The employee petitions to vacate a November 30, 1993, award on stipulation based on a substantial change in condition.  Finding no basis to vacate, we deny the petition.

The employee sustained a work-related injury to her low back on October 6, 1989, while employed by E.J. Ajax & Sons, Inc. [the employer].  An MRI performed on November 16, 1989, showed degenerative changes in the lumbar spine, including a degenerated disc at L3-4 with a small central right disc herniation, a degenerated disc and small central right disc herniation at L4-5, and a degenerated disc with a small broad-based disc herniation at L5-S1.  The employee was treated conservatively with physical therapy and chiropractic treatments.  The employer and its workers’ compensation insurer paid intermittent temporary total disability benefits from October 11, 1989, to March 16, 1990, and intermittent temporary partial disability benefits from October 23, 1989, to June 15, 1990.

The employee apparently quit working for the employer on February 3, 1992.  She then worked as an independent contractor doing courier work for Quick Silver and Silver Bullet, where she worked eleven hours a day, five days a week, performing an average of fifteen deliveries per day.  She indicated that her low back symptoms increased while she was doing this work.^[1]

On March 12, 1993, the employee filed a claim petition, seeking benefits for a 19% whole body disability, as rated by chiropractor Dr. Maria Aagesen-Reznecheck, and chiropractic expenses.  The employer and insurer responded that the employee’s alleged disability was solely the result of “significant disease processes not related to the work injury,” that the employee’s alleged disability and need for treatment were solely the result of superseding/intervening injuries, and that the employee’s work injury was “at the most, a temporary aggravation” from which the employee had recovered.

On April 8, 1993, the employee was seen by orthopedic surgeon Dr. David Holte.  At that time, the employee described her pain as being 30% in her back and 70% in her left buttock and leg.  Dr. Holte diagnosed an L5/S1 disc herniation with left leg radiculopathy, substantiated on MRI.  It was his opinion that this condition was the direct result of her work injury, and he recommended surgical decompression of the left S1 nerve root with discectomy.

On June 1, 1993, the employee was examined by independent medical examiner Dr. Mark Engasser.  According to Dr. Engasser’s review of medical records, the employee had noted the onset of back pain in 1990 and again in 1991 while playing softball.  He reviewed an MRI performed on December 29, 1992, which showed a moderately large posterolateral left-sided extruded L5-S1 disc herniation, a small contained herniation at L3-4, and a central posterior annular tear at L4-5, which he opined represented significant changes since the employee’s MRI of November 16, 1989.^[2]  Dr. Engasser concluded that the employee had sustained a 14% whole body disability related to the left-sided disc herniation at L5-S1 and that she was a surgical candidate, but he indicated that the disability and recommended surgery were related to “problems not associated with the injury of October 1989.  These would definitely include her athletic activities.”

On July 12, 1993, Dr. Holte performed a partial laminectomy at L5 and a discectomy at L5-S1 on the left.  The employee was released to return to work on July 26, 1993.  Dr. Holte’s office note for August 19, 1993, reflected that the employee was working full time without restrictions and was taking no medications.

The employee was in a motor vehicle accident [MVA] on October 19, 1993, and experienced an onset of right-sided low back symptoms.  She returned to Dr. Holte, who took her off of work.^[3]

The parties to the employee’s workers’ compensation claim reached a settlement in late October of 1993.  At that time, the employee’s claims included a claim for medical expenses for the July 1993 surgery and a claim for temporary total disability benefits from July 2 through July 23, 1993.  Under the terms of the stipulation, the employee was paid $10,000.00 for a full, final, and complete settlement, with the exception of future medical expenses.  The employee’s claimed medical expenses and some of her chiropractic expenses were also paid.  The award on stipulation was filed on November 30, 1993.

By December of 1993, the employee was complaining of low back pain and pain into the right buttocks and leg.  An MRI performed on December 15, 1993, showed multi-level disc disease and, among other things, a right-sided L4-5 disc herniation.

