The employee petitions this court to vacate an award on stipulation, served and filed in this case on April 24, 1991, on grounds that there has been a substantial change in her condition since the issuance of the award.  Finding a sufficient basis to vacate the award on stipulation, we grant the petition.

On February 19, 1977, the employee, Laurie Krueger, worked for the employer herein, B.F.S., d/b/a Pizza Hut,^[1] in Hibbing, Minnesota.  The employee was 17 years old at that time.^[2]  On February 19, 1977, she sustained a work injury to her low back while attempting to unload three 30-pound cases of lettuce.  She reported a sudden sharp pain in her low back making it difficult for her to straighten up.  She initially treated at her local emergency room and with primary care doctors.  She was diagnosed with a low back strain and underwent conservative treatment, including chiropractic and physical therapy, from the date of the injury until November 1988.  The employee received the maximum compensation rate pursuant to the then-applicable version of Minn. Stat. § 176.101, subd. 6.  The employee worked a variety of jobs off and on after the initial injury, and she indicates that she did not sustain any new or other injuries.

The employee saw Dr. Robert Wengler on May 19, 1981.  At that time, examination of her low back showed some diffuse soft-tissue guarding with localization of tenderness to the L4-5 and S1 area in the midline.  Her neurological exam was intact, and straight-leg raising was negative.  Dr. Wengler indicated that the employee had a 15 percent disability/impairment of function on the basis of her ongoing low back.

The employee subsequently filed a claim petition in 1981, alleging intermittent temporary total disability benefits and 15 percent permanent partial disability of the spine based, in part, on Dr. Wengler’s opinion.  The parties reached a to-date settlement in September 1982.  A compensation judge approved an award on stipulation on October 22, 1982.

The employee saw Dr. Mark Glazier on October 31, 1988.  At that time, the employee had tenderness to percussion over the lower spine.  She had tenderness over the right sciatic notch.  She had positive straight-leg raise on the right at 80 degrees.  She had weakness with plantar flexion in the right and was unable to support her full weight.  A November 9, 1988 myelogram and CT demonstrated a large, freely extruded fragment extending out of the disc space down to the right L5-S1 foramina.  Dr. Glazier opined that the right S1 nerve was probably obliterated by the protruding disc, and he diagnosed the employee with clear right S1 radiculopathy secondary to disc herniation.

On November 10, 1988, Dr. Glazier performed a lumbar laminectomy and discectomy, with foraminotomy, as well as removal of an extruded free fragment.  The employee’s diagnoses included herniated L5-S1 disc on the right with right S1 radiculopathy secondary to “right L4-S1 HNP.”

On January 26, 1989, Dr. Glazier wrote a letter summarizing a post-surgery examination of the employee.  He indicated that the employee was six weeks out from her decompressive laminectomy, foraminotomy, and discectomy at L5-S1 on the right.  The employee felt that her pain had significantly improved.  She could plantar flex and support her full weight.  She still had some residual numbness, but most of it had improved.  Dr. Glazier stated that the employee made satisfactory improvement following surgery and he released her from his care.

On May 23, 1990, the employee saw Dr. Wengler for a consultation regarding back and right leg pain.  The employee indicated that she had developed problems over the years.  The back and right leg pain had gradually worsened.  She did not recall any specific incident or re-injury to her low back.  Her symptoms eventually increased to a point where she limped with her right foot.  Following her 1988 surgery, as the employee started to increase her activities, she developed recurrent back and leg pain.  She was currently having pain similar to the level she had before the 1988 surgery.  She reported some pain in the right buttock, thigh, and calf.  She also had numbness in the lateral aspect of the right foot.  The right leg still felt weak as well.  A neurologic examination of the lower extremities showed that the right ankle reflex was absent when compared to the left.  The employee had decreased sensation over the lateral aspect of the right calf and right foot.  She had subjective weakness of the plantar flexors of the right foot and ankle.  She had difficulty standing on tiptoes on the right.  Straight-leg raising test was positive on the right at 30 degrees.

