Showing papers on "Prosthesis published in 1990"

Applicability of osseointegrated oral implants in the rehabilitation of partial edentulism: a prospective multicenter study on 558 fixtures.

Abstract: Nine clinical centers using the Branemark System participated in a prospective study of 159 partially edentulous patients between 18 and 70 years of age. Clinical parameters evaluated were plaque index, gingivitis, pocket depth, bleeding index, tooth mobility, and stomatognathic function. Initially, 558 fixtures were placed and 521 remained in the study following prosthesis placement (199 prostheses in 154 patients). Fixtures were lost or unaccounted for because of nonintegration prior to prosthesis fabrication (19), patient withdrawal (11), prosthodontic reasons (6), and failure during prosthetic procedures (1). Failure was primarily attributable to unfavorable bone quality, sex (more in males), and smaller fixture size. Complications and failure related to other patient characteristics are presented. After 1 year of a 5-year study, preliminary results suggest that a success rate equal to or better than that obtained with edentulous patients may be expected.

Reconstruction of severely resorbed edentulous maxillae using osseointegrated fixtures in immediate autogenous bone grafts

Abstract: A surgical technique for rehabilitation of severely resorbed edentulous maxillae using fixed prostheses or overdentures supported by osseointegrated fixtures in immediate autogenous corticocancellous bone grafts from the ilium is described. The results of the first 23 consecutively treated patients are reviewed. The mean observation time was 4.2 years (range 1 to 10 years). A total of 124 fixtures was originally placed into the grafts, supplemented with 16 fixtures inserted later into seven of the jaws. Throughout their observation period, 17 of the patients had continuously stable prostheses. The remaining five had overdentures, and one patient had resorted to a conventional complete denture. After 4 years, 12 of 16 patients had continuously stable prostheses. Corresponding values at 5 years were 7 of 8 patients. Calculated from the date of abutment connection, 82.1% and 81.6% of the original fixtures were clinically stable and radiographically osseointegrated after 4 and 5 years in function, respectively. From the date of fixture placement, the corresponding figures were 75.3% and 73.8%, respectively. The mean marginal bone loss after the first year of prosthesis function was 1.49 mm. The annual marginal bone loss thereafter was about 0.1 mm. The results indicate that this technique is worthwhile for patients with extreme maxillary atrophy and who cannot wear conventional complete dentures.

Aggressive granulomatous lesions in cementless total hip arthroplasty

Abstract: We describe six patients with aggressive granulomatous lesions around cementless total hip prostheses. Two patients previously had a cemented prosthesis in the same hip. The Lord prosthesis was used in five patients, the PCA in one. Both prostheses were made of chrome-cobalt alloy. Pain on weight-bearing occurred on average 3.2 years after the cementless arthroplasty, and at that time radiography revealed aggressive granulomatosis around the proximal femoral stem and the acetabular component in five of the patients; one had a large solitary granuloma in the proximal femur. Revision was performed on average 4.8 years after the cementless arthroplasty. At that time all granulomas had grown large in size; while waiting for revision operation, two femoral stem components fractured. All the granulomas showed a uniform histopathology, which included histiocytosis; the cause for these lesions was thought to be plastic debris from the acetabular socket.

A new low-resistance, self-retaining prosthesis (Provox™) for voice rehabilitation after total laryngectomy

Abstract: Prosthetic rehabilitation of voice after total laryngectomy has gained wide acceptance in the last 10 years. Several reliable voice prostheses have been developed and used successfully. Priorities for further development of the methods and instruments for prosthetic voice rehabilitation have led to the design of a low-resistance, self-retaining voice prosthesis (Provox) and an adapted replacement method. The results obtained in 79 patients are described. In vivo airflow resistance ranged from 1.0 to 3.8 kPa (mean = 1.9 kPa). Speech quality was good in 91% of the patients. The self-retaining properties of the prosthesis appeared to be satisfactory. The average device-life was more than 5 months. Replacement of the prosthesis with a new disposable guide wire was done quickly as an outpatient procedure. Maintenance of the prosthesis by the patient was simple. The new low-resistance, self-retaining Provox voice prosthesis and the modified replacement method appeared to further improve the results of prosthetic voice rehabilitation after total laryngectomy.

