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Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 55 - 55
1 Feb 2020
Oshima Y Watanabe N Takeoka T Iizawa N Majima T Takai S
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Introduction

Upright body posture is maintained with the alignment of the spine, pelvis, and lower extremities, and the muscle strength of the body trunk and lower extremities. Conversely, the posture is known to undergo changes with age, and muscle weakness of lower extremities and the restriction of knee extension in osteoarthritis of the knee (knee OA) have been considered to be associated with loss of natural lumbar lordosis and abnormal posture.

As total knee arthroplasty (TKA) is aimed to correct malalignment of lower extremities and limited range of motion of knee, particularly in extension, we hypothesized that TKA positively affects the preoperative abnormal posture. To clarify this, the variation in the alignment of the spine, pelvis, and lower extremities before and after TKA was evaluated in this study.

Patients and methods

Patients suffering from primary knee OA who were scheduled to receive primary TKA were enrolled in this study. However, patients with arthritis secondary to another etiology, i.e. rheumatoid arthritis, trauma, or previous surgical interventions to the knee, were excluded. Moreover, patients who suffered from hip and ankle OA, cranial nerve diseases, or severe spinal deformity were also excluded.

The sagittal vertical axis (SVA), the horizontal distance between the posterosuperior aspect of the S1 endplate surface and a vertical plumb line drawn from the center of the C7 vertebral body, is an important index of sagittal balance of the trunk. Thus, patients were classified into two groups based on the preoperative SVA with preoperative standing lateral digital radiographs: normal (< 40mm) and abnormal (≥ 40mm) groups.

The variations in the sagittal alignment of the spine, pelvis and lower extremities were evaluated preoperatively, and at 1 and 3 months postoperatively. This study was approved by an institutional review board, and informed consent for participation was obtained from the patients.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 125 - 125
1 Feb 2020
Iizawa N Oshima Y Kataoka T Majima T Takai S
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Background

In order to restore the neutral limb alignment in total knee arthroplasty (TKA), surgical procedure usually starts with removing osteophytes in varus osteoarthritic knees. However, there are no reports in the literature regarding the exact influence of osteophyte removal on alignment correction. The purpose of this study was to define the influence of osteophyte removal alone on limb alignment correction in the coronal plane in TKA for varus knee.

Methods

Twenty-eight medial osteoarthritic knees with varus malalignment scheduled for TKA were included in this study. After registration of a navigation system, each knee was tested at maximum extension, and at 30, 40 and 60 degrees of flexion before and after osteophyte removal. External loads of 10 N-m valgus torque at each angle and in both states were applied. Subsequently, the widths of the resected osteophytes were measured.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 91 - 91
1 Apr 2019
Watanabe H Majima T Tsunoda R Oshima Y Uematsu T Takai S
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Introduction

The hip hemiarthroplasty in posterior approach is a common surgical procedure at the femoral neck fractures in the elderly patients. However, the postoperative hip precautions to avoid the risk of dislocations are impeditive for early recovery after surgery. We used MIS posterior approach lately known as conjoined tendon preserving posterior (CPP) approach, considering its enhancement of joint stability, and examined the intraoperative and postoperative complications, retrospectively.

Methods

We performed hip hemiarthroplasty using CPP approach in 30 patients, and hip hemiarthroplasty using conventional posterior approach in 30 patients, and both group using lateral position with the conventional posterior skin incision. The conjoined tendon (periformis, obturator internus, and superior/inferior gemellus tendon) was preserved and the obturator externus tendon was incised in CPP approach without any hip precautions postoperatively. The conjoined tendon was incised in conventional approach using hip abduction pillow postoperatively.


Introduction

A femoral rotational alignment is one of the essential factors, affecting the postoperative knee balance and patellofemoral tracking in total knee arthroplasty (TKA). To obtain an adequate alignment, the femoral component must be implanted parallel to the surgical epicondylar axis (SEA).

We have developed “a superimposable Computed Tomography (CT) scan-based template”, in which the SEA is drawn on a distal femoral cross section of the CT image at the assumed bone resection level, to determine the precise SEA. Therefore, the objective of this study was to evaluate the accuracy of the rotational alignment of the femoral component positioned with the superimposed template in TKA.

Patients and methods

Twenty-six consecutive TKA patients, including 4 females with bilateral TKAs were enrolled.

