The significance of matching radius of curvature of the radial head implant and the capitellum in implant selection is evaluated. A mismatch of radius of curvature could lead to point loading, reducing contact area, creating large contact stresses, resulting in arthritis, pain, and other complications. Radial head (RH) implant size is chosen by reconstruction outside of the radiocapitellar joint capsule measuring the RH diameter and length, which is replicated for implant selection. RH radius of curvature (RC) is rarely part of the decision although important in determining contact area.Summary
Introduction
For injuries to the lower leg or forearm, supplemental support from soft tissue compression (STC) with a splint or brace-like system and combined with external fixation could be done effectively and quickly with a minimal of facilities in the field. Soft tissue compression (STC) in functional braces has been shown to provide rigidity and stability for most closed fractures, selected open fractures and can supplement some other forms of fracture fixation. However, soft tissue injuries are compromised in war injuries. This study was designed to evaluate if STC can provide adequate rigidity and stability either with, or without other forms of fixation techniques of simple fractures or bone defects after standardised soft tissue defects. The load was applied either axially or in bending as the bending configuration is more like conditions when positioned on a stretcher in the field.Summary
Introduction
Increased lateral ulnotrochlear joint space due to improper sizing in radial head arthroplasty may result in medial collateral ligament laxity, leading to increased osteophytes and arthritis. Radial head (RH) arthroplasty is a common response to comminuted RH fractures. Typical complications include improper sizing, leading to changes in joint kinematics. Evidence of these changes should be visible through fluoroscopic images of affected joints. The two examined changes in this study are the ulnar deviation from distal radial translation (DRT), and the widening of the lateral ulnotrochlear joint space (LUT).Summary
Introduction
Consistent load distributions with over-sizing of radial head implants show minimal variance in interosseus ligament (IOL) and triangular-fibrocartilage complex (TFCC) tension, both of which are essential in distribution of load at the elbow. Introduction:Changes in loading distribution at the elbow have not been studied with radial head (RH) arthroplasty. Difficulty arises concerning distribution variability between loading methods and magnitudes, and with implant oversizing. RC joint capsule were exposed using the Kocher approach in seven fresh-frozen cadaver Humeri. Specimens were loaded axially in an MTS machine with humeri at 90° and wrist neutral. The arms were cycled in load control between 13N–130N until steady-state was reached for each trial. After loading in neutral, the arms were rotated to 60° supination (60S) and 60° pronation (60P), the test repeated. The radial head was excised and Co-Cr implant inserted. Sizings 0mm, +2mm, +4mm were simulated using 2mm plastic spacers on the stem. A Tekscan pressure map transducer at RC recorded loading. The recorded Tekscan loads were organised according to sizing (native, 0mm, +2mm, +4mm) for each specimen. The max/min load values were recorded and the difference, ΔL was calculated. The Max and ΔL values from each sizing were percentage paired with the respective native value. The ΔL values were used to discern load distribution. A linear regression was done using the RC loading plotted against the applied load to visualise the change of load distribution with changing applied loads. Data was analyzed using one-way analysis of variance.Summary
Method
It is known that activity level correlates with wear in total joint arthroplasty. UCLA activity score surveys were sent to four hundred and sixty-seven knee and hip arthroplasty patients with good/excellent clinical outcomes as determined by one-year postoperative Knee Society (KSS) and Harris Hip (HHS) scores. The UCLA activity score was correlated with clinical outcomes and demographic data. Average UCLA score was 6.2 for hips, 6.3 for knees, indicating moderate activity levels. Hip arthroplasty UCLA score significantly correlated with age, gender and one-year Oxford score. Knee arthroplasty UCLA score significantly correlated with gender, one-year functional KSS and Oxford score. Arthroplasty patients are often warned to avoid high level activities for fear of implant loosening, failure or increased polyethylene wear. Patients with good/excellent clinical outcomes may however be inclined to participate in higher demand activities. There is need for specific information regarding patient profile and activity level following TJR. Current recommendations for activity among TJR patients may not be justified. Longer-term follow-up will elucidate specific activities which may be permissible or detrimental to implant survivorship. Survey response rate was 70.2% among THA patients at mean 40.7months. Mean UCLA score was 6.2/10, indicating moderate activity. Mean outcome scores; one-year HHS 94.8, Oxford 6.6. UCLA score significantly correlated with age, gender and one-year Oxford. Survey response rate was 81.8% among TKA patients at mean 36.6months. Mean UCLA score was 6.3/10, indicating moderate activity. Mean outcome scores; one-year KSS clinical 95.9, KSS function 95, Oxford 18.2. UCLA score significantly correlated with gender, one-year KSS function and Oxford. No significant differences among clinical outcomes and survey non-respondents. UCLA activity score survey of two hundred and twenty-five primary TKA and two hundred and forty-two primary THA patients. Patients abstracted from prospective database and pre-selected for good/excellent outcomes based on KSS and HHS at one-year. Clinical outcomes included Oxford Hip/Knee scores. UCLA, demographics and clinical outcomes correlated using Pearson’s correlation. UCLA scores indicate the average TJR patient maintains a moderate activity level. Younger male patients with low Oxford can be expected to participate in higher level activities. One THA patient underwent subsequent revision despite moderate activity level.
