Fractures of the Ankle Region in the Skeletally Immature Patient. The Salter Classification is Worthless!!

Transcription

1 Fractures of the Ankle Region in the Skeletally Immature Patient. The Salter Classification is Worthless!! Kaye E Wilkins D.V.M,M.D. President's Council/Dielmann Chair in Pediatric Orthopedics Professor of Orthopedics and Pediatrics Department of Orthopedics 7703 Floyd Curl Drive Mail Code 7774 San Antonio, Texas drkwilkins@aol.com

2 2 Introduction: A common scenario: It is a Sunday morning and a 10 year old male presents to the emergency room having sustained an injury to his left ankle in a sandlot football game. The ankle area is swollen and seems to have some pathologic valgus angulation. The radiographs taken are demonstrated in Fig.1. Figure 1. Three views of the young patient s ankle. He is seen by the orthopedic resident Dr. Jones who is on call. After he examines the patient he calls Dr Smith his orthopedic staff who is attending his church worship service. The following conversation ensues: Dr. Jones: Dr. Smith, I have this 10 year old male who injured his left ankle area in a local little league football game. He is neurovascular intact and this appears to be his only injury. The x-rays demonstrate a partially displaced Type II Salter-Harris fracture of his distal tibial physis. The fibula has a greenstick fracture of the distal shaft. Both fragments are in slight valgus with an opening gap medially in the distal tibial physis. Dr. Smith: Well, Dr Jones that tells me nothing more than the structure of the physeal pattern. Please be precise. Tell me how the fracture pattern is classified. You need to be more efficient when you take me out of a very interesting sermon!! So get on with it. You ve wasted my time by using too many words to tell me about the problem. I have to get back for the final prayer. Dr. Jones then thinks:

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4 4 Figure 2. The four fracture patterns of the Dias Tachdjian Classification C. A classification should describe three things: 1. The structural pattern 2. The treatment options 3. The Possible complications

5 5 Figure 1 Supination- Inversion patterns Stage I demonstrates only a fracture in the lateral fibular physis (dotted line). Stage II demonstrates a complete avulsion of the fibular physis (double headed arrow). There is a Salter- Harris III fracture of the medial malleous (single headed arrow).

6 6 (Fig 2.) Figure 2. Trans-epiphyseal fixation. a. Typical Stage II Supination Inversion fracture pattern. b. Following the reduction of both fractures, the medial malleolar fragment was stabilized with a trans-epiphyseal screw. Stabilization of the fibula usually is not necessary a. b. (Fig. 3) Figure 3. Complications a. Injury image of an undisplaced medial malleous (arrows) which was a part of a SI II fracture pattern. b. This went on to a growth arrest of the medial tibial physis. a. b.

7 7 (Fig. 4) Figure 4.Eversion External Rotation (PEER) fracture pattern. There is a Salter Harris Type I avulsion fracture pattern of the distal tibial physis. The fibula has failed in a greenstick pattern. 3. Treatment. The distal tibial avulsion fracture of the medial aspect of the epiphysis can be stabilized by a number of methods. (Fig 5.). a. b c. Figure 5. a. Trans-epiphyseal screws. b. Single smooth pin which should aim for the center of the physis if possible. Thus, if a growth arrest develops, it will not tend to develop an angular deformity. c. Isolated medial malleous stabilized with a single short screw.

8 8 (Fig. 6.) Persistence of interposed periosteum can stimulate the distal tibial to drift into VALGUS. a. b. c. d. e. Figure 6. Complications of PEER Patterns. a. Injury image of typical PEER lesion. b. )Best closed reduction reveals gap (arrow) between fragments indicating interposed tissue. c. Operative image demonstrating the flap of periosteum (dotted line) which was extracted. d. Standing AP radiographs of a patient in which the interposed tissue (arrow) was not extracted. The distal tibia has overgrown medially into valgus. e. Clinical appearance demonstrating the valgus alignment of the ankle (dotted line). C. Supination-External Rotation (SER) (Fig.7)

9 9 a. b. c. d. Figure 7. Supination External Rotation (SER) fracture patterns. a,c Stage I fracture pattern with rotational fracture failure pattern only in the distal tibia. b,d. Stage II fracture pattern in the distal fibular metaphysis. Notice the distal tibial fibular ligaments remain intact. fracture. X-rays may be difficult to interpret. However, the clinical appearance of external rotation of the foot is characteristic (Fig. 8). a. b. Figure 8. Pure rotation: a. A-P and Lateral images of a patient with an injury to his distal tibia. The radiographs were initially interpreted as an isolated fracture of the distal fibular metaphysis (dotted line). b. The clinical picture however demonstrates the marked external rotation of the foot. c. This was a pure Salter-Harris Type I Fracture and just derotating the distal fragment fully corrected the deformity. d. Post reduction image confirms the S-H Type I fracture pattern (dotted line). c. d.

