The employee seeks to vacate an award on stipulation for cause pursuant to Minn. Stat. §176.461, alleging that there has been an unanticipated substantial change in his medical condition since the settlement.  We conclude that cause has not been established and deny the petition to vacate.

The employee, Gerald Bell, first injured his low back on February 4, 1986, while working for Flower City as a warehouse worker.  The employee was lifting a glass table top when he felt a sharp pain in the middle of his low back.  The employee treated with a chiropractor and was off work for a few weeks, then returned to light duty work for about a month before returning to his regular warehouse duties.  CT scans in 1986 and 1988 showed moderate broad based disc herniations at L4-5 and L5-S1, indenting the thecal sac and causing mild impingement on the L5 and S1 nerve roots.  Over the next several years, the employee experienced constant nagging back pain.  He also had occasional aggravations accompanied by pain radiating down the right thigh.

In January 1987, the employee left his job at Flower City and over the next few years held various jobs including working as a restaurant manager, a cashier in a convenience store, and a cashier at a book store.

The employee continued to treat sporadically for low back aggravations without a significant change in his overall symptoms.  In January 1991, the employee was working ten-hour days as a restaurant manager and was noting more back pain.  He was referred to Dr. Phudhiphorn Thienprasit, a neurosurgeon, who first sent the employee for an MRI scan.  The scan was read as showing a central disc herniation at L5-S1 with some thecal sac compression.  There was a small subligamentous herniated disc at L4-5, which the doctor thought was not clinically significant.  Disc space narrowing and desiccation were minimally present at both the L4-5 and L5-S1 levels.  Dr. Thienprasit recommended that the employee undergo surgery in the form of a lumbar hemilaminectomy at L5-S1.  He noted that this surgery would not necessarily eliminate all of the employee’s back and leg pain.

The employee saw Dr. Robert Wengler on July 26, 1991, for an independent medical evaluation.  Dr. Wengler found that the employee’s reflexes were intact and straight leg raising was negative.  He disagreed with Dr. Thienprasit’s recommendation for an L5-S1 decompression, being reluctant to recommend surgery based on his examination findings.  Dr. Wengler also thought that it was not entirely clear which spinal level was causing the employee’s symptoms and he offered the opinion that, if the employee did undergo surgery, both the L4-5 and L5-S1 levels should be treated and that laser discectomy or nucleotomy might be preferable to an open procedure.  Dr. Wengler rated the employee as having 19 percent permanent partial disability.

In 1993, a compensation judge considered the employee’s claim for permanent partial disability compensation and for temporary partial disability benefits during a post-injury period of employment at lower wages during the first year after he left Flower City.  The compensation judge awarded the employee 14 percent permanent partial disability, but denied the temporary partial disability claim on the basis that the employee had no restrictions in effect during the period in question and that it was speculative to conclude that the reduced earnings during that period were a result of his injury. The compensation judge’s findings were affirmed by this court on appeal.

In 1994, the employee was working at UPS at a job with repetitive heavy lifting.  He had a flare up of his low back pain on July 12, 1994, and began treating with Dr. Charles Hipp at the Airport Clinic.  He was diagnosed with an acute lumbar strain.  He was placed on light duty work and physical therapy was prescribed.  By mid-August Dr. Hipp noted that the employee was moderately improved and that his back motion had returned to 80 percent of normal.

By late August, the employee was having increased low back pain and some pain down the right leg to mid-thigh.  His range of motion was markedly limited and there was tightness and spasm in the paraspinal muscles.  Dr. Hipp diagnosed a moderate severe recurrent chronic lumbar strain.  He recommended an MRI scan for comparison with the prior studies from 1986, 1988, and 1991.  The employee underwent a lumbar MRI scan on September 1, 1994.  The scan showed a small annular tear and protrusion centrally at L5-S1 without neural compression and a broad based posterior annular defect and disc protrusion at L4-5 with L5 flattening bilaterally.  These were considered stable since the prior study.  There was no new herniation.

The employee was seen again by Dr. Hipp on September 6, 1994, and his symptoms had improved.  There was still moderate low back pain but no radicular component.  Dr. Hipp considered the employee to have recovered to where he was prior to starting work at UPS.  He opined that the employee had reached MMI without increased permanency.  The employee was released to return to work subject to a 20-pound lifting restriction, which Dr. Hipp felt should have been in place before the UPS injury based on the employee’s condition.

