Adult idiopathic scoliosis treated by posterior spinal fusion and Harrington instrumentation

Ninety-one patients with idiopathic scoliosis, who underwent posterior spinal fusion and instrumentation from January 1977 to December 1982, were reviewed. All patients were 20 years or older at the time of surgery and none had undergone a prior surgical procedure. Indications for surgery included pain, progressive deformity, and pulmonary symptoms. All patients had a posterior spinal fusion with Harrington instrumentation and autogenous iliac bone graft, with the addition of segmental wiring in only eight. No patient had an anterior fusion or fusion to the sacrum. Follow-up averaged 3.5 years (range: 2-7 years). The average correction at the time of surgery was 38%, and 32% at the time of last follow-up. Seventy-nine percent of the patients reported complete relief of the symptom(s) for which they had surgery. There were 34 complications in 30 (33%) patients. Pseudarthrosis occurred in 14 (15%), requiring 15 additional procedures to achieve a solid arthrodesis. Urinary tract infection occurred in 8 (9%) patients and Harrington hook dislodgement in 5 (5%). One patient sustained a partial paraparesis with recovery to a minimal deficit. No deaths occurred. Although largely successful, posterior fusion with Harrington instrumentation for adult scoliosis has a significant incidence of pseudarthrosis and instrumentation problems.     

The Cotrel-Dubousset system--results in spinal reconstruction. Early experience in 47 patients.

Forty-seven patients were treated with spinal fusion and Cotrel-Dubousset instrumentation and were followed for an average of 28 months. Spinal procedures included: 1) posterior spinal fusion for idiopathic scoliosis (26 patients); 2) posterior pseudarthrosis repair (5 patients); 3) combined anterior/posterior fusion to the sacrum (6 patients); and 4) combined anterior/posterior osteotomies (10 patients). Group 1: Partial derotational correction was achieved for adolescent idiopathic scoliosis. Group 2: Successful pseudarthrosis repair was achieved in four patients. Group 3: A solid arthrodesis was obtained in two patients, whereas the other three patients underwent revision of sacral screw fixation for pseudarthrosis. One patient died postoperatively. Group 4: Pain relief and a balanced correction was achieved in all patients. The Cotrel-Dubousset system appears to be a versatile system and provides a wide range of possibilities for a variety of spinal problems.     

Subtotal corpectomy versus laminoplasty for multilevel cervical spondylotic myelopathy: a long-term follow-up study over 10 years.

STUDY DESIGN: A retrospective study was conducted. OBJECTIVE: To compare the long-term outcomes of subtotal corpectomy and laminoplasty for multilevel cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: No study has compared the long-term outcomes between subtotal corpectomy and laminoplasty for multilevel cervical spondylotic myelopathy. METHODS: In this study, 23 patients treated with subtotal corpectomy and 24 patients treated with laminoplasty were followed up for 10 to 14 years after surgery. Neurologic recovery, late deterioration, axial pain, radiographic results (degenerative changes at adjacent levels, alignment, and range of motion of the cervical spine), and surgical complications were compared between the two groups. RESULTS: No significant difference in neurologic recovery was found between the two groups 1 and 5 years after surgery, or at the latest follow-up assessment. Neurologic status deteriorated in one patient of the subtotal corpectomy group because of adjacent degeneration, and in one patient of the laminoplasty group because of hyperextension injury. Axial pain was observed in 15% of the corpectomy group and in 40% of the laminoplasty group (P < 0.05). In the corpectomy group, listhesis exceeding 2 mm developed at 38% of the upper adjacent levels, and osteophyte formation at 54% of the lower adjacent levels. In the laminoplasty group, kyphotic deformity developed in one patient (6%) after surgery. In the corpectomy group, the mean vertebral range of motion had decreased from 39.4 degrees to 19.2 degrees (49%) by the final follow-up assessment. In the laminoplasty group, the mean vertebral range of motion had decreased from 40.2 degrees to 11.6 degrees (29%) by the final follow-up assessment. Neurologic complications related to the surgery occurred in two patients (one myelopathy from bone graft dislodgement and one C5 root palsy from bone graft fracture) of the corpectomy group and four patients (C5 root palsy) of the laminoplasty group. All of these patients recovered over time. The corpectomy group needed longer operative time (P < 0.001) and tended to have more blood loss (P = 0.24). Six patients in the corpectomy group needed posterior interspinous wiring because of pseudarthrosis. CONCLUSIONS: Subtotal corpectomy and laminoplasty showed an identical effect from a surgical treatment for multilevel cervical spondylotic myelopathy. These neurologic recoveries usually last more than 10 years. In the subtotal corpectomy group, the disadvantages were longer surgical time, more blood loss, and pseudarthrosis. In the laminoplasty group, axial pain occurred frequently, and the range of motion was reduced severely.     

