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Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 57 - 57
1 Feb 2017
Kawate K Munemoto M Kawahara I Tamai K Uchihara Y Takemura K Ono S Tanaka Y
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Introduction

To evaluate the effect of hydroxyapatite coating, two same shape cementless stems were compared in this randomized control trial study.

Methods

Between May 2003 and February 2010, 88 patients had a primary cementless total hip arthroplasty with two different types of cementless stems. Forty-three patients had Proarc stems (P group) (Kyocera Medical, Osaka, Japan), and Forty-five patients had Proarc HA stems (HA group) (Kyocera Medical, Osaka, Japan) which was coated with thin (20 micrometer) hydroxyapatite on Proarc rough porous coating. Gender distribution, average age at surgery, average weight and average follow-up period were same in the two groups. The average follow-up period was 8.5 years (range, 5 to 13 years). The average age at the time of surgery was 63 years. Porous acetabular shells and highly crosslinked polyethylene liners made by Kyocera Medical corporation were implanted into all hips. Stems were implanted with a modified Hardinge surgical approach without trochanteric osteotomy. Harris Hip Score was used for clinical evaluation. Post-op radiographs of these patients were evaluated. Fisher's exact probability test was used for statistical analysis. P values of less than 0.05 were considered to be significant.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_8 | Pages 91 - 91
1 May 2016
Kawate K Masuda Y Munemoto M Uchihara Y Ohneda Y Tanaka Y
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Introduction

Deformity after femoral osteotomy varies between patients. Some researchers reported good results when using cemented stems for the hips after femoral osteotomy, but there are many disadvantages that obstruct ideal fixation using cemented stems. Therefore, we developed cementless custom-made stems and inserted those using a computed tomography (CT) –based navigation system

Methods

Eighteen dysplastic hips of 15 patients after intertrochanteric osteotomy were investigated in the present study. Individual computed tomography data were used to manufacture cementless custom-made femoral stems out of Ti-6Al-4V. The proximal 1/3 of each stem was coated using porous coating covered with hydroxyapatite coating. The stems were inserted using a CT-based fluoro navigation system for accuracy of insertion. The average patient age at time of surgery was 66 years, and the average follow-up period was 3.5 years.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 95 - 95
1 May 2016
Uchihara Y Kawate K Munemoto M Inagaki Y Hara R Tanaka Y
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Introduction

Hemophilia arthropathy often occurs in the ankle, knee and elbow. In contrast, hemophilic arthropathy in the hip is rare. We report short-term results of total hip arthroplasty (THA) in patients with hemophilia.

Method

Four primary THAs performed in four hemophilic patients from 2007 to 2015 were reviewed retrospectively. Two patients underwent cementless THA, and two patients had cemented THA. All patients had hemophilia A, and clotting factor replacement was performed perioperatively. Blood loss, surgery duration, complications, pre- and post-operative range of motion, and the pre- and post-operative Japanese Orthopedic Association (JOA) score were assessed.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 101 - 101
1 May 2016
Ono S Kawate K
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We recommended an early discharge if rheumatoid patients who had undergone arthroplasty could easily walk around a flat barrier-free corridor as we had a financial motive to increase the circulation rate of patients. Unfortunately, after this discharge, two of our patients fell down in their home, one breaking her leg. So we began to ask our patients to use medical pole walking, which they learned during rehabilitation, after being discharged.

There were two male and six female rheumatoid arthritis patients, with an average of 64. We required them to train in medical pole walking five times a week, 20 minutes a day for about 4–6 weeks until they were discharged. We checked for mobility, physical strength and flexibility.

After one year of medical pole walking, two patients can play golf and one patient can visit many famous places in Japan with her sister without the assistance of a cane.

At the point of 1 year after arthroplasty their time of with medical pole walking and T cane walking or free walking was improved about 5 seconds compared to the point 4 weeks after surgery.

Chair stand test after 1 year medical pole walking exercise was much improved than after 4 weeks after arthroplasty.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_2 | Pages 99 - 99
1 Jan 2016
Kawate K Munemoto M Uchihara N Tanaka Y
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Introduction

To utilize existing cancellous bone for initial stability, custom-made stems were implanted without reaming and rasping. This study reviewed the results of this non-reaming technique.

Methods

One hundred and fifty-three hips (138 patients) were followed-up for an average of 12 years (range, 8 to 18). Average age at the surgery was 59 (range, 19 to 78). Seventy percent of the etiologies were dysplastic hips including 17 hips after femoral osteotomy. The Ti-6Al-4V stems were designed using CT data and directly inserted into the femora without reaming and rasping. The stems were coated with hydroxyapatite on the porous coating at proximal 1/3. Harris hip score was used for clinical evaluation.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 103 - 103
1 Mar 2010
Kawate K Kawahara I Kataoka H Tamai K Ueha T Takemura K Takakura Y
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The material properties of gamma irradiated Ultra High Molecular Weight (UHMW) polyethylene are known to degrade during exposure to air. Though gamma inert-sterilization has been developed to decrease free radicals, the rate of degeneration of UHMW polyethylene in vivo has not well known. This study aimed to compare the properties of gamma inert-irradiated highly-cross-linked UHMW polyethylene samples after exposure to air and the properties of gamma inert-irradiated highly-crosslinked UHMW polyethylene samples after exposure to liquid.