On May 18, 1995, the employee re-injured his back while lifting cases of liquor working as a warehouse worker for Griggs Cooper.  He was treated by Dr. Lewis Gramer at the St. Anthony Clinic.  Dr. Gramer recommended that the employee observe permanent restrictions for moderate duty work with frequent lifting up to 50 pounds.

Another MRI scan of the employee’s lumbar spine was done on July 3, 1995.  The scan showed a central and right sided signal at L5-S1, producing mild CSF indentation.  The L5-S1 level was considered unchanged since the prior study.  A central and right sided annular tear at L4-5 was present, associated with focal annular thickening, indenting, and mild contact with the L5 nerve roots bilaterally.  This herniation was considered to be more prominent in the current scan than in prior studies.

The employee was seen by Dr. John Dowdle for evaluation of the Griggs Cooper injury in November 1995.  Dr. Dowdle diagnosed mechanical low back pain and degenerative disc disease at L4-5 and L5-S1.  He suggested that the employee needed to observe a 30 pound lifting limit and avoid repetitive lifting or lifting from the floor.  The doctor noted that these restrictions were based on the employee’s degenerative disc changes and intermittent symptoms over the years and he attributed  half of the need for restrictions to an underlying degenerative disc disease and half to the 1986 injury.  He opined that the episodes of increased back symptoms in 1990 and 1995 were temporary aggravations of this underlying condition, unassociated with permanency or permanent restrictions.  In his view, the employee had reached maximum medical improvement from both the 1986 injury and a 1995 aggravation at the time of his evaluation.

The employee was also seen for an IME in November 1995 by Dr. Gary Wyard.  Dr. Wyard considered the employee’s current condition to relate solely to the 1986 work injury.  In his view, the claimed 1995 injury had been at most a temporary aggravation of three months duration.  Dr. Wyard thought the employee had reached MMI and had no further permanency beyond the 14 percent already awarded.

In May 1996, the employee entered into a stipulation for a full, final, and complete settlement of both the 1986 and 1995 injury claims, except for future reasonable and necessary medical treatment relating to the 1986 work injury.  An Award on Stipulation was issued by a compensation judge on June 13, 1996.

After receiving payment from the settlement, the employee obtained training as an over-the-road trucker.  He obtained a class A driving license and in 1997 began working for Anderson Trucking.  On December 17, 1997, the employee was unloading tires while working for Anderson and experienced severe back pain.  The pain increased in intensity and the employee sought medical treatment with his family physician a few weeks later.  The employee reported that he had been battling back pain ever since 1986, but that it had recently increased in intensity after unloading tires a few weeks before and he was now unable to work.  He was referred for an MRI and then to see Dr. Sunny Kim at the Institute for Low Back and Neck Care [ILBNC].

The MRI scan, performed on January 27, 1998, showed circumferential bulging of the annulus at L5-S1 with impingement on the anterior thecal sac and contact on the transversing nerve roots bilaterally without displacement.  At L4-5, there was a severe circumferential annular bulge with impingement on the ganglion bilaterally and a parasagittal focal disc herniation with a fragment protruded inferiorly with recess narrowing and impingement on the transversing right L5 nerve root.

Dr. Kim saw the employee on February 5, 1998.  The employee’s pain was mostly in the lumbosacral area without much lower extremity radiation.  Range of motion was limited but reflexes were present and symmetrical and motor and sensation intact.  Dr. Kim prescribed physical therapy.  The employee improved and was able to return to light duty work in April 1998.  He was then placed on work hardening, and on May 12, 1998, Dr. Kim authorized him to return to work at his full ten hour per day driving schedule, noting that the employee was not going to be doing much loading or unloading.  No specific work restrictions were provided. Dr. Kim also considered MMI reached as of May 12, 1998.  No additional permanent partial disability was rated.

The employee sustained a non-Minnesota workers’ compensation injury in Texas while working for an Oklahoma trucking company, John Christner Trucking, on March 5, 2000.  The injury apparently occurred while he was unloading cases of frozen bread.  He returned to Minnesota where he was kept off work and initially treated by his family physician with physical therapy and epidural injections.  When these proved ineffective, an MRI was done in April, 2000, and he was sent back to ILBNC.

