Posterior Transpedicular Instrumentation Research Articles

Treatment of thoracolumbar fractures by temporary posterior instrumentation with selective fusion schemes

Objective This retrospective study investigated the clinical and radiographic outcomes following temporary transpedicular posterior instrumentation between two cohorts of patients with thoracolumbar fractures (TLF) who underwent selective or bi-segments intervertebral articular process fusion. Methods Patients with TLF who underwent the temporary posterior fixation with selective fusion (Group SF), or bi-segments fusion (Group BF) were studied. Superior intervertebral articular process and interlaminar fusion were performed in Group SF, whereas in Group BF, the patients underwent bi-segments fusion in both superior and inferior articular processes, as well as interlaminar fusion. We measured the distal and proximal intervertebral mobility, regional kyphotic angle, and vertebral height before and after surgery in both groups. Greenough Low-Back Outcome Score was used to assess the clinical outcomes. Results Sixty-five patients with TLF from T12 to L2 fractures were enrolled in the study period: 33 patients in the Group SF and 32 patients in the Group BF. All the patients experienced fracture healing (mean follow-up time: 19.7 months). The mean postoperative functional outcomes were 65.0 ± 2.0 points for the Low-Back Outcome Score in the Group SF and 65.2 ± 1.8 for the Group BF. A progressive regional kyphotic angle was observed with time regardless of fusion but was not significantly different between the two groups. There was a statistical difference between unfused inferior proximal adjacent and inferior distal adjacent segment regardless of fracture segments. Conclusions The strategy of selective fusion is reported to be useful for the treatment of patients with TLF. The motion in the un-fused and adjacent segment could be better regained after instrumentation removal in the selective fusion group. Level of Evidence Level 3.

From “cage to independence”: good outcomes of an unstable (burst) lumbar fracture, surgically managed with an expandable titanium vertebral cage implant, with posterior transpedicular instrumentation, and rehabilitation program – case presentation

From “cage to independence”: good outcomes of an unstable (burst) lumbar fracture, surgically managed with an expandable titanium vertebral cage implant, with posterior transpedicular instrumentation, and rehabilitation program – case presentation

INCIDENCE OF THE ADJACENT SEGMENT DISEASE TREATED AT THE ISSEMYM MEDICAL CENTER

ABSTRACT Objective: To determine the incidence and rate of disc degeneration adjacent to a lumbar fusion, as well as to analyze possible risk factors for its development. Methods: A retrospective study of a level of evidence IIB case series of 125 patients diagnosed with lumbar canal stenosis and spondylolisthesis, who underwent surgery from January 2011 to December 2016, with subsequent instrumentation and posterolateral fusion and outpatient follow-up in which the symptomatology and radiographic findings were evaluated to establish the diagnosis and management. Results: Twelve patients with adjacent segment disease were identified, with an incidence of 9.6%, higher both among female patients and in the seventh decade of life. The most frequent pathology was canal stenosis (42.4%), the most affected level was L4 / L5, and the procedure most associated with the prevalence of adjacent level degeneration was L4-L5 posterior transpedicular instrumentation. Conclusions: Sagittalization of the facet joint was a constant factor in all patients with involvement of the adjacent disc. The main clinical findings were treatment-resistant root pain and radiographic alterations characterized by spondylolisthesis, facet osteoarthritis and intervertebral disc herniation. Level of Evidence IIB; Retrospective study.

