Short- to long-term follow-up of total femoral replacement in non-oncologic patients

Principles of Defect Reconstruction After Wide Resection of Primary Malignant Bone Tumors of the Calcaneus: A Contemporary Review

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Characteristics and Epidemiology of Megaprostheses Infections: A Systematic Review

BACKGROUND

Megaprostheses were first employed in oncological orthopedic surgery, but more recently, additional applications have arisen. These implants are not without any risks and device failure is quite frequent. The most feared complication is undoubtedly the implants' infection; however, the exact incidence is still unknown. This systematic review aims to estimate in the current literature the overall incidence of megaprosthesis infections and to investigate possible risk/protective factors.

METHODS

We conducted a systematic search for studies published from July 1971 to December 2023 using specific keywords. To be included, studies needed to report either the megaprosthesis anatomical site, and/or whether the megaprosthesis was coated, and/or the surgical indication as oncological or non-oncological reasons.

RESULTS

The initial literature search resulted in 1281 studies. We evaluated 10,456 patients and the overall infection rate was 12%. In cancer patients, the infection rate was 22%, while in non-oncological patients, this was 16% (trauma 12%, mechanical failure 17%, prosthetic joint infections 26%). The overall infection rates comparing coated and uncoated implants were 10% and 12.5%, respectively.

CONCLUSIONS

The number of megaprosthesis implants is increasing considerably. In traumatological patients, the infection rate is lower compared to all the other subgroups, while the infection rate remains higher in the cancer patient group. As these devices become more common, focused studies exploring epidemiological data, clinical outcomes, and long-term complications are needed to address the uncertainties in prevention and management.

Postoperative Outcomes of Total Femur Replacement in Oncologic and Nononcologic Patients: A Systematic Review of the Literature

BACKGROUND

Total femur replacement (TFR) is used for primary reconstruction after extensive tumor resection or as a revision surgery due to prosthetic failure. Studies on TFR rates of failure and functional outcomes are scarce. The purpose of our study was to compare the modes of failure, amputation rates, and functional outcomes after TFR between oncologic and nononcologic patients.

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were for this manuscript. Our study was registered on PROSPERO (413582). Quality assessment of all studies was performed using Strengthening the Reporting of Observational Studies in Epidemiology checklist. Endoprosthesis failure was assessed using the Henderson classification and functional outcomes using the Musculoskeletal Tumor Society score. Weighted means and standard deviations were calculated.

RESULTS

Overall failure rate was similar between groups. Henderson type 4 failures were more common within the nononcologic group, while the others were more frequently found in the oncologic group. Overall amputation rate was higher in the oncologic group mainly due to type 5 failure. Amputations occurred mainly after type 4 and type 5 failures. Functional outcome was better within the oncologic group (70.5 versus 61.7, respectively; P < .001).

CONCLUSIONS

Total femoral replacement in the oncologic and nononcologic group is associated with a high rate of failure (31% and 32.5%, respectively). Overall amputation rate was higher in the oncologic group mainly due to type 5 failure. Functional outcome was better within the oncologic group.

LEVEL OF EVIDENCE

Level III.

Intussusception Allograft Prosthetic Composites in Total Hip Arthroplasty: A Salvage Operation for Extensive Femoral Bone Loss

BACKGROUND

Allograft prosthetic composites (APCs) have been used to perform revision total hip arthroplasty (THA) for massive femoral bone loss or deformity. Intussusception, or "telescoping", APC techniques have been proposed to enhance the contact area of this interface and provide superior mechanical fixation over conventional methods. The purpose of this study is to present to our knowledge, the largest series of telescoping APC THAs, along with surgical technique details and midterm (average 5-10 years) clinical results.

METHODS

Between 1994 and 2015, 46 revision THAs performed with proximal femoral telescoping APCs were retrospectively reviewed at a single institution. Overall survival, reoperation-free survival, and construct survival rates were calculated via Kaplan-Meier methods. In addition, radiographic analyses were performed to evaluate for component loosening, union at the APC-host interface, and resorption of the allograft.

RESULTS

At 10 years, the overall patient survival was 58%, reoperation-free survival was 76%, and construct survival was 95%. Reoperation was performed in 20% (n = 9) and only 2 constructs required resection. Radiographic analyses performed at latest follow-up revealed no instances of radiographic femoral stem loosening, an 86% union rate at the APC-host site, 23% with signs of some allograft resorption, and a 54% trochanteric union. The mean postoperative Harris hip score was 71 points (range, 46-100).

