Outcome analysis following posterior instrumentation, decompression, and intertransverse fusion for degenerative lumbar spondylolisthesis

P Madhuchandra; G Sunil Santhosh; KP Raju

doi:10.4103/jodp.jodp_89_22

ORIGINAL ARTICLE

Year : 2023 | Volume : 6 | Issue : 2 | Page : 149-153

Outcome analysis following posterior instrumentation, decompression, and intertransverse fusion for degenerative lumbar spondylolisthesis

P Madhuchandra, G Sunil Santhosh, KP Raju
Department of Orthopaedics, BGS Global Institute of Medical Sciences, Bengaluru, Karnataka, India

Date of Submission	02-Oct-2022
Date of Decision	25-Dec-2022
Date of Acceptance	02-Jan-2023
Date of Web Publication	3-May-2023

Correspondence Address:
P Madhuchandra
No. 757, 5^th Main Road, Isro Layout, Bengaluru - 560 078, Karnataka
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jodp.jodp_89_22

Abstract

Background: Degenerative spondylolisthesis is one of the most common causes for low back ache and radiculopathy and causes disability. Various surgical procedures have been described to achieve fusion. Intertransverse fusion (ITF) is the simplest of all with very less rates of complications. Objectives: The objective of this study was to analyze the outcomes of posterior instrumentation with pedicle screws, decompression, and ITF in degenerative lumbar spondylolisthesis based on the clinical outcome with Oswestry Disability Index (ODI) questionnaire and also to assess the fusion rates. Materials and Methods: A single-grouped, prospective interventional study was conducted from June 2015 to June 2019 in a tertiary care hospital. A total of 44 patients with Grades I and II degenerative lumbar spondylolisthesis of the Meyerding radiological grading system were included in the study. Posterior instrumentation with pedicle screws, decompression, and ITF was performed in all these patients. Patients were assessed preoperatively and postoperatively using ODI-based questionnaire. Results: The mean preoperative Oswestry score was 58.33 ± 10.66 and the mean postoperative score was 24.26 ± 12.80 at 1-year follow-up. Fifty percent had excellent and another 50% had better results with overall 100% satisfactory results, with a mean preoperative and postoperative difference of 34.07 ± 18.00 for ODI. All patients achieved radiological fusion. Conclusion: The study observed that ITF for Grades I and II degenerative lumbar spondylolistheses is a safe and simple fusion procedure with lesser rates of complications and higher rates of radiological fusion.

Keywords: Degenerative lumbar spondylolisthesis, intertransverse fusion, Oswestry Disability Index questionnaire

How to cite this article:
Madhuchandra P, Santhosh G S, Raju K P. Outcome analysis following posterior instrumentation, decompression, and intertransverse fusion for degenerative lumbar spondylolisthesis. J Orthop Dis Traumatol 2023;6:149-53

How to cite this URL:
Madhuchandra P, Santhosh G S, Raju K P. Outcome analysis following posterior instrumentation, decompression, and intertransverse fusion for degenerative lumbar spondylolisthesis. J Orthop Dis Traumatol [serial online] 2023 [cited 2023 Jun 4];6:149-53. Available from: https://jodt.org/text.asp?2023/6/2/149/375555

Introduction

Degenerative spondylolisthesis is one of the most common causes of chronic low back ache in adult individuals, especially in individuals with work involving heavy loads and manual laborers. The incidence of degenerative spondylolisthesis varies from 2.7% to 8.4% in patients above the age of 60 years, the incidence being higher in females.^[1]

Degenerative spondylolisthesis commonly occurs at the lumbar and lumbosacral spine. Spondylolisthesis in degenerative type results from the gradual arthritic changes and laxity in the facet joints and there will not be any defect in the vertebral anatomy.^[2],[3] The cause of pain in degenerative spondylolisthesis could be due to various factors. It can be due to mechanical reasons because of degeneration, it could be due to spinal canal stenosis because of the slip, or it can be due to nerve root impingement in the lateral recess.^[4]

Multiple treatment options are available in the literature for degenerative spondylolisthesis. Commonly performed surgeries are posterior instrumentation, decompression, and lumbar interbody fusion and posterior instrumentation, decompression, and intertransverse fusion or posterolateral fusion. The superiority of either of these surgeries over one another is not conclusive in the literature. Posterolateral or intertransverse fusion is simple with lesser complication rates and easy to perform even with surgeons with lesser experience. In this study, we have designed to analyze the outcome analysis following instrumented intertransverse fusion (ITF) based on the Oswestry low back pain disability questionnaire.^[5]

Materials and Methods

The study was conducted in a tertiary care center from June 2015 to June 2019. The study was conducted in a prospective manner. A prior institutional ethical committee clearance was obtained to conduct the study. All patients with degenerative spondylolisthesis who were visiting the department of orthopedics of a tertiary care center were enrolled for the study. Grade I and Grade II degenerative spondylolisthesis were included in the study. Meyerding classification system grading from I to V was used for grading the type of spondylolisthesis.^[6]

A trial of conservative method was employed in all patients enrolled for the study for 3 months with analgesics, physiotherapy, and spinal exercises and bracing. Indications for surgery included the failure of conservative therapy, instability in flexion and extension radiographs, neurological claudication with severe radiculopathy, and patients with neurological weakness. Patients with above Grade III were not included in the study. A total of 47 patients meeting the above criteria were included in the study.

