Geriatric nutritional risk index as the prognostic factor in older patients with fragility hip fractures.

This study investigated the long-term survival and incidence of secondary fractures after fragility hip fractures. The 5-year survival rate was 62%, and the mortality risk was seen in patients with GNRI < 92. The 5-year incidence of secondary fracture was 22%, which was significantly higher in patients with a BMI < 20. BACKGROUND: Malnutrition negatively influences the postoperative survival of patients with fragility hip fractures (FHFs); however, little is known about their association over the long term. OBJECTIVE: This study evaluated the ability of the geriatric nutritional risk index (GNRI) as a risk factor for long-term mortality after FHFs. METHODS: This study included 623 Japanese patients with FHFs over the age of 60 years. We prospectively collected data on admission and during hospitalization and assessed the patients' conditions after discharge through a questionnaire. We examined the long-term mortality and the incidence of secondary FHFs and assessed the prognostic factors. RESULTS: The mean observation period was 4.0 years (range 0-7 years). The average age at the time of admission was 82 years (range 60-101 years). The overall survival after FHFs (1 year, 91%; 5 years, 62%) and the incidence of secondary FHFs were high (1 year, 4%; 5 years, 22%). The multivariate Cox proportional hazard analysis revealed the risk factors for mortality as older age (hazard ratio [HR] 1.04), male sex (HR 1.96), lower GNRI score (HR 0.96), comorbidities (malignancy, HR 2.51; ischemic heart disease, HR 2.24; revised Hasegawa dementia scale ≤ 20, HR 1.64), no use of active vitamin D3 on admission (HR 0.46), and a lower Barthel index (BI) (on admission, HR 1.00; at discharge, HR 0.99). The GNRI scores were divided into four risk categories: major risk (GNRI, < 82), moderate risk (82-91), low risk (92-98), and no risk (> 98). Patients at major and moderate risks of GNRI had a significantly lower overall survival rate (p < 0.001). Lower body mass index (BMI) was also identified as a prognostic factor for secondary FHFs (HR 0.88 [p = 0.004]). CONCLUSIONS: We showed that older age, male sex, a lower GNRI score, comorbidities, and a lower BI are risk factors for mortality following FHFs. GNRI is a novel and simple predictor of long-term survival after FHFs.

A novel technique for surgical resection of spinal meningioma.

STUDY DESIGN: A technical note. OBJECTIVES: To describe and discuss a novel technique for surgical resection of spinal meningioma. SUMMARY OF BACKGROUND DATA: With conventional methods for surgical resection of isolated intradural spinal meningioma, there are two ways of dealing with the dural attachment of the tumor. One is complete resection of the involved dura together with the tumor, and the other is coagulation only of the tumor base of the dura. In the case of the novel technique herein described, the dura mater is preserved in a new manner. METHODS: In the surgical procedure a small incision is made in the surface of the dura mater after the conventional laminectomy. The spinal dura can be easily divided into two layers, comprising inner and outer layers. The outer layer is stripped away from the inner layer surrounding the tumor base. The tumor is then resected together with the inner layer alone outside the arachnoid membrane, and finally the outer layer is simply closed. RESULTS: This method has been applied to three cases. The preserved outer layer of the dura mater did not demonstrate the existence of tumor cells histologically. Neither complications nor tumor recurrence have been experienced. CONCLUSION: The authors introduced a novel technique for surgical resection of isolated intradural spinal meningioma. Using this simple procedure the outer part of the dura mater, which is not involved by the tumor, can be preserved and complicated dural reconstruction is not necessary. Furthermore, there is less risk of postoperative cerebrospinal fluid fistulas than when the dura is completely resected together with the tumor. However, long-term observation as a result of the possibility of local recurrence is strongly recommended.

Differentiation of vertebral osteomyelitis and tuberculous spondylitis by magnetic resonance imaging.

Twenty patients with vertebral osteomyelitis and 18 with tuberculous spondylitis were investigated by magnetic resonance imaging to identify the distinguishing features. The number of vertebral bodies involved was less in vertebral osteomyelitis than in tuberculous spondylitis, and the paravertebral abscesses were smaller. The magnetic resonance intensity of the involved vertebral bodies was more homogeneous in vertebral osteomyelitis than in tuberculous spondylitis. Rim enhancement with Gadolinium-DTPA was less frequent in vertebral osteomyelitis. The differentiation of the two conditions by MRI was helpful in establishing the correct diagnosis of the infection.

