Influences of Lateral Meniscus Posterior Root Tear with Different Suture Methods on Knee Biomechanics / 医用生物力学

Objective To evaluate the biomechanical effects of lateral meniscus posterior root (LMPR) tears fixed at different suture positions, so as to investigate the optimal suture method for repairing LMPR tears. Methods Eight fresh cadaveric knees were used. Each knee was tested under 6 conditions: intact knee, ruptur of LMPR, suture of LMPR to the center point of root insertion, suture of LMPR posterior, interior and later 5 mm to the center point of root insertion, respectively. The peak contact pressure, the average contact pressure and contact area were evaluated using a Tek-scan sensor positioned between the meniscus and tibial plateau, under 1 kN compressive loading, at 0 degree knee extension. Results In the lateral compartment, the average contact pressure and peak pressure significantly increased under rupture of LMPR compared with the intact state (P0.05). Conclusions The average contact pressure, the peak contact pressure and the contact area between the lateral meniscus and the tibial plateau changed obviously due to the LMPR tears. When the suture position was 5 mm lateral to the center point of root insertion, similar biomechanical function with the intact knee could be obtained.

The causes and prevention of C₅ nerve root palsy after anterior cervical decompression and fusion / 中国骨伤

<p><b>OBJECTIVE</b>To analyze the causes of muscular paralysis due to C₅ nerve root injury after anterior cervical decompression and fusion (ACDF) and explore its prevention way.</p><p><b>METHODS</b>From January 2005 to December 2015, 310 patients underwent ACDF in our hospital. Of them, 9 cases occurred muscular paralysis due to C₅ nerve root injury after operation. The clinical data of 9 patients were retrospectively analyzed. There were 8 males and 1 female, aged from 51 to 84 years with an average of 64 years. Two cases underwent internal fixation and intervertebral fusion with one segment, 6 cases with two segments, 1 case with three segments. Simple deltoid muscle weakness, pain, numbness happened in 7 cases, simultaneously biceps brachii muscle weakness, pain, numbness in 2 cases. Muscle strength was 0 grade in 1 case, 1 grade in 3 cases, 2 grades in 4 cases, 3 grades in 1 case.</p><p><b>RESULTS</b>The follow up time of 9 patients was more than 12 months and the longest was 24 months with an average of 14 months. Muscle strength of 7 patients recovered to 4-5 grades. Recovering time after operation was directly proportional to the degree of injury, those patients with muscle strength level more than 2, usually could have significant improvement within 3 weeks. The JOA score improved from 10.89±1.89 preoperatively to 8.92±1.91 postoperative C₅ nerve root palsy to 14.48±2.10 at final follow up, with significant difference(<0.05).</p><p><b>CONCLUSIONS</b>More complicated factors result in C₅ nerve root injury after ACDF. Except those suffered severe grinding contusion and amputation, most of the patients can get satisfactory prognosis. Strict control of the operation indication, selection of the right surgical segment with accurate manipulation, control of the distraction of intervertebral space and the width of the multilevel anterior cervical corpectomy, are main methods to prevent the complication.</p>

Comparative Study of Posterior Lumbar Interbody Fusion via Unilateral and Bilateral Approaches in Patients with Unilateral Leg Symptoms

OBJECTIVE: We investigated the clinical and radiological advantages of unilateral laminectomy in posterior lumbar interbody fusion (PLIF) procedure comparing with bilateral laminectomy, under the same procedural condition including bilateral instrumentation and insertion of two cages, in patients with degenerative lumbar disease with unilateral leg symptoms. METHODS: We retrospectively reviewed 124 consecutive cases of PLIF via unilateral or bilateral approach between January 2006 and April 2010. In 80 cases (bilateral group), two cages were inserted via bilateral laminectomy, and in 44 cases (unilateral group), via unilateral laminectomy. The average follow-up duration was 29.5 months. The clinical outcomes were evaluated with the Visual Analogue Scale (VAS) and the Oswestry disability index (ODI). The fusion rates and disc space heights were determined by dynamic standing radiographs and/or computed tomography. Operative times, intra-operative and post-operative blood losses and hospitalization periods were also evaluated. RESULTS: In clinical evaluation, the VAS and ODI scores showed excellent outcomes in both groups. There were no significant differences in term of fusion rate, but the perioperative blood loss and the operative time of the unilateral group were lower than that of the bilateral group. CONCLUSION: Unilateral laminectomy can minimize the operative time and perioperative blood loss in PLIF procedure. However, the different preoperative disc height between two groups is a limitation of this study. Despite this limitation, solid fusion and satisfactory symptomatic improvement could be achieved uniquely by our surgical method. This surgical method can be an alternative surgical technique in patients with unilateral leg pain.

