Thermally treated 1st generation highly crosslinked polyethylenes (HXLPE) have demonstrated reduced penetration and osteolysis rates, however, concerns still remain with respect to oxidative stability and mechanical properties of these materials. To address these concerns, manufacturers have introduced the use of antioxidants to quench free radicals while maintaining the mechanical properties of the HXLPE. Two common antioxidants are α-tocopherol (Vitamin-E) and pentaerythritol tetrakis (PBHP). These may be either mixed prior to consolidation, or diffused throughout the polymer after consolidation and irradiation. Between 2010 and 2015, 73 anti-oxidant HXLPE components were collected as a part of an IRB approved, multi-institutional retrieval analysis program during routine revision surgery. Of the seventy-three components, 30 (41%) were acetabular liners, whereas, 43 were tibial inserts. The components were fabricated from three different materials: Vitamin-E Diffused HXLPE (n=30; E1, Biomet), Vitamin-E Blended (n = 41; Vivacit-E, Zimmer) and PBHP blended (n = 2, AOX, DePuy). The hip and knee components were implanted for 0.7 ± 0.8 years (Range: 0.0–2.25 years) and 0.8 ± 1.1 years (Range: 0.0–4.5 years), respectively. Implantation time, patient weight, age, gender, and activity levels were similar between hip and knee components (Table 1). For oxidation analysis, thin slices (∼200μm) were taken from medial condyle and central eminence of the tibial inserts or the superior/inferior axis from hip components. The slices were boiled in heptane for six hours to extract lipids absorbed Introduction
Methods
To assess the efficacy of software assisted correction using six axes analyses for Blounts deformity. Between 1998 and 2000, 22 tibiae in 19 patients underwent correction of Tibia Vara with the TSF. There were six females and thirteen males. There were 8 infantile and 14 adolescent forms. The mean patient age was 9.9 years (3–16 years). Shortening was present in 18 patients, averaging 11 mm (range: 3–30 mm). The mean follow up was 2.8 years (range: 2–4.1 years). The mean preoperative varus deformity was 16.5 degrees (range, 8 to 50 degrees) which improved to 0 degree (−2 to 2 degrees), and mean procurvatum deformity was 12.2 degrees (2 to 21 degrees) which improved to 0.1 degree (−2 to 3 degrees). The plane of the deformity was an average of 31 degrees (0 to 62 degrees) from the coronal plane and the mean magnitude of the deformity was 20.5 degrees (11.3 to 3.8 degrees) Taylor spatial frame uses the six axes software assisted analysis to correct complex deformities such as Blounts disease. It is very effective in correcting the Blounts deformity and has minimal complications.
