Xiaosheng Ma

Efficacy of anterior cervical decompression and fusion procedures for monomelic amyotrophy treatment: a prospective randomized controlled trial: clinical article.

OBJECT Monomelic amyotrophy (MMA) is a benign, self-limiting lower motor neuron disease. Optimal surgical strategies-discectomy decompression and fusion (DDF) or corpectomy decompression and fusion (CDF)-for patients with aggravated symptoms (within 6 months of presentation) are controversial, particularly in those who are ineligible for conventional treatment. These 2 methods of anterior cervical decompression and fusion for MMA in patients unwilling or unable to wear a conventional cervical collar long term were evaluated. METHODS Anterior cervical decompression and fusion were performed in 48 male patients with MMA between September 2007 and September 2010. Patients were randomly treated with anterior cervical discectomy decompression with autologous iliac crest bone grafting and internal plate fixation (DDF group: 24 patients) or anterior cervical corpectomy, posterior longitudinal ligament resection, autologous iliac crest bone grafting, and internal plate fixation (CDF group: 24 patients). Subjective symptom assessments and electromyography (EMG) examinations were conducted both preoperatively and postoperatively. RESULTS Subjective assessments and EMG studies (mean follow-up duration 25.9 months) indicated improvement in 64.6% and 60% of patients, respectively. No significant correlations between the effectiveness of surgery and age at symptom onset, preoperative symptom duration, or postoperative follow-up time were found. CONCLUSIONS The lack of a significant difference in effectiveness between DDF and CDF favors DDF as more clinically applicable because of its lower procedural risks. As a second-line alternative to cervical collar treatment, surgical anterior cervical decompression and fusion via DDF or CDF may prevent further deterioration and produce good short-term therapeutic effects in patients with MMA; however, cervical collar treatment is recommended for eligible patients because of its lower associated risks.

Lumbar spinal stenosis induced by rare chronic tophaceous gout in a 29-year-old man.

Spinal gout is rare in patients younger than 45 years, occurring most commonly between ages 45 and 80 years. This article describes a 29-year-old man with a history of gout initially observed more than 20 years previously who presented with lower back pain and left lower limb weakness. Computed tomography and magnetic resonance imaging revealed severely damaged facet joints and laminae surrounding L4-S1, and materials with a granular, yellow, cheese-like appearance were observed under direct vision. Postoperative histological examination confirmed spinal gout. Complete posterior decompression was performed concurrently with interbody fusion at L4-L5 and L5-S1. Seventeen-month follow-up revealed good recovery.The mechanism by which urate crystals form preferentially in the spine as opposed to more common soft tissue sites is not well understood. Most reported spinal gout cases were located at L4-S1, which were believed to be the segments with high stresses. These cases occurred in older patients with degenerative spinal diseases and had trauma as indicators. The current authors presume that gout is more likely to exist in the mobile regions with high pressure, such as L4-S1, even in individuals with an initially healthy spine, especially with a long period of abnormal renal dysfunction. Although it is often overlooked in young patients, this condition may be more common than the literature suggests due to the high potential for misdiagnosis in relatively young patients.

Stab wound with lodged knife tip causing spinal cord and vertebral artery injuries: case report and literature review.

Study Design. Case report and literature review. Objective. To report the case of a young patient who sustained a penetrating wound with a knife tip retained in his cervical vertebrae and to review the literature. Summary of Background Data. Stab wound with foreign body retained, associated with spinal cord injury and vertebral artery injury, is not commonly reported. The timing and approach of surgical intervention are still controversial. Methods. A 17-year-old boy with a wound in the neck presented with diminishing feeling and dysfunction of the left leg and arm. Radiographs demonstrated a foreign body at the C4 level, and possible spinal cord and vertebral artery injuries were detected by computed tomography. Digital subtracted angiography showed a small lateral opening of the injured artery, which was successfully embolized. The knife tip was removed from the original wound without severe cerebrospinal fluid leakage or bleeding, Results. The patient achieved immediate improvement after the operation. Conclusion. Cases of simultaneous spinal cord injury and vertebral artery injury in which the foreign body is retained are uncommonly reported. Digital subtracted angiography is necessary for cervical penetrating wounds and surgical approach should be individualized.

Compound Muscle Action Potential Decrement to Repetitive Nerve Stimulation Between Hirayama Disease and Amyotrophic Lateral Sclerosis.

