Showing papers in "Knee Surgery and Related Research in 2016"

Patient Satisfaction after Total Knee Arthroplasty

Abstract: Total knee arthroplasty (TKA) is one of the most successful and effective surgical options to reduce pain and restore function for patients with severe osteoarthritis. The purpose of this article was to review and summarize the recent literatures regarding patient satisfaction after TKA and to analyze the various factors associated with patient dissatisfaction after TKA. Patient satisfaction is one of the many patient-reported outcome measures (PROMs). Patient satisfaction can be evaluated from two categories, determinants of satisfaction and components of satisfaction. The former have been described as all of the patient-related factors including age, gender, personality, patient expectations, medical and psychiatric comorbidity, patient's diagnosis leading to TKA and severity of arthropathy. The latter are all of the processes and technical aspects of TKA, ranging from the anesthetic and surgical factors, type of implants and postoperative rehabilitations. The surgeon- and patient-reported outcomes have been shown to be disparate occasionally. Among various factors that contribute to patient satisfaction, some factors can be managed by the surgeon, which should be improved through continuous research. Furthermore, extensive discussion and explanation before surgery will reduce patient dissatisfaction after TKA.

Analysis and Treatment of Complications after Unicompartmental Knee Arthroplasty

Abstract: Purpose To analyze the causes and types of complications after unicompartmental knee arthroplasty (UKA) and determine proper prevention and treatment methods.

Blood Management Strategies in Total Knee Arthroplasty.

Abstract: A perioperative blood management program is one of a number of important elements for successful patient care in total knee arthroplasty (TKA) and surgeons should be proactive in its application. The aims of blood conservation are to reduce the risk of blood transfusion whilst at the same time maximizing hemoglobin (Hb) in the postoperative period, leading to a positive effect on outcome and cost. An individualized strategy based on patient specific risk factors, anticipated blood loss and comorbidities are useful in achieving this aim. Multiple blood conservation strategies are available in the preoperative, intraoperative and postoperative periods and can be employed in various combinations. Recent literature has highlighted the importance of preoperative Hb optimization, minimizing blood loss and evidence-based transfusion guidelines. Given TKA is an elective procedure, a zero allogenic blood transfusion rate should be the aim and an achievable goal.

Complications and Short-Term Outcomes of Medial Opening Wedge High Tibial Osteotomy Using a Locking Plate for Medial Osteoarthritis of the Knee

Abstract: Purpose The purpose of this study was to investigate complications and radiologic and clinical outcomes of medial opening wedge high tibial osteotomy (MOWHTO) using a locking plate. Materials and Methods This study reviewed 167 patients who were treated with MOWHTO using a locking plate from May 2012 to June 2014. Patients without complications were classified into group 1 and those with complications into group 2. Medical records, operative notes, and radiographs were retrospectively reviewed to identify complications. Clinically, Oxford Knee score and Knee Injury and Osteoarthritis Outcome score (KOOS) were evaluated. Results Overall, complications were observed in 49 patients (29.3%). Minor complications included lateral cortex fracture (15.6%), neuropathy (3.6%), correction loss (2.4%), hematoma (2.4%), delayed union (2.4%), delayed wound healing (2.4%), postoperative stiffness (1.2%), hardware irritation (1.2%), tendinitis (1.2%), and hardware failure without associated symptoms (0.6%). Major complications included hardware failure with associated symptoms (0.6%), deep infection (0.6%), and nonunion (0.6%). At the first-year follow-up, there were no significant differences in radiologic measurements between groups 1 and 2. There were no significant differences in knee scores except for the KOOS pain score. Conclusions Our data showed that almost all complications of the treatment were minor and the patients recovered without any problems. Most complications did not have a significant impact on radiologic and clinical outcomes.

Causes of Failure of Anterior Cruciate Ligament Reconstruction and Revision Surgical Strategies.

