JOURNEY^◊ PFJ

Patellofemoral Joint System

Overview

Does isolated patellofemoral disease exist? What are the treatment options?

Why is precision powerful?

Although more rare than bi-compartmental or tri-compartmental osteoarthritis, isolated patellofemoral osteoarthritis (PFOA) may not be as uncommon as once thought. (graphs 1 and 2)

Patellofemoral pain can interfere with the activities of daily living, causing pain during stair climbing and chair rise. ³ While TKA is unparalleled as a procedure for pain relief and longevity, it is a large operation for isolated patellofemoral disease. The literature cites the loss of bone, meniscus, and ligaments as detriments, particularly for younger, more active patients. ⁴

Isolated PFOA in patients > 40

Clinical References

1. Davies AP; Vince AS; Shepstone L; Donell ST; Glasgow MM. The radiologic prevalence of patellofemoral arthritis. Clin Orthop 402: 206-212, 2002.

2.McAlindon RE; Snow S; Cooper C; Dieppe PA. Radiographic patterns of osteoarthritis of the knee joint in the community: The importance of the patellofemoral joint. Ann Rheum Dis 51: 844-849, 1992.

3. Laskin, RS, van Steijn, M. Total knee replacement for patients with patellofemoral arthritis. Clin Orthop 367:89-95, 1999.

4. Merchant, A. A Modular Prosthesis for Patellofemoral Arthroplasty. Clin Orthop. 436, pp. 40-46.

A new answer for isolated patellofemoral OA

First generation PFJ implants had sharp, constraining trochlear grooves and were prone to complications such as maltracking and catching of the patella. ⁵ Interest in less invasive procedures that retain the ACL for superior kinematics has increased, particularly among surgeons treating younger, more active patients. Second generation implants improved upon implant design, but instrumentation continued to be less sophisticated, relying on freehand preparation which can be highly variable. Given the relative rarity of isolated patellofemoral OA, a straightforward, easy-to-use technique is critical.

The JOURNEY PFJ System addresses the needs of surgeons performing this procedure with a simple, highly reproducible technique and an anatomic implant optimized for patellar tracking. The JOURNEY PFJ System offers surgeons looking for a less invasive, more bone and ligament sparing treatment option for more active patients the combination of proven performance and powerful precision.

Clinical References

5. Lonner, Jess. Patellofemoral Arthroplasty: Pros, Cons, and Design Considerations. Clin Othop. 428, Nov. 2004, pp. 158-165.

Benefits

Proven performance

Trochlear groove

The JOURNEY PFJ has a deepened and lateralized trochlear groove for optimized patellar tracking. It is based upon the clinically successful GENESIS^◊ II Total Knee System's trochlear groove, which has excellent published results for patellar tracking and low lateral release rates at five and ten years and uses the GENESIS II patella implant options. ^{6, 7}

Advanced bearing surface

The JOURNEY PFJ femoral implant is made of OXINIUM^◊ Oxidized Zirconium. This advanced bearing material has been shown to be 4900 times more resistant to abrasion than CoCr in lab testing. ⁸ OXINIUM technology also has a coefficient of friction that is up to half that of cobalt chrome. ⁹ Because of these qualities, patella resurfacing is optional and at the discretion of the surgeon.

Anatomic fit

The development of handed TKA femoral components allowed for more accurate fit and better patellar tracking. Surgeons using patellofemoral implants should not settle for anything less, which is why the JOURNEY PFJ system features asymmetric components for truly anatomic fit and superior patellar tracking.

Fixation

The distal peg is convergent in order to enhance fixation. The pegs for all four sizes are constant, so changes in implant sizes to optimize fit can be made through trialing.

Clinical References

6. Laskin, RS., Davis, R. Total knee replacement using the Genesis II prosthesis: a 5-year follow up study of the first 100 consecutive cases. The Knee 12 (2005) 163-167.

7. Bourne, Robert B MD, FRCSC; McCalden, Richard W MSC, MD, FRCSC; MacDonald, Steven J MD, FRCSC; Mokete, Lipalo MB, CHB; Guerin, Jeff B Math. Influence of Patient Factors on TKA Outcomes at 5 to 11 Years Follow-up. Clin Orthop; 464, Nov. 2007, 27-31.

8. Hunter, G and Long, M. Abrasive wear of oxidized Zr-2.5Nb, CoCrMo, and Ti-6A1-4V against bone cement” 6th World Biomaterials Cong Trans, Society for Biomaterials, Minneapolis, MN 1998, p. 528.

9. Poggie, RA, Wert, JJ, Mishra AK, and Davidson, JA. Friction and wear characterization of UHMWPE in reciprocating sliding contact with CoCr, Ti-6AI-4V and zirconia implant bearing surfaces. Wear and Friction of Elastomers, ASTM STP 1145, Am Society for Testing and Materials, 1992, pp. 65-81.

Powerful precision

Accurate alignment

Studies have noted the importance of aligning the patellofemoral implant in external rotation to optimize patellar tracking and reduce laterally displacing forces. ⁶ External rotation is set using a tibial or femoral alignment instrument for correct alignment.

Resurfacing trochlear instrumentation

Unlike other systems on the market, the JOURNEY◊ PFJ system does not require freehanding of the trochlear groove, but instead uses a proprietary, precise reamer for simple and accurate bone preparation.