Anterior lumbar interbody fusion using rhBMP-2 with tapered interbody cages

In a multicenter, prospective, randomized, nonblinded, 2-year study, 279 patients with degenerative lumbar disc disease were randomly divided into two groups that underwent interbody fusion using two tapered threaded fusion cages. The investigational group (143 patients) received rhBMP-2 on an absorbable collagen sponge, and a control group (136 patients) received autogenous iliac crest bone graft. Plain radiographs and computed tomographic scans were used to evaluate fusion at 6, 12, and 24 months after surgery. Mean operative time (1.6 hours) and blood loss (109.8 mL) were less in the investigational rhBMP-2 group than in the autograft control group (2.0 hours and 153.1 mL). At 24 months the investigational group's fusion rate (94.5%) remained higher than that of the control group (88.7%). New bone formation occurred in all investigational patients. At all intervals, mean postoperative Oswestry, back pain, and leg pain scores and neurologic status improved in both treatment groups with similar outcomes. In the control group, eight adverse events related to the iliac crest graft harvest occurred (5.9%), and at 24 months 32% of patients reported graft site discomfort and 16% were bothered by its appearance. Lumbar fusion using rhBMP-2 and a tapered titanium fusion cage can yield a solid union and eliminate the need for harvesting iliac crest bone graft.     

Anterior cervical discectomy without interbody fusion

BACKGROUND: The use of an interbody bone graft during anterior cervical discectomy remains a controversial topic. This study presents the outcome of 64 consecutive patients who underwent anterior cervical discectomy without an interbody fusion. METHODS: Sixty-four consecutive patients underwent anterior cervical discectomy without interbody fusion by one surgeon at Indiana University School of Medicine between April 1994 and February 1998. A retrospective analysis of these cases was performed to evaluate outcome of this procedure. Outcome was determined using the criteria of Odom and Finney. RESULTS: In our series of patients, the mean age was 49.4 years, and the mean time of follow-up was 8.5 months. The presentation was as follows: 69% radiculopathy alone, 23% combined myelopathy and radiculopathy, and 8% myelopathy. Although 31% of the patients had symptoms for more than 1 year, the mean duration of symptoms of the remainder of patients was 3.2 months. The majority of patients had single-level disease (77%); however, 25% underwent 2 level discectomies, and 2% underwent 3 level discectomies. Twenty-four patients (38%) had soft disc herniation, and 40 patients (62%) had hard disc herniation. Of the 64 patients, 91% had either good or excellent outcomes, 9% had satisfactory outcomes, and none had a poor result. Ninety-six percent of the patients with soft disc herniation had good or excellent outcomes, whereas 88% of the patients with hard disc had good or excellent outcomes (p = 0.217). Ninety-one percent of the patients who worked before surgery returned to work after their operation. None of the patients required reoperation at the operative level or exhibited instability at the operative level. Postoperative complications included transient intrascapular pain (13%), kyphotic deformity (3%), transient vocal cord paralysis (2%), and temporary dysphagia (2%). No significant difference in age or outcome existed when comparing males to females. CONCLUSION: Satisfactory results can be attained by discectomy without an interbody fusion in the surgical management of cervical disc disease.     

Anterior cervical interbody fusion with threaded cylindrical bone

The author describes some modifications of the original Cloward method of cervical intervertebral body fusion. These modifications include the intraoperative threading of the standard cylindrical graft dowel (either autologous or heterologous) and the development of two new instruments designed to insert the graft into the intervertebral space. This modified technique was tested in an experimental study using the cervical spine of cadavers, after which a series of 37 patients were operated on with this method. The results of both series are presented. The chief advantages of this type of interbody fusion over the standard technique are: 1) easier insertion of the graft into the intervertebral space; and 2) decrease in complications. Complications with cervical interbody fusion, both minor (such as partial displacement of the graft, vertebral angulation, and radicular injury) and major (such as spinal cord compression and/or contusion), are fortunately infrequent, but they are important because of their irreparable consequences.     

内窥镜技术在颈椎前路手术中的应用

目的：探讨内窥镜下颈椎前路减压植骨融合术的手术技巧与疗效。方法：2002年8月～2005年3月应用内窥镜下颈椎前路减压植骨融合术治疗20例颈椎疾患患者，均应用自制不同型号椎间旋转撑开器及特制不同角度、不同大小的网形与方形刮匙行前路椎间盘切除，单纯PEEK cage植骨融合8例，PEEK cage植骨融合加钛板内同定2例，单纯钛cage植骨融合3例，钛cage植骨融合加钛板内同定2例，椎间植骨融合加钛板内同定5例，随访观察治疗效果。结果：术后随访3～12个月，平均7个月。患者症状体征及神经功能均明显改善。术后影像学检查手术部位减压彻底。1例发生钛cage松动，其余椎间高度无丢失，维持颈椎正常生理曲度。结论：通过对椎间盘镜部分器械和技术的改进，将其应用于颈椎前路椎间盘切除、椎间融合内同定术治疗颈椎病及颈椎间盘突出症可取得满意的效果。     

Anterior cervical vertebrectomy and interbody fusion. Technical note.

