From Local to National: Kosinski v. Wladis and the Modern Standard for Medical Expert Testimony in New York Malpractice Litigation

I. Introduction

The Appellate Division, Third Department’s decision in Kosinski v. Wladis, 2025 NY Slip Op 06772 (Dec. 4, 2025), is significant on two interconnected fronts of New York medical malpractice law:

• It clarifies how trial courts must evaluate competing expert affidavits on a motion for summary judgment, emphatically reiterating that courts are “issue finders, not issue determiners,” and may not weigh the relative persuasiveness or credibility of dueling experts.
• It refines the practical application of New York’s longstanding “locality rule” by reaffirming that out-of-state medical experts who articulate national minimum standards of care cannot be discounted merely because they practice elsewhere.

The case arises from complex orbital and eyelid surgeries performed after a household fall, with plaintiffs alleging that the defendant ophthalmologist deviated from the applicable standard of care and caused a cascade of further surgeries and complications. At the core of the appellate decision is whether plaintiffs’ expert—an out-of-state ophthalmologist/plastic surgeon—raised triable issues of fact sufficient to defeat defendants’ motion for summary judgment.

II. Factual and Procedural Background

A. The underlying injury and early treatment

On May 8, 2016, plaintiff Shirley T. Kosinski fell down stairs in her home and struck her face against a door. She suffered fractures to several bone structures in and around her left orbital (eye socket) region.

On May 12, 2016, plastic surgeon Dr. Oluseyi Aliu performed initial reconstructive surgery:

• Open reduction and internal fixation of a zygomaticomaxillary complex fracture;
• Repair of an orbital floor fracture with placement of an orbital floor plate; and
• Securing of multiple bone fragments.

Subsequently, complications and concerns arose. Imaging (CT scan) revealed:

• The orbital floor plate placed by Aliu had shifted down into the maxillary sinus;
• The maxillary sinus appeared small, raising concern for “silent sinus syndrome,” a condition involving chronic obstruction and collapse of the maxillary sinus, potentially affecting orbital volume and eye position.

Because of these concerns, Kosinski was referred to defendant Dr. Edward J. Wladis, an ophthalmologist employed by defendant Ophthalmic Plastic Surgery, PLLC (collectively “defendants”).

B. The surgeries performed by Dr. Wladis

Concerned about possible silent sinus syndrome and the prior shifted plate, Dr. Wladis referred Kosinski to otolaryngologist (ENT) Dr. Carlos Pinheiro‑Neto. A joint surgery was planned:

• Pinheiro‑Neto would “clean out” the sinuses (addressing possible obstruction/collapse), and
• Wladis would place a new orbital floor implant.

On November 1, 2017, that joint procedure was performed. Notably, as later detailed in the expert submissions:

• Wladis used a Medpor implant rather than a 3D computer-printed orbital implant; and
• He stacked the new implant on top of the previously placed one, rather than removing the original plate.

After this surgery, Kosinski reported double vision and other complaints. To address eyelid retraction and cosmesis around the left eye, Wladis performed two additional surgeries:

• March 15, 2018: lower left eyelid retraction repair with flap placement;
• July 3, 2018: a further procedure to “raise” the left eyelid, again addressing eyelid malposition.

C. Subsequent treatment by other surgeons

Unsatisfied, Kosinski returned to Dr. Aliu, who referred her to Dr. Michael Grant, an ophthalmologist and plastic surgeon at the University of Maryland Medical Center. Grant performed:

• December 28, 2018: surgery to remove and replace existing implants;
• April 2019: a further surgery to address eyelid appearance issues not simultaneously addressable in December.

Thereafter, Kosinski sought care from California-based plastic surgeon Dr. Guy Massry, who in December 2020 performed a graft and cheek lift. Massry also arranged injections to treat eyelid issues including irregular eyelash growth.

D. Commencement of the action

In September 2019, prior to treatment by Massry, Kosinski and her spouse (derivatively) commenced a medical malpractice action against:

• Dr. Edward J. Wladis; and
• Ophthalmic Plastic Surgery, PLLC.

