Surgery versus conservative management in adult isthmic spondylolisthesis--a prospective randomized study: part 1

STUDY DESIGN: A prospective randomized study was performed. OBJECTIVE: To determine whether posterolateral fusion in patients with adult isthmic spondylolisthesis results in an improved outcome compared with an exercise program. SUMMARY OF BACKGROUND DATA: In spondylolisthesis, satisfactory results have been reported with both surgical and conservative management. The evidence for treatment efficacy, however, is weak because prospective randomized studies are lacking. METHODS: In this study, 111 patients were randomly allocated to an exercise program (n = 34) or posterolateral fusion with or without transpedicular fixation (n = 77). The inclusion criteria were lumbar isthmic spondylolisthesis of any grade, at least 1 year of low back pain or sciatica, and a severely restricted functional ability in individuals 18 to 55 years of age. Pain and functional disability were quantified before treatment and at 1- and 2-year follow-up assessments by visual analog scales (VAS). RESULTS: The 2-year follow-up rate was 93%. The functional outcome, as assessed by the Disability Rating Index and the pain reduction, was better in the surgically treated group than in the exercise group at both the 1- and 2-year follow-up assessments (P < 0.01). In the longitudinal analysis, the mean Disability Rating Index and pain improved in the surgical group (P < 0.0001). In the exercise group, the Disability Rating Index did not change at all, whereas the pain decreased slightly (P < 0.02). CONCLUSIONS: Surgical management of adult isthmic spondylolisthesis improves function and relieves pain more efficiently than an exercise program.     

Instrumented and noninstrumented posterolateral fusion in adult spondylolisthesis--a prospective randomized study: part 2

STUDY DESIGN: A prospective randomized study was performed. OBJECTIVE: To determine whether transpedicular fixation improves the outcome of posterolateral fusion in patients with adult isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA: The use of transpedicular fixation remains controversial. Both a positive effect and no effect from additional transpedicular fixation have been reported. METHODS: In this study, 77 patients randomly underwent posterolateral fusion with (n = 37) or without (n = 40) transpedicular fixation. The inclusion criteria were lumbar isthmic spondylolisthesis of any grade, at least 1 year of low back pain or sciatica, and severely restricted functional ability in individuals 18 to 55 years of age. RESULTS: The follow-up rate was 94%. At a 2-year follow-up assessment, the level of pain and functional disability were strikingly similar in the two groups, and there was no significant difference in fusion rate. CONCLUSIONS: Lumbar posterolateral fusion performed in situ for adult isthmic spondylolisthesis relieves pain and improves function. The use of supplementary transpedicular instrumentation does not add to the fusion rate or improve the clinical outcome.     

Determinants of cost-effectiveness in lumbar spinal fusion using the net benefit framework: a 2-year follow-up study among 695 patients

Up to one third of patients undergoing lumbar spinal fusion show no improvement after the procedure and thus, despite evidence from RCTs, there might be a rationale for observational studies clarifying indications. Similarly, selection of the right patients for the right procedure could have significant impact on cost-effectiveness, which in some countries, in turn, affects whether procedures are to be available through the National Health Service. The aim of this study was to investigate determinants of cost-effectiveness in lumbar spinal fusion. An observational cohort study with 2-year follow-up was conducted: 695 patients who underwent lumbar spinal fusion from 1996 to 2002 were included and followed for 2 years. Patients had a localized segmental pathology and were diagnosed with MRI-verified isthmic spondylolisthesis (26%) or disc degeneration (74%). The surgical techniques were non-instrumented posterolateral fusion (14%), instrumented posterolateral fusion (54%), and circumferential fusion (32%). Societal costs and improvement in functional disability (Dallas Pain Questionnaire) were transformed into a net benefit measure. Classical linear regression of the net benefit was conducted using predictors of age, sex, diagnosis, duration of pain, smoking habits, occupational status, severity of disability, emotional distress, surgical technique, and number of levels fused. The main results were that two determinants were found to negatively influence net benefit: smoking and diagnosis, whereas two others were found to be positively associated with the net benefit: severe disability and emotional distress. In conclusion, predicting net benefit reverses the picture usually seen in studies predicting clinical outcomes, because the response variable is based on improvement over time rather than end-point measures alone. Smoking habits, diagnosis, pre-operative disability, and pre-operative emotional distress were found to be significantly associated with the net benefit of spinal fusion.     

