Silver-coated endoprosthetic replacement of the proximal humerus in case of tumour-is there an increased risk of periprosthetic infection by using a trevira tube?

Poor clinical outcomes and high rates of dislocation after modular reverse shoulder arthroplasty for proximal humeral oncologic resection

PURPOSE

The shoulder is the most common site for upper extremity tumors. The aim of the study was to analyze the outcomes and the complications of modular reverse shoulder arthroplasty (RSA) after proximal humerus resection.

METHODS

We retrospectively included 15 consecutive patients who underwent a modular MUTARS™ RSA reconstruction after proximal humerus tumour resection between 2017 and 2020. The mean age was 52 years. Their clinical outcomes were assessed using the Constant-Murley score and the MSTS shoulder. Radiological outcomes were assessed based on the presence of loosening, osteolysis, and scapular notching. Complications such as dislocation, oncological recurrence, and infection were assessed. Mean follow-up time was 32.9 months (24 to 45).

RESULTS

The mean adjusted Constant score was 50.7% (min 22, max 81), and the mean MSTS score was 15.6 (min 4, max 26). We had no loosening, osteolysis, or scapular notching on the radiographs at last follow-up. We had a high complication rate of 53%: one infection, one oncological recurrence, and six dislocations (40%), of which five were re-operated.

CONCLUSION

In our experience, the MUTARS™ Implantcast™ modular RSA has poor functional results and a high rate of dislocation in the case of large proximal humerus resections below the distal insertion of the deltoid.

Prosthetic Joint Infection in Mega-Arthroplasty Following Shoulder, Hip and Knee Malignancy-A Prospective Follow-Up Study

INTRODUCTION

The risk of prosthetic joint infection (PJI) in mega-prosthesis for malignancy is increased compared with non-tumor cases. While several studies describe PJI in tumor-related arthroplasty, prospective studies comparing infection characteristics among different joints are limited. The present study analyzes mega-arthroplasty for hip, knee, and shoulder malignancy and compares the epidemiology, diagnosis, microbe spectrum, treatments, and outcomes between the different entities.

METHODS

The retrospective inclusion criteria were as follows: (1) mega-arthroplasty (2) in the hip, knee, or shoulder joint and a total femur arthroplasty (3) following a malignant bone tumor or metastasis (4) between 1996 and 2019. All included patients were prospectively followed and invited for a renewed hospital examination, and their PJI characteristics (if identified) were analyzed using both retrospective as well as newly gained prospective data. A PJI was defined according to the Infectious Disease Society of America (IDSA) and re-infection was defined according to the modified Delphi Consensus criteria.

RESULTS

In total, 83 cases of tumor mega-arthroplasty at a mean follow-up of 3.9 years could be included (32 knee, 30 hip, and 19 shoulder cases and 2 cases of total femur arthroplasty). In total, 14 PJIs were identified, with chondrosarcoma in 6 and osteosarcoma in 3 being the leading tumor entities. Knee arthroplasty demonstrated a significantly higher rate of PJI (p = 0.027) compared with hips (28.1% vs. 6.7%), while no significant difference could be found between the knee and shoulder (10.5%) (p = 0.134) or among shoulder and hip cases (p = 0.631). The average time of PJI following primary implantation was 141.4 months in knee patients, 64.6 in hip patients, and 8.2 months in shoulder patients. Age at the time of the primary PJI, as well as the time of the first PJI, did not show significant differences among the groups. Thirteen of the fourteen patients with PJI had a primary bone tumor. Statistical analysis showed a significant difference in the disadvantage of primary bone tumors (p = 0.11). While the overall cancer-related mortality in the knee PJI group (10%) was low, it was 50% in the hip and 100% in the shoulder group.

CONCLUSION

The risk of PJI in knee tumor arthroplasty is significantly increased compared with hips, while cancer-related mortality is significantly higher in hip PJI cases. At the same time, mega-prostheses appear to be associated with a higher risk of infection due to a primary bone tumor compared with metastases. The study confirms existing knowledge concerning PJI in tumor arthroplasty, while, being one of the few studies to compare three different joints concerning PJI characteristics.

