ISAKOS & Patellofemoral Foundation Traveling Fellowship for 2023-2025
Truls M. Straume-Næsheim, MD, PhD, NORWAY Elizabeth Rose Dennis, MD MS, UNITED STATES
ISAKOS eNewsletters
eNewsletter Article
2025
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It was true privilege to receive the ISAKOS & Patellofemoral Foundation Traveling Fellowship for 2023-2025. As surgeons from different continents, we utilized our unique insights into both European and American patellofemoral communities to deepen our collective understanding of patellofemoral instability (PFI) and shape our fellowship experience. Although consensus on optimal treatment is still debated, the centers we visited all agreed on a basic diagnostic algorithm with a customizable “menu a la carte” of different surgical treatment options.
Figure 1: Treatment algorithm for patients with patellofemoral instability from Dippmann C, Lavard P, et al. KSSTA 2025.
This algorithm requires the surgeon to have a well-equipped toolbox, with diverse and robust diagnostic and surgical tools to make the correct diagnosis and perform the necessary surgical procedures to not only provide the patient with stability, but optimal outcomes. One of the most valuable aspects of this travel fellowship was the opportunity to expand our toolbox and simultaneously improve our understanding of how to treat this complex patient group. Our goal is to showcase how each visit enriched our approach to the complex challenge of management of patellofemoral instability. For demonstrative purposes, we decided to utilize the aforementioned treatment algorithm, described in Figure 1 by the Danes, as the framework for our travel report. As such, rather than chronologically, we will take you through the highlights of our traveling fellowship categorized by the techniques we added to our toolbox!
Where it All Began
We are grateful to the Internation Patella Study Group (IPSG) for welcoming us as guests at their biannual meeting in Big Sky Montana in August 2024. This is where the start of our quest for patellofemoral (PF) knowledge began with our colleagues from around the world (Figure 2).
Figure 2: Patellofemoral experts and guest at IPSG in Big Sky, Montana.
Figure 3: The International Patellofemoral Study Group including traveling fellows and guests.
The first tool in the toolbox: measurements. At the IPSG we added to our extensive PF armamentarium of measurements with a few more. Dr. Dennis presented the Patella Tendon – Lateral Trochlear Ridge (PTLTR) as a measurement of instability with maltracking (Mistovich et al., 2018). New trochlear dysplasia classifications (Dr. David Dejour, Dr. Takehito Matsushita), sagittal TT-TG (Dr. Adam Yankee, (Lansdown et al., 2021)), and dynamic 3D modeling of the patellar entry point in relation to the trochlea (Dr. Fulkerson), the impact of weight-bearing on patellar height (Dr. Sillanpää), predictors of persistent J-sign after distalizing TTO (Arendt, Vial Irarrazaval) and the effects of trochleoplasty on MPFL isometry (Dr. Balcarek) added further complexity. And of course, Professor Emeritus, Dr. Robert Teige, reminded us that many of the ideas we discuss today had been seeded in his 1986 AAOS talk – history we must always honor (Figure 4).
Figure 4: Presentation at IPSG by dr. Teitge of MPFL-reconstruction with quadriceps graft and isometric testing device first presented at the 1986 AAOS meeting.
MPFL Reconstruction
We then moved into the treatment tools in our toolbox tour starting on the top with non-operative treatment and isolated MPFL-reconstruction (MPFLR). In Oslo, Norway Dr. Dennis was able to observe the dynamic sling method for MPFLR (Straume-Naesheim et al., 2022) and joined the infamous Friday wine lottery (Figure 5).
Figure 5: Oslo dynamic sling boys, dr. Straume-Næsheim and Dr. Randsborg.
In New York City, we joined Dr. Dan Green and Dr. Beth Shubin Stein at Hospital for Special Surgery (HSS) we were observed both surgeons and joined a research symposium (Figure 6). Highlights included Dr. Green’s novel insights on TT-TG changes following MPFLR and refined lateral lengthening techniques.
Figure 6: Research symposium at HSS with Dan Green and Peter Balcarek
Tibial Tubercle Osteotomies
The next stop on our toolbox tour involved exploring the tibial tubercle osteotomy. Naturally that took us to the expert in the field, John Fulkerson, who arranged an outstanding visit for us at Yale that included a tour of the paleontology museum to get insight into the evolution of the patella. We had a knowledge filled afternoon, learning from his team of researchers about their extensive study of 3D anatomy in patellofemoral patients and how they used this information to creating 3d cutting guides for doing the osteotomies in the OR. We even had time for lunch at the famous Mory’s club (Figure 7).