Posterior transpedicular debridement, decompression and instrumentation for thoracic tuberculosis in patients over the age of 60

Our aim was to evaluate the feasibility and efficiency of the application of posterior transpedicular debridement with instrumentation and fusion to the treatment of over 60-year-old patients with thoracic tuberculosis. Fifteen over 60-year-old patients with thoracic tuberculosis treated by posterior transpedicular debridement with instrumentation and fusion between August 2006 and November 2010, seven males and eight females in this study were reviewed, retrospectively. Their age ranged from 61 to 75 (mean age 63.4). The follow-up period ranged from 12 to 51 months (mean 30 months). The patients were evaluated based on vertebral body loss, kyphotic angle, fusion status of affected segment, visual analog scale (VAS) pain score, and Frankel's classification. A solid fusion was achieved in all 15 cases. No postoperative complications, chronic infection, sinus formation or significant loss of deformity correction was noted in these patients. Moreover, VAS score was reduced and Frankel's grade was recovered in all patients and there was no recurrence of the tuberculous infection. Posterior transpedicular debridement with instrumentation and fusion is a feasible and effective procedure in the treatment for thoracic tuberculosis in patients over the age of 60.

L5 vertebrectomy for the surgical treatment of tumoral and traumatic lesions of L5 vertebra

We retrospectively reviewed the clinical characteristics and the surgical results of seven patients treated with L5 vertebrectomy. The pathologies, clinical characteristics, preoperative and postoperative radiological findings, surgical techniques, and instrumentation for seven patients operated on between 1998 and 2009 are presented in this article. Biopsies were performed on all patients except those involving trauma. Patients were followed up at three-month intervals in the first year, at 6-month intervals in the second year, and on a regular basis afterward. One patient had a traumatic L5 burst fracture; the other six had tumoral pathologies in the L5 vertebrae. One tumoral lesion was a chordoma, another was a hemangioma, and the remaining four were metastatic lesions. Radiotherapy and chemotherapy were performed for the metastatic tumor patients during the postoperative period. Patients with renal cancer and chordoma survived for 3 years; patients with lung cancer and bladder cancer survived for 1 year; and patients with breast cancer survived for 16 months. The lumbosacral region presents significant stabilization problems because of the presence of sacral slope. In our opinion, if the lesion involves only the L5 vertebra, anterior cage-filled bone cement or bone graft should be performed, as dictated by the pathology and posterior transpedicular instrumentation. If the lesion involves the L4 vertebra or the sacrum and the L5 vertebra, the instrumentation can be extended to cover other segments with sacral attachments. The present cases involved only L5 vertebra and treatment with short-segment stabilization covering the anterior and posterior columns.

Early results after vertebral body stenting for fractures of the anterior column of the thoracolumbar spine

Introduction Vertebroplasty and balloon kyphoplasty have shown to improve pain and functional outcome in cases with symptomatic vertebral fractures. Although restoration of the vertebral body height and kyphosis seemed to be easier with balloon kyphoplasty, it became clear that some of the correction achieved by the balloon is lost once it was deflated. Vertebral body stent was developed to eliminate this phenomenon. To our knowledge this is the first study in describing this technique in clinical settings. Materials and methods Seventeen patients with 20 fractured vertebral bodies were included. All fractures were Type A1.3 or A3.1 (incomplete burst). Information about pain (visual analogue scale-VAS) and function (Oswestry disability index-ODI) and vertebral body deformity (vertebral angle-VA) was recorded in a prospective way at regular intervals. Patients were classified into osteoporotic group (7 patients) and traumatic groups (10 patients, younger than 60 years). Results There were 6 male and 11 female patients with mean age of 58.1 years (31–88 years). Mean follow up was 12 months. The preoperative pain level showed a mean VAS score of 8.9 in osteoporotic group and 9.7 in traumatic group. Postoperatively, in osteoporotic group, mean VAS was 4.8 at 6 weeks, 4.0 at 6 months and 2.5 at 12 months compared with traumatic fracture group where it was 2.7 at 6 weeks, 2.2 at 6 months and 1.6 at 12 months. Mean ODI in osteoporotic group was 41.7% (14–58%) and in traumatic group it was 20.4% (6–33%). Mean vertebral body angle prior to surgery in osteoporotic group was 9.7 whilst postoperatively it was 5.2°; so the mean correction achieved was 4.5°. In traumatic group preoperative VA was 13° whilst postoperatively it was 5.7°; therefore the mean correction achieved was 7.3°. None of the patients lost reduction at their last follow up. Conclusion Vertebral body stenting leads to satisfactory improvement in pain, function and kyphosis correction in the treatment of osteoporotic and traumatic fractures. Anterior spinal column, especially the fragmented superior endplate is nicely reconstructed by the stent provided it is inserted accurately. With addition of posterior transpedicular instrumentation, indications for this technique may be wider covering some Type B and C fractures with similar vertebral body damage.

