Buechel et al. in 2001 [5] presented the results of cemented and cementless New Jersey Low Contact Stress (LCS®) bicruciate sacrificing rotating platform TKRs after minimum 10 years follow up. The authors also compared results with a group of patients that had received the LCS, PCL retaining mobile bearing TKR. They reported excellent results for both cemented and uncemented RP TKRs at minimum follow-up of 10 years. More specifically, in the cemented RP primary TKR group (15 TKRs in 11 patients) the mean follow-up time was 173 months. In the cementless primary RP TKR group (47 TKRs in 35 patients) the mean follow-up time was 149 months. In the first group (cemented RP TKR) there was one patient with rotating platform dislocation. No bearing failures or component loosening were seen in patients of the second group (cementless RP TKR). Using as end point revision for any component loosening in patients with primary RP TKR the 20 year’s survivorship was 95.8 % and 99.4 % for cemented and cementless prostheses respectively. Similar excellent results were obtained for the LCS® PCL retaining mobile bearing TKR.

In another study, Huang et al. [20] presented the results of LCS® RP TKR versus the LCS PCL retained meniscal-bearing prostheses (mixed cemented and cementless). The minimum follow-up was 10 years (range 10–15 years). There were 228 knees with the meniscal bearing prostheses and 267 knees with RP prostheses. Kaplan-Meier survivorship analysis at 15 years gave 83 % survival rate for the meniscal bearing prostheses and 92.1 % survival rate for the RP prostheses. There were two early and five late (8–12 years after replacement) polyethylene dislocations in the RP TKR group. Osteolysis at the time of revision was seen in eight patients with RP TKR. The authors concluded that RP TKR performed better than the LCS meniscal bearing TKR. However, they mentioned that RP TKR results were not superior to the fixed bearing TKR designs.

In 2005, John Callaghan and colleagues [7], reported the results of the cemented LCS RP TKR with a minimum follow-up of 15 years (range 15–18 years). From an original study cohort of 86 patients (119 knees), 39 knees were available for clinical and radiological examination from 28 living patients. The authors reported excellent results, with no revision for component aseptic loosening or poor clinical results. They concluded that the cemented LCS RP is a durable TKR with results as good as those reported for fixed bearing TKR designs.

Few years later, in 2010, John Callaghan and colleagues reported results of the previous patient series at a minimum follow-up of 20 years [8]. Twenty patients (26 knees), had clinical and radiological follow-up at an average of 21 years (range 20–21 years). Authors reported that no knee required revision of any component at a minimum 20-year follow-up. One knee had radiological loosening of the femoral component. Six knees had osteolytic lesions. No knee demonstrated instability or polyethylene spin-out. The authors confirmed their previous findings regarding the durability of cemented LCS RP TKR at 20 years follow-up. They stated that these results are similar if not better than the 20 year results of other TKR devises. However, they acknowledge the fact that the average age of patients was 70 years, with only three patients under the age of 50 at the time of surgery.

Kim et al. [25] performed one-stage bilateral primary cemented TKRs in 160 patients using a fixed bearing PCL retaining TKR design (AMK; DePuy, Warsaw, Indiana) to the one side and the LCS (DePuy, Warsaw, Indiana) RP PCL sacrificing TKR at the other side of patients. 146 patients (292 knees) were available for clinical and radiological evaluation (including CT scan at the final follow-up) at a mean of 13.2 years (range 11–14.5 years). Results revealed that there was no statistical difference regarding the pre-op and post-op Hospital for Special Surgery scores, Knee society scores, range of movement or patients’ preference regarding their prostheses. Also, there was no difference regarding the radiological findings, including evidence of radiolucent lines around any of the components and lateral tilting of the patella. In the LCS RP TKR group there were two revisions for instability and one for infection. Survival with revision for any reason defined as an end point at 14.5 years post-operatively was 97 % for the AMK prostheses and 98 % for the LCS RP prostheses. Authors concluded that both prostheses yielded good results but provided no evidence to prove the superiority of the mobile-bearing over the fixed-bearing TKR.

Meftah et al. [32] presented the results of 10 years follow-up of cemented RP posterior stabilized TKR (PFC Sigma, DePuy, Warsaw, Indiana). Eighty-nine patients (106 knees) were followed-up for mean 10 years (range 9.5–11 years). They reported that at the latest follow-up 96 % had a good to excellent result according to the Knee Society pain score. Radiographic evaluation showed no mal-alignment, spin-out, aseptic loosening, or osteolysis. Survival of the prostheses with revision for any reason as an end point was calculated to 97.7 % at 10 years.

