Surgical Treatment Of Habitual Dislocation Of The Patella In Young Children: A 13 Year Follow-up Retrospective Study Good morning. Today I will present the results of a long term follow-up study about a surgical technique aimed at treating habitual patellar dislocation in the young child. Benoit Benoit, MD Yves Laflamme, MD Benoit Morin, MD Guy Grimard, MD Dominique Rouleau, MD

Habitual Patellar Dislocation = Severe Functional Disability Habitual patellar dislocation in the young child always mean severe functional disability.

Habitual Patellar Dislocation Dislocation occurs with activities of daily living Sporting activities are almost impossible …bescause dislocation occurs with ADL. Of course, getting involved in sporting activities is impossible.

Factors* Of Patellar Instability (Six) According to Insall, there are 6 factors of patellar instability. *Insall and Salvati, 2001

Factors of patellar instability 1) Patella alta First, patella alta. A L T

Radiologic Patellar Height Assessment In The Immature Patient Koshino-Sugimoto Caton-Deschamps Of these, patella alta is probably the most important one. In the young child, the Kushino-Sugimoto or the Caton-Deschamps method are the most appropriate to determine patellar height.

PT/FT = 1 Koshino-Sugimoto F F P P T T Here is how to measure patellar height with the Koshino-Sugimoto ratio. First, you draw the longitudinal axis of the patella. Then you draw a line overlying femoral and tibial physis. Finally, you join the middle of these lines and measure them. PT on FT is the ratio. T T Koshino-Sugimoto

AT/PA: 0.6-1.3 Caton-Deschamps P P A A T T Caton-Deschamps method is more simple. You draw a line over the long axis of patella’s articular surface. Then you join the inferior part of it with the anterior aspect of the tibia’s surface. AT on PA is the ratio. Caton-Deschamps

Factors of patellar instability 2) Hypoplastic Femoral Sulcus 160° Second, Hypoplastic femoral sulcus.

> 150° = Trochlear dysplasia N = 138° > 150° = Trochlear dysplasia

Factors of patellar instability 3) Patellar Dysplasia Third, patellar dysplasia. Wiberg Classification

Factors of patellar instability 4) Muscle Imbalance (VMO dysplasia) Fourth, VMO dysplasia.

Factors of patellar instability 5) Increased Q angle Fifth, Increased Q-angle.

Factors of patellar instability 6) Lower Limb Malalignment And sixth, Lower limb malalignment

Treatment options? What are the treatment options for a 9 yo child with this biomechanical problem?

No study addresses specifically habitual patellar dislocation in the young child First of all, no litterature address specifically habitual patellar dislocation in the young child.

Treatment Options Conservative Surgical Physical therapy Knee bracing In the older population, litterature suggests to start with conservative treatment for 6 months. If it fails, we should switch to surgery.

Does knee bracing prevent habitual patellar dislocation ? But does knee bracing really prevent habitual patellar dislocation?

Does physical therapy prevent habitual patellar dislocation ? And what about quad strenghtening?

+

+ 40% Recurrence rate: Garth, Am J Sports Med, 1996 According to one article, reccurence rate is 40% for recurrent patellar dislocation. Of course it would be even higher for habitual dislocation. Garth, Am J Sports Med, 1996

Surgical treatment

Literature “Patella alta must absolutely be treated to obtain a satisfactory result” Many authors, in the past, have recognized that patella alta must be addressed to treat patellar dislocation successfully. A L T A L T Caton, J. Revue Chir. Ortho., 1990

Literature A L T “Most common technical error in distal realignment is failure to correct patellar height” Insall sais tha the Most common technical error in distal realignment is failure to correct patellar height” Insall J., JBJS, 1976 Scuderi G. R., OCNA, 1992

Excessive medialization Posterior recessing Distal realignment Excessive medialization Posterior recessing Late osteoarthritis Insall, JBJS, 1976

Surgical Options In The Patient With Open Physis Roux-Golthwait Galeazzi Roux-Goldwaith and Galeazzi described the two techniques used in the growing child.

