Since component wear of t
he prost
hetic metal–polyet
hylene bearing is directly related to t
he level of patient activity, it would be logical, for patients wit
h a total
hip art
hroplasty, to advise against long-term participation in activities wit
h repeated movements T
he purpose of t
his prospective randomized study was to compare t
he type, intensity and frequency of sports activities performed after resurfacing
hip art
hroplasty (RH) or total
hip art
hroplasty (THA) using a metal-on-metal bearing.<
h4 class="
h4">Material and met
hods
h3>
This study concerned 205 hips, including 152 with a unilateral hip arthroplasty (71 THA and 81 RH). Three clinical scores were used: an overall activity score, the University of California, Los Angeles (UCLA) score and the Western Ontario McMaster Osteoarthritis Index (WOMAC) score, as well as patient satisfaction, return to sports activities (using a visual analog scale [VAS]) and frequency of factors limiting activity. Patients completed a questionnaire to determine the type, intensity and frequency of sports activities practiced pre- and postoperatively.<h4 class="h4">Resultsh3>
The mean overall activity score immediately before surgery was not statistically different between the two groups (p = 0.111). One year after surgery, the score was 17.9 in the RH group and 12.4 in the THA group (p = 0.001). At last follow-up, the mean WOMAC score was 8.1 (range 0–73, S.D. 13.1) in the RH group and 9.8 (range 0–41, S.D. 10.9) in the THA group (p = 0.409). The mean UCLA score was 7.17 in the RH goup (range 2–10, S.D. 1.90) and 6.75 in the THA group (range 2–10, S.D. 1.71) (p = 0.174). The mean satisfaction with return to sports activities as assessed on the VAS was 7.78 in the RH group and 7.43 in the THA group (p = 0.313).<h4 class="h4">Discusssionh3>
The results of this study demonstrate that the degree and intensity of postoperative sports activities are greater in the RH group than in the THA group, although this difference was less pronounced than expected. The excellent joint stability after RH (big head effect) could be one of the main factors favoring a high activity level compared to conventional THA, by limiting the episodes of dislocation and increasing the suction effect between the joint components. It is nevertheless difficult to ascertain the long-term effect of intense sports activity on the fixation of osteo-integrated implants (cups) and cemented components (femoral stem).