The influence of process and patient factors on the recall of consent information in mentally competent patients undergoing surgery for neck of femur fractures.

INTRODUCTION: Informed consent is an ethical and legal prerequisite for major surgical procedures. Recent literature has identified 'poor consent' as a major cause of litigation in trauma cases. We aimed to investigate the patient and process factors that influence consent information recall in mentally competent patients (abbreviated mental test score [AMTS] ≥6) presenting with neck of femur (NOF) fractures. METHODS: A prospective study was conducted at a tertiary unit. Fifty NOF patients (cases) and fifty total hip replacement (THR) patients (controls) were assessed for process factors (adequacy and validity of consent) as well as patient factors (comprehension and retention) using consent forms and structured interview proformas. RESULTS: The two groups were matched for ASA (American Society of Anesthesiologists) grade and AMTS. The consent forms were adequate in both groups but scored poorly for validity in the NOF group. Only 26% of NOF patients remembered correctly what surgery they had while only 48% recalled the risks and benefits of the procedure. These results were significantly poorer than in THR patients (p = 0.0001). CONCLUSIONS: This study confirms that NOF patients are poor at remembering the information conveyed to them at the time of consent when compared with THR patients despite being intellectually and physiologically matched. We suggest using preprinted consent forms (process factors), information sheets and visual aids (patient factors) to improve retention and recall.

Arthroscopy of the hip in patients following joint replacement.

Arthroscopy of the native hip is an established diagnostic and therapeutic procedure. Its application in the symptomatic replaced hip is still being explored. We describe the use of arthroscopy of the hip in 24 symptomatic patients following total hip replacement, resurfacing arthroplasty of the hip and partial resurfacing (study group), and compared it with arthroscopy of the native hip in 24 patients (control group). A diagnosis was made or confirmed at arthroscopy in 23 of the study group and a therapeutic arthroscopic intervention resulted in relief of symptoms in ten of these. In a further seven patients it led to revision hip replacement. In contrast, arthroscopy in the control group was diagnostic in all 24 patients and the resulting arthroscopic therapeutic intervention provided symptomatic relief in 21. The mean operative time in the study group (59.7 minutes (35 to 93)) was less than in the control group (71 minutes (40 to 100), p = 0.04) but the arthroscopic approach was more difficult in the arthroplasty group. We suggest that arthroscopy has a role in the management of patients with a symptomatic arthroplasty when other investigations have failed to provide a diagnosis.

Biomechanical testing of the locking compression plate: when does the distance between bone and implant significantly reduce construct stability?

AIM: To investigate in vitro the mechanical stability of a locking compression plate (LCP) construct in a simulated diaphyseal fracture of the humerus at increasing distances between the plate and bone. MATERIALS AND METHOD: A series of biomechanical in vitro experiments were performed using composite humerus sawbone as the bone model. Osteotomy created in the mid-diaphyseal region. A 10mm osteotomy gap was bridged with a seven-hole 4.5 stainless steel plate with one of four methods: a control group consisted of a dynamic compression plate applied flush to the bone and three study groups which comprised of a LCP applied flush to the bone, at 2mm and at 5mm from the bone. Standard AO technique used with locking head screws used for LCP fixation. Static and dynamic loading tests performed in a custom made jig in which the bone model was fixed both proximally and distally. Samples were subjected to cyclical compression, compression load to failure, cyclical torque and torque to failure. Plastic deformation and failure was assessed using three-dimensional measurements. Scanning electron microscopy of the plate and screw surface allowed detailed inspection of micro-fracture in areas of fatigue. RESULTS: Comparable results were achieved in both the DCP and LCP constructs in which the plate was applied at or less than 2mm from the bone. When applied 5mm from the bone the LCP demonstrated significantly increased plastic deformation during cyclical compression and required lower loads to induce construct failure. CONCLUSION: At a distance 5 mm we observe an inferior performance in the mechanical properties of the LCP construct with decrease in axial stiffness and torsional rigidity. If it is desirable for an LCP to be used the distance between plate and bone should be