Roslyn Tarrant1,2, Anne Nugent3, David Moore4,5, Pat Kiely4,5 .... Comparison between groups was performed using Pearson's chi-squared test for categorical data. Independent t-test & Mann-Whitney U tests were used to compare the mean ...
Anthropometric Characteristics and Postoperative Weight Loss in Patients with Adolescent Idiopathic Scoliosis: A Case-Control Study Roslyn Tarrant1,2, Anne Nugent3, David Moore4,5, Pat Kiely4,5 1Dept. of Clinical Nutrition, OLCHC; 2National Children’s Research Centre; Dublin 12; 3Institute of Food and Health, University College Dublin; 4OLCHC / 5Blackrock Clinic, Co. Dublin
BACKGROUND
METHODS
anthropometry including comparably lower weight, body mass index (BMI) as well as lower percentage body fat in the adolescent idiopathic scoliosis (AIS) population is increasingly recognised.
In all, 77 consecutive and eligible patients with AIS who underwent PSF were prospectively followed up from hospital admission (Jan 2010-April 2012)2. Pre- & postoperative anthropometric measurements were collected (weight, height corrected BMI, including weight loss) and standardised to Z-scores for age, using British growth reference data3.
Abnormal
Studies from Greece, Poland, Spain and Ireland1 report that approx. one quarter of patients with AIS are considered clinically underweight preoperatively – it is still unknown whether these altered anthropometric features are a symptom of AIS, or related to abnormal spinal growth. This is the first study to examine the preoperative anthropometric characteristics of AIS from an Irish perspective, and compare these measurements with those of non-AIS healthy Irish controls. As a secondary objective, we sought to quantify postoperative weight loss and assess its clinical impact on outcomes in these already very thin patients following posterior spinal fusion (PSF).
A case control study was performed4 to establish potential differences in preoperative weight, height and BMI of this AIS cohort versus non-AIS healthy age-matched controls derived from the National Teens’ Food Survey (NTFS; 2005-2006)5. Clinically severe involuntary weight loss during the hospital stay, defined as ‘greater than 10% loss of initial body weight from admission to hospital discharge’6 was assessed in relation to clinical outcomes including radiographic, nutritional, biochemical, socio-demographic, perioperative complication data, and length of hospitalisation.
RESULTS Mean age of the cohort was 15 years; 93.5% were female.
Table 1. Associations between % weight loss ≤ 10% vs. > 10% during the hospital stay, and selected characteristics and outcomes†
As shown in Figure 1, 27.3% of patients with AIS were considered undernourrished (BMI Z-score 10% was identified in almost ⅓ of patients (30.6%) after PSF. Of clinical importance, significantly increased superficial wound infection incidence was the only clinical outcome under analysis associated with greater than 10% weight loss in this Irish AIS cohort (13.6% vs. 2%, P = 0.047) (Table 1).
P < 0.0001
Parameter
≤ 10% (n = 50)
> 10% (n = 22)
P value
Weight on admission (kg), mean (SD)
51.8 (11)
51.3 (8.8)
NS
Weight at discharge (kg), mean (SD)
48.9 (11)
44.1 (7.9)
0.05
63.1 (14.9)
60.4 (9.7)
NS
Postoperative parenteral nutrition received, n (%)
6 (12)
1 (4.5)
NS
Minor perioperative complication rate, n (%) Minor complications, n (%) Gastrointestinal (ileus) Blood product transfusion Respiratory-related (e.g. pneumonia) Superficial wound infection
35 (70)
18 (81.8)
NS
6 (12) 21 (42) 10 (20) 1 (2)
1 (4.5) 13 (59.1) 5 (22.7) 3 (13.6)
NS NS NS 0.047
Major perioperative complication rate, n (%)
2 (4)
2 (9.1)
NS
Length of hospitalisation (days), median (IQR)
9 (8-11)
9.5 (8-11)
NS
Albumin at hospital discharge (g/L), mean (SD)
28 (4)
25 (4.6)
0.05
Hospital readmission rate, n (%) Reported time to achieving preoperative weight after surgery (weeks), median (IQR)
1 (2)
2 (9.1)
NS
8 (4-19)
21 (16-24)
10% may be a potentially valuable marker of wound infection risk in AIS after PSF – a novel finding that requires confirmation in future studies. Early detection and prevention of severe postoperative weight loss may prove particularly beneficial to modifying wound infection risk in this patient population.
