Table 3.

Reoperation risk for surgeon experience level: all fracture types/all operation methods

Operation method	< 3 years’ experience		> 3 years’ experience		RR a	95% CI	p-value b
	Total	Reop. (%)	Total	Reop. (%)
All fracture types:
All operation methods	5,821	403 (6.9)	25,124	1,411 (5.6)	1.2	1.1–1.4	0.001
Hemiarthroplasty	1045	53 (5.1)	11,619	470 (4.0)	1.3	0.95–1.7	0.1
Screw osteosynthesis	1,379	194 (14)	3,209	415 (13)	1.1	0.94–1.3	0.2
Hip compression screw	2,619	115 (4.4)	6,257	325 (5.2)	0.87	0.70–1.1	0.2
Short intramedullary nail	508	21 (4.1)	2,329	100 (4.3)	0.94	0.59–1.5	0.8
Long intramedullary nail	168	9 (5.4)	1,343	67 (5.0)	1.04	0.52–2.1	0.9
Undisplaced FNFs:
All operation methods	1,267	141 (11)	2,953	296 (10)	1.1	0.92–1.4	0.2
Screw osteosynthesis	1,178	139 (12)	2,519	273(11)	1.1	0.91–1.4	0.3
Hemiprosthesis	47	0 (0)	334	16 (4.8)	c	c	c
Displaced FNFs:
All operation methods	1,206	109 (9.0)	11,892	608 (5.1)	1.7	1.4–2.1	< 0.001
Screw osteosynthesis	198	54 (27)	675	137 (20)	1.4	1.0–1.9	0.04
Hemiprosthesis	982	52(5.3)	11,046	442 (4.0)	1.3	0.99–1.8	0.06
Trochanteric 2-fragmented fractures:
All operation methods	1,581	41 (2.6)	3,496	93 (2.7)	0.97	0.67–1.4	0.9
Hip compression screw	1,278	30 (2.3)	2,482	62 (2.5)	0.95	0.61–1.5	0.8
Intramedullary nail	271	8 (3.0)	948	28 (3.0)	0.95	0.43–2.1	0.9
Trochanteric multifragmented fractures:
All operation methods	1,229	65 (5.3)	3,771	198 (5.3)	1.0	0.77–1.4	0.9
Hip compression screw	949	53 (5.6)	2,394	127 (5.3)	1.1	0.80–1.5	0.6
Intramedullary nail	264	11 (4.2)	1,290	65 (5.0)	0.81	0.43–1.5	0.5
Intertrochanteric and subtrochanteric fractures:
All operation methods	287	24 (8.4)	2,016	127 (6.3)	1.3	0.87–2.1	0.2
Hip compression screw	173	17 (9.8)	767	68 (8.9)	1.1	0.62–1.8	0.8
Intramedullary nail	109	7 (6.4)	1,219	57 (4.8)	1.5	0.67–3.3	0.3

FNF: femoral neck fracture.

^aRR relative risk for reoperation. Surgeon’s experience >3 years set to 1.

^bCox regression analyses with adjustments for age group, gender, and ASA class.

^cRR could not be calculated due to no reoperations.