Purpose: To compare repetitive nerve stimulation (RNS) between Hirayama disease (HD) and amyotrophic lateral sclerosis (ALS). Methods: The 3-Hz RNS test was performed on bilateral abductor pollicis brevis, abductor digiti minimi, middle deltoid, and upper trapezius muscles in 33 HD patients and 37 ALS patients. Results: In HD patients, none of tested muscles showed any abnormal decrements (≥10%). Significant decrements were observed in 73% of the ALS patients, and decrements were more frequently observed in proximal muscles (deltoid: 70.3%; trapezius: 48.6%). Illness duration did not correlate with decrement percentage in either patient group, and there was no relationship between decrement incidence and ALS diagnostic category (P > 0.05). Conclusions: The significantly different RNS results between ALS and HD patients support the application of RNS, especially performing RNS in proximal muscles, as a supplementary test in distinguishing these two diseases, even in the early stages. These results may also imply a difference in underlying pathophysiology between ALS and HD.

Motor unit number estimation in the quantitative assessment of severity and progression of motor unit loss in Hirayama disease

OBJECTIVE To investigate motor unit number estimation (MUNE) as a method to quantitatively evaluate severity and progression of motor unit loss in Hirayama disease (HD). METHODS Multipoint incremental MUNE was performed bilaterally on both abductor digiti minimi and abductor pollicis brevis muscles in 46 patients with HD and 32 controls, along with handgrip strength examination. MUNE was re-evaluated approximately 1year after initial examination in 17 patients with HD. RESULTS The MUNE values were significantly lower in all the tested muscles in the HD group (P<0.05). Despite abnormally low MUNE values, 54.3% (25/46) of patients with HD had normal ipsilateral grip power. There was a significant inverse correlation between MUNE values and disease duration (P<0.05). A longitudinal follow-up MUNE analysis demonstrated slow progression of motor unit loss in patients with HD within approximately 1year (P<0.05), even in patients with an illness duration >4years. CONCLUSIONS A reduction in the functioning motor units was found in patients with HD compared with that in controls, even in the early asymptomatic stages. Moreover, the motor unit loss in HD progresses gradually as the disease advances. SIGNIFICANCE These results have provided evidence for the application of MUNE in estimating the reduction of motor unit in HD and confirming the validity of MUNE for tracking the progression of HD in a clinical setting.

Mast Quadrant-assisted Minimally Invasive Modified Transforaminal Lumbar Interbody Fusion: Single Incision Versus Double Incision

Background: The concept of minimally invasive techniques is to make every effort to reduce tissue damage. Certainly, reducing skin incision is an important part of these techniques. This study aimed to investigate the clinical feasibility of Mast Quadrant-assisted modified transforaminal lumbar interbody fusion (TLIF) with a small single posterior median incision. Methods: During the period of March 2011 to March 2012, 34 patients with single-segment degenerative lumbar disease underwent the minimally invasive modified TLIF assisted by Mast Quadrant with a small single posterior median incision (single incision group). The cases in this group were compared to 37 patients with single-segment degenerative lumbar disease in the double incision group. The perioperative conditions of patients in these two groups were statistically analyzed and compared. The Oswestry Disability Index (ODI) scores, Visual Analog Scale (VAS) scores, and sacrospinalis muscle damage evaluation indicators before operation and 3, 12 months postoperation were compared. Results: A total of 31 and 35 cases in the single incision and double incision groups, respectively, completed at least 12 months of systemic follow-up. The differences in perioperative conditions between the two groups were not statistically significant. The incision length of the single incision group was significantly shorter than that of the double incision group (P < 0.01). The ODI and VAS scores of patients in both groups improved significantly at 3 and 12 months postoperation. However, these two indicators at 3 and 12 months postoperation and the sacrospinalis muscle damage evaluation indicators at 3 months postoperation did not differ significantly between the two groups (P ≥ 0.05). Conclusions: Mast Quadrant-assisted modified TLIF with a small single posterior median incision has excellent clinical feasibility compared to minimally invasive TLIF with a double paramedian incision.

Abnormal flexor carpi radialis H-reflex as a specific indicator of C7 as compared with C6 radiculopathy.

