Custom total femur spacer and second-stage total femur arthroplasty as a novel approach to infection and periprosthetic fracture

Preserving the rectus femoris and improving limb function after total femoral prosthesis replacement following resection of femoral malignant tumors

Background

Current research is focused on the factors that influence the maintenance of limb function after total femoral replacement. This retrospective study investigated the difference in functional outcomes in patients with invasion of the rectus femoris vs. an intact rectus femoris that underwent total femoral replacement with a modular total femur prosthesis.

Methods

The medical records of patients who underwent total femoral replacement with a modular total femur prosthesis between July 2010 and March 2017 at our institute were retrospectively reviewed. The patients were divided into two groups: group A had invasion of the rectus femoris and group B had an intact rectus femoris. Functional status was assessed using the Musculoskeletal Tumor Society Rating Scale (MSTS) and the Harris Hip Score (HHS). Complications were assessed using the International Society of Limb Salvage classification that was published in 2011 and modified in 2014.

Results

The mean total MSTS score (23.0 ± 4.8 vs. 17.6 ± 3.1; P = 0.02) and the mean total HHS score (80.17 ± 6.24 vs. 55.38 ± 13.30; P = 0.001) were significantly higher in patients with intact rectus femoris compared with patients with invasion of the rectus femoris. Patients with an intact rectus femoris achieved significantly better limb function (support and gait) and active range of motion (P < 0.05). The overall complication rate was 35.7%.

Conclusions

Functional outcomes after total femoral replacement were significantly better in patients with an intact rectus femoris compared with patients with invasion of the rectus femoris, possibly because more muscle mass can be preserved around the femur in patients with an intact rectus femoris.

Study on the effect of artificial joint replacement for osteosarcoma

Osteosarcoma is one of the most prevalent primary malignant bone tumors that affects teenagers more than adults. In recent years, artificial femoral replacement has become more and more common. The use of artificial total femoral replacement surgery prevents the need for amputating the damaged limb, preserves the patient's ability to move and bear weight on the leg, lessens the severity of the psychological trauma, and significantly raises the patient's quality of life. To explore the treatment methods and therapeutic effects of artificial femoral replacement in the treatment of femoral osteosarcoma. The clinical data of 11 patients with femoral malignant tumors who underwent artificial femoral replacement from January 2019 to March 2022 were retrospectively analyzed. Among them, 7 males and 4 females, 11 to 40 years old, average 19.36 ± 9.44 years old. The disease duration is 2 to 7 months, with an average of 4.7 months. Before and 3 months after operation, the patients who had tumors were given a score on the visual analog scale, and their quality of life was also measured. At the most recent follow-up, both the Musculoskeletal Tumor Society score and the Harris hip score were analyzed. Eleven patients were followed up for 6 to 58 months, and an average of 21 months. Complications such as wound infection, joint dislocation, and nerve damage did not occur. In 1 patient, popliteal vein thrombus formation, and in 2 patients with osteosarcoma died from tumor progression. Visual analog scale score at 3 months after surgery and the quality-of-life scores were 3.68 ± 1.39 and 40.04 ± 4.31, respectively, which were significantly improved compared to before surgery (5.94 ± 1.19 and 22.42 ± 3.63, respectively, P < .05). At the last interview, Musculoskeletal Tumor Society score is scored from 18 to 29 points, average 22.5 ± 5.9 points, and Harris hip score is scored from 42 to 90 points, with an average score of 69.0 ± 14.7. Artificial total femoral replacement is an effective limb salvage operation in the treatment of osteosarcoma.

Total Femur Antibiotic Spacers: Effective Salvage for Complex Periprosthetic Joint Infections

BACKGROUND

A simultaneous periprosthetic joint infection (PJI) of an ipsilateral hip and knee arthroplasty is a challenging complication of lower extremity reconstructive surgery. We evaluated the use of total femur antibiotic-impregnated polymethylmethacrylate (PMMA) bone cement spacers in the staged treatment of such limb-threatening PJIs.

METHODS

Thirteen patients were treated with a total femur antibiotic spacer. The mean age at the time of spacer placement was 65 years. Nine patients had polymicrobial PJIs. All spacers incorporated vancomycin (3.0 g/40 g PMMA) and gentamicin (3.6 g/40 g PMMA), while 8 also included amphotericin (150 mg/40 g PMMA). Eleven spacers were biarticular. Twelve spacers were implanted through one longitudinal incision, while 8 of 12 reimplantations occurred through 2 smaller, separate hip and knee incisions. Mean follow-up after reimplantation was 3 years.

