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A case of congenital pseudarthrosis of the clavicle is presented. Congenital pseudarthrosis of the clavicle is a rare entity that has poorly been documented in the pediatric literature. The etiology and pathogenesis still remain obscure. The clinical and radiological appearances are characteristic. Differential diagnosis lies between postpartum fracture, posttraumatic pseudarthrosis, cleidocranial dysostosis and neurofibromatosis.
The electrodynamic field treatment, its method and fundamentals in the therapy of infected, atrophic pseudarthrosis are described. In addition to the common principles of treatment, particularly the transplantation of autologous spongious bone is of great importance. The bone graft reestablishes normal electrical conduction within the pseudarthrosis and as a reactive receptor for the applied a.c.-potentials consolidates the defect. Up to now in 8 years of employing this method 271 patients, suffering from pseudarthroses have been treated, 91 of them had an infected, often atrophic pseudarthrosis. In each group in 92% of the cases bony healing could be achieved. Some case reports demonstrate clinic and therapy.
When treating fractures, whether by closed or open technique, the event of a pseudarthrosis is always a threatening complication. Absolute immobilization of the fracture site and tissue viability are the two essential conditions to obtain ossification of a pseudarthrosis. Consequently, after a reasonable period of conservative therapy, consolidation can best be obtained by osteosynthesis associated with decortication and/or cancellous bone grafting. The application of the two biomechanical laws is demonstrated in our series of 32 cases with pseudarthrosis.
In a series of 280 high tibial osteotomies performed for osteoarthritis of the knee between 1969 and 1975, there were ten cases of pseudarthrosis, an incidence of 3.6 per cent. These ten knees (and an additional two that were referred to us) were reoperated on. In most cases the pseudarthrosis was resected and stabilized with the Charnley transfixation-compression method. Other procedures involved resection without compression (one knee), compression blade-plate fixation, and arthroplasty with a hinge endoprosthesis. All osteotomies healed eventually with the knee in satisfactory position. In spite of the initial non-union and repeated operation, all twelve patients eventually had satisfactory correction of the preosteotomy deformity, and none had a loss in walking ability. All but two patients had freedom from pain. We concluded that patients with non-union following high tibial osteotomy for osteoarthritis of the knee should undergo resection of the pseudarthrosis and transfixation compression as the treatment of choice. Endoprosthetic replacement then can be used as a salvage procedure if it is needed.
In the treatment of pseudarthrosis with only a segmental loss of bone elements a reconstruction by the Ilizarov method is too complicated, and simple decortication and plastic surgery with cancellous bone grafting is usually too slow. With reference to three cases, it is shown that simultaneous debridement and bone reaming can improve clearance of the infection. Using decortication and autologous cancellous bone grafting, it is possible to leave the center of the bone free by temporarily inserting a silicon tube. As a result cancellous bone can be saved and the danger of a relapse will be minor. In two cases this technique with the central silicon tube was applied for the first time within the scope of plastic surgery with cancellous bone. If, as in the third case, there is enough bone substance in the region of the pseudarthrosis with swelling of the soft tissue or fistulation, in selected cases reaming of the bone cavity and decortication are all that is necessary. The average length of follow up was 19 months. Only in one of our cases did local inflammation recur 9 months after clearance, which healed rapidly with conservative procedures. The other patients had no episodes of this nature. In our group, the patients achieved full weight-bearing on their leg without external support in an average of 5 months. Compared with another study conducted in Liestal, in which a similar group (infected pseudarthrosis with bone defects of 4-11 cm) was treated by the Ilizarov technique, shortening of the treatment by an average of 4 months was obtained.(ABSTRACT TRUNCATED AT 250 WORDS)
STUDY DESIGN: The authors prospectively evaluated 40 patients with paralytic scoliosis treated from 1985 to 1990 with bilateral posterior segmental instrumentation, facet fusions, local bone graft, and allograft (mostly fresh frozen) bone supplementation only. OBJECTIVES: The authors report the fusion results for these patients, and any complications referable to the use of bank bone. SUMMARY OF BACKGROUND DATA: Acceptable correction was obtained and maintained in the coronal and sagittal planes for all but two patients (the third patient with a pseudarthrosis had not lost correction). The definite pseudarthrosis rate was 7.5%. One patient had a deep wound infection. METHODS: The radiographs were graded as definitely solid, definitely a pseudarthrosis, or no instrumentation failure but difficult to visualize the whole fusion mass. The patients selected for fusion without autogenous harvesting were especially frail and had reduced pulmonary and nutritional reserve. Follow-up ranged from 2 + 2 years to 7 + 6 years, with an average of 3 + 9 years. RESULTS: In the 40 surgical patients, there were three known pseudarthroses. In 28 patients, there was a definite fusion. In the remaining nine patients (five with flaccid disease, four with spastic disease), the quality of their bone precluded definitive determination, but there was no obvious instrumentation failure or loss of correction. CONCLUSION: This study suggests that allograft bone graft is a suitable substitute for autogenous bone graft harvesting in select patients with paralysis in whom autogenous harvesting is not feasible.
