title: Tibial Tuberosity Anteromedialization for Patellofemoral Chondral Disease: Prognostic Factors.
abstract: BACKGROUND
  Tibial tuberosity anteromedialization (TTA) is a well-established treatment option for patellofemoral chondral disease that is resistant to nonoperative treatment. However, the prognostic factors of this procedure are unknown.
  
  
  OBJECTIVE
  To analyze the prognostic factors correlated with the midterm outcomes of TTA for patellofemoral chondral disease and determine the survivorship.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  Indications of TTA for chondral disease included skeletal maturity, age <65 years, <grade 3 Kellgren-Lawrence degeneration, and isolated patellofemoral pain for ≥6 months despite nonoperative treatment. Inclusion criteria were (1) patellofemoral chondral disease, (2) TTA with or without lateral release, and (3) minimum 2-year follow-up. Exclusion criteria were (1) previous knee surgeries, (2) previous patellar dislocations, (3) inflammatory/rheumatic conditions, (4) major combined procedures other than lateral release, (5) focal chondral lesions amenable to cartilage repair, and (6) severe trochlear dysplasia. The patients were prospectively evaluated radiographically and clinically using the Western Ontario and McMaster Universities Osteoarthritis Index-Short-Form (WOMAC-SF) and Kujala scores. Different clinical and radiological data were collected (preoperative, intraoperative, and postoperative) and correlated with the outcomes using multiple logistic regression. The Kaplan-Meier survivorship was also evaluated.
  
  
  RESULTS
  From January 2003 to December 2013, among 76 eligible patients, 69 patients (78 knees, 74.4% female) were included, with a mean follow-up of 67.9 ± 34.5 months (range, 24-163 months) and a mean age at the time of surgery of 43.5 ± 16.1 years. The mean preoperative WOMAC-SF (17.8 ± 5.3) and Kujala (49.3 ± 15.6) scores significantly ( P < .001) improved after surgery (WOMAC-SF: 6.6 ± 6.9; Kujala: 74.2 ± 20.5). The patients graded their operated knee as 7.2 ± 2.1 of 10 points, on average, and stated that they would undergo the surgery again in 58 (74.4%) cases. A WOMAC-SF score of >7 points (34.6% of knees) in the multiple regression model was associated with age >45 years (odds ratio [OR], 10.4; 95% CI, 2.0-55.0) and increased femoral anteversion (OR, 7.9; 95% CI, 1.4-44.1). A Kujala score of <80 points (61.5% of knees) was associated with age >45 years (OR, 12.0; 95% CI, 2.6-56.2) and foot pronation (OR, 5.1; 95% CI, 1.3-20.4). Patient satisfaction of <7 of 10 points (32.1% of knees) was associated with positive postoperative patellofemoral crepitus (OR, 3.6; 95% CI, 1.1-11.7). The Kaplan-Meier survivorship of TTA with dissatisfaction (<5/10 points) as an end point was 94% at 43 months, 88% at 77 months, and 77% at 108 months.
  
  
  CONCLUSIONS
  Overall, good outcomes and survivorship (77% at 108 months) were obtained in this case series. However, 25.6% of the patients would not undergo the surgery again. Increased age, increased femoral anteversion, foot pronation, and postoperative patellofemoral crepitus were identified as negative prognostic factors.
authors.affiliation: Ospedale Mauriziano Umberto I, University of Turin, Turin, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Rosso
authors.affiliation: Ospedale Mauriziano Umberto I, University of Turin, Turin, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Rossi
authors.affiliation: Ospedale Civico di Chivasso, Chivasso, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Governale
authors.affiliation: Ospedale S. Luigi Gonzaga, University of Turin, Orbassano, Italy.
authors.forename: Antongiulio
authors.initials: A
authors.lastname: Marmotti
authors.affiliation: Ospedale Mauriziano Umberto I, University of Turin, Turin, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Cherubini
authors.affiliation: Ospedale Mauriziano Umberto I, University of Turin, Turin, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Cottino
authors.affiliation: Ospedale Mauriziano Umberto I, University of Turin, Turin, Italy.
authors.forename: Davide Edoardo
authors.initials: DE
authors.lastname: Bonasia
mesh_terms: D000328:Adult; D002357:Cartilage Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D010329:Patella / Q000000981:diagnostic imaging / Q000601:surgery; D017060:Patient Satisfaction; D011859:Radiography; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome
keywords: chondral lesion; knee; patellofemoral; tibial tubercle anteromedialization; tibial tubercle osteotomy