(Other defendants had initially been named but were discontinued by stipulation, see n.1 of the opinion.)

Plaintiffs alleged, among other things, that:

• Wladis negligently performed the three surgeries of November 1, 2017; March 15, 2018; and July 3, 2018;
• He misdiagnosed her with silent sinus syndrome;
• He failed to correct her double vision, necessitating further invasive treatment; and
• His treatment caused ongoing structural and cosmetic abnormalities requiring subsequent surgeries by Grant and Massry.

E. Defendants’ summary judgment motion

After joinder of issue, defendants moved for summary judgment dismissing the complaint. To meet their initial burden, they submitted, among other things, an expert affidavit from Dr. Richard Dean Lisman, a board-certified ophthalmologist.

Lisman:

• Reviewed medical records and imaging;
• Stated familiarity with the applicable standard of care; and
• Opined that:
  • consideration of silent sinus syndrome was appropriate given the imaging and prior treatment;
  • the decision to coordinate sinus surgery before reimplanting an orbital floor plate was within the standard of care;
  • choosing a Medpor implant rather than a 3D-printed implant was acceptable because both can provide a customized fit;
  • stacking a new implant on top of the old one—rather than removing it—was reasonable medical judgment to avoid further trauma;
  • intraoperative testing and postoperative records showed proper implant positioning;
  • the subsequent eyelid surgeries were proper responses to persistent complaints and were performed within the standard of care; and
  • post‑injury eyelid retraction was more likely attributable to Aliu’s initial external incision rather than to Wladis’ work.

Lisman further opined that later surgeries (including procedures such as a hard palate graft) were not medically required by the standard of care but were largely cosmetic, and that allegations the implant caused gingivitis were unsupported and unlikely.

Supreme Court (Ryba, J., Albany County) accepted Lisman’s affidavit as sufficient to meet defendants’ prima facie burden, and then held that plaintiffs’ expert proof failed to raise a triable issue of fact. It characterized plaintiffs’ expert opinions as speculative and conclusory and, significantly, discounted their weight because the expert practiced out of state. The court granted summary judgment, dismissing the complaint.

F. Plaintiffs’ opposition: Dr. Grant’s expert affidavit

In opposition, plaintiffs submitted an affirmation from Dr. Michael Grant. He:

• Declared familiarity with the standard of care applicable to the evaluation and treatment of orbital floor fractures and related eyelid complications;
• Reviewed Kosinski’s records and imaging; and
• Concluded that defendants departed from accepted practice and that those departures caused Kosinski’s injuries and need for further surgery.

More specifically, Grant opined that:

• The diagnosis of silent sinus syndrome was incorrect. Given the nature of Kosinski’s traumatic injuries and existing defects, the pressure dynamics required to produce true silent sinus syndrome could not exist.
• The November 2017 surgery failed to accurately reconstruct the orbital floor. Stacking the Medpor plate on top of the existing plate was, by 2017 standards, “antiquated and ill-advised,” because:
  • It is imprecise;
  • It can leave “dead space” between implants that can trap mucus; and
  • It risks secondary infection.
  He opined that this method departed from the standard of care.
• Kosinski did not have lower eyelid retraction until after Wladis’ first surgery, and that surgery caused malposition of the eyelid, which in turn necessitated the March 2018 procedure.
• Her worsening double vision likely resulted from orbital tissues that healed in the wrong location, attributable to improper implant placement in November 2017.
• Wladis departed from the standard of care by:
  • attempting eyelid repairs before properly reconstructing the orbital floor; and
  • then having to traverse previously repaired eyelid tissues to access the orbit, thereby disturbing prior eyelid work and worsening retraction.
• The later surgeries by Grant and Massry were not cosmetic “extras,” but necessary interventions directly caused by Wladis’ negligence.

The trial court deemed this affidavit insufficient, viewing it as speculative, conclusory, and unduly discounted because the expert was licensed in another state. Plaintiffs appealed.

