Subsidence and Nonunion after Anterior Cervical Interbody Fusion Using a Stand-Alone Polyetheretherketone (PEEK) Cage

Background: The purposes of the present study are to evaluate the subsidence and nonunion that occurred after anterior cervical discectomy and fusion using a stand-alone intervertebral cage and to analyze the risk factors for the complications.Methods: Thirty-eight patients (47 segments) who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage and an autologous cancellous iliac bone graft from June 2003 to August 2008 were enrolled in this study. The anterior and posterior segmental heights and the distance from the anterior edge of the upper vertebra to the anterior margin of the cage were measured on the plain radiographs. Subsidence was defined as ≥ a 2 mm (minor) or 3 mm (major) decrease of the segmental height at the final follow-up compared to that measured at the immediate postoperative period. Nonunion was evaluated accordingto the instability being ≥ 2 mm in the interspinous distance on the flexion-extension lateral radiographs.Results: The anterior and posterior segmental heights decreased from the immediate postoperative period to the final follow-up at 1.33 ± 1.46 mm and 0.81 ± 1.27 mm, respectively. Subsidence ≥ 2 mm and 3 mm were observed in 12 segments (25.5%) and 7 segments (14.9%), respectively. Among the expected risk factors for subsidence, a smaller anteroposterior (AP) diameter (14 mm vs. 12 mm) of cages (p = 0.034; odds ratio [OR], 0.017) and larger intraoperative distraction (p = 0.041; OR, 3.988) had a significantlyhigher risk of subsidence. Intervertebral nonunion was observed in 7 segments (7/47, 14.9%). Compared with the union group, the nonunion group had a significantly higher ratio of two-level fusion to one-level fusions (p = 0.001).Conclusions: Anterior cervical fusion using a stand-alone cage with a large AP diameter while preventing anterior intraoperative over-distraction will be helpful to prevent the subsidence of cages. Two-level cervical fusion might require more careful attention for avoiding nonunion.Keywords: Anterior cervical fusion, PEEK cage, Subsidence, NonunionOAIID:oai:osos.snu.ac.kr:snu2011-01/102/0000004226/3SEQ:3PERF_CD:SNU2011-01EVAL_ITEM_CD:102USER_ID:0000004226EMP_ID:A076317DEPT_CD:801FILENAME:E031T_CiOS-2011_Yang_Subsidence and nonunion after anterior cervical.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:NCONFIRM:

Clinical and radiological evaluation of Trabecular Metal and the Smith–Robinson technique in anterior cervical fusion for degenerative disease: a prospective, randomized, controlled study with 2-year follow-up

A prospective, randomized, controlled study was carried out to compare the radiological and clinical outcomes after anterior cervical decompression and fusion (ACDF) with Trabecular Metal™ (TM) to the traditional Smith–Robinson (SR) procedure with autograft. The clinical results of cervical fusion with autograft from the iliac crest are typically satisfactory, but implications from the donor site are frequently reported. Alternative materials for cervical body interfusion have shown lower fusion rates. Trabecular Metal is a porous tantalum biomaterial with structure and mechanical properties similar to that of trabecular bone and with proven osteoconductivity. As much as 80 consecutive patients planned for ACDF were randomized for fusion with either TM or tricortical autograft from the iliac crest (SR) after discectomy and decompression. Digitized plain radiographic images of 78 (98%) patients were obtained preoperatively and at 2-year follow-up and were subsequently evaluated by two senior radiologists. Fusion/non-fusion was classified by visual evaluation of the A–P and lateral views in forced flexion/extension of the cervical spine and by measuring the mobility between the fused vertebrae. MRI of 20 TM cases at 2 years was successfully used to assess the decompression of the neural structures, but was not helpful in determining fusion/non-fusion. Pain intensity in the neck, arms and pelvis/hip were rated by patients on a visual analog scale (VAS) and neck function was rated using the Neck Disability Index (NDI) the day before surgery and 4, 12 and 24 months postoperatively. Follow-ups at 12 and 24 months were performed by an unbiased observer, when patients also assessed their global outcome. Fusion rate in the SR group was 92%, and in the TM group 69% (P < 0.05). The accuracy of the measurements was calculated to be 2.4°. Operating time was shorter for fusion with TM compared with autograft; mean times were 100 min (SD 18) and 123 min (SD 23), respectively (P = 0.001). The patients’ global assessments of their neck and arm symptoms 2 years postoperatively for the TM group were rated as 79% much better or better after fusion with TM and 75% using autograft. Pain scores and NDI scores were significantly improved in both groups when compared with baseline at all follow-ups, except for neck pain at 1 year for the TM group. There was no statistically significant difference in clinical outcomes between fusion techniques or between patients who appeared radiologically fused or non-fused. There was no difference in pelvic/hip pain between patients operated on with or without autograft. In our study, Trabecular Metal showed a lower fusion rate than the Smith–Robinson technique with autograft after single-level anterior cervical fusion without plating. There was no difference in clinical outcomes between the groups. The operative time was shorter with Trabecular Metal implants

