Biomechanical Properties of Porous Titanium Cages for Different Lumbar Interbody Fusion Surgeries / 医用生物力学

Objective To study the biomechanical properties of porous titanium cages used for different lumbar interbody fusion surgeries. Methods The three-dimensional (3D) finite element model of the lumbar spine was constructed, and mechanical parameters of porous materials were obtained by mechanical test. The biomechanical properties of porous titanium cages in anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), direct lateral interbody fusion (DLIF) were compared. Results After lumbar interbody surgery, the predicted range of motion (ROM) and the maximum stress in cage of DLIF model and ALIF model were substantially lower than those of PLIF model and TLIF model. The maximum stress in endplate of DLIF model, ALIF model and TLIF model were obviously lower than that of PLIF model. Conclusions DLIF with the porous cage showed advantages in biomechanical properties, which was simple to operate and suitable for minimally invasive surgery in clinical practice. DLIF performed the superior comprehensive properties.

Comparison of clinical efficacy between mini-invasive transforminal lumbar interbody fusion(mis-TLIF) assisted by Quadrant system and PLIF treatment for lumber spondylolisthesis / 临床外科杂志

Objective To comparison of clinical efficacy between mini-invasive transforminal lumbar interbody fusion(mis-TLIF) assisted by Quadrant system and open posterior lumbar interbody fusion (PLIF)treatment for lumber spondylolisthesis,to find a better treatment for lumbar spondylolisthesis.Methods A total of 65 cases who were under lumber spondylolisthesis were retrospectively selected from our hospital,26 cases in mini-invasive transforminal lumbar interbody fusion assisted by Quadrant system (mis-TLIF group).39 cases in open posterior lumbar interbody fusion(PLIF group).Record the incision length,intraoperative blood loss,opertive time,bed time,hospital time,pre-and post-operative visual analogue scale(VAS) and Oswestry disability index(ODI) score were recorded respectively.After surgery,the imaging(X-Ray) evalute the vertebral fusion status.Results There were no significant difference between mis-TLIF group and PLIF group in BMI [(22.77 ± 4.38) kg/m2 and (21.28 ± 5.24) kg/m2],preoperative VAS score [(6.46 ± 1.67) and (6.59 ± 1.56)],preoperative ODI score [(58.70 ± 7.19) ％ and (60.10 ± 9.56) ％] (all P ＞ 0.05).There were significant difference between two groups in incision length [(6.10 ± 0.95) cm and (11.12 ± 2.02) cm],intraoperative blood loss [(247.31 ± 36.72) ml and (340.51 ± 64.32) ml],opertive time[(179.96 ± 17.54) min and(151.85 ± 16.06) min],bed time[(3.62 ± 1.44) d and (4.98 ± 1.74) d],hospital time [(9.38 ± 2.60) d and (11.95 ± 3.61) d] (all P ＜ 0.05).Postoperatively VAS score was assesssd at 1 month [(3.15 ± 1.08]),3months [(1.58 ± 0.81)],6months [(1.08 ± 0.74)] and ODI score was(30.77 ± 6.45) ％,(25.54 ± 6.33) ％,(20.23 ± 7.05) ％,respectively in mis-TLIF group were lower than those of PLIF group (P ＜ 0.05).There were no significant difference between two groups in the fusion rate in 3 months,6 months after operation.Conclusion Mis-TLIF had a lot of advantages relative to PLIF in the treatment of lumber spondylolisthesis,be like less trauma,less bleeding,less hospital time,quick rehabilitation and good curative effect,provide a new minimally invasive method for lumber spondylolisthesis patient.

