Prospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Dec 18, 2015; 6(11): 991-995
Published online Dec 18, 2015. doi: 10.5312/wjo.v6.i11.991
Effect of body mass index on functional outcomes following arthroplasty procedures
Gokhan Polat, Hasan Huseyin Ceylan, Safak Sayar, Fatih Kucukdurmaz, Mehmet Erdil, Ibrahim Tuncay
Gokhan Polat, Department of Orthopaedics and Traumatology, Istanbul University Istanbul Medical Faculty, 34093 Istanbul, Turkey
Hasan Huseyin Ceylan, Department of Orthopedics and Traumatology, Sultanciftligi LNB State Hospital, 34265 Istanbul, Turkey
Safak Sayar, Fatih Kucukdurmaz, Ibrahim Tuncay, Department of Orthopaedics and Traumatology, Bezmialem Vakif University, 34093 Istanbul, Turkey
Mehmet Erdil, Department of Orthopaedics and Traumatology, Istanbul Medipol University, 34214 Istanbul, Turkey
Author contributions: Polat G and Erdil M contributed to the study design, data acquisition, analysis and interpretation, and manuscript drafting; Ceylan HH contributed to the data acquisition, analysis and interpretation; Sayar S contributed to the data acquisition, analysis and interpretation, and manuscript drafting; Kucukdurmaz F and Tuncay I contributed to the data interpretation.
Institutional review board statement: The study was reviewed and approved by the Istanbul Medical Faculty Department of Orthopaedics and Traumatology Institutional Review Board.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All authors declare that there is no conflict of interest.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Safak Sayar, MD, Department of Orthopaedics and Traumatology, Bezmialem Vakif University, Adnan Menderes Bulvari Vatan Caddesi, 34093 Istanbul, Turkey.
Telephone: +90-532-5406986 Fax: +90-212-4142000
Received: January 4, 2015
Peer-review started: January 5, 2015
First decision: January 20, 2015
Revised: June 5, 2015
Accepted: August 30, 2015
Article in press: August 31, 2015
Published online: December 18, 2015

AIM: To evaluate the body mass index (BMI) change in arthroplasty patients and its impact on the patients’ functional results.

METHODS: Between October 2010 and May 2013, 606 patients who were operated due to gonarthrosis, coxarthrosis, aseptic loosening of the total knee and hip prosthesis were evaluated prospectively. Patients were operated by three surgeons in three medical centers. Patients who were between 30-90 years of age and who were underwent total knee arthroplasty, total hip arthroplasty, revision knee arthroplasty, or revision hip arthroplasty were included in the study. We excluded the patients who cannot tolerate our standard postoperative rehabilitation program. Additionally, patients who had systemic inflammatory diseases, diabetes mellitus, or endochrinopathies were excluded from the study. The remaining 513 patients comprised our study group. Preoperative functional joint scores, height, weight and BMI of all patients were recorded. We used the Knee Society Score (KSS) for knee and Harris Hip Score (HHS) for hip patients. Postoperative functional scores were measured at 1st, 6th and 12th months and recorded separately at outpatient visits.

RESULTS: The mean age of the patients was 64.7 (range: 30-90) years (207 males/306 females) and the mean follow-up duration was 14.3 (range: 12-26) mo. We found that arthroplasty patients had weight gain and had an increase in BMI at the postoperative 1st, 6th and 12th months. The mean BMI of the patients was 27.7 preoperatively, 27.8 at the postoperative 1st month, 28.1 at the 6th month and 28.6 at the 12th month (P < 0.01). At the last visit, the mean postoperative HHS of the hip arthroplasty patients was 82.2 ± 7.12 (preoperatively, 52.3; 1st month, 78.2; 6th month, 81.1; 12th month, 82.2), and the mean KSS of the knee arthroplasty patients was 79.3 ± 4.31 (preoperatively, 35.8; 1st month, 75.2; 6th month, 79.1; 12th month, 79.3). Worse functional results were noted in the patients who had a BMI increase, however, this correlation was statistically significant only at the postoperative 6th month (P = 0.03).

CONCLUSION: To prevent the negative functional effects of this weight gain during the postoperative period, arthroplasty patients should be advised for weight control and risky patients should consult with a dietician.

Keywords: Body mass index, Arthroplasty, Obesity, Functional outcomes, Weight gain

Core tip: Although the patients should be expected to mobilize more easily and loose weight after arthroplasty procedures, we hypothesized that the body mass index (BMI) usually increases in the postoperative period of total joint arthroplasty of the lower extremity. We aimed to evaluate the BMI changes in arthroplasty patients and impact of BMI changes on functional results in total knee arthroplasty and total hip arthroplasty patients. In our study, we determined that lower extremity arthroplasty patients gained weight during the postoperative period and this weight gain deteriorated functional outcomes of the patients. This correlation was statistically significant at the 6th month postoperatively (P = 0.03).