Keiichi Kawanabe

Kyoto University, Kioto, Kyōto, Japan

Are you Keiichi Kawanabe?

Claim your profile

Publications (87)120.37 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A 58-year-old man developed a 14 cm limb length discrepancy with a shortened and ankylosed right hip as a sequelae of multiple surgeries for recurrent dislocation and periprosthetic joint infection. He was successfully treated by limb elongation with external fixation and subsequent revision total hip arthroplasty. We discuss the efficacy of the two-staged reconstruction with initial limb elongation.
    Hip international: the journal of clinical and experimental research on hip pathology and therapy 10/2014; · 0.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cortical onlay strut allografting is a promising surgical option to reconstruct and reinforce the deficient femur in a hip arthroplasty. However, the union of the allograft to the host bone takes a long time. To accelerate the process of cortical onlay strut allograft healing, we studied the effects of low-intensity pulsed ultrasound (LIPUS) on callus formation. From 2 wk after the operation, LIPUS was given for 20 min/d at each end of the strut allograft. The LIPUS treatment group was assigned 14 allograft transplantations, while 21 control patients were treated without LIPUS. The LIPUS treatment group formed calluses and had complete bridging between the host femur and the allograft faster after operation (16.9 and 29.4 wk after operation, respectively) compared with the control group (40.7 and 82.0 wk after operation, respectively). Our findings showed that LIPUS stimulated bone bonding between the host femur and the cortical onlay strut allografts.
    Ultrasound in medicine & biology 06/2014; · 2.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The cemented femoral stem with a distally straight cylindrical shape was designed to fill the distal femoral canal to facilitate higher cement pressurization and stability. We examined the mid-term outcomes of a stem made of titanium alloy and the efficacy of this shape. Four hundred and twenty-nine consecutive patients (505 hips), who underwent a total hip arthroplasty with the distally straight cylindrical stem made of titanium alloy as their primary hip arthroplasty at two institutes, were followed for a minimum 2 years. Loosening was defined as subsidence of over 3 mm, tilting of the femoral component, or fracture of the cement or the stem. A continuous radiolucent line along the entire interface was considered to indicate loosening, too. We examined the interface stresses on the distally straight cylindrical stem compared with a newly manufactured femoral prosthesis with a double-taper design using a finite element model study. The mean follow-up was 101.3 months after surgery. Thirty patients (30 hips) had aseptic loosening of the stems. Of these 30 hips, 18 had osteolysis, 17 showed subsidence, and 11 had cement fractures at the tip of the stem. These 11 hips had osteolysis and ectasia in the same place: the stem tip. The stem survival rate with stem loosening as the end-point was 94.4 % at 10 years and 66.9 % at 15 years. A finite element model study revealed higher stress around the tip of the cylindrical stem compared with that in the double-taper stem. The straight cylindrical stem is potentially subject to early failure because of high stress around the tip of the stem, and showed a characteristic loosening with osteolysis and ectasia at the tip of the stem.
    Journal of Orthopaedic Science 02/2014; · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: Curved peri-acetabular osteotomy (CPO) produces excellent clinical results, but the surgical procedure is technically demanding, and severe complications related to the osteotomy have been reported. To provide a safe, accurate surgical procedure, we have developed a novel method for setting the cutting line and direction. We have designed and made a custom cutting guide for individual patients. The purpose of the study was to evaluate the efficacy of this new method and cutting guide. METHODS: The cutting line was designed on a full-scale three-dimensional plaster model made from computed tomography (CT) data for each case. The surface of each plaster model was colour-coded according to the distance from the centre of the femoral head. A custom cutting guide was designed based on this cutting line on the workstation. A titanium custom cutting guide was fabricated using rapid prototyping technology. The cutting guide directed the cutting direction of the osteotome. We evaluated the outcomes for seven consecutive hips in seven patients who underwent CPO using the system between April and December 2011. All peri-operative complications were recorded. The accuracy of the cutting line was evaluated using CT data obtained two weeks after the operation. RESULTS: There were no major complications related to the osteotomy such as posterior column fracture or intra-articular osteotomy. The actual cutting line corresponded almost exactly to the planned cutting line in all cases. CONCLUSIONS: The colour-coded plaster model and the custom cutting guide were effective for avoiding severe complications associated with a CPO.