Abstract: Purpose Long-term outcomes of anterior cruciate ligament (ACL) reconstruction are good or excellent; however, 0.7%-20% of patients suffer from recurrent instability due to graft failure. The purpose of this paper was to analyse failure aetiology and the possibilities of revision surgical strategies, with a description of our experience. We obtained optimal and good results in most of our patients. Materials and methods We retrospectively reviewed 42 patients who underwent revision surgery (43 revisions) due to relapsing instability after ACL reconstruction between 2006 and 2015. We used allografts in 39 cases and autografts in 4 cases. Results The 85.7% of the patients obtained optimal results (normal knee; group A) and the 7.2% obtained good results (nearly normal knee; group B) according to the International Knee Documentation Committee score. The most frequent failure causes were traumatic events, non-anatomic tunnel placement, and lack of graft incorporation. Conclusions A correct revision surgery requires accurate patient evaluation and knee imaging. Preoperative planning starts with the identification of the cause of failure of the primary reconstruction. Then, the most suitable procedure should be determined for each case. It is also important to accurately inform the patient of all the complexity of an ACL revision surgery even if it is a procedure with high rates of excellent and good outcomes.

Conversion Total Knee Arthroplasty after Failed High Tibial Osteotomy

Abstract: Clinical results of high tibial osteotomy (HTO) deteriorate over time despite the initial satisfactory results. Several knees may require a conversion to total knee arthroplasty (TKA) because of failure such as the progression of degenerative osteoarthritis and the loss of the correction angle. It is important to know the long-term survival rate and common reason of failure in HTO to inform patients of postoperative expectations before surgery and to prevent surgical errors during surgery. In addition, it has been reported that clinical and radiological results, revision rate, and complication rate were poorer than those in patients without a previous HTO. There are few review articles that describe why conversion TKA after HTO is surgically difficult and the results are poor. Surgeons have to avoid the various complications and surgical errors in this specific situation. We would like to present the considering factors and technical difficulties during conversion TKA after HTO with a review of the literature. We could conclude through the review that the correction of deformity, lower amount of tibial bone resection, and sufficient polyethylene insert thickness, restoration of the joint line height, and adequate ligament balancing can be helpful in overcoming the technical challenges encountered during TKA following HTO.

Diagnosis and Treatment of Discoid Meniscus

Abstract: There is a greater incidence of discoid meniscus in Asian countries than in Western countries, and bilateral discoid menisci are also common. The discoid meniscus may be a congenital anomaly, and genetics or family history may play a role in the development of discoid menisci. Because the histology of discoid meniscus is different from that of normal meniscus, it is prone to tearing. Individuals with a discoid meniscus can be asymptomatic or symptomatic. Asymptomatic discoid menisci do not require treatment. However, operative treatment is necessary if there are symptoms. Total meniscectomy leads to an increased risk of osteoarthritis. Therefore, total meniscectomy is generally reserved for rare unsalvageable cases. Partial meniscectomy (saucerization) with preservation of a stable peripheral rim combined with or without peripheral repair is effective, and good short-, mid-, and long-term clinical results have been reported.

Quality of Life and Functional Independence in Patients with Osteoarthritis of the Knee.

Abstract: PURPOSE To verify the association between functional independence (FI) and quality of life (QOL) in patients with knee osteoarthritis. MATERIALS AND METHODS A cross-sectional study composed of 93 patients with knee osteoarthritis was performed. Osteoarthritis was stratified according the classification of Ahlbach. For evaluation of the patient's overall FI, the Barthel index was used. The patient's QOL was measured by means of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) questionnaire. RESULTS The mean age of the patients was 60 years (range, 54.0 to 69.5 years) and only 32 patients (34.3%) were found to be independent. Dependent or independent individuals presented difference in all domains of the QOL including physical function (p=0.001), role-physical (p=0.005), bodily pain (p=0.001), general health (p=0.004), vitality (p=0.009), social function (p=0.010), role-emotional (p=0.002) and mental health (p=0.001). Correlation between FI and QOL was different for all domains of the SF-36. Correlation with FI was strongest for physical function (r=0.609, p<0.001), followed by the domains of bodily pain (r=0.410, p<0.001) and mental health (r=0.402, p<0.001). CONCLUSIONS Our data demonstrated a strong association of FI with QOL and positive correlations with all QOL domains, indicating the greater the FI is, the higher the QOL is.

Effect of Tranexamic Acid on Blood Loss and Blood Transfusion Reduction after Total Knee Arthroplasty.

Abstract: Purpose Total knee arthroplasty (TKA) accompanies the risk of bleeding and need for transfusion. There are several methods to reduce postoperative blood loss and blood transfusion. One such method is using tranexamic acid during TKA. The purpose of this study was to confirm whether tranexamic acid reduces postoperative blood loss and blood transfusion after TKA.

