Korean J Radiol.  2018 Apr;19(2):292-300. 10.3348/kjr.2018.19.2.292.

The Correlation between the Injury Patterns of the Medial Patellofemoral Ligament in an Acute First-Time Lateral Patellar Dislocation on MR Imaging and the Incidence of a Second-Time Lateral Patellar Dislocation

• Zhang GY
• Zhu HX
• Li EM
• Shi H
• Liu W
• Zheng L
• Bai ZW
• Ding HY

• KMID: 2404926
• DOI: http://doi.org/10.3348/kjr.2018.19.2.292

Abstract

OBJECTIVE
To evaluate the correlation between the injury patterns of the medial patellofemoral ligament (MPFL) on magnetic resonance imaging in an acute first-time lateral patellar dislocation (LPD) and incidence of a second-time LPD.
MATERIALS AND METHODS
Magnetic resonance images were prospectively analyzed in 147 patients after an acute first-time LPD with identical nonoperative management. The injury patterns of MPFL in acute first-time LPDs were grouped by location and severity for the analysis of the incidence of second-time LPD in a 5-year follow-up. Independent t tests, chi-square tests and Kruskal-Wallis tests were performed as appropriate.
RESULTS
Forty-six cases (46/147, 31.3%) of second-time LPD were present at the 5-year follow-up. Fourteen (14/62, 22.6%) and 31 cases (31/80, 38.8%) were present in the partial and complete MPFL tear subgroups, respectively. Twenty-five cases (25/65, 38.5%), 11 cases (11/26, 42.3%), and 8 cases (8/47, 17%) were present in the isolated femoral-side MPFL tear (FEM), combined MPFL tear (COM), and isolated patellar-side MPFL tear (PAT) subgroups, respectively. Compared with the partial MPFL tears, complete tears showed higher incidence of a second-time LPD (p = 0.04). The time interval between the two LPDs was shorter in the complete MPFL tear subgroup (24.2 months) than in the partial tear subgroup (36.9 months, p = 0.001). Compared with the PAT subgroup, the FEM and COM subgroups showed a higher incidence of a second-time LPD (p = 0.025). The time intervals between the two LPDs were shorter in the FEM and COM subgroups (20.8 months and 19.2 months) than in the PAT subgroup (32.5 months, p = 0.049).
CONCLUSION
A complete MPFL tear, isolated femoral-side tear and combined tear in a first-time LPD predispose a second-time LPD.

Keyword

Patellar dislocation; Knee; Medial patellofemoral ligament; Recurrence; MRI

MeSH Terms

Follow-Up Studies
Humans
Incidence*
Knee
Ligaments*
Magnetic Resonance Imaging*
Patellar Dislocation*
Prospective Studies
Recurrence
Tears

Figure

• 

  Fig. 1 14-year-old girl was diagnosed with partial MPFL tear at its patellar insertion in acute first-time LPD.After 22 months, she had recurrent LPD. Axial fat-saturated proton density-weighted fast spin-echo imaging sequence shows irregularity with intraligamentous edema of MPFL at its patellar insertion (arrow) in first-time LPD. LPD = lateral patellar dislocation, MPFL = medial patellofemoral ligament

• 

  Fig. 2 16-year-old male was diagnosed with partial MPFL tear at its femoral attachment in acute first-time LPD.After 23 months, he had recurrent LPD. Axial fat-saturated proton density-weighted fast spin-echo imaging sequence shows irregularity with intraligamentous and periligamentous edema of MPFL at its femoral attachment (arrow) in first-time LPD.

• 

  Fig. 3 24-year-old man was diagnosed with complete MPFL tear at its femoral attachment in acute first-time LPD. After 16 months, he had recurrent LPD.Axial fat-saturated proton density-weighted fast spin-echo imaging sequence shows complete discontinuity of MPFL at its femoral attachment with retraction of fibers anteriorly and extensive surrounding edema (open arrow) in first-time LPD.

