This study reports the first 10-year clinical and radiological follow-up data for the Sigma PFC. The DuPuy Sigma total knee arthroplasty (TKA) is a modification of the well established Press Fit Condylar (PFC) TKA and is used extensively in the UK and worldwide. It is the most commonly used TKA in England and Wales, where it accounts for 34% of all primary TKA. A total of 235 consecutive Sigma TKAs were performed in 203 patients between October 1998 and October 1999, in our unit. Patients were seen at a specialist nurse led clinic 7 to 10 days before admission and at 6 months, 18 months, 3 years, 5 years and 7-10 years after surgery. Data was recorded prospectively at each clinic visit. Radiographs were obtained at the 5 year and 8-10 year follow-up appointment. Of 235 knees 171 (147 patients) were alive at 10 years. Twelve were lost to follow up. Nine knees (3.8%) were revised; five for infection and four underwent change of polyethylene insert. Ten-year survival with and end point of revision for any reason was 95.9%, and with and endpoint of revision for aseptic failure was 98.7%. The mean American Knee Society score was 62 at 8-10 years compared with 31 out of 100 pre-operatively. Of 109 radiographs, 47 knees had radiolucent lines but none showed radiological evidence of loosening. Our results show that the PFC Sigma knee arthroplasty performs well over the first 10 years post implantation

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. Cite this article: Bone Joint J 2013;95-B:177–80

This retrospective study evaluates the midterm results of the Rotating Platform PFC Sigma Total Knee Arthroplasty System. We reviewed 161 cases in 147 patients with an average follow-up of 5 years (4 to 7 years) operated on at our institution between June 2001 and June 2004. Patient outcomes were measured using the Oxford and American Knee Society Scores and radiographs underwent independent radiological evaluation. Average pre-operative Oxford Scores improved from 43(29-55) to 21 (13 - 44) postoperative;y and average Knee Society Scores improved from 57 (43-70) preoperatively to 80 (58-90) at last follow up. Range of movement improved from 91 degrees (70 - 110) to 113 degrees (75 - 130). There were 5 complications reported; one superficial infection treated with antibiotics, one patient required manipulation under anaesthesia at 3 months for post operative stiffness, which improved. There was one arthrotomy for dislocation of the bearing immediate postoperatively. There was one case of DVT and one non-fatal PE. There were no deep infections. The PFC Sigma Knee Rotating Platform system offers excellent mid-term results in our review

We set out to demonstrate the 10-year survivorship of the PFC sigma TKA in a young patient group. Demographic and clinical outcome data were collected prospectively at 6 months, 18 months, 3 years, 5 years and 8-10 years post surgery. The data were analysed using Kaplan Meier survival statistics with end point being regarded as death or revision for any reason. 203 patients were found to be ≤55 years at the time of surgery. Four patients required revision and four patients died. Another four patients moved away from the region and were excluded from the study. A total of 224 knees in 199 patients (101 male and 98 females.) 168 patients had a diagnosis of Osteoarthritis and 28 with inflammatory arthritis. Average age 50.6 years range 28-55 years (median 51). Ten-year survivorship in terms of revision 98.2% at ten years 95% confidence interval. Our results demonstrate that the PFC Sigma knee has an excellent survival rate in young patients over the first 10 years. TKR should not be withheld from patients on the basis of age

Aims

This study compares the PFC total knee arthroplasty (TKA) system in a prospective randomized control trial (RCT) of the mobile-bearing rotating-platform (RP) TKA against the fixed-bearing (FB) TKA. This is the largest RCT with the longest follow-up where cruciate-retaining PFC total knee arthroplasties are compared in a non-bilateral TKA study.

Introduction

Previous studies comparing cruciate retaining (CR) and cruciate sacrificing - posterior stabilised (PS) TKRs have failed to demonstrate a difference in outcomes based on numbers of patients recruited.

This large study compares clinical outcomes in groups having PS and CR TKR and reports the results at 1 and 2 years post-operatively.

