IM Nailing for Subtrochanteric Frx - Wheeless' Textbook of Orthopaedics

- Discussion:
     - see synthese proximal femoral fracture products and IM nailing of Intertrochanteric fractures
     - closed IM nailing may be applied to some distal subtrochanteric fractures;
- indications:
- interlocking nails have been used for subtroch frx when lesser trochanter remains attached to the proximal fragment;
- depending upon pattern of frx, its comminution, & shape of medullary canal, frx > 2 cm below lesser troch may be fixed w/ standard nail;
- when lesser troch is fractured, reconstruction nail w/ femoral head and neck fixation is required;
     - risks of IM nailing:
- varus angulation:
- in frxs involving subtrochanteric region, medullary canal & trochanteric area do not provide good stable purchase on proximal fragment;
- this results in varus angulation of the proximal fragment and, frequent rotational instability of the distal fragment;
- this is particularly true in high subtrochanteric fractures;
- iatrogenic fracture of proximal fragment:
- some restrict IM nailing for fractures w/ an intact ring of cortical bone on proximal fragment 2 cm below the lesser trochanter;
- some will insert the nail even if frx is up to proximal edge of trochanter;
- in either case, great care must be taken not to shatter the proximal fragment during nail insertion;
- w/ significant flexion of the proximal fragment, consider open reduction prior to nail insertion;
- if the proximal fragment does fracture during the nailing, all good options for fixation are lost;

- Technical Considerations:
- IM hip screw for peritrochanteric fractures:
- IM nail in proximal femoral shaft frx:
- technique of IM nailing:
- nail length and diameter:
- it is important to estimate length of proximal diaphyseal fragment on lateral view, becuase flexion foreshortens it on AP view;
- consider insertion of a smaller diameter flexibile nail (Synthese titanium) to help avoid shattering the proximal fragment during nail insertion;
- overreaming the canal will help avoid fracturing the proximal fragment;
- reduction:
- note that the proximal fragment is often severely flexed which can complicate the reduction, and may increase the chance of fracturing the proximal fragment;
- w/ significant flexion of the proximal fragment, consider open reduction prior to nail insertion;
           - ref: Clamp-Assisted Reduction of High Subtrochanteric Fractures of the Femur
    - entry point: (see entry point for femoral shaft frx);
           - w/ a trochanteric entry nail, start slightly medial to the specific tip of the greater trochanter;
                       - lateral entry will end up causing a highlag-screw position in the femoral head (leads to cut out)
                       - lateral entry will end up causing the fracture to reduce into varus (leads to non union and or malunion);
                       - other surgeons note that entry thru piriformis fossa risks shattering proximal fragement, especially in cases where frx procedes close to piriformis fossa;
    - reaming
           - do not ream an unreduced fracture;
           - reaming an unreduced fracture in this situation will help reenforce the malreduction after the nail is inserted;
    - proximal fixation:
- if there is any risk of propagating a fracture into the piriformis fossa, or if there is any risk of the proximal fragment slipping into varus, consider use
                     of prophylactic cerclage wires;
- w/ synthes IM nail consider use of spriral blade plate along w/ proximal interlocking screw;
- case example: this unfortunate prisoner sustained a subtrochanteric frx, as well as having AVN;

- case example: reverse obliquity frx;

Subtrochanteric fractures treated with interlocking nailing.

Subtrochanteric fractures of the femur. Results of treatment by interlocking nailing.

Reconstruction nailing for pathological subtrochanteric fractures with coexisting femoral shaft metastases.

Unreamed femoral nail with spiral blade in subtrochanteric fractures: experience of 55 cases.