Capsular contracture after breast reconstruction with silicone-gel and saline-filled implants: a 6-year follow-up

Abstract: A major problem after breast reconstruction with augmentation mammaplasty is contracture of the fibrous capsule around the prosthesis. In a series of 72 breasts in 65 women, silicone-gel and saline-filled implants were randomly selected prior to breast reconstruction. The results were judged with respect to consistency, tenderness, wrinkles, and sounds by two independent plastic surgeons according to the breast augmentation classification (BAC) and by the patients themselves. Capsular contracture was found by the surgeons in 50 percent of the gel implant group and in 16 percent of the saline implant group, which is in conformity with the results of the follow-up 5 years earlier. The incidence of deflation was 16 percent in the saline group and occurred in different sizes of both overinflated and underinflated prostheses. The degree of slow leakage from saline implants will be discussed. Despite the high rate of contractures in the gel group, 85 percent of all patients were satisfied with the result of the reconstruction.

A comparison of three varieties of noncemented porous-coated hip replacement

Abstract: We reviewed 134 primary noncemented porous-coated total hip replacements in 125 patients: 64 were DePuy AML prostheses, 20 were Howmedica PCA and 50 were Implant Technology LSF. The prostheses had been in situ for an average of 36 months, 40 months and 24 months respectively. The average pre-operative Harris hip scores were 38.2 for AML, 33.2 for PCA, and 41.0 for the LSF prostheses. The average postoperative scores were 80.7 for AML, 83.8 for the PCA, and 91.5 for LSF. Thigh or groin pain associated with the prosthesis was present in 30% of AML, 30% PCA and 8% of the LSF cases. The clinical and radiographic review showed better early results with the LSF prostheses than the others; this seemed to be related to the implant design, which provided improved initial stability and more physiological transfer of load.

Management of infection about total elbow prostheses.

Abstract: Deep infection was a complication after twelve (7.3 per cent) of 164 primary total elbow replacements. Two additional patients who had an infection about an elbow prosthesis were referred for treatment after total elbow replacement elsewhere. A statistical analysis of all of these primary total elbow arthroplasties, including the two in patients who were referred from outside institutions, identified preoperative factors that placed a patient at significant risk for subsequent infection. The risk factors included a previous operation on the elbow, a previous infection in the region of the elbow, psychiatric illness, class-IV rheumatoid arthritis, drainage from the wound after operation, spontaneous drainage after ten days, and reoperation for any reason. Three modes of treatment were used for patients who had an established infection: debridement and salvage of the implant, resection arthroplasty, and arthrodesis. After early operative debridement and suppression of the infection with long-term antibiotic therapy, three patients were able to retain the prosthesis, with restoration of range of motion and function of the upper extremity. One prosthesis was reimplanted after a six-week course of intravenous administration of antibiotics.

Ten-year socket wear in 66 hip arthroplasties Ceramic versus metal heads

Abstract: Radiographic measurements of polyethylene socket wear were performed in 33 hip prostheses with an Al2O3-ceramic head and 33 prostheses with a metal head. At 9–11 years, the average reduction of the...

Replacement of the lumbar vertebrae of sheep with ceramic prostheses

Abstract: We prepared a prosthesis for the replacement of the lumbar vertebrae of sheep, using apatite- and wollastonite-containing glass-ceramic. The material is stronger than human cortical bone and has the special feature of chemical bonding to bone. Ten sheep underwent replacement of L3 and L4 vertebrae, without bone grafting. The animals were killed at intervals from three months to 27 months after operation, and the interface between the prosthesis and bone was examined radiologically, histologically and crystallographically. Bone bonding with the prosthesis had occurred in half the implants. It took at least one year for bonding to be complete, but an apatite layer on the surface of the prosthesis was observed as early as three months after the operation, suggesting the possibility of much earlier bone bonding if more rigid fixation of the prosthesis had been provided.

Bipolar arthroplasty for 496 hip fractures.

Abstract: Four hundred ninety-six bipolar arthroplasties were performed over a 14-year period for the treatment of proximal femur fractures. A historical review, including 71 references from the 19th century to the present, was composed concerning the advances in operative techniques for the treatment of such fractures. Comparisons were then made between this series and those that used internal fixation and one-piece conventional prostheses. Immediate postoperative and long-term follow-up study results confirm findings of a previous smaller study. That previous study showed the bipolar prosthesis offered significant improvement over internal fixation in reducing morbidity and mortality. Additionally, it offered advantages over the one-piece prosthesis in terms of fit, decreased acetabular erosion, and improved function.