The employee underwent an MRI of the lumbar spine on May 23, 1990.  The report indicated:

Dr. Wengler prepared a letter dated July 23, 1990.  He opined that the employee’s recurrent right leg pain was due to the fact that the nerve root had been scarred by the surgery.  The employee had residual instability producing radicular symptoms.  Dr. Wengler considered the only viable option to be fusion surgery, but he did not recommend the procedure due to the magnitude of the surgery and the uncertain outcome.  Dr. Wengler concluded the impairment was related to the February 1977 injury and rated the employee with 30 percent permanent partial disability of the spine.  He also recommended limitations on future activities, including a lifting restriction of 10 pounds, no repetitive bending, stooping, heavy pushing or pulling.

The employee filed a second claim petition in August 1990, alleging intermittent temporary total and temporary partial disability.  She also alleged an additional 15 percent permanent partial disability and requested rehabilitation services and payment for medical expenses.  The parties reached another settlement in April 1991.  The employee received payment of $76,500.00 in exchange for a full, final, and complete settlement, with the exception of all future reasonable and necessary medical expenses related to the employee’s 1977 injury.  Before the award was executed, the parties filed an addendum to the 1991 stipulation on April 19, 1991.  As a part of that addendum, the employee acknowledged the possibility that she may experience changes in the future that could make her condition substantially worse and that her injury could involve a large amount of medical and surgical expenses and disability of a serious and prolonged nature.  An award on stipulation was served and filed on April 24, 1991.

After receiving her lump sum settlement, the employee used a portion of that payment to obtain a legal secretary certificate.  Thereafter, she has worked in multiple law firms and other agencies that were essentially desk jobs and permitted her to move about as necessary.

In her petition to vacate, the employee maintains that her low back pain returned when she experienced a flare-up in 1994, but the pain responded to conservative treatment.  In October 1996, the employee had a more significant increase in pain.

Medical records show that the employee saw Dr. Thomas Rieser at Midwest Spine Institute/Midwest Orthopedics on June 1, 1994 for an evaluation.  Following examination, Dr. Rieser diagnosed the employee with degenerative disc disease at L5-S1 and L4-5.  He also diagnosed the employee with aggravation of adhered nerve root at L5-S1, most likely secondary to prolonged sitting and a bulging disc.  The employee was complaining of low back pain, mainly on the right side.  She also had pain in her right leg, radiating down to the side of her right foot.

Dr. Rieser issued a letter dated January 22, 1995, in which he opined that the employee’s current problems were related to her 1977 workers’ compensation injury.  Dr. Rieser opined that problems secondary to her surgery were causing her current pain.

The employee saw Dr. Rieser again on October 2, 1996.  She was reporting low back pain that started the week before, with no injury, and pain radiating into her legs.  Dr. Rieser reviewed x-rays and noted degenerative changes at L4-5 and L5-S1.  He recommended an MRI.  The employee underwent an MRI of the lumbar spine on October 7, 1996.  The report indicated that the employee had a stable post-operative MRI of the lumbar spine.  It noted juvenile discogenic disease with thoracolumbar Scheuermann’s and advanced degeneration at L4-5 and L5-S1 with a high signal intensity central annular tear of the L4-5 disc, but no herniation or stenosis.

The employee saw Dr. Rieser on October 16, 1996.  He stated that the employee had severe degenerative disc disease at the L5-S1 level.  She had mild evidence of adhesion at the L5-S1 level on the right side where she had prior surgery, but there was not a severe amount of scarring present.  There were annular changes noted in the L4-5 level as well.  The employee’s options included medications, physical therapy, steroid injections, or surgical fusion.  The doctor felt the employee should learn to live with her symptoms as long as she could tolerate.

The employee followed up with Dr. Rieser on July 28, 1997.  She continued to report significant low back pain.  Her motion was limited, but neurologically she was intact.  Dr. Rieser recommended an MRI.  They also had spoken in the past about the possibility of a fusion.  The employee underwent an MRI of the lumbar spine on July 29, 1997.  She complained of low back and leg pain status post multiple low back surgeries, including L4-5 fusion and L5-S1 laminectomy.  The MRI indicated the following:

On September 4, 1997, Dr. Rieser performed an anterior/posterior fusion.  She was being assessed with multiple level degenerative disc disease at L4-5 and L5-S1.

