Failure of Less-Invasive Stabilization System (LISS) plating for periprosthetic distal femur fractures: Three case reports

Abstract

Rationale: Less-Invasive Stabilization System (LISS) plate is an internal fixation commonly used for the periprosthetic distal femur fractures. Failure associated with LISS plate has been rarely reported, and the reasons for LISS plate failure are multitudinous. Various advantages have been reported, but failures continue.

Patient concerns: We present 3 cases illustrating the failure of Less-Invasive Stabilization System (LISS) plating for periprosthetic distal femur fractures. The shaft screws of the LISS plate broke in 2 cases, and the plate placement was incorrect in 1 case. Early weight bearing, obesity, osteoporosis, and lateral collateral ligament injury due to incorrect plate placement constituted the etiologies of LISS plate failure.

Diagnosis: Failure of Less-Invasive Stabilization System (LISS) plating for periprosthetic distal femur fractures after Total knee arthroplasty.

Interventions: Three patients underwent Less-Invasive Stabilization System plates removal with replacement of the total knee arthroplasty revision surgery with rotating hinged knee prosthesis.

Outcomes: After completing the total knee arthroplasty revision surgery, all patients underwent regular follow-up examinations. Case 2 could walk unaided, without pain, final union was confirmed for both case 1 and case 3.

Conclusion: Less-Invasive Stabilization System (LISS) plate provides satisfactory results in periprosthetic fractures after Total knee arthroplasty (TKA). The LISS plate has many advantages, but failures continue to occur. The causes for failure were early weight bearing, obesity, osteoporosis, and lateral collateral ligament (LCL) injury due to incorrect plate placement in our series. We recommend that protection or properly delay of weight-bearing, active anti-osteoporosis treatment, and intraoperative fluoroscopy are the effective methods to avoid failure.

Figure 1

Anteroposterior radiographs of case 1, sustained a left Rorabeck type II closed distal femoral fracture (A), internal fixation of LISS plate was performed immediately (B). 7 months later, screws of LISS plate were broken and fracture displacement occurred again (C), underwent total knee arthroplasty revision surgery with rotating hinged knee prosthesis finally (D).

Figure 2

Anteroposterior and lateral radiographs of patient 2, the LISS plate was not centered on the femoral shaft (A), the gap of the lateral compartment was wider under varus stress (B), placement of the prosthesis was appropriate (C).

Figure 3

In case 3, the patient sustained a Rorabeck type II distal femoral fracture (A), bony callus was noted at the fracture site (B), total knee arthroplasty revision was beneficial for fracture healing.