The appellants, Sioux Trails Mental Health Center and SFM Mutual Insurance Company, appeal the compensation judge’s denial of apportionment of liability between the appellants and the Minnesota Department of Human Services (State of Minnesota).  The appellants argue that the compensation judge’s decision was not supported by substantial evidence, contained conflicting findings, and requires a remand to resolve.  We affirm.

The employee has a complicated medical history.  She was working as a nurse for each of the employers named in this proceeding when she suffered admitted work injuries on September 26, 1997, July 4, 2003, and January 4, 2010.  The State of Minnesota is the self-insured employer for the July 4, 2003, work injury.  Sioux Trails Mental Health Center was the employer for the January 4, 2010, work injury with workers’ compensation coverage provided by SFM Mutual Insurance Company (collectively Sioux Trails).

On September 26, 1997, the employee was in an automobile accident while working for Becklund Home Health (Becklund) and the State of Minnesota.  The employee suffered cervical trauma and head trauma in that accident.  In 1999, the employee underwent a lumbar laminectomy at L5-S1 which was unrelated to any compensable work injury.^[1]  On July 18, 2002, the employee underwent a cervical fusion at C5-C6.  The cervical fusion, which resulted from the September 26, 1997, work injury, left the employee unable to continue working as a direct-patient care nurse for either Becklund or the State of Minnesota due to resulting lifting restrictions.

On July 4, 2003, the employee was placing a towel under some medical cassettes which weighed about 40 pounds when she felt a pull in her neck and left shoulder which later developed into acute upper back, neck, and left shoulder pain.  Carolyn Baerg, M.D., the employee’s family physician, began a course of conservative treatment and then referred the employee to Gene Swanson, M.D., to address the employee’s increasing pain in her neck, and left scapular and trapezius areas.  A cervical MRI showed disc protrusion at C6-C7 and disc bulging at C4-C5.  The employee underwent cervical and shoulder injections without obtaining pain relief.^[2]

On May 7, 2004, the employee underwent an independent medical examination (IME) conducted by Paul Yellin, M.D, at the request of the State of Minnesota.  Dr. Yellin opined, in part, that the July 4, 2003, work injury aggravated the employee’s cervical spine condition arising from the September 26, 1997, work injury.^[3]

After the work injury in 2003, the employee began receiving a disability benefit from the Minnesota State Retirement System (MSRS).  This benefit continued through the employee’s January 4, 2010, work injury.^[4]

The employee underwent additional cervical surgery in 2006 that extended the cervical fusion to C6-C7.^[5]  On October 30, 2006, the employee was seen in a follow up examination by Timothy A. Garvey, M.D., who found her physically capable of no more than light duty work 25-30 hours per week.  Dr. Garvey recommended retraining to improve her job opportunities.^[6]

On August 20, 2007, the employee was involved in an automobile accident unrelated to employment.  The accident occurred in a parking lot and the employee suffered minor injuries: soreness to her neck, headache, dizziness, and balance problems.^[7]

In 2007, the employee entered into a stipulation with the State of Minnesota, the September 26, 1997, work injury employer, to obtain retraining.^[8]  The employee attended Mankato State University and obtained a bachelor’s degree in nursing.  While in school, the employee worked for Mankato Rehabilitation and taught at Rasmussen College.  The employee resumed working in management after completing her degree.  In 2009, the employee began working for Sioux Trails as an RN and clinic coordinator.  The position with Sioux Trails was full-time and the employee earned $68,500.00 per year.  The employee also worked part-time as a mental health nurse performing case management.  The combined full-time and part-time work resulted in a stipulated weekly wage of $1,539.46.  The work involved in these positions did not require physical work when interacting with patients or performing other job duties.

On October 1, 2008, the employee underwent an IME conducted by Gilbert Westreich, M.D., at the request of the automobile insurer, Illinois Farmers.  Dr. Westreich attributed all of the employee’s symptoms and need for medical care to her preexisting medical condition and none to the effects of the automobile accident on August 20, 2007.^[9]

The employee experienced ongoing medical problems with her neck and shoulder, but she had no difficulties working despite those symptoms.^[10]  The employee received care from Dr. Garvey, and at the Mayo Clinic for TMJ problems, dizziness, pain, and headaches.  The employee received care from Lisa R. Davidson, M.D., concerning an abnormal gait and headaches.  The employee also treated with Carolyn Bowles, M.D., and Sabrina M. Walski-Eaton, M.D.  All of these physicians directed the employee to follow a conservative treatment plan regarding her symptoms.  The employee also received chiropractic care from Teresa L. Marshall, D.C.  The employee was diagnosed with chronic pain in December 2009.  The employee continued to schedule two jobs at the same time. None of the foregoing symptoms prevented the employee from performing two jobs and working more than full-time.^[11]

