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Two cases of spinal arachnoid cysts are reported, one with Syringomyelia, Spondylosis and tethered cord syndrome, which is considered to be a congenital cyst, the other with RA and Lumbar disc herniation. The former was treated by cyst resection, S-S shunting, transpedicular fusion and resection of the terminal film. The latter was treated by cyst resection and nucleotomy. Treatment in these cases led to improvement in neurological symptoms.

It is very important that occurate diagnosis of the level and location of lumbar disc herniation is made, before surgery is carried out. Recently, the diagnosis of lumbar disc herniation has been made easier with magnetic resonance imaging.We performed a nucleotomy in 22 cases of lumbar disc herniation, which were only diagnosed by magnetic resonance imaging. All cases achieved a good results post-operatively.We concluded that we could operate upon herniated nucleus pulposus diagnosed only by MRI without myelography or CTM. But care must be taken when there is neurological disagreement, spondylosis deformens, central type herniation, old age, or cases requiring re-operation.It is more important to have static rather than dynamic information from MRI, therefore we should perform nucleotomy, rather than instrument surgery.

The main aim of percutaneous nucleotomy techniques is to reduce the volume and pressure of the affected disc while leaving all other structures unaffected. Previously percutaneous discectomies were performed under fluoroscopic guidance with or without endoscopy. In this paper we describe the combination of CT-scanning and fluoroscopy for guidance of nucleo-tomes, lasers, microendoscopes and other microinstmments. The results of percutaneous laser nucleotomy performed on 116 out-patients with chronic back pain are reported. Immediate pain relief was obtained in 92% of the patients, and improvement of neurological deficits in 59%. After 6 weeks, 87% of patients were back at work. At follow-up, 1–17 months later, overall improvement of pain symptoms of 50–100% was present in 81% of the patients; the results were better in patients with longer follow-up times. Spon-dylodiscitis occurred in one patient and a second herniation with re-operation in five patients. These results show that effective treatment of di...

The classical microsurgical approach in the treatment of herniated nucleus pulposus (HNP) has been substituted over the years by endoscopical approach, in which it is possible to practice via endoscopy a laser thermo-discoplasty, and by percutaneous laser disc decompression and nucleotomy. Percutaneous laser disc decompression and nucleotomy have been performed worldwide in more than 40,000 cases of HNP. Because water is the major component of the intervertebral disc and in HNP pain is caused by disc protrusion pressing against the nerve root, a 980 nm Diode (Biolitec AG-Germany) laser introduced via a 21-G needle under X-ray or CT-scan guidance and local anesthesia, vaporizes a small amount of the nucleous pulposus shrinking the disc and relieving the pressure on the nerve root. A multicentric retrospective study with a mean follow-up of 6 years was performed on 900 patients suffering from relevant symptoms that had been therapy-resistant for 6 months on average before consulting our department. Evaluation included 585 (65%) males and 315 (35%) females. The average age of patients operated was 46 years (18–54). The success rate at a mean follow-up of 5 years (2–6 years) was about 70% with a very low complication rate.

Removal of a herniated disc with the use of the operative microscope was first performed by Yasargil (Adv Neurosurg. 4:81–2, 1977) in 1977. However, it began to be used more and more only in the late 1980s (McCulloch JA (1989) Principles of microsurgery for lumbar disc disease. Raven Press, New York). In the 1990s, many spinal surgeons abandoned conventional discectomy with naked-eye to pass to the routine practice of microdiscectomy. The merits of this technique are that it allows every type of disc herniation to be excised through a short approach to skin, fascia and muscles as well as a limited laminoarthrectomy. For these reasons, it has been, and still is, considered the “gold standard” of surgical treatment for lumbar disc herniation, and the method used by the vast majority of spinal surgeons. In the 1990s, the advent of MRI and the progressive increase in definition of this modality of imaging, as well as histopathologic and immunochemical studies of disc tissue and the analysis of the results of conservative treatments have considerably contributed to the knowledge of the natural evolution of a herniated disc. It was shown that disc herniation may decrease in size or disappear in a few weeks or months. Since the second half of the 1990s there has been a revival of percutaneous procedures. Some of these are similar to the percutaneous automated nucleotomy; other methods are represented by intradiscal injection of a mixture of “oxygen-ozone” (Alexandre A, Buric J, Paradiso R. et al. (2001) Intradiscal injection of oxygen ozone for the treatment of lumbar disc herniations: result at 5 years. 12th World Congress of Neurosurgery; 284–7), or laserdiscectomy performed under CT scan (Menchetti PPM. (2006) Laser Med Sci. 4:25–7). The really emerging procedure is that using an endoscope inserted into the disc through the intervertebral foramen to visualize the herniation and remove it manually using thin pituitary rongeurs, a radiofrequency probe or both (Chiu JC. (2004) Surg Technol Int. 13:276–86).

Surgical Principles The disc space is evacuated with the help of a percutaneously inserted Nucleotome® Probe. The herniated nucleus pulposus material is suctioned through an opening in the probe, cut off with a cutting device and aspirated through the probe. The automated percutaneus nucleotomy can be performed in patients with small or medium sized encapsulated herniated lumbar discs, when conservative treatment failed and prior to considering a lumbar discoidectomy.

Research into the neural mechanisms underlying the symptoms of parkinsonism utilizing the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-exposed primate model have shown that the subthalamic nucleus (STN) occupies a central role. As a logical development of this theory, we have studied the effects of thermocoagulative lesions of the STN in the primate model. Such lesions can cause remarkable symptom reversal in the experimental primate model.

At present only a small number of studies have investigated psychiatric comorbidity in disc surgery patients. Objectives of this study are (1) to examine the prevalence rate of comorbid affective, anxiety, and substance-related disorders in nucleotomy patients in comparison to the German general population and (2) to investigate associations between psychiatric comorbidity and socio-demographic and illness-related characteristics.The study refers to 349 consecutive disc surgery patients (response rate 87%) between the age of 18 and 55 years. The final study sample consists of 239 lumbar and 66 cervical nucleotomy patients. Face-to-face interviews were conducted approximately 3.45 days (SD 3.170) after disc surgery, during hospital stay. Psychiatric comorbidity was assessed by means of the Composite International Diagnostic Interview (CIDI-DIA-X). The corresponding data of the German general population were derived from the German National Health Interview and Examination Survey (GHS).12-Month prevalence rates of any affective, anxiety or substance-related disorders range between 33.7% in cervical and 23.5% in lumbar disc surgery patients. Four-week prevalence rates of any affective, anxiety or substance disorder vary between 13.2% in cervical and 14.0% in lumbar nucleotomy patients. Disc surgery patients suffer more often from affective disorders and illicit substance abuse than the general population. Significant associations were found between psychiatric comorbidity and gender, as well as pain intensity.Disc surgery patients show a higher risk to suffer from mental disorders than the general population. The assessment of psychiatric distress and the assistance by mental health professionals should be considered during hospital and rehabilitation treatment.