CONCLUSION

Telescoping APCs are technically demanding, but provide reliable mechanical fixation for the reconstructing of large proximal femoral bone deficits in revision THA with excellent construct survivorship, acceptable reoperation rates, and good clinical outcomes.

LEVEL OF EVIDENCE

IV.

Total femoral arthroplasty for non-oncological indications

Aims

Total femoral arthroplasty (TFA) is a rare procedure used in cases of significant femoral bone loss, commonly from cancer, infection, and trauma. Low patient numbers have resulted in limited published work on long-term outcomes, and even less regarding TFA undertaken for non-oncological indications. The aim of this study was to evaluate the long-term clinical outcomes of all TFAs in our unit.

Methods

Data were collected retrospectively from a large tertiary referral revision arthroplasty unit's database. Inclusion criteria included all patients who underwent TFA in our unit. Preoperative demographics, operative factors, and short- and long-term outcomes were collected for analysis. Outcome was defined using the Musculoskeletal Infection Society (MSIS) outcome reporting tool.

Results

Overall, 38 TFAs were identified. The mean age was 73 years (42 to 80). All patients underwent TFA for non-oncological indications, most commonly as a consequence of infection (53%) and periprosthetic fracture (26%). The mean follow-up time was ten years (0 to 26); 63% of TFAs were considered a success based upon the MSIS outcome reporting tool. The mean time between TFA and death was 8.5 years (0.2 to 19.2), with two patients dying within one year of surgery. Within the cohort, 66% suffered at least one complication, dislocation being most common (37%); 55% of the total cohort required at least one subsequent operation. In total, 70% of TFAs undertaken for infection were considered infection-free at time of final follow-up. The percentage of mobile patients improved from 52% to 65% between pre- and postoperation, with all patients being able to at least transfer from bed to chair at time of final review.

Conclusion

This study is the largest in the UK assessing the use of TFA in patients with bone loss secondary to non-oncological conditions. It demonstrates that TFA has a significant complication profile, however it is favourable in terms of mortality and rehabilitation when compared to amputation and disarticulation.

Three-dimensional design custom-made uncemented stem for revision of cemented distal femoral endoprosthesis due to aseptic loosening

BACKGROUND

Revision of cemented distal femoral replacement (DFR) due to aseptic loosening is challenging because of the resultant femoral bone loss. This paper aims to examine the outcomes of three-dimensional (3D) design custom-made uncemented stems for revision.

METHODS

Between January 2014 and December 2020, 17 patients received 3D design uncemented stems for revision of loosed cemented DFR. The femoral bone loss was classified into four Grades, and four types of uncemented stems were designed correspondingly. The revision stems were custom-made for each patient by measuring the diameter of the medullary cavity and the anterior curvature of the femur.

RESULTS

The patient counts with their corresponding Grades of femoral bone loss were as follows: Grade I, 8 patients; Grade II, 5 patients; Grade III, 3 patients; and Grade IV, 1 patient. During the mean follow-up of 80 months, no revision failure was detected. The postoperative radiographic showed that the stem matched the femoral anterior curvature well. The femoral bone defect was completely filled by the 3D design stem in 10 of the 17 cases postoperatively. In the remaining cases, the persistent peri-stem defect was filled or partially restored during the follow-up.

CONCLUSION

3D design custom-made uncemented stem created precise, stable, and durable fixation and provided satisfactory clinical outcomes, which seems to be a viable method for cemented DFR revision.