Complications, supplementary treatment, and maintenance in edentulous arches with implant-supported fixed prostheses.

Abstract: The first 50 edentulous arches treated with osseointegrated fixed partial dentures at the Postgraduate Dental Education Center, Orebro, Sweden, were studied retrospectively with concern for complications and time used for supplementary treatment and maintenance. The longest observation period was 9 years, the shortest 3 years, and the mean 5.2 years. Twenty-two percent of the patients experienced fractures of artificial teeth and/or the acrylic resin superstructure. The most severe technical complications were fractured or bent abutment screws (three) and fracture of the framework (one). The average time for supplementary treatment and maintenance was as follows: for surgery, 0.16 hours per prosthesis and year; for prosthodontics, 0.64 hours per prosthesis and year; and for dental laboratory procedures, 1.0 hour per prosthesis and year.

Decreased pain with lower flexural rigidity of uncemented femoral prostheses.

Abstract: One hundred one consecutive uncemented hip arthroplasties (87 patients) were analyzed radiographically at 1-year follow up to relate mechanical factors to hip pain as determined by clinical pain scores. The average area moment of inertia and flexural rigidity were greater for the bone than the metal prosthesis for each type of prosthesis (AML, HG, PCA). Normalization of the flexural rigidity ratio (bone to prosthesis) for patient weight yielded a Spearman correlation coefficient of 0.232, significant at P = .02, suggesting that both applied stress and bending stiffness have an effect on pain. No relationship was seen between pain and AP, or average gap between prostheses and bone.

Leg length equalization during total hip replacement.

Abstract: A method of equalization of leg lengths during total hip replacement surgery was developed which utilizes the concept of equalizing the vertical dimensions of the resected femoral head and neck segment and the remaining hip joint cartilage space, which are removed during the procedure, with the vertical dimensions of the femoral and acetabular prostheses, which are implanted into that void. This was accomplished by determining the dimensions of the prostheses from careful preoperative templating technique and by using a simple arithmetic formula to determine the level of the femoral neck osteotomy. The level of the osteotomy was made by a measurement from the top of the dislocated head of the femur to the medial femoral neck calcar. The radiologic postoperative leg length differences of a consecutive series of 84 patients undergoing primary total hip replacement using this method were determined. The average discrepancy was 2.8 mm. Seventy-five patients (89%) were found to have a postoperative leg length discrepancy of 6 mm (1/4 inch) or less. Six patients (7%) had a discrepancy of 7 to 13 mm, and only three patients (4%) had more than 13 mm (1/2 inch) leg length difference. Using this technique only two patients (2.5%) with unilateral hip replacements had leg lengthening of more than 6 mm.

Total knee arthroplasty fixation comparison of the early results of paired cemented versus uncemented porous coated anatomic knee prostheses

Abstract: The results of 18 matched pairs of Porous Coated Anatomic knee prostheses were studied to compare the early clinical and functional performance of cemented versus uncemented fixation with an average five-year follow-up period for both. The knee score improved from a preoperative average of 35 points to a postoperative average of 90 points in the cemented group, and from 38 points to 93 points in the uncemented group. In particular, the individual pain scores and the range-of-motion values were well matched at the three-, six-, and 12-month follow-up visits and showed a steady improvement. Subjectively, all patients were pleased with the results of surgery; one-third preferred the cemented side, one-third preferred the uncemented side, and one-third found no difference in the performance of either knee. The clinical and functional performance of knee prostheses in patients who had one cemented knee and one uncemented knee were comparable and possibly unrelated to the type of fixation method.

Dislocation of a posterior stabilized total knee prosthesis. A report of two cases.

Abstract: Posterior stabilized knee prostheses have been recommended for knees with posterior cruciate deficiency, as well as for knees with prior patellectomy. Two cases are presented in which a complete dislocation of a Kinematic II Stabilizer prosthesis occurred after primary knee arthroplasty. The mechanism of dislocation was a varus or valgus stress while the knee was flexed. This previously unreported complication of dislocation after primary knee arthroplasty with a posterior stabilized knee prosthesis was, we believe, due, in part, to the design of this prosthesis, which provides little mediolateral stability in flexion, in combination with a mild degree of laxity of the collateral ligaments. This complication could be prevented by use of a prosthesis with greater inherent mediolateral stability.

