L12 Graves Ankle

Ankle Fracture UpdateOTA Resident Core Curriculum Lecture SeriesUpdated November 2010Matt Graves, M.D.University of Mississippi Medical Center

ObjectivesFollowing this session, you should be able to:

State the indication to fix isolated fibular fractures.

Define the specific articular pathology associated with SA and PAB fractures.

List the 3 common posterior malleolar fracture patterns.

State the indication to fix posterior malleolar fractures.

Enumerate the ways to ensure syndesmotic reduction.

Recommendations to Improve Retention of this MaterialWrite down the objectives

Search for the answers to the objectives in the powerpoint talk [hint- look for blue boxes]

Test yourself at the end by reviewing the objectives

Watch the show on normal view and look at the notes at the bottom of the slides. They will provide guidance to the progression of logic and sources of information. Classic references are listed throughout. Annotated recent references are listed at the end.

OutlineEvaluation: Clinical & Radiographic

Classification: Lauge-Hansen

Specific Problem Areas: Posterior Malleolus and Syndesmosis

Surgical Goals

Outcome

Evaluation:ClinicalHISTORYMechanism

Timing

Soft-tissue injury

Bone quality

Comorbidities

Associated Injuries

PHYSICAL EXAMSkin

Nerves

Vasculature

Pain

Deformity

Evaluation: RadiographicAnteroposterior ViewTibiofibular overlap ~ 10mm

Tibiofibular clear space

Evaluation: RadiographicMortise ViewGoergen JBJS 197710 degrees internal rotation of 5th MT with respect to a vertical line

Evaluation: RadiographicMortise ViewMedial joint space

Talocrural angle: 15 degrees

Tibia/fibula overlap:>1mm

Comparison Radiograph?

Evaluation: RadiographicMortise ViewWeber SICOT 1981FIBULAR LENGTH: 1. Shentons Line of the ankle2. The dime test

Evaluation: RadiographicLateral ViewPM

Talar subluxation

Distal fibular translation &/or angulation

Syndesmotic relationship

Associated or occult injuriesLateral process talusPosterior process talusAnterior process calcaneus

Evaluation: RadiographicOther Imaging ModalitiesStress ViewsGravity Manual

CTArticular involvementPosterior malleolus

MRILigament and tendon injury Talar dome lesionsSyndesmosis injuries




Surgical Goals

Outcome

Lauge-HansenCadaveric study

First word: position of foot at time of injury

Second word: force applied to foot relative to tibia at time of injuryTypes:SERSAPERPA

Lauge-HansenSeveral stages per type

Imperfect system:Not every fracture fits exactly into one category

Even mechanismspecific pattern has been questioned

Inter and intraobserver variation not ideal

Still useful and widely used

Supination-External RotationStage 1- AITFL

Stage 2- Fibula fx

Stage 3- PITFL or PM fx

Stage 4-Deltoid or MM fx70% of ankle fractures

Supination-External Rotation Stage 2: StableStandard: Closed managementLateral Injury: classic posterosuperioranteroinferior fibula fractureMedial Injury: Stability maintainedKristensen Acta Orthop Scand 1985Stage 2

Supination-External Rotation Stage 4: UnstableLateral Injury: classic posterosuperioranteroinferior fibula fractureMedial Injury: medial malleolar fracture &*/or deltoid ligament injuryStandard: Surgical management*Tornetta JBJS 2000Stage 4

SER-2 vs SER-4: How to Decide?Michelson. Clin Orthop Rel Res 2001DeAngelis Poster OTA 2003Tornetta. Poster AAOS 2004McConnell JBJS 2004Egol JBJS 2004Schock Presentation OTA 2006Zeni Presentation OTA 2006Park J Orthop Trauma 2006GOAL: TO EVALUATE DEEP DELTOID [i.e. INSTABILITY]METHOD:MEDIAL TENDERNESSMEDIAL SWELLINGMEDIAL ECCHYMOSISSTRESS VIEWS- GRAVITY OR MANUAL

Gravity Stress ExamMichelson et al. CORR 387: 178-82, 2001.

