Mortality after hip fracture in Japan: the role of nutritional status.

PURPOSE: To assess factors that influence 4-year mortality following hip fracture surgery in a Japanese population. METHODS: Records of 129 hips in 24 men and 103 women aged 50 to 103 (mean, 79) years who underwent surgery for femoral neck or trochanteric fractures were reviewed. Clinical data reviewed included age, gender, body mass index (BMI), side of fracture, fracture type, fracture stability, surgery type, interval from admission to surgery, length of hospital stay, number of pre-fracture comorbidities, pre-fracture ambulatory level, pre-fracture place of residence, preoperative dementia, preoperative skeletal traction, blood haemoglobin level, serum albumin level, number of postoperative complications, and postoperative delirium. Univariate and multiple logistic regression analyses were performed to identify the relative contribution of the variables to mortality. Receiver operating characteristic (ROC) curves were used to identify optimal cut-off levels. RESULTS: The 4-year mortality was 48%. Multiple logistic regression analysis showed that serum albumin level (p = 0.0004, odds ratio [OR] = 5.8541) and BMI (p = 0.0192, OR = 1.1693) significantly influenced mortality; the cut-off points were 36 g/l and 18.9 kg/m square, respectively, based on the ROC curves. Kaplan-Meier curves showed that survival rates were significantly worse in patients with values below these cut-off points. CONCLUSION: Serum albumin level and BMI on admission are predictive of mortality after hip fracture surgery.

Risk factors leading to total hip arthroplasty in patients with subchondral insufficiency fractures of the femoral head.

PURPOSE: To retrospectively evaluate factors leading to total hip arthroplasty (THA) in patients with subchondral insufficiency fractures (SIF) of the femoral head. METHODS. 5 men and 22 women aged 51 to 85 (mean, 72) years with SIF of the femoral head initially underwent conservative treatment. THA was later performed for 13 patients, as the hip pain became worse secondary to joint space narrowing and/ or femoral head collapse. Patient demographics and radiological variables were retrieved. Risk factors leading to THA in patients with SIF of the femoral head were identified. Receiver operating characteristic curves were used to determine optimal cut-off values for the significant risk factors. RESULTS: 2 men and 11 women aged 62 to 85 (mean, 74.9) years underwent THA and were followed up for 0.2 to 62 (mean, 13) months. The remaining 3 men and 11 women aged 51 to 81 (mean, 68) years underwent conservative treatment and were followed up for 9 to 93 (mean, 28) months. Patient age was the only risk factor for THA (p = 0.047, odds ratio = 1.13), the cutoff value being 71 years (sensitivity, 77%; specificity, 64%). The survival rate was significantly lower in patients aged 71 years or older than in those aged younger than 71 years (p < 0.05). CONCLUSION: Elderly patients with SIF of the femoral head are at higher risk of undergoing THA.

Subchondral insufficiency fracture of the femoral head may be associated with hip dysplasia: a pilot study.

BACKGROUND: Subchondral insufficiency fracture of the femoral head occurs mainly in elderly patients with osteoporosis. Spontaneous resolution is observed after nonoperative treatment in some patients whereas other show progressive joint destruction requiring THA. Several studies report the occurrence of subchondral insufficiency fracture of the femoral head in dysplastic hips. QUESTIONS/PURPOSES: We asked whether the extent of hip dysplasia or osteoporosis was greater in patients with subchondral insufficiency fracture of the femoral head than in normal control subjects. PATIENTS AND METHODS: We compared the clinical and imaging findings of 13 patients with subchondral insufficiency fractures of the femoral head and 12 patients scheduled for TKA with asymptomatic hips. Age, gender, and body mass index were comparable in the two groups. RESULTS: Higher mean Sharp angles, lower acetabular head indices, lower center-edge angles, and higher acetabular roof angles in patients with subchondral insufficiency fracture of the femoral head than in those with asymptomatic hips suggested a greater degree of hip dysplasia. Bone mineral density and serum levels of Type I collagen cross-linked N-telopeptide and bone alkaline phosphatase were similar in the two groups. CONCLUSIONS: We speculate an excessive amount of stress on the acetabular edge from dysplasia may be associated with the occurrence of subchondral insufficiency fracture of the femoral head.

Contrast-enhanced MR imaging of subchondral insufficiency fracture of the femoral head: a preliminary comparison with that of osteonecrosis of the femoral head.