Open Wedge High Tibial Osteotomy and Combined Arthroscopic Surgery in Severe Medial Osteoarthritis and Varus Malalignment: Minimum 5-Year Results

Abstract: Purpose To evaluate the radiologic and functional outcomes of medial open wedge high tibial osteotomy (HTO) combined with arthroscopic procedure in patients with medial osteoarthritis. Materials and Methods From June 1996 to March 2010, 26 patients (32 knees) who underwent medial open wedge osteotomy and arthroscopic operation for medial osteoarthritis were retrospectively reviewed. Measurements included hip-knee-ankle (HKA) angle, femorotibial angle, medial proximal tibial angle, posterior tibial slope angle, and Kellgren-Lawrence grade. Clinical evaluation was performed using Lysholm knee scoring scale and knee and function score of the American Knee Society. Results Differences between the mean preoperative and postoperative measurements were significant in all angles including the HKA angle (-5.7° and +5.5°), femorotibial angle (-1.9° and +9.8°), and medial proximal tibial angle (82.9° and 90.5°) (p<0.05). Mean Lysholm knee scoring scale was 63.6 preoperatively and 88.7 at the last follow-up, mean Knee Society knee score was 61.2 and 86.6, and mean function score was 59.3 and 87.2, respectively. All differences were significant (p<0.05). Conclusions Medial open wedge HTO in combination with arthroscopic procedure is an effective treatment method for medial osteoarthritis to treat varus deformity and an intra-articular lesion.

Comparison of Radiological Parameters between Normal and Patellar Dislocation Groups in Korean Population: A Rotational Profile CT-Based Study

Abstract: Purpose Patellofemoral instability is a common cause of anterior knee pain in adolescents and young adults. Most normal and pathological values for diagnosing patellofemoral instability are based on Western literature. We conducted this radiological study to determine normal values for different patellofemoral parameters in a Korean population and to evaluate their usefulness in diagnosis. Materials and methods We retrospectively reviewed the rotational profile computerized tomography (CT) scans of the patellar dislocation and control groups. Trochlear, patellar, rotational profile, and trochleo-patellar alignment parameters were compared between the groups. Receiver operating characteristic curves were drawn for significant parameters, and sensitivity and specificity were calculated for the cut-off values. Results There were 48 patients in the patellar dislocation group and 87 patients in the control group. In the control group and patellar dislocation group, the mean sulcus angle was 132.5° and 143.3°, respectively, trochlear depth was 6.04 mm and 3.6 mm, bisect offset was 56.4% and 99.9%, lateral patellar tilting was 9.8° and 19.2°, patellar facet asymmetry was 63.5% and 45.16%, and the tibial tuberosity-trochlear groove (TT-TG) distance was 10.91 mm and 27.16 mm, respectively. Conclusions The trochlear depth, bisect offset, patella tilting, and TT-TG distance were parameters that significantly contributed to patellar instability. Rotational profile CT can be considered a good diagnostic tool to assess all these parameters that help to identify anatomical aberration resulting in patellofemoral instability, thereby helping in formulating the most effective treatment plan.

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

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

Imageless Navigation Versus Conventional Open Wedge High Tibial Osteotomy: A Meta-Analysis of Comparative Studies.

Abstract: Purpose To summarize and compare radiological and clinical outcomes of open wedge high tibial osteotomy (HTO) using imageless computer-assisted navigation with conventional HTO.

Availability of Total Knee Arthroplasty Implants for Metal Hypersensitivity Patients.

Abstract: Purpose To provide information on the type of "hypersensitivity-friendly" components available for primary total knee arthroplasty (TKA) in the current market. Materials and Methods Implant manufactures were identified using the 2013 National Joint Registries of the United Kingdom and Sweden and contacted to obtain information about the products they offer for patients with metal hypersensitivity. Results Information on 23 TKA systems was provided by 13 implant manufacturers. Of these, 15 systems had options suitable for metal hypersensitivity patients. Two types of "hypersensitivity-friendly" components were identified: 10 implants were cobalt chrome prostheses with a "hypersensitivity-friendly" outer coating and 5 implants were made entirely from non-cobalt chrome alloys. Conclusions The results of this study suggest that several hypersensitivity TKA options exist, some of which provide the same designs and surgical techniques as the conventional implants. The information in this study can guide TKA surgeons in making informed choices about implants and identifying implants that could be examined in future controlled studies comparing outcomes between "hypersensitivity-friendly" and conventional implants.