• 

  Fig. 4 22-year-old woman was diagnosed with combined MPFL injury (complete MPFL tear at its femoral attachment and patellar insertion) in acute first-time LPD.After 7 months, she had recurrent LPD. Axial fat-saturated proton density-weighted fast spin-echo imaging sequence shows complete discontinuity of MPFL at its patellar insertion and femoral attachment with retraction of fibers and extensive surrounding edema (arrows) in first-time LPD. Note also small avulsion fracture from medial margin of patella.

Reference

1. Casteleyn PP, Handelberg F. Arthroscopy in the diagnosis of occult dislocation of the patella. Acta Orthop Belg. 1989; 55:381–383. PMID: 2603678.

2. Balcarek P, Jung K, Ammon J, Walde TA, Frosch S, Schüttrumpf JP, et al. Anatomy of lateral patellar instability: trochlear dysplasia and tibial tubercle-trochlear groove distance is more pronounced in women who dislocate the patella. Am J Sports Med. 2010; 38:2320–2327. PMID: 20713643.

3. Balcarek P, Oberthür S, Hopfensitz S, Frosch S, Walde TA, Wachowski MM, et al. Which patellae are likely to redislocate? Knee Surg Sports Traumatol Arthrosc. 2014; 22:2308–2314. PMID: 24005331.

4. Camp CL, Heidenreich MJ, Dahm DL, Stuart MJ, Levy BA, Krych AJ. Individualizing the tibial tubercle-trochlear groove distance: patellar instability ratios that predict recurrent instability. Am J Sports Med. 2016; 44:393–399. PMID: 26394888.

5. Diederichs G, Issever AS, Scheffler S. MR imaging of patellar instability: injury patterns and assessment of risk factors. Radiographics. 2010; 30:961–981. PMID: 20631363.

6. Jaquith BP, Parikh SN. Predictors of recurrent patellar instability in children and adolescents after first-time dislocation. J Pediatr Orthop. 2017; 37:484–490. PMID: 26491910.

7. Lewallen L, McIntosh A, Dahm D. First-time patellofemoral dislocation: risk factors for recurrent instability. J Knee Surg. 2015; 28:303–309. PMID: 25633361.

8. Lewallen LW, McIntosh AL, Dahm DL. Predictors of recurrent instability after acute patellofemoral dislocation in pediatric and adolescent patients. Am J Sports Med. 2013; 41:575–581. PMID: 23339838.

9. Seeley M, Bowman KF, Walsh C, Sabb BJ, Vanderhave KL. Magnetic resonance imaging of acute patellar dislocation in children: patterns of injury and risk factors for recurrence. J Pediatr Orthop. 2012; 32:145–155. PMID: 22327448.

10. Steensen RN, Bentley JC, Trinh TQ, Backes JR, Wiltfong RE. The prevalence and combined prevalences of anatomic factors associated with recurrent patellar dislocation: a magnetic resonance imaging study. Am J Sports Med. 2015; 43:921–927. PMID: 25587185.

11. Buckens CF, Saris DB. Reconstruction of the medial patellofemoral ligament for treatment of patellofemoral instability: a systematic review. Am J Sports Med. 2010; 38:181–188. PMID: 19966098.

12. Camanho GL, Viegas Ade C, Bitar AC, Demange MK, Hernandez AJ. Conservative versus surgical treatment for repair of the medial patellofemoral ligament in acute dislocations of the patella. Arthroscopy. 2009; 25:620–625. PMID: 19501292.

13. Giordano M, Falciglia F, Aulisa AG, Guzzanti V. Patellar dislocation in skeletally immature patients: semitendinosous and gracilis augmentation for combined medial patellofemoral and medial patellotibial ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2012; 20:1594–1598. PMID: 22116266.

14. Petri M, Liodakis E, Hofmeister M, Despang FJ, Maier M, Balcarek P, et al. Operative vs conservative treatment of traumatic patellar dislocation: results of a prospective randomized controlled clinical trial. Arch Orthop Trauma Surg. 2013; 133:209–213. PMID: 23138693.

15. Sillanpää PJ, Peltola E, Mattila VM, Kiuru M, Visuri T, Pihlajamäki H. Femoral avulsion of the medial patellofemoral ligament after primary traumatic patellar dislocation predicts subsequent instability in men: a mean 7-year nonoperative follow-up study. Am J Sports Med. 2009; 37:1513–1521. PMID: 19376939.

