Total knee arthroplasty in patients with extra-Articular deformity: A critical analysis

Author(s): Dr. Ponnusami Pillai Gokulakrishnan, Dr. Umamahesvaran Balaji and Dr. Mohamed Munis Ashraf

Abstract: Total knee arthroplasty is the standard of care for the patients with severe degenerative joint disease. There are still controversies among surgeons about restoring alignment in knee with Extra Articular Deformity. Some author reports corrective osteotomy to align anatomical axis there by restoring mechanical axis indirectly, while others restores mechanical axis directly using special instruments. We conduct a qualitative analysis of outcome in restoring mechanical axis directly and indirectly by, Post op alignment, Perioperative morbidity, Advantages and disadvantages of devises used for osteotomy fixation, Merits and demerits of navigation and Period of rehabilitation. Twenty five articles have been identified with Extra Articular Deformity. Twelve are evaluating outcome of single stage corrective osteotomy coupled with Total Knee Arthroplasty, two studies about dual stage Corrective osteotomy with Total Knee Arthroplasty. Seven are restoring mechanical axis by intra articular correction using computer assisting navigation, and three achieving Mechanical axis by intra articular correction using Patient Specific Instrumentation, and remaining one is a comparative study between intra articular correction with Extra Articular Deformity. Our review shows that average preoperative deformity is slightly higher (>20* in coronal plane) in Extra articular correction group than Intra articular correction. But restoration of mechanical axis is superior with intra articular correction than with corrective osteotomy, more over complications like delay in rehabilitation, non-union, delayed union, and infections at osteotomy site are reported in extra articular correction which are not there with deformities corrected intra-articularly. Considering overall outcome, extra-articular deformity corrected by intra-articular resection carries good postoperative alignment with less complication rate. But not sufficient studies are available to support intra articular correction in knee with higher degree of extra articular deformity. As most of the studies with intra articular correction of extra articular deformity provides encouraging results not much studies supporting it with higher extra articular deformity.

DOI: https://doi.org/10.22271/ortho.2018.v4.i1a.05