PURPOSE: The purpose of this study was to investigate the correlation between rotational axes of femur and tibia with the use of Linker. MATERIALS AND METHODS: This study was carried out from August 2009 to February 2010 on 54 patients (106 knees), who were diagnosed with simultaneous bilateral total knee arthroplasty. With the use of postoperative computed tomography scans, it was investigated how much the rotational angle of femoral and tibial components matched. RESULTS: The tibial component was internally rotated for the femoral component at an angle of 0.8degrees. The femoral component was externally rotated for the surgical transepicondylar axis (TEA) at an angle of 1.6 (range: from 4.8degrees of internal rotation to 7.9degrees of external rotation, SD=2.2degrees), and the tibial component was externally rotated for the surgical TEA at an average angle of 0.9 (range: from 5.1degrees of internal rotation to 8.3degrees of external rotation, SD=3.1degrees). CONCLUSION: The femoro-tibial synchronizer helped to improve the orientation and positioning of both femoral component and tibial component, and also increase the correlation of the rotational axes of the two components.
Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/*methods ; Female ; Femur/*radiography/surgery ; Humans ; Knee ; Knee Joint/*radiography/surgery ; Knee Prosthesis ; Male ; Middle Aged ; Reference Values ; Rotation ; Tibia/*radiography/surgery ; Tomography, X-Ray Computed/*methods

PURPOSE: The purpose of this study was to investigate the correlation between rotational axes of femur and tibia with the use of Linker. MATERIALS AND METHODS: This study was carried out from August 2009 to February 2010 on 54 patients (106 knees), who were diagnosed with simultaneous bilateral total knee arthroplasty. With the use of postoperative computed tomography scans, it was investigated how much the rotational angle of femoral and tibial components matched. RESULTS: The tibial component was internally rotated for the femoral component at an angle of 0.8degrees. The femoral component was externally rotated for the surgical transepicondylar axis (TEA) at an angle of 1.6 (range: from 4.8degrees of internal rotation to 7.9degrees of external rotation, SD=2.2degrees), and the tibial component was externally rotated for the surgical TEA at an average angle of 0.9 (range: from 5.1degrees of internal rotation to 8.3degrees of external rotation, SD=3.1degrees). CONCLUSION: The femoro-tibial synchronizer helped to improve the orientation and positioning of both femoral component and tibial component, and also increase the correlation of the rotational axes of the two components.
Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/*methods ; Female ; Femur/*radiography/surgery ; Humans ; Knee ; Knee Joint/*radiography/surgery ; Knee Prosthesis ; Male ; Middle Aged ; Reference Values ; Rotation ; Tibia/*radiography/surgery ; Tomography, X-Ray Computed/*methods

PURPOSE: This study directly compared clinical assessment scores and short-term systemic complications after total knee arthroplasty (TKA) between a group of patients aged 80 or older (141 patients) and another group of patients aged between 65 and 70 years (616 patients) with advanced osteoarthritis. MATERIALS AND METHODS: We retrospectively investigated 757 osteoarthritic patients who underwent primary TKA from January 2007 to January 2011 with a follow-up of 1 year. The surgery was performed using an extramedullary alignment guide instrument without invasion of the intramedullary canal to decrease embolic load and blood loss. RESULTS: At 1 year after surgery, the mean Knee Society knee score was improved in both groups (from 63.6 to 83.2 in octogenarians and from 68.3 to 89.0 in the younger group) and the level of satisfaction was excellent in both groups (8 in octogenarians and 8.3 in the younger group), even though there was no notable change in function score in the octogenarians (from 61.0 to 61.9 in the octogenarians and from 62.3 to 73.6 in the younger group). The total incidence of systemic complications (3.4% vs. 1.2%, p=0.400) and surgical complications (2.1% vs. 0.5%, p=0.229) showed no significant difference between groups. CONCLUSIONS: TKA yielded favorable clinical outcomes with a comparatively low postoperative complication rate in octogenarians despite the negligible functional improvement.
Aged, 80 and over ; Arthroplasty ; Follow-Up Studies ; Humans ; Incidence ; Knee ; Osteoarthritis ; Postoperative Complications ; Retrospective Studies

PURPOSE: We devised an intraoperatively identifiable mechanical axis (IIMA) as a reference of alignment in total knee arthroplasty (TKA). MATERIALS AND METHODS: Between February 2010 and January 2011, primary TKAs were consecutively performed on 672 patients (1007 knees) using an IIMA as a reference in the coronal plane. RESULTS: The alignment of the lower extremity improved from a mean of 11.4+/-6.7degrees (-10.3-34.4degrees) of varus preop. to 0.7+/-3.5degrees (-5.2-8.6degrees) immediately after surgery. Mean alignment of the femoral component in the coronal plane was 89.3+/-2.3degrees (83.4-97.2degrees) postop. and mean alignment of the tibial component was 90.4+/-2.2degrees (85.1-94.2degrees) postop. CONCLUSION: This study showed that IIMA could be of considerable value as a new guider of alignment that is easily accessible and highly effective during total knee arthroplasty.
Arthroplasty, Replacement, Knee/*methods ; Femur/surgery ; Humans ; Tibia/surgery