INTRODUCTION: Subchondral insufficiency fracture of the femoral head (SIF) may be confused with osteonecrosis of the femoral head (ON) due to clinical and imaging similarities. MATERIALS AND METHODS: Contrast-enhanced MR images in patients with SIF (ten hips in ten patients) were retrospectively reviewed and compared with those from patients with ON (ten hips in six patients). RESULTS: Low-signal intensity bands on T1-weighted images were present within the femoral head in all hips examined. The segment proximal to the band was contrast-enhanced following IV gadolinium administration in nine of ten hips (90%) with SIF and in none of the 10 hips with ON. CONCLUSION: These results suggest that the presence of contrast enhancement in the segment proximal to the low-signal intensity band in the femoral head may serve as a supplemental diagnostic measure for the differentiation of SIF from ON.

Analysis of wear and oxidation on retrieved bipolar polyethylene liner.

BACKGROUND: For bipolar prostheses, most of the previous studies attributed the occurrence of osteolysis to wear debris generated from the bearing surface. We looked closely into the wear debris and reported on our findings with respect to the oxidation index and the rate of wear in ultra-high molecular weight polyethylene (UHMWPE) inserts retrieved from bipolar prostheses after various spans of time in vivo. METHOD: The inserts were retrieved from the heads of three types of bipolar prosthesis (UH1, UPF1, UPF2). We retrieved 24 bipolar prostheses from 23 patients whose mean implantation period was 10.0 years (2.7-15.4 years). RESULTS: All the retrieved polyethylene had a burnished bearing surface. In all, 92% (22/24) of these inserts had indentation and roughness at the rim and flange, suggesting neck-cup impingement; periprosthetic fracture occurred in the other two inserts. The mean linear wear rate was 0.035 mm per year. The average maximum oxidation index for the inserts with osteolysis was 3.34, and it was was 3.49 for the inserts without osteolysis. We, therefore, could not detect any significant difference between the aforesaid groups of inserts. CONCLUSIONS: The results strongly suggest that most of the polyethylene wear debris was not generated from the bearing surface. Moreover, the wear debris generated from neck-cup impingement may well be the cause of an inflammatory reaction, which in turn has a strong potential to become the primary cause of osteolysis.

Short-term wear of Japanese highly cross-linked polyethylene in cementless THA.

INTRODUCTION: Production of polyethylene wear from acetabular liners is thought, in part, to mediate the periprosthetic osteolysis. This study examined the in vivo wear performance of Japanese highly cross-linked polyethylene (Aeonian) in cementless total hip arthroplasty. MATERIALS AND METHODS: Ninety-five hips received a highly cross-linked polyethylene liner, while 20 hips were implanted with conventional polyethylene. Two-dimensional linear wear was measured on radiographs and volumetric wear was then calculated. Both linear and volumetric wear rates were examined for the 1-year postoperative period as well as for the time frame beginning after 1 year ending with the final follow-up. RESULTS: The amount of linear wear was significantly lower in the cross-linked group at 3 and 5 years postoperatively (P < 0.01 and < 0.001, respectively). Linear and volumetric wear rates after 1 year postoperatively for hips with the cross-linked polyethylene were significantly reduced by 57 and 59%, respectively, when compared to rates for those who received conventional polyethylene (P < 0.01). A multiple logistic regression analysis revealed that cross-linking was a significant factor influencing linear wear rate after 1 year postoperatively with an odds ratio, exp(ss) = 10.033 (P < 0.001). CONCLUSION: These results suggest that the highly cross-linked polyethylene reduces penetration of the femoral head and may be an optimal bearing surface for patients receiving total hip arthroplasty.

Spinal epidural hematoma after removal of an epidural catheter: case report and review of the literature.

We report a case of spinal epidural hematoma after removal of an epidural catheter. The patient had no background of anticoagulant therapy or coagulopathy; sudden severe back pain occurred immediately after removal of the catheter. The chance of this occurring is estimated to be between 1:150,000 and 1:190,000. We studied 40 previous reports from 1952 to 2000, and we also investigated anticoagulant therapy and pathologic states, puncture difficulties and bleeding at the point of insertion, and its onset. In 23 cases (57.5%), anticoagulant therapy had been performed, and in 5 cases (12.5%), coagulopathy or liver dysfunction had been recognized. In 20 cases (50%), the initial symptoms were recognized within 24 hours after removal of the epidural catheter. Although spinal epidural hematoma is a very rare condition, it is a serious complication of continuous epidural anesthesia.