Arthroscopic Meniscectomy for Medial Meniscus Horizontal Cleavage Tears in Patients under Age 45.

Abstract: Purpose The purpose of this study was to evaluate the demographics, clinical features, and outcomes of arthroscopic partial meniscectomy (APM) for isolated medial meniscus horizontal cleavage tears (MMHCTs) in patients under 45 years of age. Materials and methods We retrospectively reviewed 98 patients (100 knees) under 45 years who underwent APM for MMHCTs. Clinical outcomes were assessed using International Knee Document Committee (IKDC) subjective core, Tegner activity scale, visual analog scale (VAS) pain score, and a question on the symptom relief. Results 79% were male and 70% had no trauma. The mean symptom duration was 10 months. At arthroscopy, a flap tear was identified in 75%. At a mean of 19-month follow-up, the IKDC subjective score, Tegner activity scale, and VAS pain score were significantly improved compared to the preoperative values (p=0.025, p=0.043, and p=0.032, respectively). While 85% were free of symptoms, 15% had persistent pain. No significant differences in outcomes were observed based on the tear type and the presence of flap tears. No progression or development of radiographic degenerative changes was observed in all knees. Conclusions Demographics of MMHCTs under age 45 showed a male dominance and higher frequency of non-traumatic tears. APM was beneficial to symptomatic HCTs in this cohort during the short-term follow-up. Type of HCTs and combined flap tears did not affect clinical outcomes.

Variability of Measurement of Patellofemoral Indices with Knee Flexion and Quadriceps Contraction: An MRI-Based Anatomical Study

Abstract: Poster: "ESSR 2013 / P-0093 / Variability of measurement of patellofemoral indices with knee flexion and quadriceps contraction - A MRI-based anatomical study." by: "S. Purushothamdas1, F. Almallah2, R. Kundra1; 1Walsall/UK, 2WS2 9PS/UK"

Effect of Closed Suction Drain on Blood Loss and Transfusion Rates in Simultaneous Bilateral Total Knee Arthroplasty: A Prospective Randomized Study.

Abstract: Purpose Simultaneous bilateral total knee arthroplasty (TKA) is associated with excessive blood loss and morbidity arising from postoperative reduction in hemoglobin (Hb). The purpose of this prospective randomized study was to determine if drains have any effect on blood loss, postoperative reduction in Hb levels and transfusion rates compared to no drainage in simultaneous bilateral TKAs.

Comparative Effects of Periarticular Multimodal Drug Injection and Single-Shot Femoral Nerve Block on Pain Following Total Knee Arthroplasty and Factors Influencing Their Effectiveness.

Abstract: Purpose This study compared the analgesic effects of local infiltration analgesia (LIA) and femoral nerve block (FNB) after total knee arthroplasty (TKA) and assessed factors associated with analgesia obtained by these two methods. Materials and methods Study subjects included 66 patients (72 knees) who underwent TKA for osteoarthritis of the knee. Pain visual analogue scale (VAS), the amount of analgesics used, number of days to achieve 90° of flexion of the knee joint, date of initiating parallel-bar walking, range of motion of the knee joint at discharge, and adverse events were investigated. Results The VAS scores did not differ significantly between two groups, whereas the amount of analgesics used was significantly lower in the LIA group. Preoperative flexion contracture was significantly more severe in the LIA group with high VAS compared with low VAS. No serious adverse event occurred in the LIA or FNB group. Conclusions The lower analgesic usage in the LIA group than the FNB group indicates that the analgesic effect of LIA was greater than that of singleshot FNB after TKA. There were no serious complications in either group. The postoperative analgesic effect of LIA was smaller in patients with severe than less severe preoperative flexion contracture.

Total Knee Arthroplasty for Severe Flexion Contracture in Rheumatoid Arthritis Knees.

Abstract: Flexion contracture deformities, as well as severe varus and valgus deformities of the knee joint, accompany osteoarthritis or rheumatoid arthritis (RA). In particular, severe flexion contracture deformity of the knee joint is often found in patients with RA, which renders them nonambulatory. This report describes a 26-year-old female patient diagnosed with RA 10 years ago. She had chronic joint pain, severe flexion contracture, valgus deformity in both knees, and limited range of motion in both knees and became nonambulatory. She underwent a total knee arthroplasty (TKA) and serial casting and physical therapy to restore stable joint movement and correct knee joint deformity. Her pain was successfully relieved, and she was able to walk after surgery. Here, we report the excellent results of TKA in this RA patient with severe flexion contracture of both knees.

