Summary of surgerical procedures and resulting subsidence occurrence by study.
| Authors (Year) | No. of Patients at Final Follow-Up | No. of Levels | Postoperative Follow-Up | Pedicle Screws | Implant Type | Subsidence Considered | Subsidence Occurrence | Pathology Criteria | Radiological Assessments | Clinical Assessments |
| ALIF | ||||||||||
| Behrbalk et al (2013)18 | 25 | 32 | 2, 6, 12, and 18 mo | No | PEEK (Synthes SynFix-LR) cage | >1 mm | 5/32 (15.6%)a | Only patients with grade 1 degenerative spondylolisthesis were included | CT or x-ray imaging | N/A |
| Kuang et al (2017)26 | 42 | 50 | 3, 12, and 24 mo | No | Self-anchored stand-alone PEEK cage (ROI-A Oblique; LDR Medical) | Any compromise to the endplate | 3/50 (6%)a | All spinal pathology considered Excluded high BMI (≥28 kg/m2), severe osteoporosis, spinal stenosis, disc herniation, and spondylolisthesis | CT or x-ray imaging | N/A |
| Lee et al (2017)27 | 26 | 26 | 12 and 24 mo | No | Synfix PEEK cage (Synthes) | Any breakage of the endplate | 4/26 (15.4%) | Included patients with lower back pain, severe disc space narrowing, and moderate grade of spondylolisthesis; excluded patients with deformity, history of lumbar surgery, or ossification of the ligamentum flavum | CT | VAS |
| Phan et al (2017)28 | 137 | N/A | 6 wk | No | SynFix-LR PEEK integral cage device (Depuy) | >2 mm | <49 y old 2/45 (4.4%) 50–63 y old 2/46 (4.3%) >64 y old 10/46 (21.7%) No age consideration 14/137 (10.2%) | All spinal pathology considered | CT | ODI and SF-12 |
| Rao et al (2017)29 | 147 | N/A | 6 wk and 18 mo | No | SynFix-LR PEEK integral (Depuy) for 89.1% of the patients | >2 mm | 15/147 (10.2%) | All spinal pathology considered | CT and x-ray imaging | ODI, VAS, and SF-12 |
| Tu et al (2018)30 | 13 | N/A | 3, 12, and 24 mo | No | PEEK cages (ROI-A Oblique; LDR Medical) | >2 mm | 3/13 (23.1%) | Included patients with ASD, all patients with additional spinal pathologies that were not severe were also included | CT and x-ray imaging | VAS, ODI, SF-36, and Macnab criteria |
| LLIF | ||||||||||
| Marchi et al (2013)12 | 74 | 98 | 2, 6 wk, 3, 6, and 12 mo | No | 46 with standard cages (18 mm) 28 with wide cages (22 mm) (CoRoent, NuVasive) | High grade; >50% cage collapsed in the endplate | 30%a for the standard cages and 11%a for the wide cages | Most spinal pathology included; excluded patients with damaged spine structure, compromised vertebral bodies, presence of neuromuscular disease, severe central stenosis, and significant instability and scoliosis | CT | VAS and ODI |
| Tohmeh et al (2014)31 | 140 | 223 | 12 mo minimum (average last follow-up at 15.5 mo) | Yes | 18- and 22-mm PEEK cages (CoRoent; NuVasive) | >1 mm, 2–4 mm, >4 mm | >1 mm; 15/223 (6.7%)a
2–4 mm; 71/223 (31.8%)a >4 mm; 53/223 (23.8%)a | All spinal pathology considered | Fluoroscopy and CT | ODI, VAS, and SF-36 |
| Kotwal et al (2015)32 | 118 | 237 | Minimum of 24 mo (average last follow-up at 27.5 mo) | Yes | PEEK cages (Nuvasive) for 112 patients and carbon fiber cages (Depuy Spine) for 6 patients | >2 mm | 34/237 (14.3%)a | Included neurological claudication with deformity or instability, scoliosis, spondylolisthesis, and junctional disc degeneration | X-ray imaging | VAS, ODI, and SF-12 |