Prosthetic Reconstruction of the Shoulder After Resection of Proximal Humerus Bone Tumor

Prosthetic reconstruction after wide resection of tumors of the proximal humerus presents a unique challenge. The shoulder is a complex articulation, and patients have high expectations for postoperative function. The goal of this study is to compare functional outcomes, oncologic outcomes, and complication rates for 2 reconstructive methods. Forty patients with proximal humeral tumors were reviewed retrospectively. Proximal humeral endoprosthesis (PHE) was used for 21 patients, and reverse shoulder arthroplasty (RSA) was used for 19 patients. Clinical results, oncologic outcomes, and complication rates were assessed. The functional outcomes of the patients were assessed with the Musculoskeletal Tumor Society scoring system (MSTS), the shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, and shoulder range of motion. The mean follow-up was 62±15 months. Shoulder dislocations occurred among 8 patients with PHE and 1 patient with RSA (P=.021). The other complication rates were similar for the 2 groups (P<.05). At the latest follow-up, the mean MSTS score was 68±10.3 for those with PHE and 76±7.7 for the patients with RSA (P=.72). However, the QuickDASH score was significantly better (P=.031) for those with RSA (mean, 19±6.3) compared with patients with PHE (mean, 30±4.8). Additionally, shoulder active abduction and forward flexion were significantly greater for the RSA group (P=.04 and P=.03, respectively). Five patients had local recurrence. Prosthetic reconstruction after oncologic re-section of the proximal humerus is associated with significant limitation of shoulder range of motion and a high rate of revision surgery. However, in this study, RSA was associated with fewer dislocations, improved Quick-DASH score, and greater abduction and forward flexion compared with PHE. [Orthopedics. 2022;45(6):e335-e341.].

Anatomical and reverse megaprosthesis in proximal humerus reconstructions after oncologic resections: a systematic review and meta-analysis

AIM

Anatomic (AN) Endoprosthesis (EPR) reconstructions of the shoulder after intra-articular proximal humerus (Malawer type 1) resections are characterized by early recovery and low complications rate. However, shoulder instability and limited mobility can occur. Reverse shoulder (RS) EPR has been introduced to improve functional outcome. The aim of this systematic review is to evaluate shoulder reconstructions with AN or RS EPR after Malawer type 1 resection, comparing complications and functional results.

METHODS

Through an electronic systematic search of PubMed, articles concerning EPR after shoulder Malawer type 1 resections were reviewed. Complications rate, range of motion (ROM) and functional outcome (Musculoskeletal Society Tumor Society-MSTS score) of AN and RS EPR were evaluated.

RESULTS

Sixteen studies were included. A similar complication rate was observed between AN and RS EPR rate (26.4% and 22.4%, respectively, p = 0.37). Soft tissue failure was the most frequent complication and cause of revision in both groups. Mean post-operative flexion and abduction ROM and MSTS scores were significantly higher in RS EPR, particularly among patients with preserved deltoid function (p = 0.013, p = 0.025 and p = 0.005, respectively).

CONCLUSIONS

Anatomic and reverse shoulder EPR represent safe and effective implants for shoulder reconstruction, with similar implant stability and complication rates. RS EPR significantly improves post-operative ROM and functional outcomes, especially when at least a partial function of the abductor apparatus is preserved.

Early functional and therapeutic effect of reversed tumour shoulder prosthesis reconstruction after proximal humerus tumour resection

Introduction

Reconstruction of proximal humeral tumours after resection is still controversial. And there are few articles describing oncology patients' postoperative function after reversed tumour shoulder prosthesis reconstruction. We investigated the functional results of patients who underwent reversed tumour shoulder prosthesis, including those who did not preserve the deltoid ending point.

Patients and methods

We retrospectively evaluated 16 patients with proximal humerus tumours who had undergone reversed tumour shoulder prosthesis. All patients underwent type Malawer I proximal humeral resection surgery and standard reverse tumour shoulder arthroplasty with a modular reverse shoulder prosthesis. We sutured the severed end of the deltoid to the brachialis muscle using the artificial patch for patients who had their deltoid ending point resected. Patients are rehabilitated and followed up according to our instructions.

