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PubMed1983

[Comparative circulatory studies during implantation of total endoprostheses using methylmethacrylate and BDF cement].

In every ten patients undergoing elective surgery for total hip prosthesis methylmethacrylate and BDF cement respectively were used for the implantation of the prosthesis. The results of the haemodynamic investigation demonstrate that improvement of the surgical procedure may reduce the incidence of haemodynamic parameters: After implantation of methylmethacrylate into the femoral shaft the arterial pressure decreased from 95.9 +/- 13 to 86 +/- 11 torr (P less than 0.05); the left ventricular stroke work index dropped from 49.9 +/- 5 to 42.1 +/- 7 g.m/m2 (P less than 0.01). While total peripheral resistance decreased slightly in the methylmethacrylate group, there was a small increase after implantation of BDF cement into the femoral shaft. In both groups, however we found a slight elevation of pulmonary vascular resistance after cement implantation into the femur. The determination of the serum concentration of the cement monomer did not yield any measurable serum concentrations. Heat production by polymerisation of BDF cement (maximum 45.8 +/- 6.5 Centigrade) was much less compared with the temperature which developed during the polymerisation of methylmethacrylate (maximum 63 +/- 16.4 Centigrade); therefore, the safety of clinical application seems to be greater with the new BDF cement.

Aged↗
PubMed1982

Methylmethacrylate reconstruction of large iliac crest bone graft donor sites.

Often full-thickness iliac crest grafts are necessary for various reconstructive procedures. Sometimes large defects remain in the donor ilium subsequent to their removal. Several complications have occurred as a result of these bony defects. Although several reports have been published regarding the repair of iliac herniae, little has been written about procedures to prevent these complications. A technique was devised to reconstruct the ilium with methylmethacrylate. After preparation of the defect, malleable retractors are bent to conform to the contour of the iliac crest. Methylmethacrylate is then packed into the mold made by the retractors. After hardening, the methylmethacrylate casting of the defect is trimmed and routine soft tissue closure is performed. This technique has been used in eight patients without any complications. The appearance of the waist and crests has been excellent; there have been no fractures or displacements of the mass of cement and there have been no infections. All these reconstructions have been mechanically stressed as all patients had well molded postoperative casts and/or braces. Reconstruction of the ilium with methylmethacrylate after removal of full-thickness grafts appears to be a reliable, safe, and easy technique based on a short-term follow-up of up to three years.

Adolescent↗
PubMed1993

Audiometric thresholds in osteomyelitis patients treated with gentamicin-impregnated methylmethacrylate beads (Septopal).

Use of gentamicin-impregnated methylmethacrylate beads is a relatively new and effective method of treating osteomyelitis. Although previous studies have concluded that such therapy is associated with low systemic toxicity, no data are available relating the use of this treatment to ototoxicity and hearing loss. Audiometric thresholds from 28 cases of osteomyelitis treated by surgical debridement and long-term systemic antibiotics alone (14 subjects) or gentamicin-impregnated methylmethacrylate beads either alone or combined with systemic antibiotics (14 subjects) were analyzed. Results showed one permanent threshold shift in the gentamicin-impregnated methylmethacrylate beads group (8%) versus four permanent threshold shifts in the systemic antibiotics alone group (29%). Osteomyelitis patients treated with gentamicin-impregnated methylmethacrylate beads are at no more risk and are probably at less risk of experiencing ototoxicity than patients treated with conventional long-term systemic antibiotics.

Adult↗
PubMed1986

[Determination of methylmethacrylate in expired gases after hip prosthesis cementing].