RESULTS

Twelve (92%) patients underwent reimplantation of a total femur prosthesis at a mean of 26 weeks. One patient died of medical complications 41 days after spacer placement. At latest follow-up, 3 patients had experienced PJI recurrence managed with irrigation and debridement. One required acetabular component revision for instability. All 12 reimplanted patients retained the total femur prosthesis with no amputations. Eleven (91%) were ambulatory, and 7 (58%) remained on suppressive antibiotics.

CONCLUSION

Total femur antibiotic spacers are a viable, but technically demanding, limb-salvage option for complex PJIs involving the ipsilateral hip and knee. In the largest series to date, there were no amputations and 75% of reimplanted patients remained infection-free. Radical debridement, antimicrobial diversity, prolonged spacer retention, and limiting recurrent soft tissue violation are potential tenets of success.

LEVEL OF EVIDENCE

IV.

A new biarticular cement spacer technique for infected total hip and knee arthroplasty with massive bone loss

INTRODUCTION

The management of massive femoral bone defects following prosthetic infection remains a surgical challenge, particularly when the entire femur is affected.

METHODS

We present the first results of a new biarticular cement spacer with antibiotic technique using a cephalomedullary nail for the treatment of infected hip arthroplasty involving complete femoral bone loss.

RESULTS

5 patients with a minimum follow-up of 1 year were included. In all cases 2-stage replacement due to hip periprosthetic infection was carried out, with the need for a biarticular complete femoral spacer in view of the magnitude of the bone defect. The infection was resolved in all patients, with no complications (spacer fracture or dislocation) associated to spacer use, and the patients were all able to maintain the sitting position with active knee movements between the 2 surgical stages. Improvement with respect to preoperative functional status was observed in all cases, as evidenced by the Harris Hip Score (HHS) (from 24.2 to 73; p < 0.001) and 12-Item Short-Form Health Survey (SF-12) (from 16.8 to 33.2; p = 0.001), with a lessened need for walking aids.

DISCUSSION

The described technique offers a possible solution to a number of complications observed with the use of spacers in massive defects, affording greater patient comfort and autonomy while waiting to receive total femoral replacement.

Nonmechanical Revision Indications Portend Repeat Limb-Salvage Failure Following Total Femoral Replacement

BACKGROUND

There is scant evidence to guide decision-making for patients considering total femoral replacement (TFR). We aimed to identify the indication, patient, disease, and surgical technique-related factors associated with failure. We hypothesized that failure occurs more frequently in the setting of revision surgical procedures, with infection as the predominant failure mode.

METHODS

We performed a retrospective cohort study of patients receiving total femoral endoprostheses for oncological and revision arthroplasty indications; 166 patients met these criteria. Our primary independent variable of interest was TFR for a revision indication (arthroplasty or limb salvage); the primary outcome was failure. Analyses were performed for patient variables (age, sex, diagnosis group, indication), implant variables (model, decade, length, materials), and treatment variables. We analyzed TFR failures with respect to patient factors, operative technique, and time to failure. We conducted bivariate logistic regressions predicting failure and used a multivariate model containing variables showing bivariate associations with failure.

RESULTS

Forty-four patients (27%) had treatment failure. Failure occurred in 24 (23%) of 105 primary TFRs and in 20 (33%) of 61 revision TFRs; the difference was not significant (p = 0.134) in bivariate analysis but was significant (p = 0.044) in multivariate analysis. The mean age at the time of TFR was 37 years in the primary group and 51 years in the revision group (p = 0.0006). Of the patients who had mechanical failure, none had reoccurrence of their original failure mode, whereas all 8 patients from the nonmechanical cohort had reoccurrence of the original failure mode; this difference was significant (p = 0.0001).

CONCLUSIONS

TFR has a high failure rate and a propensity for deep infection, especially in the setting of revision indications and prior infection. All failed TFRs performed for revision indications for infection or local recurrence failed by reoccurrence of the original failure mode and resulted in amputation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Treatment of a periprosthetic femur fracture around an antibiotic spacer with revision and an antibiotic plate

Infection following total hip arthroplasty can be a devastating complication, often necessitating a 2-stage surgery with the temporary placement of an antibiotic spacer. Fracture around this spacer is an uncommon complication that presents serious treatment challenges. Our manuscript details the successful surgical treatment of a previously unreported fracture around an antibiotic spacer, treated with revision to a hemiarthroplasty and placement of an antibiotic plate.

