Treatment of hip instability.

Instability after total hip arthroplasty is a major source of patient morbidity, second only to aseptic loosening. Certain patient groups have been identified as having a greater risk of instability, including patients undergoing revision arthroplasty as early or late treatment for proximal femoral fractures.

Preoperative planning to prevent instability in total knee arthroplasty.

Several factors can lead to persistent instability after total knee arthroplasty, including bone and soft tissue loss, preexisting ligamentous laxity, and poor operative technique. Achieving stability should not be equated with making the knee extremely tight, without any natural laxity.

Conversion of hip arthrodesis to total hip arthroplasty.

With the predictably good outcome now found with THA, hip arthrodesis has limited indications today. The procedure still has a role in the case of the young, heavy demand male with an isolated arthritic hip condition, and developments such as the Cobra head plate have considerably improved success rates. However, a long-term hip arthrodesis can have profound effects on a patient's daily function and activities of daily living. In addition, gait pattern is considerably affected as well as other joints such as the lower back, ipsilateral knee, and contralateral hip. Many patients with a hip arthrodesis will eventually require a takedown of the fused hip and conversion to a THA. The primary indications include fusion in malposition, pseudarthrosis, or severe pain in other joints. The surgeon undertaking such a task must be familiar with the arthrodesis techniques that have been used in the past as well as the equipment that may be required to extract the fixation hardware. Clinical assessment with particular attention to leg-length discrepancy, position of the arthrodesis, and function of the abductors is of paramount importance. The surgeon must carefully review preoperative radiographs to plan the procedure. The surgeon must also be aware of the presence of pathology in other joints. After takedown of a hip arthrodesis and conversion to a THA, patients cannot expect the result to equal the success rates of primary THA. Patients generally can expect an improvement in function and mobility. Back pain and ipsilateral knee pain are usually improved postoperatively, but the effect on contralateral hip pain is less predictable. Many patients will continue to show a positive Trendelenburg sign, but further improvement in strength of the hip abductors can be expected with time. Leg-length discrepancy is generally improved substantially after THA. However, a substantial number of patients will require a walking aid postoperatively. Overall, the risk of complications and the rates of revision after converting an arthrodesed hip to a THA are quite high. The procedure can be complex. Consideration should be given to referring these patients to a specialized center under the care of an experienced arthroplasty surgeon if preoperative planning suggests that the conversion will not be straightforward.

The impact of Magic Johnson's HIV serostatus disclosure on unmarried college students' HIV knowledge, attitudes, risk perception, and sexual behavior.

Unmarried heterosexual college students' HIV knowledge, attitudes, risk perception, and sexual behavior were assessed before and after "Magic" Johnson revealed his HIV-positive serostatus. Students examined after the disclosure showed a small, though statistically significant, increase in scores on HIV knowledge. Analyses did not reveal any other differences between the pre- and postdisclosure samples. Several differences between men's and women's scores were found, however. In addition, participants in both groups demonstrated generally positive attitudes toward HIV and people with HIV disease; rated their risk of future HIV infection as none to minimal; and reported frequently engaging in vaginal, oral, and anal intercourse without the use of condoms. These results suggest that Magic's disclosure did not significantly affect these students' attitudes, risk perception, or sexual behavior and that such students continue to engage in behaviors that may put them at risk for HIV infection.