Meeting NewsPerspective

Trochleoplasty seen as reliable treatment for severe trochlear dysplasia

David R. Diduch

BOSTON — Sulcus-deepening trochleoplasty may be a reliable and successful surgical solution to recurrent patellar instability for patients with severe trochlear dysplasia, according to results presented at the American Orthopaedic Society for Sports Medicine Annual Meeting.

David R. Diduch , MD, and colleagues collected VAS, IKDC and Kujala scores preoperatively and at 6 months and 1 year, 2 years, 3 years and 4 years postoperatively for 64 patients with severe trochlear dysplasia who underwent sulcus-deepening trochleoplasty using the Dejour method. Researchers measured the patellotrochlear index, trochlear spur height and trochlear depth preoperatively, as well as the sulcus angle preoperatively and postoperatively. Complete follow-up at a minimum of 1 year, including X-rays, physical exam and patient-reported outcome measures, were available for 43 patients.

Results showed no episodes of recurrent instability with clinically significant improvements reported by all patients. The mean preoperative IKDC score and Kujala score improved from 49.99 and 55.88, respectively, to 79.86 and 85.80, respectively. Researchers also found high satisfaction rates, with a return-to-work rate of 96.9% and a return-to-sport rate of 88.2%.

“We were able to correct the jumping J sign in all but one patient, and we corrected the instability in all of the patients,” Diduch, professor of orthopedic surgery and division head of sports medicine and head orthopedic team physician at the University of Virginia, told Healio.com/Orthopedics. “The technique centers on getting rid of that convex bump or spur and dropping it down to where it is at the level of the front of the femur. We try to create more depth but the depth is not as important as getting rid of this convex bump, so it does not kick the knee cap out to the side.”

Researchers noted arthrofibrosis developed in 10 knees and required manipulation under anesthesia, of which eight knees underwent simultaneous arthroscopic lysis of adhesions. Results showed patients had a mean knee range of motion of approximately 132.4° at the latest follow-up. Researchers found a significant decrease of the sulcus angle from 148.86° preoperatively to 135.11° postoperatively.

Despite these promising outcomes, Diduch noted sulcus-deepening trochleoplasty should be reserved for a specific patient population.

“It is a somewhat complex operation and while certainly other surgeons can learn it just like I did, I do not think it needs to be overdone just for a flat trochlear or some dysplasia,” Diduch said. “We need to reserve it for when somebody had a pronounced bump. That is a key part of why a person has instability and we cannot solve the problem in other ways.” – by Casey Tingle

 

Reference:

Carstensen SE, et al. Abstract 60. Presented at: American Orthopaedic Society for Sports Medicine Annual Meeting; July 11-14, 2019; Boston.

 

Disclosure: Diduch reports he has no relevant financial disclosures.

David R. Diduch

BOSTON — Sulcus-deepening trochleoplasty may be a reliable and successful surgical solution to recurrent patellar instability for patients with severe trochlear dysplasia, according to results presented at the American Orthopaedic Society for Sports Medicine Annual Meeting.

David R. Diduch , MD, and colleagues collected VAS, IKDC and Kujala scores preoperatively and at 6 months and 1 year, 2 years, 3 years and 4 years postoperatively for 64 patients with severe trochlear dysplasia who underwent sulcus-deepening trochleoplasty using the Dejour method. Researchers measured the patellotrochlear index, trochlear spur height and trochlear depth preoperatively, as well as the sulcus angle preoperatively and postoperatively. Complete follow-up at a minimum of 1 year, including X-rays, physical exam and patient-reported outcome measures, were available for 43 patients.

Results showed no episodes of recurrent instability with clinically significant improvements reported by all patients. The mean preoperative IKDC score and Kujala score improved from 49.99 and 55.88, respectively, to 79.86 and 85.80, respectively. Researchers also found high satisfaction rates, with a return-to-work rate of 96.9% and a return-to-sport rate of 88.2%.

“We were able to correct the jumping J sign in all but one patient, and we corrected the instability in all of the patients,” Diduch, professor of orthopedic surgery and division head of sports medicine and head orthopedic team physician at the University of Virginia, told Healio.com/Orthopedics. “The technique centers on getting rid of that convex bump or spur and dropping it down to where it is at the level of the front of the femur. We try to create more depth but the depth is not as important as getting rid of this convex bump, so it does not kick the knee cap out to the side.”

Researchers noted arthrofibrosis developed in 10 knees and required manipulation under anesthesia, of which eight knees underwent simultaneous arthroscopic lysis of adhesions. Results showed patients had a mean knee range of motion of approximately 132.4° at the latest follow-up. Researchers found a significant decrease of the sulcus angle from 148.86° preoperatively to 135.11° postoperatively.

Despite these promising outcomes, Diduch noted sulcus-deepening trochleoplasty should be reserved for a specific patient population.

“It is a somewhat complex operation and while certainly other surgeons can learn it just like I did, I do not think it needs to be overdone just for a flat trochlear or some dysplasia,” Diduch said. “We need to reserve it for when somebody had a pronounced bump. That is a key part of why a person has instability and we cannot solve the problem in other ways.” – by Casey Tingle

 

Reference:

Carstensen SE, et al. Abstract 60. Presented at: American Orthopaedic Society for Sports Medicine Annual Meeting; July 11-14, 2019; Boston.

