Press-fit Condylar Total Knee Research Articles

How do knee implants perform past the second decade? Nineteen- to 25-year followup of the Press-fit Condylar design TKA.

At 14- to 17-year followup, we reported successful outcomes of the Press-fit Condylar total knee arthroplasty (TKA) system in 160 TKAs performed between 1986 and 1989. However, there are few published reports on TKA survivorship and patient function that include patients evaluated into the third decade after surgery. The study purpose was to determine (1) the survivorship of the implant; and (2) knee function in patients with this TKA system at a mean 20-year followup. We ascertained revision status of all living patients (42 of 160 knees) and all patients (22 knees) who died since the previous study. Among patients alive at the latest followup, Knee Society function scores were obtained and radiographs were evaluated. Kaplan-Meier survivorship analysis with 95% confidence intervals was performed with revision for any reason and aseptic loosening as endpoints. A competing risks analysis with 95% confidence intervals was also performed for revision for any reason as the endpoint. At the mean 20-year (range, 19-25 years) followup, all living patients retained their original implants from the index TKA, exclusive of three polyethylene exchanges. This study demonstrates an 87% Kaplan-Meier survivorship for revision for any reason (95% confidence interval [CI], 80%-92%) and a 98% Kaplan-Meier survivorship for revision for aseptic loosening (95% CI, 93%-99%). Competing risks survivorship was 79% (95% CI, 70%-85%) at 25 years for revision for any reason. Mean Knee Society function score was 46.9. Since the previous study, three revisions have been performed, all for polyethylene wear. The Press-fit Condylar implant system continues to be successful, maintaining longevity up to 25-year followup. This is one of the longest followup studies, reporting continued successes over 20 years, and should serve as a benchmark for current-generation implants. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Ten-year results of the Press Fit Condylar Sigma total knee replacement

We report ten-year clinical and radiological follow-up data for the Sigma Press Fit Condylar total knee replacement system (Sigma PFC TKR). Between October 1998 and October 1999 a total of 235 consecutive PFC Sigma TKRs were carried out in 203 patients. Patients were seen at a specialist nurse-led clinic seven to ten days before admission and at six and 18 months, three, five and eight to ten years after surgery. Data were recorded prospectively at each clinic visit. Radiographs were obtained at the five- and eight- to ten-year follow-up appointments. Of the 203 patients, 147 (171 knees) were alive at ten years and 12 were lost to follow-up. A total of eight knees (3.4%) were revised, five for infection and three to change the polyethylene insert. The survival at ten years with an endpoint of revision for any reason was 95.9%, and with an endpoint of revision for aseptic failure was 98.7%. The mean American Knee Society Score (AKSS) was 79 (10 to 99) at eight to ten years, compared with 31 (2 to 62) pre-operatively. Of 109 knee with radiographs reviewed, 47 knees had radiolucent lines but none showed evidence of loosening.

A Clinical and Radiostereometric Study of the Cemented PFC-Sigma Prosthesis –A 5-Year Study of 29 Cases with a Fixed Bearing

The press-fit condylar (PFC) cruciate-retaining total knee prosthesis is well documented in the literature. In 1997, a modification of the femoral component was introduced, and the prosthesis was renamed PFC-Sigma. The alteration may influence the migratory and rotational pattern of the tibial component and thus long-time survival rate. In this radiostereometric analysis, we found that the micromotion of the PFC-Sigma prosthesis differs slightly from the original PFC design, an advantage of the PFC-Sigma prosthesis. The median maximum total point motion at 5 years was 0.64 mm for the PFC-Sigma design and 0.79 mm for the previous version of PFC (P = .9). However, the PFC-Sigma rotated less around the transverse (x) axis than did the PFC (medians, 0.22 mm and 0.48 mm, respectively; P = .04). From the radiostereometric, radiographic, and clinical data, we conclude that the PFC-Sigma knee prosthesis can be used with confidence.