Ethylene oxide sterilization of bone grafts. Residual gas concentration and fibroblast toxicity.

We examined the concentration of ethylene oxide in bone allografts after gas sterilization. Chips of the human femoral head were investigated. Residual gas concentration was determined by gas chromatography after the bone chips had been subjected to defatting and freeze-drying, followed by ethylene oxide gas sterilization. Bones were prepared in various ways in an attempt to reduce the concentration of residual ethylene oxide. The concentration was higher when gas sterilization was performed before freeze-drying than when it was done afterwards. An experiment performed with fibroblasts showed the high toxicity of residual ethylene oxide in bone chips, even when the concentration was very low. The growth of fibroblast was reduced more in medium which had been shaken with bones sterilized with ethylene oxide before freeze-drying than in medium which had been shaken with bones sterilized after freeze-drying. The higher residual ethylene oxide concentrations resulted in a decrease in fibroblastic culture activity. Our experiment showed the importance of reducing the residual ethylene oxide gas concentration. Defatting and freeze-drying result in lower residual ethylene oxide concentrations.

Spontaneous hemarthrosis of the knee in the elderly: etiology and treatment.

The etiology of spontaneous hemarthrosis of the knee in elderly patients with osteoarthritis is still unknown. This report discusses six cases, one that was managed with conservative measures and five in which arthroscopic evaluation and treatment were performed. These patients were elderly individuals whose chief complaint was knee pain and swelling about the joint, without an obvious history of trauma. Each of the five operative patients underwent arthroscopic surgery after repeated hemorrhage into the joint that did not respond to serial aspirations of large amounts of blood and immobilization, using a knee immobilizer. The roentgenograms of each involved knee demonstrated lateral compartment osteoarthritis. Arthroscopic examination revealed a degenerative flap tear of the posterior horn of the lateral meniscus in the five operative cases. These patients underwent arthroscopic resection of the injured lateral meniscus and did not experience a recurrence of the hemarthrosis. The origin of the bleeding was most likely from the peripheral arteries of the posterior horn of the lateral meniscus.

Evaluation of the risk of instrumentation as a foreign body in spinal tuberculosis. Clinical and biologic study.

The risk of persistence and recurrence of infection in posterior spinal instrumentation surgery for spinal tuberculosis was studied clinically and microbiologically. Eleven patients with thoracic, thoracolumbar, and lumbar spinal tuberculosis treated by debridement, anterior fusion, and combined posterior instrumentation surgery were analyzed. Seven patients had tuberculosis in both anterior and posterior spinal elements. There were no cases of persistence or recurrence of infection after surgery, and instrumentation provided immediate stability and protected against development of kyphotic deformity. The adherence properties of Mycobacterium tuberculosis to stainless steel (SUS 316) was evaluated experimentally. The results showed that posterior instrumentation surgery was not a hazard to spinal tuberculosis infection when combined with radical debridement and intensive anti-tuberculosis chemotherapy.

Bacterial adherence to bioinert and bioactive materials studied in vitro.

In vitro, bioinert stainless steel and titanium alloy, and bioactive sintered hydroxyapatite and hydroxyapatite-coated titanium materials were exposed to Staphylococcus epidermidis to study bacterial adhesion. Scanning electron microscopy showed that fibrous strands interconnected the adherent bacteria, and that background matrix enclosed bacterial colonies. This adherent mode of growth may reduce the susceptibility of the bacteria to host clearance mechanisms and antibiotic therapy. Adherence assays revealed that bacterial adherence to sintered hydroxyapatite was higher than to the other 3 materials.

Increased resistance of bacteria after adherence to polymethyl methacrylate. An in vitro study.

The pathobiology of total joint prosthesis infection was investigated in vitro. Discs of polymethylmethacrylate (PMMA) were exposed to a suspension containing cells of 10(8) per mL Staphylococcus epidermidis E-46. After 12 hours, exposed discs were rinsed with phosphate-buffered saline and placed in brain heart infusion broth containing antibiotics (2.5 mg per mL of Cephaloridine). After gentle shaking for 24 hours at 37 degrees C, the bacteria on the PMMA surface were detached and washed with phosphate-buffered saline to remove the antibiotics. Compared with the free bacteria which were detached from the PMMA by sonication immediately after exposure to the antibiotic solution, those allowed to remain adhered to the PMMA surface were more resistant to antibiotics. Scanning electron microscopy showed accumulation of bacteria surrounded by slime on PMMA discs exposed for 12 hours. Our results indicate that resistance of bacteria to antibiotics is increased after adherence to the biomaterial and formation of a slime layer.