Result

All patients were followed up for a mean of 27.4 months (13–59), and their mean age was 45.9 years (15–74). The mean length of the humeral resection was 11.6 cm (5–15). The mean shoulder mobility was 122° (82°–180°) in forward flexion; 39° (31°–45°) in posterior extension; 102° (65°–172°) in abduction; 43° (30°–60°) in external rotation; 83° (61°–90°) in internal rotation, and a mean MSTS score of 77.9% (63.3%–93.3%). The mean DASH score was 20.8 (2.5–35.8). The mean VAS score was 0.9. For patients who had their deltoid ending point resected, the mean length of the humeral resection was 14.0 cm; the mean shoulder mobility was 109° in forward flexion; 37.8° in posterior extension; 102.0° in abduction; 38.3° in external rotation; 86.3° in internal rotation, and the mean MSTS score was 78.8%; the mean DASH score was 21.6; the mean VAS score was 1.0.

Conclusion

Patients who underwent reverse tumour shoulder arthroplasty can achieve good early postoperative function, survival rate and low complication rate. In addition, patients who had their deltoid ending point removed also obtained good function after particular reconstruction.

Implant Survival, Clinical Outcome and Complications of Megaprosthetic Reconstructions Following Sarcoma Resection

Simple Summary

Malignant bone and soft tissue tumors are usually surgically removed with an envelope of healthy tissue as a barrier. If located in the long bones of the upper and lower extremity, this approach leads to a large bone defect commonly affecting a joint. One way to rebuild the bone defect and the neighboring joint is the use of a megaprosthesis that is anchored in the remaining bone comparable to a conventional joint replacement. In general this approach is popular as it provides early stability and allows the affected patient to begin rehabilitation early on. However, complications leading to long-term unplanned reoperation are common. This article provides an overview of current implant survival, types of complication and long-term outcomes of megaprostheses used following tumor resection.

Abstract

Megaprosthetic reconstruction of segmental bone defects following sarcoma resection is a frequently chosen surgical approach in orthopedic oncology. While the use of megaprostheses has gained popularity over the last decades and such implants are increasingly used for metastatic reconstructions and in non-tumor cases, there still is a high risk of long-term complications leading to revision surgery. This article investigates current implant survivorship, frequency and types of complications as well as functional outcomes of upper and lower limb megaprosthetic reconstructions.

A long-term experience with Mutars tumor megaprostheses: analysis of 187 cases

PURPOSE

Modular megaprostheses have widely replaced allografts, as a reconstructive option; however, failures of these devices remain high. Aim of this study was to analyze outcomes, survival of the implants, incidence and types of complications with Mutars modular endoprostheses at long term.

METHODS

Between 2000 and 2019, 187 Mutars prostheses were implanted in two dedicated centers: 72 upper limbs and 115 lower limbs reconstructions. Diagnoses included 107 primary malignant bone or soft tissue tumors, 65 metastases, 8 benign bone tumors and 7 non-oncologic cases. Silver-coated prostheses were used in 118/187 (63%) cases.

RESULTS

At last follow-up, 76.5% of patients had retained their implant. The overall failure rate was 23.5% at a mean of 1.7 years. There were 22 mechanical failures and 22 non-mechanical failures. The overall implant survival to all types of failure was 68% and 52% at 5 and 10 years, respectively. Infection was the most common mode of failure with an incidence of 6.9%. Implant survival to infection was better for silver-coated implants than for standard implants even if with no significant difference (p = 0.56). Functional results were satisfactory in 97% of patients.

CONCLUSIONS

The overall implant survival at long term was satisfactory with Mutars prostheses. The incidence of complications with Mutars prosthesis is in line with the incidence reported in the literature with other types of tumor prosthesis. The most frequent cause of failure was infection with a lower incidence in silver-coated prostheses; silver coating seems to prevent infection in distal femur and proximal tibia. The silver coating seems to be particularly useful in two-stage revisions with a lower incidence of secondary amputation. In higher risk patients, silver-coated prostheses are the preferable choice for the reduction of the reinfection rate. The functional results of Mutars prostheses were excellent or good in most of cases. The current paper is design to enhance the literature on megaprosthesis in tumor surgery, proven that this system is one of the most used all over the word and one of the best performing.

