A Comparison of Accuracy between the Sonography-guided Extramedullary and Intramedullary Alignment Systems for the Femoral Component in Total Knee Arthroplasty

PURPOSE: We wanted to compare the accuracy between a newly suggested sonography-guided extramedullary alignment guide system and an ordinary intramedullary alignment guide system for the femoral component alignment in Total Knee Arthroplasty (TKA). MATERIALS AND METHODS: Among the patients who underwent TKA from December 2006 to May 2007, an intramedullary technique was applied in 50 cases (the IM group) and an extramedullary technique was used in 50 cases (the EM group). The femoral component alignment angle was measured and compared postoperatively by using an anteroposterior (AP) radiograph of the knee. RESULTS: The average femoral component alignment angle was 94.96degrees (92~98degrees) in the IM group and 95.36degrees (90~99degrees) in the EM group. Both groups didn't show a significant difference. 45 cases (90%) in the IM group and 43 cases (86%) in the EM group were included in the optimal range of the femoral coronal angle (95degrees+/-2). CONCLUSION: There was no significant difference regarding the accuracy of the sonography-guided extramedullary and intramedullary femoral component alignment guide systems for performing Total Knee Arthroplasty.

The Effect of Demineralized Bone Matrix as a Graft Enhancer in Posterior Lumbar Interbody Fusion Using Cage and Local Bone Chips / 대한척추외과학회지

STUDY DESIGN: A randomized, controlled study OBJECTIVES: We wanted to investigate whether osteogenesis can be enhanced when a small amount of demineralized bone matrix (1 cc/segment) is mixed with local bone chips. SUMMARY OF LITERATURE REVIEW: Demineralized bone matrix (DBM) has been used for spinal arthrodesis. However, there are only a few reports about its use as a composite graft with local bone chips for posterior lumbar interbody fusion MATERIALS AND METHODS: Degenerative spine patients, who would normally be treated by decompression and posterior lumbar interbody fusion with using a pedicle screw system and one cage, were randomly, prospectively selected for whether they would be treated with using local bone chips mixed with 1cc of DBM (Group I: 15 patients and 19 segments) or local bone chips (Group II: 12 patients and 13 segments) for graft material. The sampling bias was investigated for gender, age, endocrine diseases, previous operation, habits (alcohol drinking, smoking), steroid medication, bone mineral density and the amount of local bone. The amount of bone formation was measured at 6 months after operation. On the sagittal and coronal reconstruction CT images, the bone formation outside of the cage was measured, and this was interpreted in a "blinded"fashion by 2 independent doctors who did not take part in the operations. RESULTS: There was no sampling bias between the 2 groups except for age (Group I= 65.3+/-7.1, Group II=58.9+/-6.0, p=0.010). The ratio of local bone chips and DBM was 5.98:1 in Group I. There was moderate concurrence between the 2 interpreters (kappa coefficiency= 0.494, p<0.001 for the sagittal plain images and kappa co-efficiency=0.467, p<0.001 for the coronal plain images) and Group I showed significantly more bone formation (p=0.003). CONCLUSION: DBM that is mixed with local bone chips, even with small amount, enhanced bone formation in the posterior lumbar interbody fusion. This is regarded to act as a graft enhancer to increase the fusion rate, even when using local bone chips for graft material, for the cases that show unfavorable conditions for fusion or for the cases that are prone to loosening of hardware.

Ceramic on Ceramic Hybrid Type Total Hip Arthroplasty in Patients with more than 65 years of Age -Minimum 5-year Follow-up Results

Purpose: This study examined the minimum five-year results of hybrid type total hip arthroplasty (THA) with ceramic-on-ceramic articulation and femoral stem fixation using cement in patients older than 65 years. Materials and Methods: From February 1999 to November 2002, a hybrid type THA with ceramic-on-ceramic articulation and femoral stem fixation using cement were performed in 47 patients (47 hips) older than 65 years of age. Among the 47 patients, 29 patients were followed up for more than 5 years. The mean age of these patients was 68.9 years (65~73years). The mean follow-up period was 74.6 months (61~107 months). The postoperative diagnosis included AVN of the femoral head in 21 hips, Osteoarthritis in 2 hips, rhematoid arhthritis in 1 hip, femoral neck fracture in 4 hips and Tuberculosis in 1 hip. The clinical results were analyzed retrospectively by the Harris hip score (HHS), hip and thigh pain, and radiologically by the level of osteolysis around acetabular cup and femoral stem, bone reabsorption by stress shielding, instability, acetabular and femoral stem anteversion, acetabular inclination and the femoral stem fixation site. Results: After surgery, the overall HHS improved from 56.3 +/- 1.4 to 92.3 +/- 1.1 points (p=0.013). Excellent and good results were obtained in 21 (72.4%) and 8 hips (27.6%), respectively. There was no case of thigh pain. Radiologically, there was no acetabular and femoral component osteolysis. Absorption by stress shielding was observed in 6 cases (20.7%) with an acetabular cup and 3 cases (10.3%) with a femoral stem. Bony stability was observed in all cases treated with an acetabular cup and possible loosening in 1 case (3.4%) treated with a femoral stem. Acetabular and femoral stem anteversion was 18.4degrees+/- 1.1 and 13.1degrees+/- 0.9 respectively. Acetabular inclination was 41.5degrees+/- 1.3. The femoral stem was inserted centrally in all cases. Complications included posterior dislocation of 1 hip (3.4%) and periprosthetic fracture of the femur in 1 hip (3.4%). There was no fracture of the ceramic component Conclusion: The mid-term results of hybrid type THA with ceramic-on-ceramic articulation and femoral stem fixation using cement were effective both clinically and radiologically in patients older than 65 years.