Non-neoplastic indications and outcomes of the proximal and distal femur megaprosthesis: a critical review

Prolonged prophylactic antibiotic use following megaprosthesis surgery may reduce periprosthetic infection

Introduction

Megaprostheses provide a reconstructive option for patients with bone loss after musculoskeletal tumor resection. However, the postoperative surgical site infection (SSI) risk is significant. This study aims to evaluate outcomes of extended postoperative antibiotic regimens in patients after megaprosthesis surgery and gather insight into strategies to minimize SSI.

Methods

This retrospective cohort study evaluated patients who underwent megaprosthesis surgery by a single surgeon at a single center from 2014 to 2022. Patient demographics, comorbidities, cancer treatment details, and antibiotic regimens were collected. Excluded were patients with less than 1 year of follow-up, active infection at time of surgery, non-healing wounds unrelated to SSI, and preoperative antibiotic regimens secondary to being immunocompromised. Measures of interest included the development of SSI within 1 year of surgery and development of antibiotic-related complications.

Results

Included were 49 patients, with a mean age of 61.2 ± 2.0 years and a mean BMI of 29.4 ± 7.0. The mean drain duration was 6.5 days (standard deviation [SD], 6.9 days), and the mean intravenous antibiotic administration duration was 6.4 days (SD, 6.9 days). The median time to drain removal was five days, and the median time for intravenous antibiotic cessation was five days. The mean total antibiotic administration duration (intravenous and oral) was 25.4 days (SD, 13.4 days). Only 1 patient in the included cohort (2.04 %) developed an SSI requiring operative intervention. No other patient within the cohort experienced an antibiotic-related complication.

Discussion

This study suggests that the site's current protocol for managing post-megaprosthesis antibiotic prophylaxis based on drain duration and incision healing status has resulted in a low rate of SSI and antibiotic-related complications. Further research is needed to validate these findings and gain additional insights into managing antibiotic prophylaxis after megaprosthesis surgery.

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.

Patient-Reported Outcomes and Range of Motion Following Knee Arthroplasty Using a Megaprosthesis in Non-Oncological Patients: A Systematic Review

BACKGROUND

This review aimed to determine outcomes following megaprostheses in non-oncological indications for knee arthroplasty, including range of motion (ROM) and patient-reported outcome measures of function, pain, and quality of life (QoL).

METHODS

A search of MEDLINE, Embase, and Cochrane via Ovid and PubMed between January 2003 and June 2023 was conducted. Studies reporting function, pain, ROM, and/or QoL in non-oncological patients who have received knee megaprostheses were included. Studies with sample sizes (n ≤ 5) were excluded. The risk of bias was assessed using the Downs and Black Quality Checklist for Health Care Intervention Studies. Central tendency measures (mean or median) were reported at each time point, and dispersion measures were extracted and reported whenever data were available.

RESULTS

A total of 30 studies (involving 1,294 megaprostheses) were included. Of which, 14 of 30 studies reviewed patients who had mixed indications; 14 of 30 looked at fracture only; 1 of 30 focused on distal femur nonunion; and 1 of 30 focused on patients who had periprosthetic infections. The average patient follow-up time was 40.1 months (range, 1.0 to 93.5). Most studies presented a high risk of bias (27 of 30), while a few (3 of 30) presented a low risk of bias. Improvements from preoperative baseline were observed in 85.7% of studies that reported baseline and follow-up data for function (12 of 14), 100.0% pain (4 of 4), 90.9% ROM (10 of 11), and 66.6% QoL (2 of 3).

CONCLUSIONS

Favorable function, pain, ROM, and QoL outcomes following knee megaprostheses in non-oncological patients were observed. Heterogeneity in outcome measures and follow-up periods prevented the pooling of data. Future comparative studies are warranted to enhance the body of evidence relating to knee megaprostheses in non-oncological patients.

Proximal Femur Megaprostheses in Orthopedic Oncology: Evaluation of a Standardized Post-operative Rehabilitation Protocol

Background

Reconstructions of the proximal femur after massive resections represent one of the main challenges in orthopedic oncology. Among the possible treatments, megaprostheses represent one of the most used and reliable reconstructive approaches. Although literature about their outcomes has flourished through the last decades, a consensus rehabilitative treatment is still far from being established.