Megaprosthesis in Non-Oncologic Settings-A Systematic Review of the Literature

Modular megaprostheses (MPs) are commonly used after bone-tumor resection, but they can offer a limb salvage solution in massive bone defects. The aim of this systematic review of the Literature is to provide a comprehensive data collection concerning the use of MPs in non-oncologic cases, and to provide an overview of this topic, especially from an epidemiologic point of view. Three different databases (PubMed, Scopus, and Web of Science) were searched for relevant articles, and further references were obtained by cross-referencing. Sixty-nine studies met the inclusion criteria, reporting on cases of MP in non-oncologic cases. A total of 2598 MPs were retrieved. Among these, 1353 (52.1%) were distal femur MPs, 941 (36.2%) were proximal femur MPs, 29 (1.4%) were proximal tibia MPs and 259 (10.0%) were total femur MPs. Megaprostheses were most commonly used to treat periprosthetic fractures (1158 cases, 44.6%), in particular in the distal femur (859, 74.2%). Overall, complications were observed in 513 cases (19.7%). Type I (soft tissue failures) and type IV (infection) according to the Henderson classification were the most frequent (158 and 213, respectively). In conclusion, patients with severe post-traumatic deformities and/or significant bone loss who have had previous septic complications should be considered as oncologic patients, not because of the disease, but because of the limited therapeutic options available. The benefits of this treatment include relatively short operative times and immediate weight-bearing, thus making MP particularly attractive in the lower limb.

The Performances of Conventional Titanium and Silver-Coated Megaprostheses in Non-oncological and Post-oncological Patients: An Analysis of Infection Failures in 142 Patients

BACKGROUND

Megaprostheses are one of the preferred choices of reconstruction after tumor resection. Periprosthetic joint infections are one of the most serious complications of joint prostheses surgeries. In this study, our aim was to analyze the efficacy of silver-coated megaprostheses in reducing the risk of prosthesis-related infection.

METHODS

One hundred forty-two patients who had undergone implantation of a mega-endoprosthesis for non-neoplastic or post-neoplastic conditions were included in this retrospective study. The end-point of the survival analysis was the prosthesis failure due to infection.

RESULTS

Thirty-eight patients had undergone implantation of a silver-coated megaprosthesis and 104 patients a megaprosthesis without silver coating. The survival analysis showed an overall infection-free survival rate of 82.3% at five years and 61.9% at 10 years. Silver-coated prostheses had an HR of 0.72 (95% CI: 0.26-2.05; P=0.54).

CONCLUSION

Implantation of a silver-coated mega-prosthesis in non-oncological patients did not significantly reduce the risk of prosthesis-related infection.

Clinical Outcomes Following Distal Femur Replacement for Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis

BACKGROUND

Management of periprosthetic distal femur fractures (PDFFs) is often complicated by poor bone quality and limited bone stock making fixation attempts challenging and prone to failure. Distal femoral replacement (DFR) is being used to treat such injuries although outcome data are mostly from small case series. We sought to systematically review the literature on DFR for PDFF to summarize their outcomes.

METHODS

PubMed, MEDLINE (EBSCO), and Cochrane Central Database were searched to identify reports of PDFFs treated with DFR. Articles reporting on 5 or more knees were systematically reviewed for clinical function, complications, and mortality. Random effects meta-analysis was used to create summary estimates and publication bias also assessed.

RESULTS

Of 287 identified and screened articles, 15 were included, 14 retrospective, reporting on 352 knees. Following DFR, 87% (95% confidence interval [CI] 71-95) of patients were able to ambulate. The mean postoperative Knee Society Score was 80 (95% CI 77-84). The risk of periprosthetic joint infection was 4.3% (95% CI 2.2-8.2). One-year postoperative mortality rate was 10% (95% CI 6-18). There was some evidence of publication bias with a trend toward smaller studies reporting lower infection risk and mortality.

CONCLUSION

DFR for PDFFs is associated with high functional outcomes and a relatively modest risk of infection. The periprosthetic joint infection and 1-year mortality rates reported here should be considered lower bounds estimates due to publication bias and loss to follow-up. Further investigation of long-term outcomes following DFR for PDFFs is warranted though short-term functional outcomes are promising.

The Use of Megaprostheses in Nononcologic Lower-Extremity Total Joint Arthroplasty: A Critical Analysis Review

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As the number of primary total joint arthroplasty (TJA) procedures continues to rise, megaprostheses have found an emerging role in more complex revision arthroplasty cases that require additional reconstruction, stability, and restoration of function.

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Megaprosthesis options have evolved: in addition to cemented prostheses, cementless and even hybrid fixation designs optimize longevity. Proximal femoral replacement (PFR), distal femoral replacement (DFR), proximal tibial replacement (PTR), and total femoral replacement (TFR) are all limb salvage options in the setting of substantial bone loss, poor bone quality, and soft-tissue compromise.

