The cement leakage in cement-augmented pedicle screw instrumentation in degenerative lumbosacral diseases: a retrospective analysis of 202 cases and 950 augmented pedicle screws.

PURPOSE: To evaluate the incidence, type and risk factors of cement leakage (CL) with cement-augmented pedicle screw instrumentation (CAPSI) in degenerative lumbosacral disease. METHODS: Two hundred and two patients using a total of 950 cement-augmented screws were enrolled. CL was classified into three types: type S: leakage via segmental veins; type B: leakage via basivertebral veins; and type I: leakage via pedicle screw instrumentation to paravertebral soft tissue. The age, gender, operation stage (primary or later stage), body mass index, bone mineral density, the number and type of augmented screw, the position of the tip of screw (lateral or internal part of vertebral body), the position of screw (left or right side), the volume of bone cement, location of the augmented vertebra (lumbar or sacrum), the type of CL and complications were recorded. Binary logistic regression correlation was used to analyze risk factors of veins leakage (type S and type B). RESULTS: The CL was observed in 165 patients (81.68%) and 335 screws (35.26%), leakage types of S, B and I were seen in 255 (76.12%), 77 (22.99%), and 30 (8.96%) of screws, respectively. Besides, double or multiple routes of leakage were seen in 27 screws. Number of augmented screw was a risk factor for vein leakage (OR 0.58; 95% CI 0.44-0.77; P = 0.000). Furthermore, the doses of cement (OR 0.79; 95% CI 0.61-0.99; P = 0.038) and the position of screw (OR 0.39; 95% CI 0.29-0.53; P = 0.000) were identified as risk factors for type S, and the doses of bone cement (OR 0.37; 95% CI 0.25-0.54; P = 0.000) and the position of the tip of screw (OR 0.07; 95% CI 0.04-0.13; P = 0.000) were risk factors for type B. CONCLUSIONS: CAPSI bears a high risk of asymptomatic CL, with a higher rate of leakage into segmental veins and basivertebral veins. As is known, more augmented screws and larger doses of cement are risk factors for veins leakage (type S and type B), while the tip of screw approaching to the midline of the vertebral body is another risk factor to type B. Thus, the CL could be reduced by the amelioration of operative techniques and procedures. These slides can be retrieved under Electronic Supplementary Material.

Mid-term results of alumina ceramic unlinked total elbow arthroplasty with cement fixation for patients with rheumatoid arthritis.

Aims: The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA). Patients and Methods: We retrospectively reviewed 87 elbows, in 75 patients with RA, which was replaced using a cemented JACE total elbow arthroplasty (TEA) between August 2003 and December 2012, with a follow-up of 96%. There were 72 women and three men, with a mean age of 62 years (35 to 79). The mean follow-up was nine years (2 to 14). The clinical condition of each elbow before and after surgery was assessed using the Mayo Elbow Performance Index (MEPI, 0 to 100 points). Radiographic loosening was defined as a progressive radiolucent line of >1 mm that was completely circumferential around the prosthesis. Results: The mean MEPI scores significantly improved from 40 (10 to 75) points preoperatively to 95 (30 to 100) points at final follow-up (p < 0.0001). Complications were noted in ten elbows (ten patients; 11%). Two had an intraoperative humeral fracture which was treated by fixation and united. One had a postoperative fracture of the olecranon which united with conservative treatment and one had a radial neuropathy which resolved. Further surgery was required for one with a dislocation, three with an ulnar neuropathy and one with a postoperative humeral fracture. Revision with removal of the components was performed in one elbow due to deep infection. There was no radiographic evidence of loosening around the components. With any revision surgery or revision with implant removal as the endpoint, the rates of survival up to 14 years were 93% (95% confidence interval (CI), 83.9 to 96.6) and 99% (95% CI 91.9 to 99.8), respectively, as determined by Kaplan-Meier analysis. Conclusion: With the appropriate indications, the mid-term clinical performance of the cemented JACE TEA is reliable and comparable to other established TEAs in the management of the elbow in patients with RA. Cite this article: Bone Joint J 2018;100-B:1066-73.

[Use of pedicle percutaneous cemented screws in the management of patients with poor bone stock]. / Utilisation de vis cimentées percutanées dans la prise en charge rachidienne des patients à faible capacité osseuse.