Management of Humeral and Glenoid Bone Defects in Reverse Shoulder Arthroplasty

Bone loss of either the glenoid or the humerus is a challenging problem in reverse total shoulder arthroplasty. When left unaddressed, it can lead to early failure of the implant and poor outcomes. Humeral bone loss can be addressed with the use of an endoprosthesis or allograft prosthetic implant. Glenoid bone loss can be treated with a variety of grafting options, such as augmented implants, patient-specific navigation, and implantation systems.

Periprosthetic Stress Shielding of the Humerus after Reconstruction with Modular Shoulder Megaprostheses in Patients with Sarcoma

(1) Background: Modular megaprosthetic reconstruction using a proximal humerus replacement has emerged as a commonly chosen approach after bone tumor resection. However, the long-term risk for revision surgery is relatively high. One factor that might be associated with mechanical failures is periprosthetic osteolysis around the stem, also known as stress shielding. The frequency, potential risk factors, and the effect on implant survival are unknown. (2) Methods: A retrospective single-center study of 65 patients with sarcoma who underwent resection of the proximal humerus and subsequent reconstruction with a modular endoprosthesis. Stress shielding was defined as the development of bone resorption around the prosthesis stem beginning at the bone/prosthesis interface. The extent of stress shielding was measured with a new method quantifying bone resorption in relation to the intramedullary stem length. All patients had a minimum follow-up of 12 months with conventional radiographs available and the median follow-up amounted to 36 months. (3) Results: Stress shielding was observed in 92% of patients (60/65). The median longitudinal extent of stress shielding amounted to 14% at last follow-up. Fifteen percent (10/65) showed bone resorption of greater than 50%. The median time to the first radiographic signs of stress shielding was 6 months (IQR 3–9). Patients who underwent chemotherapy (43/65) showed a greater extent of stress shielding compared to those without chemotherapy. Three percent (2/65) of patients were revised for aseptic loosening, and one patient had a periprosthetic fracture (1/65, 1.5%). All these cases had >20% extent of stress shielding (23–57%). (4) Conclusions: Stress shielding of the proximal humerus after shoulder reconstruction with modular megaprosthesis is common. It occurs within the first year of follow-up and might be self-limiting in many patients; however, about one third of patients shows progression beyond the first year. Still, mechanical complications were rare, but stress shielding might be clinically relevant in individual cases. The extent of stress shielding was increased in patients who underwent perioperative chemotherapy. Stress shielding can be quantified with an easy method using the stem length as a reference.

Megaprosthesis Versus Allograft Prosthesis Composite for the Management of Massive Skeletal Defects: A Meta-Analysis of Comparative Studies

PURPOSE OF REVIEW

Megaprosthesis and Allograft Prosthesis Composite (APC) are the established treatment modalities for massive skeletal defects. There are a handful of studies comparing the use of megaprosthesis and APC in the management of substantial bone loss and it has always been a topic of debate regarding the superiority of one modality over the other. Therefore, we aim to compare the functional outcome and implant survivorship of each modality including complications, revision rates, amputation rate and mortality.

RECENT FINDINGS

The Allograft Prosthesis Composite (APC) constitutes a skeletal allograft implanted with a revision type prosthesis in it. The biological environment provided by the allograft allows attachment of the muscles and tendons imparting better stability and function. However, the literature is not kind enough with APC due to associated risk of infection, disease transmission and nonunion at the graft-host junction. The megaprosthesis (MP) on the other hand is a nonbiologic modality with better survivorship but subservient functional outcome. Infection has been a major issue in both the modalities. Advancement in metallurgy using silver coated megaprosthesis also failed to provide strong evidence in preventing infection. The functional outcome is better with APC in both the upper and lower limbs. However, the survivorship is better with megaprosthesis, especially in the upper limb when revision rates were compared between the two modalities. Deep infection and mechanical complications were significantly higher in the APC group. There was no significant difference between the two groups in terms of amputation rate, mortality, and local recurrence.

LEVEL OF EVIDENCE (CEBM)

2a.