BACKGROUND: We hypothesized that a number of clinical and radiologic parameters could influence the reducibility of varus deformity in total knee arthroplasty. The aim of this study was to identify the factors correlated with reducibility of varus deformity and predict more accurately the amount of medial soft tissue release required in varus deformity total knee arthroplasty. METHODS: One hundred forty-three knees with preoperative varus alignment and medial osteoarthritis were included in this retrospective study. The total knee arthroplasties were performed using a navigation system (OrthoPilot) by single surgeon. To assess varus deformity, the authors measured preoperative mechanical axis angles and valgus stress angles. Mechanical tibial angles, mechanical femoral angles, femoral osteophyte sizes, and tibial osteophyte sizes were measured. The Ahlback grading scale was applied for radiologic parameters, and clinical parameters (age, body mass index, sex, duration of pain, and preoperative range of motion) were documented. Correlations between these factors and preoperative valgus stress angle were analyzed. RESULTS: A negative correlation was found between preoperative mechanical axis angle and preoperative valgus stress angle (p < 0.01, r = -0.38), and a positive correlation was found between the preoperative mechanical tibial angle and preoperative valgus stress angle (p = 0.01, r = 0.19). CONCLUSIONS: The present study shows that preoperative varus deformity and proximal tibial vara (measured by preoperative mechanical axis angle and mechanical tibial angle, respectively) are correlated with reducibility of varus deformity (measured by preoperative valgus stress angle), and clinical parameters (age, range of motion, duration of pain and body mass index) and other radiologic parameters (osteophyte size, severity of osteoarthritis and angulation of distal femoral joint surface) were not significantly correlated with reducibility of varus deformity.
Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/*methods ; Bone Malalignment/radiography/*surgery ; Female ; Humans ; Knee Joint/radiography/*surgery ; Male ; Middle Aged ; Osteoarthritis, Knee/radiography/*surgery ; Retrospective Studies ; Stereotaxic Techniques ; Surgery, Computer-Assisted

PURPOSE: The purpose of this study was to evaluate clinical results and accuracy of femoral cutting in the coronal plane in total knee arthroplasty (TKA) using a fixed length intramedullary guide. MATERIALS AND METHODS: From 2005 to 2008, 101 patients (154 knees) underwent TKA (NexGen LPS implant). The minimal follow-up period was 3 years (mean, 4.4 years). The patients were divided into two groups (group 1, 94< or =alpha angle<98; group 2, 94>alpha, 98< or =alpha). Mechanical axis deviation (MAD), patellar tilting angle (PTA), Knee Society Knee Score (KSKS), and Knee Society Function Score (KSFS) were measured in both groups. RESULTS: There were 120 knees in group 1 and 34 knees in group 2. There was no significant intergroup difference in the postoperative MAD (group 1, 1.59degrees; group 2, 1.91degrees). The number of outliers with > or =2degrees MAD was 65 in group 1 and 24 in group 2. The mean PTA, KSKS, and KSFS were 10.17degrees, 96.0, and 96.6, respectively, in group 1 and 11.58degrees, 84.5, and 85.5, respectively, in group 2. CONCLUSIONS: The percentage of coronal alignment outliers was relatively high (34 in 154 cases, 22%) after TKA using a fixed length intramedullary guide. However, there was no statistically significant intergroup difference in clinical results (KSKS, p=0.67; KSFS, p=0.56).
Adenine Nucleotides ; Arthroplasty ; Axis, Cervical Vertebra ; Follow-Up Studies ; Humans ; Knee ; Mycophenolic Acid

PURPOSE: To assess proper soft tissue balancing of the varus arthritic knee between posterior oblique ligament (POL) release group and superficial medial collateral ligament (SMCL) release group. MATERIALS AND METHODS: This retrospective study was performed on 186 patients who underwent minimally invasive surgery (MIS) total knee arthroplasty (TKA) from January 2011 to December 2011. Eighty-three patients were in the group of SMCL release and 103 patients were in the POL release group. We intended to use a 10 mm polyethylene insert (PE) during TKA, and retrospectively compared the actual thickness of PE between POL release group and SMCL release group. RESULTS: The mean PE thickness was 10.59+/-1.3 mm (range, 8 to 15 mm) in POL group and 11.88+/-1.8 mm (range, 10 to 18 mm) in SMCL group (p=0.001). We found a significant difference in the mean PE thickness between POL release group and SMCL release group. CONCLUSIONS: POL and deep MCL releases in MIS-TKA would be beneficial for varus deformity correction in the osteoarthritic knee.
Arthroplasty ; Benzeneacetamides ; Collateral Ligaments ; Congenital Abnormalities ; Humans ; Knee ; Ligaments ; Piperidones ; Polyethylene ; Retrospective Studies