INTRODUCTION: Management of patients with poor bone stock remains difficult due to the risks of mechanical complications such as screws pullouts. At the same time, development of minimal invasive spinal techniques using a percutaneous approach is greatly adapted to these fragile patients with a reduction in operative time and complications. The aim of this study was to report our experience with cemented percutaneous screws in the management of patients with a poor bone stock. METHODS: Thirty-five patients were included in this retrospective study. In each case, a percutaneous osteosynthesis using cemented screws was performed. Indications were osteoporotic fractures, metastasis or fractures on ankylosing spine. Depending on radiologic findings, short or long constructs (2 levels above and below) were performed and an anterior column support (kyphoplasty or anterior approach) was added. Evaluation of patients was based on pre and postoperative CT-scans associated with clinical follow-up with a minimum of 6 months. RESULTS: Eleven men and 24 women with a mean age of 73 years [60-87] were included in the study. Surgical indication was related to an osteoporotic fracture in 20 cases, a metastasis in 13 cases and a fracture on ankylosing spine in the last 2 cases. Most of the fractures were located between T10 and L2 and a long construct was performed in 22 cases. Percutaneous kyphoplasty was added in 24 cases and a complementary anterior approach in 3 cases. Average operative time was 86minutes [61-110] and blood loss was estimated as minor in all the cases. In the entire series, average volume of cement injected was 1.8 cc/screw. One patient underwent a major complication with a vascular leakage responsible for a cement pulmonary embolism. With a 9 months average follow-up [6-20], no cases of infection or mechanical complication was reported. CONCLUSION: Minimal invasive spinal techniques are greatly adapted to the management of fragile patients. The use of percutaneous cemented screws is, in our experience, a valuable alternative for spinal fixation in patients with poor bone stock. This technique allows a good bony fixation with a low rate of complications. However, rigorous preoperative planning is necessary in order to avoid complications.

An unexpected cause of severe and refractory PTH-independent hypercalcemia: case report and literature review.

Hypercalcemia is a common condition in the internal medicine practice. Sometimes its cause is not readily apparent, so extensive investigation is appropriate. Here we report an unexpected cause for hypercalcemia in an elderly woman. The case of an 82-years old woman with PTH-independent hypercalcemia, lymphocytosis, normal serum 1,25 (OH)vitamin D levels, and low serum PTHrp levels, is described. Medical history and complementary investigation were unremarkable, except for increased metabolic activity in the glutei regions, as measured by whole body 18F-FDG PET-CT. Reviewing her medical history, her sister recalled that she had been submitted to intramuscular methylmethacrylate injections, for cosmetic purposes, five years before presentation, which was confirmed by muscle biopsy. Low calcium intake, parenteral bisphosphonates, calcitonin, and glucocorticoids were used to control serum calcium levels. Methylmethacrylate injections, used cosmetically, are a new cause for hypercalcemia, even after many years. Hypercalcemia was probably due to calcitriol overproduction in foreign body granulomas. Persistent reactive lymphocytosis could be a clue for this inflammatory cause of hypercalcemia.

Clinical benefits of femoroplasty: a nonsurgical alternative for the management of femoral metastases.

BACKGROUND: Bone metastases occur frequently in advanced cancer. The spine, pelvis, ribs, skull and femur are the most affected sites. It is reported that up to 83% of the patients develop pain at some point of the disease. The patient can also develop fractures and disability, particularly in the femur.. OBJECTIVES: To evaluate the effectiveness of percutaneous femoroplasty in patients with metastatic osseous disease located in the proximal femur (trochanter, neck, and femoral head). STUDY DESIGN: A retrospective clinical review, comparing pain status "before vs after" intervention. SETTING: National Cancer Institute in Mexico. METHODS: We included patients over 18 years old, with mild to severe pain due to metastasis in the proximal femur (trochanter, neck, or head), or with a high risk of fracture according to Mirels scale (> 8 points) or severe osteoporosis according to the World Health Organization (a Karnofsky score more than 50%). Exclusion criteria were femoral fracture. We recorded the following variables age, sex, type of neoplasm, concomitant therapy, We used the Karnofsky functionality scale, the VAS pain intensity assessment, the "Mayo Clinic" scale to measure improved functionality, and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 15 Palliative (EORTC QLQ-C15-PAL) (Spanish version) questionnaires. Follow-up was performed at 7 days, one month after femoroplasty, and during the individual outpatient that lasted one year on average. RESULTS: Eighty subjects were enrolled. Seventy-three percent were women. The most frequent tumors were breast (46.3%), followed by multiple myeloma (18.7%). All patients had a decrease in the intensity of pain, analgesic consumption, and improved quality of life, at 7 and 30 days after the intervention. There were no complications with serious consequences. Two participants experienced polymethylmetacrylate (PMMA) leakage, without clinical or functional impact. In 4 patients, the needle was occluded during the filling process and we had to place another biopsy needle through the same entry site to finish the injection process. LIMITATIONS: The sample was a single group of patients evaluated before and after the femoroplasty. We did not include a control group. CONCLUSION: The results of the current report suggest that femoroplasty, a percutaneous cement placement analogous to a vertebroplasty, might be a therapeutic option for patients with metastatic bone disease of the proximal femur, providing the patient an analgesic reduction and a better quality of life.

