months). Clinical outcomes and ROM significantly improved at last follow-up (p < 0.001). Group A showed statistically inferior clinical outcomes in the last follow-up compared to group B. Four knees (5.3%) had a postoperative femoral joint line elevation of more than 5 mm. There were no serious systemic complications. One patient underwent re-revision TKA due to recurrence of infection. No stem tip impingement or cortical erosion was observed in all patients. CONCLUSIONS: Revision TKAs using a new semi-constrained revision system showed favorable short-term follow-up outcomes, with improvement in clinical scores and ROM. Moreover, by using stem offsets, no postoperative stem tip impingement or cortical erosion was found. LEVEL OF EVIDENCE: Level IV, Retrospective Case Series.

Radiographic rotational profiles of the proximal and distal humerus: analysis of 46 computed tomography scans with 3-dimensional simulation.

BACKGROUND: To date, no study has investigated the radiographic rotational profiles (RRPs) of the proximal and distal humerus. However, malrotation after minimally invasive surgery for humeral fracture has been an unsolved problem. Therefore, we aimed to investigate the RRPs of the proximal and distal humerus that linearly correlate with rotational status and show significant differences as the rotational status changes. METHODS: Forty-six computed tomography scans of the humerus were 3-dimensionally reconstructed, and 5 rotational statuses (20° and 10° of internal rotation; neutral; and 10° and 20° of external rotation) were simulated. Seven candidate RRPs of the proximal humerus and 4 candidates of the distal humerus were measured for each rotational status. The overall differences and trends in the RRPs as the rotational status changed were evaluated, and multiple comparisons were performed between the RRPs for each of the 5 rotational statuses. Moreover, the correlations between the RRPs and rotational status with adjustment of retroversion were analyzed. Finally, interobserver and intraobserver reliabilities were evaluated. RESULTS: The following proximal and distal RRPs were linearly correlated with rotational status, differed significantly between the rotational statuses, and showed a relatively low prediction error and excellent interobserver and intraobserver reliabilities: the distance from the tip of the lesser tuberosity to the lateral margin of the proximal humerus (PL1) and the medial margin of the head (PL2), as well as the PL1 to PL2 ratio (PRL), in the proximal humerus; and the distance from the medial margin of the olecranon process to the medial epicondyle (DOP), the widest width of the overlapped olecranon fossa (DOF), and the distance from the lateral margin of the capitellum to the lateral epicondyle (DC) in the distal humerus. CONCLUSION: Our findings suggest that PL1, PL2, and PRL in the proximal humerus and DOP, DOF, and DC in the distal humerus are potentially useful and reproducible RRPs for restoring the intrinsic rotational alignment in humeral fractures.

Does the degree of intraoperatively identified cartilage loss affect the outcomes of primary total knee arthroplasty without patella resurfacing? A prospective comparative cohort study.

PURPOSE: The aim of this study was to investigate whether the degree of patellar cartilage loss confirmed during index surgery affects the clinical and radiologic outcomes of total knee arthroplasty (TKA) performed without patellar resurfacing. METHODS: We prospectively divided 2012 patients with a minimum follow-up of 12 months into two groups according to intraoperatively graded cartilage lesions graded using the International Cartilage Repair Society (ICRS) system: group 1, grades 0‒2 (n = 110); group 2, grades 3‒4 (n = 102). Relevant locations, such as medial, lateral, or both facets of the patella, were also assessed. Clinical outcomes were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index, Feller's patella score, and Kujala anterior knee pain score. Radiographic outcomes included patellar tilt angle and lateral patellar shift on Merchant's view. RESULTS: Clinical and radiographic outcomes were not significantly different between the two groups. No patient underwent secondary patellar resurfacing. Although the lateral facet was significantly more involved, there were no significant differences in outcomes. CONCLUSIONS: The degree of intraoperatively identified patellar cartilage loss did not affect the short-term outcomes following primary TKA without patellar resurfacing. Level of evidence II: Prospective comparative study.