| Malham et al (2015)33 b | 128 | 178 | 6 wk and 3, 6, and 12 mo (average last follow-up at 25.1 mo) | 56 without and 72 with fixations | PEEK cages with 18- and 22-mm width (NuVasive) | Compromised endplate | 13/125 (10.4%) 6 had pedicle screws and 7 didn’t have the posterior fixation | All spinal pathology considered | CT | VAS, ODI, and SF-36 |
| Tempel et al (2015)34 | 335 | 712 | 12 mo | No | 22-mm wide PEEK cages | A loss of more than 25% of the disc height | 29/335 (8.7%) patients with subsidence | All spinal pathology considered | X-ray imaging | N/A |
| Isaacs et al (2016)35 | 29 | 36 | 6, 12 wk, 6, 12, and 24 mo | Yes | 16 patients with 18-mm width titanium cages (CoRoent XL, NuVasive), 86 patients with 18-mm width PEEK XLIF (NuVasive) | >3 mm | 1/30 (3.3%) | Only patients with grade I or II degenerative spondylolisthesis were considered | CT (12 mo) | VAS, ODI, and SF-36 |
| Yen et al (2017)10 | 140 | 247 | 1, 3, 6, and 12 mo | 37.1% No 62.9% Yes | 18–22-mm wide 50–60-mm long PEEK cages | A loss of more than 25% of the disc height | 22/79 (27.8%)a without pedicle screws, 30/168 (17.9%)a with pedicle screws | All spinal pathology considered | X-ray imaging | N/A |
| Du et al (2017)36 | 39 | 39 | 6 mo | Yes | 18–22-mm wide cages | Low grade; >25% cage collapsed in the endplate High grade; >50% cage collapsed in the endplate | Low grade; 2/39 (5%) High grade; 0% | All spinal pathology considered | X-ray imaging | ODI, VAS, and SF-12 |
| Bocahut et al (2018)9 | 69 | 82 | 12 mo | No | Avenue L cage (Zimmer) | >4 mm | 20/63 (32%) | All spinal pathology considered | CT imaging | VAS and ODI |
| Tempel et al (2018)34 | 297 | 623 | 6 wk, 3, 6, 12, and 24 mo | No | 18-h and 22-mm wide PEEK | Low grade; >25% cage collapsed in the endplate High grade; >50% cage collapsed in the endplate | Low grade; 12/297 (4.04%) High grade; 22/297 (7.4%) | All spinal pathology considered | X-ray imaging and CT | N/A |
| Chen et al (2019)23 | 107 | 126 | 3 d, 3, 12, and 24 mo | No | PEEK cages | Low grade; >25% cage collapsed High grade; >50% cage collapsed in the endplate | High grade; (26.9%) | Included all patients with degenerative disease | X-ray imaging and CT | JOA and VAS |
| Jung et al (2019)37 | 84 | 84 | 1, 3, 6, 12, and 24 mo | Yes | PEEK cages | >3 mm | Patients with osteopenia 7/41 (17.1%) Patients with normal bone mineral density 4/43 (9.3%) | All spinal pathology considered | X-ray imaging | VAS and ODI |
| Ko et al (2019)38 | 29 | 29 | Minimum of 12 mo (average last follow-up at 33.6 mo) | Yes | PEEK with titanium coating Clydesdale cage (Medtronic) | >2 mm | 6/29 (20.7%) | Included only patients with degenerative spondylolisthesis | X-ray imaging | VAS and ODI |
| Park et al (2019)39 | 40 | 62 | 3 and 24 mo | No | N/A | Low grade; >25% cage collapsed in the endplate High grade; >50% cage collapsed in the endplate | Low grade; 11/62 (17.7%)a High grade; 8/62 (12.9%)a | Included only patients with ASD needing revision surgery | X-ray imaging | VAS and ODI |
