Abstract
This 10-year-old boy was hit by a car while crossing the road and sustained a closed head injury with GCS 8/15. He has been intubated because he is combative. A secondary survey has revealed this associated limb injury (Figure 16.1).
I can see a shoulder trauma series with an AP and an attempted shoot-through or trans-scapular view. It’s not quite a lateral Y-view I’m suspecting as the radiographer couldn’t get the correct projection. There’s a transverse fracture of the metaphysis, which is angulated medially due to the pull of the pectoralis major. If he was conscious I would specifically look at the axillary nerve function.
Structured oral examination question 1
EXAMINER: This 10-year-old boy was hit by a car while crossing the road and sustained a closed head injury with GCS 8/15. He has been intubated because he is combative. A secondary survey has revealed this associated limb injury (Figure 16.1).
CANDIDATE: I can see a shoulder trauma series with an AP and an attempted shoot-through or trans-scapular view. It’s not quite a lateral Y-view I’m suspecting as the radiographer couldn’t get the correct projection. There’s a transverse fracture of the metaphysis, which is angulated medially due to the pull of the pectoralis major. If he was conscious I would specifically look at the axillary nerve function. I’d also document the vascular status of the arm.
EXAMINER: Assume that there is no associated neurovascular deficit. How are you going to manage this patient?
CANDIDATE: My concern is that the fracture fragments are completely translated with no bony contact and the distal fragment is being pulled medially into the axilla. As he has a closed head injury of unknown prognosis, he may not be able to be nursed upright for some time. I would consider surgical intervention in this child for ease of nursing.
When the child was stable, I would plan to take him to theatre after appropriately counselling the parents, marking the child and the WHO checklist. I would screen with the image intensifier to check the shoulder is in joint and realign the fracture with gentle traction.
EXAMINER: What if it doesn’t reduce closed?
CANDIDATE: I would ask the anaesthetist to give muscle relaxant for the MUA. If the fracture doesn’t reduce closed I would do a limited open reduction through a deltopectoral approach (internervous plane: axillary and the medial and lateral pectoral nerves). In terms of the fracture, I would stabilize this with retrograde K-wires from the lateral side through a mini-incision. The long head of the biceps can sometimes get interposed in the fracture, blocking reduction.
The major structure at risk from percutaneous K-wires is the axillary nerve. Its surface landmark is 5 cm from the lateral edge of the acromion. The nerve is a branch of the posterior cord, and travels through the quadrangular space with the posterior circumflex vessels before going anterior around the surgical neck, underneath the deltoid.
EXAMINER: What do you think about this postop radiograph (Figure 16.1c)? I thought these fractures were usually managed conservatively?
CANDIDATE: I can see the fracture is reduced and held with K-wires from the lateral side obliquely into the medial metaphysis. One of them is crossing the growth plate, and on this view, there’s no penetration of the surface of the head. The reduction is in slight varus, but overall, it’s well aligned. I would be careful about allowing the patient to mobilize before the wires come out at 4 weeks; I’d anticipate there might be limited hold in the metaphysis. Taking the wires out will need another GA as they are threaded, and you could screen it at the time to check it was united.
For proximal humerus fractures in young children, almost any level of deformity is acceptable, for instance, bayonet apposition, as the remodelling potential is so great. Typically, these are managed conservatively in a sling for a short time.
In children older than 13 with little growth remaining there is an argument for accepting less deformity, such as < 30° angulation or < 50% translation, although there’s no consensus in the literature about what level of deformity is an absolute indication for fixation, and there is a higher incidence of stiffness compared to patients treated non-operatively [1].
Figure 16.1a and 16.1b Displaced proximal humerus fracture.
Figure 16.1c Anteroposterior (AP) radiograph, shoulder following K-wire fixation.
Structured oral examination question 2
EXAMINER: This 7-year-old child fell from swings in the park sustaining a closed injury (Figure 16.2a and 16.2b).
CANDIDATE: I can see AP and lateral radiographic views of the left elbow. I’m assuming this is an isolated injury and I would like to get additional views of the wrist. My initial priority is to assess the neurovascular status and splint the limb. This is a Monteggia injury where there is a displaced and volarly angulated ulna fracture in addition to an anterior dislocated radial head.
EXAMINER: Let’s assume there is available time to do this on the trauma list and you are taking the child to theatre. What are the principles of treating this injury? What would be your surgical plan?
CANDIDATE: By restoring the ulna length this should reduce the radial head. I would initially attempt a closed reduction by traction. If length, alignment and rotation were correct and with restoration of the radiocapitellar alignment, I would stabilize the ulna with an elastic nail. If I had any doubts about the reduction, I would plate it.
EXAMINER: How do you perform an elastic nailing? What problems do you anticipate arising if you try to use a nail for this?
CANDIDATE: Patient is positioned supine, arm board, bipolar (diathermy), tourniquet and image intensifier screen positioned within unrestricted view.