III. Summary of the Appellate Division’s Opinion

The Third Department reversed, with costs, and denied defendants’ motion for summary judgment. It held that:

1. Defendants did meet their initial burden through Lisman’s detailed, nonconclusory expert affidavit establishing compliance with the standard of care and lack of causation.
2. However, plaintiffs also met their shifted burden. Dr. Grant’s affidavit:
   • Articulated an applicable standard of care;
   • Identified specific departures by Wladis; and
   • Connected those departures to Kosinski’s injuries in a nonconclusory and nonspeculative manner.
   Thus, it created genuine issues of fact.
3. Supreme Court erred by:
   • Misapplying the “locality rule” to devalue an out-of-state expert who was testifying to national minimum standards; and
   • Improperly weighing the competing expert affidavits, effectively choosing defendants’ version over plaintiffs’, which is impermissible at the summary judgment stage.
4. Because material factual disputes exist concerning both standard of care and causation, the matter must be remitted to Supreme Court for further proceedings (i.e., the case proceeds toward trial or other disposition on a full record).

IV. Detailed Analysis

A. Summary-judgment framework in medical malpractice

The court restates the familiar burden-shifting framework for medical malpractice summary judgment, heavily relying on recent Third Department authority:

“A movant seeking dismissal of a medical malpractice claim bears the initial burden of presenting factual proof, generally consisting of affidavits, deposition testimony and medical records, to rebut the claim of malpractice by establishing that they complied with the accepted standard of care or did not cause any injury to the patient” (Naylor v Ellis Hosp., 235 AD3d 1130, 1131 [3d Dept 2025]; see Marshall v Rosenberg, 196 AD3d 817, 818 [3d Dept 2021]).

Once the defendant meets that burden, the burden shifts:

“[T]he burden shifted to plaintiff[s] to present expert medical opinion evidence that there was a deviation from the accepted standard of care and that this departure was a proximate cause of [the] injur[ies]” (Schwenzfeier v St. Peter's Health Partners, 213 AD3d 1077, 1080 [3d Dept 2023]).

The plaintiff’s expert opinion:

“should not be speculative or conclusory but should address specific assertions made by the physician’s experts, setting forth an explanation of the reasoning and relying on specifically cited evidence in the record” (Lubrano-Birken v Ellis Hosp., 229 AD3d 873, 875 [3d Dept 2024]).

Applying these standards, the Third Department found:

• Defendants met their initial burden via Lisman’s detailed explanation of why the clinical decisions—diagnosing possible silent sinus syndrome, coordinating sinus and orbital surgery, choosing and stacking implants, and performing staged eyelid procedures—were consistent with accepted practice and not causative of the claimed harms.
• The burden therefore shifted to plaintiffs to demonstrate a triable issue through competent expert evidence.

B. Plaintiffs’ expert and the locality rule

1. The locality rule: origin and erosion

The “locality rule” originates from the Court of Appeals’ 1898 decision in Pike v Honsinger, 155 NY 201, and is summarized in Wulbrecht v Jehle, 89 AD3d 1470, 1470 (4th Dept 2011):

“the prevailing standard of care governing the conduct of medical professionals demands that a doctor exercise that reasonable degree of learning and skill that is ordinarily possessed by physicians and surgeons in the locality where the doctor practices” (internal quotation marks, brackets, ellipsis and citations omitted).

The Court of Appeals reaffirmed the rule’s existence in Nestorowich v Ricotta, 97 NY2d 393, 398 (2002), though the rule has been increasingly questioned in light of modern medicine.

The Third Department itself has previously commented on the rule’s diminishing justification. In Payant v Imobersteg, 256 AD2d 702, 705 (3d Dept 1998), the court noted that:

“the development of vastly superior medical schools and postgraduate training, modern communications, the proliferation of medical journals, along with frequent seminars and conferences, have eroded the justification for th[is] rule.”

In Kosinski, the court updates and extends this critique, explicitly referencing the Internet era:

“With the rise of the Internet and the attendant ease with which information is disseminated, this is even more true today.”

2. The key refinement in Kosinski: national standards and out-of-state experts

The opinion crystallizes the practical limit on using the locality rule to exclude or discount out-of-state experts:

“Thus, where, as here, a medical expert proposes to testify about minimum standards applicable throughout the United States, the locality rule should not be invoked” (Payant, 256 AD2d at 705; see Scott v Santiago, 230 AD3d 933, 936 n 3 [3d Dept 2024]; Riley v Wieman, 137 AD2d 309, 315 [3d Dept 1988]).