Manual Stress Exam

versus Both are effectiveGravity stress requires XR education. Manual stress requires time and more radiation exposure.

Schock et al. JBJS 89B: 1055-59, 2007.

SER-2 vs. SER-4: How To Decide?Indication to fix isolated fibular fractures

Decision-Tree:Understand the LogicAssumptions:Fibular fractures associated with a stable ankle mortise heal without significant functional consequence.Fibular fractures associated with an unstable ankle mortise heal with significant functional problemsbecause instability allows for talar shift.

Decision Tree:Understand the LogicStress ViewSplintage

Decision-Tree:Understand the LogicDoes a Positive Ankle Stress Test Indicate the Need for Operative Treatment?MRI to evaluate all patients with lateral malleolar fracture and positive stress test (n=21).If deep deltoid partially intact nonop treatmentGood clinical outcomes.OTA Annual Meeting. Foot & Ankle Section. Paper #24, 2006.

Choose a technique to evaluate stability. Base your decision to operate on your findings and the risk:benefit ratio.Indication to fix isolated fibular fractures

Supination AdductionStage 1: transverse Weber A or B fibula

Stage 2: vertical medial malleolus

Supination Adduction: Stage 2Lateral Injury: transverse fibular fracture at/below level of mortiseMedial injury: vertical shear type medial malleolar fractureBEWARE OF IMPACTIONMcConnell J Orthop Trauma 2001

Supination Adduction: Stage 2Important to restore:Ankle stabilityArticular congruency- including medial impaction

SADConsider anteromedial approach

Marginal impaction reduction +/- grafting

Medial antiglide plate

Specific articular pathology associated with SA

Pronation-External RotationStage 1 - deltoid or medial malleolus

Stage 2- AITFL and IO membrane

Stage 3 spiral Weber C fibula

Stage 4 PITFL or posterior malleolus

Pronation External Rotation: Stage 4Medial injury: deltoid ligament tear &/or transverse medial malleolar fractureLateral Injury: spiral proximal lateral malleolar fractureHIGHLY UNSTABLESYNDESMOTIC INJURY COMMON

PERTibia radiograph

Syndesmostic disruption expected

Restore:Fibular length and rotationAnkle mortiseSyndesmotic stability

Pronation-AbductionStage 1 transverse MM

Stage 2 PITFL or PM fracture

Stage 3 compression bending fibula fracture

Pronation-AbductionMedial injury: tranverse to short oblique medial malleolar fractureLateral Injury: comminuted impaction type lateral malleolar fracture

PABMedial malleolar fixation drives stability. Go there 1st.

Fibular comminution length stable construct?

Stress the syndesmosis last

JBJS 89A: 276-81, 2007

PABSpecific articular pathology associated with PAB

PAB:Specific Articular Pathology




Surgical Indications and Goals

Outcome

Posterior Malleolus FracturesFunction:Stability- prevents posterior translation of talus & enhances syndesmotic stabilityWeight bearing- increases surface area of ankle joint

Posterior Malleolus Fractures: Radiographic EvaluationFracture pattern:Variable

Difficult to assess on standard lateral radiographExternal rotation lateral view [Decoster FAI 2000]CT scan [Haraguchi JBJS 2006]

Posterior Malleolus Fracture: Radiographic EvaluationIndication for fixation: > 25% joint surface on lateral

Problem: Fragment size hard to determine on lateral viewReason: Fracture orientation not purely in coronal planeNearly always associated with the pull of the posterior tib-fib ligamentlarger laterally than mediallyobliquely orientedinvolves the incisura

Haraguchi et al. JBJS 2006but other fracture patterns have also been defined

Posterior Malleolus FractureHaraguchi et al. JBJS 2006Type I- posterolateral oblique typeType II- medial extension typeType III- small shell type67%19%14%3 common PM fracture patterns

