Body mass index (BMI) is a topical area of interest in the field of lower limb arthroplasty. It has been well established that BMI can influence post-operative outcomes. This study compares post-operative outcomes, including satisfaction rates, length of stay (LOS) and radiographic findings in different BMI groups following total hip arthroplasty (THA). We retrospectively evaluated all non-navigated THAs performed at our institution from 2006–2016. Case-notes were reviewed for dichotomised satisfaction score, LOS and radiographic parameters including inclination, anteversion, limb length discrepancy (LLD) and offset discrepancy. Patients were classified into 4 groupings based on BMI (underweight (<24.5), healthy (24.5–30), obese (30–40), severely obese (>40)). Appropriate statistical analyses were performed to identify between group differences.Introduction
Methods
The literature quotes up to 20% dissatisfaction rates for total knee replacements (TKR). Swedish registry and national joint registry of England and Wales confirm this with high volumes of patients included. This dissatisfaction rate is used as a basis for improving/changing/modernising knee implant designs by major companies across the world. We aimed to compare post TKR satisfaction rates for navigated and non navigated knees.Background
Aim
Patients with osteoarthritis (OA) of the knee commonly alter their movement to compensate for deficiencies. This study presents a new numerical procedure for classifying sit-to-walk (STW) movement strategies. Ten control and twelve OA participants performed the STW task in a motion capture laboratory. A full body biomechanical model was used. Participants were instructed to sit in a comfortable self-selected position on a stool height adjusted to 100% of their knee height and then stand and pick up an object from a table in front of them. Three matrices were constructed defining the progression of the torso, feet and hands in the sagittal plane along with a fourth expressing the location of the hands relative to the knees. Hierarchical clustering (HC) was used to identify different strategies. Trials were also classified as to whether the left (L) and right (R) extremities used a matching strategy (bilateral) or not (asymmetrical). Fisher's exact test was used to compare this between groups. Clustering of the torso matrix dichotomised the trials in two major clusters; subjects leaning forward (LF) or not. The feet and hands matrices revealed sliding the foot backward (FB) and moving an arm forward (AF) strategies respectively. Trials not belonging in the AF cluster were submitted to the last HC of the fourth matrix exposing three additional strategies, the arm pushing through chair (PC), arm pushing through knee (PK) and arm not used (NA). The control participants used the LF+FBR+PK combination most frequently whereas the OA participants used the AFR+PCL. OA patients used significantly more asymmetrical arm strategies, p=0.034. The results demonstrated that control and OA participants favour different STW strategies. The OA patients asymmetrical arm behaviour possibly indicates compensating for weakness of the affected leg. These strategy definitions may be useful to assess post-operative outcomes and rehabilitation progress.
Surgical site infection (SSI) remains a concern following total hip arthroplasty (THA). We aimed to identify risk factors for post-operative SSI in THA. All primary THAs performed in our institution during 2009–2010 were included, giving 1832 cases in 1716 patients. Cohort demographics were mean age 67.9 years (SD10.2), mean BMI 29.6 (SD5.3), 60% female and 90.2% primary indication of osteoarthritis. Post-operative SSI within one year was identified either through hospital infection control records or from Information Services Division (NHS Scotland). Demographic and peri-operative data for known or suspected risk factors for SSI were collected from clinical records. Groups were compared using independent t-tests and chi-squared tests as appropriate.Introduction
Patients/Materials & Methods