In other words:

• An expert’s physical practice location (e.g., Maryland, California) does not, by itself, disqualify their testimony in a New York medical malpractice action.
• If the expert describes and applies a national minimum standard of care—something plausibly uniform in contemporary practice—courts should not invoke the locality rule to disregard that testimony.
• The relevant question is the expert’s familiarity with the standard of care applicable to the procedure and specialty, not the expert’s mailing address.

The Third Department explicitly notes that Supreme Court’s reliance on Grant’s out-of-state practice to discount his opinions was conceded by defendants to be erroneous and is squarely rejected.

C. The court’s treatment of expert affidavits

1. The defense expert (Lisman)

The Appellate Division affirms that Lisman’s affidavit was:

• “sufficiently detailed and nonconclusory”; and
• adequate to establish no departure from the standard of care and lack of causation, thereby satisfying defendants’ prima facie burden.

The opinion lists key points that satisfied that burden:

• Rational basis for considering silent sinus syndrome given prior imaging and symptomatology;
• Appropriateness of performing sinus surgery first, before reimplanting the orbital plate;
• Equivalence, for standard-of-care purposes, of Medpor and 3D-printed implants in this context;
• Reasonableness of stacking implants to avoid trauma from removing a settled plate;
• Documented intraoperative and postoperative checks showing adequate implant positioning;
• Attribution of eyelid retraction and cosmetic deficits more to Aliu’s initial approach than to Wladis’ work;
• Characterization of later surgeries as cosmetic or elective rather than required by negligence.

This underscores that, in medmal cases, the defense can satisfy summary judgment by having a qualified specialist review the full record and coherently explain why each contested decision was within the standard of care and non-causative.

2. The plaintiffs’ expert (Grant)

The central controversy is whether Dr. Grant’s affidavit was too speculative and conclusory. The Third Department firmly answers “no,” pointing to concrete features of Grant’s opinions that align with the standards in Lubrano-Birken, Schwenzfeier, and Matney:

• Grant identified the standard of care—accurate reconstruction of the orbital floor and proper sequencing of orbital and eyelid repairs.
• He pinpointed specific departures:
  • Misdiagnosis of silent sinus syndrome in a clinical scenario where, due to existing trauma, the necessary pressure dynamics were impossible;
  • Use of an “antiquated and ill-advised” practice of stacking orbital floor implants, with explanation of resulting anatomic and infectious risks;
  • Performing eyelid repair before definitive orbital reconstruction, then reentering through the repaired eyelid to reach the orbit.
• He articulated causation:
  • Eyelid malposition and retraction developed only after the November 2017 surgery and were directly attributable to that surgery;
  • Worsening diplopia (double vision) flowed from orbital tissue healing in abnormal positions due to improper implant placement;
  • Later surgeries (by Grant and Massry) were medically necessary responses to those deficits, not cosmetic enhancements.

Crucially, Grant directly engaged with Lisman’s points—for example, disagreeing that:

• Stacking implants was within the contemporary standard of care; and
• Later surgeries were cosmetic or attributable solely to the original trauma or Aliu’s incision.

By doing so, he satisfied the requirement that a plaintiff’s expert “address specific assertions made by the physician’s experts” and “set forth an explanation of the reasoning” with record-based support (Lubrano-Birken, 229 AD3d at 875).

3. Prohibition on weighing experts at summary judgment

The appellate court emphasizes the limited role of a motion court on summary judgment:

“On a motion for summary judgment, the evidence must be viewed ‘in a light most favorable to the nonmoving party’ and that party must be accorded ‘the benefit of every reasonable inference from the record proof, without [the court] making any credibility determinations’” (Lubrano-Birken, 229 AD3d at 875).

And:

“The role for the court in this respect ‘is issue finding, not issue determination’” (Matney v Boyle, 237 AD3d 1382, 1385 [3d Dept 2025]).