Aims. The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery. Methods. A total of 454 consecutive patients who underwent cementless TKA between August 2004 and December 2021 were reviewed. The mean follow-up was ten years. Plain radiographs were analyzed for radiolucent lines. Patients who underwent revision TKA were recorded, and the cause for revision was determined. Data from the National Joint Registry for England, Wales, Northern Island, the Isle of Man and the States of Guernsey (NJR) were compared with our series. Results. No patients in our series had evidence of radiolucent lines on their latest radiological assessment. Only eight patients out of 454 required revision arthroplasty, and none of these revisions were indicated for aseptic loosening of the tibial baseplate. When compared to data from the NJR annual report, Kaplan-Meier estimates from our series (2.94 (95% confidence interval (CI) 1.24 to 5.87)) show a significant reduction in cumulative estimates of revision compared to all cemented (4.82 (95% CI 4.69 to 4.96)) or cementless TKA (5.65 (95% CI 5.23 to 6.10)). Our data (2.94 (95% CI 1.24 to 5.87)) also show lower cumulative revision rates compared to the most popular implant (PFC Sigma Cemented Knee implant fixation, 4.03 (95% CI 3.75 to 4.33)). The prosthesis time revision rate (PTIR) estimates for our series (2.07 (95% CI 0.95 to 3.83)) were lower than those of cemented cases (4.53 (95% CI 4.49 to 4.57)) from NJR. Conclusion. The NexGen trabecular (tantalum) cementless implant has lower revision rates in our series compared to all cemented implants and other types of cementless implants, and its use in younger patients should be encouraged. Cite this article: Bone Jt Open 2024;5(4):277–285

Introduction. Both mobile bearing and fixed bearing unicompartmental knee arthroplasty (UKA) have demonstrated clinical success. However, much debate persists about the superiority of a single design. Currently most clinical data is based on high volume centers data, however to reduce bias, we undertook a through review of retrospective national joint registries. In this study, we aim to investigate UKA implant utilization and survivorship between 2000 and 2018. Methods. Ten annual joint registry reports of various nations were reviewed. Due to the variable statistical methods of reporting implant use and survivorship we focused on three registries: Australia (AOANJRR), New Zealand (NZJR), United Kingdom (NJR) for uniformity. We evaluated UKA usage, survivorship, utilization and revision rates for each implant. Implant survivorship was reported in the registries and was compared within nations due to variation in statistical reporting. Results. UKAs accounted for 7.24–10.3% of all primary knee surgeries. The most popular implants were, in order of popularity, the Oxford (ZimmerBiomet, Warsaw IN), ZUK (Smith & Nephew, Memphis TN / LimaCorporate, Udine, Italy), Sigma HP (DePuy, Warsaw IN), Miller-Galante (ZimmerBiomet Warsaw IN), and Preservation (DePuy, Warsaw IN) models. UKA revision rates varied by nation and ranged from 8.22%–12.8%. The Sigma HP and ZUK designs had the lowest total percent revised in the registries-Australian (3.6% and 5.1%, respectively) and New Zealand (2.5% and 1.96%, respectively)-and demonstrated among the highest 10-year survivorship in the United Kingdom registry. The United Kingdom registry reports a greater number of mobile versus fixed bearing UKA undergoing revision for dislocation and/or subluxation and instability. Conclusion. Preference for implant design as well as survivorship rates varied significantly by nation. The fixed bearing ZUK and Sigma HP implants were among the highest performing implants across the three registries

Abstract. Introduction. The role of patellar resurfacing in total knee arthroplasty remains controversial. We questioned the effect of patellar resurfacing on the early and late revision rates after total knee arthroplasty. Materials and Methods. We analysed the data of cumulative revisions of primary knee replacement from the NJR 19th Annual Report. NJR included secondary patellar resurfacing as a revision. We compared differences in the 3-year and 15-year revision rates between the patellar resurfacing and non-resurfacing for the different combinations of total knee replacements using a paired t-test. We performed subgroup analysis for the five combinations with the highest volumes. Results. Twenty-seven implant combinations had the 15-year revision rates reported. Patellar resurfacing group had lower mean 3-year revision rate of 1.68 (SD 0.7) compared to 2.02 (SD 0.9) in non-resurfacing group (p=0.05). However, 15-year revision rate was similar between the two groups (mean 5.7, SD 2.1 vs. mean 5.7, SD 2.2; p = 0.46). High volume implants showed that two combinations (NexGen CR and PS) had similar revision rates at 3 and 15 years between resurfacing and non-resurfacing groups. Three combinations (PFC Sigma CR and PS and Genesis 2 CR) had higher revision rate in non-resurfacing group at 3 years (p=0.01) and the difference persisted at 15 years (p=0.05). Conclusions. Although revision rate in total knee arthroplasty was higher without patellar resurfacing at 3 years, at 15 years the difference was not significant. However, the higher revision without patellar resurfacing can be prosthetic combination specific which surgeons need to be aware of

This retrospective study evaluated the midterm clinical and radiographic outcomes of a second-generation total knee replacement system. In a multicentre consecutive series of 1512 patients, 1970 knees were treated with the PFC Sigma knee system (Depuy, Warsaw, Indiana). The patients were reviewed for functional outcome, and underwent independent radiographic evaluation at a mean follow-up of 7.3 years (5 to 10). A total of 40 knees (2%) required revision, 17 (0.9%) for infection. The incidence of osteolysis was 2.2%. The ten-year survival with revision for any cause other than infection as the endpoint was 97.2% (95% CI 95.4 to 99.1). The PFC Sigma knee system appears to provide excellent results in the medium term

