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Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 123 - 123
1 Mar 2013
Matsumoto T Muratsu H Kubo S Tei K Sasaki H Matsuzaki T Matsushita T Kurosaka M Kuroda R
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Backgrounds

In order to permit soft tissue balancing under more physiological conditions during total knee arthroplasties (TKAs), we developed an offset type tensor to obtain soft tissue balancing throughout the range of motion with reduced patella-femoral (PF) and aligned tibiofemoral joints and reported the intra-operative soft tissue balance assessment in cruciate-retaining (CR) and posterior-stabilized (PS) TKA [1, 2]. However, the soft tissue balance in unicompartmental knee arthroplasty (UKA) is unclear. Therefore, we recently developed a new tensor for UKAs that is designed to assist with soft tissue balancing throughout the full range of motion. The first purpose of the present study is to assess joint gap kinematics in UKA. Secondly, we attempted to compare the pattern in UKA with those in CR and PS TKA with the reduced PF joint and femoral component placement, which more closely reproduces post-operative joint alignment.

Methods

Using this tensor, we assessed the intra-operative joint gap measurements of UKAs performed at 0, 10, 30, 45, 60, 90, 120 and 135° of flexion in 20 osteoarthritic patients. In addition, the kinematic pattern of UKA was compared with those of CR and PS TKA that were calculated as medial compartment gap from the previous series of this study.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 257 - 257
1 Mar 2013
Matsuzaki T Matsumoto T Kubo S Muratsu H Matsushita T Oka S Nagai K Kurosaka M Kuroda R
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Introduction

Appropriate intraoperative soft tissue balancing is recognized to be essential in total knee arthroplasty (TKA). However, it has been rarely reported whether intraoperative soft tissue balance reflects postoperative outcomes. In this study, we therefore assessed the relationship between the intra-operative soft tissue balance measurements and the post-operative stress radiographs at a minimum 1-year follow-up in cruciate-retaining (CR) TKA, and further analyzed the postoperative clinical outcome.

Methods

The subjects were 25 patients diagnosed with osteoarthritis with varus deformity and underwent primary TKA. The mean age at surgery was 72.0 ± 7.5 years (range, 47–84 years). The Surgeries were performed with the tibia first gap technique using CR-TKA (e motion, B. Braun Aesculap) and the image-free navigation system (Orthopilot). We intraoperatively measured varus ligament balance (°, varus angle; VA) and joint component gap (mm, center gap; CG) at 10° and 90° knee flexion guided by the navigation system, with the patella reduced. At a minimum 1-year follow-up, post-operative coronal laxity at extension was assessed by varus and valgus stress radiographs of the knees with 1.5 kgf using a Telos SE arthrometer (Fa Telos) and that at flexion was assessed by epicondylar view radiographs of the knees with a 1.5-kg weight at the ankle. After calculating postoperative VA and CG from measurements of radiographs, measurements and preoperative and postoperative clinical outcome, such as Knee Society Clinical Rating System (Knee score; KSS, Functional score; KSFS) and postoperative knee flexion, were analyzed statistically using linear regression models and Pearson's correlation coefficient.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XL | Pages 183 - 183
1 Sep 2012
Takahara S Muratsu H Nagai K Matsumoto T Kubo S Maruo A Miya H Kuroda R Kurosaka M
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Objective

Although both accurate component placement and adequate soft tissue balance have been recognized as essential surgical principle in total knee arthroplasty (TKA), the influence of intra-operative soft tissue balance on the post-operative clinical results has not been well investigated. In the present study, newly developed TKA tensor was used to evaluate soft tissue balance quantitatively. We analyzed the influence of soft tissue balance on the post-operative knee extension after posterior-stabilized (PS) TKA.

Materials and Methods

Fifty varus type osteoarthritic knees implanted with PS-TKAs were subjected to this study. All TKAs were performed using measured resection technique with anterior reference method. The thickness of resected bone fragments was measured.

Following each bony resection and soft tissue releases, we measured soft tissue balance at extension and flexion of the knee using a newly developed offset type tensor. This tensor device enabled quantitative soft tissue balance measurement with femoral trial component in place and patello-femoral (PF) joint repaired (component gap evaluation) in addition to the conventional measurement between osteotomized surfaces (osteotomy gap evaluation). Soft tissue balance was evaluated by the center gap (mm) and ligament balance (°; positive in varus) applying joint distraction forces at 40 lbs (178 N).

