The employee alleges that there has been an unanticipated and substantial change in her medical condition and petitions to vacate a stipulation which was the subject of an award in January 1999.  Finding that the employee has established cause as defined by the statute, we grant the petition.

The employee, Amanda Tudahl, worked for the employer, Greeley Health Care, as a nursing assistant.  On October 17, 1996, she sustained an admitted injury to her low back when attempting to help a patient back into his wheelchair.  She felt the sensation of a “pop” and “tear” in her back and the onset of low back pain.  A few days later, the pain extended into her buttock and left leg.

The employee initially sought treatment with her family physician at the Stillwater Medical Group where she was diagnosed with a lumbosacral strain, taken off work and placed on anti-inflammatory medications.  When she failed to improve, she was referred to Dr. Bruce Bartie at St. Croix Orthopedics, who saw her on November 8, 1996.  X-rays showed decreased L5-S1 disc space and mild spondylosis at L4-5 and L5-S1.  The employee’s symptoms showed a left L4 sensory radicular pattern, so Dr. Bartie recommended an MRI scan to rule out a lateral disc herniation.  The MRI, performed on November 12, showed only a tiny disc protrusion of doubtful significance.

The employee was reevaluated by Dr. Bartie in January 1997.  She was still having severe back pain radiating through the buttocks and into the left lower extremity, and reported being unable to do most activities.  Dr. Bartie suggested discography be done to assist in diagnosis.  On February 21, 1997, Dr. Bartie reviewed the results of the discography and noted that it clearly revealed degenerative spondylosis at what the discogram referred to as the L4-5 level, but which most recent physicians have referred to as L5-S1.^[1]  Higher levels were unremarkable.  Dr. Bartie opined that the employee had pre-existing degenerative changes prior to her work injury, which the work injury had aggravated on a mechanical basis from internal disruption with a prolapsed disc.  The employee was advised to avoid repetitive lifting, twisting and bending.  Dr. Bartie also noted that if the employee had no significant improvement from conservative care, anti-inflammatory medications and home exercise, a stabilization procedure of the L5-S1 area could be considered.

On March 6, 1997, the employee returned to St. Croix Orthopedics with an acute exacerbation of her pain.  Dr. Bartie noted that surgery might be considered at L4-5 [i.e., L5-S1].  The employee was seen on March 24, 1997, at United Neurosurgery Associates by Dr. Dan Tynan for a neurosurgical consultation.  Dr. Tynan diagnosed lumbar degenerative disc disease, which disc dehydration and bulging at the level the discogram referred to as L4-5 [L5-S1].  He thought that the employee’s pain was primarily discogenic, and did not consider her a very good candidate for surgery.  Instead, he suggested that she continue with conservative treatment, to include steroid injections and a pain clinic.  The employee began treating with Dr. Conor O’Neill at the Comprehensive Spine Clinic.

On May 12, 1997, the employee telephoned her family physician at the Stillwater Medical Group to report increasing back pain.  She stated that Dr. O’Neill felt she was no longer responding to pain clinic measures and should proceed with surgical evaluation, and she wanted to have surgery as soon as possible.  Her physician recorded that he then contacted Dr. Tynan to discuss the employee’s complaints.  According to the notes of the conversation, Dr. Tynan felt she had a 70 percent chance of some pain relief from surgery, but that the employee should anticipate a sub-maximal recovery.  He was described as not enthusiastic about the proposed surgery but thought it might be her only option.

The employee was seen by Dr. Thomas V. Rieser at the Midwest Spine Institute on July 8, 1997, for a second surgical opinion.  She was still having pain in the low back, bilateral hip, left groin, left buttock, and the left lower extremity to the foot.  Dr. Rieser’s diagnosis was of internal derangements at L4-5 [L5-S1] with persistent and chronic lower back pain that had been unresponsive to conservative management.  He thought that the recommended fusion surgery was reasonable, so long as the employee’s pain was significant enough that she believed the risks of surgery were warranted, but only if she understood that the procedure would not make her back normal or pain free.

On July 14, 1997, the employee underwent a posterior L4-5 [L5-S1] lateral mass lumbar fusion with instrumentation and left-sided posterior iliac crest bone graft.