Use of allograft bone for posterior spinal fusion in idiopathic scoliosis

Eighty-seven adolescents with idiopathic scoliosis (77 female and 10 male patients) who underwent posterior spinal fusion with instrumentation using only allograft bone for graft material were evaluated retrospectively. The average age at surgery was 14 years 3 months. Each patient had a minimum 2-year followup, with an average of 3 years 5 months followup. The average preoperative curve was 59 degrees thoracic (range, 31 degrees-90 degrees) and 52 degrees lumbar (range, 21 degrees-65 degrees). At followup, the thoracic curve measured an average of 35 degrees and the lumbar curve measured an average of 34 degrees. The average loss of correction from the immediate postoperative period until last followup was 6.5 degrees or 11% in the thoracic curve and 10 degrees or 19% in the lumbar curve. There were seven reoperations; one of these reoperations involved repair of a pseudarthrosis. There was one clinical infection. The typical patient had a 2-ounce allograft at an average cost of $800. The patients' average loss of correction, complication rate, and reoperation rate compare favorably with results reported in other series using autograft bone. The authors of this study showed the ability of allograft bone to produce reliable results with a satisfactory outcome. The potential advantages of using allograft must be weighed against the potential disadvantages before recommending its routine use.     

Combined anterior and posterior surgeries in the treatment of spinal tuberculous spondylitis

Methods for the treatment of tuberculous spondylitis still are controversial. The authors treated 32 consecutive patients with a two-stage surgical technique combined with antituberculous chemotherapy for 1 year. After anterior debridement, fusion with autogenous anterior iliac tricortical strut bone graft was done, and in a second stage, posterior instrumentation and fusion with autogenous posterior iliac corticocancellous bone graft was done 11 days (range, 4-22 days) later. Postoperatively, patients were encouraged to ambulate with brace protection as early as possible. Twenty-nine patients were followed up for a minimum of 2 years (median, 4.7 years; range, 2-10 years) of whom 28 patients achieved solid fusion (97%). All patients had improvement of back pain including the only patient with pseudarthrosis. Neurologic deficits completely recovered in 84% (16 of 19) of patients after 3 months. Kyphotic deformity improved in all 29 patients (34.6 degrees versus 17.3 degrees ) with the average correction angle of 17.3 degrees. Clinically, 27 patients had achieved a satisfactory outcome (93%). There were no evident surgical complications. The authors, therefore, recommend a two-stage surgical technique combined with antituberculous chemotherapy to treat patients with severe vertebral body destruction attributable to tuberculosis because of its high success rate and a low complication rate.     

Combined anterior and posterior fusion for spinal deformity in myelomeningocele

Since 1973, 50 of 54 children have been treated by the author with a combined anterior and posterior fusion. Twenty males and 34 females, ranging in age from 1 to 16 years, have been followed for a mean period of 5.5 years. Sixteen patients with a kyphosis averaging 113 degrees (range, 77 to 170 degrees) had correction of deformity to a mean of 35 degrees. Thirty-seven patients with a scoliosis averaging 73 degrees (range, 20 to 135 degrees) had correction to an average of 34 degrees (range, 0 to 75 degrees). There were 4 cases of deep wound infection successfully treated with drainage and antibiotics and only one case required implant removal after fusion/maturation. A pseudarthrosis was noted by radiograph in 6 patients, 3 of whom had isolated asymptomatic lumbosacral pseudarthroses. Three patients had pseudarthrosis at the thoracolumbar junction. These required repair and were successfully treated by supplemental posterior fusion resulting in an overall pseudarthrosis rate of 5.7%. Anterior fusion of the dysraphic spine allows greater correction of both spinal deformity and pelvic obliquity in addition to contributing significant strength to the fusion mass. Segmental spinal instrumentation with sublaminar and pedicular wiring to custom-contoured Luque rods provides excellent correction and immediate postoperative stability.     

