OPINION
BUTTS, Justice.This is an appeal from a summary judgment granted in favor of Dr. Dennis Gutz-man in a medical malpractice action brought by Pete and Mercy Arguello.
Pete Arguello consulted Dr. Gutzman on April 9, 1987, complaining of pain in his right knee. Gutzman diagnosed the condition as a torn medial meniscus and operated on April 24. During the surgery, Dr. Gutzman discovered a bucket handle tear of the medial meniscus. In the attempt to repair the meniscus, one of the jaws of the instrument he was using broke and went into Arguello’s knee. Unable to locate the broken piece through arthroscopic visualization or x-rays, Gutzman performed an arthrotomy. He found the piece and, using posterior palpation, brought the broken instrument up to remove it. Arguello was released from the hospital a few days later, and thereafter underwent physical therapy.
The Arguellos filed suit, cause no. 88-CI-16341, against Gutzman, alleging misrepresentation, lack of informed consent, and negligence in the use of the instrument and in failing to inspect it prior to surgery. Gutzman moved for summary judgment on the basis that there was no genuine issue as to any material fact regarding two essential elements of the Arguellos’ medical negligence action, breach of duty and proximate causation. Gutzman’s affidavit was filed in support of the motion for summary judgment.
The Arguellos responded that Gutzman’s affidavit and supplemental affidavit contained conclusory statements and raised genuine fact issues concerning Gutzman’s use of the instrument. Gutzman’s affidavits, deposition, and answers to interrogatories, and Pete Arguellos’ affidavit, were submitted in support of the response. Gutzman filed a supplemental affidavit.
The trial court entered an order granting the motion for summary judgment in favor of Gutzman on the negligence claim. The Arguellos appealed the interlocutory summary judgment. This court dismissed the appeal for lack of jurisdiction. The trial court subsequently ordered the false representation and lack of informed consent claims severed from the negligence cause of action and given cause no. 88-CI-16341-A.
The Arguellos’ point of error on appeal is that the trial court erred in granting summary judgment because they presented sufficient summary judgment evidence to create a fact issue and Gutzman failed to prove that no genuine material fact issue existed as to one or more of the essential elements of the Arguellos’ cause of action.
A defendant who moves for summary judgment has the burden of proving that no material issue of fact exists as to the plaintiff’s cause of action and that it is entitled to judgment as a matter of law. See Griffin v. Rowden, 654 S.W.2d 435 (Tex.1983); City of Houston v. Clear Creek Basin Authority, 589 S.W.2d 671 (Tex.1979); TEX.R.CIV.P. 166a(c). This may be accomplished by disproving as a matter of law one or more of the elements essential to the plaintiff’s claims. Anderson v. Snider, 808 S.W.2d 54 (Tex.1991). Once the defendant establishes its entitlement to judgment as a matter of law, the plaintiff, as nonmovant, must present summary judgment proof to establish a fact issue. Clear Creek, 589 S.W.2d at 678. In deciding whether a disputed material fact issue precludes summary judgment, the reviewing court will take as true all evidence favoring the nonmovant. Nixon v. Mr. Property Management Co., 690 S.W.2d 546, 549 (Tex.1985); Montgomery v. Kennedy, 669 S.W.2d 309, 311 (Tex.1984). Every reasonable inference from the evidence will be indulged in favor of the nonmovant, and any doubts will be resolved in his favor. Nixon, 690 S.W.2d at 549; Montgomery, 669 S.W.2d at 311.
*586The essential elements of a plaintiffs malpractice cause of action are a duty requiring the physician to conform to a certain standard of conduct; the applicable standard of care and its breach; injury; and a causal connection between the breach of the standard of care and the harm. Elam v. Yale Clinic, 783 S.W.2d 638, 642 (Tex.App. — Houston [14th Dist.] 1989, no writ); Tilotta v. Goodall, 752 S.W.2d 160, 161 (Tex.App. — Houston [1st Dist.] 1988, writ denied); Pinckley v. Gallegos, M.D., P.A., 740 S.W.2d 529, 531 (Tex.App. — San Antonio 1987, writ denied). See Hood v. Phillips, 554 S.W.2d 160, 165-66 (Tex.1977); Bowles v. Bourdon, 148 Tex. 1, 219 S.W.2d 779, 782 (1949). Gutzman’s motion averred his entitlement to summary judgment as a matter of law because of the lack of a material fact issue concerning the elements of breach of duty and proximate cause.
Gutzman’s first affidavit set out his educational and professional background; his diagnosis of Arguello’s condition as a torn medial meniscus; the details of the surgical procedure he performed; and the post-operative treatment. He stated he was familiar with the standard of care for the diagnosis and treatment of a patient such as Arguel-lo and that, in his expert opinion based upon a reasonable degree of medical probability, his diagnosis and treatment of Ar-guello were in accordance with the appropriate standard of care. Gutzman also stated that the instrument did not break as a result of any action or inaction on his part, he used the instrument properly and correctly, and that based upon a reasonable degree of medical probability, no act or omission on his part caused or contributed to any injuries suffered by Arguello.
