Achieving high flexion after total knee arthroplasty (TKA) is one of the most important clinical results, especially in eastern countries where the high flexion activities, such as kneeling and squatting, are part of the important lifestyle. Numerous studies have examined the kinematics after TKA. However, there are few numbers of studies which examined the kinematics during deep knee flexion activities. Therefore, in the present study, we report analysis of mobile-bearing TKA kinematics from extension to deep flexion kneeling using 2D-3D image matching technique. The subjects were 16 knees of 8 consecutive patients (all women, average age 75.9), who underwent primary mobile-bearing PS TKA (P.F.C. sigma RP-F: Depuy Orthopedics Inc., Warsaw, IN, USA) between February 2007 and May 2008. All cases were osteoarthritis with varus deformity. Postoperative radiographs were taken at the position of extension, half-squatting and deep flexion kneeling 3 month after the surgery, and the degrees of internal rotation of the tibial component was measured by 2D-3D image matching technique. Pre- and post-operative ROM was recorded. Then, we compared the absolute value and relative movement of tibial internal rotation between extension, half-squatting and deep flexion kneeling, and evaluated the correlation of the ROM and the internal rotation.Introduction
Materials and Methods
Accurate soft tissue balancing has been recognized as important as alignment of bony cut in total knee arthroplasty (TKA). In addition, using a tensor for TKA that is designed to facilitate soft tissue balance measurements throughout the range of motion with a reduced patello-femoral (PF) joint and femoral component in place, PF joint condition (everted or reduced) has been proved to have a significant effect for intra-operative soft tissue balance. On the other hand, effect of patellar height on intra-operative soft tissue balance has not been well addressed. Therefore, in the present study, we investigated the effect of patellar height by comparing intra-operative soft tissue balance of patella higher subjects (Insall-Salvati index>1) and patella lower subjects (Insall-Salvati indexâ‰/1). The subjects were 30 consecutive patients (2 men, 28 women), who underwent primary PS TKA (NexGen LPS-flex PS: Zimmer, Warsaw, IN, USA) between May 2003 and December 2006. All cases were osteoarthritis with varus deformity. Preoperative Insall-Salvati index (ISI) was measured and patients were divided into two groups; the patella higher group (ISIï1/4ž1: 18 knees average ISI was 1.12) and the patella lower group (ISIâ‰/1; 12 knees average ISI was 0.94). Component gap and ligament balance (varus angle) were measured using offset-type tensor with 40lb distraction force after osteotomy with the PF joint reduced and femoral trial in place at 0, 10, 45, 90, 135 degrees of knee flexion. Data of two groups were compared using unpaired t test.Introduction
Materials and methods
Total knee arthroplasty (TKA) with a computer-assisted navigation system has been developed to improve the accuracy of the alignment of osteotomies and implantations. One of the most important goals of TKA is to improve the flexion angle. Although accurate soft tissue balancing has been recognized as an essential surgical intervention influencing flexion angle, the direct relationship between post-operative flexion angle and intra-operative soft tissue balance during TKA, has little been clarified. In the present study, therefore, we focused on the relationship between them in cruciate-retaining (CR) TKA with a navigation system. The subjects were 30 consecutive patients (2 men, 28 women), who underwent primary CR TKA (B. Braun Aesculap, e-motion) between May 2006 and December 2009. TKAs were performed using a image-free navigation system (OrthoPilot; B. Braun Aesculap, Tuttlingen, Germany). All cases were osteoarthritis with varus deformity. Average patient age at the time of surgery was 74.0 years (range, 62-86 years). After all bony resections and soft tissue releases were completed appropriately using a navigation system with tibia-first gap technique, a tensor was fixed to the proximal tibia and the femoral trial was fitted. Using the tensor that is designed to facilitate soft tissue balance measurements throughout the range of motion with a reduced patello-femoral (PF) joint and femoral component in place, the joint component gap and ligament balance (varus angle) were measured after the PF joint reduced and femoral component in place (Fig.1). Assessments of joint component gap and ligament balance were carried out at 0°, 30°, 60°, 90°, 120° flexion angle, which were monitored by the navigation system. Joint component gap change values during 30°- 0°, 60°- 0°, 90°- 0°, 120°- 0° flexion angle were calculated. The correlation between post operative flexion angles and pre-operative flexion angle, intra-operative joint component gaps, joint component gap change values and ligament balances were assessed using linear regression analysis.Introduction
