Aims

Preprint servers allow authors to publish full-text manuscripts or interim findings prior to undergoing peer review. Several preprint servers have extended their services to biological sciences, clinical research, and medicine. The purpose of this study was to systematically identify and analyze all articles related to Trauma & Orthopaedic (T&O) surgery published in five medical preprint servers, and to investigate the factors that influence the subsequent rate of publication in a peer-reviewed journal.

The purpose of this study was to devise a simple but reliable radiological method of identifying a lumbosacral transitional vertebra (LSTV) with a solid bony bridge on sagittal MRI, which could then be applied to a lateral radiograph.

The vertical mid-vertebral angle (VMVA) and the vertical anterior vertebral angle (VAVA) of the three most caudal segments of the lumbar spine were measured on MRI and/or on a lateral radiograph in 92 patients with a LSTV and 94 controls, and the differences per segment (Diff-VMVA and Diff-VAVA) were calculated. The Diff-VMVA of the two most caudal vertebrae was significantly higher in the control group (25° (sd 8) than in patients with a LSTV (type 2a+b: 16° (sd 9), type 3a+b: -9° (sd 10), type 4: -5° (sd 7); p < 0.001). A Diff-VMVA of ≤ +10° identified a LSTV with a solid bony bridge (type 3+4) with a sensitivity of 100% and a specificity of 89% on MRI and a sensitivity of 94% and a specificity of 74% on a lateral radiograph. A sensitivity of 100% could be achieved with a cut-off value of 28° for the Diff-VAVA, but with a lower specificity (76%) on MRI than with Diff-VMVA.

Using this simple method (Diff-VMVA ≤ +10°), solid bony bridging of the posterior elements of a LSTV, and therefore the first adjacent mobile segment, can be easily identified without the need for additional imaging.

Cite this article: Bone Joint J 2013;95-B:1533–7.

Introduction

ACL reconstruction using hamstring tendons has gained general acceptance. However, it has been recommended to seek a tight fit of the tendon in the bone canal in order to provide circumferential contact and healing of the graft, and to prevent secondary tunnel widening. Recent findings show, that the graft dynamically adapts to pressure in the canal resulting in a potentially loose graft-bone contact. It was the goal of this study to understand the viscoelastic behaviour of hamstring grafts under pressure and to develop a new method for tendon pre-conditioning to reduce the graft volume before implantation, in order to reduce the necessary bone canal diameter to accommodate the same graft.

Introduction

Following tear of its tendon, the muscle undergoes retraction, atrophy and fatty infiltration. These changes are inevitable and considered irreversible and limit the potential of successful repair of musculotendinous units. It was the purpose of this study to test the hypothesis that administration of anabolic steroids can prevent these muscular changes following experimental supraspinatus tendon release in the rabbit.

Introduction: Additional tendon length is occasionally needed for the surgical reattachment of retracted tendons and for lengthening of intact but contracted tendons. To achieve additional length with the known techniques such as the z-plasty, the tendon needs to be cut through entirely and loses its continuity. The purpose of this study was to develop a new method for tendon lengthening, where continuity is preserved and a high amount of additional length is achievable.

Methods: Calf Achilles tendons (n=35) were harvested immediately after slaughter and 5 tendons were assigned to groups I to VII. Angles of 60° (group I and IV), 45° (group II and V) and 30° (group III and VI) were cut. In group IV to VI mattress suture stitches were made along the cutting lines. The mean length increase of the helical cuts was used to define the intended length of group VII, where a z-plasty was performed. Maximal tensile force (Fmax) and additional achieved lengthening at Fmax (LFmax) were determined for each tendon using a materials testing machine. Data were statistically analyzed using ANOVA for inter-group differences and Spearman-correlation for cut angle to additional length relations at a significance level of p< 0.05.

Results: Tendons which were cut helically and sutured (group IV to VI) could achieve higher Fmax than the helically cut tendons without suturing (group I to III). The length and tensile force could be partially controlled by choice of the angle of the helical cut; In the groups for which the cut tendons were not sutured, LFmax was negatively correlated to the cut angle (r=−0.66, p=0.010) and positively correlated to the Fmax (r=0.72, p=0.003). If the helical cut tendons were sutured, there was no correlation of LFmax and cut angle (r=−0.01, p=0.96), but strong positive correlation of Fmax and cut angle (r=0.89, p< 0.0001). Helical cut tendon could achieve higher amount of additional length and tensile strength than tendons lengthened using z-plasty; in group VII, a LFmax of 72%±10% was achieved by a Fmax of 70N±15N. Other than in groups III and IV, where the cut angle was 30°, resulting in 179%±80% and 113%±10%, respectively, significant higher tensile force capacities (from a minimum of 80N±54N in group II to maximally 222N±62N in group IV) was achieved.

Discussion: Helical cutting of tendons allows lengthening tendons to an amount not possible with conventional methods. The lengthened coil-shaped tendon remains in continuity and has the potential to withstand considerable loads also without additional suture reinforcement. The behavior of the helical cut tendon in vivo is not known. However, the preservation of continuity might be favorable not only in regard to high tensile forces but also to healing.