Katsufumi Uchiyama

Prevalence of radiographic findings of femoroacetabular impingement in the Japanese population

BackgroundFemoroacetabular impingement (FAI) is one factor known to cause pain and osteoarthritis (OA) of the hips. Although secondary OA due to hip dysplasia is common among Japanese populations, primary OA is seldom observed. Concomitantly, FAI is also thought to be uncommon in Japan, but relatively few epidemiological studies have addressed this issue. This study aimed to clarify the prevalence of radiographic findings of FAI in a Japanese population and to evaluate whether FAI is a risk factor for the development of arthritic changes.MethodsWe retrospectively examined 87 patients who underwent unilateral hip osteotomy with a Charnley category A hip joint on the contralateral side. Anteroposterior-view radiographs of the non-operated hip joint were assessed for the presence of hip dysplasia, as well as pistol grip deformity and crossover sign indicative of cam-type and pincer-type impingement, respectively. The presence of arthritic changes in the non-operated hip joint was assessed in follow-up radiographs, and factors contributing to the development of arthritis were determined by survival analysis.ResultsOf the 87 hips examined, dysplasia was noted in 38 (43.6%). While no pistol grip deformity was observed, crossover sign, which is indicative of pincer-type impingement, was identified in 9 of 38 dysplastic hips (23.7%) and 15 of 49 non-dysplastic hips (30.6%). Arthritic changes were present in 13 of 38 dysplastic hips (34.2%) and 11 of 49 non-dysplastic hips (22.4%). Survival analysis revealed that the presence of the crossover sign in non-dysplastic hips was significantly associated with the development of arthritis.ConclusionsThe prevalence of the crossover sign in hips in a Japanese population is similar to that reported in Western populations, despite the fact that FAI is believed to be less prevalent in the Japanese population. Furthermore, the presence of the crossover sign in non-dysplastic hip joints is associated with the development of arthritis. Based on our results, pincer-type impingement could be commonly associated with the development of arthritis in Japanese populations.

Radiological evaluation of allograft reconstruction in acetabulum with Ganz reinforcement ring in revision total hip replacement

BackgroundIn revision total hip replacement (THR), cages and rings are commonly used for the reconstruction of bone defects that are due to mechanical loosening of the acetabular cup and migration of the femoral head prosthesis. The purpose of this study was to evaluate the radiological results of the use of Ganz reinforcement rings with bone allografts in acetabular revision THR.MethodsWe reviewed 30 hips of 28 patients who underwent allograft reconstruction of the acetabulum with a Ganz reinforcement ring in revision THR. The average postoperative follow-up period was 8 years. The position of the acetabular socket was measured on anteroposterior radiographs. Loosening of the acetabular component was defined as a change in the cranial or central direction of the cup or a change in the cup inclination angle at the time of last follow-up. In cases of segmental bone defects in weight-bearing areas, we used two or three strut screws prior to incorporation of the Ganz reinforcement ring to act as struts for the ring. Kaplan-Meier survivorship analysis was performed. The end point was revision surgery done because of defined loosening of the acetabular component at the time of the last follow-up.ResultsAll five acetabular components (16.7%) defined as showing aseptic loosening were type D defects (cranio-central defects), but no patient needed revision surgery during the follow-up period. Nine revision surgeries with strut screws for type D acetabular bone defects were performed. The calculated Kaplan-Meier survival rate at 5 years was 96.0%, and the rate at 10 years was 80.2%, using defined loosening of the acetabular component as the end point.ConclusionsAllograft reconstruction of the acetabulum with a Ganz reinforcement ring is a useful technique for revision THR. Occasionally, a special technique (the strut screw technique) was required for the reconstruction of type D bone defects.

Hammering sound frequency analysis and prevention of intraoperative periprosthetic fractures during total hip arthroplasty.

Adequate fixation at the time of cementless stem implantation depends on the operators experience. An objective evaluation method to determine whether the stem has been appropriately implanted may be helpful. We studied the relationship between the hammering sound frequency during stem implantation and internal stress in a femoral model, and evaluated the possible usefulness of hammering sound frequency analysis for preventing intraoperative fracture. Three types of cementless stem (BiCONTACT®, SL-PLUS®, and AI-Hip®) were used. Surgeons performed stem insertion using a procedure similar to that employed in a routine operation. Stress was estimated by finite element analysis, the hammering force was measured, and frequency analysis of hammering sound data obtained using a microphone. Finite element analysis showed a decrease in the hammering sound frequency with an increase in the estimated maximum stress. When a decrease in frequency was observed, adequate hammering had occurred, and the continuation of hammering risked fracture. Based on the relationship between stress and frequency, the evaluation of changes in frequency may be useful for preventing the development of intraoperative fractures. Using our method, when a decrease in frequency is observed, the hammering force should be reduced. Hammering sound frequency analysis may allow the prediction of bone fractures that can be visually confirmed, and may be a useful objective evaluation method for the prevention of intraoperative periprosthetic fractures during stem insertion.

