Showing papers on "Prosthesis published in 1998"

Risk Factors for Prosthetic Joint Infection: Case-Control Study

Abstract: We conducted a matched case-control study to determine risk factors for the development of prosthetic joint infection. Cases were patients with prosthetic hip or knee joint infection. Controls were patients who underwent total hip or knee arthroplasty and did not develop prosthetic joint infection. A multiple logistic regression model indicated that risk factors for prosthetic joint infection were the development of a surgical site infection not involving the prosthesis (odds ratio [OR], 35.9; 95% confidence interval [CI], 8.3-154.6), a National Nosocomial Infections Surveillance (NNIS) System surgical patient risk index score of 1 (OR, 1.7; 95% CI, 1.2-2.3) or 2 (OR, 3.9; 95% CI, 2.0-7.5), the presence of a malignancy (OR, 3.1; 95% CI, 1.3-7.2), and a history of joint arthroplasty (OR, 2.0; 95% CI, 1.4-3.0). Our findings suggest that a surgical site infection not involving the joint prosthesis, an NNIS System surgical patient risk index score of 1 or 2, the presence of a malignancy, and a history of a joint arthroplasty are associated with an increased risk of prosthetic joint infection.

Patient outcomes after knee replacement.

Abstract: A prospective, observational cohort investigation was performed to help understand the impact of knee replacement on patients with knee osteoarthritis in community practice. Of those, 291 patients (330 knees) were eligible and willing to participate. Forty-eight orthopaedic surgeons referred 563 patients from 25 institutions within the state of Indiana. Demographics, patient completed health status, satisfaction, independent radiographic measures, surgeon reported intraoperative factors, hospital discharge factors, and independent physical examinations were recorded. A minimum 2-year followup was obtained in 92% of the patients. At followup, 88% were satisfied, 3% were neutral, and 9% were dissatisfied with the results of their knee surgery. The physical composite score improved from 27.4 +/- 0.4 (range, 13.3-50.3) to 37.7 +/- 0.7 (range, 12.9-61.3) at two years. Maximal improvement in physical composite score was seen in patients who had their surgery performed in institutions that performed greater than 50 knee replacements per year in patients with Medicare insurance; who had a better mental health status at baseline; who had surgery performed on Monday, Friday, or Saturday; who were older; who were treated with a posterior cruciate sparing device; and who had worse preoperative function. A lower likelihood of complications were found with surgeons who performed greater than 20 knee replacements per year; midweek surgeries; in patients with more severe preoperative knee dysfunction; patients with fewer comorbidities; patients with less preoperative stiffness; patients being treated by younger surgeons; and in patients undergoing unilateral knee replacement. Among voluntarily participating physicians, knee replacement can be a highly effective medical technology with high levels of patient satisfaction and low rates of complications.

Prolonged Suppressive Antibiotic Therapy for Infected Orthopedic Prostheses

Abstract: Prolonged suppressive antibiotic therapy may be an alternative to removal of infected orthopedic prostheses in some patients. However, the efficacy of prolonged suppressive antibiotics is not well established. We retrospectively reviewed 18 patients with infected orthopedic prostheses who had been treated with prolonged antimicrobial suppression during the last 10 years. Eighteen episodes of infection were identified in these 18 patients. There were nine men and nine women, and the mean age was 66 years (range, 31-83 years). All patients had a functional prosthesis and were treated with surgical debridement, retention of the prosthesis, and administration of intravenous antibiotics for 6-8 weeks, followed by prolonged oral antibiotic suppression. Fifteen of the 18 patients appear to have had a good response and have been able to retain a functional prosthesis. Complications related to antibiotic suppression occurred in 22% but did not necessitate discontinuation of the antibiotic therapy. Prolonged antibiotic suppression is a reasonable alternative to surgery in selected patients with infected orthopedic prostheses.

Treatment outcomes of patients with implant-supported fixed partial prostheses.

