Gerald E. Rodts

Anterior cervical plating enhances arthrodesis after discectomy and fusion with cortical allograft.

OBJECTIVE Anterior plate fixation has gained widespread acceptance for the treatment of cervical spondylosis, theoretically enhancing the rate of arthrodesis. There are few studies comparing fusion rates after anterior cervical discectomy and fusion (ACDF) with and without a plate. The purpose of this study was to evaluate the efficacy of anterior cervical plating for fusion enhancement after one- and two-level ACDF with cortical allograft. METHODS A retrospective review was performed with 251 patients who underwent one- or two-level ACDF with cortical allograft and plate stabilization between 1993 and 1999. An independent surgeon reviewer determined fusion status and complications. A successful fusion was defined by the absence of lucency around the graft, evidence of bridging bone between the endplate and the graft, and the absence of movement on dynamic imaging scans. Follow-up data, ranging from 9 months to 3.6 years, were available for 233 patients. A control group of 289 patients who underwent ACDF without plating was described in a previously published report by the senior author (RWH). Therefore, a total of 540 patients were evaluated for determination of the efficacy of anterior cervical plating with cortical allograft bone. Statistical significance was determined by &khgr;2 test. RESULTS The fusion rates for one- and two-level ACDF with anterior fixation were 96 and 91%, respectively, compared with 90 and 72% for one- and two-level ACDF without anterior fixation. The observed increases in fusion rates for both one- and two-level procedures proved to be statistically significant (P < 0.05). There were no recorded infectious, neurological, or graft-related complications among the cohort treated with anterior cervical plating. Compared with the results for the cohort treated without anterior cervical plates, there was a statistically significant decrease in the graft-related complication rate with the application of plates (P < 0.001). Two patients who received plates were noted to have adjacent-segment degenerative changes that required surgical intervention. No hardware fractures were noted; however, one patient was noted to have a single displaced screw, without clinical consequences. CONCLUSION The use of anterior cervical plating after one- and two-level ACDF with allograft cortical bone significantly enhanced arthrodesis. The improved fusion rate and negligible complication rate associated with anterior cervical plating are compelling factors justifying its use in the treatment of cervical spondylosis.

Laminoplasty versus laminectomy and fusion for multilevel cervical myelopathy: an independent matched cohort analysis.

Study Design. A matched cohort clinical and radiographic retrospective analysis of laminoplasty and laminectomy with fusion for the treatment of multilevel cervical myelopathy. Objectives. To compare the clinical and radiographic outcomes of two procedures increasingly used to treat multilevel cervical myelopathy. Summary of Background Data. Traditional methods of treating multilevel cervical myelopathy (laminectomy and corpectomy) are reported to have a notable frequency of complications. Laminoplasty and laminectomy with fusion have been advocated as superior procedures. A comparative study of these two techniques has not been reported. Methods. Medical records of all patients treated for multilevel cervical myelopathy with either laminoplasty or laminectomy with fusion between 1994 and 1999 at our institution were reviewed. Thirteen patients that underwent laminectomy with fusion were matched with 13 patients that underwent laminoplasty. All patients and radiographs were independently evaluated at latest follow-up by a single physician. Results. Cohorts were well matched based on patient age, duration of symptoms, and severity of myelopathy (Nurick grade) before surgery. Mean independent follow-up was similar (25.5 and 26.2 months). Both objective improvement in patient function (Nurick score) and the number of patients reporting subjective improvement in strength, dexterity, sensation, pain, and gait tended to be greater in the laminoplasty cohort. Whereas no complications occurred in the laminoplasty cohort, there were 14 complications in 9 patients that underwent laminectomy with fusion patients. Complications included progression of myelopathy, nonunion, instrumentation failure, development of a significant kyphotic alignment, persistent bone graft harvest site pain, subjacent degeneration requiring reoperation, and deep infection. Conclusions. The marked difference in complications and functional improvement between these matched cohorts suggests that laminoplasty may be preferable to laminectomy with fusion as a posterior procedure for multilevel cervical myelopathy.

Anterior cervical discectomy with freeze-dried fibula allograft. Overview of 317 cases and literature review.