Posterior Malleolus Fractures: Indications for FixationStabilityPosterior translation of talus*ER of talus [syndesmotic widening]

Articular congruenceStress = Force/AreaExcessive stressposttraumatic arthritis Maximize area for stress distribution****contact stress changes significantly with posterior malleolar size >33% [Hartford CORR 1995]*fibula and anterior tibiofibular ligament act as primary restraint [Raasch JBJS 1992]

Posterior Malleolus Fracture: FixationScrews

Plates

Syndesmotic InjuryFUNCTION:

Stability- resists external rotation, axial, & lateral displacement of talus

Weight bearing- allows for standard loading

SyndesmosisIF INSTABILITY PRESENT OPERATIVE INTERVENTIONOBTAINING & MAINTAINING ANATOMIC REDUCTION REDUCES LONG TERM DISABILITY & IMPROVES sMFAWeening JOT 2005Leeds JBJS 1984

Syndesmosis:InstabilityHow do you determine if instability is present?Manual Stress Test

When do you perform the manual stress test?After you have fixed the other indicated components of the fracture

Before FixationAfter Fixation4342Syndesmosis:Obtaining a ReductionTornetta JBJS 2001DF unnecessary

Syndesmosis:Obtaining a ReductionIncidence of malreduction based on CT scan standard: >50%Gardner et al. FAI 27: 788-92, 2006.

Ways to ensure appropriate reduction:Direct visualizationFAI 30: 419-26, 2009Radiographic imaging in multiple planesInjury 35: 814-18, 2004.

Problem?The CT definition of an anatomic syndesmosisElgafy et al. Skeletal Radiology 39: 559-64, 2010

Syndesmosis:Maintaining a ReductionSingle Screw3 corticesSingle Screw4 cortices2 Screws6 cortices2 Screws8 cortices

Syndesmosis:Maintaining a Reduction3.5 mm vs 4.5 mm screw(s)

3 cortices vs 4 cortices

Retain vs Removal

Metallic vs Bioabsorbable

NO CONSENSUS




Surgical Goals

Outcome

Surgical GoalsAO Manual, 2nd Edition




Surgical Goals

Outcome

OutcomeAt one year following surgery, patients are generally doing well

Most have few restrictions and little pain

There is a significant improvement at one year compared to six months

Younger age, male sex, absence of diabetes, and lower ASA class are predictive of functional recovery at one yearEgol JBJS 2006

OutcomeFracture severity influences the rate of development and the latency time to endstage ankle arthritis.

The occurrence of postop complications has a negative influence on long-term results.

The patients age at the time of injury correlated negatively with the OA latency time (i.e. if you are older when you sustain an ankle fracture, you are more likely to develop end-stage OA sooner than if you had been younger).Horisberger et al. J Orthop Trauma 2009

OutcomeSpecific findings in the history noted to have an adverse effect on outcome include:Advanced age

Osteoporosis

Diabetes mellitus

Peripheral vascular disease

Female sex

High American Society of Anesthesiology (ASA) classGanesh et al. JBJS 87A: 1712-1718, 2005Egol et al. JBJS 88: 974-979, 2006SooHoo et al. JBJS 91A: 1042-1049, 2009

OutcomeSocial factors noted to be independent predictors of lower physical function postoperativelySmoking

Alcohol use

Lower level of educationBhandari et al. J Orthop Trauma 18: 338-45, 2004.

ComplicationsPerioperativeMalreductionInadequate fixationIntra-articular hardware penetrationEarly PostoperativeWound edge dehiscence/necrosisInfectionCompartment syndromeLateStiffnessDistal tibiofibular synostosisMalunionNonunionPost-traumatic arthritisHardware related complicationsComplex regional pain syndrome type 1Leyes Foot Ankle Clin 2003




Surgical Goals

Outcome

Special Scenario: The Diabetic Ankle Fracture

Diabetic Ankle FracturesProblems:Diabetes mellitus is a common medical condition that is increasing in prevalenceBoth closed and open management of ankle fractures in diabetics have higher complication rates

Solution:So do we change the indications and goals of treatment?

