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    Distal Tibia Non-union After Seemingly Successful Fracture Reduction

    A 48-year-old male patient with a closed extra-articular distal tibia and fibula fracture undergoes early definitive fixation with open reduction and internal fixation with locking plates. Although the reduction is anatomic, the fixation failed. What happened, and what could the surgeon have done differently?

    Author

    Brandon J. Yuan, MD

    Introduction

    A 48-year-old male patient with a history of nicotine dependence (less than 1 pack per week) presents with a closed extra-articular distal tibia and fibula fracture that occurred in a twisting injury on a wet surface, falling from standing height (Figure 1). No CT scan was obtained, and the patient was taken to the operating room for surgical fixation of this injury.

    Figure 1. Initial radiographs showing closed extra-articular distal tibia and fibula fracture.

    Many high-energy distal tibia fractures that require open exposures through the zone of injury warrant consideration for temporary external fixation to restore stability, length, and alignment. This will allow time for the soft tissue swelling associated with the initial trauma to resolve prior to imparting additional surgical trauma to the limb.

    However, the history and radiographs of this injury imply a relatively low-energy mechanism, and the soft tissue envelope may be acceptable for immediate definitive surgical management. In addition, use of a medullary device may be appropriate for this extra-articular injury, allowing for minimal additional soft tissue trauma to the distal leg.

    Initial Treatment

    The surgeon opted for early definitive fixation, utilizing open reduction and internal fixation with locking plates. Several aspects of the case can be analyzed.

    The fixation goals for the tibia appear to have been direct reduction of the simple oblique fracture pattern and primary bone healing. The tibia was approached first through a direct medial incision, and the quality of the reduction looks excellent. The fibula reduction is acceptable. Both reductions were secured with locking plates (Figure 2).

    Figure 2. Postoperative radiographs showing tibia and fibula reductions secured with locking plates.

    What Could Have Been Improved?

    A simple fracture pattern is best treated with direct open reduction and interfragmentary compression. Although direct reduction of both fractures was obtained, it does not appear as though any attempt at interfragmentary compression was made. Both plates are locking implants, and the exclusive use of locking screws, including the screws crossing the fracture, serves to rigidly stabilize the fracture without true compression.

    The fracture is left with a small gap, too large to allow for primary bony healing. In addition, the construct is too rigid to allow for any motion at the fracture site to stimulate callus formation and secondary bone healing. The outcome is predictable: Minimal non-bridging callus formation, implant failure (broken screws failing simultaneously at the plate/screw interface distally), and non-union.

    This predicted mode of failure is confirmed on ankle radiographs obtained 8 weeks following surgery (Figure 3). They demonstrate broken screws, minimal callus formation, and re-displacement of the fracture with lateral translation and proximal migration.

    Figure 3. Radiographs showing failed fixation, with broken screws, minimal callus formation, and re-displacement of the fracture.

    Other Considerations

    Use of a medullary nail with several interlocking screws placed in the short distal segment could have been successful, as a medullary implant with a long working length would have allowed for a small amount of motion at the fracture site and potential for secondary bone healing.

    Use of an anterolaterally based non-locking distal tibia plate may have more effectively resisted the predicted mode of failure – proximal and lateral translation of the distal segment – by allowing the plate to directly buttress the apex of the oblique fracture.

    Referral to Author’s Clinic

    The patient was initially placed into a short-leg cast by the treating surgeon at this point. He presented to the author’s clinic after continued failure of non-operative management several weeks later. It is notable that some callus did start to form only after the implants broke and stability was lost; however, progressive deformity is evident (Figure 4). Of note, the fibular fixation appears to be stable.

    Figure 4. Radiographs showing progressive deformity following failure of non-operative management.

    At this point, options for managing the patient include the following:

    • Revision internal fixation with bone graft, utilizing a plate. This has the advantage of removing the previous implants, allowing for correction of deformity and use of biologic augmentation. Most important, this would allow for direct reduction and interfragmentary compression of the long oblique fracture line, giving the fracture a chance to heal with primary bone healing.
    • Revision internal fixation with bone graft, utilizing a medullary nail. This approach may have the advantage of changing fixation types. However, it would require removal of multiple broken screws from the distal tibia, which may compromise fixation of the interlocking bolts in an already short segment.

    Prior to any revision procedure, the surgeon must rule out underlying infection or endocrine abnormality that may have contributed to delayed bone healing. Preoperatively, the patient’s C-reactive protein, erythrocyte sedimentation rate, white blood cell count, and endocrine labs (vitamin D, thyroid-stimulating hormone, parathyroid hormone, alkaline phosphatase, calcium, and phosphorus) were within normal limits. In addition, the patient was counselled on the importance of smoking cessation and was referred to our nicotine cessation clinic.

    Revision Procedure and Follow-Up

    The patient agreed to undergo a revision procedure. Goals of the revision were to:

    • Remove the prior locked implants on the tibia
    • Mobilize the fracture and restore the reduction of the tibia
    • Compress the fracture

    Removal of the prior locked implants required a medial approach. Although placement of the plate on the lateral surface of the tibia would have been mechanically advantageous, it would have required an additional approach, leading to stripping of both the medial and lateral tibia. Given that the primary goals of surgery were to mobilize and re-reduce the fracture, and then provide interfragmentary compression, this did not require placement of an anterolateral plate. Thus, we elected to place the fixation medially again.

    The implants were removed, fracture was mobilized with an osteotome, and the canal was re-established on either side of the fracture. A universal distractor was utilized to restore length (Figure 5).

    Figure 5. The implants have been removed, the fracture has been mobilized, and the canal has been re-established on both sides of the fracture (left). To restore length, a universal distractor was utilized (right).

    Next, the fracture was compressed with a clamp and 3.5-mm lag screws. The construct was neutralized with a medially based non-locking plate (Figure 6). The fracture was also augmented with proximal tibia bone autograft. Radiographs demonstrate restoration of alignment of the tibia (Figure 7).

    Figure 6. Compression of the fracture with a clamp and lag screws (left). A medially based non-locking plate was used to neutralize the construct (right).

    Figure 7. Restoration of tibial alignment.

    One year after the original injury, the tibia demonstrated complete remodeling and osseous union (Figure 8). Of note, 2 lag screws and 2 screws in the proximal aspect of the plate broke prior to complete union. Although the fracture was compressed and rigidly stabilized, the fracture healed with some callus where the bone graft was applied. The patient notes prominence of the proximal aspect of the plate.

    Figure 8. Complete union of the fracture 1 year after the patient’s injury.

    Key Points

    • Simple fracture patterns – particularly those treated with direct reduction and plate fixation – do well with interfragmentary compression and rigid stabilization.
    • Although periarticular locked plates can be very useful in treating certain articular fractures, the use of locked screws precludes interfragmentary compression (unless extrinsic compression is applied first, as with a clamp). In this case, the plates functioned to rigidly stabilize a well-reduced fracture without interfragmentary compression. Despite the initial anatomic reduction, the lack of compression reliably leads to implant failure and non-union.
    • When considering the approach for non-union surgery, the reason for the lack of healing must first be ascertained. This fracture appears to possess adequate biologic capacity to heal; however, it lacked the appropriate mechanical environment for union. The primary goal of the non-union surgery is, thus, to address the mechanical shortfalls of the prior construct. Bone graft was added in this case from the ipsilateral proximal tibia, but it would have been acceptable to treat this non-union without biologic supplementation.

    Author Information

    Brandon J. Yuan, MD, is an Assistant Professor in the Division of Orthopedic Trauma, Mayo Clinic, Rochester, Minnesota.

    Disclosure

    The author has no disclosures relevant to this article.