Posterior cervical fusion failure in three morbidly obese patients following circumferential surgery

BACKGROUND: The stability of multilevel anterior corpectomy with fusion (ACF) is often enhanced by simultaneous posterior fusion (PF) which provides a "posterior tension band." Three morbidly obese patients undergoing circumferential surgery had posterior fusions performed without autogenous iliac crest graft to avoid donor site morbidity. METHODS: Three morbidly obese patients (300-350 lbs.), averaging 48 years of age, presented with rapidly progressive moderate/severe myelopathies. Magnetic resonance imaging (MRI) and computed tomography (CT) studies demonstrated severe ventral ossification of the posterior longitudinal ligament. Two to four level plated ACFs were performed utilizing fibula strut allograft and plates. Posterior spinous process wiring/fusion from C2-T1 were completed with braided titanium cables, fibula strut allografts, Inductive Conductive Matrix (a form of demineralized bone matrix), and allograft bone to avoid iliac crest donor site morbidity in such morbidly obese patients. Halo devices were utilized until fusion was documented on postoperative X-ray and 2D-CT studies subsequently obtained 3, 6, and up to 12 months postoperatively. Patients were followed an average of 3 years. RESULTS: Postoperatively, all 3 patients demonstrated mild residual myelopathy (Nurick Grade 0-I). Nevertheless, all 3 exhibited posterior pseudarthroses accompanied by anterior strut/plate extrusion (1 patient), partial anterior graft pseudarthrosis (1 patient), and a delayed strut fracture (1 patient). The first 2 patients required secondary posterior fusions performed with autogenous iliac crest graft, while the third fused with 6 months of additional bracing. CONCLUSIONS: Following circumferential cervical procedures, posterior fusions failed in 3 morbidly obese patients where iliac crest autograft was omitted in an attempt to avoid donor site morbidity.     

Shear fracture-dislocations of the thoracic and lumbar spine associated with forceful hyperextension (lumberjack paraplegia).

Twelve patients sustained a shear fracture-dislocation of their thoracic or lumbar spines by a hyperextension mechanism of injury. Ten male and two female patients were injured; their average age was 29 years (range, 22 months to 56 years). Ten fracture-dislocations occurred in the thoracic spine, one at the thoracolumbar junction, and one in the lumbar spine. Eleven patients had complete paraplegia, and one had incomplete paraplegia at the time of injury. Dural tears were found in six of the patients. Eleven patients were treated by posterior spinal fusion with instrumentation, and one was treated with a brace. Three patients were treated with Harrington distraction rods alone, six had Harrington distraction rods supplemented with a midline Harrington compression rod or interspinous wiring, and two were treated with Cotrel-Dubousset instrumentation. No patient was lost to follow-up. The average length of follow-up was 3.5 years (range, 1-9 years). Six of the patients treated with Cotrel-Dubousset instrumentation or Harrington distraction rods supplemented with either a midline compression rod or interspinous wiring healed anatomically; two patients developed pseudarthroses. None of the patients treated with Harrington distraction rods alone healed in an anatomic position. The use of Harrington distraction rods alone was associated with overdistraction and nonanatomic alignment of the spine. The disruption of the anterior stabilizing structures of the spine associated with hyperextension injuries necessitates the use of instrumentation that can stabilize the spine and prevent overdistraction. This injury can be successfully treated with Cotrel-Dubousset or Harrington distraction rods supplemented with either a midline compression rod or interspinous wiring.     

A biomechanical evaluation of cervical spinal stabilization methods in a bovine model. Static and cyclical loading

A bovine model was developed for biomechanical evaluation of surgical procedures stabilizing traumatic cervical injuries disrupting the anterior and posterior spinal column. Cervical spinal segments and C4-5 functional spinal units were tested statically, and C4-5 functional spinal units were tested cyclically in evaluation of 1) the intact cervical spine, 2) Rogers' wiring method, 3) Bohlman's triple-wire technique, 4) sublaminar wiring, 5) anterior cervical plate instrumentation, and 6) posterior hook plate stabilization. Anterior cervical plate instrumentation proved inadequate, and was the least rigid, with axial and flexural loading (P less than 0.05). There was no significant difference between each of the three posterior wiring methods, and all generally restored stability to equal that of the uninjured intact cervical spine. Posterior hook plating with an interspinous bone graft serving as an extension block was the most effective method in reducing flexural stress across the injured C4-5 segment (P less than 0.05). Cyclical in vitro testing was the most sensitive method in highlighting mechanical differences between instrumentation systems, particularly with "on-line" continuous measurement of anterior and posterior strains. Anterior cervical plate stabilization does not appear to confer enough stability in cervical facet injuries to obviate the need for posterior cervical stabilization procedures. The recently developed posterior hook plate technique offers biomechanical advantages that should be weighed against the greater technical precision needed for insertion and the increased potential for neurologic and vascular complications.     