10 10 (Fig. 9.) Figure 9 Correction of the rotation.: a. Injury images demonstrate a Stage I external rotational deformity (curved arrow) of the distal tibial (dotted lines).b. The fracture was easily reduced by simply internal the distal fragment to close the gap.(arrows). D. Supination-Plantar Flexion (SP) 1. Fracture patternsm (Fig. 10) Figure 10 Supination Plantar Flexion fracture pattern.: a.line drawing demonstrating the Salter- Harris Type II fracture pattern of the distal tibia. The distal fragment is usually displaced posteriorly and distally ( curved arrow) b. The fibula usually fails in an apex anterior greenstick failure pattern (dotted line). (Fig. 11)

11 11 Figure 11 The steps in reducing the usual Supination-Plantar Flexion fractures.. 1. Apex anterior plastic deformation of the fibula. 2. Interposed tissue in the fracture site (similar to PEER injuries). b. Distal tibial arrest (rare). E. Special Adolescent Distal Tibial Injuries Variants of the Supination-External rotation forces are altered by the early closure of the distal tibial Physis (Fig.12). Figure 12. Asymetric closre of the distal tibia. As the patient matures, the distal tibial physis closed first in the center then progresses to the medial cortex. This leaves the lateral portion open, predisposing it to failure from an external rotation force. 1. Juvenile Tillaux. a. Mechanism; The fragment is pulled off in an anterior lateral direction by the anterior Tib-Fib ligament.(fig. 13).

12 12 a. b. c. Figure 13. Juvenile Tilleaux Fracture patters. a. Line drawing demonstrating the pull of the anterior Tib-Fib ligament. b. Injury image demonstrating the fracture fracment (dotted line and arrow). c. The anterior displacement is evident in this lateral image (arrow). (Fig. 14) pronation a.

13 13 b. c. Figure 14. Reduction and stabilization. a. This fracture was seen fresh. Manipulating the distal fragment into internal rotation with pronation of the foot reduced the fracture gap (arrows). The fragment was then stabilized with a smooth pin combined with an arthrogram to check the congruity of the articular surface. c. The pin was the replaced with a percutaneously placed screw. 2. Triplane fractures (Fig. 15) (Fig. 16) (Fig. 17a) (Fig. 17b,c).

14 14 a. b. Figure 15. Triplane fracture lines. a. Line drawing demonstrating the three classic fracture lines as described by Marmor. b. Coronal images (plain film and CT) demonstrating the fracture lines in that plane. this alone could be confused with a Tillaux fracture pattern. c. Saggital plane images which demonstrates the posterior coronal fragment confirming that this is a true Tri-Plane fracture. c. Figure 16 Triplane variants: Medial Here the posterior vertical metaphyseal spike is posterior medial. Lateral The classic tri-plane has the posterior vertical spike posterior lateral. a. b.

15 15 Figure 17 Supplemental imaging. a The presence of a comminuted fracture of the fibula indicates that there was severe displacement of the distal tibial fragment. This requires an aggressive approach in the treatment. b. Standard A-P and lateral images of a tri-plane do not demonstrate the true structure of the intra-articular fracture lines. c. A C-T image through the epiphysis shows the vertical fracture line to be in the saggital plane. c. c. Treatment d) Steinman pins can be used as joysticks to manipulate the individual fragments. It is very important to know the alignment of the fracture lines as the screws need to be perpendicular to the fracture surfaces (Fig.18.). a b..

16 16 Figure 18. Determining the alignment of the fracture surfaces. a, Plain film image demonstrating only the fracture lines in the coronal plane. 1. the vertical saggital epiphysis fracture line. 2. The horizontal fracture through the physis. b. Saggital image demonstrating 3. the vertical coronal fracture line c,d. A horizontal CT cut through the epiphysis demonstrates the vertical fracture line in in the saggital plane. Thus, any fixation device needs to be placed in the coronal plane to cross the fracture line perpendicularly. d. C-T Image through the distal metaphysis shows the fracture line to be in the coronal plane. In both planes the fragments are externally rotated (arrows). a. b e. Once the alignment of the fracture lines has been determined, Steinman pins are placed in the fragments perpendicular to the fracture surfaces and in such a manner that they will correct the rotation of the fragments. These pins are then used to correct the rotation and reduce the fracture. Once the fracture is reduced, one of the pins is driven into the opposite fragment to stabilize the reduction (Fig. 19). Figure 19. Joystick reduction. a. Steinman pins are placed in each of the two fragments perpendicular to the fracture surfaces. The pins are then rotated to close the fracture gap (curved arrows). b. Once the fracture is reduced one of the pins is then driven into the opposite fragment to stabilize the reduction. f. Final stabilization. The pins are then replaced with lag screws to secure the fragments. An arthrogram is performed to determine the accuracy of the articular surface reduction (Fig.20). The fracture is then stressed to determine the stability of the reduction and the patient is immobilized with a splint and early motion is initiated. Weight bearing is allowed at usually 3 weeks when there is the appearance of callous. Figure 20. Final stabilization. Lateral and A-P images of the prior fracture in which lag screws have been placed across the fracture fragments as the final stabilizers. The arthrogram (dotted line) confirms the congruity of the articular surface.

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18 18 Fig 21 Figure 21. Avascular necrosis of the distal tibia. a A very comminuted fracture of the distal tibia involving the entire epiphysis. It was reduced by an open reduction with a satisfactory alignment achieved. b. Six months later there is a large area of avascular necrosis. a. b.

19 19 Figure 23. Avascular necrosis of the distal tibia metaphysis. a A very comminuted fracture of the distal tibia involving the tibial metaphysis. Satisfactory alignment was achieved. b. Six months later there is a large area of avascular necrosis in the metaphysis.. a. b.

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