Abstract: Implant and prosthesis success for 77 partially edentulous patients, provided with 97 fixed prostheses, supported by 230 Branemark implants, in place for up to 12 years (mean 5.41 years), were documented in this study. Implant losses per location mirrored their placement, with no difference between zones I and II or between the maxilla and mandible. The implant success rate was 94%, and continuous prosthesis stability was 97%. These results indicate that the Branemark implant-supported fixed partial prosthesis is a highly efficacious treatment.

Major replantation versus revision amputation and prosthetic fitting in the upper extremity: A late functional outcomes study

Abstract: The functional outcomes of amputated arms that were either replanted or had a prosthesis were compared. In addition, factors that influenced the functional outcome of replants were evaluated. The Carroll test was used to evaluate functional capacity of 22 successful upper extremity replantations at or proximal to the wrist as well as 22 amputees (at similar levels) fitted with a variety of prosthetic devices. The outcome was excellent or good in 8 (36%) replanted limbs. This proportion was statistically higher than those grades in the prosthetic group. When the groups were more closely matched (adults with below elbow injuries), the replantation group had 6 (50%) good or excellent outcomes and the prosthetic group had none. An analysis of covariance of the replatations demonstrated a statistical association between a better outcome in younger patients with more distal injuries. This study indicates that replantation produces superior functional results compared with amputation and a prosthesis.

Outcome after hemiarthroplasty for femoral neck fractures in the elderly : Update on fractures of the hip

Abstract: A prospective outcome study was performed on 270 patients, 65 years of age and older, who sustained a femoral neck fracture and underwent hemiarthroplasty. The treatment compared was the use of a noncemented unipolar versus either a cemented or a press fit bipolar prosthesis. The outcome variables assessed included the occurrence of a postoperative complication, length and cost of hospitalization, and function in various quality of life measurements. Patients who underwent bipolar hemiarthroplasty with either a cemented or a press fit prosthesis had better pain relief and function than patients who had a noncemented unipolar prosthesis at a minimum of 24 months after surgery. However, the mean hospitalization cost for patients who had a bipolar prosthesis was $12,290 compared with $8876 for a unipolar prosthesis.

Postoperative analgesia with "3-in-1" femoral nerve block after prosthetic hip surgery

Abstract: Purpose To evaluate the efficacy of a single shot “3-in-1” femoral nerve block for prosthetic hip surgery in association with general anaesthesia on post-operative analgesia.

Dental prosthesis ingested and impacted in the esophagus and orolaryngopharynx

Abstract: Objective: Impacted foreign bodies in the trachea and esophagus are common. In the esophagus, these are usually bones, while for the trachea, it is commonly some form of seed or nut. The incidence of impacted dental prostheses is not highlighted in the literature. They usually have a definite history of ingestion, frequently during trauma, seizures, or Sleep. Prompt management in a safe and effective manner is required if significant morbidity, and even mortality, is to be avoided. Method: The records of all patients who presented to the University Hospital in Kuala Lumpur with a definite history of foreign-body ingestion in the form of a dental prosthesis were reviewed, and their respective radiographs reassessed. Results: There were 21 patients with impacted dental prostheses from a total of 200 patients who had impacted foreign bodies (11.5). Indirect laryngoscopy detected five of these dentures, and in only seven were the dentures seen on plain radiography (33)-all of which had metal wires attached. Of the 21 patients, 16 had the foreign bodies removed endoscopically; 2 could not be removed and were allowed to pass through the gastrointestinal tract under close monitoring; and 3 whose dental prostheses were not detected and who subsequently passed the foreign bodies. Conclusions: Impacted dental prostheses appear to constitute a significant proportion of impacted foreign bodies in the orolaryngopharynx. The majority are radiolucent. In the presence of positive history or/and symptoms, endoscopic examination and removal is suggested if possible to reduce morbidity. No serious complications have been seen.