Ossification of the posterior longitudinal ligament. Results of anterior cervical decompression and arthrodesis in sixty-one North American patients

BACKGROUND: Ossification of the posterior longitudinal ligament is commonly associated with cervical myelopathy. Surgical treatment is a matter of controversy. We report on a series of patients who were managed with anterior cervical decompression and arthrodesis for the treatment of cervical myelopathy associated with ossification of the posterior longitudinal ligament. METHODS: We retrospectively reviewed the records for all sixty-five patients who had been managed with anterior decompression and arthrodesis for the treatment of cervical ossification of the posterior longitudinal ligament and associated neurologic compression from 1982 to 2001. Sixty-one patients (thirty-nine men and twenty-two women) were followed for at least two years (or until the time of death). The average number of vertebrae resected was 2.2. The average duration of follow-up for the sixty surviving patients was four years (range, two years to fifteen years and four months). The preoperative, six-week postoperative, and final follow-up clinical status (including neurological function as assessed with the Nurick grading system) was recorded for each patient. RESULTS: Fifty-six of the sixty-one patients had neurological improvement, with an average improvement of 1.5 Nurick grades at the time of the final follow-up. Eight patients had absent dura at the time of surgery and, of these, five had development of a cerebrospinal fluid fistula. Eight patients had development of new neurological signs and/or symptoms in the upper extremity postoperatively. Eight patients required reoperation because of a painful pseudarthrosis (one patient), strut-graft dislodgment (three), cerebrospinal fluid leakage (three), or compression of a nerve root caudad to the area of the original procedure (one). One patient died as the result of cardiac arrest on the third postoperative day. Fifty-eight patients had an osseous fusion, one had an asymptomatic nonunion, and one had a symptomatic pseudarthrosis that was treated with revision surgery. CONCLUSIONS: Anterior decompression and arthrodesis is an effective way to achieve pain relief and neurological improvement in North American patients of non-Asian descent who have cervical myelopathy associated with ossification of the posterior longitudinal ligament. The risk of durocutaneous fistula, graft dislodgment, and postoperative neurological symptoms appears to be high in patients with cervical myelopathy associated with this condition.     

Interspinous wiring without bone grafting for nonunion or delayed union following anterior spinal fusion of the cervical spine

Nine patients who had unsuccessful anterior interbody fusion or subtotal spondylectomy and fusion for cervical spondylosis were treated by interspinous wiring without bone grafting. Bone union was confirmed during a mean postoperative period of 2 years and 2 months in seven patients by the disappearance of clear zones observed preoperatively in the disc space, and by continuity of the trabeculae in radiograms. One of the two patients in whom the procedure failed to unite the site of nonunion had received technically inadequate wiring with slight mobility at the wiring site; in the other patient, the grafted bone had collapsed and no sclerotic shadow of the nonunion site was seen at the time of surgery. Both patients underwent wiring after considerable intervals from the time of the initial anterior spinal fusion. We found that satisfactory bone union can be obtained for nonunion or delayed union following anterior cervical spinal fusion by interspinous wiring without further bone grafting if applied to properly selected patients.     