Comparison of Functional Outcomes following Surgical Decompression and Posterolateral Instrumented Fusion in Single Level Low Grade Lumbar Degenerative versus Isthmic Spondylolisthesis

Background

The two most common types of surgically treated lumbar spondylolisthesis in adults include the degenerative and isthmic types. The aim of this study was to compare the functional outcomes of surgical decompression and posterolateral instrumented fusion in patients with lumbar degenerative and isthmic spondylolisthesis.

Methods

In this retrospective study, we reviewed the clinical outcomes in surgically treated patients with single level, low grade lumbar degenerative, and isthmic spondylolisthesis (groups A and B, respectively) from August 2007 to April 2011. We tried to compare paired settings with similar initial conditions. Group A included 52 patients with a mean age of 49.2 ± 6.1 years, and group B included 52 patients with a mean age of 47.3 ± 7.4 years. Minimum follow-up was 24 months. The surgical procedure comprised neural decompression and posterolateral instrumented fusion. Pain and disability were assessed by a visual analog scale (VAS) and the Oswestry Disability Index (ODI), respectively. The Wilcoxon and Mann-Whitney U-tests were used to compare indices.

Results

The most common sites for degenerative and isthmic spondylolisthesis were at the L4-L5 (88.5%) and L5-S1 (84.6%) levels, respectively. Surgery in both groups significantly improved VAS and ODI scores. The efficacy of surgery based on subjective satisfaction rate and pain and disability improvement was similar in the degenerative and isthmic groups. Notable complications were also comparable in both groups.

Conclusions

Neural decompression and posterolateral instrumented fusion significantly improved pain and disability in patients with degenerative and isthmic spondylolisthesis. The efficacy of surgery for overall subjective satisfaction rate and pain and disability improvement was similar in both groups.     

Long-term clinical, functional and radiological outcome 21 years after posterior or posterolateral fusion in childhood and adolescence isthmic spondylolisthesis

Long-term radiological studies have shown that a high rate of fusion can be achieved with posterolateral spondylodesis. Radiological findings, however, do not always correlate with patient satisfaction and outcome. No studies have been conducted on the long-term results of functional outcome, including spinal mobility and trunk strength measurements, after operative treatment of spondylolysis and spondylolisthesis, as compared with the reference population. Of 129 consecutive patients with isthmic spondylolisthesis operated on with spondylodesis between 1977 and 1987, 107 (83%) participated in the study. Posterior spondylodesis was performed in 29 (27%) patients and posterolateral spondylodesis in 78 (73%) patients. The average follow-up time was 20.9 years (range 15.1–26.2 years). Radiographs obtained preoperatively and at the 2-year and final follow-ups were assessed for quality of the fusion and degenerative changes. Outcome was assessed at the last follow-up by physical examination, spinal mobility and non-dynamometric trunk strength measurements, and calculation of Oswestry disability index (ODI) scores. The fusion rate was 66% after posterior fusion and 83% after posterolateral fusion. Degenerative changes in the lumbar intervertebral discs above the fusion level were noted in 13 (12%) patients. At the final follow-up 14% of patients reported back pain often or very often. The mean ODI score was 7.6 (0–68). Moderate disability was found in 6% of patients and severe disability in 1%; one patient was crippled. No correlation was found between disc degeneration or solidity of the fusion and the ODI score. Non-dynamometric trunk strength measurements corresponded with the reference values. Lumbar flexion, but not extension, was diminished when compared with that of the reference population. The overall long-term clinical outcome is good in patients with spondylolysis and spondylolisthesis operated on with posterior or posterolateral fusion. The clinical and radiological outcomes do not, however, appear to correlate with each other. Lumbar flexion is diminished, but the patients perform, on average, as well as the general population in non-dynamometric trunk strength measurements.     