16. Sillanpää PJ, Salonen E, Pihlajamäki H, Mäenpää HM. Medial patellofemoral ligament avulsion injury at the patella: classification and clinical outcome. Knee Surg Sports Traumatol Arthrosc. 2014; 22:2414–2418. PMID: 25059336.

17. Zhang GY, Zheng L, Ding HY, Li EM, Sun BS, Shi H. Evaluation of medial patellofemoral ligament tears after acute lateral patellar dislocation: comparison of high-frequency ultrasound and MR. Eur Radiol. 2015; 25:274–281. PMID: 25187383.

18. Zhang GY, Zheng L, Feng Y, Shi H, Liu W, Ji BJ, et al. Injury patterns of medial patellofemoral ligament and correlation analysis with articular cartilage lesions of the lateral femoral condyle after acute lateral patellar dislocation in adults: an MRI evaluation. Injury. 2015; 46:2413–2421. PMID: 26462959.

19. Zhang GY, Zheng L, Shi H, Ji BJ, Feng Y, Ding HY. Injury patterns of medial patellofemoral ligament after acute lateral patellar dislocation in children: correlation analysis with anatomical variants and articular cartilage lesion of the patella. Eur Radiol. 2017; 27:1322–1330. PMID: 27352088.

20. Zhang GY, Zheng L, Shi H, Liu W, Zhang L, Qu SH, et al. Correlation analysis between injury patterns of medial patellofemoral ligament and vastus medialis obliquus after acute first-time lateral patellar dislocation. Knee Surg Sports Traumatol Arthrosc. 2016; 12. 27. [Epub]. DOI: 10.1007/s00167-016-4408-3.

21. Zheng L, Shi H, Feng Y, Sun BS, Ding HY, Zhang GY. Injury patterns of medial patellofemoral ligament and correlation analysis with articular cartilage lesions of the lateral femoral condyle after acute lateral patellar dislocation in children and adolescents: an MRI evaluation. Injury. 2015; 46:1137–1144. PMID: 25724397.

22. Askenberger M, Arendt EA, Ekström W, Voss U, Finnbogason T, Janarv PM. Medial patellofemoral ligament injuries in children with first-time lateral patellar dislocations: a magnetic resonance imaging and arthroscopic study. Am J Sports Med. 2016; 44:152–158. PMID: 26602152.

23. Balcarek P, Walde TA, Frosch S, Schüttrumpf JP, Wachowski MM, Stürmer KM, et al. Patellar dislocations in children, adolescents and adults: a comparative MRI study of medial patellofemoral ligament injury patterns and trochlear groove anatomy. Eur J Radiol. 2011; 79:415–420. PMID: 20638212.

24. Elias DA, White LM, Fithian DC. Acute lateral patellar dislocation at MR imaging: injury patterns of medial patellar soft-tissue restraints and osteochondral injuries of the inferomedial patella. Radiology. 2002; 225:736–743. PMID: 12461254.

25. Lippacher S, Dejour D, Elsharkawi M, Dornacher D, Ring C, Dreyhaupt J, et al. Observer agreement on the Dejour trochlear dysplasia classification: a comparison of true lateral radiographs and axial magnetic resonance images. Am J Sports Med. 2012; 40:837–843. PMID: 22238057.

26. Bitar AC, Demange MK, D'Elia CO, Camanho GL. Traumatic patellar dislocation: nonoperative treatment compared with MPFL reconstruction using patellar tendon. Am J Sports Med. 2012; 40:114–122. PMID: 22016458.

27. Köhlitz T, Scheffler S, Jung T, Hoburg A, Vollnberg B, Wiener E, et al. Prevalence and patterns of anatomical risk factors in patients after patellar dislocation: a case control study using MRI. Eur Radiol. 2013; 23:1067–1074. PMID: 23192374.

28. Schoettle PB, Zanetti M, Seifert B, Pfirrmann CW, Fucentese SF, Romero J. The tibial tuberosity-trochlear groove distance; a comparative study between CT and MRI scanning. Knee. 2006; 13:26–31. PMID: 16023858.

