IM Nailing of Pediatric Femur Fractures : Wheeless' Textbook of Orthopaedics

- Discussion:
    - see pediatric femur frx
    - commonest site of fracture of the femoral shaft is in its middle third, where normal anterolateral
            bowing of diaphysis is at its maximum;
- torsional force produced by indirect violence results in a long spiral or oblique frx, whereas a
            transverse frx is caused by direct trauma;
- green stick frx are more common in the distal third;
    - birth frx from OB trauma, usually occur in mid 1/3 & are transverse;
- excessive bleeding ( > 500 ml) or more is not uncommon;
- source of bleeding is usually the profundus femoris artery which course around femoral shaft, the
                     vessels of richly vascular muscles enveloping the femur, or the vessels in bone itself;
    - diff dx:
            - child abuse;
- bone tumor
- be suspcious of femoral shaft fractures occuring from low energy trauma such as a football pile up;
- poor quality films may mask a NOF, UBC, or even osteosarcoma;

- Operative Considerations:
- children who have uncontrolled muscle spasticity, such as those w/ head injuries or severe cerebral palsy, do not tolerate external
immobilization well;

- IM Nailing: rigid nails:
      - IM nailing using rigid nails may be indicated in children as young as 12-13 years;
      - concern is that IM nailing in immature patients may cause AVN
      - position:
   - consider placing the patient in the lateral position which will allow the hip to be flexed so that the guide wire can be placed
                      posterior to the medius tendon;
             - ref: Patient positioning on the operative table for more accurate reduction during elastic stable intramedullary nailing of the femur: a technical note.
      - entry hole for rigid nails:
   - after the age of 7 most of growth to greater trochanter is appositional and not physeal (it has been observed that trochanteric
                        growth arrest after age 7 will not correct congenital coxa vara);
   - consider placement of the guide pin thru the medial 1/3 of the greater trochanter;
   - standard IM nail placement into the piriformis fossa may disrupt the posterior branch of the MFCA (blood supply to hip);
   - also note that insertion of the nail anterior to the piriformis fossa, may place the patient at risk for femoral shaft fracture;
             - note: make sure that small diameter nails (9 mm) are available;
             - Townsend DR and Hoffinger S (2000) authors describe results of a technique in which the nail is placed through the tip
                    of the greater trochanter (avoiding the piriformis fossa and possible damage to medial circumflex artery);
- between 1988 and 1995, the authors performed this procedure on 34 patients, who ranged in age from 10 - 17 years;
- there were no infections, nonunions, rotational deformities, or implant failures.
- 20 patients with open physes had a followup of 2 years or more.
- no patient had avascular necrosis of the femoral head develop.
- the authors recommend the trochanteric tip entry point for IM nailing in children;
     - references:
            - Intramedullary nailing of femoral shaft fractures in children via the trochanter tip
            - Antegrade intramedullary nailing of pediatric femoral fractures using an interlocking pediatric femoral nail and a lateral trochanteric entry point.
            - Proximal Femoral Radiographic Changes After Lateral Transtrochanteric Intramedullary Nail Placement in Children
            - Intramedullary nailing of femoral fractures in children through the lateral aspect of the greater trochanter using a modified rigid humeral intramedullary nail: preliminary results of a new technique in 15 children.
            - Closed, locked intramedullary nailing of pediatric femoral shaft fractures through the tip of the greater trochanter.
            - Premature greater trochanteric epiphysiodesis secondary to intramedullary femoral rodding
            - Interlocking intramedullary nailing of femoral-shaft fractures in adolescents: preliminary results and complications
            - Fixation of Length-Stable Femoral Shaft Fractures in Heavier Children: Flexible Nails vs Rigid Locked Nails
            - A systematic review of rigid, locked, intramedullary nail insertion sites and avascular necrosis of the femoral head in the skeletally immature.
            - Locked intramedullary nailing in the treatment of femoral shaft fractures in children younger than 12 years of age: indications and preliminary report of outcomes.
            - Twenty-Year Experience with Rigid Intramedullary Nailing of Femoral Shaft Fractures in Skeletally Immature Patients
            - The management of pediatric subtrochanteric femur fractures with a statically locked intramedullary nail.
            - Debate: a healthy 12-year-old boy with an isolated mid-diaphyseal femur fracture should be treated with an antegrade, locked, intramedullary rod.