Total hip replacement using methylmethacrylate can induce early intraoperative hypoxaemia caused, according to some authors, by alveolar gas dilution by acrylic monomer vapour. In order to test this hypothesis, expired monomer was measured in ten patients undergoing total hip replacement carried out under narconeuroleptanalgesia. Methylmethacrylate was collected by adsorption on activated charcoal and measured by gas chromatography. The quality of expired monomer was 25 +/- 10 micrograms after cotyloid sealing. It is of 264 +/- 396 micrograms after femoral sealing; the most important excretion took place in the first three minutes, and its total duration may exceed 18 min. A simple calculation showed quite convincingly that the volume of expired monomer vapour was not sufficient to explain the hypoxaemia: impaired arterial oxygenation associated with the use of methylmethacrylate is not due to a dilution technique.

Aged↗
PubMed1989

Fixation of fractures of the lower cervical spine using methylmethacrylate and wire: technique and results in 99 patients.

Surgical stabilization of traumatic fracture-dislocations of the lower cervical spine with wire and methylmethacrylate remains a controversial procedure. Yet, the resultant immediate fixation with minimal patient morbidity seems to indicate that this method provides an ideal stabilization construct. We describe and report the outcome of a technique of posterior cervical fixation with methylmethacrylate and wire for stabilization of traumatic fractures of the lower cervical spine. Over a 12-year period, 124 fracture-dislocations of the lower cervical spine in 99 patients (mean age, 32 years; range, 15-76 years) were treated at this institution using a posterior methylmethacrylate and wire technique. Eighty-two patients had a posterior element fracture; 28 had a vertebral compression with posterior ligamentous injury; and 14 had a ligamentous injury alone. Thirty-six patients were neurologically intact upon admission, while the rest had radiculopathy or partial or complete myelopathy. Ninety-one patients were available for follow-up [mean, 18.6 months; range, 1-100 months (8.33 years)]. Eighty-eight patients (97%) had a stable fixation and 77 (85%) had resumed preoperative activity or were working but with a residual deficit. Complications included fixation failure requiring a second operation in 3 patients, nonlethal pulmonary embolism in 2 patients, lethal pulmonary embolism in 1 patient, and a superficial wound infection in 3 patients (none affected the underlying fixation construct). These results indicate that this technique is a safe, simple, and effective method for stabilizing the lower cervical spine that allows rapid patient mobility with minimal morbidity.

Adolescent↗
PubMedDate not supplied

[Changes in the secretion of gonadoliberin, gonadotropins, and ovarian hormones in rats under chronic exposure to low concentrations of methylmethacrylate].

Chronic influence of small concentrations of methylmethacrylate in inhalations (at the level of a maximum permissible dose of 50 mg/m3 and in its 10-fold excess) after short-term enhancement of the hypothalamo-hypophyseo-gonad system (in one month after exposure to a dose at maximum permissible concentration) is quickly followed by suppression of its function. The use of methylmethacrylate for 4 months revealed a decrease in ovarian mass, the blood level of progesterone and a rise of secretion of FSH and LH with a simultaneous decrease in the level of gonad-releasing hormone in the mediobasal hypothalamic structures. It indicates primary gonad damage of the reproductive system and preservation of a normal reaction of the hypothalamohypophyseal factor, responding by activation on the feedback principle. In 4 months a high embryotoxic and teratogenic effect of methylmethacrylate was observed.

Animals↗
PubMed1986

Inhibition of isoproterenol positive atrial chronotropic effect by methylmethacrylate polymer and monomer.

Atria from rats exposed in vivo to methylmethacrylate polymer or monomer were superfused and chronotropic responses to isoproterenol determined. Control and polymer-exposed atria superfused with oxygen-saturated buffer yielded dose-response curves which were essentially identical with regard to maximal increase and potency of isoproterenol. Control atria superfused with buffer containing 70% of possible oxygen saturation showed a 10-fold decrease in isoproterenol potency and a maximal effect approximately 75-80% that of fully oxygenated atria. Atria exposed to methylmethacrylate polymer and superfused with 70% oxygen saturated buffer showed a 100-fold decrease in isoproterenol potency and a maximal effect approximately 25% that of fully oxygenated control atria. Exposure of rats to methylmethacrylate monomer in vivo resulted in complete abolition of the chronotropic response to isoproterenol in atria superfused with 70% oxygen saturated media.