A randomised controlled trial of cemented versus cementless press-fit condylar total knee replacement

We report the long-term survival of a prospective randomised consecutive series of 501 primary knee replacements using the press-fit condylar posterior cruciate ligament-retaining prosthesis. Patients received either cemented (219 patients, 277 implants) or cementless (177 patients, 224 implants) fixation. Altogether, 44 of 501 knees (8.8%) underwent revision surgery (24 cemented vs 20 cementless). For cemented knees the 15-year survival rate was 80.7% (95% confidence interval (CI) 71.5 to 87.4) and for cementless knees it was 75.3% (95% CI 63.5 to 84.3). There was no significant difference between the two groups (cemented vs cementless; hazard ratio (HR) 0.83, 95% CI 0.45 to 1.52, p = 0.55). When comparing the covariates there was no significant difference in the rates of survival between the side of operation (HR 0.58, p = 0.07), age (HR 0.97, p = 0.10) and diagnosis (HR 1.25 p = 0.72). However, there was a significant gender difference, with males having a higher failure rate with cemented fixation (HR 2.48, p = 0.004). Females had a similar failure rate in both groups. This single-surgeon series, with no loss to follow-up, provides reliable data of the revision rates of one of the most commonly-used total knee replacements. The survival of the press-fit condylar total knee replacement remained good at 15 years, irrespective of the method of fixation.

Survivorship Analysis at 15 Years of Cemented Press-Fit Condylar Total Knee Arthroplasty

We performed a survival analysis on 354 cemented primary press-fit condylar total knee arthroplasties in 277 patients with prospective follow-up (mean, 8.8 years; range, 0.3-16.9 years). The number of patients alive reaching 15 years at follow-up for survival analysis was 15. The cumulative survival rate at 15 years was 81.7% (95% confidence interval, 72.1%-88.5%), using revision for all causes as our end point. Indications for revision in our patient group were aseptic loosening 4.5%, infection 2.3%, and exchange of polyethylene insert 1.1%. Our results indicate that the cemented press-fit condylar total knee arthroplasty has a good long-term survival, at 15 years, based on revision as the end point.

THE MARK COVENTRY AWARD: Sterilization and Wear-related Failure in First- and Second-generation Press-fit Condylar Total Knee Arthroplasty

We compared the incidence of wear-related failures between two large cohorts of patients undergoing total knee arthroplasty implanted with identical modular tibial trays and polyethylene inserts sterilized by different methods. A total of 1183 second-generation press-fit condylar prostheses having inserts packaged and sterilized in an oxygen-free environment were assessed at a minimum 5-year followup (mean, 7.0 years). Wear-related failure was defined as (1) osteolysis greater than 100 mm2 or (2) revision of the implant resulting from osteolysis, polyethylene wear, chronic synovitis, and/or effusion. Wear-related survivorship was calculated using Kaplan-Meier survival analysis. Results were compared with our previously published study of 1287 first-generation press-fit condylar modular knees having inserts sterilized by gamma irradiation in air at 5-year minimum followup (mean, 7.8 years). The wear-related failure rate for the second-generation design was 1.1% and 10-year survivorship was 97.0% compared with 8.3% failure and 87.7% 10-year survival for the first-generation design. For second-generation components, patient age was the only variable correlated with wear-related failure. For first-generation components sterilized in air, several variables were correlated to wear-related failure with shelf age of the polyethylene insert being the most important factor. These data emphasize the dramatic effect improvements in polyethylene manufacturing, specifically sterilization methods, can have on implant survivorship. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Press-Fit Condylar Design Total Knee Arthroplasty

The Press-Fit Condylar total knee arthroplasty implant design has been used by many orthopaedic surgeons over the last twenty years. The design has survived with relatively minor modifications and remains a popular implant system today. The present study represents the fourteen to seventeen-year results for our patients who were described in our previous report on the eight to ten-year results. The senior author performed 160 consecutive total knee arthroplasties with use of the Press-Fit Condylar cruciate-retaining device in 134 patients between 1986 and 1989. The mean age of the patients at the time of the index procedure was 70.5 years. Follow-up data were available for sixty-three of sixty-four surviving knees. Surviving patients were followed for a mean of 15.8 years. The knees were evaluated on the basis of Knee Society function and clinical scores, radiographs, and survivorship analysis. The mean Knee Society function score was 65, and the mean clinical score was 89. The overall survival rate of the knee was 91.5% with revision for any reason as the end point and 97.2% with aseptic loosening as the end point. The rate of revision of the tibial insert because of wear-related aseptic loosening was 2.5%. We found no relationship between revision and the shelf life or method of sterilization of the polyethylene insert. Radiolucent lines were present in 62% (twenty-one) of thirty-four knees; all radiolucent lines were nonprogressive. None of the implants were loose according to the criteria of the Knee Society. This long-term analysis indicates that the Press-Fit Condylar total knee implant is a successful implant system with excellent longevity.