Wukich, Kline. JBJS 90: 1570-78, 2008Chaudhary et al. JAAOS 16: 159-70, 2008

Diabetic Ankle FracturesAnswer- NOUnstable ankle fractures in diabetics are still best treated with anatomic restoration of the ankle mortise and stable internal fixation, but

Because the soft tissue complications are higher, increased care must be given to atraumatic soft tissue techniques (limb at level of heart, careful of SQ incisions)

Because the osseous complications are higher, increased care must be given to empowering fracture fixation constructs (screws from fibula into tibia, double stacked 1/3 tubular plates)

Postoperative care varies in that immobilization, non-weightbearing mobilization, and subsequent protected weightbearing all take a longer course (SLC 6-12 weeks, NWB 12 wks)

SummaryAt this point, you should be able to:

State the indication to fix isolated fibular fractures.

Define the specific articular pathology associated with SA and PAB fractures.

List the 3 common posterior malleolar fracture patterns.

State the indication to fix posterior malleolar fractures.

Enumerate the ways to ensure syndesmotic reduction.

Thank You

Anotated Bibliography of Recent Articles of InterestSooHoo NF, Krenek L, Eagan MJ, Gurbani B, Ko CY, Zingmond DS: Complication rates following open reduction and internal fixation of ankle fractures. J Bone Joint Surg Am 2009;91(5):1042-1049. Prognostic Level II. Californias discharge database was queried for patients that had undergone ORIF of an ankle fracture over a ten year period with complications reviewed and discussed. Open injuries, diabetes, and peripheral vascular disease were strong risk factors for short-term complications.

Strauss EJ, Frank JB, Walsh M, Koval KJ, Egol KA: Does obesity influence the outcome after the operative treatment of ankle fractures? J Bone Joint Surg Br 2007;89(6):794-798. Retrospective review evaluating the number of comorbities, incidence of complications, time to fracture union, fracture type, and level of function between obese and non-obese patients with ankle fractures. At two years postop, obesity did not seem to have an effect on the incidence of complications, time to fracture union, or level of function.

White BJ, Walsh M, Egol KA, Tejwani NC: Intra-articular block compared with conscious sedation for closed reduction of ankle fracture-dislocations. A prospective randomized trial. J Bone Joint Surg Am 2008;90(4):731-734. Therapeutic Level I. Prospective, randomized trial comparing conscious sedation and intraarticular block for analgesia and the ability to allow for ankle fracture reduction and application of a splint. No difference in analgesia or allowance for reduction was noted. The intraarticular block allowed for a shorter average time for reduction and splinting.

Anotated Bibliography of Recent Articles of InterestBoraiah S, Paul O, Parker RJ, Miller AN, Hentel KD, Lorich DG: Osteochondral lesions of talus associated with ankle fractures. Foot Ankle Int 2009;30(6):481-485. Level IV. Retrospective case series evaluating the incidence and effect of osteochondral lesions of the talus in ankle fractures that were operatively treated. All patients were assessed preoperatively by MRI and functional outcome was measured at a minimum of 6 months using Foot and Ankle Outcome Scoring. Osteochondral lesions were noted in 17% of cases but showed no statistically significant effect on outcome.

Koval KJ, Egol KA, Cheung Y, Goodwin DW, Spratt KF: Does a positive ankle stress test indicate the need for operative treatment after lateral malleolus fracture? A preliminary report. J Orthop Trauma 2007;21(7):449-455. Retrospective review of patients who had a positive ankle stress test after an isolated Weber B lateral malleolar fracture. An MRI was ordered to evaluate the status of the deep deltoid ligament. If the deep deltoid was partially torn, patients were treated non-operatively. At a minimum 12 month followup, all fractures had united without evidence of medial clear space widening or post-traumatic arthritis.