To prepare a template, all knees received CT scans with a 2.5 mm slice thickness preoperatively. Serial three slices of the CT images, in which the medial epicondyle and/or lateral epicondyle were visible, were selected. Then, these images were merged into a single image onto which the SEA was drawn. Thereafter, another serial two CT images, which were taken at approximately 9 mm proximal from the femoral condyles, were also selected, and the earlier drawn SEA was traced onto each of these pictures. These pictures with the SEA were then printed out onto transparent sheets to be used as potential “templates” (Fig. 1-a).

In the TKA, the distal femur was resected with the modified measured resection technique. Then, one template, whichever of the two potential templates, was closer to the actual shape, was selected and its SEA was duplicated onto the distal femoral surface (Fig. 1-b). Following that, the distal femur was resected parallel to this SEA.

The rotational alignment of the femoral component was evaluated with CT scan postoperatively. For convention, an external rotation of the femoral component from the SEA was given a positive numerical value, and an internal rotation was given a negative numerical value.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_6 | Pages 38 - 38
1 Mar 2017
Takai S
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Radiographic assessment of component rotation has been impossible without using computed tomography or magnetic resonance imaging. The purpose of the present study was to assess the rotational alignment of the femoral component using plane radiography. Eighty-three patients from 89 knees who underwent primary total knee arthroplasty (TKA) were evaluated radiographically before and after surgery using kneeling view, a postero-anterior projection vertical to the tibia at 70 to 80° flexion of the knee. In this view, the transepicondylar axis and posterior condylar line can be seen. The condylar twist angle was 5.7±1.6° preoperatively and 2.6±0.9° postoperatively. The external rotation of the femoral component was 3.2±1.1°. Plane kneeling view radiographs taken before and after TKA can be used to assess the rotational alignment of the femoral component. Axial images of patellofemoral articulation were then superimposed to the kneeling view images along the outline of the femoral component. Combination of kneeling view and axial view can demonstrate the relationship between the rotational alignment of the femoral component and the patellofemoral joint after TKA.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_6 | Pages 37 - 37
1 Mar 2017
Takai S
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Soft tissue balancing remains the most subjective and most artistic of current techniques in total knee arthroplasty. The flexion gap is traditionally measured at approximately 45 degree of hip flexion and 90 degree of knee flexion on the operation table. Despite of aiming equal joint gaps or tensions in flexion and extension, influence of the thigh weight on the flexion gap has not been documented. Therefore, the purpose of this study was to examine the flexion gaps in the 90–90 degree flexed position and the traditional 45–90 degree flexed position of hip-knee joints.

Thirty patients with osteoarthritic knee underwent total knee arthroplasty. After the PCL sacrifice, soft tissue releases, and bone cuts. Biomechanical properties of the soft tissue were obtained during the surgery, using the specially designed system. The system consists of two electric load cells in the tensioning device, digital output indicators, and an XY plotter. Load displacement curves were obtained in extension and in flexion. 160N was applied to open the joint gaps in the traditional 45–90 degree flexed position and the 90–90 degree flexed position of hip-knee joints. The flexion gap in the 90–90 degree flexed position of hip-knee joints was 2.1±1.2mm wider than that in the traditional 45–90 degree flexed position of hip-knee joints. The flexion gap had significant difference between the two different hip flexion angles. To avoid the influence of the thigh weight and obtain equal joint gaps or tensions in flexion and extension, the flexion gap should be checked in the 90–90 degree flexed position of hip-knee joints. Interestingly, the stiffness of curves obtained from the lateral in flexion is 1/3 lower than the other three. Therefore, it is very difficult to match these four.

The effect of patellar position on soft tissue balancing in TKA is also under debate. We developed the digital tensor system to measure the load (N) and the distance (mm) of extension and flexion gaps in medial and lateral compartment separately with setting of femoral component trial. The gap load and distance in extension and flexion position of PS and CR TKA in both patella everted and reset position were measured. Thirty-four patients who underwent primary TKA for medial type osteoarthritis using medial parapatellar approach were included. The load was measured at the gap distance, which is equal to the sum of implants including polyethylene insert. In extension, there was no significant difference between the load in patella everted and reset position in both PS-TKA and CR.-TKA. In flexion, there was a significant decrease of the load, which is comparable to the increase of gap distance of approximately 2mm, by resetting the patella from eversion in PS-TKA. There was, however, no significant difference in CR-TKA by resetting the patella. There was no significant difference in the ratio of medial / lateral load in both PS-TKA and CR.-TKA. Soft tissue balancing of PS-TKA with medial parapatellar approach should be performed after resetting the patella. It is still unclear whether we can adjust these materials precisely and constantly or not.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 134 - 134
1 Feb 2017
Majima T Matsui S Nishiike O Takahashi K Oshima Y Iizawa N Takai S
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Introduction

