Structural allograft as an option for treating infected hip arthroplasty with massive bone loss

Lyophilized Human Bone Allograft as an Antibiotic Carrier: An In Vitro and In Vivo Study

Background: Antibiotics delivered from implanted bone substitute materials (BSM) can potentially be used to prevent acute infections and biofilm formation, providing high concentrations of antibiotics at the surgical site without systemic toxicity. In addition, BSM should allow osteoconductivity supporting bone healing without further surgery. Promising results have been achieved using lyophilized bone allografts mixed with antibiotics. Methods: In this study specially prepared human bone allografts were evaluated as an antibiotic carrier in vitro and in vivo. The efficacy of different antibiotic-impregnated bone allografts was measured by drug release tests in vitro and in vivo and bacterial susceptibility tests using four bacterial species usually responsible for implant-associated infections. Results: The loading procedures of allograft bone substitutes with antibiotics were successful. Some of the antibiotic concentrations exceeded the MIC90 for up to 7 days in vitro and for up to 72 h in vivo. The susceptibility tests showed that S. epidermidis ATCC 12228 was the most susceptible bacterial species in comparison to the other strains tested for all antibiotic substances. Vancomycin and rifampicin showed the best results against standard and patient-isolated strains in vitro. In vivo, new bone formation was comparable in all study groups including the control group without antibiotic loading. Conclusions: Human bone allografts showed the capacity to act as customized loaded antibiotic carriers to prevent acute infections and should be considered in the management of bone infections in combination with systemic antimicrobial therapy.

The survivorship of revision total hip replacement with severe proximal bone deficiency using a modular taper fluted prosthesis

Contemporary uncemented femoral revision hip systems have become commonly used over the past decade and have enabled the reconstruction of leg length, offset and anteversion as independent variables through the use of modular junctions. Modular junction failures between the proximal body and distal stem have been described with revision systems, although this is rare. We sought to identify the survivorship of one revision system in a salvage arthroplasty scenario where no host bone support of the modular junction was present. From a series of 136 patients, 15 patients (16 hips) were identified without host bone support of the modular junction with a mean radiological follow up of over 6 years (76 months +/- 35 months). There have been no cases of prosthetic fracture over the follow-up duration, with two revisions performed for reasons of aseptic loosening and infection. The mean BMI of the study group was 30.2 with 78% of the cohort classified as overweight or obese. It is well recognised that, host bone support of the modular junction is preferable, however the satisfactory outcomes over the midterm in these complex patients suggests that modular revision systems remain an option.

Complex Reconstruction for Acetabular Pathologic Fracture in Unusual Chondroblastoma With Aneurysmal Bone Cyst

Treating bone loss with complex arthroplasty poses a significant challenge for the arthroplasty surgeon. When considering a reconstructive case after pathologic fracture and oncologic excision, a multidisciplinary approach with reliance on arthroplasty principles is critical. An 18-year-old patient presented with a complex acetabular pathologic fracture through a chondroblastoma with a secondary aneurysmal bone cyst. An outside institution performed a biopsy and placed a hip-spanning external fixator. Multidisciplinary planning led to tumor excision, complex acetabular arthroplasty reconstruction including structural bone grafting, and internal fixation. At the third year of follow-up, there was no evidence of mechanical loosening of the hip arthroplasty, reoperation, or tumor recurrence. The structural graft was completely osseointegrated, confirmed by a computed tomography scan obtained at 2 years postoperatively. This report demonstrates an unusual location of chondroblastoma, presenting with acetabular fracture definitively treated with complex multidisciplinary reconstruction leading to an excellent outcome in a young patient.

A Retrospective Observational Cohort Study of Periprosthetic Hip Infection Treated by one-stage Method Including Cases With Bone Graft Reconstruction

Purpose:

Prosthetic joint infection (PJI) is a devastating complication that can affect hip arthroplasty. Its treatment is extremely difficult, and issues regarding the optimal treatment remain unanswered. This study intended to show the effectiveness of the one-stage treatment of PJI.

Materials and Methods:

A retrospective observational cohort study performed from July 2014- August 2018. All patients with suspected PJI were included. Major and minor criteria developed by the International Consensus on Periprosthetic Joint Infection (ICPJI) was used to define infection. Laboratory tests and image exams were performed, and all patients were followed for at least 2 years.