Posterior lumbar interbody fusion versus posterolateral fusion in spondylolisthesis: a prospective controlled study in the Han nationality

In this prospective study, our aim was to compare the clinical outcome of posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) in spondylolisthesis. A total of 138 patients with spondylolisthesis were randomly assigned to two groups: those operated on with pedicle screw fixation and posterior lumbar interbody fusion by autografting (PLIF), and those operated on with pedicle screw fixation and posterolateral fusion by autografting (PLF). The patients were followed-up for four years. Clinical evaluation was carried out using the Oswestry disability index (ODI) and pain index (VAS). Radiography was performed preoperatively and postoperatively to assess the fusion. Both surgical procedures were effective, but the PLF group showed more complications related to hardware biomechanics. There was no significant statistical difference in clinical and functional outcome in the two groups. The PLIF group presented a better fusion rate than the PLF group.     

Uninstrumented in situ fusion for high-grade childhood and adolescent isthmic spondylolisthesis: long-term outcome

BACKGROUND: Intermediate-term radiographic studies have shown that anterior and circumferential techniques result in high fusion rates in patients with high-grade spondylolisthesis, whereas posterolateral fusion is less successful. We are not aware of any long-term comparative studies in which these three methods have been evaluated with regard to functional outcome, including systematic spinal mobility and trunk strength measurements. METHODS: Sixty-nine of eighty-three consecutive patients with high-grade isthmic spondylolisthesis who underwent posterolateral (twenty-one), anterior (twenty-three), or circumferential (twenty-five) uninstrumented spondylodesis between 1977 and 1991 participated in the study. The average duration of follow-up was 17.2 years. Radiographs that were made preoperatively and at the time of the most recent follow-up were assessed with regard to fusion quality and degenerative changes. Outcome was assessed at the time of the most recent follow-up by independent observers on the basis of a physical examination, spinal mobility and nondynamometric trunk strength measurements, and Oswestry Disability Index scores. RESULTS: The mean preoperative vertebral slip was 61% in the posterolateral fusion group, 63% in the anterior fusion group, and 71% in the circumferential fusion group. The final fusion rate was 86% (eighteen of twenty-one) in the posterolateral fusion group, 100% (twenty-three of twenty-three) in the anterior fusion group, and 96% (twenty-four of twenty-five) in the circumferential fusion group. A decrease in lumbar intervertebral disc height at the first mobile level superior to the fusion was noted in five patients in the posterolateral fusion group, seven patients in the anterior fusion group, and one patient in the circumferential fusion group (p = 0.037). The mean Oswestry Disability Index score was 9.7 for the posterolateral fusion group, 8.9 for the anterior fusion group, and 3.0 for the circumferential fusion group (p = 0.035). Nondynamometric trunk strength measurements corresponded with referential values. Abnormally low lumbar flexion affected the posterolateral and circumferential fusion groups more often than the anterior fusion group (p = 0.0015). The percentage of slip showed inverse correlations with lumbar flexion, lumbar extension, and trunk side-bending. CONCLUSIONS: As assessed on the basis of patient-based outcomes, circumferential in situ fusion provided slightly better long-term results than did posterolateral or anterior in situ fusion. When the radiographic and functional results were combined with the patient-based outcomes, the overall differences between the three groups were small.     

椎弓根器械复位固定后两种不同融合方法对腰椎峡部裂型滑脱的疗效比较

目的观察比较椎弓根器械复位固定后两种不同融合法PLF与PLIF对峡部裂型滑脱的疗效。方法Ⅱ度以内腰椎峡部裂型滑脱共47例,一组22例,椎弓根器械复位固定后行PLF(PLF组);另一组25例,椎弓根器械复位固定后行PLIF(PLIF组)。对两组的临床疗效(ODI评分)、X线影像学结果(包括:滑脱矫正、滑脱节段椎间隙高度改变、滑脱节段前突角改变及骨融合)及并发症进行对比观察。结果术后即刻X线影像学结果,包括:滑脱矫正、滑脱节段椎间盘高度、滑脱节段前突角,两组间无显著差异(P>0.05);术后2年随访时,滑脱矫正及滑脱节段椎间隙高度的维持上PLIF组优于PLF组(P<0.05),骨融合率及滑脱节段前突角两组间无显著差异(P>0.05),但两组间临床疗效(ODI评分)及并发症发生率无显著差异(P>0.05),内固定失败率PLF组高于PLIF组。结论椎弓根器械复位固定并PLF与PLIF都是治疗Ⅱ度以内腰椎峡部裂型滑脱的有效方法,PLIF在对滑脱矫形的维持及结构的稳定上具有优越的力学性能,PLF后期易出现矫正丢失及内固定失败,但临床疗效不受明显影响。     