Posteriore und transforaminale lumbale interkorporelle Fusion (PLIF/TLIF) zur Therapie des lokalisierten Segmentaufbrauchs der LWS

Chronic intractable low back pain is one of the most common orthopaedic diagnoses, with an enormous socioeconomic impact. The surgical treatment by posterior transpedicular instrumentation and interbody fusion of the affected segments is an established procedure after exhaustion of conservative therapies. Due to different study data on the clinical and functional results after posterior (PLIF) and transforaminal (TLIF) interbody fusion, our own patient population was analysed retrospectively. Included were 143 patients who had been treated surgically at our institution between 1999 and 2006 by one of the two methods (PLIF, n = 68; TLIF, n = 75). In addition to general demographic data, results of three questionnaires (Oswestry disability index, numeric rating scale, Roland Morris score) were retrospectively analysed before surgery and in the general follow-up - identifying clinical and functional results of patient satisfaction. All patients had been suffering in spite of the exhaustion of conservative therapies for at least six months of chronic low back pain prior to surgery. The mean age at surgery was 52 years. The complication rate was 23 %, the revision rate 15 %. Overall, there was a high patient satisfaction in follow-up. In ODI, a significant decrease in pain-related disability was observed from 49.8 % preoperatively to 24.7 % after surgery (p < 0.0001). This functional improvement was present in all aetiological subgroups irrespective of the fusion length. A statistically significantly better functional outcome was achieved in the ODI in the PLIF group (improvement 27.2 % vs. 23.1 %, p < 0.0001). The preoperative baseline regarding pain was assessed in the NRS on average at 6.5 points. Postoperatively, it decreased to 3.34 points (p < 0.0001). The functional limitation due to existing back pain was assessed preoperatively with an average of 13.08 points. Postoperatively a significant reduction to 6.19 points was observed (p < 0.0001). Group- or operation-specific differences were not statistically significant. The data of this study indicate that both TLIF and PLIF techniques are possible surgical treatment methods for patients with resistant chronic low back pain. With both techniques a clear benefit regarding quality of life and function for the operated patients is achievable, if the correct surgical indication is given.

Posterior lumbar interbody fusion versus posterolateral fusion with instrumentation in the treatment of low-grade isthmic spondylolisthesis: midterm clinical outcomes

The purpose of this study was to compare the methods of posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) in cases of isthmic Grades 1 and 2 lumbar spondylolisthesis, and to evaluate the clinical efficacy of the procedures. Operations were performed in 50 patients with lumbar spondylolisthesis in the authors' clinics between 2001 and 2007. Indications for surgery were low-back pain with or without sciatica and neurogenic claudication that had not improved after at least 6 months of conservative treatment. The study included 33 female and 17 male patients, with mean ages of 50.6 years in the PLIF group and 47.3 years in the PLF group. These patients were randomly allocated into 2 groups: decompression, posterior transpedicular instrumentation, and PLF (Group 1; 25 patients) and decompression, posterior transpedicular instrumentation, and PLIF (Group 2; 25 patients). In the PLIF group, titanium cages were used, and autograft material was obtained from the decompression. In the PLF group, bone fragments collected from the iliac crest were used as autografts. A minimum 18-month follow-up was available in all patients. For clinical evaluation, a visual analog scale, Oswestry Disability Index, and the 36-Item Short Form Health Survey were used. Improvements in pre- and postoperative spondylolisthesis, segmental angles, fusion ratios, and postoperative complications were evaluated radiologically. The average follow-up period was 3.3 years. Based on the etiologies, isthmic spondylolisthesis was detected in all patients. The spondylolisthesis levels in the patients who underwent PLIF were located at L3-4 (5 patients, 20%); L4-5 (14, 56%); and L5-S1 (6, 24%), whereas the levels in the ones treated with PLF were located at L3-4 (4 patients, 16%); L4-5 (13, 52%); and L5-S1 (8, 32%). In the clinical evaluations, good or excellent results were obtained in 22 (88%) cases in the PLIF group and 19 (76%) cases in the PLF group. Fusion ratios were 100% in the PLIF group and 84% in the PLF group. Both lumbar lordosis and the segmental angle showed greater improvement in the PLIF group. There was no difference in the complication rates for each group. Based on early clinical outcomes and the fusion ratios of adult isthmic spondylolisthesis, the authors found PLIF to be superior to PLF.