Cervical disc herniation and cervical spondylosis surgically treated by Cloward procedure: a 10-year-minimum follow-up study

BACKGROUND: Cervical degenerative pathology produces pain and disability, and if conservative treatment fails, surgery is indicated. The aim of this study was to determined whether anterior decompression and interbody fusion according to Cloward is effective for treating segmental cervical degenerative pathology and whether the results are durable after a 10-year-minimum follow-up. MATERIALS AND METHODS: Fifty-one patients affected by single-level cervical degenerative pathology between C4 and C7 were surgically treated by the Cloward procedure. Clinical evaluation was rated using the Neck Disability Index (NDI) and the visual analog scale (VAS). At last follow-up, the outcomes were rated according to Odom's criteria. On radiographs, the sagittal segmental alignment (SSA) of the affected level and the sagittal alignment of the cervical spine (SACS) were measured. RESULTS: Average NDI was 34 preoperatively and 11 at last follow-up. Average VAS was 7 preoperatively and 1 at last follow-up. According to Odom's criteria, the outcome was considered excellent in 18 cases, good in 22, and fair in 11. Average SSA was 0.5 +/- 2.1 preoperatively, 1.8 +/- 3.8 at 6 months, and 1.8 +/- 5.7 at last follow-up. Average SACS was 16.5 +/- 4.0 preoperatively, 20.9 +/- 5.8 at 6 months, and 19.9 +/- 6.4 at last follow-up. Degenerative changes at the adjacent levels were observed in 18 patients (35.3%). CONCLUSIONS: The Cloward procedure proved to be a suitable and effective technique for treating segmental cervical degenerative pathology, allowing good clinical and radiographic outcomes even at a long-term follow-up

Diagnosing Cervical Fusion: A Comprehensive Literature Review

STUDY DESIGN: Comprehensive literature review. PURPOSE: To document the criteria for fusion utilized in these studies to determine if a consensus on the definition of a solid fusion exists. OVERVIEW OF LITERATURE: Numerous studies have reported on fusion rates following anterior cervical arthrodesis. There is a wide discrepancy in the fusion rates in these studies. While factors such as graft type, Instrumentation, and technique play a factor in fusion rate, another reason for the difference may be a result of differences in the definition of fusion following anterior cervical spine surgery. METHODS: A comprehensive English Medline literature review from 1966 to 2004 using the key words anterior, cervical, and fusion was performed. We divided these into two groups: newer studies done between 2000 and 2004, and earlier studies done between 1966 and 2000. These articles were then analyzed for the number of patients, follow-up period, graft type, and levels fused. Moreover, all of the articles were examined for their definition of fusion along with their fusion rate. RESULTS: In the earlier studies from 1966 to 2000, there was no consensus for what constituted a solid fusion. Only fifteen percent of these studies employed the most stringent definition of a solid fusion which was the presence of bridging bone and the absence of motion on flexion and extension radiographs. On the other hand, the later studies (2000 to 2004) used such a definition a majority (63%) of the time, suggesting that a consensus opinion for the definition of fusion is beginning to form. CONCLUSIONS: Our study suggests that over the past several years, a consensus definition of fusion is beginning to form. However, a large percentage of studies are still being published without using stringent fusion criteria. To that end, we recommend that all studies reporting on fusion rates use the most stringent criteria for solid fusion following anterior cervical spine surgery: the absence of motion on flexion/extension views and presence of bridging trabeculae on lateral x-rays. We believe that a universal adoption of such uniform criteria will help to standardize such studies and make it more possible to compare one study with another