»

Dislocation is one of the most common complications after PFR, likely due to the loss of soft-tissue integrity, most notably the hip abductor musculature from the greater trochanter. The utilization of dual-mobility constructs, larger femoral heads, elevated acetabular liners, and constrained acetabular liners may reduce the risk of instability and improve overall hip function.

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Patients with megaprostheses may be more prone to periprosthetic joint infection and surgical site infection given multiple variables, such as the lengthy nature of the surgical procedure, prolonged wound exposure, extensive soft-tissue dissection and resection, poor soft-tissue coverage, and poorer host status.

»

Despite advances in technology, complication and revision rates remain high after megaprosthesis reconstruction. Therefore, thorough attention to patient-specific factors must be considered for appropriate use of these constructs.

Interimplant femoral fractures

The number of hip or knee arthroplasties, and internal fixations of the proximal and distal femur, is increasing in proportion to the growing and ageing population, whose life expectancy is lengthening. Thus, fractures of the femur between proximal and distal implants, although rare, are becoming more frequent. Women over the age of 70, with fragile bones and whose ends of the two implants are close to each other ("kissing implants") are particularly vulnerable to them. Reliable and reproducible fracture classifications exist when it comes to 2 prostheses, but they are less well established in the presence of one, or even two, non-prosthetic implants. Their treatment is difficult and must consider the possibility of fracture consolidation while ensuring or restoring the stability and role of the implants. Whether it is the main element of treatment or a complement to prosthesis revision, locked plating forms the basis of the treatment but it must be rigorous, considering that failures are mainly the result of technical errors. Other more invasive treatments (total femoral arthroplasty, cortical sleeves) are offered more rarely if consolidation appears compromised.

Modular Total Femur Replacement for Staged Total Femur Replacement

As the numbers of arthroplasties performed worldwide increase, so do complications such as prosthetic joint infection. Cases that require a two-stage revision of a total femur replacement in the femur pose an ongoing challenge to the modern orthopedic surgeon. Unlike antibiotic spacers in hip and knee arthroplasty, there lacks a commercially available cement spacer for use in total femur replacements. We describe a novel technique for the intraoperative fabrication of a total femur spacer which uses modular components. As such, our technique is unique as it is modular and, therefore, highly customisable to each individual patient. Individual components can be made by different members of the team simultaneously and then assembled to make the final construct, thereby minimizing operative time. Furthermore, the inherent stability of the spacer allows immediate partial weightbearing and functional rehabilitation while patients are waiting for their second-stage procedure.

Different outcomes after proximal femoral replacement in oncologic and failed revision arthroplasty patients - a retrospective cohort study

Background

Proximal femoral replacement (PFR) is a technically demanding procedure commonly performed to restore extensive, oncological or non-oncological bone defects in a severely debilitated patient collective. Depending on different indications, a varying outcome has been reported. The aim of the study was to assess the functional outcomes and complication rates of PFR with the modular Munich-Luebeck (MML) femoral megaprosthesis (ESKA/Orthodynamics, Luebeck, Germany), and to highlight outcome differences in patients treated for failed revision total hip arthroplasty (THA) or malignant bone disease.

Methods

A retrospective review of patients treated with PFR for failed THA or malignant tumor disease between 2000 and 2012 was performed. Patient satisfaction, functional outcome (VAS, SF-12, MSTS, WOMAC, TESS), complications and failure types (Henderson’s failure classification) were assessed. A Kaplan-Meier analysis determined implant survival.

Results

Fifty-eight patients (age: 69.9 years, BMI: 26.7 kg/m², mean follow-up: 66 months) were included. The mean SF-12 (physical / mental) was 37.9 / 48.4. MSTS averaged 68% at final follow-up, while mean WOMAC and TESS scored 37.8 and 59.5. TESS and WOMAC scores demonstrated significantly worse outcomes in the revision group (RG) compared to the tumor group (TG). Overall complication rate was 43.1%, and dislocation was the most common complication (27.6%). Implant survival rates were 83% (RG) and 85% (TG; p = n.s.) at 5 years, while 10-year survival was 57% (RG) and 85% (TG, p < 0.05).

Conclusions

PFR is a salvage procedure for restoration of mechanical integrity and limb preservation after extensive bone loss. Complications rates are considerably high.

Functional outcomes and 10-year implant survival rate were worse in the RG compared to the TG. Strict indications and disease-specific patient education are essential in preoperative planning and prognosis.