    International Orthopaedics 04/2013; · 2.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: National arthroplasty registers are valuable tools for reporting on an updated epidemiologic survey of arthroplasties and for evaluating the performance of implants and operative procedures through the early identification of failure risk factors. More than ten registers have been launched globally, but no national register has been reported in Asia. In February 2006, a pilot project of the Japan Arthroplasty Register (JAR) for total hip arthroplasty (THA) and total knee arthroplasty/unicompartmental knee arthroplasty (TKA/UKA) was launched by the Japanese Orthopaedic Association (JOA). Data obtained include information about patients, primary and revision arthroplasty operative procedures, and implants and materials used. The JAR office accumulated and processed all data and reports annually. Up to May 2011, 83 of 130 hospitals nominated by the JOA (64 %) participated in the JAR pilot project. From 2006 to 2011, 33,080 data collection forms were submitted; 17,534 for THA and 17,269 for TKA/UKA. A brief summary of the annual report of the JAR is available from The Japanese Society for Replacement Arthroplasty web site at . A national arthroplasty register is a useful tool for evaluating the outcomes of interventions and the materials used in arthroplasties and for providing rapid feedback to practitioners and patients about any failure of THA and TKA/UKA. As the first national arthroplasty register in Asia, the JAR will help guide the development of registers of arthroplasty characteristics specific to Asian populations.
    Journal of Orthopaedic Science 06/2012; 17(4):358-69. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The clinical outcomes and radiological findings for cemented titanium stems remain controversial. In 2004, we produced a straight-collared double-tapered stem made from a titanium alloy with a smooth surface for cemented total hip arthroplasty. In this study, we retrospectively examined the mid-term outcomes of this stem. We retrospectively reviewed 61 hips that had undergone primary cemented total hip arthroplasty with a collared smooth double-tapered titanium alloy femoral stem, after a minimum of 5 years (mean 6.1, range 5.0-7.3). Patients were evaluated preoperatively and postoperatively with the Merle d'Aubigné and Postel hip score. Radiographic examination was performed for evaluation of the cementing technique, the alignment of the stem, subsidence within the cement mantle, radiolucent lines at the cement-bone or cement-stem interface, cortical hypertrophy, and calcar resorption. The clinical evaluation by the Merle d'Aubigné and Postel hip score was improved from 9.4 ± 1.9 preoperatively to 15.9 ± 1.6 at the time of final follow-up. The overall survival rate was 100% at 7 years, when radiological loosening or revision for any reasons was used as the endpoint. Five stems subsided less than 1 mm vertically. Nonprogressive radiolucence at the cement-bone interface occurred in six hips, without osteolysis. Cortical hypertrophy was observed in five hips and second-degree calcar resorption in 11 hips. Our results in this study show good outcomes for cemented, collared, smooth, double-tapered titanium alloy femoral stems at a minimum follow-up of 5 years.
    Journal of Orthopaedic Science 09/2011; 16(6):689-97. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We retrospectively reviewed 40 hips in 36 patients who had undergone acetabular reconstruction using a titanium Kerboull-type acetabular reinforcement device with bone allografts between May 2001 and April 2006. Impacted bone allografts were used for the management of American Academy of Orthopaedic Surgeons Type II defects in 17 hips, and bulk bone allografts together with impacted allografts were used for the management of Type III defects in 23 hips. A total of five hips showed radiological failure at a mean follow-up of 6.7 years (4.5 to 9.3), two of which were infected. The mean pre-operative Merle d'Aubigné score was 10 (5 to 15) vs 13.6 (9 to 18) at the latest follow-up. The Kaplan-Meier survival rate at ten years, calculated using radiological failure or revision of the acetabular component for any reason as the endpoint, was 87% (95% confidence interval 76.3 to 97.7). A separate experimental analysis of the mechanical properties of the device and the load-displacement properties of bone grafts showed that a structurally hard allograft resected from femoral heads of patients with osteoarthritis should be preferentially used in any type of defect. If impacted bone allografts were used, a bone graft thickness of < 25 mm was acceptable in Type II defects. This clinical study indicates that revision total hip replacement using the Kerboull-type acetabular reinforcement device with bone allografts yielded satisfactory mid-term results.
    Journal of Bone and Joint Surgery - British Volume 09/2011; 93(9):1194-200. · 2.69 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Several types of acetabular reinforcement devices are used to prevent the collapse of grafted bone in revision total hip arthroplasty. However, it remains unclear how the stress is reduced by different devices. We used finite element analysis to evaluate 4 types of acetabular reinforcement devices: Kerboull-type device, Burch-Schneider anti-protrusio cage, Mueller ring, and Ganz ring. The control was a socket fixed with bone cement without any reinforcement devices. The stress distribution on the inner surface of each socket was calculated by binarization image processing. For all 4 reinforcement devices, the stress was reduced to less than one-half of that in the control. All the devices were useful for preventing the collapse of bulk bone grafts applied to load-bearing defects.
