Appellant, Enic C. Clevenger, suffered an industrial accident on August 9, 1955, while employed by respondent, Potlatch Forests, Inc. The facts and circumstances of the accident were considered by this Court in Clevenger v. Potlatch Forests, Inc., 82 Idaho 383, 353 P.2d 396, in which case an award in the amount of $1800.00 for partial permanent disability was affirmed. Following said accident appellant continued his employment except intermittently for periods when because of recurrences of pain he was unable to work. About May 1, 1960, his condition became worse and he finally ceased work on June 27, 1960. Following the accident appellant consulted several physicians and at times was conservatively treated with medication and therapy. *197On August 17, 1960, a myelogram was taken and two days later a laminectomy was performed on appellant’s low back. He returned to work on December 5, 1960.
During the summer of 1960 appellant made several attempts to contact the manager of respondent surety, Workmen’s Compensation Exchange, with a view of discussing his need for further treatment. He was unsuccessful in such efforts and authorization to have surgery performed was not obtained.
On January 30, 1961, appellant filed with the Industrial Accident Board a “Petition for reimbursement for medical benefits procured by claimant, pursuant to Sec. 72-307 I.C.” Under said petition appellant seeks recovery of medical and kindred expenses incurred by him on account of medical and surgical treatment, together with hospital care subsequent to July 29, 1960, which expenses were incurred in connection with the examination and surgery hereinabove mentioned, allegedly necessitated by his accidental injury of August 9, 1955. From an order denying reimbursement this appeal is taken.
The specifications of error are directed to the “Ultimate Finding and Ruling” of the Board, copy of which follows:
“The operation performed by Dr. Baranco was not emergent (ff. 86-7), but elective (f. 90). The man was ambulatory (f. 86). He could continue to live and possibly work with his discomfort, as he had in the past. That the operation was necessary, as the Board finds, is best shown by the ultimate event — • the man returned to his regular work, which he then performed without pain.
“Nevertheless, Clevenger’s election to have the operation was unreasonably belated. He could have exercised such election in 1956, or at any time thereafter within four years after the accident. His recovery herein is barred by Sec. 72-607, Idaho Code, the provisions of which apply to any form of compensation, including medical and kindred expenses under Sec. 72-307.”
Appellant’s assignments of error I and III are essentially identical, wherein it is contended that the Board erred in ruling that medical attention provided for by I.C. § 72-307, or reimbursement in the event of failure to supply medical attention, are barred by I.C. § 72-607.
I.C. § 72-307 provides:
“The employer shall provide for an injured employee such reasonable medical, surgical or other attendance or treatment, nurse and hospital service, medicine, crutches and apparatus, as may be required or be requested by the employee immediately -after an injury, mid for a reasonable' time thereafter. If the employer fails to provide the *198same, the injured employee may do so at the expense of the employer. All fees and other charges for such treatment and services and compensation therefor shall be subject to regulation by the board. The pecuniary liability of the employer for the treatment and other service herein required shall be limited to such charges as prevail in the same community for similar treatment of injured persons of a like standard of living when such treatment is paid for by the injured person. In determining what fees and charges are reasonable, the board shall consider the increased security of payment afforded by this act.” (Italics supplied)
I.C. § 72-607 provides:
“On application made by any party within four years of the date of the accident causing the injury, on the ground of a change in conditions, the board may at any time, but not oftener than once in six months, review any agreement or award, and on such review may make an award ending, diminishing or increasing the compensation previously agreed upon or awarded, subject to the maximum and minimum provided in this act, and shall state its conclusions of fact and rulings of law,’ and immediately send to the parties a copy of the award, but this section shall not apply to a commutation of payments under section 72-321.” (Italics supplied)
I.C. § 72-607 in 1957 was amended to provide that the application must be made within five years of the date of the accident. However such amendment is not retroactive and since the accident here involved occurred in 1955 the four year limitation applies. Wanke v. Ziebarth Const. Co., 69 Idaho 64, 202 P.2d 384; Kelley v. Prouty, 54 Idaho 225, 30 P.2d 769.
The issue here presented requires a determination whether the time limit imposed by I.C. § 72-607 applies to the attendance and services provided for by I.C. § 72-307.
The record discloses that the only award made in this cause was entered on December 11, 1959, in favor of appellant in the amount of $1800.00 as specific indemnity for partial permanent low back disability. Appellant’s petition specifically states that the requested reimbursement is sought pursuant to I.C. § 72-307; it does not allege any change of condition or seek a modification of the award.
No other petition for medical or surgical expenses has been filed -by appellant nor has any order, other than the one appealed from been entered by the Board relative to appellant’s medical or surgical expenses.
In appellant’s original petition, upon the hearing of which an award of $1800.00 for partial permanent disability was made, i( is *199stated that “At the present time claimant is in need of surgery for the repair of injuries to a disc or discs in his back.” However, no medical or surgical expenses were requested by the petition, nor did the Board allow or disallow any sum as such expense. The following quoted statement of the Board contained in the findings and order here appealed from is convincing that the Board did not, in the original proceedings, consider the allowance or denial of any medical expenses incurred by appellant, to-wit:
“In the original proceedings no recovery was sought for total temporary disability compensation or for medical expenses, such matters having been previously adjusted between the parties.”
The record does not contain a finding by the Board as to the extent that medical treatment or care was required by appellant from the date of the accident to the time of his surgery. However the findings do indicate that he had repeatedly consulted physicians and specialists. There had been no finding that appellant was medically or surgically healed of his injury prior to his surgery.