On May 15, 2000, the employee was seen by Dr. Charles Burton at ILBNC.  The doctor reviewed the MRI scan, noting that it showed advanced degenerative changes at L4-5 and L5-S1 with central disc protrusions at both levels, and significant secondary changes to the facet joints.  There was a high intensity annular tear at L5-S1.  Dr. Burton recommended that the employee attend a low back rehabilitation program, quit smoking, and stop working as a truck driver.  He noted that if the employee failed to improve, he might be a candidate for fusion surgery.

The employee failed to improve and a further MRI was performed on January 3, 2001.  It showed disc degeneration from L3-4 through L5-S1, a moderate contained central disc herniation at L5-S1 effacing both S1 nerve roots, and early degenerative grade 1 spondylolisthesis at L4 on L5 with moderate central stenosis and moderate subarticular compression of the L5 nerve roots.  The employee elected to proceed with the option of surgery, and on January 31, 2001, he underwent an L3 inferior and L4, L5 and S1 laminectomy with medial facetectomies.  Central stenosis was found during surgery at L4-5 and L5-S1 and was addressed with nerve decompression.  A strut stabilization fusion was performed from L3 to the sacrum.

Following the surgery, the employee was off work until March 14, 2001, when he was released to light duty work.  On June 13, 2001, Dr. Burton released the employee to moderate duty work on a permanent basis, with the recommendation that he not return to truck driving.  Dr. Burton rated the employee with a 20 percent permanent partial disability.

The employee testified that he received Oklahoma workers’ compensation benefits through June, 2001, and then settled his remaining Oklahoma claims on a full, final, and complete basis in return for a lump sum payment.

After he was released to work by Dr. Burton, the employee initially found work as a bartender but soon returned to truck driving.  Between 2001 and 2007, he worked for several different trucking companies.  In April 2007, the employee began working as a driver for Postal Fleet Service, a company which contracted with the U.S. Postal Service to haul mail between postal facilities in the Twin Cities area.

On September 18, 2007, the employee was seen by Dr. David Gilbertson at the St. Anthony Park Clinic for low back and hip pain which the employee did not associate with any specific trauma.  He was diagnosed with lumbar disc strain and degeneration with left hip bursitis.

The following day, September 19, 2007, the employee notified his employer that he would not be at work that day due to back pain.  The employee next worked on September 20, 2007.  On arriving at work on that date, he was observed to be in significant pain, but decided to work anyway.  The employee alleged that he sustained a further low back injury later that same day when he was standing in the back of a truck trailer arranging carts and was struck in the back by a large empty mail cart that rolled down from the opening of the trailer.  He returned to Dr. Gilbertson and reported that his prior pain was nothing like what he was now experiencing.  On September 24, 2007, Dr. Gilbertson noted that the employee was reporting that his low back pain extended down his left leg.  Straight leg raising was somewhat positive.  The doctor recommended an MRI scan and a referral to a neurosurgeon for possible lumbar disc herniation.

An MRI performed on February 5, 2008, showed the prior laminectomy at the L4-5 and L5-S1 levels.  There was disc degeneration at L4-5 with mild narrowing.  Persistent or recurrent midline disc bulging was seen at L4-5 and L5-S1 with an associated annular tear at L5-S1 but no evidence of involvement of neural elements.  Impingement was present on the exiting left L4 nerve root.

The employee began treating with Dr. Maria Zorawska at the Central Minnesota Spine Center.  When seen on February 5, 2008, he reported that his pain was mainly at the left side of his low back and radiated to the left lateral thigh and calf to the ankle.  Dr. Zorawska noted that the employee’s pain did not show an L5 distribution.  The employee had an absent left knee jerk for which the L4 nerve would be responsible.  Because there was L4 impingement on the MRI, she believed the L4 nerve root was the cause of the leg pain.  She scheduled a diagnostic L4 nerve root injection.  The injection was done on February 26, 2008, and the employee reported a significant decrease in pain immediately following injection.

In March, 2008, the employee was seen by Dr. Kim at ILBNC.  Dr. Kim noted that the employee had been managed initially with injections by Dr. Zorawska but without much benefit.  He recommended an L4-L5 lumbar foraminal discectomy, or in the alternative, that the employee undergo further physical therapy and injections and allow more time for his symptoms to improve.  The employee elected to proceed to surgery.