Deformity with palmar bone resorption can be observed in 20-50% of scaphoid pseudarthroses. A palmar wedge-shaped defect develops after repositioning and debridement of the pseudarthrosis. In the present paper 16 cases in which operations with cancellous bone grafting and palmar buttress plate osteosynthesis in addition were performed are presented. In all but 1, the pseudarthrosis united. All patients were pain-free at follow-up examination a minimum of 9 months (mean 28 months) only slightly reduced. Grip strength and mobility were after operation. The persisting pseudarthrosis necessitated wrist arthrodesis because of radiocarpal arthrosis. Metal slackening with erosion and rupture of the flexor pollicis longus tendon occurred in 1 patient. Palmar buttress plating is a biomechanically consistent form of osteosynthesis. It neutralizes all relevant forces. This means that cancellous bone grafts are sufficient, whereas lag screw or tension band osteosyntheses need cortico-cancellous grafts to resist compression forces. Stability and better chances of healing of pure cancellous bone grafts are the main advantages of palmar buttress plating in scaphoid pseudarthroses.
During the period from 1 May 1990 to 30 November 1994, a total of 62 humeral shaft fractures were treated in the Department of Traumatology of the University of Bonn. In 42 instances the fracture was internally stabilized primarily, while in 13 instances the humeral shaft fractures were treated according to a regimen including primary stabilization, usually in an external fixateur, soft tissue reconstruction and delayed open reduction and internal fixation using an AO plate. The delayed stabilization was carried out 9.1 days, on average, after the injury. Seven pseudarthroses were treated electively. The indication for surgery was in 28 cases the associated injuries, 18 times the fracture type or form, 7 times a primary neurological deficit, 7 times a pseudarthrosis and twice the underlying systemic disease. A majority of the patients were involved in a motor vehicle accident. An open fracture was seen 6 times. Of the 19 primary radial palsies, 79% were associated with fractures of the distal diaphysis. The complication rate of 11% is comparable to that reported following intramedullary stabilization. No infection, pseudarthrosis or long-term radial palsy was observed. In three instances, twice following the revision of a pseudarthrosis, a temporary radial palsy was noted. All these neurological deficits resolved by the 6th postoperative day. Bony union was achieved after 16.2 weeks. If the surgeon adheres to the proper indications for open reduction and internal fixation, the compression plating of the humeral shaft fracture is a viable alternative to other forms of stabilization.
Humeral shaft fractures can be treated either conservatively or operatively. Plating of the humerus is the established operative method, but recently interest has also been focussed on intramedullary nailing. Fifty-nine cases of humeral fractures treated with intramedullary nailing (Seidel/Marchetti-Vicenzi/Prévot) from January 1991 to December 1995 (44 fractures after trauma, 11 pathological fractures, 3 pseudarthroses, 1 re-fracture). Closed reduction in 55/59 cases. One infection (soft tissue); 2/48 pseudarthrosis (indication for nailing: pseudarthrosis!). No iatrogenic palsy of the radial nerve. Functional postoperative treatment in all 44 cases of humeral fractures after adequate trauma. One poor functional result: periarticular ossification after retrograde nailing, possibly connected with long-term respiratory treatment after trauma. Treatment of humeral shaft fractures by intramedullary nailing is favoured in our clinic (low complication rates, excellent or good functional results, limited approaches, small scars). Proximal fractures should be treated by the Seidel nail (stable interlocking of the proximal fragment); very distal fractures need Prévot nailing (reaming of condylar canals). All other fractures of the humeral shaft can be treated by each of the implants used in our clinic. Pathological fractures are an excellent indication for intramedullary stabilization. These patients benefit from stable fixation without intense surgical trauma. Pseudarthrosis, according to our limited experience, seems to require plating plus bone grafting. Plating is also recommended if revision of the radial nerve becomes necessary.