STUDY DESIGN A retrospective review of 317 patients to determine the efficacy of allogeneic fibula arthrodesis after anterior cervical discectomy. OBJECTIVE To examine the efficacy of allogeneic fibula as an alternative fusion substrate after anterior cervical discectomy, and to determine the effects of cigarette smoking on the healing of fibula allografts. SUMMARY OF BACKGROUND DATA The use of autogeneic iliac crest is associated with graft harvest complications in up to 20% of patients. Most studies reporting on the use of allogeneic iliac crest cite a high collapse rate. Few studies exist that note the efficacy of allogeneic fibula in this procedure and the effects of cigarette smoking on fusion rate. METHODS From 1988 to 1993, 317 patients underwent grafting by the Smith-Robinson technique with allogeneic fibula after anterior cervical discectomy. Patients who described themselves as habitual cigarette smokers or who smoked during the perioperative or postoperative period were categorized as smokers. All patients were immobilized in a rigid cervical orthosis (Philadelphia collar) for at least 10 weeks postoperatively. RESULTS A minimum of 2 years follow-up was achieved in 289 patients. In all, 162 men and 127 women had a total of 311 levels grafted, and the mean follow-up period was 33 months (range, 24 to 51 months). Of patients who received allogeneic fibula at one level, 90% (242/269) achieved radiologic fusion. The fusion rate was 92% (182/198) among nonsmokers compared with 85% (60/71) among smokers (not a statistically significant difference; P = 0.120). After two-level procedures, 72% (13/18) of the patients showed fusion. The fusion rate was 50% (2/4) among smokers compared with 79% (11/14) among nonsmokers (P = 0.53). When one-level arthrodesis (90%) was compared with two-level arthrodesis (72%), the difference approached statistical significance (P = 0.054). Neither of the two patients, both nonsmokers, who received grafts at three levels achieved fusion. There were no infections, and no grafts collapsed. Two grafts extruded (0.6%), but these were partial and did not require reoperation. Both patients fused and constituted the only patients with more than 10 degrees of angulation in the series. Graft subsidence occurred in 5% (17/311) of the grafts, mostly in the beginning of the series, and was not problematic. This phenomenon was thought to have been caused by overaggressive removal of the cortical endplate. CONCLUSION Allogeneic fibula is an effective substrate for use in achieving fusion after anterior cervical discectomy. Maximal results are achieved with its use at one level in nonsmokers. Cigarette smoking decreased the fusion rate with allogeneic fibula in the anterior cervical spine, but not by a statistically significant amount.

C1-C2 transarticular screw fixation for atlantoaxial instability : a 6-year experience

OBJECTIVEWe review a 6-year, single-center experience using the technique of C1–C2 transarticular screw fixation for atlantoaxial instability in 75 consecutive operations. METHODSThe study group was composed of 43 men and 32 women, with a mean age of 44 years (range, 8–76 yr). Each patient had documented atlantoaxial instability. In 28 patients (37%), atlantoaxial instability was a result of trauma; in 22 patients, (29%), it was a result of rheumatoid arthritis; in 16 patients (21%), it was a result of prior surgery; and in 9 patients (12%), it was a result of congenital abnormalities. All patients underwent stabilization with C1–C2 transfacetal screws and a posterior interspinous construct. Nine patients had unilateral screws placed. Postoperatively, the patients were maintained in a rigid cervical orthosis for a mean of 11 weeks (range, 8–15 wk); five patients were immobilized with halo fixation for a mean of 13 weeks (range, 10–16 wk). The mean follow-up period was 2.4 years (range, 1–5.5 yr). RESULTSOsseous fusion was documented in 72 patients (96%). There were no hardware failures; however, three patients developed pseudarthrosis. Two superficial wound infections (one at the graft site and one at the cervical incision site) required antibiotic therapy. Four patients had transient suboccipital hypesthesia. No instances of an errant screw, dural laceration, or injury to the vertebral artery, spinal cord, or hypoglossal nerve were noted. CONCLUSIONC1–C2 transarticular screw fixation supplemented with an interspinous construct yielded a 96% fusion rate, with a low incidence of complications. We attribute our successful outcomes to careful preoperative assessment and meticulous surgical technique.

