Custom-made Spacer Research Articles

MID-TERM RESULTS OF THE NEW ENDO-SPACER TECHNIQUE IN TWO-STAGE SEPTIC EXCHANGE SURGERY FOR PERIPROSTHETIC JOINT INFECTION OF THE HIP

Mechanical failure due to dislocation, fracture and acetabular wear as well as persistence of infection are the main complications associated with the use of hip spacers in the treatment of periprosthetic joint infections (PJI).We have developed a novel, custom-made spacer as part of two-stage septic hip replacement and present the two- to five-year results after reimplantation.We prospectively examined a total of 73 patients over our study period in whom our new spacer technique was used. The technique includes a dual mobility inlay and a cemented straight stem in combination with antibiotic-loaded PMMA bone cement which allows full weight bearing meanwhile the interim period. The follow-up ranged between 24 and 60 months after reimplantation as second stage of a two-stage approach. The patients were contacted as part of the follow-up using a questionnaire concerning reoperation, reinfection as well as hip function by using the Harris Hip Score.72 patients (98,6%) could be reimplanted, one patient is still using the spacer prothesis for 45 months because of excellent functional results with a Harris Hip Score of 95, nevertheless reimplantation is planned. The reinfection rate was less than 7% after reimplantation. The dislocation rate was 5%, and in total there was an overall complication rate of less than 10%. The Harris Hip Score was significantly improved.The ENDO spacer surgical technique is a promising option in the treatment of periprosthetic joint infections (PJI) for two-stage septic exchange with a low dislocation rate and good infection control after reimplantation. In addition, it enables early mobilization with the possibility of full weight-bearing in the interval between spacer implantation and reimplantation.

Mechanical complications and infection control comparison of custom-made and prefabricated articular hip spacers in the treatment of periprosthetic infection.

The purpose of our study was to compare the complication rate and the outcomes of custom-made spacers (C-spacers) and prefabricated articular spacers (P-spacers) in the treatment of periprosthetic infection. In this retrospective study, 78 patients (44 females, 34 males; mean age: 68.5±9.48 years; range, 47 to 82 years) with articular spacers implanted in our institution were analyzed between January 2009 and December 2019. We recorded implant results as per mechanical complications, infection control, the interval from surgery to definitive hip replacement, and the rate of achieving recovery of joint function after stage two arthroplasty. There were 29 revised spacers; 18 of them were C-spacers and 11 were P-spacers (p=0.0383). A total of 16 dislocations were recorded, of which six were dislocations of C-spacers, and 10 were dislocations of P-spacers (p=0.0082). Additionally, we registered four spacer breakages, all of which occurred in C-spacers (p=0.295). C-spacers failed early, at an mean interval of 2.2 weeks after implantation, and P-spacers failed later, with an mean of 9.3 weeks after implantation (p=0.0187). A total of nine reinfection complications of spacers were registered; only one infection of P-spacers, and eight infections related to C-spacers (p=0.2583). Definitive revision total hip arthroplasty (rTHA) after spacer explantation and successful treatment of the infection occurred in 63 cases out of 78 patients. Definitive rTHA occurred after the use of C-spacers in 41 (78%) patients and after the use of C-spacers in 22 (84%) patients (p=0.7816). C-spacers had a mean interval from spacer implantation to definitive rTHA of 6.56±6.03 months, and P-spacers had a mean interval of 4±1.93 months (p=0.0164). Custom-made spacers were shown to have lower mechanical complication rates than prefabricated ones but more infection complications. Prefabricated spacers had more dislocations and fewer breakages. Custom-made spacer mechanical failures occurred earlier compared to prefabricated ones.

Electrodialysis desalination: The impact of solution flowrate (or Reynolds number) on fluid dynamics throughout membrane spacers

The incorporation of a spacer among membranes has a major influence on fluid dynamics and performance metrics. Spacers create feed channels and operate as turbulence promoters to increase mixing and reduce concentration/temperature polarization effects. However, spacer geometry remains unoptimized, and studies continue to investigate a wide range of commercial and custom-made spacer designs. The in-depth discussion of the present systematic review seeks to discover the influence of Reynolds number or solution flowrate on flow hydrodynamics throughout a spacer-filled channel. A fast-flowing solution sweeping one membrane's surface first, then the neighboring membrane's surface produces good mixing action, which does not happen commonly at laminar solution flowrates. A sufficient flowrate can suppress the polarization layer, which may normally require the utilization of a simple feed channel rather than complex spacer configurations. When a recirculation eddy occurs, it disrupts the continuous flow and effectively curves the linear fluid courses. The higher the flowrate, the better the membrane performance, the higher the critical flux (or recovery rate), and the lower the inherent limitations of spacer design, spacer shadow effect, poor channel hydrodynamics, and high concentration polarization. In fact, critical flow achieves an acceptable balance between improving flow dynamics and reducing the related trade-offs, such as pressure losses and the occurrence of concentration polarization throughout the cell. If the necessary technical flowrate is not used, the real concentration potential for transport is relatively limited at low velocities than would be predicted based on bulk concentrations. Electrodialysis stack therefore may suffer from the dissociation of water molecules. Next studies should consider that applying a higher flowrate results in greater process efficiency, increased mass transfer potential at the membrane interface, and reduced stack thermal and electrical resistance, where pressure drop should always be indicated as a consequence of the spacer and circumstances used, rather than a problem.

