Henry Larocca

Fusion rates in multilevel cervical spondylosis comparing allograft fibula with autograft fibula in 126 patients

Surgical fusion results are presented from a retrospective study of 126 consecutive multilevel discectomy and vertebrectomy cases for spondylosis to evaluate fusion rates using autograft and allograft fibula strut graft for reconstruction. The nonunion rate was high in both groups: 27% of the autograft group and 41% of the allograft group. The nonunion rate increased with increasing numbers of motion segments fused. Age and sex were not significant factors.

Postoperative infections in spinal implants : classification and analysis : a multicenter study

A multicenter study was undertaken to analyze postoperative wound infections after posterior spinal instrumentation and fusion. The infection rate of these procedures has been documented in multiple reports. From these results, a classification scheme was developed that can guide therapy and determine the populations at risk. The patients were categorized according to two parameters, the first being the severity or type of infection, and the second being the host response or physiologic classification of the patient. This classification scheme is based on the clinical staging system for adult osteomyelitis developed by Cierny. The severity of infection is divided into three groups. Group 1 is a single-organism infection, either superficial or deep. Group 2 is a multiple-organism, deep infection. Group 3 is multiple organisms with myonecrosis. The host response, likewise, is divided into three classes. Class A is a host with normal systemic defenses, metabolic capabilities, and vascularity. Class B patients demonstrate local or multiple systemic diseases, including cigarette smoking. Class C requires an immunocompromised or severely malnourished host. Our data have demonstrated that single organisms, Group 1, generally can be dealt with by single irrigation and debridement, and closure over suction drainage tubes without the use of an inflow-irrigation system. The Group 2 patients, with multiple organisms and deep infection, required an average of three irrigation debridements. They have a higher percentage of successful closures with closed inflow-outflow suction irrigation systems when compared to simple suction drainage systems without constant inflow irrigation. Multiple- organism infections with myonecrosis, Group 3, are ex@ceedingly difficult to manage, and portend a poor outcome. Patients without normal host defenses, Classes B and C, are at high risk for developing postop@erative wound infection. Specifically, this study demon@strated that cigarette smoking may be a significant risk factor.

The developmental segmental sagittal diameter of the cervical spinal canal in patients with cervical spondylosis.

The role of the narrow cervical spinal canal in the expression of clinical syndromes in the cervical spine was investigated in a retrospective review of 63 patients with symptomatic cervical spondylosis refractory to conservative therapy. The measurement of the developmental segmental sagittal diameter, determined at the level of the pedicle, and of the spondylotic segmental sagittal diameter, determined at the level of the disc, were applied. When divided into, groups based on anatomic variance around an average size midcervical diameter of 17 mm, 40 patients were found to have less than the average size of midcervical canal. A spondylosis index was computed for the narrow canal group at 2.08 mm per segment and for the wide canal group at 3.29. Canal dimensions are determinants of symptom production and neurologic compromise.

Repeat Lumbar Surgery: A Review of Patients With Failure from Previous Lumbar Surgery Treated by Spinal Canal Exploration and Lumbar Spinal Fusion

Thirty-six patients with chronic back and/or leg pain following previous lumbar surgery who underwent both spinal canal exploration and spinal fusion were subjected to retrospective review. The purpose was to determine the probability of success for this surgical approach. Twenty (56%) of the 36 patients had a satisfactory result. In 15 patients with multiple objective findings of an ongoing radiculopathy, 11 (73%) improved. Only nine (43%) of 21 patients improved if these preoperative criteria were absent. Analysis according to the type of surgery performed in the spinal canal demonstrated improvement in (a) 17 (74%) of 23 patients who had wide bony decompression, (b) eight (61%) of 12 patients who had discectomy, and (c) seven (47%) of 15 patients who had an extensive neurolysis. In 17 patients whose time interval between the previous operation and present reconstruction was greater than 18 months, 13 (76%) improved. Only seven (36%) of 19 patients with a shorter time interval improved. The presence of pseudarthrosis was a poor indication for repeat lumbar surgery. The number of previous lumbar surgeries may not necessarily preclude a satisfactory outcome. Solid fusion correlated highly with a satisfactory outcome. Best results are obtained when objective preoperative findings indicate the presence of a surgically correctable abnormality.

Fibular Strut Graft in Reconstructive Surgery of the Cervical Spine

The procedures for operative treatment of cervical spinal disease and injury have proven to be technically simple and to have a low incidence of postoperative morbidity. There are occasional technical difficulties, however, which have been encountered during these procedures, one of the most common being graft failure for a variety of reasons. Work currently being done on the efficacy of a technique to circumvent graft failure is reported here. Segments of fibula have been used to secure stability and arthrodesis in the management of 26 patients with disease or injury of the cervical spine. Surgical objectives have been uniformly achieved in 19 patients with proper selection and adequate followup. Early technical problems are described.

