2015 ISAKOS Biennial Congress ePoster #1221
Body Mass Index Affects Knee Strength Recovery Following ACL Reconstruction
Gulcan Harput, PT,PhD, Ankara TURKEY
Gul Baltaci, PhD, Ankara TURKEY
Ahmet Atay, Prof., MD, Ankara TURKEY
Hamza Özer, MD, Prof., Ankara TURKEY
Hacettepe University, Ankara, --- Click to select State/Province ---, TURKEY
FDA Status Not Applicable
Summary: Body mass index (BMI) greater than 24.9 kg/m2 adversely affects the knee muscle strength recovery following ACL reconstruction. Delayed recovery of the knee muscles due to higher BMI may be a risk factor for degenerative changes in long term after surgery.
Lower BMI has been shown to a predictive factor of early return of pre-injury level after ACL reconstruction. However, there is no study in the literature to show how BMI affects knee muscle strength recovery following ACL reconstruction.The aim of this study was to compare knee muscle strength recovery at first, second, third and six months after surgery between ACL recontructed patients whose BMI was greater than 24.9 kg/m2 and whose BMI was normal (BMI:19-24.9 kg/ m2).
Sixty-seven patients who had ACL reconstruction by using hamstring tendon autograft were included in this study. Patients were divided into two groups according to their BMI. Patients in Group 1 (n=34) had normal BMI levels which were between 19-24.9 kg/m2 and the patients in Group 2 (n=33) had higher BMI levels which were greater than 24.9 kg/m2. Isokinetic dynamometer (IsoMed®2000 D&R GmbH, Germany) was used to measure isometric, concentric and eccentric strength of quadriceps and hamstring muscles. Isometric strength was measured at 1st ,2nd ,3rd and 6th months after surgery. In addition, concentric isokinetic test at 60°/s and 180°/s angular velocities and eccentric isokinetic test at 90°/s angular velocity were performed at 6th months after surgery. Student t test was used to determine the significant differences between groups in terms of muscle strength recovery.
Isometric strength: There were significant differences between groups in isometric quadriceps and hamstrings strengt at first (quadriceps: p=0.04), second (quadriceps:p=0.04, hamstrings,p=0.01), third (quadriceps:p=0.02,hamstrings,p=0.004) and sixth months (quadriceps, p=0.005,hamstrings,p=0.01) after surgery. Group 1 had greater isometric quadriceps and hamstring strength following surgery when compared to the Group 2.
Concentric and eccentric strength: There were also significant differences between groups in concentric strength of quadriceps and hamstring muscles at 180°/s (quadriceps: p=0.002, hamstrings: p=0.004) and at 60°/s (quadriceps: p=0.002, hamstrings: p=0.008). In addition, eccentric strength of the muscles were significantly different between groups (quadriceps: p=0.001, hamstrings: p=0.02). Concentric and eccentric strength of quadriceps and hamstring muscles were greater in Group 1 compared to the Group 2.
Discussion:This study showed that BMI greater than 24.9 kg/m2 adversely affected the knee muscle strength recovery following ACL reconstruction. Delayed recovery of the knee muscles due to higher BMI is thought be a risk factor for degenerative changes in long term after surgery. Therefore, ACL reconstructed patients should be aware of this risk and weigth loss should be recommended for those patients.