Fusion Rates of Instrumented Lumbar Spinal Arthrodesis according to Surgical Approach: A Systematic Review of Randomized Trials

BackgroundLumbar spine fusion rates can vary according to the surgical technique. Although many studies on spinal fusion have been conducted and reported, the heterogeneity of the study designs and data handling make it difficult to identify which approach yields the highest fusion rate. This paper reviews studies that compared the lumbosacral fusion rates achieved with different surgical techniques.MethodsRelevant randomized trials comparing the fusion rates of different surgical approaches for instrumented lumbosacral spinal fusion surgery were identified through highly sensitive and targeted keyword search strategies. A methodological quality assessment was performed according to the checklist suggested by the Cochrane Collaboration Back Review Group. Qualitative analysis was performed.ResultsA literature search identified six randomized controlled trials (RCTs) comparing the fusion rates of different surgical approaches. One trial compared anterior lumbar interbody fusion (ALIF) plus adjunctive posterior transpedicular instrumentation with circumferential fusion and posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF). Three studies compared PLF with circumferential fusion. One study compared three fusion approaches: PLF, PLIF and circumferential fusion.ConclusionsOne low quality RCT reported no difference in fusion rate between ALIF with posterior transpedicular instrumentation and circumferential fusion, and PLIF and circumferential fusion. There is moderate evidence suggesting no difference in fusion rate between PLF and PLIF. The evidence on the fusion rate of circumferential fusion compared to PLF from qualitative analysis was conflicting. However, no general conclusion could be made due to the scarcity of data, heterogeneity of the trials included, and some methodological defects of the six studies reviewed.

Descompresión medular e instrumentación en un caso de variante sólida de quiste óseo aneurismático en raquis lumbar

We report a 8-year-old boy with two month history of pain and stiffness in his left lower extremity. On x-ray, MRI and scintigraphy examinations a lytic lesion affecting the body and posterior arc of his third lumbar vertebral become evident. The tumour was excised through a double, anterior and posterior approach; spinal fusion with posterior transpedicular instrumentation was also performed in the same procedure; in order to achieve solid fusion tricortical liofilized graft was also inserted. Histological studies evidenced finding compatible with aneurysmal bone cyst solid variant. Five years after surgery the patient is pain free and no recurrence is evident under diagnostic images tools. For the treatment of aneurysmal bone cyst of the spine we recommend complete excision of the tumour in a combined anterior and posterior one staged procedure, together with hardware instrumentation and bone graft, no recurrence or instability is seen after five years followup.