The management of patellae with a severe bony deficiency during revision total knee arthroplasty is a challenging problem. However, using a technique of augmentation with transcortical wiring of an onlay-type prosthesis allowed the authors to revise a deficient patellae successfully. After making the decision to revise the existing patellar component, the procedure was found to be technically straightforward. Furthermore, the procedure does not require sophisticated instruments, only an onlay-type prosthesis, cement and wires. This technique entails fixing wires to the three pegs of the patellar component, passing the wires through drill holes in the anterior cortex and, after compression of a cemented prosthesis, augmenting the fixation by twisting the wires anteriorly. We believe that stable fixation and painless articulation will be obtained with the described technique for deficient patellae.
Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/*methods ; Bone Cements ; *Bone Wires ; Humans ; Knee Prosthesis ; Middle Aged ; Patella/*surgery ; Prosthesis Design ; Prosthesis Implantation/*methods

PURPOSE: Alignment is an important factor in the long-term success of total knee arthroplasty. In the total knee arthroplasty, the conventional extramedullary femoral alignment system has significant error in femoral coronal alignment, since it is difficult to find the femoral head center and it is time consuming to determine during the operation. The purpose of our study was to evaluate the accuracy of the newly-designed marker system for extramedullary femoral alignment that uses radiologic distance between the 2 femoral head centers. MATERIALS AND METHODS: Between July 2008 and July 2009, 90 patients (100 knees) with knee osteoarthritis underwent total knee arthroplasty using the femoral extramedullary femoral guide system. We measured the distance between the femoral head centers using the radiologic picture archiving and communication system (PACS, General Electric, Milwaukee, WI) system preoperatively, then plastic rods and metal pegs were used to simulate the inter femoral head center distance. By placing the center of the plastic rod after marking the inter femoral head center distance on the central body line, we could trace the coronal mechanical axis. We measured the angle between the femoral mechanical axis and the femoral component in standing long leg antero-posterior radiograph to assess radiologically the accuracy of coronal alignment postoperatively. RESULTS: The average femoral length in the study group was 402.5+/-16.2 mm. The mean distance between the femoral head and the center of the marker was 49.6+/-17.9 mm. The average error in estimation of the distance between the femoral head center and the metal peg of the marker was 3.78+/-3.14 mm. The positional error in alignment was 1degrees or less in 90% and 2degrees or less in 100% of knees. The average angle of femoral component to femoral mechanical axis was 89.9+/-1.5degrees (range 84.4-93.6degrees). The coronal alignment of the femoral components was within 90degrees+/-3degrees in -96% of cases. CONCLUSION: Our results suggest that the clinical method reported here is a simple and reliable method to localize the center of the femoral head during total knee arthroplasty.
Arthroplasty ; Axis, Cervical Vertebra ; Head ; Humans ; Knee ; Leg ; Osteoarthritis, Knee ; Plastics ; Radiology Information Systems

PURPOSE: Recently, a mobile ultracongruent polyethylene insert was used to increase joint stability in the posterior cruciate ligament sacrificed total knee arthroplasty with non-posted mobile bearing. However, as yet there have been no reports about this implant. In this study, the clinical and radiological results of surgery using the implant were analyzed through a navigation system. MATERIALS AND METHODS: The subjects included 95 cases of 70 patients to whom the rotating tibial implant was applied after posterior cruciate ligament resection among the patients who underwent total knee arthroplasty from September 2006 to December 2008. The follow-up duration was at least 24 months, and 40 months on average. For clinical evaluation, the knee score and functional scores were measured preoperatively and at the time of final follow-up. With reference to a 5 mm joint line change measurement recorded by the navigation system, which can affect the clinical result, the comparison and evaluation were performed by dividing the subjects into group I (< or =5 mm) and group II (>5 mm). Radiological evaluation was performed by measuring the angle of the mechanical axis of the lower extremities and the patella tilting angle preoperatively and at the time of final follow-up using plain radiographs. RESULTS: Seventy subjects (95 cases) were followed up for at least 24 months. According to the clinical results, the mean KSS knee score improved from a preoperative score of 43.4 to a final follow-up score of 90.6 (p<0.0001). In addition, the mean functional score improved from a preoperative score of 51 to a final follow-up score of 88.4 (p<0.0001). Finally, the mean joint line change, which can affect the clinical result, was 5.82 mm, ranging from -1 to 12 mm. The clinical and radiological evaluations were performed by dividing the subjects into two groups in relation to the reference value of 5 mm, but no significant difference was found. The mechanical axis angles of the lower extremities improved from the preoperative value of varus 10.01degrees to the final follow-up value of varus 1.89degrees, and the difference was significant (p<0.0001). The mean patella tilting angles were 8.8degrees and 9.3degrees, respectively, at the time before the operation and after the final follow-up; this difference was not significant (p=0.89). CONCLUSION: Good clinical and radiological results were observed after at least two years of follow-up subsequent to total knee arthroplasty, in which a rotating ultracongruent polyethylene insert was applied after posterior cruciate ligament resection using a navigation system.
Arthroplasty ; Axis, Cervical Vertebra ; Follow-Up Studies ; Humans ; Joints ; Knee ; Lower Extremity ; Patella ; Polyethylene ; Posterior Cruciate Ligament ; Reference Values ; Ursidae