On January 4, 2010, the employee experienced a fall in which she struck her head, left shoulder, left hip, and left knee.  The employee received treatment for that injury from her primary physicians at the Mankato Clinic.  The employee experienced weakness in her arms and legs, left shoulder and cervical spine stiffness, muscle spasms over her ribs, and bladder incontinence.  The employee described increased low back symptoms and spasming after the January 4, 2010, work injury.  The employee returned to work until January 27, 2010.  On February 5, 2010, Dr. Davidson took the employee off of work until she could be seen by Dr. Buss.^[12]

The employee was treated by Dr. Baerg, Dr. Davidson, and Dr. Garvey following the January 4, 2010, work injury.  Additional imaging and thoracic epidural injections were performed.  Imaging showed herniation and disc protrusion at levels T5 through T8.^[13]  The employee assessed her neck symptoms as 60-70% worse after the 2010 fall.  The employee ascribed her thoracic spine symptoms to her being disabled from work.  The employee assessed her thoracic spine condition as contributing over 50% of her back pain with her cervical spine next in severity, and her low back contributing the least.^[14]

On December 23, 2010, the employee was examined by Todd M. Hess, M.D., at the United Pain Clinic for bilateral arm weakness resulting in the employee losing grip strength and experiencing numbness and tingling.  The employee described work as very difficult due to her overall condition and the lack of pain relief.  The employee returned to Dr. Hess three or four times since the initial referral.^[15]

On March 11, 2013, the employee underwent an IME conducted by Nolan M. Segal, M.D., at the request of Sioux Trails and SFM.  Dr. Segal opined that the employee did not need any additional care or treatment arising out of the January 4, 2010, work injury.  Dr. Segal concluded that the employee was appropriately rated at 17% permanent partial disability (PPD) under Minn. Rule 5223.0370, subps. 4.D., 4.D.(1), and 5.B, and apportioned 14.5% to the September 26, 1997, work injury and the remaining 2.5% to the July 4, 2003, work injury.  Dr. Segal also rated the employee at 2.5% PPD for her thoracic spine, unattributable to any work injury.  Regarding her lumbar spine, Dr. Segal rated the employee at 10% PPD, which he could not relate to any of the employee’s work injuries.  Regarding permanent total disability (PTD), Dr. Segal attributed 50% of the disability to idiopathic causes unrelated to any work injury, 35% to the September 26, 1997, work injury, and 15% to the July 4, 2003, work injury.  In an update on January 31, 2014, Dr. Segal attributed any ongoing medical treatment in the same percentages as the PTD allocation (50%, 35%, and 15%, respectively).^[16]

On November 5, 2013, Dr. Baerg provided a narrative report that summarized the employee’s numerous surgeries and noted that she had always been able to function and remain employed at “a very good job.”  Dr. Baerg opined that the January 4, 2010, work injury significantly aggravated the employee’s surgical spine, left shoulder, and core spine injuries and resulted in the employee only being able to perform sporadic or part-time activities.  Dr. Baerg opined that the employee should be considered completely disabled.^[17]

On April 9, 2014, the employee underwent an IME conducted by Mark C. Engasser, M.D., at the request of Becklund and its insurer, RTW.  Dr. Engasser attributed some permanent partial aggravation of the thoracic disc herniation at T5-T6 to the September 26, 1997, work injury.  Dr. Engasser opined that the September 26, 1997, work injury was not a substantial contributing factor in the employee's current symptoms.  Dr. Engasser attributed the employee’s current symptoms to disc degeneration through aging and the work injuries in 2003 and 2010.  No opinion was offered on ratings for PPD or PTD allocation.  For future medical treatment, Dr. Engasser allocated 60% to degenerative disc conditions unrelated to any work injury, 30% to the July 4, 2004, work injury, and 10% to the January 4, 2010, work injury.  Dr. Engasser attributed none of the employee’s low back condition to any of the employee’s work injuries.  He also noted that the employee had injuries outside of work that were factors in the condition of the employee’s thoracic and cervical spine.^[18]