Study design Therapeutic treatment of intervertebral disc repair using cells. Objective The goal of the study was to test the hypothesis that repair of a damaged disc is possible using autologous adipose tissue derived stem and regenerative cells (ADRCs). Summary of background data Degradation resulting from either acute or chronic repetitive disc injury leads to disc degeneration. However, if a damaged disc could be repaired in the early stages, before the onslaught of degradation, then the disc degeneration process may be slowed down. Methods Twelve dogs underwent a partial nucleotomy at 3 lumbar levels (L3-L4, L4-L5, and L5-L6); adjacent levels served as nonoperated controls. The animals (or discs) were allowed to recover from the surgery for 6 weeks. At that time subcutaneous adipose tissue was harvested and ADRCs were isolated. The 3 experimental discs that had undergone a partial nucleotomy were randomized to receive: (1) ADRCs in hyaluronic acid carrier (Cells/HA); (2) HA only; or (3) No Intervention. Assessments of the 3 experimental discs plus the 2 adjacent untouched discs were made using MRI, radiography, histology, and biochemistry. The animals were killed at 6 months and at 12 months. Results Repair in this study was specifically demonstrated through histology and biochemical analysis. Disc levels receiving ADRCs more closely resembled the healthy controls as evidenced in matrix translucency, compartmentalization of the anulus, and in cell density within the nucleus pulposus. Matrix analysis for Type-II collagen and aggrecan demonstrated evidence of a statistically better regenerative stimulation to the disc provided by ADRCs when compared to either the HA only or no intervention treatments. Conclusion Autologous adipose tissue derived stem and regenerative cells, as used in this disc injury model, were effective in promoting disc regeneration, as evidenced by disc matrix production and overall disc morphology.

Background Context Discectomy is a common procedure for treating sciatica. However, both the operation and preceding herniated disc alter the biomechanical properties of the spinal segment. The disc mechanics are also altered in patients with chronic contained herniation. The biomechanical properties of the disc can potentially be restored with an elastomeric nucleus replacement implanted via minimally invasive surgery. Purpose The purpose of this study was to determine whether the compressive characteristics of the intervertebral disc after a nucleotomy can be restored with an elastomeric nucleus replacement. Study Design A finite element model of the L4–L5 intervertebral disc was created to investigate the effect of the implantation of an elastomeric nucleus replacement on the biomechanical properties of the disc under axial loading. Method A L4–L5 physiologic intervertebral disc model was constructed and then modified to contain a range by volume of nucleotomies and nucleus replacements. The material properties of the nucleus replacement were based on experimental data for an elastomeric implant. The compressive stiffness, radial annular bulge, and stress distribution of the nucleotomy and nucleus replacement models were investigated under displacement-controlled loading. Results Removal of nucleus pulposus from the physiologic disc reduced the force necessary to compress the disc 2 mm by 50%, altered the von Mises stress distribution, and reduced the outward radial annular bulge. Replacing the natural nucleus pulposus of the physiologic disc with an artificial nucleus reduced the force required to compress the disc 2 mm by 10%, indicating a restoration of disc compressive stiffness. The von Mises stress distribution and annular bulge observed in the disc with an artificial nucleus were similar to that observed in the physiologic disc. Conclusion This study demonstrates that despite having different material properties, a nucleus replacement implant can restore the axial compressive mechanical properties of a disc after a discectomy. The implant carries compressive load and transfers the load into annular hoop stress.

INTRODUCTION: During microsurgical disc operation, usually a sequestrectomy and a nucleotomy are performed. Whether a nucleotomy is necessary in any case is disputed. The aim of this study is to examine this question on the basis of clinical results and to compare rates of recurrence between the two groups. METHODS: A prospective analysis was performed in 100 patients with sequestrectomy and the first 100 consecutive patients with microdiscectomy out of a cohort of 1 245 patients, who were operated by six surgeons between 2003 and 2006. The study is designed with special emphasis on the actual pain status, the functional capacity and recurrence. RESULTS: Despite more comorbidities the hospitalization was significantly shorter in the sequestrectomy-treated group. This group revealed more favourable results on pain scales (VAS visual analogue scale). The percentage of back pain in the discectomy-treated group was significantly higher. This went along with a significantly higher consumption of painkillers. At follow-up (34 months after surgery on average), there were no differences in the activities of daily live, measured by patient's questionnaires (ODI Oswestry low back pain disability questionnaire). Complete questionnaires were available for 46 of the sequestrectomy patients, and for 45 of the discectomy patients. Early reherniation occurred in two patients after discectomy and late reherniation in one patient after sequestrectomy. CONCLUSIONS: Sequestrectomy alone is a safe operative modality. Sequestrectomy does not seem to entail a higher rate of recurrences compared with microdiscectomy and the results are as favourable as or better than results after discectomy.

Intervertebral disc (IVD) degeneration involves a series of biochemical and morphological changes leading to loss of spinal stability and flexibility. Cell therapy is promising to reconstitute IVDs with new cells, however, sustained metabolic activity seems crucial for an active contribution to regeneration. The aim of the present study was to establish methods for separate follow up of persistence and activity of autologous porcine mesenchymal stem cells (pMSC) after implantation into IVDs of Goettingen minipigs in vivo in order to conclude about the potential of such an intervention strategy. For quantitative follow up, the transfer matrix was supplemented with Al(2)O(3) particles and pMSC which were retrovirally labeled with firefly luciferase (pMSC-Luc). Six mature Goettingen minipigs underwent matrix based cell transfer after partial nucleotomy of lumbar IVDs (n = 24). Day 0 and day 3 segments were analyzed for retained volume of Al(2)O(3) particles by micro-computed-tomography (muCT) and for cell activity by luciferase enzyme assessment. Three days after injection a reduction of Al(2)O(3) particles (P = 0.028) to about 9% and of pMSC-Luc activity to about 7% of initial values (P = 0.003) was detected, which suggests loss of 90% of the implant material under in vivo conditions without evidence for reduced pMSC-Luc metabolic activity (P = 0.887). In conclusion, separate follow up of implant material and cell activity was possible and unravels problems with in vivo implant persistence after annular puncture rather than quick loss of cell activity. Therefore, IVD-regeneration-strategies should increasingly focus on annulus reconstruction in order to reduce implant loss due to annular failure.