The employee saw Dr. Rieser again on September 1, 1999.  At that point, she was two years post two-level fusion L4-5 and L5-S1.  Dr. Rieser described the x-ray imaging as looking “quite good” and assessed the fusion as “excellent.”  Straight-leg raising was at 90/90, flexion, and fingertips to the floor was at six inches.  Extension was 75 percent of normal.  She was to return on an as-needed basis.  The employee also filled out a pain diagram on September 1, 1999.  She indicated that she had a little more than “none” for back pain.  This was a reduction from one year earlier.  She reported no leg pain.  The employee also indicated that she was using no medications for pain.  The employee was pleased with the outcome.

The employee returned to see Dr. Rieser on November 28, 2006.  She reported symptoms of low back pain and right buttock pain extending into the anterior thigh and knee.  On November 25, 2006, the employee noticed significant right upper leg aching/pain.  By this time, the employee had been working many years for her husband in his law practice.  She assisted with bookkeeping.  This was a sedentary position.  X-rays showed “retained hardware at L4-5 and L4-S1 fusion.”  The employee also had mild degenerative narrowing at L3-4.  She had slight scoliosis, although that had not changed significantly since 1999.  Disc height was slightly less than what it had been in 1999, and there was a slight retrolisthesis present at L3-4.  Dr. Rieser diagnosed the employee with degenerative disc disease above the fusion and recommended an MRI.

The employee underwent an MRI of the lumbar spine on November 28, 2006.  The report indicated that there was a small lateral disc herniation on the right at L3-4.  There was a solid anterior fusion of the spine from L4 to the sacrum.  Mild degenerative disc disease was noted at L2-3 and L3-4 levels.  The report also noted “susceptibility artifact overlying the posterior elements at the levels of L4 and L5 likely secondary to the presence of laminar screws and hooks.”  Pedicle screws were present at the level of the first sacral segment.  Midline laminectomy defects were demonstrated at the L5-S1 level.

The employee saw Dr. Rieser on December 6, 2006.  She had undergone an MRI scan, which revealed a lateral disc herniation at L3-4 on the right side.  The employee had retained hardware, and the doctor felt it might be worthwhile to remove it because of low back pain issues.  He did not feel it was creating the right leg problems she was having.  He opined a discectomy may be required in the future.  The doctor was inclined to operate on the disc first to see how she responded.

The employee saw Dr. Kristen Zeller at Midwest Spine Institute on May 8, 2007.  The employee was experiencing right lower extremity radicular symptoms, assessed as arising from a disc fragment at L3-4 and her history of a prior fusion at L4-5 and L5-S1.  The employee was given a right-sided L3-4 transforaminal epidural steroid injection on May 8, 2007.

In a letter dated July 9, 2008, Dr. Rieser indicated that the employee, subsequent to her fusion, had increasing changes of the L3-4 and L2-3 levels.  The doctor felt the employee’s problems necessitating her fusion were related to the work injury in 1977.  He also felt that the transitional segments had developed degeneration subsequent to the fusion and as a result of the stresses above the fusion.  Therefore, he opined that the employee’s ongoing issues were also related to the work injury of 1977.

The employee underwent an MRI of the lumbar spine on July 23, 2008.  The report noted anatomic alignment and good bony fusion at L4-5 and L5-S1, along with stable moderate right foraminal bulging of the L3-4 disc with possible impingement on the right L3 nerve root.

On August 12, 2008, Dr. Zeller performed a provocative discography at L1-2, L2-3, and L3-4.  The doctor was able to stimulate pain sensations from the bottom two disc levels, making it unlikely that hardware was creating the low back pain pattern.  The employee had degenerative problems, according to Dr. Zeller.

The employee underwent a whole body bone scan on October 8, 2008.  The impression was no significant acute abnormality.  The employee also underwent a CT of the pelvis with attention to the SI joints.  The CT scan showed fairly advanced degenerative changes to the SI joints, bilaterally.

On October 16, 2008, the employee underwent removal of the hardware at L4 through S1, which was performed by Dr. Rieser.  The employee also underwent partial laminectomy at L3-4 and decompression at the L3-4 level along with the L4 nerve roots bilaterally.

