The purpose of this study was to demonstrate postoperative improvement and high satisfaction rates after a surgical approach that includes arthroscopic labral repair only, in patients with borderline dysplasia, without instability. Between September 2009 and December 2011, patients less than 50 years old who underwent hip arthroscopy for symptomatic intra-articular hip disorders, with a lateral center-edge (CE) angle between 20 and 25, were included in this study. Patients with Tönnis grade 2 or greater, hip joint space narrowing, severe hip dysplasia, hip joint instability and Legg-Calve-Perthes disease were excluded. Patient-reported outcome scores, including the modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Arthritis index (WOMAC), and visual analog scale (VAS) for pain were obtained in all patients preoperatively and at 1, 2, and 3 years postoperatively.Purpose
Methods
To evaluate the clinical and radiographic outcomes of total knee arthroplasty using Vega® Knee System (B Braun-Aesculap, Tuttlingen, Germany) [Fig. 1] designed to allow high flexion by shortening the length of posterior condylar flange of femoral component after at least 2 year and to assess the occurrence of periprosthetic osteolysis and loosening at final follow-up. Of the patients who underwent total knee arthroplasty using Vega® Knee System between April 2011 and May 2013, 40 patients (46 knees) were enrolled. The mean age of the patients at the time of surgery was 72.3 years and the mean follow-up period was 29.4 months. Clinical parameters, including Knee Society Knee score, Knee Society Function score, maximal flexion and range of motion were evaluated. Relationship between postoperative maximal flexion and radiographic factors including the posterior tibial slope, the femoral condylar offset and the change of the posterior flange length of femoral condyle was analyzed. Also, the occurrence of periprosthetic osteolysis and loosening was assessed.Objectives
Materials and Methods
In this study, we investigated the long-term clinical results and survivorship of minimally invasive unicompartmental knee arthroplasty (UKA) by collecting cases that have been implanted for >10 years ago. Medial UKA on 180 cases in 142 patients was performed over a period of 1 year after the first introduction of minimally invasive UKA from January 2002 to December 2002. Among these, 166 cases in 128 patients who underwent Oxford phase 3 medial UKA using the minimally invasive surgery, with the exclusion of 14 cases including 10 cases of follow-up loss and 4 cases of death, were selected as the subject. The mean age of the patients at the time of surgery was 61 years, and the duration of the follow-up was minimum 10 years. All the preoperative diagnosis was osteoarthritis of the knee joint. Clinical and radiographic assessments were measured by the Knee Society clinical rating system, and the survival analysis was confirmed by the Kaplan–Meier method with 95% confidence interval (CI).Background
Methods
To identify the modes of failure after total knee arthroplasty (TKA) in patients ≤ 55 years of age and to compare with those ≥ 56 years of age in patients who underwent revision TKA. We retrospectively reviewed 256 revision TKAs among patients who underwent TKA for knee osteoarthritis between January 1992 and December 2012. The causes of TKA failure were analyzed and compared between those ≤ 55 years of age and those ≥ 56 years of age. The age at the time of primary surgery was ≤ 55 years in 30 patients (31 knees) and ≥ 56 years in 210 patients (225 knees).Purpose
Materials and Methods
Among many factors that influence the outcomes of Total Knee Arthroplasties (TKAs), the mechanical alignment has played major roles for the success of TKA, the survival rates of the implants, and patient functionality. Most, but not all, studies have shown that alignment of the mechanical axis in the coronal plane within a range of 3° varus/valgus is associated with improved long-term function and increased survival rates. Robot-assisted TKA has been developed to improve improves the accuracy and precision of component implantation and mechanical axis (MA) alignment. We hypothesised that robot-assisted TKA would lead to a more accurate leg alignment and component implantation, and thus, improve radiological and clinical outcomes. Between January 2003 and December 2004, a total of 98 primary TKA procedures were compared: 49 using a robotic-assisted procedure and 49 using conventional manual techniques. The cohorts were followed for 121.2 and 119.5 months on average, respectively. Radiographic assessments of the patients were performed preoperatively and at final follow-up and made according to the Knee Society Roentgenographic Evaluation System (KSRES) which included measurements of the coronal mechanical axis and sagittal and coronal inclinations of femoral and tibial components. The radiographic measurements were made using a PACS (Picture Archiving and Communication System). Clinical assessments were performed preoperatively, and at a final follow-up date that was a minimum of postoperative nine years. The clinical results included ranges of motion (ROM), Hospital for Special Surgery (HSS) scores, Western Ontario and McMaster University (WOMAC) scores (for pain and function). The radiographic results showed no statistical differences when comparing the means of the two groups. When considering outliers (defined as error ≥ ±3°) for the mechanical axis, femoral coronal and sagittal inclinations, and tibial coronal and sagittal inclinations, the ROBODOC group had zero outliers for all measurements except for one in tibial sagittal inclination. On the other hand, the conventional group had 12 outliers for mechanical axis, 2 for femoral coronal inclination, 3 for femoral sagittal inclination, 3 for tibial coronal inclination, and 4 for tibial sagittal inclination. However, there were no statistically significant differences between groups for ROM, HSS, or WOMAC scores at the final follow-up. The results of this study support previous work and demonstrate that the ROBODOC-assisted implantation of TKA results in better radiographic outcomes and better ligament balance with equivalent safety when compared to conventional TKA at a minimum follow-up of nine years.
