The Journal of bone and joint surgery. American volume
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J Bone Joint Surg Am · Aug 1997
Randomized Controlled Trial Clinical TrialResurfacing of the patella in total knee arthroplasty. A prospective, randomized, double-blind study.
During a two-year period, eighty-nine patients who were scheduled to have a total knee arthroplasty for the treatment of degenerative osteoarthrosis were randomly assigned to one of two groups: resurfacing of the patella or retention of the patella. All patients received the same posterior cruciate-sparing prosthesis, and all operations were performed by, or under the direct supervision of, one of us. Three patients died in the early postoperative period. ⋯ The postoperative clinical scores, the postoperative development of anterior pain, and the need for subsequent resurfacing were not predicted by the presence of preoperative anterior pain, obesity, or the grade of chondromalacia observed intraoperatively. Because of the short duration of follow-up, these results should be considered preliminary. Additional follow-up is planned.
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J Bone Joint Surg Am · Aug 1997
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of fixation screws for the scaphoid during application of cyclical bending loads.
Matched pairs of scaphoids from cadavera were stressed with ramped intensity cyclical bending loads after osteotomy and fixation of one scaphoid with a Herbert screw and fixation of the other with an AO 3.5-millimeter cannulated screw, a Herbert-Whipple screw, an Acutrak cannulated screw, or a Universal Compression screw. The AO screw, Acutrak screw, and Herbert-Whipple screw demonstrated superior resistance to cyclical bending loads compared with the Herbert screw. The Universal Compression screw did not provide better fixation than the Herbert screw because of fractures that occurred at the time of insertion. The AO screw and the Herbert screw were then tested in a separate setup in which a segment of volar cortex had been removed in addition to the simple osteotomy. The loss of volar cortex greatly diminished the quality of the fixation provided by both of the screws during application of ramped intensity cyclical bending loads. ⋯ A fixation device in the scaphoid must be able to withstand the stresses that are placed on the scaphoid as a result of its position spanning the proximal and distal carpal rows. Also, because of the prolonged time required for healing of fractures or non-unions of the scaphoid, the device must be able to withstand many such cycles of stress. The present study demonstrates that commonly used screws for fixation of the scaphoid vary significantly (p < 0.005) in their ability to resist cyclical bending loads.
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J Bone Joint Surg Am · Aug 1997
Long-term results of total hip replacement in young patients who had ankylosing spondylitis. Eighteen to thirty-year results with survivorship analysis.
We determined the long-term results of total hip replacement in a series of young patients who had ankylosing spondylitis. Between 1966 and 1978, forty-three Charnley low-friction arthroplasties were performed in twenty-four patients who had an average age of 28.8 years (range, nineteen to thirty-nine years) at the time of the operation. There were seventeen men and seven women. ⋯ The probability of survival of the acetabular components was 73 per cent (61 to 84 per cent) at twenty years and 70 per cent (57 to 83 per cent) at thirty years. The probability that both components would survive was 91 per cent (82 to 100 per cent) at ten years, 73 per cent (61 to 84 per cent) at twenty years, and 70 per cent (57 to 83 per cent) at thirty years. The Charnley low-friction arthroplasty provided consistently good long-term results, with a low rate of complications and revisions, in this group of young patients.