The Result of Minimal Invasive Anterior Lumbar Interbody Fusion with Posterior Lumbar Interbody Fusion on Degenerative Lumbar Flat Back Disease

STUDY DESIGN: Restrospective study. OBJECTIVES: We tried to find out the effects of minimal invasive anterior lumbar interbody fusion (ALIF) combined with posterior lumbar interbody fusion for degenerative lumbar flat back disease. SUMMARY OF LITERATURE REVIEW: ALIF combined with PLIF is effective in correcting lumbar lordosis. However, the complication rate with conventional ALIF is higher on the lower level. MATERIALS AND METHODS: 21 cases (9 men and 12 women, 46-83 years of age) of having undergone minimal invasive ALIF and PLIF due to degenerative flat back disease were reviewed. The follow-up period was an average of 23 months. We compared the pre-postoperative pain, the functional outcome, the correction of sagittal imbalance and lordotic angle. RESULTS: At final follow-up, 21 cases with the solid fusion experienced a great improvement in their lower back pain(VAS: 7.3 --> 2.6) and leg pain (VAS: 7.0 --> 2.7) and ODI(38.5 --> 18.1). And we experienced correction in sagital imbalance. On levels with anterior fusion, lordotic angle is corrected 6.3 degrees while on levels with posterior fusion, lordotic angle is corrected 9.7 degrees. Plumb line is corrected by 5.2cm, and no complication was found in the follow-up period. CONCLUSIONS: Combined surgery with minimal invasive anterior lumbar interbody fusion and posterior fusion is an effective procedure on patients who need long level surgery for correction of lumbar deformity and decompression.

Management of Deep Wound Infection After Posterior Lumbar Interbody Fusion With Cages

STUDY DESIGN: Retrospective study OBJECTIVES: The purpose of this study was to analyze patients who developed deep wound infections after receiving PLIF for degenerative lumbar disease, and report the treatment outcomes. SUMMARY OF LITERATURE REVIEW: Few studies have examined deep wound infections after PLIF, and there is some controversy regarding whether screws or cages need to be removed to treat infections. MATERIALS AND METHODS: Nine cases(spinal stenosis 6, spondylolisthesis 3) developed a deep wound infection after PLIF from 2001 to 2007. The mean follow up was 48 months (24-72). The clinical results were evaluated using MacNab's criteria. RESULTS: The diagnosis of infection was made based on the clinical symptoms and signs, and inflammatory markers, such as ESR and CRP. The time to diagnosis was less than one week (2), three weeks (2), six weeks (1) and three months or more (4). Bacterial identification was performed on seven cases. MRSA was detected in one of them, and no bacteria were identified in the other six. In two of them, the infection subsided with antibiotic therapy only. In 7 cases, removal of the cage and anterior iliac strut graft was needed for infection control. In four cases, loosened screws were removed during debridement. In 2 cases, additional surgery for pseudarthrosis was required after curing the infection. CONCLUSIONS: In deep infections after PLIF, early diagnosis and bacterial identification are important for reducing the need for a later radical operation. It is recommended that blood markers of infection be measured with a short follow-up period. In a case of persistent infection against prolonged antibiotics, removal of the cage or screw is needed to treat the infection earlier.

Comparison between posterior lumbar fusion with pedicle screws and posterior lumbar interbody fusion with pedicle screws in adult spondylolisthesis

The purpose of this study was to compare patients with lumbar spondylolisthesis submitted to two different surgical approaches, and evaluate the results and outcomes in both groups. In a two-year period, 60 adult patients with lumbar spondylolisthesis, both isthmic and degenerative, were submitted to surgery at the Biocor Institute, Brazil. All patients were operated on by the same surgeon (FLRD) in a single institution, and the results were analyzed prospectively. Group I comprised the first 30 consecutive patients that were submitted to a posterior lumbar spinal fusion with pedicle screws (PLF). Group II comprised the last 30 consecutive patients submitted to a posterior lumbar interbody fusion procedure (PLIF) with pedicle screws. All patients underwent foraminotomy for nerve root decompression. Clinical evaluation was carried out using the Prolo Economic and Functional Scale and the Rolland-Morris and the Oswestry questionnaire. Mean age was 52.4 for Group I (PLF), and 47.6 for Group II (PLIF). The mean follow-up was 3.2 years. Both surgical procedures were effective. The PLIF with pedicle screws group presented better clinical outcomes. Group I presented more complications when compared with Group II. Group II presented better results as indicated in the Prolo Economic and Functional Scale.