Background Surgery for disc herniations can be complicated by two major problems: painful degeneration of the spinal segment and re-herniation. Therefore, we examined an absorbable poly-glycolic acid (PGA) biomaterial, which was lyophilized with hyaluronic acid (HA), for its utility to (a) re-establish spinal stability and to (b) seal annulus fibrosus defects. The biomechanical properties range of motion (ROM), neutral zone (NZ) and a potential annulus sealing capacity were investigated. Methods Seven bovine, lumbar spinal units were tested in vitro for ROM and NZ in three consecutive stages: (a) intact, (b) following nucleotomy and (c) after insertion of a PGA/HA nucleus-implant. For biomechanical testing, spinal units were mounted on a loading-simulator for spines. In three cycles, axial loading was applied in an excentric mode with 0.5 Nm steps until an applied moment of ± 7.5 Nm was achieved in flexion/extension. ROM and NZ were assessed. These tests were performed without and with annulus sealing by sewing a PGA/HA annulus-implant into the annulus defect. Results Spinal stability was significantly impaired after nucleotomy (p < 0.001). Intradiscal implantation of a PGA-HA nucleus-implant, however, restored spinal stability (p < 0.003). There was no statistical difference between the stability provided by the nucleus-implant and the intact stage regarding flexion/extension movements (p = 0.209). During the testing sequences, herniation of biomaterial through the annulus defect into the spinal canal regularly occurred, resulting in compression of neural elements. Sewing a PGA/HA annulus-implant into the annulus defect, however, effectively prevented herniation. Conclusion PGA/HA biomaterial seems to be well suited for cell-free and cell-based regenerative treatment strategies in spinal surgery. Its abilities to restore spinal stability and potentially close annulus defects open up new vistas for regenerative approaches to treat intervertebral disc degeneration and for preventing implant herniation., Journal of Orthopaedic Surgery and Research, 4, ISSN:1749-799X

Nucleus caudalis dorsal root entry zone lesions (open trigeminal nucleotomy) are a surgical procedure which can achieve pain control without major complications in the difficult clinical setting of deafferentation-type facial pain. Two patients are reported, who had relief of pain, but also experienced neurological complications. One patient succumbed to pulmonary complications, which provided the opportunity for anatomic analysis of the lesioned area, which is discussed in detail. Potential modifications of the surgical technique are suggested.

Fifteen cadaveric dissections have been performed to determine the anatomic relationships of nucleotomy guide wires. All the 44 guide wires inserted were found to be in contact with at least one nerve root (eight transfixed a root). Guide wires passing anterior to the nerve roots always passed anterior to the center of the disc. Lateral displacement of the skin entry point made safe entry to the center of the disc impossible. Nerve root transfixion is likely to be a significant complication in percutaneous nucleotomy. Entry to the center of the disc avoiding the nerve roots is simplest if the skin entry is as near to the midline as possible.

Recent advancements in biomaterial technologies have fostered growth in alternative surgical procedures to fusion surgery for treatment of early stages of degenerative disc disease. One application of immediate interest is that of nucleus replacement (NR). Novel materials are being developed to better match the nonlinear biomechanical properties of the native tissue [1]. The effects of changing the motion segment unit (MSU) properties via surgery (nucleotomy) or the placement of an NR material, changes the work required to move the altered spine condition through a prescribed kinematic path. The closer the loading mechanics of the altered spine are to the intact spine condition, the more likely the device will restore the native properties. The objective of this study was to use a kinematics based testing methodology to evaluate compliant materials being considered for NR devices.Copyright © 2008 by ASME

Previous studies postulated that an axial compression of lumbar intervertebral discs causes a complex strain pattern on the annulus. This pattern is not fully understood, since most studies measured only the uniaxial ultimate tensile strain of the annulus. The aim of this study was to investigate surface strains and their relation to disc bulging. This work was extended to study some defects that are relevant for the intermediate process of finite element modeling. Six specimens (L2-3) with a median age of 51 years were utilized for this in vitro study. Specimens were loaded with pure moments (2.5-7.5Nm) in the principal directions. The anatomy was subsequently reduced in three steps: (1) ligamentous and bony posterior structures, (2) anterior and posterior ligaments and (3) nucleus. Measured were ranges of motion, three-dimensional disc bulging and surface strains of the outer annulus. Lateral bending showed the largest axial strains (9.7%) for intact specimens, which increased to 15.1% after the removal of posterior structures. Disc bulging was largest in flexion with 1.56mm, which increased to 2.06mm after step (1). Defect (2) caused that flexion yielded the largest axial strains with 22.6% and 2.17mm of bulging. We could also determine a constriction effect of these ligaments. Nucleotomy did not essentially increase anterior disc bulging in flexion, but inward disc bulging increased by 0.55mm, in extension. Due to the increase in the complexity of finite element models, it is difficult to obtain data from the literature for validation purposes. This study presents new data, which assist in the development of such models.

Die Nukleotomie bzw. Diskektomie stellt bei klinisch symptomatischen Bandscheibenprotrusionen oder -prolapsen den bisherigen Goldstandard der operativen Therapien dar. In Folge des Nukleusverlustes kommt es allerdings vielfach zu einem Fortschreiten der degenerativen Kaskade in dem betroffenen Bewegungssegment. Häufig sind Folgeeingriffe notwendig und am Ende der Behandlung steht die Fusion. Die rigide Instrumentation der Spondylodese geht jedoch mit einer Reihe von bekannten Nachteilen einher. Die Entwicklung eines Behandlungsansatzes mit dem Ziel des Erhaltes einer größeren physiologischen Funktionalität, der Restabilisierung des betroffenen Bewegungssegmentes und das Verhindern des Fortschreitens der Degeneration würde somit eine Vielzahl von Vorteilen bieten. Das Ziel dieser in vivo Studie am Schafsmodell war es, den Nutzen eines experimentellen dynamischen Stabilisationssystems am nukleotomierten Wirbelsäulensegment L3-L4 im Vergleich zur alleinigen Nukleotomie zu untersuchen. Von 40 Schafen wurden 20 Tiere im Segment L3-L4 nukleotomiert und anschließend zusätzlich mit einem dorsalen dynamischen Stabilisationssystem versorgt (Gruppen I A, II A: n = 10). Die verbleibenden 20 Schafe wurden im gleichen Segment lediglich nukleotomiert und dienten als Kontrollgruppen (Gruppen I B, II B: n = 10). Die Tiere der Gruppen I A und I B wurden nach 12 und die Tiere der Gruppen II A und II B wurden nach 48 Wochen euthanasiert. Im Anschluss ist das Segment L3-L4 histologisch aufgearbeitet und semiquantitativ histomorphologisch sowie histomorphometrisch analysiert worden. Das von uns verwendete Degenerationsmodell der partiellen Nukleotomie führte innerhalb eines Jahres zu einer ausgeprägten Bandscheibendegeneration, nicht jedoch zu Veränderungen der Facettengelenke. Durch die zusätzliche Implantation eines dorsalen dynamischen Stabilisationssystems nach Nukleotomie am Schafsmodell konnte nach Ablauf beider Standzeiten kein statistisch signifikanter Unterschied der Degeneration der Bandscheibe und ihrer angrenzender Gewebe beobachtet werden. Der Einsatz dieses dynamischen Stabilisationssystems im Rahmen einer klinischen Studie ist nach den hier vorliegenden histologischen Ergebnissen nicht zu empfehlen., Currently, microsurgical nucleotomy is the state of the art treatment for clinical symptomatic disc protrusion or prolapses. As a result of loss of the nucleus a progressive degeneration of the treated motion segment is often observed. Reoperations are frequently necessary and a segmental fusion operation is often the last option for treatment of recurrent disc prolapses. Development of a treatment, which avoids the disadvantages of rigid instrumentation of interbody fusion, would be advantageous in various indications. The aim of this in vivo study on animal model was to investigate the effects of an experimental dynamic stabilization system on the lumbar segment L3-L4 after nucleotomy compared with a control group. Forty sheep underwent standardized partial anterolateral nucleotomy at lumbar segment L3-L4. After randomization, twenty animals underwent additional dynamic stabilization of L3-L4 (group IA, IIA). The remainder serve as control groups (group IB, IIB). Animals of group IA and IB were sacrificed after 12 weeks and group IIA and IIB after 48 weeks. Lumbar discs L3-L4 with adjacent subchondral trabecular bone were harvested and analyzed macroscopically and histologically. An image-analyzing computer program was used to measure histomorphometric indices of bone structure. Partial nucleotomy of the ovine lumbar disc leads to distinctive histological signs of disc degeneration within 12 months, but not to changes of facet joints. By using additional posterior dynamic stabilization after nucleotomy in ovine model no significant difference in degeneration of disc and adjacent tissue was observed. On the basis of results of this study the clinical use of experimental dynamic stabilization system is not to recommend.

