Abstract
Background
The literature quotes up to 20% dissatisfaction rates for total knee replacements (TKR). Swedish registry and national joint registry of England and Wales confirm this with high volumes of patients included. This dissatisfaction rate is used as a basis for improving/changing/modernising knee implant designs by major companies across the world.
Aim
We aimed to compare post TKR satisfaction rates for navigated and non navigated knees.
Methods
This was a retrospective analysis of prospectively collected data. All patients undergo comprehensive preoperative evaluation and comprehensive consent process and same rehabilitation protocols are followed as standard practice. Two groups were established depending on whether surgery was performed with or without computer navigation. We included 229 patients in each group. There were nine bilateral cases in the navigated group giving a total of 238 knees. Both groups were similar at the time of surgery (navigated: 68 years (sd9);; BMI 32.46;; (sd5.19);; OKS: 42.2 (sd7.5);; non-navigated: 70 years (sd9);; BMI 32.36;; (sd5.26);; OKS: 42.4 (sd7.3)). The satisfaction rates are recorded as very satisfied, satisfied, unsure or dissatisfied.
Results
Of the 238 navigated knees 227 (95.4%) were very satisfied or satisfied;; while of the 229 non-navigated knees 205 (89.5%) were very satisfied or satisfied. Only 3 (1.3%) navigated knees and 9 (3.9%) non-navigated knees were dissatisfied. Seven (2.9%) navigated knees and fifteen (6.6%) non-navigated knees were unsure. The navigated group showed better satisfaction (p=0.049) compared to the non-navigated group and better satisfaction than previously published satisfaction rates [3].
When combining dissatisfaction and unsure responses the navigated group again performed significantly better than the non-navigated group (p=0.021)
Satisfaction rates were also compared with published literature, which suggest that 82–89% of TKA patients are satisfied and that navigation has no effect on satisfaction [3]. Our data for the non-navigated knees are similar to high end of the published data. This goes to show that comprehensive education of patients, high volume surgeons and elective arthroplasty unit along with comprehensive consent process can achieve best results.
We have also shown that navigation influences satisfaction rates.
There were no differences in 6 week OKS data with scores of 28.1 (sd= 8.0) and 28.8 (sd=7.8) for navigated and non-navigated groups(p=0.623), The same was also true for range of flexion/extension (92.1° [sd=13.4°& 91.3° [sd=14.1°, p=0.360) and length of hospital stay in days (median=5 [min=2, max=37], median=5 [min=2, max=19], p=0.959);; for navigated and non-navigated groups respectively. Of those navigated knees reported as ‘dissatisfied’ and ‘unsure’, 50.0% (5 knees) were due to pain in the knee. For non-navigated knees, 66.7% (16 knees) stated knee pain as the reason for being ‘dissatisfied’ or ‘unsure’.
Conclusion
A modern elective arthroplasty service can deliver high satisfaction rates. Use of computer navigation further improves even the best conventional satisfaction rates. Industry should promote better surgical techniques rather than bringing out new implants to improve satisfaction rates in total knee replacements.