The employee was evaluated for vocational rehabilitation services in November 1997 and was determined to be a qualified employee for rehabilitation services.  She was seen at the University of Wisconsin Assistive Technology and Assessment Center on January 1, 1998, for a vocational and rehabilitation assessment.  The assessment resulted in a recommendation that the employee brush up on some academic skills, and possibly consider vocational retraining, a sentiment echoed by Dr. O’Neill on April 21, 1998, when he noted that the employee had recently had a significant increase in pain after starting to work as a cashier in a grocery check out line in work that exceeded her restrictions.  The employer and insurer, however, insisted that rehabilitation efforts be oriented initially toward vocational placement.

On June 30, 1998, Dr. O’Neill signed an MMI Report which also rated the employee with a 22.5 percent permanent partial disability, citing Minn.R. 5223.0070, subp. 1.D.^[2]

The employee was seen by Dr. O’Neill on August 18, 1998.  Dr. O’Neill noted that the employee had continued to experience persistent pain and impairment following her fusion, complicated by severe depression and anxiety which resulted from her continuing pain and limitations.  He recommended that the employee continue ongoing mental health treatment for her depression and continue with vocational rehabilitation efforts.  He did not recommend further steroid injections or physical therapy, but noted further that a repeat surgical procedure might be considered if the employee’s condition worsened in the future.

On October 28, 1998, the employee was seen again by Dr. Rieser.  She was concerned that the hardware from her fusion surgery might be causing some of her discomfort.  Dr. Rieser reminded her that he had advised her that fusion surgery never resolved 100 percent of a patient’s pain, and that a degree of residual discomfort after the surgery had been anticipated.  He noted that her symptoms were definitely improved from what was present prior to surgery, and that her fusion remained stable.  While he acknowledged that the hardware could now be removed, he did not think that necessary as he thought that she had primarily myofascial pain and would simply have to live with that.  He opined that the employee had reached maximum medical improvement.  He authorized her to return to work on a progressive basis starting at four hours per day and slowly increasing to full time over two months, with restrictions against repetitive lifting or lifting more than 20-25 pounds, and limiting bending to about once every 30 minutes.

In January 1999, the employee and the employer and insurer entered into a stipulation for settlement, which included recitals of their respective claims.  The employee was claiming compensability for an alleged consequential psychological condition, alleging an underpayment of certain wage loss benefits, claiming eligibility for ongoing wage loss benefits and permanency, and entitlement to further rehabilitation or retraining.  The employer and insurer denied the alleged consequential injury and alleged that the employee was no longer temporarily totally disabled, had an earning capacity which would permit her to earn wages comparable to those earned pre injury, had been paid all benefits to which she was entitled, and had sustained no permanency greater than at most 12 percent.  In the stipulation, the employee accepted a lump sum payment in return for a full, final and complete settlement of all claims arising out of the October 17, 1996, work injury, with the exception of reasonable and necessary future medical treatment exclusive of home nursing, psychological care, chronic pain treatment, passive care and chiropractic treatment.  A compensation judge issued an Award on Stipulation on January 14, 1999.

Vocational rehabilitation assistance had continued throughout 1998 but was discontinued as a result of the parties’ settlement.

The medical records provided in this case show only a few treatments for low back pain in 1999 and 2000, and then fail to show any further treatment by the employee for low back pain until 2006.  The employee apparently did not return to ongoing employment during this period; in an affidavit submitted in support of her petition, she states that she did, however, engage in sporadic employment performing housekeeping work.  Social Security documents in evidence indicate that the employee filed an application for disability benefits on July 19, 2006, covering the period from September 30, 2004, but that the claims were initially denied.  At some point, according to the employee’s affidavit, she found and started a job for an employer that is denoted as “Federal Form” but which appears to be Federal Foam Technologies in New Richmond, Wisconsin.

On April 4, 2006, the employee was seen by a physician’s assistant at the Midwest Spine Institute, where she reported that she had experienced a flare up in her symptoms with increased low back and left leg pain in February of that year.  X-rays showed grade II spondylolysis above the prior fusion.

The employee was also seen at the Stillwater Medical Group on June 7, 2006, with severe low back pain, very bad for the past two weeks with “terrible” spasms and with radiating symptoms down the right leg.  The doctor noted that the employee’s records showed a history of back surgery, but that the employee had not been seen at the clinic for about five or six years.  Examination showed no significant neurologic deficits.

An MRI scan was done on July 31, 2006.  The scan was read as showing grade II spondylolisthesis of L4 anterior to L5 with advanced up/down foraminal compromise bilaterally.  The L5 through S1 levels were noted to be post fusion with no recurrent or residual disc identified.