Materials and methods

We evaluated the functional results of all our oncologic cases treated between 2016 and 2022 that could follow our standardized post-operative rehabilitative approach, consisting in progressive hip mobilization and early weight-bearing.

Results

Twenty-two cases were included in our study. On average, their hospitalization lasted 15.1 days. The seated position was achieved on average within 3.7 days after surgery, the standing position reached 5.4 after surgery, while assisted deambulation was started 6.4 days after surgery. After a mean post-operative follow-up of 44.0 months, our patients' mean MSTS score was 23.2 (10-30). Our data suggested a statistically significant inverse linear correlation between post-operative functionality and patients' age, resection length, and the start of deambulation.

Conclusions

A correct rehabilitation, focused on early mobilization and progressive weight-bearing, is crucial to maximize patients' post-operative functional outcomes.

Megaprosthesis use in Paprosky III/IV femoral defects in non-oncological patients: analysis of survival, clinical, and functional outcomes after an average follow-up of five years

PURPOSE

To determine the survival and patient-reported outcomes in non-oncological patients treated with proximal femoral resection (PFR) using MEG for femoral reconstruction.

MATERIALS AND METHODS

This retrospective study included 16 patients. Demographic variables and complications developed were analyzed. Clinical-functional outcomes were measured using the modified Harris score (mHSS), numeric Pain Rating Scale (NPRS) and Musculoskeletal Tumor Society (MSTS) score. MEG survival was estimated using a Kaplan-Meier survival analysis.

RESULTS

Average follow-up was 5 years (range, 1-9). The 75% of patients were overweight and women with an average age of 74.2 ± 5.9-years (BMI of 28.5 ± 4.2 kg/m2). The main cause of MEG was periprosthetic infection (43.7%). The 50% of patients had post-surgical complications regarding with MEG, being the most frequent seromas and MEG dislocation. Implant survival was 93.4% and 80.9% at 3 and 7 years of follow-up, respectively. The functional results at the end of the follow-up with respect to the pre-surgical state improved from 9.5 ± 2.6 to 3 ± 0.9 mean NPRS and 26.5 ± 6.8 to 69.5 ± 13.5 mean mHHS, p < 0.001, respectively. The mean MSTS score was 68.1% that these results were considered excellent.

CONCLUSIONS

The MEG for reconstruct III-IV femoral defects is a good therapeutic option that offers an acceptable clinical-functional result. Short-term and medium-term survival was greater than 80%. The most frequent complications are seromas and MEG dislocation. The use of constrained liner and abductor system reconstruction is essential to prevent the dislocation.

Distal Femur Megaprostheses in Orthopedic Oncology: Evaluation of a Standardized Post-Operative Rehabilitation Protocol

BACKGROUND AND OBJECTIVES

Megaprostheses are the most used reconstructive approach for patients who have undergone massive resection of their distal femurs due to bone tumors. Although the literature about their outcomes has flourished in recent decades, to date, a consensus on rehabilitative treatment is yet to be established. In this study, we report on our experience with our latest standardized rehabilitation program, evaluating our results in a mid-to-long-term scenario.

MATERIALS AND METHODS

We evaluated the functional results of all our oncologic patients treated between 2016 and 2022 who could follow our standardized post-operative rehabilitative approach, consisting of progressive knee mobilization and early weight-bearing.

RESULTS

Sixteen cases were included in our study. The average duration of the patients' hospitalization was 12.2 days. A standing position was reached on average 4.1 days after surgery, while assisted walking was started 4.5 days after surgery. After a mean post-operative follow-up of 46.7 months, our patients' mean MSTS score was 23.2 (10-30). Our data suggest that the sooner patients could achieve a standing position (R = -0.609; p = 0.012) and start walking (R = -0.623; p = 0.010), the better their final functional outcomes regarding their MSTS scores.

CONCLUSIONS

Rehabilitation should be considered a pivotal factor in decreeing the success of distal femur megaprosthetic implants in long-surviving oncologic patients. Correct rehabilitation, focused on early mobilization and progressive weight-bearing, is crucial to maximizing the post-operative functional outcomes of these patients.

