In the Matter of the Worker's Compensation Claim Of: Christina S. Hirsch, an Employee of Border Foods, Inc. v. State of Wyoming ex rel. Wyoming Workers' Safety and Compensation Division, 323 P.3d 1107

Christina Hirsch had prior lumbar surgeries (2003–2004) after a workplace slip; she was asymptomatic from late 2004 until 2009.
On May 17, 2009 Hirsch slipped at work, injuring her right ankle; the Division accepted and authorized ankle-related benefits under a separate 2009 file.
Following the ankle injury and surgeries, Hirsch developed recurring low-back pain and urinary incontinence first clearly documented December 2009; she underwent T12–L1 discectomy and L5–S1 fusion in March 2010.
Hirsch claimed the 2009 fall and subsequent use of crutches/boot aggravated her preexisting lumbar condition (or constituted a second compensable injury) and sought medical and temporary total disability benefits; the Division denied coverage for the back surgery and disability.
At the contested hearing, treating spine surgeon Dr. Neal testified the May 2009 incident and use of crutches more likely than not materially aggravated Hirsch’s L5–S1 symptoms; the Division’s examiners (Drs. Ruttle and Tallerico) concluded the back surgery was unrelated to the 2009 ankle injury and pointed to preexisting degenerative disease with earlier MRIs.
OAH denied benefits (finding no persuasive causal connection); the district court affirmed after a limited remand/supplementation (video of the 2009 incident), and the Supreme Court of Wyoming affirmed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether substantial evidence supports OAH’s denial of benefits for Hirsch’s post-2009 back condition	Hirsch: Dr. Neal’s opinion shows, more likely than not, the May 2009 incident and use of crutches materially aggravated her preexisting L5–S1 condition (or caused a second compensable injury)	Division: Independent exams show long-standing degenerative disease and no causal link between the 2009 ankle injury/boot use and the later spine surgery; lack of immediate back complaints undermines causation	Affirmed: OAH’s factual findings supported by substantial evidence; Hirsch met burden of production but failed burden of persuasion; tribunal credited Division’s experts over Dr. Neal

Birch v. State ex rel. Wyoming Workers’ Safety & Comp. Div., 319 P.3d 901 (Wyo. 2014) (administrative-review standards and substantial-evidence framework)
Little v. State ex rel. Dep’t of Workforce Servs., Workers’ Comp. Div., 308 P.3d 832 (Wyo. 2013) (medical expert testimony standards for causation; burden-of-production explained)
Hayes v. State ex rel. Wyoming Workers’ Safety & Comp. Div., 307 P.3d 843 (Wyo. 2013) (causal connection requirement and when preexisting-condition aggravation is compensable)