Adolescent Idiopathic Scoliosis : A Deformity in Three Dimensions

Scoliosis is a complex three-dimensional deformity of the spine. Even though it has been known for centuries, treatment of the deformity has focused on correcting only in the frontal plane. In the last decades, the need for three-dimensional assessment regarding scoliosis has been highlighted to better understand the cause and the principles of treating scoliosis. The overall aim of this dissertation is to provide knowledge to assess scoliosis as a three-dimensional problem. The severity of scoliosis is measured with the Cobb angle from standing radiographs. Computed tomography (CT) examinations are used throughout this thesis. The first paper investigates the difference in Cobb angle measured from standing radiographs and supine CT examinations. The standing radiographs had larger Cobb angles with a mean difference of 11° and a linear correlation between the two examinations from 128 consecutive patients with adolescent idiopathic scoliosis (AIS) planned for surgery. The second paper compares the axial shape of vertebrae in 20 patients with AIS with a reference group. Clear asymmetry was observed in all vertebrae – superior and inferior end vertebrae as well as the apical vertebra – compared with corresponding vertebrae among the reference group. The asymmetry was most pronounced in the apical vertebra. A novel parameter, frontal vertebral body rotation (FVBR), was introduced to describe the internal rotation of the vertebrae in the axial plane. Pelvic incidence (PI) is a measurement of the position of the sacrum in relation to the femoral heads. This is relevant in scoliosis because PI determines the pelvic configuration acting as a foundation to the spine. PI has traditionally been measured from standing radiographs. The third study investigates PI three-dimensionally, based on low-dose CT examinations, in 37 patients with Lenke type 1 or 5 curves compared with a reference group. A significantly higher PI was observed in patients with Lenke type 5 curves compared with the reference group and patients with Lenke type 1 curves. Severe AIS is treated with corrective surgery. Two approaches are available: the predominant posterior approach and the anterior approach. In the fourth paper, these two approaches are evaluated with regard to three-dimensional correction, how well the correction is maintained over a 2-year follow-up and patient-reported outcome measures. Twenty-seven patients treated with the posterior approach and 26 patients treated with the anterior approach, all with Lenke type 1 curves, were included. Fewer vertebrae were fused in the anterior group, but the posterior group had a better correction of the deformity in the frontal plane. No difference was observed regarding three-dimensional correction and patient-reported outcome measures. AIS is truly a complex three-dimensional deformity. More research is needed to fully comprehend the complexity of the scoliotic spine

Leptin and the Intersection of Cardiovascular Disease, Metabolism, and Adipose Tissue

According to the World Health Organization, cardiovascular disease (CVD) is a group of disorders of the heart and blood vessels, and it is the leading cause of death worldwide. The risk factors for CVD are divided into two major classes: non-modifiable (age, gender, family history) and modifiable (including tobacco use, type 2 diabetes mellitus (T2DM), physical inactivity, unhealthy diet, abdominal obesity, high cholesterol, dyslipidemia, and stress). Because CVD is a major cause of mortality and morbidity, new and clinically useful biomarkers of cardiovascular risk are of essence. Since obesity is a risk factor for CVD, new ways to achieve weight loss are also important.   In this thesis, the focus is on leptin, a metabolic hormone with a pivotal function in the balance of appetite and satiety, and inducing weight loss. The adipose tissue releases leptin, with plasma levels of leptin reflecting the total adipose mass. Since it is related to both fat mass and cardiovascular risk, and is pro-inflammatory, it has been studied as a potential link between obesity, inflammation, hypertension, and vascular function.    In paper I, we aimed to see if repeated cold exposure increased metabolic rate and/or brown adipose tissue (BAT) volume in humans. Out of 28 recruited participants, we allocated 16 to expose themselves to cold for one hour every day for six weeks, while 12 were controls, instructed to avoid cold exposure. Through magnetic resonance imaging, we found that supra-clavicular BAT volume had increased in an on-treatment analysis of the cold exposure group.    In paper II, we used baseline data from 720 participants in “Cardiovascular Risk factors In Patients with Diabetes—a Prospective study in Primary care” (CARDIPP), all of whom had T2DM and were 55-66 years old at recruitment. We followed patients for incidence of ischemic heart disease (IHD) mortality and morbidity for 4-7 years, using the national Swedish Cause of Death and Hospitalization Registries. Our study showed that serum leptin levels related positively to the hazard ratio in both men and women, and predicted IHD independently of age, HbA1c, BMI, systolic blood pressure, and LDL/HDL-cholesterol ratio. This supports the use of serum leptin in patients with T2DM to add independent prognostic information in terms of IHD. When adding pulse wave velocity (PWV) and intima-media thickness to the model as markers of arterial stiffness, the finding of increased risk of IHD related to leptin levels remained statistically significant in men, but not in women.   In paper III, we aimed to discover novel associations between leptin and circulating proteins, to possibly link leptin with the development of CVD in patients with T2DM. Using proximity extension assay, we investigated associations between 88 plasma proteins in the CARDIPP population. We replicated the associations passing the significance threshold in patients with T2DM in an independent cohort and found that adipocyte fatty acid binding protein (A-FABP) was significantly associated with leptin in both cohorts, more so in men than women. A-FABP can be found in white adipocytes and macrophages, and some studies have identified it as a circulating biomarker for metabolic syndrome, T2DM, and cardiovascular events.   Finally, in paper IV, we analyzed data from 1 658 men and 1 678 women aged 50 to 65 when included in “The Swedish CardioPulmonary bioImage Study” (SCAPIS), focusing on leptin and its possible correlation with PWV. In bivariate correlations, we found log transformed leptin, and inflammatory markers IL-6, IL-18, and CRP, were all correlated in both men and women. In a multivariable linear regression, log transformed leptin correlated positively with PWV, independently of home blood pressure, smoking, non-HDL, BMI, T2DM, and IL-6, IL-18, and CRP. This suggests it may be possible to use leptin as a marker for PWV and arterial stiffness. In conclusion, this thesis provides new insights into leptin and its potential associations with other circulating proteins, and its connection to cardiovascular disease and inflammation, both in patients with T2DM and in healthy subjects. It also provides more insight into brown adipose tissue.

