State of Minnesota, Respondent, vs. Donnelle Williams, Appellant.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1998).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C3-98-1632

Barbara Jean Fairbanks,

Appellant,

vs.

David B. Ketroser, MD, et al.,

Respondents.

 Filed March 9, 1999

 Affirmed

 Kalitowski, Judge

Hennepin County District Court

File No. 9520312

Jason R. Vohnoutka, Mazzitelli and Associates, P.A., 3109 Hennepin Avenue South, Minneapolis, MN 55408-2612 (for appellant)

William M. Hart, Rodger A. Hagen, Kevin J. Craig, Meagher & Geer P.L.L.P., 4200 Multifoods Tower, 33 South Sixth Street, Minneapolis, MN 55402-3788 (for respondent)

Terry L. Wade, Anne E. Workman, 2800 LaSalle Plaza, 800 LaSalle Avenue, Minneapolis, MN 55402-2015 (for amicus curiae Minnesota Trial Lawyers Association)

Considered and decided by Anderson, Presiding Judge, Kalitowski, Judge, and Shumaker, Judge.

 U N P U B L I S H E D O P I N I O N

 KALITOWSKI, Judge

Appellant Barbara Jean Fairbanks challenges the district court's grant of summary judgment to respondent Dr. David B. Ketroser, arguing the district court: (1) erred in determining appellant failed to establish causation; (2) erred by impermissibly weighing the evidence at summary judgment; and (3) failed to provide appellant adequate time to prepare her argument on causation. We affirm.

 FACTS

Appellant suffered from ongoing back problems that worsened in January of 1994. On Friday, January 21, the problems were so severe that her chiropractor recommended she contact a neurologist or go to an emergency room. After consulting the phone book and trying to contact several other neurologists, appellant left a phone message with respondent. Respondent called appellant back at approximately 4:45 p.m. Appellant described her symptoms to respondent who recommended certain pain killers and scheduled an appointment for 9:00 a.m., Monday, January 24.

Appellant awoke on Saturday morning with more pain. She phoned family members, who called 911. Appellant was taken by ambulance to Abbott Northwestern Hospital (Abbott) where she was examined by two doctors but was not admitted. Appellant was discharged from the emergency room at 2:20 p.m.

On Sunday, January 23, appellant went to Fairview Riverside Hospital. After examinations she was admitted to the hospital Sunday evening. On Monday, January 24, appellant was seen by a neurologist who diagnosed cauda equina syndrome and recommended immediate surgical evaluation. Appellant was taken to the surgery unit about four hours later and was operated on at about 12:40 p.m. Monday. Although appellant's back pain was relieved by the surgery, appellant was left with permanent neurological dysfunction.

Appellant brought suit against respondent and four additional defendants: Abbott, Emergency Care Consultants, P.A. (the organization responsible for staffing the Abbott Emergency Department), and the two physicians who examined appellant at Abbott. The latter four defendants entered into settlement agreements with appellant.

Respondent moved for summary judgment on the issue of causation. The judge originally assigned to the case denied the summary judgment motion and the case was set for trial. The case was assigned to a different judge who, sua sponte, re-opened the causation issue without notice on the day of trial. The judge gave each party ten minutes to prepare oral arguments and, after hearing the arguments, granted summary judgment in favor of respondent, finding appellant failed to establish legal causation.

 D E C I S I O N

 I.

A motion for summary judgment shall be granted when the pleadings, depositions, answers to interrogatories, and admissions on file, together with the affidavits, if any, show there is no genuine issue of material fact and either party is entitled to a judgment as a matter of law. Minn. R. Civ. P. 56.03. When reviewing a grant of summary judgment, the reviewing court must decide whether there are any genuine issues of material fact and whether the district court erred in its application of the law. State by Cooper v. French, 460 N.W.2d 2, 4 (Minn. 1990). Appellate courts must view the evidence in the light most favorable to the party against whom the judgment was granted. Fabio v. Bellomo, 504 N.W.2d 758, 761 (Minn. 1993).

To establish a prima facie case of medical malpractice, a plaintiff must introduce expert testimony demonstrating: (1) the standard of care recognized by the medical community as applicable to the particular defendant, (2) that the defendant departed from that standard, and (3) that the defendant's departure was a direct cause of the plaintiff's injuries.