Active knee extension in spine position was measured by lateral X-ray at 4 weeks post-operatively. The effect of each parameter (soft tissue balance evaluations, thickness of polyethylene insert and resected bone) on the post-operative knee extension was evaluated using simple linear regression analysis. P<0.05 was considered statistically significant.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XL | Pages 129 - 129
1 Sep 2012
Oka S Matsumoto T Kubo S Muratsu H Sasaki H Matsushita T Kuroda R Kurosaka M
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Introductions

In cruciate-retaining total knee arthroplasty (TKA), among many factors influencing post-operative outcome, increasing the tibial slope has been considered as one of the beneficial factors to gain deep flexion because of leading more consistent femoral rollback and avoiding direct impingement of the insert against the posterior femur. In contrast, whether increasing the tibial slope is useful or not is controversial in posterior-stabilized (PS) TKA, Under such recognition, accurate soft tissue balancing is also essential surgical intervention for acquisition of successful postoperative outcomes in TKA. In order to permit soft tissue balancing under more physiological conditions during TKAs, we developed an offset type tensor to obtain soft tissue balancing throughout the range of motion with reduced patello-femoral(PF) and aligned tibiofemoral joints and have reported the relationship between intra-operative soft tissue balance and flexion angles. In this study, we therefore assessed the relationship between intra-operative soft tissue balance assessed using the tensor and the tibial slope in PS TKA.

Materials and methods

Thirty patients aged with a mean 72.6 years were operated PS TKA(NexGen LPS-Flex, Zimmer, Inc. Warsaw, IN) for the varus type osteoarthritis. Following each bony resection and soft tissue release using measure resection technique, the tensor was fixed to the proximal tibia and femoral trial prosthesis was fitted. Assessment of the joint component gap (mm) and the ligament balance in varus (°)was carried out at 0, 10, 45, 90and 135degrees of knee flexion. The joint distraction force was set at 40lbs. Joint component gap change values during 10-0°,45-0°, 90-0°, 135-0° flexion angle were also calculated. The tibial slopes were measured by postoperative lateral radiograph. The correlation between the tibial slope and values of soft tissue balance were assessed using linear regression analysis.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 242 - 242
1 Jun 2012
Tei K Shibanuma N Kubo S Matsumoto T Matsumoto A Tateishi H Kurosaka M Kuroda R
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Introduction

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.

Materials and Methods

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.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 121 - 121
1 Jun 2012
Kubo S Sasaki H Matsumoto T Muratsu H Ishida K Takayama K Oka S Tei K Sasaki K Kuroda R
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Introduction

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).

Materials and methods

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.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 237 - 237
1 Jun 2012
Takayama K Kubo S Matsumoto T Ishida K Sasaki K Matsushita T Kurosaka M Kuroda R
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Introduction

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.

Materials and methods

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.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 143 - 143
1 Jun 2012
Matsumoto T Kubo S Muratsu H Ishida K Takayama K Matsushita T Tei K Kurosaka M Kuroda R
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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.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 440 - 440
1 Nov 2011
Tei K Matsumoto T Kubo S Sasaki K Ishida K Shibanuma N Muratsu H Kurosaka M Kuroda R
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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.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 464 - 464
1 Nov 2011
Matsumoto T Kubo S Muratsu H Ishida K Tei K Sasaki K Matsushita T Kurosaka M Kuroda R
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Purpose: A common difficulty with manually-performed total knee arthroplasties (TKAs) is obtaining accurate intra-operative soft tissue balancing, an aspect of this procedure that surgeons traditionally address through their “subjective feel” and experience with an unphysiological joint condition. We have therefore developed a new tensor for TKAs that enables us to assess for soft tissue balancing throughout the range of motion about the knee with a reduced patello-femoral (PF) joint and femoral component in place. This tensor permits us to intra-operatively reproduce the post-operative alignment of the PF and tibio-femoral joints. The main purpose of this study is to compare ligament balance in cruciate-retaining (CR) and posterior-stabilized (PS) TKAs.

Methods: Using the tensor, we intra-operatively compared the ligament balance measurements of CR and PS TKAs performed at 0, 10, 45, 90 and 135° of flexion, with the patella both everted and reduced. From a group of 40 consecutive females (40 varus osteoarthritic knees) blinded to the type of implant received, we prospectively randomized 20 patients to receive a CR TKA (NexGen CR Flex) and the other 20 patients a PS TKA (NexGen LPS Flex). The CR TKA group had a mean age of 73.7 ± 1.3 years while the PS TKA group had a mean age of 73.8 ± 1.7 years.

Results: The mean values of varus angle in CR TKA with the knee at 0, 10, 45, 90 and 135 degrees of flexion were 3.0, 3.2, 2.7, 4.2 and 5.1 ° with the patella everted, and 3.9, 4.2, 2.5, 2.0 and 2.0 ° with the patella reduced. The mean values of varus angle in PS TKA at these same degrees of flexion, respectively, were 3.0, 4.1, 6.0, 6.2 and 6.1 ° with the patella everted, and 3.8, 4.1, 6.3, 6.3 and 4.9 ° with the patella reduced. While the ligament balance measurements with a reduced patella of PS TKAs slightly increased in varus from extension to mid-range of flexion (p< 0.05), these values slightly decreased for CR TKA (p< 0.05). Additionally, the ligament balance at deep knee flexion was significantly smaller in varus for both types of prosthetic knees when the PF joint was reduced (p< 0.05).