| Rentenberger et al (2019)40 | 122 | 258 | 12 mo | No | PEEK cage Nuvasive Inc. or COUGAR system (Depuy) | High grade; >50% cage collapsed in the endplate | High grade; 69/258 (26.7%)a | All spinal pathology considered | X-ray imaging and CT | N/A |
| Agarwal et al (2020)41 | 297 | 623 | 6 wk, 3, 6, 12, and 24 mo | No | 18- and 22-mm cages | Low grade; >25% cage collapsed in the endplate High grade; >50% cage collapsed in the endplate | Low grade; 10/297 (3.4%) High grade; 20/297 (6.7%) | All spinal pathology considered | X-ray imaging | N/A |
| Okano et al (2020)42 | 96 | 210 | Between 6 and 12 mo | No | PEEK cage (Nuvasive) or COUGAR system (Depuy Spine) | High grade; >50% cage collapsed in the endplate | 38/96 (39.6%) 58/210 (27.6%)a | All spinal pathology considered | X-ray imaging or CT | N/A |
| OLIF | ||||||||||
| Woods et al (2017)43 | 137 | 340 | 6 mo | Yes | PEEK with titanium coating (Medtronic CLYDESDALE) | Any breach of the endplate adjacent to disc space | 6/137 (4.4%) | All spinal pathology considered | CT and x-ray imaging | N/A |
| Lin et al (2018)44 | 25 | 25 | 6, 12, and 24 mo | Yes | PEEK Clydesdale; (Medtronic) | >2 mm | 3/20 (15%) | All spinal pathology considered Excluded patients with severe canal stenosis, spinal tumor, infection, fractures, and previous L4-L5 surgery | X-ray imaging | VAS and ODI |
| Chang et al (2019)45 | 169 | 262 | 3, 6, and 12 mo | Yes | PEEK cages | >25% cage collapsed in the endplate | 62/168 (36.9%) 85/261 (32.6%)a | All spinal pathology considered | X-ray imaging | ODI, SF-36, VAS, and JOA back pain evaluation questionnaire |
| Lin et al (2019)13 | 67 | 107 | 6, 12, and 24 mo | Yes | 18–22-mm wide, 8–16-mm high, 40–55-mm long, PEEK cages Clydesdale (Medtronic) | >3 mm | 19/107 (17.8%)a | Included all degenerative spinal disease Excluded infection, trauma, neoplasm, and patient with previous lumbar surgery | CT | VAS, ODI, and Macnab criteria |
| Liu and Feng (2019)46 | 14 | 20 | Minimum of 12 mo (last follow-up in the range of 12–45 mo) | Yes | (Clydesdale Spinal System, Medtronic) | >25% cage collapsed in the endplate | 1/14 (7.1%) | Included all degenerative spinal disease Excluded infection, spinal tumor, vertebral fracture, hypertrophic ligamentum flavum, lesions involving L5-S1, fused facet, and patient with severe spondylolisthesis | X-ray imaging | VAS and ODI |
| Mun et al (2019)47 | 74 | 74 | Minimum 6 mo (average last follow-up at 12.1 mo) | Yes | Large round PEEK cage (Perimeter, Medtronic) | >2 mm | (25.3%) | All spinal pathology considered Excluded patient with infection, tumor, and congenital anomalies | X-ray imaging | VAS and ODI |
| Wen et al (2019)48 | 74 | 74 | 24 mo | Yes; bilateral and uni-lateral | N/A | High grade; >50% cage collapsed in the endplate | High grade; 13/74 (17.6%) | All spinal pathology considered Excluded high BMI (≥35 kg/m2), severe osteoporosis, lumbar infection, lumbar tumor, and patient with previous lumbar surgery | X-ray imaging | VAS and ODI |
| PLIF | ||||||||||
