Periprosthetic knee fractures. A review of epidemiology, risk factors, diagnosis, management and outcome

Abstract

Background and aim of the work: Periprosthetic knee fractures incidence is gradually raising due to aging of population and increasing of total knee arthroplasties. Management of this complication represents a challenge for the orthopaedic surgeon. Aim of the present study is to critically review the recent literature about epidemiology, risk factors, diagnosis, management and outcome of periprosthetic knee fractures.

Methods: A systematic search of Embase, Medline and Pubmed was performed by two reviewers who selected the eligible papers favoring studies published in the last ten years. Epidemiology, risk factors, diagnostic features, clinical management and outcome of different techniques were all reviewed.

Results: 52 studies including reviews, meta-analysis, clinical and biomechanical studies were selected.

Conclusions: Correct clinical management requires adequate diagnosis and evaluation of risk factors. Conservative treatment is rarely indicated. Locking plate fixation, intramedullary nailing and revision arthroplasty are all valuable treatment methods. Surgical technique should be chosen considering age and functional demand, comorbidities, fracture morphology and location, bone quality and stability of the implant. Given the correct indication all surgical treatment can lead to satisfactory clinical and radiographic results despite a relevant complication rate.

Keywords: periprosthetic knee fractures, TKA, complications, management, supracondylar, patella, tibia.

Figure 1.

a, b) AP and Lateral x-rays showing a periprosthetic distal femur fracture in a 70 yrs old patient occurring on a long stemmed hinged revision knee prosthesis implanted 3 years before. c, d) AP and Lateral x-rays obtained after open reduction and internal locking plate fixation

Figure 2.

a, b) AP and Lateral x-rays of an undisplaced periprosthetic knee fracture of the distal femur (Rorabeck type I) in a 78yrs old female patient. c,d) AP and Lateral x-rays obtained after internal locking plate fixation

Figure 3.

Radiographic lateral view of 3 different cases of Rorabeck type II distal femur periprosthetic knee fracture. These fractures can be differently classified according to Su et al. a) Su Type I: the fracture is located proximal to anterior femoral flange. b) Su Type II: the fracture extends cranially into the diaphysis starting from the anterior flange level. c) Su Type III: the fracture line begins at the level of the anterior flange and extends distally into the epiphysis

Figure 4.

a, b) AP and lateral x-rays showing a distal femur periprosthetic knee fracture in a 80yrs old female patient treated 3 months before with a long cephalo-medullary nail for a subtrocantheric fracture. c, d, e) Radiographs obtained after open reduction internal locking plate fixation. A monocortical proximal screw, metal cerclages locked on the plate and bicortical screws inserted thorough the locking nail holes were all used to obtain stable fixation

Figure 5.

Femoral shaft fracture occurring between a too short locking plate implanted to treat a periprosthetic knee fracture and a previously implanted trocantheric nail in a 82 yrs old female patient. a, b) Radiographs showing the diaphyseal fracture between the two implants. c, d) AP and lateral x-rays obtained after plate removal, open reduction and new internal fixation with a longer locking plate sufficiently overlapping with the intramedullary nail to avoid stress raisers