Periprosthetic fractures are a recognised complication of total knee arthroplasty. They may occur intraoperatively or postoperatively and risk factors have been identified which may predispose an individual to such a complication.

We report seven cases of periprosthetic tibial fractures following LCS total knee arthroplasty, a complication only encountered by the senior author following a change in practice from a cemented implant to a cementless one.

In light of this previously unreported complication in our unit, we have attempted to identify common features within this group of patients, that may have contributed to fracture occurrence.

Statistical analysis revealed a highly significant risk of periprosthetic tibial fracture in those patients with a preoperative neutral or valgus knee. Age, gender and diagnosis did not appear to significantly increase the risk of fracture. All patients displayed evidence of reduced bone mineral density in the lumbar spine and femoral neck regions on dual energy x-ray absorptiometry scanning.

We feel that those patients with a preoperative neutral or valgus knee and local evidence of osteopenia represent a high-risk group, in whom particular care in alignment should be taken. In this group it may also be preferable to have the tibial component inserted with cement fixation.