 Fabio, 504 N.W.2d at 762. To satisfy the direct cause element in medical malpractice actions, the plaintiff must present expert testimony establishing that it is more probable than not that the damages resulted from the malpractice. Harvey v. Fridley Medical Ctr., 315 N.W.2d 225, 227 (Minn. 1982). Failure to present such evidence mandates dismissal, either by summary judgment or directed verdict. Leubner v. Sterner, 493 N.W.2d 119, 121 (Minn. 1992). This rule is premised on a concern that juries should not base assessment of liability upon speculation as to the possible causes of a plaintiff's injuries. Id.

Here, appellant's expert witnesses were prepared to testify at trial that appellant's permanent neurological problems were more likely than not caused by the delay in having surgery. Specifically, the experts stated that appellant had 48 hours from Friday to have surgery and that after this time it became more likely than not that appellant would suffer permanent neurological problems. Appellant contends the district court erred in determining this testimony did not satisfy the direct cause standard. We disagree.

Appellant's only expert testimony addressing respondent's alleged breach of the standard of care in the medical community stated:

If [respondent] could not see [appellant], and if he could not be certain that bowel and bladder function and muscle function in the legs were intact, then the standard of care required that [respondent] refer [appellant] to another doctor or to an emergency care facility.

(Emphasis added.) Thus, respondent's alleged negligence, based on a single phone conversation late on a Friday afternoon, was a failure to refer appellant to another doctor or to an emergency care facility. Appellant, however, went to an emergency care facility on her own on Saturday. Because respondent was examined in an emergency room on Saturday, respondent's alleged negligent failure to refer was the direct cause of appellant's injury only if appellant could establish injury as a result of the delay in diagnosis and surgery between Friday evening and appellant's emergency room visit on Saturday.

The district court correctly pointed out that appellant failed to present expert testimony that it is more probable than not that the delay in surgery between Friday and Saturday caused appellant's injuries. Appellant's expert testimony establishes only that it is more likely than not that the 48-hour delay between Friday and Sunday caused appellant's injuries. We therefore conclude the district court correctly granted summary judgment in favor of respondent.

 II.

Appellant contends the district court erred by impermissibly weighing the evidence in granting summary judgment. We disagree. The district court did not weigh the evidence. Rather, the district court found that appellant failed to present any evidence that respondent's alleged negligence, which resulted in a delay in treatment between the Friday phone conversation and the Saturday visit to the emergency room, more likely than not caused appellant's injuries.

 III.

Appellant contends the district court erred by requiring the parties to prepare arguments on causation on the day of trial, with only ten minutes' notice. Rule 56.03 requires ten days from the time a motion is filed until the time fixed for the hearing on the motion. However, district courts may grant summary judgment sua sponte if there are no genuine issues of material fact. McElwain v. Van Beek, 447 N.W.2d 442, 446 (Minn. App. 1989), review denied (Minn. Dec. 20, 1989). In such cases, unless the objecting party can show prejudice from "lack of notice or other procedural irregularities, or was not afforded a meaningful opportunity to oppose summary judgment," appellate courts should not disturb the inherent power of the district court to grant summary judgment. Id. at 447. Moreover, Minnesota courts have previously stated that, "[s]eldom should lack of notice prejudice a party, as each party should be fully prepared on the facts applicable to the case in order to participate in the pre-trial." Wikert v. Northern Sand & Gravel, Inc., 402 N.W.2d 178, 182 (Minn. App. 1987) (quoting Niazi v. St. Paul Mercury Ins. Co., 265 Minn. 222, 227, 121 N.W.2d 349, 353 (1963)), review denied (Minn. May 18, 1987).

Here, appellant has failed to establish prejudice because: (1) appellant had previously responded to a summary judgment motion on the same issue; and (2) appellant even now is unable to point to expert testimony establishing that the delay between Friday and Saturday more likely than not caused appellant's injuries. Thus, while we do not endorse the district court's procedure, we conclude that any error caused by it was harmless.

 IV.

Respondent contends the amicus curiae brief of the Minnesota Trial Lawyers Association (MTLA) is overly argumentative and should not have been considered. The purpose of an amicus curiae brief is to explain the reasons a particular rule of law should be adopted in a particular case in a nonadversarial fashion. State v. Rosenfeld, 540 N.W.2d 915, 924 (Minn. App. 1995). Amicus brief should not argue that a particular party should prevail. Id. While we agree the MTLA's brief was argumentative, we conclude the brief was not beyond acceptable limits and respondent was in no way prejudiced.

 Affirmed.