Animals↗
PubMed1985

Methylmethacrylate blood levels in patients with femoral neck fracture.

The blood levels of monomeric methylmethacrylate were measured in 20 patients with fracture of the femoral neck, treated with a Thompson prosthesis under spinal anesthesia. Monomeric methylmethacrylate was detected in the blood stream in all patients; the maximum levels (mean 6.44 micrograms/ml, range 0.05-31.89 micrograms/ml) were measured 30 s after insertion of the Thompson prosthesis. A moderate drop in systolic blood pressure and a marked reduction of arterial oxygen tension was noted after cementation and insertion of the prosthesis; the mean maximum drops were 10.1 mm Hg (range 0-32 mm Hg) and 6.1 mm Hg (range 0-13.5 mm Hg) No dose-dependent correlation could be established between the levels of monomeric methylmethacrylate and the drop in arterial blood pressure or arterial oxygen tension.

Aged↗
PubMed1979

Effects of monomeric methylmethacrylate on ocular tissues.

Toxic effects of high doses of monomeric methylmethacrylate were demonstrated in rabbit eyes. These effects were not related to surgical manipulation. Monomeric methylmethacrylate caused limbal hyperemia, corneal edema, corneal neovascularization, iris engorgement, anterior chamber inflammation, iris atrophy, and cataract. The doses of monomeric methylmethacrylate needed to produce these lesions were much higher than the amount of monomer available for leaching out of implanted intraocular lenses.

Animals↗
PubMedDate not supplied

Does the use of methylmethacrylate cement in total shoulder replacement induce hemodynamic or pulmonary instability?

STUDY OBJECTIVE: To investigate whether the use of methylmethacrylate cement causes hemodynamic or pulmonary instability during total shoulder replacement surgery. DESIGN: Prospective, nonrandomized study. SETTING: Operating room. PATIENTS: 9 ASA physical status I and II patients. INTERVENTIONS: A 20-gauge radial artery catheter was placed in the wrist opposite the surgical site. Sedation with midazolam was provided, and a pulmonary artery catheter was placed through an 8.5-Fr introducer into the patient's right internal jugular vein. MEASUREMENTS AND MAIN RESULTS: Before induction of anesthesia, systolic, diastolic, and mean arterial blood pressures; heart rate; central venous pressure; systolic, diastolic, and mean pulmonary artery pressures; pulmonary capillary wedge pressure; and thermodilution cardiac output measurements were obtained. Arterial and mixed venous blood gas samples also were collected and analyzed for calculation of Qs/Qt. These hemodynamic and pulmonary parameters were measured again just before cementing of each prosthesis with methylmethacrylate cement and at 1, 5, 10, and 20 minutes after cementing. There were no statistically significant changes in any of the measured hemodynamic parameters at any time. There was no statistically significant difference in the calculated intrapulmonary shunt fraction. CONCLUSION: In this study population, the use of methylmethacrylate for total shoulder replacement was not associated with adverse hemodynamic events or increased intrapulmonary shunting.

Aged↗
PubMed2000

Functional assessment of chest wall integrity after methylmethacrylate reconstruction.

BACKGROUND: All patients with extensive resection of the anterolateral chest wall and the sternum followed by reconstruction with methylmethacrylate substitutes were assessed prospectively 6 months after the operation to delineate chest wall integrity with pulmonary function and cine-magnetic resonance imaging. METHODS: Twenty-six patients underwent chest wall reconstruction by use of methylmethacrylate between 1994 and 1998 due to primary tumors in 35%, metastases in 27%, T3 lung cancer in 19%, and debridement for radionecrosis and osteomyelitis in 19% of patients. Three to eight ribs were resected and additional sternum resection was performed in 39% of patients. RESULTS: There was no 30-day mortality. All patients were extubated after the operation without need for reintubation. Prosthesis dislocation occurred in 1 patient and infection in 2 patients during follow-up. Nineteen patients (73%) suffered no restrictions of daily activities. Clinical examination revealed normal shoulder girdle function in 77% of patients. There was no significant difference between preoperative and postoperative FEV1 (forced expiratory volume in 1 second) measurements in patients with lobectomy or wedge resections. Cinemagnetic resonance imaging revealed concordant chest wall movements during respiration in 92% of patients without paradoxical movements or implant dislocations being observed. CONCLUSIONS: Large defects of the anterolateral chest wall and sternum can be reconstructed efficiently with methylmethacrylate substitutes with minimal morbidity and excellent cosmetic and functional outcome.

