Table 2.
Results for all instrumentation sets
| Variables | CVR | CVS | PSR | PSS | P value | ||
| CVR versus PSR | CVR versus CVS | PSR versus PSS | |||||
| IDT* | 00:02:29 (00:04:58) | 00:03:54 (00:06:49) | 00:01:14 (00:01:56) | 00:07:50 (00:19:52) | 0.006† | 0.433† | 0.021‡ |
| IAT* | 00:09:22 (00:13:31) | 00:12:35 (00:06:59) | 00:07:25 (00:12:31) | 00:15:01 (00:21:03) | 0.133‡ | 0.067‡ | 0.013‡ |
| IST* | 00:11:52 (00:17:55) | 00:16:30 (00:10:41) | 00:08:49 (00:23:26) | 00:22:51 (00:36:29) | 0.022† | 0.025‡ | 0.0005† |
| SST* | 00:30:10 (00:36:44) | 00:34:51 (00:28:25) | 00:25:43 (00:19:30) | 00:31:54 (00:25:05) | 0.054‡ | 0.258‡ | 0.017‡ |
| PT* | 01:03:10 (00:38:02) | 01:05:28 (00:23:22) | 00:58:10 (00:23:04) | 00:58:46 (00:19:35) | 0.054‡ | 0.57‡ | 0.814‡ |
| ICT* | 00:05:13 (00:09:14) | 00:02:39 (00:03:35) | 00:02:50 (00:04:18) | 00:02:39 (00:05:02) | 0.002† | 0.025† | 0.754‡ |
| IPT* | 00:03:37 (00:06:00) | 00:02:24 (00:05:57) | 00:03:14 (00:07:26) | 00:01:39 (00:03:05) | 0.18† | 0.109‡ | 0.041† |
| ICuT* | 00:09:15 (00:15:05) | 00:05:03 (00:09:32) | 00:06:04 (00:10:11) | 00:04:18 (00:06:22) | 0.004‡ | 0.015‡ | 0.117‡ |
| TIT* | 01:25:12 (00:28:12) | 01:23:26 (00:48:03) | 01:15:48 (00:41:34) | 01:17:59 (00:23:28) | 0.004‡ | 0.199† | 0.585‡ |
| IST* | 74:16:29 (216:19:45) | N/A | 85:11:48 (451:58:40) | N/A | 0.536† | N/A | N/A |
| nTrays | 3.74 (2) | N/A | 2.89 (1) | N/A | <0.0001† | N/A | N/A |
| Missing equipment | 1.48 (5) | N/A | 0.22 (1) | N/A | 0.009† | N/A | N/A |
| Blood loss (mL) | 898.87 (1135.83) | 936.82 (502.90) | 785.24 (1784.97) | 811.96 (1112.08) | 0.358‡ | 0.773‡ | 0.888‡ |
| OKS (preoperative) | 20.55 (29) | 25 (11) | 20.53 (25) | 24.38 (14) | 0.994‡ | 0.143‡ | 0.183‡ |
| OKS (6 weeks) | 32.44 (25) | 30.33 (7) | 33.07 (20) | 25.8 (18) | 0.782‡ | 0.608‡ | 0.031‡ |
| OKS (1 year) | 40.87 (17) | 35.67 (22) | 36.85 (19) | 36.67 (28) | 0.05‡ | 0.205‡ | 0.544† |
| Length of hospital stay | 5 (11) | 5.17 (5) | 4.56 (7) | 4.13 (3) | 0.988† | 0.507† | 0.862† |
Data expressed as mean (range).
nTrays denotes number of conventional instrument trays used per surgery.
Bold values denote statistical significance.
*Data presented in the format of (hours):(minutes):(seconds).
†Mann-Whitney test.
‡Independent samples t-test.
CVR, conventional/reusable; CVS, conventional/single use; IAT, instrument assembly time=scrub nurse started decanting first tray—scrub nurse finished decanting instruments; ICT, instrument count time=scrub nurse started counting instruments—scrub nurse finished counting instruments; ICuT, instrument clean-up time=scrub nurse started counting instruments—instrument trays closed and taken to sluice room; IDT, instrument decant time=instrument trays entered operating room—scrub nurse opened first tray; IPT, instrument packing time=scrub nurse started packing instruments—instrument trays closed and taken to sluice room; IST, instrument sterilisation time=time instruments were picked up by sterilisation unit (SU)—time instruments were dispatched from SU; IST, instrument set-up time=scrub nurse started assembling instruments—scrub nurse finished assembling instruments; N/A, not applicable; OKS, Oxford Knee Score; PSR, patient specific/reusable; PSS, patient specific/single use; PT, procedure time=knife to skin—closure with last clip; SST, surgical set-up time=scrub nurse performs first task—knife to skin; TIT, total instrument time=scrub nurse opened first tray—instrument trays closed and taken to sluice room.