Patellar Resurfacing in Total Knee Arthroplasty

Background: Anterior knee pain following total knee arthroplasty is a common complaint and typically is attributed to the patellofemoral joint. The purpose of the present study was to compare the outcome of resurfacing and nonresurfacing of the patella, particularly with regard to anterior knee pain, and to clarify the indications for patellar resurfacing at the time of total knee arthroplasty. Methods: We performed a prospective, randomized study of 514 consecutive primary press-fit condylar total knee replacements. The patients were randomized to either resurfacing or retention of the patella. They were also randomized to either a cruciate-substituting or a cruciate-retaining prosthesis as part of a separate trial. The mean duration of follow-up was 5.3 years (range, two to 8.5 years), and the patients were assessed with use of the Knee Society rating, a clinical anterior knee pain score, and the British Orthopaedic Association patient-satisfaction score. The assessment was performed without the examiner knowing whether the patella had been resurfaced. At the time of follow-up, there were 474 knees. Thirty-five patients who had a bilateral knee replacement underwent resurfacing on one side only. Results: The overall prevalence of anterior knee pain was 25.1% (fifty-eight of 231 knees) in the nonresurfacing group, compared with 5.3% (thirteen of 243 knees) in the resurfacing group (p < 0.0001). There was one case of component loosening. Ten of eleven patients who underwent secondary resurfacing had complete relief of anterior knee pain. The overall postoperative knee scores were lower in the nonresurfacing group, and the difference was significant among patients with osteoarthritis (p < 0.01). There was no significant difference between the resurfacing and nonresurfacing groups with regard to the postoperative function score. Patients who had a bilateral knee replacement were more likely to prefer the resurfaced side. Conclusions: As the present study showed a significantly higher rate of anterior knee pain following arthroplasty without patellar resurfacing, we recommend patellar resurfacing at the time of total knee replacement when technically possible. Level of Evidence: Therapeutic study, Level I-1a (Randomized controlled trial [significant difference]). See Instructions to Authors for a complete description of levels of evidence.

Press fit condylar total knee arthroplasty: radiographic evaluation at a 5-year follow-up

The three standard views are necessary for the radiographic evaluation of a total knee arthroplasty, by the measurement of knee alignment, components position and prosthetic interface. We radiographically evaluated 100 Press-Fit Condylar (PFC) total knee replacements in 66 women and 18 men (mean age, 69.5 years), at a mean follow-up of 5 years. The indication for implantation was osteoarthritis in 87% of the cases and rheumatoid arthritis in 11%. Radiographs were done at 3 and 6 months and then every year after implant, and each time were compared to the postoperative controls. The postoperative alignment had in 98% of the knees a valgus angle between 5° and 7°. Radiolucencies were found around the femoral component in 8% of the knees, and in the views of the tibial tray in 33%. The thicknesess of the radiolucent lines was 1 mm and was not progressive in 98% of the prostheses. One case presented aseptic loosening signs. Evaluation of total joint arthroplasty must be clinical, radiological and with annual intervals, in order to discover early failure signs. Concerning the present study, aseptic loosening is not a complication of the total knee arthroplasty evaluated for a medium follow-up of five years.

A randomised, controlled trial of cemented versus cementless press-fit condylar total knee replacement

We have carried out a long-term survival analysis of a prospective, randomised trail comparing cemented with cementless fixation of press-fit condylar primary total knee replacements. A consecutive series of 501 replacements received either cemented (219 patients, 277 implants) or cementless (177 patients, 224 implants) fixation. The patients were contacted at a mean follow-up of 7.4 years (2.7 to 13.0) to establish the rate of survival of the implant. The ten-year survival was compared using life-table and Cox’s proportional hazard analysis. No patient was lost to follow-up. The survival at ten years was 95.3% (95% CI 90.3 to 97.8) and 95.6% (95% CI 89.5 to 98.2) in the cemented and cementless groups, respectively. The hazard ratio for failure in cemented compared with cementless prostheses was 0.97 (95% CI 0.36 to 2.6). A comparison of the clinical outcome at ten years in 80 knees showed no difference between the two groups. The survival of the press-fit condylar total knee replacement at ten years is good irrespective of the method of fixation and brings into question the use of more expensive cementless implants.

