Background Modular tibial trays have been utilized in TKA for more than 20 years. However, concerns have been raised about modular implants and it is unclear whether these devices are durable in the long term. Questions/purposes We determined (1) survival, (2) relationship of age and polyethylene thickness with revision, (3) function, and (4)

Background: Unicompartmental and total knee arthroplasty (UKA and TKA) have demonstrated excellent mid- and long-term outcomes and have been compared in clinical series for decades; however, to our knowledge, no study has sufficiently matched UKA and TKA cohorts on preoperative osteoarthritis severity. The purpose of this study was to evaluate patient-reported outcomes of radiographically and demographically matched UKA and TKA cohorts. Methods: One hundred and thirty-five UKAs and 135 TKAs were matched by patient age, sex, body mass index, and American Society of Anesthesiologists Physical Status (ASA-PS) classification as well as preoperative osteoarthritis severity in medial and lateral tibiofemoral and patellofemoral compartments (Kellgren-Lawrence grading system). Patient-reported outcome measures for pain, function, activity level, and satisfaction were evaluated at minimum 1-year follow-up via components of the modern Knee Society Score, the University of California Los Angeles (UCLA) activity-level score, and a Likert satisfaction scale. Results: The patients in the UKA group reported significantly less pain, a higher activity level, and greater satisfaction while performing several functional activities and could walk for a longer amount of time before stopping due to knee discomfort compared with those in the TKA group (p ≤ 0.038). In addition, a greater proportion of patients in the UKA than in the TKA group were “satisfied or very satisfied” with their knee replacement surgery at minimum 1-year follow-up (90% versus 81%; p = 0.043). Conclusions: With minimum 1-year follow-up, patients who underwent UKA reported significantly higher function, less pain, and a greater level of patient satisfaction than a radiographically and demographically matched TKA cohort. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background: Tibial tubercle-trochlear groove (TT-TG) distance is currently used at our institution to determine tibial tubercle medialization required in Fulkerson osteotomies. If the correlation between a modified lateral patellar edge (LPE) and the transfer distance was found to be stronger than its correlation with TT-TG, it would suggest that the best measurement to use is actually modified LPE. Methods: The electronic medical records of 32 patients who underwent Fulkerson osteotomy procedures with femoral nerve stimulation were reviewed and measured. For each patient, modified LPE was measured on quadriceps active hyperextension MRI, and TT-TG was measured on passive extension MRI. Correlation between both TT-TG and LPE and tibial tubercle transfer distance was then determined and analysed. Results: The correlation between TT-TG and actual intra-operative tibial tubercle transfer distance in Fulkerson osteotomy procedures with intra-operative femoral nerve stimulation was found to be weak at 0.436 (p <0.05). The correlation between modified LPE and actual intra-operative tibial tubercle transfer distance was found to be strong at 0.697 (p <0.001). Conclusions: The correlation between modified LPE and actual intra-operative tibial tubercle transfer distance was stronger than the correlation between TT-TG and tibial tubercle transfer distance. This suggests that the modified LPE may actually be a better preoperative determinant than the currently-utilized TT-TG of the transfer distance required during Fulkerson osteotomy procedures. Level of evidence: Level II, diagnostic study.

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