A Qayum, M Panigrahi, V Sreedhar, M Vijayasaradhi, A Kumar
degenerative spondylolisthesis, isthmic spondylolisthesis, vas score, [tlif]
A Qayum, M Panigrahi, V Sreedhar, M Vijayasaradhi, A Kumar. TLIF With Minimally Invasive Spinal Fixation For Spondylolisthesis. The Internet Journal of Minimally Invasive Spinal Technology. 2008 Volume 3 Number 4.
The objective of this study is to discuss the procedure and the advantages of this minimally invasive percutaneous technique for fixation of spondylolisthesis. Literature is full of various fusion methods for spondylolisthesis. We studied this minimal invasive method 9[n=9] patients were operated by minimal invasive instrumentation for Spondylolisthesis from Jan 07 to July 08 at Nizam’s Institute of Medical Sciences. 3[33.3%] of the nine were male patients and 6 [66.6% were females]. Age range was from 40 to 58 years. 1 patient [11.1%] had spondylolisthesis at L3-4 level, 6 [66.6%] at L4-5 level and the 2 [22.2%] at L5- S1 level. 6 [66.6%] had Grade I listhesis and 3 [33.3%] had Grade II listhesis. 4 patients [44.4%] had degenerative type of Spondylolisthesis , 4 [44.4%] had lytic type and one [11.1%] had post-operative discectomy status.Pain decreased in all the patients [mean decrease in VAS score of 7.8].There was no incidence of post-operative neurological deficits in any patient. There was less amount of muscle dissection leading to less operative blood loss and less post-operative pain and discomfort to the patient. The average surgery to discharge time period is 4 days. The average operating time is 4.5 hours. This is a safe procedure and another lesser invasive tool in the surgeon’s armamentarium for Grade I & II listhesis. It is effective in producing pain relief as well as causing less morbidity to the patient.
Abbreviations used: VAS-visual analogue score, TLIF-Transforaminal lumbar interbody fusion
Spondylolisthesis is a penalty for erect posture.Originol description was of lytic listhesis, later degenerative was described. It causes various degrees of morbidity and most commonly occurs at the lumbosacral junction at L5/S1 level. Aetiologically it has 5 types: congenital or dysplastic, isthmic, degenerative, traumatic, and pathologic (Wiltse, 1976)11. Besides conservative treatment, in persons with incapacitating symptoms surgery is indicated. The surgical aim is to stabilize the segment and decompress the neural elements if needed. Albee and Hibbs separately published their initial work on spinal fusion. Their methods were applied quickly to cases involving trauma, tumors, and, later, scoliosis. In the latter half of the 20th century, spinal fusion was used increasingly to treat degenerative disorders of the spine, including degenerative spondylolisthesis and degenerative scoliosis. Degenerative spondylolisthesis is observed more frequently as the population ages. Up to 5.8% of men and 9.1% of women have this type of spondylolisthesis.
The etiology of spondylolisthesis is multifactorial.269 A congential predisposition ,posture, gravity, rotational forces, and high concentration of stress loading all play parts in its development . The following aetiological types are adapted from Wiltse et al (1961)11:The dysplastic ,Isthmic,degenerative,traumatic,pathological.
Meyerding grading  include: Grade 1 - Less than 25% of vertebral diameter ,Grade II - 25-50% ,Grade III - 50-75% ,Grade IV - 75-100% and Grade V Spondyloptosis - Greater than 100%. Indications for surgical intervention (fusion) include : Neurological signs - Radiculopathy (unresponsive to conservative measures), myelopathy, neurogenic claudication, Type 1 and type 2 slips, with evidence of instability, progression of spondylolisthesis, traumatic spondylolisthesis, Iatrogenic spondylolisthesis ,Type 1,2 (degenerative) spondylolisthesis with gross instability and incapacitating pain1,postural deformity and gait abnormality.
The goal of surgery is to decompress the neural elements and immobilize the unstable segment or segments of the spinal column. This is usually performed with elimination of motion across the facet joint and the intervertebral disc through arthrodesis. Fusion: Multiple methods exist to achieve intersegmental fusion in the lumbosacral spine of which widely used methods include: Posterolateral (intertransverses): Most surgeons use the intertransverse or transverse process/sacral ala arthrodesis with the use of iliac crest autograft alone or in conjunction with allograft. This may be performed over one or multiple levels with high success rates (up to 90%) of fusion. Some surgeons prefer a 2-level fusion (i.e., L4-S1) for treating high-grade (>50%) spondylolisthesis . Segmental spinal instrumentation allows rigid fixation of the fused segments and the possibility of performing reduction of the segment with spondylolisthesis. Lumbar interbody fusion: Biomechanically interbody fusion increases the stability of the spinal segment by placing structural bone graft in compression in the anterior and middle columns and increases the overall surface area of the bony fusion. It can be done with posterior (i.e, posterior lumbar interbody fusion [PLIF]), transforaminal lumbar interbody fusion[TLIF] or anterior (i.e, anterior lumbar interbody fusion [ALIF]) approaches. TLIF is essentially an extended PLIF which was developed in response to some technical problems in PLIF.The main difference between two posterior fusion procedures is that TLIF involves removal of an entire facet joint on one side, whereas PLIF is usually done on both sides by removing only part of fact joint. A growing number of surgeons use interbody grafts to augment their posterolateral fusion techniques to achieve higher rates (>95%) of arthrodesis. Cages have far more better results in terms of disc height maintenance and indirect neural decompression than bone grafts alone11 .It should be noted that grade 2 or higher slips are predisposed to higher rates of graft complications. Fixation Although the use of spinal instrumentation in skeletally immature patients is considered optional by some surgeons ,for some patients with isthmic-type spondylolisthesis, most spinal surgeons believe that rigid fixation is needed to achieve a solid fusion reliably. For degenerative-type slips, fixation has been shown to achieve higher rates of solid arthrodesis.