The positive effect of posterolateral lumbar spinal fusion is preserved at long-term follow-up: a RCT with 11–13 year follow-up

Introduction Few studies have investigated the long-term effect of posterolateral lumbar spinal fusion on functional outcome. Aim To investigate the long-term result after posterolateral lumbar spinal fusion with and without pedicle screw instrumentation. Methods Questionnaire survey of 129 patients originally randomised to posterolateral lumbar spinal fusion with or without pedicle screw instrumentation. Follow-up included Dallas Pain Questionnaire (DPQ), Oswestry Disability Index (ODI), SF-36 and a question regarding willingness to undergo the procedure again knowing the result as global outcome parameter. Results Follow-up was 83% of the original study population (107 patients). Average follow-up time was 12 years (range 11–13 years). DPQ-scores were significantly lower than preoperatively in both groups (P < 0.005) and no drift towards the preoperative level was seen. No difference between the two groups were observed (instrumented vs. non-instrumented): DPQ Daily Activity mean 37.0 versus 32.0, ODI mean 33.4 versus 30.6, SF-36 PCS mean 38.8 versus 39.8, SF-36 MCS mean 49.0 versus 53.3. About 71% in both groups were answered positively to the global outcome question. Patients who had retired due to low back pain had poorer outcome than patients retired for other reasons, best outcome was seen in patients still at work (P = 0.01 or less in all questionnaires, except SF-36 MCS P = 0.08). Discussion Improvement in functional outcome is preserved for 10 or more years after posterolateral lumbar spinal fusion. No difference between instrumented fusion and non-instrumented fusion was observed. Patients who have to retired due to low back pain have the smallest improvement.     

非椎间隙狭窄型峡部裂腰椎滑脱症的手术治疗

目的：探讨非椎间隙狭窄型峡部裂腰椎滑脱的手术治疗。方法对50例非椎间隙狭窄型峡部裂型腰椎滑脱患者采用短节段固定加椎板、横突间后外侧植骨融合的手术方法进行治疗。结果50例患者症状改善优良率达96％,植骨融合率100％。结论短节段内固定加后外侧植骨融合的手术方法具有手术时间短,不暴露椎管,避免对神经根及硬脊膜的误伤,出血少,费用低等优点。是治疗非椎间隙狭窄型峡部裂腰椎滑脱的一种有效方法。     

Long-term functional and radiographic follow-up of surgically treated isthmic spondylolisthesis

We studied patients treated surgically for isthmic spondylolisthesis since 1968, with special emphasis on a detailed functional assessment. We followed up 22 patients for an average of 15 years, with a mean age at time of surgery of 18 years. All patients underwent a thorough physical examination and were evaluated with radiographs at baseline and at follow-up. The functional status of patients at the time of follow-up was assessed with 2 self-report pain and function instruments. All surgical procedures included spinal fusion, 12 of which included internal fixation by using Harrington distraction rods with sacral bars. At final follow-up, there was no statistically significant difference in mean slip percentage or mean slip angle compared with baseline radiographs. Functional evaluation was compared with a control group consisting of 52 patients. We conclude that the long-term radiographic and functional outcome is excellent for patients treated surgically for isthmic spondylolisthesis.     

Lumbar spinal fusion. Outcome in relation to surgical methods, choice of implant and postoperative rehabilitation