In order to achieve good clinical results in TKA, soft tissue balance is important. Soft tissue balance is closely related to knee kinematics which affects clinical results.

Modified gap balancing technique is one of the standard techniques for posterior stabilized (PS) TKA. On the other hand, appropriate load for the measurement of gap balance has not been established.

The purpose of the present study is to measure the mechanical properties of soft tissue structure of knee sleeve in flexion and extension during PS TKA using newly developed balancer. The understanding of the mechanical properties is crucial. In particular if these properties are used as input for surgical procedures, standard technique for many surgeons will be established.

Materials and Methods

Medial compartmental osteoarthrosis (OA) patients (13 female and 7 male) were evaluated. Average age, BMI, and Varus deformity were 72.1 years, 26.9, and 12 degrees, respectively.

The newly developed center paddle balancer consists of a built-in spring (Fig. 1). Figure 2 shows the sequence of surgery and measurements. In the surgery, we measured the balance (degrees in Figure 1, A) and distance (mm in Figure 1, B) in extension with a load (Figure 1,C) at transition zone of toe region to linear region. Then, applying the load until flexion gap was the same as that in extension with a patella reduction, we measured the femoral component rotation from the balancer (degrees in Figure 1, A). The anterior and posterior femoral cuts were performed according to measured femoral component rotation which angle is parallel to tibial cut surface.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 24 - 24
1 Feb 2017
Iizawa N Oshima Y Kataoka T Matsui S Takai S
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Introduction

For restoration of neutral limb alignment in Total Knee Arthroplasty (TKA), we usually start by removing osteophytes in varus osteoarthritic knees. However, we have found no reports in the literature regarding research on the exact influence of osteophyte removal on angle correction. The purpose of this study was to define the influence of osteophyte removal on limb alignment correction in the coronal plane in TKA.

Materials and Methods

Nine patients with varus malalignment that were scheduled for TKA were included in this study. Only patients with degenerative osteoarthritis were considered. After registration of a navigation system, each knee was tested at maximum extension, and 30 and 60 degrees of flexion before and after osteophyte removal. The same examiner applied all external loads of 10 N-m valgus torque at each angle and in both states. Subsequently, the widths of the osteophytes were measured. All data were analyzed statistically using paired t-test and correlation coefficient. A significant difference was determined to be present for P < .05.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 105 - 105
1 May 2016
Oshima Y Takai S Fetto J
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Background

Total knee arthroplasty (TKA) is the highly developed procedure for sever osteoarthritic knee, in which there are two major concepts; Cruciate Retaining design (CR) and Posterior Stabilized design (PS). The femoral roll back movement is enforced with the post-cam mechanism in the PS, however, this structure associates with the complications, i.e. wear and dislocation. The CR has been developed to obtain the knee stability with native posterior cruciate ligament (PCL) in TKA. However, the preservation of the PCL can limit knee exposure and increase the technical challenge of surgery. We hypothesized that the knee exposure was easily achieved after the PCL was released, however, the PCL was repaired and the posterior stability was re-established after the TKA with time if it was released subperiostealy.

Objective

The objective of this study was to evaluate the varying of the posterior stability after the PCL-released CR TKA.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_8 | Pages 87 - 87
1 May 2016
Kataoka T Iizawa N Mori A Oshima Y Matsui S Takai S
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Introduction

Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in TKA.

