A number of dynamic stabilization systems have been used to overcome the problems associated with spinal fusion with rigid fixation recently and the demand for an ideal dynamic stabilization system is greater for younger patients with multisegment disc degeneration. Nitinol, a shape memory alloy of nickel and titanium, is flexible at low temperatures and regains its original shape when heated, and the Nitinol shape memory loop (SML) implant has been used as a posterior tension band mostly in decompressive laminectomy cases because the Nitinol implant has various characteristics such as high elasticity and a tensile force, flexibility, and biological compatibility. The reported short-term outcomes of the application of SMLs as posterior column supporters in cervical and lumbar decompressive laminectomies seem to be positive, and complications are minimal except for the rare occurrence of pullout and fracture of the SML. However, there was no report of neurological complications related to neural compression in spite of the use of the loop of SML in the epidural space. The authors report a case of delayed development of radiating pain caused by subsidence of the SML resulting epidural compression.
Alloys ; Elasticity ; Epidural Space ; Hot Temperature ; Humans ; Intervertebral Disc Degeneration ; Laminectomy* ; Memory* ; Nickel ; Pliability ; Spinal Fusion ; Titanium

A rare case of chronic pain of entrapment neuropathy of the sciatic nerve successfully relieved by surgical decompression is presented. A 71-year-old male suffered a chronic right buttock pain of duration of 7 years which radiating to the right distal leg and foot. His pain developed gradually over one year after underwenting drainage for the gluteal abscess seven years ago. A cramping buttock and intermittently radiating pain to his right foot on sitting, walking, and voiding did not respond to conventional treatment. An MRI suggested a post-inflammatory adhesion encroaching the proximal course of the sciatic nerve beneath the piriformis as it emerges from the sciatic notch. Upon exploration of the sciatic nerve, a fibrotic tendinous scar beneath the piriformis was found and released proximally to the sciatic notch. His chronic intractable pain was completely relieved within days after the decompression. However, thigh weakness and hypesthesia of the foot did not improve. This case suggest a need for of more prompt investigation and decompression of the chronic sciatic entrapment neuropathy which does not improve clinically or electrically over several months.
Abscess ; Aged ; Buttocks ; Chronic Pain ; Cicatrix* ; Decompression* ; Decompression, Surgical ; Drainage ; Foot ; Humans ; Hypesthesia ; Leg ; Magnetic Resonance Imaging ; Male ; Muscle Cramp ; Pain, Intractable ; Sciatic Nerve* ; Thigh ; Walking

The powers of the low-frequency(LF) and high-frequency(HF) components characterizing heart rate variability (HRV) appear to reflect, in their reciprocal relationship, changes in the state of the sympatho-vagal balance occurring during orthostatic stress with head-up tilt. We studied 24 healthy volunteers (median age, 23.1 years) who were subjected after a rest period to a series of passive head-up tilt steps chosen from the following angles: 0 degree. 15 degrees, 30degrees, 45degrees, 70degrees, and 90degrees under the condition of frequency controlled respiration(0.25Hz) in order to get data of the Korean young adults. During head-up tilt, heart rate and normalized low frequency power(LF(N : 0.05-0.15 Hz) of HRV showed significant increase(p=0.000), but normalized high frequency power(HFN : 0.2-0.3 Hz) and total power showed progressive decrease(p=0.000, p<0.01 respectively). Male showed significantly higher LF(N and lower HFN than female at tilt table angle 0degree(p<0.01). Power spectral analysis of HRV appears to be capable of providing a noninvasive quantitatibve evaluation of graded changes in the state of the sympatho-vagal balance.
Female ; Healthy Volunteers ; Heart Rate* ; Heart* ; Humans ; Male ; Young Adult*