Allograft bone in spinal fusion for adolescent idiopathic scoliosis

OBJECTIVE

The purpose of this long-term study was to determine the efficacy of allograft bone for spinal fusion for adolescent idiopathic scoliosis. Prior studies comparing allograft and autograft have been short term.

METHODS

This multicenter retrospective study was carried out on 111 patients with 132 total curves fused for adolescent idiopathic scoliosis. Minimum follow-up was 5 years (average 72 months). A variety of segmental instrumentation was used, with most being dual-rod, multiple-hook constructs.

RESULTS

Average preoperative curve was 59 degrees with immediate correction to 29 degrees (51%) and final follow-up of 32.24 degrees (45.4%). Average loss of correction was 3.5 degrees (5.9%). There were three pseudarthroses, one infection, and no rod breakage.

CONCLUSION

Pseudarthrosis rate of 2.7% and loss of correction of 5.9% are comparable with or better than those in previous reports using autogenous bone graft and either segmental or nonsegmental instrumentation.

Painful non-union of the fibula in football player following fracture of the leg

We report the case of a young football player operated on for a middle shaft fracture of the right leg with a Kuntscher nail. After 8 months, when he started to play football again, he suffered from a painful pseudoarthrosis of the region at the transition from the median to the lower third of the fibula. Because of the severity of the pain, and due to the lack of a well-defined and stated surgical option, a subtraction osteotomy was performed in order to remove the cause of the ache. The patient was revisited 3 and 6 months later, and showed complete disappearance of the pain and a full return to sport activities. In light of the good result obtained, we consider the osteotomy operation a reliable and easy-to-perform method in treating non-unions of the fibula.

Posterior transcanal lumbar interbody fusion for septic vertebral fracture pseudarthrosis and sitting imbalance

STUDY DESIGN

Case report.

OBJECTIVE

To describe a new method to treat septic pseudarthrosis of the lumbar spine via a transcanal approach.

SUMMARY OF BACKGROUND DATA

Septic pseudarthrosis of the spine after multiple unsuccessful anterior and posterior surgeries for vertebral fracture represents a challenge for spine surgeons.

METHODS

Septic pseudarthrosis associated with dorsal fistula developed in a 40-year-old paraplegic man after unsuccessful combined anterior and posterior instrumentation for L3-burst fracture and sagittal sitting imbalance caused by collapsing spine.

RESULTS

The instrumentation was removed together with meticulous pseudarthrosis debridement, fistula excision, and intravenous antibiotics plus continuous irrigation. Three months later, the pseudarthrosis area was approached via a posterior transcanal route because of the preceding multiple anterior transperitoneal and retroperitoneal surgeries. Posterior interbody instrumentation and fusion were performed with titanium mesh cages filled with autologous iliac bone graft. Pedicle screw-rod instrumentation was additionally applied to reinforce the interbody fusion and restore lumbar lordosis. Following this operation, the patient was ambulated with a custom made plastic jacket in his wheelchair. The postoperative course was uneventful, and the patient regained his sitting ability progressively. Four months later, the blood count analysis was within normal limits. Radiologically, there was a complete fusion at the level of instrumentation, while the preoperative lost lumbar lordosis was sufficiently restored. The patient was reemployed 6 months after surgery in his previous work in a sitting position, and, during the last observation 4 years later, he had normal labor analysis and lumbar lordosis.

CONCLUSION

This extremely rare case focuses on the use of the transcanal approach to treat adequately lumbar septic pseudarthrosis and restore lumbar lordosis in definitively paraplegic patients in whom no anterior approach can be used.

Complications in spondylolisthesis surgery

STUDY DESIGN

Selected references are cited to illustrate the current status of approaches to surgical complications in isthmic spondylolisthesis surgery.

OBJECTIVE

To minimize untoward events and outcomes in the surgical treatment of spondylolisthesis, an awareness of complications and pitfalls specific to spondylolisthesis surgery is necessary.

