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At least 487 records · Page 27Linked to original sources

Treatment of the infected total knee arthroplasty with insertion of another prosthesis. The effect of antibiotic-impregnated bone cement.

Eighty-six patients with 89 infected total knee arthroplasties were treated with insertion of another prosthesis. Treatment was not according to an established protocol for parameters, such as delay between removal of the infected prosthesis and insertion of the new prosthesis, duration of antibiotics, use of antibiotic-impregnated cement spacers or beads, and use of antibiotic-impregnated cement for prosthetic fixation at revision surgery. Final followup averaged 52 months (range, 6-126 months). Complications occurred in 30 (33.7%) knees, with recurrent deep infection developing in 10 (11.24%) knees. Patient age, medical diagnosis, type of microorganism, duration of parenteral antibiotics, delay between the resection and revision surgery, and use of antibiotic-impregnated cement spacers or beads were not correlated with the cure rate of infection. Use of antibiotic-impregnated bone cement for prosthesis fixation at revision surgery was the only variable that correlated with the cure rate of deep infection. Seven (28%) of the 25 knees without antibiotic-impregnated cement for prosthesis fixation developed recurrent infection compared with 3 (4.7%) of 64 knees with antibiotic-impregnated cement for prosthesis fixation. This difference was statistically significant (p = 0.0025, log-rank test).

Adult↗

[Experiences with the Groningen voice prosthesis after laryngectomy].

The tracheoesophageal puncture technique with insertion of a valved prosthesis for speech rehabilitation after total laryngectomy is a reliable and simple procedure for successful vocal rehabilitation. The available voice prosthesis can be separated into indwelling and non-indwelling types. The details of the indwelling long-term prostheses (low-pressure Groningen Prosthesis, Nijdam, prosthesis, Provox prosthesis) are discussed. These prostheses need limited patient care. Replacement of the indwelling prosthesis is a simple out-patient procedure, although it is best performed by an ENT-specialist. The local complication rate is low and generally not significant. Hand-free speech is now possible by placement of a tracheostoma valve. Current experiences are encouraging for continued use.

Contraindications↗

[The Sixtine metatarsophalangeal prosthesis at first glance. Preliminary results in 74 cases].

The Sixtine prosthesis is a metallic, hemiconical, flat concave, metatarsophalangeal interposition prosthesis, with a rim on the phalangeal end, with a lateral capsular fixation or a temporary fixation by axial pinning. Seventy-four cases using a Sixtine prosthesis were reviewed with a minimum follow-up of 2 years. The range of motion was improved (+12.4 degrees), as was the phalangeal valgus (18.2 degrees for 30.2 degrees), but weight bearing on the ventral side of the first toe was very often lost in spite of the complete preservation of the flexor hallucis brevis. The complication rate was 9.5% with 8% subluxations, which do not influence the final result. The comparison of patients who kept the prosthesis, and of patients in whom the prosthesis was systematically retrieved after one year, shows that the prosthesis may be left in place and that retrieval is only indicated in cases of complications or subluxation.

Adult↗

Implant position record and implant position cast: minimizing errors, procedures and patient visits in the fabrication of the milled-bar prosthesis.

This article describes a new rationale and method involved in the fabrication of a patient detachable prosthesis supported by a milled bar. This simple procedure improves prosthesis retention. The overdenture is processed directly over a milled bar, which provides an intimate relation between the bar and the acrylic resin denture base to create resistance against rotational and lateral forces acting on the prosthesis. Incorporating simple and predictable attachments, with low maintenance needs, controls resistance to dislodgment along the path of insertion of the prosthesis. The concepts used in the fabrication of the milled bar include an implant position record (IPR) and an implant position cast (IPC) to reduce the need for time-consuming procedures, such as sectioning the cast bar and soldering it to make it fit the abutments. This procedure also reduces the number of patient visits required of the completion of the prosthesis.

Dental Abutments↗

Primary Souter-Strathclyde total elbow prosthesis in rheumatoid arthritis.