The acetabulum: a prospective study of three-phase bone and indium white blood cell scintigraphy following porous-coated hip arthroplasty.

Abstract: Although few studies address the use of three-phase bone scanning (TPBS) and indium-111-labeled white blood cell scintigraphy (111In-WBC) in hip arthroplasty utilizing a porous-coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ form that seen with the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous-coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and 111In-WBC at approximately 7 days, and 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the acetabulum. All 25 prostheses (144 of 144 scans) demonstrated increased uptake on the bone-phase images. Although this activity decreased with time, 76% had persistent uptake at 24 mo. Twenty-three of 25 prostheses (126 of 140 scans) showed increased uptake on 111In-WBC scintigraphy, invariably decreasing with time, but with 37% having significant uptake at 24 mo. Scintigraphic patterns in the uncomplicated porous-coated hip arthroplasty patient appear to differ from patterns described in cemented prostheses.

Hydroxylapatite ossicular replacement prostheses: preliminary results.

Abstract: Hearing results and extrusion rate for 89 consecutive patients receiving hydroxylapatite prostheses for hearing reconstruction were evaluated and compared to a control group of 75 patients who had received homograft bone or Plasti-Pore prostheses. At the 3-month follow-up, there were no cases of extrusion of the hydroxylapatite prostheses. Hearing success was defined as a postoperative air-bone gap of less than or equal to 15 dB for incus prostheses and partial ossicular replacement prostheses or less than or equal to 25 dB for incus-stapes prostheses and total ossicular replacement prostheses. There was a statistically significant difference in the distribution-of-success rate by prosthesis type for the hydroxylapatite. Incus, incus-stapes, and total ossicular replacement prosthesis results were similar, but partial ossicular replacement prosthesis results were poorer. The overall success rate in the hydroxylapatite group was 51.2%; in the control group, it was 60%. Hearing results tended to be better with the hydroxylapatite incus prosthesis than with the homograft bone incus, but poorer with the hydroxylapatite partial ossicular replacement prosthesis than with the Plasti-Pore. Several technical modifications of the prosthesis that may improve results with the hydroxylapatite partial ossicular replacement prosthesis are suggested. Hydroxylapatite middle ear prostheses appear to be a reasonable alternative to other more commonly used prostheses, which carry disadvantages related to the use of human tissue.

Long-term use of polyurethane breast prostheses: a 14-year experience.

Abstract: I have used polyurethane prostheses for the past 14 years, implanting 220 implants into 130 patients who desired breast reconstruction after subcutaneous mastectomy or cancer ablation or simply breast augmentation. I theorize that a polyurethane-covered implant resists contracture, retaining its compressibility because the fibroblasts proliferate into the polyurethane in many different directions. When the fibrils contract, the forces of contracture counterbalance one another, resisting contracture. However, when smooth prostheses are implanted, fibrils are directed in a circular fashion around the implant and naturally contract, leading to firmer breasts. There were 115 prostheses inserted following subcutaneous mastectomy, and 22 percent developed contracted capsules. Seven implants became exposed because of skin necroses; one was removed because of a Staphylococcus infection; and two patients developed a combination of polyurethane and silicone granulomas. These developed only with the earlier implant, where there was shedding of the polyurethane sponge layer and silicone bled from the low-viscosity silicone used in the earlier implants. No granulomas were noted with the currently used Surgitek Replicon implant. Eighty-five breasts were reconstructed after cancer ablation with polyurethane implants, and the contracture rate was 2.3 percent. Other complications were minimal. A smaller group of patients had augmentation mammaplasty, and 20 prostheses were placed in 10 patients. A 15 percent contracture rate was noted in this group. In this study, 82 percent of patients were followed for up to 14 years. Capsular contractures occurred in 30 implants between 1 and 11 years, for an average recurrence at 6.3 years. The overall contracture rate was 13 percent. Other complications were minimal. All implants were placed subcutaneously or subglandularly, and all were drained.

Effects of age and prosthesis material on in vitro cartilage retention of laryngoplasty prostheses in horses.