Dr. Rieser saw the employee on August 1, 2006.  He wrote that she had been doing reasonably well and then gradually became worse.  Flexion was normal, extension was limited, and there was step off at the L4-5 level.  Motor and sensory were intact.  The doctor reviewed spinal imaging and noted that it revealed excellent fusion at L5-S1, but that at L4-5 there was a severe step off due to severe degeneration at L4-5, a transitional level above her fusion.  Dr. Rieser felt that the employee’s fusion had eventually caused increased stiffness and degenerative changes at the level above.  He recommended decompression surgery and fusion at the L4-5 level.

The employee was seen by Dr. Wallenfriedman at United Neurosurgery Associates on October 23, 2006, for a second surgical opinion.  The history given was that the employee had done well after her initial fusion at L5-S1, with resolution of her back pain, but eight years after the fusion developed considerable back pain and bilateral lower extremity pain, left greater than right, to the big toes with numbness in all toes.  It was noted that the employee was currently working for “Federal Phone” [sic], but had gone on medical leave due to her recent symptoms.  The doctor reviewed the MRI from July 31, 2006, and commented that it appeared as if the L4 level had collapsed into the L5 vertebral body.  Dr. Wallenfriedman’s diagnosis was of an unstable level with spondylolisthesis above the previous fusion level.  She recommended an L4-5 anterior interbody fusion with pedicle screws.  She did not think it would be necessary to extend the fusion to the L3-4 level, although she noted a risk that L3-4 might similarly start to undergo degenerative changes after about ten years.

Dr. Jeffrey C. Dick saw the employee on November 30, 2006, for an examination and surgical opinion on behalf of the employer and insurer.  Dr. Dick noted that the employee had done relatively well following the initial surgery until about February, 2006, and since then had gradually progressive low back pain and bilateral leg pain.  He diagnosed the employee as post posterior fusion at L5-S1 with a partially segmented disc at S1-2, and severe adjacent segment degeneration and a Grade II spondylolisthesis of L4 on 5 with bilateral foraminal stenosis.  He considered the employee’s worsened condition to be the result of adjacent segment degeneration as a consequence of the prior surgery.  Since it was determined that the prior fusion resulted from the work injury, Dr. Dick stated that the current L4-5 condition was also related to the work injury.  He considered the proposed second surgery reasonable and necessary.

The employer and insurer agreed to the surgery.  On December 29, 2006, the employee underwent surgery consisting of arthrodesis at L4 through S1, decompressive laminectomy at L4, and interbody fusion, bilateral foraminotomy and microdiscectomy at L4-5, with bone grafting and removal and replacement of pedicle screws.

After the fusion, the employee initially had postoperative resolution of her back and leg pain.  However, her symptoms eventually returned.  On May 30, 2007, Dr. Wallenfriedman saw the employee to review MRI studies and x-rays done to assess the return of pain.  The employee was experiencing pain down the left paraspinous muscle and into the left leg in an L5 radicular pattern.  She also had trochanteric bursitis with sensitivity over the left trochanter.  There was no evidence on the MRI or CT scans of nerve impingement.  The doctor noted that pain had started in a delayed fashion with a sudden onset.  She recommended a CT myelogram and other studies.  She also suggested that the employee see an orthopedist for injection of her hip.

The MRI showed no evidence of nerve root impingement.  The CT myelogram, done on July 9, 2007, showed postoperative changes including broad-based laminectomy with no stenosis. Nerve roots exiting to L4 appeared to abut the disc, with osteophyte changes laterally.  Because it was felt she did not have surgical lesion, the employee was referred for pain management and rehabilitation to Dr. Helms at the Sister Kenny Rehabilitation Institute.

The employee’s Social Security disability case was decided on October 25, 2008.  In its decision, the Social Security Administration determined that the employee had been unable to engage in any substantial gainful activity since August 1, 2006.

On May 19, 2009, the employee petitioned this court to vacate the 1999 award on stipulation.  Prior to filing their reply, the employer and insurer had the employee reexamined by Dr. Dick, on July 23, 2009.  The employee told Dr. Dick that her symptoms remained unchanged between his last IME evaluation in 2006 and the L4-5 level fusion in December, 2006.  After the surgery, her symptoms were initially about 30 percent improved but later returned and gradually progressed to involve not only the left leg but the right leg as well.  The employee also stated that Dr. Wallenfriedman had told her she might need still further surgery.  Dr. Dick’s diagnosis was of failed lumbar surgery syndrome complicated by chronic pain syndrome.  He offered the opinion that the employee’s current and past symptoms were more related to psychological issues than to her work injury.  In his view, there was no significant change in the employee’s diagnosis since her prior surgery, noting that adjacent segment degeneration is common after fusion surgery and concluding that it would not have been unreasonable to have expected ongoing degeneration.  In his view, the employee was still capable of employment under the same restrictions that were in effect on March 5, 1998.  Dr. Dick did not believe that the employee needed further medical treatment for the 1997 work injury.