BACKGROUND: Total elbow arthroplasty is a well-established treatment for the painful elbow joint in patients with rheumatoid arthritis. We present the results of what we believe to be the first prospective study of the Souter-Strathclyde total elbow prosthesis. METHODS: Between June 1982 and December 2000, 204 primary total elbow prostheses were inserted in 166 patients who had rheumatoid arthritis. No patient was lost to follow-up. The mean duration of follow-up was 6.4 years. All patients were examined preoperatively, at one and two years postoperatively, and at regular intervals thereafter. RESULTS: Six of the 204 elbows had pain at rest at the time of the latest follow-up. Ten patients (ten elbows) without previous neurological symptoms had development of paresthesias in the distribution of the ulnar nerve postoperatively. Patients who had pain at rest or at night and those who had ulnar nerve symptoms preoperatively were found to have a significant chance of having the same complaints postoperatively. Pain at rest or at night and a decrease in function during the follow-up period were associated with humeral loosening. Twenty-four elbows had revision of the total elbow prosthesis because of loosening of the humeral component (ten), loosening after fracture (six), dislocation (four), infection (two), restricted range of motion (one), or fracture of the middle part of the humeral shaft, proximal to the prosthesis (one). One prosthesis was removed because of humeral loosening, and eight were removed because of deep infection. Another five prostheses were radiographically loose at the time of the latest follow-up. The rate of implant survival, according to the method of Kaplan-Meier, was 77.4% after ten years and 65.2% after eighteen years. CONCLUSIONS: Total elbow replacement is associated with a high complication rate and therefore may be warranted only for seriously disabled patients. Currently, the results associated with the Souter-Strathclyde total elbow prosthesis are comparable with the results associated with other prostheses, but loosening of the humeral component remains a concern. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Activities of Daily Living↗

Influence of prosthesis fit and the effect of a luting system on the prosthetic connection preload: an in vitro study.

PURPOSE: It was the aim of this study to evaluate the efficiency of a luting technique that is said to compensate for misfits of implant-supported prostheses by means of a combined screw retained-luted fixation of the prostheses to the supporting abutments. MATERIALS AND METHODS: One three-unit prosthesis was made on cylindric abutments, and one was made on conical abutments. Two more prostheses were made, one on the cylindric and one on the conical abutments, with the luting system. The preload was measured in different fit and misfit situations, with and without the use of the luting system. The preload is a combination of internal preload (positive axial forces), which is a clamping load that keeps the implant-prosthesis components together, and external preload (axial forces and bending moments), which is the result of a deformation of the implant-prosthesis complex during fixation caused by prosthesis misfit. The external preload on the supporting abutments after screw tightening the prostheses was used as an indicator for the quality of fit of the prostheses. RESULTS: The axial forces were lower and the bending moments were higher in cases of misfit in comparison with the optimal fit situation. The luting system generally did not decrease the registered external preload. Except for one test condition, even higher bending moments were registered on the supporting abutments when the luting system was used. CONCLUSION: For the prostheses evaluated in this study, the luting system was not effective in reducing the external preload on the supporting implants caused by prosthesis misfit. Although the luting system could compensate for visual misfit, it failed to really improve the load conditions of the supporting implants.

Cementation↗

The effect of the Angelchik prosthesis on esophageal and gastric function.

The effects of the Angelchik prosthesis on esophageal and gastric function were investigated in 17 patients (11 men and six women; median age, 57 years; age range, 36 to 88 years) who underwent surgery for treatment of gastroesophageal reflux disease. All patients demonstrated unequivocal reflux, either at endoscopy or 24-hour pH testing. There was a significant increase in lower esophageal sphincter pressure after surgery, and no patient demonstrated abnormal reflux on pH testing. Gastric emptying of liquids and solids was not altered by surgery. Six months after surgery, all symptoms except dysphagia had significantly improved. Thirty-three months after surgery, six patients described symptoms as severe as or worse than those before surgery. Four patients had the prosthesis removed, two because of dysphagia alone, one because of reflux and dysphagia, and one because of flatulence and bloating. The patients who required removal of the prosthesis because of dysphagia had gross delay of esophageal emptying. We conclude that the Angelchik prosthesis is an effective antireflux device, but it interferes with esophageal function in some patients, requiring removal of the prosthesis. We think the rate of removal of the prosthesis is too high for its routine use in the treatment of gastroesophageal reflux disease.

Adult↗

Upper dental prosthesis instability consecutive to the resection of a cerebral tumor.

A 57-year-old female patient was evaluated for an unstable maxillary dental prosthesis. The patient stated that approximately 2 weeks prior to this consultation the prosthesis was relined four times. Despite this, it often had a tendency to shift during meals. On the other hand, she is very satisfied with a complete fixed prosthesis on implants in the mandibular arch. She has been wearing this latter lower prosthesis for the same length of time as the upper prosthesis. She indicated that a similar problem existed with the former upper prosthesis, resulting in her consulting a prosthodontist.

