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AAOS Now

Published 2/1/2015
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Mary Ann Porucznik

Stem Cell, Complication Papers Receive Awards

A study on the use of autogenous bone marrow stem cells to treat femoral head osteonecrosis, and two papers on complications after total joint arthroplasty (TJA) were recognized for outstanding research during the 2014 annual meeting of the American Association of Hip & Knee Surgeons.

Lawrence D. Dorr Award
“Core Decompression with Autogenous Bone Marrow Stem Cells for the Treatment of the Femoral Head Osteonecrosis,” authored by Reza Mostafavi Tabatabaee, MD; Sadegh Saberi, MD; Javad Parvizi, MD, FRCS; and Mahmoud Frazan, MD, received the Lawrence D. Dorr Award. The study aimed to evaluate the effects of core decompression and the implantation of autologous bone marrow containing mononuclear cells (MNCs) on osteonecrosis of the femoral head.

This randomized, controlled clinical trial evaluated 28 patients with nontraumatic osteonecrosis of the femoral head (stage I, II, or III, according to the Association Research Circulation Osseous classification). Patients were randomly assigned to treatment with core decompression combined with autologous bone marrow MNC implantation (group A) or core decompression only (group B). Patients were evaluated for 2 years, using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, Visual Analogue Scale (VAS) index, and magnetic resonance imaging (MRI) of the femoral head.

Mean WOMAC and VAS scores for both groups declined in both groups at 2 years. However, scores for group A were significantly lower than those in group B and MRI findings for group A showed improvements, while those for group B showed worsening. In addition, three patients from group B underwent hip arthroplasty during the follow-up period.

“Injection of concentrated bone marrow into the necrotic femoral head could be effective in the early stages,” wrote the authors, “and result in reduced pain and joint discomfort, delayed deterioration, and even improvement of the disease.”

James A. Rand Award
A paper by Paul M. Courtney, MD; Joshua C. Rozell, MD; Christopher M. Melnic, MD, and Gwo-Chin Lee, MD, addressing “Who Should Not Undergo Short-Stay Hip and Knee Arthroplasty? Risk Factors Associated with Major Medical Complications Following Primary Total Joint Arthroplasty” was presented with the James A. Rand Award.

Noting that medical economics are driving shorter hospital stays and that “improvements in anesthesia, pain, and rehabilitation protocols have made short-stay and outpatient TJA a possibility,” the authors raised concerns about patient safety and the penalties associated with hospital readmission. They sought to define the incidence and timing of perioperative medical complications following total knee and total hip arthroplasty (TKA/THA) and to identify the independent risk factors associated with these complications.

This retrospective review of prospectively collected data (medical comorbidities, demographics, and postoperative in-hospital complications) involved a consecutive series of 1,012 patients who underwent primary TKA/THA over a 10-month period. Researchers defined and classified complications, identifying a subgroup of patients who experienced a medical complication after 24 hours or longer following surgery. They used univariate and multivariate logical regression analyses to identify risk factors and generate a model to determine which patients were best suited for a short-stay primary TJA.

Most medical complications (59 out of 70) occurred after 24 hours following surgery. Independent risk factors included chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), coronary artery disease (CAD), and cirrhosis. “Patients with a history of COPD, CHF, CAD, and cirrhosis should not undergo short-stay primary THA or TKA,” they concluded.

AAHKS Clinical Award
“Can the American College of Surgeons (ASC) Risk Calculator Predict 30-day Complications after Knee and Hip Arthroplasty?” asked Adam I. Edelstein, MD; Linda I. Suleiman, MD; Rishi Khakhkhar, BA; Michael Moore; Mary J. Kwasny, ScD; Matthew D. Beal, MD; and David W. Manning, MD, the authors of the AAHKS Clinical Award-winning paper.

To answer that question, they assessed whether the ASC’s National Surgical Quality Improvement Program (NSQIP) online surgical risk calculator could predict 30-day complications for a series of publicly reported Medicare patients who underwent THA or TKA in 2009. Patient demographic and comorbidity data were retrospectively input and patient-specific risk probabilities were recorded for several complication/outcome categories.

In addition, researchers noted whether any of these incidents occurred during the 30-day postoperative period. They used binomial logistic regression modeling to compute the odds ratios of a complication occurring and c-statistic values to determine risk probability predictive values.

The patient cohort included 128 TKA and 78 THA patients, with a mean age of 74 years. No patient was lost to follow-up. The number of 30-day complications was as follows:

  • serious = 20
  • any = 32
  • urinary tract infection = 9
  • venous thromboembolism = 9
  • reoperation = 6
  • discharge to a rehabilitation facility = 115
  • death = 1

Although risk estimates were significantly associated with event occurrence in the serious and any complication categories, event predictability was poor. Risk estimates for discharge to a rehabilitation facility demonstrated both association and predictability, but neither association nor predictability was found in any other category.

The authors concluded that “the ACS-NSQIP risk calculator has poor predictive value for 30-day complications for THA and TKA.” They recommended additional research to develop an accurate risk stratification tool for these surgeries and facilitate equitable provision and reimbursement of patient care.

Mary Ann Porucznik is managing editor of AAOS Now. She can be reached at porucznik@aaos.org

Additional Information
Download the PDF version of the entire Final Program Booklet including abstracts.