Page 25 - ISAKOS 2018 Newsletter Volume 2

CURRENT CONCEPTS
Patellar Resurfacing
The question of whether to resurface the patella or to leave the native patella unresurfaced continues to be debated among orthopaedic surgeons. Some of the traditional indications for patellar resurfacing include older age, anterior knee pain, patellofemoral symptoms, radiographic changes in patellofemoral joint, inflammatory arthropathy (e.g., rheumatoid arthritis), obesity, intraoperative maltracking, history of patellar dislocation, and a nonanatomical patellar trochlear groove on the femoral component. In contrast, the traditional recommendations for not resurfacing the patella have included a short, thin patella; younger age; osteoarthritis or non-inflammatory arthritis; well-preserved patellar cartilage; congruent patellar tracking intraoperatively; an inadequate patellar size or thickness for resurfacing; and a femoral component with an anatomic trochlear groove for the native patella.
Our survey revealed that almost half (49.8%) of South American surgeons prefer to resurface the patella in every case, 26.4% never resurface the patella, and 23.77% resurface the patella optionally. We believe patellar resurfacing may be increasing due to medicolegal implications.
In our group, surgeons favor resurfacing the patella; however, in some cases, we may decide not to resurface the patella on the basis of the intraoperative findings.
Computer Navigation
Computerized assistance to guide and aid in implantation (a technique known as navigation) was developed to increase the accuracy of prosthesis insertion. Considering that failures related to bone cuts and extremity alignment occur in up to 8% of patients, emerging efforts to reduce this rate are worthy. Navigation has demonstrated better results in terms of component positioning when compared with standard practice.
During the last few years, the emphasis has been on simplifying navigation systems, especially in terms of image capture. Thanks to newly developed optic systems, previous image capture is no longer needed, extending the use of navigation systems in clinical practice.
Despite the use of a guidance system, navigation presents the potential for errors resulting from software failures, inadequate instrument calibration, and incorrect landmark recognition. This last point is the most critical issue, because the surgeon is responsible for providing adequate anatomic references for an appropriate prosthesis insertion. Recent studies have shown that a 2-mm inaccuracy when recognizing femoral condyles produce a rotational error of 1° in the femoral component. Thus, although navigation may improve component alignment, errors can still occur during the process of making the bone cuts, leading to component malposition.
This limitation has led to the development of robotic-assisted TKA in an effort to facilitate the preparation of bone surfaces. The term robot refers to any mechanical device that is accurately controlled by a computer with the use of intelligent software.
Our survey revealed that only 4.5% of South American surgeons use computer navigation routinely in their practices. Even fewer (0.75%) use robotic surgery. On the other hand, almost 30% of Australian surgeons use computer navigation as an aid during TKA surgery, with a similar rate in Germany. However, only about 1% of surgeons in the United States use navigation.
While we do not currently use navigation/robotic surgery in our practice, we believe that it is an important component of the future of knee arthroplasty.
Conclusions
As there are no specific prosthesis registries for Latin America, we think that our survey provides valuable information regarding the preferences among surgeons in our region. We estimate that TKA procedures have doubled in our region in the last 5 years. This trend implies an enormous challenge for our region in terms of developing adequate health and economic policies to meet the increasing need for prosthetic knee surgery as well as the expected future increase in revisions.
19 I N T E R N AT I O N A L SPORTS MEDICINE FELLOWS CONFERENCE
th January 18 – 20, 2019 Carlsbad, California
2019 ISAKOS
ISMF Scholarship
ISAKOS is pleased to offer the opportunity to
three international sports medicine fellows to
attend the International Sports Medicine Fellows Conference in Carlsbad, California. This scholarship is intended to promote better understanding and communication regarding injuries or conditions as related to sports medicine.
APPLY TODAY!
Deadline September 15 isakos.com/Awards/ISMFScholarship
ISAKOS NEWSLETTER 2018: VOLUME II 23