Condylar constrained knee prosthesis and rotating hinge prosthesis for revision total knee arthroplasty for mechanical failure have not the same indications and same results

Abstract

Purpose: This study aimed to evaluate whether there are any differences in outcomes and complication rates between condylar constrained knee (CCK) and rotating hinge knee (RHK) prostheses used for the first revision of total knee arthroplasty (rTKA) after mechanical failure. Methods: Sixty-three consecutive non-septic revisions of posterior stabilized implants using 33 CCK and 30 RHK prostheses were included. Clinical evaluation and revision rate were compared between the two groups at two years minimum follow-up. Results: The CCK group had significantly better clinical outcomes and satisfaction rates compared to patients with RHK (KSS-knee 70.5 versus 60.7 (p < 0.003) and KSS-function 74.9 versus 47.7 (p < 0.004) at 3.7 (2.0–9.4) years mean follow-up. Moreover, the clinical improvement was significantly higher for the CCK group concerning the KSS-Knee (+23.9 vs. +15.2 points, p = 0.03). The postoperative flexion was significantly better in the CCK group compared to the RHK group (115° vs. 103°, p = 0.01). The prosthesis-related complications and the re-revision rate were higher in the RHK group, especially due to patellofemoral complications and mechanical failures. Conclusions: CCK prostheses provided better clinical and functional outcomes and fewer complications than RHK prostheses when used for the first non-septic rTKA. CCK is a safe and effective implant for selected patients, while RHK should be used with caution as a salvage device for complex knee conditions, with particular attention to the balance of the extensor mechanism.

Análise funcional e isocinética comparativa entre implantes com estabilização posterior e rotatórios constritos (hinge) em artroplastias do joelho

“…Although relevant, this value is lower than the average number of complications observed in arthroplasties using constrained implants, which range from 9.2 to 63%. 10,[23][24][25][26][27][28] Most studies demonstrate an incidence of 30 to 40% of complications, the most common being: infections, injuries to the extensor mechanism, and fractures. 10,24,26,29,30 As limitations of our research, we can mention the high number of exclusions, which occurred not only in our study but also in other similar researches that showed a follow-up loss of up to 65%.…”

“…10,[23][24][25][26][27][28] Most studies demonstrate an incidence of 30 to 40% of complications, the most common being: infections, injuries to the extensor mechanism, and fractures. 10,24,26,29,30 As limitations of our research, we can mention the high number of exclusions, which occurred not only in our study but also in other similar researches that showed a follow-up loss of up to 65%. 18,30 This can be partially explained by the social profile of the patients and the institution where the research was conducted.…”

“…8 Therefore, it is believed that modern constrained implants enable better clinical results; however, a limited number of studies evaluate the functional results of these implants, especially in the Brazilian population, and we also observed a reduced number of studies comparing the results of implants with different degrees of constriction. 9,10 Therefore, the objective of the present study was to compare the function and muscle strength of the limb between patients undergoing surgery using primary implants with posterior stabilization and patients with rotating hinged implants. We believe that patients with Hinge implants will have lower limb muscle strength and/or worse joint function, potentially related to the implant, but also due to the greater complexity of primary cases or because they are used in patients undergoing revision TKA, therefore, with several previous surgeries.…”

“… 8 Therefore, it is believed that modern constrained implants enable better clinical results; however, a limited number of studies evaluate the functional results of these implants, especially in the Brazilian population, and we also observed a reduced number of studies comparing the results of implants with different degrees of constriction. 9 10 …”

Condylar constrained and rotating hinged implants in revision knee arthroplasty show similar survivorship and clinical outcome: a systematic review and meta‐analysis

“…Furthermore, the selection of articles in which both implants are potentially indicated provides for a more robust comparison. The objectives of this systematic review are: compare the survival rates of a CCK and an RHK [7], compare the differences in clinical outcomes between these two types of implants [8] and evaluate if there is a higher reoperation rate with RHK compared to CCK [9]. We hypothesised that survivorship and clinical outcome at final follow-up would be worse for the RHK prosthesis due to higher constraint.…”