The employee saw Dr. Rieser on October 27, 2008, for further discussion of discogram reports, EMG, and abdominal CT.  The abdominal CT revealed some SI joint changes.  The EMG showed old neurologic changes, chronic along L5 and S1.  The discogram yielded discomfort at L2-3.  The doctor recommended a repeat discogram one segment at a time, adding any additional fusion above her current levels may be more debilitating, but leaving this option open.  Removing hardware would be reasonable, as well considering spinal cord stimulation.  The doctor planned on doing a bone scan, a CT scan, and removing the hardware.

The employee saw Dr. Zeller on November 26, 2008.  She reported increasing low back pain and some radiating lower extremity symptoms.  The employee reported that the recent hardware removal had not helped her pain at all.  She was noted to have degenerative disc changes with increasing pain patterns above the fusion site involving L2-3 and L3-4.

The employee saw Dr. Zeller on January 6, 2009.  The doctor indicated that the conservative treatment was ineffective.  They considered pain management as an option.  They agreed to proceed with a spinal cord stimulator.  The employee did well with the trial, and she underwent implantation of a spinal cord stimulator on January 19, 2009, at University of Minnesota Medical Center.  Dr. Joseph Perra performed a T8, T9 laminotomy with placement of a surgical dorsal column stimulator electrode.

The employee saw Dr. Rieser on October 22, 2009.  He noted that the employee had a spinal cord stimulator, which had helped to some degree.  However, the employee reported having breakthrough pain.

The employee met with Dr. Rieser on November 17, 2009, to discuss her recent CT scan of the lumbar spine.  That scan revealed degenerative changes at L3-4.  The scan also indicated some changes at L2-3.  The employee had severe changes in the SI joints bilaterally as well.  Dr. Rieser also noted that it was reasonable to consider a fusion at L2-3 and L3-4.  Dr. Rieser also noted that the employee might be a candidate for SI joint fusion surgery, but Dr. Rieser did not perform such procedures.

The employee underwent a series of SI joint injections at Midwest Spine Institute from December 2009 to February 2010.  Eventually, the employee proceeded with SI joint fusions, performed by Dr. David Polly at the University of Minnesota Medical Center.  Her left SI joint fusion took place on October 25, 2010, and the right SI joint fusion took place on February 28, 2011.  As of April 2011, the employee was reporting pain on the left side.  She was rating back pain at 10 and leg pain at 8.  Dr. Polly assessed the employee with markedly improved symptoms in the right SI joint.  Back pain patterns were of an unclear etiology.  There was also a concern for loosening of left-sided SI joint implants.

The employee saw Dr. Polly again on November 17, 2011.  She was assessed with SI joint dysfunction status post fusion with excellent result on the right and modest result on the left.  She was also diagnosed with degenerative lumbar scoliosis with pain pattern.

The employee noted that she has currently continued with conservative treatments, including injections.  Despite this treatment, she maintains that she is still in substantial pain and severely disabled.  She argues that she cannot perform most activities of daily living, including cooking or cleaning.  She is currently receiving SSDI disability benefits.  She spends most of her time lying down and attempting to keep her pain down.  The employee is trying to avoid further fusion surgery to additional levels.  The employee is awaiting on a further CT/myelogram in order to discuss with Dr. Polly whether he would recommend further surgical intervention with regard to the L2 and L3 levels.  A left SI joint fusion revision is also under consideration.

This court has jurisdiction to set aside an award on stipulation upon a showing of good cause.  Minn. Stat. §§ 176.461 and 176.521, subd. 3.  “Cause” is limited to fraud, a mutual mistake of fact, newly discovered evidence, or a substantial change in medical condition since the time of the award.  Minn. Stat. § 176.461(b).  For petitions to vacate awards on stipulation entered into before July 1, 1992, such as the stipulation at issue here, it is not required to show that the substantial change in condition was clearly not anticipated and could not reasonably have been anticipated.  See Minn. Stat. § 176.461 (prior to 1992 amendment); Franke v. Fabcon, Inc., 509 N.W.2d 373, 49 W.C.D. 520 (Minn. 1993).