Techniques for abductor reattachment in proximal femoral replacement for non-oncological reconstructions: a narrative review

Background and Objective

Proximal femoral replacement due to revision hip arthroplasty or catastrophic proximal femur fracture fixation failures with considerable proximal femur bone loss can lead to a substantial loss of function of the soft tissue around the hip and the abductor muscles in particular. Surgical techniques of gluteus medius repair and/or abductor mechanism reattachment/reconstruction are widely debated in the literature, but it is quite rarely dealt with in the context of megaprosthesis and femoral reconstruction, particularly in non-oncologic patients. The aim of this study is to present a narrative review of the literature on techniques for abductor reattachment in proximal femoral replacement for non-oncological reconstructions.

Methods

MEDLINE, Embase, and Cochrane databases were searched by two researchers independently from inception until February 1st, 2023 (923 for MEDLINE and 963 for Embase; Cochrane is a composite of multiple databases and thus does not report a standard inception date). Articles examining proximal femoral reconstruction with megaprosthesis or allograft prosthesis were included. Studies concerning cadaver and oncologic patients were excluded. If the researchers failed to find an agreement on whether to include a study, the senior researcher would make a final decision in such cases. Data were extracted and stored, and qualitative synthesis was performed.

Key Content and Findings

A total of 1,157 articles from MEDLINE, 11,187 articles from Embase, and 0 articles from Cochrane were identified. Of 12,344 articles, the structured screening process revealed 10 eligible trials. Four different types of abductor musculature reconstruction/reinsertion were identified.

Conclusions

Multiple and complex revision hip arthroplasties as well as multiple surgical procedures for proximal femur fracture fixations failures may have a great impact on proximal femur bone stock condition and soft tissue preservation requiring the use of a proximal femur megaprosthesis. In such cases, the abductor mechanism reconstruction and/or reattachment is achievable with different techniques that can be resumed in four different groups: direct suture to the prosthesis, trochanteric sleeve osteotomy, muscle-to-muscle suture, and synthetic tube augmentation suture.

Diagnosis and management of METS-Stanmore Morse taper failure

We describe clinical semiology in 6 cases of METS-Stanmore distal femoral Morse taper impaction failure: from obvious forms with intraprosthetic dislocation to chronic forms with less obvious symptoms: instability, piston sensation, rotational disorder in gait. The diagnostic procedure in chronic forms is described, notably with dynamic examination under fluoroscopy. Reduction and re-impaction by external maneuver can be attempted; in case of failure or of any suspicion of taper disassembly, the 2 modular implant components have to be replaced. Finally, we provide a review of the literature on this rare but serious complication. LEVEL OF EVIDENCE: IV.

The Megaendoprosthesis in Revision Arthroplasty - a Cost-revenue Analysis in the aG-DRG System

Megaendoprosthesis offer a viable treatment in complex revision arthroplasty cases with good functional outcome. In the context of a neoplastic indication, the diagnosis-related group (DRG) I95A is usually assigned with a relative weight of 4.906 (2021). In contrast, in revision arthroplasty, the appropriate DRG is assigned, depending on the joint replacement. The additional costs compared to the invoiced DRG are to be compensated by agreeing on hospital-specific individual fees. These complex revision arthroplasties set high technical and operative demands and are mainly performed in specialised departments. We conducted a cost-benefit analysis of the use of the megaendoprosthesis in revision cases in a specialised orthopaedic clinic, as a single centre study. The question we sought to answer was: Is cost recovery possible in the modified German DRG system (aG-DRG)?A retrospective single centre analysis of treatment costs was performed. From 2018 to 2020, 113 patients treated with a megaendoprosthesis reconstruction in a referral centre due to extensive bone loss after aseptic or septic revision of a hip or knee prosthesis were included in the study. Relevant case-related cost drivers of the aG-DRG matrix (including staff and material costs of the operating theatre area and the ward) were taken into account. The actual costs were determined according to the specifications of the calculation manual published by the German institute for the remuneration system in hospitals (InEK). For each case, the contribution margin was calculated by relating the hospital's internal costs to the corresponding cost pool of the aG-DRG matrix.According to the DRG system 2021, 17 different DRGs were used for billing - in 70% based on a patient clinical complexity level (PCCL) ≥ 4. Compared with the InEK calculation, there is a deficit of -2,901 € per case in the examined parameters. The costs of physicians show a shortfall in both the operating theatre and on the ward. Implant costs, which were supposed to be compensated by hospital-specific additional charges, show a hospital-specific shortage of -2,181 €. When analysing the risk factors for cost recovery, only these showed a significant difference.Implantation of the megaendoprosthesis in revision arthroplasty is often the last option to preserve limb function. At present, despite a high degree of specialisation and process optimisation, this treatment cannot be provided cost-effectively even in tertiary care. The politically desired specialised department structure requires sufficient reimbursement for complex cases. The economic outcome of each treatment case is often unpredictable, however the surgeon is confronted with these cases and is expected to treat them. The high standard deviation indicates large differences in the cost/revenue situation of each individual case. Our results show for the first time a realistic cost analysis for megaprosthesis in revision arthroplasty and underline the importance of an adequate hospital-specific charge, individually agreed by the funding units. The calculation should include not only the implant costs, but also the increased staff costs (increased, complex planning effort, quality management, surgery time, etc.).