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

Abstract: Introduction Numerous methods of medial soft tissue release for severe varus deformity during total knee arthroplasty (TKA) have been reported. These include tibial stripping of the superficial medial collateral ligament (MCL), pie-crusting technique, and medial epicondylar osteotomy. However, there are inherent disadvantages in these techniques. Authors hereby present a novel quantitative method: femoral origin release of the medial collateral ligament (FORM).

The Optimal Suture Site for the Repair of Posterior Horn Root Tears: Biomechanical Evaluation of Pullout Strength in Porcine Menisci.

Abstract: Purpose: There are few studies on biomechanical evaluation of suture points in repair of root tears. The purpose of this study was to determine the point of greatest pullout strength for root tear repair. Materials and Methods: A total of 120 fresh porcine medial menisci were obtained. The red-red and red-white zones of the meniscus were divided by two lines designated as lines A and B (groups A and B). Groups A and B were further divided into three groups each by dividing lines A and B into three points: 3, 5, and 7 mm from the meniscal ligament root insertion. Vertical meniscal repair was performed on each point. The pullout failure strength was tested using a biaxial servohydraulic testing machine. Results: The average maximal load at failure was significantly greater in group A than group B (87.65 vs. 62.93; p<0.001) The average length at maximal load failure was greater in group A than group B (4.35 vs. 3.2; p<0.001). Among the subgroups of 3, 5, and 7 mm in both groups A and B, 7 mm showed the greatest maximal load (p<0.001). Conclusions: The pullout strength was statistically significantly greater in group A than group B and in the 7 mm subgroup than the 3 and 5 mm subgroups. Thus, the 7 mm subgroup in group A showed the greatest pullout strength.

The Efficacy of Medial Patellofemoral Ligament Reconstruction Combined with Tibial Tuberosity Transfer in the Treatment of Patellofemoral Instability

Abstract: A systematic review of the literature was undertaken to evaluate the efficacy of medial patellofemoral ligament (MPFL) reconstruction combined with tibial tuberosity transfer (TTT) in the treatment of patellofemoral instability. Using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic search was carried out to identify and review the published literature pertinent to MFPL reconstruction combined with TTT. Relevant studies were critically appraised with narrative data synthesis. Studies that met the eligibility criteria were suitable for appraisal and consisted of case series and therapeutic series (levels IV & III). All studies had inherent variations in outcomes reporting and limited follow-up. Combined treatment offers restoration of normal anatomy, thus adding clinical value to the currently recommended anatomic approach to MPFL reconstruction. Nevertheless, the current body of evidence does not determine the threshold at which patellofemoral axis requires the need for adjunctive distal realignment as opposed to MPFL reconstruction alone. This review highlighted numerous recurring limitations in the conduct and presentation of the studies, which inadvertently mitigated the interpretation of their results. Future priority should be awarded to larger randomised controlled trials utilising validated patient reported outcome measures.

The SPECT/CT Evaluation of Compartmental Changes after Open Wedge High Tibial Osteotomy.

Abstract: Purpose: The purpose of this study was to evaluate compartmental changes using combined single-photon emission computerized tomography and conventional computerized tomography (SPECT/CT) after open wedge high tibial osteotomy (OWHTO) for providing clinical guidance for proper correction. Materials and Methods: Analysis was performed using SPECT/CT from around 1 year after surgery on 22 patients who underwent OWHTO. Postoperative mechanical axis was measured and classified into 3 groups: group I (varus), group II (0˚ -3˚ valgus), and group III (>3˚ valgus). Patella location was evaluated using Blackburne-Peel (BP) ratio. On SPECT/CT, the knee joint was divided into medial, lateral, and patellofemoral compartments and the brighter signal was marked as a positive signal. Results: Increased signal activity in the medial compartment was observed in 12 cases. No correlation was observed between postoperative mechanical axis and medial signal increase. Lateral increased signal activity was observed in 3 cases, and as valgus degree increased, lateral compartment`s signal activity increased. Increased signal activity of the patellofemoral joint was observed in 7 cases, and significant correlation was observed between changes in BP ratio and increased signal activity. Conclusions: For the treatment of medial osteoarthritis, OWHTO requires overcorrection that does not exceed 3 valgus. In addition, the possibility of a patellofemoral joint problem after OWHTO should be kept in mind.

