Session X - Geriatrics
Sun., 10/10/04 Geriatrics, Paper #62, 8:53 am
Locked Plates Combined with Minimally Invasive Insertion Technique Is the Treatment of Choice for Periprosthetic Supracondylar Femur Fractures above a Total Knee Arthroplasty
Purpose: The multitude of options for the treatment of periprosthetic supracondylar femur fractures associated with total knee arthroplasty (TKA) is a testament to the lack of superiority of any. Retrograde intramedullary nailing associated with a TKA prosthesis with a narrow or closed intracondylar space either limits the diameter for a retrograde nail or completely obviates its use. Furthermore, the wide metaphyseal and diaphyseal spaces often associated with these elderly patients can result in sub-optimal fixation for intramedullary devices. Traditional plate fixation is prone to varus collapse. Blade plates or condylar screws have limited applicability for very distal fractures or when associated with a TKR prosthesis with a deep intracondylar box. Distal femoral replacement has limited longevity. New locked-plate devices offer many theoretic advantages. The multiple locked distal screws provide a fixed angle to prevent varus collapse and the ability to address distal fractures even when associated with a deep intracondylar box. These devices can also be inserted with relative ease with use of minimally invasive techniques. The purpose of this study was to evaluate the efficacy of a locked plate designed for treatment of periprosthetic supracondylar femur fractures above a TKA.
Methods: Thirteen consecutive adult patients with supracondylar femur fractures above a well-fixed non-stemmed TKA (OTA 33A) treated with the Locking Condylar Plate (Synthes, Paoli, Pennsylvania, USA) were included in this prospective and Institutional Review Board-approved study. All patients (1 male, 12 female, with an average age of 73 years; range, 50 to 91) were available for follow-up at an average of 16 months (range, 9 to 44). According to the OTA classification, there were two 33A1, three 33A2, and eight 33A3 fractures. All fractures were closed. Indirect reduction methods without bone graft were used in all cases.
Results: All 13 patients healed after the index procedure (100%) without infectious complications. No patient required additional surgery. Postoperative fracture alignment was satisfactory (within 5°) in all cases. In two patients, there was progressive deformity in the coronal plane associated with fracture of screws in the proximal fragment, from 1° to 6° of varus in one case and from 2° to 6° valgus in the other. There was no change in alignment in any other patient. Twelve of the 13 patients returned to their baseline ambulatory status and one declined from a community to household ambulator. Four patients required additional ambulatory support compared with baseline. Functional outcome based on the Lower Extremity Measure (LEM) returned to baseline by 6 months (average LEM at 6 months, 63).
Conclusions: We believe that results seen from this study, 100% union after the index procedure, a high rate of return to baseline function, with few associated complications (no infections, no re-operations, and only two cases with minor progression of coronal plane deformity), represent excellent outcomes. Therefore, we advocate the use of locked plates combined with minimally invasive insertion technique for the treatment of periprosthetic supracondylar femur fractures above a TKA.