Continued growth of the proximal part of the tibia after prosthetic reconstruction of the skeletally immature knee. Estimation of the minimum growth force in vivo in humans.
We studied five skeletally immature patients who had a cemented endoprosthetic replacement involving the proximal part of the tibia because of a malignant tumor. In each patient, the cement-column fractured, allowing additional physeal growth. With plain radiographs and scanograms, we determined the cross-sectional areas of the physes, the cement-mantle, and the tibial component. Using the known tensile strength of polymethylmethacrylate cement, we then calculated the minimum force that the growth plates must have overcome to fracture the cement. This averaged 584 newtons per square centimeter. This observation of continued tibial growth after partial physeal ablation with a cemented prosthesis in skeletally immature patients presented a unique opportunity to estimate the force generated in the human physis during growth.
Safran
M R
MR
Division of Orthopaedic Surgery, University of California, Los Angeles School of Medicine 90024-6902.
Eckardt
J J
JJ
Kabo
J M
JM
Oppenheim
W L
WL
D001696:Biomechanical Phenomena; D001843:Bone Cements; D001846:Bone Development / Q000502:physiology*; D002648:Child; D005260:Female; D005266:Femoral Neoplasms / Q000601:surgery; D006132:Growth Plate / Q000502:physiology*; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D013718:Tensile Strength; D013977:Tibia / Q000254:growth & development*
D001843:Bone Cements