Chronic low back pain (CLBP) has become one of the most common causes of disability in adults under 45 years of age and is consequently one of the most common reasons for early retirement in industrialised societies. Accordingly, CLBP represents an expensive drain on society's resources and is a very challenging area for which a consensus for rational therapy is yet to be established. The spinal fusion procedure was introduced as a treatment option for CLBP more than 70 years ago. However, few areas of spinal surgery have caused so much controversy as spinal fusion. The literature reveals divergent opinions about when fusion is indicated and how it should be performed. Furthermore, the significance of the role of postoperative rehabilitation following spinal fusion may be underestimated. There exists no consensus on the design of a program specific for rehabilitation. Ideally, for any given surgical procedure, it should be possible to identify not only possible complications relative to a surgical procedure, but also what symptoms may be expected, and what pain behaviour may be expected of a particular patient. The overall aims of the current studies were: 1) to introduce patient-based functional outcome evaluation into spinal fusion treatment; 2) to evaluate radiological assessment of different spinal fusion procedures; 3) to investigate the effect of titanium versus stainless steel pedicle screws on mechanical fixation and bone ingrowth in lumbar spinal fusion; 4) to analyse the clinical and radiological outcome of different lumbar spinal fusion techniques; 5) to evaluate complications and re-operation rates following different surgical procedures; and 6) to analyse the effect of different rehabilitation strategies for lumbar spinal fusion patients. The present thesis comprises 9 studies: 2 clinical retrospective studies, 1 clinical prospective case/reference study, 5 clinical randomised prospective studies and 1 animal study (Mini-pigs). In total, 594 patients were included in the investigation from 1979 to 1999. Each had prior to inclusion at least 2 years of CLBP and had therefore been subjected to most of the conservative treatment leg pain, due to localized isthmic spondylolisthesis grades I-II or primary or secondary degeneration. PATIENT-BASED FUNCTIONAL OUTCOME: Patients' self-reported parameters should include the impact of CLBP on daily activity, work and leisure time activities, anxiety/depression, social interests and intensity of back and leg pain. Between 1993 and 2003 approximately 1400 lumbar spinal fusion patients completed the Dallas Pain Questionnaire under prospective design studies. In 1996, the Low Back Pain Rating scale was added to the standard questionnaire packet distributed among spinal fusion patients. In our experience, these tools are valid instruments for clinical assessment of candidates for spinal fusion procedures. RADIOLOGICAL ASSESSMENT: It is extremely difficult to interpret radiographs of both lumbar posterolateral fusion and anterior interbody fusion. Plain radiographs are clearly not the perfect media for analysis of spinal fusion, but until new and better diagnostic methods are available for clinical use, radiographs will remain the golden standard. Therefore, the development of a detailed reliable radiographic classification system is highly desirable. The classification used in the present thesis for the evaluation of posteroalteral spinal fusion, both with and without instrumentation, demonstrated good interobserver and intraobserver agreement. The classification showed acceptable reliability and may be one way to improve interstudy and intrastudy correlation of radiologic outcomes after posterolateral spinal fusion. Radiology-based evaluation of anterior lumbar interbody fusion is further complicated when cages are employed. The use of different cage designs and materials makes it almost impossible to establish a standard radiological classification system for anterior fusions. BONE-SCREW INTERFACE: Mechanical binding at the bone-screw interface was significantly greater for titanium pedicle screws than it was for stainless steel. This could be explained by the fact that the titanium screws had superior bone on-growth. There was no correlation between screw removal torques and pull-out strength. Clinically, the use of titanium and titanium-alloy pedicle screws may be preferable for osteoporotic patients and those with decreased osteogenesis. OUTCOME: The present series of studies observed significant long-term functional improvement for approximately 70% of patients who had undergone lumbar spinal fusion procedure. Solid fusion as determined from radiographs ranged from 52% to 92% depending on the choice of surgical procedure. The choice of surgical procedure should relate to the diagnosis, as patients with isthmic spondylolisthesis (Grades I and II) are best served with posterolateral fusion without instrumentation, and patients with disc degeneration seem to gain most from instrumented posterolateral fusion or circumferential fusion. COMPLICATIONS: The number of perioperative complications increased with the use of pedicle screw systems to support posterolateral fusions and increased further with the use of circumferential fusions. There was no significant association between outcome result and perioperative complications. The risk of reoperation within 2 years after the spinal fusion procedure was, however, significantly lower for those who had received circumferential fusion in comparison to posterolateral fusion with instrumentation. Furthermore, the risk of non-union was found to be significantly lower for patients who had received circumferential fusion as compared to posterolateral fusion with and without instrumentation. The complications of sexual dysfunction and fusion at non-intended levels were found to be significant but without influence on the overall outcome. REHABILITATION: The patients in the Back-café group performed a succession of many daily tasks significantly better and moreover had less pain compared with both the Video and Training groups 2 years after lumbar spinal fusion. The Video group had significantly greater treatment demands outside the hospital system. This study demonstrates the importance of the inclusion of coping schemes and questions the role of intensive exercises in a rehabilitation program for spinal fusion patients.     

