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    Periprosthetic Tibial Shaft Fracture after Kinematically Aligned TKA

    A 67-year-old female patient with a history of a primary left total knee arthroplasty presents with a periprosthetic tibial fracture that occurred while she was walking up the stairs. What is the best approach to manage this patient?

    Authors

    Timothy L. Tan, MD; Keith P. Connolly, MD; and P. Maxwell Courtney, MD

    Introduction

    Periprosthetic fractures of the tibia following total knee arthroplasty (TKA) are much less common than periprosthetic femur fractures, with an incidence of around 1%. [1,2] Risk factors include component malalignment, loosening, and instability, with 1 small series identifying varus positioning of the tibia as a risk factor for periprosthetic fracture. [1,3,4]

    Kinematically aligned TKA has become an increasing popular alternative to traditional mechanical alignment, with the goal of matching the native varus of the proximal tibia and native valgus of the distal femur while minimizing soft tissue releases. Although a recent meta-analysis found equivalent results and slightly improved functional outcomes with kinematically aligned TKA compared with mechanically aligned TKA, [5] concerns exist regarding patellar maltracking and long-term survivorship of the prosthesis with a varus tibial component. To date, no study has identified an association between kinematic alignment and periprosthetic fractures, but further study is needed.

    Case Presentation

    A 67-year-old female with a history of a primary left total knee arthroplasty performed with a kinematic alignment technique presented after feeling her knee “snap” when going up the stairs.

    The patient had been doing well since undergoing left TKA 8 months prior and had been ambulating with a cane. After this incident, however, she was unable to bear weight on the knee. She had also undergone right TKA 16 months prior to presentation. Both procedures were done without navigation or robotics.

    Her past medical history included Parkinson’s disease, hypothyroidism, diabetes mellitus, and bladder cancer in remission.

    Physical Exam

    • Height: 5 feet, 6 inches; weight: 161 pounds; body mass index: 26 kg/m2
    • Well-healed midline incision
    • Obvious deformity of the proximal tibia
    • Knee range of motion limited due to pain
    • Normal distal lower extremity motor and sensory exams
    • Palpable pedal pulses

    Imaging

    Figure 1. Radiographs taken after the index arthroplasty procedure.

    Figure 2. Radiographs on presentation demonstrate a periprosthetic tibial shaft fracture distal to a cementless TKA.

    Diagnosis

    • Acute periprosthetic tibial shaft fracture below a kinematically aligned TKA with possible loosening of the tibial component

    Treatment

    There were several considerations for the management of this patient:

    • Could this fracture be treated with open reduction and internal fixation (ORIF) of the tibia without a revision of the components?
    • If attempting revision of the prosthesis with an ORIF, would multiple incisions need to be created?
    • Did a neutral mechanical axis of the tibia need to be restored for a successful long-term result?

    We carefully discussed the risks and benefits of surgical treatment with the patient. Although she had been functioning well prior to her injury, we identified radiolucent lines underneath the tibial baseplate and felt it necessary to correct her mechanical alignment to neutral with a longer-stemmed tibial prosthesis. For rotational stability, we also chose to do supplementary fixation with a lateral variable angle locking plate.

    • The fracture was first reduced using a lateral approach to the tibia with a skin bridge less than 6 cm from the prior midline incision. Point-to-point reduction clamps were used to achieve reduction, followed by a small one-third tubular plate to temporarily hold the reduction.
    • Using a standard medial parapatellar incision, the femoral and tibial prostheses were removed and the tibia was found to be loose intraoperatively.
    • We utilized a hybrid technique with press-fit stems and cement on the metaphysis for fixation and augments on the femoral and tibial components to correct the alignment and distalize the joint line.
    • The tubular plate was removed and supplementary fracture fixation was performed with a lateral variable angle locking plate (Figure 3).

    Figure 3. Immediate postoperative radiographs demonstrate a revision prosthesis with hybrid fixation of the femoral and tibial stems and a supplemental lateral locking plate.

    Follow-up

    • The patient was made toe-touch weight-bearing immediately postoperatively and was allowed to advance weight-bearing at 6 weeks following repeat radiographs (Figure 4).
    • She is doing well at 3 months postoperatively, with range of motion from 0° to 110°.

    Figure 4. Radiographs from the patient’s 6-week postoperative follow-up visit.

    Surgical Pearls

    • Kinematic alignment may be a risk factor for periprosthetic fracture of the tibia, but further studies are needed.
    • It is important to achieve mechanical alignment when revising a kinematically aligned knee, which may have predisposed the patient to fracture.
    • The use of press-fit stems on the femur and tibia will guide mechanical alignment, as the stems will fill the intramedullary canal.
    • Although intramedullary fixation is biomechanically stronger than a plate alone, a supplemental lateral plate provides for rotational stability.

    Author Information

    Timothy Tan, MD, is a resident at The Rothman Institute and Thomas Jefferson University, Philadelphia, Pennsylvania. Keith P. Connolly, MD, is an adult reconstruction fellow at The Rothman Institute and Thomas Jefferson University, Philadelphia, Pennsylvania. P. Maxwell Courtney, MD, is an assistant professor of orthopaedic surgery at Thomas Jefferson University Hospital and attending surgeon at The Rothman Institute, Philadelphia, Pennsylvania.

    Adult Reconstruction Section Editor, Rothman Institute Grand Rounds

    P. Maxwell Courtney, MD

    Disclosures

    The authors have disclosures relevant to this article.

    References

    1. Rand JA, Coventry MB. Stress fractures after total knee arthroplasty. J Bone Joint Surg Am. 1980;62:226–233.
    2. 30. Felix NA, Stuart MJ, Hanssen AD. Periprosthetic fractures of the tibia associated with total knee arthroplasty. Clin Orthop Relat Res. 1997;(345):113–124.
    3. Dennis DA. Periprosthetic fractures following total knee arthroplasty. J Bone Joint Surg Am. 2001;83:120–130.
    4. Ritter MA, Carr K, Keating EM, Faris PM, Meding JB. Tibial shaft fracture following tibial tubercle osteotomy. J Arthroplasty. 1996;11:117–119.
    5. Courtney PM, Lee GC. Early Outcomes of Kinematic Alignment in Primary Total Knee Arthroplasty: A Meta-Analysis of the Literature. J Arthroplasty. 2017 Jun;32(6):2028-2032.e1