In Kosinski, Supreme Court violated this principle by:

• Labeling plaintiffs’ expert opinions “speculative and conclusory” when, in fact, they were detailed and directly responsive to defendants’ contentions; and
• “seem[ing] to have weighed one expert’s opinion against the other,” effectively deciding issues of credibility and medical judgment that belong to a jury.

The Third Department holds that because both sides presented competent, conflicting expert evidence on:

• Whether the standard of care was met; and
• Whether any departures proximately caused Kosinski’s injuries and subsequent surgeries,

summary judgment was inappropriate. Properly viewed in the light most favorable to the nonmoving party (plaintiffs), Grant’s affidavit raised material questions of fact requiring resolution by a factfinder.

D. Precedents cited and their influence

1. Naylor v Ellis Hosp., 235 AD3d 1130 (3d Dept 2025)

Relied upon for the fundamental statement of the defendant’s initial burden in a medmal summary judgment motion: defendants must show either (a) no departure from accepted practice or (b) no causation. Kosinski follows that framework: it accepts that defendants satisfied prima facie but focuses on the sufficiency of plaintiffs’ rebuttal.

2. Marshall v Rosenberg, 196 AD3d 817 (3d Dept 2021)

Cited both for the initial burden language and for the general summary judgment principle that courts cannot make credibility determinations. Kosinski uses it to underscore that the presence of dueling experts typically precludes summary judgment.

3. Schwenzfeier v St. Peter’s Health Partners, 213 AD3d 1077 (3d Dept 2023)

Provides the articulation that once a defendant meets its burden, plaintiff must present expert proof of both deviation and proximate cause. Kosinski applies that rule and finds plaintiffs complied, in contrast to cases where plaintiffs’ experts were found genuinely speculative or wholly conclusory.

4. D'Orta v Margaretville Mem. Hosp., 154 AD3d 1229 (3d Dept 2017); Goldschmidt v Cortland Regional Med. Ctr., Inc., 190 AD3d 1212 (3d Dept 2021)

These cases reinforce what constitutes a sufficient defense expert showing and the resultant shift of burden to plaintiffs. Kosinski aligns with this line of authority: it does not disturb the standard for defendants’ initial burden; rather, it clarifies when plaintiffs’ expert rebuttal meets the corresponding threshold.

5. Lubrano-Birken v Ellis Hosp., 229 AD3d 873 (3d Dept 2024)

Cited for two important propositions:

• The qualitative standard for plaintiffs’ expert affidavits: they cannot be speculative or conclusory and must specifically answer the defense expert.
• The general summary judgment standard: evidence is viewed in the light most favorable to the nonmovant without credibility determinations.

Kosinski uses Lubrano-Birken as a benchmark, concluding that Grant’s affidavit meets the standard contemplated there and that the trial court’s characterization was inconsistent with that precedent.

6. Pike v Honsinger, 155 NY 201 (1898); Nestorowich v Ricotta, 97 NY2d 393 (2002); Wulbrecht v Jehle, 89 AD3d 1470 (4th Dept 2011)

These cases supply the doctrinal backbone of the locality rule. Pike and Nestorowich emanate from the Court of Appeals; Wulbrecht distills the formulation at the Appellate Division level. Kosinski does not abolish the rule but narrows when it may be invoked, especially where modern medicine supports truly national standards.

7. Payant v Imobersteg, 256 AD2d 702 (3d Dept 1998); Scott v Santiago, 230 AD3d 933 (3d Dept 2024); Riley v Wieman, 137 AD2d 309 (3d Dept 1988)

These Third Department cases highlight the erosion of the locality rule’s original rationale. Payant is particularly influential in Kosinski, which quotes and extends its reasoning, now adding explicit reference to the Internet and modern information sharing.

Together, they support Kosinski’s holding that where an expert speaks to “minimum standards” of care that are national in scope, the locality rule should not be used to exclude or disparage that expert’s testimony.

8. Matney v Boyle, 237 AD3d 1382 (3d Dept 2025)

Relied upon for the classic statement that on summary judgment the court’s task is “issue finding, not issue determination.” Kosinski uses Matney to emphasize that Supreme Court overstepped by effectively choosing between competing expert narratives instead of simply asking whether a genuine factual dispute exists.

