Obesity has no adverse effect on the outcome of unicompartmental knee replacement at a minimum follow-up of seven years

Abstract

The significance of weight in the indications for unicompartmental knee replacement (UKR) is unclear. Our hypothesis was that weight does not affect the long-term rate of survival of UKRs. We undertook a retrospective study of 212 UKRs at a mean follow-up of 12 years (7 to 22). The patients were distributed according to body mass index (BMI; < vs ≥ 30 kg/m(2)) and weight (< vs ≥ 82 kg). Kaplan-Meier survivorship analysis was performed and ten-year survival rates were compared between the sub-groups. Multimodal regression analysis determined the impact of the various theoretical contraindications on the long-term rate of survival of UKR. The ten-year rates of survival were similar in the two weight subgroups (≥ 82 kg: 93.5% (95% confidence interval (CI) 66.5 to 96.3); < 82 kg: 92.5% (95% CI 82.5 to 94.1)) and also in the two BMI subgroups (≥ 30 kg/m(2): 92% (95% CI 82.5 to 95.3); < 30 kg/m(2): 94% (95% CI 78.4 to 95.9)). Multimodal regression analysis revealed that weight plays a part in reducing the risk of revision with a relative risk of 0.387, although this did not reach statistical significance (p = 0.662). The results relating weight and BMI to the clinical outcome were not statistically significant. Thus, this study confirms that weight does not influence the long-term rate of survival of UKR.

Does obesity influence early outcome of fixed-bearing unicompartmental knee arthroplasty?

“…Conversely, Cavaignac et al 20 had showed that obesity had no adverse outcome in UKA patients with 10-year survival rates of 93%. In a study by Xing et al 21 with 178 patients, the outcome of UKA was not influenced by patient's age, BMI and early degeneration in the PFJ.…”

Bariatric Surgery Prior to Total Knee Arthroplasty is Associated With Fewer Postoperative Complications

“…Additionally, obesity has also been associated with longer hospital stays and increased health care costs in patients undergoing TKA [26]. Some conflicting evidence exists debating the effect of obesity on postoperative complications and outcomes after TKA, as several studies have failed to demonstrate significant differences in outcomes and complication rates between obese and non-obese patients receiving TKA [33][34][35][36].…”

“…Additionally, obesity has also been associated with longer hospital stays and increased health care costs in patients undergoing TKA [26]. Some conflicting evidence exists debating the effect of obesity on postoperative complications and outcomes after TKA, as several studies have failed to demonstrate significant differences in outcomes and complication rates between obese and non-obese patients receiving TKA [33][34][35][36].Bariatric surgery, including both gastric bypass and gastric (lap) banding techniques, is an increasingly utilized and effective method to achieve significant long-term weight loss [37]. Although nonoperative weight loss interventions are typically initial options for most obese patients, bariatric surgery can result in greater weight loss than nonoperative strategies and can often result in reductions in the comorbidities commonly associated with obesity, such as diabetes and hypertension The Journal of Arthroplasty xxx (2015) xxx-xxx…”

Trends in Unicompartmental Knee Arthroplasty

“…14 In another study that compared two groups according to body mass index (BMI; < vs ≥ 30 kg/m 2 ), 10-year survival rates were reported to be similar in the two weight subgroups. 15 A study of UKA in the presence of ACL deficiency showed no significant difference between the ACL intact groups at an average 5-year follow-up. 16 A recently trending approach to UKA with ACL deficiency is simultaneous or subsequent ACL repair.…”