Decennial trends in hip fractures over 20 years in Yamagata Prefecture, Japan.

BACKGROUND: Hip fracture is among the most common injuries in elderly people. We aimed to investigate the decennial trends in hip fractures in patients ≥65 years of age. METHODS: A questionnaire was distributed to all hospitals with a Department of Orthopaedic Surgery in Yamagata Prefecture to collect data on hip fractures occurring in 1996, 2006 and 2016. RESULTS: The response rate was 100%. The total numbers of hip fractures in 1996, 2006 and 2016 were 665, 1169 and 1,728, respectively (crude incidence: 258, 373 and 494 per 100,000 person-year, respectively). Injuries frequently occurred in the early morning and daytime morning in 1996. In contrast, they frequently occurred in activity times (e.g., morning and afternoon) in 2006 and 2016. Among the patients, 80-90% were injured by simple falls, and 70-80% were injured indoors. The incidence of trochanteric fractures was approximately 1.8-1.9 times greater than incidence of neck fractures in all years. Especially, trochanteric fractures in females of ≥90 years of age markedly increased. The rate of surgical treatment was the same in 1996 and 2006, but was lower in 2016. In 1996, the percentage of independent walkers at discharge and 1 year later was almost the same. In 2006 and 2016, the rate of independent walkers was low at discharge, but increased 1 year later. The rate of discharge to home decreased gradually. The combined percentage of patients discharged to home and to rehabilitation institutions in 2006 and the percentage of patients who entered the regional referral clinical pathway in 2016 were both approximately 70%, with no marked changes observed. CONCLUSIONS: Hip fractures, especially trochanteric fractures in super-aged females, increased. Discharge to home decreased, and the use of the regional referral clinical pathway was widespread. Ambulation ability was reduced at discharge, but improved after 1 year.

Back-side wear in HexLoc cups clinico-radiological, immunohistopathological, finite element, and retrieval analysis studies.

The HexLoc locking system was designed to prevent back-side wear of the polyethylene liner in the modular cementless metal-backed acetabular cup, but failed. Back-side wear was analyzed using clinico-radiological data, immunohistopathology, finite element modeling (FEM, and retrieval analysis. Screw holes allowed entry of titanium oxide and exit of polyethylene particles. Birefringent polyethylene wear particles were found behind the metal cup in macrophages containing pro-inflammatory tumor necrosis factor-α and interleukin-1ß, whereas fibroblast-like cells stained for osteoclastogenic receptor activator of nuclear factor kappa B ligand (RANKL). Computerized tomography revealed granulomas (83% versus 17 %) and cortical destruction (50% versus 5%) better than radiographs. In FEM, a change of the abduction angle from 45 to 60 deg, and liner thickness from 4.8 mm to 2.5 mm, increased the back-side wear by 90% and 120%, respectively. Screw holes were stress concentration areas; their removal decreased wear by 40%. Modeling results were validated in retrieved implants, which demonstrated extensive back-side wear damage of liners with a high abduction angle. Combined clinico-radiological, immunohistopathological, FEM, and retrieval analysis disclosed that back-side wear in the HexLoc design is sensitive to the abduction angle, liner thickness, and presence of screw holes.

Postoperative prophylactic effect of fondaparinux for prevention of deep venous thrombosis after cemented total hip replacement: a comparative study.

The aim of this study was to estimate the effective administration procedure of fondaparinux for prevention of venous thromboembolism after cemented total hip replacement (THR) in Japanese patients. The study included 471 Japanese patients. The dose regimens were 2.5 mg daily for 14 days (2.5 mg/14 day group) or 10 days (2.5 mg/10 day group), 1.5 mg daily for 10 days (1.5 mg group), 2.5 mg daily for the first 3 postoperative days and 1.5 mg daily for the subsequent 7 days (Mixed group), and no administration of fondaparinux (Control group). Deep venous thrombosis (DVT) was diagnosed by ultrasonography on postoperative day 3 or 4 and day 14. The 2.5 mg/14 day, 2.5 mg/10 day and Mixed groups were regarded as one group in the assessment on postoperative day 3 or 4, and denoted as the 2.5 mg group. The incidence of DVT on postoperative day 3 or 4 in the 2.5 mg group was significantly lower than that in the Control and 1.5 mg groups. On postoperative day 14, the incidence of DVT in the 1.5 mg and Mixed groups was significantly lower than that in the Control group in both the intention-to-treat and per-protocol analyses. The incidence in the 2.5 mg/10 day and 2.5 mg/14 day groups was significantly lower than that in the Control group in only the per-protocol analysis. The results suggest that the administration protocol of the Mixed group is effective in preventing DVT in Japanese patients undergoing cemented THR.

