High contrast between lumbar nerve roots and surrounding structures using dual echo 3D turbo spin echo additional fusion images.

PURPOSE: We performed lumbar spinal magnetic resonance imaging of three-dimensional (3D) dual echo volumetric isotropic turbo spin echo acquisition (DE-VISTA) and constructed DE-VISTA additional fusion images (DE-VISTA-AFI), which is the addition of DE-VISTA proton density-weighted images (DE-VISTA-PDWI) to DE-VISTA T2-weighted images (DE-VISTA-T2WI). The aim of this study was to clarify whether DE-VISTA-AFI was able to clearly delineate spinal nerve roots. METHODS: A total of 677 patients underwent lumbar MR imaging, and the signal ratio (SR) between cerebrospinal fluid and nerve roots inside the dural sac and the SR between fat and nerve roots outside the dural sac were estimated using DE-VISTA-AFI, DE-VISTA-PDWI, DE-VISTA-T2WI, and 2D-T2WI. RESULTS: The SR between cerebrospinal fluid and nerve roots inside the dural sac on DE-VISTA-AFI was higher than that on DE-VISTA-PDWI (p < 0.0001) and on 2D T2WI (p < 0.0001). The SR between the fat tissue and nerve roots outside the dural sac on DE-VISTA-AFI was higher than that on DE-VISTA-PDWI (p < 0.0001) and 2D T2WI (p < 0.0001). CONCLUSION: DE-VISTA-AFI could clearly delineate the entire length of the lumbar nerve roots that run from the cauda equina in the spinal fluid through to the fat in the lateral recess, intervertebral foramen, and outside the intervertebral foramen.

Delineation of extensor tendon of the hand by MRI: usefulness of "soap-bubble" mip processing technique.

To evaluate the capability of the "Soap-Bubble" maximum intensity projection (MIP) processing technique in visualisation of extensor tendons of the hand, 36 intact subjects and seven patients with surgically confirmed extensor tendon rupture were examined. Three-dimensional T1-weighted turbo spin echo (3DT1TFE) MRI was performed using a sensitivity encoding flex coil, followed by Soap-Bubble MIP processing. For patients with extensor tendon ruptures, MRI findings and intraoperative findings were compared. As results, with only 3DT1TFE sequence, the entire extensor tendons that run along the arch of the hand were not shown on one image, but were visualised with addition of Soap-Bubble MIP. Although delineation of the extensor pollicis longus was poor in 27/43 subjects, it was much improved by the combination of water-suppression technique. MRI findings and intraoperative findings agreed in all patients. Soap-Bubble MIP processing with addition of water-suppression technique is considered useful for visualising the extensor tendons of the hand.

Usefulness of braided polyblend polyethylene suture material for flexor tendon repair in zone II by the side-locking loop technique.

Flexor tendon injuries in zone II were treated in 14 fingers of 13 patients with our method. Firstly, a 2-strand core suture was made by the side-locking loop technique using a USP 2-0-sized braided polyblend polyethylene suture, then 7-strand peripheral cross-stitches were added using a USP 5-0-sized monofilament nylon suture. Post-operative exercises included passive flexion and extension without external fixation on the next day of surgery. Average follow-up observation period was 18 months. As results, the Strickland method of assessment for surgical outcome showed excellent in eight digits and good in five digits, though there was a poor outcome in one digit. Our suture method enabled early post-operative mobilisation exercise without using a splint, while preventing adhesion between the repaired tendon and peripheral tissues, which is considered to provide far greater ultimate tensile strength and a smaller gap at the sutured site than by the conventional method.

Comparison of elastic versus rigid suture material for peripheral sutures in tendon repair.