O objetivo foi comparar dois grupos de pacientes portadores de espondilolistese lombar que foram submetidos a dois procedimentos cirúrgicos distintos, avaliando os resultados clínicos levando em consideração a qualidade de vida. Durante o período de 1998 a 2001 sessenta pacientes portadores de espondilolistese da coluna lombar ístmica e degenerativa foram submetidos a tratamento cirúrgico no Hospital Biocor em Belo Horizonte, por um mesmo cirurgião foram analisados prospectivamente. Os primeiros trinta pacientes foram submetidos a fusão posterior com parafusos pediculares e os trinta seguintes a fusão posterior com parafusos pediculares associada a fusão intersomática posterior. Os pacientes foram submetidos a liberação radicular com laminectomia e foraminotomia. A avaliação clínica foi feita utilizando as escalas de Prolo Econômico e Funcional, o questionário de Rolland-Morris e de Oswestry. Os resultados clínicos apresentaram que os dois procedimentos realizados foram eficazes. Houve maior número de complicações relacionadas com a biomecânica no grupo que foi submetido somente à fusão posterior e o grupo submetido à fusão posterior associada a fusão intersomática apresentou melhores resultados com retorno as atividades diárias e melhora da qualidade de vida.

Clinical application of spinous process forming in posterior lumbar interbody fusion / 中国矫形外科杂志

[Objective]To explore the feasibility and clinical effects of spinous proscess forming in posterior in the treatment of lower lumbar diseases. [Methods]Seventy-seven cases suffered from lower lumbar diseases were treated using spinous proscess forming as interbody fusion material.The cases included 35 of lumbar disc herniation,21 of spondylolysis,11 of degenerative spondylolisthesis and 10 of spinal canal stenosis.The clinical data and imaging results were investigated.[Results]Seventy-two patiens were followed up for 1 to 2 years while 5 were lost.During following-up,no loosened internal fixation,broken nail or stick,infravertebra prolapsed,or detachment recurrence was found.Preoperative the height of intervertebral space was 8.5?1.9 mm,10.9?1.8 mm at 2 weeks postoperatively and was 10.7?1.7 mm at last follow-up.The height of intervertebral space were significantly increased postoperatively with statistically significant difference(P

Posterior circumferential fusion for severe lumbar stenosis of the elderly / 中国矫形外科杂志

[Objective]To evaluate the application and effectiveness of circumferential fusion for the treatment of severe lumbar stenosis of the elderly.[Method]Eighty-three elderly patients with severe lumbar stenosis were treated with circumferential fusion through one-stage posterior approach(PLIF+PLF)from November 2001 to May 2004 at author's department.Postoperative complications were observed.All patients were followed-up for 24~42 months.JOA scoring system was used to evaluate the operative outcome.Plain radiographs and CT were used to judge fusion status.[Result]All patients were able to ambulate 12~14 days after operation.Symptomatic deep venous thrombosis(DVT)happened in three patients.Ten patients had worsening pain in the back and lower extremities temporarily.At final follow-up,low back pain was relieved significantly.JOA scores improved from(13.6?3.8)points before surgery to(22.3?4.6)points.Bone fusion was achieved in all operated intervertebral spaces.[Conclusion]Posterior circumferential fusion is one of safe,effective and reasonable treatment choises for elderly patients with severe lumbar stenosis.

Comparison of Posterior Lumbar Interbody Fusion with Posterolateral Fusionin Degenerative Lumbar Spinal Disorders / 대한정형외과학회잡지