Comparison of the Mini-open versus Laparoscopic Approach for Anterior Lumbar Interbody Fusion: A Retrospective Review

OBJECTIVE The anterior lumbar interbody fusion (ALIF) procedure has become an accepted fusion technique for treating patients with degenerative disorders of the lumbar spine. Many consider laparoscopic ALIF to be the least invasive approach. A modification of the open laparotomy—the “mini-open” approach—is an attractive alternative. In this retrospective review, a comparison of these two ALIF approaches is presented. METHODS We conducted a retrospective review of 98 patients who underwent ALIF procedures between 1996 and 2001 in which either a mini-open or a laparoscopic approach was used. Patient demographics, intraoperative parameters, length of hospitalization, and technique-related complications associated with the use of these two approaches were compared. The subset of patients who underwent L5–S1 ALIF procedures was analyzed separately. Statistical analysis was conducted with &khgr;2 and Student’s paired t tests. RESULTS Between 1996 and 2001, a total of 98 patients underwent ALIF. A laparoscopic approach was used in 47 of these patients, and the mini-open technique was used in the other 51 patients. Operative preparation and procedure time were longer with the use of a laparoscopic approach, and significantly greater during L5–S1 ALIF procedures (P < 0.05). A marginal but significant increase in length of stay was observed after mini-open ALIF procedures (P < 0.05). The immediate postoperative complication rate was greater after mini-open ALIF procedures, 17.6 versus 4.3% (P < 0.05); however, the rate of retrograde ejaculation was higher in the laparoscopic group, 45 versus 6% (P < 0.05). CONCLUSION Both the laparoscopic and mini-open techniques are effective approaches to use when performing ALIF procedures. On the basis of the data obtained in this retrospective review, the laparoscopic approach does not seem to have a definitive advantage over the mini-open exposure, particularly in an L5–S1 ALIF procedure. In our opinion, the mini-open approach possesses a number of theoretical advantages; however, the individual surgeon’s preference ultimately is likely to be the dictating factor.

The mini-open transforaminal lumbar interbody fusion.

The mini-open approach for transforaminal lumbar interbody fusion is described in detail. Operating room setup and surgical positioning are demonstrated. Our methods of retractor placement and techniques for optimal surgical exposure are discussed. The surgical technique used for decompression and fusion is presented in detail. The surgical pearls and pitfalls of the mini-open TLIF are described and illustrated.

Pediatric Occipitocervical Arthrodesis

Object: Few reports exist on the options and effectiveness of craniocervical stabilization in the pediatric population compared with the adult literature. Traditional options in children include onlay grafting and semi-rigid occipitocervical wiring. Recently, reports on the use of rigid internal fixation devices such as occipitocervical plates and contoured loops have provided excellent results in adults, and their use has often obviated the need for external orthosis. The purpose of this article is to report our experience with both traditional and newer rigid internal fixation methods for occipitocervical fusion in children. Methods: During the past 4.5 years, 14 children (ages 4 months to 16 years) have undergone occipitocervical fusion. Indications for fusion included trauma (n = 4), congenital instability/stenosis (n = 6), postinfectious instability (n = 1) and basilar invagination (n = 3). Techniques using onlay grafting (n = 3) as well as rigid internal fixation using plates (n = 1) and contoured craniocervical titanium loops (n = 10) were used. Postoperative orthosis included halo vests (n = 7), minerva jackets (n = 3), sterno-occipital mandibular immobilizer (n = 1), and a cervical collar (n = 3). Long-term follow-up (range 13–58 months) was available for 13 of the 14 children. Conclusions: While each occipitocervical fusion in pediatric patients requires a customized treatment plan, we believe children older than 12 months of age should be considered candidates for rigid internal fixation methods. The rigidity afforded by this method may eliminate the need for rigid external orthotic support in selected individuals. In our experience, anatomic constraints in children less than 1 year old usually require fusion with more traditional onlay techniques. Long-term follow-up studies are still required to assess the effects of rigid internal fixation in the skeletally immature spine.