SUMMARY OF BACKGROUND DATA

Pseudarthrosis is the most common complication, and factors that contribute are vertebral geometry, bone grafting options and technique, and immobilization with instrumentation constructs or an orthosis. There has been an increase in neurologic deficits associated with spondylolisthesis surgery during the period of 1996 to 2002. Neurologic sequelae can include cauda equina syndrome, root lesions, autonomic dysfunction, and chronic pain. These can result from reduction maneuvers, instrumentation, and after surgery, although neurologic deficit can occur without identifiable causes. Restoring or maintaining the physiologic sagittal contour of the lumbar spine is a necessary component of surgical planning.

METHODS

Literature review.

RESULTS

Problems and complications associated with the surgical treatment of spondylolisthesis are well documented in the medical literature.

CONCLUSIONS

The occurrence of pseudarthrosis, neurologic deficits, and transition syndromes such as spondylolisthesis acquisita, S1-S2 deformity, and adjacent segment syndrome can be minimized with proper planning and attention to surgical technique.

Hamartoma involving the pseudarthrosis site in patients with neurofibromatosis type 1

Congenital pseudarthrosis is a rare disease with variable clinical effects. The disease remains 1 of the most controversial pediatric entities in terms of etiopathogenesis, therapy, and prognosis. Between 0.5% and 2.2% of patients with neurofibromatosis demonstrate pseudarthrosis in any of the long bones. The exact origin of the lesion is even unclear; although several attempts have been made to determine the type of tissue involving the pseudarthrosis site, only fibrous tissue has been documented in different reports. We present 2 unrelated Mexican patients (male and female) with familial neurofibromatosis and congenital pseudarthrosis of the tibia and fibula. Histochemical and immunostain studies after surgical resection of the affected ends from the pseudarthrosis site of both patients showed a picture compatible with hamartoma. This is the first time when histologic evidence of hamartomatous tissue involving the pseudarthrosis site is presented.

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.

Maintenance of interbody space in one- and two-level anterior cervical interbody fusion: comparison of the effectiveness of autograft, allograft, and cage

The use of allografts, autologous iliac crest grafts, and cages for anterior cervical fusion is well documented, however there is no comparison regarding the effectiveness of maintaining the interbody space with the three approaches. We retrospectively measured the rate and amount of interspace collapse, segmental sagittal angulations, clinical results, and radiographic fusion success rates to determine which is the best fusion material. We assessed 73 patients who had one- and two-level cervical discectomies and interbody fusions without instrumentation. The three groups had similar clinical results and fusion rates. However, in the autograft group union occurred in 4 months. In the allograft group, union did not occur until 5.54 months. Moreover, the loss of cervical lordosis (2.75 degrees) was less in the cage group than in the allograft group (9.23 degrees). Additionally, the anterior interspace collapse (1.73 mm) in the cage group was less than the collapse recorded in the autograft group (2.82 mm) and in the allograft group (4 mm). An interspace collapse of 3 mm or greater was observed in 56.1% of the patients in the allograft group, compared with only 19% of the patients in the cage group. We showed that the cage is superior to the allograft and autograft in maintaining cervical interspace height and cervical lordosis after one-level and two-level anterior cervical decompression procedures.

LEVEL OF EVIDENCE

Therapeutic study, Level III-2 (retrospective cohort study).

The radiographic failure of single segment anterior cervical plate fixation in traumatic cervical flexion distraction injuries

STUDY DESIGN

A radiographic review of 87 patients with either unilateral or bilateral facet dislocations or fracture/dislocations treated with anterior cervical discectomy, fusion, and plating.

OBJECTIVE

The primary objective of this study was to report the incidence of radiographic failure and factors that would predispose to this loss of alignment. The secondary objective was to report the rate of pseudarthrosis.