Vascularized bone grafts for congenital pseudarthrosis of the tibia

Eight vascularized fibula grafts and two vascularized rib grafts were used for the treatment of 10 Boyd's Type II congenital pseudarthrosis of the tibia. All but one vascularized fibula graft united within 4 months. The two vascularized rib grafts did not unite until receiving a conventional bone graft. Nine spontaneous fractures were seen in four patients; all were subsequently treated successfully with cast or conventional bone graft. Corrective osteotomies were done in two patients. Follow-up averaged 8 years and 5 months (range, 5 years and 1 month to 14 years and 4 months). Average age at end of follow-up was 13 years and 6 months (range, 7 years and 10 months to 20 years and 4 months). After bony union was achieved, shortening of the affected leg averaged 3.8 centimeters, flexion deformity averaged 20 degrees, and valgus deformity averaged 24 degrees. In three patients, whose leg discrepancy averaged 4.9 centimeters, the leg was lengthened at an average patient age of 13 years and 9 months (age range, 11 years and 7 months to 15 years and 2 months). The resulting limb length discrepancy averaged 2.2 centimeters. Vascularized bone grafting is a reliable technique for achieving bony union in congenital pseudarthrosis of the tibia. Residual shortening may be corrected later by limb lengthening. © 1997 Wiley-Liss, Inc. MICROSURGERY 17;459–469 1996     

Treatment of severe spondylolisthesis by anterior and posterior reduction and stabilization. A long-term follow-up study

Twenty-two consecutive unselected patients who had severe spondylolisthesis were treated by a first-stage posterior decompression (Gill procedure) and a posterolateral arthrodesis, followed by halo-skeletal traction, and then by a second-stage anterior interbody arthrodesis, followed by immobilization in a cast. Nineteen patients had complete clinical and radiographic evaluation, with an average follow-up of five years (range, two to seven and one-half years). The slip angle averaged 71 degrees preoperatively, was corrected to an average of 31 degrees by reduction, and averaged 28 degrees at follow-up. The average preoperative percentage of slippage (98 per cent) did not change substantially. A pseudarthrosis developed in four patients, all of whom had a reoperation. The neurological deficits that had been present in ten patients preoperatively had completely resolved in all but one at follow-up. One patient had a cauda equina syndrome and two patients had a neuropathy of the root of the fifth lumbar nerve as a result of the reduction; complete recovery occurred in two patients and partial recovery, in one. Alignment in the sagittal plane was restored in seventeen patients, and the back pain and radicular symptoms were relieved in all patients except one who had had those symptoms preoperatively.     

Video-assisted ALIF with cage and anterior plate fixation for L5-S1 spondylolisthesis

INTRODUCTION: Spondylolysis and spondylolisthesis grade 0, 1, and 2 are mainly asymptomatic but with aging process and different factors some back pain can occur and lead to chronic low back pain. The conservative treatment with physiotherapy and steroid injection is the gold standard but in some cases is not efficient enough and a surgical treatment is proposed. OBJECTIVES: The goal of this study is to propose a new technique to treat grade 0, 1, and 2 spondylolisthesis with an anterior video-assisted fusion and stabilization. METHODS: Twenty patients with chronic low back pain since more than 2 years and resistant to conservative therapy were included in this protocol. Clinical signs and radicular pain were noted. They were evaluated preoperatively and postoperatively until the last follow up using Oswestry score and visual analog score (VAS) for leg and back pain. X-rays showed grade 0 (8 cases), 1 (10 cases), and 2 (2 cases) spondylolisthesis according to Meyerding classification with disc collapse (bulging disc). MRI showed in all cases a disc degeneration with at least black disc and/or endplates changes with Modic I or II. All patients were operated using an anterior video-assisted retroperitoneal approach, with discectomy and fusion using an anterior impacted cage filled with autologous cancellous bone from the iliac crest and an anterior fixation with a triangular plate (Pyramid, Medtronic, Memphis). The follow up at 3, 6, 12, and 24 months was done with clinical and radiologic evaluation. In case of problem a computed tomography scan was performed. RESULTS: There were 11 women and 9 men, with and average age of 39 years old and a BMI of 25.6. All spondylolistheses occurred at level L5. The average slippage was 19%. All L5S1 discs were black, 8 had a Modic I changes in the endplates and 2 had Modic II. The shape of L5 vertebra was abnormal (trapezoidal) in 7 cases. All anterior approaches were performed without vascular, urologic, or digestive complication. Blood loss was inferior to 100 mL. All patients had a soft brace for 8 weeks postoperatively. There was no retrograde ejaculation for the 9 men and no sexual dysfunction reported by the women. One patient had no pain relief and was reoperated for posterior pedicular screw fixation. It was obvious that there was a pseudarthrosis even after the posterior fixation and an anterior transperitoneal revision was performed with the removal of the interbody device and iliac crest bone graft packing alone. A propioni bacterium acnes germ was found responsible for the anterior nonunion. This revision surgery with antibiotics treatment was successful. One of the patients with grade 2 had an additional posterior screw fixation with a minimally invasive pedicle screw system (Sextant, Medtronic, Memphis). Nineteen patients had a good fusion at 2 years follow-up (95%), mean Oswestry score improved from 74% preoperative to 21% postoperative at the last follow-up. Visual analog score (VAS) for back pain improved from 6.5 to 2.7 and VAS for leg pain improved from 6.2 to 3.4. Satisfaction rate was 90%. All active patients except two, were back to work at an average of 5.5 months (6 wk to 1 y). The 2 patients still not working were the nonunion and a work compensation. CONCLUSIONS: The results of this technique compare favorably with posterior stabilization and fusion (posterior lumbar interbody fusion and postero-lateral fusion) reported in the literature. Unlike posterior lumbar interbody fusion, however, it seems that the complication rate due to the approach is much lower, the fusion rate is similar. Grade 2 SPL is the limitation of the technique. The main advantage of the technique is to avoid posterior muscle damage and a quick recovery with no blood loss. Preservation of adjacent level disease can be assessed only after long-term follow-up.     