In a letter reported dated March 26, 2008, Dr. Zorawska expressed the view that the employee’s low back and left thigh pain was due to the disc herniation at L4-5, compressing the left L4 nerve root.  She noted that the employee’s pain prior to the 2007 alleged work injury had been in a similar distribution but got worse after the 2007 work incident at Postal Fleet Services.  In her view, the 2007 MRI showed an enlargement of the herniated disc at L4-5 when compared to the scan of 2001.

The employee underwent a left L4-5 foraminal discectomy performed by Dr. Kim on May 5, 2008, at Douglas County Hospital in Alexandria.  During surgery, tissue was found which exerted severe pressure on the left L4 nerve root.  Following the surgery, the employee had resolution of the pain down his leg.

On September 11, 2008, the employee was seen by Dr. Richard Strand for an independent medical examination at the request of the insurer for Flower City.  The employee’s symptoms at that time were back pain without leg pain.  There was no spasm on examination, but range of motion of the back was somewhat decreased in flexion and extension.  Straight leg raising was negative.  Dr. Strand’s diagnosis was multiple level degenerative disc disease.  He offered the opinion that the employee’s symptoms after September 20, 2007, were 80 percent due to an injury on that date, with the remainder split between the 1986 and 2000 injuries.  He considered the employee capable of working full time with restrictions on lifting more than 50 pounds, and no pushing, pulling, or repetitive bending.  Dr. Strand believed the employee had reached MMI and did not need further treatment. He did not rate the employee’s permanent partial disability.

The employee was seen for another IME by Dr. Tilok Ghose on September 20, 2008.  The doctor found no significant findings on examination other than absent reflexes.  He considered the 1986, 2000, and 2007 injuries to be substantial factors which resulted in the development of the employee’s low back condition and PPD rating, which he set at 10.5 percent. In his view, the employee could work within the restrictions provided by Dr. Kim.

On September 30, 2008, Dr. Kim released the employee to return to work driving if he limited lifting to no more than 50 pounds and changed position every hour.  In a health care provider report dated January 21, 2009, Dr. Kim rated the employee with 27.5 percent permanency pursuant to Minn. R. 5223.0070, subp. 1D, and with a further nine percent under Minn.R. 5223.0070, subp. 1B(2).

The employee brought a claim for benefits based on the 1997 admitted injury and the 2007 alleged injury.  Following a hearing on October 9, 2008, a compensation judge determined that the employee had not sustained the alleged 2007 work injury.  The judge further found that the 1986 work injury was a substantial contributing cause of the employee’s low back problems and medical treatment after September 20, 2007, but that the other admitted or alleged Minnesota work injuries were not.  The 1986 employer and insurer were found to bear responsibility for payment of the medical expenses between September 20, 2007, and the date of hearing.  The judge found that the employee’s claims for temporary disability benefits during the period at issue were barred by the prior stipulation for settlement.

On April 21, 2009, the employee petitioned this court to vacate the Award on Stipulation, served and filed on June 13, 1996, on the basis of an unanticipated substantial change in medical condition.

Minn. Stat. §176.421 allows this court to set aside an award for cause.  Cause as defined by the statute includes 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 his 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):

We have reviewed these factors to compare the employee’s condition as of the date of the settlement in 1996 with his subsequent condition up to the date of the most recent medical information provided to us.  As a preliminary matter, we note that there is an unappealed finding that the 1986 work injury remains a substantial contributing cause of the employee’s condition from and after September 20, 2007.  The employer and insurer concede that causation is here established for purposes of the employee’s petition.

We consider first whether there has been a significant change in the nature and diagnosis of the employee’s underlying lumbar condition.  Scans as early as 1986 and 1988 revealed moderate broad based disc herniations at L4-5 and L5-S1, indenting the thecal sac and causing mild impingement on L5 and the S1 nerve roots.  The most recent MRI performed on February 5, 2008, showed persistent or recurrent midline disc bulging at the same L4-5 and L5-S1 levels.  While this scan and the other recent scans also reflect the employee’s two surgeries, there has been no development of significant new and distinct conditions at these two levels or at any other levels.  The employee’s pre-settlement diagnosis was essentially that of mechanical low back pain and degenerative disc disease at L4-5 and L5-S1, the latter including the herniations at those levels.  As recently as 2008, Dr. Strand’s diagnosis was similarly of multiple level degenerative disc disease, again referring to the same levels.  There is no evidence suggesting that the employee’s current low back problems are anything other than the same conditions diagnosed prior to the stipulation for settlement.