Status of Bone Allografting in Japan - Nation-Wide Survey of Bone Grafting Performed from 1995 through 1999.

We report the status of bone allografting in Japan on the basis of the information obtained through questionnaires performed by the Japanese Orthopaedic Association (JOA). JOA performed a nation-wide survey in 2000, in order to clarify the current status of musculoskeletal tissue grafting in the orthopaedic practices in Japan. Conducted period was for 5 years from 1995 to 1999. As the results of this survey, it had been clarified that 92,984 bone graftings, which included autografts, allografts and synthetic bone substitutes, were performed during conducted 5 years. While the allografts were used only in 3,212 cases (3%), autograftings were performed in 64,193 cases (69%), synthetic bone substitutes were used in 25,576 cases (28%) in this series. The proportion of the number of operations for use bone substitutes increased every year, whereas that autografting decreased. The proportion of the number of allografting remained almost unaltered. Of the 706 institutions which answered to have experiences of tissue grafting, only 193 (27%) performed allograft.Since Kitasato University Hospital Bone Bank was developed in 1971, we have applied to clinical while doing basic research for preserved bone allograft. When extensive bone graft is required, allograft is very useful. In Japan, however, allograft is not performed widely. The foundation of regional bone banks is expected to resolve this problem. Since excision of bone preparations from cadaver donors is not common, bone allografts are not supplied sufficiently at present. It is needed to develop a network connecting bone banks in Japan. The enlightenment activities to the ordinary people and medical institutions will also be required.

Quality assessment for processed and sterilized bone using Raman spectroscopy

To eliminate the potential for infection, many tissue banks routinely process and terminally sterilize allografts prior to transplantation. A number of techniques, including the use of scanning electron microscopy, bone graft models, and mechanical property tests, are used to evaluate the properties of allograft bone. However, as these methods are time consuming and often destroy the bone sample, the quality assessment of allograft bones are not routinely performed after processing and sterilization procedures. Raman spectroscopy is a non-destructive, rapid analysis technique that requires only small sample volumes and has recently been used to evaluate the mineral content, mineral crystallinity, acid phosphate and carbonate contents, and collagen maturity in human and animal bones. Here, to establish a quality assessment method of allograft bones using Raman spectroscopy, the effect of several common sterilization and preservation procedures on rat femoral bones were investigated. We found that freeze–thawing had no detectable effects on the composition of bone minerals or matrix, although heat treatment and gamma irradiation resulted in altered Raman spectra. Our findings suggest Raman spectroscopy may facilitate the quality control of allograft bone after processing and sterilization procedures.

Two-Stage Revision Total Hip Arthroplasty for Periprosthetic Infections Using Antibiotic-Impregnated Cement Spacers of Various Types and Materials

Antibiotic-impregnated hip cement spacers of various types and materials have been used in the treatment of periprosthetic hip infections. We developed a handmade spacer by using polymethylmethacrylate (PMMA) and/or α-tricalcium phosphate (α-TCP). In this study, we retrospectively reviewed the surgical outcomes in 36 consecutive patients treated with 2-stage revision total hip arthroplasty by using our antibiotic-impregnated hip cement spacers. We aimed to analyze the infection control and reinfection rates after revision surgery. Moreover, we analyzed the possible predictors of postoperative reinfection. After exclusion of 1 patient who died immediately after the first-stage surgery, infection was controlled in 33 of the 36 hips (success rate, 91.7%). Two of these 33 hips underwent resection arthroplasty. Of the 36 hips that had been treated with the antibiotic-cement spacer, 31 hips (86.1%) were eligible for the second-stage prosthesis re-implantation. The 31 protocol hip joints of patients followed up for >6 months (mean, 48.6 months). Ten of these 31 hips (32.3%) became reinfected. No possible predictor examined differed significantly between the reinfection-positive and reinfection-negative groups. However, spacers consisting of PMMA cement alone were associated with the highest risk of reinfection. Therefore, α-TCP-containing antibiotic-impregnated hip cement spacers might decrease the reinfection rate in patients undergoing re-implantation.

Results and prognostic factors of valgus osteotomy in middle-aged patients with advanced or terminal osteoarthritis of the hip