Adult↗
PubMed1994

Methylmethacrylate bone cement does not release histamine in patients undergoing prosthetic replacement of the femoral head.

This study was designed to see if methylmethacrylate monomer bone cement released histamine in 13 patients undergoing total hip replacement surgery with a cemented prosthesis, compared with seven control patients receiving a cementless porous-coated prosthesis. Blood samples for plasma concentrations of histamine were obtained before the start of anaesthesia, immediately before insertion of methylmethacrylate bone cement into the shaft of the femur in the cemented fixation group or before insertion of the femoral component of the prosthesis in the cementless fixation group, and 15, 30 and 60 min after the start of implantation of the prosthesis. In both groups, changes in plasma histamine did not differ significantly from baseline before implantation of cement. There were no significant differences between groups. We conclude that methylmethacrylate bone cement does not release histamine during total hip replacement surgery.

Aged↗
PubMedDate not supplied

The evolution of stability in cervical spinal constructs using either autogenous bone graft or methylmethacrylate cement. A follow-up report on a canine in vivo model.

Thirty-six adult mongrel dogs underwent either a posterior C4-C5 bone graft or methylmethacrylate-cerclage wire construction procedure to simulate the analogous human stabilization procedures. The dogs were divided into groups of six and allowed to live 1, 2, or 3 months after surgery. At the appropriate time they were killed and their C4-C5 spinal segments excised and studied radiologically, mechanically, and histologically. In addition, the C4-C5 spinal segments from 15 other mongrel dogs were excised and either left intact as normal (five) or prepared as one of the two constructs (five each) described above. They were also tested mechanically to provide immediate postoperative stability data. At some time during the first postoperative month the methylmethacrylate constructs lost mechanical stability. In addition, fibrous tissue was noted to have grown between the posterior laminal surface and the cement mass during this same time. Radiologically, loosening was obvious by the second postoperative month. The bone graft constructs were mechanically equivalent to or superior to the normal dogs by the second postoperative month. Likewise, they were well on their way to solid fusion radiologically and histologically by the same time. Impressed by the rapidity of deterioration in mechanical stability for the methylmethacrylate constructs, the authors further questioned their usefulness in cases of traumatic cervical spinal instability. The bone graft constructs continued to appear to be a reliable way to achieve ultimate spinal stability.

Animals↗
PubMedDate not supplied

Posterior cervical fusions using cerclage wires, methylmethacrylate cement and autogenous bone graft. An experimental study of a canine model.

