Archives of orthopaedic and trauma surgery
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Arch Orthop Trauma Surg · Jan 1990
Case ReportsWhich X-ray views are required in juvenile ankle trauma?
Although ankle sprains are probably the most common injury in adolescent sports people, epiphyseal injuries are missed on the presumption of a ligamentous tear. The risk of damaged ligaments has been overemphasized while the potentially dangerous epiphyseolysis has been understressed. An oblique X-ray of the ankle joint is indicated prior to "stress" pictures.
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Arch Orthop Trauma Surg · Jan 1990
Kinematics of the patellofemoral joint. Investigations on a computer model with reference to patellar fractures.
Patellofemoral kinematics were studied on a computer model. The articulating point of the patella moves from distal to proximal during flexion, until the quadriceps tendon starts to turn around the femur tendo-femoral gliding. The pattern of patellofemoral movement consists of a gliding and rolling component, the latter at its maximum at the beginning of flexion. ⋯ The distal part of the patella is the part with mechanical stress at all angles of flexion. The conclusions to be drawn for treatment are that fractures within the proximal and central part of the patella need a very high stability of internal fixation, the distal part of the patella less so. Postoperative treatment must take into account the changing contact area, because the peak stress is always at the contact area.
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Arch Orthop Trauma Surg · Jan 1990
Case ReportsMassive wear of a steel ball head by ceramic fragments in the polyethylene acetabular cup after revision of a total hip prosthesis with fractured ceramic ball.
The purpose of this case study of severe metallosis is to draw the attention of orthopedic surgeons to extremely serious results of this kind in the event of the fracture of the ceramic ball in a total hip prosthesis. Eleven months after implantation of a KJF hip prosthesis with an aluminum oxide ceramic ball in combination with a polyethylene acetabular cup, fracture of the ceramic ball was observed. After examining the polyethylene cup during the revision operation, the operating orthopedic surgeon merely replaced the fractured ceramic ball with a metal ball head made of stainless steel. ⋯ It is these extremely hard ceramic fragments that were responsible for the massive wear of the steel ball head, the hardness of which is approximately ten times less than that of aluminum oxide ceramic. The fracture of the ceramic ball further resulted in damage to the metal taper of the stemmed femoral component. In cases of this kind it is consequently absolutely essential to remove both the polyethylene cup and the ball head, and--if necessary--the femoral component as well.
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Temporary impairment of blood supply has been suggested to cause bone remodeling. The degradation of cells and matrix and the attraction of resorbing cells were examined in this study. ⋯ Both supernatant from the aged bone specimens and ground bone particles exhibited significant chemotactic activity that was specifically attracting monocytes. It is suggested that soluble bone matrix proteins or degeneration products liberated during ischemic damage to cortical bone initiate the resorptive process.
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Arch Orthop Trauma Surg · Jan 1990
Clinical TrialLimb lengthening and three-dimensional deformity corrections. A retrospective clinical study.
Different methods of limb lengthening as used at the Orthopedic Surgery Clinic of the Medical School, University of Zagreb, are compared. The results of operations performed between 1979 and 1989 on 111 patients are presented. These patients were subjected to surgery aimed at length equalization of limbs and/or correction of three-dimensional deformities. ⋯ These advantages manifest themselves in a reduced number of operations, lower incidence of infection and improved bone regeneration. It is preferable to perform corticotomy at the metaphysis site because of its optimum blood supply and its higher potential for osteogenesis. With corticotomy performed at the diaphysis site, satisfactory results were observed in only one-third of the cases.