Material And Methods
In the present study all patients were asked history and subjected to thorough clinical examination. The preoperative VAS scores were noted down.The preoperative dynamic x-rays were taken and the intervertebral disc heights and slip grade (Meyerding grade) were measured. Patient’s written and informed consent was taken. All the investigations relevant from the point of view of anaesthesia were done and the pre-anaesthetic clearance was taken before surgical procedure. Operative technique: After satisfactory induction of anaesthesia, the patient was positioned prone on a four-poster frame and all pressure points were well padded. A standard midline posterior approach was used to expose the spine as per the level of involvement. With a midline skin and paramedian muscle splitting incision ,the hidden area of Mcnab was resected which includes unilateral partial facetectomy and hemi-hemilaminectomy Lateral margin of ligamentum flavum was identified and partially resected.Nerve root of involved level was identified and kept safe with gel foam pledgets. The total discectomy and complete removal of cartilaginous endplate was performed at the degenerated level.The level involved was fixed with transpedicular monoaxial or polyaxial screws using minimal invasive stab incisions with percutaneous cannulated screw fixation followed by insertion of precontoured rods over the screw slots using sextant jig. After the reduction maneuver and distraction of intervertebral space the interbody spacer was placed.Final construct was tightened in compression to achieve lordosis. All these steps were done using C-ARM.We did not perform any SSEP during the procedure.Haemostasis was achieved and stab wounds were closed in layers. Patient was subjected to X-ray Lumbosacral spine[ AP & Lateral views] on first postoperative day. After surgery patients were braced in LSO for a period of 3 months for comfort.Patient was discharged on third post operative day and advised to follow the OPD on tenth day for removal of stitches and subsequently to every three months for about 18 months. The total operative time averaged 4.5 hours(Range 3-5hrs).The estimated blood loss was 100ml(Range 50-150 ml)
This study involved (n=9).6 [66.6%] were females and 3 [33.3%] were males. Patients Included were: Patients having age of 40-58 years, symptomatic patient with disturbed ADL,single level L3/4, L4/L5 or L5/S1 Grade I or grade II spondylolisthesis. Patients with severe osteoporosis,recent spondylodiscitis subchondral sclerosis,visual and cognitive impairement were excluded. All the patients underwent transforaminal discectomy after a muscle splitting approach and unilateral partial facetectomy. Short segment posterior fixation was done using using sextant instrumentation [medtronics,USA] underc-arm control. In 55.5%(n=5 ) patients titanium cages were used while in 44.4 %(n=4) patients PEEK Cage was used .The mean follow-up period was 18 months.
Among nine (n=9) patients,66.6%(n=6) were females and 33.3%(n=3) were males.11.1% (n=1) were having L3/L4 ,66.6%(n=6) were having L4/L5 and 22.2%[n=2] were having L5/S1 spondylolisthesis. 66.6%(n=6) were of grade I and 33.3%(n=3) were of grade II spondylolisthesis.6 patients [n=6] were of degenerative spondylolisthesis,2 patients[ n=2] of lytic variety and one patient [n=1]was of post-discectomy status.Reduction was achieved in all the patients and well maintained postoperatively.
There was no incidence of post-operative neurodeficit.We observed less amount of muscle dissection, less operative blood loss,less postoperative pain and average hospitalization of 4 days.
There was a significant decrease in pain with mean VAS score improvement of 7.8, postoperatively at the end of follow up period of 18 months1. There was no case of fresh neurodeficit, implant loosening, loss of reduction, infection, subsidence or pseudoarthrodesis during this whole period of follow up.
Advantages of Procedure
This surgery eliminates need for a large midline incision and significant muscle dissection. Paraspinal muscles are bluntly split, rather than divided, leading to potentially shorter periods of hospitalization and recovery. Both the pedicle screws and pre-contoured rods are placed through stab incisions.An ideal lateral to medial screw trajectory is used and as such significant paraspinous muscle dissection is avoided. There is least retraction of dural sac [not exposed] and nerve root.
L5/S1 level gives a harder time to the surgeon due to high lumbosacral kyphus or high iliac crests. The procedure has a steep learning curve
It is a safe procedure, less invasive in nature and effective in producing pain relief1 besides causing less morbidity to the patient. It provides anterior column support and posterior tension band. It is a unilateral approach without need to expose the dura. It provides the benefits of a 360੦ fusion without performing an anterior approach. Patient rehabilitation is faster.