BACKGROUND: For secure tendon repair, while core suture materials have been previously investigated, the optimum material for peripheral sutures remains unclear. METHODS: Transected bovine gastrocnemius tendons were repaired by 2-strand side-locking loop technique using no.2 braided polyblend polyethylene thread for the core suture. Then, 8-strand peripheral cross-stitches were added using either 2-0 rigid sutures (braided polyblend polyethylene) or USP 2-0-sized elastic sutures (nylon). The holding area of each peripheral suture was set at either 3 × 1 mm (shallow holding) or 6 × 2 mm (deep holding). Therefore, 4 groups were compared (the shallow-rigid, deep-rigid, shallow-elastic, and deep-elastic groups). The gap formation, ultimate tensile strength, and suture migration state were measured after 500 cyclic loadings (from 10 to 200 N). METHODS: The shallow-rigid group had inferior outcomes compared to the other groups. Although the deep-rigid group had the smallest gap and highest ultimate strength, all peripheral sutures had failure prior to core suture rupture. The two elastic groups showed no significant differences, irrespective of the size of the holding area. Suture migration did not occur in the two elastic groups until the ultimate strength was reached and the core suture ruptured. INTERPRETATION: Depending on the suturing method, rigid suture material may not be appropriate for peripheral sutures, when accompanying rigid core suture material. If peripheral sutures can be made with accurate deep holding, rigid suture material will provide favorable outcome. However, in other cases, elastic suture material is considered best for supporting a rigid core suture, as elasticity is another important factor for peripheral sutures.

Tension band fixation for treatment of patellar fracture: novel technique using a braided polyblend sutures and ring pins.

AIM: To evaluate a new tension band fixation technique for patellar fracture using braided polyblend sutures (PBSs) and ring pins (RPs). METHODS: A total of 13 patients (average: 58.2 years) with transverse or comminuted patellar fractures were treated by this technique. From the 4th week after the surgery, normal activities of daily living were permissible. RESULTS: Bone union was achieved at a mean 3 months from surgery, without any cases of failure, redislocation or postoperative complication. At 12 months after surgery, mean Lysholm score was 93.6, knee motion was extension 0.8 degrees to flexion of 134.6 degrees and visual analogue pain score was 0.5. CONCLUSION: The new tension band fixation technique using braided polyblend sutures resulted in good outcomes and is considered clinically effective for patellar fracture reduction.

Prevention and treatment of amputation neuroma by an atelocollagen tube in rat sciatic nerves.

To evaluate the potential of the atelocollagen tube as a cap for amputation neuromas, the histological and histochemical characteristics of the neuroma and spinal cord were compared with those following silicone capping. Four weeks after the transection of 18 rat sciatic nerves, the amputated neuroma was resected, and the nerve stump inserted into an atelocollagen or silicone tube. The histological changes in the nerve ends and c-fos expression in the dorsal horn of the fourth lumbar spinal cord were evaluated at 4 weeks postoperatively. The regenerated nerve structure in the atelocollagen or silicone tube was very thin. In contrast, a typical bulbous neuroma was observed in the control group (the nerve stump was left in place). The atelocollagen and silicone tube groups demonstrated fewer c-fos-expressed cells in the spinal cord than the controls. These results suggest that capping by an atelocollagen tube, like that by a silicone tube, might successfully prevent an amputated neuroma from forming, and suppress induced pain. The atelocollagen tube may be a promising biomaterial for the prevention or treatment of a painful amputation neuroma.

Expression of neuropeptides and cytokines at the extensor carpi radialis brevis muscle origin.

To reveal whether neuropeptides and cytokines affect the pathogenesis of tennis elbow, expressions of substance P, calcitonin gene-related peptide, interleukin 1 alpha, and transforming growth factor beta1 at the origin of the extensor carpi radialis brevis muscle were investigated in patients with tennis elbow (n = 10). Innervation in the origin was determined with use of the protein gene product 9.5. Substance P-like immunoreactivity and calcitonin gene-related peptide-like immunoreactivity were observed in the nerve fibers around small vessels without apparent infiltration of inflammatory cells. Cells showing positive interleukin 1 alpha or transforming growth factor beta1 immunoreactivity were noted in small vessels and the dense collagen meshwork in 5 of 10 cases. The results suggested that these neuropeptides and cytokines might promote inflammation and stimulate proliferation and matrix synthesis of fibroblasts, contributing to the pathology of tennis elbow.

Mechanoreceptors in the anterior cruciate ligament contribute to the joint position sense.

We have investigated the correlation between the number of mechanoreceptors in anterior cruciate ligament (ACL) remnants and the joint position sense just before an ACL reconstruction in 29 patients. The number of mechanoreceptors was evaluated histologically, using the Gairns gold chloride method. Mechanoreceptors were also found in patients who had a long interval between injury and the operation. A joint position sense test was done within 3 days before surgery. We found a positive correlation between the number of mechanoreceptors and accuracy of the joint position sense, suggesting that proprioceptive function of the ACL is related to the number of mechanoreceptors. Therefore, we should consider preserving ACL remnants during ACL reconstruction.