Assessment of cortical bone elasticity and strength: mechanical testing and ultrasound provide complementary data.

Cortical bone is a compact tissue with anisotropic macroscopic mechanical properties determined by a microstructure and the quality of a mineralised collagen matrix. Anisotropic elastic properties and strength are usually measured on different groups of sample which can hardly be pooled; as a consequence little is known on the relationships between strength and elasticity in the different anatomical directions. A method is presented to measure on a same cortical bone sample: (1) Young's modulus and strength (sigma(max)) in the longitudinal direction; (2) stiffness (C(11)) in the transverse direction. Longitudinal and transverse direction are taken along and perpendicular to the diaphysis axis, respectively. Ultrasonic techniques yield Young's modulus (E(a)) and C(11); three-point bending tests yield Young's modulus (E) and sigma(max). The relationships between strength, elasticity and density and their anatomical distributions were investigated for 36 human femur samples. (i) A marginal negative correlation was obtained for E(a) and C(11) (R=-0.21; p=0.08); (ii) sigma(max) was significantly correlated to E and E(a) (R approximately 0.5; p<0.005) but not to C(11) (p>0.2); (iii) density was not correlated with E and moderately with strength (R=0.38; p<0.3). Small density variability (+/-30 kg m(-3)) may partly explain the results. The techniques presented are suited to a systematic characterization of bone samples.

Function, disability, and health-related quality of life after allograft-prosthesis composite reconstructions of the proximal femur.

BACKGROUND: Factors affecting function, disability and health-related quality of life after allograft-prosthesis composite reconstructions have been poorly studied. METHODS: Retrospective study of eighteen patients who underwent reconstruction with proximal femoral allograft-prosthesis composites and answered questionnaires to assess hip function (Postel and Merle d'Aubigné, self-reported Harris Hip Score), disability (Toronto Extremity Salvage Score), and health-related quality of life (SF-36). RESULTS: The median Toronto Extremity Salvage Score was 76 (IQR: 48-85), the median self-reported Harris Hip Score was 90 (IQR: 48-95) and the median Postel and Merle d'Aubigné score was 17 (IQR: 12-17). Older age, female gender, and presentation with a pathologic fracture were associated with increased disability and poorest function. The median Physical Component Summary score was 44 (IQR: 39-45) and Mental Component Summary scores were 49 (IQR: 46-56). Male gender and recurrence of disease were associated with poorer health-related quality of life. There was a high degree of correlation between function, disability scores and Physical Component Summary score. CONCLUSIONS: Patients' characteristics at presentation such as age, gender, and occurrence of a pathologic fracture play an important role in determining disability, function, and health-related quality of life after allograft-prosthesis composite reconstruction of the proximal femur.

Structural allograft and cemented long-stem prosthesis for complex revision hip arthroplasty: use of a trochanteric claw plate improves final hip function.

UNLABELLED: Extensive bone loss raises formidable challenges in total hip revision. The aim of this study was to evaluate the results of reconstruction using a cemented long-stem and massive structural allograft implanted in a filleted proximal femur, with and without the use of a trochanteric claw plate. Between 1988 and 2001, 44 revisions were performed in 42 patients. After a transtrochanteric approach, the femur was cut longitudinally. A long, cemented Charnley-type prosthesis was used, and flaps of the residual femur were folded around the allograft. The greater trochanter was reinserted with wires in all revisions, and with both wires and a claw plate in 20 revisions. Mean follow-up was 7.15 years (range: 3-16); seven patients, died and four were lost to follow-up. The follow-up exceeded five years in 34 patients. The major complication was nonunion of the greater trochanter, which occurred in 25 cases. Six dislocations, one recurrence of infection, two mechanical loosening, and two fractures below the stem were also recorded. The use of a trochanteric claw plate significantly improved final hip stability, even in patients with nonunion. Femoral reconstruction with a massive structural allograft is reliable and long-lived, and serious complications and long-term resorption are uncommon. The use of a trochanteric claw plate significantly improves final hip stability. LEVEL OF EVIDENCE: Therapeutic study, level III (retrospective comparative study).

Surgical treatment of pigmented villonodular synovitis of the hip.

BACKGROUND: Pigmented villonodular synovitis of the hip is a rare disease. Synovectomy is generally accepted as the only surgical treatment for the disorder, but there have been few studies with a sufficient sample size and duration of follow-up to allow the evaluation of long-term outcomes. The aim of this study was to determine the long-term outcome of the treatment in sixteen patients. METHODS: Sixteen patients (nine men and seven women), with a mean age of 35.5 years at the time of surgery, were treated between 1970 and 1996. Complete synovectomy was performed in all patients; in addition, three had a cup arthroplasty, four had a total hip arthroplasty, and one had a monopolar arthroplasty. Clinical and radiographic outcomes were evaluated retrospectively at a mean of 16.7 years postoperatively. Only one patient was followed for less than eight years. RESULTS: Nine patients needed repeat surgery, but only one had recurrent synovitis, as detected with pathological examination fourteen years after treatment with synovectomy and cup arthroplasty. Secondary osteoarthritis developed in all eight patients who had been treated with synovectomy alone, and four of them required a total hip arthroplasty within the follow-up period. CONCLUSIONS: These results support earlier data indicating that osteoarthritis consistently develops in patients with pigmented villonodular synovitis of the hip. Complete synovectomy seems to be effective in preventing recurrence of the synovitis, but it does not appear to prevent the development of secondary osteoarthritis.

Positive effect of patient education for hip surgery: a randomized trial.

The current trial compared patient education before total hip arthroplasty with the usual verbal information. A randomized, controlled 24-month prospective single-center study was done. Patients scheduled for a first elective total hip arthroplasty for primary hip osteoarthritis were enrolled. All patients were given the usual information and an information leaflet and completed a self-evaluation questionnaire (Spielberger State and Trait Anxiety Inventory). The patients were assigned randomly to two groups: Group 1 attended a collective multidisciplinary information session 2 to 6 weeks before surgery and the control group did not attend. All patients completed another State Anxiety Inventory just before surgery and then 1 and 7 days after surgery. One hundred patients were randomized. Forty-eight attended the collective information session. Patients receiving education were significantly less anxious just before surgery than patients in the control group, in linear regression after adjustment for gender, trait and state anxiety at baseline, depression score, and health assessment questionnaire score. They experienced less pain before surgery and were able to stand sooner. However, the trend toward lower anxiety scores was not statistically significant after surgery. Patient education decreases preoperative anxiety and pain in patients having hip surgery.