Correlation between Magnetic Resonance Imaging Characteristics of the Patellar Tendon and Clinical Scores in Osgood-Schlatter Disease.

Abstract: purpose: This study aims to evaluate magnetic resonance imaging (MRI) findings in young adults with symptomatic Osgood-Schlatter disease (OSD) and compare those in young adults without OSD. m aterials and m ethods: We compared MRI findings between young adults with OSD (OS group, n=30) and the equivalent number of young adults without OSD (control group). Visual analog scale scores and Kujala scores were evaluated and correlation analysis was performed in the OS group. r esults: In the OS group, MRI revealed that the patellar tendon was attached to the tibia more widely, resulting in a reduced free tendon portion, and more proximally to the articular surface (p<0.001). The correlation analysis between MRI findings and clinical scores showed statistically significant correlations (p<0.01). In the OS group, 43% presented with patellar tendinopathy or bone marrow edema at the distal attachments. conclusions: Compared to the control group, the relatively small free portion and relatively proximal attachment of the patellar tendon were observed with MRI in the OS group. The free portion of the patellar tendon was positively correlated with the clinical scores. Patellar tendinopathy was also frequently encountered in the OS group.

Changes in Femoral Posterior Condylar Offset, Tibial Posterior Slope Angle, and Joint Line Height after Cruciate-Retaining Total Knee Arthroplasty

Abstract: Purpose Changes in the femoral posterior condylar offset (PCO), tibial posterior slope angle (PSA), and joint line height (JLH) after cruciate-retaining total knee arthroplasty (CR-TKA) were evaluated to determine their influence on the flexion angle.

High Tibial Osteotomy for Medial Knee Osteoarthritis.

Abstract: treatment for medial knee osteoarthritis with varus deformity. This lower extremity realignment procedure is used to relieve pain and correct varus deformity of the knee joint. Preoperative planning to determine the correction gap and angle has a significant effect on postoperative results of HTO. However, postoperative correction can be incongruent with the preoperative plan, even with the use of a navigation system and computer imaging. In a clinical situation, postoperative correction may be influenced by several factors, such as muscle action in walking and ligament balance. Still, the main purpose of HTO is relief of pain caused by osteoarthritis, rather than correction of the deformity, and most patients have shown improvement in clinical symptoms. However, good long-term results can be expected if accurate correction can be achieved through careful preoperative planning. Traditionally, the cable method using a radiopaque line or a metal rod has been popular for the determination of correction in HTO as it allows real-time monitoring of the mechanical axis during surgery; however, the results can deviate due to nonweight bearing status and the influence of limb rotation during osteotomy, and it can increase radiation exposure during evaluation of the hip and ankle centers. Accordingly, preoperative planning using full-length weight bearing lower limb radiographs has recently been introduced for calculation of the correction angle and gap in weight bearing status using a picture archiving and communication system (PACS) or special software. In this issue, we present a report comparing the two methods; the report showed that the PACS method yielded more accurate results with less radiation exposure. Some surgeons have suggested that HTO using a navigation system results in an accurate correction angle. However, navigation-assisted HTO is performed in the non-weight bearing status, and thus the correction angle will change postoperatively in weight bearing status. In general, the Fujisawa point (a point 62.5% from the end of the medical tibial condyle) is considered the optimal location of the mechanical axis for deformity correction in HTO. In the meantime, there are interesting reports stating that determination of the correction angle in open wedge HTO should consider the mechanical axis of the contralateral knee for balanced alignment of the lower extremities. This issue of Knee Surgery and Related Research contains a report on open wedge HTO combined with arthroscopic surgery, which emphasized intra-articular debridement. The abrasion of eroded cartilage and removal of cartilage debris improved mechanically-induced symptoms. Usually, a donor site defect is neglected after autogenous iliac bone grafting. However, there have been some interesting reports, including a report by Lee et al. published in this issue, showing that reconstruction of the iliac crest with bone cement decreases donor site pain and morbidity after autogenous iliac bone grafting in open wedge HTO. A metal plate is frequently used for HTO. There are several reports on complications related to the plate, including screw loosening, metal failure, loss of correction angle, and infection. However, Seo et al. reported that only minor complications were noted after HTO using a strong locking plate, and they concluded that the strong locking plate should be used for open wedge HTO due to many advantages it offers. HTO is often performed in patients with medial knee osteoarthritis with varus deformity. Preoperative counseling with the patient is very important; the patient should be aware that the High Tibial Osteotomy for Medial Knee Osteoarthritis

Patterns and Influencing Factors of Medial Meniscus Tears in Varus Knee Osteoarthritis

Abstract: Purpose To investigate the patterns of medial meniscus (MM) tears in patients with varus knee osteoarthritis who underwent total knee arthroplasty and analyze the factors that could affect MM tears.

