Moses, Alex M.

Introduction: The use of modular components provides several advantages in total knee arthroplasty (TKA), including exchange of the polyethylene insert while retaining the stable components in the revision TKA. Compared to full, non-modular component revision TKA, isolated polyethylene exchange (IPE) has the advantage of decreased morbidity, faster rehabilitation, and acceptable outcomes. Methods: A review of published literature on revision TKA was conducted, with a specific focus on studies evaluating the use of IPE for managing complications such as stiffness, instability, and periprosthetic joint infection (PJI). Results: IPE with downsizing may be considered for patients with mild stiffness and stable, well-positioned implants that have increased polyethylene thickness, though expectations for motion gain should be cautious. There is no clear consensus on IPE for instability. Some studies report high re-revision rates, while others show clinical and functional improvement when the TKA is well-aligned, well-fixed, and intraoperative gap balance is achieved. Additionally, irrigation and debridement with polyethylene exchange (IDPE) may be effective for acute TKA PJI management, particularly within the first two weeks of symptom onset. Conclusions: Based on current literature, IPE in aseptic TKA revisions may be effective for stiffness or instability when implants are well-fixed and well-aligned—particularly if polyethylene constraint can be adjusted for instability or downsized for stiffness. The role of IDPE in acute TKA PJI is better defined in the literature, with strong emphasis on its time-sensitive effectiveness—most notably within the first two weeks of symptom onset.

Background: Total knee arthroplasty (TKA) and hindfoot reconstruction (HFR) are often used to treat osteoarthritis and deformities of the knee and hindfoot. Despite the proven clinical effectiveness of these treatments, postoperative patient dissatisfaction is high. The knee and ankle are adjacent joints in the lower extremity, and angular deformity of either joint is known to affect positioning of the anatomical and mechanical axes of the entire limb. Although it is understood this relationship exists, there are limited studies evaluating outcomes of ipsilateral procedures on patients with pathologies of both knee and hindfoot. This article aims to evaluate whether TKA or TAA/HFR sequencing influences postoperative outcome. The study hypothesis is that TKA prior to TAA/HFR results in lower reoperation. Methods: A retrospective chart review using Current Procedural Terminology ( CPT ) codes was performed encompassing all patients who underwent TKA in conjunction with a variety of hindfoot procedures. All procedures were performed at a single academic medical site between 2000 and 2022. Exclusion criteria included those patients not having both ipsilateral TKA and hindfoot procedures or those lacking conclusive postoperative data. The primary outcome of this study was to identify significant reoperations such as adjacent joint arthrodeses, hardware removal, or unrelated ipsilateral limb surgery. Secondary outcomes included identification of revision procedures including revision TKA or revision HFR and other postoperative complication data. Results: This study included 158 patients, with 79 patients in each group. In the TKA-first group, the mean follow-up time was 10.24 years (range, 1.10-22.42 years) and the mean time to HFR was 5.94 years. In the HFR-first group, the mean follow-up time was 9.01 years (range, 1.01-23.55 years) and the mean time to TKA was 5.51 years. In patients who underwent TKA first, the mean reoperation rate was not significantly different from those who underwent HFR/TAA first, 30.4% vs 19.0% ( P = .12). In patients who underwent TKA first, the rate of HFR reoperations (22.78%) was greater than TKA reoperations (7.59%) ( P < .01). The revision rate was higher in the TKA-first group (17.7%) when compared to the HFR-first group (6.3%) ( P = .03). Additionally, there were more revision HFR procedures in the TKA-first group (9/79) compared with the HFR-first group (1/79) ( P = .009). Conclusion: In contrast to the study hypothesis that TKA first would result in less reoperation, our study found that TAA or HFR performed before TKA had an overall lower complication rate. However, these findings should be interpreted cautiously as the sample size was limited. Level of Evidence: Level III, retrospective cohort study.

Bone autografts are frequently harvested for use in foot and ankle surgery. A commonly used harvest site is the iliac crest; however, because of known morbidity with this site, the tibia and calcaneus are attractive alternatives. There remains limited understanding regarding the osteogenic potential of autografts from each of these locations. In this review, we provided an update of the known data on bone autografts from the iliac crest, tibia, and calcaneus, focusing on the total cells harvested from each site as well as the presence of osteogenic osteoprogenitor cells. Level of Evidence: Level V, expert opinion.