Initially I’d screen (with the image intensifier) and mark the physis and the fracture with a skin marker. The nail is sized according to one-third diameter of the isthmus. By pre-bending, the nail has elastic recoil, which exerts a force in the intramedullary canal to reduce the fracture.
Elastic nails are best suited to diaphyseal fractures. This is metaphyseal and near the entry point for the nail, so I’d have a low threshold for open reduction and plate fixation with a one-third tubular plate or LCP.
EXAMINER: Let’s say the nail doesn’t work. Even when you plate the ulna, the radial head does not reduce. What do you do?
CANDIDATE: I’d recheck I had properly reduced the fracture. In some cases, the ulna is plastically deformed, so you have to osteotomize it, but I don’t think that’s happening here.
In this case I would suspect that the annular ligament is either torn or interposed, blocking reduction of the radial head.
I’d open the radiocapitellar joint via a Kocher’s approach (between the anconeus and ECU). It is possible to reconstruct the annular ligament with a fascial sling. This fascia can be obtained from a number of sites within the upper limb, e.g. triceps fascia.
Figure 16.2a and 16.2b Anteroposterior (AP) and lateral radiographs, left elbow.
Figure 16.2c and 16.2d Intraoperative image intensifier anteroposterior (AP) and lateral radiographs, left proximal ulna.
Structured oral examination question 3
EXAMINER: This 6-year-old child is a new referral to the fracture clinic, please look at and describe these radiographs (Figures 16.3a and 16.3b).
CANDIDATE: These are AP and lateral radiographic views in plaster. There is a displaced lateral condyle fracture which is easiest to see on the AP. This looks like a Milch type 2 and the fracture line extends from the trochlear groove into the metaphysis. Because it’s extending from the medial side of the lateral ridge of the sulcus, the ulnohumeral articulation is unstable.
A Milch type 1 is lateral to the ulnohumeral articulation: going through the capitellar physis into the metaphysis. This is the equivalent of a Salter Harris type IV. A more recent and practical classification by Jakob describes three types. Type 1: under 2 mm of displacement, indicating the presence of a cartilaginous hinge. Type 2: where there is between 2 and 4 mm of displacement with intact intra-articular cartilage on arthrogram. Type 3: greater than 4 mm of intra-articular displacement.
EXAMINER: What problems can you foresee with this fracture?
CANDIDATE: These are intra-articular fractures and have a higher incidence of specific complications:
Non-union due to synovial interposition from the joint surface, causing persistent elbow instability.
Fishtail deformity from a fracture gap between the condyles, central area of avascular necrosis or physeal bar.
Apparent cubitus varus due to lateral periosteal overgrowth, after the fracture heals, causing a cosmetic deformity.
Cubitus valgus occurs from physeal arrest of the lateral capitellar physis, which can cause a tardy ulna nerve palsy.
In undisplaced fractures, assessing the intra-articular component of the fracture can be difficult on plain radiographs, as the distal humerus is cartilaginous. In these cases, an MRI or EUA and arthrogram may be useful to assess the fracture further.
EXAMINER: How do you surgically manage displaced fractures?
CANDIDATE: The aim is to restore articular congruity. For those fractures where the arthrogram demonstrates an articular hinge or mildly displaced (< 2 mm) fractures, the fracture can be stabilized with percutaneous divergent wires.
For those fractures that are displaced, visualizing the articular surface is required. This can be achieved with a lateral approach to the elbow. Avoid dissecting around the posterior aspect of the capitellar fragment as this can devascularize the fragment. Reduce the fracture and hold with at least two divergent K-wires. These can either be buried or left outside of the skin.
Figure 16.3a and 16.3b Anteroposterior (AP) and lateral radiographs, left elbow.
Figure 16.3c and Figure 16.3d Intraoperative arthrogram of left elbow, and postop radiograph in cast.
Figure 16.3e and 16.3f Anteroposterior (AP) and lateral radiographs, left elbow after healing.
Structured oral examination question 4
EXAMINER: This 7-year-old boy was waiting for his dinner and fell outside in the back garden (Figure 16.4a).
CANDIDATE: This is a lateral radiograph in a skeletally immature patient, which demonstrates a displaced supracondylar fracture. Typically, the mechanism is a fall with the elbow extended and axial loading. My first priority is assessment of the child and limb. I’m assuming this is an isolated injury?[Yes.] I would check vascularity by checking the radial and ulna pulse, capillary refill and ensuring the hand is warm and well perfused. I would check the motor and sensory function of the median, radial and ulna nerves. I would examine the antecubital fossa to see if the skin was under threat: such as a pucker sign due to buttonholing through brachialis. I would splint in a position of comfort after intranasal diamorphine.
EXAMINER: The child has a pink hand that’s perfused but no palpable radial pulse. There is no motor or sensory deficit.
CANDIDATE: While the evidence is a pink, perfused hand without any neurological deficit, it can be elevated and observed [2,3]: if the child is fasted and I can get him to theatre at a reasonable time, my preference is to operate on him that evening.