Total knee arthroplasty in patients with severe obesity: outcomes of standard keeled tibial components versus stemmed universal base plates

Abstract

Background Patients with severe obesity [body mass index (BMI) ≥ 40 kg/m2] potentially overload the tibial component after total knee arthroplasty (TKA), risking tibial subsidence. Using a cemented single-radius cruciate-retaining TKA design, this study compared the outcomes of two tibial baseplate geometries in patients with BMI ≥ 40 kg/m2: standard keeled (SK) or universal base plate (UBP), which incorporates a stem. Methods This was a retrospective, single-centre cohort study with minimum 2 years follow-up of 111 TKA patients with BMI ≥ 40 kg/m2: mean age 62.2 ± 8.0 (44–87) years, mean BMI 44.3 ± 4.6 (40–65.7) kg/m2 and 82 (73.9%) females. Perioperative complications, reoperations, alignment and patient-reported outcomes (PROMS): EQ-5D, Oxford Knee Score (OKS), Visual Analogue Scale (VAS) pain score and satisfaction were collected preoperatively, and at 1 year and final follow-up postoperatively. Results Mean follow-up was 4.9 years. SK tibial baseplates were performed in 57 and UBP in 54. There were no significant differences in baseline patient characteristics, post-operative alignment, post-operative PROMs, reoperations or revisions between the groups. Three early failures requiring revision occurred: two septic failures in the UBP group and one early tibial loosening in the SK group. Five-year Kaplan–Meier survival for the endpoint mechanical tibial failure was SK 98.1 [94.4–100 95% confidence interval (CI)] and UBP 100% (p = 0.391). Overall varus alignment of the limb (p = 0.005) or the tibial component (p = 0.031) was significantly associated with revision and return to theatre. Conclusions At early to mid-term follow-up, no significant differences in outcomes were found between standard and UBP tibial components in patients with BMI ≥ 40 kg/m2. Varus alignment of either tibial component or the limb was associated with revision and return to theatre.

No differences in long‐term clinical outcomes and survival rate of navigation‐assisted versus conventional primary mobile‐bearing total knee arthroplasty: A minimum 10‐year follow‐up

“…The MPTA was defined as the medial angle between a line parallel to the tibial component and the anatomical axis of the tibia. Outliers of postoperative HKA angle were defined as more than 3 degrees or less than −3°, and outliers of the LDFA and MPTA were defined as >93 degrees or <87 degrees, as defined in a previous study [13, 22]. The γ and δ angles were defined as the femoral and tibial implant positions in the sagittal plane, respectively.…”

Cementless TKA use as an alternative to cemented TKA in high BMI patients: A systematic review and meta‐analysis

“…Obese patients undergoing TKA are at increased risk of developing complications such as infection and aseptic loosening [ 20 ]. However, even with these challenges, high BMI patients achieve similar outcomes to nonobese patients [ 13 ], and it has been shown that TKA remains cost‐effective for the obese patient [ 12 ].…”