BIMALLEOLAR FRACTURES mechanism and anapath.pptx

in this topic we did a reminder of bimalleolar fractures

1. BIMALLEOLAR FRACTURES ( MECHANISM+ANAPATH ) PRESENTED BY: DR AGGOUN

2. PLAN I.DEFINITION II.ANATOMIC RECALL III.MECHANISM IV.ANAPATH V.ANATOPATHOLOGICAL CLASSIFICATIONS VI.CONCLUSION VII.REFERENCES

3. DEFINITION fractures involve both the lateral and medial malleoli at the distal ends of the fibula and tibia, respectively. These two bones articulate with the talus to form the ankle( tibiotalar ) joint . The ankle is supported by ligaments on both the medial and lateral sides that stabilize the foot under the leg and lock the fibula and tibia together. These fractures can affect these ligaments, too. Damage to the ligaments, instead of a fracture of one of the malleoli, still produces an unstable fracture that will likely need surgical intervention

4. ANATOMIC RECALL

5. MECHANISM 1 . Direct shock: very rare, providing open foot and ankle fractures 2 . Indirect shock: 90% of cases, foot blocked in external physiological position (eversion or inversion) on which is exercised the indirect mechanism by fall of the patient which transmits to the jambier skeleton a vulnerative force which acts on the malleolar clamp either according to a frontal component ( ABD , ADD ) or according to a rotational component , it is the rotation of the leg around a vertical axis . 03 mechanisms: - By abduction - By adduction - Rotation

6. MECHANISM a. Adduction fracture: the foot blocked in inversion falls from the body laterally inside, the adduction puts in tension the external osteo -ligament system which can: - Either break: sprain - Or pull the external malleolus according to transverse line under tubercular; the talus tilts inside, will bump against the IM and the fracture according to a vertical or oblique line, sometimes there is a fracture of the internal part of tibial pilon

7. MECHANISM b. Abduction fracture: foot blocked in Eversion ( Talus, pronation , abduction ) , body falls laterally out . Abduction: puts tension on the osteo – internal ligament system which can: - Either break (sprain) - Or pull the MI in a transverse line If the mechanism continues, the released talus tilts outside and will put pressure on the external malleolus that tends to move away from the tibial gutter. The 02 inf tibio –fibular ligts break causing a diastasis then we will have: - LLE rupture: bi-malleolar equivalent - Either a fracture is the ext malleolus above the tibial tubercles ant and post (high or low) the talus may fracture the outer portion of the tibial pilon

8. MECHANISM c. Rotational fracture: most often external The talus rotates outwards around a vertical axis, exerting pressure on the lateral malleolus: If the talus continues to rotate, the medial side of the bone rests on the lateral edge of the medial malleolus, breaking it (transverse line). If the trauma continues, the talus blows out the posterior margin of the tibia.

9. ANAPATH 1.Fracture line a. EM: 03 types : Subtubercular line : often transverse Inter-tubercular line : often oblique, spiral Supra-tubercular line : - Low-lying: spiral, transverse, oblique, comminuted - Highly situated: maximum at the level of the neck of the fibula: classic Maisonneuve fracture

10. ANAPATH b. IM : Line of the tip of the IM that tears the LLI (bi-malleolar equivalent) Transverse line across the middle of the cheek Transverse line flush with pilon Basial malleolar line oblique upwards and outwards, very unstable fracture NB: vertical FR of the Ant tubercule : FR WAGSTAFFE - LE FORT

11. ANAPATH 2. associated bone lesions : A. mortise roof lesions : - marginal post FR :Extra-articular tearing of the tibial insertion of the post tibiofibular ligament - COTTON tri-malleolar FR - Ant marginal FR: ASTLEY -COOPER RF Tearing of anterior tubercle by Ant tibio -fibular ligt - FR compression of medial tibial pilon (Adduction ) - Cartilaginous compression: of pilon or talar dome B. Fracture of talus: osteoarticular lesion , Dc Rx difficult: CT scan

12. ANATOMOPATHOLOGICAL CLASSIFICATIONS Based on : THE MECHANISM OF INJURY THE HEIGHT OF THE FIBULAR LINE IN RELATION TO THE SYNDESMOSIS Three classifications: LAUGE - HANSEN (1942) DANIS - WEBER DUPARC - ALNOT (1969)

13. DUPARC AND ALNOT CLASSIFICATION It based on the MECHANISM and the HEIGHT OF THE FIBULAR line compared to the fibular tubercles . Four types

14. DUPARC AND ALNOT CLASSIFICATION Type I: undertubercular FR due to Adduction 5 % The foot is blocked in inversion and the body falls on the opposite side. - EM: transverse subtubercular line (below the TPI lgts ) or rupture of the LLE if the malleolus resists . - IM: vertical or oblique basimalleolar line, sometimes compression of the medial part of the tibial pilon . - Syndesmosis: intact, no diastasis

15. DUPARC AND ALNOT CLASSIFICATION Type II: supra-tubercular with abduction fracture : the foot is locked in eversion, the body falls laterally the LM line is supratubercular , transverse with external communition the IM line is transverse at the midpoint or tip the syndesmosis is damaged

16. DUPARC AND ALNOT CLASSIFICATION Type III: supra-tubercular external rotation fracture : the foot is locked in eversion and the body falls in internal rotation o the LM line is spiral above the tubercle or intertubercular the IM line is transverse osyndesmosis is affected Frequently associated with fracture of the posterior margin

17. DUPARC AND ALNOT CLASSIFICATION Type IV: inter-tubular external rotation FR EM: oblique intertubercular line or spiral passes between the TPI ligaments IM : transverse line or LLI rupture if MI resists -Syndesmosis: - LPT post is ruptured, or torn from its bony insertion (tri-malleolar RF ) - LPT Ant maybe ruptured or not

18. LAUGE - HANSEN CLASSIFICATION The Lauge -Hansen classification system is used for classifying ankle injuries based on injury mechanisms with predictable patterns and imaging findings The Lauge -Hansen system uses two-word descriptors : -the first word describes the position of the foot at the time of injury (supination or pronation ) -the second word describes the deforming force direction (abduction , adduction, or external rotation ) Based on these two factors, at least 13 different patterns have been described:

19. LAUGE - HANSEN CLASSIFICATION

20. LAUGE - HANSEN CLASSIFICATION

21. DANIS-WEBER CLASSIFICATION A simple system for classification of lateral malleolar fractures relating to the level of the fracture in relation to the distal tibiofibular syndesmosis . type A: below the level of the syndesmosis ( infrasyndesmotic ) type B: distal extent at the level of the syndesmosis type C: above the level of the syndesmosis ( suprasyndesmotic )

22. CONCLUSION Bimalleolar fractures typically occur due to excessive force applied to the ankle, particularly involving foot eversion or high-energy impact. While pinpointing the exact mechanism can be challenging, understanding the general contributing factors is valuable for both treatment and future risk reduction.

23. REFERENCES Scheer RC, Newman JM, Zhou JJ, Oommen AJ, Naziri Q, Shah NV, Pascal SC, Penny GS, McKean JM, Tsai J, Uribe JA. Ankle Fracture Epidemiology in the United States: Patient-Related Trends and Mechanisms of Injury. J Foot Ankle Surg. 2020 May-Jun;59(3):479-483. [ PubMed] Brockett CL, Chapman GJ. Biomechanics of the ankle. Orthop Trauma. 2016 Jun;30(3):232-238. [PMC free article] [PubMed ] https://www.orthobullets.com/trauma/1047/ankle-fractures?hideLeftMenu=true