. 2021 Jul 30;12(6):1282–1296. doi: 10.1177/21925682211034500

Table 3.

Primary and Secondary Outcomes.

Title	Definition of PJK used in study	Definition of PJF used in study	Group	PJK	RR	PJF incidence	Clinical outcome	Complications
Tether (tether only (TO) + tether and crosslink (TC))
Alluri et al 2020²⁸	Postoperative PJA ≥ 20°	PJK necessitating revision surgery	PS	32%	18%	_NR	ODI*,	All 62%
Alluri et al 2020²⁸	Postoperative PJA ≥ 20°	PJK necessitating revision surgery	TC	33%	0%	_NR	ODI*,	All 49%
Buell et al 2018²⁹	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	Mechanical failure at UIV or just above and/or proximal junctional posterior discoligamentous failure	PS	45%*	5%	5%	_NR	_NR
			TO	34%	9%	9%	_NR	“None related to tether”
			TC	18%*	4%	4%	_NR	“None related to tether”
Buell et al 2019³⁰	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	None, although revision surgery for PJK is mentioned	PS	55%	6%	_NR	_NR	_NR
Buell et al 2019³⁰	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	None, although revision surgery for PJK is mentioned	TO + TC	32%	5%	_NR	_NR	“None related to tether”
Iyer et al 2020³¹	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	PJF not reported	PS	29%	5%	_NR	_NR	_NR
Iyer et al 2020³¹	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	PJF not reported	TO	27%	0%	_NR	_NR	_NR
Line et al 2020³²	PJK not reported	PJA ≥ 28.0° and change PJA ≥ 21.6° OR Upper thoracic PJF: proximal junctional anterolisthesis ≥8 mm and change in proximal junctional anterolisthesis ≥8 mm Lower thoracic PJF: proximal junctional anterolisthesis ≥3 mm and change in proximal junctional anterolisthesis ≥3mm	PS	_NR	_NR	20%	_NR	_NR
Line et al 2020³²	PJK not reported		TO	_NR	_NR	16%	_NR	_NR
Safaee et al 2018³³	PJA change ≥ 10° postoperative compared to preoperative value	PJK requiring surgical revision	PS	_NR	18%*	_NR	_NR	_NR
Safaee et al 2018³³		PJK requiring surgical revision	TO	16%	4%*	_NR	_NR	_NR
Rodriguez-Fontan et al³⁴	PJA change ≥ 10° than pre-op	Symptomatic PJK with or without instrumentation failure and or vertebral fracture at UIV+2	PS	#38%	_NR	#38%	_NR	_NR
Rodriguez-Fontan et al³⁴	PJA change ≥ 10° than pre-op		TO	#15%	_NR	#15%	_NR	_NR
2 level prophylactic vertebroplasty (2-PVP)
Ghobrial et al 2017³⁵	Postoperative PJA ≥ 10°	Revision surgery as a consequence of PJK (Proximal extension of fusion), or refractory pain	PS	36%*	13%*	16%	_NR	Major: 16†, Minor: 6†
Ghobrial et al 2017³⁵	Postoperative PJA ≥ 10°		2-PVP	24%*	0%*	0%	_NR	Major: 16†, Minor: 6†
Han et al 2019³⁶	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	Bony failure, ligamentous failure, instrument failure (implant breakage and pullout of UIV fixation).	PS	46%	14%	32%	_NR	Major 7, Minor 2
Han et al 2019³⁶	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op		2-PVP	46%	4%	39%	_NR	Major 1, Minor 2
Hart et al 2008³⁷	PJK not reported	Proximal junctional acute collapse requiring extension of instrumented fusion	PS	_NR	_NR	15%	_NR	_NR
Hart et al 2008³⁷	PJK not reported		2-PVP / 3-PVP	_NR	_NR	0	_NR	“None related to 2-PVP”
