Treatment of Unstable Subtrochanteric Fractures: Cephalomedullary Nailing

G. Yves Laflamme, M.D., FRCSC
Montral, QC

Cephalomedullary (CM) nails are antegrade femoral intramedullary nails designed for fixation into the femoral head and neck. Their main use is to treat selected, complex proximal femoral fractures. In the 1970's, Zickel was one of the first to design a short, double-curve intramedullary device for subtrochanteric (ST) fractures. He reported one of the highest union rates and one of the lowest implant failure rates for the time1.

With the advent of interlocking nails in the late 80's, many surgeons, dissatisfied with plate fixation, started to use these nails for ST fractures. The Russell-Taylor Reconstruction Nail (Smith and Nephew, Memphis, TN) was the first of the second generation nails that provided a biologically-friendly implant which had enough fatigue strength to outlast fracture healing2. Various manufacturers have introduced newer generations of CM nails since. Although they vary in diameter and cross-sectional design, it is their proximal screw geometry that allows improved proximal fixation3,4.

The treatment of ST fractures is particularly challenging for any orthopaedic surgeon. Comminution and displacement create a very unstable situation through the most highly stressed area in the body5. Intramedullary (IM) fixation offers several advantages over plate and screw fixation: 1) because the IM nail is closer to the central axis of the femur than a laterally positioned plate, the bending load on the implant is reduced; 2) IM nails act as load-sharing devices capable of withstanding cyclic loading and early weight-bearing in fractures having cortical contact; 3) IM fixation offers a simple minimally invasive technique that maintains the blood perfusion to the fracture. Indirect reduction techniques have also been described for plating the subtrochanteric region with excellent union rates6. However, minimally invasive plating or "biological" plating using a standard DCS or AO blade plate is technically more challenging even for expert trauma surgeons.

Numerous classifications of ST fractures have been proposed over the years, none have been universally accepted2. As for intertrochanteric fractures, stability is dependent on the presence or absence of a postero-medial buttress. The most useful classification system for ST fractures is that proposed by Russell and Taylor which is based on the presence or absence of fracture involvement of the lesser trochanter (medial calcar) and the greater trochanter (piriformis fossa).

For ST fractures with lesser trochanter involvement (Type 1B), a CM nail, which fixes the femoral head and neck bypassing the proximal femoral comminution, is probably the ideal indication7. For ST fractures with significant trochanteric and piriformis fossa comminution, CM nailing is still a controversial issue. An improper starting point and a poorly inserted nail will accentuate the fracture displacement and lead to a malreduction2,7,8.
laflamme1.jpg
Figure 1A & 1B
Radiographs of a 74-year-old male. (A) Preoperative radiograph shows a comminuted subtrochanteric fracture of the right femur ( type 2b) (B) Postoperative antero-posterior radiograph at three months after CM nailing with a large proximal diameter nail (17mm) for maximal strength.

CM nailing is technically demanding surgery. The subtrochanteric region is an area of high stress concentration submitted to multiple deforming forces. The flexed, abducted and externally rotated proximal fragment can predispose to excessive posterior reaming with a risk of blowout during nail insertion2,5. A proper starting point for nail insertion is needed to obtain adequate reduction and prevent residual anterior angulation and varus deformity7. The surgeon should be familiar with adjunct techniques of reduction including pointed trocars, Schanz pins, channel reamer, lateral positioning and he or she should not hesitate to open the fracture site for provisional fixation if needed.

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Figure 2
Radiographs showing a segmental fracture of the proximal femur in a young 24 year-old female. Postoperative radiographs at seven months after IM fixation using a small proximal diameter (13mm) Recon nail to minimize damage to the gluteus medius tendon.

The literature concerning the treatment of subtrochanteric fractures is relatively poor. Most reports study the more common unstable intertrochanteric fractures comparing treatment by short stem CM nailing to plating devices9,10,11,12. The Evidence-Based Working Group in Trauma reviewed the literature of unstable pertrochanteric fractures (AO/OTA 31-A3)13. Based upon the current available evidence, they reported the following: 1) trochanteric nail has a significantly lower reoperation rate than 95 plate device14,15; 2) failure rates with a sliding hip screw are too high to recommend its use; 3) further studies are needed to evaluate abductor function and true patient "functional outcomes". A recent cohort study evaluating functional outcome of intertrochanteric fractures showed a significantly earlier recovery with a trochanteric device compared to extramedullary fixation16.

