Value of preoperative computed tomography in predicting the local staging of cancer of the tongue at primary surgery.

Preoperative staging is essential for the planning of treatment of cancer. This study was designed to evaluate the accuracy of computed tomography (CT) in predicting the local stage of tongue cancer by comparing it with the gold standard of histopathology. A total of 233 patients with newly-diagnosed tongue cancer was retrospectively reviewed, and the size of the tumour and the status of the cervical lymph node were compared between CT images and histopathological results. Patients with stage II cancer were followed up to assess the influence of inaccurate preoperative staging on prognosis. The accuracy of local staging by CT was 47.6% (111/233), with 59.7% (139/233) for tumour stage, and 70.4% (164/233) for nodal stage. The greatest dimension of the tumour on the CT image was about 2mm less than that measured by histopathology. The estimated volume of tumour was a quarter smaller. The accuracy of predicting malignant lymph nodes by CT was 68.9% (n=161). Among patients with stage II disease, simultaneous neck dissection was less likely in the understaged group than in the accurately staged one. The reoperation rate was a little higher but not significantly so. We conclude that the accuracy of CT in predicting local staging for tongue cancer was only moderate, because it underestimated the size of the tumour and needed to improve the criteria for detecting malignant lymph nodes. Understaging on CT images may influence the prognosis of patients with early stage tongue cancer.

Total knee arthroplasty for severe haemophilic arthropathy: long-term experience in Taiwan.

A number of articles have investigated the outcomes of total knee arthroplasty (TKA) and causes of prosthetic failure in patients with haemophilic arthropathy. The aims of this retrospective study were to evaluate the clinical and functional outcomes of TKA and causes of prosthetic failure in patients with haemophilic arthropathy. A consecutive series of 35 TKA in 26 patients with haemophilic arthropathy were performed between November 1985 and October 2006 by one experienced surgeon. The mean age at index operation was 34.2 years old (range: 23.4-47 years) and the mean follow-up duration was 82.2 months (range: 12-218 months). Clinical assessment included range of flexion, range of extension and total range of motion (ROM). Functional evaluation comprised pain score and functional score by Dr. Insall's Knee Society Clinical Rating System. The average preoperative ROM was 63.2 degrees with flexion contracture 15 degrees , whereas the average postoperative ROM was 79.8 degrees with flexion contracture 5.5 degrees . Improvement of range of flexion was 7.1 degrees (P = 0.16); improvement of range of extension was 9.5 degrees (P < 0.01). Average increase of total ROM was 16.6 degrees (P = 0.02). Pain score by Knee Society was 7.1 points preoperatively and 48 points postoperatively (P < 0.01); functional score by Knee Society was 42 points preoperatively and 77.1 points postoperatively (P < 0.01). Three patients received manipulations because of an inadequate ROM. Three infection episodes were treated with debridement and one of them received arthrodesis after removal of prosthesis. Two patients received revision TKA. One of them was because of loosening of femoral component. The other one received revision TKA because of insert wear. Though improvement in range of flexion is insignificant in haemophilic arthropathy of knee after TKA, it showed significant increase in total ROM after operation, especially in improvement of flexion contracture. It also showed great pain relief and significant functional gain. Under the circumstance of acceptable infection rate and complication, TKA is an effective method to achieve pain relief and gain better function in patients with haemophilic arthropathy of knee. The data of this study confirm those previously published by many authors.

Stress analysis of the distal locking screws for femoral interlocking nailing.

In femoral locked nailing, the distal locking screws are vulnerable to mechanical failure. Biomechanical studies have shown that the stress on these screws is substantially affected by the fit of the nail in the medullary canal. In this study, a "closed form" mathematical model based on elastic beam-column theory was developed to investigate how the nail-cortical contact, which was simulated by a linear elastic foundation, affected the stress on the distal locking screws. Providing data for the model was a construct of a fractured femur with an intramedullary locked nail loaded by an eccentric vertical load. The stress on the locking screw was analyzed as a function of the distance from the fracture to the locking screw in the distal fragment under two situations: with and without nail-cortical contact in the distal fragment. With nail-cortical contact, the screw stress decreased as the length of nail-cortical contact and the distance between the distal locking screw and the fracture site increased, but this stress contrarily increased when the nail reached the femoral region at which the screw length increased. The screw stress was much higher without nail-cortical contact than with contact and continued to increase as the nail was inserted further. The mathematical model developed here can be a convenient means of rapid stress evaluation and parametric analysis for locked femoral nailing. It may be used to improve the design of interlocking nails and surgical technique.