29. Brown GD, Ahmad CS. Combined medial patellofemoral ligament and medial patellotibial ligament reconstruction in skeletally immature patients. J Knee Surg. 2008; 21:328–332. PMID: 18979937.

30. Conlan T, Garth WP Jr, Lemons JE. Evaluation of the medial soft-tissue restraints of the extensor mechanism of the knee. J Bone Joint Surg Am. 1993; 75:682–693. PMID: 8501083.

31. Desio SM, Burks RT, Bachus KN. Soft tissue restraints to lateral patellar translation in the human knee. Am J Sports Med. 1998; 26:59–65. PMID: 9474403.

32. Philippot R, Boyer B, Testa R, Farizon F, Moyen B. The role of the medial ligamentous structures on patellar tracking during knee flexion. Knee Surg Sports Traumatol Arthrosc. 2012; 20:331–336. PMID: 21748394.

33. Balcarek P, Ammon J, Frosch S, Walde TA, Schüttrumpf JP, Ferlemann KG, 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; 26:926–935. PMID: 20620792.

34. Felus J, Kowalczyk B. Age-related differences in medial patellofemoral ligament injury patterns in traumatic patellar dislocation: case series of 50 surgically treated children and adolescents. Am J Sports Med. 2012; 40:2357–2364. PMID: 22962292.

35. Kepler CK, Bogner EA, Hammoud S, Malcolmson G, Potter HG, Green DW. Zone of injury of the medial patellofemoral ligament after acute patellar dislocation in children and adolescents. Am J Sports Med. 2011; 39:1444–1449. PMID: 21372313.

36. Putney SA, Smith CS, Neal KM. The location of medial patellofemoral ligament injury in adolescents and children. J Pediatr Orthop. 2012; 32:241–244. PMID: 22411327.

37. Sillanpää PJ, Mäenpää HM, Mattila VM, Visuri T, Pihlajamäki H. Arthroscopic surgery for primary traumatic patellar dislocation: a prospective, nonrandomized study comparing patients treated with and without acute arthroscopic stabilization with a median 7-year follow-up. Am J Sports Med. 2008; 36:2301–2309. PMID: 18762668.

38. Zhang GY, Zheng L, Shi H, Qu SH, Ding HY. Sonography on injury of the medial patellofemoral ligament after acute traumatic lateral patellar dislocation: injury patterns and correlation analysis with injury of articular cartilage of the inferomedial patella. Injury. 2013; 44:1892–1898. PMID: 24074831.

39. Aragäo JA, Reis FP, de Vasconcelos DP, Feitosa VL, Nunes MA. Metric measurements and attachment levels of the medial patellofemoral ligament: an anatomical study in cadavers. Clinics (Sao Paulo). 2008; 63:541–554. PMID: 18719768.

40. Kikuchi S, Tajima G, Yan J, Kamei Y, Maruyama M, Sugawara A, et al. Morphology of insertion sites on patellar side of medial patellofemoral ligament. Knee Surg Sports Traumatol Arthrosc. 2017; 25:2488–2493. PMID: 26744281.

41. Panagiotopoulos E, Strzelczyk P, Herrmann M, Scuderi G. Cadaveric study on static medial patellar stabilizers: the dynamizing role of the vastus medialis obliquus on medial patellofemoral ligament. Knee Surg Sports Traumatol Arthrosc. 2006; 14:7–12. PMID: 16001289.

42. Weber-Spickschen TS, Spang J, Kohn L, Imhoff AB, Schottle PB. The relationship between trochlear dysplasia and medial patellofemoral ligament rupture location after patellar dislocation: an MRI evaluation. Knee. 2011; 18:185–188. PMID: 20494581.

43. Erickson BJ, Mascarenhas R, Sayegh ET, Saltzman B, Verma NN, Bush-Joseph CA, et al. Does operative treatment of first-time patellar dislocations lead to increased patellofemoral stability? A systematic review of overlapping meta-analyses. Arthroscopy. 2015; 31:1207–1215. PMID: 25636989.

