Severe Coronal Deformity Correction with a Modification of the Transpsoas Technique: Technical Note

Case Presentation

Austin Neurosurg Open Access. 2015;2(1): 1026.

Severe Coronal Deformity Correction with a Modification of the Transpsoas Technique: Technical Note

Namath S. Hussain¹* and Rod J. Oskouian²

¹Department of Neurosurgery, Penn State Hershey Medical Center, USA

²Department of Neurosurgery, Swedish Medical Center, USA

*Corresponding author: Namath S. Hussain,Department of Neurosurgery, Penn State Hershey Medical Center, 30 Hope Drive, EC110, Hershey, PA 17033, USA

Received: January 13, 2015; Accepted: June 12, 2015; Published: June 15, 2015


Objective: To review the proper patient selection and the rationale for the transpoas technique and when it should be applied as a useful approach in spine surgery. Our study aims to describe a technical variance with regard to the lateral transpoas interbody access and fusion technique.

Methods: Using two descriptive cases, we aim to illustrate how this technical variance can be utilized to the spine surgeon’s advantage in cases where the patient’s anatomy brings along additional challenges to the traditional technique. Emphasis was placed on examining and describing coronal pathology and how it can be corrected.

Results: Preoperative films along with intraoperative pearls are reviewed along with postoperative film results such that the reader will gain a balanced overview of the transpsoas technique and how its versatility can be applied for coronal pathology.

Conclusion: The transpoas technique can be modified to provide the spine surgeon with the ability to correct severe coronal deformity in a safe manner.

Keywords: Lateral interbody fusion; Retroperitoneal; Transpsoas; Minimally invasive spine surgery; Spine fusion


Coronal deformity correction continues to be one of the most difficult challenges for scoliosis surgeons [1]. The minimally invasive lateral retroperitoneal transpsoas approach has become an increasingly popular corridor to correct coronal deformity. Scoliosis is a common cause of axial back pain with attendant signs and symptoms of radiculopathy, most commonly ipsilateral to the concavity of the coronal deformity [1,2]. Neurogenic claudication or instability along with varying degrees of spondylolisthesis are often encountered [3]. Abnormal spinal biomechanics due to these unbalanced forces can lead to paraspinal muscle fatigue and pain with associated degrees of Degenerative Disc Disease (DDD) which many patients undergo surgical intervention for. Chronic compression from foraminal stenosis and DDD can lead to extremity weakness, sensory disturbances, and pain [4,5]. Many different surgical approaches for the treatment of pain caused by severe coronal deformity have been developed and can range from the simple limited decompression to multi-level fusion procedures [3,6]. Prior to choosing a particular surgical technique, the goals of surgery must be clearly defined. The approach must be selected based on these goals, tempered with patient-specific anatomical and physiological factors that affect related risks and complications [4,7,8]. Neuromonitoring and other adjuncts must be utilized when needed to improve safety [4]. Open posterior approaches necessitate paraspinal muscle dissection and ligament removal which may lead to postoperative kyphotic or coronal deformity due to loss of facets and other stabilizing structures [2,6,9-11].

The minimally invasive Lateral Transpsoas Interbody Fusion (LTIF) has become an increasingly popular means of fusion because it obviates the need to disrupt the paraspinal corridor that the posterior and transforaminal approaches require [5,12,13]. Many authors have also cited the advantage of being able to indirectly decompress the foramina through the placement of a large graft that can increase disc space height [4,5,14] and improve fusion rates [12]. The attendant risks of lumbar plexus injuries from this approach can be decreased with a comprehensive understanding of patient-specific regional anatomy; especially when there is a degree of coronal deformity which can lead to stretching of the psoas over a rigid convex spine. Utilization of directional intraoperative Electromyography (EMG) is an important key to identifying the location of the femoral and other nerves [4,15].

LTIF is a new minimally invasive technique to approach the spine from a lateral corridor that has been in used for the past six years. As more and more data are collected with regard to anatomy, technique, and complications [4,13], clinicians are becoming more comfortable with utilizing the technique for a wide variety of indications and pathologies. As surgeons become more skilled at using the technique for DDD and other more common pathologies [12], they have ventured into more complex cases with unique anatomic challenges [5,16]. Deformity correction is an area where industry-surgeon collaborations have brought new products into the market that have improved surgeons’ abilities to gain access to the disc space in a safe manner and correct fixed deformities without the attendant risks associated with open, more invasive approaches. We detail in our report the use of a new technique variance of the transpsoas approach for deformity correction utilizing angled instrumentation to gain access to severely coronally offset disk spaces and a new set of instrumentation to gain access safely to correct deformity and gain an adequate fusion. This new technique has been used at our institution for the past three years with excellent results but has not been reported in the literature as of yet.


We examined the preoperative and intraoperative films of two patients who underwent elective LTIF. We have used this technique in over ten cases over the past two years. We have performed over 200 LTIF procedures over the past two years. Fusion status, deformity correction, and construct integrity were assessed with dynamic radiographs. Both patients underwent LTIF with the companybranded version known as an extreme lateral interbody fusion (XLIF; NuVasive, San Diego, CA, USA) with an 18-26 mm × 8-10 mm × 50-60 mm cage. The vertebral body below was used to determine the docking landmark for the transpsoas retractor. Directional EMG was utilized to ensure docking of the retractor was anterior to the femoral nerve. Disc height restoration with the large interbody graft improved forminal cross-sectional area and with partial correction of the coronal deformity.


There were no anesthesia-related intraoperative complications or surgical adverse events. Both patients experienced transient postoperative anterior thigh numbness that resolved by 3 months. There were no permanent neurological deficits. There were no hardware failures or pseudoarthrosis noted during follow up.

Case presentation 1

Our first patient presented with severe axial low back pain and right lower extremity radiculopathy without any lower extremity weakness. Radiographs and CT imaging of the lumbar spine (Figure 1), (Figure 2) revealed severe degenerative disease with massive osteophyte buildup leaving the patient with severe right foraminal stenosis at multiple lumbar levels. The patient was taken to the operating room for LTIF at the L2-3 and L3-4 levels. Preoperative films (Figure 1), (Figure 2), intraoperative films with slides inserted (Figure 3), and postoperative films (Figure 4), (Figure 5) are shown.