Creating a dual articulating antibiotic spacer for management of an infected total femur prosthesis hemiarthroplasty

The gold standard for management of chronic periprosthetic joint infections is a 2-stage revision arthroplasty with the first stage being explantation, debridement, and placement of a spacer. While there are implants designed to manage periprosthetic infections in hip and knee arthroplasty, there are not any commercially available implants designed to specifically manage an infected total femur megaprosthesis. This creates a unique surgical challenge and requires custom construction of a spacer to be performed by the surgeon intraoperatively. Here, we present our surgical technique for manufacturing a dual articulating total femur spacer. This technique facilitates range of motion at both the hip and knee joints, provides stability for axial loading in the extremity, and preserves the acetabulum while the patient undergoes antibiotic therapy to eradicate the infection.

Preliminary outcomes of proximal femur megaspacers

There are very few therapeutic alternatives for patients with proximal femoral epiphyseal bone deficit combined with a fracture at another level and signs of infection. This combination can be successfully managed with a proximal femur megaspacer. This article is intended to review our variation of this technique and to show the initial results obtained from 11 cases. Of these 11 cases, there were 6 women and 5 men. The mean age was 66 years. The average number of previous surgeries was 3. Definitive prosthetic reconstructive treatment was achieved in 7 of these 11 subjects. The average time to reimplantation was 11.7 months. Fractures or nonunion healed uneventfully. Bone union and infection control were achieved in 10 of the 11 patients.

[Total femoral replacement for treating femur malignant tumor]

Objective

To investigate the procedure and effectiveness of total femoral replacement for treating femur malignant tumor.

Methods

The clinical data of 9 patients with femoral malignant tumors who underwent total femoral replacement between July 2013 and March 2017 were retrospectively analyzed. There were 5 males and 4 females, aged 16-75 years with an average of 44.8 years. The disease duration ranged from 2 to 6 months with an average of 3.5 months. There were 5 cases of osteosarcoma (3 cases were staged as Enneking ⅡB, 2 cases were staged as Enneking Ⅲ), 1 case of malignant fibrosarcoma (staged as Enneking ⅡB), 1 case of chondrosarcoma (staged as Enneking ⅠB), 2 cases of femoral muti-metastasis of lung cancer with pathological fracture. The visual analogue scale (VAS) score and the quality of life (QOL) score of the tumor patients were evaluated before operation and at 3 months after operation. The Musculoskeletal Tumor Society (MSTS) score and Harris hip score (HHS) were evaluated at last follow-up.

Results

Nine patients were followed up 11-58 months, with an average of 21 months. No complication such as wound infection, joint dislocation, and nerve injury occurred. One patient developed popliteal vein thrombosis, and 2 patients with osteosarcoma died of tumor progression. The VAS score and QOL score at 3 months after operation were 3.2±1.2 and 40.6±5.4 respectively, which were significantly improved when compared with preoperative ones (5.9±0.8 and 22.3±4.2 respectively) ( t=11.314, P=0.000; t=-7.794, P=0.000). At last follow-up, the MSTS score was 15-29 with an average of 21.1, and the HHS score was 44-90 with an average of 66.5.

Conclusion

Total femoral replacement is an effective limb salvage procedure for the treatment of femoral malignant tumors, which can effectively restore the weight-bearing and walking function, relieve pain, and improve the quality of life.

[Advances in total femur replacement]

Objective

To summarize the advances of total femur replacement in recent years.

Methods

The literature related to total femur replacement was reviewed, and the indications, techniques, prosthesis design, complications, rehabilitation, and function were summarized.

Results

The indication of total femur replacement is a wide involvement of the femur, skip lesions and a huge bone defect in revision. Watson-Jone is the main incision in the proximal, and then the full length of the thigh to the patella. Vascular and nerve bundle, abduction muscles are well protected, and combined or costumed prosthesis are replaced. The prosthesis design progresses, showing a diversified prostheses. Complication is frequent and varied. Rehabilitation in early stage is physical therapy, weight training is evolutionary. The main function evaluation system is Musculoskeletal Tumor Society (MSTS) score.

Conclusion

Total femur replacement is effective in limb salvage. Large sample size and long-term follow-up study should be carried out to unify indications and functional exercise standards and reduce postoperative complications.

Biarticular total femur spacer for massive femoral bone loss: the mobile solution for a big problem

Bone cement spacers loaded with antibiotic are the gold standard in septic revision. However, the management of massive bone defects constitutes a surgical challenge, requiring the use of different nails, expensive long stems, or cement-coated tumor prostheses for preparing the spacer. In most cases, the knee joint must be sacrificed. We describe a novel technique for preparing a biarticular total femur spacer with the help of a trochanteric nail coated with antibiotic loaded cement, allowing mobility of the hip and knee joints and assisted partial loading until second step surgery. This technique is helpful to maintain the length of the leg, prevent soft tissue contracture, and help eradicate the infection preserving the patient comfort and autonomy while waiting to receive total femoral replacement.