Since 1986, percutaneous intradiscal laser nucleotomy (PILN) has been studied in the authors' laser laboratory. The purpose of this report is to develop PILN as an alternative to chemonucleolysis and percutaneous discectomy, which are currently applied, and to establish a safe, easy, accurate and short-time therapy method for lumbar disc herniation. After laser irradiation, intradiscal pressures (IDP) decreased and the nucleus pulposus was gradually replaced with cartilaginous fibrous tissue. The evaluation of heat distribution with thermocouples and thermography was done to determine safe optimum irradiating conditions and to develop a new double-lumen needle and a bare quartz fiber. Neodymium-yttrium-aluminum-garnet (Nd-YAG) laser devices have been improved for easy and safe use, and a new tip type pressure transducer has been made for improved therapeutic results using this new method.

In spite of the good or excellent long-term results in 60% to 80% of the cases reported in the literature, the efficacy of the less invasive percutaneous nucleolysis in the treatment of therapy-resistant lumbar compression of the nerve root in patients with lumbar disk protrusion still remains controversial. On the one hand, there is discussion about the actual effectiveness of the enzymes injected and their local activity in bringing about the desired long-lasting nerve-root decompression. On the other hand, the presumed advantage of he method is questioned. It is said that postoperative morbidity is decreased and shortened, and that job rehabilitation is faster, especially with people performing hard physical work. More recently, the same can be said for the much-vaunted method of percutaneous automated diskectomy and nucleotomy. It was only possible to use these less invasive treatment techniques with approx. 10% of the author' patients with therapy-resistant lumbar compression syndromes of the nerve root caused by disk protrusion. In 85% of all patients treated, CNL produced a good or satisfactory result as regards the relief of sciatica and neurological disturbances. These long-term results cannot be transferred to job-rehabilitation results, as a critical review of 133 cases has shown. The authors were able to examine 108 of the 133 patients approx. one year after nucleolysis. In the group of businessmen, government officials, white-collar workers, and students, there was a correlation between long-term neurological results and job rehabilitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous lumbar discectomy has gained growing interest during recent years as an alternative to open surgery for protrusions and non-sequestrated subligamentous intervertebral disc herniations. As a less invasive method it competes with chemonucleolysis. At least two modifications are known to date: automated percutaneous lumbar discectomy (APLD) with a 2-mm suction probe and non-automated, discoscopy-monitored percutaneous lumbar discectomy with a suction rongeur and a motor-driven shaver (NAPLD). In this study these two methods are compared for the amount of material extracted, dependence upon the degree of degeneration of the disc and intrinsic technical problems, using 20 human cadaver lumbar specimens for experimental testing. Total nucleotomy was not possible with either method. APLD yielded significantly less material and proved to be less effective in severely degenerated intervertebral discs than the NAPLD procedure, as preexisting gaps within the degenerated nucleus pulposus allowed the tissue to shift away from the tip of the 2-mm probe and facilitated displacement of the probe within the anulus fibrosus. By contrast, the rongeur, which first cuts the material to be removed and then carries it away by suction, was much more effective. Further data to support the advantages of non-automated percutaneous nucleotomy are discussed. Pretreatment of the disc with chymopapain did not result in a higher yield of nucleus material when combined with APLD.

Pre-clinical in vitro tests are needed to evaluate the biomechanical performance of new spinal implants. For such experiments large animal models are frequently used. Whether these models allow any conclusions concerning the implant’s performance in humans is difficult to answer. The aim of the present study was to investigate whether calf, pig or sheep spine specimens may be used to replace human specimens in in vitro flexibility and cyclic loading tests with two different implant types. First, a dynamic and a rigid fixator were tested using six human, six calf, six pig and six sheep thoracolumbar spine specimens. Standard flexibility tests were carried out in a spine tester in flexion/extension, lateral bending and axial rotation in the intact state, after nucleotomy and after implantation. Then, the Coflex interspinous implant was tested for flexibility and intradiscal pressure using another six human and six calf lumbar spine segments. Loading was carried out as described above in the intact condition, after creation of a defect and after implantation. The fixators were most easily implantable into the calf. Qualitatively, they had similar effects on ROM in all species, however, the degree of stability achieved differed. Especially in axial rotation, the ROM of sheep, pig and calf was partially less than half the human ROM. Similarly, implantation of the Coflex interspinous implant caused the ROM to either increase in both species or to decrease in both of them, however, quantitatively, differences were observed. This was also the case for the intradiscal pressure. In conclusion, animal species, especially the calf, may be used to get a first idea of how a new pedicle screw system or an interspinous implant behaves in in vitro flexibility tests. However, the effects on ROM and intradiscal pressure have to be expected to differ in magnitude between animal and human. Therefore, the last step in pre-clinical implant testing should always be an experiment with human specimens.

