Similar to the preoperative evaluation, postoperative management of the kinematically aligned (KA) patient does not stray from traditional management. Outpatient surgery, physical therapy, and office and radiographic evaluations will certainly vary among surgeons. This chapter presents some framework for optimal care of the KA total knee arthroplasty (TKA) patient.
Given the short-term data and lack of long-term data, patients should be followed closely, and data collection with regards to clinical outcomes and radiographic results is imperative.
Immediate Postoperative Management
Postoperative care of the TKA patient is in a current state of evolution. Advancements in anesthesia and multimodal pain control have made outpatient TKA a common pathway. TKA technique has not been identified as a factor for choosing inpatient or outpatient pathways for patients. There are no aspects of the surgical technique that would increase patient risk in the outpatient surgery setting. Given the fact that KA involves fewer soft tissue releases than other techniques, there may be an advantage to calipered KA, with less postoperative pain, which may facilitate outpatient management. However, this has not yet been proven. If a physician is comfortable with outpatient TKA using mechanical alignment (MA) techniques, there should be no issues transitioning to the KA technique and still using an outpatient pathway.
Physical therapy has long been a staple in postoperative protocols for TKA. With the advent of bundled payments and cost reductions, many traditional postoperative care modalities are being scrutinized for their necessity. A recent study determined that unsupervised home programs were not inferior to formal outpatient postoperative physical therapy. Many of the authors in this book use a home therapy program after KA TKA, supplemented when necessary with formal therapy in patients who are having trouble with their recovery. Again, a surgeon utilizing a postoperative protocol that includes formal outpatient physical therapy would not need to change once they transition to utilizing a KA technique.
The need for radiographs and the number of follow-up visits after TKA are both elements of the postoperative protocol that are difficult to standardize. Immediate postoperative short-film X-rays after KA TKA will often appear startling when compared with traditional MA TKA radiographs. This is largely because radiology technicians are taught to align the cassette with the long axis of the tibia and frequently are not able to obtain a true anterior-posterior (AP) view of the knee. The rotation effectively increases the projected slope of the tibia on the two-dimensional plate, whereas placing the tibia parallel to the cassette makes the joint line appear artificially in varus relative to the “floor” when the image is viewed on a screen. Therefore, immediate postoperative X-rays of the knee are of little value. Full-length, standing cassette radiographs are preferred for evaluating and confirming restoration of patient’s pre-arthritic alignment ( Figs. 16.1 and 16.2 ). Full-length hip-knee-ankle images are often more easily obtained 6 weeks to 3 months postop. However, a standing short cassette AP and lateral knee can be used to check the joint line inclination angle and posterior tibial slope on the tibial side, and femoral joint line angle, posterior offset, and rotation of the femoral component. When assessing for rotation, only a computed tomography (CT) scan can reliably assess a true rotational measurement.