    The Journal of arthroplasty 06/2011; 26(7):1061-6. · 1.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Total hip arthroplasty (THA) for the treatment of severe dislocation of the hip is a technically demanding procedure. In most previous reports, techniques and clinical outcomes using cementless prostheses are widely reported, but there have been few reports on the technique and outcomes using cemented prostheses. The purpose of this study was to evaluate the outcomes of a cemented THA with a simultaneous subtrochanteric femoral shortening transverse osteotomy in patients with Crowe type III or IV developmental dysplasia of the hip. We retrospectively reviewed 15 hips in 11 patients who underwent cemented THA with subtrochanteric femoral shortening transverse osteotomy and with placement of the acetabular component at the level of the anatomic hip center. Patients were evaluated preoperatively and postoperatively with the Merle d'Aubigné and Postel hip score. Radiographic examination was performed to evaluate the level of the femoral osteotomy site, of the radiographic leg lengthening, and of bone union. The clinical evaluation by the Merle d'Aubigné and Postel hip score was improved from 8.1 ± 2.5 preoperatively to 15.1 ± 1.3 at the time of final follow-up. Radiographic evidence of bone union at the osteotomy site appeared at more than 6 months after operation. Moreover, there were 3 (20%) nonunions that needed reoperation. No acetabular and femoral components exhibited radiological loosening at the time of final follow-up. In addition, one delayed union causing thigh pain was treated with low-intensity pulsed ultrasound that accelerated bone formation. Our results in this study indicate that we should prevent instability at the transverse osteotomy site and an adequate intercalary cortical bone graft is needed to prevent nonunion in cemented THA combined with a subtrochanteric femoral shortening transverse osteotomy. We should apply this procedure with caution in patients, especially those who show less potential bone formation activity.
    Journal of Orthopaedic Science 03/2011; 16(3):270-7. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Impaction bone grafting allows restoration of the acetabular bone stock in revision hip arthroplasty. The success of this technique depends largely on achieving adequate initial stability of the component. To obtain well-compacted, well-graded allograft aggregates, we developed an ex vivo compaction device to apply it in revision total hip arthroplasty on the acetabular side, and characterized mechanical properties and putative osteoconductivity of allograft aggregates. Morselized allograft bone chips were compacted ex vivo using the creep technique and subsequent impaction technique to form the bone aggregates. Impaction allograft reconstruction of the acetabulum using an ex vivo compaction device was performed on eight hips. The mechanical properties and three-dimensional micro-CT-based structural characteristics of the bone aggregates were investigated. In clinical practice, this technique offered good reproducibility in reconstructing the cavity and the segmental defects of the acetabulum, with no migration and no loosening of the component. In vitro analysis showed that the aggregates generated from 25 g fresh-frozen bone chips gained compression stiffness of 13.5-15.4 MPa under uniaxial consolidation strain. The recoil of the aggregates after compaction was 2.6-3.9%. The compression stiffness and the recoil did not differ significantly from those measured using a variety of proportions of large- and small-sized bone chips. Micro-CT-based structural analysis revealed average pore sizes of 268-299 μm and average throat diameter of pores in the bone aggregates of more than 100 μm. These sizes are desirable for osteoconduction, although large interconnected pores of more than 500 μm were detectable in association with the proportion of large-sized bone chips. Cement penetration into the aggregates was related to the proportion of large-sized bone chips. This study introduces the value of an ex vivo compaction device in bone graft compaction in clinical applications. In vitro analysis provided evidence that compaction of sequential layers of well-compacted, well-graded bone aggregates, i.e., the aggregates comprising smaller sized chips at the host bone side and larger sized chips at the component side, may have the advantages of initial stability of the acetabular component and biological response of the grafted aggregates.
