Verticalisation of the sacrum, pelvic version and sacro-pelvic relationship in severe spondylolisthesis

To study the changes in spatial orientation of the sacrum and pelvis in severe spondylolisthesis. Study design: Analysis of standing lateral radiographs of the spine in patients with Grades III, IV and V spondylolisthesis. Measurements of angles subtended by [1] each sacral vertebra with the vertical, [2] the pelvic brim with the horizontal and [3] each sacral vertebra with the pelvic brim. The sacrum verticalises progressively with increasing severity of spondylolisthesis. However the pelvis becomes horizontal by only half the amount of verticalisation, through remodeling by the lateral sacral epiphyses and posterior widening of the upper two intersacral joints. The study confirms our clinical suspicion that sacral verticalisation is not accompanied by an equal amount of pelvic retroversion. This fact has an important bearing on the technique of manipulative reduction of spondylolisthesis

Diastases of the proximal tibial physis in tibia vara

Previous histopathologic Studies of the proximal tibial physis in tibia vara have shown changes similar to those seen in slipped capital femoral epiphysis. The present paper describes radiographic widening of almost the entire upper tibial physeal plate in 6 knees with adolescent tibia vara, and opening of the lateral part of the proximal tibial physis in 4 knees with juvenile Blount's disease. These appearances, which suggest a diastasis of the physis, resolved after corrective tibial osteotomy. Forces acting across the proximal tibial physis are discussed. We postulate that the physical properties of the proximal tibial epiphysis and its response to mechanical forces acting upon it are age related. These factors determine the radiographic differences between juvenile and adolescent tibia vara