Predisposing Factors Related to Prosthetic Use by People with a Transtibial and Transfemoral Amputation

Abstract: A survey was conducted to evaluate prosthetic use and factors predisposing to prosthetic use among 396 adults with unilateral amputations. A response rate of 76% was obtained. Eighty-five percent of the respondents were prosthetic wearers; 53% actively used their prosthesis for the majority of their indoor activities; and 64% did so for the majority of their outdoor activities. Adaptation to the amputation and prosthesis and level of amputation were significantly correlated with prosthetic wear and active use indoors and outdoors. Presence of arthritic problems in the nonamputated limb were negatively related to prosthetic wear, but for activities outdoors, muscle cramps and sores were the limiting factors. Long delays in limb fitting, prolonged training, cardiac and respiratory problems, and constant stump pain were significantly related to disuse. Linear and logistic regression analyses further identified the combined factors that could be predictive of prosthetic use.

Modular shoulder prosthesis

Abstract: A modular shoulder prosthesis including a head having a semi-spherical articulation surface bounded by an articular margin disposed in an articular plane generally normal to a head axis. The head further includes a backside disposed opposite the articulation surface and separated from the articulation surface by the articular margin. The prosthesis also includes a stem portion with a proximal end and a distal shaft for insertion into a medullary canal along a shaft axis. A coupling structure is adapted to removably attach the head to the stem through motion in the articular plane.

Immediate weightbearing after uncemented total hip arthroplasty

Abstract: Radiographic subsidence of the femoral prosthesis and clinical results after unilateral and simultaneous bilateral uncemented total hip arthroplasty were compared. Patients who had bilateral total hip arthroplasty began weight-bearing as tolerated on both lower extremities the day after surgery. Patients who had undergone unilateral total hip arthroplasty were maintained at 10% weightbearing on the operative limb for 6 weeks after surgery. Patients in both groups were matched for age, gender, and weight. Minimal followup was 2 years. There was no difference between the two groups in terms of clinical results. Radiographic assessments were performed immediately after surgery, 6 weeks after surgery, and again at 2 years after surgery. Radiographs were reviewed by a single observer and analyzed with a digitized data recorder. Increased subsidence of the femoral prosthesis within the bilateral group was found at 6 weeks. The mean subsidence of the femoral prosthesis at 6 weeks for the bilateral total hip arthroplasty group was 0.86 mm (range, 0.18-2.60 mm) and for the unilateral group was 0.39 mm (range, 0.07-1.46 mm). However, subsidence occurring between 6 weeks and 2 years averaged 0.50 mm (range, 0.09-1.10 mm) for the bilateral group and 0.54 mm (range, 0.03-0.99 mm) for the unilateral group. This difference was not significant. At the 2-year followup, all femoral prostheses in both groups appeared radiographically stable with evidence of bone ingrowth and no indications of loosening. Thus, immediate weightbearing after bilateral total hip arthroplasty in this study resulted in more initial subsidence (during the first 6 weeks after surgery) of the femoral prosthesis but did not preclude the prosthesis from becoming stable and achieving bone ingrowth. Patients in both groups obtained satisfactory clinical results. Because initial stability and bone ingrowth are factors influenced by prosthesis design, the results of this study may not be applicable to all implants.

Bone-resorbing cytokines in serum of patients with aseptic loosening of hip prostheses

Abstract: Our aim was to determine if the serum levels of bone-resorbing cytokines (IL-1β, TNF-α, IL-6, GM-CSF) are altered in patients with aseptic loosening of a total hip prosthesis, and if such levels are influenced by the type of implant. We determined cytokine levels in sera from 35 patients before revision for failed total hip arthroplasty and compared them with those in 25 healthy donors. We also assessed the soluble receptor of interleukin-2 (sIL-2r) in serum as an indication of a specific immune reaction against the implant. Our findings showed that the sIL-2r and TNF-α serum level did not change. The IL-6 level was not significantly altered, but was higher in patients with TiAlV prostheses than in those with a CrCoMo implant and in patients with cemented prostheses. The IL-1β level was found to be higher in those with a TiAlV cemented prosthesis than in the control group (p = 0.0001) and other groups of patients (p = 0.003 v uncemented TiAlV, p = 0.01 v cemented CrCoMo, p = 0.001 v uncemented CrCoMo). The GM-CSF level significantly increased in patients compared with healthy subjects (p = 0.008), and it was higher in those with cemented than with uncemented implants (p = 0.01). Only patients with cementless CrCoMo prostheses had levels of GM-CSF similar to those of the control group. The highest GM-CSF concentrations were observed in patients treated with non-steroidal anti-inflammatory drugs (NSAIDs) in the last months before revision (p = 0.04). In addition, when massive osteolysis was observed, the level of GM-CSF tended to decrease to that of the control group.