| Suzuki et al (2013)49 | 19 | 19 | Minimum 12 mo (average last follow-up at 54.6 mo) | Yes | 2 PEEK, parallelepiped (REC) cages 16.4–14.6 wide 12.0–11.0 high (Telamon-S/-C/-, 22.0 mm length; Medtronic) or Brantigan I/F cage 11.0 mm wide, 11.0 mm height, 23.0 mm length (Depuy, Raynhem) | >2 mm | 3/19 (15.8%) | Included patients with osteoporotic vertebral collapse with neurologic deficit | X-ray imaging | VAS |
| Lee et al (2017)27 | 30 | 30 | 12 and 24 mo | Yes | 2 PEEK cages (Medtronic) | Any breakage of the endplate | 3/30 (10%) | Included patients with lower back pain, leg pain, neurogenic intermittent claudication, moderate disc space narrowing, and severe grade of spondylolisthesis Excluded, patient with deformity, with history of lumbar surgery, and ossification of the ligamentum flavum | CT imaging | VAS |
| Oh et al (2017)50 | 129 | 139 | 3, 6, and 12 mo; Minimum of 12 mo (average last follow-up at 49.2 mo) | Yes | PEEK cage (O.I.C. cages; Stryker) | 1–3 and >3 mm | >3 mm 22/139 (15.8%)a | All spinal pathology considered | CT imaging | VAS, ODI, and SF-36 |
| Tu et al (2018)30 | 27 | N/A | 3, 12, and 24 mo | Yes | PEEK cages (Libeier; Orthopedic) | >2 mm | 2/27 (7.4%) | Included patients with ASD (all patients with additional spinal pathologies who were not severe were also included) | CT | VAS, ODI, SF-36, and Macnab criteria |
| Park et al (2019)39 | 40 | 44 | 3 and 24 mo | Yes | N/A | Low grade; >25% cage collapsed in the endplate High grade; >50% cage collapsed in the endplate | Low grade; 10/44 (22.7%)a High grade; 4/44 (9.1%)a | Included only patients with ASD needing revision surgery | X-ray imaging | VAS and ODI |
| TLIF | ||||||||||
| Kim et al (2013)14 | 104 | 122 | Minimum 24 mo (last follow-up range from 24 to 45 mo) | Yes | Bullet-shaped PEEK cage (Capstone; Medtronic) | >2 mm | >2 mm; 10/122 (8.2%)a
>4 mm; 8/122 (6.6%)a | All spinal pathology considered | X-ray imaging | N/A |
| Isaacs et al (2016)35 | 26 | 29 | 6, 12 wk; 6, 12, and 24 mo | Yes | PEEK cages | >3 mm | 2/26 (7.7%) | Included only patients with grade I or II degenerative spondylolisthesis | CT (12 mo) and magnetic resonance imaging (3 mo) | VAS, ODI, and SF-36 |
| Choi et al (2016)51 | 21 | 21 | 6 and 12 mo | Yes | Banana-shaped cage (Crescent, Medtronic) or straight cage (Opal, Depuy) | >2 mm | 7/21 (33.3%) | All spinal pathology considered | X-ray imaging and CT | VAS, ODI, and patient satisfaction rate |
| Kuang et al (2017)26 | 40 | 48 | 3, 12, and 24 mo | Yes | PEEK cage (Libeier) | Any compromise to the endplate | No cage subsidence | Most spinal pathology considered Excluded high BMI (≥28 kg/m2), severe osteoporosis, spinal stenosis, disc herniation, and spondylolisthesis | CT or x-ray imaging | |
| Lee et al (2017)27 | 21 | 21 | 12 and 24 mo | Yes | PEEK Capstone cage (Medtronic) | Any breakage of the endplate | 8/21 (38.1%) | Included patients with lower back pain, leg pain, moderate disc space narrowing, and unilateral intervertebral foraminal stenosis Excluded, patients with deformity, with history of lumbar surgery, or ossification of the ligament flavum | CT | VAS score |
| Lin et al (2017)11 | 76 | 76 | 3, 6, 12, and 24 mo | Yes | Banana-shaped cage or straight cage | >2 mm | 14/30 (46.7%) | Included symptomatic spinal stenosis, grade I and II spondylolisthesis, herniated nucleus pulposus, and other clinical symptoms Excluded patients with previous lumbar surgery | CT | VAS and ODI |
