David J. Mayman
PARK CITY, Utah — In a presentation at the Joint Arthroplasty Mountain Meeting, David J. Mayman, MD, discussed techniques for performing lateral unicompartmental knee arthroplasty in patients with isolated lateral compartment arthritis and correctable deformity.
Mayman noted that, unless the surgeon has a lateral specific unicompartmental knee implant, sizing can be more difficult on the lateral side compared with the medial side. The lateral side of the knee also has a wider flexion gap, he added.
“If you try to stuff that lateral side so the lateral side feels like the medial side, you are going to be way overstuffing the lateral side of the knee,” Mayman said in his presentation.
Performing a lateral arthrotomy will place the implant underneath the patellar tendon and may make it difficult to get the rotation of the tibial implant correct, according to Mayman. He noted it is easier to get the rotation of the tibial component correct when coming from the medial side of the knee.
Surgeons need to make sure the implant is tracking centrally when using a medial implant and to avoid overhang over the lateral side of the femur.
“There are more implants that are slightly more anatomically shaped, but it is a real balancing act between not being in the notched in flexion and not overhanging anterolateral when you put these implants on the lateral side of the knee,” Mayman said. – by Casey Tingle
Mayman DJ. Lateral UKA. Presented at: Joint Arthroplasty Mountain Meeting; Feb. 10-13, 2019; Park City, Utah.
Disclosure: Mayman reports he has stock or stock options in Imagen and OrthAlign; is a board or committee member for Knee Society; and is a paid consultant, paid presenter or speaker and receives research support from Smith & Nephew.