A novel hybrid type (custom-made plus off-the-shelf) total femoral PROSTALAC

INTRODUCTION

Treatment of periprosthetic joint infection following revision-Total Hip Arthroplasty is more problematic when there is poor bone quality and severe bone loss. Migration of revision prosthesis with a long stem to the knee joint in infected cases makes treatment more complex. In these cases, total femoral replacement is the only treatment option and eradication of infection is mandatory before the replacement. In 2-staged reconstruction treatment, there is a need for a PROSTALAC to replace the whole femur.

METHODS

We describe here a novel hybrid type (custom-made plus off-the-shelf) total femoral PROSTALAC for cases in need of whole femoral bone and femoral component removal for the treatment of periprosthetic joint infection in total hip arthroplasty.

RESULT

Both sides of the PROSTALAC have anatomical joint surfaces, so the articulation with the acetabulum proximally is expected to be more stable. The off-the-shelf anatomic joint surface of the PROSTALAC distally allows articulation compatible with a proximal tibial off-the-shelf spacer.

CONCLUSIONS

This simple hybrid-type total femoral PROSTALAC can be adjusted to femoral length, has anatomical joint surfaces that produce a more stable articulation, and can articulate with an off-the-shelf proximal tibial spacer.

Current concepts in total femoral replacement

Total femoral replacement (TFR) is a salvage arthroplasty procedure used as an alternative to lower limb amputation. Since its initial description in the mid-20^th century, this procedure has been used in a variety of oncologic and non-oncologic indications. The most compelling advantage of TFR is the achievement of immediate fixation which permits early mobilization. It is anticipated that TFR will be increasingly performed as the rate of revision arthroplasty rises worldwide. The existing literature is mainly composed of a rather heterogeneous mix of retrospective case series and a wide assortment of case reports. Numerous TFR prostheses are currently available and the surgeon must understand the unique implications of each implant design. Long-term functional outcomes are dependent on adherence to proper technique and an appropriate physical therapy program for postoperative rehabilitation. Revision TFR is mainly performed for periprosthetic infection and the severe femoral bone loss associated with aseptic revisions. Depending on the likelihood of attaining infection clearance, it may sometimes be advisable to proceed directly to hip disarticulation without attempting salvage of the TFR. Other reported complications of TFR include hip joint instability, limb length discrepancy, device failure, component loosening, patellar maltracking and delayed wound healing. Further research is needed to better characterize the long-term functional outcomes and complications associated with this complex procedure.

Treatment of infected nonunion total knee arthroplasty periprosthetic fracture using a stemmed articulating spacer

BACKGROUND

We present a case of multifocal infection involving the left total hip replacement and the right total knee replacement of a patient, further complicated by an infected non-union of a periprosthetic fracture of the right knee. This required the unique simultaneous management of both infection eradication and fracture stabilization in the knee.

METHODS

Both sites were treated with a two-stages procedure, including the novel use of a stemmed articulating spacer for the right knee. This spacer was made combining a retrograde humeral nail, coated with antibiotic-impregnated cement, and a pre-formed articulating cement spacer. The patient was able to weight-bear on this spacer.

RESULTS

The fracture went on to unite, and a second stage was performed with the use of stemmed prosthesis and augments. She remains infection free two years after the second stage operation.

CONCLUSIONS

The use of a stemmed articulating knee spacer can facilitate infection eradication and fracture stabilization while preserving some motion and weight-bearing ability in the two-stages management of an infected periprosthetic fracture of the knee.

LEVEL OF EVIDENCE

Level V (Case report).

