Masahiro Kurosaka

A biomechanical comparison of different surgical techniques of graft fixation in anterior cruciate ligament reconstruction

Different surgical methods of graft fixation in ACL re construction were examined to determine the effects on mechanical properties of the reconstructed ACL. Ten human cadavers were used in this study. Six different types of grafts were studied. The tendon grafts were removed from each cadaver and fixed to femurs and tibias as ACL substitutes with different surgical fixation methods, leaving femur-reconstructed graft- tibia preparations. The surgical techniques used were staple fixation, tying sutures over buttons, and screw fixation. In the latter, the screws were introduced through femoral and tibial drill holes from the outside in order to achieve interference fit as described by Lam bert. Tensile testing demonstrated that the original ACL is significantly stronger than the graft used for recon struction in linear load, stiffness, and maximum tensile strength. All of the failures of the reconstructed ACL grafts occurred at the fixation site, indicating that the mechanically weak link of the reconstructed graft is located at the fixation site. Among the different meth ods of fixation, one-third of the patellar tendon secured with a cancellous screw, especially with a custom de signed large diameter screw, showed significantly higher values. Although many other factors affect the success of ACL reconstruction, our study indicates that the method of surgical fixation is the major factor influencing the grafts mechanical properties in the im mediate postoperative period.

Joint surgery up to date

1. Recent Advances and Problems in Total Joint Replacement.- Biomechanics of Endoprostheses of the Hip and Adaptive Reactions of the Bone.- Management of Femoral Bone Stock Deficiency in Total Hip Replacement.- Bone Grafting of Acetabular Deficiencies in Total Hip Replacement.- Follow-up Results of Chiari Pelvic Osteotomy for Patients with Acetabular Dysplasia.- Discussion I.- Total Condylar Knee Replacement: Late Results.- Principles of Alignment in Primary and Revision Knee Replacement.- Discussion II.- Biomechanics of the Ankle.- Current Status of Total Ankle Replacement.- Discussion III.- 2. Problem Case Presentation and Surgical Decision Making.- Segmental Comminuted Open Supracondylar Fracture of the Distal Femur.- Management of Splayfoot: Report of a Case.- Application of Machining Principles: Use of the Questor Saw Jig in TKR for Severe Valgus Hyperextension Osteoarthritis of the Knee.- Treatment of Infected Total Knee Arthroplasty.- Cup Arthroplasty in a 31-year-old Female with Neglected Congenital Dislocation of the Hip.- Postscript.- Postscript.- Author Index.

Early Loosening after Total Knee Arthroplasty with Minimal Incision Surgery: A Report of Two Cases and A Review of the Literature

Advances in surgical techniques and equipment have recently encouraged the use of minimal incision surgery (MIS) in total knee arthroplasty (TKA). However several complications have been reported following MIS, among which, early loosening is one of the most serious issues. We report two cases that experienced early loosening of the tibial component within three months of surgery, and received revision surgery within three years of primary MIS TKA. The cases were compared with 50 other cases which received MIS TKAs by the same technique, and it was hypothesized the failures in the two relatively young patients may have been caused by virus implantation of the tibiae component and a large bony cut in the proximal tibia, possibly as a result of limited working space during surgeries.