Techniques and outcomes of hip abductor reconstruction following tumor resection in adults

The function of the abductor mechanism (AM) of the hip can be disturbed, or even compromised, following tumor resection in the hip area. The consequences are instability (limping, dislocation), pain and altered walking ability. Several reconstruction techniques can be used for the same AM sacrifice. After defining the AM, this lecture will discuss the best technique for a given type of bone and muscle resection. These reconstruction techniques depend on exactly where the AM was sacrificed. For zone 1 resections of the ilium and/or iliac gluteal insertions, reconstruction is often optional. When muscle from the AM is resected, especially when the gluteal tendon is detached from its trochanteric insertion, isolated reconstruction can be done or reconstruction in combination with a tendon allograft or an allograft and/or tendon transfer from the surrounding area. This sacrifice, whether followed by reconstruction or not, in most cases leads to a good functional outcome, except when a complete musculotendinous unit or the superior gluteal nerve is sacrificed. Isolated resection of the greater trochanter is rare; however, this completely disrupts the continuity of the AM and justifies reconstruction, often using a bone-tendon allograft. Proximal femur resection is the most common scenario. The extent of the trochanteric resection and the gluteal tendon attachments drives the type of prosthesis used. The two most used techniques consist in an allograft sleeve over a long cemented femoral stem (allograft prosthesis composite - APC) or a modular proximal femoral endoprosthesis (megaprosthesis) with a specific AM fixation system (small plate or wire cerclage, resorbable or metal wire, synthetic reattachment tube). These two techniques yield nearly identical long-term functional outcomes with complications specific to each: osteolysis and fracture for APC, failure of tendon reattachment for megaprosthesis. Beyond these technical considerations, one must consider the poor availability of massive bone allografts. This is a highly relevant issue in France, and partially explains the shift to reconstruction with a megaprosthesis. Lastly, we will look at the different clinical and diagnostic tests used to evaluate the function of the AM in an oncology context and the outcomes of the various types of reconstruction.

Silver-coated megaprosthesis in prevention and treatment of peri-prosthetic infections: a systematic review and meta-analysis about efficacy and toxicity in primary and revision surgery

AIM

Prosthetic joint infection (PJI) is a common complication following orthopedic megaprosthetic implantations (EPR), estimated up to 50%. Silver coatings were introduced in order to reduce the incidence of PJI, by using the antibacterial activity of silver. Three different silver coatings are available: MUTARS^® (Implantcast), Agluna^® (Accentus Medical), PorAg^® (Waldemar Link). The aim of this review is to provide an overview on efficacy and safety of silver-coated EPR both in primary and revision surgery, comparing infection rate according to the type of implant.

METHODS

Through an electronic systematic search, we reviewed the articles concerning silver-coated EPRs. Infection rate, silver-related complications, local and blood concentrations of the silver were evaluated. Meta-analyses were performed to compare results from each study included.

RESULTS

Nineteen studies were included. The overall infection rate in patients with silver-coated implants was 17.6% (133/755). Overall infection rate in primary silver-coated EPR was been 9.2% (44/445), compared to 11.2% (57/507) of non-silver-coated implants. The overall infection rate after revisions was 13.7% (25/183) in patients with silver-coated EPR and 29.2% (47/161) when uncoated EPR were used, revealing a strength statistically significative utility of silver coatings in preventing infections in this group (p: 0.019). Generally, the use of MUTARS^® EPR had produced an almost constant decrease in the incidence of primary PJI but there are few data on the effectiveness in revisions. The results from the use of Agluna^® in both primary and revisions implants are inconstant. Conversely, PorAg^® had proven to be effective both in PJI prevention but, especially, when used in PJI revision settings. Local argyria was reported in 8 out of 357 patients (2.2%), while no systemic complications were described. Local and blood concentrations of silver were always reported very far to the threshold of toxicity, with the lowest concentration found using PorAg^®.

CONCLUSIONS

Silver-coated EPRs are safe and effective in reduction in PJI and re-infection rate, in particular when used in higher risk patients and after two-stage revisions to fight PJI.

