Disease Progression After Lateral and Medial Unicondylar Knee Arthroplasty.

BACKGROUND: Medial unicompartmental knee arthroplasty (UKA) has been a successful option for treatment of arthritis in patients with a healthy lateral compartment. However, lateral UKA is less common and results are less consistent. The purpose of this study is to compare progression of radiographically evident osteoarthritis in unoperated compartments during 5 years after lateral and medial UKA. METHODS: We undertook serial radiographic evaluation of 20 lateral and 114 medial UKA performed by the senior author during calendar years 2007-2008. Anteroposterior, lateral, and skyline radiographs obtained preoperatively and 1 and 5+ (mean, 5.3; range, 5.1-6.4) years postoperatively were independently graded for osteoarthritis in the unoperated tibiofemoral (TF) and patellofemoral (PF) compartments using established scales of Kellgren (0-4 point global scale for osteoarthritis), Ahlbäck (0-5 point scale based on joint space narrowing), and Altman (0-12 point composite criteria score). Rates of disease progression were compared between lateral and medial UKA groups using bivariate methods and multilevel growth models that adjusted for baseline characteristics. RESULTS: All mean disease grades for the TF and PF compartments increased (worsened) over time. The adjusted rate of Kellgren grade change was statistically (P < .05) faster for lateral UKA in the TF and PF compartments, as was Ahlbäck change in the TF compartment. Kellgren grade for the TF compartment of lateral and medial UKA groups increased 1.1 vs 0.6 points on average over 5 years adjusted for age, sex, and body mass index (P < .001). CONCLUSION: Surgeons should consider the propensity for faster disease progression after UKA in evaluating patients with isolated lateral compartment disease. LEVEL OF EVIDENCE: Level III, therapeutic study.

Human papillomavirus type 18 variant lineages in United States populations characterized by sequence analysis of LCR-E6, E2, and L1 regions.

While HPV 16 variant lineages have been well characterized, the knowledge about HPV 18 variants is limited. In this study, HPV 18 nucleotide variations in the E2 hinge region were characterized by sequence analysis in 47 control and 51 tumor specimens. Fifty of these specimens were randomly selected for sequencing of an LCR-E6 segment and 20 samples representative of LCR-E6 and E2 sequence variants were examined across the L1 region. A total of 2770 nucleotides per HPV 18 variant genome were considered in this study. HPV 18 variant nucleotides were linked among all gene segments analyzed and grouped into three main branches: Asian-American (AA), European (E), and African (Af). These three branches were equally distributed among controls and cases and when stratified by Hispanic and non-Hispanic ethnicities. Among invasive cervical cancer cases, no significant differences in the three HPV variant branches were observed among ethnic groups or when stratified by histopathology (squamous vs. adenocarcinoma). The Af branch showed the greatest nucleotide variability when compared to the HPV 18 reference sequence and was more closely related to HPV 45 than either AA or E branches. Our data also characterize nucleotide and amino acid variations in the L1 capsid gene among HPV 18 variants, which may be relevant to vaccine strategies and subsequent studies of naturally occurring HPV 18 variants. Several novel HPV 18 nucleotide variations were identified in this study.