Repair partitioned index with partitions "marked as LOADING" (ORA-29952)

I have a partitioned index on a very very large table.  Four of the over 2000 partitions are marked as LOADING.  The partitions are NOT loading at this time, but they are preventing the use of the index.  Is there a way to repair the index without rebuilding the entire thing?  Partitions marked as failed can be rebuilt, but partitions marked as loading cannot.  I’ve tried to drop the index partition, but I get an ORA-29952.  Every attempt results in a ORA-29952.   I appreciate any ideas.