Mechanical complications of hip spacers: a systematic review of the literature

Abstract

Introduction Temporary spacers used in the staged revision of a hip prosthetic joint infection (PJI) have been associated with several mechanical complications with very variable reported general complications rates up to 73%. The aim of this systematic review was to assess the mechanical complications associated with hip antibiotic-loaded spacers when treating periprosthetic hip PJI. Methods Through an electronic systematic search of PubMed, articles reporting mechanical complications of spacers used in the treatment of hip PJI were reviewed. Dislocations, spacer fracture, femoral fractures, and acetabular lysis rates were evaluated. Results Forty studies were included. Standardized molded spacers had a significantly higher weighted mean of total mechanical complication rates (37.2%) when compared to standardized preformed spacers (13.8%, p = 0.039), while no significant difference was found between molded spacers and manually shaped spacers. Spacer dislocation was the most frequent complication. No significant difference in mechanical complication rate was found between spacers with and without any metallic component. Conclusions Spacer placement in chronic PJI of the hip with bone and soft-tissue defects is challenging and bears a high risk of mechanical failures and progressive bone loss during the interim period. A careful patient selection for spacer implantation is mandatory.

Two-stage revision in periprosthetic joint infection of the hip using a new intraoperatively molded articulating spacer design

“…Recent studies suggest avoiding prolonging the interval period to reduce mechanical complications and infection recurrence risks 24 , 25 . In a recent systematic review that analyzed mechanical complications observed during the interval period, the authors reported a weighted mean of 19% for mechanical complications 12 . Spacer dislocation was the most frequent one described in 10.8% of cases.…”

“…Peri-spacer and spacer fractures accounted for 3.5% of cases, respectively. Finally, "acetabular complications," such as acetabular osteolysis and pelvic protrusion, were described in 1.2% of cases 12 . In this study, the complication rate reported using the Spaceflex hip G21 spacer is significantly lower than that reported in the literature.…”

“…Biomechanical factors such as reduced offset or leg shortening may raise dislocation risk due to inappropriate soft tissue tension 28 , 29 . Similarly, an undersized spacer at the acetabular or femoral side could increase the dislocation risk due to spacer instability or mobilization 12 , 26 , 27 . Adductor muscle deficit or a severe bone defect may also result in a higher dislocation rate because they are associated with greater difficulty in achieving spacer stability intraoperatively and during the interval period 28 , 29 .…”

“…However, although many studies tried comparing the outcomes and complication rates of different devices, there is still no consensus on which articular spacer is the most appropriate 10 , 11 . On the other hand, mechanical complications, such as dislocation or spacer and periprosthetic femur fractures, occur more frequently with articulating spacers, especially in handmade ones 12 .…”

Finite element analysis of the mechanical strength of a new hip Spacer

“…However, mechanical complications occur to varying degrees with either type of Spacer. Spacer complication rates reported so far are very variable, reaching up to 73% [ 15 ]. Spacer fracture [ 16 , 17 ] and implant dislocation [ 17 , 18 ], among others, are frequent.…”