Clinical orthopaedics and related research
-
Reasons for reoperation after knee revision surgery are implant loosening, sepsis, extensor mechanism problems, fractures of bone or prosthetic components, wear debris, and limited range of motion. The purpose of this study was to review the complications requiring reoperation in a large number of condylar revision total knee arthroplasties to determine the incidence and outcome after treatment. Six hundred fifty-five condylar revision total knee arthroplasties performed during a ten-year period were retrospectively reviewed. ⋯ All patients were observed for an average of 7.5 years. Twenty-four knees (52%) were considered clinical failures because of pain, limited motion, instability, and sepsis. Awareness of these failure modes may help to prevent complications by strict attention at the time of revision surgery to protection of the patellar tendon attachment and collateral ligaments, balancing of the extensor mechanism, preservation of the patellar blood supply, proper component position and sizing, restoration of the mechanical axis, and use of more constrained implant designs.
-
Clin. Orthop. Relat. Res. · Jan 1993
Occlusion of arterial flow in the extremities at subsystolic pressures through the use of wide tourniquet cuffs.
Tourniquet-induced peripheral neuropathy is at least partially attributable to excessive forces applied to the nerves beneath cuffs inflated to high pressures. Lowering the inflation pressure to the minimum necessary to obtain an effective arrest of blood flow distal to the tourniquet cuff should increase the safety of these systems. Tourniquet cuffs with widths varying from 4.5 cm to 80 cm were applied to the upper and lower extremities of 34 healthy, normotensive volunteers. ⋯ The occlusion pressure was inversely proportional to the ratio of tourniquet cuff width to limb circumference and was in the subsystolic range at a cuff width to limb circumference ratio above 0.5. Wide tourniquet cuffs can achieve an effective arrest of the regional arterial circulation at subsystolic pressures of inflation. Wide cuffs may reduce the risk of tourniquet-induced injury to underlying soft tissues by lowering the inflation pressure required to secure a bloodless field.