Roux-Goldthwait The Roux-Goldthwait procedure splits the patellar tendon. The lateral half is transferred medially, under its medial counterpart.

Galeazzi The Galeazzi procedure is a tenodesis of the semitendinosus. transfers the semitendinosus to the inferior pole of the patella. From there, it courses through a drill hole placed obliquely through the patella, exiting the superior lateral aspect. The tendon is then sutured to the soft tissues. This provides a medial tether and effectively alters the net vector of the patellar tendon toward the medial side. Typically, the vastus medialis is advanced approximately one-third the width of the patella.

Roux-Goldthwait Galeazzi P A T E L VS But none of these techniques treat patella alta.

P A T E L Roux-Goldthwait Galeazzi

Bony procedures not appropriate Elmslie-Trillat And as you can figure, bony procedures on tibial tubercle are not appropriate in the immature child… A, B: The Elmslie-Trillat technique shifts the tibial tubercle medially. The tubercle stays in the same plane. C: The Fulkerson modification involves an oblique cut that results in anterior translation as the tubercle is moved medially. This reduces the patellofemoral contact forces while shifting the pull of the patella medially. D: The Maquet procedure moves the tibial tubercle anteriorly by inserting a block of bone. This diminishes the patellofemoral contact forces but does not medialize the pull of the patellar tendo Fulkerson

Tibial tubercule transfer on the knee with open physis Genu recurvatum …because they will lead to genu recurvatum by closing the the anterior part of the tibial plateau’s physis

In summary, the soft tissue procedures that are described to treat recurrent patellar dislocation in the patient with open physis are:

Long term follow-up (13.8 years) Goal of our study Clinical evaluation of a new procedure to correct patella alta in children with patellar instability Long term follow-up (13.8 years) The goal of Our study is the Clinical evaluation of a procedure to correct patella alta in children with patellar instability. We have a mean of 13.8 years of follow-up.

Materials and methods Retrospective study

Materials and methods Retrospective study 12 consecutive knees treated surgically in young children from 1988 to 1994

Materials and methods Retrospective study 12 knees in young children treated surgically Follow-up: 10-17 years (mean 13.8 years)

Materials and methods Retrospective study 12 knees in young children treated surgically Follow-up: 10-17 years (mean 13.8 years) Mean age at surgery: 10 years (6-14 years)

Materials and methods Retrospective study 12 knees in young children treated surgically Follow-up: 10-17 years (mean 13.8 years) Mean age at surgery: 10 years (6-14 years) Mean age at last follow-up: 25 years

Materials and methods Inclusion criterias Habitual patellar dislocation Functional limitations in activities of daily living Symptoms of more than 1 year duration Inclusion criterias were:

Failure of conservative treatment (bracing and physical therapy) Growth plates opened at time of surgery

Materials and methods Preoperative clinical evaluation High-riding patella VMO dysplasia Normal Q-angle Positive apprehension test Lateral patellar laxity IV/IV At preop clinical evaluation, all patients presented:

Radiographic measures Sulcus angle Patellar height …were measured at each visit

Surgical technique Proximal realignment: Distal realignment: NEW! Lateral release VMO advancement Distal realignment: Complete patellar tendon lowering Hughston technique Our surgical technique involved a formal proximal realignment as described by Hughston with a lateral release and a VMO advancement and reefing. The innovation in our technique involved a complete patellar tendon lowering. NEW!

Patellar tendon dissection Tibial tubercule Patellor tendon exposed. Periosteum is removed distal to patellar tendon insertion to form the receiving bed. Here, patella has to be lowered by 2.5 cm as templated preop. Templated advancement: 2.5 cm Patellar tendon

Patellar tendon elevation Tibial tubercle Patellar tendon is elevated off tibial tubercule with a scalpel

Tendon preparation Receiving bed Transosseous sutures The receiving bed on tibial metaphysis is prepared. Criss-cross sutures exit the tendon distally and will be anchored with transosseous stitches…

Distal tendon transfer …as shown on this picture.