Background Nucleotomy is a standard procedure for treating disc prolapse. It can reduce intervertebral disc height, flattening and displacing the disc, which could lead to a painful narrowing of the foramina due to nerve root compression. The purpose of this study was to investigate the disc displacement of a complete spinal segment with and without nucleotomy. We hypothesized that a nucleotomy under a certain load combination might amplify disc displacement. Methods A laser scanner was developed for recording three-dimensional disc displacement of six loaded L4-5 specimens for three conditions: intact, disc with vertebral bodies and subsequent nucleotomy. Specimens were exposed to pure moments of 7.5 N m in the three principal anatomical directions. Disc displacement was obtained at maximal deflection. A finite element model was validated and subsequently utilized to determine disc displacement. The task of the finite element model was to provide supplemental data for the posterolateral region, which could not be measured from intact specimens. Findings Disc displacement measurements of intact specimens were limited to the anterior part of discs, whereas the finite element model was able to provide the missing data of the dorsal disc region. The simulation of load combinations showed that the highest disc displacement was 1.9 mm at the lateral or posterolateral region. The nucleotomy increased the disc displacement up to 2.1 mm, whereas the displacement zenith migrated posterolaterally. Interpretation These results could be a possible explanation for disadvantages of nucleotomy as a treatment. With the methodology presented here, we would be able to assess the performance of nucleus implants by determining the disc displacement map. This could also give us appropriate information of the annular deformation, which is needed for the development of motion preserving implants.

Many investigators have performed studies on specific defect situations or determined the contribution on isolated structures. Investigating the contribution of functional structures requires obtaining the kinematic response directly on spinal segments. The purpose of this study was to quantify the function of anatomical components on lumbar segments for different loading magnitudes. Eight spinal segments (L4-5) with a median age of 52 years (ranging from 38 to 59 years) and a low degree of disc degeneration were utilized for the in vitro testing. Specimens were mounted in a custom-built spine tester and loaded with pure moments (1-10 N m) to move within three anatomical planes at a loading rate of 1.0 degrees /s. Anatomy was successively reduced by: ligaments, facet capsules, joints and nucleus. Data were evaluated for range of motion, neutral zone and lordosis angle. Transection of posterior ligaments predominantly increased specimen flexion for all bending moments applied. Supraspinous ligament also indicated to resist in extension slightly, whereas the facet capsules did not. Facet joints contributed to axial rotation, but not in lateral bending. The anterior longitudinal ligament was found to slightly resist in axial rotation, but strongly in extension. Nucleotomy caused largest increase of all movements. The unloaded posture of the specimens changed after ligament dissection, indicating ligament pretension. The region of lumbar spine is interesting for finite element (FE) simulation due to the high evidence of disc degeneration and injuries. This study may help to understand the function of specific anatomical structures and assists in FE model calibration. We suggest to start a calibration procedure for such models with the smallest functional structure (annulus) and to cumulatively add further structures.

Mechanical function of the intervertebral disc is maintained through the interaction between the hydrated nucleus pulposus, the surrounding annulus fibrosus, and the superior and inferior endplates. In disc degeneration the normal transfer of load between disc substructures is compromised. The objective of this study was to explore the mechanical role of the nucleus pulposus in support of axial compressive loads over time. This was achieved by measuring the elastic slow ramp and viscoelastic stress-relaxation mechanical behaviors of cadaveric sheep motion segments before and after partial nucleotomy through the endplate (keeping the annulus fibrosus intact). Mechanics were evaluated at five conditions: Intact, intact after 10,000cycles of compression, acutely after nucleotomy, following nucleotomy and 10,000cycles of compression, and following unloaded recovery. Radiographs and magnetic resonance images were obtained to examine structure. Only the short time constant of the stress relaxation was altered due to nucleotomy. In contrast, cyclic loading resulted in significant and large changes to both the stiffness and stress relaxation behaviors. Moreover, the nucleotomy had little to no effect on the disc mechanics after cyclic loading, as there were no significant differences comparing mechanics after cyclic loading with or without the nucleotomy. Following unloaded recovery the mechanical changes that had occurred as a consequence of cyclic loading were restored, leaving only a sustained change in the short time constant due to the trans-endplate nucleotomy. Thus the swelling and redistribution of the remaining nucleus pulposus was not able to fully restore mechanical behaviors. This study reveals insights into the role of the nucleus pulposus in disc function, and provides new information toward the potential role of altered nucleus pulpous function in the degenerative cascade.

Background An important step in finite element modeling is the process of validation to derive clinical relevant data. It can be assumed that defect states of a finite element model, which have not been validated before, may predict wrong results. The purpose of this study was to show the differences in accuracy between a calibrated and a non-calibrated finite element model of a lumbar spinal segment for different clinical defects. Methods For this study, two geometrically identical finite element models were used. An in vitro experiment was designed, deriving data for the calibration. Frequently used material properties were obtained from the literature and transferred into the non-calibrated model. Both models were validated on three clinical defects: bilateral hemifacetectomy, nucleotomy and interspinous defects, whereas in vitro range of motion data served as control points. Predictability and accuracy of the calibrated and non-calibrated finite element model were evaluated and compared. Findings Both finite element models could mimic the intact situation with a good agreement. In the defects, the calibrated model predicted motion behavior with excellent agreement, whereas the non-calibrated model diverged greatly. Interpretation Investigating the biomechanical performance of implants and load distribution of different spinal structures by numerical analysis requires not only good agreement with the intact segment, but also with the defect states, which are initiated prior to implant insertion. Because of more realistic results the calibration method may be recommended, however, it is more time consuming.

The idea of a tissue engineered nucleus implant is to seed cells in a three-dimensional collagen matrix. This matrix may serve as a scaffold for a tissue engineered nucleus implant. The aim of this study was to investigate whether implantation of the collagen matrix into a spinal segment after nucleotomy is able to restore disc height and flexibility. The implant basically consists of condensed collagen type-I matrix. For clinical use, this matrix will be used for reinforcing and supporting the culturing of nucleus cells. In experiments, matrixes were concentrated with barium sulfate for X-ray purposes and cell seeding was disclaimed in order to evaluate the biomechanical performance of the collagen material. Six bovine lumbar functional spinal units, aging between 5 and 6 months, were used for the biomechanical in-vitro test. In each specimen, an oblique incision was performed, the nucleus was removed and replaced by a collagen-type-I matrix. Specimens were mounted in a custom-built spine tester, and subsequently exposed to pure moments of 7.5 Nm to move within the three anatomical planes. Each tested stage (intact, nucleotomy and implanted) was evaluated for range of motion, neutral zone and change in disc height. Removal of the nucleus significantly reduced disc height by 0.84 mm in respect to the intact stage and caused an instability in the segment. Through the implantation of the tissue engineered nucleus it was possible to restore this height and stability loss, and even to increase slightly the disc height of 0.07 mm compared with the intact stage. There was no statistical difference between the stability provided by the implant and intact stage. Results of movements in lateral bending and axial rotation showed the same trend compared to flexion/extension. However, implant extrusions have been observed in three of six cases during the flexibility assessment. The results of this study directly reflect the efficacy of vital nucleus replacement to restore disc height and to provide stability to intervertebral discs. However, from a biomechanical point of view, the challenge is to employ an appropriate annulus fibrosus sealing method, which is capable to keep the nucleus implant in place over a long-time period. Securing the nucleus implant inside the disc is one of the most important biomechanical prerequisites if such a tissue engineered implant shall have a chance for clinical application.