This report discusses the authors' technique in performing anterior cervical vertebrectomy and interbody fusion for multilevel cervical disease. The technique is performed with a high-speed drill and bone-bank fibular strut graft. After decompression of the cervical canal, ledges are made in the intact vertebral bodies to create a rectangular bed for safe seating of the bone graft. The bone-bank fibular strut graft is a feasible alternative to autograft. The simplified and safe nature of this procedure reduces postoperative morbidity as well as the length of hospital stay.     

Assessment of effects of rhBMP-2 on interbody fusion with a novel rat model

BACKGROUND CONTEXTThe effects of using off-label recombinant human bone morphogenetic protein (rhBMP)-2 for interbody fusion are controversial. Although animal models of posterolateral fusion are well-established, establishing animal models to validate the safety and efficacy of interbody fusion is difficult, which may contribute to the inconsistent clinical results.PURPOSETo develop a novel animal model of interbody fusion in rat coccygeal vertebrae without destroying bony endplates.STUDY DESIGNAn experimental animal study.METHODSForty-five male Sprague-Dawley rats underwent coccygeal interbody fusion without violating vertebral endplates. The animals were divided into three different groups based on the materials that were implanted into the interbody space (1) allogeneic iliac bone (IB) alone (IB group), (2) IB and 3 µg of rhBMP-2 (BMP low-dose group), or (3) IB and 10 µg of rhBMP-2 (BMP high-dose group). Fusion rates were investigated using microcomputed tomography 6 weeks after the operation. The incidence of adverse events, including soft-tissue swelling, delayed wound healing, osteolysis, and ectopic bone formation were evaluated. The total number of adverse events (using the adverse event score) in each group and the swelling ratio (calculated using the surgical site tissue volume [TV; TV on postoperative day 1/preoperative TV]) were also evaluated.RESULTSThe fusion rates in the BMP low- and high-dose groups (33.3% and 46.7%) were not significantly different, but both were significantly higher than that in the IB group (0%) (p=.042 and .006, respectively). Significant differences in the incidence of osteolysis, adverse event scores, and swelling ratios were observed only between the BMP high-dose and IB groups (p=.043, .006 and .014, respectively).CONCLUSIONSWe developed a novel rat model of interbody fusion in which the vertebral endplates were not violated, reflecting the normal clinical setting. rhBMP-2 use increased the fusion rate, but a higher dose of rhBMP-2 did not lead to a higher fusion rate than that for low-dose rhBMP-2; conversely, it led to an increase in the occurrence of adverse events.CLINICAL SIGNIFICANCEThis novel rat model of coccygeal interbody fusion that preserved bony endplates has clinical significance for validating the effectiveness of biologics or bone graft substitutes before clinical trial.     

Anterior interbody fusion of the cervical spine with coralline hydroxyapatite.

STUDY DESIGN: A nonrandomized, retrospective human study of patients requiring anterior discectomy and reconstruction from C3 to T1. The pattern of incorporation, presence or absence of disc space collapse, maintenance of correction, and clinical outcomes were considered. OBJECTIVE: To determine the efficacy of coralline hydroxyapatite as a bone replacement in anterior interbody fusions of the cervical spine used in conjunction with rigid plate fixation. SUMMARY OF THE BACKGROUND DATA: Autograft is the gold standard for anterior interbody fusion of the cervical spine. Reported complication and morbidity rates with the use of autograft are as high as 21%. Using allograft instead of autograft presents numerous problems including lower rates of fusion. Other bone substitutes such as ceramics and polymethylmethacrylate are ineffective for fusion. METHODS: Twenty-six skeletally mature patients underwent anterior decompression, stabilization, microdiscectomy, and reconstruction with Pro Osteon 200 (Interpore Cross International, Irvine, CA) coralline hydroxyapatite and AO anterior cervical locking plates. Iliac crest autograft, local bone, and allograft were not used. RESULTS: The minimum follow-up period was 2 years (average, 30 months). There was no evidence of plate breakage, screw breakage, resorption of the implant, or pseudarthrosis. Two patterns of incorporation were identified. The implant incorporated totally in 100% of the disc spaces. Average hospital stay was 1.6 days. The average decrease in pain was 75.8%. There was no evidence of nonunion. CONCLUSIONS: The use of Pro Osteon 200 with rigid anterior plating seems promising as a bone replacement in the cervical spine. The incorporation rate is exceedingly high, and the complication rate nonexistent.     