Double-blind dose finding study of mefloquine-sulfadoxine-pyrimethamine in children with acute falciparum malaria.

Three different doses of a combination of mefloquine-sulfadoxine-pyrimethamine (MSP), given double-blind as a single dose to 60 children, were evaluated for efficacy and tolerance. The children, 42 boys and 18 girls aged between 5 and 15 years, received a mefloquine dose equivalent to 1, 1.5, or 2 standard MSP (Fansimef) tablets. Radical cure was obtained in all patients with only mild to moderate side effects of nausea and vomiting, which were not worse in the higher dose groups. For children living in an endemic malarious area, a single dose of mefloquine 7.1-12.5 mg/kg, given in combination with sulfadoxine (14.3-25.0 mg/kg) and pyrimethamine (0.7-1.3 mg/kg), is a safe and effective treatment for uncomplicated chloroquine-resistant Plasmodium falciparum malaria. This dose of MSP is approximately 10 mg/kg, 20 mg/kg and 1.0 mg/kg respectively of mefloquine, sulfadoxine and pyrimethamine, which is equivalent to a single standard tablet of Fansimef (mefloquine, 250 mg; sulfadoxine, 500 mg; pyrimethamine, 25 mg) given to a child weighing 20-30 kg.

Oxidative injury induced by synthetic humic acid polymer and monomer in cultured rabbit articular chondrocytes.

Humic substance has been proposed as one of the causative factors of Kashin-Beck disease (KBD), an endemic osteoarthritic disorder with necrosis of chondrocytes widely prevalent in some regions of China. In order to exclude the complications of natural humic substance, here we prepared phenolic polymers of synthetic humic acid (SHA) by oxidation of phenolic monomer, the protocatechuic acid (PCA). The biological effects of SHA and PCA on primary culture of rabbit articular chondrocytes were investigated. We found that not only SHA but also PCA caused chondrocyte injury, as evidenced by the loss of cell viability measured with methylthiazol tetrazolium (MTT) assay and the increased release of intracellular lactate dehydrogenase (LDH). Both SHA and PCA could result in lipid peroxidation and glutathione (GSH) depletion in chondrocytes, indicating that oxidative stress may be involved in chondrocyte injury. Furthermore, a marked increase in intracellular calcium level ([Ca2+]i) occurred after chondrocytes treated with SHA or PCA. These results suggest that chondrocyte injury elicited by SHA or PCA may be mediated through the occurrence of oxidative stress and the disruption of intracellular Ca2+ homeostasis. Data also suggest that the monomeric phenolic acid may be considered one of the causative factors of KBD in addition to humic substance.

Management of rigid post-traumatic kyphosis.

STUDY DESIGN: Rigid post-traumatic kyphosis after fracture of the thoracolumbar and lumbar spine represents a failure of initial management of the injury. Kyphosis moves the center of gravity anterior. The kyphosis and instability may result in pain, deformity, and increased neurologic deficits. Management for symptomatic post-traumatic kyphosis always has presented a challenge to orthopedic surgeons. OBJECTIVES: To evaluate the surgical results of one stage posterior correction for rigid symptomatic post-traumatic kyphosis of the thoracolumbar and lumbar spine. SUMMARY OF BACKGROUND DATA: The management for post-traumatic kyphosis remains controversial. Anterior, posterior, or combined anterior and posterior procedures have been advocated by different authors and show various degrees of success. METHODS: One vertebra immediately above and below the level of the deformity was instrumented posteriorly by a transpedicular system (internal fixator AO). Posterior decompression was performed by excision of the spinal process and bilateral laminectomy. With the deformed vertebra through the pedicle, the vertebral body carefully is removed around the pedicle level, approximating a wedge shape. The extent to which the deformed vertebral body should be removed is determined by the attempted correction. Correction of the deformity is achieved by manipulation of the operating table and compression of the adjacent Schanz screws above and below the lesion. RESULTS: Thirteen patients with post-traumatic kyphosis with symptoms of fatigue and pain caused by slow progression of kyphotic deformities received posterior decompression, correction, and stabilization as a definitive treatment. The precorrection kyphosis ranged from 30-60 degrees, with a mean of 40 degrees +/- 10.8 degrees. After correction, kyphosis was reduced to an average of 1.5 degrees +/- 3.8 degrees, with a range from -5 degrees to 5 degrees. The average angle of correction was 38.8 degrees +/- 10.4 degrees, with a range from 25 degrees to 60 degrees. Significant difference was found between pre- and post-operative kyphosis measures (P < 0.001). The follow-up period for all patients was 2 years, and the average kyphosis angle measured at the moment was 3.8 degrees +/- 3 degrees with a range from -3 degrees to 8 degrees. Substantial overall improvement was achieved in the 13 patients. CONCLUSION: This method provides single-stage posterior decompression, correction, and stabilization on as definitive management for post traumatic kyphosis of the thoracolumbar and lumbar spine.