Outcomes:

Success rate (2018 ICPJI definition to success) in treatment of PJI using one-stage revision method. Clinical and functional outcomes defined by Harris Hip Score (HHS).

Results:

Thirty-one patients were screened and 18 analyzed. 69.85 ± 9.76 years was the mean age. Mean follow-up time was 63.84 ± 18.55 months. Ten patients had acetabular defects and required bone graft reconstruction. Sixteen patients were classified as Tier 1, 1 as Tier 3D, and as 1 Tier 3E. Almost 90% of patients submitted to one-stage revision with acetabulum graft reconstruction were free of infection. The overall infection survival rate was 78.31±6.34 months. Candida albicans and sinus tract were statistically significant in univariate Cox’s analysis. The predictor of one-stage revision surgery failure that remained final Cox’s regression model was C. albicans (hazard ratio [HR]: 4.47).

Conclusion:

Treatment through one-stage revision surgery associated with 6 months of antimicrobial is a viable option with acceptable results even when bone graft reconstruction is necessary. C. albicans was a strong predictor of failure in this cohort.

Evading the host response: Staphylococcus "hiding" in cortical bone canalicular system causes increased bacterial burden

Extremity reconstruction surgery is increasingly performed rather than amputation for patients with large-segment pathologic bone loss. Debate persists as to the optimal void filler for this "limb salvage" surgery, whether metal or allograft bone. Clinicians focus on optimizing important functional gains for patients, and the risk of devastating implant infection has been thought to be similar regardless of implant material. Recent insights into infection pathophysiology are challenging this equipoise, however, with both basic science data suggesting a novel mechanism of infection of Staphylococcus aureus (the most common infecting agent) into the host lacunar-canaliculi network, and also clinical data revealing a higher rate of infection of allograft over metal. The current translational study was therefore developed to bridge the gap between these insights in a longitudinal murine model of infection of allograft bone and metal. Real-time Staphylococci infection characteristics were quantified in cortical bone vs metal, and both microarchitecture of host implant and presence of host immune response were assessed. An orders-of-magnitude higher bacterial burden was established in cortical allograft bone over both metal and cancellous bone. The establishment of immune-evading microabscesses was confirmed in both cortical allograft haversian canal and the submicron canaliculi network in an additional model of mouse femur bone infection. These study results reveal a mechanism by which Staphylococci evasion of host immunity is possible, contributing to elevated risks of infection in cortical bone. The presence of this local infection reservoir imparts massive clinical implications that may alter the current paradigm of osteomyelitis and bulk allograft infection treatment.

Use of morselized allografts for acetabular reconstruction during THA revision: French multicenter study of 508 cases with 8 years' average follow-up

BACKGROUND

In the context of acetabular reconstruction, bone defects can be filled with processed or unprocessed bone allografts. Published data are often contradictory on this topic and few studies have been done comparing processed allografts to fresh-frozen ones. This led us to conduct a large study to measure the factors impacting the survival of THA revision: (1) type of allograft and cup, (2) technical factors or patient-related factors.

HYPOTHESIS

Acetabular reconstruction can be performed equally well with frozen or processed morselized allografts.

MATERIALS AND METHODS

This retrospective, multicenter study of acetabular reconstruction included 508 cases with a minimum follow-up of 5 years. The follow-up for the frozen grafts was shorter (7.86 years±1.89 [5-12.32]) than that of the processed grafts (8.22 years±1.77 [5.05-15.48]) (p=0.029). However, the patients were younger at the time of the primary THA procedure in the frozen allograft group (51.5 years±14.2 [17-80]) than in the processed group (57.5 years±13.0 [12-94]) (p<0.001) and were also younger at the time of THA revision (67.8 years±12.2 [36.9-89.3] versus 70 years±11.7 [25-94.5]) (p=0.041).