To date, there are only a few studies that provide data to efficiently calibrate finite element models for the spine due to its complexity. In a recent study, we quantified the range of motion rotation and the lordosis angle. This paper provides complementary results regarding two more parameters, intradiscal pressure and vertebral translation. All parameters were obtained as a function of stepwise anatomical reduction, loading direction and magnitude. Eight lumbar spinal segments (L4-5) with a median age of 52 years (38-59 years) and no signs of disc degeneration were used for the in vitro testing. A miniaturized pressure probe was implanted into the nucleus. An ultrasound-based motion-tracking system was employed to record spatial movements of several landmarks on the specimens. The center of L4, the anterior, posterior, left and right point of the lower endplate of L4 were digitized as landmarks and its translation was determined. Specimens were loaded with pure moments (1-10Nm) in the three principal anatomical planes at a loading rate of 1.0 degrees /s. Anatomy was stepwise reduced by cutting different ligaments, facet capsules and joints and removing nucleus. Translation analysis showed that the L4 center point had its largest displacement in sagittal direction and almost none vertically. Removal of the supra- and interspinous, flaval ligaments showed a slight increase and further removal of structures, a higher increase of translation. Axial rotation also was accompanied with L4 to elevate when torsion was applied. This effect was found to be larger with progressing defects. Nucleotomy exhibited the most unstable situation for specimens. Results of the intradiscal pressure indicated a large increase after removing the facet capsules and joints. Furthermore, it was found that intradiscal pressure correlated well with data of range of motion for rotation. Predicting and simulating clinical defects, surgical intervention or treatment methods requires a well performed calibration based on in vitro data, whereas it is important to adapt all including structures with as many known parameters as possible. Results provided by these studies may be used as a database for researchers aiming to calibrate or validate finite element models of L4-5 segments.

Knowledge of the functional role of the nucleus pulposus is critical for the development and evaluation of disc treatment strategies to restore mechanical function. While previous motion segment studies have shown that nucleotomy alters disc mechanics, disruption of the annulus fibrosus may have influenced these experiments. The objective of this study was to determine the mechanical role of the nucleus pulposus in support of axial loads via a trans-endplate nucleotomy procedure. Sheep motion segments were randomly assigned to three groups: control, limited nucleotomy, and radical nucleotomy. Mechanical testing consisted of 20 cycles of compression–tension, a 1-h creep, and a slow constant-rate compressive ramp test. Nucleotomy led to increased axial deformations, in particular an elongated neutral zone, a greater range of motion, and altered creep behavior. In general, the elastic properties exhibited a graded response with respect to the amount of nucleus material removed. This graded effect can be attributed to swelling of the nucleus pulposus in the limited nucleotomy group, whereas little swelling was observed in the radical group. The findings of the present study indicate that functional evaluation of nucleus pulposus replacements and disc implants should include range of motion measures (including neutral zone) and viscoelastic creep experiments in addition to considering compressive stiffness.

Cell therapy seems to be a promising way to reconstitute degenerated discs. We elucidate the basic aspects of intervertebral disc (IVD) cell therapy to estimate its potential in disc regeneration. Cell transfer efficiency and survival was quantified by luciferase expression after injection of recombinant cells into healthy, nucleotomized or mechanically degenerated rabbit IVDs in vitro, in situ or in vivo. A two-component fibrin matrix was adapted to allow injection of a fluid cell suspension that quickly polymerizes in IVDs. Thirty-five to fifty percent of matrix injected cells remained in the nucleus and transition zone in contrast to a rapid loss of medium-injected cells. Nucleotomy, which reduces intradiscal pressure, was crucial to the survival of the transferred cells over 3 days and nutritional enrichment of the fibrin matrix with potent biomolecules from serum significantly enhanced cell viability. In conclusion, advanced matrix substitutes are needed for efficient transfer and improved cell survival in the low-nutrient intradiscal environment to further improve disc cell therapy.

Low back pain (LBP) is a spine pathology involving the lumbar facet joints in 15–45% of the cases (Manchikanti et al. 1999) but the mechanism behind LBP due to the facet joints is still unclear. In...

Iatrogenic intervertebral disc space infection is encountered following microsurgical discectomy, percutaneous laser disc decompression, automated percutaneous lumbar nucleotomy operations, and discography. The purpose of this paper is to present a case report and review the literature on the uncommon origins of pyogenic spondylodiscitis and to emphasize the significance of prophylactic antibiotic therapy following transrectal ultrasonography-guided needle biopsy of the prostate (TUGNBP). According to the authors, this is the first reported case of pyogenic spondylodiscitis as a complication of TUGNBP in the English language literature.

Purpose: To compare intraoperative and postoperative effects of Nagahara phaco-chop and stop-and-chop phacoemulsification nucleotomy techniques. Setting: Department of Ophthalmology, SBMU First Aid and Traumatology Hospital, Ankara, Turkey. Methods: Seventy patients were evaluated prospectively in 2 groups. The Nagahara phaco-chop nucleotomy technique was performed in Group 1 (35 eyes) and the stop-and-chop technique in Group 2 (35 eyes). There were no significant between-group differences. The mean phaco time, phaco power, effective phaco time, time to achieve maximum vision, corneal thickness increase relative to the preoperative values, and time to return to the preoperative values were determined. All parameters in both groups were statistically compared using the chi-square test and the independent-samples t test. Results: The mean phaco time was 1.3 minutes ± 0.7 (SD), phaco power was 16.7% ± 5.0%, and effective phaco time was 14.9 ± 11.8 seconds in Group 1 and 1.8 ± 0.9 minutes, 20.0% ± 6.2%, and 22.3 ± 14.2 seconds, respectively, in Group 2. The mean time to achieve maximum vision postoperatively was 6.9 ± 3.7 days in Group 1 and 11.7 ± 7.7 days in Group 2. The mean postoperative corneal thickness increase in Group 1 and Group 2 was 52.3 ± 84.5 μm and 111.6 ± 151.2 μm, respectively, and the mean time to return to preoperative pachymetry values, 9.8 ± 5.7 days and 13.7 ± 10.0 days, respectively. There were significant between-group differences in these parameters. Conclusions: The Nagahara phaco-chop technique had fewer negative effects on the corneal endothelium as less ultrasonic energy was used. This accelerated the functional healing process and the return to preoperative physiologic values.

