Sulcus deepening trochleoplasty for patellofemoral instability: A series of 34 cases after 15 years postoperative follow-up.
BACKGROUND
Trochlear dysplasia is one of the main elements of patellofemoral instability. Although correction by trochleoplasty seems logical, the long-term outcome of this procedure is unknown and the progression to osteoarthritis has not been clarified. Thus, we performed a retrospective study of a series of sulcus deepening trochleoplasties with a 15-year follow-up whose goal was to (1) evaluate the long-term clinical outcome and radiological rate of osteoarthritis, and (2) define the results in relation to the type of instability and the grade of dysplasia.


OBJECTIVE
Sulcus deepening trochleoplasty is an effective procedure to stabilize the patellofemoral joint that does not increase the risk of osteoarthritis.


METHODS
This retrospective study analyzed 34 sulcus deepening trochleoplasties based on clinical scores (IKS, Lille, Kujala and Oxford scores) and radiological results (stage of osteoarthritis according to the Iwano score) after a mean follow-up of 15 years (12-19 years). An Insall procedure was systematically associated with an anterior tibial tubercle transfer in 17 cases (7 prior tibial transfers).


RESULTS
No recurrent objective instability was observed. Seven knees had additional surgery after a mean follow-up of 7 years (2-16): 7 underwent conversion to total knee arthroplasty because of progression of osteoarthritis and one knee had tibial tubercle transfer for pain and episodes of the knee giving way. The mean Lille, Kujala and IKS scores increased from 53.3 (30-92), 55 (13-75) and 127 (54-184) to 61.5 (25-93), 76 (51-94) and 152.4 (66-200) respectively between preoperative and follow-up assessment (P<0.05) (revisions included). Functional outcome was significantly better for dysplasia with supratrochlear spurs (IKS score 168 [127-200] versus 153 [98-198] and Kujula score 81.5 [51-98] versus 76 [51-94] [P<0.05]). Patients were satisfied in 65% of the cases and the total mean Oxford score was 24.1/60 (12-45 points). Occasional pain was present in 53% of the cases. The trochlear prominence decreased from 4.9 mm (3-9 mm) to -1.2mm (-7-4mm). Ten cases of preoperative patellofemoral osteoarthritis were identified, but none with>Iwano 2, while osteoarthritis was present in 33/34 cases at the final follow-up with 20 cases>Iwano 2 (65%).


CONCLUSIONS
Sulcus deepening trochleoplasty corrects patellofemoral stability even in patients with severe dysplasia and the long-term functional outcome is better in this group. It does not prevent patellofemoral osteoarthritis. It should be limited to severe dysplasia with supratrochlear spurs and associated with procedures to realign the extensor apparatus.
Université Lille Nord de France, 59000 Lille, France; Services d'orthopédie, hôpital Salengro, CHRU de Lille, place de Verdun, 59037 Lille cedex, France. Electronic address: thomas.rouanet@gmail.com.
T
T
Rouanet
Nord-Genou, hôpital privé La-Louvière, 69, rue de la Louvière, 59042 Lille, France.
F
F
Gougeon
Centre orthopédique Santy, 24, avenue Paul Santy, 69008 Lyon, France.
J M
JM
Fayard
Centre de chirurgie orthopédique, clinique de Saint-Omer, 71, rue Ambroise-Paré, 62575, Blendecques, France.
F
F
Rémy
Université Lille Nord de France, 59000 Lille, France; Services d'orthopédie, hôpital Salengro, CHRU de Lille, place de Verdun, 59037 Lille cedex, France.
H
H
Migaud
Université Lille Nord de France, 59000 Lille, France; Services d'orthopédie, hôpital Salengro, CHRU de Lille, place de Verdun, 59037 Lille cedex, France.
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G
Pasquier
D000293:Adolescent; D000328:Adult; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005269:Femur / Q000601:surgery; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D031222:Patellar Dislocation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D055815:Young Adult
Patellofemoral instability; Trochlear dysplasia; Trochleoplasty