Strategies of management of traumatic periprosthetic acetabular fractures around a pre-existing total hip arthroplasty

Abstract

Introduction: and aim: Traumatic peri-prosthetic fractures are relatively rare fractures that pose a significant surgical challenge. They have a fracture pattern that is different from its iatrogenic counterpart. This study aimed at reviewing the modalities of treatment of such injuries, proposing a treatment algorithm and reporting the outcomes of these injuries.

Patients and methods: We propose an algorithm for management of traumatic peri-prosthetic acetabular fractures which depends on fracture displacement, implant stability and associated bone loss.Twelve patients with traumatic peri-prosthetic acetabular fractures were treated between January 2012 and December 2018. All patients were treated surgically. Patients were allowed immediate weight bearing as pain allowed. Assessment was carried out using the Oxford Hip Score (OHS) and the Merle D'aubigné score (MDP).

Results: Mean patient age 71 (range: 59-80). 8 patients underwent implant removal, fracture fixation and re-implantation of revision acetabular cup (displaced fracture, unstable implant, adequate bone stock). Three patients required acetabular reconstruction (inadequate bone stock). One patient underwent revision acetabular component. One patient suffered from recurrent dislocation that required surgical intervention. Mean follow up was 27 Months (range 12-48). Mean OHS was 36 (range 10-47). Mean MDP was 12 (range 9-18) with 80% excellent and good results.

Conclusion: Surgical management of peri-prosthetic acetabular fractures can produce good to excellent results provided adequate assessment and surgical planning have been carried out. Fracture displacement, implant stability and bone stock should be carefully assessed.

Keywords: Acetabular trauma; Peri-prosthetic acetabular fracture; Revision arthroplasty.

Fig. 1

The 4R approach to assessing peri-prosthetic acetabular fractures.

Fig. 2

Algorithm for surgical management of traumatic peri-prosthetic acetabular fractures.

Fig. 3

A: 59 year old male, fall at home 6 weeks after primary THA for osteoarthritis. B: CT showing posterior wall and posterior column fracture. C: Implant removed with large portion of posterior wall and column which was attached to the implant and was carefully removed from the implant. D: intra-operative image after fixing the posterior wall and posterior column. E: post operative image showing fixation of the posterior acetabular fracture with two reconstruction plates and implanting a revision shell, fixed in situ with multiple screws. F: One year follow up AP radiograph.

Fig. 4

A: 64 year old female with bilateral hip OA. Had right THA and fell early onto her right hip sustaining the injury below. B: Axial CT cut. Fracture classified as anterior column posterior hemi-transverse. C: intra-operative fluroscopy after implant removal and fracture fixation. D: Post operative radiograph after fracture fixation and revision with a tacetabular metal socket. E: Five year post-perative AP radiograph.

Fig. 5

A: 69 year old lady, fall at home following right hip arthroplasty dating more than 10 years prior to injury. B: CT scan showing transverse type fracture with medial bone defect. C: intra-operative image of posterior wall/column reduction and fixation, bone stock was poor and deficient medially and posteriorly. D: Reconstruction with cup-cage construct. E: post-operative AP radiographs. F: One year post-operative AP radiographs.

Fig. 6

A: 63 year old female, road traffic injury. Transverse fracture pattern with superior implant migration and postero-superior acetabular defect. B: Intra-operative fluoroscopy showing column fixation with column screws after implant removal. C&D: Post operative images showing outcome after acetabular reconstruction with augments to restore postero-superior defect. E: Three year post-operative follow up AP radiograph.

Fig. 7

A: 74 year old female. Fell and sustained a periprosthetic fracture around left THA. Presented late with marked displacement and leg length discrepancy with sciatic nerve palsy. CT angiogram scan showed that iliac vessels were adhered to the intra pelvic cup. This was therefore left in situ. B: Reconstruction of the posterior column defect was performed using a trabecular metal buttress augment and a revision acetabular shell with multiple screws.