Mo. Rev. Stat. § 86.103
Any amounts which may be paid or payable by the said cities under the provisions of any workers' compensation or similar law to a member or to the dependents of a member on account of any disability or death shall be offset against and payable in lieu of any benefits payable out of funds provided by the said cities under the provisions of sections 86.010 to 86.193 on account of the same disability or death. In case the present value of the total commuted benefits under said workers' compensation or similar law is less than the pension reserve on the benefits otherwise payable from funds provided by the said cities under sections 86.010 to 86.193, then the present value of the commuted payments shall be deducted from the pension reserve and such benefits as may be provided by the pension reserve so reduced shall be payable under the provisions of sections 86.010 to 86.193.
§ 86.103, RSMo