PURPOSE: This study compared the surgical treatment results between posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) with pedicle screw fixation in degenerative lumbar spinal disorders. MATERIALS AND METHODS: In 45 cases of PLF (group I) and 45 cases of PLIF (group II), lumbar lordosis, segmental lordosis, bone union and complications were considered to be an evaluation criterion. Kim's functional evaluation scale was used for the clinical results. RESULTS: The average lumbar lordosis in group I was 36.84+/-8.31 degrees preoperatively, 40.58+/-7.61 degrees postoperatively and 35.73+/-7.61 degrees at the last follow up. On the other hand, the respective changes in the average lumbar lordosis were 31.53+/-7.09 degrees, 39.11+/-7.21 degrees, and 35.47+/-7.76 degrees in group II. Definitive solid union was obtained in 41 cases in group I (91.1%) and 43 cases in group II (95.6%). The rate of complications was 24.4% (11 cases) in group I and 2.2% (6 cases) in group II, and a satisfactory functional outcome were obtained in 43 cases (95.6%) in group I and 41 cases (91.1%) in group II. CONCLUSION: Both PLF and PLIF on short segment fusion provided satisfactory bone union and clinical results. In segmental lordosis, there were no significant differences between the two groups. However, PLIF was more effective in preventing lumbar lordosis and complications than PLF. A longer term follow up will be needed to evaluate the adjacent segmental degeneration and maintenance of the sagittal balance.

Posterior Lumbar Interbody Fusion via a Unilateral Approach

This study sought to determine the outcomes of posterior lumbar interbody fusion (PLIF), via a unilateral approach, in selected patients who presented with unilateral leg pain and segmental instability of the lumbar spine. Patients with a single level of a herniated disc disease in the lumbar spine, unilateral leg pain, chronic disabling lower back pain (LBP), and a failed conservative treatment, were considered for the procedure. A total of 41 patients underwent a single-level PLIF using two PEEK(TM) (Poly-Ether-Ether-Ketone) cages filled with iliac bone, via a unilateral approach. The patients comprised 21 women and 20 men with a mean age of 41 years (range: 22 to 63 years). Two cages were inserted using a unilateral medial facetectomy and a partial hemilaminectomy. At follow-up, the outcomes were assessed using the Prolo Scale. The success of the fusion was determined by dynamic lumbar radiography and/or computerized tomography scanning. All the patients safely underwent surgery without severe complications. During a mean follow-up period of 26 months, 1 patient underwent percutaneous pedicle screw fixation due to persistent LBP. A posterior displacement of the cage was found in one patient. At the last follow up, 90% of the patients demonstrated satisfactory results. An osseous fusion was present in 85% of the patients. A PLIF, via a unilateral approach, enables a solid union with satisfactory clinical results. This preserves part of the posterior elements of the lumbar spine in selected patients with single level instability and unilateral leg pain.

Posterior Lumbar Interbody Fusion via a Unilateral Approach

This study sought to determine the outcomes of posterior lumbar interbody fusion (PLIF), via a unilateral approach, in selected patients who presented with unilateral leg pain and segmental instability of the lumbar spine. Patients with a single level of a herniated disc disease in the lumbar spine, unilateral leg pain, chronic disabling lower back pain (LBP), and a failed conservative treatment, were considered for the procedure. A total of 41 patients underwent a single-level PLIF using two PEEK(TM) (Poly-Ether-Ether-Ketone) cages filled with iliac bone, via a unilateral approach. The patients comprised 21 women and 20 men with a mean age of 41 years (range: 22 to 63 years). Two cages were inserted using a unilateral medial facetectomy and a partial hemilaminectomy. At follow-up, the outcomes were assessed using the Prolo Scale. The success of the fusion was determined by dynamic lumbar radiography and/or computerized tomography scanning. All the patients safely underwent surgery without severe complications. During a mean follow-up period of 26 months, 1 patient underwent percutaneous pedicle screw fixation due to persistent LBP. A posterior displacement of the cage was found in one patient. At the last follow up, 90% of the patients demonstrated satisfactory results. An osseous fusion was present in 85% of the patients. A PLIF, via a unilateral approach, enables a solid union with satisfactory clinical results. This preserves part of the posterior elements of the lumbar spine in selected patients with single level instability and unilateral leg pain.