Brain Neoplasms↗

Role of loads and prosthesis material properties on the mechanics of the proximal femur after total hip arthroplasty.

The objective of this study was to establish the role of loads and prosthesis material properties on the mechanics of the proximal femur after total hip arthroplasty. We developed a three-dimensional finite element model of an intact human femur and the same femur with a conventional collared straight-stem femoral component. Using published data, we defined two sets of loading conditions: one that represented three phases of gait, and one that represented four different extreme loads. The four extreme loads were based on the peak joint contact forces that occur during stair ascent and isometric contraction of various muscle groups. The model was analyzed with three different material properties for the prosthesis, including cobalt-chromium alloy, titanium alloy, and a carbon fiber-reinforced polymer (CFRP) laminate. We assumed that the implant was stable, with rigid bonding, collar contact, and no cement. To address femoral component loosening, we examined the shear stresses at the implant-bone interface; to address adaptive bone remodeling, we examined the principal stresses in the supporting cortical bone relative to those in the intact femur. Our analyses of the various loading conditions demonstrated large out-of-plane bending movements and torsional moments, especially for the load representing stair ascent. Based on stepwise multiple regressions, the maximum shear stresses at the implant-bone interface in the distal region were dependent on the total applied axial force and torsion; the maximum shear stresses in the proximal region were dependent on the axial component of the joint contact force alone. Reduction in the prosthesis stiffness, by substitution of the CFRP material properties, resulted in lower interface shear stresses at the distal end of the stem and higher interface shear stresses at the more proximal sections, consistent with the findings of others. We fit equations, based on composite beam theory, to the maximum implant-bone interface shear stresses and the cortical bone principal stresses as a function of the axial modulus of the prosthesis. These equations can be used to estimate the maximum stresses at the interface and in the cortical bone that would be predicted by similar models, for the same prosthesis constructed of alternative materials, relative to the stresses in the intact femur. The nonlinear nature of these relationships was such that the cortical bone stresses changed more rapidly, as a function of the prosthesis modulus, for lower values of elastic modulus, especially in the more proximal sections.

Biomechanical Phenomena↗

Cardiovascular management of pregnant women with a heart valve prosthesis.

This study of 14 pregnancies in 11 patients with a Starr-Edwards valve prosthesis (nine mitral, two aortic) shows that cardiac functional capacity deteriorated to class III (New York Heart Association criteria) in only 1 woman. The deterioration occurred during the third trimester and the patient's condition improved with medical therapy. Careful medical control diminished the incidence of heart failure in these patients. Six of nine pregnant women with a mitral valve prosthesis were treated continuously with coumarin and three discontinued the therapy gradually before the third trimester of pregnancy. In five pregnant women (three with an aortic valve prosthesis, two with a mitral valve prosthesis) no anticoagulant agents were used. No embolic episodes or severe hemorrhagic complications were seen. One newborn whose mother received coumarin during the first trimester had bilateral hand polydactylia. There were no maternal deaths. One neonate died after fetal stress necessitating the only cesarean section. These results suggest that women with an artificial heart valve tolerate pregnancy well and that anticoagulant therapy is not mandatory in pregnant women with an aortic valve prosthesis, or in the few women with a mitral valve prosthesis not already receiving coumarin at the onset of pregnancy.

Adult↗

Comparison of noninvasive techniques in evaluation of the nontissue cardiac valve prosthesis.

The ability of bedside auscultation, echophonocardiography and cinefluoroscopy to detect prosthetic valve malfunction was compared in 81 patients with a Bjork-Shiley aortic or mitral valve prosthesis or a Beall mitral valve prosthesis. In 32 patients with an abnormal mitral valve prosthesis proved by cardiac catheterization, the sensitivities of auscultation, echophonocardiography and cinefluoroscopy were 94, 78 and 88 percent, respectively. In 25 patients with a normal mitral valve prosthesis, the specificities were 96, 64 and 89 percent, respectively. Twelve patients had an abnormal aortic valve prosthesis; the sensitivities of auscultation, echophonocardiography and cinefluoroscopy were 92, 58 and 33 percent, respectively. In 12 patients with a normal aortic valve prosthesis, the specificities were 100, 75 and 92 percent, respectively. Auscultation can detect almost all cases of malfunction of nontissue prosthetic valves. Echophonocardiography and cinefluoroscopy can detect most cases of malfunction of mitral valve prostheses, but false positive studies are common; both procedures are less useful in detecting malfunction of aortic valve prostheses.