Cemented and non-cemented replacements of the trapeziometacarpal joint

Abstract: We performed 88 primary ball-and-socket arthroplasties of the trapeziometacarpal joint in 84 patients (69 women and 15 men) with a mean age of 61 years (37 to 81). Cemented de la Caffiniere prostheses were implanted in 43 joints from 1988 to 1991 and 45 cementless Ledoux implants were used between 1992 and 1994. Of the 61 surviving prostheses still in situ, 51 were reviewed clinically and radiologically with a mean follow-up of 25 months for the Ledoux and 63 months for the de la Caffiniere implant. The survival rate for the Ledoux prosthesis was 58.9% at 16 months and for the de la Caffiniere implant 66.4% at 68 months. Loosening occurred in 15% of the Ledoux stems, in 46% of the Ledoux cups, in 24% of the de la Caffiniere stems and in 28% of the de la Caffiniere cups. Both prostheses behaved similarly, and it is clear that a constrained ball-and-socket prosthesis is not suitable for the trapeziometacarpal joint.

An evaluation of the use made of cosmetic and functional prostheses by unilateral upper limb amputees

Abstract: There is currently a distinction drawn between a prosthesis considered to be provided for purely cosmetic reasons and a functional prosthesis provided to enable the amputee to achieve basic hand function. Using video analysis the study reported in this paper demonstrates that for nonmanipulative actions cosmetic prostheses are actively used in the performance of everyday tasks as frequently as functional prostheses. The study provides evidence for a cosmetic prosthesis to be presented to an amputee as a realistic initial prosthesis and not as the option of last resort if a functional prosthesis is rejected. It is also recommended that training is provided in the use of cosmetic prostheses in two-handed tasks.

Reconstruction of nasal defects with implant-retained nasal prostheses.

Abstract: Predictable biomechanical retention of nasal prostheses can now be achieved using Branemark osseointegrated implants. These prostheses are tissue compatible, simple in design and easy to place, can be worn independently of spectacles and can in the majority of cases be provided soon after surgical excision. We have treated 14 patients (30 implants) 8 of whom had the implants placed at the time of surgical excision of the tumour. The longest survival so far has been 62 months (mean 38 months). Craniofacial osseointegration changes patients' perceptions of a nasal prosthesis and improves quality of life. Initial reconstructive surgery after radical nasal excision should be limited to reconstruction of the upper lip and preparation of the surgical defect for an implant-retained prosthesis.

A survey of upper-limb prosthesis users in oxfordshire

Abstract: The design of a new device should embrace the needs of the target population A survey of prosthetic limb users was performed at the Oxford Limb-Fitting Centre, Headington, Oxford, as part of the specification for an intelligent hand prosthesis Users of prosthetic limbs were questioned about the positive and negative attributes of their limb and were asked about their wishes for the design of prostheses A questionnaire was devised to address this and sent to 80 subjects; 69% responded It was found that light weight, durability, ease of cleaning, longevity of operation (up to 12 hours), and suitability for driving were highlighted as priorities This information was incorporated into the design of a new powered hand prosthesis This article reviews the results of the survey and makes comparisons with similar studies Finally, recommendations are made for the designs of any new prosthesis system

Dental prosthetic reconstruction of osseointegrated implants placed in irradiated bone.