Strome lewende water : 'n interpretasie van Johannes 7:37-39 met verwysing na die huttefees, vir die konteks van wit Suid-Afrikaners in die 21e eeu

Thesis (MPhil (Ancient Studies. Centre for Bible Interpretation and Translation in Africa))--Stellenbosch University, 2006.This thesis explores the invitation and promise extended by Jesus in John 7:37-39 from the Jewish perspective against the background of the water libation ceremony that takes place during the Feast of Tabernacles, with the aim of offering an enriched interpretation of the text for Christian believers. Traditionally the words of Jesus in verses 37 and 38 are interpreted according to verse 39 as a reference to the pouring out of the Holy Spirit after Jesus has been glorified. Such an interpretation does not take into account the Jewish background against which the text is set. The work gives a broad overview of the unique contents and message of the Gospel of John. The genre of the gospel is discussed, the author and the origin of the work are considered, as are the world of the author and the first readers, the composition of the text, the language and language usage and the purpose of the work. A consideration of the interpretations of John 7:37-39 given by other commentators is offered in detail. Questions resulting from the text are discussed, such as which day is meant by the phrase “the last and greatest day of the feast” in verse 37, and, who is meant to be the source of the living water promised by Jesus in verse 38: Jesus himself or the believer. The historical background of the Feast of Tabernacles is explored. The institution of the feast as a harvest festival as well as the connection of the feast with the exodus from Egypt and the re-institution of the Law after the Exile are considered. The elements of the feast as expressed in the text of the Old Testament are discussed and references to the feast in the texts of the Old and New Testaments are supplied. The symbolism of water in the Old and New Testament is studied. Water is used as a symbolic expression of God’s power in the creation narrative and in God’s presence in nature. In the Old Testament water is also used as evidence of God’s blessing but when water is withheld it is seen as a symbol of God’s judgement. My own interpretation of John 7:37-39 first considers the text as a narrative against the larger background of the Gospel of John, and second uses a socio-historical perspective of the passage with a consideration of the location of Jesus’ invitation against the backdrop of the events of the feast. The situation of the ‘new’ South Africa after 1994 is described and the general feeling of pessimism amongst white South Africans is explored in the light of reports in the media and letters to newspaper editors. A parallel is drawn with the situation of the Jewish festival goers in John 7:37-39 to suggest that Jesus’ promise can also be applied to white South Africans to generate a positive feeling and a new identity. The conclusion is reached that the new life of blessing as promised by the text should not stop with the receivers but should flow through them to be a blessing to others