| Choi et al (2018)52 | 84 | 84 | 6 and 12 mo | Yes | Banana-shaped cage (Crescent, Medtronic) Straight cage (Opal, Depuy) | >2 mm | Banana-shaped; 14/44 (31.8%) Straight cages; 7/40 (17.5%) | All spinal pathology considered Excluded patients with metabolic bone disease, infection, spinal trauma, and tumors | X-ray imaging | VAS and ODI |
| Lin et al (2018)44 | 25 | 25 | 6, 12, and 24 mo | Yes | PEEK Opal (Depuy) or PEEK Capstone (Medtronic) | >2 mm | 6/20 (30%) | Most spinal pathology considered Excluded patients with severe canal stenosis, spinal tumor, infection, fractures, and previous L4-L5 surgery | X-ray imaging | VAS and ODI |
| Pereira et al (2018)7 | 117 | 117 | 6 and 12 mo | Yes | Bullet-shaped PEEK cage | >3 mm | 25/117 (21.4%) | All spinal pathology considered Excluded patients with infection, tumor, trauma, and previous lumbar surgery | CT | ODI, Odom criteria, and Stanford score |
| Ko et al (2019)38 | 41 | 41 | Minimum 12 mo (average last follow-up at 27.2 mo) | Yes | PEEK capstone cage (Medtronic) | >2 mm | 21/41 (51.2%) | Included only patients with degenerative spondylolisthesis | X-ray imaging and CT | VAS and ODI |
| Mun et al (2019)47 | 74 | 74 | Minimum 6 mo (average last follow-up at 22.3 mo) | Yes | A single (PEEK) cage (Capstone, Medtronic) | >2 mm | (25.3%) | All spinal pathology considered Excluded patients with infection, tumor, and congenital anomalies | X-ray imaging | VAS and ODI |
| Park et al (2019)53 | 784 | 881 | 18 mo | Yes | INNESIS PEEK cages (BK MEDITECH) Rotation-type cages (PLIVIOS PEEK cages [Depuy, Raynham]) Bullet-shaped cages (Capstone PEEK cages [Medtronic]) | >2 mm | 36/881 (4.1%)a | All spinal pathology considered | X-ray imaging | N/A |
| Zhou et al (2019)54 | 145 | 145 | 3, 6, and 12 mo | Yes | PEEK cage (Capstone, Medtronic) | >2 mm | 23/145 (15.9%) | All spinal pathology considered Excluded patients with infection, tumor, trauma, and previous lumbar surgery | X-ray and CT imaging | VAS and ODI |
| Zhao et al (2020)5 | 76 | 76 | 60 mo | Contoured and straight rod | PEEK material and cuboid shape (arched appearance) from Stryker | Low grade; >25% cage collapsed in the endplate High grade; >50% cage collapsed in the endplate | Low grade; 9/76 (11.8%) High grade; 6/76 (7.9%) | Most spinal pathology considered Excluded patients with previous lumbar surgery history, neurological lesions, peripheral neuropathy and other diseases entities | X-ray imaging | VAS, ODI, and JOA |
Abbreviations: ALIF, anterior lumbar interbody fusion; ASD, adjacent segment disease; BMI, body mass index; CT, computed tomography; JOA, Japanese Orthopaedic Association ; LLIF, lateral lumbar interbody fusion; ODI, Oswestry Disability Index; OLIF, oblique lumbar interbody fusion; PEEK, polyetheretherketone; PLIF, posterior lumbar interbody fusion; SF-12, 12-Item Short Form Health Survey; TLIF, transverse lumbar interbody fusion; VAS, visual analog scale; XLIF, extreme lateral interbody fusion.
↵a Subsidence reported by levels.
↵b Less than 80% follow-up.