BackgroundFrom 1979 to 2005, a total of 279 hips in 249 patients with advanced and/or terminal-stage osteoarthritis of the hip underwent valgus osteotomy. Among them, we reviewed 256 hips in 229 patients (91.8%) with a minimum follow-up of 1 year. We reviewed the clinical and radiological results and analyzed prognostic factors that may have affected the postoperative outcome.MethodsClinical evaluation was made according to the Japanese Orthopaedic Association Hip score (JOA score). Radiological evaluation was made according to the criteria of Itoman. The Kaplan-Meier method was used to calculate the probability of survival of valgus osteotomy from the time of the operation until the endpoint of a subsequent operation. To examine prognostic factors, clinical parameters and radiographic measurements were compared between patients in an improved group and an aggravated group. Additionally, clinical parameters and radiographic measurements were used to evaluate the JOA score at the latest follow-up.ResultsThe mean JOA score was 52.6 before the operation; it was 80.6, showing the most marked improvement, 5 years after the operation, gradually decreased thereafter; and it was 65.0 after 20 years. Radiological results were good or fair in 78% even 10 years after the operation. The survival rates were 91%, 63%, and 52%, respectively, at 10, 15, and 20 years after valgus osteotomy. Concerning prognostic factors, the improved group tended to show preoperative good range of motion and unilateral involvement. Concerning the association between prognostic factors and the JOA score at the latest follow-up observation, the JOA score was significantly lower for an acetabular head index (AHI) <60% than for AHI ≥60%.ConclusionsValgus osteotomy is effective joint-preserving surgery for advanced or terminal-stage osteoarthritis of the hip in middle-aged patients, and it is acceptable for clinical and radiological evaluation. If the AHI is <60%, valgus osteotomy should be combined with Chiari’s pelvic osteotomy.

The expense for one implantation of a banked bone allograft from a cadaveric donor and the issues affecting current advanced medical treatment in the Japanese orthopaedic field

Demand for banked bone allografts is increasing in Japan; however, there are too few bone banks and the bone bank network is not well-established. One reason for this was lack of funding for banks. Bone banks had to bear all material expenses of banked bone allografts themselves because this was not designated a covered expense. In December 2004, the Japanese government started a new “Advanced Medical Treatment” administration system which allowed an approved institution to charge the expense of authorized advanced medical treatments directly to patients. The treatment named “Cryopreserved allogenic bone and ligamentous tissue retrieved from cadaveric donor” was approved as an advanced medical treatment in March 2007. We present the calculation method and the expense per implantation of a banked bone allograft from a cadaveric donor under this treatment and raise issues which affect this advanced medical treatment and remain to be resolved in the Japanese orthopaedic field.

Revision total hip replacement using a cementless interlocking distal femoral stem with allograft-cemented composite and the application of intramedullary and onlay cortical strut allografts: two case reports.

Abstract It is often difficult to perform repeated revision total hip replacement (re-THR) after prosthesis loosening stemming from infection, mechanical loosening, and osteolysis. Reasons for this include the size of the bone defect and poor quality of the remaining bone. We have previously performed revision surgery using a cementless interlocking distal femoral stem with segmental cortical allograft-cemented composite for reconstruction in the presence of circumferential bone loss of the proximal femur according to Gustilo classification type IV [1]. However, in the case where the distal femur had a stovepipe canal due to osteoporosis, osteolysis, and infection, it was difficult to achieve stable fixation to the distal femoral cortical bone using a cementless interlocking distal femoral stem. Therefore, a cortical strut allograft is inserted into the femoral bone canal on the medial side, followed by the insertion of an interlocking stem. A further cortical strut allograft is inserted on the lateral side of the distal femur. In addition, the distal onlay allograft should pass over the allograft–host bone junction. The two allografts are finally secured with interlocking screws. The bone allografting to augment femoral bone deficiency was performed using mainly cadaveric bone allografts obtained from our bone bank [2, 3]. In this report, we describe two cases of re-THR involving the use of intramedullary and onlay cortical strut allografts with a cementless interlocking distal femoral long stem to achieve favorable fixation stability. The two patients were asked if the data from the case could be submitted for publication, and both gave their consent

Pre-operative simulation of periacetabular osteotomy via a three-dimensional model constructed from salt

Introduction: Periacetabular osteotomy (PAO) is an effective joint-preserving procedure for young adults with developmental dysplasia of the hip. Although PAO provides excellent radiographic and clinical results, it is a technically demanding procedure with a distinct learning curve that requires careful 3D planning and, above all, has a number of potential complications. We therefore developed a pre-operative simulation method for PAO via creation of a new full-scale model. Methods: The model was prepared from the patient’s Digital Imaging and Communications in Medicine (DICOM) formatted data from computed tomography (CT), for construction and assembly using 3D printing technology. A major feature of our model is that it is constructed from salt. In contrast to conventional models, our model provides a more accurate representation, at a lower manufacturing cost, and requires a shorter production time. Furthermore, our model realized simulated operation normally with using a chisel and drill without easy breakage or fissure. We were able to easily simulate the line of osteotomy and confirm acetabular version and coverage after moving to the osteotomized fragment. Additionally, this model allowed a dynamic assessment that avoided anterior impingement following the osteotomy. Results: Our models clearly reflected the anatomical shape of the patient’s hip. Our models allowed for surgical simulation, making realistic use of the chisel and drill. Our method of pre-operative simulation for PAO allowed for the assessment of accurate osteotomy line, determination of the position of the osteotomized fragment, and prevented anterior impingement after the operation. Conclusion: Our method of pre-operative simulation might improve the safety, accuracy, and results of PAO.