    Journal of Orthopaedic Science 01/2011; 16(1):26-37. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cup arthroplasty was used in the initial attempts to preserve the bone stock of the femoral head and neck for hip reconstruction. However, little conclusive data are available regarding its long-term survivorship. We present a long-term survivorship analysis (mean follow-up, 19.3 years; range, 5-36.6 years) after vitallium mold arthroplasty in 77 secondary osteoarthritic hips. Kaplan-Meier survivorship analysis predicted a survival rate for vitallium mold arthroplasty of 81.6% (95% confidence interval [CI], 76.7-86.5) at 20 years and 59.1% (95% CI, 51.8-66.5) at 30 years, with conversion to total hip arthroplasty as the endpoint. The mean Merle d'Aubigné and Postel hip score showed a significant decrease in mobility from 4.12 (range, 3.18-5.86) 6 months after the operation to 3.19 (range, 1.7-4.6) at the last follow-up. No significant differences were observed for the pain score from 6 months after the operation (5.05; range, 4.2-5.9) to the last follow-up (4.46; range, 2.88-6.04)) or score for the ability to walk, from 6 months after the operation (2.5; range, 1.4-3.6) to the last follow-up (3.13; range, 1.59-4.67). Radiographically, the proximal and medial migration of the cup measured at the last follow-up was 10.4 +/- 5.4 mm (P < 0.01) and 0.2 +/- 2.1 mm (P > 0.05), respectively. Our results indicate inferior long-term survivorship after vitallium mold compared with that after Charnley low-friction arthroplasty.
    Journal of Orthopaedic Science 07/2010; 15(4):459-62. · 0.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Basic fibroblast growth factor (FGF-2) exerts anabolic actions on bone formation. Here we investigated the potential effects of recombinant human FGF-2 (rhFGF-2) on the repair process of osteonecrosis of the femoral head (ONFH) and the development of secondary osteoarthritis (OA) in adult rabbits. ONFH was induced by intramuscular injection with methylprednisolone, and vascular occlusion of the capital femoral epiphysis by electrocoagulation, in adult Japanese white rabbits. Animals were randomized into two groups: treatment and control. The treatment group was given a single local injection into the femoral head of 100 μg rhFGF-2 in 100 μl gelatin hydrogel microspheres 8 weeks after the ONFH procedure, and the control group was given phosphate-buffered saline in 100 μl gelatin hydrogel microspheres. Morphological, histopathological, and radiologic analyses, including micro-computed tomography scans and magnetic resonance imaging, showed collapse of the femoral head and progression of articular cartilage degeneration in the control group at 16 weeks after the single local injection of rhFGF-2. In contrast, rhFGF-2 treatment resulted in new bone formation in the femoral head and prevented the femoral head from collapsing. In addition, the changes in OA, assessed by the modified Mankin score, was significantly lower in the treatment group. Our results indicate that a single local injection of rhFGF-2 microspheres promoted the repair of the osteonecrotic femoral head and inhibited femoral head collapse and OA progression. rhFGF-2 may be a promising strategy for the treatment of ONFH.
    Journal of Bone and Mineral Metabolism 03/2010; 28(6):608-16. · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A composite bone cement designated G2B1 that contains beta tricalcium phosphate particles was developed as a bone substitute for percutaneous transpedicular vertebroplasty. In this study, both G2B1 and commercial PMMA bone cement (CMW1) were implanted into proximal tibiae of rabbits, and their bone-bonding strengths were evaluated at 4, 8, 12 and 16 weeks after implantation. Some of the specimens were evaluated histologically using Giemsa surface staining, contact microradiography (CMR) and scanning electron microscopy (SEM). Histological findings showed that G2B1 contacted bone directly without intervening soft tissue in the specimens at each time point, while there was always a soft tissue layer between CMW1 and bone. The bone-bonding strength of G2B1 was significantly higher than that of CMW1 at each time point, and significantly increased from 4 weeks to 8 and 12 weeks, while it decreased significantly from 12 weeks to 16 weeks. Bone remodeling of the cortex under the cement was observed especially for G2B1 and presumably influenced the bone bonding strength of the cement. The results indicate that G2B1 has bioactivity, and bone bonding strength of bioactive bone cements can be estimated fairly with this experimental model in the short term.
    Journal of Materials Science Materials in Medicine 10/2009; 21(1):139-46. · 2.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the clinical results of cross-linked polyethylene (CLPE) and to compare the CLPE wear against zirconia and stainless steel heads, we studied the radiographic wear after a minimum 3-year follow-up in total hip arthroplasty (THA). Ninety-four hips were randomly implanted with a 22.225-mm head cemented THA-the group of non-CLPE against zirconia and CLPE against 2 different zirconias and stainless steel. The linear wear rate was significantly lower in the group of CLPE against zirconia (0.067, 0.059 mm/y) and against stainless steel (0.068 mm/y) compared with non-CLPE against zirconia (0.170 mm/y). In the short-term results, the wear performance of CLPE against zirconia was superior to that of non-CLPE; however, it did not show a better wear rate than CLPE against stainless steel. Furthermore, long-term investigations will be necessary for understanding CLPE wear in vivo.