Gutzman’s supplemental affidavit details the appropriate standard of care for the diagnosis and treatment of a patient such as Arguello. The patient is initially evaluated through a history and physical examination. When the orthopedic surgeon suspects the patient suffers from a tom medial meniscus, the surgeon should propose an arthroscopic medial mensicetomy. During the procedure, a scope is put into the knee for visualization, followed by probing, and removal of the damaged cartilage within the knee, or ligament reconstruction. If an instrument should break during the surgery, the standard of care requires the surgeon to search for and remove the instrument by use of arthroscopic visualization and x-ray. Gutzman referred to his previously executed affidavit, and stated that “no undue pressure or traction was asserted by me while ... using the meniscus grabber” and that “my use of the arthroscopic device in question was in accordance with the appropriate standard of care”. He further stated that it was not his responsibility, as orthopedic surgeon, to examine the devices prior to surgery.
Pete Arguello testified in his affidavit and supplemental affidavit that as a result of the incident, he was hospitalized for several days, experiences continuous knee pain, and is unable to obtain employment or engage in recreational activities.
Gutzman testified in his deposition that he told Arguello his diagnosis of cartilage damage. Prior to surgery the instruments are normally checked by the operating room technician. It is uncommon for the instruments to break. He listed several factors that can cause the instrument to break: the position of the instrument, the particular procedure being performed, the instrument itself, and the anatomical arrangement of the patient. When asked again as to what can cause the instrument to break, Gutzman testified there are two possibilities: misuse and defect.
The Arguellos agree that Gutzman’s affidavits state the appropriate standard of care. However, they contend that granting a summary judgment on the basis that no fact issue was created due to the lack of expert testimony establishing that the treatment or diagnosis of Gutzman constituted negligence and was a proximate cause of Arguello’s injuries was error. The Arguellos argue the summary judgment evidence establishes that a fact issue exists whether Gutzman applied undue pressure or traction while using the instrument in question and that such issue was not conclusively negated as a matter of law by the summary judgment evidence.
*587A movant s right to summary judgment can be proved solely on the un-controverted testimony of an expert witness if the subject matter is such that a trier of fact would be “guided solely by the opinion testimony of experts, if the evidence is clear, positive and direct, otherwise credible and free from contradictions and inconsistencies, and could have been readily controverted”. Anderson v. Snider, 808 S.W.2d at 55; Tex.R.Civ.P. 166a(c). The affidavit of an interested expert witness can support summary judgment if it meets the requirements of Rule 166a, even if that expert is a party to the suit. Anderson, 808 S.W.2d at 55. If an interested expert witness presents legally sufficient evidence in support of a motion for summary judgment, the opposing party must produce other expert testimony to controvert the claims. Id.
The question is whether Gutzman’s affidavits, deposition transcript, and interrogatory answers were sufficient to negate at least one of the elements of the Arguel-los’ claim. In Charles v. Zamora, M.D., 811 S.W.2d 174 (Tex.App.—Corpus Christi 1991, writ denied), a doctor accused of negligence moved for summary judgment on the basis that his treatment met the appropriate standard of care and that he had not breached his duty to appellant. In his affidavit, the doctor set forth the standard of care and showed, with specificity, his compliance with that standard in treating the plaintiff. The defendant failed to respond with controverting expert testimony. The court held that the affidavit was sufficient to negate the elements of breach of the applicable standard of care and a causal connection between the breach of care and the harm suffered. Id. at 177. See also Milkie v. Metni, 658 S.W.2d 678 (Tex.App.—Dallas 1983, no writ).
Similarly, Gutzman’s affidavits delineate the standard of care necessary in using the meniscus grabber and in removing it should it break during surgery. He lists the specific acts he performed while using it in the operation. Gutzman’s expert testimonial evidence is clear, positive, direct, and free from contradictions and inconsistencies and readily controvertible. Tex.R.Civ.P. 166a(c). Gutzman produced evidence that he complied with the standard of care, and thereby negated all fact issues regarding the essential elements of breach and causation.
In a medical malpractice case, the requisite proof of negligence must be established through expert testimony. Shook v. Herman, 759 S.W.2d 743, 747 (Tex.App.—Dallas 1988, writ denied) (citing Hood v. Phillips, 554 S.W.2d 160, 165-66 (Tex.1977)). The burden shifted to the Ar-guellos to produce other controverting expert medical testimony. Anderson, 808 S.W.2d at 55; Milkie, 658 S.W.2d at 681.
Res Ipsa Loquitur
Expert testimony is necessary when the alleged negligence is of such a nature as not within the experience of the layman. Roark v. Allen, 633 S.W.2d 804, 809 (Tex.1982), citing Hood v. Phillips, 554 S.W.2d at 165. Accordingly, the Arguellos had the burden of presenting expert medical testimony controverting Gutzman’s evidence on the issues of breach of the applicable standard of care and its causal connection to the injury or harm.