Vacation of awards on stipulation is allowed to assure compensation proportionate to the degree and duration of disability.  Franke, 509 N.W.2d at 376, 49 W.C.D. at 524.  In describing vacation of awards, the Minnesota Supreme Court explained that:

The employee argues that since the full, final, and complete settlement in April 1991, she has suffered a substantial change in medical condition.  To establish cause to justify vacating an award on the grounds of a change in medical condition, a petitioner must provide evidence of a substantial deterioration in the petitioner’s condition or significant additional disability since the time of the settlement and must show a causal relationship between the injury covered by the award and the petitioner’s present condition.  See Davis v. Scott Moeller Co., 524 N.W.2d 464, 51 W.C.D. 472 (Minn. 1994).  The petitioner’s change in condition is generally considered in the context of a change in diagnosis, a change in the employee’s ability to work, additional permanent partial disability, the necessity for more costly and extensive medical care than previously anticipated, a causal relationship between the injury covered by the settlement and the current condition, and the contemplation of the parties at the time of the settlement.  Fodness v. Standard Cafe, 41 W.C.D. 1054, 1060-61 (W.C.C.A. 1989).

At the time of the settlement in April 1991, the employee was diagnosed with and was treating for issues related with L4-5 and L5-S1, as well as radiculopathy primarily on the right.  Dr. Wengler opined that the employee’s condition and impairment were related to the February 1977 injury.  He rated the employee with 30 percent permanent partial disability of the spine, and he recommended limitations on future activities, including a lifting restriction of 10 pounds and no repetitive bending, stooping, and no heavy pushing or pulling.  An L5-S1 fusion was a reasonable consideration.

Currently, the employee is being diagnosed with and treating for ongoing low back issues as well as significant problems with her SI joints, left primarily, and problems with adjacent low back segments, including L2-3 and L3-4.  The employer and insurer argue that the employee’s condition has not changed so substantially as to meet the threshold required by pre-1992 statutes and case law.  They cite Olson v. Vision Ease, slip op. (W.C.C.A. June 18, 1997), in support of their opposition to a vacation here.

In Olson, stenosis had been present at two levels at the time of the award, and although the employee’s back condition was degenerative, the employee had acknowledged in the stipulation that her condition could deteriorate.  The employee was arguing that her condition had worsened with regard to her low back, but she also argued that she had developed a mental health condition, for which no causation had been established.  Here, by contrast, the employee has incurred new diagnoses relating to her SI joints, and she has experienced a substantial worsening of her back at the levels of her spine adjacent to her fusion.  The employee has also provided medical opinions supporting causation arising from the work injury of problems related to adjacent levels.  Therefore, we conclude that the change in diagnosis factor weighs in the employee’s favor.

The employee in Olson was unable to return to employment outside of a brief attempt at part-time, light-duty work.  By contrast, the employee in this proceeding returned to work after retraining and worked in sedentary employment until 2005.  The employee maintains that she is now severely limited in functionality, including in many activities of daily living and unable to engage in any substantial work activity.  The employee’s receipt of SSDI disability benefits supports this contention.  For these reasons, the change in the employee’s ability to work weighs in the employee’s favor.

The employee has incurred significant medical expenses, which has been costly and extensive.  The employee argues that these expenses could not have been anticipated in 1991.  The employer and insurer argue that because the 1991 stipulation left medical expenses open, “that factor carries less weight in determining whether a substantial change in condition has occurred.”  Olson, slip op. (citing Miedema v. Brown Group, Inc., slip op. (W.C.C.A. Apr. 12, 1996).  While that may be accurate, this factor tilts in the employee’s favor.

The employee asserts that all of her current issues are related to her initial injury.  She has provided causation opinions from Dr. Rieser indicating that, at a minimum, the employee’s adjacent level issues in her spine are causally related to her initial injury.  There have also been a number of diagnostic procedures intended to rule out other potential causes such as rheumatoid arthritis.  The employee argues that her SI joints have failed as well because of stress related to her fusion surgery.  While there may not have been a specific opinion in that regard, there is sufficient evidence in the record as a whole to conclude that there is a causal relationship between the 1977 injury covered by the settlement and the current medical conditions.

The employer argues that vacation of the settlement is improper where permanent partial disability was resolved by settlement and the employee has not provided a medical opinion that supports an additional rating.  Vacation of the award will allow the employee to proceed under multiple theories, if medically supported.  The employee has shown that she is now totally disabled from employment and that her low back injury has had a potential impact on her S1 joints, bilaterally.  We conclude that the employee has adequately demonstrated good cause, and fairness requires that the employee’s petition to vacate the 1991 award on stipulation be granted.