The employee essentially contends, however, that there has been a progression or worsening of the pre-stipulation herniations at the L4-5 and L5-S1 levels, leading to the need for surgical treatment, and that this progression constitutes a substantial unanticipated change in condition.  While we agree with the implicit argument that an extensive and unanticipated worsening of a known condition may, in some cases, provide sufficient cause for vacation of an award, we do not consider the progression here to have been reasonably unanticipated.  It is not unusual for a herniated disc, or two herniated discs, causing mild or intermittent nerve root impingement, to worsen and result in a condition where surgery is recommended.  Whether that is “unanticipated” may depend upon the extent to which the doctors have recognized and informed the employee about that possibility prior to a stipulation for settlement.  Here, however, the employee was already advised as early as February 1991 that surgery might be advisable to treat his L5-S1 disc, and in October of the same year, Dr. Wengler noted that surgery, if it were done, should be performed at both the L5-S1 and L4-5 levels.  Despite the surgical recommendations, the employee had the good fortune to be able to continue to defer the surgery and function without much change in his symptoms for a decade before he needed to follow through on the early surgical recommendations.

Because the prospect of surgical treatment was not unanticipated, we cannot automatically conclude that the surgeries in 2001 and 2008 constitute more costly and extensive medical care of the type that might lead us to vacate the 1996 Award on Stipulation.  The employee argues that, even if some form of surgery might have been anticipated, he did not have reason to anticipate that two surgeries would ultimately be performed.  We note, however, that the 1996 stipulation left open the employer’s obligation to pay for reasonable and necessary medical treatment associated with the 1986 injury, and that the employer and insurer have already been ordered to pay for the medical expenses from September 20, 2007, through the date of hearing on October 9, 2008.^[1]  As this court has noted on several occasions, where medical expenses are not closed out by the award that the employee is seeking to vacate, less emphasis may be appropriate on the question whether the employee needed more costly and extensive medical care than initially anticipated.  Burke v. F & M Asphalt, 54 W.C.D. 363 (W.C.C.A. 1996).

Similarly, we note that, while the employee’s physicians have now rated him with a greater permanency than the 14 percent paid to him prior to the stipulation for settlement, all of the additional permanency is based solely on ratings for the surgical treatment rendered for his low back problems.  To the extent that surgery was not unanticipated, the corresponding increase in permanency also fails to reflect an unanticipated change in condition.

Finally, comparing the situation prior to the stipulation with that now present, there has not been a significant change in the employee’s ability to work.  Although formal permanent medical restrictions were not imposed for some time after the 1986 work injury, the employee himself testified in 1995 that after the 1986 injury he “stopped doing manual labor jobs [and] . . . tried to find the easiest jobs I could that my back could handle.”  He generally restricted his lifting to about 25-30 pounds, and would consider lifting 50 pounds only on a very infrequent basis, perhaps once a month.^[2]  Dr. Gramer, the employee’s treating physician in May 1995, concluded that the employee was capable of work requiring lifting up to 50 pounds.  In November 1995, Dr. Dowdle examined the employee and noted that he needed to observe a 30 pound lift limit and to avoid repetitive lifting or lifting from floor level.  The employee’s current restrictions, as set by his treating doctor, Dr. Kim, on September 30, 2008, allowed the employee to return with moderate  restrictions, with lifting not to exceed 50 pounds. Dr. Strand, an IME in 2008, also agreed that the employee was able to work with a 50 pound lifting limit.

The employee points to extensive periods of time off work associated with the symptoms leading up to, and the recovery from, his two surgeries.  We think the question is not so much whether there were intermittent periods of total disability associated with the need for surgical treatment, but whether there has been a significant change in the employee’s ability to work on a continuing basis. No such change is shown in the evidence before us.

We conclude that the employee has failed to show a substantial change in medical condition since the time of the award on stipulation sufficient to constitute cause to set aside the award under Minn.Stat. §176.461.  The employee’s petition is denied.