Fig. 3
a Pre-op long leg AP view radiograph of a 76-year-old female with severe medial OA where LDFA is measured at 87.5° (valgus) and MPTA at 88.1° (varus), leading to an arithmetic HKA of 0.6°. b Immediate post-op AP radiograph showing uncemented TKA implants in acceptable orientation: 88.0° LDFA, 0° MPTA and arithmetic HKA of 2.0°. c Patient sustained a fall in stairs 4 weeks after surgery. Sudden and persisting pain and swelling were present. This is an AP view radiograph, 8 weeks post-op, showing a 5° valgus shift of the tibial implant (MPTA changed from 90° to 95° (LDFA was maintained at 88.0°). d Patient being unsatisfied with her lower limb alignment (HKA: 7° valgus) and having medial knee pain (medial collateral ligament over tensioned), she requested a TKA revision surgery. During revision procedure, the femoral implant was well fixed and considered well aligned. Tibial implant was revised alone, changing its orientation and using a cemented version. AP view radiograph post revision showing tibial implant’s MPTA at 88.0°, combined leading to an arithmetic HKA of 0° when combined with the femoral implant LDFA of 88.0°. e Removal of the well-fixed uncemented tibial implant was demanding, especially to break the osseous bonding behind the keel. Here is a photograph of the removed uncemented tibial implant where cancellous bone attachment is observed on the whole porous surface