Eighteen patients with symptomatic radioscaphoid arthritis had scaphoid excision and capitolunate arthrodesis. Eight patients also had a silicone scaphoid replacement. The follow-up period averaged 3 years. Fusion was solid in 12 cases at an average of 8 weeks, and pain was significantly less at follow-up evaluation. Six patients had a pseudarthrosis and five had persistent pain. Immobilization in the pseudarthrosis group averaged 6 weeks, which was significantly less than the group that fused. Two patients underwent successful repeat fusions. Wrist extension averaged 26 degrees, flexion 34 degrees, radial deviation 11 degrees, and ulnar deviation 24 degrees. Grip strength averaged 25 kg. Presence of an implant had no significant effect on motion or strength. Pin track infection and pseudarthrosis were the main complications. Pain relief, functional motion, good strength, and patient satisfaction can be expected after scaphoid excision and solid capitolunate arthrodesis. Kirschner wires should be buried subcutaneously to avoid infection. The addition of a scaphoid implant offered no advantage over simple scaphoid excision.
STUDY DESIGN: To prospectively evaluate major complications associated with the application of dynamic ABC plates (Aesculap, Tuttlingen, Germany) to multilevel Anterior Corpectomy/Fusion (ACF) followed by posterior fusion (C2-C7 PF). OBJECTIVES: To determine whether dynamic ABC (Aesculap, Tuttlingen, Germany) plates would minimize major complications (plate/graft extrusion, pseudarthrosis) while maximizing neurological outcomes in 40 consecutive patients undergoing simultaneous multilevel ACF/PF with halo application. SETTING: USA. METHODS: Patients averaged 53 years of age and preoperatively exhibited severe myeloradiculopathy (Nurick Grade 3.9). MR/CT studies documented marked ossification of the posterior longitudinal ligament/spondylostenosis. Surgery included two to four level ACF utilizing fibula strut allograft and ABC plates. Posterior spinous process wiring/fusions utilized braided titanium cables. The average operative time was 8.9 h. Fusion was confirmed on dynamic X-rays/CTs (3-12 months postoperatively). The average follow-up interval was 2.7 years. Outcomes (3 months-2 years postoperatively) were assessed utilizing Odom's Criteria, Nurick Grades, and SF-36 questionnaires. RESULTS: Major complications included one pseudarthrosis requiring secondary PWF. Minor complications in six patients included two pulmonary emboli (PE), two tracheostomies, and five superficial wound infections. At 1 year postoperatively, marked improvement was observed in all patients utilizing Odom's criteria (38 excellent/good), Nurick Grades (mild radiculopathy 0.4), and the SF-36 (3 Health Scales; Role Physical (12.5-38.6), Bodily Pain (39.9-65.5), and Role Emotional (53.8-75.8)]. The 2-year postoperative data showed minimal additional improvement. The average time to fusion was 6.3 months. CONCLUSION: Patients undergoing multilevel ACF/PF demonstrated marked neurological improvement (SF-36), and only one of 40 developed a delayed pseudarthrosis.
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.
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. Forty 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.
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.
STUDY DESIGN: A retrospective study of 16 patients who underwent the modified Robinson anterior cervical discectomy and fusion at three operative levels. OBJECTIVES: To provide long-term follow-up data on the surgical success and patient outcome of three-level anterior cervical discectomies and fusions. SUMMARY OF BACKGROUND DATA: The success of arthrodesis for anterior cervical fusion depends on several factors, including the number of surgical levels. To the authors' knowledge, there are no long-term follow-up reports to describe the arthrodesis rate and outcome for patients having specifically three-level discectomy and fusion procedures. METHODS: Sixteen patients, with an average age of 59 years, were followed for an average of 37 months. All had an anterior discectomy, burring of the endplates, and placement of an autogenous tricortical iliac crest graft at three levels. All patients had follow-up office visits with examinations and radiographs. Radiographic union, postoperative pain relief, and neurologic recovery were evaluated. RESULTS: Only 9 (56%) of the 16 patients went on to achieve solid arthrodesis at all three levels. Of the seven patients with pseudarthrosis, two had severe pain and required revision; two had moderate pain and three no pain. Of the nine with the solid fusion, three had mild pain and six no pain, a statistically significant difference in comparing the two outcomes (P < 0.01). All patients with preoperative motor deficit recovered, but two patients in whom a pseudarthrosis had developed had limited improvement in function until the nonunion was surgically repaired. CONCLUSIONS: A three-level modified Robinson cervical discectomy and fusion results in an unacceptably high rate of pseudarthrosis. Although not all pseudarthroses are painful, these data suggest that those with a successful fusion have a better outcome. It is recommended that these patients undergo additional or alternative measures to achieve arthrodesis consistently.