The Results of PFC Total Knee Arthroplasty: comparative study of cruciate retaining versus substitution and cement versus cementless fixation

Purpose : To analyze clinical, radiological results and survival rates of Press Fit Condylar total knee arthroplasty and compare the results of cruciate-retaining versus cruciate-substitution, and cement versus cementless fixation. Materials and Methods : We analyzed 364 patients, 520 knees, which had undergone PFC total knee arthroplasty during the period January 1988 to January 1999. Average follow-up period was 7.1 years (3-14 years). Cases were divided into 2 categories: cruciate-retaining (CR) versus substitution (CS) and cement versus cementless fixation. The clinical results were evaluated using the Hospital for Special Surgery knee scoring system and radiological results were obtained by measuring tibiofemoral angle using Bauer’s method. Survivorship analysis was performed using Kaplan-Meier method with revision for any reason as the end point. Results : Clinical, radiological results and the survival rate in the cruciate substitution group were slightly better than those of the cruciate retaining group but no statistical difference was found. Survival rate in the cemented group was significantly higher than that in the cementless group. Clinical and radiological results of the cemented group were better but there was no statistical significance between the two groups. Conclusion : No differences were found in the postoperative results of the CR and CS groups. Survival rate in the cemented group was superior to that of the cementless group, which was used even in good bone stock and less deformed cases. This results may be related to a design problem of the cementless prosthesis.

The effect of surgeon experience on component positioning in 673 press fit condylar posterior cruciate-sacrificing total knee arthroplasties

Abstract: Component angles of 673 Press Fit Condylar (PFC) total knee arthroplasties were measured from standard short-leg radiographs. The femoral and tibial resections were performed with intramedullary and extramedullary instrumentation. The mean coronal tibial component angle was 88.59° (SD, 2.28°; range, 78-98°), with 17.1% having values <87° and 1.9% having values >93°. The mean coronal femoral component angle was 97.43° (SD, 3.44°; range, 84-115°), with 9.1% having values <94° and 13.1% having values >100°. An ideal tibiofemoral angle of 4° to 10° of valgus was achieved in 75.3% of patients, being <4° in 18.6% and >10° in 6.1%. Alignment was not significantly different between consultant and trainee surgeons. Although varus positioning of the tibial component was the commonest error, the wide range of femoral component angles signifies problems with standard intramedullary femoral guides.

Survival analysis of cemented Press-Fit Condylar total knee arthroplasty

We performed a survival analysis on 354 cemented primary Press-Fit Condylar (PFC) total knee arthroplasties (TKA) in 277 patients with prospective follow-up (mean, 6 years; range, 2-11.7 years). No patient was lost to follow-up. Using revision for all causes as the endpoint, the cumulative survival rate at 10 years was 95.5% (95% confidence interval, 90.1%-98.1%). The 10-year clinical outcome available on 41 patients was good, with significant improvement in pain and mobility assessments using the Nottingham data collection system. Our results indicate that the cemented PFC TKA has good long-term survival based on revision as the endpoint. Revision for implant failure is rare and brings to question modifications to this prosthesis.

The Press-Fit Condylar total knee system: 8- to 10- year results with a posterior cruciate-retaining design

A total of 108 consecutive Press-Fit Condylar total knee arthroplasties were performed in 94 patients. All patients had implantation with a cemented posterior cruciate-retaining design, which included resurfacing of the patella. Mean age at surgery was 70 years (range, 35-87 years). Patients were followed for a mean of 9 years (range, 8-10 years) with follow-up for all surviving patients. The average postoperative functional knee score was 96 points. Nonprogressive radiolucent lines were present in 59%. One patellar component was radiographically loose. Five knees underwent revision procedures, none for aseptic loosening. Survivorship was 93.4% at 9 years with revision for any reason as the endpoint and 98.7% with aseptic loosening as the endpoint. This knee arthroplasty shows excellent results at 8 to 10 years with no patients lost to follow-up.