Schock HJ, Pinzur M, Manion L, Stover M: The use of gravity or manual-stress radiographs in the assessment of supination-external rotation fractures of the ankle. J Bone Joint Surg Br 2007;89(8):1055-1059. Gravity and manual stress tests were compared in supination external rotation ankle fractures. Gravity-stress was determined to be as reliable and perceived as more comfortable than manual-stress.

Anotated Bibliography of Recent Articles of InterestSiegel J, Tornetta P III: Extraperiosteal plating of pronation-abduction ankle fractures. J Bone Joint Surg Am 2007;89(2):276-281. Therapeutic Level IV. Retrospective review of consecutive patient series managed with extraperiosteal plating of fibular fractures in pronation-abduction type injuries. Extraperiosteal plating was found to be an effective method of stabilization that led to predictable union.

Miller AN, Carroll EA, Parker RJ, Boraiah S, Helfet DL, Lorich DG: Direct visualization for syndesmotic stabilization of ankle fractures. Foot Ankle Int 2009;30(5):419-426. Level III. Case control. An established protocol for treatment of ankle fractures with syndesmotic injury was evaluated retrospectively. Patients that underwent stabilization of the syndesmosis with direct visualization were compared with historic controls that underwent indirect fluoroscopic syndesmotic visualization. All patients had postoperative CT scans. Based on their definition of an anatomic syndesmotic reduction, malreductions were significantly decreased in the direct visualization group.

Herscovici D Jr, Scaduto JM, Infante A: Conservative treatment of isolated fractures of the medial malleolus. J Bone Joint Surg Br 2007;89(1):89-93. Retrospective evaluation of patients with conservative treatment of isolated medial malleolar fractures. High rates of union and good functional results were noted with conservative treatment.

Thank YouReturn to Lower Extremity IndexE-mail OTA about Questions/CommentsIf you would like to volunteer as an author for the Resident Slide Project or recommend updates to any of the following slides, please send an e-mail to [email protected]

*AP defined as long axis of foot in true vertical position.

Tib fib overlap defined by Pettrone in classic article [JBJS 1983. Quantitative criteria for the prediction of results after displaced ankle fractures]. 146 displaced ankle fractures treated operatively or nonoperatively with an attempt to determine the factors associated with poor outcomes. It was used to evaluate the stability of the syndesmosis on both the AP and mortise radiographs. 10mm and 1mm were used respectively. Prognostic reduction significance for outcome in this study were [in descending order]: lat mal, med mal, deltoid, syndesmosis, post mal. The number of overall structures remaining displaced after reduction was an excellent predictor of the overall result.

Tibiofibular clear space defined in the same article. It has subsequently been reevaluated multiple times [Harper Foot Ankle 1993; Park et al JOT 2006]. The tibiofibular clear space is an evaluation of the posterior aspect of the syndesmosis.

Talar tilt originated ??? One early reference is Joy et al JBJS 1974. In this it was defined by measuring the distance between the articular surfaces of the tibia and talus in the medial and lateral parts of the joint as seen on the AP. *In the adult, the coronal plane of the ankle is oriented in about 15 20 degrees of ER with reference to the coronal plane of the knee, and therefore the lateral malleolus is slightly posterior to the medial malleolus. To obtain a true AP of the tibiotalar articulation [i.e. a mortise view], the ankle must be positioned with the medial and lateral malleoli parallel to the tabletop; that is, in about 15-20 degrees of internal rotation. This was best achieved by internally rotating the foot so that the lateral border of the fifth metatarsal was 10 degrees internally rotated with respect to a vertical line.*The medial clear space has been defined as the distance between the lateral border of the medial malleolus and the medial border of the talus at the level of the talar dome [Joy et al JBJS 1974]. The idea dates back at least to the 1940s [Burns 1943]. It is considered to be representative of the status of the deep deltoid ligament. It varies depending on the position of the radiograph, the stress on the ankle, and the injury to the ankle. Historically a space wider than 4mm was considered to be abnormal. More recently, a medial clear space of greater than or equal to 5mm on radiographs taken in dorsiflexion with an external rotation stress was found to be most predictive of deep deltoid ligament transection after distal fibular fracture [Park et al. JOT 2006].