Treatment of Unstable Thoracolumbar Burst Fractures by Indirect Reduction and Posterior Stabilization: Short-Segment Versus Long-Segment Stabilization

In order to compare short-segment stabilization with long-segment stabilization for treating unstable thoracolumbar fractures, we studied fifty patients suffered from unstable thoracolumbar burst fractures. Thirty of them were managed with long-segment posterior transpedicular instrumentation and twenty patients with short-segment stabilization. The mean follow up period was 5.2 years. Pre-operative and post-operative radiological parameters, like the Cobb angle, the kyphotic deformation and the Beck index were evaluated. A statistically significant difference between the two under study groups was noted for the Cobb angle and the kyphotic deformation, while, as far as the Beck index is concerned, no significant difference was noted. In conclusion, either the long-segment or the short-segment stabilization is able for reducing the segmental kyphosis and the vertebral body deformation postoperatively. However, as time goes by, the long-segment stabilization is associated with better results as far as the radiological parameters, the indexes and the patient’s satisfaction are concerned.

Descompresión medular e instrumentación en un caso de variante sólida de quiste óseo aneurismático en raquis lumbar

We report a 8-year-old boy with two month history of pain and stiffness in his left lower extremity. On x-ray, MRI and scintigraphy examinations a lytic lesion affecting the body and posterior arc of his third lumbar vertebral become evident. The tumour was excised through a double, anterior and posterior approach; spinal fusion with posterior transpedicular instrumentation was also performed in the same procedure; in order to achieve solid fusion tricortical liofilized graft was also inserted. Histological studies evidenced finding compatible with aneurysmal bone cyst solid variant. Five years after surgery the patient is pain free and no recurrence is evident under diagnostic images tools. For the treatment of aneurysmal bone cyst of the spine we recommend complete excision of the tumour in a combined anterior and posterior one staged procedure, together with hardware instrumentation and bone graft, no recurrence or instability is seen after five years followup.

Additional screws fixation on fractured vertebrae versus only short-segment posterior instrumentation for thoracolumbar A3 fracture without neurologic deficit

To compare the clinical results of additional screws fixation on fractured vertebrae versus only short-segment posterior transpedicular instrumentation for A3 thoracolumbar fracture without neurologic deficit. Clinical data of 52 cases of thoracolumbar burst fracture without neurologic deficit were retrospectively analyzed. All patients were divided into 2 groups due to different instrumentation and all fractures were classified as type A3 according to AO Classification.From January 2005 to December 2006, 23 cases in group A were treated by short-segment posterior instrumentation combined with additional screws fixation on fractured vertebrae. There were 18 male and 5 female with a mean age of (35.3+/-8.3) years. The fracture segment included 1 in T11, 9 in T12, 11 in L1 and 2 in L2. From January 1999 to December 2004, 29 cases in group B were treated only by conventional short-segment posterior transpedicular instrumentation. There were 20 male and 9 female with a mean age of (37.3+/-6.8) years. The fracture segment included 1 in T11, 7 in T12, 20 in L1 and 1 in L2. The clinical effect and radiographic measurements were respectively compared preoperatively, immediate and 2 years postoperatively. All patients were followed up and the mean follow-up time was (37.4+/-10.9) months (from 24 to 48 months). There was no statistic difference of mean JOA and VAS score between 2 groups preoperatively, immediate and 2 years postoperatively (P>0.05). The average immediate postoperative correction of Cobb's angle was 13.7 degrees+/-7.7 degrees in group A, which was statistically significantly higher than that of 8.8 degrees+/-5.0 degrees in group B (P<0.01). The mean kyphosis correction loss of 2.9 degrees+/-1.5 degrees in group A was statistically significantly lower than that of 5.0 degrees+/-2.9 degrees in group B 2 years postoperatively (P<0.01). The average restoration of anterior height of fractured vertebral body immediate postoperatively was (29.4+/-6.0)% and (21.7+/-6.9)% respectively. The mean correction loss of anterior height 2 years postoperatively was (3.1+/-0.8)% and (6.6+/-3.0)% respectively. The average restoration of posterior height of fractured vertebral body immediate postoperatively was (8.5+/-3.2)% and (6.1+/-1.8)% respectively. The mean correction loss of posterior height 2 years postoperatively was (2.0+/-0.8)% and (3.4+/-1.0)% respectively. There were significant differences in average restoration of anterior/posterior height immediate postoperatively and correction loss of anterior/posterior height 2 years postoperatively between the 2 groups (P<0.01). According to fracture fragments protruded into the spinal canal on immediate postoperative CT image, there were complete reduction in 11 cases (47.8%) and partial reduction in 12 cases (52.2%) in group A, which was statistically significantly better than those in group B (P<0.01). There was no severe neurologic complications and no other complications related to additional screws fixation postoperatively. Pedicle screw breakage occurred in 2 cases in group B and none in group A. Better initial kyphosis correction and less loss of correction 2 years after operation can be obtained by using additional screws fixation on fractured vertebra for thoracolumbar A3 fracture without neurologic deficit.

