Per Ludvigsen

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The present study investigates the effect of distraction frequency on the development of tensile force in the tissues during lengthening. Two patients with bilateral Ilizarov leg lengthening underwent distraction with high frequency in one leg and low frequency in the other. The clinical situation represented a unique model for investigating the effect of(More)
This paper presents an in vivo test for assessment of regenerate axial stiffness after the distraction phase of lengthening therapy. The test result supplements radiography in evaluating bone healing and assists in determining when the regenerate stiffness is sufficient for removal of the external fixator. The test is non-invasive and does not require(More)
Strain gauges are currently the default method for measuring deformation in bone. Strain gauges are not well suited for in vivo measurements because of their size and because they are difficult to use in bone. They are also unsuitable for repeated measurements over time since they cannot be left in the patient. The optical Bragg grating fibres behave like(More)
The purpose of this investigation was to compare the tissue response during mono- and bifocal limb lengthening. The study includes four patients undergoing leg lengthening. All patients started out bifocally with a total diurnal distraction of 1.75 mm, but proceeded monofocally with a rate of 1 mm a day when the distal distraction was terminated due to(More)
The axial stiffness of the regenerate is an indicator of bone healing after fracture or distraction osteogenesis. The axial stiffness may be assessed clinically by measuring the sharing of load between fixator and limb during loading. The aim of this study was to find out how to perform the stiffness test in order to minimize the influence of confounding(More)
We performed pre- and 2-3.5-year postoperative isokinetic knee-testing to assess thigh muscle function in 9 patients undergoing bilateral femoral lengthening by callotasis. The median femoral lengthening was 17 (12-18) percent. The angular testing velocities were 60 degrees/sec (strength) and 180 degrees/sec (endurance). Only small changes in muscle(More)
A case of intussusception into the enteroanastomosis associated with a Billroth II gastric resection is presented. The case is discussed in the light of jejunogastric intussusceptions, described for the first time in 1917, about 30 years after the first gastrojejunostomy. For 30 years enteroanastomosis has been a general procedure in connection with the(More)
There is a need for a strong suture technique that allows early active mobilisation after repair of flexor tendons, but the best method has not yet been found. The aim of this study was to compare the modified Kessler suture biomechanically with a newer, two-strand suture. Eighteen porcine tendons were cut and repaired according to either the grasping(More)
A post hoc comparison of the mechanical factors that affected the outcome of experimental metaphyseal- and diaphyseal-lengthening osteotomies in sheep tibiae was performed. The resulting motions between bone segments at the metaphyseal and diaphyseal levels were estimated using measured fixator stiffnesses, postural muscle activity, ground reaction forces,(More)
To the Editor, We read with interest the article by Shyam et al. entitled “Leg lengthening by distraction osteogenesis using the Ilizarov apparatus: a novel concept of tibia callus subsidence and its influencing factors”, which was recently published in your journal in 2009 [1]. The authors found that all of their callotasis segments had subsidence ranging(More)