Abstract: Nineteen patients who were treated for oncologic pathology by surgery and radiotherapy (average dose = 57 Gy) received prosthetic reconstruction with 53 implants placed in the residual mandible or maxilla and/or replacement bone graft. Implants were placed within a minimum period of 5 months after radiotherapy. The healing period before placement of the prosthesis also was at least 5 months. Two to six implants were placed as a function of tooth loss and required prosthetic design. Prostheses included both removable and fixed restorations. Two implants were lost as a result of osseointegration failure. Fifteen implants in six patients could not be followed throughout the study because of patient expiration. Patients were followed up to 68 months and for an average of 38 months. No osteoradionecrosis phenomenon was seen in this study. However, caution is urged in placing implants in irradiated bone because of the potential for osteoradionecrosis. Patients should be carefully selected and a strict therapeutic protocol should be followed.

One-stage revision of periprosthetic fractures around loose cemented total hip arthroplasty.

Abstract: Fourteen cases of femoral fracture occurring about a loose cemented proximal femoral prosthesis are presented. All fractures occurred with relatively minor trauma, and significant preinjury osteolysis was present in all cases. Treatment consisted of immediate surgical revision of the loose femoral component using a long-stem noncemented component in conjunction with cerclage wiring. In most instances, morselized bone graft was used. Strut grafts were used in seven cases to improve stability. Two patients with extensive bone loss were unable to support a prosthesis and were treated with whole femoral allografts. Follow-up ranged from 24 to 84 months (mean, 49 months), except for one patient lost to follow-up at 12 months; evaluations consisted of Harris hip scores and radiographic analysis for fracture healing and implant stability. All fractures healed, and patient function increased dramatically. Postoperative Harris hip scores increased to an average of 74 points. Complications consisted of one postoperative fracture and four patients with femoral component loosening. No cases of component loosening were seen in the five cases in which components were designed for distal stability (four fully porous-coated, one fluted). Of the seven cases relying on proximal stability, two cases of early loosening and two cases of late loosening occurred. We recommend revision with long-stem, cementless implants in conjunction with cerclage wiring and strut grafts for the treatment of femoral fractures about loose cemented hip prostheses. Implant stability distal to the fracture is emphasized.

Salvage of failed femoral megaprostheses with allograft prosthesis composites.

Abstract: The records of 11 consecutive adult patients who underwent revision of a failed femoral megaprosthesis (aseptic loosening, nine; periprosthetic fracture, one; and prosthesis fracture, one) to an allograft prosthesis composite were reviewed retrospectively. Complications included radiographic component subsidence in two patients (18%), hip instability in three patients (27%), deep infection in two patients (18%), and allograft fractures in two patients (18%). Five patients (45%) required subsequent reoperations; four patients underwent removal of the allograft prosthesis composite at a mean of 16 months (range, 5-41 months) and one patient (9%) with hip instability underwent revision of the failed megaprosthesis to a constrained acetabulum. Reconstruction of a failed femoral megaprosthesis is a complex problem caused by extensive bone loss and violation of soft tissue attachments. Despite a high complication rate, six patients (55%) remained ambulatory and had mild or no pain at a mean followup exceeding 5.5 years.

Ankle prostheses. Mid-term results after Thompson-Richards and STAR prostheses

Abstract: Thirty-seven patients with 20 cemented Thompson-Richards prostheses and 19 cementless S. T. A. R. prostheses (2 bilateral cases) were followed up after 1-12 years. Rheumatoid arthritis was the main diagnosis in both populations, with females dominating. The investigation was based on the Kofoed ankle score. At follow-up the total scoring improved to 86.9 pts. in S. T. A. R. and to 77.7 pts. in T. R. P. replacement. The radiological examination showed a high rate of radiolucency for the tibial component (53.3 %) in cemented T. R. P.; subsidence of talar component was seen in 3 cases with T. R. P. In cementless S. T. A. R. prosthesis only 3 cases showed small radiolucent lines of the flat tibial component. Talar subsidence was not seen at all. In T. R. P. we had two revisions due to prosthesis loosening and one maleollar fracture, giving a cumulative estimated survival rate of 87 % at 12 years. In the S. T. A. R. prosthesis group two revisions had to be performed because of one meniscal breakage and correction of meniscal height. The estimated survival rate at 6 years was 94.3 %.

