ANKLE FRACTURES

1. ANKLE FRACTURES PRESENTED BY SPENCER F. SCHUENMAN D.O. GARDEN CITY HOSPITAL

2. ANATOMY • The ankle is a complex joint consisting of three distinct functional articulations. • Tibia and fibula • Tibia and talus • Fibula and talus • Each of these articulations are reinforced by a group of ligaments

3. ANATOMY CONT. • The tibia and fibula form a mortise which provides a constrained articulation for the talus. • The articular surface of the distal tibia (plafond) and the mortise is wider superiorly and anteriorly to accommodate the wedge shaped talus. • This provides some intrinsic stability especially during weight bearing.

4. ANATOMY CONT. • Ankle stability is provided by a combination of three factors. • Bony architecture • The joint capsule • Ligamentous structures (three distinct groups) • Syndesmotic ligaments • Medial collateral ligaments • Lateral collateral ligaments

5. Syndesmotic Ligaments • Comprised of 4 ligaments • Anterior tibiofibular • Posterior tibiofibular • Transverse tibiofibular • Interosseous

6. Medial Collateral • Superficial and deep Deltoids • Posterior tibiotalar • Tibiocalcaneal • Tibionavicular

7. Lateral Collateral • Anterior Talofibular ligament (weakest) • Posterior Talofibular ligament • Calcaneofibular Ligament

8. Tendons and Neurovascular Structures • Thirteen Tendons, two major arteries and veins, and five nerves cross the ankle joint • Four groups of Tendons • Posterior • Achilles and Plantaris • Tibialis Posterior • Flexor Digitorum Longus • Flexor Hallucis Longus • Innervated by Tibial Nerve

9. Tendons and Neurovascular Structures • Anterior • Tibialis Anterior • Extensor Digitorum Longus • Extensor Hallucis Longus • Peroneus Tertius • Innervated by Deep Peroneal nerve • Peroneus Longus and Brevis • Innervated by Superficial Peroneal nerve

10. Anterior N/V bundle Anterior Tibial artery and Deep Peroneal nerve Lies anterior between the EHL and Tib. Ant.. Superficial Sensory Nerves Saphenous nerve-ant. to med. malleolus Superficial Peroneal nerve-ant to midline dorsal foot Sural nerve-post to the fibula Posterior N/V bundle Neurovascular Bundles

11. Ankle Biomechanics • A lateral talar shift of 1mm will decrease surface contact by 40% and a 3 mm shift results in a >60% decrease. • The fibula is essential to providing lateral stability, and maintaining congruency between the talus and the plafond. • A minimum of 10 degrees of dorsiflexion and 20 degrees of plantarflexion are required for normal gait.

12. Clinical Evaluation • Assess the neurovascular status • Assess the condition of the soft tissues • Always palpate proximal and midshaft fibula for tenderness • Reduce a dislocated ankle immediately to prevent pressure or impaction injuries to the talar dome

13. Radiographic Evaluation • AP-Look for talar shift (medial joint widening) and syndesmotic disruption • Lateral- The dome of the talus should be centered under the tibia and congruous with the tibial plafond. Also posterior malleolus fxs can be identified. • Mortise- Taken in 15-20 degrees of internal rotation to offset the rotation of the malleoli. You should see a symmetric joint space on all sides.

14. Classifications-Lauge-Hansen • Four patterns, based on pure injury sequences, each subdivided into stages of increasing severity • System takes into account (1) the position of the foot at the time of injury; (2) the direction of the deforming force. • Based on cadaveric studies • The patterns may not always reflect clinical reality.

15. Supination-adduction (SA) • Accounts for 10-20% of malleolar fxs • The only type assoc. with medial displacement of the talus • I. Fibula fx transverse • II. Med. Malleolus vertical fx or disruption

16. Supination-external rotation (SER) • Accounts for 40-75% of malleolar fxs • I. Disruption of ant talofibular ligament • II. Spiral oblique fx fibula • III. Disruption PTF lig or post malleolar fx • IV. Deltoid disruption or Med malleolar fx

17. Pronation-abduction (PA) • Accounts for 5-20% of malleolar fxs • I. Transverse fx med malleolus or rupture of deltoid • II. Rupture of syndesmotic lig or avulsion fx • III. Transverse or short oblique fibular fx at or above joint line

18. Pronation-external rotation (PER) • Accounts for 5-20% of malleolus fxs • I. Transverse fx med malleolus or rupture of deltoid • II. Disruption of ant tibiofibular lig with or without avulsion fx • III. Spiral fx above level of syndesmosis (3-5cm proximal) • IV. Rupture of post tib/fib lig or post malleolus