A Novel Endosteal Reconstruction of the Femur from Distal Femoral Remnant Using 3D-Printed Titanium Rings: A Two-Case Report

CASE

Femur reconstruction with only the distal femoral remnant is challenging because of poor bone volume required for stem fixation. Although proximal femoral replacement, total femur replacement, allograft prosthesis composite, and custom porous tantalum implants are options, hybrid fixation enhanced by endosteal reconstruction with three-dimensional (3D)-printed porous titanium rings to reconstruct the femur without supporting isthmus has not been described. We report 2 cases with satisfactory 34- and 22-month follow-up results of hybrid fixation enhanced by endosteal reconstruction with 3D-printed porous titanium rings.

CONCLUSION

This novel method provides a solution to revise loosened femoral endoprosthesis with only distal femoral remnant.

Megaprostheses in Nononcologic Hip and Knee Revision Arthroplasty

Megaprostheses as a means of limb salvage originated in orthopaedic oncology, and implant evolution was initially driven by developments within this field. Improvements in imaging modalities and in chemotherapeutics prolonged patient survival and promoted a transformation in the surgeon's mentality from salvage operation to functional limb reconstruction. As primary arthroplasty operations became more popular, megaprostheses found new utility in hip and knee revision arthroplasty. In this capacity, these implants provided much needed alternatives to traditional arthroplasty revision options for addressing massive bone loss and complex periprosthetic fractures. The indications for megaprostheses continue to expand with advances in design, stability, and overall longevity. Thus, greater numbers of orthopaedic surgeons in arthroplasty and traumatology have to be familiar with this technology. Importantly, each anatomic location presents unique considerations for reconstruction; however, additional variables such as the quantity of bone loss, the quality of remaining bone stock, and fracture type also influence implant selection. Ultimately, there is still much to be optimized in the use of megaprostheses for hip and knee revision arthroplasty. High multifactorial complication and revision surgery rates compared with conventional prostheses make these implants for many a "last resort" option.

Total Femoral Replacement- A Case Report

Total femoral replacement(TFR) is a well-recognized salvage procedure performed after multiple failed endoprosthetic replacements, which result in severely compromised bone stock and damaged structural integrity. TFR is performed as an alternative to lower limb amputation, restoring femoral integrity and enabling patients to resume ambulation. TFR is expected to be performed more frequently as the worldwide rate of revision arthroplasty increases due to improved patient survival rates and their underlying diseases, exceeding the functional life of endoprosthetic arthroplasty. We present a 74-year-old, overweight woman with an extensive surgical history with respect to her right knee. Her right lower extremity x-rays showed a long-cemented stem knee tumour prosthesis and a Garden 4 subcapital fracture of the ipsilateral hip. Due to multiple surgeries of the knee and femur in the past, a total femoral replacement was required to be performed. The procedure was successful, and the expected outcome was met. A successful procedure performed by a skilled and experienced surgical team, a thorough rehabilitation program, and prompt post-operative management of complications, can overcome the high incidence of infection and dislocation to preserve the limb with improved functionality and reduce pain. TFR is a drastic operative intervention that can preserve the quality of life for most patients.

Modular megaprostheses in the treatment of periprosthetic fractures of the femur

Background

Periprosthetic fractures (PPF) of the femur remain challenging, especially in patients with previous multiple revisions. Modular megaprostheses (mMPs) are rarely used in this indication; however, in some cases mMPs seem to be the last chance for limb salvage. We aimed to evaluate the clinical outcome of PPFs of the femur treated by modular mMPs at our institution.

Patients and methods

In this study 33 patients (27 female; mean age 79 years) with a PPF after total hip or total knee arthroplasty (no tumor indications) were treated using modular proximal (mPFR; n = 12), distal (mDFR; n = 14) or total (mTFR; n = 7) femur replacement. A retrospective evaluation regarding mortality and revision rates was performed. Failures with need for revision were classified.

Results

At a mean follow up of 60 months (range 0–178 months), the total mortality rate as well as total revision rate were both found to be 39%. At 1 year follow-up the mortality rate was highest within the mDFR group, and less revisions were necessary in the mPFR group, however both findings were not significantly. Those patients, who had revision surgery before PPF, were found to have higher revision rate after implantation of mMP. In the mPFR group, dislocation was the most frequent failure, within the mDFR and the mTFR group infection. In one case amputation of the lower limb was necessary.