Line et al 2020³²	(see Line et al 2020 above)	(see Line et al 2020 above)	PS	_NR	_NR	20%	_NR	_NR
Line et al 2020³²	(see Line et al 2020 above)	(see Line et al 2020 above)	2-PVP	_NR	_NR	12%	_NR	_NR
Martin et al 2013³⁸	PJA change ≥ 10° postoperative compared to preoperative value	acute proximal junctional fracture/fixation failure or substantial PJK that required revision or extension of the fusion proximally	2-PVP	8%	5%	5%	‡ODI, ‡SF-36, ‡SRS-24	Major 6, Minor 13
Raman et al 2017³⁹	PJA change ≥ 10° postoperative compared to preoperative value	Proximal junctional fracture, fixation failure or kyphosis requiring extension of fusion within 6 months of surgery	2-PVP	28%	5%	5%	_NR	Major 21, Minor 19
Theologis and Burch 2015⁴⁰	PJK not reported	Proximal junctional fracture	PS	_NR	_NR	21%	ODI*, ‡VAS leg pain	_NR
			PVP	_NR	_NR	22%	‡ODI, ‡VAS back pain, ‡VAS leg pain*	_NR
			2-PVP	_NR	_NR	5%	‡ODI, ‡EQ-5D, ‡EQ-Vas, ‡VAS back pain, ‡VAS leg pain*	_NR
Transverse process hooks (TPH)
Hassanzadeh et al 2013⁴¹	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	PJF not reported	PS	30%*	7%*	_NR	ODI, ‡SRS-22	Major 7, Minor 15
Hassanzadeh et al 2013⁴¹	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	PJF not reported	TPH	0%*	0%*	_NR	ODI, ‡SRS-22	Major 3, Minor 13
Line et al 2020³²	(see Line et al 2020 above)	(see Line et al 2020 above)	PS	_NR	_NR	20%	_NR	_NR
Line et al 2020³²	(see Line et al 2020 above)	(see Line et al 2020 above)	TPH	_NR	_NR	7%	_NR	_NR
Matsumura et al 2018⁴²	PJK not reported	Fracture at UIV (Fx) or PJA > 20° (PJA)	PS	_NR	_NR	27% (27%PJFx, 0% PJA > 20°)	_NR	_NR
Matsumura et al 2018⁴²	PJK not reported	Fracture at UIV (Fx) or PJA > 20° (PJA)	TPH	_NR	_NR	18% (12% PJFx, 6% PJA > 20°)	_NR	_NR
Flexible rods (FR)
Lee et al 2019⁴³	Postoperative PJA ≥ 10° and ≥ 10° change than pre-op	Classified as progressive PJK or PJFx	PS	53%*	_NR	15%	_NR	_NR
			PS	53%*	_NR	38%	_NR	_NR
			FR	10%*	_NR	0	_NR	_NR
			FR	10%*	_NR	0%	_NR	_NR
Multilevel stabilization screws (MLSS)
Sandquist et al 2015⁴⁴	PJK not reported	None, although revision surgery for fractures or instrumentation failure at the proximal junction is reported	MLSS	0%	_NR	0%	_NR	_NR
Sublaminar Tapes (ST)
Viswanathan et al 2018⁴⁵	PJK not reported	Unclear	SLB	8%	_NR	0%	‡ODI, ‡VAS pain,, ‡VAS back pain, ‡SF-36	Major 9, Minor 27

Data is presented as relative value (%).

*Indicates that the mentioned study has reported these values as significantly different between groups.

^‡Indicates that the mentioned study reported a significant improvement from pre-operative to final follow-up.

^#Indicates that the mentioned study reported PJK and PJF combined, and did not report separate values.

2-PVP: 2-level prophylactic vertebroplasty, FR: flexible rod, MLSS: multilevel stabilization screws, PJA: proximal junctional angle, PJFx: proximal junctional fracture, PS: pedicle screw at the UIV (control group), RR: revision rate for PJK, ST: sublaminar tapes, TC: tether attached to crosslink at the UIV, TO: tether only at the UIV, TPH: transverse process hooks, UIV: upper instrumented vertebrae.