In degenerative disorders of the spine such as disc herniation, intervertebral discs can affect neural tissue, which may result in pain as demonstrated in both basic science and clinical investigations. Previous A disc herniation model in rats (n=58) was used. The L4 nerve root was exposed to a) nucleus pulposus (3mg), b) notochordal cells (25,000 cells) or c) chondrocyte-like cells (25,000 cells). Four control groups were included: 1) application of nucleus pulposus (3 mg) and mechanical displacement of the spinal nerve complex, 2) sham operated animals, 3) application of cell diluent (50 μl) and 4) naïve animals. Seven days after surgery the L4 nerve roots with their dorsal root ganglion were harvested and prepared for blinded neuropathological examinations using light microscopy.Introduction
Material and method
Patients with transfemoral amputation (TFA) often
experience problems related to the use of socket-suspended prostheses.
The clinical development of osseointegrated percutaneous prostheses
for patients with a TFA started in 1990, based on the long-term
successful results of osseointegrated dental implants. Between1999 and 2007, 51 patients with 55 TFAs were consecutively
enrolled in a prospective, single-centre non-randomised study and
followed for two years. The indication for amputation was trauma
in 33 patients (65%) and tumour in 12 (24%). A two-stage surgical
procedure was used to introduce a percutaneous implant to which
an external amputation prosthesis was attached. The assessment of
outcome included the use of two self-report questionnaires, the
Questionnaire for Persons with a Transfemoral Amputation (Q-TFA)
and the Short-Form (SF)-36. The cumulative survival at two years’ follow-up was 92%. The
Q-TFA showed improved prosthetic use, mobility, global situation
and fewer problems (all p <
0.001). The physical function SF-36
scores were also improved (p <
0.001). Superficial infection
was the most frequent complication, occurring 41 times in 28 patients
(rate of infection 54.9%). Most were treated effectively with oral
antibiotics. The implant was removed in four patients because of loosening
(three aseptic, one infection). Osseointegrated percutaneous implants constitute a novel form
of treatment for patients with TFA. The high cumulative survival
rate at two years (92%) combined with enhanced prosthetic use and
mobility, fewer problems and improved quality of life, supports
the ‘revolutionary change’ that patients with TFA have reported
following treatment with osseointegrated percutaneous prostheses. Cite this article:
We developed an animal model of stretch injury to nerve in order to study in vivo conduction changes as a function of nerve strain. In 24 rabbits, the tibial nerve was exposed and stretched by 0%, 6% or 12% of its length. The strain was maintained for one hour. Nerve conduction was monitored during the period of stretch and for a one-hour recovery period. At 6% strain, the amplitude of the action potential had decreased by 70% at one hour and returned to normal during the recovery period. At 12% strain, conduction was completely blocked by one hour, and showed minimal recovery. These findings have clinical implications in nerve repair, limb trauma, and limb lengthening.
1. Stretching of the tibial nerve cut 2 centimetres above the ankle has been the subject of an experimental study in rabbits. 2. The effects on intraneural microcirculation, on vascular permeability, and on the barrier function of the perineurium have been analysed with the aim of determining the extent to which a divided nerve can be stretched without interfering with the process of repair. 3. The results obtained may prove valuable for understanding basic mechanisms and for establishing certain important limitations when end-to-end suture of a nerve trunk is performed under some degree of tension in man.