Conclusion

mMPs represent a valuable option in PPFs of the femur. Infection and dislocation remain the most frequent complications. Prospective clinical studies are required to further define the outcome of mMPs in PPFs of the femur.

Salvage of Distal Femoral Replacement Loosening with Massive Osteolysis Using Impaction Grafting: A Report of 2 Cases

CASE

Salvage of 2 cases of distal femoral replacement loosening with massive osteolysis using impaction grafting are presented with 9- and 11-year follow-ups.

CONCLUSION

Surgeons should keep impaction grafting in their armamentarium for cases of failed DFR with severe osteolysis. Doing so may allow for preservation of the native hip and deferment of more radical procedures (i.e. total femur replacement) that have high rates of complication and poor survivorship.

A modified technique of mega prosthesis revision on non-neoplastic patient: Case report

Introduction

Mega prosthesis is mainly used for the treatment of the oncologic patient whose limb underwent salvage surgery that caused the limb to lose significant bone or soft tissue. In recent years, mega prosthesis can also be used to treat non-oncologic patients.

Presentation of case

We presented a case of a 40-year-old male with chief complain of pain on the right knee 5 months before admission. Four years previously, the patient sustained motor vehicle accident that fractured his head of femur dan distal femur. He underwent 2-staged surgery for his femoral head and distal femur. However, he presented a year later with signs of non-union and finally underwent mega prosthesis surgery on his distal femur. During his follow up, he experienced a fracture on his prosthesis 3 years later and was referred to our institution. Physical examination shows deformity and slight varus on the right knee, and limited range of motion. The patient then underwent implant revisions.

Discussion

After 12 months of post revision surgery follow-up, the patient was able to walk independently. Our patient has not had any sign or episode of failure after the follow up for 12 months. According to literature, the incidence of failure is mostly at 48-72 months post implantation.

Conclusion

The problem for this patient maybe caused by the mechanical fatigue of the implant due to stress addressed to the implant. Our current technique of revisions procedure hopefully will enhance the power of the mega prosthesis for further usage.

Humeral head necrosis associated to shaft non-union with massive bone loss: a case report

Humeral non-union is a rare complication in shaft fractures, as well as humeral head necrosis is a possible complication in fracture involving the proximal third especially in four-part fractures. The presence of head osteonecrosis and diaphyseal non-union in the same arm represents a formidable challenge for an orthopaedic surgeon. We could not find any similar report in the literature dealing with this issue thus far. We present a case of a 65 years old woman referred to our hospital being affected by an atrophic humeral diaphyseal non-union with a massive bone loss (>10cm) associated to a humeral head osteonecrosis following a previous surgical procedures with a clear loosening of the hardware. At our institution,she was treated with hardware removal and insertion of a diaphyseal antibiotic spacer with Gentamycin for 2 months suspecting an active septic process at the union site despite negative cultural exams. Finally, she was treated with a cemented modular humeral megaprosthesis. At 20 months follow up, the patient, despite a reduced shoulder range of motion, referred to a pain-free recovery to an almost normal lifestyle, including car driving with no major disturbances. This case suggests that, in extreme selected cases following several failed treatments, megaprosthesis can represent a viable solution, especially in huge bone loss associated to joint degeneration, to ensure an acceptable return to a normal lifestyle.

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.

Survivorship of Megaprostheses in Revision Hip and Knee Arthroplasty for Septic and Aseptic Indications: A Retrospective, Multicenter Study With Minimum 2-Year Follow-Up

Background

The use of megaprostheses in nononcologic patients has been associated with complication rates greater than 50%. In patients with prior periprosthetic joint infection (PJI) with subsequent two-stage reimplantation, this complication rate may be even higher. This study was to investigate the outcomes of megaprostheses in nononcologic patients undergoing revision hip/knee arthroplasty.

Methods

We retrospectively studied patients who underwent megaprosthesis replacements from 1999 to 2017 at 5 hospitals with minimum 24 months of follow-up. Patients were stratified based on history of prior PJI (septic vs aseptic) and location of the megaprosthesis (the hip or knee). Postoperative complications were classified as soft-tissue failure, aseptic loosening, structural failure, and infection.