Should megaprosthesis implants be a viable option in elderly patients after distal femur and periprosthetic distal femur fractures?-a retrospective cohort study

Background

Distal femur fractures (DFF) and periprosthetic distal femur fractures (PDFF) in elderly patients are challenging to manage, often requiring the use of distal femur replacement (DFR) implants to manage severe bone loss and comminution. The study's main purpose was to analyze outcomes and complications of DFR implant after DFF or PDFF at our institution to understand the feasibility and reliability of this treatment considering a review of the current literature.

Methods

Fourteen consecutive patients undergoing total knee replacement with megaprosthesis implant from January 1st, 2017 to January 1st, 2021, at our institution were retrospectively analyzed. Inclusion criteria were age ≥65 years and DFF or PDFF after primary total knee arthroplasties (TKA) implantation. Patient-reported outcome measures (PROMs) such as Knee Society Score (KSS) and Oxford Knee Score (OKS) were analyzed, as well as radiographic pre- and post-operative imaging. Complications were recorded from the early postoperative period to the last follow-up.

Results

Nine patients were diagnosed with PDFF and five with DFF. At a mean follow-up of 30.7 months (range, 12 to 69 months), the mean KSS knee score was 79.5±11.2; the mean KSS function score was 69.0±17.9. The mean OKS was 31.6±8.9. The mean age at intervention was 82.1±7.6 years. Two delayed wound closures and one chronic prosthetic joint infection (PJI) were observed. No death was observed at the last follow-up.

Conclusions

Megaprosthesis implants could be a suitable option in elderly, arthritic patients diagnosed with complicated DFFs and PDFFs, allowing joint function preservation and a rapid return to daily activities. DFR remains an intervention burdened by devastating complications that must be considered in the treatment choice.

The major proximal femoral defects: megaprosthesis in non oncological patients - A case series

We identified 39 patients (23 female and 16 male) underwent hip revisions through mega-prosthesis. The most common causes were periprosthetic fractures, periprosthetic osteolysis and consequences of infected arthroplasty. The average follow-up was 5 years (2.1 to 6.5), and average age was 69 years (47 to 78). At the final follow-up all the implants resulted functional and osteointegrated. The Merle D'Aubignè and Postel hip rating scale was used for the evaluation, better results were observed in periprosthetic fractures. Postoperative complications occurred in eight patients. Thus, megaprosthesis were a reasonable surgical option in the management of major femoral defects.

Bone loss in aseptic revision total knee arthroplasty: management and outcomes

Background

Although several techniques and implants have been developed to address bone loss in revision total knee arthroplasty (rTKA), management of these defects remains challenging. This review article discusses the indications and management options of bone loss following total knee arthroplasty based on preoperative workup and intraoperative findings.

