The effect of bone quality on the outcome of ingrowth total knee arthroplasty

Bone quality generally is felt to be an important consideration when planning total knee arthroplasty (TKA). This prospective study was conducted to see if bone quality, as assessed intraoperatively in 346 knees, affects the outcome of ingrowth TKA. Group A consisted of 272 knees with good or excellent bone quality in all areas and Group B consisted of 74 knees with fair or poor bone in at least one area. The average follow-up was 48 months, with 301 knees (87%) available for follow-up. Group A knees had more males, were heavier, had fewer patients with rheumatoid arthritis, and exhibited more varus. Preoperatively, Groups A and B had modified Hospital for Special Surgery (HSS) knee scores that averaged 55 and 48, respectively. At 4 years post-surgery, Groups A and B had HSS scores of 92 and 90, respectively. Fluoroscopic radiographs of the bone-prosthesis interfaces showed 13% incomplete radiolucencies in Group A and 7% in Group B. A complete radiolucency was seen in one patient in Group A. Based on these results, it can be concluded that bone quality as determined by gross intraoperative inspection had little effect on the 4-year outcome of this ingrowth TKA.