Rockwood Children CH8

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SECTION TWO • Upper Extremity

exposed out of the skin. Pin removal is in the office at 4 weeks with continuation of the cast for 6 weeks. Ulnar physeal fractures may also be irreducible in Galeazzi-equivalent injuries. This also has been reported to be secondary to interposed periosteum, extensor tendons, or joint capsule. 56,86,122,127,151,172,201 Open reduction must be executed with care to avoid further violating the physis. External Fixation External fixation rarely is indicated for fractures in skeletally immature patients. Though a viable treatment option, 180 the success rates of both closed reduction and percutaneous pin- ning techniques make external fixation unnecessary for uncom- plicated distal radial fractures in children. Presently, indications for external fixation include distal radius fractures with severe associated soft tissue injuries. Major crush injuries, open frac- tures, or replantations after amputation requiring additional soft tissue coverage are all indications for external fixation. Sup- plemental external fixation also may be necessary for severely comminuted fractures to maintain length and provide addi- tional stability to pin or plate constructs. Standard application of the specific fixator chosen is done with care to avoid injury to the adjacent sensory nerves and extensor tendons. Preoperative Planning Preoperative planning and patient positioning are similar to as described above. A host of commercially available external fix- ators may be utilized, with selection of pin diameter based on fracture location and patient size. Surgical Approach In general, external fixation for distal radius fractures in chil- dren spans the radiocarpal articulation. Although nonbridging (or wrist joint sparing) constructs may be utilized, the small size of the distal radial epiphysis in young children often pre- cludes the ability to obtain adequate purchase with external fix- ator pins. For this reason, typical constructs involve fixator pin placement through the index metacarpal and more proximal radial diaphysis. Distally, a dorsoradial incision is made over the mid-diaphyseal region of the index metacarpal. Dissection is performed through the subcutaneous tissues. The periosteum may be incised via an open approach, and careful limited subperiosteal elevation will allow for the first dorsal interosseous and adductor pollicis muscles

to retract safely. Percutaneous techniques may also be utilized, with care taken to avoid inadvertent injury to the radial sensory nerve, extensor tendons, or intrinsic muscles. Proximally, a dorsoradial approach in the region of the distal radial metadiaphysis is made. Again, identification and retrac- tion of the radial sensory nerve are performed. Deep dissection will allow visualization of the characteristic “bare area” between the musculotendinous units of the first and second extensor compartments. A longitudinal periosteal incision is created, facilitating safe and direct placement of external fixator pins.

Technique

✔ ✔ External Fixation: SURGICAL STEPS

❑❑ Perform an initial closed reduction under fluoroscopy ❑❑ Expose mid-diaphyseal index metacarpal down to bone via a dorsoradial incision ❑❑ Incise the periosteum longitudinally ❑❑ Limit subperiosteal elevation and retract the first dorsal interosseous and adductor pollicis muscles ❑❑ Place two terminally threaded parallel pins into the index metacarpal using a drill guide placed down to bone ❑❑ Expose the radial metadiaphysis down to bone via a dorsoradial approach ❑❑ Identify and retract the radial sensory nerves ❑❑ Expose the bare area between the first and second extensor compartments ❑❑ Incise the periosteum longitudinally ❑❑ Place two terminally threaded parallel pins into the radius proximal to the fracture site using a drill guide placed down to bone ❑❑ Perform traction and additional reduction under fluoroscopy ❑❑ Attach radiolucent bars to the pins ❑❑ Add a smooth percutaneous K-wire via the radial styloid dorsally if needed ❑❑ Close prior surgical incisions ❑❑ Place sterile bandages to the incisions and pin sites Exposure and pin placement are described as above. Follow- ing placement of two terminally threaded pins distal and prox- imal to the fracture, appropriate traction and reduction may be performed. Use of double-stacked radiolucent bars will increase construct rigidity and facilitate radiographic evaluation. After fluoroscopic confirmation of pin placement and acceptable fracture alignment, prior surgical incisions may be closed primarily and sterile bandages and/or petroleum gauze may be applied to the pin sites.

Authors’ Preferred Method of Treatment for Fractures of the Distal Radius and Ulna (Algorithm 8-1)

Torus Fractures Torus fractures may be safely and effectively treated with removable splint immobilization for 3 weeks. Incomplete Greenstick Fractures Closed reduction and long-arm cast immobilization are per- formed for displaced greenstick fractures with greater than

10 degrees of angulation. With isolated distal radial fractures, it is imperative to reduce the DRUJ with appropriate forearm rotation. A long-arm cast with three-point molding is used for 3 to 4 weeks. Radiographs are obtained every 7 to 10 days until there is sufficient callus formation. A short-arm cast or volar wrist splint is then used until full healing, generally at 4 to 6 weeks after fracture reduction. Therapy rarely is required.