Main text

Various imaging modalities are available that can be augmented with intraoperative examination to provide a clear classification of a bony defect. For this reason, the Anderson Orthopaedic Research Institute (AORI) classification is frequently used to guide treatment. The AORI provides a reliable system by which surgeons can classify lesions based on their size and involvement of surrounding structures. AORI type I defects are managed with cement with or without screws as well as impaction bone grafting. For AORI type IIA lesions, wedge or block augmentation is available. For large defects encompassing AORI type IIB and type III defects, bulk allografts, cones, sleeves, and megaprostheses can be used in conjunction with intramedullary stems.

Conclusions

Treatment of bone loss in rTKA continues to evolve as different techniques and approaches have been validated through short- and mid-term follow-up. Extensive preoperative planning with imaging, accurate intraoperative evaluation of the bone loss, and comprehensive understanding of all the implant options available for the bone loss are paramount to success.

Revision arthroplasty with megaprosthesis after Girdlestone procedure for periprosthetic joint infection as an option in massive acetabular and femoral bone defects

Background and aim:

To evaluate the clinical outcomes of patients treated with Girdlestone procedure (GP) or excision arthroplasty (EA) for periprosthetic infection with massive bone defects and undergoing revision arthroplasty.

Methods:

All patients treated with EA or GP for hip periprosthetic infection between 2014 and 2017 and sustaining revision arthroplasty (RA) were included in the study. Patients with less than 24 months of follow-up or less than 12 months between GP or EA and RA were excluded. Any sign of implant mobilization or periprosthetic fracture was assessed through X-ray. Patients were evaluated with D’aubigne-Postel hip score before RA and at the last follow-up. Mann-Whitney U test was used to assess differences between pre-RA surgery and last follow-up. P value was set as <0.05.

Results:

Twelve patients meet the inclusion criteria (mean follow-up 58+/-9.72 months). No radiographic sign of implant mobilization or periprosthetic fracture was reported. A significant difference was found for each parameter of the D’Aubigne-Postel score (p < 0.0001); none of the patients reached more than fair results in the absolute hip score. The difference between pre and post-operative global status showed a fair improvement. A significant difference was found for leg length discrepancy between pre and post RA (p<0.0001).

Conclusions:

Conversion from EA or GP to RA in patients suffering from massive acetabular and femur defects is challenging; conversion procedure is able to reduce patients’ disability and to improve walking ability. (www.actabiomedica.it)

Megaprostheses for the revision of infected hip arthroplasties with severe bone loss

Background

Periprosthetic hip infections with severe proximal femoral bone loss may require the use of limb salvage techniques, but no agreement exists in literature regarding the most effective treatment. Aim of this study is to analyze the infection eradication rate and implant survival at medium-term follow-up in patients treated with megaprostheses for periprosthetic hip infections with severe bone loss.

Methods

Twenty-one consecutive patients were retrospectively reviewed at a mean 64-month follow-up (24–120). Functional and pain scores, microbiological, radiological and intraoperative findings were registered. Kaplan Meier survival analysis and log rank test were used for infection free survival and implant survival analyses.

Results

The infection eradication rate was 90.5%, with an infection free survival of 95.2% at 2 years (95%CI 70.7–99.3) and 89.6%(95%CI 64.3–97.3) at 5 years. Only two patients required major implant revisions for aseptic implant loosening. The most frequent complication was dislocation (38.1%). The major revision-free survival of implants was 95.2% (95%CI 70.7–99.3) at 2 years and 89.6% (95%CI 64.3–97.3) at 5 years. The overall implant survival was 83.35% (CI95% 50.7–93.94) at 2 and 5 years. Subgroup analyses (cemented versus cementless MPs, coated versus uncoated MPs) revealed no significant differences at log rank test, but its reliability was limited by the small number of patients included.

Conclusions

Proximal femoral arthroplasty is useful to treat periprosthetic hip infections with severe bone loss, providing good functional results with high infection eradication rates and rare major revisions at medium-term follow-up. No conclusions can be drawn on the role of cement and coatings.

Rotating Hinge Distal Femur Replacement: A Turn for the Worse

Preoperatively periprosthetic joint infection with a postoperative complication of 180° rotation of the press-fit femoral component is a rare event, and knowledge of this possible complication is important for arthroplasty surgeons.