Preliminary research on the clinical classification of the brachial plexus root injury in adult / 中华显微外科杂志

Objective To explore the clinical classification of the brachial plexus root injury in adult.MethodsAll 155 cases of adult brachial plexus root injury in the First Affiliated Hospital of Sun Yat-sen University,were collected and analyzed on their characteristic,operative methods,and clinical outcome so as to find the distribution and incidence of different type of brachial plexus root injury and set up the clinical classification of adult brachial plexus root injury.ResultsBrachial plexus root injuries in adult could be classified into three types and seven subtypes.Type A is upper brachial plexus root injury,including type AⅠ (C5,C6 completely avulsion or rupture injury,with/without phrenic nerve injury),type AⅡ (C5-C7 completely injury),and type AⅢ (C5-C7 completely injury accompanied with C8,T1 incompletely injury).Type B is lower brachial plexus root injury,including type BⅠ[ C8,T1 (with/without C7)completely injury ] and type BⅡ (C8,T1,C7 completely injury,accompanied with C5、6 incompletely injury).Type C is total brachial plexus root injury,including type CⅠ(C5-T1 completely root avulsion) and type CⅡ(C7-T1 root avulsion accompanied with C5、6 root or trunkrupture).For the cases of every type,u pper brachial plexus root injury type A have 86 cases,in which type AⅠ 6 cases,type AⅡ 27 cases and type AⅢ 53 cases; lower brachial plexus root injury type B have 6 cases,in which type BⅠ 2 cases and type BⅡ 4 cases; total brachial plexus root injury type C have 63 cases,in which type CⅠ 51 cases and type CⅡ 12 cases. ConclusionExcept the upper,lower,and total three types,brachial plexus root injuries in adult could be classified further into seven subtypes.The distribution of different type of adult brachial plexus root injury is overbalance:upper type A (55.5％) is more often seen,total type C(40.6％) followed and lower type B(3.9％) is the least seen.In upper brachial plexus root injury,type AⅢ(61.6％) is more often seen,type AⅡ(31.4％) followed and type AⅠ(7％) is less seen.

Survival and Pathway of Regenerative Motoneurons after Brachial Plexus Root Injury / 中国康复理论与实践

@#ObjectiveTo observe the survival and pathway of regenerative axons of spinal motoneurons following root injury of brachial plexus (BPI) and to investigate the correlation between the pathway of regenerative axons and the recovery of motor function. Methods48 adult male SD rats were randomly divided into four groups: crush group, cut group, avulsion group and the control group. 2 months later, the functional recovery was evaluated with Grooming test. Fluorogold labeled regenerative motoneurons retrogradely when injected into the motor or sensory branch of musculocutaneous nerve. 3 d later, the C5-8 spinal cord were harvested and the regenerative motoneurons were counted. The survival neurons were counted with neutral red staining. ResultsThe number of survival neurons in the cut group (1005±89) were more than that of the avulsion group （881±76）, but less than the crush group (1126±25). The control group was the most (1900±39）. The regenerative motoneurons reinnervated motor branch were much more than that of the sensory branch in all groups. For the Grooming test, the grade in the crush group (3.42) was much higher than that of the avulsion (1.75) and cut (1.75) group. ConclusionRegenerative axons of spinal motoneurons reinnervate the motor branch after BPI. The number of survival neurons is different after different injuries, which associated with the motor functional recovery.