Aims. The outcomes of total knee arthroplasty (TKA) depend on many factors. The impact of implant design on patient-reported outcomes is unknown. Our goal was to evaluate the patient-reported outcomes and satisfaction after primary TKA in patients with osteoarthritis undergoing primary TKA using five different brands of posterior-stabilized implant. Patients and Methods. Using our institutional registry, we identified 4135 patients who underwent TKA using one of the five most common brands of implant. These included Biomet Vanguard (Zimmer Biomet, Warsaw, Indiana) in 211 patients, DePuy/Johnson & Johnson Sigma (DePuy Synthes, Raynham, Massachusetts) in 222, Exactech Optetrak Logic (Exactech, Gainesville, Florida) in 1508, Smith & Nephew Genesis II (Smith & Nephew, London, United Kingdom) in 1415, and Zimmer NexGen (Zimmer Biomet) in 779 patients. Patients were evaluated preoperatively using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lower Extremity Activity Scale (LEAS), and 12-Item Short-Form Health Survey questionnaire (SF-12). Demographics including age, body mass index, Charlson Comorbidity Index, American Society of Anethesiologists status, sex, and smoking status were collected. Postoperatively, two-year KOOS, LEAS, SF-12, and satisfaction scores were compared between groups. Results. Outcomes were available for 4069 patients (98%) at two years postoperatively. In multiple regression analysis, which separately compared each implant group with the aggregate of all others, there were no clinically significant differences in the change of KOOS score from baseline to two-year follow-up between any of the groups. More than 80% of patients in each group were satisfied at this time in all domains. In a multivariate regression model, patients in the NexGen group were the most likely to be satisfied (odds ratio (OR) 1.63; p = 0.006) and Optetrak Logic patients were the least likely to be satisfied (OR 0.60; p < 0.001). Conclusion. TKA provides improvement in function and satisfaction regardless of the type of implant. We could not demonstrate superiority of one design above others across these groups of implants, and any price premium for one above the other systems may not be justified. Healthcare administrators may find these similarities in outcomes helpful when negotiating purchasing contracts. Cite this article: Bone Joint J 2019;101-B(7 Supple C):48–54

Background. The purpose of this study was to evaluate the clinical and radiographic outcomes of the rotating-platform, posterior-stabilized PFC Sigma at fifteen-year follow-up. Methods. Between January 2000 and November 2001, two hundred consecutive patients underwent TKA with a rotating-platform, posterior stabilized total knee arthroplasty with cement. All patients have been followed prospectively and all patients with minimum 12 year follow up were included in this analysis. Forty-nine TKAs were available for our final analysis with a mean follow up of 16.0 years. Results. The improvements in Knee Society pain and function scores were 44 to 83. The 15-year Koos Jr interval scores for cohort was 76.2. The range of motion improved from 111° to 115°. The prevalence of residual pain was 32.5%, painless crepitation was 15% and 5% reporting painful crepitation at 15-year follow up via PROMs. Kaplan-Meier analysis revealed that the survivorship was 100% due to mechanical failure as an endpoint, and 95% as reoperation as an end-point. Conclusions. At fifteen-year follow up, the rotating-platform, posterior stabilized arthroplasty demonstrated excellent survivorship and radiographic results. Peripatellar crepitation, occasionally requiring excision, remains an issue. For figures, tables, or references, please contact authors directly

Aims

Loosening of components after total knee arthroplasty (TKA) can be associated with the development of radiolucent lines (RLLs). The aim of this study was to assess the rate of formation of RLLs in the cemented original design of the ATTUNE TKA and their relationship to loosening.

Aims

This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision.

We report the ten-year survival of a cemented total knee replacement (TKR) in patients aged < 55 years at the time of surgery, and compare the functional outcome with that of patients aged > 55 years. The data were collected prospectively and analysed using Kaplan-Meier survival statistics, with revision for any reason, or death, as the endpoint. A total of 203 patients aged < 55 years were identified. Four had moved out of the area and were excluded, leaving a total of 221 TKRs in 199 patients for analysis (101 men and 98 women, mean age 50.6 years (28 to 55)); 171 patients had osteoarthritis and 28 had inflammatory arthritis. Four patients required revision and four died. The ten-year survival using revision as the endpoint was 98.2% (95% confidence interval 94.6 to 99.4). Based on the Oxford knee scores at five and ten years, the rate of dissatisfaction was 18% and 21%, respectively. This was no worse in the patients aged < 55 years than in patients aged > 55 years. These results demonstrate that the cemented PFC Sigma knee has an excellent survival rate in patients aged < 55 ten years post-operatively, with clinical outcomes similar to those of an older group. We conclude that TKR should not be withheld from patients on the basis of age