SUMMARY OF BACKGROUND DATA

Biomechanical and clinical data conflict regarding the appropriate approach and method of fixation of distractive flexion cervical injuries. Unilateral and bilateral facet fracture subluxations may be surgically stabilized by anterior cervical discectomy, fusion, and plating, posterior instrumentation, or both. There are no documented reports of the rate of radiographic failure of this procedure when limited to a single level injury from a distractive flexion mechanism.

METHODS

Inclusion criteria were all single-level unilateral and bilateral facet fracture dislocations or subluxations treated with a single-level anterior cervical discectomy, fusion, and plating. Retrospectively, 107 cases were identified (87 with complete radiographs) from January 1994 to December 2001. Radiographic failure was defined as a change in translation of greater than 4 mm and/or change in angulation of greater than 11 degrees between the immediate postoperative films and the most recent follow-up. Fusion was assessed radiographically.

RESULTS

A 13% incidence of radiographic loss of alignment is reported in 87 unilateral and bilateral facet fracture subluxations stabilized with anterior cervical discectomy, fusion, and plating. Radiographic failure correlated with the presence of endplate compression fracture and facet fractures on injury radiographs. There was no correlation between radiographic failure and age, gender, surgeon, unilateral or bilateral injury, plate type, level of injury, degree of translation, or sagittal alignment at the time of injury.

CONCLUSION

Loss of postoperative alignment occurred in 13% of facet fracture subluxations treated with anterior cervical discectomy, fusion, and plating. Concern regarding mechanical failure of flexion/distraction injuries should be high when they are associated with fractures of either the facets or of the endplate. Endplate fracture was associated with both mechanical failure and pseudarthrosis.

[Humeral shaft fractures]

Since Lorenz Böhler postulated in his 1964 summary with the title "Against the operative treatment of fresh humeral shaft fractures" that the operative treatment is the exception in the therapy of humeral fractures times have changed. In the last years a conservative treatment of a humeral fracture is the exception and only used after straight indications. The operative therapy nowadays is the gold standard because of the development of new intramedullar and rotation stable implants in addition to the classical osteosynthesis with the plate. But even the external fixator for primary stabilisation in polytrauma patients or as rescue procedure after complications should be in repertory of every orthopedic surgeon. Attention should be put on the avoidance of primary and the correct treatment of secondary nerval lesions, esp. of the radial nerve. Here we are tending to the operative revision of the nerve in indistinct cases. In the treatment of the seldom humeral shaft fracture of the child conservative treatment is to prefer; in complications a resolute shift to a final operative stabilisation of the fracture is necessary.

Surgical Excision of Symptomatic Lumbar Spinous Process Pseudoarthrosis

BACKGROUND

Isolated spinous process fractures of the thoracic or lumbar spine are not well described in the literature. Initial conservative treatment of these fractures can result in resolution of symptoms without lasting effect. However, in cases where localized pain persists despite appropriate treatment, pseudoarthrosis should be suspected.

METHODS

The diagnosis, surgical treatment, and outcome of one patient with isolated pseudoarthrosis of the lumbar spine that failed conservative treatment and was surgically excised are reviewed.

RESULTS

Following excision of the spinous process pseudoarthrosis, the patient's pain resolved, allowing return to competitive sports without limitation.

CONCLUSIONS

In certain cases, excision of an isolated spinous process pseudoarthrosis can improve patients' back pain. However, prior to surgery, conservative treatment must be exhausted and other causes of back pain must be ruled out.

Long adult deformity fusions to L5 and the sacrum. A matched cohort analysis

STUDY DESIGN

A matched cohort analysis of long adult deformity fusions according to distal fusion level (L5 vs. S1). OBJECTIVE.: To compare the results of long adult deformity fusions to either L5 or the sacrum in the presence of a "healthy" 5-1 disc using a matched cohort analysis.

SUMMARY OF BACKGROUND DATA

For adult spinal deformity, the decision often arises whether to terminate a long fusion at L5 or the sacrum. The decision is especially challenging in the presence of a "healthy" (Grade 0 to 1 degeneration) 5-1 disc.