Circumferential fusion for cervical kyphotic deformity

OBJECT The treatment of cervical kyphotic deformity is challenging. Few prior reports have examined combined anterior/posterior correction methods, and fusion rates and standardized outcomes are rarely cited in literature examining these techniques. The authors present their midterm results with cervical kyphosis correction. METHODS The authors retrospectively reviewed the charts of 30 patients with cervical kyphotic deformity who underwent circumferential spine surgery between 2001 and 2007. The causes of the deformity included chronic fracture in 17 patients, degenerative disease in 10, and tumor in 3. Anterior procedures included discectomies and corpectomies/osteotomies at 1 or more levels with fusion. Posterior operations included decompression and/or osteotomies with lateral mass or pedicle fixation. Preoperative and postoperative Ishihara kyphosis indices, modified Japanese Orthopaedic Association (mJOA) scores, and Nurick grades were analyzed. Arthrodesis was assessed via dynamic radiographs, and CT scans were used to assess fusion in questionable cases. RESULTS One patient was lost to follow-up. Two patients died within 1 month of surgery. The follow-up period in the remaining 27 patients ranged from 1 to 6.4 years (mean 2.6 years). Ishihara indices improved from a preoperative mean of -17.7 to a postoperative mean of +11.4. The mean Nurick grades improved from 3.2 preoperatively to 1.3 postoperatively. The mJOA scores improved from a preoperative mean of 10 to 15 postoperatively. All surviving patients who underwent follow-up showed postoperative fusion except 1 patient with renal failure and osteoporosis (95% fusion rate). The overall rate of complications (major and minor) was 33.3%. CONCLUSIONS In cases of cervical kyphosis, management with decompression, osteotomy, and stabilization from both anterior and posterior approaches can restore cervical lordosis. Furthermore, such surgical techniques can produce measurable improvements in neurological function (as measured with Nurick grades and mJOA scores) and achieve high fusion rates. However, there is a significant rate of complications.

Occipitocervical Fixation : Long-Term Results

Study Design. The study is a retrospective review of 58 patients who underwent occipitocervical fusion between 1997 and 2001. Objectives Our objective is to study the clinical results after occipitocervical fixation with long-term follow-up and assess factors contributing to clinical success. Methods Data from patient charts, operative notes, physician office notes, and imaging studies were incorporated in the study. Myelopathy was assessed using a Nurick scale for preoperative and postoperative evaluation. Fusion was assessed using cervical plane films with flexion and extension views. Results Mean follow-up was 36 months, with all patients having a greater than 1-year follow-up. The most common pathology was congenital cranial settling (41%) followed by trauma (22%) and rheumatoid arthritis (17%). Myelopathy was the most common presentation (62%) followed by pain (28%). A successful fusion occurred in 48 out of 51 patients (94%). Symptoms improved in 86% of patients, whereas 35% improved 1 Nurick grade. Complications occurred in 30% of patients. The cervical wound infection rate was 5%. The rate of adjacent level degeneration was 7%. The mortality rate was 1.7%. Conclusions Occipitocervical instrumentation allows for very high fusion rates without the need for halo vest immobilization. All patients with successful fixation have pain resolution. Myelopathy improves in most patients, whereas one-third of patients demonstrate dramatic improvement.

Posterior cervical Laminoplasty using a new plating system: Technical note

Background: Laminoplasty is well described in the Japanese literature as a surgical option for treating ossification of the posterior longitudinal ligament (OPLL). The open door technique has gained increasing popularity in the United States and Europe to treat not only OPLL but also cervical stenotic myelopathy. An obstacle to its widespread use is the lack of a suitable fixation plate to adequately secure the fractured lamina to the lateral mass. Our objective was to demonstrate the advantages of a novel miniplate (Ti-Mesh LP system; Medtronic Sofamor Danek, Memphis, TN, USA) that is ideally suited for fixing the lamina to the lateral mass. Methods: We used the Ti-Mesh LP miniplate system to perform laminoplasties on five patients, all male, with a mean preoperative Nurick score of 2.8. Four patients had congenital cervical stenosis with myelopathy and one had OPLL. Open door laminoplasties were performed on all patients. The plates were implanted with a claw positioned on the trapdoor lamina and a flat plate on the lateral mass. Results: The system was implanted successfully in all patients. The mean number of levels fixated was 4.4. There were no intraoperative or postoperative complications after >5 months follow-up. Conclusions: The new Ti-Mesh LP cranial miniplate and screw system facilitates posterior cervical laminoplasty procedures by eliminating the need to contour cranial miniplates for use in the cervical spine. Its unique claw construct and angled design are ideal for holding a trapdoor laminoplasty in the open position. We have used this system successfully and without complications to perform decompressive posterior cervical laminoplasties in five patients.