Traitement par kyphoplastie à foyer ouvert des métastases rachidiennes

Introduction Metastatic spine fractures are very frequent, often occurring in patients with severe medical conditions. Open kyphoplasty and vertebroplasty are part of the classic management of this of fracture. In certain conditions such as spinal cord compression caused by epidural metastatic cancer or collapse of the vertebral body implying a local kyphosis, surgery should allow decompression of the spinal cord and stabilisation of the spine in a simple act. The purpose of this study is to assess a surgical technique combining surgical decompression by laminectomy frequently associated with posterior transpedicular instrumentation and at the same time, an open kyphoplasty to stabilize the anterior part of the spine. Material and methods The same procedure was performed in 14 patients during an 18-month period. The average age of the patients was 54 years. All patients suffered severe pain before the surgical procedure (VSA mean: 7). Neurological deficiency was noted in 10 of the 14 patients with this spinal cord compression. Nineteen vertebrae were treated; a short posterior instrumentation was necessary in 11 patients. The average operative time was 90 minutes. Of the patients with neurological deficiency, the clinical status improved after surgery in all. The average VSA of this series 3 days after surgery was 2. The mean quantity of PMMA injected was 7 cc. Two PMMA leaks, one in the intervertebral disc and one forward, were identified on the postoperative CT scan. The average hospital stay was 7 days. Conclusion This procedure enables surgical decompression, vertebral body consolidation and consequently spinal stabilization of the spine. We did not have any complications related to this procedure which, particularly for the elderly population, is an attractive alternative to major surgery such as vertebrectomy.

Residual mobility of instrumented and non-fused segments in thoracolumbar spine fractures

The surgical management of thoracolumbar fractures presents potential benefits. However, the surgery solve the instability by fusion of mobile segments. We incorporate in our treatment algorithms, the use of restricted arthrodesis at injured levels, regardless of longer instrumentations, as well as the use of non-fused transitory stabilizations, based on the conviction that in non-fused segments without traumatic disc injury, mobility persists once the instrumentation is removed. The goals of this study were to compare the mobility of non-fused segments after hardware removal to a normal range of motion and to find prognostic pre-op imaging patterns. We reviewed 21 consecutive patients who underwent surgery with preservation of mobile segments (non-fused segments included in the construction) in order to recover mobility after removal of instrumentation, performed between 1995 and 2001. All patients were treated by indirect reduction with posterior transpedicular instrumentation. Clinical and radiological outcome was analyzed after an average follow-up of 46.6 months. Satisfactory subjective outcome results were obtained in 94.7%. The dynamic radiological follow-up study showed 75% (21 segments) with normal or decreased range of motion (ROM) and 25% (7 segments) without mobility. The non-fused segments with hardware removal before 10 months of evolution presented a normal or decreased mobility in 83.2% while the segments with hardware removal after 10 months showed 68.8% of mobility. The intervertebral disc (IVD)'s with normal initial MRI morphology preserved their mobility in 81.9%. Complications occurred in four patients: two superficial wound infections and two patients presented a late fracture of one USS Schanz. The results of this study prove that in thoracolumbar fractures, non-fused spinal segments included in pedicular instrumentation maintained mobility in a high percentage once the hardware is removed. 75% of the segments presented a normal or decreased ROM.

