Articles: joint-instability-etiology.
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Retrospective chart review. ⋯ Gunshot wounds to the head and neck had a high rate of concomitant cervical spine fracture. Neurologically intact patients have a lower rate of fracture than those presenting with a spinal cord injury or altered mental status. In this small series of patients, the only unstable cervical spine injuries were detected in patients with a spinal cord injury. The data suggest that spinal precautions and/or a hard cervical collar should not be maintained at the expense of delaying or hindering emergent life-saving airway or hemodynamically stabilizing procedures, particularly in awake, neurologically intact patients. However, the cervical collar and spinal precautions should be resumed after such procedures are completed and continued until a more definitive evaluation of spinal stability can be performed.
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Comparative Study
Preclinical testing of femoral hip components: an experimental investigation with four prostheses.
Existing standards for the preclinical testing of femoral hip implants have been successful in the objective of guaranteeing the implant's fatigue strength. There is a need for an experimental test which could ensure prostheses were not susceptible to aseptic loosening. In this study we measure the relative movement between the prosthesis and the bone of four different cemented femoral component designs in in vitro tests. ⋯ With regard to the steady state inducible displacements of the prostheses, those of the Charnley, Exeter, and Lubinus decreased or were stable with respect to time, whilst those of the Müller typically increased with respect to time. It is concluded that migration is not a suitable basis for in vitro comparison of prosthesis designs. However inducible displacement trends provide a clinically comparable performance ranking.
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Rev Chir Orthop Reparatrice Appar Mot · Sep 2005
[Recent fractures of the radial head associated with elbow instability treated with floating Judet prosthesis].
Fracture of the radial head associated with elbow instability is infrequent. We report a retrospective series of floating Judet prostheses implanted for comminutive fractures of the radial head associated with elbow laxity caused either by dislocation or rupture of the medial collateral ligaments. ⋯ The floating Judet prosthesis allows optimal adaptation of the implant to anatomy and function. For us, these implants are indispensable when the radial head fracture is associated with elbow instability. The indication for prosthesis may be questionable if the non-fixed fracture is free of associated ligament injury, as suggested by the good long-term reported after simple resection. Rigorous operative technique is crucial, with careful restitution of the radial height. The quality of the result is related to the degree of capsule and ligament injury even after optimal implant positioning. Preventive treatment against periarticular ossification should be systematic.
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Whole cervical spine model with muscle force replication was subjected to simulated frontal impacts of increasing severity, and resulting injuries were evaluated via flexibility testing. ⋯ Middle (C2-C3 to C4-C5) and lower (C6-C7 and C7-T1) cervical spine were at risk for injury during frontal impacts, for the experimental conditions studied.
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J Bone Joint Surg Am · Jul 2005
Posterolateral rotatory instability of the elbow following radial head resection.
Resection is a common procedure for the treatment of comminuted fractures of the radial head. While radial head resection is associated with a high success rate when performed for appropriate indications, a number of well-defined biomechanical complications have been reported following this procedure, including proximal migration of the radius, the development of valgus deformity, and recurrent elbow instability in the acute setting. However, posterolateral rotatory instability has not previously been recognized as a complication of radial head resection. While the absence of the radial head makes the diagnosis difficult, we have identified a series of patients with posterolateral rotatory instability following radial head resection. We believe that this instability is secondary to unrecognized lateral ulnar collateral ligament deficiency. ⋯ Clinicians should be aware that posterolateral rotatory instability may be a cause of unexplained elbow pain and instability following radial head resection. This diagnosis has implications for the prevention and treatment of this condition.