Object. The authors conducted a study to determine the results of decompressive surgery without fusion in selected patients who presented with radicular compression syndromes caused by degenerative lumbar spondylolisthesis and in whom there was no evidence of hypermobility on flexion—extension radiographs. Methods. The medical records and radiographs obtained in 49 patients were reviewed retrospectively. Clinical status was quantified by summing self-assessed Prolo Scale scores. All 49 patients (55% female, mean age 68.7 years) presented with leg pain accompanied by lumbalgia in 85.7% of the cases. Preoperatively the median sum of Prolo Scale scores was 4. The mean preoperative degree of forward vertebral displacement was 13.5% and was located at L-4 in 67% of the cases. Osseous decompression alone was performed in 53%, and an additional discectomy at the level of displacement was undertaken in the remaining patients because of herniated discs. Major complications (deep wound infection) occurred in 2%. During a mean follow-up period of 3.73 years, 10.2% of the patients underwent instrumentation-assisted lumbar fusion when decompression alone failed to resolve symptoms. At last follow up the median overall Prolo Scale score was 8. Excellent and good results were demonstrated in 73.5% of the patients. Prolonged back pain (r = 0.381) as well as the preoperative degree of displacement (r = 0.81) and disc space height (r = 0.424) influenced outcome (p ≤ 0.05); additional discectomy for simultaneous disc herniation at the displaced level did not influence outcome (p > 0.05). Conclusions. These results appear to support a less invasive approach in this subgroup of elderly patients with degenerative lumbar spondylolisthesis—induced radicular compression syndromes and without radiographically documented hypermobility. Additional discectomy for simultaneous disc herniation of the spondylolisthetic level did not adversely influence the outcome. Complication rates are minimized and fusion can eventually be performed should decompression alone fail. A prospective controlled study is required to confirm these results.

Phaco one-chop, a hybrid of the phaco-chop, stop-and-chop, and phaco-flip techniques, has 3 main phaco phases: embedding the phaco tip and chopping, flipping the right heminucleus without nucleus rotation, and evacuating the remaining left heminucleus in the bag. Of 198 eyes evaluated, 86% had a Lens Opacities Classification System III cataract grade of 3 to 6. The mean equivalent phaco time (EPT) was 1.9 seconds; for the densest cataracts, the highest phaco power needed was 5.3%. The mean overall power was 2.1%. Thus, the phaco one-chop method requires less EPT and phaco power and allows greater surgeon control for efficiency and predictability than the techniques from which it was derived.

The technique used to incise the disc during discectomy may play a role in the subsequent healing and change in biomechanical stiffness of the disc. Several techniques of lumbar disc annulotomy have been described in clinical reports. The purpose of this paper was to study the influence of annulotomy technique on motion segment stiffness using a finite element model. Four incision methods (square, circular, cross, and slit) were compared. The analyses showed that each of the annular incisions produced increase in motions under axial moment loadings with circular incision producing the largest change in the corresponding rotational motion. Under shear loading mode, cross and slit-type annular incisions produced slightly larger changes in the principal motions of the disc than square and circular incisions. All other incision types considered in the current study produced negligibly small increase in motion under rest of the loading conditions. In addition to annulotomy, when nucleotomy was also included in the analyses, once again cross and slit incisions produced larger change in motion under shear loading mode as compared to the other two incision types. A comparison between the four types of annular incisions showed that cross incision produced an increase in motion larger than those produced by the other three incisions under flexion/extension and lateral moment loading and both shear force loadings. Circular incision produced the largest increase in motion under axial moment load in comparison to those produced by square, cross, and slit incisions. Sagittal plane symmetry was influenced by the incision injury to the motion segment leading to coupled motions as well as increased facet loads. From the study it can be concluded that the increase in flexibility of the disc due to annulotomy depends on the type of annulotomy, and the annulotomy also produce asymmetrical deformations leading to increased facet loading.

A retrospective analysis of long-term follow-up results more than 10 years after a standard nucleotomy for lumbar disc herniation with the Love method was done to determine the effectiveness of this procedure. Nucleotomy according to Love was the standard treatment for lumbar disc herniation before the various minimally invasive alternatives were recently introduced. Without long-term follow-up analysis of Love operations, evidence-based evaluation of those new methods is impossible. We believe that the standard nucleotomy procedure should now be evaluated precisely. In this study we present a comparison of 1-year follow-up results to the results more than 10 years after lumbar nucleotomy. Seventy-six consecutive patients who had undergone lumbar nucleotomy were identified. It was possible to assess 54 (71.1%) of the cases more than 10 years after surgery. The initial and final outcomes were assessed using the MacNab classification and the Japanese Orthopaedic Association (JOA) score. With the MacNab classification a successful outcome 1 year after surgery was achieved in 87.0% of the cases. At the final follow-up, this result was reduced to 74.1%. Seven patients required a second operation and patients under 21 years of age were at risk for reoperation. Patient overall satisfaction with the results of the standard nucleotomy was high. The disc height of the operation site significantly decreased after surgery; nevertheless, this did not affect the clinical outcome. A standard lumbar nucleotomy according to Love is a safe and reliable method of treating selected patients with lumbar disc herniations.

Study design Advancement in tissue engineering provides a promising approach to recover the functionality of the degenerated intervertebral disc. In our study, a nucleus pulposus (NP) cell-seeded collagen II/hyaluronan/chondroitin-6-sulfate (CII/HyA/CS) tri-copolymer construct was implanted into the disc space directly after nucleotomy in a rabbit model. Objective The aim of this study was to investigate whether the NP cell-seeded CII/HyA/CS tri-copolymer constructs could regenerate the degenerated disc in vivo after implantation into the rabbit nucleotomy model. Summary of background data Nucleotomy is one of the most prevalent surgical modalities to treat degenerative disc disease, which could achieve good short-term effects of pain relieve, whereas removal of the entire or partial NP changes the biomechanical characteristics of the remaining disc and the adjacent vertebral segments and a series of long-term complications such as accelerated annulus and the facet joints degeneration may ensue. Therefore, it is necessary to think about possible procedures immediately after the primary nucleotomy surgery to avoid these complications. Methods NP cells isolated from thoracic and lumbar spines of New Zealand White rabbits of approximately 3 weeks of age and 1 kg in weight were labeled with a 5- (and-6) -carboxyflurescein diacetate succinimidyl ester (CFDA-SE) fluorescent dye and seeded within the CII/HyA/CS scaffold by a centrifugation method. After in vitro culture for 1 week, NP cell-seeded CII/HyA/CS tri-copolymer constructs were allografted into the disc defects of recipient rabbit immediately after nucleotomy of the lumbar spine. The Bradner Disc Index and the T2-weighted signal intensity index were determined using lateral plane radiographs and magnetic resonance imaging at 4, 12, and 24 weeks after the operation. Finally, the operated discs were explanted for gross morphological observation, histological evaluation, and cell viability assessment. Animals with only nucleotomy and cell-free CII/HyA/CS scaffold implantation served as controls. Results In our study, we could demonstrate that the T2-weighted signal intensity index of the operated discs decreased in all three groups 1 month after surgery and the index of the cell-containing scaffold insertion group was significantly higher than that of the other two groups. After 24 weeks, the index of the cell-containing scaffold insertion group increased significantly. However, further decline was observed in both the noninsertion group and the scaffold insertion group. In radiographic analysis, the narrowing of the intervertebral disc space was significantly retarded by the cell-scaffold hybrids implantation up to 24 postoperative weeks. Furthermore, the gross morphology and histological evaluation indicated that the allografted NP cells were viable and showed extracellular matrix production. Conclusion In our study, we had constructed rabbit NP cell-seeded CII/HyA/CS tri-copolymer implants in vitro. Immediately after nucleotomy of the recipient rabbit, we allografted the precultured cell-scaffold hybrids into the lacuna of the disc. Results documented survival of the allografted NP cells and extracellular matrix deposition, which finally resulted in maintenance of disc height and restoration of T2-weighted signal intensity on magnetic resonance imaging.