Objective: The H-reflex of the flexor carpi radialis (FCR H-reflex) has not been commonly used for the diagnosis of cervical radiculopathy when compared with the routinely tested soleus H-reflex. Although both S1 and S2 roots innervate the soleus, the H-reflex is selectively related to S1 nerve root function clinically. Flexor carpi radialis is also innervated by two nerve roots which are C6 and C7. Although they are among the most common roots involved in cervical radiculopathy, few studies reported if the attenuation of the FCR H-reflex is caused by lesions affecting C7 or C6 nerve roots, or both. We aimed to identify whether an abnormal FCR H-reflex was attributed to the C7 or C6 nerve root lesion, or both. The sensitivities of needle electromyography, FCR H-reflex, and provocative tests in unilateral C7 or C6 radiculopathy were also compared in this study. Methods: A concentric needle electrode recorded bilateral FCR H-reflexes in 41 normal subjects (control group), 51 patients with C7 radiculopathy, and 54 patients with C6 radiculopathy. Clinical, radiological, and surgical approaches identified the precise single cervical nerve root involved in all patient groups. The H-reflex and M-wave latencies were measured and compared bilaterally. Abnormal FCR H-reflex was defined as the absence of the H-reflex or a side-to-side difference over 1.5 milliseconds which was based on the normal side-to-side difference of the H-reflex latency of 16.9 milliseconds (SD = 1.7 milliseconds) from the control group. We also determined standard median and ulnar conduction and needle electromyography. The provocative tests included bilateral determination of the Shoulder Abduction and Spurlings tests in all radiculopathy group patients. Results: Abnormal FCR H-reflexes were recorded in 45 (88.2%) of C7 radiculopathy group patients, and 2 (3.7%) of C6 radiculopathy group patients (P < 0.05). Needle electromyography was abnormal in 41 (80.4%) of C7 radiculopathy patients and 43 (79.6%) of C6 radiculopathy patients. Provocative tests were positive in 15 (29.4%) of C7 radiculopathy patients and 25 (46.3%) of C6 radiculopathy patients. Conclusions: Flexor carpi radialis H-Reflex provides a sensitive assessment of evaluating the C7 spinal reflex pathway. Clinically, a combination of the FCR H-reflex with needle electromyography may yield the highest level of diagnostic information for evaluating clinical cases of C7 radiculopathy.

Evaluation of characteristics and surgical outcomes in cervical spondylotic amyotrophy

Background: Cervical spondylotic amyotrophy (CSA) is a rare clinical syndrome resulting from cervical spondylosis. Surgical treatment includes anterior cervical decompression and fusion (ACDF), and laminoplasty with or without foraminotomy. Some studies indicate that ACDF is an effective method for treating CSA because anterior decompression with or without medial foraminotomy can completely eliminate anterior and/or anterolateral lesions. We retrospectively evaluated outcome of surgical outcome by anterior cervical decompression and fusion (ACDF). Materials and Methods: 28 CSA patients, among whom 12 had proximal type CSA and 16 had distal type CSA, treated by ACDF, were evaluated clinicoradiologically. The improvement in atrophic muscle power was assessed by manual muscle testing (MMT) and the recovery rate of the patients was determined on the basis of the Japanese Orthopedic Association (JOA) scores. Patient satisfaction was also examined. Results: The percentage of patients, who gained 1 or more grades of muscle power improvement, as determined by MMT, was 91.7% for those with proximal type CSA and 37.5% for those with distal type CSA (P < 0.01). The JOA score-based recovery rates of patients with proximal type and distal type CSA were 60.8% and 41.8%, respectively (P < 0.05). Patient satisfaction was 8.2 for those with proximal type CSA and 6.9 for those with distal type CSA (P < 0.01). A correlation was observed among the levels of improvement in muscle power, JOA score based recovery rate, patient satisfaction and course of disease (P < 0.05). Conclusion: ACDF can effectively improve the clinical function of patients with CSA and result in good patient satisfaction despite the surgical outcomes for distal type CSA being inferior to those for proximal type CSA. Course of disease is the fundamental factor that affects the surgical outcomes for CSA. We recommend that patients with CSA undergo surgical intervention as early as possible.

Can an Endplate-conformed Cervical Cage Provide a Better Biomechanical Environment than a Typical Non-conformed Cage?: A Finite Element Model and Cadaver Study.

To evaluate the biomechanical characteristics of endplate‐conformed cervical cages by finite element method (FEM) analysis and cadaver study.

Radiologic Analysis of Kinematic Characteristics of Modic Changes Based on Lumbar Disc Degeneration Grade

OBJECTIVE The kinematic characteristics of Modic changes (MCs) in the lumbar spine have rarely been reported; furthermore, the effect of disc degeneration (DD) on segmental motion has not been considered in analyzing the motion characteristics of MCs. Therefore, this study was designed to evaluate the kinematic characteristics of MCs based on different DD grades. METHODS 894 patients with 4470 lumbar segments were reviewed, and those with MCs were selected for segmental motion evaluation. MC type was defined as 0, I, II, and III, and DD grade was classified into 5 groups from grade A to grade E. Segmental angular and translational motion were calculated from X-ray images in positions of flexion and extension, and the absolute values of the differences were recorded. RESULTS MCs were observed in 308 segments from 260 patients. No MC was found in DD grade A, and MC III was not observed in DD grade B. MC I was found to significantly increase angular motion in the DD grade E group, and MC II could enlarge translational motion in the DD grade D group (all P < 0.05); MC III had the lowest segmental motion in both angular and translational motion; There was no statistical difference in angular and translational motion between MC I and II in all DD grade groups (all P > 0.05). CONCLUSIONS MC III indicates the final stable phase of segmental motion. MC I might increase angular motion, and MC II would increase certain translational motions in the segments that were believed to be stable.