✓ Only four cases of Type I odontoid fracture have been previously described in the English literature. Most authors consider this lesion to be stable, although the mechanism(s) of injury has not been clearly elucidated. A case of Type I odontoid fracture in association with atlanto-occipital and atlantoaxial dislocation resulting in death is presented. The normal ligamentous anatomy is reviewed and proposed mechanisms for this injury are discussed. The radiographic features of all reported cases of this type are reviewed. It is proposed that the Type I odontoid fracture is a likely manifestation of atlanto-occipital instability and rarely occurs as an isolated or stable injury.
Eric W. Scott, Regis W. Haid Jr. and David Peace
Alexander F. Post, Prithvi Narayan and Regis W. Haid Jr.
✓ The authors report on the management of occipital neuralgia secondary to an abnormality of the atlas in which the posterior arch was separated by a fibrous band from the lateral masses, resulting in C-2 nerve root compression. The causes and treatments of occipital neuralgia as well as the development of the atlas are reviewed.
Report of two cases
Matthew T. Mayr, Stephen Hunter, Scott C. Erwood and Regis W. Haid Jr
✓ The authors describe two cases of calcifying pseudoneoplasms, rare degenerative lesions that mimic tumor or infection. One case involved the cervical spine and the second the thoracic spine. Both patients experienced progressive myelopathy from extradural compression of the spinal cord. The radiological evaluation, pathological findings in the lesions, treatment, and follow up are described. Total or subtotal excision can relieve symptoms and prevent recurrence of this lesion.
Bryan Barnes, Gerald E. Rodts, Mark R. McLaughlin and Regis W. Haid Jr.
Object. The authors retrospectively reviewed a series of 35 patients with mechanical low-back or one- to two-level discogenic pain; the patients underwent lumbar interbody fusion in which threaded cortical bone dowels (TCBDs) were placed to treat degenerative disc disease. The purpose of the study was to delineate fusion rates and outcome data in this series of patients.
Methods. The series was composed of 18 women and 17 men whose mean age was 46 years (range 17–76 years). There were nine active cigarette smokers. All patients presented with symptoms consistent with mechanical low-back or discogenic pain, and magnetic resonance imaging revealed degenerative changes related to disc collapse at one or two vertebral levels. For placement of the TCBDs, 23 patients underwent posterior lumbar interbody fusion (PLIF), whereas 12 patients underwent anterior lumbar interbody fusion (ALIF). In all except one patient undergoing PLIF, pedicle screw and rod constructs were used without posterolateral fusion. In all patients undergoing ALIF except one, TCBDs were used as stand-alone devices without supplemental fixation. At follow up the success of fusion was determined by static lumbar radiography and/or computerized tomography scanning. The degree of lumbar lordosis at the diseased level was measured immediately postoperatively and compared with that documented on follow-up radiological studies. Outcomes were assessed using a modified Prolo Scale. Excellent and good outcomes were considered satisfactory, and fair or poor outcomes were considered unsatisfactory.
In 28 patients (eight ALIF and 20 PLIF) radiological and clinical follow-up data were considered adequate. The mean follow-up duration was 12.3 months. Overall satisfactory outcome was 60%; 70% satisfactory outcome was noted in PLIF patients and 38% in ALIF patients. Osseous fusion was present in 95% of the patients in the PLIF group and in 13% of those in the ALIF group. Complications included one L-5 nerve root injury and two postoperative wound infections, all in patients who underwent PLIF; in an ALIF patient lateral breakout of one implant occurred at 8 months postoperatively.
Conclusions. Analysis of the mean 12.3 month follow-up data indicates that there is a dramatically higher fusion rate in PLIF compared with ALIF procedures when TCBDs are used. The authors believe that it is important to note that in all the PLIF procedures except one, supplemental pedicle screw/rod constructs were used, whereas in ALIF procedures no supplemental fixation was performed. The results thus suggest that TCBDs are best used in PLIF in conjunction with pedicle screw and rod constructs.
Praveen V. Mummaneni, Valli P. Mummaneni, Regis W. Haid Jr., Gerald E. Rodts Jr. and Rick C. Sasso
The correction of chin-on-chest deformity is challenging and requires combined anterior and posterior approaches to the cervical spine. The authors describe a cervical osteotomy technique for the correction of chin-on-chest deformity in patients with ankylosing spondylitis (AS). This procedure can be accomplished using a posterior screw rod construct combined with an anterior hybrid plate system.
In patients with AS, a “front-back-front” approach may be necessary because of the deformity's rigidity. The authors describe the complicated intubation and anesthetic requirements for this approach. They performed an anterior discectomy, cervical osteotomy, and unilateral pediculectomy but did not place anterior instrumentation. Via a posterior approach, laminectomies, facetectomies, and the contralateral pediculectomy were then undertaken. A posterior cervical screw/rod system was placed and loosely connected to titanium rods. Intraoperatively the deformity was corrected by placing the neck in extension combined with compression of the posterior screws on the rods. The posterior construct is then tightened. Finally, an anterior cervical approach is performed to place a structural interbody graft and a hybrid anterior cervical plate construct.
The authors have successfully used this approach to correct a chin-on-chest deformity in a patient with ankylosing spondylitis. At 1-year follow-up examination, excellent resolution of the deformity and solid fusion had been achieved. They prefer to perform this procedure by using state-of-the-art anterior and posterior instrumentation systems.