 

Disclosure: Diduch reports he has no relevant financial disclosures.

    Perspective
    John P. Fulkerson

    John P. Fulkerson

    The following are important points to consider regarding Diduch’s presentation regarding their trochleoplasty results at the 2019 American Orthopedic Society of Sports Medicine Annual Meeting:

    1. Half of their trochleoplasty patients were revisions of unsuccessful earlier surgeries;

    2. Twenty percent of their trochleoplasty patients developed arthrofibrosis and required manipulation. Eight of 64 needed an arthroscopic lysis of adhesions. Trochleoplasty undoubtedly adds risks beyond doing MPFL surgery alone;

    3. Their trochleoplasty patients all had MPFL reconstruction also, so we cannot assume, based on their findings, that trochleoplasty alone confers stability. With added MPFL reconstruction, trochleoplasty confers stable 1-year follow-up results; and

    4. We do not yet know the long-term consequences of trochlea articular alteration.

    At the same session in which Diduch presented his study, Beth Shubin Stein, MD, reiterated her earlier findings that isolated MPFL reconstruction works well despite trochlea dysplasia at the 2019 American Orthopedic Society of Sports Medicine Annual Meeting in Boston. In this study of 121 patients, isolated MPFL reconstructions were done for patella instability patients, 92% of whom had Dejour B, C or D trochlea dysplasia. Only three patients had postoperative instability and 94.5% of the patients returned to sports at 1 year.

    Diduch presented his successful 1-year results using trochleoplasty combined with MPFL reconstruction for treatment of recurrent patella dislocations in patients with Dejour B and D dysplasia. Additionally, Seth Sherman, MD, presented another study at this meeting showing that tibial tubercle transfer, when needed in the treatment of recurrent patella instability, adds no significant morbidity.

    Those treated in the Erickson and Shubin Stein study using MPFL reconstruction alone to treat recurrent patella instability had very low morbidity and no redislocation at 2 years.

    The patients treated in Diduch’s study presumably had more serious structural dysplasia and Diduch illustrated in his presentation the need for trochleoplasty in patients with a prominent jumping J sign — in other words, a patella that is visually and structurally impaired by a very prominent supratrochlear spur causing the patella to jump laterally in extension. Such patients likely comprise less than 5% of patella instability patients seen in an average sports medicine practice.

    Some take-home messages are:

    1. Despite trochlea dysplasia, which is often present in patella instability patients, MPFL reconstruction works well for treatment of recurrent patella instability, so one must have a very good reason to add anything more;

    2. Tibial tubercle transfer, when needed, adds little risk and is important to unload lateral articular lesions or establish balanced tracking and minimize risk of future arthritis; and

    3. Trochleoplasty, when accompanied by MPFL reconstruction, is effective treatment for recurrent patella instability but has a 20% risk of arthrofibrosis and should be reserved for revision surgery and patients with a prominent J sign. Patella alta lowers the threshold for a trochleoplasty. Also, it is a difficult surgery to do well that alters articular cartilage as well as subchondral bone with unknown long-term consequences. Trochleoplasty candidates should perhaps be referred to an expert skilled in this procedure. 

    A key point of Diduch’s study is that, properly done, by a highly trained and skilled trochleoplasty surgeon, trochleoplasty when combined with MPFL reconstruction, works well for patella stabilization for those relatively few patients with a prominent J sign and severe trochlea dysplasia. One might choose to add trochleoplasty when MPFL reconstruction alone, with or without tibial tubercle transfer surgery is insufficient, by objective criteria, and in selected revision surgeries of failed previous patella instability surgery in the presence of severe trochlea dysplasia. This is likely less than 5% of patella instability patients in a standard sports medicine practice

    My own experience of more than 40 years in a patellofemoral surgery practice, is that very few patients need a trochleoplasty (less than 5% of my instability patients) including patients with a flat, Dejour B proximal trochlea when patella malalignment and articular damage are corrected by tibial tubercle transfer, medially, distally and/or anteromedially, and then stabilized anatomically by MPFL or MQTFL reconstruction.

    Medial patellofemoral complex (as described by Tanaka) reconstruction (MPFL or MQTFL) alone, with tibial tubercle transfer to correct alignment and/or unload patella articular lesions, remains the mainstay of patella stabilization surgery, with minimal risk of complication. Diduch’s study gives us further insight into the short-term benefit of well-done trochleoplasty when needed for severe trochlea dysplasia and combined with MPFL reconstruction, despite a 20% risk of arthrofibrosis.

    Reference:

    Erickson BJ, et al. Am J Sports Med. 2019;doi:10.1177/0363546519835800.

    • John P. Fulkerson, MD
    • Orthopedic Associates of Hartford, P.C.
      Clinical professor of orthopedic surgery
      University of Connecticut School of Medicine
      President, The Patellofemoral Foundation
      Harford, Connecticut

    Disclosures: Fulkerson reports he receives royalties from DJO Global and is a patent holder for DJO Global.

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