Distal femoral fractures: A comparison between single lateral plate fixation and a combined femoral nail and plate fixation

OBJECTIVES

Distal femoral fractures occur in patients with osteoporotic bone and also as a consequence of high energy trauma. The recognised treatment options include closed or open reduction of the fracture and fixation using a locking plate or a femoral nail. Both these fixation modalities have some drawbacks. There is a risk of metalwork failure with single lateral locking plates and limited distal fixation with intramedullary nails. Since January 2018, we started using augmented fixation of distal femoral fractures using a combination of a retrograde femoral nail and a lateral locking plate. This study compares the outcomes of single lateral femoral plating (SLP) and combined nail-plate fixation (NPF).

METHODS

This is a single centre retrospective case control study including all patients who sustained distal femoral fractures (OTA 33-A2, 33-A3, 33-C, 33-V3B and 33-V3D) over the study period. Outcomes for SLP were compared to NPF. The principal outcome measure was fracture union. Secondary outcome measures were reoperation rate, mortality and post-operative weight bearing status.

RESULTS

67 distal femoral fractures were included in the study. 19 patients had peri‑prosthetic fractures. 40 were treated by SLP, 27 were managed with NPF.  23 (58%) patients in the SLP group were given instructions to non-weight bear or Toe touch weight bear for 6 weeks post-surgery compared to 1 (4%) in the NPF group (p = 0.000004). 7 (18%) patients treated with SLP had metalwork failure due to a non-union compared to none treated with NPF (p = 0.04). 11 fractures in the SLP group failed to unite compared to no non-unions in the NPF group (p = 0.01). These differences were magnified when assessing older (>50 years old) patients.

CONCLUSIONS

Augmented fixation of distal femoral fractures using a nail plate fixation provided significantly higher union and enabled early weightbearing compared to single plate fixation. We recommend nail plate fixation for the treatment of distal femoral fractures, particularly in osteoporotic fractures.

One-Stage Hip Revision Arthroplasty Using Megaprosthesis in Severe Bone Loss of The Proximal Femur Due to Radiological Diffuse Osteomyelitis

Managing substantial proximal and/or distal femoral bone defects is one of the biggest challenges in chronic hip periprosthetic joint infection. Most authors use two-stage arthroplasty with a temporary antibiotic-loaded cement spacer for the management of these patients. In this study, we show our experience with one-stage exchange arthroplasty in managing severe bone defects due to radiological-extensive proximal femoral osteomyelitis. Two patients were included in the study. They showed radiological-extensive proximal femoral osteomyelitis, and they were treated with one-stage exchange arthroplasty using megaprosthesis. Diffuse osteomyelitis was confirmed in both cases; in one case, the histology was compatible with osteomyelitis, and the other case had a positive culture identified in a bone sample. At a minimum of a four-year follow-up, the patients did not reveal any clinical, radiological or laboratory signs of infection. In conclusion, one-stage exchange arthroplasty and megaprosthesis is an option for the treatment of chronic hip periprosthetic joint infection associated with radiological-diffuse proximal femoral osteomyelitis.

A prospective study on outcome of patient-specific cones in revision knee arthroplasty

BACKGROUND

Cones are known to be good substitutes for metaphyseal and diaphyseal bone loss during revision total knee arthroplasty (RTKA). Often the off-the-shelf cones do not fit to the individual patient's anatomy. New 3D-printing additive technologies allow to develop patient-specific cones. The aim of this prospective study was to describe their outcome.

METHODS

From 2017 until 2020, 35 patient-specific titanium cones (15 femoral and 20 tibial) were implanted during 31 RTKAs (45% varus-valgus constrained implants and 55% rotating hinges). Clinical outcome was evaluated using KSS, WOMAC and FJS-12 scoring systems at 12 and 24 months. No patients were lost for follow-up.