Knee injury rating scales

Background and purpose An increasing number of lumbar fusions are performed using allograft to avoid donor-site pain. In elderly patients, fusion potential is reduced and the patient may need supplementary stability to achieve a solid fusion if allograft is used. We investigated the effect of instrumentation in lumbar spinal fusion performed with fresh frozen allograft in elderly patients.

Methods 94 patients, mean age 70 (60–88) years, who underwent posterolateral spinal fusion either non-instrumented (51 patients) or instrumented (43 patients) were followed for 2–7 years. Functional outcome was assessed with the Dallas pain questionnaire (DPQ), the low back pain rating scale pain index (LBPRS), and SF-36. Fusion was assessed using plain radiographs.

Results Instrumented patients had statistically significantly better outcome scores in 6 of 7 parameters. Fusion rate was higher in the instrumented group (81% vs. 68%, p = 0.1). Solid fusion was associated with a better functional outcome at follow-up (significant in 2 of 7 parameters). 15 patients (6 in the non-instrumented group and 9 in the instrumented group) had repeated lumbar surgery after their initial fusion procedure. Functional outcome was poorer in the group with additional spine surgeries (significant in 4 of 7 parameters).

Interpretation Superior outcomes after lumbar spinal fusion in elderly patients can be achieved by use of instrumentation in selected patients. Outcome was better in patients in which a solid fusion was obtained. Instrumentation was associated with a larger number of additional surgeries, which resulted in a lesser degree of improvement. Instrumentation should not be discarded just because of the age of the patient.     

Comparison of one-level minimally invasive and open transforaminal lumbar interbody fusion in degenerative and isthmic spondylolisthesis grades 1 and 2

Minimally invasive lumbar fusion techniques have only recently been developed. The goals of these procedures are to reduce approach-related soft tissue injury, postoperative pain and disability while allowing the surgery to be conducted in an effective manner. There have been no prospective clinical reports published on the comparison of one-level transforaminal lumbar interbody fusion in low-grade spondylolisthesis performed with an independent blade retractor system or a traditional open approach. A prospective clinical study of 85 consecutive cases of degenerative and isthmic lower grade spondylolisthesis treated by minimally invasive transforaminal lumbar interbody fusion (MiTLIF) or open transforaminal lumbar interbody fusion (OTLIF) was done. A total of 85 patients suffering from degenerative spondylolisthesis (n = 46) and isthmic spondylolisthesis (n = 39) underwent one-level MiTLIF (n = 42) and OTLIF (n = 43) by two experienced surgeons at one hospital, from June 2006 to March 2008 (minimum 13-month follow-up). The following data were compared between the two groups: the clinical and radiographic results, operative time, blood loss, transfusion needs, X-ray exposure time, postoperative back pain, length of hospital stay, and complications. Clinical outcome was assessed using the visual analog scale (VAS) and the Oswestry disability index. The operative time, clinical and radiographic results were basically identical in both groups. Comparing with the OTLIF group, the MiTLIF group had significantly lesser blood loss, lesser need for transfusion, lesser postoperative back pain, and shorter length of hospital stay. The radiation time was significantly longer in MiTLIF group. One case of nonunion was observed from each group. Minimally invasive TLIF has similar surgical efficacy with the traditional open TLIF in treating one-level lower grade degenerative or isthmic spondylolisthesis. The minimally invasive technique offers several potential advantages including smaller incisions, less tissue trauma and quicker recovery. However, this technique needs longer X-ray exposure time.     

