Recently, short shaped stem becomes popular in total hip arthroplasty (THA). Advantages of the short stem are preserving femoral bone stock, thought to be less thigh pain, suitable for minimally invasive THA. However, bony reaction around the short stem has not been well known. The purpose of this study was to compare the two years difference of radiographic change around the standard tapered round stem with the shorter tapered round stem. Evaluation was performed in 96 patients (100 joints) who underwent primary THA. Standard tapered round stem (Bicontact D stem) was used in 44 patients from January 2011 to May 2013. Shorter stem (Bicontact E stem) was used in 56 patients from May 2015 to March 2016. The proximal shapes of these two stems are almost the same curvature. The mean age at surgery was 64 years. The mean BMI at surgery was 24.0 kg/m2. Eighty-six patients had osteoarthrosis and 10 patients had osteonecrosis. Evaluation was performed 2 years after surgery with standard AP radiographs. The OrthoPilot imageless navigation system was used during surgery. Evaluation of the stem fixation, stress shielding, and cortical hypertrophy were carried out.INTRODUCTION
MATERIALS AND METHODS
The results of modified gap balancing and measured resection technique have been still controversial. We compared PS-type TKAs for osteoarthritis performed using the modified gap technique and the measured resection to determine if either technique provides superior clinical results. The modified gap technique was used in 85 knees, and the measured technique using preoperative CT was used in 70 knees. To compare intra-operative soft tissue balance, bone gap and component gap were measured using original two paddle tensor (20,30,40lb) at 0 degree extension and 90 degrees flexion. To assess the post-operative patella congruency and soft tissue balance, we measured patella tilt, condylar twist angle (CTA) and condylar lift-off angle (LOA) in radiographs. Finally, we evaluated postoperative clinical result (1–5 years) KOOS. Statistical analysis was used by StatView.INTRODUCTION
METHODS
Long term results of Total Hip Arthroplasty (THA) are affected by wear of articulation. Ceramic on ceramic articulation have been used especially for young patients because of its low wear and bio-inert property. However, because of its hardness, it is concerned that ceramic fracture, chipping, or squeaking might happen with ceramic on ceramic articulation. The purpose of this study was to investigate over 10-years clinical and radiographic results of ceramic bearing cementless THA.Introduction
Objective
Recently, the short stem has become popular in total hip arthroplasty (THA). The advantages of the short stem are that it preserves femoral bone stock, possibly results in less thigh pain, and is suitable for minimally invasive THA. However, because of the short stem, malposition may happen during surgery. The purpose of this study was to compare the stem alignment, which was measured by CT, between the standard tapered round stem and the shorter tapered round stem. CT evaluation was performed in 28 patients (29 joints) who underwent primary THA. The standard tapered round stem (Bicontact D stem) was used in 13 patients. The shorter stem (Bicontact E stem) was used in 16 patients (17 joints). The proximal shapes of these two stems have almost the tame curvature. The mean age at surgery was 68 years. The mean BMI at surgery was 23.3 kg/m2. Eighteen patients had osteoarthrosis, 3 patients had osteonecrosis, and 1 patient had femoral neck fracture. All surgeries were performed in the supine position with the direct anterior approach. The OrthoPilot imageless navigation system was used during surgery. Evaluation of the stem antetorsion angle (AA), flexion angle (FA), and varus angle (VA) were carried out.INTRODUCTION
MATERIALS AND METHODS
Several papers have reported the efficacy of an imageless navigation system in acetabular cup orientation during total hip arthroplasty (THA). Also, an imageless navigation system is useful for recovering leg length discrepancy. However, no study has evaluated the accuracy of the stem antetorsion angle (SAA) with an imageless navigation system in THA. The purpose of this study was to evaluate the accuracy of the stem antetorsion angles, which were measured by CT with the CT-free navigation system. Also, we evaluate the factors that affect the inaccuracy. CT evaluation was performed in 60 patients (60 joints) who underwent primary THA from December 2011 to March 2014. Fifty-nine patients were female. The mean age at surgery was 67 years. The mean BMI at surgery was 24.0 kg/m2. Fifty-four patients had osteoarthrosis, 5 patients had osteonecrosis, and 1 patient had femoral neck fracture. All surgeries were performed in the supine position with the direct anterior approach. The OrthoPilot imageless navigation system was used during surgery. An Excia stem was used in 47 patients and a Bicontact stem was used in the other 13. Evaluation of SAA was carried out. Instead of SAA, the navigation indicates the rasp antetorsion angle based on the hip-knee-ankle plane during surgery. SAA based on the posterior condylar plane was measured with CT by using 3D THA plannning software. The accuracy of the imageless navigation system was evaluated by comparison of the navigation values obtained during surgery with the CT measured values. Correlations were analyzed with Pearson correlation analysis.INTRODUCTION
MATERIALS AND METHODS
