Research Article

A Trend for Increased Risk of Revision Surgery due to Deep Infection following Fast-Track Hip Arthroplasty

Table 2

Rates of infection-related revision surgery by patient demographic and clinical characteristics ( = 4,406).

CharacteristicInfection-related revision surgery within 3 months?Statistics and effect sizes
No
= 4,381 (99.43%)
Yes
  (0.57%)

Gender, ; phi = 0.040
 Male ( = 1,246)1,233 (98.96%)13 (1.04%)
 Female ( = 3,160)3,148 (99.62%)12 (0.38%)
Age in years ( = 4,406)69.6 (10.3)71.7 (9.6), ;
Age group ( = 4,406), ; phi = 0.015
 ≤70 years ( = 2,195)2,185 (99.54%)10 (0.46%)
 >70 years ( = 2,208)2,193 (99.32%)15 (0.68%)
Body mass index ( = 2,831)26.2 (4.4)25.9 (4.7), ;
ASA score ( = 3,713), ; phi = 0.013
 () Healthy ( = 608) 604 (99.34%) 4 (0.66%)
 () Mild disease ( = 2,543)2,528 (99.41%)15 (0.59%)
 () Severe disease () 555 (99.11%) 5 (0.89%)
 () Life-threatening disease () 2 (100%) 0 (0%)
Surgery duration (hrs : mins; = 3,713)1 : 08 (0 : 17)1 : 09 (0 : 16), ;
Length of hospital stay (days)7.66 (2.80)7.96 (3.32), ,
Surgery type, ; phi = 0.035
 Standard THA ( = 4,167)4,146 (99.50%)21 (0.50%)
 Fast-track THA ( = 239) 235 (98.33%)4 (1.67%)
Prosthesis type ( = 4,178)
 Standard THA ( = 4,167), ; phi = 0.004
  Cemented ( = 2,296)2,285 (99.52%)11 (0.48%)
  Uncemented ( = 1,871)1,861 (99.47%)10 (0.53%)
 Fast-track THA ()Fisher’s Exact Test, , phi = 0.086
  Cemented ()72 (100%)0 (0%)
  Uncemented ()163 (97.6%)4 (2.4%)

Note. THA = total hip arthroplasty. While some of the comparisons are statistically significant, the effect sizes are quite small.
Body mass index was not routinely recorded prior to January 2007, and ASA classification and surgery duration were not routinely recorded prior to April 2004, and thus reduced sample sizes were available for these variables. ASA scores () and () were combined for analysis.
Two outliers were excluded from the length of stay analysis, one patient was hospitalized 63 days with an infection developing on day 12 and the other was hospitalized for 95 days without infection.
Because prosthesis type was confounded with surgery type (uncemented prostheses were more common among fast-track surgeries than among standard surgeries), the analysis of prosthesis type was conducted separately for each surgery type.
Fisher’s Exact Test was used due to the low expected cell frequencies in this analysis.