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Review
. 2019 Nov 16:20:70-77.
doi: 10.1016/j.jor.2019.11.018. eCollection 2020 Jul-Aug.

When does the patella dislocate? A systematic review of biomechanical & kinematic studies

V Dewan  1 , M S L Webb  2 , D Prakash  3 , A Malik  3 , S Gella  3 , C Kipps  4
Affiliations
Review

When does the patella dislocate? A systematic review of biomechanical & kinematic studies

V Dewan et al. J Orthop. .

Abstract

Background: Patellar dislocations are a significant injury with the potential for long term problems. Little work has been done on establishing the mechanism by which this injury occurs.

Objectives: To determine the mechanism of injury of a patella dislocation based on the available published literature and compare them to already proposed theories.

Methods: A systematic review of the literature was conducted following searches performed on MEDLINE, EMBASE and ProQuest from the earliest year of indexing using the following search terms in any combination: "patella", "dislocation", "mechanism of injury", "anatomy", "biomechanical" and "risk factor". A broad inclusion criteria was used that included studies that looked at patellar dislocations and instability with respect to the patellofemoral joint (PFJ) kinematics or altered kinematics of the PFJ. Studies that did not address the kinematics or biomechanics of the PFJ were excluded. Studies were appraised based on their methodology using a combination of the Critical Appraisal Skills Programme tool and the Quality Appraisal for Cadaveric Studies.

Results: 113 studies were identified from a search of MEDLINE, EMBASE and ProQuest databases. Following application of our inclusion criteria, a total of 23 studies were included in our review. 18 of these studies were cadaveric biomechanical studies. The remaining studies were anatomical, imaging based, and a computer simulation based study.

Conclusions: These biomechanical and kinematic studies provide some evidence that a dislocation is likely to occur during early knee flexion with external rotation of the tibia and contraction of the quadriceps. There is limited evidence to support other elements of proposed mechanisms of dislocation.

Keywords: Biomechanical; Cadaveric; Patella; Patellofemoral dislocation.

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Conflict of interest statement

None of the authors have any conflicts of interest to disclose.

Figures

Fig. 1
Fig. 1
PRISMA flow diagram of literature search.
See this image and copyright information in PMC

References

    1. Casteleyn P.P., Handelberg F. Arthroscopy in the diagnosis of occult dislocation of the patella. Acta Orthop Belg. 1989;55:381–383. - PubMed
    1. Hsiao M. Incidence of acute traumatic patellar dislocation among active-duty United States military service members. Am J Sports Med. 2010;38(10):1997–2004. - PubMed
    1. Van Mechelen W., Hlobil H., Kemper H.C. Incidence, severity, aetiology and prevention of sports injuries. A review of concepts. Sport Med. 1992;14:82–99. - PubMed
    1. Critical Appraisal Skills Programme CASP cohort study checklist. 2017. http://docs.wixstatic.com/ugd/dded87_5ad0ece77a3f4fc9bcd3665a7d1fa91f.pdf Available at: Accessed: Date Accessed.
    1. Wilke J., Krause F., Niederer D. Appraising the methodological quality of cadaveric studies: validation of the QUACS scale. J Anat. 2015;226(5):440–446. - PMC - PubMed

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