Comparison of Sagittal Contour and Posterior Disc Height Following Interbody Fusion

Segmental restoration of sagittal contour is recognized as critical for improved long-term success following instrumented lumbar fusions. As such, the use of wedged implants has become more popular. Few studies exist to assess the postoperative lordotic and disc height changes following these varied techniques in spinal fusion. An observational radiographic study examining lumbar sagittal contour and posterior intervertebral disc space height following posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) was conducted using vertical cages (VCs), wedged structural allograft (WSA), and threaded cylindrical cages (TCCs). Forty-nine consecutive patients (59 spinal segments) were evaluated following single- or two-level interbody fusion with either stand-alone TCCs (n = 18 levels), WSA with posterior transpedicular compression instrumentation (n = 25 levels), or VCs with posterior transpedicular compression instrumentation (n = 16 levels). Standing lumbar radiographs were measured by two independent observers preoperatively, immediately postoperatively (within 1 week), at 6-week follow-up (range 4-8 weeks), and postoperatively (at 1-year follow-up) for segmental lordosis at each level undergoing posterior interbody arthrodesis and posterior intervertebral disc space height to assess indirect nerve root decompression. At the 1-year follow-up, postoperative lordosis was improved in the VC group (+5.3 degrees ; P < 0.005), whereas it decreased in the WSA group (-0.9 degrees ; P = 0.407) and TCC group (-3.5 degrees ; P < 0.005). The posterior disc space height decreased in the VC group (-0.5 mm; P = 0.109), whereas it increased for both the WSA group (+1.2 mm; P = 0.05) and the TCC group (+0.8 mm; P = 0.219). PLIF with stand-alone TCC and PLIF (or TLIF) with WSA and posterior transpedicular instrumentation results in an increased posterior disc height and thus improved indirect nerve root decompression. PLIF (or TLIF) with VC and posterior transpedicular instrumentation results in an overall decrease in posterior disc height. However, TCC and WSA resulted in a loss of lumbar lordosis, whereas VC resulted in an increase in lumbar lordosis.

Patient-Based Outcomes Analysis of Patients With Single Torsion Thoracolumbar—Lumbar Scoliosis Treated With Anterior or Posterior Instrumentation

Since the advent of single, stiff rod anterior instrumentation, and now dual rod anterior instrumentation, most thoracolumbar-lumbar scoliosis is treated with an anterior approach. We have previously reported a retrospective comparison of patients with single torsion thoracolumbar-lumbar scoliosis treated with either anterior or posterior instrumented fusion. The purpose of this study is to examine the patient-based outcomes in this cohort of patients at an average of 5 years (anterior instrumentation) and 9 years (posterior instrumentation). Inclusion criteria were as follows: 1) single torsion thoracolumbar or lumbar curve of <or=70 degrees; 2) thoracic curve bends to <or=20 degrees on nonstressed supine bends; and 3) thoracic kyphosis of <or=60 degrees. Fourteen patients were treated with posterior transpedicular instrumented fusion from 1989 to 1993 (none treated with anterior discectomy). Fourteen patients were treated with anterior, single, solid rod instrumented fusion from 1993 to 1996. SRS 22 was performed after surgery in 12 of 14 patients from the posterior group (average 9.2 years) and in 14 of 14 patients from the anterior group (average 5.1 years). Posterior: The average age was 14.8 years (range 12-17.8 years). Curve correction at average 6.5 years (range 4.0-10.9 years) was 75%. The average lower instrumented vertebra was L3.1. There were no complications. Twelve of 14 patients completed SRS 22 at an average of 9.2 years (range 6.2-10.9 years). Domain scores for Pain, Self-Image, Function, Mental Health, Satisfaction, and Total were 3.8, 4.1, 4.0, 3.8, 4.5, and 4.1, respectively. Anterior: The mean age was 14.5 years (range 12.5-16.5 years). Curve correction at average 4.8 years (range 2.3-7.6 years) was 63% (instrumented segment 89%). The average lower instrumented vertebra was L2.6. Complications included one intercostal neuritis that resolved with suture removal, one broken inferior screw that healed with some loss of correction, and one pseudarthrosis treated successfully with posterior fusion. Fourteen of 14 patients completed SRS 22 at an average of 5.3 years (range 2.0-7.6 years). Domain scores for Pain, Self-Image, Function, Mental Health, Satisfaction, and Total were 4.1, 4.3, 4.4, 4.0, 4.5, and 4.3, respectively. There were no statistically significant differences in any of the domains or the Total score, although there was a trend toward improved function in the patients treated anteriorly. The follow-up was statistically longer in the posterior group. At an average of 9 years of follow-up, patients treated with posterior transpedicular instrumentation have equivalent patient-based outcomes to patients treated with anterior single solid rod instrumentation at an average of 5 years of follow-up.