44. Nwachukwu BU, So C, Schairer WW, Green DW, Dodwell ER. Surgical versus conservative management of acute patellar dislocation in children and adolescents: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2016; 24:760–767. PMID: 26704809.

45. Palmu S, Kallio PE, Donell ST, Helenius I, Nietosvaara Y. Acute patellar dislocation in children and adolescents: a randomized clinical trial. J Bone Joint Surg Am. 2008; 90:463–470. PMID: 18310694.

46. Sillanpää PJ, Mäenpää HM. First-time patellar dislocation: surgery or conservative treatment? Sports Med Arthrosc. 2012; 20:128–135. PMID: 22878653.

47. Sillanpää PJ, Mattila VM, Mäenpää H, Kiuru M, Visuri T, Pihlajamäki H. Treatment with and without initial stabilizing surgery for primary traumatic patellar dislocation. A prospective randomized study. J Bone Joint Surg Am. 2009; 91:263–273. PMID: 19181969.

48. Smith TO, Donell S, Song F, Hing CB. Surgical versus non-surgical interventions for treating patellar dislocation. Cochrane Database Syst Rev. 2015; CD008106. PMID: 25716704.

49. Wang SN, Qin CH, Jiang N, Wang BW, Wang L, Yu B. Is surgical treatment better than conservative treatment for primary patellar dislocations? A meta-analysis of randomized controlled trials. Arch Orthop Trauma Surg. 2016; 136:371–379. PMID: 26718351.

50. Nomura E, Inoue M, Kobayashi S. Long-term follow-up and knee osteoarthritis change after medial patellofemoral ligament reconstruction for recurrent patellar dislocation. Am J Sports Med. 2007; 35:1851–1858. PMID: 17724092.

51. Howells NR, Barnett AJ, Ahearn N, Ansari A, Eldridge JD. Medial patellofemoral ligament reconstruction: a prospective outcome assessment of a large single centre series. J Bone Joint Surg Br. 2012; 94:1202–1208. PMID: 22933491.

52. Kita K, Tanaka Y, Toritsuka Y, Amano H, Uchida R, Takao R, et al. Factors affecting the outcomes of double-bundle medial patellofemoral ligament reconstruction for recurrent patellar dislocations evaluated by multivariate analysis. Am J Sports Med. 2015; 43:2988–2996. PMID: 26435448.

53. Matsushita T, Kuroda R, Oka S, Matsumoto T, Takayama K, Kurosaka M. Clinical outcomes of medial patellofemoral ligament reconstruction in patients with an increased tibial tuberosity-trochlear groove distance. Knee Surg Sports Traumatol Arthrosc. 2014; 22:2438–2444. PMID: 24584694.

54. Nelitz M, Dreyhaupt J, Reichel H, Woelfle J, Lippacher S. Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents with open growth plates: surgical technique and clinical outcome. Am J Sports Med. 2013; 41:58–63. PMID: 23111806.

55. Steiner TM, Torga-Spak R, Teitge RA. Medial patellofemoral ligament reconstruction in patients with lateral patellar instability and trochlear dysplasia. Am J Sports Med. 2006; 34:1254–1261. PMID: 16567459.

56. Wagner D, Pfalzer F, Hingelbaum S, Huth J, Mauch F, Bauer G. The influence of risk factors on clinical outcomes following anatomical medial patellofemoral ligament (MPFL) reconstruction using the gracilis tendon. Knee Surg Sports Traumatol Arthrosc. 2013; 21:318–324. PMID: 22538501.

57. Balcarek P, Walde TA, Frosch S, Schüttrumpf JP, Wachowski MM, Stürmer KM. MRI but not arthroscopy accurately diagnoses femoral MPFL injury in first-time patellar dislocations. Knee Surg Sports Traumatol Arthrosc. 2012; 20:1575–1580. PMID: 22095485.

58. Nomura E, Horiuchi Y, Inoue M. Correlation of MR imaging findings and open exploration of medial patellofemoral ligament injuries in acute patellar dislocations. Knee. 2002; 9:139–143. PMID: 11950578.