Argenson et al. [2] prospectively followed-up 104 patients (108 knees) that received a posterior-stabilized, rotating platform, total knee arthroplasty device (LPS- Flex Mobile; Zimmer, Warsaw, Indiana) for a minimum of 10 years (mean 10.6 years -range, 10–11.8 years). The authors reported no periprosthetic osteolysis and no evidence of implant loosening on follow-up radiographs. The average Knee Society knee and function scores improved from 34 to 94 points and from 55 to 88 points, respectively. Two knees were revised, one because of infection and one because of failure of the medial collateral ligament as the result of a fall. There was no spinout of polyethylene insert. The 10-year survival rate, with revision for any reason as the end point was calculated to be 98.3 %.

In another interesting prospective randomized trial, Kim et al. [24] evaluated the long-term clinical and radiographic results of fixed-bearing TKR (AMK; DePuy, Warsaw, Indiana) and mobile-bearing, rotating platform TKR (LCS RP; DePuy) in patients with osteoarthritis younger than 51 years of age. One hundred eight patients (216 knees) were included in the study. All patients had simultaneous bilateral sequential total knee arthroplasties and had a fixed-bearing implant in one knee and a mobile-bearing implant in the other. The mean follow-up period was 16.8 years (range, 15–18 years). At the latest follow-up there was no significant difference between the two groups to the studied parameters, including the Knee Society clinical score and Hospital for Special Surgery knee score, the range of movement and the alignment of the knee. Radiographic analysis and CT scans showed tibial osteolysis in two knees (2 %) in the fixed bearing TKR group, but no tibial osteolysis in the LCS RP group. There were five revisions in the fixed bearing TKR group (one for infection, two for wear of the polyethylene and two for aseptic loosening) and three revision in the LCS RP group (one for infection and two for instability). The rate of survival, at 16.8 years postoperatively, was 95 % for the AMK fixed bearing prosthesis and 97 % for the LCS RP prosthesis, when revision was defined as the end point. The authors concluded that no significant advantage could be demonstrated between fixed bearing and mobile bearing prostheses in this group of patients younger than 51 years old.

In a more recent study, Ulivi et al. [41] prospectively evaluated the long-term performance of a cemented posterior stabilized rotating platform TKR design (PFC Sigma, DePuy, Warsaw, Indiana). One hundred twelve knees were followed up for minimum 10 years (mean 11.5 ± 1.4 years). Five patients (3 %) had undergone revision; one for aseptic loosening, one due to infection and two patients due to anterior knee (patella) pain. These two patients underwent patella resurfacing. All patients had significant improvement to the tested clinical scores, including the Knee Society Score (KSS) and the Oxford Knee Score and the Visual Analogue Scale (VAS) score. Interestingly, the prevalence of anterior knee pain at final follow-up was 16.2 % (17 knees). Of note is that no patient had patella resurfacing during the initial surgery. Survivorship analysis revealed 96.6 % survival at 11.5 years when we consider revision for any cause and a 100 % survival with mechanical failure as endpoint.

There are several well conducted systematic reviews and meta-analyses published in the so far literature, comparing mobile –bearing versus fixed-bearing TKR designs [6, 22, 27, 34, 38, 39, 42, 44]. These studies have failed to show significant differences regarding the clinical scores, the radiological results, the prostheses related complications, the patient preference or the overall survivorship of the prostheses. Most of the studies, however, included mixed mobile bearing designs and short to mid-term follow-up time. On the other hand, Hopley et al. [18] recently published a well-designed meta-analysis, of papers reporting survivorship and clinical and function Knee Society Scores (KSS) of the LCS RP TKR. Outcomes were compared with non-LCS knees in the Swedish knee registry. Results revealed that the KSS scores were comparable for LCS RP and non-LCS RP knees at up to 15 years of follow-up. Excluding studies with less than mean 10 years follow-up, the authors reported incidence of osteolysis and loosening 1.4 % and incidence of instability (including spin-out) 1.4 % for the LCS RP group. Interestingly, the overall survivorship of the LCS RP TKR implanted between 1981 and 1997 and 1988 and 2005 was higher than that reported in the Swedish Knee Registry for knees implanted between 1991 and 1995 and 1996 and 2009, respectively.

Our personal (unpublished) experience with RP TKA designs the last 15 years has been excellent. We have not experienced complications, other than infections, and we have not revised any prostheses due to instability, loosening or wear.