Figure 7: Lunch with Dr. Fulkerson and his research team Mory’s in New Haven, CT
Trochleoplasty Tour
Our patellofemoral traveling fellowship would not be completed without a deep dive into trochleoplasty and its variety of techniques. The first stop was a visit to the University of Minnesota to see the original Dejour thick flap technique from the queen of the patella surgery, Dr. Liza Arendt (Figure 8).
Figure 8: Dr. Elizabeth Arendt and Dr. Elizabeth Dennis at the University of Minnesota.
Next stop was London Ontario to visit Alan Getgood to learn his version of the open thin flap along with many other complex osteotomies as a bonus (Figure 9).
Figure 9: Alan Getgood ,Truls Straume-Næsheim and Elizabeth Dennis
You cannot go on a trochleoplasty tour without visiting Denmark. We visited Peter Lavrad, Christian Dippmann and Kristoffer Barfod at Bispebjerg, Copenhagen who have performed more than 800 cases of trochleoplasties the last 10 years using the Bereiter thin flap open technique (Figure 10).
Figure 10: The Bispebjerg team; Christian Dippmann, Peter Lavrad, and Kristoffer Barfod
Next on our Danish trochleoplasty tour we visited Lars Blond at Aleris, Køge, to learn about arthroscopic trochleoplasty from its inventor (Figure 10).
Figure 11: Truls Straume-Næsheim and Elizabeth Dennis with Lars Blønd at Aleris
Rotational and Coronal Plane Correction
We then expanded our knowledge qeust into the long bones to learn about rotational and coronal plane correcting osteotomies. We were fortunate to see some of these techniques from the Danes. However, our last stop on the tour before Munich was to visit El Rey de Rotation, Vicente Sanchis-Alfonso in Valencia, who arranged an outstanding visit for us with the opportunity to examine and observe intraoperatively many patients with complex patellofemoral pathology including instability and anterior knee pain. We learned a great deal from him about the effect of femoral anteversion and external tibial torsion on both instability and pain (figure 12). It was also fascinating to see how they used intraoperative neuromonitoring to prevent peroneal nerve injury when performing infra tuberosity rotational osteotomies on the tibia.
Figure 12: Sangria and case study at Vincente Sanchis-Alfonso’s amazing local paella restaurant
For the final tool in treatment algorithm, the coronal plane correction, we will refer back to our time in New York at HSS again. There we experienced a coronal plan correction in combination with patellar stabilization from Dr. Beth Shubin Stein and Dr. Austin Fragomen, and had dinner had dinner with Truls’s 3d bone models of complex PI cases, that he brought on tour with him (Figure 13).
Figure 13: Beth Shubin Stein and Truls M. Straume-Næsheim discussing the menu a la carte of patella instability treatment in New York City
Final Reflections
Our traveling fellowship equipped us with powerful tools, new mentors and lifelong colleagues. We learned an incredible amount on this patellofemoral traveling fellowship but like any worthwhile endeavor, more understanding reveals more questions, so the quest for the holy grail of patellofemoral surgery continues!
We want to sincerely thank ISAKOS, PFF, and our hosts for their generosity of time, knowledge and curiosity and for making this fellowship opportunity possible.
References
- Lansdown, D. A., Christian, D., Madden, B., Redondo, M., Farr, J., Cole, B. J., & Yanke, A. B. (2021). The Sagittal Tibial Tubercle-Trochlear Groove Distance as a Measurement of Sagittal Imbalance in Patients with Symptomatic Patellofemoral Chondral Lesions. Cartilage, 13(1_suppl), 449S-455S. https://doi.org/10.1177/1947603519900802
- Mistovich, R. J., Urwin, J. W., Fabricant, P. D., & Lawrence, J. T. R. (2018). Patellar Tendon-Lateral Trochlear Ridge Distance: A Novel Measurement of Patellofemoral Instability. Am J Sports Med, 46(14), 3400-3406. https://doi.org/10.1177/0363546518809982
- Straume-Naesheim, T. M., Randsborg, P. H., Mikaelsen, J. R., & Aroen, A. (2022). Medial patellofemoral ligament reconstruction is superior to active rehabilitation in protecting against further patella dislocations. Knee Surg Sports Traumatol Arthrosc, 30(10), 3428-3437. https://doi.org/10.1007/s00167-022-06934-3