Use of a New Knee Prosthesis as an Articulating Spacer in Two-Stage Revision of Infected Total Knee Arthroplasty

Abstract: Purpose To report our experience with two-stage revision using a new femoral component (NFC) spacer (Depuy Synthes) as an articulating spacer. Materials and methods In this retrospective study, we reviewed 22 two-stage revisions that were performed using an NFC spacer in 22 patients suspected of having an infected total knee arthroplasty (TKA) from December 2010 to March 2013. The result was considered successful when eradication of infection was achieved using only one NFC spacer. Results The average time from primary TKA to the first stage procedure was 29.1 months and the average time from the first stage procedure until the final second stage procedure was 12.7 weeks. The average range of motion increased from 82° preoperatively to 104° postoperatively. The American Knee Society Knee score increased from 29.3 points to 66 points. The Function score increased from 29.5 points to 64 points. Four cases were reinfected after two-stage revision. The mean follow-up was 37.6 months. Conclusions The new articulating spacer showed promising short-term results both with regard to eradication of infection and functional improvement.

Incidences of Deep Vein Thrombosis and Pulmonary Embolism after Total Knee Arthroplasty Using a Mechanical Compression Device with and without Low-Molecular-Weight Heparin.

Abstract: Purpose To investigate the incidence of thromboembolic events and complications related to bleeding after total knee arthroplasty (TKA) with a mechanical compression device alone or in combination with low-molecular-weight heparin (LMWH). Materials and methods A total of 489 TKA patients (776 knees) were retrospectively reviewed for the incidence of thromboembolic events and complications related to bleeding. While 233 patients (354 knees) were treated with a mechanical compressive device without LMWH, 256 patients (422 knees) were treated with the mechanical compressive device along with LMWH. Results The incidences of deep vein thrombosis (DVT) and pulmonary embolism (PE) were 15 of 375 knees (4.0%) and 5 of 375 knees (1.3%), respectively, in the group that used only a mechanical compressive device, and 14 of 401 knees (3.4%) and 5 of 401 knees (1.2%), respectively, in the group that used the mechanical compressive device with LMWH. There was no significant difference between the two groups (p=0.125 and p=0.146, respectively). The postoperative hemovac drainage amount was 635±57 mL in the group with a mechanical compressive device only and 813±84 mL in the group with the device and LMWH; therefore, the amount of drainage was significantly greater in the latter group (p=0.013). Conclusions Mechanical compression alone for prophylaxis against DVT and PE after TKA can be an attractive option in Korean patients.

Comparison of Difference in Hematologic and Hemodynamic Outcomes between Primary Total Knee Arthroplasty and Revision of Infected Total Knee Arthroplasty.

Abstract: PURPOSE This study is to identify preoperative cautions for revision of infected total knee arthroplasty (TKA) by understanding the differences in hematologic and hemodynamic changes between primary TKA and revision of infected TKA. MATERIALS AND METHODS The study included 40 patients in each of the two groups: one group with patients who underwent TKA and the other group with patients who underwent revision of infected TKA. All patients matched for age and body mass index. The following data were compared between the groups: changes in blood pressure, variations in hemoglobin level, amount of postoperative blood loss and transfused blood, incidence of blood transfusion, white blood cell (WBC) count, albumin level, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and liver enzyme level. RESULTS The hemoglobin levels, transfusion rate, and the amount of blood loss were significantly higher in the revision group (p=0.012). In both groups, CRP reached the highest level on the 3rd postoperative day but it was normalized 2 weeks postoperatively; however, the revision TKA group showed a greater tendency to normalization (p=0.029). There were significant differences between the groups in ESR, WBC, blood pressure, and changes in liver enzyme levels. CONCLUSIONS Revision of infected TKA results in greater hemodynamic variations than primary TKA. Therefore, more efforts should be made to identify pre- and postoperative hemodynamic changes and hematologic status.