Reconstruction of the lumbar spine using AO DCP plate internal fixation.

Augmentation of lumbar spine fusion with internal fixation using pedicle screw systems has gained wide currency because it offers rigid stabilization to foster fusion healing. The AO DCP plate has been employed in Europe as a spinal implant with pedicle fixation using 6.5 mm, full-threaded cancellous bone screws with success. This report details the experience of using this device for lumbar spine fusion in a series of 46 North American patients with a mean follow-up of 1.25 years (range 1-2.5 years). Thirty-one patients had had prior lumbar spine surgery with poor outcomes, and 15 had had no prior surgery. All were treated surgically for lumbar degenerative disease with canal decompression, internal fixation with AO plates, and fusion with autologous bone grafting posterolaterally. Complications included two early and one delayed wound infection; five cases of screw loosening; three cases of screw breakage; and three cases of screw impingement upon a nerve. Results of surgery in 17 patients with failed interbody fusion included good to excellent pain relief in 59%, and solid fusion in 76%. In 14 patients with failed posterior surgery the good to excellent pain relief rate was 79% and the fusion rate was 86%. In 15 patients undergoing primary surgery there was 89% good to excellent pain relief and a solid fusion rate of 87%. The benefits accruing from augmentation of the fusion with internal fixation using AO DCP plates are positive and justify its continued use. Complications encountered in the early experience have been significantly reduced in subsequent series, indicating the existence of a “learning curve” effect which would mandate specific training of spinal surgeons in the technique.

Reconstruction of failed lumbar surgery with narrow AO DCP plates for spinal arthrodesis.

Forty-five patients underwent surgical reconstruction with transpedicular fixation of the lumbar spine with narrow AO DCP plates. Preoperatively, all patients underwent spinal imaging with either magnetic resonance imaging, computed tomography, or myelogram as well as provocative discography to determine the location and the number of symptomatic segments. The minimum follow-up in this series was 2 years. The determination of solid posterior fusion in the presence of plate instrumentation was difficult. The patients in the series were classified as having 1) solid fusion; 2) radiographic flaws within the posterolateral fusion without implant failure; or 3) frank pseudarthrosis with implant failure. Thirty-six (80%) of the patients had a solid fusion, 9 of whom required an additional anterior interbody fusion to obtain symptom control. Twenty percent of the patients in the series had radiographic evidence of reabsorption without implant failure. Four patients in the series (8.8%) had screw breakage, three of which required anterior interbody fusions. The highest rate of reabsorption and pseudarthrosis implant failure was in the 12 patients who had three-level instrumentation; 33% of these patients required anterior interbody fusion to obtain a solid arthrodesis. The average preoperative pain scale was 8.9, and the average postoperative pain scale was a 3.3. Twenty-two patients in the series were cigarette smokers and had a slightly lower fusion rate than non-smokers. They did, however, have a higher use of narcotics after surgery. Fourty percent of the patients in this series continued to have radiculopathy after their reconstruction. This study demonstrates the utility of transpedicular fixation in salvage lumbar surgery in obtaining a solid arthrodesis with a beneficial clinical result. Anterior interbody fusions are highly successful in the management of pseudarthrosis and implant failure after transpedicular instrumentation.

A Taxonomy of Chronic Pain Syndromes: 1991 Presidential Address, Cervical Spine Research Society Annual Meeting, December 5, 1991

This article has had as its purpose the delineation of the complexity of the production of pain on an organic basis as opposed to any psychological amplification. The issues addressed apply directly to the problem of spinal pain. Classical nociception arising in the structures of the spine thus would include the application of mechanical and chemical stimuli to muscles, ligaments, apophyseal joint capsules, bone, and other structures with adequate innervation, particularly the anterior dura and its extensions. Disease and injury productive of direct nociception are well understood sources of spinal pain. Less well understood, but of at least equal importance in the spinal pain problem, are the activities within the central nervous system that control the transfer of nociceptive information to the higher centers. These activities account for some of the variability known to occur in the experience of pain. Further, the fact that the nervous system changes its activities in response to chronic pain, particularly that arising from damaged neural elements, is of paramount importance in understanding how chronic pain syndromes differ so greatly from simple nociceptive events. Insidious deafferentation ongoing in spinal nerve roots subject to chronic compression and fibrosis offers a fertile field for research into the origin of permanent pain in patients in whom application of accepted therapies does not result in relief. All of this material must be considered by the clinician who is challenged with analyzing spinal pain problems in patients.