RESULTS

There were more complications overall in the frozen allograft group (46/242=19.0%) than the processed allograft group (35/256=13.2%) (p=0.044) with more instances of loosening in the frozen group (20/242 [8.2%]) than in the processed group (6/266 [3.3%])(p=0.001). Conversely, the dislocation rate (16/242=6.6% vs. 17/266=6.4%) (p=0.844) and infection rate (18/242=7.4% vs. 15/266=5.7%) (p=0.264) did not differ between groups. The subgroup analysis reveal a correlation between the occurrence of a complication and higher body mass index (BMI) (p=0.037) with a higher overall risk of complications in patients with a BMI above 30 or under 20 (p=0.006) and a relative risk of 1.95 (95% CI: 1.26-2.93). Being overweight was associated with a higher risk of dislocation (relative risk of 2.46; 95% CI: 1.23-4.70) (p=0.007). Loosening was more likely to occur in younger patients at the time of the procedure (relative risk of 2.77; 95% CI: 1.52-6.51) (p=0.040) before 60 years during the revision. Lastly, patients who were less active preoperatively based on the Devane scale had an increased risk of dislocation (relative risk of 2.51; 95% CI: 1.26-8.26) (p=0.022).

DISCUSSION

Our hypothesis was not confirmed. The groups were not comparable initially, which may explain the differences found since the larger number of loosening cases in the frozen allograft group can be attributed to group heterogeneity. Nevertheless, morselized allografts appear to be suitable for acetabular bone defect reconstruction. A randomized study would be needed to determine whether frozen or processed allografts are superior.

LEVEL OF EVIDENCE

III, comparative retrospective study.

Mortality During Total Hip Periprosthetic Joint Infection

BACKGROUND

We sought to understand the mortality rate of periprosthetic joint infection (PJI) of the hip undergoing 2-stage revision for infection.

METHODS

Database search, yielding 23 relevant studies, totaled 19,169 patients who underwent revision for total hip PJI.

RESULTS

One-year weighted mortality rate was 4.22% after total hip PJI. Five-year mortality was 21.12%. Average age was 65 years. When comparing the national age-adjusted risk of mortality and the reported 1-year mortality risk in this systematic review, the risk of death after total hip PJI is significantly increased (odds ratio 3.58, P < .001).

CONCLUSION

The mortality rate during total hip revision for infection is high. When counseling a patient regarding complications of this disease, death should be discussed.

Cup-cage reconstruction for severe acetabular bone loss and pelvic discontinuity: Mid-term Results of a Consecutive Series of 35 Cases

AIMS

Severe acetabular bone loss and pelvic discontinuity (PD) present particular challenges in revision total hip arthroplasty. To deal with such complex situations, cup-cage reconstruction has emerged as an option for treating this situation. We aimed to examine our success in using this technique for these anatomical problems.

PATIENTS AND METHODS

We undertook a retrospective, single-centre series of 35 hips in 34 patients (seven male, 27 female) treated with a cup-cage construct using a trabecular metal shell in conjunction with a titanium cage, for severe acetabular bone loss between 2011 and 2015. The mean age at the time of surgery was 70 years (42 to 85) and all patients had an acetabular defect graded as Paprosky Type 2C through to 3B, with 24 hips (69%) having PD. The mean follow-up was 47 months (25 to 84).

RESULTS

The cumulative five-year survivorship of the implant with revision for any cause was 89% (95% confidence interval (CI) 72 to 96) with eight hips at risk. No revision was required for aseptic loosening; however, one patient with one hip (3%) required removal of the ischial flange of the cage due to sciatic nerve irritation. Two patients (6%; two hips) suffered from hip dislocation, whereas one patient (one hip) required revision surgery with cement fixation of a dual-mobility acetababular component into a well-fixed cup-cage construct. Two patients (6%; two hips) developed periprosthetic infection. One patient was successfully controlled with a two-stage revision surgery, while the other patient underwent excision arthroplasty due to severe medical comorbidities. For the whole series, the Harris Hip Score significantly improved from a mean of 30 (15 to 51) preoperatively to 71 (40 to 89) at the latest follow-up (p < 0.001).

CONCLUSION

Our findings suggest that cup-cage reconstruction is a viable option for major segmental bone defects involving the posterior column and PD. It allows adequate restoration of the acetabulum centre with generally good stability and satisfactory postoperative function. Instability and infection remain drawbacks in these challenging revision cases. Cite this article: Bone Joint J 2018;100-B:1442-48.

The patient-specific Triflange acetabular implant for revision total hip arthroplasty in patients with severe acetabular defects: planning, implantation, and results

Aims

Few reconstructive techniques are available for patients requiring complex acetabular revisions such as those involving Paprosky type 2C, 3A and 3B deficiencies and pelvic discontinuity. Our aim was to describe the development of the patient specific Triflange acetabular component for use in these patients, the surgical technique and mid-term results. We include a description of the pre-operative CT scanning, the construction of a model, operative planning, and surgical technique. All implants were coated with porous plasma spray and hydroxyapatite if desired.