MATERIALS AND METHODS

A total of 95 adult deformity patients that underwent fusion from the thoracic spine to either L5 or the sacrum were sorted according to five preoperative criteria: 5-1 disc status, patient age, smoking status, number of levels fused, and sagittal balance. Two cohorts (L5, 27 patients; sacrum, 12 patients) were precisely matched according to the five criteria. Patients were evaluated at 2-year minimum follow-up according to radiographic data, complications, and SRS-24 outcomes.

RESULTS

Correction of sagittal imbalance was superior for sacrum patients (C7 plumb line: L5, 0.9 cm; sacrum, 3.2 cm; P = 0.03). At latest follow-up (L5, 5.2 years; sacrum, 3.7 years), 67% of L5 patients had radiographic evidence of advanced 5-1 disc degeneration and the L5 cohort tended to have inferior sagittal balance (C7 plumb line: L5, +4.0 cm; sacrum, +1.2 cm; P = 0.06). The sacrum cohort, however, required more surgical procedures (L5, 1.7; sacrum, 2.8; P = 0.03) and experienced a greater frequency of major complications (L5, 22%; sacrum, 75%; P = 0.02), including nonunion (L5, 4%; sacrum, 42%; P = 0.006) and medical morbidity (L5, 0%; sacrum, 33%; P = 0.001). SRS-24 scores reflected a similar patient assessment of outcome and function for the two cohorts (L5, 89; sacrum, 87).

DISCUSSION AND CONCLUSION

At 3 to 5 years' mean follow-up, long adult fusions to the sacrum required more procedures and had a higher frequency of complications than similar fusions to L5. For fusions to L5, subsequent subjacent disc degeneration is common and may be associated with a forward shift in sagittal balance. The ultimate influence of these factors on long-term outcomes remains to be seen.

Safety and efficacy of Isola instrumentation and arthrodesis for adolescent idiopathic scoliosis: two- to 12-year follow-up

STUDY DESIGN

Retrospective case series including patient outcome assessment.

OBJECTIVE

To study the safety and efficacy of Isola instrumentation in comparison with similar series.

SUMMARY OF BACKGROUND DATA

Both the technique and technology used in the surgical treatment of adolescent idiopathic scoliosis continue to evolve, the common theme since the 1980s being provision of instrumentation stable and strong enough to eliminate the need for postoperative immobilization. The purpose of this study is to determine the safety and efficacy of a system deliberately integrating hook, wire, and screw anchors to deliver torsional and countertorsional corrective loads.

METHODS

A total of 185 consecutive patients, index patient included, were treated by posterior instrumentation and arthrodesis from January 1989 through December 2000. Safety was studied by complications, and reoperation type and occurrence. Effectiveness was studied by deformity correction and health-related quality of life questionnaire response. Variables affecting effectiveness were sought. A total of 179 patients (97%) had outcome assessment at an average of 6 years postoperative, and 176 had radiographic evaluation at an average of 5 years postoperative.

RESULTS

There were no deaths, spinal cord or nerve root problems, or acute posterior wound infections. Proven pseudarthrosis occurred in 4 patients (2.2%) and delayed deep wound infection in 2 patients (1.1%). The implant-related reoperation rate was 8% and was necessary more often in the first quarter of the series (17% vs. 4.6%, P = 0.0062). The largest Cobb angle averaged 62 degrees preoperative and 23 degrees at latest follow-up, 63% correction. The largest angle of trunk inclination averaged 16.7 degrees before surgery and 9.9 degrees at latest follow-up, a 39% correction (P < 0.0001). Eighty-eight percent of patients were satisfied or very satisfied with the outcome. The principal problems identified were the need for a stronger transverse connector, stable end-instrumented vertebrae foundations, and convex thoracic anchorage.

CONCLUSIONS

Isola instrumentation seems to be at least as safe and effective as other instrumentations being used for the surgical treatment of adolescent idiopathic scoliosis.