A computer simulation of rotational acetabular osteotomy for dysplastic hip joint: does the optimal transposition of the acetabular fragment exist?

For young patients who have early signs of coxarthrosis resulting from acetabular dysplasia, periacetabular osteotomies for correcting abnormal stress distribution can be useful for preventing the progression of the disease. However, it is difficult to confirm the optimal transposition of the osteotomized acetabular fragment. To deal with this problem, we devised a computer program to support preoperative planning. Hip images obtained by computed tomography were loaded into our program, and a three-dimensional voxel model was created. Then, osteotomy was simulated and the pressure distribution was analyzed with a rigid-body spring analysis (computational nonlinear mechanical analysis). The three-dimensional pressure distributions in seven dysplastic hips were evaluated before and after virtual rotational acetabular osteotomy. A peak pressure was calculated for every 5 degrees of rotation of the acetabular fragment. The peak pressure decreased gradually and increased again afterward, indicating the optimal transposition of the acetabular fragment. The postoperative peak pressure decreased to about 40% in the most improved case. This program allows the hip joint mechanics to be evaluated easily so that the advantages and disadvantages of various surgical methods can be examined biomechanically prior to surgery.

Infliximab acts directly on human osteoclast precursors and enhances osteoclast formation induced by receptor activator of nuclear factor kappaB ligand in vitro.

Infliximab is known to protect against the development of joint destruction. In the present study, we sought to determine whether Infliximab acts directly on human osteoclast precursors and influences monocyte-osteoclast differentiation induced by receptor activator of nuclear factor kappaB ligand (RANKL) in vitro. Peripheral blood mononuclear cells (PBMCs) isolated from rheumatoid arthritis (RA) patients and normal controls were cultured in the presence of RANKL and macrophage colony stimulating factor. Infliximab, antihuman tumor necrosis factor alpha (TNFalpha), antihuman TNF soluble receptor p55 (TNFR p55), and antihuman TNF soluble receptor p75 (TNFR p75) antibodies were added. Osteoclast formation was determined by assessing the number of tartrate-resistant acid phosphatase (TRAP) staining cells and the extent of lacunar resorption. Addition of Infliximab resulted in a marked increase in the number of TRAP-positive multinucleated cells (TRAP(+) MNCs) and in the extent of lacunar resorption compared with the control cultures. Antihuman TNFalpha antibody showed the same effect; however, the addition of neither TNFR p55 nor TNFR p75 antibody affected the extent of TRAP(+) MNCs and lacunar resorption. Our results suggest that infliximab acts directly on early osteoclast precursors, and stimulates osteoclast formation and lacunar resorption induced by RANKL in vitro.

Subchondral cyst of the tibia secondary to Wilson disease.

We present the case of a 40-year-old male patient who had been suffering from Wilson disease for over 20 years, whose knee was diagnosed as osteoarthritis combined with subchondral cyst of the tibia. Preoperative examinations (X-ray, CT and MRI) confirmed the diagnosis. The microscopic examination detected thickening of the synovial membrane, and histopathological findings revealed that lymphoid cells and plasma cells were infiltrated at the synovial membrane. On copper-specific staining, no copper pigmentation was identified. However, the energy-dispersive X-ray (EDX) microanalysis revealed copper pigmentation in high concentration. These findings may contribute to our better comprehension of the development process of the arthropathy in patients with Wilson disease. The combination of subchondral cyst with Wilson disease is extremely rare, as only about 16 such cases have been reported in the English literature.

Biomechanical study of load transfer of the pubic ramus due to pelvic inclination after hip joint surgery using a three-dimensional finite element model.

We studied load-stress distribution in the pelvis using a three-dimensional finite element model. The results showed that the load-stress on the pubic superior ramus was high in the normal pelvic position without sagittal or coronal inclination following that of the acetabulum in the pelvis. The load-stress on this area was not affected by sagittal pelvic inclination, but it was affected significantly by coronal pelvic inclination. The superior pubic load-stress on the side of the longer leg was higher than that on the opposite side. The tensile stress on the pubic ramus on the side of the longer leg significantly increased compared with compressive stress. We had a patient who had an insufficiency fracture of the pubic ramus on the side of an overcorrected leg after hip joint surgery, so we examined the cause of it. Although insufficiency fractures of the pubic superior ramus are caused by various static and kinetic factors, the alternation of coronal pelvic inclination is an especially important factor in such fractures after hip joint surgery.