Pseudarthrosis after spinal fusion for scoliosis. A comparison of autogeneic and allogeneic bone grafts

This study was undertaken to compare the incidence of pseudarthrosis in fusions supplemented with autogeneic and frozen allogeneic grafts. The records of 208 patients with adolescent idiopathic scoliosis who were treated by posterior fusion and Harrington instrumentation were studied. The fusion was supplemented by an autogeneic iliac bone graft in 114 patients and by an allogeneic bank bone graft in 94 patients. The fusion mass was explored in all patients with suspected pseudarthrosis; therefore, all pseudarthroses reported in this series were proved by surgical exploration. Pseudarthrosis developed in five patients (4.4%) receiving an autogeneic graft and in five patients (5.3%) receiving an allogeneic graft. The incidence of pseudarthrosis was not significantly different at the 95% level of certainty. Average blood loss and operative time were determined for all patients. The decreases in average blood loss and operative time in those patients receiving allogeneic grafts were significant (p less than .01). Thus, based on the incidence of pseudarthrosis, allogeneic frozen bank-stored bone is an attractive alternative to autogeneic iliac bone for fusion supplementation in the treatment of scoliosis. Total operative time and blood loss can be decreased, and possible complications associated with a donor site can be avoided.     

Reoperation rates for acute graft extrusion and pseudarthrosis after one-level anterior corpectomy and fusion with and without plate instrumentation: etiology and corrective management

BACKGROUND: Reoperation rates after one-level anterior cervical corpectomy with fusion (ACF) performed without and with plates need further evaluation. METHODS: Reoperation rates for graft extrusion and symptomatic pseudarthrosis were analyzed following 48 nonplated (1989-1996) and 35 plated (1997-2000) one-level ACF. Preoperatively, patients typically exhibited mild/moderate myelopathy attributed to spondylostenosis and ossification of the posterior longitudinal ligament (OPLL). Thirty-five ACF were performed with plates: 3 Orion, 12 Atlantis, and 20 ABC Aesculap plates. Fusion was documented on both dynamic X-rays and 2- or 3-dimensional CT studies 3 and 6 months postoperatively, or until fusion occurred. Follow-up averaged 82 months for the nonplated patients, and 21 months for the plated patients. RESULTS: Out of 48 nonplated patients, 3 developed immediate graft extrusions within 24 hours of surgery requiring graft replacement. Another 2 exhibited symptomatic pseudarthrosis 6 months postoperatively, and required secondary posterior wiring with fusion (PWF). In comparison, 1 of the 35 patients with plated one-level ACF developed plate displacement 6 weeks postoperatively, while 3 exhibited symptomatic pseudarthrosis 6 months after surgery, and required secondary posterior wiring and fusion (PWF). CONCLUSIONS: Comparison of one-level ACF performed with and without plates showed that plating did not appear to reduce pseudarthrosis or graft extrusion rates.     

