During the data extraction period from October 15, 2015, to December 31, 2019, 10989 orthopedic surgical cases were queried from the data warehouses of the participating hospitals. We excluded 1071 patients—444 patients due to the unavailability of surgical procedure data and 627 patients because they belonged to procedure groups with fewer than 20 patients. This resulted in 9918 patients from 44 intervention groups for the analysis (Additional file 1: overview of procedures, pain outcomes and admission days).
Figure 1. Patient flow diagram
Half of the patients were from OLVG Hospital (52%, 5201), followed by Maasstad Hospital (35%, 3446) and UMCU (13%, 1271) (Fig. 1, patient flow diagram). Among the patients, 60% (6319) were female, and the median age was 63 years (SD 16). Furthermore, 53% (5598) of the patients were classified as American Society of Anaesthesiologists Physical Status (ASA) II. General anaesthesia was recorded in 40% (4190) of the patients, while spinal anaesthesia was recorded in 41% (4357) of the patients see Table 1 Patient and Anaesthesia Characteristics.
Table 1
Patient and Anaesthesia Characteristics
Age, mean (SD) | 63 (16) |
Gender female, N (%) | 5968 (60%) |
ASA1 (healthy person), N (%) ASA2 (mild systemic disease), N (%) ASA3 (severe systemic disease), N (%) ASA4 (severe systemic disease that is a constant threat), N (%) | 2016 (20%) 5370 (54%) 2152 (22%) 70 (1%) |
General anaesthesia, N (%) General anaesthesia and local regional, N (%) General anaesthesia and epidural, N (%) Local regional, N (%) Spinal and local regional, N (%) Spinal (with or without sedation), N (%) | 3827 (39%) 1368 (14%) 48 (0.5%) 194 (2%) 128 (1%) 4323 (44%) |
*The following types of anaesthesia (combinations): spinal anaesthesia and epidural analgesia, procedural sedation and analgesia are not listed in the table due to low (< 20) absolute numbers.
Primary outcome
During the first postoperative period, ranging from 3 to 24 hours, the highest pain score was recorded in 97% (9606) of the patients, with a median NRS score of 4 (IQR 3).
During the second postoperative period, ranging from 24 to 48 hours, the highest pain score was recorded in 82% (8153) of the patients, with a median NRS score for pain of 4 (IQR 3). During the third postoperative period, which ranged from 48 to 72 hours, the highest pain score was recorded in 51% (5.014) of the patients, with a median NRS score for pain of 3 (IQR 2). Among the procedures with the highest pain scores during the three postoperative periods, open reduction and implantation of the device into the humerus (e.g., plate fixation) was at the top of the ranking, with a median NRS for pain of 6 (IQR 3) in the 3- to 48-hour postoperative period and a median NRS for pain of 5 (IQR 3) in the 48- to 72-hour postoperative period. Additionally, open shoulder joint procedures, open ankle procedures and open fusion of the lumbar spine were among the top ten procedures with the highest median pain scores (Figs. 2, 3 and 4: Orthopaedic procedures ranked from the highest median to lowest median NRS for pain, 3 to 24, 24 to 48 and 48 to 78 hours after surgery, respectively). A stratified overview of postoperative pain related to the anaesthesia technique (e.g., general anaesthesia compared to general anaesthesia combined with local regional technique) is included in the Additional files 3 to 8. The results of this stratified analysis showed that open reduction and implantation of devices into the humerus (e.g., plate fixation), open shoulder joint procedures, and open ankle procedures were among the top ten procedures associated with high median pain, with only small differences in the median NRS for postoperative pain between the different anaesthesia techniques.
Figure 2: Orthopaedic procedures with the highest to lowest median NRS scores for pain 3 to 24 hours after surgery
Figure 3: Orthopaedic procedures with the highest to lowest median NRS scores for pain 24 to 48 hours after surgery
Figure 4: Orthopaedic procedures with the highest to lowest median NRS scores for pain, 48 to 72 hours after surgery
Secondary outcome
Severe pain (NRS score equal to or greater than 8) was recorded in 6% (641) of the patients during the initial 3 to 24 hours after surgery. At 24 to 48 hours and 48 to 72 hours after surgery, 5% (498) and 2% (161) of the patients, respectively, experienced severe pain (Table 2). Overall pain, median highest recorded pain score and severe pain).
Table 2
Overall pain, median highest recorded pain score and severe pain
Postoperative period | Recordings, N (%) | Median highest NRS (IQR) | Severe pain (NRS 8 to 10), N (%) |
3 to 24 hours | 9606 (97%) | 4 (3) | 641 (6%) |
24 to 48 hours | 8567 (82%) | 4 (3) | 498 (5%) |
48 to 72 hours | 5014 (51%) | 3 (2) | 161 (2%) |