On April 11, 1995, Dr. Holte noted that the employee was still working fulltime but was having continued symptoms from right S1 nerve root compression.  He then referred her to Dr. Frank Wei, who examined her on April 19, 1995.  At that time, the employee gave a history of having experienced an onset of back and right buttock discomfort in relation to the October 1993 car accident.  Dr. Wei diagnosed a recurrent disc herniation at L5-S1 with right radicular symptoms.

At the time of an October 1, 1997,  examination by Dr. Aageson-Reznecheck, the employee related that she had been in a work accident on September 26, 1997, while working as a courier for Silver Bullet, when she fell and landed on her left side, hitting her left hand, back, left knee, and left shoulder.

The employee treated with Dr. Aageson-Reznecheck again on June 21, 1999, for complaints of right buttock pain after having participated in a two-day, 150-mile bike ride.  Chiropractic records from 1999 and 2000 reflect that the employee was engaged in strenuous activities, including biking long distances, white water rafting, running, bowling, shoveling snow, and baling hay.^[4]

An MRI performed on November 13, 2001, showed, among other things, a moderate-sized extruded central and right disc herniation at L4-5, with impingement on the right S1 nerve root.  The employee returned to Dr. Holte on November 20, 2001.  He recommended surgery, and a right L4-5 discectomy was performed on November 26, 2001.

On March 19, 2002, when the employee complained of low back, bilateral buttock, and right leg and foot pain, another MRI was performed.  That scan was interpreted to show a central disc herniation at the L5-S1 level with impingement of the right S1 nerve root, up-down right-sided lateral spinal stenosis with mild impingement on the right L5 nerve root ganglion, and a large extruded central and right-sided posterolateral disc herniation at L4-5 with severe impingement on the right L5 nerve root and mild impingement on the left L5 nerve root.  Dr. Holte performed a revision right L4-5 discectomy on April 15, 2002.

The employee was seen by Dr. Manuel Pinto on October 22, 2002.  After reviewing the MRIs performed on December 29, 1992, and December 15, 1993, Dr. Pinto opined in his letter of February 20, 2003, that the employee’s car accident was the most probable cause of the L5-S1 herniation noted on MRI after that accident, but that both the work injury and the car accident were significant contributors to the employee’s need for treatment.  He did not propose surgery at that time.

The employee returned to Dr. Holte on July 8, 2003.  He noted that an MRI scan report from April 16, 2003, noted a large recurrent disc herniation on the right side, which was producing severe compression of the right L5 root.  Dr. Holte recommended a revision decompression of the right L4-5 disc, and surgery was performed on October 6, 2003.^[5]

The employee was seen by Dr. Holte on May 19, 2005, for complaints of progressively worsening back pain.  She also complained of bilateral hip pain and occasional right leg radiculopathy.  An MRI performed on May 24, 2005, showed significant interval loss at L4-5, stable post-operative changes at L5-S1, and no change in the disc herniation at L2-3.  In his August 21, 2008, office note, Dr. Holte indicated that when he last saw the employee eleven months previous,^[6] he had “recommended a fusion when she was ready.”

On July 13, 2010, the employee filed a petition to vacate the 1993 award on stipulation based on a substantial change in condition.  The employer and insurer object.

An award on stipulation may be vacated only for “cause,” including “an unanticipated substantial change in the employee’s medical condition.”  Minn. Stat. § 176.421.  A number of factors are relevant when evaluating whether there has been a substantial change in the employee’s medical condition, including:

The employee does not argue that there has been a change in diagnosis.

The employee contends that she quit working for the employer in 1992 because the employer was unable to offer her continuing employment.  She then went to work as a courier and was working full time without restrictions as of August 19, 1993.

The employee contends that the MVA on October 19, 1993, resulted in her inability to work for various periods between that time and August 15, 1994, and that she was also unable to work after March 1998.^[7]  We could find no medical records indicating that the employee was taken off work at that time or that the employee’s condition at that time was related to her work injury.