Materials and Methods

This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with an intact knee (S0), and thereafter femoral arthroplasty only (S1), tibial arthroplasty (S2), release of the dMCL (S3), and finally, release of the POL (S4). The same examiner applied all external load of 10 N-m valgus and a 5 N-m internal and external rotation torque at each flexion angle for the each cutting state. All data were analyzed statistically using one-way ANOVA and we investigated the correlation between the medial gap and the rotation angle. A significant difference was determined to be present for P < .05.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 66 - 66
1 May 2016
Murase K Tsutsumi S Takai S
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The Total Knee Replacement (TKR) has been used as the effective treatment for osteoarthritis of the knee. The load of the knee joint is generally applied at the heel strike as the impact loading. In the elderly who had muscle weakness or weakening eyesight, it can be anticipated that more excessive loads are often added to the knees when they stumble or trip over. And the varus / valgus alignments of the femur and tibia differs among patients. However, most finite element analyses considering the effect of the alignments have rarely been performed.

In this study, the mounting angle of the tibia component in the TKR knee was changed, and the effect of the change on the load transfer was assess using finite element analyses. Based on the CT images, the three-dimensional finite element models of the natural knee joint and TKR knee joint were created [Fig. 1]. Each model was constructed from hexahedoral elements with the isotropic material. The numbers of nodes and elements were 10,666 and 8,677 respectively. Under normal alignment, 5 degrees of varus, and 5 degrees of valgus knee, the static analyses at an applied load of 1000N and impact analyses at an applied load of 50 kg were performed. LS-DYNA ver760 software was used for the analyses.

The finite element analyses results showed that under the static loading, no stress shielding was observed in the tibial cancellous bone of the intact knee or TKR knee, and the maximum compressive stress was 1.5 MPa. While under the impact loading, the compressive stress generated inside of the cancellous bone was three times higher in the TKR knee joint than that in the intact knee, and the load transfer time was reduced. This result reveals that the cancellous bone have load bearing function especially in the impact condition.

When the impact load was applied to the varus and valgus TKR knee, the stress shielding was observed in the tibial cancellous bone, especially in the varus condition. In a case where the tibia component was mounted by tilting it at −5 to 5 degrees depending on the varus/valgus of the knee, the stress shielding was alleviated; the distribution of load was almost the same as that of the TKR knee joint model under the normal alignment [Fig.2]. The effect of a slight difference in the alignment on the stress distribution is expected to be a contributor to determine artificial knee joint shape, loading condition, and other design factors in developing revision arthroplasty or custom-made implant.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_8 | Pages 48 - 48
1 May 2016
Iizawa N Mori A Majima T Kawaji H Matsui S Takai S
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Precise biomechanical knowledge of individual components of the MCL is critical for proper MCL release during TKA. This study was to define the influences of the deep MCL and the POL on valgus and rotatory stability in TKA using six cadaveric knees with sequential sectioning sequence. A CT-free navigation system monitored motion after application of valgus loads and internal and external rotation torques at 0°, 20°, 30°, 60°, and 90°of knee flexion. Significant increases of rotatory instability were seen on release of the deep MCL. And, rotatory instability further increased after release of the POL. Surgical approach of retaining the deep MCL and POL has a possibility to improve the outcome after primary TKA.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 23 - 23
1 May 2016
Matsui S Majima T Mominoki K Koizumi R Kawaji H Takahashi K Takai S
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Introduction

Some patients complain ingrown pain or discomfort after implanting Co-Cr conventional endprosthesis of the hip. Some of this complaint may be attributable for effect on cartilage metabolism. It have been reported that ceramic is bioinert for biological tissue. On the other hand, metal including cobalt-chrome (Co-Cr) have some detrimental effect on biological tissue. However, there is no report concerning acetabular cartilage metabolism after hip endprosthesis implantation.

In the present study, we hypothesized that ceramic head have small detrimental effect on cartilage cell metabolism. Specific aim of the study is to compare the protein level of inflammation related cytokines, amount of hyaluronic acid (HA) in culture media, and cartilage mRNA expression in organ culture model of hip end prosthesis implanted using ceramic head and Co-Cr head.

Materials and Methods

Six acetabulum of 3 matured crossbred pig (average weight: 36 +/− 3.6kg) was retrieved. Animal experiment was performed under the rules of ethical committee of animal experiment. Average diameter of pig acetabulum was 26.3 +/− 0.6 mm. Just after sacrifice, mechanical loading using Instron testing machine with 26mm diameter of Co-Cr in right hip and Ceramic heads in left hip was performed in culture media. Ten thousand cycles of cyclic compression and rotation load (1.5kN to 0.15kN of compression and 12 degrees of rotation) to cartilage was applied at 1Hz (Figure 1).