Failure of a cemented all-polyethylene patellar component of a press-fit condylar total knee arthroplasty

A 65-year-old woman had a posterior cruciate-retaining cemented Press-Fit Condylar (PFC; Johnson & Johnson Professional, Inc., Raynham, MA) knee replacement with resurfacing of the patella using a cemented all-polyethylene, 3-peg component. Five years postoperatively, the patient developed anterior knee pain. The patella tracked normally, but radiographs showed a shift of the patellar component. At revision, there was shear failure of all 3 fixation pegs and loosening of the component. Revision with a cemented Press-Fit Condylar Sigma patellar 3-peg component (Johnson & Johnson Professional, Inc., Raynham, MA) was performed.

Cement Versus Cementless Fixation In Total Knee Arthroplasty

A prospectively studied group of 55 uncemented Press Fit Condylar total knee arthroplasties was compared retrospectively with a matched group of 51 cemented Press Fit Condylar total knee arthroplasties at a mean of 10 years after operation. For the cemented group, the pain and function scores improved from 32 and 45 preoperatively to 95 and 77, respectively. For the uncemented group the scores improved from 33 and 50 preoperatively to 93 and 60, respectively. There were 10 revisions in the uncemented group for femoral or tibial aseptic loosening or osteolysis compared with two revisions in the cemented group. Exclusive of problems related to patellar metal backing, survival to revision for aseptic failure or radiographic loosening was 72% in the uncemented group and 94% in the cemented group at 10 years. A significantly higher revision rate was found in the uncemented compared with cemented total knee arthroplasty of the Press Fit Condylar design.

Cemented versus uncemented press fit condylar total knee arthroplasty: Results of a matched pair study at ten years

Cemented versus uncemented press fit condylar total knee arthroplasty: Results of a matched pair study at ten years

Press-fit condylar total knee arthroplasty: 5- to 9-year follow-up evaluation

Between November 1984 and December 1987, 378 consecutive Press-Fit Condylar (PFC, Johnson & Johnson Professional, Raynham, MA) total knee arthroplasties were performed in 290 patients. The average age at surgery was 67 years (range, 22–91 years). The average follow-up period was 6.5 years (range, 5–9 years). Scoring was carried out according to the Knee Society scoring system. The average preoperative knee score was 28, and the average postoperative knee score was 88. The average preoperative functional knee score was 49, and the average postoperative functional knee score was 72. Ninety-five percent of the patients had no pain on level walking and were satisfied with their functional result. The average postoperative knee flexion was 110°. No implant showed any evidence of radiographic loosening. There were 17 complications, all requiring reoperation. Complications included excessive wear of a metal-backed patella in 8 knees. If complications resulting from the earlier use of a metal-backed patella are eliminated, the overall complication rate is 2.9%, which is comparable to or lower than the rates for other total knee systems with similar follow-up periods.

The incidence and causes of re-operation after press-fit condylar (PFC) total knee arthroplasty

One thousand consecutive posterior cruciate-retaining primary total knee arthroplasties were retrospectively reviewed to determine the incidence and reasons for reoperation (Table 1). Follow-up ranged from 2 to 11 years, with an average follow-up of 6 years. There were 35 re-operations — an incidence of 3.5%. Complications were divided into those associated with the femoral component, the tibial component, patello-femoral articulation, and miscellaneous problems.The prosthesis utilized during this study was the press-fit condylar (PFC), (Johnson and Johnson, Raynham, Mass, USA).10 The first implant was in November 1984 (Fig. 1).

Kinematic condylar total knee arthroplasty. 14-year survivorship analysis of 208 consecutive cases.

We performed an independent survivorship analysis on 208 Kinematic Condylar knee replacements with a minimum follow-up of ten years and a mean of 12 years. Seven patients had been lost to follow-up. At ten years the estimated survival was 92% (95% confidence limits 95% and 87%) and when stratified for diagnosis and thickness of polyethylene there was no statistical difference (p > 0.05) in survivorship of knees with osteoarthritis or rheumatoid arthritis. We conclude that the original design of the Kinematic Condylar knee replacement has a good record and that adequate evaluation of new designs of implant should be undertaken before they are widely introduced.