Surgical Treatments for Lumbar Disc Disease in Adolescent Patients; Chemonucleolysis / Microsurgical Discectomy/ PLIF with Cages

The herniated lumbar disc (HLD) in adolescent patients is characterized by typical discogenic pain that originates from a soft herniated disc. It is frequently related to back trauma, and sometimes it is also combined with a degenerative process and a bony spur such as posterior Schmorl's node. Chemonucleolysis is an excellent minimally invasive treatment having these criteria: leg pain rather than back pain, severe limitation on the straight leg raising test (SLRT), and soft disc protrusion on computed tomography (CT). Microsurgical discectomy is useful in the cases of extruded or sequestered HLD and lateral recess stenosis due to bony spur because the nerve root is not decompressed with chymopapain. Spinal fusion, like as PLIF, should be considered in the cases of severe disc degeneration, instability, and stenosis due to posterior central bony spur. In our study, 185 adolescent patients, whose follow-up period was more than 1 year (the range was 1 - 4 years), underwent spinal surgery due to HLD from March, 1998 to December, 2002 at our institute. Among these cases, we performed chemonucleolysis in 65 cases, microsurgical discectomy in 94 cases, and posterior lumbar interbody fusion (PLIF) with cages in 33 cases including 7 reoperation cases. The clinical success rate was 91% for chemonucleolysis, 95% for microsurgical disectomy, and 89% for PLIF with cages, and there were no non- union cases for the PLIF patients with cages. In adolescent HLD, chemonucleolysis was the 1st choice of treatment because the soft adolescent HLD was effectively treated with chemonucleolysis, especially when the patient satisfied the chemonucleolysis indications.

The Posterior Decompression and Posterior Lumbar Interbody Fusion Using a Mini-open Technique: New Suggestion of Minimally Invasive Technique A Preliminary Report / 대한정형외과학회잡지

PURPOSE: To introduce mini-open posterior decompression with posterior lumbar interbody fusion (PLIF) and to assess its clinical outcomes. MATERIALS AND METHODS: Eight patients who underwent L4-5 posterior decompression with PLIF using a mini-open technique were followed up for an average 8 months. Three patients had degenerative lumbar spinal stenosis and five patients had spinal stenosis with degenerative spondylolisthesis. We performed posterior decompression with PLIF through a mini-incision (2.5 cm paramedian incision at the both sides) including percutaneous pedicle screw fixation. The operative time, amount of blood loss and complications were analyzed. Clinical outcomes were assessed by using McNab criteria and VAS (visual analogue scale) for postoperative back pain. RESULTS: The mean operative time was 172.5 min (range, 130-235 min). The mean amount of intraoperative blood loss was 178.1 mL (range, 95-310 mL). All procedures were completed without transfusion. VAS for back pain rapidly reduced from 10 on the immediate postoperative day to 3 on the third day and 2 on the seventh day. At the last follow up, five patients had no back pain and the three remaining patients had a VAS 0.75. The clinical outcomes were excellent in 5 patients and good in 3 patients. CONCLUSION: Mini-open posterior decompression and the PLIF technique offer a useful minimally-invasive modality for the treatment of single level spinal stenosis.

Pyogenic L4-5 Spondylitis Managed with Percutaneous Drainage Followed by Posterior Lumbar Interbody Fusion: A Case Report / 대한척추외과학회지

STUDY DESIGN: A case report and review of literature OBJECTIVE: Mostly operative treatment for pyogenic spondylits has been performed via anterior approach, which is often followed by greater morbidity and late sequelae. Efficacy of percutaneous drainage and posterior lumbar interbody fusion (PLIF), which are increasingly applied with favorable results, as an alternative of anterior surgery was investigated. MATERIAL AND METHOD: A case of pyogenic L4-5 spondylitis with psoas abscess but without neurologic deficit in a 66-year old lady was reviewed. Percutaneous drainage under fluoroscopic guide was performed. 7 weeks later, curettage of disc space and posterior lumbar interbody fusion using autogeous graft was performed to get rid of dead space and achieve stability. Administration of antimicrobial agents followed. RESULTS: Infection was controlled successfully. Clinical features including ambulatory function improved. Solid fusion was achieved. SUMMARY: In treating pyogenic spondylitis with moderate abscess, percutaneous drainage and posterior lumbar interbody fusion seemed to be one of alternatives of anterior surgery.

