In City of Philadelphia v. Workers' Compensation Appeal Board (Smith), 860 A.2d 215 (Pa. Cmwlth. 2004), the employer issued a Notice of Compensation Payable (NCP) describing the claimant's injury as a "lower back strain." Subsequently, the employer filed a termination petition, asserting that the claimant had fully recovered. During the termination proceeding, the claimant's medical expert testified that the claimant suffered from post-traumatic lumbar radiculopathy and herniated discs and likely would be unable to resume any medium or heavy labor job. Relying on that testimony, the Workers' Compensation Judge (WCJ) denied the termination petition and, in doing so, redefined the claimant's injury to include post-traumatic lumbar radiculopathy and herniated discs. The Workers' Compensation Appeal Board (WCAB) affirmed. On appeal in Smith, this court reversed. Considering the second paragraph of section 413(a) of the Workers' Compensation Act (Act), the Court reasoned that, before the radiculopathy and herniated discs could be found compensable, it was incumbent upon the claimant to file either a review petition to amend the NCP or a claim petition to establish a causal connection between the additional injuries and the work accident. The Court determined that, in the absence of either petition, the credible testimony of the claimant's medical expert was irrelevant to the issue raised in the termination petition, i.e., whether the claimant recovered from the back "strain" accepted by the employer in the NCP. Moreover, because there was no evidence that the alleged additional injuries existed at the time the NCP was issued, the Court held that the decision in Samson Paper Company & Fidelity Engraving v. Worker's Compensation Appeal Board (Digiannantonio), 834 A.2d 1221 (Pa. Cmwlth. 2003), did not provide the WCJ in Smith authority to amend the NCP.