Evaluation of four biodegradable, injectable bone cements in an experimental drill hole model in sheep.

Four cement applications were tested in this investigation. Two dicalcium phosphate dihydrate (DCPD-brushite) hydraulic cements, an apatite hydraulic fiber loaded cement, and a calcium sulfate cement (Plaster of Paris) were implanted in epiphyseal and metaphyseal cylindrical bone defects in sheep. The in vivo study was performed to assess the biocompatibility and bone remodeling of four cement formulations. After time periods of 2, 4, and 6 months, the cement samples were clinically and histologically evaluated. Histomorphometrically, the amount of new bone formation, fibrous tissue, and bone marrow and the area of remaining cement were measured. In all specimens, no signs of inflammation were detectable either macroscopically or microscopically. Cements differed mainly in their resorption time. Calcium sulfate was already completely resorbed at 2 months and showed a variable amount of new bone formation and/or fibrous tissue in the original drill hole over all time periods. The two DCPD cements in contrast were degraded to a large amount at 6 months, whereas the apatite was almost unchanged over all time periods.

Calcium sulfate cement in contained traumatic metaphyseal bone defects.

The aim of this study was to evaluate prospective patients with periarticular fractures where a meta physeal bone defect was grafted with high compressive calcium sulfate cement. The calcium sulfate cement MIIG X3, (Wright Medical Technology, Inc, Arlington, TN) was used in 45 patients with periarticular fractures--distal radial, tibial plateau, humeral head, and calcaneal fractures--to fill the metaphyseal defect. All fractures were treated either with open or closed reduction, fracture fixation, and the cement was applied openly or closed. Radiographs were evaluated for fracture reduction, joint line gap, and step, as well as for rate of graft replacement by bone. All fractures united without an additional procedure. There were no wound infections or other complications attributed to the graft. At three-month follow-up, a complete graft replacement by bone was observed in all fractures. Joint line step was not developed in any patient, but a joint line gap of 3 mm was observed postoperatively in one patient with a tibial plateau fracture. Loss of reduction occurred in one patient with an extra-articular distal radial fracture treated with closed reduction and k-wire fixation. Cement that escaped into the joint or the surrounding soft tissues was not visible at the six-week follow-up. In conclusion, the results of this study confirm the safety and the efficacy of this cement when it is used as graft with the appropriate fixation method in traumatic metaphyseal bone defects.

Hemolysis and survival of autologous red blood cells salvaged after cemented and uncemented total hip arthroplasty.

Autotransfusion is widely used after total hip arthroplasty (THA), but there are concerns about damage of red blood cells (RBCs) collected after surgery. In this study, we wanted to determine the damage and survival of RBCs salvaged after cemented THA and after uncemented THA and to compare the results. In this prospective study of 60 patients-30 who underwent cemented THA and 30 who underwent uncemented THA-postoperative autotransfusion systems (BIODREN; B.E.R.C.O., Modena, Italy) were used. Levels of potassium and free hemoglobin in the postoperative blood samples were analyzed. Before transfusion, salvaged RBCs were labeled with radioactive chromium-51, and their survival was measured. In blood salvaged after cemented THA, medium potassium level was 4.1 mmol/L (range, 3.2-5.6 mmol/L), and mean free hemoglobin level was 327 mg% (range, 120-410 mg%). In blood salvaged after uncemented THA, mean potassium level was 4.2 mmol/L (range, 3.1-5.5 mmol/L), and mean free hemoglobin level was 296 mg% (range, 130-402 mg%). In the cemented group, RBC survival was 73% at 48 hours after transfusion (range, 61%-79%), and mean time from 100% activity to 50% activity was 21 days (range, 14.2-28.2 days). In the uncemented group, RBC survival was 75% at 48 hours after transfusion (range, 68%-82%), and mean time from 100% to 50% activity of radio-labeled RBCs was 22 days (range, 16.2-29.4 days). There were no statistically significant differences in potassium levels, free hemoglobin levels, or RBC survival between the cemented and uncemented groups. Blood salvaged after surgery was not significantly damaged. Our study results confirmed that washing blood collected after surgery is not necessary. Not washing this blood is safe and decreases allogeneic transfusion in orthopedic procedures.

