Total knee arthroplasty after distal femoral osteotomy long-term survivorship and clinical outcomes

Abstract

Aims There is little literature about total knee arthroplasty (TKA) after distal femoral osteotomy (DFO). Consequently, the purpose of this study was to analyze the outcomes of TKA after DFO, with particular emphasis on: survivorship free from aseptic loosening, revision, or any re-operation; complications; radiological results; and clinical outcome. Patients and Methods We retrospectively reviewed 29 patients (17 women, 12 men) from our total joint registry who had undergone 31 cemented TKAs after a DFO between 2000 and 2012. Their mean age at TKA was 51 years (22 to 76) and their mean body mass index 32 kg/m2 (20 to 45). The mean time between DFO and TKA was ten years (2 to 20). The mean follow-up from TKA was ten years (2 to 16). The prostheses were posterior-stabilized in 77%, varus-valgus constraint (VVC) in 13%, and cruciate-retaining in 10%. While no patient had metaphyseal fixation (e.g. cones or sleeves), 16% needed a femoral stem. Results The ten-year survivorship was 95% with aseptic loosening as the endpoint, 88% with revision for any reason as the endpoint, and 81% with re-operation for any reason as the endpoint. Three TKAs were revised for instability (n = 2) and aseptic tibial loosening (n = 1). No femoral component was revised for aseptic loosening. Patients under the age of 50 years were at greater risk of revision for any reason (hazard ratio 7; p = 0.03). There were two additional re-operations (6%) and four complications (13%), including three manipulations under anaesthetic (MUA; 10%). The Knee Society scores improved from a mean of 50 preoperatively (32 to 68) to a mean of 93 postoperatively (76 to 100; p < 0.001). Conclusion A cemented posterior-stabilized TKA has an 88% ten-year survivorship with revision for any reason as the endpoint. No femoral component was revised for aseptic loosening. Patients under the age of 50 years have a greater risk of revision. The clinical outcome was significantly improved but balancing the knee was challenging in 13% of TKAs requiring VVC. Overall, 10% of TKAs needed an MUA, and 6% of TKAs were revised for instability. Cite this article: Bone Joint J 2019;101-B:660–666.

Total knee arthroplasty after distal femoral osteotomy: a systematic review and current concepts

“…Duplicates were recognized and deleted using the Mendeley program, reaching the number of 242 articles. After checking titles, abstracts and full texts, 237 articles were then excluded reaching a final number of 5 papers [8][9][10][11][12] eligible for this review (Figure 1).…”

“…The study by Chalmers et al [11] wanted to report long-term results and survivorship of cemented TKA after DFO; they observed reliable improvement in clinical outcomes with primary implants and selective utilization of femoral stems; 13% of TKAs required a varus-valgus constrained implant, and 6% revision rate for implant instability was reported.…”

“…All the included studies [8][9][10][11][12] analysed a low number of patients. Future studies will surely have a larger sample size.…”

“…Most of the included patients underwent a lateral DFO rather than medial one. In four studies [8,9,11,12] the average interval time between DFO and TKA was more than 10 years. In the other paper [10], the mean time was 4 years.…”

“…In four of the five studies analysed [9][10][11][12], staged hardware removal was performed before TKA in 20.8% of patients; 59.7% of hardware were removed during TKA and in 19.4% of cases they had been left in-situ. One study did not mention this specific aspect of the surgery [8].…”