   - flexible nails:  (see synthes technique manual)
           - may be indicated in children between 5-12 years of age for difficult fractures or for obese patients;
- in children older that 12 years of age flexible or rigid nails may be used depending on the circumstances;
- flexible pins are placed from the distal femoral metaphysis in a retrograde manner
- typically one pin is inserted medially and one is inserted laterally;
- in the study by Bar-on, et al. (1997), flexible IM nails were compared to external fixation in a prospective study;
- consisted of a prospective study w/ 19 patients w/ age ranges from 5-13 years;
- in their study, time to full wt bearing, ROM, and return to school were all faster in the flexibile nail group;
- nails were inserted from the proximal end for more proximal fractures and from the distal end for more distal fractures;
- there were no cases of limb length inequality nor malunion in the nail group;
           - malrotation:
                  - (70%) subtrochanteric femur frx and 5/7 (71%) supracondylar femur frxs healed with anterior angulation of about 5°
                  - ref: Elastic nailing for pediatric subtrochanteric and supracondylar femur fractures.
           - controversies:
                  - higher incidence of complications (bending of nails) in children heavier than 100 lbs;
                  - time for nail removal spans between 6-12 months, when circumferential callus appears tobe solid and the fracture line is
                          no longer visible;
                          - with early removal, there is a concern of a higher rate of malunion; (Gulati, letter to the editor) (Wall replies)
           - references:
                         - External fixation or flexible intramedullary nailing for femoral shaft fractures in children. A prospective, randomised study.
                         - The operative stabilization of pediatric diaphyseal femur fractures with flexible intramedullary nails: a prospective analysis.
                         - Titanium elastic nails for pediatric femur fractures: a multicenter study of early results with analysis of complications
                         - Ender rod fixation of femoral shaft fractures in children
                         - Elastic stable intramedullary nailing of femoral shaft fractures in children
                         - Comparison of Titanium Elastic Nails with Traction and a Spica Cast to Treat Femoral Fractures in Children
                         - Limb Geometry After Elastic Stable Nailing for Pediatric Femoral Fractures
                         - Decreased Complications of Pediatric Femur Fractures With a Change in Management
                         - Antegrade versus retrograde titanium elastic nail fixation of pediatric distal-third femoral-shaft fractures: a mechanical study.
                         - Femur Fracture in Preschool Children: Experience with Flexible Intramedullary Nailing in 72 children
                         - Assessing leg length discrepancy following elastic stable IM nailing for paediatric femoral diaphyseal fractures
                         - Flexible intramedullary nailing in paediatric femoral shaft fractures
                         - Fixation of Length-Stable Femoral Shaft Fractures in Heavier Children: Flexible Nails vs Rigid Locked Nails
                         - Use and abuse of flexible intramedullary nailing in children and adolescents.
           - references for prebending:
                         - Does the extent of prebending affect the stability of femoral shaft fractures stabilized by titanium elastic nails?

   - ender rod fixation:
          - in the report by Cramer KE, et al., Ender rod fixation for pediatric femoral shaft fractures evaluated in a prospective study;
          - 57 frx in 52 patients were evaluated;
          - patients were younger than 14 years, and had fractures in the middle 3/5, and canal size greater than 7 mm;
          - there were no delayed unions and all fractures healed within 12 weeks
          - ref: Ender rod fixation of femoral shaft fractures in children

- Complications:
- potential complications:
- include avascular necrosis (as long as proximal physis is open) & risk of injury to trochanteric growth center

- 13-year-old male sustained femoral shaft frx which was treated w/ IM nail;
- one year later the patient developed AVN; (the nail was subsequently removed)

Ligamentous instability of the knee in children sustaining fractures of the femur: A prospective study with knee examination under anesthesia

Intramedullary nailing of femoral fractures in adolescents

Immediate percutaneous intramedullary fixation and functional bracing for the treatment of pediatric femoral shaft fracture

Intramedullary nailing versus submuscular plating in adolescent femoral fracture