Endoprosthetic Reconstruction of the Upper Extremity in Oncologic Surgery

In 1943, Austin Moore successfully reconstructed a proximal femur using a Vitallium endoprosthesis. This marked the first successful alternative to amputation in oncologic surgery. However, it was not until the introduction of high-resolution axial imaging and improved chemotherapeutics that the feasibility of limb salvage began to improve. Today, limb salvage surgery can be used to treat most oncologic conditions of the extremities, the most popular reconstruction option being endoprostheses. Megaprostheses use has expanded to nononcologic indications with severe bone loss, including infections, revision arthroplasty, and severe periarticular trauma and its sequelae. The proximal humerus and scapula are challenging for reconstruction, given the complex anatomy of the brachial plexus, the accompanying vascular structures, and the dynamic stabilizers of the relatively nonstable glenohumeral joint. The midhumerus is difficult because of the close location of the radial nerve, whereas the distal humerus is challenging because of the proximity of the brachial artery and its bifurcation, radial, ulnar, and median nerves, and lack of soft-tissue coverage. Despite these challenges, this review demonstrates that many series show excellent mid- to long-term results for pain relief and function restoration after megaprosthetic reconstruction of the scapula and humerus after bone resections for oncologic and nononcologic reasons.

Antimicrobial silver-coating for locking plates shows uneventful osteotomy healing and good biocompatibility results of an experimental study in rabbits

Infections after internal fixation of fractures remain a challenge. Silver is known for its antimicrobial activity, including activity against multi-resistant strains. The aim of the current study was to analyze the biocompatibility and potential influence on the osteotomy healing process of a silver-coating technology for locking plates compared to silver-free locking plates in an established rabbit model. The implants used in this study were 7-hole titanium locking plates, and plasma electrolytic oxidation (PEO) silver-coated equivalents. A total of 24 rabbits were used in this study (12 coated, 12 non-coated). An osteotomy of the midshaft of the humerus was created and the humerus stabilized with the 7-hole locking plates with a total of 6 screws. Radiographs were taken on day 0, week 2, 4, 6, 8, and 10 for continuous radiographical evaluation. All animals were euthanized after 10 weeks and further assessment was performed using X-rays, micro-CT, non-destructive four-point bending biomechanical testing and semi-quantitative histopathological evaluation. Furthermore, silver concentration was measured in the blood, kidney, liver, spleen, brain, feces and soft tissue around the plate. Radiographs showed normal undisturbed and completed healing of the osteotomy in all animals without any differences between the two groups over the entire observation period. Micro-CT analysis revealed overall tissue volume as well as tissue density to be comparable between the two groups. Mechanical testing showed comparable stiffness with an average stiffness relative to contralateral bones of 75.7 ± 16.1% in the silver-free control group compared to 69.7 ± 18.5% (p-value: 0.46). Semi-quantitative histopathological evaluation showed no remarkable difference in the analysis of the osteotomy gap healing or in the surrounding soft tissue area. There were detectable silver concentrations in the soft tissue around the plate after 10 weeks. Silver in the blood was only found in 3 animals within the first two weeks and all animals were free of silver afterwards. There were no detectable silver concentrations in the brain, liver, spleen, axillary lymph nodes and kidney. This study shows undisturbed osteotomy healing of the presented antimicrobial silver surface coating and a good biocompatibility in this rabbit model.

[Complication profile and revision concepts for megaprosthetic reconstruction following tumour resection at the hip]

BACKGROUND

Tumourous destruction of the periacetabular region and the proximal femur is a typical consequence of either primary malignant bone tumour manifestation or skeletal metastatic diseases. Pathological fractures of the proximal femur and periacetabular regions due to primary manifestation or metastatic disorders are frequent.

OBJECTIVES

Presentation of the most common complications of tumour endoprostheses at the hip and a description of management strategies, including therapeutic recommendations and concepts for complication avoidance.

MATERIALS AND METHODS

The current knowledge and our own experience of complication management with the use of megaprostheses around the hip are presented.

RESULTS

Compared to elective/primary total hip arthroplasty, megaprosthetic reconstructions following tumour resections have an increased rate of postoperative deep infections, dislocations, incidence of pathological and periprosthetic fractures and of deep vein thrombosis. The postoperative mortality and local tumour recurrence along with deep infections represent the most serious complications.