9. Schultz v Albany Med. Ctr. Hosp., 238 AD3d 1286 (3d Dept 2025)

The opinion’s directive “compare Schultz” indicates that Schultz is an example where plaintiffs’ expert submissions truly were speculative or conclusory, justifying dismissal. By distinguishing Kosinski from Schultz, the court signals that:

• Not every plaintiff’s expert affidavit suffices; but
• Where, as here, the expert gives a detailed counter-narrative grounded in record evidence and medical reasoning, summary judgment should be denied.

E. Impact and significance

1. For the locality rule and expert selection

While the locality rule remains formally intact, Kosinski accelerates its functional erosion by:

• Reaffirming that national minimum standards of care are often appropriate benchmarks in modern, highly standardized specialties (such as ophthalmic plastic surgery and orbital surgeries); and
• Clarifying that an expert from another state is perfectly competent to testify in a New York malpractice case if they are familiar with such national standards and the procedures at issue.

Practically, this:

• Gives plaintiffs more freedom to retain truly specialized out-of-state experts without fear that courts will automatically discount them for “locality” reasons.
• Signals to litigants that challenges to an expert’s qualifications must focus on specialty and knowledge, not geographic residence.
• Pushes the practice further away from parochial local standards and toward uniform professional norms, especially in subspecialty areas where education, training, and practice are nationally harmonized.

2. For summary judgment practice in medical malpractice cases

The case strengthens a recurring theme in Third Department jurisprudence: where both sides present qualified experts offering plausible, conflicting accounts of standard of care and causation, summary judgment is generally inappropriate.

Key lessons for practitioners:

• Defense counsel can still obtain summary judgment by:
  • Securing detailed, record-based opinions that either deny any departure from accepted practice or break the chain of causation; and
  • Targeting any gaps or speculative leaps in plaintiffs’ expert submissions.
• Plaintiffs’ counsel should ensure that their experts:
  • Clearly state familiarity with the applicable standard of care;
  • Identify specific ways in which the defendant’s conduct departed from that standard;
  • Explain, in concrete medical terms, how those departures caused the alleged injuries;
  • Directly address the defense expert’s principal assertions.

Kosinski demonstrates that when plaintiffs do all of the above, even in the face of a strong defense affidavit, the case should go to a jury.

3. Proximate cause in complex treatment chains

The case also has implications for causation in scenarios involving multiple treating physicians and sequential surgeries. Defendants here argued that:

• Injuries stemmed from the original fall or Aliu’s initial surgery; and/or
• Subsequent surgeries by Grant and Massry were cosmetic rather than medically necessary responses to any alleged negligence by Wladis.

Grant, by contrast, explicitly tied:

• New eyelid problems and double vision to the November 2017 surgery;
• Further deterioration to allegedly improper surgical sequencing; and
• Later surgeries to the need to correct Wladis’ work, not to independent, cosmetic preferences.

The Third Department’s holding—that such competing narratives create triable issues—affirms that causation in multi-physician, multi-procedure settings typically presents factual questions unsuitable for resolution on summary judgment where competent expert disagreement exists.

V. Clarification of Key Legal and Medical Concepts

A. Summary judgment

Summary judgment is a procedural device for disposing of cases without a trial where there is no genuine dispute as to any material fact and the moving party is entitled to judgment as a matter of law. The key point in Kosinski is that:

• When both sides submit conflicting but competent expert affidavits, the court generally cannot choose one over the other at the summary judgment stage.

B. Prima facie showing

A “prima facie” showing means the moving party’s evidence, if uncontradicted, would warrant judgment in its favor. In medmal summary judgment:

• Defendants meet their prima facie burden by demonstrating either compliance with the standard of care or lack of causation through qualified expert opinion.

C. Locality rule

The locality rule historically required that a physician be judged by the standard of care in the community where he or she practiced. Modern courts, particularly the Third Department, have recognized that:

• With standardized training and information sharing, many specialties operate under a national standard; and
• Where an expert testifies to such national minimal standards, there is little justification for excluding or diminishing that testimony based on locality.