Summary Background Mycobacterium xenopi spinal infections were diagnosed in 1993 in patients who had undergone surgical microdiscectomy for disc hernia, by nucleotomy or microsurgery, in a private hospital. Contaminated tap water, used for rinsing surgical devices after disinfection, was identified as the source of the outbreak. Several cases were recorded in the 4 years after implementation of effective control measures because of the long time between discectomy and case detection. The national health authorities decided to launch a retrospective investigation in patients who were exposed to M xenopi contamination in that hospital. Methods Mailing and media campaigns were undertaken concurrently to trace exposed patients for spinal infections. Patients were screened by magnetic resonance imaging (MRI), and the scans were reviewed by a radiologist who was unaware of the diagnosis. Suspected cases had discovertebral biopsy for histopathological and bacteriological examination. Findings Of 3244 exposed patients, 2971 (92%) were informed about the risk of infection and 2454 (76%) had MRI. Overall, 58 cases of M xenopi spinal infection were identified (overall cumulative frequency 1·8%), including 26 by the campaign (mean delay in detection 5·2 years, SD 2·4, range 1–10 years). Multivariate analysis showed that the risk of M xenopi spinal infection was related to nucleotomy and high number of patients per operating session. Interpretation Failures in hygiene practices could result in an uncontrolled outbreak of nosocomial infection. Patients who have been exposed to an iatrogenic infectious hazard should be screened promptly and receive effective information.

Compared to open nucleotomy, percutaneous lumbar disc decompression (PLDD) has several advantages for treating lumbar herniated nucleus pulposus (HNP). PLDD can be performed under local anesthesia and as an outpatient procedure. This allows earlier return to normal daily activity. From the surgical point of view, it requires no muscular and ligamentous tissue dissection and does not lead to intraoperative nerve injuries or perineural fibrosis. Since first introduced by Hijikata [2] percutaneous discectomy has undergone several modifications. Onik [7] developed automated nucleotomy, and Schreiber [9] performed the procedure under a discoscope, in an attempt to improve the technique.

Postoperative spondylodiscitis is a well-known complication of lumbar disc surgery, affecting between 0.1 and 1.7% of patients.1 It is usually due to contamination by skin flora. Usual pathogens are Staphylococcus aureus and Staphylococcus epidermidis . In industrialised countries, brucellosis is a rare condition, almost exclusively found in cattle-exposed patients such as farmers, shepherds and veterinarians. Brucella osteomyelitis is rarer still, although it mostly affects the spine. A 43-year-old man had undergone dorsolateral transmuscular sequestrectomy and nucleotomy including Nebacetin-irrigation L3/4 for an extraforaminal left-sided herniated lumbar disc (figure 1A). The early postoperative course was uneventful. Figure 1 (A) CT scan of the left-sided extraforaminal herniated lumbar disc at L3/4. (B) Sagittal and (C) axial T2-weighted MRI scans of the spondylodiscitis L3/4 before therapy showing a high signal intensity of the intervertebral disc L3/4 with obvious involvement of the vertebrae L3 and 4. (D) Sagittal and (E) axial T2-weighted MRI scans 3 months after dismissal showing normal signal intensity of the intervertebral disc and slightly increased signal intensity of the adjacent vertebrae. Two months later, he appeared with a 4-week history of lower back pain, fever, chills and profuse sweating. The plain x-ray showed no signs of spondylodiscitis, but the initial MRI revealed typical findings of spondylodiscitis at L3/4 (figure 1B, C). The patient was ordered …

Forty-six cases of lumbar disc herniation treated by posterior nucleotomy without bone fusion were reviewed. These cases consisted of 28 males and 18 females. The age range was from 14 to 72 with an average of 41 years. The mean follow-up period was 5 years and 4 months.The average improvement rate by the J. O. A. score was 80.6 percent. The improvement rate of S. L. R. was high, but the improvement rate of lumbago was low.On roentgenograms, there was a tendency for an advancing disc space to narrow, which revealed disc degeneration, but no significant correlation was recognized between the rate of improvement and the roentgenographical changes.

Purpose To perform a comparative evaluation of phaco-chop versus stop-and-chop nucleotomy techniques of phacoemulsification. Setting Dr. Rajendra Prasad Center for Ophthalmic Sciences, New Delhi, India. Methods Forty eyes of 40 patients with immature senile cataract were included in the study. Twenty eyes each were randomly assigned to have phaco-chop (Group 1) or stop-and-chop (Group 2) nucleotomy during phacoemulsification. The main parameters were corneal endothelial count, effective phaco time, volume of infusion fluid used, central corneal pachymetry, best corrected visual acuity (BCVA), and intraoperative complications during nucleotomy. Follow-up visits were scheduled at 1, 4, and 12 weeks. Results The mean effective phaco time was 27 seconds ± 18 (SD) in Group 1 and 28 ± 16 seconds in Group 2. The mean corneal endothelial cell loss was 6.89% and 7.17%, respectively, at the end of 12 weeks. The difference between groups was not significant. An anterior capsule tear occurred in 3 eyes in Group 1 and 1 eye in Group 2. All eyes achieved a BCVA of 20/20 at the end of 4 weeks. There were no significant between-group differences in any intraoperative or postoperative parameter. Conclusion The phaco-chop and the stop-and-chop nucleotomy techniques were equally efficacious for nuclear management during phacoemulsification.