The talocrural angle is the superomedial angle formed by the intersection of a line joining the tips of both malleoli and of a line perpendicular to the distal tibial articular surface. This originated in 1976 [Sarkisian , Cody, J Trauma].

Note tib fib overlap is measured on both the AP and the mortise view. [Pettrone et al. JBJS 1983]. The number revealing likely instability is different by a factor of ten.*Fibular length can be defined by:Shentons line of the ankleThe dime testOther measurements [eg bimalleolar angular measurements [Rolfe et al Foot and Ankle 1989]Comparison radiographs always useful*Widened anterior joint space on true lateral radiograph should increase suspicion for external rotation/posterior translation of talus which can occur with syndesmotic wideningPlain radiographs are by far the most common tool to evaluate osseous pathology in the ankle. Stress radiographs will be discussed in more detail.

CT scan can be especially useful in the variants that are transitional between ankle fractures and pilon fractures. They also will more clearly define posterior malleolar fracture patterns.

MRI has been used for evaluation of soft tissue injuries [i.e. severity of deep deltoid tear and distal tibiofibular syndesmotic tears] as well as to diagnose osteochondral talar dome lesions.*FRACTURES OF THE ANKLE II. Combined Experimental-Surgical and Experimental-Roentgenologic InvestigationsN. LAUGE-HANSEN, M.D. RANDERS, DENMARKArchives of Surgery 1950 vol. 60 (5) pp. 957-85.**Remember the injury starts on the tight side of the ankle! The lateral side is tight in supination, while the medial side is tight in pronation.

Note commonality and importance of staging in decision-making for treatment.**Recently even this has been questioned [Koval Presentation OTA 2006]. It is plausible that the degree of instability makes a difference in functional outcome. That is, incomplete deep deltoid injuries could lead to a widened medial joint space with stressbut still heal with nonoperative treatment in a stable position, with no apparent functional problems in the short term [average 18 months].*What about this case? Obvious instability with stress. Virtually anatomic talar position with splintage. We know from Harpers 1980 article that the deltoid willl heal without operative repair. If it heals in the splinted position, why wont that lead to normal function?*Basically, instability that cant be managed with closed techniques should be managed with surgery. The more deep deltoid you have intact, the less instability you have. The less instability you have, the more likely you will be able to manage it with closed techniques.