Initial evaluation on subsidence of cemented collarless polished tapered stem applied to the patients with narrow femoral medullar canal.

PURPOSE: The geometry of the proximal femur is one of the important factors for choosing the suitable stem. We have been applied cemented collarless polished tapered (CPT) stem to the patients with small femur. Radiographic evaluation was performed to access the clinical feature of the stem in early stage of the follow-up. METHODS: One hundred total hip arthroplasties with CPT system were performed between October 2004 to February 2006. This study focused on the 53 cases to whom size 1 or smaller sized stem were implanted, and its post-operative period was 41 months (30-46 months). Morphologic classification of preoperative proximal femur, stem alignment, thickness of the cement mantle, cementing technique, subsidence of the stem, improvement in the bone-cement interface, and stress shielding were assessed. RESULTS: The size of the inserted stem was X-SMALL in one case, SMALL in two cases, SIZE 0 in 12 cases, and SIZE 1 in 38 cases. Canal shape of proximal femur was stovepipe type in five cases, normal type in 43 cases, and champagne-flute type in five cases. There was no subsidence in eight cases. 44 stems subsided within 1 mm, one stem subsided 1 to 2 mm, and no stem subsided over 2 mm. In 39 of 45 cases, subsidence was appeared within six months after operation. Marked progressive and excessive subsidence was not seen after the two years of follow-up. CONCLUSIONS: Short term radiographic results of THA with CPT stem to small femur were satisfactory with less unfavorable radiographic findings, which imply contribution to longer survivorship of the stem.

Antibiotics-impregnated cement spacers in the first step of two-stage revision for infected totally replaced hip joints: report of ten trial cases.

BACKGROUND: Periprosthetic infection is one of the serious complications after total hip arthroplasty (THA). This study analyzed the perioperative and postoperative status of patients who underwent antibiotics-impregnated cement spacer technique in the first step of the two-stage revision. METHODS: Ten joints of the nine patients (mean age, 65 years; seven women, two men) received two-stage revision as a result of infection that appeared after primary THAs in seven joints, aseptic revision in one, and recurrent type in two. An antibiotics-impregnated cement spacer made by a mold system was applied in the femoral side of all joints. An acetabular spacer was made by hand using a cup gauge in eight joints with extensive tissue loss. RESULTS: The change of leg length after the first stage was -2.2 mm, and range of hip flexion was 72 degrees on average, respectively. Patients could walk with crutches after the first stage, except one patient with simultaneous infections of both hips and one with fracture of the cement spacer. One fracture of femoral cement spacer, and one dislocation of femoral spacer accompanied by fracture of acetabular cement spacer and curable recurrent infection, were found. In all cases of the second-stage procedure, the acetabular side was reconstructed with allogeneic bone graft with cross plate and that of the femur was by impaction bone grafting method. In the latest follow-up, reconstructed implants were stable. Seven patients could walk without any supportive devices and two could walk with the support of a T-cane. CONCLUSIONS: An antibiotics-impregnated cement spacer in the first step of the two-stage revision was effective not only to compensate tissue loss after removal of the implants and to minimize discrepancy of leg length, but also to contribute to improvement of perioperative and postoperative daily activities of the patient's life as well as treatment of the infection.

Total hip replacement in patients eighty years of age and older.