Incorporation of methotrexate in calcium phosphate cement: behavior and release in vitro and in vivo.

The application of antibiotic-loaded calcium phosphate bone cement in the treatment and prevention of osteomyelitis suggests that calcium phosphate cement could also be used as an anticancer drug carrier to reduce the local recurrence of bone tumors and systemic toxicities of chemotherapy. We added 0 to 400 mg of methotrexate to 40 g cement, with final methotrexate concentrations of 0% to 1% (weight/weight). The setting times, mechanical properties, microstructures, and in vitro methotrexate release kinetics of these methotrexate-calcium phosphate bone cement specimens were evaluated, along with in vivo methotrexate release kinetics in 24 rabbits. Methotrexate did not significantly alter the cement setting time. The compressive and tensile strengths of the methotrexate-calcium phosphate bone cement specimens were significantly less when 400 mg methotrexate was used, compared to control samples without methotrexate addition. Nevertheless, the cement remained compliant with the minimum requirements for clinical application. The scanning electron microscopy micrographs showed that the basic crystal structure did not alter. The methotrexate release kinetics in vitro and in vivo confirmed that methotrexate-calcium phosphate bone cement was a monolithic matrix system, with a burst effect in the initial stage and a sudden drop thereafter. Drug delivery in vivo was faster than in vitro. We estimated that the incorporated methotrexate could be continuously released over 2 to 4 months at a higher than minimum concentration. The methotrexate had no apparent toxicity on the host rabbits, even at the highest dose of methotrexate tested. The methotrexate-calcium phosphate bone cement system may be a potentially effective therapy for bone tumors in humans.

Noncardiac surgery brain injury: etiologic factors and prevention.

EXCERPT: During total joint arthroplasty, showers of bony spicules, marrow fat, and clot are carried by venous blood to the lungs, creating conditions not unlike those present in patients who have suffered traumatic long bone fractures. There is recent evidence that, like the fat embolism syndrome (FES), which often has a component of neurologic dysfunction, total joint arthroplasty and femoral nailing are associated with intraoperative brain embolization as determined by transcranial Doppler ultrasonography, and magnetic resonance brain imaging. Although there are good data demonstrating that intraoperative brain embolization occurs during total joint arthroplasties, the makeup and, even more importantly, the clinical significance of these emboli remain speculative. Brain microemboli resulting from cardiac surgery occur by the millions and may cause focal ischemia resulting in significant neurologic dysfunction. Our studies suggest that the major source of these microemboli is lipid droplets of the patient's fat that drip into the blood in the surgical field. This lipid-laden blood is aspirated and then returned to the patient via the cardiopulmonary bypass (CPB) apparatus. Our investigations have focused on the causes (microemboli), consequences (brain damage), and strategies for elimination of brain lipid microemboli resulting from salvaged blood collected during surgery.

Successful transpedicular lumbar interbody fusion by means of a composite of osteogenic protein-1 (rhBMP-7) and hydroxyapatite carrier: a comparison with autograft and hydroxyapatite in the sheep spine.

STUDY DESIGN: Transpedicular lumbar interbody fusion (TLIF) was performed in a sheep model comparing three treatment groups: a composite of osteogenic protein (OP)-1 and hydroxyapatite carrier (HA), HA without OP-1, and autograft. OBJECTIVE: To evaluate the efficacy of the composite of OP-1 and HA (HA-OP-1) in achieving reliable TLIF. SUMMARY OF BACKGROUND DATA: Anterior fusion techniques directly address disc-related problems and achieve primary axial stability. However, they are characterized by high morbidity. Alternatively, the theoretically advantageous posterior TLIF technique using autograft fails clinically because it lacks compressive stability. METHODS: In 36 sheep, lumbar vertebrae L4 to L6 were instrumented posteriorly. Endoscopically assisted TLIF of L4 to L5 was performed. In 12 sheep, the defect was filled with injectable HA-OP-1. Another 12 sheep were treated with HA and another 12 with autograft. Animals were killed at 8 weeks and evaluated by radiologic, histologic, and histomorphometric analysis and by fluorochrome labeling. RESULTS: Only 10 autograft sheep were available for evaluation. Radiologically and histologically, TLIF with HA-OP-1 led to a fusion rate of 10 in 12 compared with autograft (one in 10 fused) and HA (two in 12 fused) ( = 0.0016). Semiquantitative radiologic and histologic scoring also revealed significant differences with superiority of HA-OP-1 ( = 0.0011). Compared with HA, HA-OP-1 presented significantly more ossification at the bone-cement interface ( = 0.0003) and less cement resorption ( = 0.0209). In four of 12 HA sheep, excessive resorption was responsible for local aseptic inflammation. CONCLUSIONS: Biointegration of the osteoconductive HA does not occur, because shear forces cause early HA fracture, subsequent fragmentation, and gross resorption (initiating severe inflammation in four of 12 sheep). In contrast, osteoinductive effects of HA-OP-1 enable bio-integration, resulting in full osseous composite sheathing and solid fusion. By use of this composite, TLIF is successfully applied in sheep. Harvesting autograft and the anterior approach are avoided.

