SpineUniverse Case Study Library

Facet Arthropathy with Back Pain, Stenosis, Synovial Cyst and L5 Radiculopathy

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This surgeon is a consultant of Medtronic, but received no compensation for this case discussion.


The patient is a 67-year-old female with intermittent back pain that has become somewhat more severe for one year. She was referred to a physiatrist 5 months prior to my treatment after development of pain referring down her left leg. She underwent a series of blocks for back pain and a left L5 radiculitis without weakness.

When I saw her, she continued with a primary complaint of back pain with an increasing radicular component to the leg.

She is a non-smoker, with a slightly short, stout build. Hypertension is her underlying medical risk factor.


Pain is primarily low back with referral to the left leg in an L5 distribution. She has an antalgic gait with limited flexion related to pain.

She has focal and moderately severe weakness in dorsiflexion and eversion of the left ankle, and associated numbness to the dorsum of the foot.

Pre-treatment Images

Standing posteroanterior (PA) and lateral x-rays.

Limited spine films demonstrate facet arthropathy is greater at L5 with minimal degenerative subluxation.

standing posteroanterior lumbar x-rayFigure 1A

standing lateral lumbar x-rayFigure 1B

Sagittal MRIs reveal central stenosis with a synovial cyst at L4-L5.

sagittal MRI; synovial cyst at L4-L5Figure 2A

sagittal MRI; synovial cyst at L4-L5Figure 2B

Axial MRIs demonstrate central and lateral recess stenosis with facet arthropathy.

axial MRI; L4-L5Figure 3A

axial MRI; L4-L5Figure 3B

axial MRI; L4-L5Figure 3C


Degenerative Disc Disease, noting:

  • Facet arthropathy with back pain and spinal stenosis
  • Synovial cyst
  • L5 radiculopathy

Suggest Treatment

Indicate how you would treat this patient by completing the following brief survey. Your response will be added to our survey results below.

Selected Treatment

  • Minimally invasive midline approach: laminectomy with decompression of stenosis and excision of the synovial cyst; bilateral interbody fusion using local bone graft
  • Submuscular approach, with segmental disconnection of the tendons on the adjacent margins of the L4-L5 spinous process, using the Medtronic Midline Retractor (Medtronic, Inc.)
  • O-arm® Surgical Imaging System (Medtronic, Inc.)
  • CAPSTONE® PEEK Spinal System (Medtronic, Inc.)
  • Medialized screw fixation (technique pioneered by Richard Hynes, MD) with cortical threaded CD HORIZON® LEGACY™ Cortical Bone Screw (Medtronic, Inc.)

Through a midline incision, the dorsolumbar fascia is opened. The erector spinae and multifidus tendons are detached from L5 and L4 spinous process respectively.

minimal accessFigure 4A

minimal accessFigure 4B

minimal accessFigure 4C

The midline retractor is positioned over the lamina and articular processes of L4 elevating the multifidus arising from L3 and the cephalad levels. The retractor is constrained by the tendons inserting to as it is inserted into the superior articular processes of L5 and traversing to the articular process of S1.

MAST midline retractor positioned over the lamina, L4Figure 5A

L4 pedicle screw holesFigure 5B

An asymmetric tip on the retractor follows the contour over the articular process and engages under the tendon to the tip of L5, and under the margin of muscle and tendon traversing to the sacral articular process.

retraction; deep fascicle of multifidus optimizes exposureFigure 6

Stepwise bilateral approach to fusion using the midline retractor system. The muscle is retracted over the facet capsule with retraction constrained by insertions to the superior articular process.

bilateral approach to fusion; MAST QUADRANTFigure 7

The deep fascicle of the multifidus is engaged by the retractor blade.

L2-L4; deep fascicle of the multifidus engaged by retractor bladeFigure 8A. L2 to L4

L3-L5; deep fascicle of the multifidus engaged by retractor bladeFigure 8B. L3 to L5

Figure 9 illustrates the exposure over the lamina and articular process. Screw placement is cephalad under the deep fascicle of the multifidus and neurovascular elements.

illustration; exposure over the lamina and articular processFigure 9

Figures 10A and 10B show L4 placement.

intra-operative, L4 placementFigure 10A

intra-operative, L5 placement

Figure 10B

Figure 11 shows L5 placement.

intra-operative, L4 placement

Figure 11

An osteotome was used to cut across the lamina and inferior articular processes of L4, including the inferior margin of the spinous process of L4. The figure visualizes the cartilage of the articular process of L5 and adjacent ligamentum.

osteotome cuts lamina and inferior articular processFigure 12

Figure 13 displays dissection of the synovial cyst from the dura with decompression of the left lateral recess. The right side decompression is complete.

