Prevention of pseudo-patella baja during total knee arthroplasty.

PURPOSE: Pseudo-patella baja (PPB) is a surgical complication that can arise from total knee arthroplasty and occurs when the patella tendon is not shortened but the level of the femorotibial joint line is elevated. The goal of this study was to assess the performance of a technique specifically designed to prevent the occurrence of PPB and its radiological results. METHODS: Ninety-nine patients undergoing total knee arthroplasty were included. Patients were divided into a non-correction group and a correction group. The correction group were applied an additional metal block in order to reduce the excess resection of the distal femur. To evaluate PPB, the change in the pre- and postoperative joint line was measured using the modified Blackburne-Peel Index (BPI). RESULTS: In the non-correction group, 68 of 74 cases showed an occurrence of PPB (92 %), in the correction group, 6 of 57 cases showed an occurrence of PPB (11 %). The preoperative-modified BPI of the non-correction group was not significantly different from that of the correction group (0.6 ± 0.1 vs. 0.6 ± 0.2). The modified BPI decreased significantly in the non-correction group after TKA (0.6 ± 0.1 vs. 0.2 ± 0.1, p < 0.05). However, the modified BPI did not change significantly in the correction group after TKA (0.6 ± 0.2 vs. 0.6 ± 0.2). CONCLUSION: The comparison of preoperative and postoperative radiological results showed that our intervention maintained the joint line without elevation. We proposed an effective method to prevent various complications due to the joint line elevation that occur in PPB. LEVEL OF EVIDENCE: III.

Association between TLR1 polymorphisms and alopecia areata.

Toll-like receptors (TLRs) may contribute to the process of autoimmune attacks on hair follicles. To investigate whether the TLR1 gene polymorphisms are associated with the development and clinical features of alopecia areata (AA), a case-control comparison of two single nucleotide polymorphisms (SNPs) (rs4833095, Asn248Ser and rs5743557, -414C > T) of TLR1 were studied in 239 AA patients and 248 controls. Using multiple logistic regression model, odds ratios, 95% confidence intervals and corresponding p values were estimated. Clinical features were analyzed based on the age of onset, family history, type of AA, nail involvement and body hair involvement. The missense SNP rs4833095 was significantly associated with the development of AA (codominant2, p = 0.002; recessive, p = 0.001; log-additive, p = 0.0071; and allele frequency, p = 0.0066). The promoter SNP rs5743557 was weakly associated with the development of AA (codominant2, p = 0.019; recessive, p = 0.032; log-additive, p = 0.020; and allele frequency, p = 0.03). In the clinical features, rs4833095 was only weakly associated with age of onset between 15 and 50 years (codominant2, p = 0.043 and recessive, p = 0.022). The results suggest that rs4833095 of TLR1 may be associated with the susceptibility for AA in the Korean population.

Easy identification of mechanical axis during total knee arthroplasty.

PURPOSE: We devised an intraoperatively identifiable mechanical axis (IIMA) as a reference of alignment in total knee arthroplasty (TKA). MATERIALS AND METHODS: Between February 2010 and January 2011, primary TKAs were consecutively performed on 672 patients (1007 knees) using an IIMA as a reference in the coronal plane. RESULTS: The alignment of the lower extremity improved from a mean of 11.4±6.7° (-10.3-34.4°) of varus preop. to 0.7±3.5° (-5.2-8.6°) immediately after surgery. Mean alignment of the femoral component in the coronal plane was 89.3±2.3° (83.4-97.2°) postop. and mean alignment of the tibial component was 90.4±2.2° (85.1-94.2°) postop. CONCLUSION: This study showed that IIMA could be of considerable value as a new guider of alignment that is easily accessible and highly effective during total knee arthroplasty.

Soft Tissue Balancing of Varus Arthritic Knee in Minimally Invasive Surgery Total Knee Arthroplasty: Comparison between Posterior Oblique Ligament Release and Superficial MCL Release.

PURPOSE: To assess proper soft tissue balancing of the varus arthritic knee between posterior oblique ligament (POL) release group and superficial medial collateral ligament (SMCL) release group. MATERIALS AND METHODS: This retrospective study was performed on 186 patients who underwent minimally invasive surgery (MIS) total knee arthroplasty (TKA) from January 2011 to December 2011. Eighty-three patients were in the group of SMCL release and 103 patients were in the POL release group. We intended to use a 10 mm polyethylene insert (PE) during TKA, and retrospectively compared the actual thickness of PE between POL release group and SMCL release group. RESULTS: The mean PE thickness was 10.59±1.3 mm (range, 8 to 15 mm) in POL group and 11.88±1.8 mm (range, 10 to 18 mm) in SMCL group (p=0.001). We found a significant difference in the mean PE thickness between POL release group and SMCL release group. CONCLUSIONS: POL and deep MCL releases in MIS-TKA would be beneficial for varus deformity correction in the osteoarthritic knee.