On May 14, 2014, Dr. Yellin conducted a follow-up IME of the employee at the request of the State of Minnesota.  Dr. Yellin opined that the employee’s condition at C4-C5 and C6-C7 was worsened by the July 4, 2003, work injury and that injury was a substantial contributing cause of a permanent aggravation of the employee’s preexisting cervical spine conditions.  Dr. Yellin opined that there was no injury to the thoracic or lumbar spine arising from the July 4, 2003, work injury.  Dr. Yellin considered restrictions to be necessary from the July 4, 2003, work injury in conjunction with the preexisting C5-C6 cervical fusion.  These restrictions included five pounds lifting, no lifting above shoulder level, no overhead work, and no extension of the employee’s neck when positioning her head.  Dr. Yellin was of the opinion that the employee could work within those restrictions.  Regarding PTD, Dr. Yellin agreed with Dr. Segal’s conclusion that the employee was appropriately rated at 17% permanent partial disability and also agreed with Dr. Segal’s allocation.  As to PPD, Dr. Yellin rated the employee under Minn. Rule 5223.0370, subps. 4.D., 4.D.(1), and 5.A., at 14.5%.  Dr. Yellin also rated the employee at 2.5% PPD for her thoracic spine under Minn. Rule 5223.0380, subp. 3.B., and apportioned 50% to preexisting conditions and 50% to the January 4, 2010, work injury.  Apportionment of medical treatment for the cervical spine by Dr. Yellin was 85% to the September 26, 1997, work injury, and 15% to the July 4, 2003, work injury.  All of the thoracic spine treatment was allocated to the January 4, 2010, work injury.^[19]

On February 23, 2015, Dr. Hess was deposed regarding his opinions on the employee’s condition.  Dr. Hess attributed 100% of the employee’s thoracic injury and lumbar injury to the January 4, 2010, work injury.  Dr. Hess also attributed 100% of the employee’s inability to work to the January 4, 2010, work injury.  The cervical spine was assessed by Dr. Hess to be 12.5% from the January 4, 2010, work injury and 12.5% from the July 4, 2003, work injury.^[20]

The employee filed a Claim Petition on September 3, 2014, which was combined with a Request for Formal Hearing filed on or about February 2, 2015, and an Objection to Discontinuance filed on February 25, 2015.  The parties entered into a partial stipulation for settlement in which it was agreed that the employee was permanently and totally disabled from employment from January 10, 2010, onward, that the employee sustained an injury to her left side, left knee, hip, low back, thoracic spine, cervical spine, shoulder, and head as a result of the January 4, 2010, work injury, and that the remaining listed issues were to be heard by a compensation judge.  The remaining issues were as follows:  1) the nature and extent of the employee’s various work injuries; 2) appropriate apportionment of PTD between the State of Minnesota and Sioux Trails; 3) whether a statutory credit applies to the PTD award and, if so, its effect; and 4) the appropriate apportionment of medical expenses between the insurers.  The partial stipulation incorporated by reference the terms of the prior stipulations entered into in 1999, 2001, 2003, and 2007.^[21]

The matter was heard before Compensation Judge Catherine Dallner at the Office of Administrative Hearings on February 26, 2015.  The compensation judge made findings regarding the issues presented by the parties.  The judge determined that the employee suffered permanent injury to her cervical spine, thoracic spine, and lumbar spine; a permanent aggravation of her chronic pain syndrome, and injuries to her left shoulder and left knee.  The judge allocated 100% of the medical expenses for treatment of the lumbar spine, thoracic spine, left shoulder, and left knee to the January 4, 2010, work injury, payable by Sioux Trails.  The medical expenses for chronic pain were attributed 87.5% to the January 4, 2010, work injury, 6.25% to the July 4, 2003, work injury, and 6.25% to the September 26, 1997, work injury.  The medical expenses for treatment of the employee’s cervical spine were allocated 50% to the January 4, 2010, work injury, 25% to the July 4, 2003, work injury, and 25% to the September 26, 1997, work injury.  The compensation judge found that Sioux Trails was not entitled to contribution for permanent total disability benefits paid to the employee.  Sioux Trails appealed the denial of contribution for PTD benefits.