right superior articular process; ligamentum flavum over the duraFigure 13

Figures 14A and 14B show the completed posterior lumbar interbody fusion (PLIF) using CAPSTONE® PEEK Interbody Spacers with local bone.

left-sided dissection of synovial cyst from duraFigure 14A

bilateral interbody graft completedFigure 14B

The right-side L4 screw hole is palpated upon entering the laminar surface just cephalad to the joint.

right-side L4 screw holeFigure 15

Illustrative intra-operative imaging reflects the entry for a cortical threaded screw at the cephalad level: three millimeters from the margin of the pars interarticularis projecting to the 5 or 7 o'clock orientation in the pedicle.

pedicle screw entry pointFigure 16A

pedicle screw entry pointFigure 16B

The spine photograph, with legend, delineates surface landmarks used to define initial screw placement. I use the keel of the pars interarticularis as the primary landmark and Rick's fossa to define the position along the pars.




Keel of pars interarticularis



Origin of the longissimus fascicle,
accessory process



Rick's fossa


Articular margin



sawbone illustrates key anatomyFigure 17A

sawbone photograph delineates surface landmarksFigure 17B

The cortical threaded screw is placed into the right L4 pedicle.

placement of cortical threaded screwFigure 18

In Figure 19, the final screw construct is seen overlying the decompressed canal and foramina.

final screw placement; canal decompressionFigure 19

Final intra-operative images show the L4 and L5 screws. Intra-operative confirmation of screw placement with O-arm® images at L4 and L5.

L4, L5 pedicle screw placementFigure 20A

L4, L5 pedicle screw placementFigure 20B

L4, L5 pedicle screw placementFigure 20C

L4, L5 pedicle screw placementFigure 20D


Medtronic Technology Featured
Medtronic Midline Retractor
CD HORIZON® LEGACY™ System Cortical Bone Screw
O-arm® Surgical Imaging System
CAPSTONE® PEEK Spinal System

Michelson Technology at Work






Two-weeks post-op: the patient's pre-op pain was relieved with near complete recovery of strength. She was on no medication with minimal back pain.

Three-months post-op: minimal residual soreness was present. The patient was advised that she could return to normal activity, with a strengthening and conditioning program, as desired.


Note to patients
As you read this please keep in mind that all treatment and outcome results are specific to the individual patient. Results may vary. There are some risks associated with minimally invasive spine surgery, including transitioning to a conventional open procedure, neurological damage, damage to the surrounding soft tissue.  In addition, instrument malfunction such as bending, fragmentation, loosening, and/or breakage (whole or partial). Please consult your physician for a complete list of indications, warnings, precautions, adverse events, clinical results, and other important medical information.

This therapy is not for everyone. Please consult your physician. A prescription is required. For further information, please call MEDTRONIC at (800)876-3133.


Case Discussion

The scenario is a common presentation that is seen by spine surgeons throughout the country. This is a patient with nerve compression and degeneration, with symptoms of both low back pain and radicular nerve issues. The critical component of any successful spinal intervention or treatment is to identify the pain generator. In this patient, it does appear that the nerve compression matches the level of the symptoms and the neurological deficits, and the arthritis does account for the low back pain. Surgery is typically the last step, and it does appear that this patient had failed conservative care.

As for surgical options, if the patient desires a surgical intervention, there is a host of different options that many surgeons would consider given the symptoms and the pathology present. If the low back pain was not an issue, and the radicular component was temporarily alleviated with the nerve blocks, a decompressive procedure would be appropriate given the absence of instability. If there is instability, at least consider a fusion and discuss this with the patient. The patient has a facet cyst, which is a sign of facet pathology. If the flexion/extension radiographs did not show subluxation or instability, the facet cyst could be resected. However, one must be aware of the facet pathology and the potential for facet-mediated instability, which could be worsened by even a small micro-decompression.

In this case, the surgeon opted for a decompression and fusion using a less invasive approach. I think this is a very reasonable option given the fact that there are hints of potential instability and the facet cyst, the presence of significant low back pain, and the degenerative changes. It is important to note that performing this surgery in the traditional method versus the less invasive method is both viable and very effective option. There may be a benefit from the less invasive approach in terms of less blood loss and potentially a shorter hospital stay.1 These potential benefits need to be balanced against the surgeon's comfort level, the possibility of incomplete decompression, and less bone surfaces for osseous healing. It appears that the patient is doing well, and I believe it was a good decision.

1Fessler R, Khoo L. Minimally Invasive Cervical Microendoscopic Foraminotomy: An Initial Clinical Experience. Neurosurgery. 51:37-45, 2002 (statistical significance not specified).


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