Abstract
Partial knee arthroplasty is making a resurgence as many patients and surgeons are realising that there are good options for preserving normally functioning knee tissues when facing end-stage knee OA without having to automatically proceed to TKA. What are potential advantages of this type of reasoning and could “less be more”? Limited comparative data exists comparing the functional results of partial and total knee replacement surgery. This study will report on patient satisfaction and residual symptoms following TKR, fixed bearing PKR, and mobile bearing PKR. What do the patients say when we aren't around?
TKA is not a benign treatment for isolated unicompartmental knee disease. A multicenter study examining 2,919 TKA's and UKA's found lower rates of overall complications at 11% for TKA's and 4.3% for UKA's. Significant variables for TKA included longer length of stay, more patients sent to an ECF, higher manipulation rate, higher readmission, ICU admission, and transfusion rates. Bolognesi, et al examining 68,790 TKA and UKA, reproduced these results with lower DVT/PE, deep infection rates and lower death rates. The 1 year and 5 year revision rates were higher for UKA's and have been hypothesised to be lower thresholds for revision of dissatisfied UKA vs a TKA with well-fixed implants.
Functional improvements may be better for UKA vs TKA further substantiating the evidence that “less is more” for the surgical treatment of isolated compartmental disease of the knee.
We conducted a multicenter independent survey of 1,263 patients (age 18–75) undergoing primary TKR and PKR for non-inflammatory knee DJD. We examined 13 specific questions regarding pain, satisfaction, and residual symptoms after knee arthroplasty. An independent third party (University of Wisconsin Survey Center) collected data with expertise in collecting healthcare data for state and federal agencies. Multivariate analysis was conducted, significance was set at p<0.05 and adequate power >0.8 was achieved. We controlled for gender, age, income, minority status, and surgical location in the multivariate analysis.
Univariate analysis revealed PKR patients were more likely to be younger, male, and have an income greater than $25,000 than TKR patients. Multivariate analysis showed that mobile bearing PKR patients were 1.81 times more likely to report that their operative knee felt “normal” (p = 0.0109) and 2.69 more likely to report satisfaction with ability to perform activities of daily living than TKR recipients (p = 0.0058). Mobile bearing PKR patients were 44% less likely to report grinding/popping/clicking in the knee (p = 0.0142), 39% less likely to report knee swelling (p = 0.0351), and 40% less likely to report knee stiffness in the last 30 days (p = 0.0167) compared to TKR's. Fixed bearing PKR patients were 51% less likely to experience problems getting in and out of a car compared to TKR patients (p = 0.0129). Fixed bearing PKR's were 60% less likely to be satisfied with the degree of pain relief than TKR (p = 0.0113). The remaining questions revealed a trend for advantages in all categories for the MB-PKR compared to TKR but did not reach statistical significance.
This study demonstrated that patient satisfaction is higher for MB-PKR than TKR with patients more likely reporting the knee to feel normal and that they were more able to perform activities of daily living. Fixed bearing devices were slightly more likely to report less pain relief than TKR. Mobile bearing partial knee replacement had fewer residual symptoms than fixed bearing PKR.