Development of a New Zealand white rabbit model of spinal pseudarthrosis repair and evaluation of the potential role of OP-1 to overcome pseudarthrosis

STUDY DESIGN

Posterolateral lumbar fusions were performed in nicotine-exposed, New Zealand white rabbits. Animals that developed a pseudarthrosis were then regrafted with no graft, autograft, or osteogenic protein-1 (OP-1).

OBJECTIVES

To establish a model of pseudarthrosis repair and to evaluate the ability of OP-1 to induce fusion in this model.

SUMMARY OF BACKGROUND DATA

OP-1 has been shown to have a 100% fusion rate in an established rabbit fusion model, even in the presence of nicotine, which is known to inhibit fusion.

METHODS

Forty-four New Zealand white rabbits underwent posterolateral lumbar fusion with iliac crest autograft. To maximize the incidence of pseudarthroses, nicotine was administered to all rabbits. At 5 weeks, the spines were explored, and all pseudarthroses were redecorticated and grafted with no graft, autograft, or OP-1. At 10 weeks, the rabbits were killed and fusions masses were assessed with manual palpation, radiography, computed tomography, and/or histology.

RESULTS

Nine rabbits (20%) were lost to complications. Thirty-four (94%) had pseudarthroses on exploration at 5 weeks. By manual palpation at 10 weeks, 1 of 10 (10%) pseudarthroses that received no graft fused, 5 of 12 (42%) pseudarthroses that received autograft fused, and 9 of 11 (82%) pseudarthroses that received OP-1 fused. Computed tomography and histology further characterized the fusion masses.

CONCLUSIONS

This study establishes a model for treatment of pseudarthroses. OP-1, which has previously been shown to have 100% fusion rate in animal models, outperformed autograft and induced fusion in 82% of rabbits.

Korrektureingriffe am kindlichen Ober- und Unterarm

The causes of post-traumatic deformities of the upper and lower arm shafts as well as the complete elbow are 90% iatrogenic, in the area of the proximal humerus and the distal lower arm they are about 90% the result of chance (premature closure of the growth plate). In general, corrections of deformities are possible at any age, dependent on the patient's symptoms, the expected development, the location of the deformity and its changes during development. The correction technique should allow for the removal of all of the components of the deformity, and to retain the results until healing is complete and the patient's motor stability is ensured. Due to the high percentage of iatrogenic deformities, the optimisation of the primary therapy should receive particular attention rather than increasing the indications for a correction.

Pseudarthrosis presenting as a late complication of meningococcal septicaemia and disseminated intravascular coagulation

Late skeletal complications of meningococcal septicaemia and disseminated intravascular coagulation are well recognised in children and are largely centred on the growing epimetaphyseal region of long bones. In this article we describe a case of pseudarthrosis of the mid-ulna presenting 18 months following a devastating episode of meningococcal septicaemia in a 3-year-old boy. Radiographs and MRI demonstrated the ulna abnormality. We briefly review the late skeletal complications of the disease and other causes of pseudarthrosis.

Pseudarthrosis of the first rib in the overhead athlete

Fractures of the first rib are uncommon in athletes and present a different clinical entity from traumatic first rib fracture associated with high energy thoracic trauma. These fractures are stress induced and precipitated by chronic muscular forces acting on the first rib. Typically they heal with conservative treatment. This report describes a fracture of the first rib in a tennis player that developed into a symptomatic pseudarthrosis as a result of persistent overhead activities. Symptoms mimicked ipsilateral shoulder injury. Pseudarthrosis of the first rib should be included in the differential diagnosis of chronic persistent shoulder pain in the overhead athlete.