Lumbar Root Injury by the Leakage of Bone Cement after the Percutaneous Vertebroplasty: A case report

Percutaneous vertebroplasty is being increasingly used to treat compression fractures of vertebrae. Although it is said that this technique has minimal risk, we experienced a root injury after percutaneous vertebroplasty. A 62 year old woman suffered from weakness of the right lower extremity immediately after percutaneous vertebroplasty. We observed bone cement leakage into the spinal canal of the second through the fourth lumbar level, resulting in root injury. Weakness of the patient improved after the physical therapy. We should be aware of the neurologic complications of percutaneous vertebroplasty.

Intraoperative Spinal Nerve Root Injuries during Surgery for Degenerative Low Back Disease / 대한척추외과학회지

STUDY DESIGN: A retrospective study OBJECTIVE: To analyze incidence, causes and prognosis of the spinal nerve root injury during the degenerative low back surgery. SUMMARY OF LITERATURE REVIEW: There were very few studies about intraoperative spinal nerve root injuries during low back surgery. MATERIALS AND METHODS: Six hundred and twenty seven patients underwent degenerative low back surgery from Jan 1990 to Jan 2001 were included in this study. All patients were operated on by the first author and operation records made by the author himself were reviewed. Eight cases of intraoperative spinal nerve root injury were identified and causes and level of injuries, preoperative diagnosis, types of surgery and follow-up clinical results were analyzed. RESULTS: Eight cases of nerve root injury were developed during 5 posterior laminotomies for discectomy and 3 instrumentation and fusion. Spinal nerve root injuries were caused by Kerrison punch in 4 cases, pituitary forcep in 2, rongeur in 1, and not certain but probably by Kerrison punch in 1 case. The levels of injuries were 5th lumbar nerve root in 4 cases, and 1st sacral nerve root and 2nd lumbar nerve root in 1 case respectively. Two cases had sacral nerve rootlet injury with paramedian dural tear but the level of root injury was uncertain. Six of 8 patients had symptoms. There were sensory loss in 4 patients, pain in 2, and one patient had both sensory loss and loss of big toe extension power. Neurological symptoms were not improved throughout the follow-up period, but 2 patients who had pain were resolved their symptoms by 3 months. CONCLUSIONS: Incidental spinal nerve root injury occurred in 1.3 percentage of the patients who underwent low back surgery. Half of them had neurologic symptoms and they showed poor prognosis. However motor deficit was relatively uncommon and it might be related to the anatomical characteristics of spinal nerve root.

Root Injury after Percutaneous Vertebroplasty in Compression Fracture: Case Report / 대한척추외과학회지

The first image-guided percutaneous vertebroplasty was performed in France in 1984. Percutaneous vertebroplasty recently has been introduced as a therapeutic alternative for the treatment of pain associated with compression fracture. Several European reports have described excellent results for treatment of compression fracture, and complications were minor and infrequent. We experienced a case of root injury after percutaneous vertebroplasty in compression fracture, which was treated by posterior decompression and removal of the cement.

Surgical Experience of Transpedicular Screw Fixation of the Lumbar Spine

Transpedicular screw fixation of the lumbar spine has evolved rapidly and become one of the reliable methods to application. We treated 42 cases of lumbar spine disease using above method from October, 1987, to Febuary, 1993. The disease entities were spondylolisthesis 24 cases(58%), spondylolysis 14 cases(33%), fracture and dislocation 3 cases(7%), postsurgical instability 1 case(2%). The most frequent clinical symptom and sign was low back pain with radiating pain accompanying limitation of straight leg raising, which clinical outcome was excellent with wide laminectomy. The transpedicular screw fixation allow adequate neural decompression, short segment fixation and prevention of motion limitation of lumbar spine. But one of the important complication driven with this method was root injury which must be prevented by surgen's throught knowledge to pedicular anatomy and meticulous operative technique. The instrument failure is also the troublesome problem. The appropriate bone fusion will be the acceptable strategy to overcome the eventual possibility of instument failure.