The infectivity of gametocytes of Plasmodium falciparum from patients treated with artemisinin.

Twenty-seven patients with gametocytes of Plasmodium falciparum (PF) were divided into groups A, B, and C. A daily dose of 1200 mg artemisinin was given for 5 days to group A, a state dose of 750 mg of mefloquine to group B and a single dose of 750 mg mefloquine combined with 45 mg primaquine to group C. After treatment, the gametocyte count was taken daily, and infectivity of the gametocytes to Anopheles dirus via membrane feeding was also studied. Results showed that in group A, the density of gametocyte and infectivity were significantly reduced on days 4, 7, 14 and 21 after treatment; In group B, the gametocytes were significantly reduced on days 7, 14 and 21 and infectivity was significantly cut down on days 14 and 21 after medication. In group C, gametocytes disappeared in 5 out of 9 patients with failure of infecting mosquitoes in all 9 patients on day 4 after treatment. These indicate that artemisinin can effectively influence the infectivity of gametocytes of PF. Artemisinin is much better in blocking the transmission of PF malaria than mefloquine.

Spinal deformities among children under 10 years old: a clinical analysis of 41 cases.

In order to investigate the number, types, severity and the various treatments of spinal deformity among children under 10 years old, a retrospective survey of registered patients in the scoliosis clinic at the National Taiwan University Hospital was performed. Between August 1982 and December 1988, there were 41 children who had scoliosis with a Cobb angle larger than 10 degrees and the onset was before 10 years of age. This number accounted for 3.8% of all scoliotic patients during the same time period. Of these children, 19 had idiopathic scoliosis (46.3%), 7 with infantile and 12 with juvenile; the other 19 were due to congenital, and the remaining 3 were postradiation, a resection of Wilms' tumor in 2 and neuroblastoma in 1. In the congenital group, hemivertebra (13 patients) outnumbered other causes. Twenty three patients (56%) underwent surgical correction, the rest were either under regular observation (9 patients), bracing (7 patients) or electrical stimulation (2 patients). The average preoperative Cobb angle in the operated groups was much larger, being 67.6 degrees in the infantile; 52.4 degrees in the juvenile; 57 degrees in the congenital; and 62 degrees in the postradiation. For those without an operation, the angles were smaller than 30 degrees. The indications for surgery were that the curvature was in progression, which could not be controlled by conservative means, or that in some congenital cases, the curve had the potential tendency to exacerbate. From the present study, the percentage of scoliosis under 10 years of age was far less than the adolescent group in our clinic.(ABSTRACT TRUNCATED AT 250 WORDS)

Plate fixation for anterior cervical interbody fusion.

From April 1989 to April 1990, 13 patients with cervical spinal fracture/dislocation, spondylosis or metastasis were treated at the respective hospitals. There were 4 women and 9 men whose ages ranged from 25 to 70 years (mean 45 years). All of them were treated with neural decompression, bone grafting and anterior spinal interbody fusion. All iliac crest or fibular bone grafts were anchored to the vertebral bodies with plates and screws. The clinical outcomes were evaluated retrospectively. The results showed that all had improvement of neurological symptoms and signs. The radiographic evaluation revealed satisfactory alignment and sound union of the cervical spine in all 13 patients. No serious complications were found except screw loosening in two instances without impairment of clinical results. We concluded that anterior cervical plates provide effective stabilization which is essential for good results. Furthermore, from this study and a review of the literature, we advocated that it was not necessary for the tip of the screws to reach or even penetrate the posterior cortex of the vertebral body.

Gait analysis after total knee replacement for degenerative arthritis.