RESULTS

In all cases, there were no technical difficulties in adapting the cones to both the host bone and the revision implant. By the time of performing data analysis (January 2021), none of the 31 patients needed revision surgery for any reason. At 12 months of follow-up, the mean values of scores for knee function improved significantly from baseline (p < 0.01): KSS-103.00 (min 100-max 111, SD 5.35), WOMAC-16.5 (min 9-max 24, SD 6.45), FJS-12-61.60 (min 52-max 76, SD 9.20). At 24 months, the trend towards improvement of functional results continued but did not reached statistical significance comparing to 12 months: KSS was 105.92 (min 95-max 155, SD 16.18), WOMAC-14.07 (min 0-max 42, SD 12.42), FJS-12-83.78 (min 65-max 97, SD 09.64). Radiographic signs of osteointegration were detected within the first 6 month after surgery in all cases. Loosening of femoral or tibial components as well as peri-prosthetic infection was not observed in any of the patients during the follow-up.

CONCLUSION

The original additive technology for designing and producing patient-specific metaphyseal and diaphyseal cones with different porosity zones for extensive femoral and tibial bone defects in RTKA is precise and clinically effective solution, at least in the short term. It could be a valid alternative to "off-the-shelf" cones or sleeves as well as structural allografts and even mega-prosthesis, but a longer follow-up period is required to assess its medium- and long-term reliability.

Survivorship and clinical outcomes of proximal femoral replacement in non-neoplastic primary and revision total hip arthroplasty: a systematic review

BACKGROUND

Several studies have evaluated the survivorship and clinical outcomes of proximal femoral replacement (PFR) in complex primary and revision total hip arthroplasty with severe proximal femoral bone loss; however, there remains no consensus on the overall performance of this implant. We therefore performed a systematic review of the literature in order to examine survivorship and complication rates of PFR usage.

METHODS

A systematic review of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A comprehensive search of PubMed, MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews was conducted for English articles using various combinations of keywords.

RESULTS

In all, 18 articles met the inclusion criteria. A total of 578 PFR were implanted. The all-cause reoperation-free survivorship was 76.6%. The overall complication rate was 27.2%. Dislocation was the most common complication observed and the most frequent reason for reoperation with an incidence of 12.8 and 7.6%, respectively. Infection after PFR had an incidence of 7.6% and a reoperation rate of 6.4%. The reoperation rate for aseptic loosening of the implant was 5.9%. Overall, patients had improved outcomes as documented by postoperative hip scores.

CONCLUSION

PFR usage have a relatively high complication rate, however, it remains an efficacious treatment option in elderly patients with osteoporotic bone affected by severe proximal femoral bone loss. Modular designs have shown reduced dislocations rate and higher survivorship free from dislocation. However, PFR should only be used as salvage procedure when no other reconstruction options are available.

The risk for complications and reoperations with the use of mega prostheses in bone reconstructions

Background

Despite a relatively high risk for complications and reoperations, mega prostheses are considered a useful method for reconstruction of bone defects after tumour resections. The total number of reoperations has not previously been described, and little is known about the complication rate of mega prostheses used for other indications than primary bone tumours.

Questions/purposes

The current retrospective observational study aimed to describe the patient population treated with mega prostheses at Sahlgrenska University Hospital, Sweden, during 14 consecutive years, reports the complications leading to reoperation and the number and type of reoperations for different kinds of complications, and reports on implant survival.

Methods

All patients treated with a mega prosthesis, regardless of surgical indication and anatomical location, at Sahlgrenska University Hospital during the period 2006–2019 were identified. The medical records for all patients were reviewed. Data regarding age, sex, diagnosis, site of disease, bone resection length, chemotherapeutical treatment and postoperative complications including infections and oncological outcome, were collected and evaluated.

Results

One hundred and fourteen patients treated with 116 mega prostheses were included in the study. The predominant indication for primary surgery with a mega prosthesis was sarcoma of either bone or soft tissue (53.5% of the patients). In total 51 prostheses (44%) did not require any reoperation after the primary surgery. The most common reason for reoperation was infection (22%) followed by soft tissue failure (13%). The risk for prosthetic infection was significantly higher in the group of patients operated due to sarcoma compared with all other indications for surgery regardless of surgical site (p = 0.004).

Conclusion

The study reveals a total reoperation rate of 56% after reconstructive surgery using mega prostheses. Despite the high reoperation rates, at the end of the study period, 83% of the patients had still a functioning prosthesis. Therefore, the use of mega prostheses can be considered a reliable method for reconstruction of large bone defects in selected patients.

Level of Evidence

Level IV, therapeutic study.

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.

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.

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.