Predictors and Reduction Techniques for Irreducible Reverse Intertrochanteric Fractures

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Predictors and Reduction Techniques for Irreducible Reverse Intertrochanteric Fractures

Hip fractures are a growing concern as populations age, and most require surgery to help patients regain mobility and avoid long-term complications. For many trochanteric (hip) fractures, doctors use closed reduction—realigning bones without making large incisions—followed by internal fixation (screws, nails, or plates). But some fractures resist closed reduction: these are called irreducible and need more targeted approaches.

Reverse intertrochanteric fractures, a specific type of hip fracture, are particularly tricky. Unlike common trochanteric fractures (where the break runs from the top of the thigh bone to the inner hip), reverse fractures have a reverse break line—from the outer, lower hip to the inner, upper thigh. They’re unstable, and few studies have focused on why they’re hard to reduce or how to fix them.

To fill this gap, a team from Peking University Third Hospital (Beijing, China) analyzed 113 reverse intertrochanteric fractures treated between 2006 and 2018. Their goal: identify displacement patterns (how bones shift) in irreducible fractures, test reduction techniques, and find predictors of irreducibility. The study was published in the Chinese Medical Journal in 2019.

What Are Reverse Intertrochanteric Fractures?

Reverse intertrochanteric fractures fall under the AO/OTA 31-A3 classification, meaning the main break runs distolateral to proximomedial (from the outer, lower hip to the inner, upper thigh). This reverse line, combined with muscle pull (e.g., adductors pulling the thigh bone inward) and gravity (causing the thigh bone to sag backward), makes these fractures unstable and hard to realign with closed methods.

How the Study Worked

The team reviewed 1,174 trochanteric fracture cases and selected 113 reverse fractures. They defined a fracture as irreducible if closed manipulation didn’t achieve:

  1. Good alignment: Normal/slightly valgus (outward) neck-shaft angle on the front-back (AP) X-ray; <20° angulation on the side (lateral) view.
  2. Minimal displacement: Less than one “cortical thickness” (bone width) of shift on AP/lateral views.

Fractures that failed these criteria (even after closed attempts) were labeled irreducible. The team then:

  • Categorized displacement patterns using intra-operative fluoroscopy (real-time X-rays).
  • Tested reduction techniques (e.g., bone hooks, clamps, Schanz screws).
  • Used statistical analysis to find predictors of irreducibility (e.g., age, fracture type, bone displacement).

Key Findings

Of the 113 reverse fractures:

  • 67% were irreducible (76 cases)—more than half couldn’t be fixed with closed methods.
  • Six displacement patterns emerged, each requiring a different technique.

Most Common Displacement Pattern: Medial Displacement + Posterior Sagging

Thirty patients (39% of irreducible cases) had a thigh bone that shifted inward (medial) relative to the hip ball (head-neck fragment) and sagged backward (posterior). Closed reduction failed because muscle pull and gravity kept the bone misaligned.

Reduction technique: Surgeons used a bone hook to pull the thigh bone outward and a mallet to lift it forward. They kept the hook in place during fixation to maintain alignment.

Other Patterns & Techniques

  1. Posterior Sagging Alone (11 patients): The thigh bone sagged backward, even if the front-back view looked aligned.
    • Technique: A Schanz screw (attached to a G-arm X-ray machine) acted as a “joystick” to lift the bone. Surgeons controlled the G-arm remotely to avoid radiation.
  2. Lateral Femoral Wall Malalignment (11 patients): The outer hip bone (lateral wall) was misaligned, even if inner bones touched.
    • Technique: K-wires (thin pins) to realign and hold the lateral wall before fixation.
  3. Sagittal Plane Lateral Wall Separation (9 patients): The outer wall had a vertical break (coronal line) and shifted.
    • Technique: Clamps to realign the wall + cannulated screws to fix it. A locking plate was used if screws blocked nail insertion.
  4. Lateral Displacement + Posterior Sagging (9 patients): Thigh bone shifted outward and sagged backward.
    • Technique: A periosteum elevator to push the hip ball backward + mallet to lift the thigh bone.
  5. Medial Displacement Alone (6 patients): Thigh bone shifted inward, but the side view was aligned.
    • Technique: Bone hook to pull the thigh bone outward.

Predictors of Irreducibility

The study found three factors that made a fracture 7–8 times more likely to be irreducible:

  1. Medial displacement of the thigh bone (AP view): Muscle pull from adductors (inner thigh muscles) made closed reduction hard.
  2. Displaced lesser trochanter: The small inner hip bone (lesser trochanter) was detached, so muscles (iliopsoas) couldn’t stabilize the thigh bone.
  3. Displaced lateral femoral wall: A broken outer hip wall meant free bone fragments, complicating alignment.

Follow-Up & Outcomes

After using targeted techniques:

  • 70% of fractures had “good” reduction (53 cases).
  • 20% had “acceptable” reduction (15 cases).
  • 11% remained “poor” (8 cases).

Over 24 months (average follow-up), 13% of patients had implant failure (e.g., screw breakage, nail loosening). Failure rates were higher with poor reduction:

  • 9% for good reduction.
  • 13% for acceptable reduction.
  • 38% for poor reduction.

Why This Matters

Reverse intertrochanteric fractures are unstable and hard to reduce—but this study gives surgeons a roadmap:

  • Preoperative planning: If a fracture has the three predictors (medial shift, displaced lesser trochanter/lateral wall), surgeons can prepare for open reduction.
  • Targeted techniques: Matching the displacement pattern to the right tool (bone hook, Schanz screw) improves results.
  • Reduction quality: Good alignment cuts implant failure risk, helping patients recover faster and avoid complications like long-term bed rest.

Conclusion

More than half of reverse intertrochanteric fractures can’t be fixed with closed methods—but knowing why (predictors) and how (techniques) to reduce them can help surgeons improve outcomes. The study’s findings are a key step toward better care for patients with these challenging fractures.

References

  1. Bhandari M, Swiontkowski M. Management of acute hip fracture. New England Journal of Medicine 2017;377:2053–2062.
  2. Moehring HD, Nowinski GP, Chapman MW, Voigtlander JP. Irreducible intertrochanteric fractures of the femur. Clinical Orthopaedics and Related Research 1997;339:197–199.
  3. Kim Y, Dheep K, Lee J, et al. Hook leverage technique for reduction of intertrochanteric fracture. Injury 2014;45:1006–1010.
  4. Gotfried Y. The lateral trochanteric wall: a key element in the reconstruction of unstable pertrochanteric hip fractures. Clinical Orthopaedics and Related Research 2004;425:82–86.

doi.org/10.1097/CM9.0000000000000493

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