Respondents cite Wanke v. Ziebarth Const. Co., supra, as supporting their contention. In that case the Court specifically stated that it was not therein determining how the statutes here involved should be construed. The application in that case was based upon a “change in conditions” and the Board had previously found that claimant was “surgically healed of his injuries”. The following quotation from said decision strongly indicates that neither the Board nor the Court was convinced that the physical trouble in connection with which recoupment of disbursements for medical treatment was sought, was the result of a compensable injury. While referring to I.C. § 72-307, the Court stated:
“Nor do we find any language therein which impliedly requires an employer to provide treatment for undiscovered physical troubles arising after all the known injuries have been treated and taken care of.”
While the furnishing to the injured employee of medical, surgical, hospital services and other attendance or treatment as required by I.C. § 72-307 may be treated as payment of compensation, such is not the subject of an agreement or award which is contemplated under the provisions of I.C. § 72-607, as being subject to modification on the ground of a change in conditions. It is a change as to the disability of the injured employee which authorizes the modification of an award or agreement under I.C. 72-607. Mahoney v. City of Payette, 64 Idaho 443, 133 P.2d 927. The attendance mentioned in said statute, I.C. § 72-307, is required to be furnished *200“immediately after an injury, and for a reasonable time thereafter.”
The issue here presented was considered by this Court in Irvine v. Perry, 78 Idaho 132, 299 P.2d 97, wherein Irvine did not assert any change of condition nor ask for a modification of an award as provided in I.C. § 72-607, but sought a determination of his right to medical attendance as provided in I.C. § 72-307. His condition from the time of the injury was permanent, requiring continual medical treatment. This Court held that I.C. § 72-607 had no application to the situation and that the Industrial Accident Board was correct in holding:
“ * * * the four-year limitation thereof does not apply to medical attendance, as defined in sec. 72-307, in a case of total and permanent disability, as defined in sec. 72-311, particularly when the. original injury causes continuous or recurrent symptoms which require medical attendance.”
Although permanent disability was involved in the Irvine case such disability was not controlling in determining his claimed right to medical treatment. The nature or extent of disability is not determinative of an injured employee’s right to the attendance provided for in said § 72-307, it is the necessity for such services that controls. Among the primary duties of an employer to an injured workman is to furnish him reasonable medical, surgical or other treatment necessary to rehabilitate him and as far as possible restore his health, usefulness and earning capacity. Koegler v. C. F. Davidson Co., 69 Idaho 416, 209 P.2d 728. By said § 72-307 it is contemplated that the injured workman shall be provided with reasonable medical, surgical and other treatment when and for such period as such services or treatment are reasonably necessary. The Board erred in concluding that, exclusive of any other reason, appellant’s failure to exercise an election to have surgery within the four year period specified in § 72-607 bars his right to recovery under his petition.
Appellant contends that the Board erred in finding that “Clevenger’s election to have the operation was unreasonably belated.” From the language used it must be assumed the Board felt that appellant should have elected to have the operation at an earlier date. However, in view of other findings, we do not construe said finding as a conclusion on the part of the Board that the surgery did not take place within a reasonable time after the injury, within the meaning of I.C. § 72-307.
Hereafter we will refer to the “other findings” above mentioned but we consider it proper to here discuss briefly what is meant by “within a reasonable time” as used in I.C. § 72-307. What is a reasonable time within which an act is to *201be performed depends on the subject, the situation of the parties and the circumstances attending the ' performance. (12 Am.Jur. 855) A “reasonable time” means a period which is created because of some justifiable reason. In determining what is a reasonable time for claimant to receive medical treatment and supplies we look to the statute and the facts and circumstances of the particular case. Generally a reasonable time would be as long as the condition and necessity for treatment exists. (Irvine v. Perry, supra.)
As to the necessity for the operation the Board made the following specific finding:
“That the operation was necessary, as the Board finds, is best shown by the ultimate event — the man returned to his regular work, which he then performed without pain.”
The Board also made the following finding which we consider inconsistent with a conclusion that the operation was unreasonably belated:
“The desirability of a diagnostic myelogram and the possibility of surgery of some type had been considered by his attending physician and consultants and examining specialists in 195.6 and these matters were discussed with plaintiff. Though his complaints of pain were symptomatic of a herniated disc, none of the physicians had found sufficient evidence to make such a diagnosis. Pain symptoms, however, were suggestive of nerve root impingement, but the physicians could only speculate upon the precise pathology. * * * Under urging over a period of two or three years from two of his relatives, he finally visited Dr. Baranco, who had surgically treated both of them. Dr. Baranco in performance of the laminectomy discovered precisely the cause of the patient’s symptoms.”
Dr. Baranco was consulted by appellant in 1960 and, as we construe the foregoing finding, was the first doctor to discover precisely the cause of appellant’s symptoms. His attending physician and consultants and examining specialists previously consulted, had not found sufficient evidence to make a like diagnosis — they could only speculate upon the precise pathology. The finding indicates that appellant submitted to repeated examinations, but prior to August 17, 1960, no one knew for certain what was causing appellant’s distress and symptoms. The record shows that two days after submitting to a myelogram (by which his condition was correctly diagnosed) the surgery (laminectomy) was performed and in less than four months appellant was back at work and “feeling fine”.
Since the Board denied appellant’s petition for an improper reason the order denying reimbursement is reversed and the cause remanded to the Board with instruc*202tions to determine whether the services (the cost of which appellant claims reimbursement) were furnished within a reasonable time after the accident as specified in I.C. § 72-307 and whether the charges therefor are reasonable. Costs to appellant.
TAYLOR, McQUADE and McFADDEN, JJ., concur.