Bone Hook Reduction Technique Combined with Lateral Parapatellar Arthrotomy for Periprosthetic Distal Femoral Fractures Following Total Knee Arthroplasty: A Technical Note.

OBJECTIVE: To report a bone hook reduction technique combined with lateral parapatellar arthrotomy for periprosthetic distal femoral fractures following total knee arthroplasty (TKA). METHODS: From April 2012 to June 2018, a total of 31 knees who underwent this technique for the treatment of periprosthetic distal femoral fractures following TKA were retrospectively reviewed. Through a lateral parapatellar arthrotomy, the vastus lateralis fascia was dissected from the muscle belly to allow anteromedial mobilization of the muscles. With direct visualization of the posteriorly angulated distal fragment, a bone hook was placed on the anterior flange of the femoral component. The hook was then elevated to correct the posteriorly angulated and shortened distal fragment. The coronal and sagittal alignments of the distal segment with the femoral shaft were confirmed using fluoroscopic images, and internal fixation was performed using an anatomically pre-contoured lateral locked plate. Once the overall length and sagittal plane alignment were restored, the plate was inserted via the previous articular approach. The plate was centered on the femur using anteroposterior and lateral fluoroscopy and then fixed. RESULTS: A total of 28 patients underwent internal fixation using the bone hook reduction technique combined with lateral parapatellar arthrotomy for the treatment of periprosthetic distal femoral fractures following TKA. The average age at operation was 70.9 years (range, 62-83 years), and the average follow-up period was 17.5 months (range, 12-48.5 months). Fractures were classified as Su type I (13/28 [46.4%]), type II (11/28 [39.3%]), and type III (4/28 [14.3%]). Bone union was confirmed radiographically in all patients. CONCLUSION: The bone hook reduction technique is a simple and effective method to reduce the distal fragment in periprosthetic distal femoral fractures following TKA.

Development of convolutional neural network model for diagnosing meniscus tear using magnetic resonance image.

BACKGROUND: Deep learning (DL) is an advanced machine learning approach used in diverse areas, such as image analysis, bioinformatics, and natural language processing. A convolutional neural network (CNN) is a representative DL model that is advantageous for image recognition and classification. In this study, we aimed to develop a CNN to detect meniscal tears and classify tear types using coronal and sagittal magnetic resonance (MR) images of each patient. METHODS: We retrospectively collected 599 cases (medial meniscus tear = 384, lateral meniscus tear = 167, and medial and lateral meniscus tear = 48) of knee MR images from patients with meniscal tears and 449 cases of knee MR images from patients without meniscal tears. To develop the DL model for evaluating the presence of meniscal tears, all the collected knee MR images of 1048 cases were used. To develop the DL model for evaluating the type of meniscal tear, 538 cases with meniscal tears (horizontal tear = 268, complex tear = 147, radial tear = 48, and longitudinal tear = 75) and 449 cases without meniscal tears were used. Additionally, a CNN algorithm was used. To measure the model's performance, 70% of the included data were randomly assigned to the training set, and the remaining 30% were assigned to the test set. RESULTS: The area under the curves (AUCs) of our model were 0.889, 0.817, and 0.924 for medial meniscal tears, lateral meniscal tears, and medial and lateral meniscal tears, respectively. The AUCs of the horizontal, complex, radial, and longitudinal tears were 0.761, 0.850, 0.601, and 0.858, respectively. CONCLUSION: Our study showed that the CNN model has the potential to be used in diagnosing the presence of meniscal tears and differentiating the types of meniscal tears.

A novel open synovectomy technique using an arthroscopy shaver blade in revision surgery to treat infected total knee arthroplasty: a technical note.