Patients and Methods

A multicentre, retrospective review of 95 complex acetabular reconstructions in 94 patients was performed. A total of 61 (64.2%) were female. The mean age of the patients was 66 (38 to 85). The mean body mass index was 29 kg/m² (18 to 51). Outcome was reported using the Harris Hip Score (HHS), complications, failures and survival.

Results

The mean follow-up was 3.5 years (1 to 11). The mean HHS improved from 46 (15 to 90) pre-operatively to 75 (14 to 100). A total of 21 hips (22%) had at least one complication with some having more than one; including dislocation (6%), infection (6%), and femoral complications (2%). The implant was subsequently removed in five hips (5%), only one for suspected aseptic loosening.

Conclusion

The Triflange patient specific acetabular component provides predictable fixation with complication rates which are similar to those of other techniques.

Cite this article: Bone Joint J 2018;100-B(1 Supple A):50–4.

[Biological downsizing : Acetabular defect reconstruction in revision total hip arthroplasty]

BACKGROUND

Periacetabular bony defects remain a great challenge in revision total hip arthroplasty. After assessment and classification of the defect and selection of a suitable implant the primary stable fixation and sufficient biological reconstitution of a sustainable bone stock are essential for long term success in acetabular revision surgery. Biological defect reconstruction aims for the down-sizing of periacetabular defects for later revision surgeries.

TECHNIQUE

In the field of biological augmentation several methods are currently available. Autologous transplants feature a profound osseointegrative capacity. However, limitations such as volume restrictions and secondary complications at the donor site have to be considered. Structural allografts show little weight bearing potential in the long term and high failure rates. In clinical practice, the usage of spongious chips implanted via impaction bone grafting technique in combination with antiprotrusio cages for the management of contained defects have shown promising long time results. Nevertheless, when dealing with craniolateral acetabular and dorsal column defects, the additional implantation of macroporous metal implants or augments should be considered since biological augmentation has shown little clinical success in these particular cases.

PROSPECT

This article provides an overview of the current clinically available biological augmentation methods of peri-acetabular defects. Due to the limitations of autologous and allogeneic bone transplants in terms of size and availability, the emerging field of innovative implantable tissue engineering constructs gains interest and will also be discussed in this article.

Removal of an Infected Hip Arthroplasty Is a High-Risk Surgery: Putting Morbidity Into Context With Other Major Nonorthopedic Operations

BACKGROUND

Two-stage revision remains the most common approach to periprosthetic joint infection of total hip arthroplasty (THA) in the United States. The postoperative risks associated with removal of an infected prosthesis and placement of a spacer have not been thoroughly studied.

METHODS

Patients who underwent THA implant removal and spacer placement for infection were identified in a large administrative database. Morbidity and mortality rates were assessed for the 90-day postoperative period and readmission rates were assessed at 30 days postoperatively. These outcomes were then compared with those after coronary artery bypass grafting, carotid endarterectomy, prostatectomy, pancreatoduodenectomy (Whipple procedure), and kidney transplant.

RESULTS

Implant removal and spacer placement for THA periprosthetic joint infection (n = 10,386) had a 30-day readmission rate of 11.1% and 90-day mortality rate of 2.6%. Major complications were seen in 15.3% patients. Postoperative morbidity was often higher in these patients when compared with other procedures studied. Ninety-day mortality rates were significantly higher compared with carotid endarterectomy, prostatectomy, and kidney transplant (odds ratio [ORs] between 2.1 and 12.5; P < .0001). Readmission rates at 30 days were significantly higher than all other groups including coronary artery bypass grafting and Whipple (ORs between 1.4 and 8.2; P < .0001).

CONCLUSION

Removal of an infected THA with spacer placement is a high-risk surgery. This large study that includes over 10,000 patients helps quantify the risks of readmission, morbidity, and mortality. The rates of adverse outcomes are higher than those for many nonorthopedic operations typically considered to be major surgery.