Total hip revision with custom-made spacer and prosthesis: A case report

BACKGROUNDBoth periprosthetic joint infections (PJIs) and severe femoral segmental defects are catastrophic complications of total hip arthroplasty (THA), and both present a significant challenge in revisional surgery. There are limited data available to guide clinical decision making when both occur concurrently. CASE SUMMARYA 61-year-old woman presented with a 6-mo history of a sinus tract at the site of her original THA incision. Radiological imaging revealed a total hip joint implant with an ipsilateral segmental femoral defect. Based on histological, radiological, laboratory, and clinical features, a diagnosis of concurrent chronic PJI and segmental femoral defect (Type IIIB, Paprosky classification) was made. After multidisciplinary team discussion, three-dimensional (3D)-printed, custom-made antibiotic spacers were created that could be used to mold antibiotic-loaded cement spacer. These were placed following PJI debridement in the first stage of revision surgery. After the PJI was eliminated, a 3D-printed, custom-made, femoral prosthesis was created to repair the considerable femoral defect. After 20-mo follow-up, the patient had excellent functional outcomes with a near-normal range of hip movement. So far, neither evidence of recurrent infection nor loosening of the prosthesis has been observed. CONCLUSIONWe describe a case of “two-stage, custom-made” total hip revision to treat PJI with a concurrent segmental femoral defect. Use of a personalized, 3D-printed spacer and proximal femoral prosthesis led to satisfactory hip function and no early postoperative complications. Use of a customized implant provides surgeons with an alternative option for patients where no suitable spacer or implant is available. However, the long-term function, longevity, and cost-effectiveness of the use of custom-made prostheses have yet to be fully explored.

The direct anterior approach: treating periprosthetic joint infection of the hip using two-stage revision arthroplasty.

Either one- or two-stage revision arthroplasties can be used for the treatment of chronic periprosthetic joint infection (PJI) after total hip arthroplasty (THA). We report our results following two-stage revision surgery performed through the direct anterior approach (DAA) interval using a custom-made articulating spacer. Between 2009 and 2014, 49 patients (49 consecutive procedures) had surgery through either a DAA or extended DAA approach. Each patient received perioperative intravenous administration of antibiotics. A custom-made spacer was implanted after explanting cup and stem and following extensive debridement. Broad-spectrum antibiotics were administered during the immediate perioperative period and then adjusted according to the infecting organism. Complication rates and eradication rates were observed. WOMAC patient assessments were administered preoperatively and one-year postoperatively. Of the 49 study patients, five had a recurrence of the infection after the second-stage revision, five had a proximal periprosthetic fracture during the first stage procedure and one patient had a transient femoral nerve palsy that resolved fully within the first postoperative year. 30 different microorganisms were identified on intraoperative specimens. The average time between first and second stage procedure was 65.7days (range 21-132days). Eradication of infection was defined as healed wound without fistula, no drainage, no recurrence of the infection, no subsequent surgical intervention for persistent or perioperative infection after second stage revision and no long-term (> 6months) antimicrobial suppression therapy. Eradication rate of infection in our study was 89.8%. Postoperative WOMAC scores improved significantly CONCLUSION: The preliminary clinical results for the custom-made spacer technique implanted through the DAA are promising. Therefore, we believe the DAA can be used safely as a standard operative approach for two-stage revision procedures.

Preliminary results of a novel spacer technique in the management of septic revision hip arthroplasty.

Mechanical failure due to dislocation, fracture and acetabular wear is a major complication associated with the use of spacers in the management of periprosthetic joint infection (PJI). We have developed a novel custom-made spacer in the setting of two-stage septic revision hip arthroplasty and present the preliminary results of our technique. Between May 2015 and November 2017, 30 patients underwent hip revision using the ENDO spacer technique in the setting of a two-stage septic exchange arthroplasty. The technique involves the dual mobility liner and the downsized stainless cemented straight stem in combination with antibiotic-loaded PMMA bone cement. The primary outcome measure was the overall spacer complication rate, particularly spacer dislocation. Furthermore, functional outcome using the Harris Hip Score (HHS) before spacer implantation and prior re-implantation was evaluated. The mean age of the patients was 69.8years (range from 45 to 85; SD = 9.9years). No microorganisms were preoperatively found in 23 (76.7%) cases. Successful re-implantation was performed in all patients after a mean spacer duration time of 53.6days (range 14-288days; SD = 48.2). Spacer-related complications occurred in only two patients (6.7%). The HHS significantly improved from 34.0 (range 3-62; SD = 15.1) to 48.1 (range 11-73; SD = 15.7) (p = 0.0008). The ENDO spacer surgical technique is a feasible option in the treatment of periprosthetic joint infection (PJI), with a low dislocation rate. Furthermore, it allows early mobilization with the possibility of full-weight bearing.

