Original ArticleThe Short-Term Results of 3 Common UKA Implants During Different Periods in Sweden
Section snippets
Material and Methods
The Swedish Knee Arthroplasty Register (SKAR) was initiated in 1975, and details regarding the design of the register have been reported previously [3]. The register is prospective, and all hospitals performing knee arthroplasty surgery in Sweden participated. The operating unit was registered, but the identities of the individual surgeons were not. A revision is defined as only being those reoperations in which implant components are added, removed, or exchanged.
Statistics
The end point used for survival statistics after primary arthroplasty was the first true revision done for any reason. To make the different periods more comparable, only events occurring during each period were included. Thus, unrevised patients alive by the end of each of the periods were classified as successful cases, whereas deceased unrevised cases were classified as withdrawals at the date of death.
Cumulative revision rate (CRR) curves were produced using the life table method using
Results
During period IV (1999-2004), the most commonly used UKA implants in Sweden were the Link, Oxford, and M/G, which accounted for 88% of all reported operations. During this period, the use of MIS for UKA gained popularity (Fig. 1), although it varied by implant model to what extent and to how fast the surgeons adopted MIS (Table 1). The number of operations per unit was low, and those units performing most averaged less than 7 implants a month during a 5-year period. The number of implants and
Discussion
At the time when the SKAR was initiated in 1975, Swedish surgeons were using UKA in 80% of their cases [6]. However, at that time, the modern TKA had only recently been introduced, and through the years, its use has constantly increased so that in 2004 UKA only accounted for 10% of cases (SKAR annual report 2005). Still, it is fair to say that Swedish surgeons have been well acquainted with this type of surgery, which has been relatively common in comparison to many other countries. However,
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Why Do Medial Unicompartmental Knee Arthroplasties Fail Today?
2016, Journal of ArthroplastyCitation Excerpt :However, these reports were mainly older studies, and the low polyethylene wear incidence can be attributable to the many improvements in polyethylene design and processing over the years. It is known that the improved implants had less wear [73] and a lower failure rate [74] than the original implants and 36 of the 39 studies in this systematic review are published in 2005 or later. A limitation of our study is the number of patients in the midterm and late group.
Survival analysis and functional outcome of the Oxford unicompartmental knee replacement up to 11 years follow up at a District General Hospital
2015, Journal of OrthopaedicsCitation Excerpt :Based on level 1 evidence (RCTs) it has been shown that minimally invasive approaches used for TKR yield better short term results (<1 year post op) than standard approaches however after 1 year the results are comparable.29,30 However, several authors support the use of minimally invasive techniques for implantation of UKR, with low revision rates and good functional outcomes in the short term31,32 – only one study warned of poor outcomes unless proper instrumentation and training was utilised for such approaches.33 The majority of our knees (81.5%) were implanted via minimally invasive techniques and produced excellent results comparable to, although not statistically significantly better than, those implanted with standard approaches.
Knee replacement
2012, The LancetCitation Excerpt :National joint-replacement registries are now one of the best and most important sources of comparative data for knee-replacement surgery.80–82 They not only provide data for individual implants, but also establish variation in outcome related to patient characteristics, surgical techniques, and surgeon experience.83–85 The initial focus of the first national registry, the Swedish knee-replacement project, was to collect data for short-term complications.
Polyethylene damage and deformation on fixed-bearing, non-conforming unicondylar knee replacements corresponding to progressive changes in alignment and fixation
2010, Clinical BiomechanicsCitation Excerpt :Attention to prolonging survivorship of unicondylar knee replacements (UKR) and the introduction of new surgical techniques emphasize the necessity for aligning UKR components within nominally defined ranges (Gulati et al., 2009; Kasodekar et al., 2006). However, deviations from nominal UKR alignment can occur as a result of initial component malalignment or progressive changes in component position during in vivo function (Assor and Aubaniac, 2006; Larsson et al., 1988; Robertsson and Lidgren, 2008). Alignment deviations in some designs are linked to the most common indications for UKR revision, including progressive arthritis in the non-operated compartment and loosening (Borus and Thornhill, 2008; Collier et al., 2006; Hernigou and Deschamps, 2004a).
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Benefits or funds were received in partial or total support of the research material described in this article from Swedish Medical Research Council (MFR 09509), Stiftelsen för bistånd åt vanföra i Skåne, Socialstyrelsen/Landstingsförbundet and the Medical Faculty.