Mark R. McLaughlin, Jonathan Y. Zhang, Brian R. Subach, Regis W. Haid Jr. and Gerald E. Rodts Jr.
In recent years, there has been an unprecedented increase in the number of patients undergoing treatment with interbody fusion devices for degenerative disease of the lumbar spine. These devices can be placed either anteriorly or posteriorly. With the advent of minimally invasive surgery and the increasing ability of general surgeons to perform transperitoneal procedures laparoscopically, a new laparoscopic technique has been developed for placing lumbar interbody fusion devices. Although this procedure has some advantages over posterior lumbar interbody fusion, it is not without significant risk, and the learning curve is steep. The authors review a series of 32 consecutive patients who underwent single-level laparoscopic anterior lumbar interbody fusion at L4–5 or L5–S1 over a 2-year period for the treatment of single-level lumbar degenerative disease. In this report they review the technical aspects of the procedure and the important lessons they have learned through their early experience with this technique.
Shushil Shilpakar SK, Mark R. McLaughlin, Regis W. Haid Jr., Gerald E. Rodts Jr. and Brian R. Subach
In this article the authors describe the management of Type II odontoid fractures with special attention to operative technique and avoidance of complication. Anterior odontoid screw fixation is a procedure the authors have performed over the last 8 years in cases with acute Type II and rostral Type III odontoid fractures. In cases of Chronic Type II odontoid fractures and in patients with transverse ligament disruption, the authors prefer to undertake posterior transarticular facet screw fixation supplemented by bone graft and interspinous C1–2 wiring.
The technical aspects of these procedures are described with a focus on operative nuances. Selection criteria and techniques that the authors have refined over the years have helped them to optimize success rates and minimize complications.
Bryan Barnes, Mark R. McLaughlin, Barry Birch, Gerald E. Rodts Jr. and Regis W. Haid Jr.
The authors retrospectively reviewed a series of cases involving mechanical low-back or disogenic pain; 35 patients underwent lumbar interbody fusion in which threaded cortical bone dowels (TCBDs) were placed to treat degenerative disc disease.
The series was composed of 18 females, and 17 males whose mean age was 46 years (range 17-76 years). There were nine smokers in the group. All patients presented with symptoms consistent with mechanical low-back or discogenic pain, and magnetic resonance imaging–documented degenerative changes and disc collapse greater than 50%, as compared with the adjacent normal-appearing level, were confirmed. Twenty-three patients underwent a posterior lumbar interbody fusion (PLIF) procedure for placement of the TCBD, whereas 12 underwent an anterior lumbar interbody fusion (ALIF) procedure for placement of the TCBD. In all patients undergoing PLIF procedures pedicle screw and rod constructs were used without posterolateral fusion except one. In all cases of ALIF except one TCBDs were used as “stand-alone” devices without supplemental fixation. All TCBDs were packed with morselized cancellous autograft prior to implantation. The success of fusion was determined at follow-up intervals and was defined as: the absence of lucency around the TCBD; an increase in subchondral endplate sclerosis; and the presence of bridging bone incorporating the anterior bone graft as demonstrated on static lumbar radiographs and/or computerized tomography scans. Stability was also determined by an absence of movement on dynamic lumbar radiographs. The degree of lumbar lordosis at the diseased level was measured immediately postoperatively and compared with the change in lordosis at follow up. Outcomes were assessed using a modified Prolo outcome scale and rated as excellent, good, fair, or poor. Excellent and good outcomes were considered satisfactory; fair or poor outcomes were considered unsatisfactory.
In 27 patients radiographic and clinical follow-up results were considered adequate (nine ALIF and 18 PLIF patients). The mean follow-up duration was 7.9 months. Overall satisfactory outcome was 70%: a 77% satisfactory outcome in PLIF patients and a 55% in ALIF patients. Osseous fusion was present in 94% of the patients in the PLIF group and in 33% of those in the ALIF group. Complications included one L-5 nerve root injury and two postoperative wound infections, all in patients who underwent PLIF; there was also a case of breakout of one implant at 8 months postoperatively. The degree of vertebral body angulation measured at last follow up compared with the measurement obtained immediately postoperative was 3.4° of kyphosis in the ALIF group and 3.1° of kyphosis in the PLIF group, which represented an 11% and 9% loss of lordosis, respectively.
Preliminary results indicate that there is a dramatically higher fusion rate in PLIF compared with ALIF procedures in which TCBDs are used. There is a corresponding trend seen in patient outcomes, but no distinct difference seems apparent in terms of restoration of lordosis when performing either procedure. The results suggest that TCBDs may best be used in PLIF procedures in conjunction with pedicle screws and rod constructs. Moreover, in patients in whom TCBDs and supplemental tension band constructs are used fusion rates appear to be comparable with those reported in other series but at a faster rate (94% at 7.9 months mean follow up). Longer follow-up periods and a larger series of patients are needed to confirm these preliminary observations.
Joseph T. Alexander, Charles L. Branch Jr., Brian R. Subach and Regis W. Haid Jr.
✓ Polyhydroxy acids are a promising class of resorbable materials with potential applications in spinal surgery. One such polymer, MacroPore (MacroPore Biosurgery, Inc.), offers a balance of strength, predictable degradation, lack of stimulus of foreign body reaction, and biocompatibility with neural tissue. MacroPore can be formed into an array of shapes and can be manufactured, sterilized, and stored using conventional techniques. Limited clinical experience has been gained with resorbable implants used as load-sharing devices in a posterior lumbar interbody fusion construct.