D. Standard of care

“Standard of care” in malpractice cases refers to the degree of skill and learning ordinarily possessed and exercised by reasonably prudent physicians in the same field under similar circumstances. The dispute in Kosinski centers on:

• Whether diagnosing silent sinus syndrome and using a stacked implant configuration in 2017 met that standard; and
• Whether the sequence and technique of orbital and eyelid surgeries complied with accepted modern practice.

E. Proximate cause

Proximate cause is a legal concept that requires a sufficiently direct causal link between the alleged negligence and the injury. In this case, the questions include:

• Did Wladis’ choices in diagnosis and surgical technique cause the double vision and eyelid deformities?
• Were the subsequent surgeries by Grant and Massry necessitated by those choices, or by earlier trauma and surgeries, or elective/cosmetic?

Grant’s affidavit, accepted as sufficient for summary judgment purposes, asserts that Wladis’ actions were the proximate cause of the ongoing issues and later surgeries.

F. Silent sinus syndrome and orbital floor implants (medical concepts, briefly)

• Silent sinus syndrome is a condition involving chronic obstruction and collapse of the maxillary sinus, often leading to sinking of the orbital floor and changes in eye position. Here, Lisman viewed it as a legitimate concern; Grant contended it was impossible given the trauma-induced defects.
• Orbital floor implants (e.g., Medpor vs 3D-printed) are used to reconstruct the orbital floor after fractures. “Stacking” implants involves placing a new plate atop an old one rather than removing the original. Grant characterized stacking as outdated and risky; Lisman defended it as reasonable under the circumstances.

VI. Practical Implications for Future Cases

A. For plaintiffs

• Do not hesitate to retain out-of-state subspecialist experts in complex cases if they can credibly speak to national standards.
• Ensure expert affirmations:
  • Explicitly state the expert’s familiarity with the applicable standard of care (local and/or national);
  • Detail specific departures and link them causally to injuries;
  • Address the defense expert’s competing explanations; and
  • Avoid pure speculation or broad, unsupported assertions.
• Use Kosinski to counter defense arguments that your expert is unqualified simply because they practice in another jurisdiction.

B. For defendants

• Continue to rely on strong, well-explained expert affidavits to seek summary judgment, particularly where plaintiffs’ experts are truly deficient.
• Recognize that geographic attacks on an opposing expert will carry less weight; challenges should focus on:
  • Whether the expert is actually familiar with the relevant specialty and procedures; and
  • Whether their opinions are speculative, unsupported, or internally inconsistent.
• Use cases like Schultz to show where plaintiffs’ experts fall below the threshold of sufficiency, contrasting them with fact-rich affidavits like Grant’s in Kosinski.

C. For trial courts

• Be cautious in branding an expert affidavit “conclusory” or “speculative” where it:
  • Lays out a clear alternative theory of negligence and causation; and
  • Engages directly with the opposing expert’s positions.
• Resist the temptation to evaluate which expert is “more persuasive” on a cold record. That is quintessentially a jury function.
• Apply the locality rule narrowly, especially where the specialty and procedures at issue are governed by widely recognized national standards.

VII. Conclusion

Kosinski v. Wladis is a significant Third Department decision that:

• Reaffirms and sharpens the burden-shifting framework for summary judgment in medical malpractice actions;
• Clarifies that detailed, record-based expert affidavits by plaintiffs will defeat summary judgment even where defendants present strong contrary expert evidence;
• Limits the practical reach of the locality rule by holding that it should not be invoked to discredit out-of-state experts who speak to national minimum standards of care; and
• Reminds trial courts that their role on summary judgment is to find issues, not resolve them, particularly where medical experts squarely disagree on standard of care and causation.

In an era of nationally standardized medical education and instantaneous access to clinical knowledge, the decision moves New York malpractice practice further away from parochial, locality-bound standards and toward a more modern, nationally informed conception of medical negligence. For litigants and courts alike, Kosinski underscores that when competent experts disagree on the core medical questions, those disputes must be resolved in the crucible of trial rather than disposed of on paper.