Does a Positive Ankle Stress Test Indicate Need for Operative Treatment?Kenneth J. Koval, MD (n); Kenneth A Egol, MD (n);Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USAIntroduction: Historically, patients who present with an isolated lateral malleolus fracture with >4mm clear space widening on radiographic stress testing are deemed to have an unstable ankle and are advised to have surgery. However, this protocol may be associated with a high rate of false positive results, therefore subjecting people to surgery unnecessarily. At our institution, we have been using a standardized protocol employing MRI to evaluate ankle stability and need for surgery following a positive manual stress test for isolated lateral malleolus fractures. The purpose of this study was to evaluate the results using this standardized protocol.Methods: Between December 2003 and June 2005, patients who had a positive ankle stress test (5 mm clear space widening) after Weber B (OTA Type 44-B) lateral malleolus fracture were further evaluated with use of MRI. If the MRI indicated the deep deltoid was completely disrupted, the patient was advised to have operative ankle repair. However, if the MRI demonstrated that the deep deltoid was intact or only partially disrupted, the patient was treated nonoperatively in a walking boot with weight bearing ambulation as tolerated. Patients were followed until fracture union and contacted at 6-month minimum follow-up to answer a functional questionnaire (SF-36) and return for clinical (AOFAS) and radiographic evaluation. Statistical analyses were performed to determine whether: (1) there was a relationship between the amount of clear space widening and MRI findings (eg, intact or partially torn deltoid ligament, degree or syndesmotic injury) and (2) there was a relationship between radiographic or MRI findings and clinical or radiographic outcomes.Results: 21 patients had an MRI after a positive ankle stress test and comprised the study group. There were 12 men and 9 women with an average age of 27 years (range, 16-62). All patients had sustained the fracture as a result of a low-energy fall. Medial clear space on stress testing ranged from 5 to 8 mm. 19 of 21 patients (90%) had evidence of partially torn deep deltoid ligament and were treated nonoperatively, while 2 patients had MRI findings of a complete deep deltoid injury and underwent surgical treatment. These two patients had clear space measurements of 5 and 8 mm respectively. No ankle had evidence of complete syndesmotic tear on MRI. There was no correlation between the clear space measurement and MRI results. All 21 patients were doing well at latest follow-up (average 18 months) with AOFAS scores in the 90s and minimal complaints of ankle pain, stiffness, or reduced activity level compared to preinjury. All 21 fractures united without evidence of ankle incongruity on latest follow-up radiographs. No correlation was found between radiographic or MRI findings and clinical or radiographic outcomes.Conclusion/Significance: Using our protocol, we were able to identify and provide effective nonoperative care to 19 patients who otherwise might have undergone operative treatment after isolated lateral malleolus fracture. Further work is needed to identify the subset of patients who could be treated nonoperatively without need for MRI scanning*Note the difference in these two lateral ankle radiographs. This is the same patient. This patient had bilateral SAD ankle fractures. One (your left) was fixed with reduction of the medial gutter comminution. The other was not. Note the difference in the anterior portion of the subchondral shadow. This is commonly the area of articular impaction and can be seen on the lateral radiograph as well as the AP/mortise.**Extraperiosteal plating of pronation abduction type ankle fractures was for the following reason: the incidence of nonunion associated with fixation of the fibula in this fracture patttern was noted to be higher [Limbird, Aaron. Laterally comminuted fractures of the fibula. JBJS 1987. Ebraheim et al. FAI 1987.] Surgeons were recommending bone grafting of fibular fractures associated with comminution because traditional techniques of ORIF were not working well for these fractures. Extraperiosteal plating and indirect reduction techniques maintain as much fracture viability as possible. Going to the lateral side second allows medial malleolar reduction to center the talus, thereby pulling the lateral ligamentous complex and potentially allowing for fibular reduction. Length stability may be provided by an intact lateral ligamentous complex. Fibular length is evaluated via the dime test and Shentons line of the ankle as noted on previous slides. If the fibula remains short, then reduction and a length stable construct is required.*Just like a SAD ankle fracture potentially has medial gutter comminution, a PAB ankle fracture potentially has lateral gutter comminutiontypically in the form of chaput fragment impaction. *Open PAB injuries typically present with a medial transverse open wound and an extruded tibia. This intraoperative image nicely shows the anterolateral gutter impaction.*Photos taken from McMinn textbook on Foot and Ankle Anatomy****even this 33% number is maybe questionable as some feel that contact stresses just shift to a more anteromedial location following pm fxs [Fitzpatrick JOT 2004]. Because of this and other biomechanical articles, the size issue is debatable. That is, there is no clear indication of how big it has to be before one must fix it to prevent stress concentration. The stability issue is not controversial. If the ankle joint is unstable to posterior translational stress, it must be reduced and fixed.*A medial injury is thought to be required for a syndesmotic injury to alter loading [Boden JBJS 1989]*Plain radiographic reduction parameters may be inadequate for assessing the quality of reduction [Gardner FAI 2006]. That stated, the definition of an anatomic syndesmosis is variable in the literaturelikely secondary to individual variability in anatomy.Instability should be assessed after osseous injuries have been stabilized.