BACKGROUND: This article introduces a novel open synovectomy technique using an arthroscopy shaver blade to effectively remove intra-articular synovitis during revision surgery for infected primary total knee arthroplasty. METHODS (TECHNIQUES): Open synovectomy is performed using a 4.2-mm arthroscopy shaver blade, and the handpiece is connected to suction drainage. Suction is supplied through the central cylinder of the shaver blade to bring the debrided fragments of soft tissue into the window. Grossly inflamed, reddened, diseased synovium is debrided to reveal yellowish, healthy synovium. The inflamed tissues of the knee joint (suprapatellar pouch, medial and lateral gutters, and peripatellar area) are debrided. Then, with maintaining full flexion of the knee joint, a shaver equipped with a longer bar can be used to easily access the medial and lateral posterior compartments, which are generally difficult to access. RESULTS: During a mean of 13.5-month follow-up, there was no recurrent infection in either group; however, patients who underwent the novel technique improved significantly faster in terms of acute serological markers during the first period. CONCLUSIONS: This technique yielded favorable outcomes compared with the conventional technique. In particular, it may facilitate the approach to the posterior joint space, which is difficult to access.

The Design of the Patellar Component Does Not Affect the Patient-Reported Outcome Measures in Primary Posterior-Stabilized Total Knee Arthroplasty: A Randomized Prospective Study.

This randomized comparative study was conducted to investigate the outcomes of patellar resurfacing with a medialized dome or an anatomical type in patients receiving primary unilateral posterior-stabilized TKA. Between March 2019 and January 2021, 98 knees were randomly assigned to receive patellar resurfacing by a medialized dome type (group D, 49 knees) or an anatomic type (group A, 49 knees). The primary outcome was the Knee Injury and Osteoarthritis Outcome Score. The secondary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index, Feller's patella score, the Kujala anterior knee pain score, knee joint range of motion (ROM), and postoperative complications, including periprosthetic patellar fracture, patellar tilt angle, and lateral patellar shift. Patient-reported outcomes were not significantly different between the two groups. The ROM of the knee joint was significantly better in group A at six months after surgery (p = 0.021). No complications such as patellar fractures were observed. The anatomic type of patellar component showed a significant improvement of the patellar tilt angle after surgery compared with the medialized dome type of component. However, there were no significant differences in patient-reported clinical outcomes between the two groups during the follow-up period of 12 months.

New Classification for Periprosthetic Distal Femoral Fractures Based on Locked-Plate Fixation Following Total Knee Arthroplasty: A Multicenter Study.

BACKGROUND: This study aimed to establish a new classification using locked-plate fixation for periprosthetic distal femoral fracture (PDFF) following total knee arthroplasty (TKA) and to determine when dual locked-plate fixation is necessary through defining this classification. METHODS: One-hundred fifteen consecutive PDFFs that underwent operative treatment were reviewed from 2011 to 2019 with minimum 1-year follow-up. Most PDFFs were fixed with single or dual locked-plate fixations using the minimally invasive plate osteosynthesis technique. Based on preoperative radiographs, PDFFs were classified according to the level of main fracture line relative to the anterior flange of femoral component: type I and II, main fracture line located proximal and distal to the anterior flange; and type III, component instability regardless of fracture line requiring revisional TKA. Furthermore, type II fractures were subclassified based on the direction of fracture beak as follows: type IIL, lateral-beak; type IIM, medial-beak. The incidence, treatment methods, and complications were analyzed according to the classification. RESULTS: Incidences of type I, IIL, IIM, and III were 64.4%, 8.7%, 24.3%, and 2.6%, respectively. Meanwhile, most PDFFs in type I and II were treated with lateral single locked-plate fixations, except for type IIM, which was treated with either single or dual locked-plate fixations. Overall complications were significantly higher in type II (28.9%) than in type I (10.8%, P = .019). In type IIM, bone union-related complications were significantly higher in single locked-plate fixation (50.0%) than in dual locked-plate fixation (5.6%; P = .013). CONCLUSION: The new classification provides practical and obvious strategies for the treatment of PDFF following TKA using locked-plate fixation. For type IIM fracture, dual plate fixation is necessary to prevent fixation failure or nonunion.

