Desmond M. Dall

Surgical management of intra- and postoperative fractures of the femur about the tip of the stem in total hip arthroplasty.

Six techniques for the surgical management of fractures of the femur about the tip of the stem of a total hip arthroplasty were evaluated. Seven embalmed human femurs were prepared to receive the correct-size femoral component of a total hip system. A transverse osteotomy was performed at the level of the tip of the stem. Stability and strength of each reconstruction were tested on each femur under semidynamic loading conditions. This study showed that cementless revision to a long-stem prosthesis does not provide adequate stability. The highest strength and stability were achieved by supplementing the long-stem conversion with allograft struts and cable cerclage. Good results were obtained by lateral compression plating with unicortical screws proximally. Failure was due to pull-out of the proximal screws.

Survivorship of cemented total hip arthroplasty in patients 50 years of age or younger.

One hundred fifty-six Charnley low-friction arthroplasties performed in patients 50 years of age or younger are reviewed. Excluding sepsis, survivorship analysis showed a 12% probability of mechanical failure at 10 years. The detailed clinical and radiological results of 130 hips with a 3-16-year follow-up period are presented. Revision surgery was required in 14 hips (10.8%), for the following reasons: sepsis (2.3%), loose sockets (2.3%), loose stems (5.4%), and stem fracture (0.8%). Evidence of radiological loosening indicative of pending failure was present in 14 hips (12.0%). At 10 years the predicted failure rate of the surviving hips was 12%.

811 Charnley hips followed for 3–17 years

10-12 year survivorship analysis of 811 primary or conversion Charnley arthroplasties showed 89 percent probability of mechanical survival (revision excluding sepsis). The mechanical failure rate was 7 percent, and more stems required revision than sockets. The anterio-posterior radiographs of 630 unrevised hips, with a minimum 3-year follow-up, were evaluated using the CART system of terminology. Cement-bone radiolucency was present in 50 percent of sockets and 18 percent of stems. Substantial loosening was present in 6 percent with 94 percent probability of survival at 10-12 years.

Charnley Low-friction Arthroplasty of the Hip: Long-term Results in South Africa

Long-term results of 98 Charnley low-friction arthroplasties were followed for a period of a mean of 12 years; 98 of 470 operations qualified for this strict long-term study, 78 (79.6%) with excellent results. If excessive medialization of the cup is avoided, socket complications appear to be minimal (4%). The majority of femoral component failures resulted from femoral stem breakage. Only four hips (4.08%) developed loosening of the femoral stem.

A Biomechanical and Clinical Review: The Dall-Miles Cable System

The Dall-Miles Cable System (Stryker Orthopaedics, Mahwah, NJ, USA) has been in clinical use since 1983. It was initially developed for reattachment of the greater trochanter in low-friction arthroplasty of the hip. The clinical uses have evolved considerably over the years. It is now used largely as a cerclage system, particularly in revision total hip arthroplasty (THA). A biomechanical review includes a comparison of the mechanical strength of different cerclage systems. The strength of wire and cable fastening systems is examined. The importance of fatigue strength is presented and discussed. The relationship between tensile strength and fatigue performance is analyzed, and comparative data are presented. A review of the clinical use of cable cerclage is presented, including fixation of the greater trochanter in various trochanteric osteotomy approaches to the hip, the use of the system in revision THA, femoral allografts, its use in fixation of periprosthetic fractures of the femur in THA, and the use of the system in augmentation of other forms of fracture fixation, emphasizing its value in the treatment of fractures in soft bone.