Conclusion: Accordingly, we conclude that the ligament balance kinematic patterns differ between everted and reduced patellae, as well as between PS and CR TKA.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 465 - 465
1 Nov 2011
Ishida K Matsumoto T Kubo S Tsumura N Kitagawa A Kurosaka M Kuroda R
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Background: The use of computer-assisted navigation system had proved to result in consistently accurate alignment of prosthesis in total knee arthroplasty (TKA), however, the clinical midterm to long-term results remains unclear. The objective of this study is to investigate whether clinical results after computer-assisted TKA is superior to the conventional surgical method at midterm, minimum for 5 years follow-up.

Materials: From October 2002 to May 2003, we implanted 30 posterior stabilized total knee prostheses (PFC Sigma; DePuy Inc) using a computed tomography-free navigation system (Vector Vision) for patients diagnosed as osteoarthritis. A control group of 30 matched total knee prostheses of the same type were implanted via a classical, surgeon-controlled technique. Midterm 5 year clinical results including range of motion and Knee Society Clinical Rating Score were compared with these groups. The navigation group was comprised of 23 women and 4 men with a mean age of 81.0 years (range: 56–89 years) at final follow-up and the manual group was comprised of 23 women and 4 men with a mean age of 78.2 years (range: 51–87 years).The results were analyzed statistically and differences of p < 0.05 were considered statistically significant.

Results: Mean follow-up duration was 68.9 months (range: 60–78 months) in the navigation group and 72.8 months (range: 60–80 months) in the manual group. Total 6 patients (3 patients in each group) were lost to follow-up because of their death or lost contact. The follow-up rate was 90 %. No revision or reoperations were required in this study. The average preoperative knee society knee score (KSS) and knee society functional score (KSFS) in the navigation group were 52.9 points (range: 43–77 points) and 51.4 points (range: 25–80 points), respectively and the average postoperative scores were 89.7 points (range: 64–100 points) and 79.7 points (range: 40–100 points), respectively. The average preoperative KSS and KSFS in the manual group were 50.7 points (range: 43–77 points) and 50.3 points (range: 10–80 points), respectively, and the average postoperative scores were 89.6 points (range: 70–100 points) and 75.2 (range: 5–100 points), respectively. No significant differences were noted between the two groups both pre-and postoperatively. The average preoperative range of motion (ROM) in the navigation group was 105.0° (75°–125°); −8.6° (range: 0° to −25°) for extension and 113.6° (range: 85°–135°) for flexion, respectively. The average postoperative ROM was 113.8° (85°–130°); −1.0° (range: 0° to −10°) for extension and 117.0° (range: 105°–130°) for flexion, respectively. The average preoperative ROM in the manual group was 102.5° (65°–140°); −10.2° (range: 0° to −25°) for extension and 112.7° (range: 75°–140°) for flexion, respectively, the average postoperative ROM was 106.9° (80°–130°); −0.0° (range: 0°) for extension and 106.9° (range: 80°–130°) for flexion, respectively. Although no significant difference was found between preoperative ROM for the two groups, the navigation group showed a significantly better ROM compared to the manual group.

Conclusions: Minimum 5-year follow-up of computer-assisted TKA used in the present study revealed that better ROM was achieved, compared with the conventional surgical method. KSS and KSFS were equally good among these two groups. The results focused on the radiographically malaligned patients and further longer follow-up were needed to reveal whether computer-assisted TKA has true clinical benefits compared with the conventional surgical method.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 448 - 448
1 Nov 2011
Sasaki K Kubo S Matsumoto T Ishida K Tei K Matsushita T Kurosaka M Kuroda R
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Purpose: Continuous femoral nerve block (CFNB) has been revealed to be a safe and effective method to decrease postoperative pain after total knee arthroplasty (TKA).

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.

Methods: Sixty patients who received primary TKA for osteoarthritis were divided into three groups based on the duration to receive CFNB for 0day, 2days or 5days (twenty patients for each group). Ropivacaine 2mg/mL was given through the femoral nerve catheter using elastomeric infusers (delivering 2ml/hr for each group).

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.

Results: At 1st and 3rd day postoperatively, the VAS was significantly better in the CFNB 2 days and CFNB 5 days group than in the CFNB 0 day group (P< 0.05).

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.

Discussion: Postoperative use of CFNB reduced pain at first 3days, and shorten the time to acquire stable walking ability after TKA. We conclude that CFNB should be kept for 5days after surgery to decrease pain and accelerate rehabilitation program after TKA.