Long-term outcomes evaluation after pars defect repair in adult low-grade isthmic spondylolithesis

Adult low-grade isthmic spondylolisthesis is often treated by posterolateral lumbar fusion (PLF), with a certain rate of complications and non-return to work. Alternatives to fusion, like pars defect repair (PDR), were used with encouraging results in young populations and athletes but their outcomes were rarely evaluated for adult patients. This retrospective study quantitatively analysed the long-term outcomes in adult isthmic spondylolisthesis patients treated by PLF or PDR. At a mean follow-up of 9 years, clinical, socio-professional, radiological data and Stauffer-Coventry score were available for 59 patients (39 cases treated by PLF and 20 treated by PDR). The overall clinical outcomes were comparable in both populations (88% in the PDR and 80% in PLF group 1), with a larger proportion of excellent results (56% vs. 10%) and of return to work in the PDR group. Radiological quantitative analysis highlighted stationary evolution and comparable outcomes for the two groups, except for vertebral slip evolution and adjacent level degeneration rate. Abnormal kinematic patterns outlined for PLF patients 20% of pseudarthrosis and 42% of adjacent levels hypermobility and for PDR ones low mobility for the levels adjacent to instrumented vertebra in 40% of cases. Quantified analysis of biomechanical parameters interpreted altogether with clinical outcome, complications and economic burden of the patient, provided accurate objective data for a better appreciation of global outcome, allowing for a preliminary view on long-term outcomes after PDR in adult low-grade isthmic spondylolisthesis, which were not presented in literature until now.     

Minimally invasive anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation for isthmic spondylolisthesis.

BACKGROUND CONTEXT: Most surgeons have thought that posterior decompression is necessary to treat isthmic spondylolisthesis with leg pain. However, the surgical procedure not only requires wide muscle dissection but can also lead to spinal instability. The authors' treatment concept for isthmic spondylolisthesis is one-stage anterior reduction and posterior stabilization with minimally invasive surgical procedure without touching the spinal thecal sac and nerve. PURPOSE: To investigate a new surgical concept of minimally invasive anterior-posterior fusion without posterior decompression for the treatment of isthmic spondylolisthesis with leg pain. STUDY DESIGN: This is a retrospective study of 73 patients with isthmic spondylolisthesis who underwent minimally invasive anterior lumbar interbody fusion (mini-ALIF) followed by percutaneous pedicle screw fixation (PF) between October 2000 and February 2002. PATIENT SAMPLE: A total of 73 patients with low-grade isthmic spondylolisthesis (46 with Grade 1 and 27 with Grade 2) who underwent mini-ALIF followed by percutaneous PF were retrospectively analyzed. There were 20 men and 53 women, with a mean age of 50.6 (range, 19 to 77) years. All patients had low back pain and referred or radicular leg pain or neurogenic intermittent claudication in walking or standing. Average duration of symptoms was 26 (range, 3 to 120) months. OUTCOME MEASURES: The clinical outcome was graded according to the modified Macnab criteria. METHODS: The authors retrospectively reviewed clinical and radiological data of 73 patients who had isthmic spondylolisthesis. All patients underwent mini-ALIF and percutaneous PF on the same day between October 2000 and February 2002. The mean follow-up period was 16 months (range, 12 to 26). RESULTS: The mean operating time, blood loss and hospital stay were 210 minutes, 135 ml and 4.1 days, respectively. No blood transfusion was necessary. Clinical outcome was excellent in 26 patients (35.6%), good in 43 (58.9%), fair in 3 (4.1%) and poor in 1 (1.4%). The fusion rate was 97.3% (71 of 73). There were 6 cases (8.2%) of mini-ALIF complications and 6 (8.2%) of percutaneous PF complications. There were no postoperative neurologic deficits. CONCLUSIONS: Mini-ALIF followed by percutaneous PF is an efficacious alternative for low-grade isthmic spondylolisthesis, and posterior decompression is not necessary to relieve leg symptoms. This minimally invasive combined procedure offers many advantages, such as preservation of posterior arch, no nerve retraction, less blood loss, excellent cosmetic results, high fusion rate and early discharge.     

Uninstrumented posterolateral spinal arthrodesis: is it the gold standard technique for I° and II° grade spondylolisthesis in adolescence?

