Mo. Rev. Stat. § 477.152
Whenever a vacancy occurs after September 3, 1970, in the office of commissioner of the supreme court, a judge shall be appointed in the manner prescribed by sections 25(a)-(g), article V of the Constitution of Missouri to serve on the court of appeals. Appointments under this section shall be made to the districts of the court of appeals in the following order: eastern, western, southern, eastern, western, eastern.
(L. 1971 S.B. 117 § 3, A.L. 1978 H.B. 1634)
Effective 1-2-79