UHMW polyethylene samples were machined from heat-compressed sheet made of medical grade GUR 1050 (Ticona, Kelsterbach, Germany). Samples were rectangular, where the dimensions were 50mm in length, 5 mm in width and 2 mm in thickness. Samples were divided into four groups of 0, 60, 100 and 200 kGy irradiation in N2 gas. These samples were then exposed to air or Ringer’s solution for half a year. Dynamic vis-coelastic measurements and, Fourier Transform Infrared Spectrometry (FTIR) and Electron Spin Resonance (ESR) analyses were performed on samples immediately after inert-irradiation, after half-year-exposure to 25°C air (Air-exposure) and after half-year-exposure to 37°C Ringer’s solution (Liquid-exposure). Dynamic viscoelastic measurements were conducted over a temperature range of −150 to 350°C using a Dynamic Mechanical Spectrometer (Seiko Instruments, Osaka, Japan). FTIR analysis was conducted using a Perkin-Elmer Spectra BX (Norwalk, CT) with 100-μm thick slices. ESR analysis was also conducted using a JES-TE200 (Nippon-Denshi, Akishima, Japan).

Although the dynamic viscoelastic performance of 0 kGy irradiated storage sample was not different from that of original sample, the loss tangent value (tanδ, E”/E’) of 60, 100 and 200 kGy irradiated storage samples was different from that of original samples (Fig. 1). The difference of Liquid-exposure was larger than that of Air-exposure. Although a FTIR peak at 1718 cm-1 wave numbers was not observed in 0 kGy irradiated storage sample, obvious peak was observed in 100 and 200 kGy irradiated storage samples (Fig. 2). The peak of Liquid-exposure was larger than that of Air-exposure. The ESR analysis showed free radicals in storage samples.

The dynamic viscoelastic performance of 60, 100, 200 kGy irradiated storage sample was different from that of original sample, whereas the performance of 0 kGy irradiated storage sample was not different from that of original sample. The difference of Liquid-exposure was larger than that of Air-exposure. The storage modulus value of 60, 100, 200 kGy irradiated Liquid-exposure decreased and the reason for this was thought to be chain scission by oxidation for half-year exposure to Ringer’s solution. Obvious FTIR peak at 1718 cm-1 wave numbers was observed in 100 and 200 kGy irradiated storage samples. The peak of Liquid-exposure was larger than that of Air-exposure. This indicated that the oxidation of Liquid-exposure quickly progressed during half-year storage and the reason for this was thought to be chain scission by high liquid temperature. The results of the present study suggested that the properties of gamma irradiated UHMW polyethylene quickly degraded in vivo.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_IV | Pages 420 - 420
1 Apr 2004
Kawate K Ohmura T Hiyoshi N Teranishi T Yokoi K Tamai K Takakura T
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Introduction: We compared the discrepancies between postoperative femoral component and the preoperatively predicted postoperative femoral component anteversions from CT data in cases of cementless THA, in which custom-made femoral components prepared from CT data were inserted directly without reaming or broaching.

Materials and methods: The subjects were 44 females (51hips) and 11 males (11 hips) with an average age at surgery of 54 years (range, 21–74). The average duration of follow-up was 44 months (range, 24–75). The femoral component was designed from 2 circles showing the corner of the medial and lateral rims of the component along the medial and lateral inner cortex on each CT slice. The anterior and posterior rims of the component were designed as lines connecting the 2 circles. From a CT slice of the planned osteotomy site and a slice passing through the knee, the preoperative femoral neck anteversion was measured. The postoperative femoral component anteversion was measured from the CT slice passing through the center of the ball and the slice passing through the knee.

Results: The mean discrepancy between the postoperative femoral component anteversion and the preoperatively predicted postoperative anteversion was 1.9° (range, −29.5–38). The average preoperative Harris hip score was 44 points (range, 17–80). At the most recent follow-up, the score was 88 points (range, 51–98). Sixty-one hips were evaluated as bone-ingrown fixations and one hip was evaluated as a stable fibrous fixation. There were no loosed femoral components.

Discussion and conclusion: There were 22 hips whose discrepancy between the postoperative femoral component anteversion and the preoperatively predicted postoperative anteversion was over 10°. However, the rotational angle on insertion did not influence the stability of the custom-made femoral component in this short-term follow-up survey. This probably indicates the effectiveness of the non-reaming or non-broaching technique.