We retrospectively reviewed the outcome of uninstrumented posterolateral spinal arthrodesis in 49 patients with lumbar isthmic spondylolisthesis grades I° and II° in adolescent patients in the time of surgery, who participate at follow-up, between 1980 and 1995. The goal of our study is to analyse the clinical and radiographic imaging at long follow-up in uninstrumented posterolateral arthrodesis and to evaluate the efficiency and the validity of surgical technique in young patients (<18 years). All patients had failed previous conservative treatment. The average age at follow-up was 33.5 years (range 25–42 years) and the average follow-up time was 19.7 years (range 12–27 years). The clinical outcome measures were the Oswestry Disability Index, the SF-36, and the visual analogic score. All measures assessed the endpoint outcomes at 20 years after surgery. The outcome of spinal fusion was good with 43 (87.7%) patients attaining solid fusion, pseudoarthrosis in 6 patients (12.3%). None of our patients complained of excessive postoperative wound pain. Additionally, no complications, such as wound infection, were encountered. Satisfactory results were obtained in 94% of patients and this was closely associated with the rate of successful fusion. The results suggest that clinical outcome is closely related to the attainment of solid fusion.

     

两种手术方式治疗退变性腰椎滑脱症的疗效比较

[目的]对比椎弓根钉内固定联合单枚Cage斜形放置椎间植骨融合与椎弓根钉内固定后外侧融合治疗退变性腰椎滑脱的临床疗效。[方法]单节段退变性腰椎滑脱患者44例,按手术方式分为:Ⅰ组23例,行椎弓根器械复位固定后单枚Cage斜形放置的椎体间融合;Ⅱ组21例,行椎弓根器械复位固定后外侧融合。对两组术后JOA评分,腰腿痛VAS评分,影像学进行随访。[结果]随访15~36个月,两组间JOA评分、骨融合率无显著性差异(P>0.05);Ⅰ组在下腰痛缓解的VAS评分、Taillard指数、相对椎间隙高度的维持方面优于Ⅱ组(P<0.05)。[结论]单枚融合器附加椎弓根钉的椎间植骨融合是治疗退变性腰椎滑脱更为理想的方法。     

Uninstrumented posterolateral spinal arthrodesis: is it the gold standard technique for I° and II° grade spondylolisthesis in adolescence?

We retrospectively reviewed the outcome of uninstrumented posterolateral spinal arthrodesis in 49 patients with lumbar isthmic spondylolisthesis grades I° and II° in adolescent patients in the time of surgery, who participate at follow-up, between 1980 and 1995. The goal of our study is to analyse the clinical and radiographic imaging at long follow-up in uninstrumented posterolateral arthrodesis and to evaluate the efficiency and the validity of surgical technique in young patients (<18 years). All patients had failed previous conservative treatment. The average age at follow-up was 33.5 years (range 25–42 years) and the average follow-up time was 19.7 years (range 12–27 years). The clinical outcome measures were the Oswestry Disability Index, the SF-36, and the visual analogic score. All measures assessed the endpoint outcomes at 20 years after surgery. The outcome of spinal fusion was good with 43 (87.7%) patients attaining solid fusion, pseudoarthrosis in 6 patients (12.3%). None of our patients complained of excessive postoperative wound pain. Additionally, no complications, such as wound infection, were encountered. Satisfactory results were obtained in 94% of patients and this was closely associated with the rate of successful fusion. The results suggest that clinical outcome is closely related to the attainment of solid fusion.     

Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis

Spondylolisthesis is a heterogeneous disorder characterized by subluxation of a vertebral body over another in the sagittal plane. Its most common form is isthmic spondylolisthesis (IS). This study aims to compare clinical outcomes of posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF) with posterior instrumentation in the treatment of IS. We performed a randomized prospective study in which 80 patients out of a total of 85 patients with IS were randomly allocated to one of two groups: PLF with posterior instrumentation (group I) or PLIF with posterior instrumentation (group II). Posterior decompression was performed in the patients. The Oswestry low back pain disability (OLBP) scale and Visual Analogue Scale (VAS) were used to evaluate the quality of life (QoL) and pain, respectively. Fisher's exact test was used to evaluate fusion rate and the Mann-Whitney U test was used to compare categorical data. Fusion in group II was significantly better than in group I (p=0.012). Improvement in low back pain was statistically more significant in group I (p=0.001). The incidence of neurogenic claudication was significantly lower in group I than in group II (p=0.004). In group I, there was no significant correlation between slip Meyerding grade and disc space height, radicular pain, and low back pain. There was no significant difference in post-operative complications at 1-year follow-up. Our data showed that PLF with posterior instrumentation provides better clinical outcomes and more improvement in low back pain compared to PLIF with posterior instrumentation despite the low fusion rate.