[Successful treatment by PCPS of cardiac arrest related to the use of bone cement in cementedendoprosthesis of the femoral head: a case report].

A 65-year-old female with pulmonary tuberculosis and systemic sarcoidosis developed sudden cardiac arrest after the use of bone cement in cementedendoprosthesis of the femoral head. Cardiac arrest was difficult to manage with ordinary CPR and PCPS was immediately instituted. After resuscitation, the patient suffered from intraabdominal hemorrhage due to hepatic injury caused by CPR. On the 1st post-operative day the patient required surgical treatment to stop bleeding and was then weaned from PCPS. The patient required ventilatory support over next 7 days, but survived without neurological sequelae. When anesthetizing an elderly patient with preexisting cardiopulmonary disease for cementedendoprosthesis, PCPS should be considered in case of cardiac arrest due to the use of bone cement.

Percutaneous vertebroplasty with polymethylmethacrylate. Technique, indications, and results.

Percutaneous vertebroplasty with acrylic cement consists of injecting polymethylmethacrylate into vertebral bodies destabilized by osseous lesions. The aim is to obtain an analgesic effect by reinforcing lesions of the spine. The major indications are vertebral angiomas, osteoporotic vertebral crush syndromes, and malignant spinal tumors. The clinically significant complications occur predominantly in patients with spinal metastatics, but in the great majority of cases they resolve with medical treatment.

Thermal effects of acrylic cementation at bone tumour sites.

The use of acrylic bone cement as an adjunct to surgical excision of giant cell tumour of bone appears to reduce the incidence of tumour recurrence. Possible mechanisms for this apparent tumour inhibition include cytotoxic effects from the methylmethacrylate monomer and tissue hyperthermia from the heat of polymerization of the cement. This work presents a method for the prediction of temperature fields and resulting tissue necrosis arising from the implantation of polymethylmethacrylate (PMMA) at the site of a curretted giant cell tumour of bone. This is accomplished using a two-dimensional model based on geometry obtained from digitized MRI images of the distal femur. A general-coordinate, non-orthogonal grid generation technique is used and solutions are obtained with an alternating-direction implicit (ADI) finite-difference scheme. The nodal temperature histories are then used to evaluate the effect of variable defect size on the zone of thermally induced cell necrosis. The results suggest the depth of the necrotic region is quite sensitive to the size of the implant. In at least some cases, the heating effect is sufficient to cause significant necrosis of tumorigenic cells. Implanting a large mass of acrylic may risk overkill, damaging substantial amounts of healthy tissue.

Alumina as a filler for bone cement: a feasibility study.

A composite bone cement of Alcoa A-10 Alumina and very finely ground poly(methyl methacrylate) beads (PMMA) was fabricated. It was tested in an attempt to improve on the conventionally used pure PMMA bone cement. By knowing the densities of the powders and their volumes, the mass of each was calculated for the most efficient packing of PMMA and Al2O3 powders and a 65% PMMA: 35% Al2O3 ratio by weight composition was determined. This was tested, as well as the pure cement so comparisons could be made. Cylinders for the strength tests were also made of silane treated Al2O3. The compositions were tested for compressive and tensile strengths. The pure PMMA, composite and silane treated composite had compressive strengths of 79.64 +/- 13.0, 83.17 +/- 4.8, and 71.52 +/- 8.6 MPa and the tensile strengths were 6.69 +/- 0.6, 5.12 +/- 0.3, and 7.12 +/- 0.5 MPa respectively. Also the 65%-35% PMMA-Al2O3 composite required 64% less monomer for mixing than did the pure cement which is thought to be better for tissue healing. The maximum temperature attained from room temperature was 110 degrees-115 degrees C for both cements. The composite took 6.5 min longer to reach its peak temperature than did the pure cement. The bone cements were implanted for one week in a rabbit and both compositions seemed acceptable by the tissue.