Limb salvage for malignant bone and soft-tissue tumours of the shoulder girdle.

We treated 15 patients with malignant bone and soft-tissue tumours of the shoulder girdle using limb salvage operations involving resection of the proximal humerus, scapula and clavicle. The oncological and functional outcomes were evaluated in all patients after an average of 5 (1-13) years. Oncological evaluation revealed that in 11 patients with adequate surgical margins six were continuously disease free and two had no evidence of disease. Three patients with marginal surgical margins had all died. We suggest that only where adequate surgical margins can be obtained should operations be performed. Forequarter amputation is still indicated in patients with complicated neurovascular involvement. Functional evaluation showed that scapular resections, especially glenoid resections, provided poor results (mean score 54%) in comparison with patients without such resection (mean score 82%).

Proinflammatory cytokine (TNFalpha/IL-1alpha) induction of human osteoclast formation.

TNFalpha and IL-1alpha are potent stimulators of bone resorption in vivo and in vitro. Recently, it has been demonstrated that these two cytokines directly induce osteoclastogenesis in mouse marrow cultures. This study determined whether TNFalpha (+/- IL-1alpha) is also capable of inducing human osteoclastogenesis. The CD14(+) monocyte fraction of human peripheral mononuclear cells was cultured with TNFalpha +/- IL-1alpha in the presence of M-CSF. TNFalpha induced the formation of multinucleated cells (MNCs) which were positive for TRAP, VNR and cathepsin K and showed evidence of resorption pit formation. IL-1alpha stimulated TNFalpha-induced lacunar resorption two- to four-fold. Osteoprotegerin, the decoy receptor for RANKL, did not inhibit this process. Anti-human IL-1alpha neutralizing antibodies significantly inhibited resorption without inhibiting the formation of TRAP(+)/VNR(+) MNCs. These results suggest that, in the presence of M-CSF, TNFalpha is sufficient for inducing human osteoclast differentiation from circulating precursors by a process which is distinct from the RANK/RANKL signalling pathway.

Influence of aeration, storage, and rinsing conditions on residual ethylene oxide in freeze-dried bone allograft.

Bone allografts sterilized with ethylene oxide gas (EO) are used in the field of orthopedic surgery, and the reduction of the EO residual concentration is an urgent clinical matter. We therefore investigated the efficacy of aeration and the effects of varied preservation periods and rinsing conditions on the reduction of EO residuals in freeze-dried bone allografts in the present study. Before aeration, the EO residual level was 12.6 ppm, and, after the repeating of aeration at 60 degrees C once, two times, and three times, the level decreased to 10.9 ppm, 3.1 ppm, and 0.47 ppm, respectively. Regarding the duration of preservation at room temperature, the mean EO residual level was 10.5 ppm, 4.9 ppm, and 4.6 ppm, 1, 2, and 3 weeks after EO sterilization, respectively. By rinsing with physiological salt solution, the level was decreased to 6.9 ppm by 5-min rinsing with 100 ml. Rinsing with 500 ml of this solution decreased the levels to 3.9 ppm, 2.8 ppm, and 2.0 ppm when done for 1, 5, and 10 min, respectively. Rinsing with 2000 ml of this solution decreased the levels to 3.6 ppm, 2.6 ppm, and 1.7 ppm when done for 1, 5, and 10 min, respectively. These experimental results with chip bone allografts lead us to recommend repeated preoperative aeration and more than 2 weeks' preservation before use for reducing the residual EO concentration. It was also evident that intraoperative rinsing with 500 ml of physiological saline for 10 min reduced the EO residual level.

Qualitative analysis of polyethylene wear in a bipolar femoral prosthesis: A case report.

We researched the qualitative changes in the polyethylene of a bipolar head retrieved at revision occurring in vivo using optical microscopy and Fourier transform infrared spectroscopy. The bearing surface of the outer head was smooth with no definable scratches delamination. However, the evidence of delamination of the beveled throat region and cracking at the base of the leaf was noticed. The degree of oxidation was different in each area of the polyethylene in the bearing component and that of the rim was shown to be higher than that of the bearing surface. Comparing the rate of ketone and ester, ketone binding was frequently found around the prosthetic rim rather that at the bearing surface. However, the ratio of ester at the surface was higher than that at the deep area of the same rim. We considered these results showed local environmental effects in vivo play a significant role in dictating the response.