This prospective randomised controlled double-blind trial compared two types of PFC Sigma total knee replacement (TKR), differing in three design features aimed at improving flexion. The outcome of a standard fixed-bearing posterior cruciate ligament-preserving design (FB-S) was compared with that of a high-flexion rotating-platform posterior-stabilised design (RP-F) at one year after TKR. The study group of 77 patients with osteoarthritis of the knee comprised 37 men and 40 women, with a mean age of 69 years (44.9 to 84.9). The patients were randomly allocated either to the FB-S or the RP-F group and assessed pre-operatively and at one year post-operatively. The mean post-operative non-weight-bearing flexion was 107° (95% confidence interval (CI) 104° to 110°)) for the FB-S group and 113° (95% CI 109° to 117°) for the RP-F group, and this difference was statistically significant (p = 0.032). However, weight-bearing range of movement during both level walking and ascending a slope as measured during flexible electrogoniometry was a mean of 4° lower in the RP-F group than in the FB-S group, with 58° (95% CI 56° to 60°) versus 54° (95% CI 51° to 57°) for level walking (p = 0.019) and 56° (95% CI 54° to 58°) versus 52° (95% CI 48° to 56°) for ascending a slope (p = 0.044). Further, the mean post-operative pain score of the Western Ontario and McMaster Universities Osteoarthritis Index was significantly higher in the RP-F group (2.5 (95% CI 1.5 to 3.5) versus 4.2 (95% CI 2.9 to 5.5), p = 0.043). Although the RP-F group achieved higher non-weight-bearing knee flexion, patients in this group did not use this during activities of daily living and reported more pain one year after surgery

Aims

This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates.

We describe a cohort of patients with a high rate of mid-term failure following Kinemax Plus total knee replacement inserted between 1998 and 2001. This implant has been recorded as having a survival rate of 96% at ten years. However, in our series the survival rate was 75% at nine years. This was also significantly lower than that of subsequent consecutive series of PFC Sigma knee replacements performed by the same surgeon. No differences were found in the clinical and radiological parameters between the two groups. At revision the most striking finding was polyethylene wear. An independent analysis of the polyethylene components was therefore undertaken. Scanning electron microscopy revealed type 2 fusion defects in the ultra-high molecular weight polyethylene (UHMWPE), which indicated incomplete boundary fusion. Other abnormalities consistent with weak UHMWPE particle interface strength were present in both the explanted inserts and in unused inserts from the same period. We consider that these type 2 fusion defects are the cause of the early failure of the Kinemax implants. This may represent a manufacturing defect resulting in a form of programmed polyethylene failure

This was a retrospective analysis of the medium- to long-term results of 46 TC3 Sigma revision total knee replacements using long uncemented stems in press-fit mode. Clinical and radiological analysis took place pre-operatively, at two years post-operatively, and at a mean follow-up of 8.5 years (4 to 12). The mean pre-operative International Knee Society (IKS) clinical score was 42 points (0 to 74), improving to 83.7 (52 to 100) by the final follow-up. The mean IKS score for function improved from 34.3 points (0 to 80) to 64.2 (15 to 100) at the final follow-up. At the final follow-up 30 knees (65.2%) had an excellent result, seven (15.2%) a good result, one (2.2%) a medium and eight (17.4%) a poor result. There were two failures, one with anteroposterior instability and one with aseptic loosening. The TC3 revision knee system, when used with press-fit for long intramedullary stems and cemented femoral and tibial components, in both septic and aseptic revisions, results in a satisfactory clinical and radiological outcome, and has a good medium- to long-term survival rate

We aimed to determine the reliability, accuracy and the clinical role of digital templating in the pre-operative work-up for total knee replacement. Initially a sample of ten pre-operative digital radiographs were templated by four independent observers to determine the inter- and intra-observer reliability of the process. Digital templating was then performed on the radiographs of 40 consecutive patients undergoing total knee replacement by a consultant surgeon not involved with the operation, who was blinded to the size of the implant inserted. The Press Fit Condylar Sigma Knee system was used in all the patients. The size of the implant as judged by templating was then compared to that of the size used. Good inter- and intra-observer agreement was demonstrated for both femoral and tibial templating. However, the correct size of the implant was predicted in only 48% of the femoral and 55% of the tibial components. Albeit reproducible, digital templating does not currently predict the correct size of component often enough to be of clinical benefit