Using quantitative gait analysis and clinical evaluation, the functional results of 18 total knee replacement (TKR) in 13 patients who had osteoarthritis were evaluated. Nine knees each were replaced by Insall-Burnstein (I/B) posterior stabilized design or Miller-Galante (M/G) prosthesis. The former was fixed by cement and needed to sacrifice posterior cruciate ligament (PCL), while the latter was inserted without cement, and PCL could be reserved. The follow-up period ranged from 21 to 77 months. At the final follow-up, the overall functional knee score was 94.1 points (I/B 95.0 versus M/G 92.2). The average active knee flexion was 109.7 degrees (I/B 116.4 degrees versus M/G 102.9). For gait analysis, three cameras synchronized with 2 AMTI force plates were connected to the VICON system to provide kinetic and kinematic data during level walking. The data were compared with the non-operated side; and with younger subjects as normal control. They were supposed to possess normal knee functions. In patients after knee prosthesis, they tended to have slower velocity, shorter step length and less cadence. They also showed shorter swing and longer stance phases. In the M/G knee ground, the duration for double-limb support was longer, but shorter for single-limb support. The angles of knee flexion-extension of both prosthetic groups became narrower. Their ground reaction forces in both vertical and medio-lateral directions were larger than in the control groups, probably due to quadriceps dysfunction and subtle imbalance of the soft tissue-prosthesis complex around the joint.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical studies of the anterior spinal fixators after corpectomy in pigs.

An unstable corpectomy porcine spinal model was created for the testing of anterior spinal fixators including: Kaneda device (KD), combination of Polster-Brinckmann prosthesis and Zielke implant (PBZ), and a new prototype device (CH). These spinal implants were examined in a one above/one below corpectomy model to determine the relative stiffness of each construct and the deformation of the adjacent discs under loading. The results indicated that the relative torsion and flexion stiffness were higher for the tested spines fixed with KD and CH. However, the relative compression stiffness of the tested spines was the same for all devices. The rigidity of the spinal constructs, which were measured around the corpectomy region showed the same tendency as above. However, the stiffness of CH and KD constructs were significantly higher than that of the PBZ construct under flexion and torsion. The difference in deformation of the upper and lower adjacent discs was not obvious among the intact spine and the spinal constructs with different devices. Clinical relevances: The corpectomy model represents a "worst case" scenario of spinal instability. In many conditions, spinal reconstructive surgery can restore axial compressive, torsional, and flexural rigidity to normal levels. These experimental conclusions apply to acute restoration of stability, rather than to rigidity after long-term cyclical loading. These three anterior fixators extended to only one cephalad level and one caudal level beyond the corpectomy defect. The new prototype device (CH) has a stability to the Kaneda device. The superior mechanical strength and simpler operative procedure of the new device provide for a potential clinical advantage in restoration of unstable spinal conditions.

Experimental structural scoliosis in rabbits.

Structural scoliosis was produced by purely posterolateral mechanical tethering of the spine with ligation of the scapula to the opposite pelvic bone in rabbits during the growing period. It is a simple and easy method without direct trauma to the spine. When the tethering force occurred discontinuously or only in the coronal plane by drawing of the scapula to the ipsilateral pelvic bone in 17 rabbits, spinal deformity could not be produced. The model provided evidence of biplanar deformity as one of the initial factors for the development of structural scoliosis.

Triple innominate osteotomy and rotational acetabular osteotomy in the treatment of congenital hip dysplasia.

Congenital hip dysplasia is a developmental disease which predisposes patients to osteoarthritis of the hip. We compare the results and complications of triple innominate osteotomy and rotational acetabular osteotomy in the treatment of this disease. Between 1984 and 1992, 27 patients with 30 dysplastic hips received reconstructive procedures at National Taiwan University Hospital. Fourteen patients (16 hips) with a median age of 18 years were treated by triple innominate osteotomy. Nine of 16 hips had concomitant femoral osteotomy. Another 13 patients (14 hips) with a median age of 24 years were treated by rotational acetabular osteotomy. We compared the radiologic and functional results, complications and satisfaction of the patients in these two groups. Patients who underwent rotational osteotomy showed more correction in roof obliquity than patients who had triple innominate osteotomy. The functional results when evaluated by Harris scores, were better in patients who had triple innominate osteotomy than rotational osteotomy. Complications included one resubluxation of the hip in each group as well as one perforation of the hip joint and one pin break and nonunion at the osteotomy site in the rotational osteotomy group. Patients who had triple innominate osteotomy were more satisfied with the results. With proper selection of patients and accurate performance of the procedure, both triple innominate osteotomy and rotational osteotomy may be used effectively for the treatment of congenital hip dysplasia. However, in our study, patients who underwent rotational osteotomy had better anatomic correction, while those who underwent triple innominate osteotomy had better functional results.