Abstract: Cartilage retention strengths of laryngoplasty prostheses were compared in larynges of 2-, 3-, and 4-year-old horses, using doubled polyester and expanded polytetrafluoroethylene prostheses. Bilateral laryngoplasties were performed on each of 15 (seven 2-year-old, two 3-year-old, and six 4-year-old) larynges, which were collected at an abbatoir. Prostheses were secured to a mechanical testing machine, and tension causing arytenoid cartilage abduction was applied, until total failure of the cartilage or prosthesis resulted. Tension caused cricoid cartilage failure in 1 specimen, and muscular process cartilage failure in the remainder. There was no significant effect of age, prosthetic material, or side of prosthesis placement on cartilage retention of the prostheses. Additionally, frequency of multiple load-displacement peaks, indicating partial muscular process failure, was not affected by age or prosthetic material variables.

Exposed endoprosthesis. Management protocol using muscle and myocutaneous flap coverage.

Abstract: A tenet in the orthopedic community is that dehiscent wounds overlying exposed prostheses should be treated by implant removal and delayed reconstruction. A management protocol using thorough debridement and irrigation and muscle flap coverage was accomplished in four patients with exposed endoprostheses after total arthroplasty or limb salvage surgery. Predisposing factors for late wound dehiscence in the four oncology patients were preoperative radiation and chemotherapy as well as multiple subsequent reoperations. In this study, all four prostheses and extremities were retained without the need for prosthetic removal or exchange. No infections developed. Late aseptic wound dehiscence with exposed conventional or tumor endoprosthesis need not be managed with prosthetic removal, arthrodesis, or amputation. This one-stage procedure avoided infection, allowed early mobilization, shortened hospitalization and, most important, avoided amputations.

Use of lower limb prosthesis among elderly amputees.

Abstract: Forty-seven elderly patients (21 males and 26 females) with lower limb amputation, and with prostheses fitted were studied. Their ages ranged from 65 years to 91 years old, with an average of 75.4 years. The three most common contributory causes for amputation were diabetes mellitus, vascular occlusion and carcinoma of the skin. Among the lower limb amputations, below knee amputation was the most common (93.6%). About 30% of the patients developed complications from prostheses, the 3 most common in order of frequency were stump pain, pressure ulcers and stump infection. Male patients tended to do better with prostheses than female patients. More male patients wanted prostheses for mobility, while most female patients cited cosmesis as the reason for wanting a prosthetic leg. More male patients used the prostheses more frequently and this was associated with a higher level of function in terms of self care and mobility. Reasons for non-usage of prosthesis were poor-fitting sockets, floppy stump, stump ulcers and infection. Carers of male amputees tended to cope better than those caring for female amputees. Both the present age of patient, and the age at amputation were found not to be a factor in deciding the frequency of usage of prosthesis, and the outcome of success in rehabilitation of the amputee. Psychological factors played an important role in the outcome of rehabilitation. Eighty-five percent of patients who functioned at a lower level despite a relative lack of serious medical condition cited psychological reasons for their poor performance, among which were age and the 'expected' loss of mobility with amputation.

Treatment of breast contractures with open capsulotomy and replacement of gel prostheses with polyurethane-covered implants.

Abstract: Capsular contracture around gel and gel-saline implants is the most common complication following breast augmentation and reconstruction. Thirty-one patients with postaugmentation gel-implant contractures were treated with open capsulotomy and replacement with polyurethane-covered implants. Eighty-seven percent remain soft after a minimum follow-up of 14 months. Results of replacement after subcutaneous mastectomy and reconstruction are more varied and less successful. Results in 14 patients are presented.

Are unconstrained components essential in total knee arthroplasty? Long-term results of the Blauth knee prosthesis.

Abstract: For 17 years, the Blauth total knee prosthesis has been implanted with its basic constructional features remaining unchanged. While it is true that the prosthetic components are constrained by a mechanical hinge, load transmission is actually effected in accordance with the low-friction principle through the cup-shaped condylar surfaces. Packing of the prosthesis in the bone is ensured by large load-bearing surfaces and by specific elements intended for rotational stability. In a comprehensive follow-up review, 497 implants were studied over a period of one to 15 years (average, 45 months). Aseptic loosening occurred in only 1.2% of the prostheses, and deep infection was found in 3% of the patients in the follow-up review. According to survival statistics, the probability of finding prostheses without deep infection or loosening after more than ten years is 89%. The efficiency of total knee arthroplasty (TKA) by hinged prostheses should therefore not be judged by the results obtained with the pioneer implants, which date back to the beginnings of TKA. The clinical results obtained clearly demonstrate that there is 90 degrees knee flexion in more than 88% of the implants. A subjective appraisal demonstrated substantially less pain compared with the preoperative findings. Problems originating from the patella were recorded in less than 10%. However, in 1985, an improved prosthetic design was introduced that also provided for the replacement of the posterior surface of the patella and for a proximally extended patellar bearing. The position of the hinge and implant packing remained unchanged. The results obtained so far with the modified prosthetic design are very good.