Dr. Dick also responded to a question posed by the employer and insurer whether there had been any increase in the employee’s permanent partial disability in light of Dr. O’Neill’s 1998 rating of 22.5 percent.  In response, he opined that Dr. O’Neill had not rated the employee correctly in 1998.  In his view, the employee had sustained a 12.5 percent permanency in 1998 and was now at 20 percent as a result of her deterioration and surgery at the second level.  However, he again expressed the view that the increased permanent partial disability could reasonably have been anticipated because patients commonly develop degenerative problems adjacent to the level of a fusion, and this was known to the medical profession in 1999.

Minn. Stat. §176.421 governs this court’s authority to set aside an award.  Cause to set aside an award is defined in the statute as including a substantial change in the employee’s medical condition since the time of the award which could not reasonably have been anticipated.  The employee contends that such cause is present in this case.

In considering whether there has been a substantial change in medical condition, this court has generally applied the factors set forth in Fodness v. Standard Café, 41 W.C.D. 1054 (W.C.C.A. 1989):

The employer and insurer contend that the employee has failed to demonstrate that any of the factors, with the exception of that of causation, support her petition to vacate.  In addition, they contend that, to the extent that we might conclude that any of the factors did support a substantial change in the employee’s condition, such changes should reasonably have been anticipated at the time of the stipulation.  We will consider in succession each of the factors, and the issue of whether any changes were reasonably to be anticipated.

The employer and insurer contend that there has been no change in diagnosis, pointing out that the employee had a pre-stipulation diagnosis of degenerative disc disease, and that her diagnosis at present remains essentially one of degenerative disc disease.  This argument, however, implicitly requires us to accept that there is no significant difference between having degenerative disc disease which is serious and symptomatic at multiple levels and having it at a single level.  The employer and insurer have offered no medical support for the idea that a disc condition requiring fusion surgery at multiple levels should be deemed equivalent to a condition requiring fusion surgery at a single level, nor do we think that such support could reasonably be offered.  We decline to adopt a definition of change in diagnosis which fails to differentiate multiple level conditions from those at single levels.

The only lumbar level which the employee’s physicians identified as medically significant to her condition prior to the date of the award on stipulation was the L5-S1 level, which was treated by fusion surgery in 1997.  No significant problem was diagnosed at the L4-5 level until 2006, more than seven years after the employee entered into the stipulation for settlement.  It appears clear that the diagnosis of grade II spondylolisthesis of L4 anterior to L5 with advanced up/down foraminal compromise was new since the award.  The physicians who reviewed the new, L4-5 disc problem, including Dr. Dick, all considered that it required extensive surgical treatment.  We conclude that this condition represented a significant change in the employee’s diagnosis.

This factor is mixed in this case.  The evidence is somewhat contradictory with respect to the employee’s ability to work both pre-stipulation conditions and at present.  We note that after the employer was unable to provide the employee with continued work within her restrictions, the employee found only one job of very brief duration during the two years prior to the award on stipulation.  On the other hand, the restrictions prior to the stipulation were not such as would normally lead a reasonable person to assume that future employment was unlikely.  We note further that at the time the parties entered into the stipulation for settlement, vocational rehabilitation activities were ongoing, which were discontinued solely as a result of the settlement.  And, although there was vocational opinion that the employee could benefit from some additional course work or perhaps even retraining, we note that the rehabilitation experts then involved in the case apparently continued to view the employee as employable.

The current situation is also ambiguous.  The employee’s work history since the date of the award on stipulation is less than clear.  It appears that the employee was engaged primarily in sporadic work as a housekeeper for most of the period between the date of the stipulation and the summer of 2006.  However, shortly prior to the surgical recommendations by Dr. Rieser on August 1, 2006, she had found and started a job with Federal Foam, at which she was unable to continue as a result of her need for the second surgery.  Because of the timing of the inception of this job, and the lack of evidence as to its nature and how long the employee actually worked, we cannot be entirely sure that she would have been able to perform the job but for her new L4-5 symptoms.  Thus its significance in resolving the question whether there has been a change in ability to work is uncertain.