BACKGROUND: The number of people eighty years of age and older in developed countries is increasing, with a concomitant increased demand for total hip replacement. We analyzed the outcomes of total hip arthroplasty for patients in this age group using data from the Finnish National Arthroplasty Registry. METHODS: Data from the Finnish Arthroplasty Registry on 6540 patients (6989 hips) who were eighty years of age or older at the time of a total hip arthroplasty, performed between 1980 and 2004, were evaluated with use of survival analyses. Factors affecting survivorship rates were sought, and the reasons for revision were identified. RESULTS: The mean age of the patients undergoing a primary total hip arthroplasty was 82.7 years. The mean longevity of 3065 patients who died following total hip arthroplasty was 5.1 years. With revision total hip arthroplasty for any reason as the end point, Kaplan Meier survivorship was 97% (95% confidence interval, 96% to 97%) at five years (2617 hips) and 94% (95% confidence interval, 93% to 95%) at ten years (532 hips). Of the 195 hip replacements that required revision, 183 had information on the reason for revision. Eighty-four (46%) were revised for aseptic loosening; thirty-six (20%), for recurrent dislocation; twenty-four (13%), for a periprosthetic fracture; and twenty-three (13%), for infection. Seven hundred and twenty-nine patients had undergone hybrid fixation (a cemented stem and a cementless cup). The survivorship of these replacements was significantly better than that for replacements with cementless fixation in 399 patients (p < 0.05). CONCLUSIONS: In patients who had a total hip arthroplasty when they were more than eighty years old, the prevalence of aseptic loosening was less than that encountered in younger patients, but recurrent dislocation, periprosthetic fracture, and infection were more common in this age group. Cementation of the femoral stem demonstrated better long-term results than cementless fixation, indicating that it may provide better initial fixation and, therefore, longer life-in-service.

Novel types of COMP mutations and genotype-phenotype association in pseudoachondroplasia and multiple epiphyseal dysplasia.

Mutations in the gene encoding cartilage oligomeric matrix protein ( COMP) cause two skeletal dysplasias, pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED). More than 40 mutations have been identified; however, genotype-phenotype relationships are not well delineated. Further, mutations other than in-frame insertion/deletions and substitutions have not been found, and currently known mutations are clustered within relatively small regions. Here we report the identification of nine novel and three recurrent COMP mutations in PSACH and MED patients. These include two novel types of mutations; the first, a gross deletion spanning an exon-intron junction, causes an exon deletion. The second, a frameshift mutation that results in a truncation of the C-terminal domain, is the first known truncating mutation in the COMP gene. The remaining mutations, other than a novel exon 18 mutation, affected highly conserved aspartate or cysteine residues in the calmodulin-like repeat (CLR) region. Genotype-phenotype analysis revealed a correlation between the position and type of mutations and the severity of short stature. Mutations in the seventh CLR produced more severe short stature compared with mutations elsewhere in the CLRs ( P=0.0003) and elsewhere in the COMP gene ( P=0.0007). Patients carrying mutations within the five-aspartates repeat (aa 469-473) in the seventh CLR were extremely short (below -6 SD). Patients with deletion mutations were significantly shorter than those with substitution mutations ( P=0.0024). These findings expand the mutation spectrum of the COMP gene and highlight genotype-phenotype relationships, facilitating improved genetic diagnosis and analysis of COMP function in humans.

Autosomal dominant precocious osteoarthropathy due to a mutation of the cartilage oligomeric matrix protein (COMP) gene: further expansion of the phenotypic variations of COMP defects.

We report on a Japanese family of four generations with an autosomal dominant precocious osteoarthropathy. The cardinal clinical manifestations of affected individuals were painful weight-bearing large joints, which started in late childhood or adolescence. The radiological hallmarks included coxa plana, mild epiphyseal dysplasia of the knee, and round talar domes with tibiotalar slant in childhood, which evolved into degenerative joint diseases in adulthood. The disease phenotype was cosegregated with a mutation of the cartilage oligomeric matrix protein (COMP) gene in the family members, who underwent molecular evaluation. COMP mutations have been reported in a mild form of multiple epiphyseal dysplasia (MED), Ribbing type, as well as allied disorders with more severe manifestations, such as MED Fairbank type and pseudoachondroplasia. Unlike previously reported cases with the Ribbing type, the present patients did not have short stature or brachydactyly. This report expands further the phenotypic variations of COMP defects.