Magnetic resonance imaging of vertebral compression fractures.

In this study, magnetic resonance imaging (MRI) was used to analyze the signal intensity and vascularity of compression fractures of vertebrae in 74 patients. The possibility of nonunion was assessed according to the specific image findings and clinical presentation. All patients had chronic back pain for more than 3 months and compression fractures of the vertebrae initially demonstrated by plain radiography. Pre-enhanced T1 and T2*-weighted images (*multiplaner gradient recall sequence) and postenhanced MRI were obtained. Images were divided into three categories according to the signal intensity of the fractured vertebrae such as hyperintensity (n = 35), hypointensity (n = 24) on T1-weighted image and necrotic type compression fractures of the vertebrae (n = 15). Of the 15 necrotic-type cases, 13 disclosed "fluid"-containing space at the collapsed vertebrae and two showed "air"-containing space at the vertebral body. We believe that these findings are pathognomonic signs of nonunion of the collapsed vertebrae. Surgical specimens were obtained from the four patients whose vertebrae showed necrosis and granulation tissue. After posterior spinal instrumentation, the collapsed vertebral body regained the height and presence of the open end-plate of the vertebra on postoperative lateral radiography. The superior capabilities of MRI offers useful criteria that make the diagnosis of nonunion in compression fractures of the spine possible. Thus, a space with "fluid" or "air" collection at the anterior aspect of a collapsed vertebra as well as strong enhancement with Gd-DTPA at the posterior aspect of the collapsed vertebra may be considered to be pathognomonic signs of nonunion of the fractured vertebra.

Dose findings of dihydroartemisinin in treatment of falciparum malaria.

Forty patients with uncomplicated P. falciparum malaria were respectively treated in an open randomized comparative study of dihydroartemisinin tablets given at total doses of 480 mg over 5 days and 640 mg over 7 days in a drug-resistant malaria endemic area in Hainan, China. The result showed that all patients were clinically cured. In 5-day and 7-day groups, the mean fever clearance times (FCT) were 26.1+/-10.2 and 21.1+/-11.8 hours respectively; the mean parasite clearance times (PCT) were 58.7+/-20.9 and 59.4+/-20.9 hours respectively, which showed no significant difference. 28-day follow-ups were accomplished on 39 and 37 cases respectively in two groups, the recrudescence rates were 20.5% (8/39) in 5-day group, while 2.7% (1/37) in 7-day group with significant difference (chi2=4.19, p<0.05). No clinical drug-related side effect was found in two groups during treatment.

[The infectivity of gametocytes of Plasmodium falciparum from patients treated with artemisinine].

27 patients with gametocytes of P. falciparum were divided into groups A, B and C. 1,200 mg of artemisinine was given as a daily dose for 5 days to group A, 750 mg of mefloquine plus 45 mg of primaquine as a single dose to group C. After medication, gametocyte count was observed daily in addition to the infectivity of gametocytes of P. falciparum to Anopheles dirus. In group A, the density of gametocytes and the infectivity were significantly reduced on days 4, 7, 14 and 21 during the study. In group B, the density of gametocytes was significantly reduced on days 7, 14 and 21 and the infectivity was obviously lowered on days 14 and 21 after medication. In group C, gametocytes disappeared in 5 out of 9 patients with the failure of infection to mosquitoes on day 4 after treatment. This indicates that artemisinine can effectively influence the infectivity of gametocytes of P. falciparum. Artemisinine is superior to mefloquine in blocking the transmission of P. falciparum malaria.

[Gene typing of merozoite surface protein 1 of Plasmodium falciparum isolates from Hainan Province].

OBJECTIVE: To identify the genotype of merozoite surface protein 1 (MSP1) of Plasmodium falciparum isolates from Hainan Province. METHODS: Nested PCR was applied to amplify the MSP1 of Blocks 2 and 3 Plasmodium falciparum isolates from Hainan Province. Two allelic family representative gene fragments were sequenced. RESULTS: From 36 out of 39 blood samples from Plasmodium falciparum patients, 44 gene fragments of blocks 2 and 3 of the MSP1 were amplified, of which the MAD20-type allele was dominant(75%). followed by K1-type allele. No RO33-type allele was found. The mixed infection rate of the two different allelic type was 19.4%. Sequence analysis showed that the sequences of MAD20- and K1-type isolates from Hainan Province were highly homologous to that of the MAD20 and K1 allelic prototypes. CONCLUSION: Two principal allelic types of MSP1 gene, MAD20- and K1-type, exist in malaria endemic areas in Hainan Province, the MAD20-type being the dominant.

p53 directly regulates αA- and ßA3/A1-crystallin genes to modulate lens differentiation.