Results

Of the 42 patients, 19 were in the septic cohort and 23 were in the aseptic cohort. The overall complication rate was 28.6%. Complication rates for the septic and aseptic cohorts were 32% and 26%, respectively (P = .74). By anatomic location, there were 2 of 13 (15%) and 10 of 29 (34%) complications in the hip and knee groups, respectively (P = .28). In the septic cohort, there were no (0%) complications in the hip group and 6 of 14 (43%) complications in the knee group (P = .13), all due to infection. In the aseptic cohort, there were 2 of 8 (25%) and 4 of 15 (27%) complications in the hip and knee groups, respectively (P = 1.0).

Conclusions

There is no difference in the postoperative complication rates between the septic or aseptic cohorts undergoing revision hip or knee megaprosthesis replacements. In patients with prior PJI, proximal femoral replacements have improved short-term survivorship compared with distal femoral or proximal tibial replacements.

Allogenic bone graft for femoral defect augmentation in hip revision arthroplasty: A case series

Cortical bone loss in revision hip arthroplasty requires an adequate stabilization to achieve a durable implant fixation. This case series shall illustrate possible indications for the use of allogenic grafts in revision hip arthroplasty. Twelve patients with femoral bone loss were treated with allografts. In addition to established clinical scores, the radiological follow-ups were analyzed for hints of implants loosening and the osteointegration of the allografts. After a mean follow-up of 3.0 years the mHHS was 61.3 points and the UCLA 3.8. One patient showed a non-progressive radiolucency around the hip implant. The osteointegration of all allogenic grafts happened on time. Up to the last follow-up no revision surgery of the hip implants and the associated femoral bone graft was observed. Allogenic bone grafts present a method for biological stabilization in situations of large femoral cortical bone defects in revision hip arthroplasty.

Total femur prosthesis in oncological and not oncological series. Survival and failures

Total femur prosthesis (TFP) can be used in both oncological and prosthetic revision surgery. A retrospective analysis of 32 patients receiving a TFP at a single Center between 2002 and 2018 was performed. The average follow-up was 60 months. Revision implant free survival (RIFS) of the implants was 87% at 5 and 10 years and 72% at 15 years. Overall implant survival (OIS) of the prosthesis was 90% at 5, 10 and 15 years. Complications observed: two soft tissue failures, two infection failure and one tumor progression failure.

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.

Total femur replacement in non-oncologic indications: Functional and radiological outcomes from a French survey with a mean 6 years' follow-up

INTRODUCTION

There are few published studies on total femur replacement (TFR) because its indications are rare. Other than malignant diseases, the indications extend to revisions and interprosthetic femur fractures; however, the outcomes of these indications have not been well defined. The aim of this retrospective survey was to analyze the complication rate and functional outcomes of these newer indications.

HYPOTHESIS

The morbidity and outcomes after TFR are comparable to those reported in the literature for non-cancer indications.

MATERIAL AND METHODS

Between 1997 and 2016, 29 TFR procedures were done at 6 French teaching hospitals in 15 women and 14 men, average age 68±14 years [32-85]. The primary indication was degenerative joint disease in the hip and/or knee in 16 cases, mechanical failure of the implant used after tumor resection in 11 cases and femur fracture in 2 cases. The mean number of surgical procedures before TFR was 3.6 (maximum 5) at the hip and 4.5 (maximum 10) at the knee. Six different models were implanted consisting of a rotational hinge knee (except in one case); 20 patients received a dual mobility system and 9 a standard hip replacement bearing. The femoral shaft was partially conserved 21/29 times and the trochanter 25/29 times.

RESULTS

Five patients suffered a general complication and 12 suffered a local complication (including 4 hematomas and 2 hip dislocations). Eight patients (28.6%) suffered a surgical site infection, although three had a prior infection. Among the 12 patients with a history of infection or progressive infection before the TFR, 9 healed and 3 had the infection continue. At a minimum follow-up of 2 years and mean of 6 years, 23 TFR implants were still in place and not infected; the other 6 had been removed or were infected, including one patient who underwent disarticulation. The median survival of the non-infected TFR was 15 years. At 10 years, 70% of TFR implants were still in place and non-infected. Walking was possible with or without a cane in 15 patients (51.7%), with two canes or a walker in 12 patients (41.3%) and impossible in 2 patients. Active knee flexion averaged 79.4°±30.3° [0°-120°]; 17 patients (62.9%) had 90° or more flexion; two patients (7.4%) had no flexion. The extension deficit averaged 3.7°±7°[-20° to 10°] and 20 patients had no flexion deformity. The leg length difference averaged 1.3cm±2.3 [0-10]; 19 patients (67.8%) had no difference in leg length.