Posterior Fusion of Spondylolisthesis (Posterolateral Fusion and Posterior Lumbar Interbody Fusion) / 대한척추외과학회지

Spondylolithesis is defined as forward slipping of a vertebral body on distal vertebra, and this slipping causes a spectrum of symptoms from mild back pain to overt spinal stenosis. The various treatment modality for spondylolisthesis is introduced. In general, the slip of lesser than 50 per cent can be successfully treated with in situ fusion in children and early adolescent without neurologic deficit. Operative reduction of spondylolisthesis may be indicated in cauda equina syndrome, progressive slip surpassing 40 to 50 per cent, major deformity causing decompensation or distress, major pain or deficit plus two or more risk factor. Risk factors for in situ fusion include the following: slip angle greater than 25 degrees, trapezoidal L5, rounded sacral end plate, hyperlordosis exceeding 50 degrees L2-S1, L5 radiculopathy requiring decompression, female adolescents, excess lumbosacral mobility, sign of sacral root stretch. Stabilization after decompression of high grade isthmic spondylolisthesis is difficult due to insufficiency of fusion base, gap between the bases and incompetent anterior disc support. So posterior lumbar interbody fusion(PLIF) offered anterior support, reduction of the deformity and a broad fusion base may be applied. PLIF may be indicated in spinal stenosis with narrow euroforaminal space, isthmic spondylolisthesis with instability after removal of posterior structure of vertebra, grade 3,4 isthmic spondylolisthesis, failure of posterolateral fusion, symptomatic degenerative disc disease.

The results of the Posterior Lumbar Interboby Fusion using Titanium mesh cage for Spondylolisthesis / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study analysing and comparing what between posterior lumbar interbody fusion plus posterior lateral fusion(PLIF+PLF) and PLF alone for Spondylolisthesis(Degenerative type+Isthmic type). Thirty patients were treated by posterior lumbar interbody fusion(PLIF) using Harms' cage and posterolateral fusion(PLF) with transpedicular screw fixation. Forty-nine patients were treated by posterolateral fusion with transpedicular screw fixation. OBJECTIVES: This is to verify the advantages of adding posterior lumbar interbody fusion using Harms' cage to the usual posterolateral fusion with transpedicular screw fixation SUMMARY OF BACKGROUND DATA: Interbody fusions have certain distinct mechanical advantages over posterolateral ones. Autologous cancellous bone is the preferred graft material, but might be soft to maintain the disc space during fusion. METHODS: Union rate, slip reduction, sagittal angle correction, disc height restoration, and clinical results by Lin's criteria were analysed. RESULTS: Nonunion was observed in 5 PLF cases(10%) and one PLIF case(3%). Loss of slip reduction was 0.7% in PLIF and 2.59% in PLF(P<0.05). Loss of sagittal angle correction was 1.27degreein PLIF and 3.65degreein PLF(P<0.05). Loss of disc height restoration was 2.6% in PLIF and 7.6% in PLF(P<0.05). Clinical evaluation in PLIF+PLF was excellent in 67%, good in 30%, and fair in 3%. Clinical evaluation in PLF was excellent in 59%, good in 33%, and fair in 8%. More excellent results were noted in PLIF+PLFcases. CONCLUSIONS: Adding posterior lumbar interbody fusion using Harms' cage showed better radiological results and more excellent clinical results compared to posterolateral fusion with transpedicular screw fixation.

The Change of Segmental Sagittal angle in Low - grade spondylolisthesis after Pedicular Screw Fixation with or without PLIF - PLIF + PLF versus PLF groups - / 대한정형외과학회잡지

For more than 80% of body weight is transmitted through the anterior and middle column, the interbody gap produced by operative reduction of spondylolisthesis is potential risk factor for redisplacement, implant failure, pseudoarthrosis and kyphosis. In biomechanical aspect, augmentation of the anterior column support by interbody fusion is desirable to prevent above problems in surgical treatment of spondylolisthesis. Recently, circumferential fusion is recommended in high-grade spondylolisthesis (grade III, IV, or V ), but there is some controversy about additional interbody fusion in posterior instrumentation for low-grade spondylolisthesis (grade I or II ). So, the purpose of this retrospective study was to compare the segmental sagittal angle in 35 patients of low-grade spondylolisthesis who was performed posterior instrumentation with or without posterial lumbar interbody fusion (PLIF) and to find out the risk factors of the loss of segmental sagittal angle in cases of posterior instrumentation without posterial lumbar interbody fusion (PLIF).