Matched-Pair Analysis of Magnetic Resonance Images for Location of the Common Peroneal Nerve in Valgus Knees: Comparison with the Varus Knees.

This study aimed to assess the distance and angular location of the common peroneal nerve (CPN) on axial magnetic resonance imaging (MRI) in the valgus knees and compare the measurements with those obtained from the control group. We compared the location of the CPN according to the type of alignment by performing a subgroup analysis. From January 2009 to December 2019, we identified 41 knees with preoperative MRI in patients who underwent total knee arthroplasty (TKA) for valgus deformity (valgus group). We performed one-to-two matched-pair analysis to a cohort of patients who underwent MRI but were not candidates for TKA (control group), according to sex and age. The valgus group was classified according to the grading system reported by Ranawat et al, and the control group was also subdivided according to the hip-knee-ankle (HKA) angle obtained from lower extremity scanography: neutral (-3 to +3 degrees from the neutral mechanical axis), valgus (> +3 degrees), and varus alignment (< -3 degrees). Distance between the CPN and posterolateral cortex of the tibia at the knee joint (distance J) and tibial cut level (distance C) were measured. Angle of the CPN from the central anteroposterior axis of the tibia (angle α) was measured. We compared the measurements between the groups. Distance J was significantly closer in the valgus group (p < 0.001), whereas angle α was significantly smaller in the valgus group (p < 0.001). However, no significant differences were found in the subgroup analysis. Moreover, a significant correlation was found between distance J and the HKA angle (p < 0.001). The location of the CPN in the valgus knees was closer to the posterolateral cortex of the tibia at the joint level and showed a smaller angle than that in the other aligned knees. We recommend that lateral soft tissue release for valgus knees should not be performed at the joint line. The results of this study suggest that this would be less safe than a release performed at the level of the proximal tibial bone resection.

Comparison of tibial plateau fracture surgical outcomes between young and elderly patients: are outcomes really poorer in the elderly?

INTRODUCTION: Several studies have reported that total knee arthroplasty (TKA) is a suitable solution to treat elderly patients with complex tibial plateau fractures. The purpose of the present study was to compare surgical treatment outcomes after open reduction internal fixation (ORIF) between elderly and younger patients. MATERIALS AND METHODS: We reviewed patients with plateau fracture (OTA/AO classification types 41B and 41C) who underwent ORIF at two academic trauma centers between November 2006 and October 2019. Of the 341 patients, 76 were ultimately included in the younger group (< 60 years old) and 77 in the elderly group (≥ 60 years). The average follow-up was 24 months (range 12-96 months). The primary outcome was any common complication of plateau fracture, namely post-traumatic arthritis and alignment change. Conversion to TKA, Reduction loss, coronal malalignment, non-union, union time, infection, and limb length discrepancy (LLD) were also assessed. RESULTS: The elderly group had a significantly higher prevalence of diabetes, but there were no other significant differences between the groups in terms of patient demographics, fracture characteristics, and operation characteristics. We detected no differences between the groups in terms of post-traumatic arthritis (p = 0.216), alignment change (p = 0.093), conversion to TKA (p = 0.681), reduction loss (p = 0.079), coronal malalignment (p = 0.484), non-union rate (p = 0.719), infection (p = 0.063), LLD (p = 0.154), or time to union (p = 0.513). Logistic regression analysis revealed that age > 60 years was not associated with treatment failure, defined as either post-traumatic arthritis greater than grade II or non-union (p = 0.468). OTA/AO classification type 41C2 (p = 0.019), type 41C3 (p = 0.008), and malreduction (p = 0.050) were significant risk factors for failure. CONCLUSION: Age ≥ 60 years is not an independent risk factor of poor radiographic outcome and high complication rate in tibial plateau fractures. This indicates that ORIF is still a good solution to treat elderly patients, similar to their younger counterparts.