Deep infection after hip arthroplasty

Periprosthetic joint infection (PJI) complicates between 0.5% and 1.2% primary total hip arthroplasties (THAs) and may have devastating consequences. The traditional assessment of patients suffering from PJI has involved the serological study of inflammatory markers and microbiological analysis of samples obtained from the joint space. Treatment has involved debridement and revision arthroplasty performed in either one or two stages.

We present an update on the burden of PJI, strategies for its diagnosis and treatment, the challenge of resistant organisms and the need for definitive evidence to guide the treatment of PJI after THA.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):27–30.

Modified Girdlestone arthroplasty and hip arthrodesis using the Ilizarov external fixator as a salvage method in the management of severely infected total hip replacement

BACKGROUND

Resection arthroplasty or hip arthrodesis after total hip replacement (THR) can be used to salvage the limb in case with deep infection and severe bone loss. The Ilizarov fixator provides stability, axial correction, weight-bearing and good fusion rates.

MATERIALS AND METHODS

We retrospectively assessed the outcomes of 37 patients with severe periprosthetic infection after THR treated between 1999 and 2011. The treatment included implant removal, debridement and a modified Girdestone arthroplasty (29 cases) or hip arthrodesis (seven cases) using the Ilizarov fixator. The Ilizarov fixation continued from 45 to 50 days in the modified arthroplasty group and 90 days in the arthrodesis group. One case was treated using the conventional resection arthroplasty bilaterally.

RESULTS

Eighteen months after treatment, infection control was seen in 97.3% cases. Six hips were fused as one patient died in this group. Limb length discrepancy (LLD) averaged 5.5 cm. The Harris hip score ranged from 35 to 92 points. Hip joint motion ranged from 10° to 30° in the modified arthroplasty group. All subjects could walk independently or using support aids. No subluxation or LLD progression was observed.

CONCLUSION

The modified Girdlestone arthroplasty and hip arthrodesis using the Ilizarov apparatus results in sufficient ability for ambulation and good infection control in cases of failed THR associated with severe infection.

Radiography versus multidetector computed tomography in assessing graft integration after acetabular reconstruction

PURPOSE

To compare radiography with multidetector computed tomography (MDCT) in the evaluation of graft integration following acetabular reconstruction for failed total hip arthroplasty (THA).

METHODS

Records of 5 men and 6 women aged 60 to 78 (mean, 71.8) years who underwent acetabular reconstruction using structural allografts for severe acetabular deficiency secondary to aseptic loosening (n=9) or septic loosening (n=2) were reviewed. The mean survival time of the THA was 136.4 (range, 12-360) months. Acetabular defects were classified as IIC (n=2), IIIA (n=3), or IIIB (n=6). Structural allografts were fixed with impaction followed by a reinforcement ring (n=10), an antiprotrusio cage (n=2), and/or an oblong cup (n=1) with gentamicineloaded cement. Cup loosening, graft integration, and graft resorption were evaluated using radiography. In addition, graft integration was evaluated using MDCT.

RESULTS

At a mean follow-up of 4.2 (range, 2-11) years, the survival of the acetabular reconstruction was 90.9%. No patient had any signs of infection. One patient underwent reoperation 22 months later for dislocation secondary to abductor deficiency caused by nonunion of the trochanteric fracture. According to radiography, all patients had graft integration. One patient had definitive and another had possible cup loosening. Four patients had minor graft resorption. According to MDCT, graft integration was complete in only one patient, partial >50% in 3, partial <50% in 4, and absent in 2.

CONCLUSION

MDCT is more accurate than radiography in evaluating graft integration following acetabular reconstruction.

A technique for decision-making in cementless femoral revision hip arthroplasty

Classification systems for femoral revision of a failed THA fail to address several of the more critical determinants. The aim of the present study was to assess the reliability of a simplified algorithm for decision making during cementless reconstruction for femoral loosening with respect to stem length, stem design and the need for an extended trochanteric osteotomy. Four observers with different levels of clinical experience blindly assessed 40 X-rays of hips scheduled for a femoral revision. Intra-observer and inter-observer reliability of 4 radiographic criteria were assessed: 1) diaphyseal bone loss extension to the isthmus; 2) proximal femoral remodelling; 3) presence of cement; and 4) cortical thickness. Inter-observer agreement relating to the four criteria was good (κ = 0.66) for the extension to isthmus, moderate (κ = 0.57) for proximal femoral remodelling and very good for presence of cement (κ = 1) and cortical thickness (κ = 0.88). Intra-observer agreement was good for extension to isthmus and proximal femoral remodelling and very good for presence of cement and cortical thickness. Based on these criteria, an algorithm has been developed to describe 4 reconstruction options. The algorithm seems reliable for decision making during femoral cementless revision, but research into comparison with intraoperative findings is still required.