STUDY DESIGN: A preliminary outcome assessment study of titanium cage implants with anterior cervical plating in anterior cervical reconstruction. OBJECTIVES: To evaluate the efficacy and safety of using titanium cage implants and anterior plating in cervical reconstruction. SUMMARY OF BACKGROUND DATA: Anterior decompression and interbody fusion is a widely accepted surgical treatment for patients with cervical spondylosis. Tricortical iliac crest autograft has been the gold standard but is associated with morbidity at the bone graft donor site, whereas allograft fibula is associated with pseudarthrosis. Problems such as pseudarthrosis, graft collapse, and extrusion still persist with the accepted method of harvesting and implanting bone autografts. METHODS: Thirty-four patients were treated by channel corpectomy followed by placement of a titanium cage packed with autogenous bone graft from the vertebral bodies to reconstruct the anterior column. An anterior cervical plate was added in 30 of 34 cases that involved decompression of two or more levels. The follow-up period ranged from 24 to 56 months, with an average follow-up period of 32 months, and included examination and radiography. RESULTS: Six months after surgery, there was radiographic evidence of fusion in 97% of the patients. Eighty-eight percent of the patients (30 of 34) did not experience any complications (neither cage dislodgment nor hardware failure). Four patients had complications that included pseudarthrosis (1), extruded cage (1), cage in kyphosis (1), and radiculopathy (1). CONCLUSIONS: Titanium cages provide immediate strong anterior column support with minimum hardware complications and avoid bone graft-site morbidity. Titanium cages, with concomitant use of anterior plating, offer an effective and safe alternative to bone autografts.
STUDY DESIGN: A retrospective study of adults with long fusion to the sacrum using three different fixations was performed. OBJECTIVE: To compare the long-term clinical results and complications associated with three methods of lumbosacral fixation for adult spine deformities: Luque-Galveston, combined iliac and sacral screws, and sacral screws. SUMMARY OF BACKGROUND DATA: The preferred technique for long fusion to the sacrum is controversial, and surgery for adult deformity is fraught with significant technical difficulties and high complication rates. No clinical study compares the long-term outcome of long fusion to the sacrum using these different methods of lumbosacral fixation. METHODS: This study included 54 consecutive patients who underwent elective combined anterior and posterior surgical reconstruction for adult spine deformity with a minimum follow-up period of 2 years. The patients were divided into three groups on the basis of the surgical method used for the posterior spine instrumentation. Group 1 consisted of 11 patients with smooth L-rod and segmental sublaminar wire instrumentation (Luque-Galveston technique). Group 2 consisted of 36 patients with posterior Isola segmental instrumentation and combined iliac and sacral screws. Group 3 consisted of 12 patients with Isola segmental instrumentation using bicortical sacral screws. Five patients were revised to another fixation group, giving a total of 59 cases. Radiographic, clinical results, and long-term outcome data were obtained using the modified Scoliosis Research Society (SRS) outcome instrument. RESULTS: There were 26 late complications. Pseudarthrosis developed in 10 patients, requiring revision surgery: 4 (36%) in the Group 1, 5 (14%) in Group 2, and 1 (8.5%) in Group 3. Comparison of the modified SRS outcomes showed no difference among the groups. The average SRS grand total score was 73.4% for Group 1, 70.9% for Group 2, and 62.6% for Group 3. Overall, 76% of the patients were satisfied with their outcome. The presence of perioperative complications or pseudarthrosis significantly correlated with a lower satisfaction score (P = 0.012 and P = 0.048, respectively). Sagittal plane decompensation significantly correlated with a higher pain score (P = 0.035). Patients with prior surgeries scored lower on the self-image questions than patients with no prior surgery (P = 0.007). CONCLUSIONS: Attention to sagittal balance is critical in these patients. Revision surgery is as safe and effective as primary surgery. According to the current findings, the Luque-Galveston fixation technique has an unacceptably high rate of pseudarthrosis, and this method is not recommended for adult deformities. Currently, the authors are using bicortical and triangulated sacral screws with an anterior interbody support in patients with good bone stock, but only when the spine balance is restored. Otherwise, they recommend using iliac fixation, although there is a higher rate of painful hardware, requiring removal.
