ABSTRACT
BACKGROUND: Vertebral compression fractures are counted among the most common complications of osteoporosis. For treatment, a new, alternative implant has been developed (BeadEx, Expandis, Hof HaCarmel, Israel). The aim of the present in vitro study was to evaluate whether this implant is able to restore the initial height and three-dimensional stability after fracture and whether it is able to maintain this height and stability during complex cyclic loading. METHODS: The BeadEx implant consists of small titanium rolls, which are pressed into the vertebral body through specially designed, hollow pedicle screws. The height and the three-dimensional flexibility of 18 bisegmental spine specimens (nine T12-L2, nine L3-L5) was measured, first, before and after creating a wedge compression fracture at the middle vertebral body (L1 resp. L4), second, after treatment of the fracture, and, third, during and after complex cyclic loading. The fractures were treated either with BeadEx plus internal fixator, BeadEx plus bone cement or vertebroplasty for comparison. FINDINGS: The height before fracture could almost be restored by BeadEx plus bone cement but not by BeadEx plus fixator and vertebroplasty. The total height loss after cyclic loading was smallest with BeadEx plus bone cement (in median -4.7mm with respect to the intact specimens) but -6.2mm with BeadEx plus fixator and -7.8mm with vertebroplasty. The three-dimensional stability of the specimens was clearly higher if treated with BeadEx plus fixator than with BeadEx plus bone cement or vertebroplasty. INTERPRETATION: From a biomechanical point of view, BeadEx plus bone cement can be recommended as an alternative to vertebroplasty in the treatment of osteoporotic vertebral body fractures. BeadEx plus fixator can be recommended if additional stability is needed.
Subject(s)
Fractures, Compression/physiopathology , Fractures, Compression/surgery , Joint Instability/physiopathology , Osteoporosis/complications , Spinal Fractures/physiopathology , Spinal Fractures/surgery , Spinal Fusion/instrumentation , Biomechanical Phenomena/methods , Bone Plates , Bone Screws , Cadaver , Equipment Failure Analysis , Fractures, Compression/etiology , Fractures, Spontaneous/etiology , Fractures, Spontaneous/physiopathology , Fractures, Spontaneous/surgery , Humans , In Vitro Techniques , Joint Instability/etiology , Joint Instability/prevention & control , Joint Prosthesis , Lumbar Vertebrae/physiopathology , Lumbar Vertebrae/surgery , Osteoporosis/physiopathology , Osteoporosis/surgery , Prosthesis Design , Range of Motion, Articular , Recovery of Function , Spinal Fractures/complications , Spinal Fusion/methods , Thoracic Vertebrae/physiopathology , Thoracic Vertebrae/surgery , Treatment OutcomeABSTRACT
Developmental dislocation of the hip (DDH) is 1 of the commonest problems of the infant locomotive system. While its natural history is usually unpredictable, it is fully agreed that early diagnosis and treatment are essential. We present an 86-year-old man in whom asymptomatic bilateral DDH was diagnosed incidentally. This is apparently the second such case reported in the orthopedic literature.
