Habitual Patellar Dislocation of the Adult: Surgical Technique and Case Report.

Abstract

Background: Habitual patellar dislocation (HPD) is a rare patellar instability knee condition. Although it is more common in children, it can also be observed in adults. This is an extremely debilitating condition in which the patella is reduced in full extension and dislocates with every flexion movement, typically at 30° of knee flexion. There is typically a significant contracture of the iliotibial band, lateral retinaculum, vastus lateralis, and even the quadriceps muscle/tendon unit, as well as potentially bony alterations. Given the unique pathogenic behavior of this condition, compared with classic patellar instability, the surgical technique is unique and must be well recognized. We present the surgical technique of an HPD of the left knee of an adult male patient.

Indications: After failure of physical therapy, surgical treatment is indicated.

Technique description: We performed a 4-in-1 procedure through a medial patellofemoral ligament (MPFL) reconstruction using a tenodesis of the quadriceps tendon, tibial tubercle osteotomy for anteromedialization, lateral retinaculum lengthening with vastus lateralis release, and quadriceps tendon lengthening.

Results: Range of motion (ROM) exercises are encouraged from day 1 to prevent recurrent contracture of the lateral soft tissues. After 26 months of follow-up, the patient had almost no pain, full ROM, a stable patella, and Kujala and Single Assessment Numeric Evaluation scores of 80 and 77, respectively. Although he returned to recreational activities, he decided not to resume playing soccer.

Discussion/conclusion: HPD of the adult is a rare entity, in which a meticulous surgical procedure on a step-by-step basis should be performed. Anatomic reconstruction of the MPFL and management of the soft-tissue structures are key to allowing for a safe early ROM and better outcomes. Although different surgical techniques have been described, larger case series are needed.

Patient consent disclosure statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.