LEVEL OF EVIDENCE

Level II, Development of diagnostic criteria on consecutive patients.

Component selection in revision total hip arthroplasty

Component selection for revision total hip arthroplasty is important for creating a stable hip, providing offset to maximize joint mechanics, and restoring appropriate leg lengths. On the femoral side, fully porous coated stems, modular tapered stems, and proximal femoral replacements can be used depending on the level of bone loss. For the acetabulum, smaller defects can be contained using second-generation porous coating hemispherical cups, whereas larger acetabular defects can be contained with cup cages, cages, or custom triflange implants. In addition, acetabular liners can improve stability through altered cup version, dual mobility, or constraint of the femoral head.

[Reconstruction of metadiaphyseal bone defects of the femur with cortical strut allografts in periprosthetic bone loss]

OBJECTIVE

Biological augmentation and stabilization of high-grade bone defects with structural allografts from donor femur halfs.

INDICATIONS

Severe bone defects with aseptic loosening of hip prosthesis, periprosthetic femoral fracture or non-union, possibly even in cases of a healed infection.

CONTRAINDICATIONS

Local or systemic infection.

SURGICAL TECHNIQUE

The two modeled strut allografts are temporary fixed epiperiostal anterolateral and -medial with wire cerclages, while protecting the vascular supplying linea aspera of the femur. With the thus stabilized femur, the leg can be placed in the four-position in order to prepare the medullary canal of the revision prosthesis. Finally, the uncemented revision prosthesis is hammered in under successive tightening of the wire cerclages. With this "cracking technique", stem is stabilized and the grafts have repositioning, augmentative, and supportive function.

POSTOPERATIVE MANAGEMENT

Partial weight-bearing postoperatively for 12 weeks. X-ray control during surgery, 10 days postoperatively, after 6 and 12 weeks and every 1-2 years.

RESULTS

In four different studies, 123 patients were stabilized from December 1991 to June 2011 due to an extensive periprosthetic femoral bone defect and/or periprosthetic fracture, refracture, or non-union with strut allografts. After an average follow-up of 3.8 years (range 0.3-11 years), the average Harris Hip Score was 80.8 (range 44-100). During this time, there was 1 refracture, 103 stable stems, 20 fibrous stable stems, 9 patients with low graft resorption, and 122 patients with radiographic healing of the strut allografts based on classification according to Emerson et al. (Clin Orthop Relat Res 285:35-44, 1992).

Partial two-stage exchange for infected total hip arthroplasty: a preliminary report

BACKGROUND

One common approach to the infected total hip arthroplasty (THA) calls for a staged revision, including removal of all components. However, removal of well-fixed femoral components can result in bone loss and compromised fixation; it is not known whether it is effective to leave a well-fixed femoral component in situ, remove only the acetabular component, débride thoroughly, place a spacer, and delay reimplantation.

QUESTIONS/PURPOSES

The purposes of this study were to determine (1) the frequency of infection recurrence; (2) the frequency of death; and (3) the Harris hip scores of patients treated with a "two-stage partial exchange" approach.

METHODS

A retrospective analysis from 2000 through January 2011 revealed 19 patients with infected THA treated with partial two-stage exchange including complete acetabular component removal, aggressive soft tissue débridement, retention of the well-fixed femoral stem, placement of an antibiotic-laden cement femoral head on the trunnion of the retained stem, postoperative course of antibiotics, and delayed reimplantation. Indications for this treatment included those patients whose femoral component was determined to be well fixed and its removal would result in significant femoral bone loss and compromise of future fixation. During the study period, this represented 7% (19 of 262) of the patients whom we treated for a chronically infected THA. Minimum followup was 2 years (mean, 4 years; range, 2-11 years). None of the 19 patients in this series were lost to followup. We defined failure as recurrence of infection in the same hip or the use of long-term suppressive antibiotics.

RESULTS

Two patients (11%), both with prior failure of two-staged treatment of infection, failed secondary to recurrence of infection at an average of 3.3 years. There were no patient deaths within 90 days. The mean Harris hip score was 68 (range, 31-100; best score is 100).

