Effect of total knee arthroplasty on the spinopelvic parameters: A systemic review and metanalysis

Sagittal spinopelvic alignment (SSA) is essential for preserving a stable and effective upright posture and locomotion. Although alterations in the SSA are recognised to induce compensatory modifications in the pelvis, hips, and knees, the inverse relationship concerning knee pathology undergoing total knee arthroplasty (TKA) has been examined by a limited number of studies, yielding inconclusive results.

To generate evidence of the effect of TKA on the SSA from existing literature.

Databases like PubMed, EMBASE, and Scopus were used to identify articles related to the "knee spine syndrome" phenomenon using a combination of subject terms and keywords such as "spinopelvic parameters", "sagittal spinal balance", and "total knee arthroplasty" were used with appropriate Boolean operators. Studies measuring the SSA following TKA were included, and research was conducted as per preferred reporting items for systematic review and meta-analysis guidelines.

A total of 475 participants had undergone TKA, and six studies measuring SSA were analysed. Following TKA, pelvic tilt was the only parameter that showed significant changes, while lumbar lordosis (LL), pelvic incidence, and sacral slope were non-significant, as evident from the forest plots.

The body's sagittal alignment is a complex balance between pelvic, spine, and lower extremity parameters. TKA, while having the potential to correct the flexion contracture, can also correct it. Still, the primary SSA for spinal pathology, i.e., LL, may not be corrected in patients with co-existent spinal degenerative disease.