Culture media was analyzed for protein levels of inflammation related cytokines and amount of HA. Relative quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) from acetabular cartilage was performed as previously reported using specific primer sets for type II collagen, aggrecan, TNF-alpha, Interleukine-1 and 6, and MMP-1, 3, 13.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_8 | Pages 47 - 47
1 May 2016
Iizawa N Mori A Oshima Y Matsui S Kataoka T Takai S
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Introduction

Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on kinematics in TKA.

Materials and Methods

This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with femoral arthroplasty only (S1), and thereafter sequentially; medial half tibial resection with spacer (S2), ACL cut (S3), tibial arthroplasty (S4), release of the dMCL (S5), and finally, release of the POL (S6). The same examiner applied all external loads of 10 N-m valgus and 5 N-m internal and external rotation torques at each flexion angle and for each cut state. The AP locations of medial and lateral condyles were determined as the lowest point on each femoral condyle. All data were analyzed statistically using paired t-test. A significant difference was determined to be present for P < .05.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 76 - 76
1 Jan 2016
Nakamura H Takahashi K Sato A Takai S
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Back ground

In 1970's, condylar type knee prosthese with anatomic design appeared, however, joint flexion was not satisfactory. Y/S II total knee arthroplasty (TKA) was developed to obtain deep flexion together with bilateral ligament balance in 1980. The articular surface of the tibial component was flattened to permit femoral shift posteriorily during knee flexion. Medial and lateral soft tissue release was determined by a unique ligament tensor both at flexion and extension. A metal tray was embedded in polyethylene, which had a shape of glasses frame. Though the usage of Y/SII TKA was finished in 1984, we here studied its long term surgical results using the Kaplan-Meyer method.

Study design

From 1988 to 1991, 122 knees were replaced by Y/SII TKA in 81 patients with rheumatoid arthritis (RA). Among them, 24 joints in 12 patients were examined directly. The average age of follow-up was 19.5 years. The survival rate was investigated according to medical records.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 60 - 60
1 Jan 2016
Murase K Tamamura S Takai S Tsutsumi S Tanaka E
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The interface condition between the prosthesis and the bone tissue must play important roles during dynamic loading transfer through the knee joint. In this study, the three- dimensional impact finite element (FE) simulations were performed to investigate the impact stress propagation.

The FE models of a totally replaced knee joint were constructed with the high shape fidelity. The models included the cortical and cancellous bone, articular cartilage, bone marrow, and the artificial femoral and tibial components. The artificial components were set to the femoral and tibial contact area. The FE meshes had 7251 nodal points and 5547 hexahedral elements (Figure 1).

The interfacial condition between the artificial component had two kind of contact situations, bonding situation and no-bonding ones. In the bonding situation, the interface between the artificial components and the cancellous bone had fully fixations. The no-bonding allowed the tie-breaking of each other although the interface had the high coefficient of friction. The three kind of the impact loading (1, 5, and 10kgW) were applied from the proximal femur to the distal side of tibia.

In the FE simulations, the impact stress propagated to the tibia through the TKR joint components during several milliseconds. On the interfacial surface at the cancellous side of the proximal tibia, the difference in the stress distribution was observed according to the contact situation of the TKR component (Figure 2). The fully fixation (tied to each other) model showed the high compressive stress on the interface. On the other hand, in the no-bonding model, the compressive stress distributed discontinuously and the high compressive stress was observed only in the hole area and edge of the tibial component during the impact loading. In previous research, the cancellous bone had important roles for the load transmission inside the joint especially under the impact loading condition. However, this study indicated that the stress shielding was caused by the imperfect bonding at the interface. More consideration of the interface situation between the bone and component is required to keep stability for impact loading.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 147 - 147
1 Jan 2016
Sato A Nakamura H Takahashi K Takenouchi K Kawaji H Takai S
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Purpose

Clinical outocome of revision total elbow arthroplasty(TEA) in rheumatoid arthritis(RA) patients were evaluated.

Methods

Clinical outocome of revision TEA that underwent between 2005 and 2013 were evaluated. Causes of revision, implanted revised prosthesis, a clinical score (the Japanese Orthopaedic Association (JOA) elbow assessment score), the arc of motion and complications were investigated. Totally, 6 patients underwent revision TEA. The patients were females with a mean age of 60.4 years (range, 32 to 72).