Tendon attached Finally, patellar tendon new insertion is secured with multiple peripheral stitches.

Results

Mean patellar tendon lowering: 1.6 cm Mean surgical patellar tendon lowering according to preoperative templating was 1.6 cm (1 cm to 2.5 cm)

Results Last follow-up Instability: 0/12 Pain: 1/12 at last follow-up no one redislocated and patellofemoral pain was slight in one patient

Results Last follow-up Lateral glide test Apprehension test Normal in 11/12

Results Lysholm knee score at last follow-up: Mean: 98/100 The most common complaint was minimal discomfort with squating

Recreational activities Results Recreational activities Preop Last f-up (13.8 y) Limited 12/12 1/12 Preop all patients were at least limited in recreational activities. Postop, one is still limited

Results Sulcus Angle Preop 6 m 3.8 y 13.8 y Mean 160° 157° 147° Interesingly, preop mean sulcus angle was 160°, and 13 years later, it went down to 147°.

Mean Patellar Height (Caton-Deschamps) Results Patellar Height Preop 6 m 3.8 y 13.8 y Mean Patellar Height (Caton-Deschamps) N: 0.6-1.3 1.53 0.96 0.97 1.11 All patellas were high before surgery. At follw-up, mean patellar height is in the normal range

Early postoperative complications (3) 1 redislocation (undercorrection) Early reoperation Now stable 1 wound abcess Surgical drainage, Antibiotics Healed 1 peroneal nerve neurapraxia Recovered completely Cast compression?

Late postoperative complications Two patella bajas (Caton ratio) in children operated at 6 and 7 years old

Discussion

Discussion Risks of osteoarthritis minimized by: no unnecessary medialization no posterior recessing high rate of patellofemoral stability Our distal patellar tendon advancement involves: 1+2 and restores patellofemoral stability

Discussion Anatomic repositioning of the patella eliminates delay of patellar engagement maximizes buttressing effect of the lateral condyle, and… By this technique,

…seems to remodel the shallow throchlea in the immature patient

Conclusion Realistic goals were achieved: Functional knee stability Return to active life

Conclusion Addressing patellar height is paramount in the immature patient

Conclusion Patella baja occurred in two patients No clinical or radiological consequence Consequences in the futur??

Conclusion Trochlear remodeling occurs secondary to distal tendon transfer in the immature patient But the most interesting,

Thank you

Who is right? Caton normal Insall: Patella baja

Lateral retinacular release alone in reccurent patellar dislocation 21% redislocation rate (7/33 knees)¹ 35% redislocation rate (7/20 knees)² Dandy and Desai, JBJS Br, 1989 Aglietti et al, J Orthop, 1994

Radiographic Evaluation Lateral 45° Lateral 90° Merchant view Preoperative Postoperative Intermediate follow-up (mean 3.8 years) Latest follow-up (mean 13.8 years) These four xrays were done: Preoperative Postoperative Intermediate follow-up (mean 3.8 years) Latest follow-up (mean 13.8 years)

Results Patellar Height Preop 6 m 3.8 y 13.8 y 1.53 0.96 0.97 1.11 Mean Patellar Height (Caton-Deschamps) N: 0.6-1.3 1.53 0.96 0.97 1.11 Mean Patellar Height (Koshino-Sugimoto) 1.28 1.06 All patellas were high before surgery. At follw-up, mean patellar height is in the normal range

Conclusion The described surgical procedure is a comprehensive and effective approach to habitual patellar dislocation in young children

Lateral release Extended lateral release

Patient preparation First, patient prep

Physical exam (under anesthesia) PE under GE

Lateral release Extended lateral release

VMO advancement

Wound closed Wound is closed in layers.