An 8- to 10-year review of the Rotaglide total knee replacement

The Rotaglide mobile-bearing total knee arthroplasty: no difference between cemented and hybrid implantation

PURPOSE

The optimal fixation of the Rotaglide total knee arthroplasty's (TKA) components is controversial. It is hypothesized that the hybrid fixation (cementless femoral component) in a mobile-bearing TKA system might cause increased rate of loosening--especially in the femoral part--and finally failure of the arthroplasty. Consequently, the aim of this study was to compare the survival and revision rates and also the clinical and radiological outcomes of the cemented and hybrid fixation of the Rotaglide TKA.

METHODS

One hundred patients, who underwent TKA with the Rotaglide prosthesis, were randomly placed in two groups. In the first group, the prosthesis was cemented, and in the second group, the hybrid technique was used. Revision and mortality rates were compared after 8-12 years of follow-up. Knee and Osteoarthritis Outcome Score (KOOS) questionnaire and the Knee Society Roentgenographic Evaluation and Scoring System were used to demonstrate clinical and radiographic differences.

RESULTS

There were no statistically significant differences in revision (n.s.) or mortality (n.s.) rates between the two treatment arms. The clinical outcome at the time of last follow-up (mean 9.5 years, SD ± 1.4) ranged from very good to excellent (77.8 ± 17.5 for the cemented group and 77.2 ± 20.4 for the hybrid group). No statistically significant differences in all KOOS subscales. Radiographs showed no significant difference in prosthesis alignment and no evidence of loosening between groups.

CONCLUSION

The hypothesis that the hybrid fixation in a mobile-bearing TKA system might cause increased rate of loosening and finally failure of the arthroplasty was not confirmed. The fixation technique (cemented or hybrid) had no influence on the prosthesis's survivorship, and also on mortality rates, clinical and radiographic outcomes in a mean follow-up time of 9.5 ± 1.4 years. The Rotaglide TKA is a safe and reliable prosthesis regardless the fixation technique.

Elevated cytokine expression of different PEEK wear particles compared to UHMWPE in vivo

Due to their mechanical properties, there has been growing interest in poly-ether-ether-ketone (PEEK) and its composites as bearing material in total and unicompartmental knee arthroplasty. The aim of this study was to analyze the biological activity of wear particles of two different (pitch and PAN) carbon-fiber-reinforced- (CFR-) PEEK varieties in comparison to ultra-high-molecular-weight-polyethylene (UHMWPE) in vivo. The authors hypothesized no difference between the used biomaterials. Wear particle suspensions of the particulate biomaterials were injected into knee joints of Balb/c mice, which were sacrificed after seven days. The cytokine expression (IL-1β, IL-6, TNF-α) was analyzed immunohistochemically in the synovial layer, the adjacent bone marrow and the articular cartilage. Especially in the bone marrow of the two CFR-PEEK varieties there were increased cytokine expressions compared to the control and UHMWPE group. Furthermore, in the articular cartilage the CFR-PEEK pitch group showed an enhanced cytokine expression, which could be a negative predictor for the use in unicondylar knee systems. As these data suggest an increased proinflammatory potential of CFR-PEEK and its composites in vivo, the initial hypothesis had to be refuted. Summarizing these results, CFR-PEEK seems not to be an attractive alternative to UHMWPE as a bearing material, especially in unicompartmental knee arthroplasty.

The Rotaglide mobile bearing knee arthroplasty A 10- to 13-year review from an independent centre

The Rotaglide knee arthroplasty has a highly congruent mobile meniscal bearing allowing both rotation and antero-posterior translation. We reviewed 137 consecutive primary arthroplasties in 120 patients at mean 11.1 years (10-12.9) following surgery. No cases were lost to follow-up. Hospital for Special Surgery (HSS) and American Knee Society (AKSS) scores were recorded at a review clinic. Radiographs were assessed using the Knee Society's roentgenographic evaluation system. Forty-two patients had died, leaving 78 patients (87 knees) available for review. Sixty-four patients (70 knees) were assessed at a clinic and in 14 (17 knees) clinical outcomes were obtained via telephone and their most recent radiographs were assessed. There were three cases of aseptic loosening and one deep infection requiring revision surgery. Two meniscal bearings were replaced with thicker inserts, one following bearing fracture and one following bearing dislocation. Survival at 11 years for aseptic loosening was 97.6% (95% CI 94.3 to 1.0) and survival using re-operation for any cause was 95.3% (95% CI 90.8 to 99.8). The Rotaglide mobile-bearing total knee replacement demonstrates good survivorship and outcome scores at 11 years following surgery.

Rotaglide total knee arthroplasty: a long-term follow-up study

BACKGROUND

Mobile-bearing knee designs represent an alternative to conventional fixed-bearing implants in total knee arthroplasty. The purpose of this study was to determine the clinical results of a mobile-bearing knee implant.

METHODS

From 1990 to 1998, 326 primary consecutive mobile-bearing total knee prostheses were implanted in 260 patients who had a mean age and standard deviation of 66.7 ± 6.9 years. Femoral and tibial components were cemented in all knees, and the patella was resurfaced in 199 knees (61%). Patients were evaluated with the use of the Knee Society clinical rating system and radiographic examinations. Complications were noted, and survivorship of the prostheses was determined.