In reviewing cases on appeal, the Workers’ Compensation Court of Appeals must determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.”^[22]  Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.”^[23]  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.^[24]  Similarly, “[f]actfindings are clearly erroneous only if the reviewing court on the entire evidence is left with a definite and firm conviction that a mistake has been committed.”^[25]  Findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of the evidence or not reasonably supported by the evidence as a whole.”^[26]

Where a dispute exists between two or more insurers as to which is responsible for payment of permanent total disability benefits and in what amounts, the compensation judge is the authorized factfinder to resolve all related issues, including reimbursement and equitable apportionment in the distribution of permanent total disability benefits.^[27]

In the present case, the appellants do not challenge the compensation judge’s findings of fact as to apportionment under the Hengemuhle standard of review.^[28]  The appellants further state that they accept the judge’s choice of expert medical opinions in accordance with Nord v. City of Cook.^[29]  What the appellants challenge and seek on appeal is a remand to the compensation judge “for a determination of whether or not the injury of July 4, 2003, is responsible for all disability apportioned to that injury and the injury of 1997 and how such an apportionment is effectuated”^[30] under the Workers’ Compensation Act.

Appellants contend that the compensation judge committed an error of law by failing to apply her findings of fact regarding medical care to the allocation of responsibility for payment of permanent total disability benefits between the State of Minnesota and Sioux Trails.   Appellants reason that, since the responsibility for the medical care is divided between responsible insurers for the various dates of injury, so too must the responsibility for PTD benefits be divided, as the disability arose out of those various injuries.  To that end, appellants argue that the compensation judge issued an inconsistent decision that should be remanded.  In support of their position, appellants point to specific language in the memorandum accompanying the judge’s decision.

An employer and its insurer are liable for an employee’s medical expenses when the need for treatment is due in substantial part to the work injury.^[31]  The employer and its insurer remain responsible for any resulting medical treatment caused from the effects of the work injury unless there is a superseding, intervening cause that breaks the chain of causation.^[32]  Liability continues despite an intervening, nonwork-related condition where the work-related injury is a substantial contributing cause of the ongoing disability.^[33]

In arriving at a decision, the compensation judge must resolve conflicts in expert medical testimony, and the judge’s choice of an expert opinion is usually upheld unless the facts assumed by the expert in rendering an opinion are not supported by the evidence.^[34]  Where evidence is conflicting or more than one inference may reasonably be drawn from the evidence, the findings of the compensation judge are to be upheld.^[35]  In the present case, there is ample medical evidence to support the compensation judge’s determination that the employee’s ongoing medical treatment is allocable between the insurers in the percentages set forth in the findings and order.  As stated previously, none of the parties appealed the compensation judge’s findings regarding compensability or allocation of responsibility for medical treatment provided to the employee.

Medical treatment is compensable where it is reasonable and necessary to cure and relieve the employee of the effects of a work injury.^[36]  The responsibility for permanent total disability, however, lies with the “injury which totally and permanently incapacitates the employee from working . . . .”^[37]

In her memorandum, the compensation judge reasoned that insofar as the employee completed retraining and changed her vocational focus, the employee was able to work at superior compensation at more than full-time employment despite the effects of her September 26, 1997, work injury and her July 4, 2003, work injury.  This ability to work extended to the date of her January 4, 2010, work injury.  There was no showing that the employee suffered any meaningful impairment in work ability in her new vocational endeavors prior to the January 4, 2010, work injury.  From this, the compensation judge could reasonably conclude that the two prior work injuries did not substantially contribute to the employee’s work disability after her January 4, 2010, work injury.

In addition to the factual circumstances regarding ability to maintain employment, the record contains both the medical opinion of Dr. Hess and the testimony of the employee.  Dr. Hess opined that 100% of the thoracic injury was attributable to the January 4, 2010, work injury and that was the sole reason for the employee’s disability from working.  The employee testified that the pain from the thoracic back injury was the reason she could not work.  Substantial evidence supports the compensation judge’s conclusion that 100% of the responsibility for PTD benefits was payable by Sioux Trails and no award of contribution was appropriate.

The contention by Sioux Trails that the compensation judge’s decision was contradictory relies primarily on one sentence in the judge’s eight page memorandum.  That sentence makes reference to “this 87.5% of the employee’s inability to work is caused by the employee’s work-related injury of January 4, 2010.”  We agree that this language is inconsistent and perhaps confusing.  But the context of the surrounding sentences is the description of the employee’s ongoing medical treatment allocation.  As described above, the compensation judge allocated 87.5% of one category of the employee’s medical treatment costs to the January 4, 2010, work injury.  From this we conclude that the compensation judge made a typographical error in the description of the allocation.  Moreover, the underlying facts contained in the employee’s medical record supports the judge’s legal conclusion that Sioux Trails is responsible for 100% of the employee’s PTD benefits.  No reversal or remand is appropriate under that circumstance.^[38]

Affirmed as modified.