Three- and four-level anterior cervical discectomy and fusion with plate fixation: a prospective study

STUDY DESIGN: A prospective study of 15 patients who underwent modified Smith-Robinson anterior cervical discectomy and fusion at three or four operative levels stabilized with an unicortical anterior plate. OBJECTIVES: To provide medium-term follow-up data on the surgical success and patient outcome of three- and four-level anterior cervical discectomies and fusions and to determine the effect that plate fixation has on the results. SUMMARY OF BACKGROUND DATA: The success of arthrodesis for anterior cervical fusion depends on several factors, including the number of surgical levels. The arthrodesis rate and outcome for patients having three- and four-level discectomy and fusion procedures is disappointing. Internal fixation putatively improves these parameters. METHODS: Fifteen patients (average age, 51 years; range, 35-77), were observed for an average of 42 months (range, 25-73) All had an anterior discectomy, burring of the endplates, placement of an autogenous tricortical iliac crest graft at three (12 patients) or four (3 patients) levels, and application of a Cervical Spine Locking Plate. All patients had follow-up office visits with examinations and radiographs. Radiographic union, postoperative pain relief, and neurologic recovery were evaluated. RESULTS: Solid arthrodesis was achieved at all levels in only 7 (47%) of the 15 patients after a single procedure. Of the 8 patients with pseudarthrosis, 3 had sufficient pain to necessitate revision surgery (with pain relief in two), 1 had pain without further surgery, and 4 no pain. Of the 7 with solid fusion, 3 had persistent pain, and 4 had none. Two in this group had a second procedure. All 4 patients with preoperative myelopathy improved, and 10 of the 11 with radiculopathy had resolution of arm symptoms. CONCLUSIONS: Three- and four-level modified Robinson cervical discectomy and fusion results in an unacceptably high rate of pseudarthrosis. The Cervical Spine Locking Plate alone does not appear to improve the arthrodesis rate.     

Anterior and posterior spinal fusion for paralytic scoliosis

Twenty-three patients with paralytic scoliosis were treated with a combination of anterior and posterior spinal instrumentation and fusion. The sequence was anterior surgery first in 19 patients and posterior surgery first in 4. The average age was 14.4 years. Preoperative correction with a halo-hoop apparatus was performed in 12 patients. The average preoperative curve for the group measured 100 degrees, and the average postoperative curve at a mean follow-up time of 21 months was 37 degrees. The mean loss of correction was 8 degrees. Although superior hook dislodgment occurred in 5 patients, no pseudarthrosis or beinding of the fusion mass was documented.     

The value of anterior cervical plating in preventing vertebral fracture and graft extrusion after multilevel anterior cervical corpectomy with posterior wiring and fusion: indications, results, and complications

Anterior cervical plates were added to anterior corpectomy and fusion (ACF) with posterior wiring and fusion (PWF) to prevent vertebral fracture and graft extrusion in patients with ossification of the posterior longitudinal ligament and spondylostenosis. From January 1989 to March 1997, 22 patients had an average 2.5-level ACF without plates and an average 5-level PWF with halo placement (average follow-up, 4 years). From April 1997 to October 1998, 22 patients had an average 2.8-level ACF with Orion plating and an average 5.4-level PWF with halo devices (patients were followed for an average of 11 months). Vertebral fracture and graft extrusion requiring revision developed in three (14%) patients without plates within 24 hours of surgery, whereas neither of these occurred in patients with plates (by Fisher's test: nonsignificant p value = 0.2326). Ultimately, all 44 patients had fusion. Thus far, vertebral fractures and graft extrusions have not been observed for 22 patients undergoing plated circumferential cervical surgery.     

Autogenic versus allogenic bone grafts in anterior lumbar interbody fusion

Between 1987 and 1993, 94 consecutive patients with painful spondylolisthesis underwent combined anterior and posterior fusion. The average age at operation was 40 years (range, 16-65 years). Posterior fusion was performed in all patients using pedicle screw systems, and anterior fusion was accomplished with autogenic or allogenic bone grafts. Patients retrospectively were assigned to two groups. In Group 1, anterior fusion was performed with autogenic bone grafts harvested from the iliac crest (n = 65; 146 segments) and in Group 2 allogenic bone grafts were taken from femoral heads (n = 39; 86 segments). The incidence of pseudarthrosis was evaluated on lateral tomograms 24 months after surgery. The mean clinical followup time was 4 years (range, 3-8 years). Pseudarthrosis was found in seven fused levels (3%) managed with autogenic bone grafts (Group 1) and in seven patients (8%) managed with allogenic bone grafts (Group 2). This incidence of pseudarthrosis was not significantly different between the two groups. Considering the possible complications associated with harvesting iliac crest bone, the use of allogenic bone appears justified.