Restoring the pre-morbid anatomy of the proximal humerus is a
goal of anatomical shoulder arthroplasty, but reliance is placed
on the surgeon’s experience and on anatomical estimations. The purpose
of this study was to present a novel method, ‘Statistical Shape
Modelling’, which accurately predicts the pre-morbid proximal humeral anatomy
and calculates the 3D geometric parameters needed to restore normal
anatomy in patients with severe degenerative osteoarthritis or a
fracture of the proximal humerus. From a database of 57 humeral CT scans 3D humeral reconstructions
were manually created. The reconstructions were used to construct
a statistical shape model (SSM), which was then tested on a second
set of 52 scans. For each humerus in the second set, 3D reconstructions
of four diaphyseal segments of varying lengths were created. These
reconstructions were chosen to mimic severe osteoarthritis, a fracture
of the surgical neck of the humerus and a proximal humeral fracture
with diaphyseal extension. The SSM was then applied to the diaphyseal
segments to see how well it predicted proximal morphology, using
the actual proximal humeral morphology for comparison.Aims
Materials and Methods
Aims. Little is known about the risk factors that predispose to a rupture of the posterior cruciate ligament (PCL). Identifying risk factors is the first step in trying to prevent a rupture of the PCL from occurring. The morphology of the knee in patients who rupture their PCL may differ from that of control patients. The purpose of this study was to identify any variations in bone morphology that are related to a PCL. Patients and Methods. We compared the anteroposterior (AP), lateral, and Rosenberg view radiographs of 94 patients with a ruptured PCL to a control group of 168 patients matched by age, sex, and body mass index (BMI), but with an intact PCL after a knee injury.
The most important complication of treatment of developmental dysplasia of the hip (DDH) is avascular necrosis (AVN) of the femoral head, which can result in proximal femoral growth disturbances leading to pain, dysfunction, and eventually to early onset osteoarthritis. In this study, we aimed to identify morphological variants in hip joint development that are predictive of a poor outcome. We retrospectively reviewed all patients who developed AVN after DDH treatment, either by closed and/or open reduction, at a single institution between 1984 and 2007 with a minimal follow-up of eight years. Standard pelvis radiographs obtained at ages one, two, three, five, and eight years, and at latest follow-up were retrieved. The Bucholz-Ogden classification was used to determine the type of AVN on all radiographs. Poor outcome was defined by Severin classification grade 3 or above on the latest follow-up radiographs and/or the need for secondary surgery. With statistical shape modelling, we identified the different shape variants of the hip at each age. Logistic regression analysis was used to associate the different modes or shape variants with poor outcome.Aims
Methods