CONCLUSIONS

In comparison to primary arthroplasty, the risk of failure and complications following tumour-endoprosthetic replacement is increased. Precise surgical planning and careful selection and preoperative preparation of suitable patients should be performed in close interdisciplinary cooperation with final decision-making on an interdisciplinary tumour board. Wide resection and advanced reconstruction, as well as complicated palliative stabilization due to malignant bone tumour growth around the hip joint should be performed in musculoskeletal tumour centres with profound expertise in osteosynthetic and endoprosthetic reconstruction and consecutive complication management of the pelvis and the proximal femur.

What Is the Survival and Function of Modular Reverse Total Shoulder Prostheses in Patients Undergoing Tumor Resections in Whom an Innervated Deltoid Muscle Can Be Preserved?

BACKGROUND

After proximal humerus resection for bone tumors, restoring anatomy and shoulder function remains demanding because muscles and bone are removed to obtain tumor-free surgical margins. Current modes of reconstruction such as anatomic modular prostheses, osteoarticular allografts, or allograft-prosthetic composites and arthrodeses are associated with relatively poor shoulder function related to loss of the deltoid and rotator cuff muscles. Newer prosthetic designs like the reverse total shoulder arthroplasty (RTSA) are felt to be useful in other reconstructions where rotator cuff function is compromised, so it seemed logical that it might help in tumor reconstructions as well in patients where the deltoid muscle and its innervation can be preserved.

QUESTIONS/PURPOSES

In patients with a tumor of the proximal humerus that can be resected with preservation of the deltoid muscle, (1) What complications are associated with tumor resection and reconstruction with a modular RTSA? (2) What are the functional results of modular RTSA in these patients?

METHODS

From January 2011 to January 2018, we treated 52 patients for bone tumors of the proximal humerus. Of these, three patients were treated with forequarter amputation, 14 were treated with standard modular proximal humerus implants, seven were treated with allograft-prosthetic composites (RTSA-APC), and 28 were treated with a modular RTSA. Generally, we used anatomic modular prosthetic reconstruction if during the tumor resection none of the abductor mechanism could be spared. Conversely, we preferred reconstruction with RTSA if an innervated deltoid muscle could be spared, but the rotator cuff and capsule could not, using RTSA-APC or modular RTSA if humeral osteotomy was distal or proximal to deltoid insertion, respectively. In this study, we retrospectively analyzed only patients treated with modular RTSA after proximal humerus resection. We excluded three patients treated with modular RTSA as revision procedures after mechanical failure of previous biological reconstructions and three patients treated after December 2016 to obtain an expected minimum follow-up of 2 years. There were nine men and 13 women, with a mean (range) age of 55 years (18 to 71). Reconstruction was performed in all patients using silver-coated modular RTSA protheses. Patients were clinically checked according to oncologic protocol. Complications and function were evaluated at final follow-up by the treating surgeon (PR) and shoulder surgeon (AC). Complications were evaluated according to Henderson classification. Functional results were assessed with the Musculoskeletal Tumor Society score (range 0 points to 30 points), Constant-Murley score (range 0 to 100), and American Shoulder and Elbow Surgeons score (range 0 to 100). The statistical analysis was performed using Kaplan-Meier curves.

RESULTS

Complications occurred in five of 22 patients; there was a shoulder dislocation (Type I) in four patients and aseptic loosening (Type II) in one. Function in these patients on the outcomes scales we used was generally satisfactory; the mean Musculoskeletal Tumor Society score was 29, the mean Constant score was 61, and the mean American Shoulder and Elbow Surgeons score was 81.

CONCLUSIONS

Although this was a small series of patients with heterogeneous diagnoses and resection types, and we were not able to directly compare the results of this procedure with those of other available reconstructions, we found patients treated with RTSA achieved reasonable shoulder function after resection and reconstruction of a proximal humerus tumor. It may not be valuable in all tumor resections, but in patients in whom the deltoid can be partly spared, this procedure appears to reasonably restore short-term shoulder function. However, future larger studies with longer follow-up are needed to confirm these findings.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Advances in tumour endoprostheses: a systematic review

Tumour endoprostheses have facilitated limb-salvage procedures in primary bone and soft tissue sarcomas, and are increasingly being used in symptomatic metastases of the long bones.

The objective of the present review was to analyse articles published over the last three years on tumour endoprostheses and to summarize current knowledge on this topic. The NCBI PubMed webpage was used to identify original articles published between January 2015 and April 2018 in journals with an impact factor in the top 25.9% of the respective category (orthopaedics, multidisciplinary sciences).