Long Term Follow up Results of Threaded Fusion Cage(T.F.C.) in Surgical Treatment of Spondylolisthesis

The goal of operation in spondylolisthesis is improving radiculopathy and relieving lower back pain preventing further progression of the slip, through decompression of neural elements and fusion of spinal pseudoarthrosis, respectively. The author performed the posterior lumbar interbody fusion technique using a Threaded Fusion Cage(T.F.C.) for 41 patients as the surgical treatment for mild spondylolisthesis. All patients enrolled in the study were implanted with a T.F.C. at a single unstable level. We have investigated the outcome results for at least one year(mean 25.8 months). Of these patients 95% have shown solid fusions. Using the Prolo scale for economic and functional rating, the combined results of excellent, good score is 51%, but clinically symptomatic improvement is 66%. Therefore, posterior lumbar interbody fusion using T.F.C. was useful in treatment of mild degree spondylolisthesis.

Adding Posterior Lumbar Interbody Fusion to Pedicle Screw Fixatin and Posterolateral Fusion after Decompression in Spondylolytic Spondylolisthesis / 대한정형외과학회잡지

STUDY DESIGN: This is a retrospective study analyzing 76 patients treated by decompression, pedicle screw instrumentatin and fusion for spondylolytic spondylolisthesis with symptomatic spinal stenosis. OBJECTIVES: This is to verify the advantages of adding posterior lumbar interbody fusion (PLIF) to the usual posterolateral fusion (PLF) with pedicle screw instrumentation. SUMMARY OF BACKGROUND DATA: Stabilization after decompression of spondylolytic spondy- lolisthsis is difficult due to insufficiency of fusion base, gap between the bases and incompetent anterior disc support. PLIF offers anterior support, reduction and a broad fusion base. METHODS: Forty patients were treated with PLF and 36 were treated with additional PLIF. They were compared for union, reductin of the deformity and clinical results. RESULTS: The patients were followed up for more than 2 years (mean: 4.6 years). Nonunion was observed in 3 PLF cases (7.5%) and none in PLIF. Reduction of slippage was 28.3% in PLF and 41.6% in PLIF (p < 0.05). In PLF group, 8 patients (20%) had recurrence of deformity with loss of reduction more than 50%. Hardware failures occurred in 2 with PLF. There was no major neurologic complications in both groups. Both groups had a few difference in the satisfactory results, but some difference in the excellent result by Kirkaldy-Willis criteria. Excellent result was 45% in PLF and 75% in PLIF. CONCLUSIONS: Addition of PLIF to PLF following a complete decompression and pedicle screw flxation is a recommendable procedure for the treatment of spondylolytic spondylolisthesis with spinal stenosis.

Clinical, Radiological Analysis of Threaded Fusion Cage(TFC) in Surgical Treatment of Spondylolisthesis

The indications for surgical treatment of spondylolisthesis are as follows:pain unrelieved by conservative treatment. Persistent neurologic signs. Progression of the slip or slip greater than 50 per cent. Postural deformity or walking difficulty due to tight hamstring muscles. The goal of operation for spondylolisthesis is to relieve radiculopathy and low back pain, and to prevent further progression of the slip through decompression of neural elements and fusion for pseudoarthrosis. The authors performed the posterior lumbar interbody fusion using Threaded Fusion Cage(TFC) on 23 patients with spondylolisthesis. All patients have been followed for 3 to 12 months. We then studied the clinical and radiological outcomes of these patients and verified the relationship between clinical outcomes and radiological findings. Summaries of the results are as followings. 1) Successful bone fusion was achieved in 20 out of 23 cases(87%). 2) Neurological signs were improved in 20 out of 23 cases(87%). 3) The majority of cases which demonstrated radiologic bone fusion also showed clinical improvement. Posterior lumbar interbody fusion using TFC was useful in the treatment of mild degree spondylolisthesis.