Materials and methods
Using a tensor for total knee arthroplasty (TKA) that is designed to facilitate soft tissue balance measurements with a reduced patello-femoral (PF) joint, we examined the influence of pre-operative deformity on intra-operative soft tissue balance during posterior-stabilized (PS) TKA. Joint component gap and varus angle were assessed at 0, 10, 45, 90 and 135° of flexion with femoral trial prosthesis placed and PF joint reduced in 60 varus type osteoarthritic patients. Joint gap measurement showed no significant difference regardless the amount of pre-operative varus alignment. With the procedures of soft tissue release avoiding joint line elevation, however, intra-operative varus angle with varus alignment of more than 20 degrees exhibited significant larger values compared to those with varus alignment of less than 20 degrees throughout the range of motion. Accordingly, we conclude that pre-operative severe varus deformity may have the risk for leaving post-operative varus soft tissue balance during PS TKA.
Recently, many researches of minimal incision surgery (MIS) total knee arthroplasty (TKA) have been reported, however very few of these contain clinical results. Regardless of this, MIS TKA is widely promoted as an improvement over traditional TKA. Although traditional TKA allows for excellent visualization, component orientation, fixation, and has been associated with remarkable long-term implant survival, many patients expect an extremely small incision, minimal or no pain and discomfort associated with their surgery, and certainly no increase in the complication rate. While there is some evidence that short term benefits may occur, there is concern that there may be an increase in complications with the use of MIS technique. We report here cases that malalignments in early phase were occurred after MIS TKAs. A consecutive series of MIS TKA for varus osteoarthritis undertaken by 2 surgeons at 2 centers during 2-year priod (2006–2007) was reviewed. During this interval, 50 MIS TKAs were performed. The mean age was 75.6 years (range 54 to 88 years). Cases for post-operatively infection were excluded. There were 2 cases that early failures due to varus sinking of tibial component were confirmed in early phase (7 and 3 months after primary surgery). We analyzed data between early failed cases and non-failed cases. Patients with early failure were younger, which showed a trend toward significance (p=0.11; failed; 66.5, non-failed; 75.9 years). There was no difference in amount of both medial and lateral side of distal femoral cut between early failed cases and non-failed cases. Proximal tibial cut was significantly larger in early failed cases compared with non-failed cases (p=0.01; failed; 16.5±4.5, nonfailed; 11.4±6.6). There was no difference in Femorotibial angle (FTA) after surgery between them. Substantial backgrounds of occurring early failure after MIS TKA are not still clarified, however, very early failure were occurred in patients, who had significant large cut of proximal tibia, in our experienced cases. MIS TKA may lead to varus imbalance due to increased amount of bony cut and decreased medial soft tissue release. Henceforth, the high prevalence of MIS failures occurring in early phase is disturbing, because of limited working space and warrants further investigation.
However, optimal duration for CFNB to decrease pain and accelerate rehabilitation program after TKA has not been addressed. We, therefore, compared three groups of patients which had different duration of CFNB (0, 2, and 5days) in this study.
Outcomes including visual analog scale (VAS) pain scores and range of motion (ROM) were compared at 1st, 3rd, 6th, 14th and 21th days after surgery. In addition, the postoperative date when patients could walk stably with parallel bar, walker, or T-cane were recorded and compared.
ROM did not show significant difference among the three groups over postoperative days 1st to 21st (P>
0.05), although groups with the CFNB showed greater ROM at all time points. The CFNB 5 days group obtained stable walking ability with T-cane earlier than other groups (P<
0.05). No patient had any side effect by having CFNB in this study.