19. Classifications-Weber • Types A,B, and C • Based o the level of the fibular fx: the more proximal, the greater the risk of syndesmotic disruption and associated instability • A. Fx below the level of the syndesmosis, avulsion fx resulting from supination of foot. • B. Oblique or spiral fx caused by ext rotation, begins near or at the level of the syndesmosis • C. Fx of fibula above the syndesmosis with almost always assoc med malleolus fx

20. Weber Classification

21. Fracture Variants • Maisonneuve fracture- originally described as and ankle injury with a fracture of the proximal third of the fibula. An external rotation-type injury. Resemble PER fxs. • Curbstone fracture-avulsion fx off the posterior tibia produced by a tripping mechanism. • Leforte-Wagstaffe fracture-anterior fibular tubercle avulsion fracture by the anterior tibiofibular ligament, usually associated with SER fx patterns. • Tilaux-Chaput fracture-avulsion of anterior tibial margin by the ant tibiofibular ligament; counterpart to the LeForte-Wagstaffe fx.

22. Pediatric Classification-Dias and Tachjian • Lauge-Hansen principles correlated with the Salter-Harris classification • Classification simplified by noting the direction of physeal displacement, Salter-Harris type, and location of the metaphyseal fragment. • The four types of classification aids in determining the proper maneuver for closed reduction.

23. Supination-inversion (SI) • Grade I- adduction forces avulse the distal fibular epiphysis (Salter I or II) • Grade II- tibial fx, usually SH III or IV • Require ORIF if displaced • High rate of growth disturbances

24. Supination-plantar flexion (SPL) • The plantarflexion force displaces the epiphysis directly posteriorly, resulting in a SH I or II fx. Fibular fxs are not described with this mechanism.

25. Supination-external rotation (SER) • Grade I- the external rotation force results in a SH II fx of the distal tibia. Distal fragment is displaced post. • Grade II- with further external rotation, a spiral fx of fibula is produced.

26. Pronation-eversion-external rotation (PEER) • A SH I or II fx of the distal tibia occurs simultaneously with a transverse fibular fx. A Thurston-Holland fragment, when present is lateral or posterolateral.

27. Juvenile Tillaux fracture • A SH type III fx involving the anterolateral distal tibia. This takes place in children ages 10-14 when the physis is not yet completely closed.

28. Triplane fractures • A group of fractures that have in common the appearance of a SH III fx on the AP x-ray and a SH II fx on lateral x-ray.

29. Treatment • Incidence of posttraumatic arthritis in the ankle is greater than 90% for displaced fxs and less than 10% for those with accurate stable reduction • The goal of treatment is to restore the ankle joint anatomically. Fibular length and rotation must be restored to obtain an anatomic reduction.

30. Closed Treatment • Only undisplaced, stable fracture patterns with an intact syndesmosis can be treated closed. • If anatomic reduction is achieved with closed manipulation, a short leg cast can be placed for 4-6 weeks. • All fxs should be reduced as well as possible in the emergency room, regardless of eventual treatment.

31. Open Treatment • ORIF is indicated for failure to obtain or maintain a closed reduction. • Widened mortise greater than 1-2 mm should be reduced and fixed if it cannot be stabilized with closed means. • ORIF should be carried out immediately, or, if the soft tissue is in question,wait 4-7 days until swelling subsides.

32. Open Treatment of the Fibula • Restoration of fibular length and rotation is essential in obtaining an accurate reduction. • The fibula is generally held with a lag screw and a 1/3 tubular plate. • Fractures up to the midshaft should be fixed. • Fibula fxs above the syndesmosis generally require a syndesmotic screw. Cottons test can be performed to test for the integrity of the syndesmotic ligament. • The syndesmotic screw is placed 1.5-2.0cm above the joint under max dorsiflexion.

33. Treatment of the Medial and Posterior Malleoli • Medial malleolar fxs can be held with one or two cancellous screws perpendicular to the fx line or with tension bands • Indication for fixation of the posterior malleolus are involvement of >25% of the articular surface, >2 mm displacement, or persistent posterior subluxation of the talus.

34. Treatment of Open Fractures • These require immediate irrigation and debridement in the operating room. • Stable fixation is important prophylaxis against infection and helps soft tissue healing. • Reports have shown that immediate internal fixation can be done with a low incidence of infection • Avoid use of a tourniquet, closed surgical incisions, and leave open wounds open. • Repeat debridement every 2-3 days until the wound is clean, then delayed closure can be performed.

35. Complications • Nonunion-rare; usually the medial malleolus when treated closed. • Malunion • Wound problems • Infection-<2% of closed fxs; leave implants alone when stable, even with deep infection. • Posttraumatic arthritis-seen with 10% of anatomically reduced fxs and 90% of malreduced fxs; usually seen by 18 months • Reflex sympathetic dystrophy • Compartment syndrome of foot