Finally, there is also ambiguity as to the employee’s current ability to work.  Dr. Dick has offered restrictions that would suggest no significant change in the employee’s abilities.  On the other hand, the Social Security Administration has determined that the employee has been unable to work since August 1, 2006, due to the combination of the medical conditions at issue in this matter.  While we are not bound by the social security determination on that issue, we note that it was based not only on the medical opinions of Dr. Helms and Dr. Wallenfriedman, but also on the opinion of Dr. Andrew Steiner, a neutral medical expert it appointed to review the case.

Although the evidence is equivocal, we conclude the employee has provided sufficient evidence showing that there has been a change in her ability to work for us to view this factor as at least mildly supportive of her petition.

The employer and insurer’s expert, Dr. Dick, has offered the opinion that the employee’s pre stipulation L5-S1 condition warranted a permanency rating of 12.5 percent, while rating the L5-S1 and new L4-5 conditions taken together with a current permanency of 20 percent.  While the employee did receive a 22.5 percent permanency rating from Dr. O’Neill prior to the stipulation, Dr. Dick specifically noted that he considered that rating erroneous.  It is thus clear that Dr. Dick believed that there has been a significant increase in the employee’s permanent partial disability compared with that which she had prior to the stipulation.

The employee points to the second surgery as demonstrating a need for more costly and expensive medical care since the date of the stipulation.  In addition to the defense that this care could reasonably have been anticipated, which we discuss below, the employer and insurer assert that because future medical expenses were left open by the stipulation for settlement, and because the employee’s recent medical care has in fact been paid by the insurer, this factor is of little weight.  However, we have previously noted that, even where medical benefits are left open, the need for more expensive medical care than anticipated remains useful evidence bearing on whether there has been a substantial change in an employee’s condition.  See, e.g., Vellieux v. Catholic Charities, slip op. (W.C.C.A. Mar. 8, 2007).  The additional treatment in this case is significant, and, if unanticipated, constitutes evidence of a substantial change in the employee’s condition.

All medical experts expressing an opinion on the question have acknowledged a causal relationship between the L4-5 condition and surgery and the work injury, including Dr. Dick in his opinion of November 30, 2006.  While Dr. Dick’s most recent report expressed the opinion that psychological issues might play a greater role than the work injury in the employee’s current and past symptoms, he does not dispute that there was a causal connection between the work injury and the L4-5 condition and resulting surgery.

The argument on which the employer and insurer have most strongly relied in opposing the employee’s petition is the contention that the employee could reasonably have anticipated her L4-5 lumbar degeneration and surgery, and by extension any associated decreased ability to work or increased permanency.  This argument is predicated on the premise that fusion surgery at a lumbar vertebral level not infrequently causes an eventual disc problem at one or more adjacent levels, because of the increased strain placed on those levels by the rigidity of the spine at the level of the fusion.  Both Dr. Dick and Dr. Rieser have opined that the employee’s L4-5 problems did arise due to such a process.  The employer and insurer further rely on Dr. Dick’s statement that this process was well known in 1999, when the employee entered into the stipulation.  Thus, the employer and insurer contend, such a result should reasonably have been anticipated.

We disagree.  The issue here is not whether medical science might have anticipated the possibility that the medical process here might occur, or even on whether the employee’s physicians could or should have anticipated it.  Rather, the issue is focused on the understanding of the parties to the stipulation, and particularly on that of the party seeking vacation of the award.  Here, there was no indication either in the medical records or in the language of the stipulation or other pre-stipulation records, to suggest that the employee was specifically advised that she would likely develop significant symptoms and require surgery at an adjacent level.

In addition, the question is not whether a specific change in condition might conceivably occur, but one of what was reasonably anticipated.  We have previously noted that “there is a clear distinction between risks and reasonably anticipated results.”  Renneker v. Master Mark Prods., slip op. (W.C.C.A. Jan. 7, 2005), at 8.  To find that a change in condition was or should have reasonably been anticipated requires that the evidence indicate not only that the occurrence of the specific change of condition was, or should have been, apprehended, but also that its probability be sufficiently great that a reasonable person would anticipate a strong likelihood that it might actually take place.

Here, there is nothing in the record to indicate that the employee, at the time of the stipulation, had any reason to anticipate that her L5-S1 fusion would eventually cause the L4-5 level, which had not been implicated in work injury and which was not then heavily degenerated or symptomatic, to deteriorate to the extent that further extensive surgery at this new level would be required.

We conclude that the employee’s petition is sufficiently supported by the evidence that vacation of the 1999 Award on Stipulation is appropriate.