Treatment of thoracolumbar burst fractures without neurologic deficit by indirect reduction and posterior instrumentation: bisegmental stabilization with monosegmental fusion.

This study retrospectively reviews 20 sequential patients with thoracolumbar burst fractures without neurologic deficit. All patients were treated by indirect reduction, bisegmental posterior transpedicular instrumentation and monosegmental fusion. Clinical and radiological outcome was analyzed after an average follow-up of 6.4 years. Re-kyphosis of the entire segment including the cephaled disc was significant with loss of the entire postoperative correction over time. This did not influence the generally benign clinical outcome. Compared to its normal height the fused cephalad disc was reduced by 70% and the temporarily spanned caudal disc by 40%. Motion at the temporarily spanned segment could be detected in 11 patients at follow-up, with no relation to the clinical result. Posterior instrumentation of thoracolumbar burst fractures can initially reduce the segmental kyphosis completely. The loss of correction within the fractured vertebral body is small. However, disc space collapse leads to eventual complete loss of segmental reduction. Therefore, posterolateral fusion alone does not prevent disc space collapse. Nevertheless, clinical long-term results are favorable. However, if disc space collapse has to prevented, an interbody disc clearance and fusion is recommended.

Interbody cage stabilisation in the lumbar spine

We performed a biomechanical study on human cadaver spines to determine the effect of three different interbody cage designs, with and without posterior instrumentation, on the three-dimensional flexibility of the spine. Six lumbar functional spinal units for each cage type were subjected to multidirectional flexibility testing in four different configurations: intact, with interbody cages from a posterior approach, with additional posterior instrumentation, and with cross-bracing. The tests involved the application of flexion and extension, bilateral axial rotation and bilateral lateral bending pure moments. The relative movements between the vertebrae were recorded by an optoelectronic camera system. We found no significant difference in the stabilising potential of the three cage designs. The cages used alone significantly decreased the intervertebral movement in flexion and lateral bending, but no stabilisation was achieved in either extension or axial rotation. For all types of cage, the greatest stabilisation in flexion and extension and lateral bending was achieved by the addition of posterior transpedicular instrumentation. The addition of cross-bracing to the posterior instrumentation had a stabilising effect on axial rotation. The bone density of the adjacent vertebral bodies was a significant factor for stabilisation in flexion and extension and in lateral bending.

Transpedicular short-segment fusions for treatment of lumbar burst fractures.

A retrospective review of 13 patients who underwent decompression and transpedicular instrumentation for lumbar burst fractures is presented. Average follow-up was 22.5 months. Eighty-four percent of patients reported little or no pain at follow-up. Sixty-nine percent of patients returned to full preinjury activity. Radiographic review demonstrated an average postoperative progression of kyphosis of 8.7%. Anterior vertebral body height was unchanged between preoperative evaluation and follow-up. Although short-segment posterior transpedicular instrumentation with VSP plates did not reestablish or maintain anatomic alignment of the lumbar spine after burst fractures, the clinical outcome was excellent.