Cemented and non-cemented replacements of the trapeziometacarpal joint

Abstract: We performed 88 primary ball-and-socket arthroplasties of the trapeziometacarpal joint in 84 patients (69 women and 15 men) with a mean age of 61 years (37 to 81). Cemented de la Caffiniere prostheses were implanted in 43 joints from 1988 to 1991 and 45 cementless Ledoux implants were used between 1992 and 1994. Of the 61 surviving prostheses still in situ, 51 were reviewed clinically and radiologically with a mean follow-up of 25 months for the Ledoux and 63 months for the de la Caffiniere implant. The survival rate for the Ledoux prosthesis was 58.9% at 16 months and for the de la Caffiniere implant 66.4% at 68 months. Loosening occurred in 15% of the Ledoux stems, in 46% of the Ledoux cups, in 24% of the de la Caffiniere stems and in 28% of the de la Caffiniere cups. Both prostheses behaved similarly, and it is clear that a constrained ball-and-socket prosthesis is not suitable for the trapeziometacarpal joint.

Head and neck replacement endoprostheses for pathologic proximal femoral lesions

Abstract: Records of 28 patients with pathologic lesions in the proximal femur treated by implantation of a femoral head and neck replacement prosthesis between 1984 and 1995 were reviewed. Mean clinical followup was 47.8 months in the eight living patients and 15.8 months in the 20 patients who had died. The underlying diagnosis was metastatic disease or myeloma in 22 patients. The most frequently occurring indication for implantation of this device was a pathologic fracture in 26 patients (18 displaced, eight impending), followed by resection and reconstruction in two patients. All femoral components were cemented: 23 were bipolar hemiarthroplasties and five were total hip arthroplasties. Implant survivorship was good (93%), with only two prostheses removed during the followup period, both for infection. However, radiographic analysis revealed increasing lucencies with time, particularly in the most proximal zones, resulting in radiographic failure in an additional case. Deep infection occurred in three cases, leading to resection arthroplasty in two patients. Periprosthetic fractures occurred in three cases, but only one occurred intraoperatively. Despite a high complication rate, the good implant survival during the shortened life span of these patients supports the continued use of femoral head and neck replacement prostheses in this population.

Is there a future for hinged prostheses in primary total knee arthroplasty? A 20-year survivorship analysis of the Blauth prosthesis.

Abstract: The Blauth prosthesis is a hinged total knee replacement. We have evaluated 422 consecutive primary total knee arthroplasties using this design in 330 patients with a maximum follow-up of 20 years (mean 6). The mean age of the patients at the time of operation was 70 years (29 to 87). Using endpoints of infection, removal because of aseptic loosening, removal for any cause, and the worst case as definitions of failure, the cumulative rates of survival at 20 years were 93.6%, 96.0%, 94.4% and 86.8%, respectively. The cumulative rate of survival of the patients themselves was 14.4% (24% in patients with osteoarthritis and 9% in these with rheumatoid arthritis) after 20 years. Our survivorship analysis shows that hinged knee prostheses, when they are biomechanically well designed, can yield a satisfactory long-term outcome, similar to those of the best prostheses of the resurfacing type. Hinged knee prostheses continue to be of value in patients with severe deformity or instability of the knee.

Bone loss around 2 different types of hip prostheses.

Abstract: Dual energy x-ray absorptiometry (DXA) allows the measurement of bone mineral density (BMD) around an uncemented hip prosthesis. The aims of this study were: 1) to determine the reproducibility of periprosthetic BMD measurements; 2) to delineate the time course of bone loss that occurs after insertion of a hip prosthesis; and 3) to compare the bone loss around two different types of hip prosthesis. We studied 20 patients: 11 had Bateman and 9 had porous-coated anatomic prostheses inserted. The mean bone loss in 20 patients between 6 and 52 weeks after surgery was 6%. The greatest loss during this period was 18% and occurred from the proximal medial cortex. We conclude that measurement of periprosthetic bone mass by DXA is a precise technique. Bone loss was rapid in the first 6 months following total hip replacement. There was no difference in the bone loss occurring around the two prostheses studied.