Instability of the syndesmosis has a prerequisite of a medial injury that is not treated [superficial or deep deltoid tear]. It should not be evaluated until the remaining portions of the ankle have been fixed.*The idea behind dorsiflexing the ankle prior to clamping the syndesmosis is based on the concept that the talus is shaped like a frustrum [wider anteriorly than posteriorly] such that clamping in plantarflexion could allow for overconstraining the ankle. The original recommendations came from a single cadaveric article using 1NM of force.This was challenged by Tornetta et al in the above noted study. Dorsiflexion was measured in 19 cadavers before syndesmotic screw placement and after placing a 4.5mm lag screw with the ankle in plantarflexion. There was no significant difference. He postulated that dorsiflexion is not necessary [i.e. overconstraint doesnt occur]. While not necessary, dorsiflexion may still be useful at times to center the talus in the mortise. *Obtaining a reduction is important. The question is how to do so. There has been recent concern that we were malreducing more than we originally thought [i.e. that intraoperative radiographic parameters may be deceiving]. This concern was based on evaluating the syndesmotic reduction of treated disruptions by using a postoperative CT scan with a specific definition of an anatomic syndesmosis. This definition was based on a symmetric distance between the fibula and the incisura at the anterior and posterior portion of the syndesmosis. This definition has recently been questioned by a new publication which evaluated uninjured ankles via a CT scan. This is on the next slide.*There is significant variability noted in the population. This recent study provides information that questions the previous definition of an anatomic syndesmosis on CT scan. It is possible that we are doing better than what has been suggested in the previous articles.

AbstractObjective The purpose of this study was to determine the shape and measurements of the normal distal tibiofibular syndesmosis on computed tomographic scans and to identify features that could aid in the diagnosis of syndesmotic diastasis using computed tomography (CT). Materials and methods CT scans of 100 patients with normal distal tibiofibular syndesmoses were reviewed retrospectively. In 67% the incisura fibularis was deep, giving the syndesmosis a crescent shape. In 33% the incisura fibularis was shallow, giving the syndesmosis a rectangular shape. The measurements of both types were taken using the same reference points.Results The mean age of the patients was 40 years, and there were 53 men and 47 women. The mean width of the distal tibiofibular syndesmosis anteriorly between the tip of the anterior tibial tubercle and the nearest point of the fibula was 2 mm. The mean width of the distal tibiofibular syndesmosis posteriorly between the medial border of the fibula and the nearest point of the lateral border of the posterior tibial tubercle was 4 mm. In men the mean width of the distal tibiofibular syndesmosis, anterior and posterior, was 2 mm and 5 mm, respectively, and in women it was 2 mm and 4 mm, respectively.Conclusion This study provides measurements of the normal tibiofibular syndesmosis to aid in the diagnosis of occult diastasis.**After obtaining an anatomic reduction, it is important to maintain that reduction until healing. *Note difference in level of syndesmotic screw placement. There is evidence that placing screws closer to the syndesmosis leads to less widening [McBryde FAI 1997]. General recommendation is approximately 2 cm above the tibiotalar joint but not directly into the cartilage of the syndesmosis.There are many options and no consensus. Individualize treatment based on degree of instability.*This is an interesting case of a revision of a syndesmotic malreduction. The images on top denote the postoperative mortise, lateral, and CT scan which reveal an anterior translation of the distal fibula and debris in the distal tibiofibular syndesmosis. Note the relationship of the posterior border of the fibula to the posterior malleolus on the lateral radiograph. The images on bottom denote the revision. Her uninjured ankle was evaluated radiographically to ensure the appropriate relationships were restored. *

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L12 Graves Ankle