Aortic Valve↗

Light-cured combination obturator prosthesis.

A technique for the fabrication of an open combination (hard-resilient) obturator prosthesis with VLC materials for patients undergoing partially edentulous maxillectomy is described. VLC denture resins and resilient liners are an exciting innovation in prosthodontic treatment and offer the maxillofacial prosthodontist a wider choice of treatment modalities. The technique and the resultant obturator prosthesis have the following advantages: 1. The ease and rapidity of the technique saves time for both the patient and the maxillofacial prosthodontist by introducing the open obturator prosthesis at the earliest opportunity. 2. The combination open obturator prosthesis provides a stable record base for securing jaw relation records. 3. The thickness and resiliency of the obturator prosthesis can be managed more easily. Flexibility and resiliency can be modified by the thickness of the resilient liner or by adding a rigid scaffolding according to the clinical requirements. 4. Prostheses are easy to repair or modify by using increments of VLC hard or resilient materials. 5. The combination VLC obturator prosthesis provides stability, retention, and decreased weight and obduration of residual palatal defects. 6. The technique can be used for partially edentulous or edentulous patients after maxillary resection.

Acrylic Resins↗

Effect of a femoral head prosthesis on megavoltage beam radiotherapy.

A few patients undergoing pelvic irradiation present with a prosthetic hip. The presence of this metal object often interferes with the lateral treatment fields if a four-field box irradiation technique is used. Measurements of the effect such a prosthesis may have on the dose delivered to the pelvis for beams of 60Co gamma rays and 10 MV and 25 MV X-rays, as a function of field size and depth have been made. The results show a strong variation in the dose behind the prosthesis depending on the position of the measurement, with little or no increase through the center of the head or ball, but a sharp drop either around its circumference or along the stem of the prosthesis. Measurements made with ionization chambers through the head of the prosthesis indicate an average dose decrease of approximately 2% for 25 MV X rays and average increases of approximately 2% for 10 MV X rays and 5% for 60Co. There is little variation with field size and depth except close to the prosthesis, at 25 MV. Measurements also indicate an increase in dose close to the upstream surface of the prosthesis at all energies, but in the downstream direction, only the data at 25 MV shows an increase.

Hip Prosthesis↗

Experimental study of replacing circumferential tracheal defects with new prosthesis.

PURPOSE: To investigate the feasibility of using a new tracheal prosthesis made of biomaterials to replace extensive circumferential tracheal defects. DESCRIPTION: Three types of tracheal prostheses were developed and studied. Type I prosthesis was used in 8 mongrel dogs (group A), type II in 4 dogs (group B), and type III in 4 dogs (group C). EVALUATION: In group A, one died from prosthetic dehiscence, another from anastomotic leakage, and the others had uneventful postoperative courses. The implanted prosthesis was completely incorporated with the recipient trachea, where different lengths of reepithelialization occurred on the luminal surface of the reconstructed trachea. Macroscopic examination showed scattered and different sizes of neo-ossification surrounding the implanted prosthesis. The prosthesis was radioopaque when exposed to routine x rays. In contrast, a relatively high number of complications occurred postoperatively in groups B and C. CONCLUSIONS: Type I tracheal prosthesis, with further improvements, may be the optimal tracheal graft to replace circumferential tracheal defects, and appears very promising for clinical application.

Anastomosis, Surgical↗

Neer Award 2005: The Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty.

