Medical Board panel hears arguments in 2017 knee‑surgery review of Dr. Brad Penenberg

The Medical Board of California, Panel B, heard oral argument March 14, 2025, in the accusation against Dr. Brad Penenberg, an orthopedic surgeon, over the preoperative evaluation and postoperative management of a patient who underwent a revision total knee replacement on Dec. 5, 2017; the panel took the matter under submission and will deliberate in closed session.

The dispute centers on whether Penenberg failed to obtain appropriate, up‑to‑date laboratory testing and medical coordination before the December 2017 surgery, and whether any preoperative shortcomings or postoperative care failures amounted to unprofessional conduct. Raymond McMahon, counsel for Penenberg, told the panel that "Everything that doctor Penenberg did in this case was consistent with the standard of care." Deputy Attorney General Giovanni Mejia argued the surgeon “failed to assume proper responsibility over the patient’s stability” and should have sought more timely labs and nephrology involvement given the patient’s complex cardiac and renal history.

McMahon told the panel that the patient had multiple preoperative clearances: an internist (Dr. Ishaya) completed a clearance on Nov. 8, 2017; a cardiologist (Dr. Geff) evaluated and cleared the patient on Dec. 4, 2017; and the anesthesiologist cleared the patient on the morning of Dec. 5. McMahon said the patient had stable end‑stage renal disease managed with dialysis for five years and that the nephrologist who had been treating the patient referred him to orthopedic care. Counsel emphasized that the surgical team found the intraoperative course uneventful and that the patient’s acute deterioration occurred the morning after surgery.

Mejia, representing the executive director of the Medical Board, urged the panel that the evidence showed the patient’s health could change rapidly and that more current labs—“within 24 hours,” in his expert’s view—were required for a patient with end‑stage renal disease and cardiac comorbidities. Mejia also pointed to gaps in record keeping and the fact that the treating nephrologist was not aware of the Dec. 5 surgery until late that night, after the patient had already undergone the procedure.

Panel members asked questions about timeline and postoperative monitoring. Board Chair Dr. Richard Thorpe, an internist by training, pressed counsel and the respondent about why perioperative potassium monitoring and postoperative dialysis had not occurred as expected. McMahon and Dr. Penenberg said nursing staff had contacted the medicine service multiple times the day of and after surgery and that Penenberg was not notified that treating medicine or nephrology teams were not responding; counsel emphasized the accusation focuses on preoperative conduct, not postoperative management.

No final disciplinary action was taken at the hearing. The parties submitted their arguments, the record was closed, and the panel said it would go into closed session to deliberate; the parties will receive a written decision at a later date.

Sources: oral argument before the Medical Board of California, Panel B, Office of Administrative Hearings, March 14, 2025; statements by Raymond McMahon (counsel for respondent) and Giovanni Mejia (Deputy Attorney General).