Inhibition of bacterial adhesion by tobramycin-impregnated PMMA bone cement.

We investigated the effect of tobramycin-impregnated polymethylmethacrylate (PMMA) bone cement on the adhesion and colonization of Staphylococcus epidermidis. The pattern of colonization was quantitated using plate count techniques and electron microscopy. Colonization of the tobramycin-impregnated disc surface by adhesive bacteria was demonstrated but it was less than in the control disc. This finding suggests that tobramycin may reduce bacterial adherence and proliferation on the PMMA surface.

Location of peptidoglycan and teichoic acid on the cell wall surface of Staphylococcus aureus as determined by immunoelectron microscopy.

Anti-peptidoglycan (PG) and anti-teichoic acid (TA) antibodies were prepared from sera of rabbits immunized with the cell wall fraction of Staphylococcus aureus Cowan I by the specific adsorption technique with purified teichoic acid or peptidoglycan. The anti-PG antibody recognized the trichloroacetic acid-treated walls (TCA wall) prepared from S. aureus, Bacillus subtilis, and Micrococcus luteus but did not react with teichoic acid or proteins extracted from the cell wall of Staphylococcus. The anti-TA antibody specifically reacted with cell wall teichoic acid of beta-type sugar configuration. The reaction sites of these antibodies on the cell wall of S. aureus Wood 46 were determined by immunoelectron microscopy using colloidal gold as a probe. The anti-TA antibody reacted mostly with the fibrous electron-dense mass on the cell surface. The reaction was also seen on the inner surface of the cell wall. The anti-PG antibody reacted with the fibrous structures and also directly on the cell wall surface. The distribution of the probes on the cell wall surface examined with the scanning electron microscope showed that there was no localized distribution in respect to the cell division. We knew from these observations that the external surface of the cell wall of Staphylococcus is covered with the fibrous mass which consists mostly of teichoic acid but partially of peptidoglycan.

The inhibition of bacterial adhesion to a tobramycin-impregnated polymethylmethacrylate substratum.

Tobramycin sulfate powder (1.2 g) was mixed with Palacos polymethylmethacrylate (PMMA) bone cement (40 g) to produce 100 discs containing 5.9 mg tobramycin per disc. These discs were used to evaluate the inhibition of bacterial adhesion to an antibiotic-laden biomaterial. Tobramycin-impregnated PMMA discs and control discs containing no tobramycin were exposed in vitro to Staphylococcus epidermidis. Colonization was quantitated using plate count techniques and electron microscopy. Tobramycin-impregnated surfaces reduced adhesive bacteria colonization by 1 log relative to control discs. These observations suggest that tobramycin-impregnated PMMA may not be significantly effective in preventing colonization of the biomaterial substratum and PMMA may be a poor choice as a drug delivery vehicle in biomaterial and compromised tissue-centered infections.

Standing radiographs cannot determine the correction in high tibial osteotomy.

The use of standing radiographs to determine correction angles for high tibial osteotomy is not appropriate because the relative angle of the articular surfaces (condylar-plateau angle) in the weight-bearing knee changes after the osteotomy. This may give unpredictable results postoperatively. We found that the condylar-plateau angle in postoperative standing films is very similar to that seen in non-weight-bearing supine views, and suggest that these latter radiographs be used for pre-operative planning. We describe our early results, using a special osteotomy jig, in 140 knees.

Distribution of capsular materials on the cell wall surface of strain Smith diffuse of Staphylococcus aureus.

The fine structure of the capsule of Staphylococcus aureus Smith diffuse was examined by the technique of freeze-substitution and immunoelectron microscopy. The cell surface was covered with a thick layer consisting of fine fibrous structures which were absent from an unencapsulated strain, Smith compact. Anti-teichoic acid antibody did not react with this surface layer but reacted with the surface of strain Smith compact. Anti-capsular antibody, made from the serum of a rabbit immunized with strain Smith diffuse and specific absorption with unencapsulated strain Wood 46, reacted with the fibrous layer of the Smith diffuse strain. Since the anti-teichoic acid antibody did not react with the encapsulated strain Smith diffuse, the capsular layer acts as a barrier to penetration of the anti-teichoic acid antibody through the capsular layer. A portion of a few cell surfaces of the encapsulated strain remained accessible to the anti-teichoic acid antibody. The capsular layer in this portion of the cell surface was thin, and this surface seemed to be a new cell wall surface created by the cell separation.