Patellar Instability in the Skeletally Immature
- 208 Downloads
Purpose of Review
This review will focus on the evaluation and management of patellar instability in the developing patient.
A large number of surgical techniques have been described to prevent recurrent patellofemoral instability in the pediatric population, including both proximal and distal realignment procedures. The wide variety of treatment options highlights the lack of agreement as to the best surgical approach. However, when a comprehensive exam and workup are paired with a surgical plan to address each of the identified abnormalities, outcomes are predictably good.
Patellar instability is a common knee disorder in the skeletally immature patient that presents a unique set of challenges. Rates of re-dislocation in pediatric and adolescent patients are higher than in their adult counterparts. Careful consideration of the physeal and apophyseal anatomy is essential in these patients. While the majority of primary patellar instability events can be treated conservatively, multiple events often require surgical intervention.
KeywordsPediatric patellar instability MPFL Growth plate Guided growth Modified Grammont
Compliance with Ethical Standards
Conflict of Interest
All authors declare that they have no conflict of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: • Of importance
- 4.• Sanders TL, Pareek A, Hewett TE, Stuart MJ, Dahm DL, Krych AJ. High rate of recurrent patellar dislocation in skeletally immature patients: a long-term population-based study. Knee Surg Sports Traumatol Arthrosc. 2017. Skeletally immature patients had a high rate of recurrent instability , 10% of patients in this long term study developed contralateral dislocation and 20% of patients had arthritis at 20 year follow up. Google Scholar
- 10.• Christensen TC, Sanders TL, Pareek A, Mohan R, Dahm DL, Krych AJ. Risk factors and time to recurrent ipsilateral and contralateral patellar dislocations. Am J Sports Med. 2017;45(9):2105–10. Study of 584 patients after 1 st time patella dislocation. At 20 years after a first-time lateral patellar dislocation, the cumulative incidence of recurrent ipsilateral patellar dislocations was 36.0%, compared with 5.4% for contralateral dislocations. Identified female sex, trochlear dysplasia, elevated TT-TG distance, patella alta, and age <18 years at the time of the first dislocation were all associated with ipsilateral recurrence. CrossRefPubMedGoogle Scholar
- 11.Askenberger M, Janarv PM, Finnbogason T, Arendt EA. Morphology and anatomic patellar instability risk factors in first-time traumatic lateral patellar dislocations: a prospective magnetic resonance imaging study in skeletally immature children. Am J Sports Med. 2017;45(1):50–8.CrossRefPubMedGoogle Scholar
- 16.Grelsamer RP, Meadows S. The modified Insall-Salvati ratio for assessment of patellar height. Clin Orthop Relat Res. 1992;282:170–6.Google Scholar
- 23.• Jaquith BP, Parikh SN. Predictors of recurrent patellar instability in children and adolescents after first-time dislocation. J Pediatr Orthop. 2017;37(7):484–90. Reprinted as Table 3, this paper identifies risk factors to predict recurrent instability in the skeletally immature population. CrossRefPubMedGoogle Scholar
- 26.Liu JN, Steinhaus ME, Kalbian IL, et al. Patellar instability management: a survey of the International Patellofemoral Study Group. Am J Sports Med. 2017:363546517732045.Google Scholar
- 50.Galeazzi R. Nuove appliccazioni del trapianto musculare e tendineo [in Italian]. Ard Di Orthop Milano. 1922;38:315–23.Google Scholar
- 52.Hall JE, Micheli LJ, McManama GB Jr. Semitendinosus tenodesis for recurrent subluxation or dislocation of the patella. Clin Orthop Relat Res. 1979;144:31–5.Google Scholar
- 58.• Fabricant PD, Yen YM, Kramer DE, Kocher MS, Micheli LJ, Heyworth BE. Fixation of chondral-only shear fractures of the knee in pediatric and adolescent athletes. J Pediatr Orthop. 2017;37(2):156. Recently presented series calls to attention that traumatic cartilage only shear injuries may be fixed contrary to previous teachings. CrossRefPubMedGoogle Scholar
- 59.• Bachmann M, Rutz E, Brunner R, Gaston MS, Hirschmann MT, Camathias C. Temporary hemiepiphysiodesis of the distal medial femur: MPFL in danger. Arch Orthop Trauma Surg. 2014;134(8):1059–64. Article demonstrates the risk to normal anatomy when placing temporary hemiepiphysiodesis in the growing child. CrossRefPubMedGoogle Scholar
- 61.Parikh SN. Surgical correction for patellar instability and genu valgum in skeletally immature patients. Patellofemoral foundation. Update. 2017;Google Scholar
- 63.• Zaman S, White A, Shi WJ, Freedman KB, Dodson CC. Return-to-play guidelines after medial patellofemoral ligament surgery for recurrent patellar instability: a systematic review. Am J Sports Med. 2017:363546517713663. Systematic review that emphasizes that more research and work needs to be done to determine safe and effective guidelines for return to play after MPFL. Google Scholar
- 64.Krych AJ, O'Malley MP, Johnson NR, et al. Functional testing and return to sport following stabilization surgery for recurrent lateral patellar instability in competitive athletes. Knee Surg Sports Traumatol Arthrosc. 2016.Google Scholar