However, on June 2, 2005, Dr. Holte completed a functional capacities evaluation indicating that the employee was physically incapable of sustained physical activity.  The disability he noted on that form was “severe instability at L4-5.”  Vocational expert Jan Lowe opined on June 30, 2009, that the employee is not employable in sustained gainful employment.

We cannot determine whether there has been a change in the employee’s ability to work because, at the time of the settlement, the employee had been released to return to work without restrictions due to her work injury but had been taken off work by her doctors due to the motor vehicle accident.  The employee was unable to work at the time of the settlement and is apparently unable to work now.  In any event, change in ability to work must be related to the work injury.  Schueler v. William Miller Scrap Iron & Metal, slip op. (W.C.C.A. Mar. 3, 2000).

The employee contends that, at the time of the settlement, the independent medical examiner, Dr. Engasser, and her treating chiropractor had rated her as having a 14% whole body disability, and she further contends that, after fusion surgery, she will have an additional 20% impairment.  We note initially, however, that Dr. Aagesen-Reznecheck had rated the employee as having a 19% impairment at the time of the stipulation.  Also, no additional permanency ratings have been issued since the settlement.  An anticipated rating, based on a future surgery, is not sufficient to establish additional permanency for purposes of vacating the award.

The employee points out that she has undergone three surgeries for her lumbar spine condition since the time of the award on stipulation, and she argues that, at the time of the settlement, she anticipated that she would require only conservative care in the future.  The employer and insurer contend that the independent medical examiner and treating doctors were recommending surgery at the time of the stipulation.  The medical records do not suggest that anyone was suggesting surgery at the time of the stipulation.  However, where medical expenses are not closed out by the award on stipulation, the need for additional care is generally given less emphasis.  Burke v. F & M Asphalt, 54 W.C.D. 363 (W.C.C.A. 1996).  At the same time, three additional surgeries subsequent to a settlement is at least relevant to a determination as to whether the employee has undergone a substantial change in condition, if these surgeries are causally related to the work injury.

The employee first relies on a November 30, 1994, report from chiropractor Dr. Frank Heller for support for her claim that her worsened condition is causally related to her work injury.  Dr. Heller reviewed the MRI taken on December 6, 1993, after the MVA, and opined that the employee had disc herniations at L5-S1, L4-5, and L3-4, prior to that accident.  It was his opinion that the MVA did not result in any permanent injury.  It was further his opinion that the “subjective complaints” that the employee had at that time were “related to her prior problem.”  At no point, however, did he give an opinion that any of the disc herniations were caused, aggravated, or accelerated by the work injury.

The employee also relies on the report of Dr. Pinto.  That report, however, also fails to contain a definitive opinion as to causation for the employee’s herniated discs or need for surgery.  In fact, Dr. Pinto opined that the MVA was the “most probable cause” of the L5-S1 disc herniation noted after that accident.  Dr. Pinto’s report predated the petition to vacate by more than 7 years and does not contain any recommendations for any surgery.

What we are left with is a work injury in 1989, with left-sided symptoms compatible with an L5-S1 disc herniation.  Surgery was performed at L5-S1 on the left prior to the stipulation.  The employee was released to return to work without restrictions prior to the stipulation.  The subsequent surgeries were for right-sided L4-5 disc herniations.  The first surgery at that level was performed 12 years after the employee’s work injury, after she had been performing courier work that had lead to a progressive worsening of low back symptoms, and after she had been engaged in physically active recreational activities.  Both subsequent surgeries were also performed at the L4-5 level.  While Dr. Holte opined that the L5-S1 surgery was causally related to the work injury, there is no medical opinion that the injuries to or surgeries at the L4-5 level are causally related to the work injury.

The employee has not established a causal relationship between her 1989 work injury and her current medical condition.  The petition to vacate is therefore denied.