Zonal Fixation With Metaphyseal Sleeves in Reconstruction of Bone Defects in Complex Primary and Revision Total Knee...

The purpose of this study was to evaluate the clinical, radiological, and functional outcomes of bone-loss reconstruction in revision and complex primary total knee arthroplasty (TKA) using metaphyseal sleeves.

Between 2009 and 2023, 170 patients (175 knees) who underwent TKA with metaphyseal sleeves were included. Bone defects were classified using the Anderson Orthopaedic Research Institute system. Clinical and radiological outcomes were analyzed.

Of the 175 knees, 152 were revisions and 23 were complex primary procedures, in which 141 tibial and 102 femoral sleeves were used. The mean follow-up was 64.6 months (range, 19 to 185). The prosthesis types included posterior-stabilized (n = 15), semiconstrained (n = 115), rotating hinge (n = 33), and distal femoral replacement (n = 12). The most common defects were Anderson Orthopaedic Research Institute type IIb (80 femoral, 60 tibial), followed by type IIa (73 tibial, 15 femoral) and type III (16 femoral, five tibial). Intraoperative fractures occurred in 4.5% of knees (six femoral and two tibial). Prosthesis removal and arthrodesis were required in three knees for deep infection, and one tibial sleeve was revised for aseptic loosening. The mean preoperative hip-knee-ankle angle was 165.7° (range, 145 to 191), improving to 177.9° (range, 167.9 to 177.7) postoperatively. The joint line was restored to within five mm of the preoperative level in 152 knees (85%). The mean Oxford Knee Score improved from 19.0 preoperatively to 34.9 postoperatively. Kaplan-Meier survivorship for revision for any cause was 94%, and survivorship for revision for aseptic loosening was 98.4% at both five and 10 years.

Metaphyseal sleeves provide reliable fixation and effective reconstruction of substantial bone defects, both in revision and complex primary TKA, resulting in excellent clinical and radiological outcomes with high implant survivorship.