Design and development of a contoured ossicular replacement prosthesis: clinical trials of 125 cases.

Abstract: A columellar ossicular replacement prosthesis has been developed to simplify ossiculoplasties. The hydroxylapatite head has flattened egg-shaped contours set on a teflon shaft. One hundred and twenty-five prostheses have been implanted and the results of eighty-two cases between five and eighteen months' maturity are presented. Sixty-six percent of good risk partial ossicular replacement prosthesis (PORP) cases achieved air-bone closure within ten decibels and eighty-five percent within twenty decibels. Of all total ossicular replacement prosthesis (TORP) and PORP cases, 51.5 percent closed to within ten decibels and 69.5 percent to within twenty decibels. The design has simplified the preparation and implantation techniques and the prosthesis can be used in most ossiculoplasty situations. A malleus handle is not required and interposition of cartilage is unnecessary. The simplicity of the prosthesis should provide particular benefits for the occasional or trainee otologist.

One-stage arthroplasty of the ipsilateral shoulder and elbow.

Abstract: Twenty 1-stage ipsilateral shoulder and elbow joint replacements were performed in 17 patients from 1988 to 1998 in the Nottingham Shoulder and Elbow Unit, Nottingham, England. There were 12 women and 5 men with a mean age at operation of 57 years. All 17 patients had rheumatoid arthritis. The indication for performing the 2 joint replacements in 1 stage was severe symptomatic involvement of both joints. The shoulder was replaced first, with the patient being repositioned and redraped for the elbow replacement. The follow-up averaged 5 years 2 months (range, 23 months to 13 years 8 months). All patients had significant pain relief and improvement in function, and 12 of the 15 patients reviewed would have been prepared to have the same procedure on the other side, if it became necessary (in 3, this had been done). The procedure offers major advantages because the number of anesthetics is reduced, it is more cost-effective, and it facilitates functional rehabilitation.

Femoral fractures following total hip prosthesis

Abstract: Fractures of the ipsilateral femur after hip arthroplasty are a serious problem. In most cases, minimal trauma is responsible for the fracture. Predisposing factors, such as severe osteoporosis, loosening of the stem of the prosthesis, or cortex perforations, are often found. Such fractures occurred between 1979 and 1989 in 30 patients, i.e. 2.3% of our patients who had received primary prosthesis and 2.9% of those who had undergone revision. The patients' ages at the time of fracture ranged from 41 to 88 years (mean 63 years), 33% of the patients in these group being female. The time lapse from implantation of the prosthesis to the fracture varied between 1 month and 11 years (mean 4.4 years). The fracture was at the level of the proximal trochanteric region in 3% of these patients, between the trochanteric line and the tip of the prosthesis in 20%, and below the tip of the prosthesis in 70%. Operative treatment was performed in 29 patients. Fractures were fixed with a compression plate in 19 (63%), and in 3 the plate fixation was reinforced with intramedullary cement. In 2 osteoporotic patients with supracondylar fractures the osteosynthesis ruptured and a successful revision operation with cement was performed. In 3 others internal fixation was combined with replacement of the prosthesis; 3 patients received a Wagner revision prosthesis and 1 a long-stem Protek tumor prosthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Knee arthroplasty using a cementless PCA prosthesis with a porous-coated central tibial stem. Clinical and radiographic review at five years.

Abstract: In 44 consecutive patients, 60 porous-coated anatomic total knee (PCA) prostheses with a porous-coated central tibial stem were implanted without using cement. The clinical results and bony remodelling have been assessed after five years' follow-up. The average Hospital for Special Surgery knee score was 33.1 before operation and 95.7 at the latest follow-up, while the average range of movement improved from 63 degrees to 123 degrees. No subsidence or migration of the components was seen. A radiodense line appeared around the components at six months to one year after the operation and became more dense with time. There was no evidence of bone resorption related to stress-shielding in the tibial plateau.