Although the use of stems in revision total knee arthroplasty (RTKA) enhances survival by improving the stability of implant, questions as to the optimal fixation method as well as the vertical extent of the cement, remain unanswered. This study aimed 1) to determine the correlation between the vertical extent of cement and implant loosening; and 2) to determine the minimum cementing extent for a stable implant in revision TKA with a hybrid technique. We retrospectively analyzed 109 stemmed RTKAs with average follow-up of 63 months. In each case, a single varus-valgus constrained implant was used and fixed with a hybrid technique. During surgery, stem was partially covered with cement beyond stem-implant junction. Stability of implant was evaluated according to the modified Knee Society Radiographic Scoring System. Cementing extent was defined as length from implant base to the end of the radiopaque line around the stem. The correlation between the vertical cementing extent and implant stability was analyzed, and the minimal vertical cementing extent for a stable implant was evaluated with a scatter plot.Purpose
Materials and Methods
Over the past twenty years, the Low Contact Stress Rotating Platform (LCS RP) showed good results. Buechel and Pappas invented the Buechel-Pappas Knee (B-P Knee) system that is a modified version of the LCS system with different material (titanium), axial rotation limiting bar and improved conformity. The purpose of this prospective randomized study was to compare the 2-year clinical outcomes between two implants in the same patients who had been operated with bilateral TKAs. We prospectively enrolled 107 patients and 18 patients were lost to follow-up. Therefore, 89 patients (178 knees; mean age, 69.8±6.0years) were included in the study. The range of motion and clinical scores such as Knee Society score (KSS), Hospital for Special Surgery score (HSS) and Western Ontario and McMaster University (WOMAC) scores were measured preoperatively and postoperatively. At each follow-up, patients also complete a Likert scale questionnaire regarding subjective pain, lightness, left-right side preference (naturalness and satisfaction) and subjective instability. There were no significant differences in all preoperative variables between the two groups(
This study aimed to determine the optimal formulation of antibiotic-loaded bone cement (ALBC) for periprosthetic joint infection (PJI) using both in vitro and in vivo models incorporating various combinations of gram-positive and gram-negative antibiotics. The in vitro antibiotic release characteristics and antibacterial capacities of ALBCs loaded with either 4 g of vancomycin or teicoplanin and 4 g of ceftazidime, imipenem, or aztreonam were measured against methicillin-susceptible S. aureus, methicillin-resistant S. aureus, coagulase-negative staphylococci, Pseudomonas aeruginosa and Escherichia coli. ALBC spacers with superior in vitro antibacterial capacity were then implanted into ten patients (five females and five males between 29 and 75 years of age) diagnosed with chronic hip/knee PJIs and antibacterial activities within joint fluid were measured. The average duration of ALBC spacer implantation was 80 days (range, 36–155 days). Antibiotic concentrations and antibacterial activities of joint fluid at the site of infection were measured during the initial period as well as several months following spacer implantation. Cement samples loaded with vancomycin/ceftazidime or teicoplanin/ceftazidime exhibited equal or longer antibacterial duration against test bacteria as compared with other ALBCs. Joint fluid samples exhibited antibacterial activity against the test microorganisms including ATCC strains and clinically isolated strains. There were no adverse systemic effects, infection at second stage re-implantation, or recurrent infection at final follow-up. Vancomycin/ceftazidime ALBC provided broad antibacterial capacity both in vitro and in vivo and was shown to be an effective and safe therapeutic measure in the treatment of hip/knee PJIs. We thank H.Y. Hsu for performing bioassay.
The objective of this study was to compare the elution characteristics, antimicrobial activity and mechanical properties of antibiotic-loaded bone cement (ALBC) loaded with powdered antibiotic, powdered antibiotic with inert filler (xylitol), or liquid antibiotic, particularly focusing on vancomycin and amphotericin B. Cement specimens loaded with 2 g of vancomycin or amphotericin B powder (powder group), 2 g of antibiotic powder and 2 g of xylitol (xylitol group) or 12 ml of antibiotic solution containing 2 g of antibiotic (liquid group) were tested. Vancomycin elution was enhanced by 234% in the liquid group and by 12% in the xylitol group compared with the powder group. Amphotericin B elution was enhanced by 265% in the liquid group and by 65% in the xylitol group compared with the powder group. Based on the disk-diffusion assay, the eluate samples of vancomycin-loaded ALBC of the liquid group exhibited a significantly larger inhibitory zone than samples of the powder or the xylitol group. Regarding the ALBCs loaded with amphotericin B, only the eluate samples of the liquid group exhibited a clear inhibitory zone, which was not observed in either the xylitol or the powder groups. The ultimate compressive strength was significantly reduced in specimens containing liquid antibiotics. Adding vancomycin or amphotericin B antibiotic powder in distilled water before mixing with bone cement can significantly improve the efficiency of antibiotic release than can loading ALBC with the same dose of antibiotic powder. This simple and effective method for preparation of ALBCs can significantly improve the efficiency of antibiotic release in ALBCs. We thank H.Y. Hsu for performing the bioassay.
Soft-tissue balancing is crucial in total knee arthroplasty, but proper release of medial collateral ligament is a challenging procedure. It has been well recognized that medial gap tends to be more tight than lateral gap in varus knees after surgery. The purpose of this study is to investigate the incidence and predictable factors of medial tibial bone remodeling following navigation-assisted total knee arthroplasty. One hundred and sixty-six consecutive patients (221 knees) who underwent navigation-assisted total knee arthroplasty and followed during a minimum of 1 year were included in this study. Radiographic examination including anteroposterior and lateral view of both knees were performed at a regular follow-up schedules of 6 weeks, 3 months, 6 months, 1 year and thereafter, annually after surgery. An independent investigator identified the presence of medial tibial bone remodeling at each follow-up. All information on potential factors affecting medial tibial remodeling were retrieved and classified into 2 types (patient- and surgery-related).Background and Purpose
Materials and methods