UNLABELLED: Forty-eight adult mongrel dogs underwent posterior exposure of C4-C5, fixation of the two posterior spinous processes together with a no. 20-gauge cerclage wire, posterior element decortication, wound irrigation and the following: bone fusions (application of a standard volume of iliac crest autograft), polymethylmethacrylate (PMMA) fusions (application of a standard volume of methylmethacrylate cement), Combination 1 fusions (application of one-half the volume of graft used in the bone fusions, over the facet joints. Methylmethacrylate cement was pressed into position centrally to surround the posterior spinous processes and cerclage wire), Combination 2 fusions (application of the same volume of graft used in the bone fusions, over the facet joints. Methylmethacrylate cement was applied as in the Combination 1 fusions). For each preparation, six animals survived 2 weeks or 3 months. All had monthly lateral cervical radiographs. At the appropriate times, they were killed and their C4-C5 segments excised and studied mechanically and histologically. At 2 weeks all of the above preparations were mechanically inferior to normal C4-C5 segments in respect to at least one of the parameters studied. At 3 months, the bone fusions and both combination fusions had developed sufficient mechanical stability so that they were equivalent to normal segments. At this time, the PMMA fusions remained inferior to the "normals." The mechanical data for the PMMA and both combination fusions was corroborated by the histology which demonstrated a fibrosynovial layer between the cement masses and underlying posterior element bone. In the 3-month combination fusions, the lateral aspects of the posterior elements had been spanned by a fusion mass. CLINICAL RELEVANCE: Previously, the authors defined some of the problems associated with constructs modeled by their PMMA fusions. This work confirms the previous research. It also demonstrates that ultimate spinal stability is produced by combination constructs. Because of the 2-week mechanical data, it is recommended that when combination constructs are used clinically, the patient's neck be protected by an external orthosis in the early postoperative period.

Animals↗
PubMed1982

Viability and osteogenicity of bone graft coated with methylmethacrylate cement.

The idea of utilizing bone grafts during hip arthroplasty has been discussed in the literature and clinical successes have been indicated. These communications, however, did not relate to long-term results. Thus, to date, we still lack sufficient understanding as to the fate of bone grafts when they are coated with methylmethacrylate. In order to elucidate the above issue further an experimental study has recently been initiated in an attempt to provide answers to the following questions: a) do bone grafts remain viable when they are held in place with methylmethacrylate bone cement? and b) do such grafts retain their osteogenic potential? In the present study osteotomies were made in the femora of dogs and cortico-cancellous strips of autogenous bone were placed around the osteotomy site. The grafts were then surrounded by polymethylmethacrylate bone cement. Mechanical examination and morphological studies, performed 3, 6 and 10 months following surgery, revealed the elaboration of fibro-osseous union. Our present findings tend to indicate that bone grafts, even if they are covered with methylmethacrylate bone cement, still retain their viability as well as their osteogenic potential.

Animals↗
PubMed1978

The effect of methylmethacrylate on the bacterial inhibiting properties of normal human serum.

In vitro evaluation of the effect of known concentrations of methylmethacrylate on the bacterial inhibiting properties of normal human serum has been carried out. In low concentrations, methylmethacrylate was found to abolish almost completely the growth inhibition of Staphylococcus epidermidis by normal human serum. Normal human serum did not have an effect on growth of Staphylococcus aureus. It did inhibit growth of Escherichia coli, but there was no reversal of this effect by methylmethacrylate.

Bacteria↗
PubMed1978

The effect of methylmethacrylate on bacterial phagocytosis and killing by human polymorphonuclear leukocytes.

The phagocytic and bactericidal activities of human polymorphonuclear leukocytes in the presence of methylmethacrylate were determined by in vitro techniques. It was found that methylmethacrylate in concentrations as low as 0.156 per cent significantly decreased the ability of leukocytes to phagocytose and kill strains of Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli. The evidence indicates that methylmethacrylate impairs the killing more than the phagocytosis by the leukocytes.

Blood Bactericidal Activity↗
PubMed1977

The effect of methylmethacrylate on complement activity.

The effect of methylmethacrylate on the activity of the complement sequence has been investigated in vitro by standard hemolysis techniques. It was demonstrated that concentrations of methylmethacrylate monomer as low as .25% inhibit the reactions of the complement sequence by 50%. Methylmethacrylate concentrations of 2.5 to 5.0% abolished all complement activity. This effect is on the late-acting components of the complement sequence which are important for chemotaxis of polymorphonuclear leukocytes, immune adherence of bacteria to polymorphonuclear leukocytes, phagocytosos of bacteria by polymorphonuclear leukocytes, and bacteriolysis.

Bacteria↗