Trochleoplasty by Arthroscopy in Patients with Patellofemoral Instability and Severe Trochlear Dysplasia. Surgical Techniques: Step by Step

Authors:

Guillermo Natera, MD
Holy Family Clinic. Armenia – Colombia.

Manuel F. Mosquera Arango, MD *
La Carolina Clinic, Bogotá – Colombia. 
Erasmo Clinic, Valledupar – Colombia.

* email address: mosco61@gmail.com

The main author declares that he has a conflict of interest as an Arthrex-ISO instructor for this surgery in Colombia.

INTRODUCTION

Patellofemoral instability is a multifactorial disease that mainly affects young people at the end of their growth period and is manifested by recurrent dislocations of the patella(s) in sports practices or even in activities of daily living. Unlike acute traumatic dislocation, this disease may not be preceded by an acute high-energy traumatic event and always has factors that predispose to recurrence. The most frequent found are in order of prevalence¹: dysplasia of the trochlea that can be present in up to 95%, the high patella, lateralization of the insertion of the patellar tendon measured in the distance TT-TG (tibial tuberosity - trochlear groove) , insufficiency of the medial restrictors; the patellofemoral and patellotibial ligaments measured in patellar inclination and known as patellar tilt, torsional disorders of the femur and tibia, angular deformities predominantly genu-valgus, and finally hypermobility.

Considering that the most present and luxating factor is dysplasia of the trochlea, since the last century several surgical techniques have been designed to correct it, with augmentation surgeries such as Albee², and subtractive surgeries such as the Bereiter technique³, which in common they seek to give a normal concave shape to the diseased trochlea that is convex. The most popular technique today is the Dejour deepening trochleoplasty⁴, a technique performed openly that resects the bump when it is present and deepens the sulcus with two osteotomies that include the cartilage and subchondral bone currently fixed with sutures and implants, without knots (knotless). The majority of published articles are based on this surgery, which show that it is a highly effective technique to stabilize the patellofemoral joint, but with some complications such as the high incidence of arthrofibrosis and the presence of osteoarthritis in the medium term ^5,6.

In this video we publish our modified arthroscopic technique from Blond⁷ and performed since 2010 by the main author (MM), which resects the subchondral bone and bump of the anterior, superior and lateral aspect of the femoral groove with tripod fixation, using absorbable sutures and knotless threaded implants (knotless Swive Lock Arthrex. Fl).

SURGICAL TECHNIQUE DESCRIPTION:

Step by step: 

1. Evaluation of trochlea dysplasia via antero-lateral portal and proximal original groove marking.
2. Introduction Knotless threading loaded with 6 vycril sutures 1, 0.5 cms above the femoral sulcus.
3. Superolateral flexible cannula placement.
4. Evaluation of trochlear dysplasia and presence of bump from the superolateral portal.
5. Definition of approach angle and superomedial flexible cannula placement.
6. Distal anterior synovial resection and exposure of the bone of the supracondylar area.
7. Marking Introduction of the first proximal knotless that reduces, fixes and reproduces the new sulcus, which is more lateral than the original.  
8. Deepening of the sulcus by subchondral bone subtraction from the center to the superior side with resection of the bump.
9. Resection of the subchondral bone closest to the cartilage.
10. Cartilage flap reduction test to verify adequate reduction and concavity of the sulcus.
11. Recovery of the first 4 strands of the suture and definition of the entry site of the knotless thread in the direction of the new center of the sulcus.
12. Introduction of the first proximal knotless that reduces, fixes and reproduces the new sulcus, which is more lateral than the original.
13. Introduction of the second proximal knotless that reduces the superolateral aspect of the sulcus
14. Introduction of the third knotless (optional) medial to the central fixation to reduce the superomedial aspect of the sulcus.
15. Evaluation of the new groove and its congruence with the patella after fixing the graft of the reconstruction of the medial patellofemoral ligament.
16. End of procedure

RESULTS

In 2010, Blond et al published their arthroscopic surgical technique and in 2014 they showed their results by adding the reconstruction of the medial patellofemoral ligament in 31 patients and 37 knees, confirming their good results⁸. Recently, Blond and Weisskirchner⁹ published a retrospective case series of 16 knees in 15 patients, where they performed the arthroscopic trochleoplasty procedure plus reconstruction of the medial patellofemoral ligament, evaluating their results and correlating by resonance the shape of the pre and post surgery, finding anatomical parameters very similar to the normal trochlea post-surgery and with improvement in all functional scales.

REFERENCES:

1. Dejour H, Walch G, Nove-Josserand L, Guier C. Factors of patellar instability: an anatomic radiographic study. Knee Surg Sports Traumatol Arthrosc. 1994;2(1):19–26.
2. Albee F. Bone graft wedge in the treatment of habitual dislocation of the patella. Med Rec 1915;88:257–259.
3. Bereiter H., Gautier E. Trochleoplasty as surgical approach for the treatment of recurrent patella instability in patients with trochlear dysplasia of the femur. Arthroskopie. 1994;7:281–286.
4. Dejour D. Saggin P. The sulcus deepening trochleoplasty, the Lyon's procedure. Int Orthop. 2010;34:311–316.
5. Davies MR, Allahabadi S, Diab TE, et al. Sulcus-deepening trochleoplasty as an isolated or combined treatment strategy for patellar instability and trochlear dysplasia: A systematic review. Arthrosc Sports Med Rehabil. 2020;2:e661–e669.
6. Rouanet T, Gougeon F, Fayard JM Sulcus deepening trochleoplasty for patellofemoral instability: A series of 34 cases after 15 years postoperative follow-up. Orthop Traumatol Surg Res. 2015;101:443–447.
7. Blønd L, Schöttle PB The arthroscopic deepening trochleoplasty. Knee Surg Sports Traumatol Arthrosc. 2010;18:480–485.
8. Blønd L, Haugegaard M. Combined arthroscopic deepening trochleoplasty and reconstruction of the medial patellofemoral ligament for patients with recurrent patella dislocation and trochlear dysplasia..Knee Surg Sports Traumatol Arthrosc. 2014 Oct;22(10):2484-90.
9. Blønd L, Weisskirchner K. Trochlear Shape and Patient-Reported Outcomes After Arthroscopic Deepening Trochleoplasty and Medial Patellofemoral Ligament Reconstruction: A Retrospective Cohort Study Including MRI Assessments of the Trochlear Groove. Orthop J Sports Med. 2023 May 22;11(5) 

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