It is well established that the tumor suppressor p53 plays major roles in regulating apoptosis and cell cycle progression. In addition, recent studies have demonstrated that p53 is actively involved in regulating cell differentiation in muscle, the circulatory system and various carcinoma tissues. We have recently shown that p53 also controls lens differentiation. Regarding the mechanism, we reveal that p53 directly regulates c-Maf and Prox1, two important transcription factors to control cell differentiation in the ocular lens. In the present study, we present further evidence to show that p53 can regulate lens differentiation by controlling expression of the differentiation genes coding for the lens crystallins. First, the αA and ßA3/A1 gene promoters or introns all contain putative p53 binding sites. Second, gel mobility shifting assays revealed that the p53 protein in nuclear extracts from lens epithelial cells directly binds to the p53 binding sites found in these crystallin gene promoters or introns. Third, exogenous wild type p53 induces dose-dependent expression of the luciferase reporter gene driven by different crystallin gene promoters and the exogenous dominant negative mutant p53 causes dose-dependent inhibition of the same crystallin genes. Fourth, ChIP assays revealed that p53 binds to crystallin gene promoters in vivo. Finally, in the p53 knockout mouse lenses, expression levels of various crystallins were found down-regulated in comparison with those from the wild type mouse lenses. Together, our results reveal that p53 directly regulates expression of different sets of genes to control lens differentiation.

Operative repair of symptomatic spondylolysis following a positive response to diagnostic pars injection.

From 1989 to 1996, 275 patients (245 male and 20 female) with back pain symptoms and spondylolysis of the lumbar spine were reviewed. All patients were evaluated by a protocol that included nonoperative treatment, bone scan, and pars injection. Only those whose symptoms failed nonoperative measures, showing negative bone scan and positive pars injection, were regarded as candidates for surgical management. Pars injection with Marcaine was done, and there were 93 cases with a positive response of reproducing symptoms and symptom relief. Patients then received autogenous bone grafting and internal fixation of the pars interarticularis defect. The internal fixation devices used included translaminar screws (AO 3.5 cancellous screw) for the most frequent level of L5, hook screws for levels above L4, and augmentation with wire for cases with concomitant spinal bifida occulta. The average age of the surgical group (85 male and 8 female) was 23 years (range: 19-35 years). After a follow-up averaging 30.4 months (range: 24-48 months), fusion results were 87%. Clinical results of 85 cases (91.3%) were excellent to good; 8 cases were fair; there were no poor cases. Direct repair of the pars defect by internal fixation and bone grafting was done to preserve involved motion segment and to prevent abnormal stresses at adjacent levels. These procedures seemed to be clinically effective.

Prevention of postlaminectomy membrane: experimental and clinical observations.

An animal experimental study was performed to investigate the prevention of scar formation after laminectomy by applying Gelfoam, a free-fat graft and steroids as interposing material between the dura and muscles. There were 52 adult guinea pigs equally divided into four groups. They were sacrificed 2 weeks, 4 weeks and 12 weeks respectively after surgery. In the control group, there was young fibrous tissue at 2 weeks, which became more mature at 4 weeks. At 12 weeks, it became mature with varying thickness and canal extension. In the steroid group, it showed the same picture as the control group. In the Gelfoam group, there was foreign body reaction with disintegration of Gelfoam at 2 to 4 weeks. At 12 weeks, however in the free-fat graft group, viable fat graft could be seen at the laminectomy site with little fibrous tissue overlying the dura. In the clinical part, from September 1981 to September 1984, one of the authors (PQC) performed 100 laminectomies on patients with various causes of low back pain. A piece of free subcutaneous fat was laid on dura before wound closure. At follow-up, there was no adverse effect pertaining to its application. Most patients had considerable pain relief after the surgery. From the above observation, we believe that a free-fat graft is a simple and effective way to prevent postlaminectomy membrane. Steroids and Gelfoam do not have such advantage.