We read the article entitled “The Influence of Endplate Morphology on Cage Subsidence in Patients with Stand-Alone Oblique Lateral Lumbar Interbody Fusion (OLIF) 1 ” with great interest. The author investigated the correlation between endplate morphology and cage subsidence following OLIF. This was a valuable work since it could help in finding a feasible method to predict cage subsidence and gathering evidence for future cage designment. We appreciated the tremendous work by the authors. But also, we have a concern regarding the study:
1. The author classified the endplate morphology only into 2 types: flat and concave. However, many previous studies have classified it into flat, sunken, and irregular.2,3 We have observed that the irregular endplates are common, accounting for 12.0% of all types in our patients. Therefore, the relationship between irregular endplate and cage subsidence should also be clarified, which is missing in the present study.
2. Cage subsidence in the present study was measured from the vertebral endplate to the caudal or cranial margin of the cage. It actually contains the concavity depth of endplate, which makes the depth of cage sink into the endplate not accurately measured, and thus may cannot accurately determine the relationship between the cage subsidence and endplate morphology.
References
- 1.Hu Z, He D, Gao J, et al. The influence of endplate morphology on cage subsidence in patients with stand-alone oblique lateral lumbar interbody fusion (OLIF). Global Spine Journal. 2021:2192568221992098. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Pappou IP, Cammisa FP, Jr, Girardi FP. Correlation of end plate shape on MRI and disc degeneration in surgically treated patients with degenerative disc disease and herniated nucleus pulposus. Spine J. 2007;7(1):32-38. [DOI] [PubMed] [Google Scholar]
- 3.Lakshmanan P, Purushothaman B, Dvorak V, Schratt W, Thambiraj S, Boszczyk M. Sagittal endplate morphology of the lower lumbar spine. Eur Spine J. 2012;21(Suppl 2):S160-S164. [DOI] [PMC free article] [PubMed] [Google Scholar]