STUDY DESIGN: Prospective comparative randomized clinical and radiologic study. OBJECTIVE: This study was conducted to compare the short-term effects of rigid versus semirigid and dynamic instrumentation on the global and segmental lumbar spine profile, subjective evaluation of the result, and the associated complications. BACKGROUND DATA: Lumbar spine fusion with rigid instrumentation for degenerative spinal disorders seems to increase the fusion rate. However, rigid instrumentation may be associated with some undesirable effects, such as increased low back pain following decrease of lumbar lordosis, fracture of the vertebral body and pedicle, pedicle screw loosening, and adjacent segment degeneration. The use of semirigid and dynamic devices has been advocated to reduce such adverse effects of the rigid instrumentation and thus to achieve a more physiologic bony fusion. MATERIALS AND METHODS: This study compared 3 equal groups of 45 adult patients, who underwent primary decompression and stabilization for symptomatic degenerative lumbar spinal stenosis. The patients of each group were randomly selected and received either the rigid (Group A), or semirigid (Group B), or dynamic (Group C) spinal instrumentation with formal decompression and fusion. The mean ages of the patients who received rigid, semirigid, and dynamic instrumentation were 65 +/- 9, 59 +/- 16, and 62 +/- 10 years, respectively. All patients had detailed roentgenographic study including computed tomography scan and magnetic resonance imaging before surgery to the latest follow-up observation. The following roentgenographic parameters were measured and compared in all spines: lumbar lordosis (L1-S1), total lumbar lordosis (T12-S1), sacral tilt, distal lordosis (L4-S1), segmental lordosis, vertebral inclination, and disc index. The SF-36 health survey and Visual Analogue Scale was used before surgery to the latest evaluation. RESULTS: All patients were evaluated after a mean follow-up of 47 +/- 14 months. Both lumbar and total lordosis correction did not correlate with the number of the levels instrumented in any group. Total lordosis was slightly decreased after surgery (3%, P < 0.05) in Group C. The segmentallordosis L2-L3 was increased after surgery by 8.5% (P < 0.05) in Group C, whereas the segmentallordosis L4-L5 was significantly decreased in Group Aand C by 9.8% (P = 0.01) and 16.2% (P < 0.01), respectively. The disc index L2-L3 was decreased after surgery in Group A and C by 17% (P < 0.05) and 23.5% (P < 0.05), respectively. The disc index L3-L4 was increased in Group C by 18.74% (P < 0.01). The disc index L4-L5 was after surgery decreased in all 3 groups: Group A by 21% (P = 0.01), Group B by 13% (P < 0.05), and Group C by 13.23% (P < 0.05). The disc index L5-S1 was significantly decreased in Group B by 13% (P < 0.05). The mean preoperative scores of the SF-36 before surgery were 11, 14, and 13 for Groups C, B, and A, respectively. In the first year after surgery, there was a significant increase of the preoperative SF-36 scores to 65, 61, and 61 for Groups C, B, and A, respectively, that represents an improvement of 83%, 77%, and 79%, respectively. In the second year after surgery and thereafter, there was a further increase of SF-36 scores of 19%, 23%, and 21% for Groups C, B, and A, respectively. The mean preoperative scores of Visual Analogue Scale for low back pain for Groups C, B, and A were 5, 4.5, and 4.3, respectively, and decreased after surgery to 1.9, 1.5, and 1.6, respectively. The mean preoperative scores of the Visual Analogue Scale for leg pain for Groups C, B, and A were 7.6, 7.1, and 6.9, respectively, and decreased after surgery to 2.5, 2.5, and 2.7, respectively. All fusions healed radiologically within the expected time in all three groups without pseudarthrosis or malunion. Delayed hardware failure (1 screw and 2 rod breakages) 1 year and 18 months after surgery without radiologic pseudarthrosis was observed in 2 patients in Group C. Asymptomatic radiolucent areas were shown around pedicle screws in the pedd pedicle screws in the pedicles L5 and S1 in 2, 3, and 4 cases in Group C, A, and B, respectively. There was no adjacent segment degeneration in any spine until the last evaluation. DISCUSSION AND CONCLUSION: This comparative study showed that all three instrumentations applied over a short area for symptomatic degenerative spinal stenosis almost equally after surgery maintained the preoperative global and segmental sagittal profile of the lumbosacral spine and was followed by similarly significant improvement of both self-assessment and pain scores. Hardware failure occurred at a low rate following dynamic instrumentation solely without radiologically visible pseudarthrosis or loss of correction. Because of the similar clinical and radiologic data in all three groups and the relative small number of patients that were included in each group, it is difficult for the authors to make any recommendation in favor of any instrumentation.