Ordered that the order is affirmed insofar as appealed from, with costs.
Contrary to the plaintiff's contention, the defendants established, through competent evidence, their prima facie entitlement to judgment as a matter of law ( see Posokhov v Oselkin, 44 AD3d 921; Starr v Rogers, 44 AD3d 646, 648; see also Tessier v New York City Health Hosps. Corp., 177 AD2d 626). In opposition, the affidavit of the plaintif's undisclosed expert failed to raise a triable issue of fact, as it contained only conclusory and unsupported allegations ( see Alvarez v Prospect Hosp., 68 NY2d 320, 324-325; Posokhov v Oselkin, 44 AD3d 921; Starr v Rogers, 44 AD3d at 648; Keevan v Rifkin, 41 AD3d 661, 662; Bumbaca v Bonanno, 39 AD3d 577, 578-579; Cai Qiang Li v Yang, 36 AD3d 642; Bowman v Chasky, 30 AD3d 552, 553; cf. Rivera v Anilesh, 8 NY3d 627).
The plaintiffs remaining contentions are without merit.