Mass. Gen. Laws ch. 241, § 28: Mortgagee, etc., of co-tenant

Section 28. A person having a mortgage, attachment or other lien on the share of a co-tenant shall be concluded by the decree, so far as it relates to the partition and the assignment of the shares; but his lien shall remain in full force upon the part assigned to or left for such co-tenant, or, in the event of a sale, upon the share of such part owner in the proceeds, and may be enforced in the manner provided in section nineteen.