Based upon current knowledge, long stem CM nails are the implants of choice to treat femoral ST fractures2,7,17. All subtrochanteric fractures can be stabilized with long stem CM nails, regardless of the fracture pattern or degree of comminution. Short stem CM nail cannot be recommended for ST fractures because of the many iatrogenic problems and relatively high complication rate9,12,16. Further studies are needed to evaluate the new generation plates and indirect reduction methods for subtrochanteric fractures. Will they eliminate the complications inherent to conventional plating?

References

  1. Zickel R.E. An intramedullary fixation device for the proximal part of the femur. J Bone Joint Surg 1976;58:866-72.
  2. Russel T.A., Taylor J.C. Subtrochanteric fractures of the femur. Browner B.D., Jupiter J.B., Levine A.M., Trafton P.G., editor. Skeletal Trauma. 2nd edition. Philadelphia, PA: WB Saunder; 1992.p1832-78.
  3. Kubiak E.N., Bong M., Park S.S., Egol K., Koval K.J. Intramedullary fixation of unstable intertrochanteric hip fractures: one or two lag screws. J Orthop Trauma. 2004 Jan;18(10:12-7.
  4. Strauss E., Frank J., Lee J., Kummer F.J., Tejwani N.. Helical blade versus sliding hip screw for the treatment of unstable intertrochanteric hip fractures: a biomechanical evaluation. Injury 2006 Oct; 37(10):984-9.
  5. Bedi, A. Toan Le T. Subtrochanteric femur fractures. Orthop Clin North Am 2004;35 :473-483.
  6. Kinast C., Bolhofner B.R., Mast J.W., et al. Subtrochanteric fractures of the femur: results of treatment with the 95 degrees condylar blade-plate.Clin Orthop 1989; 122-130
  7. French B.G., Tornetta P. 3rd. Use of an interlocked cephalomedullary nail for subtrochanteric fracture stabilization. Clin Orthop Relat Res. 1998,Mar;(348): 95-100
  8. Sims S.H. Subtrochanteric femur fractures. Orthop Clin North Am. 2002 Jan; 33 (1):113-26.
  9. Ekstrom W., Karlsson-Thur C., Larsson S., Ragnarsson B., Alberts K.A. Functional Outcome in Treatment of Unstable Trochanteric and Subtrochanteric Fractures With the Proximal Femoral Nail and the Medoff Sliding Plate. J Orthop Trauma. 2007 Jan;21(1):18-25
  10. Miedel R., Ponzer S., Tornkvist H., Soderqvist A., Tidermark J. The standard Gamma nail or the Medoff sliding plate for unstable trochanteric and subtrochanteric fractures. A randomised, controlled trial. J Bone Joint Surg Br. 2005 Jan; 87(1):68-75.
  11. Utrilla A.L., Reig J.S., Munoz F.M., Tufanisco C.B. Trochanteric gamma nail and compression hip screw for trochanteric fractures: a randomized, prospective, comparative study in 210 elderly patients with a new design of the gamma nail. J Orthop Trauma. 2005 Apr;19(4):229-33
  12. O'Brien P.J., Meek R.N., Blachut P.A., Broekhuyse H.M., Sabharwal S. Fixation of intertrochanteric hip fractures: gamma nail versus dynamic hip screw. A randomized, prospective study. Can J Surg. 1995 Dec;38(6):516-20.
  13. Kregor P.J., Obremskey W.T., Kreder H.J., Swiontkowski M.F., Evidence- Based Orthopaedic Trauma Working Group. Unstable pertrochanteric femoral fractures. J Orthop Trauma. 2005 Jan; 19(1): 63-6
  14. Pelet S., Arlettaz Y., and Chevally F. Osteosynthesis of per- and subtrochanteric fractures by blade plate versus gamma nail. A randomized prospective study. Swiss Surg, 2001: (7): 126-33
  15. Sadowski C., Lubbeke A., Saudan M., Riand N., Stern R., Hoffmeyer P. Treatment of reverse oblique and transverse intertrochanteric fractures with use of an intramedullary nail or a 95 degrees screw-plate: a prospective, randomized study. J Bone Joint Surg Am. 2002 Mar; 84-A(3):372-81
  16. Bienkowski P., Reindl R., Berry G.K., Iakoub E., Harvey E.J. A new intramedullary nail device for the treatment of intertrochanteric hip fractures: Perioperative experience. : J Trauma. 2006 Dec; 61(6):1458-62.
  17. Barquet A., Francescoli L., Rienzi D. Intertrochanteric-subtrochanteric fractures: treatment with the long gamma-nail. J Orthop Trauma 2000; 14:324-8.

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