IL-12 promotes myeloid-derived suppressor cell recruitment and bacterial persistence during Staphylococcus aureus orthopedic implant infection

Staphylococcus aureus is a leading cause of human prosthetic joint infections (PJIs) typified by biofilm formation. We recently identified a critical role for myeloid-derived suppressor cells (MDSCs) in S. aureus biofilm persistence. Proinflammatory signals induce MDSC recruitment and activation in tumor models; however, the mechanisms responsible for MDSC homing to sites of biofilm infection are unknown. In this study, we report that several cytokines (IL-12p40, IL-1β, TNF-α, and G-CSF) and chemokines (CXCL2, CCL5) were significantly elevated in a mouse model of S. aureus PJI. This coincided with significantly increased MDSC infiltrates concomitant with reduced monocyte, macrophage, and T cell influx compared with uninfected animals. Of the cytokines detected, IL-12 was of particular interest based on its ability to possess either pro- or anti-inflammatory effects mediated through p35-p40 heterodimers or p40 homodimers, respectively. MDSC recruitment was significantly reduced in both p40 and p35 knockout mice, which resulted in enhanced monocyte and neutrophil influx and bacterial clearance. Adoptive transfer of wild-type MDSCs into infected p40 knockout animals worsened disease outcome, as evidenced by the return of S. aureus burdens to levels typical of wild-type mice. Tissues obtained from patients undergoing revision surgery for PJI revealed similar patterns of immune cell influx, with increased MDSC-like cells and significantly fewer T cells compared with aseptic revisions. These findings reveal a critical role for IL-12 in shaping the anti-inflammatory biofilm milieu by promoting MDSC recruitment.

Industrially prefabricated cement spacers: do vancomycin- and gentamicin-impregnated spacers offer any advantage?

BACKGROUND

Industrially preformed antibiotic-loaded cement spacers are useful to facilitate the second stage of two-stage exchange arthroplasty for infected THAs and TKAs. However, whether gentamicin alone or a combination of antibiotics (such as vancomycin and gentamicin) is more effective is not known.

QUESTIONS/PURPOSES

We therefore sought to compare industrially prefabricated spacers containing either gentamicin or gentamicin and vancomycin with respect to (1) infection control, (2) complications, and (3) quality of life, pain, and patient satisfaction.

METHODS

We performed a review of 51 patients with chronic infections treated at one center using either gentamicin or vancomycin and gentamicin-prefabricated spacers. The former were used exclusively from January 2006 until May 2009, and the latter from June 2009 until July 2011, and there was no overlap. We collected data on demographics, immunologic status (McPherson classification), prosthetic joint infection location, type of prosthesis, microbiologic results, and time between stages. We evaluated the primary outcome of infection control or recurrence after at least 12 months followup. We also recorded complications. Each patient completed a quality-of-life survey, VAS, and a self-administered satisfaction scale.

RESULTS

The overall infection control rate was 83% after a mean followup of 35 months (range, 12.4-64.7 months). There were no differences between gentamicin and vancomycin and gentamicin spacers in terms of infection eradication (80 % versus 85 %, respectively; p = 0.73), nor in terms of complications, quality of life, pain, or satisfaction scores.

CONCLUSIONS

Prefabricated, antibiotic-loaded cement spacers has been proven effective for infection control in TKAs and THAs but with the numbers available, we did not find any differences between a gentamicin or vancomycin and gentamicin-prefabricated spacer, and therefore, we are unable to validate the superiority of the combination of vancomycin and gentamicin over gentamicin alone. Because of the higher costs involved with vancomycin and gentamicin spacers, and the potential risks of unselective use of vancomycin, further comparative studies are necessary to evaluate their role in the treatment of infected THAs or TKAs.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Management of total femoral bone loss using a hybrid cement spacer surgical technique

Standard treatment for an infected total hip arthroplasty is 2-stage revision. Bone loss in infected total hip arthroplasty presents specific challenges during the first stage. This is especially the case when there is massive or complete loss of the femoral bone stock. We describe a technique successfully used in the setting of total femoral bone loss using a hybrid cement spacer. We describe 2 cases illustrating the technique and perioperative course. This technique is a potential solution for total femoral bone loss that allows the individual to maintain mobility before definitive surgery.

Staged custom, intramedullary antibiotic spacers for severe segmental bone loss in infected total hip arthroplasty

Introduction. Total hip arthroplasty (THA) infections with severe bone loss pose significant reconstructive challenges. We present our experience with two-stage hip reimplantation using an intramedullary, antibiotic-impregnated nail. Methods. Three patients with infected THA with severe proximal femoral bone loss (Mallory type IIIB or greater) were treated using a custom antibiotic spacer. Clinical outcomes and any complications were recorded. Average followup was 49 months from final reimplantation. Results. Mean age at spacer placement (stage 1) was 53 years. The mean Harris Hip Score at final followup was 80. Two patients had asymptomatic heterotopic ossification, and one patient had a 2 cm leg-length discrepancy. Conclusions. A custom intramedullary nail antibiotic spacer is a reliable option in the staged management of the infected THA with severe proximal femoral bone loss. Benefits of this technique include limb salvage with maintenance of leg length, soft tissue tension, and functional status.