Similar rate of infection eradication for functional articulating, prefabricated and custom-made spacers in 2-stage revision of the infected total hip: a literature review.

2-stage revision with the use of an antibiotic-loaded interval spacer is therapy of choice in late periprosthetic joint infection for most surgeons. For the spacer, either a prefabricated, functional articulating or custom-made spacer can be used. Little is known about which type of spacer provides optimal outcome after 2-stage revision. The aim of this study was to determine which type of spacer provides the best results, when used in 2-stage revision of an infected THA. We performed a systematic review of the literature to analyse which type of interval spacer provides highest infection eradication rate and best functional outcome after a minimum 2 year follow-up. Exclusion criteria were follow-up of less than 2 years, single-stage revision, or 2-stage revision without use of a spacer. 25 studies were included. Infection eradication rate was similar with rates of 96%, 93% and 95% for the prefabricated-, functional articulating- and custom-made spacers respectively. Functional outcome was scarcely described. Postoperative HHS was 81, 90 and 83 respectively. Functional articulating spacers achieve a comparable rate of infection eradication in the treatment of periprosthetic hip joint infections as compared to preformed or custom-made antibiotic-loaded spacers. There is insufficient evidence concerning rehabilitation and functional outcome after 2-stage revision hip arthroplasty to advocate or discourage the use of either kind of interval spacer.

Mating of a Prostalac Spacer with an Intramedullary Nail for Reconstruction of an Infected Interprosthetic Femoral Shaft Fracture: A Case Report

Reconstruction for concurrent infection of an ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) is a challenge. We report a 2-stage reconstruction of a THA for chronic infection of both the THA and TKA with severe femoral bone loss secondary to interprosthetic fractures. The reconstruction involved using a custom-made, temporary, antibiotic-impregnated PROSTALAC spacer mated with an intramedullary nail. The acetabulum was then exposed and the necrotic cartilage was removed and curetted. The acetabulum was reamed to accept a PROSTALAC acetabular shell. The shell was cemented into the acetabulum with antibiotic cement. The custom-made spacer was then inserted distally first into the tibia. The distal end of the intramedullary nail was interlocked with a bicortical bolt to minimise nail rotation. Antibiotic-impregnated cement was moulded around the nail and spacer. The proximal end of the spacer was then reduced into the acetabular socket, and the joint was irrigated and the wound closed. A customised abduction brace was fitted, and partial weight bearing was allowed. Sufficient leg length, soft-tissue tension, and range of hip motion were restored, and a total femur and constrained liner was re-implanted 4 months later. Mating of an intramedullary nail with a PROSTALAC spacer is a viable reconstructive option.

Intramedullary knee spacer in 2-stage revision knee surgery with segmental bone loss

In 2-stage revision knee surgery ending with a tumor prosthesis, the bone loss is so large that in the interim period the patient can be treated with (1) rest in bed with or without skeletal traction, (2) external fixation, or (3) a custom-made spacer. Apart from the technical challenge of eradicating these infections, the stabilization of the knee and preservation of leg length until reimplantation can be a problem. We present our early experience with a new type of knee spacer for patients with very large bone loss.

Technical Notes and Tips: Use of Olive-Tipped Wire with Moulded Antibiotic-Loaded Cement Spacer in 2-Stage Revision Hip Arthroplasty Aids in Easy Removal

In two stage revision for septic loosening of a total hip, the cement spacer from the first stage functions as a spacer and carrier of antibiotics.1 We use the antibiotic-loaded cement spacer moulded in the shape of a hemi-arthroplasty. On occasion, we have had difficulty in removing the spacer due to cement fracture and retained pieces of cement in the femoral canal. We now incorporate an olive-tipped wire into the cement mould and curve it at the proximal end. The spacer is then inserted into the proximal femur and joint is reduced (Fig. 1). At the second stage, the hip joint is dislocated and the curved proximal end of the wire is used to pull the cement spacer out in single piece thus preventing fracture. A custom-made spacer allows introduction of additional heat-stable antibiotics. Problems from removal of a fractured stem of cement are overcome by using an olive-tipped wire as support. Figure 1 X-ray showing introduction of wire.