    The Journal of arthroplasty 09/2009; 24(8):1216-20. · 1.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present the long-term results (mean follow-up, 11.8 years; range, 6.3-15.4 years) of cemented total hip arthroplasty with acetabular bulk bone grafting in 147 dysplastic hips using improved surgical techniques. Operations were performed through a direct lateral approach with partial trochanteric osteotomy to avoid nonunion of the greater trochanter. Bioresorbable poly(l-lactide) screws were used for fixation of the acetabular bone grafts to prevent any possible delayed remodeling. Preoperative planning using computer simulation was performed to estimate the optimal size and position of the acetabular component. Analysis predicted rates of survival of the acetabular component of 96% and 91% at 15 years, with revision for aseptic loosening and radiologic loosening as the end points, respectively. Our results indicate excellent long-term clinical and radiographic survivorship of a cemented acetabular component with bulk autograft for acetabular dysplasia.
    The Journal of arthroplasty 08/2009; 25(5):716-20. · 1.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study reviewed a series of cemented total hip arthroplasty (THA) for dysplasia, with structural autograft fixed with poly-L-lactic acid screws. Grafted bone union was confirmed radiologically in every case, and there were no cases of early collapse or extravasation of grafted bone. Kaplan-Meier survivorship analysis of socket revision, radiologic loosening of the socket, and the appearance of a radiolucent line greater than 1 mm in the graft-socket interface as the end points indicated survival rates of 99%, 97.1%, and 63.5% at 10 years and 96.6%, 90.2%, and 56.1% at 15 years, respectively. The results of this study indicated that poly-L-lactic acid screws are safe and useful for the fixation of acetabular bone graft concomitant to cemented THA with a careful rehabilitation program.
    The Journal of arthroplasty 07/2009; 24(8):1146-51. · 1.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the conversion of an arthrodesed hip to a total hip arthroplasty, the osteotomy of the femoral neck and the placement of the acetabular socket are difficult procedures as anatomical abnormalities hamper identification of the femoral neck and of the original center of the acetabulum. A 59-year-old woman who had a hip arthrodesis for dysplastic osteoarthritis at 21 years of age underwent total hip arthroplasty for relief of back pain, achievement of good gait function, and improvement of activities of daily living. In this report, we introduce a technical solution, using a computed tomography-based navigation system to determine the site and direction of the femoral neck osteotomy and the positioning of the acetabular socket.
    The Journal of arthroplasty 03/2009; 24(8):1292.e1-4. · 1.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A method has been developed for creating a bioactive coating on titanium by alkaline and heat treatment, and shown that it forms a thin layer of hydroxyapatite (HA) on the surface of implants when soaked in simulated body fluid. A series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface was performed, and followed up the patients for a mean period of 4.8 years. There were no instances of loosening or revision, or formation of a reactive line on the porous coating. Although radiography just after operation showed a gap between the host bone and the socket in over 70% of cases, all the gaps disappeared within a year, indicating the good osteoconduction provided by the coating. Alkaline-heat treatment of titanium to provide a thin HA coating has several advantages over plasma-spraying, including no degeneration or absorption of the HA coating, simplicity of the manufacturing process, and cost effectiveness. In addition, this method allows homogeneous deposition of bone-like apatite within a porous implant. Although this was a relatively short-term study, treatment that creates a bioactive surface on titanium and titanium alloy implants has considerable promise for clinical application.
    Journal of Biomedical Materials Research Part B Applied Biomaterials 02/2009; 90(1):476-81. · 2.31 Impact Factor
  • Key Engineering Materials - KEY ENG MAT. 01/2009;
  • Journal of the American Geriatrics Society 01/2009; 56(12):2363-5. · 4.22 Impact Factor

Publication Stats

808 Citations
120.37 Total Impact Points


  • 1991–2014
    • Kyoto University
      • Department of Orthopaedic Surgery
      Kioto, Kyōto, Japan
  • 2009–2013
    • Kobe City Medical Center General Hospital
      Kōbe, Hyōgo, Japan
  • 2008
    • Harbin Medical University
      • Department of Orthopedic Surgery
      Charbin, Heilongjiang Sheng, China