Maxillary post-traumatic outcome correction literature review and our experience. Part I: maxillary bone non-unions-"poor bone positioning"

Still today, there is no classification of non-unions in maxillofacial traumatology. There is a broad spectrum of definitions that simultaneously describe the pathological conditions and functional implications determined by the anatomical location of the fractures and the time factor. In this article the authors describe a literature review about bone non-union classification. Weber, in 1973, introduced the term "pseudo-arthrosis" to describe an altered process of bone healing characterised by the presence of fibrous tissue interposed between the fracture segments, that was lined with cartilaginous tissue and joined by a capsule; Spiessl, in 1988, used the term "non-union" to define any alteration of the bone healing process after a time period of more than 6 months from the initial traumatic event; Rosen, in 1990, proposed a new classification of the modes of altered bone healing in fractures, distinguishing 5 categories: delayed consolidation, non-union, non-union vascular, non union avascular, pseudoarthrosis. The authors also talk about "poor bone positioning". This factor describes the incorrect anatomical position of the bone fragments despite perfectly normal healing according to Gruss. In this article they also discuss about the treatment of non-unions and the treatment of occlusal alterations caused by poor post-traumatic bone positioning.

[New surgical treatment procedures in fractures of the distal tibia (LCP, MIPO)]

All along the operative treatment of distal tibial fractures is a difficult procedure. In most cases the clinical situation is characterized by small distal fragments in combination with crucial soft-tissue conditions. That's why complications as primary or secondary displacements, mal unions, delayed or non unions and as well as a high rate of deep wound infection are often seen. Thus internal fixations with traditional implants (standard screws and plates) could consider inevitable this crucial biology and biomechanics only insufficiently. The nowadays available internal fixators with optional angular-stable screws expand the possibilities of internal fixation in these severe situations. Their minimal invasive application (MIPO, Minimally Invasive Plate Osteosynthesis) takes care of the soft tissue and reduces the surgical trauma furthermore. With the variety of their possible applications (combination of angular stability with standard application) also the demands increase, however, both onto the surgeons, but also onto the general practitioners in the aftercare. The combination of most different tactics in one implant results in the consequence, that at the same bone simultaneously direct and indirect bone healing will be expected. The radiological differentiation between desired and unwanted healing processes becomes thus difficult. Pre- and perioperative procedures require from the trauma surgeon a huge infrastructure and a high measure of biomechanical and biological experience. In the postoperative management of these injuries an unlimited cooperation between traumatologists and general practitioners is indispensable for a further successful course.

Late complications of adult idiopathic scoliosis primary fusions to L4 and above: the effect of age and distal fusion level

STUDY DESIGN A retrospective analysis of primary cases of adult idiopathic scoliosis treated with long instrumented fusions from the thoracic spine proximally to segments that range from T11 to L4 distally.

OBJECTIVE

To analyze whether patients requiring revision surgery had lower postoperative SRS-24 scores; age >or=40 years correlated with higher rates of revision surgery; disc degeneration below the fusion occurred more commonly with a more distal lowest instrumented vertebra or older patient age (>or=40 years); and whether smokers had higher rates of major complications or revision surgery.

SUMMARY OF BACKGROUND DATA

Few reports describe complications related to primary long fusions using modern 2+ rods, hook/pedicle screw instrumentation methods in the treatment of adult idiopathic scoliosis.

METHODS

Sixty-seven patients were analyzed with an average age of 38.8 years (range 21-61 years). The average clinical follow-up was 7.8 years (range 2-16 years): 42 patients had >5 years follow-up, including 23 patients with >10 years follow-up. Patients were categorized by age (< or >or=40 years) and level of the lowest instrumented vertebra (T11-L2 vs. L3-L4). Upright radiographs and postoperative SRS-24 questionnaires from the latest follow-up date were analyzed.

RESULTS

Patients requiring revision surgery had lower total score (average 72.0) than those that did not (total score = 94.2; P = 0.01). More specifically, patients with pseudarthrosis had lower total scores (average 74.7) than those without (average total score = 93.5; P = 0.02). When analyzing age, there were similar rates of pseudarthrosis, but higher rates of transition syndrome (2) and sagittal/coronal imbalance (1 each) in patients >or=40 years. Subsequent distal disc degeneration did not correlate significantly with more distal lowest instrumented vertebra or older patient age. Smokers did not have higher rates of major complications or revision surgery than nonsmokers.