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_2 | Pages 58 - 58
1 Jan 2016
Iizawa N Mori A Matsui S Oba R Satake Y Takai S
Full Access

Introduction

Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in TKA.

Materials and Methods

This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with femoral arthroplasty only (S1), and thereafter sequentially, medial half tibial resection with spacer (S2), ACL cut (S3), tibial arthroplasty (S4), release of the dMCL (S5), and finally, release of the POL (S6). The same examiner applied all external loads of 10 N-m valgus and 5 N-m internal and external rotation torques at each flexion angle and for each cut state. All data were analyzed statistically using two-way ANOVA and paired t-test. A significant difference was determined to be present for P < .05.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 179 - 179
1 Dec 2013
Takai S Kawaji H Iizawa N
Full Access

Introduction:

Although the risk of pulmonary embolism (PE) or other embolic events associated with total joint arthroplasty have been recorded for some time, to date no direct means of these events in human arthroplasty have reported. This prospective study was designed to clarify the pathophysiologic mechanism of PE after total knee arthroplasty (TKA).

Methods:

Nine patients fulfilling the following selection criteria were included in this prospective study: diagnosis of osteoarthosis, age 60 to 75 years, cemented primary TKA. All patients had a baseline pulmonary perfusion scan 2 days prior to the surgery. TKA was performed in the standard manner under general anesthesia. Monitoring of the heart chambers during the course of the TKA was performed using a 5 MHz ultrasonic transducer placed into the esophagus. The 4-chamber view plane of the heart was then imaged using a 2-dimensional echocardiography. A tip of the catheter inserted from the contralateral femoral vein was also placed in the inferior vena cava to harvest the venous blood flowed from the suffered lower extremity before and after tourniquet release. All patients had pulmonary perfusion scans 3 hours after TKA and on the 21st postoperative day. The ventilation-perfusion scan was compared with the baseline perfusion scan.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 178 - 178
1 Dec 2013
Takai S Iizawa N Kawaji H
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Anterior cruciate ligament (ACL) of four major knee ligaments is most crucial ligament to maintain normal knee kinematics. It is well know that ACL dysfunction causes secondary osteoarthritis of the knee. The influence of age on the biomechanical properties of the ACL was examined. The structural properties of 27 pairs of human cadaver knees without OA were evaluated. Specimens were equally divided into three groups of nine pairs each based on age: younger (22 to 35 years), middle (40 to 50 years), and older (60 to 97 years). Tensile tests of the femur-ACL-tibia complex were performed at 30 degrees of knee flexion with the ACL aligned vertically along the direction of applied tensile load. Structural properties of the femur-ACL-tibia complex, as represented by the linear stiffness, ultimate load, and energy absorbed, were found to decrease significantly with specimen age.

On the other hand, little has been written about the arthritic ACL. This study was designed to evaluate the relationship among ROM, cross sections of the intercondylar notch and the macroscopic condition of ACL degeneration. Fifty osteoarthritic patients who underwent TKA as a result of severe osteoarthritis were randomly selected. Occupation rate of the osteophytes to the notch width were measured at the anterior 1/3, middle 1/3, and posterior 1/3 notche images obtained from preoperative tunnel view. ROM was measured preoperatively and under anesthesia. Macroscopic conditions of the ACL and PCL were classified into four types of Normal, Frayed, Partial rupture, and Absent.

The macroscopic ACL conditions were Normal: 12 cases, Frayed: 15 cases, Partial rupture: 14 cases, and Absent: 9 cases. The macroscopic PCL conditions were Normal: 34 cases, Frayed: 9 cases, Partial rupture: 7 cases, and Absent: 0 case. Occupation rate of the osteophytes to the notch correlated to the preoperative varus deformity (p < 0.05). In terms of ACL, the occupation rate of the osteophytes to the notch were 22.9%, 28.8%, 46.0%, and 81.8% in Normal, Frayed, partial ruptured, and Absent, respectively. The patients with more than 40% occupation rate and less than 110 degree of knee flexion angle showed either partial rupture or absent of the ACL during the surgery. Those results correlated with the degree of OA deterioration. We conclude that occupation rate of the osteophytes to the notch poor preoperative ROM is a good predictor of evaluating the ACL degeneration in osteoarthritic knee. We also conclude that ACL dysfunction due to joint space narrowing accelerates the advancement of the knee OA.