Posterior lumbar interbody fusion using rhBMP-2

The use of biological technologies for the treatment of degenerative spinal diseases has undergone rapid clinical and scientific development. BMP strategies have gained wide support for an inherent potential to improve the ossification process. It has been extensively studied in combination with various techniques for spinal stabilisation from both anterior and posterior approach. We studied the fusion process after implantation of rhBMP-2 in 17 patients with degenerative lumbar spine diseases in combination with dorsal fixation with pedicle screws and poly-ether-ether-ketone (PEEK) interbody cages. We used 12 mg rhBMP-2 carried by collagen sponge, 6 mg in every cage. Patient follow up consisted of pre-operative radiographic and clinical evaluation. Similar post-operative evaluations were performed at 3 and 6 months. Clinical assessment demonstrated clear improvement in all patients despite evidence of vertebral endplate osteoclastic activity in the 3-month radiographs. The 6-month radiograph, however, confirmed evidence of fusion, and no untoward results or outcomes were noted. While previous studies have shown exclusively positive results in both fusion rates and process, our study demonstrated an intermediate morphology at 3 months during the ossification process using Induct Os in combination with peek-cages using a PLIF-technique. The transient resorption of bone surrounding the peek cage did not result in subsidence, pain or complication, and fusion was reached in all cases within a 6-month-controlled evaluation. Although there was no negative influence on clinical outcome, the potential for osteoclastic or metabolic resorption bears watching during the post-surgical follow up.     

Perioperative complications with rhBMP-2 in transforaminal lumbar interbody fusion

Bone morphogenetic protein (BMP) is commonly used as an ICBG substitute for transforaminal lumbar interbody spine fusion (TLIF). However, multiple recent reports have raised concerns regarding a substantial incidence of perioperative radiculopathy. Also, given the serious complications reported with anterior cervical BMP use, risks related to swelling and edema with TLIF need to be clarified. As TLIF related complications with rhBMP-2 have generally been reported in small series or isolated cases, without a clear denominator, actual complication rates are largely unknown. The purpose this study is to characterize perioperative complications and complication rates in a large consecutive series of TLIF procedures with rhBMP-2. We reviewed inpatient and outpatient medical records for a consecutive series of 204 patients [113 females, 91 males, mean age 49.3 (22–79) years] who underwent TLIF using rhBMP-2 between 2003 and 2007. Complications observed within a 3-month perioperative interval were categorized as to etiology and severity. Wound problems were delineated as wound infection, hematoma/seroma or persistent drainage/superficial dehiscence. Neurologic deficits and radiculopathies were analyzed to determine the presence of a clear etiology (screw misplacement) and identify any potential relationship to rhBMP-2 usage. Complications were observed in 47 of 204 patients (21.6%) during the 3-month perioperative period. Major complications occurred in 13 patients (6.4%) and minor complications in 34 patients (16.7%). New or more severe postoperative neurologic complaints were noted in 13 patients (6.4%), 6 of whom required additional surgery. These cases included one malpositioned pedicle screw and one epidural hematoma. In four patients (2.0%), localized seroma/hematoma in the area of the foramen caused neural compression, and required revision. In one additional patient, vertebral osteolysis caused foraminal narrowing and radiculopathy, but resolved without further surgery. Persistent radiculopathy without clear etiology on imaging studies was seen in six patients. Wound related problems were seen in six patients (2.9%), distributed as wound infection (3), hematoma/seroma (1) and persistent drainage/dehiscence (2). Overall, this study demonstrates a modest complication rate for TLIF using rhBMP-2. While perioperative complications which appeared specific to BMP usage were noted, they occurred infrequently. It will be necessary to weigh this incidence of complications against the complication rate associated with ICBG harvest and any differential benefit in obtaining a solid arthrodesis.     