CONCLUSIONS

Patients with adult idiopathic scoliosis and long fusions had similar pseudarthrosis rates, but higher rates of transition syndrome when lowest instrumented vertebra was L3-L4 relative to levels T11-L2. When categorized by age, complication rates were similar in each group. Patients with pseudarthroses or other diagnoses requiring revision surgery had lower SRS-24 total scores than those without (P = 0.02 and P = 0.01, respectively).

[Multiple-level instrumented anterior cervical fusion: a risk factor for pseudoarthrosis? A prospective study with a minimum of 3-year follow-up]

PURPOSE OF THE STUDY

This prospective study with minimal 3-year follow-up was performed to compare fusion rates, course of fusion, collapse incidence and occurrence of subsidence in one- and two-level instrumented anterior cervical fusions (ACDF) and thus to proof the hypothesis that use of internal fixation decreases the risk of non-union in bi-segmental ACDFs to the same level that can be expected in mono-segmental procedure.

MATERIAL

In 79 consecutive patients operated upon by the Smith-Robinson technique for degenerative process of cervical spine in one or two levels was applied single instrumentation system in order to ensure ideal condition for solid bone fusion of 113 grafts (45 in one and 68 in two levels). All the patients were invariably followed for a minimum of 3 years.

METHODS

Radiological criteria were used for evaluation of intervertebral fusion, graft collapse and its subsidence and results were statistically analyzed using M-L Chi-square test for the comparison of fusion and collapse incidence and further Chi-square test for the analysis of fusion course. All these figures were calculated at the level of significance 0.05 (alpha=0.05).

RESULTS

Overall, no significant difference was observed in achieving solid bone fusion 3 years after the surgery in one- and two-level procedures (95.6% vers. 92.6%, p=0.522), neither the bone graft collapse rate was of significant difference (2.2% vers. 7.6%, p=0.208). In single-level group the time to bone fusion was significantly shorter (p<0.001). When pooling the data into autologous and allogenic graft subgroup, there was observed no statistically significant difference in achieving union in autologous subgroup (100% vers. 90.9%, p=0.142); in allogenic subgroup this situation was similar: no significant difference in fusion rate (93.3% vers. 93.5%, p=0.980) was observed. In both auto- and allogenic subgroups monosegmentally implanted grafts fused more readily (p<0.001). There was no case of graft subsidence in any investigated group.

DISCUSSION

Our prospective study did not find any statistically significant difference in graft collapse and fusion rate when comparing one- and two-level instrumented ACDFs 3 years after the surgery. Plating system used in our patients brings more stability to operated segments and thus presumably prevents micromotions in postoperative period. Micromovements seems to be the major risk factor for non-union in non-instrumented multilevel cervical fusion. Other risk factor that should be considered in non-instrumented procedure is increase in compressive forces that are also partially eliminated by the semirigid internal fixation. Significantly delayed time to union observed in two level fusions shows most probably on increased number of surfaces that must be consolidated during the bone-healing process.

CONCLUSION

This study demonstrates that internal fixation used in multilevel ACDF decreases risk of pseudoarthrosis to the same level that can be expected in monosegmental procedures.

Pseudarthrosis after lumbar spine fusion: nonoperative salvage with pulsed electromagnetic fields

We studied 100 patients in whom symptomatic pseudarthrosis had been established at more than 9 months after lumbar spine fusion. All patients were treated with a pulsed electromagnetic field device worn consistently 2 hours a day for at least 90 days. Solid fusion was achieved in 67% of patients. Effectiveness was not statistically significantly different for patients with risk factors such as smoking, use of allograft, absence of fixation, or multilevel fusions. Treatment was equally effective for posterolateral fusions (66%) as with interbody fusions (69%). For patients with symptomatic pseudarthrosis after lumbar spine fusion, pulsed electromagnetic field stimulation is an effective nonoperative salvage approach to achieving fusion.

