Increased Femoral Component Size Options Improves Manipulation Rate in Females and Knee Society Clinical Scores in Males.

INTRODUCTION: The gender-specific total knee arthroplasty (TKA) debate focuses on differences in distal femoral mediolateral to anteroposterior aspect ratio between males and females. However, randomized studies have been unable to demonstrate significant differences in outcomes utilizing gender-specific implants. No studies have examined the effect of intermediate femoral component sizes on outcome. We compared outcomes before and after intermediate sizing availability. MATERIALS AND METHODS: We identified 331 patients (413 knees) who underwent primary TKA between 2003 and 2004 with a single complete knee system. There were 121 males and 210 females. Three intermediate femoral sizes were added in March 2004 to the six initial options. Patients before March 2004 were assigned to group 1 (n=178), and after to group 2 (n=235). RESULTS: Follow-up averaged 8.5 years. Preoperative demographics and clinical scores were similar between groups. Knee Society (KS) clinical and functional scores improved in females in both groups, but there was no significant difference. Male patients in group 2 had a significant improvement in KS clinical scores compared to male patients in group 1 (group 1: 33.9, group 2: 41.1; p=0.01). Females in group 2 had significantly less need for manipulation, 1.9%, versus females in group 1, 8.7% (p=0.01). MUA rates were similar for men between groups. Overall, there were 19 revisions (4.6%) with no differences between groups or by genders. Once intermediate sizes were available, they were used in 48% of females and 13% of males. The average femoral component size for females in group 1 was 65 mm and decreased in group 2 to 62.5 mm. The average size of femoral components in males was 70 mm in both groups. CONCLUSIONS: Availability of intermediate size femoral component sizes was associated with a lower rate of manipulation in female patients. Greater KS clinical score improvement was observed in men after availability of additional femoral sizes.

Molded Articulating Cement Spacers for Two-Stage Treatment of Infected THA and TKA.

Articulating spacers have been reported to promote greater range of motion, preserve bone, facilitate reimplantation, and enhance functional recovery, as well as provide a vehicle for local administration of antibiotics. The purpose of this study was to review patients treated at our center for deep hip and knee infection with two-staged exchange using molded, articulating antibiotic-laden cement spacers following debridement. A query of our practice registry revealed 84 patients (84 hips) and 177 patients (182 knees) diagnosed with deep infection after THA and TKA respectively, and treated with two-staged exchange using molded articulating cement spacers. Mean follow-up was three years in both groups. Second-stage reimplantation was accomplished in 81 hips, and reinfection occurred in 11 of those (14%), with three responding to a single irrigation and debridement (I&D) procedure, one undergoing two I&Ds, one chronically infected diabetic patient treated with one-stage exchange to cemented components, five patients undergoing multiple procedures including repeat two-staged exchange in four, and one patient declining further treatment. Harris hip score at most recent averaged 69. Second-stage reimplantation was accomplished in 177 knees, and reinfection occurred in 28 of those (16%). Range of motion improved from 93° preoperatively to 101° at most recent, Knee Society clinical scores improved from 46 to 76, and functional scores improved from 32 to 47. Treatment of deep infection after total joint arthroplasty using molded, articulating antibiotic-laden acrylic cement spacers was successful in eradicating infection in 83% of hips (70 of 84) and 82% of knees (149 of 182) at an average of three years after reimplantation.

The current trends for lateral unicondylar knee arthroplasty.

Unicompartmental osteoarthritis of the knee is a relatively common disease that is seen in 40% of the population. Although disease isolated to the medial compartment of the knee is more common, isolated lateral disease also frequently exists (25% vs 10%). However, surgeons perform medial unicondylar knee replacement at a ratio of 10:1 when compared with lateral unicondylar knee replacement. This may be attributed to lack of familiarity or the increased difficulty of the procedure. Recent literature suggests that with proper patient selection, surgical technique, and implant choice, early survivorship ranges from 95% to 99%.