Selection of an optimum thickness of polyethylene insert in total knee arthroplasty (TKA) is important for the good stability and range of motion (ROM). The purpose of this study is to investigate the amount of change of ROM as the thickness of trial insert increase. The study included 86 patients with 115 knees undergoing TKA from October 2012 to February 2014. There were 17 men and 69 women with an average age of 75±8 (58–92) years. The implants posterior stabilized knee (Scorpio NRG, Stryker) was used and all prostheses were fixed with cement. The ROM was measured by the goniometer under the general anesthesia at the time of operation in increments of 1°. Preoperative flexion angle was measured by passively flexing the patient's hip 90 degrees and allowing the weight of the leg to flex the knee joint (Lee et al 1998). Extension angle was measured by holding the heel and raising the leg by another examiner. During TKA, flexion and extension angle was measured in a similar manner when each insert trial (8, 10, 12, and 15mm) was inserted. After the wound closure and removing the draping, ROM was measured again. Statistical analysis of range of motion was performed using a paired t-test to determine significanceIntroduction
Material and Method
Planning of the stem antetorsion angle (SAA) is difficult with radiograph before THA. 3D THA planning software with CT is useful for planning the cup and the stem implantation angles before THA. However, even using the 3D planning software, we sometimes experience the different SAA during surgery compare to the planned SAA. The purpose of this study was to compare the implanted SAA with the preoperative planned SAA, which was planned by using 3D THA planning software. CT evaluation was performed in 44 patients (5 males) who underwent primary THA. The mean age at surgery was 67 years (range 26–85 years). The mean BMI at surgery was 24.1kg/m2 (15.6–31.7kg/m2). Forty-one patients had osteoarthrosis, 2 patients had osteonecrosis, and 1 patient had femoral neck fracture. All surgeries were performed in the supine position with the direct anterior approach. The OrthoPilot imageless navigation system (BBraun/Aesculap) was used during surgery. Excia stem was used in 34 patients and Bicontact stem was used in 10 patients. Planning of the surgery was performed using 3D THA planning software (ZedHip, Lexi). After surgery, SAA was measured with CT by the same 3D THA planning software. SAA was evaluated by comparison of the planned values before surgery with the CT measured values. Also, the shape of the femur and the stem were evaluated.Introduction
Materials and Methods
Malrotation of a femoral component is a cause of patellofemoral maltracking after total knee arthroplasty (TKA). We have developed a balanced gap technique in posterior stabilized total knee arthroplasty (PS-TKA) using an original tensor instrument. One of characteristics of this instrument is the ability to measure gaps even if there is a bone defect, because it has two paddles, and we can attach block augmentations. In addition it can measure the gap after a reduction of the patella with an offset mechanism. In the balanced gap technique, the femoral component rotation is decided by a tibial cut surface and ligaments balance using the tensor device. This study investigated retrospectively whether rotational alignment of femoral component rotation influenced patellofemoral joint congruency in PS- TKA. We evaluated the radiographs of 52 knees of 42 patients, who underwent TKA (NexGen LPS-Flex, fixed surface, Zimmer) by one surgeon (S.A.) for osteoarthritis or rheumatoid arthritis. All procedures were performed through a medial parapatellar approach and a balanced gap technique using a developed versatile tensor device. We measured lateral patella tilt and lateral patella shift at post-op. 6 months. To assess the rotational alignment of femoral component rotation, condylar twist angle (CTA) was measured, and to assess the postoperative flexion gap balance, a condylar lift-off angle (LOA) was measured using the epicondylar view radiographs.Introduction
Material and Methods
Fracture classification of femoral trochanteric fracture is usually based on plain X-ray. However, complications such as delayed union, non-union, and cut out are seen in stable fracture on X-ray. In this study, fracture was classified by 3D-CT and relationship to X-ray classification was investigated. 48 femoral trochanteric fractures (15 males, 33 female, average age: 82.6) treated with PFNA-II were investigated. Fracture was classified to 2part, 3part(5 subgroups), and 4part with combination of 4 fragments in CT; Head (H), Greater trochanter (G), Lesser trochanter (L), and Shaft (S). 5 subgroups of 3 part fracture were (1) H+G (S: small fragment) + L-S, (2) H + G (B:big fragment) + L-S, (3) H + G-L + S, (4) H + G (W:whole) + S, and (5) H + L + G-S. Numbers of each group were as follows; 2 part: 11, 3 part (1) : 7, 3 part (2) : 12, 3 part (3) : 10, 3 part (4) : 2, 3 part (5) : 3, 4 part : 3. 3 part (3), (4), (5) and 4 part are considered as unstable, however, 6 cases in these groups were classified in A1–1 or A1–2 stable fracture in AO classification. 10 fractures in Evans and 5 fractures in Jensen classification classified as stable were unstable in CT evaluation. It is sometimes very difficult to classify the femoral trochanteric fracture by plain X-ray. Classification with 3D-CT is very useful to distinguish which fracture is stable or unstable.