Stellenwert und Vorteil neuer winkelstabiler Implantate bei Schaftfrakturen (LCP vs. Nagel)

Der goldene Standard zur Behandlung von Schaftfrakturen langer Röhrenknochen des Erwachsenen bleibt nach wie vor die Marknagelosteosynthese. Das operative Verfahren ist standardisiert und meist minimal-invasiv, die primäre Heilungsrate ist hoch, und Komplikationen treten selten auf. Für Problemzonen (metadiaphysärer Übergang), bei schlechter Knochenqualität und bei anderen relativen Kontraindikationen für den Marknagel (enger Markkanal, Frakturen beim Adoleszenten und beim Polytrauma) bieten die neuen winkelstabilen Schrauben-Platten-Systeme (LISS, LCP) eine ausgezeichnete Alternative für die operative Stabilisierung. Die damit erreichte sehr hohe Primärstabilität in Kombination mit neu entwickelten, weichteilschonenden Operationstechniken (MIPO = Minimalinvasive Plattenosteosynthese) bieten die Grundlagen für eine funktionelle Nachbehandlung und eine möglichst rasche und komplikationsarme Knochenheilung.

Complications and outcomes of pedicle subtraction osteotomies for fixed sagittal imbalance

STUDY DESIGN

Radiographic analysis, outcomes analysis (pain scale, Oswestry, SRS-24), and accumulation of complications. Outcomes and complications collected prospectively. Radiographic analysis performed retrospectively.

OBJECTIVES

To assess the benefits and stress complications of pedicle subtraction osteotomies for patients with fixed sagittal imbalance.

SUMMARY OF BACKGROUND DATA

Few reports on pedicle subtraction osteotomies exist in the peer-review literature for conditions other than trauma and ankylosing spondylitis.

MATERIALS AND METHODS

Thirty-three consecutive patients with sagittal imbalance treated with lumbar pedicle subtraction osteotomy at one institution (minimum 2-year follow-up) were analyzed. Complications were also analyzed for the entire group of consecutive pedicle subtraction osteotomies done at our institution to date (n = 66).

RESULTS

For the 33 patients with minimum 2-year follow-up, there were significant improvements in the overall Oswestry score (P 0.0001) and pain score (P = 0.0001). Most patients reported improvement in pain and self-image and reported overall satisfaction based on ultimate SRS-24 questionnaire. There was one pseudarthrosis in the lumbar spine through an area of pedicle subtraction osteotomy (area of previous laminectomy and nonunion), and six patients had thoracic pseudarthroses (levels other than the osteotomy level) and one patient had a pseudarthrosis at L5-S1. Two patients had acute angular kyphosis at the thoracolumbar junction at the proximal end of the construct. Five patients who experienced transient neurologic deficits resolved their deficits after central canal enlargement.

CONCLUSIONS

The clinical result with pedicle subtraction osteotomy is reduced with pseudarthrosis in the thoracic or lumbar spine and subsequent breakdown adjacent to the fusion. For patients with a degenerative sagittal imbalance etiology the results were worse and the complications were higher. Central canal enlargement is critical.

Revision strategies for lumbar pseudarthrosis

Management and avoidance of lumbar pseudarthrosis are among the most common and challenging tasks faced by reconstructive spine surgeons. The risks of pseudarthrosis can be broadly divided into two categories: those within a surgeon's control and those not within his/her control. These include biological factors, graft choices, site preparation, and surgical design. The authors review the biological factors that affect fusion and how they can be manipulated to avoid or manage lumbar pseudarthrosis. Surgical planning and construct design to prevent or treat pseudarthrosis will also be discussed. Additionally, the importance of restoring sagittal balance will be reviewed.