Patients were evaluated for age, sex, duration symptoms, and clinical details such as neurological claudication, radiculopathy, symptoms of stenosis, and neurological weakness. The level of spondylolisthesis and any progression of listhesis during the course of conservative treatment were recorded. Preoperative scoring was recorded using the Oswestry low back pain disability questionnaire. A total of nine different parameters were included in the questionnaire. They included intensity of pain, activities of personal care, lifting, walking, sitting, standing, sleeping, traveling, and employment or homemaking. Five points were assigned for each parameter, with a maximum score of 45. Total score less than 20 indicates minimal disability, score between 20-40 means moderate disability, 40-60 means severe disability, 60-80 means crippled and above 80 indicates patient is bed bound [Table 1].

Table 1: Modified Oswestry low back pain disability questionnaire

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Surgical technique

Under general anesthesia, the patient was placed supine first and autologous bone graft was harvested from the anterior iliac crest in the form of thin slivers ideally measuring about 4 cm in length. Around 4 to 5 pieces were harvested. After wound closure and dressing, the patient was positioned prone. A midline incision was made spanning over the affected vertebrae, and paraspinal muscles were retracted and transverse processes of both vertebrae on both sides were exposed before proceeding further. Pedicle screws were inserted based on anatomical landmarks and with fluoroscopic assistance. Then, decompression was performed by doing laminectomy, the medial part of the facet was removed where ever required, and lateral recess stenosis was cleared off. Finally, ITF was performed by decorticating the transverse processes and placing the harvested slivers of bone graft. Postoperative radiographs were obtained to confirm the position of the implants.

Study measures and statistics

All patients were discharged 1 week to 10 days following surgery. All patients were mobilized from the 2^nd day of surgery with the help of lumbosacral brace. Patients were followed up regularly at 1 month, 3 months, 6 months, and 1 year. Patients' consent was obtained and the survey was taken preoperatively based on Oswestry low back pain disability questionnaire and also during each follow-up. Radiographs were taken during each follow-up to assess the fusion till the fusion was achieved. Bone union was graded on radiographs: Grade 0, no visible gap; Grade 1, amorphous noncontiguous bone; Grade 2, amorphous contiguous bone; and Grade 3, trabecular bone. Outcomes were assessed by comparing preoperative and postoperative Oswestry scoring. The paired t-test was used to evaluate and compare the preoperative and postoperative parameters. SPSS 17 (IBM, Chicago, IL, USA) was used for data analysis. The P < 0.05 was considered statistically significant.

Results

A total of 47 numbers of patients who met the inclusion criteria were enrolled in the study. A minimum 3 months course of conservative methods were employed in all the patients, failing which the patients were operated upon by doing posterior instrumentation and decompression and ITF. Three patients were lost to follow-up in the middle of the study. The remaining 44 patients were included in the study and evaluation of the outcome.

The majority of the patients were females. Thirty among 44 patients were females (68.18%) and 14 were males (31.82%). The female-to-male ratio was 2.1:1 in our case series. The age of the patients in our case series ranged from 45 to 70 years with a mean of 56.2 years. Eighteen of our patients were above the age of 60 years. All the patients had a minimum follow-up of 6 months and the mean follow-up was 14.5 months.

Spondylolisthesis in our series was seen most commonly at L4–L5 level with 32 (72.72%) cases and rest 12 cases, it was at L5–S1 level (27.28%). As per the Meyerding grading system, 28 of our cases belonged to Grade I spondylolisthesis (63.6%) and 16 cases were of Grade II (36.7%). Demographic and clinical characteristics of the patients are summarized in [Table 2]. The mean operative time was 2½ h and the average blood loss was 500 ml. Postoperatively Lumbosacral Corset was given to all patients for a minimum period of 3 months. Spinal exercises were started from 3^rd week.

Table 2: Baseline demographic and clinical profile

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Preoperative assessment was done and recorded for all the patients. Backache was the most common presentation in our series with 33 (75%) patients presenting with back pain. Claudication was seen in 29 (66%) patients, radiculopathy was seen in 11 (30%) patients, and 4 (11%) patients presented with neurological deficits. Postoperatively back pain was relieved in 90% of patients, Claudication pain was relieved in 83% of the patients, radiculopathy was relieved in 82% of the patients, and neurological deficits recovered in 75% of the patients. In one patient, neurological deficit was presented for more than an year and did not recover postoperatively.

