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DOI: 10.1055/s-0034-1398373
First-Time Patellofemoral Dislocation: Risk Factors for Recurrent Instability
Publikationsverlauf
27. Oktober 2014
17. November 2014
Publikationsdatum:
29. Januar 2015 (online)
![](https://www.thieme-connect.de/media/jks/201504/lookinside/thumbnails/10-1055-s-0034-1398373_140028ssa-1.jpg)
Abstract
Patellofemoral instability is a complex problem, which can be difficult to manage. The purpose of this study was to describe the demographics of patients with a first-time patellofemoral dislocation, and identify risk factors for recurrent instability. This was a single institution, institutional review board–approved, retrospective review of >2,000 patients with a patellar dislocation between 1998 and 2010. Inclusion criteria are as follows: (1) no prior history of patellofemoral subluxation or dislocation of the affected knee; (2) X-rays within 4 weeks of the initial instability episode; and (3) a dislocated patella requiring reduction, or history/findings suggestive of acute patellar dislocation (effusion/hemarthrosis, tenderness along the medial parapatellar structures, and apprehension with lateral patellar translation). Clinical records and radiographs were reviewed. The Caton-Deschamps and Insall-Salvati indices were used to evaluate patella alta. Trochlear dysplasia was assessed using the Dejour classification system. Skeletal maturity was graded based on the distal femoral and proximal tibial physes, using one of the following categories: open, closing, or closed. Three hundred twenty-six knees (312 patients) met the aforementioned criteria. There were 145 females (46.5%) and 167 males (53.5%), with an average age of 19.6 years (range, 9–62 years). Thirty-five patients (10.7%) were treated with surgery after the initial dislocation. All others were initially managed nonoperatively. Of the 291 patients managed nonoperatively, 89 (30.6%) had recurrent instability, 44 (49.4%) of which eventually required surgery. Several risk factors for recurrent instability were identified, including younger age (p < 0.01), immature physes (p < 0.01), sports-related injuries (p < 0.01), patella alta (p = 0.02), and trochlear dysplasia (p < 0.01). Sixty-nine percent of patients with a first-time patellofemoral dislocation will stabilize with conservative treatment. However, patients younger than 25 years with trochlear dysplasia have a 60 to 70% risk of recurrence by 5 years. This information is helpful when counseling patients on their risk for recurrent instability and determining the most appropriate treatment plan. The clinical tool shown in Fig. 4 may be especially useful.
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References
- 1 Atkin DM, Fithian DC, Marangi KS, Stone ML, Dobson BE, Mendelsohn C. Characteristics of patients with primary acute lateral patellar dislocation and their recovery within the first 6 months of injury. Am J Sports Med 2000; 28 (4) 472-479
- 2 Buchner M, Baudendistel B, Sabo D, Schmitt H. Acute traumatic primary patellar dislocation: long-term results comparing conservative and surgical treatment. Clin J Sport Med 2005; 15 (2) 62-66
- 3 Fithian DC, Paxton EW, Stone ML , et al. Epidemiology and natural history of acute patellar dislocation. Am J Sports Med 2004; 32 (5) 1114-1121
- 4 Nietosvaara Y, Aalto K, Kallio PE. Acute patellar dislocation in children: incidence and associated osteochondral fractures. J Pediatr Orthop 1994; 14 (4) 513-515
- 5 Shea KG, Grimm NL, Belzer J, Burks RT, Pfeiffer R. The relation of the femoral physis and the medial patellofemoral ligament. Arthroscopy 2010; 26 (8) 1083-1087
- 6 Arendt EA, Fithian DC, Cohen E. Current concepts of lateral patella dislocation. Clin Sports Med 2002; 21 (3) 499-519
- 7 Stefancin JJ, Parker RD. First-time traumatic patellar dislocation: a systematic review. Clin Orthop Relat Res 2007; 455 (455) 93-101
- 8 Dejour D, Le Coultre B. Osteotomies in patello-femoral instabilities. Sports Med Arthrosc Rev 2007; 15 (1) 39-46
- 9 Cash JD, Hughston JC. Treatment of acute patellar dislocation. Am J Sports Med 1988; 16 (3) 244-249
- 10 Bollier M, Fulkerson JP. The role of trochlear dysplasia in patellofemoral instability. J Am Acad Orthop Surg 2011; 19 (1) 8-16
- 11 Cofield RH, Bryan RS. Acute dislocation of the patella: results of conservative treatment. J Trauma 1977; 17 (7) 526-531
- 12 Hawkins RJ, Bell RH, Anisette G. Acute patellar dislocations. The natural history. Am J Sports Med 1986; 14 (2) 117-120
- 13 Mäenpää H, Lehto MU. Patellar dislocation. The long-term results of nonoperative management in 100 patients. Am J Sports Med 1997; 25 (2) 213-217
- 14 Lewallen LW, McIntosh AL, Dahm DL. Predictors of recurrent instability after acute patellofemoral dislocation in pediatric and adolescent patients. Am J Sports Med 2013; 41 (3) 575-581
- 15 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
- 16 Thévenin-Lemoine C, Ferrand M, Courvoisier A, Damsin JP, Ducou le Pointe H, Vialle R. Is the Caton-Deschamps index a valuable ratio to investigate patellar height in children?. J Bone Joint Surg Am 2011; 93 (8) e35
- 17 McCarroll JR, Shelbourne KD, Porter DA, Rettig AC, Murray S. Patellar tendon graft reconstruction for midsubstance anterior cruciate ligament rupture in junior high school athletes. An algorithm for management. Am J Sports Med 1994; 22 (4) 478-484
- 18 Hsiao M, Owens BD, Burks R, Sturdivant RX, Cameron KL. Incidence of acute traumatic patellar dislocation among active-duty United States military service members. Am J Sports Med 2010; 38 (10) 1997-2004
- 19 Balcarek P, Ammon J, Frosch S , et al. Magnetic resonance imaging characteristics of the medial patellofemoral ligament lesion in acute lateral patellar dislocations considering trochlear dysplasia, patella alta, and tibial tuberosity-trochlear groove distance. Arthroscopy 2010; 26 (7) 926-935
- 20 Lippacher S, Reichel H, Nelitz M. Radiological criteria for trochlear dysplasia in children and adolescents. J Pediatr Orthop B 2011; 20 (5) 341-344