The Journal of bone and joint surgery. American volume
-
J Bone Joint Surg Am · Apr 2008
Noninvasive quantification of human nucleus pulposus pressure with use of T1rho-weighted magnetic resonance imaging.
Early diagnosis is a challenge in the treatment of degenerative disc disease. A noninvasive biomarker detecting functional mechanics of the disc is needed. T1rho-weighted imaging, a spin-lock magnetic resonance imaging technique, has shown promise for meeting this need in in vivo studies demonstrating the clinical feasibility of evaluating both intervertebral discs and articular cartilage. The objectives of the present study were (1) to quantitatively determine the relationship between T1rho relaxation time and measures of nucleus pulposus mechanics, and (2) to evaluate whether the quantitative relationship of T1rho relaxation time with the degenerative grade and glycosaminoglycan content extend to more severe degeneration. It was hypothesized that the isometric swelling pressure and compressive modulus would be directly correlated with the T1rho relaxation time and the apparent permeability would be inversely correlated with the T1rho relaxation time. ⋯ T1rho-weighted magnetic resonance imaging has a strong potential as a quantitative biomarker of the mechanical function of the nucleus pulposus and of disc degeneration.
-
J Bone Joint Surg Am · Apr 2008
The effect of postoperative range of motion on functional activities after posterior cruciate-retaining total knee arthroplasty.
Range of motion is recognized as an important indicator of the success of a total knee replacement; however, an optimal range of motion has yet to be defined. This study was designed to determine the optimal range of motion for knee function after total knee arthroplasty with a posterior cruciate-retaining prosthesis. ⋯ The best functional results following total knee arthroplasty are achieved with 128 degrees to 132 degrees of motion. A postoperative flexion contracture and hyperextension of >or=10 degrees are associated with a poorer outcome except that stair-climbing is improved with more motion.
-
J Bone Joint Surg Am · Mar 2008
Publication bias in orthopaedic research: an analysis of scientific factors associated with publication in the Journal of Bone and Joint Surgery (American Volume).
Positive outcomes are common in the orthopaedic literature, and there are many who believe it may be due to the preferential publication of studies with positive findings-a phenomenon known as publication bias. The purpose of this investigation was to determine whether positive findings rendered a manuscript submitted to The Journal of Bone and Joint Surgery (American Volume) more likely to be accepted for publication. ⋯ We found no evidence of publication bias in the review of manuscripts for publication by The Journal of Bone and Joint Surgery, as positive and nonpositive studies were accepted at similar rates. The dearth of nonpositive studies in the orthopaedic literature is of concern, and may be due largely to investigator-based factors. Orthopaedic researchers should submit negative and neutral studies for publication, confident that the likelihood of acceptance will not be influenced by the direction of study findings.
-
J Bone Joint Surg Am · Mar 2008
Results of polyaxial locked-plate fixation of periarticular fractures of the knee. Surgical technique.
Locked-plate fracture-fixation techniques and designs continue to evolve. Polyaxial locking plates that allow screw angulation and end-point locking have become available; however, there are no clinical data documenting their strength and efficacy, to our knowledge. The purpose of this study was to evaluate the clinical performance of a variable-axis locking plate in a multicenter series of periarticular fractures about the knee. ⋯ The variable-axis locking plates performed well, with a high rate of fracture union and no evidence of varus collapse due to failure of the polyaxial screw fixation, in a series of complex fractures about the knee. Complication rates were similar to those for historical controls treated with fixed-trajectory locking plates. Polyaxial locking plates offer more fixation versatility without an apparent increase in mechanical complications or loss of reduction.
-
J Bone Joint Surg Am · Mar 2008
Angle-stable and compressed angle-stable locking for tibiotalocalcaneal arthrodesis with retrograde intramedullary nails. Biomechanical evaluation.
Retrograde intramedullary nailing is an established procedure for tibiotalocalcaneal arthrodesis. The goal of this study was to evaluate the effects of angle-stable locking or compressed angle-stable locking on the initial stability of the nails and on the behavior of the constructs under cyclic loading conditions. ⋯ Regardless of the bone model, the nails with angle-stable or compressed angle-stable locking had better initial stability and better stability following cycling than did the nails with static locking.