RESULTS

The mean follow-up period was 156 ± 27.3 months, with maximum follow-up at eighteen years. The mean Knee Society knee score improved from 32.4 ± 21.2 preoperatively to 92.6 ± 10.0 at the time of the last follow-up (p = 0.00), and the mean Knee Society functional score improved from 39.3 ± 18.7 preoperatively to 66.7 ± 18.6 at the time of the last follow-up (p = 0.00). Mean knee flexion improved from 92.3° ± 14.5° preoperatively to 112.1° ± 13.4° at the time of the last follow-up (p = 0.00). There were twenty-four (7.4%) knees that required revision. In eighteen (5.5%) knees, worn out or broken polyethylene was found and a polyethylene-only exchange was done. Six knees (1.8%) were fully revised. The survival rate was 0.96 (95% confidence interval, 0.93 to 0.98) at ten years and 0.87 (95% confidence interval, 0.79 to 0.93) at eighteen years.

CONCLUSIONS

A fully congruent, mobile-bearing total knee prosthesis had excellent survivorship during the ten to eighteen-year follow-up interval.

Mid-term survivorship results for a rotating-platform knee prosthesis

Interest in mobile-bearing knee prostheses is increasing in the US market. We studied results at 2 to 5 years with a mobile-bearing system that includes a cobalt-chrome tibial tray and femoral component with a polyethylene cruciate-retaining tibial component insert that allows rotation around a central axis and can be used with cruciate-retaining or posterior-stabilized femoral components. The inserts used in this study were cruciate retaining and did not include the posterior-stabilized design. The goal of this study was to demonstrate the function and safety of this prosthesis along with the lack of spinout, which is a major concern in the mobile-bearing knee. Four hundred thirty-five knees constituted the study cohort and underwent survivorship analysis and complication reporting. Routine clinic evaluations included pre- and postoperative radiographs and Knee Society knee and function scores at 6 and 12 weeks and every 2 years. The most recent follow-up data within 2 to 5 years was included for the study along with survey data. Flexion at most recent follow-up averaged 125°. Knee Society score at most recent visit averaged 88 of 100. Knee Society function score averaged 83 of 100. Radiographic results were available for 226 knees, with 97.3% assessed as normal and 6 with these issues: patella stress fracture (3), aseptic tibial loosening (1), patellar osteolysis (1), and patella aseptic loosening (1). In comparison with the fixed-bearing knee equivalent, this mobile-bearing knee demonstrated at least equivalent results in terms of survivorship, function, and patient satisfaction in the short- and mid-term.

Clinical and radiographic outcomes of Image-Based Computer-Assisted Total Knee Arthroplasty: An Evidence-based Evaluation

Conventional instrumentation systems have limited accuracy in determining the crucial landmarks needed for alignment in total knee arthroplasty (TKA). Given this, the image-based navigation system was introduced to improve the accuracy of implantation of components into the femur and tibia. PubMed, EMBASE, Web of Science, and Evidence-Based Medicine databases were electronically searched to identify eligible studies published until October 2008. A systematic review and meta-analysis of 6 randomized/quasi-randomized controlled trials that compared image-based navigation and conventional techniques was conducted. The operative time was longer in the navigation group in 3 studies. Moreover, there was a higher rate of achieving mechanical leg axis within the range of 3° deviation in patients undergoing navigated TKA. However, all studies between the 2 groups were similar in range of motion, knee scores, and postoperative complication rates at the last follow-up. Overall, these short-term follow-up trials show that there were similar early clinical outcomes between image-based navigation and conventional techniques.

Mid-term results with a highly congruous mobile-bearing knee prosthesis

Two hundred and six consecutive total knee arthroplasties were performed in 180 patients with a highly congruous mobile-bearing knee prosthesis. At mean follow-up of 78 months (range: 60-102 months), the outcomes of 181 knees in 158 patients were evaluated using the American Knee Society's Knee and Functional scoring system and Radiological scoring system. Mean values for Knee and Function scores were 92.6 and 81.1, respectively versus 51.8 and 43.4 preoperatively; mean flexion range was 113.6 degrees versus 110.8 degrees preoperatively. There were no cases of bearing dislocation and no radiological signs of loosening or osteolysis. Secondary patella resurfacing was done in 7 of 52 knees in which the patella was not primarily resurfaced. Arthroplasty survival with revision for aseptic loosening as the endpoint was 100% (95% CI: 97.7-100) at 5 years and at 8 years (95% CI: 87.2-100); with revision of the arthroplasty for any reason including one revision for infection as the endpoint, survival was 99.5% (95% CI: 96.9-100) at 5 years and at 8 years (95% CI: 86.9-100). The overall results were satisfactory and compared with those of other mobile-bearing knee prostheses featuring full or partial congruence. No significant differences were noted for range of motion, knee scores and function scores between two subsets of knees that received a bearing allowing only rotation or rotation and 5 mm anteroposterior translation. Longer follow-up is needed to evaluate possible benefits of high congruence and of specific modes of bearing mobility with respect to wear and bony fixation.

Five-year results of the Innex total knee arthroplasty system

The clinical and radiographic results of 174 female and 86 male Innex (Zimmer, Warsaw, Indiana) mobile bearing total knee arthroplasty systems (245 patients) were evaluated, with particular emphasis on gender-related differences at five-year follow-up. Pre-operative Knee Society (KS) function and total scores were lower in women than in men. All KS scores showed a significant improvement at follow-up, but women still obtained lower KS function scores than men. Self-reported function was significantly better for male knees. No gender differences were observed for component alignment, while the occurrence of radiolucent lines, endosteal cavitations, and wear was significantly greater in male knees. Male Innex mobile bearing knees exhibited better clinical function and satisfaction than their female peers at five-year follow-up, despite inferior radiographic findings and higher revision rates.