This clinical study was performed to analyze the midterm results and potential complications of the reverse prosthesis in different diagnosis. Forty-five consecutive patients with Grammont prosthesis were evaluated clinically and radiographically with a mean follow-up of 40 months (range, 24-72 months). The indication was a massive and irreparable cuff tear associated with arthrosis (CTA) in 21 cases, fracture sequelae (FS) with arthritis in 5 cases, and failure of a revision arthroplasty (revision) in 19 cases. Fourteen complications occurred in 11 patients. 3 dislocations, 3 deep infections (all 3 in the revision group), 1 case of aseptic humeral loosening, 2 periprosthetic humeral fractures, 1 intraoperative glenoid fracture, 1 wound hematoma, 2 late acromial fractures, and 1 axillary nerve palsy. Of the patients, 10 (22%) required further surgery: 4 reoperations, 4 prosthesis revisions, and 2 prosthesis removals. Complications were higher in revision than in CTA (47% vs. 5%). All 3 groups showed a significant increase in active elevation (from 55 degrees preoperatively to 121 degrees postoperatively) and Constant score (from 17 to 58 points) but no significant change in active external rotation (from 7 degrees to 11 degrees ) or internal rotation (S1 preoperatively and postoperatively). Of the patients, 78% were satisfied or very satisfied with the result and 67% had no or slight pain. However, the postoperative Constant score, adjusted Constant score, and American Shoulder and Elbow Surgeons shoulder score were all significantly higher in the CTA group with as compared with the revision group (P = .01, .004, and .002, respectively). Scapular notching was seen in 24 cases (68%). No glenoid loosening was observed at current follow-up, even when the notch extended beyond the inferior screw (28% of cases). Atrophy of severe fatty infiltration of the teres minor was associated with lower external rotation (15 degrees vs 0 degrees , P = .02) and lower functional results (Constant score of 46 points vs 66 points, P < .007). The Grammont reverse prosthesis can improve function and restore active elevation in patients with incongruent cuff-deficient shoulders; active rotation is usually unchanged. Results are less predictable and complication and revision rates are higher in patients undergoing revision surgery as compared with those in patients with CTA. Results of the reverse prosthesis depend on the diagnosis and on the remaining cuff muscles, specifically the teres minor. Surgeons should be vigilant with regard to low-grade infection in revision surgery.

Aged↗

Survival analysis of rats implanted with porous titanium tracheal prosthesis.

BACKGROUND: Surgical treatment of a malignancy in the trachea may lead to a long resection that has to be reconstructed with an artificial prosthesis. However, most of the available prostheses encounter inflammatory rejection and mechanical constraint problems. To improve tracheal rehabilitation a porous titanium prosthesis was developed. The aim of this study was to test the biocompatibility of this novel material. METHODS: Seventeen rats had a partial tracheal prosthesis made of porous titanium inserted in the cervical trachea. The histologic analysis of the tissue surrounding the prosthesis was performed in 11 surviving animals after a period of 15 to 41 days. RESULTS: Fibroblast colonization of titanium pores and a ciliary cylindrical epithelial layer developed on the endoluminal side of the prosthesis and the inflammatory reaction was minimal. CONCLUSIONS: The results of this short-term study validate, from surgical and histologic standpoints, the usefulness of a porous titanium tracheal prosthesis.

Animals↗

A dedicated prosthesis for open thoracostomy.

Due to our dissatisfaction with the mutilation caused by the skin-lined open thoracostomy, we have developed a dedicated prosthesis that is expected to avoid or to substitute for the classic operation. The prosthesis is a corrugated silicone tube with an oval flange at one end (to fix it internally) and a mobile ring on the other (to fix it externally). It is inserted at the bottom of the empyematic cavity after 3 cm of a rib is removed. We have used it in 20 patients whose empyema was secondary to pneumonia (12) or complications of pneumonectomy (4), lobectomy (2), decortication (1), or pleuroscopy (1). Six of those patients have already been cured and their prosthesis removed after 54 to 305 days. In 1 with a persistent postpneumonectomy bronchopleural fistula the device was removed after 299 days and the patient was submitted to a limited thoracoplasty. Six other patients still have unresolved cavities and have been using the prosthesis for 63 to 302 days. Seven patients died of their underlying disease (bilateral pneumonia, 2; acquired immunodeficiency syndrome, 2; mesothelioma, 1; heart failure and pulmonary embolism, 1; unknown, 1) after using the prosthesis for 11 to 160 days. In those patients from whom the prosthesis already has been removed, the scar looks like those commonly seen after removal of an ordinary chest tube. Based on these early favorable results we feel most encouraged to persist in this research. Nevertheless, we are aware that a larger number of patients and a longer follow-up will be necessary before we may make definitive recommendations.

Empyema, Pleural↗

An implant-supported fixed-removable prosthesis with a milled tissue bar and Hader clip retention as a restorative option for the edentulous maxilla.

Restoration of the edentulous maxilla with implant retained and supported prosthesis is challenging because of inherent anatomic limitations present after the loss of teeth. A fixed-removable prosthesis is one treatment choice for restoration of the edentulous maxilla with implants. This prosthesis meets the requirements for esthetics, phonetics, comfort, and hygiene, as well as favorable biomechanical stress distribution to the implants. This article presents a procedure for fabrication of a fixed-removable prosthesis with a precision milled bar, Hader clip attachments, and a superstructure prosthesis. The criteria for patient selection and the advantages and disadvantages of this prosthesis are discussed.

Centric Relation↗