磷酸钙人工骨在颈椎前路椎间融合治疗颈椎病中的应用

目的:探讨磷酸钙人工骨在颈椎前路椎间融合治疗颈椎病中的应用效果。方法:2000年9月至2002年9月应用磷酸钙人工骨椎间融合结合钛板颈前路手术治疗41例颈椎病患者,随访32例共48个节段,采用JOA评分判定手术疗效,X线片判定融合效果。结果:随访18.2±7.8个月,全部患者术后未见任何过敏或毒性反应,无皮疹、高热及深部感染。JOA评分从术前10.93±2.48分提高到术后14.54±2.19分(P<0.001)。术后X线片未见人工骨塌陷、移位或脱入椎管,无钛板或螺钉松动及折断。术后48个节段中47个节段获得椎间融合,融合时间15.6±7.4个月。结论:磷酸钙人工骨可替代自体骨应用于颈椎前路椎间融合手术。     

Anterior cervical interbody fusion with a titanium box cage: early radiological assessment of fusion and subsidence.

BACKGROUND CONTEXT: The use of stand-alone cervical interbody cages in anterior cervical discectomy with fusion (ACDF) has become popular, but high subsidence rates have been reported in the literature. PURPOSE: The authors present short-term radiological results of a titanium box cage with regard to fusion and subsidence. Reliable fusion and lack of subsidence may influence long-term clinical results. Early radiological data are necessary before implementation of this device on a larger scale can be accepted. STUDY DESIGN/SETTING: Retrospective radiological quality assessment study. PATIENT SAMPLE: ACDF using the titanium cage was performed in 71 consecutive patients at 106 levels. Diagnoses included cervical disc disease (57) and cervical spinal stenosis (14) after failed conservative treatment. OUTCOME MEASURES: Subsidence and kyphosis were assessed on lateral cervical radiographs made directly postoperative and at 3- and 6-month follow-up. At 6-month follow-up, lateral flexion-extension radiographs were made to assess fusion. METHODS: Subsidence of the cage was defined as a decrease in total vertical height of the two fused vertebral bodies as measured on the lateral cervical radiographs made 3 and 6 months postoperatively compared with the directly postoperative radiographs. Segmental kyphosis was measured as the angle between the posterior borders of the two vertebral bodies on the lateral radiograph. RESULTS: No patients were lost to follow-up. Fusion was achieved after 6 months in all patients. At 3 and 6 months postoperative the same 10 cages (each in a different patient) had subsided. The C6-C7 level was significantly more frequently involved compared with all other levels. A segmental kyphotic alignment was observed in five patients at the C6-C7 level and in one patient at the C4-C5 level. CONCLUSIONS: For patients with cervical disc disease, the high subsidence tendency of the cage into the end plate of predominantly C7 is a disturbing phenomenon found in this study. A modified cage design that improves and extends contact with the inferior surface could be expected to reduce subsidence into C7.     

Anterior interbody fusion using the cervical spine locking plate

Surgical Principles The Cervical Spine Locking Plate system (CSLP) is designed to perform anterior fusions of the cervical and upper thoracic spine. The screws are locked in the H shaped plate providing intrinsic angle stability. Early osseous integration is enhanced by titanium plasma spray coating and by the hollow and perforated design of the screws. These features enhance the primary and secondary stability of the fixation. Therefore the penetration of the posterior cortex of the vertebra with the screws is not necessary, which is a decisive asset compared to conventional plate systems. This essentially diminishes the intraoperative risks. The primary stability is superior to that of conventional plate systems as the screws are tightly locked into the plate in convergence.     

颈前路减压植骨钢板内固定术治疗脊髓型颈椎病的初步疗效

目的：分析颈前路减压钢板内固定术治疗脊髓型颈椎病的临床疗效。方法：对１０３例脊髓型颈椎病患者行颈前路减压植骨钢板内固定术,并对临床结果进行Ｏｄｏｍ’ｓ法疗效评定及影像学分析。结果：１０３例中获随访９９例,临床疗效优良８０％,植骨融合率为９７．９％（９７／９９）,其中单节段椎间融合率为１００％（１２／１２）,多节段椎间融合率为９７．７％（８５／８７）。结论：颈前路钢板内固定对于脊髓型颈椎病的治疗是有     

Anterior discectomy without interbody fusion for cervical disc herniation

Summary Between 1985 and 1990, 68 patients with cervical radiculopathy due to soft disc herniation were treated by anterior cervical discectomy without interbody fusion. Eleven patients were unavailable for follow-up examination. The mean follow-up was 23 months (range 12–54 months). Both clinical and radiographic follow-ups were done, and 92% of the patients was found to have excellent or good clinical results. Radiographic follow-up revealed that 34% had fused spontaneously and 66% developed fibrous healing of the disc space with an average range of mobility of 2.07 deg. All patients were shown to be stable on flexion-extension films. Complications included two transient CSF leaks. No neurologic deficits arose. One patient was reoperated and fused for intractable residual neck pain. We conclude that anterior cervical discectomy without interbody fusion is a simple, safe and effective procedure for patients with soft disc herniation.