DISCUSSION

Our starting hypothesis was confirmed for the complication rate and clinical outcomes. The benefits of dual mobility cups are emphasized. While the indications for TFR are rare, they will likely increase in the coming years.

LEVEL OF EVIDENCE

IV, Retrospective cohort study….

Mechanisms of failure and survival of total femoral endoprosthetic replacements

AIMS

The aim of this study was to evaluate the prosthesis characteristics and associated conditions that may modify the survival of total femoral endoprosthetic replacements (TFEPR).

PATIENTS AND METHODS

In all, 81 patients treated with TFEPR from 1976 to 2017 were retrospectively evaluated and failures were categorized according to the Henderson classification. There were 38 female patients (47%) and 43 male patients (53%) with a mean age at diagnosis of 43 years (12 to 86). The mean follow-up time was 10.3 years (0 to 31.7). A survival analysis was performed followed by univariate and multivariate Cox regression to identify independent implant survival factors.

RESULTS

The revision-free survival of the implant was 71% at five years and 63.3% at ten years. Three prostheses reached 15 years without revision. The mean Musculoskeletal Tumor Society score in the group was 26 (23 to 28). The mechanisms of failure were infection in 18%, structural failures in 6%, tumour progression in 5%, aseptic loosening in 2%, and soft-tissue failures in 1%. Prostheses used for primary reconstruction after oncological resections had lower infection rates than revision implants (8% vs 25%; p = 0.001). The rates of infection in silver-coated and non-silver-coated prosthesis were similar (17.4% vs 19.%; p = 0.869). The incidence of hip dislocation was 10%. Rotating hinge prosthesis had a lower failure rate than fixed hinge prosthesis (5.3% vs 11%). After Cox regression, the independent factors associated with failures were the history of previous operations (hazard ratio (HR) 3.7; p = 0.041), and the associated arthroplasty of the proximal tibia (HR 3.8; p = 0.034). At last follow-up, 11 patients (13%) required amputation.

CONCLUSION

TFEPR offers a reliable reconstruction option for massive bone loss of the femur, with a good survival when the prosthesis is used as a primary implant. The use of a rotating hinge at the knee and dual mobility bearing at the hip may be adequate to reduce the risk of mechanical and soft-tissue failures. Infection remains the main concern and there is insufficient evidence to support the routine use of silver-coated endoprosthesis. Cite this article: Bone Joint J 2019;101-B:522-528.

Distal femoral reconstruction following failed total knee arthroplasty is accompanied with risk for complication and reduced joint function

Background

Substantial bone loss following failed total knee arthroplasty (TKA) represents a major challenge in revision arthroplasty, that can require distal femoral reconstruction (DFR). In this study, we aimed to assess the clinical outcome and the complication frequencies of individuals who underwent DFR with modular megaprostheses. Additionally, we aimed to compare functional outcome measures after DFR in these sophisticated cases to an age-matched control group of total knee prostheses to quantify the potential loss of function.

Methods

A retrospective chart review of 30 consecutive patients after DFR from 1997 to 2017 with a mean age of 74.38 years (± 10.1) was performed. Complications were classified according to the Henderson classification. Knee Society Score (KSS) was calculated and range of motion (ROM) was assessed.

Results

Thirteen (43.3%) patients had at least one complication requiring revision surgery. Revision-free survival was 74.8% at one year, 62.5% at three and 40.9% at 10 years post-op. Soft-tissue failure complications were found in three (10.0%) patients, aseptic loosening in four (13.3%) patients, structural failure in one (3.3%) patient and infection in eight (26.6%) patients. Of those with infection, five (16.6%) experienced ongoing prosthetic joint infection and three (10.0%) developed new infection after distal femur reconstruction. Patients with DFR achieved 69.3% of KSS pain score, 23.1% KSS function score and 76.2% of ROM compared to patients with primary TKA.

Conclusions

DFR after failed TKA represents a treatment procedure with high risk for complication in this particular group. Despite the prospect of rapid postoperative mobilization, reduced functionality, range of motion and mobilization have to be considered when choosing this treatment option.