The Arguellos pleaded generally as to the doctor’s use of the orthoscopic device in question, “because the nature of the negligence is plainly within the common knowledge of Layman (sic), the doctrine of res ipsa loquitur is applicable.” It was further alleged that the instrument was used by the doctor when it broke and would not have occurred without negligence on his part.
Res ipsa loquitur is a rule of evidence, often referred to as a doctrine. In a medical malpractice case, the plaintiff consistently has been required to prove breach of duty and proximate causation by medical testimony. Jim M. Perdue, Res Ipsa Loquitur: Applicability to Malpractice Cases in Texas, 10 Tex.Tech.L.Rev. 371, 372 (1979). The article states:
[I]f the plaintiff cannot present expert testimony that a violation of the proper medical standard has occurred proximately causing his injuries, he has failed to present evidence sufficient to be sub*588mitted to the jury. Because of this bifurcated approach, the doctrine of res ipsa loquitur generally has been held to be inapplicable in Texas medical malpractice cases, (emphasis added). The rationale for the doctrine’s non-applicability is that the ordinary medical negligence case involves complex issues beyond the common knowledge of laymen.
Id. at 373. As noted in the article, an exception may exist where the negligence alleged is in the use of mechanical instruments, operating on the wrong part of the body, or leaving surgical equipment inside the body. See Rayner v. John Buist Chester Hosp., 526 S.W.2d 637, 639 (Tex.Civ.App.—Waco 1975, writ ref’d n.r.e.). However, Texas courts in medical malpractice cases have required that negligence and proximate cause be proved by medical testimony and have held that the doctrine of res ipsa loquitur is inapplicable except when the alleged malpractice and injuries are plainly within the common knowledge of laymen. See Perdue, supra, at 373.
The use of the instrument in question must be a matter plainly within the common knowledge of laymen. Irick v. Andrew, 545 S.W.2d 557 (Tex.Civ.App.— Houston [14th Dist.] 1976, writ ref'd n.r.e.). In Williford v. Banowsky, 563 S.W.2d 702 (Tex.Civ.App.—Eastland 1978, writ ref’d n.r.e.), the dental patient sued for a cut received when the dentist was using a high-speed rotary instrument. The court of appeals upheld the ruling of the trial court— instructing a verdict for the defendant. The plaintiff argued that under the doctrine of res ipsa loquitur a fact question was raised. The appellate court disagreed, holding that none of the recognized exceptions to the requirement of the necessity of medical testimony were applicable. “The proper use of a high-speed rotary instrument in a dental treatment is no more a matter plainly within the common knowledge of laymen than the use of an x-ray machine.” Thus, the proper use of the particular instrument must be a matter plainly within the common knowledge of laymen. “Because it would be a rare situation in which the proper use of a medical instrument would be a matter within the common knowledge of laymen, application of the doctrine of res ipsa loquitur in this situation would be limited.” Perdue at 374-75.
In the present case the proper use of a meniscus grabber, an arthroscopic device employed by orthopedic surgeons, is not a matter plainly within the common knowledge of laymen. Consequently, breach of duty and causation must be proved by medical testimony. As previously stated, the Arguellos failed to controvert the medical testimony of Gutzman on the issues of standard of care, breach and causal connection.
The statements in Gutzman’s affidavits could have been readily controverted by expert medical testimony. Moreover, the mere possibility that an act of negligence might have been the proximate cause of damages is not sufficient to support recovery. Tilotta, 752 S.W.2d at 163. Proof of mere possibilities will not support a fact issue. See Duffv. Yelin, 751 S.W.2d 175, 176 (Tex.1988). Conflicting inferences do not arise from the deposition, interrogatories’ answers, and the affidavits. The Arguellos wholly failed to produce controverting expert medical evidence to rebut the summary judgment evidence presented by defendant. Gutzman’s affidavits were sufficient to negate both the elements of breach of the applicable standard of care and a causal connection between the breach of care and the harm suffered. The trial court properly granted Gutzman’s motion for summary judgment. The point is overruled.
The Arguellos filed their notice of appeal under cause number 88-CI-16341-A, the cause number given to the severed undisposed issues in this case. Gutzman’s cross-point is that this court, therefore, does not have jurisdiction over the appeal.
In City of San Antonio v. Rodriguez, 828 S.W.2d 417 (1992), the appellants timely filed a notice of appeal in the proper court with the correct style but the wrong cause number. The court held that a court of appeals has jurisdiction over an appeal when the appellant files an instrument that is “a bona fide attempt to invoke appellate *589court jurisdiction.” Id. (quoting Grand Prairie Indep. Sch. Dist. v. Southern Parts Imports, Inc., 813 S.W.2d 499, 500 (Tex.1991)).
This court has previously granted the Arguellos’ motion to amend the notice of appeal and transcript and denied Gutz-man’s motion to dismiss. All requirements of notice were met except the use of the cause number. Dr. Gutzman was not disadvantaged or misled in any manner. The cross-point is overruled. The judgment is affirmed.