The following search-terms were used: tumour endoprosthesis, advances tumour endoprosthesis, tumour megaprosthesis, prosthetic reconstruction AND tumour. We identified 347 original articles, of which 53 complied with the abovementioned criteria.

Articles were categorized into (1) tumour endoprostheses in the shoulder girdle, (2) tumour endoprostheses in the proximal femur, (3) tumour endoprostheses of the knee region, (4) tumour endoprostheses in the pelvis, (5) (expandable) prostheses in children and (6) long-term results of tumour endoprostheses.

The topics of interest covered by the selected studies largely matched with the main research questions stated at a consensus meeting, with survival outcome of orthopaedic implants being the most commonly raised research question.

As many studies reported on the risk of deep infections, research in the future should also focus on potential preventive methods in endoprosthetic tumour reconstruction.

Cite this article: EFORT Open Rev 2019;4:445-459. DOI: 10.1302/2058-5241.4.180081

[Endoprosthetic replacement of the proximal humerus in revision shoulder arthroplasty]

OBJECTIVE

Reconstruction of proximal humeral bone defects in the setting of shoulder revision arthroplasty by implantation of a modular humeral component.

INDICATIONS

Severe segmental humeral bone defects in revision total shoulder arthroplasty, after tumor resection, trauma, pathological fractures, post-infectious or after failed osteosynthesis.

CONTRAINDICATIONS

Acute or chronic local infections, large diaphyseal bone defects preventing adequate anchorage of the prosthesis, very short life expectancy (<3 months).

SURGICAL TECHNIQUE

Removal of the implant using an extended deltopectoral approach. Periarticular arthrolysis with preservation of neurovascular structures. Resection of the meta-diaphyseal bone and reconstruction of the humeral length with the help of different extension sleeves and a modular humeral component. Soft tissue management is crucial, especially with reverse shoulder arthroplasty.

POSTOPERATIVE MANAGEMENT

Three weeks postoperatively immobilization in a shoulder sling, active assisted movement therapy by gradual pain-adapted increase of movement, muscle coordination, and strength.

RESULTS

The results of 11 consecutive patients treated with a modular humeral component due to a failed shoulder arthroplasty between 2008 and 2016 were evaluated retrospectively. Mean length of reconstruction was 100 mm. Due to recurrent dislocations one patient required revision and conversion to a reverse component. No cases of aseptic loosening or periprosthetic infection were observed.

Megaprosthesis versus Allograft Prosthesis Composite for massive skeletal defects

Massive skeletal defects are encountered in the setting of tumors necessitating excision, failed total hip arthroplasty with periprosthetic bone loss, periprosthetic fracture, complex trauma, multiple failed osteosynthesis and infection. Reconstruction of the segmental defects poses a tremendous challenge to the orthopaedic surgeons. The goal of osseous reconstruction of these defects is to restore the bone length and function. Currently the most commonly employed methods for reconstruction are either a megaprosthesis or an Allograft Prosthesis Composite (APC). Megaprosthesis, initially created for the treatment in neoplastic pathologies are being used for the non-neoplastic pathologies as well. The longevity of these implants is an issue as majority of the patients receiving them are the survivors of oncologic issue or elderly population, both in which the life expectancy is limited. However, the early complications like instability, infection, prosthetic breakage and fixation failure have been extensively reported in several literatures. Moreover, the megaprostheses are non-biological options preventing secure fixation of the soft tissue around the implant. The Allograft Prosthesis Composites were introduced to overcome the complications of megaprosthesis. APC is made of a revision-type prosthesis cemented into the skeletal allograft to which the remaining soft tissue sleeve can be biologically fixed. APCs are preferred in young and low risk patients. Though the incidence of instability is relatively low with the composites as compared to the megaprosthesis, apart from infection, the newer complications pertaining to APCs are inevitable that includes non-union, allograft resorption, periprosthetic fracture and potential risk of disease transmission. The current review aims to give an overview on the treatment outcomes, complications and survival of both the megaprostheses and APCs at different anatomic sites in both the upper and lower limbs.