The Influence Of Obesity in Stage IIB Posterior Tibial Tendon Dysfunction Corrective Surgery

Abstract

Category: Hindfoot Introduction/Purpose: In the western population prevalence of posterior tibial tendon dysfunction (PTTD) is said to be 3.3% and it is one of the most commonly undiagnosed foot and ankle pathologies. Stage IIB disease according to Johnson and Strom criteria is managed surgically and there are literature demonstrating good clinical outcomes. Obesity being a global epidemic it affects the patient both biomechanically and biochemically. Aim of the study was to investigate the influence of obesity on functional outcome scores, incidence of postoperative surgical site infection (SSI), and repeat surgery after corrective surgery for stage IIB posterior tibial tendon dysfunction (PTTD). Methods: Between January 2007 and December 2013, 102 patients who underwent corrective surgery for stage IIB PTTD at a tertiary hospital were evaluated. We categorized the group with a BMI less than 30 kg/m as control and the group with BMI more than 30 kg/m as obese. The patients were prospectively followed for 2 years. AOFAS mid foot and hind foot scores, mid foot and hind foot VAS scores, SF36 physical and mental function scores were measured pre-operative, post-operative 6 months and post-operative 24 months. SPSS was used for statistical analysis. P value <0.05 was considered as a significant value. Results: 19.6 percent of our study population was obese, there were 38 males and 64 females. The average age of the population was 44.3years and the average BMI for the population was 28.78kg/m 2 . Clinical outcomes are as follows SF36 physical function score demonstrated statistical significance (p=0.0001, CI -22.20 to -9.80), AOFAS midfoot scores (p=0.82, CI -9.55 to 7.56), AOFAS hindfoot scores (p=0.23, CI -10.60 to 2.60), Midfoot Visual Analogue Scores (p=0.54, CI 0.31 to 0.76), Hindfoot Visual Analogue Scores (p=0.45, CI 0.21 to 0.68) and SF36 mental health scores (p=0.99, CI -5.76 to 7.74) did not demonstrate any significance (6%) in the control group and 10% in the obese group required repeated surgery for complications. Conclusion: Both groups of patients who underwent corrective surgery for stage IIB pttd demonstrated good functional outcomes but there was a significantly higher risk of repeat surgery in the obese group. Obese patients should not be excluded from stage IIB PTTD corrective surgery but patients should be counselled of the higher risk percentage.