CONCLUSIONS

Insofar as 89% of patients in this series were clinically free of infection at a minimum of 2 years, we believe partial two-stage exchange may represent an acceptable option for patients with infected THA when femoral component removal would result in significant bone loss and compromise of reconstruction. Further study is required on this approach.

Two-stage revision total hip arthroplasty for periprosthetic infections using antibiotic-impregnated cement spacers of various types and materials

Antibiotic-impregnated hip cement spacers of various types and materials have been used in the treatment of periprosthetic hip infections. We developed a handmade spacer by using polymethylmethacrylate (PMMA) and/or α-tricalcium phosphate (α-TCP). In this study, we retrospectively reviewed the surgical outcomes in 36 consecutive patients treated with 2-stage revision total hip arthroplasty by using our antibiotic-impregnated hip cement spacers. We aimed to analyze the infection control and reinfection rates after revision surgery. Moreover, we analyzed the possible predictors of postoperative reinfection. After exclusion of 1 patient who died immediately after the first-stage surgery, infection was controlled in 33 of the 36 hips (success rate, 91.7%). Two of these 33 hips underwent resection arthroplasty. Of the 36 hips that had been treated with the antibiotic-cement spacer, 31 hips (86.1%) were eligible for the second-stage prosthesis re-implantation. The 31 protocol hip joints of patients followed up for >6 months (mean, 48.6 months). Ten of these 31 hips (32.3%) became reinfected. No possible predictor examined differed significantly between the reinfection-positive and reinfection-negative groups. However, spacers consisting of PMMA cement alone were associated with the highest risk of reinfection. Therefore, α-TCP-containing antibiotic-impregnated hip cement spacers might decrease the reinfection rate in patients undergoing re-implantation.

Two-stage treatment of hip periprosthetic joint infection is associated with a high rate of infection control but high mortality

BACKGROUND

Periprosthetic infection after total hip arthroplasty (THA) is a devastating complication. Reported rates of infection control range from 80% to 95% but mortality rates associated with treatment of infected THA are also substantial and we suspect underreported.

QUESTIONS/PURPOSES

For patients selected for two-stage treatment of infected THA we therefore determined (1) mortality; (2) rate of reimplantation; and (3) rate of reinfection.

METHODS

We identified 202 patients (205 hips) with infected primary or revision THA treated with a two-stage protocol between 1996 and 2009 in our prospectively collected practice registry. Patients underwent two-stage treatment for infection, including removal of all implants and foreign material with implantation of an antibiotic-laden cement spacer in the first stage followed by intravenous culture-specific antibiotics for a minimum of 6 weeks. Second-stage reimplantation was performed if erythrocyte sedimentation rate and C-reactive protein were trending toward normal and the wound was well healed. Thirteen patients (13 hips) were lost to followup before 24 months. The minimum followup in surviving patients was 24 months or failure (average, 53 months; range, 24-180 months).

RESULTS

Fourteen patients (7%; 14 hips) died before reimplantation and two were not candidates because of medical comorbidities. The 90-day mortality rate after the first-stage débridement was 4% (eight patients). Of the 186 patients (189 hips) who underwent reimplantation, 157 (83%) achieved control of the infection. Including all patients who underwent the first stage, survival and infection control after two-stage reimplantation was 76%.

CONCLUSION

Two-stage treatment of deep infection in primary and revision THA is associated with substantial mortality and a substantial failure rate from both reinfection and inability to perform the second stage.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Hip painful prosthesis: surgical view

Painful hip prosthesis is the most feared immediate and remote complication of a primary implant and usually represents the failure of one or more therapeutic moments. In cases of aseptic implant failure, the causes invoked may be represented by an incorrect indication, the quality of materials, local and general condition of the patient and especially from a bad joint biomechanics. In cases of septic loosening, however, the cause of failure to be found in the location of pathogens within the implant. In planning a revision is necessary to respect many important steps. They are represented by the exact identification of the causes of failure, the correct preoperative planning, by respecting the skin incisions, the proper choice of the prosthesis, planning the surgical technique, and finally by an appropriate rehabilitation program.In the evaluation of hip failure the first diagnostic step is to recognize exactly those aseptic and septic forms anyway to exclude the diagnosis of infection.