Postoperative clinical assessment was done at each follow-up visit and based on the results classified as <20% excellent, 21%–40% better, 41%–60% unchanged, and >60% as worse. Postoperative assessment showed excellent results in 50% of the patients and better results in another 50%. Hence, all patients showed satisfactory results. The mean preoperative Oswestry score was 58.33 ± 10.66 and the mean postoperative score was 24.26 ± 12.80. There was a significant improvement in all the patients with a mean preoperative and postoperative difference of 34.07 ± 18.00 for the Oswestry Disability Index (ODI).

We encountered few intra- and postoperative complications in our series. Two of our patients had dural tear with cerebrospinal fluid leak. Dural repair was done in both cases. Two patients had superficial wound infections and one patient had wound dehiscence. All three patients were diabetics. However, infection subsided, and the wound healed after a course of oral antibiotics and regular wound dressings.

Kant et al. grading system was used to evaluate the radiological union of the fusion.^[7] In this Grades 0 and 1 are pseudoarthrosis and Grades 2 and 3 are good unions. In our series, all patients achieved bony union. Seventy percent of the patients showed Grade 3 union and the remaining 30% showed Grade 2 union [Figure 1]a and [Figure 1]b.

Figure 1: (a) Postoperative X-ray of Grade I L4-L5 Spondylolisthesis insitu fusion was done. (b) Follow up X-ray of the same patient showing complete fusion

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Statistical analysis

In our study, the preoperative ODI was 58.33 ± 10.66 and at the final follow postoperative follow-up the mean ODI was 24.26 ± 12.80. The paired t-test was used to evaluate and compare the preoperative and postoperative ODI scores. P < 0.001 showed a statistically significant reduction in the scores [Table 3].

Table 3: Comparison of Oswestry Disability Index before and after surgery

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Discussion

Degenerative spondylolisthesis is one of the most common causes for low back ache, claudication, and radiculopathy. It is one of the leading causes for disability. Various treatment options exist for spondylolisthesis ranging from conservative treatment to surgical treatment. The conservative treatment options include rest, medications, spinal exercises, physiotherapy, and lumbosacral corsets. Certain cases which are resistant for conservative treatment have to be treated by surgical methods. The most common surgical procedures for symptomatic spondylolisthesis are decompression, posterior instrumentation with either ITF or posterior lumbar interbody fusion (PLIF). PLIF requires high surgical skills and risk of damaging the dura and neural structures is high whereas ITF is more simpler procedure, can be easily performed and with no risk of dural or neural involvement.

Degenerative spondylolisthesis is common in females in previous studies. In our study also, the majority of the cases were in females with a ratio of 2.1:1. L4–L5 is the most common level of listhesis and Grade I listhesis is the most common. Our study is consistent with previous studies. As per the study by Ayling et al., the time to recovery following surgery is 12 months for the ODI.^[8] In our study, the minimum follow-up was 6 months and the mean follow-up was 14.5 months.

There was a significant change in the mean of ODI from 58.33 before surgery to 24.26 after the surgery with a significant P < 0.001. Our findings were comparable to the ODI scores in the previously published studies in the literature.

Comparison of clinical outcomes such as clinical results, fusion rate, nonunion, relief of back pain, radiculopathy, and neurological deficits in our series is compared with the other studies in the literature [Table 4].^{[9],[10],[11],[12],[13]}

Table 4: Comparison of outcomes with other studies

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France et al. evaluated 71 patients who underwent ITF, and 80% of the patients showed satisfactory results.^[12] Suk et al. showed 95% satisfactory results in patients with ITF.^[11] In a study by Madan and Boeree, 81% with ITF showed satisfactory results.^[13]

In our series, we had 50% excellent and 50% better results with an overall satisfactory result of 100%, which correlated well with most of the studies. The radiological bony union rates were 100% in our series with no incidences of nonunion. The radiological fusion rate was better than that reported in other series.^{[9],[10],[11],[12],[13]}

Intertranverse fusion is a relatively easier procedure, with not much technical difficulties. The risk of injuring the neural elements, and dura when doing interbody fusion will not be there in ITF. ITF provides good relief from back pain, radiculopathy, and claudication. In addition, there is added advantage of very good union rates.

Limitations

Although it was a prospective study, our study had some limitations. The sample size of the study could have been higher. Furthermore, a comparative study with PLIF would have been better and would have given much more conclusive recommendations. Radiological fusion can be better confirmed by computed tomography scans to rule out pseudofusions.

Conclusion

With the ITF, we achieved a great clinical improvement with 100% satisfactory results and also 100% radiological fusion. The change in the mean ODI before and after surgery was statistically significant. Being a simple procedure, easy to perform, with good clinical and radiological results and lesser complication rates, we recommend ITF for degenerative spondylolisthesis.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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