Individualized reconstruction for severe periprosthetic fractures around the tumor prosthesis of knee under assistance of 3D printing technology: A case report

Revision surgery for periprosthetic fracture of distal femur after endoprosthetic replacement of knee joint following resection of osteosarcoma

Purpose

Periprosthetic fracture (PPF) is one of the severe complications in patients with osteosarcoma and carries the risk of limb loss. This study describes the characteristics, treatment strategies, and outcomes of this complication.

Methods

Patients were consecutively included who were treated at our institution between 2016 and 2020 with a PPF of distal femur. The treatment strategies included two types: 1) open reduction and internal fixation with plates and screws and 2) replacement with long-stem endoprosthesis and reinforcement with wire rope if necessary.

Results

A total of 11 patients (mean age 12.2 years (9-14)) were included, and the mean follow-up period was 36.5 (21-54) months. Most fractures were caused by direct or indirect trauma (n = 8), and others (n = 3) underwent PPF without obvious cause. The first type of treatment was performed on four patients, and the second type was performed on seven patients. The mean Musculoskeletal Tumor Society (MSTS) score was 20 (17-23). All patients recovered from the complication, and limb preservation could be achieved.

Conclusion

PPF is a big challenge for musculoskeletal oncologists, particularly in younger patients. Additionally, PPF poses a challenge for orthopedic surgeons, as limb preservation should be an important goal. Hence, internal fixation with plates and endoprosthetic replacement are optional treatment strategies based on fracture type and patient needs.

Current Concepts in the Resection of Bone Tumors Using a Patient-Specific Three-Dimensional Printed Cutting Guide

Orthopedic oncology has begun to use three-dimensional-printing technology, which is expected to improve the accuracy of osteotomies, ensure a safe margin, and facilitate precise surgery. However, several difficulties should be considered. Cadaver and clinical studies have reported more accurate osteotomies for bone-tumor resection using patient-specific cutting guides, especially in challenging areas such as the sacrum and pelvis, compared to manual osteotomies. Patient-specific cutting guides can help surgeons achieve resection with negative margins and reduce blood loss and operating time. Furthermore, this patient-specific cutting guide could be combined with more precise reconstruction using patient-specific implants or massive bone allografts. This review provides an overview of the basic technologies used in the production of patient-specific cutting guides and discusses their current status, advantages, and limitations. Moreover, we summarize cadaveric and clinical studies on the use of these guides in orthopedic oncology.

Use of three-dimensional-printed custom-made prosthesis to treat unicondylar femoral defect secondary to pathological fracture caused by giant cell tumor

Objective

To evaluate the short-term effectiveness of using a three-dimensional (3D)-printed custom-made prosthesis to repair unicondylar femoral defects.

Methods

We retrospectively reviewed 26 patients with a primary pathological fracture of the distal femur caused by a giant cell tumor. All patients had unicondylar defects involving the articular surface. Twelve patients were treated with a 3D-printed custom-made prosthesis to repair the unicondylar defect (3D-printed group). The other 14 patients were treated with total knee replacement (TKR group). The operation time, blood loss, Musculoskeletal Tumor Society score, range of motion, local recurrence, and complications were statistically compared.

Results

The operation time was significantly shorter and the blood loss was significantly less in the 3D-printed group than in the TKR group. The Musculoskeletal Tumor Society scores were significantly higher in the 3D-printed group than in the TKR group from 3 to 24 months postoperatively. The range of motion was significantly better in the 3D-printed group than in the TKR group at 6 and 9 months postoperatively.

Conclusions

3D-printed custom-made prostheses provide better short-term functional results than does TKR.

Clinical study of 3D printed personalized prosthesis in the treatment of bone defect after pelvic tumor resection

Background

/Objective: In recent years, prostheses have been widely used for limb reconstruction after pelvic tumour resection. However, prostheses are associated with problems leading to tumour recurrence, poor implant matching, defects after tumour resection, and easy implant looseness or failure. To achieve a precise preoperative design, complete tumour resection, and better anatomical structure matching and prosthesis stability, this study used three-dimensionally (3D)-printed osteotomy guides and personalised prostheses for reconstruction after pelvic tumour resection. This study aimed to explore the early clinical efficacy of 3D printed personalised prostheses for the reconstruction of bone defects after pelvic tumour resection.

Methods

A total of 20 patients (12 males, 8 females) with pelvic tumours surgically treated at our hospital between October 2014 and October 2019 were selected. There were 10 cases each of giant cell bone tumours and osteochondrosarcomas. According to Enneking zoning, there were 11 and 9 cases with tumours located in zones I and II, respectively. All cases were equally divided into conventional and 3D printing groups. For repair and reconstruction, a nail rod system or a steel plate was used in the conventional group while individualised 3D-printed prostheses were used in the 3D printing group. The surgical incision, duration of surgery, intraoperative blood loss, and the negative rate of resection margins in postoperative tumour specimens were examined. The follow-up focused on tumour recurrence, complications, and the Musculoskeletal Tumor Society (MSTS) score.

Results

All cases were followed-up for 6-24 months. The average incision length, duration of surgery, amount of intraoperative blood loss, and MSTS score of the 3D printing group were 10.0 ± 3.1 cm, 115.2 ± 25.3 min, 213.2 ± 104.6 mL, 23.8 ± 1.3, respectively, and those of the conventional group were 19.8 ± 8.4 cm, 156.8 ± 61.4 min, 361.4 ± 164.2 mL, and 18.3 ± 1.4, respectively. Histological tumour specimen examination showed nine and three cases with negative resection margins in the 3D printing group and the conventional group, respectively. The abovementioned indicators were significantly different between both groups (P < 0.05).

Conclusion

Applying 3D printed surgical guides and personalised prostheses for pelvic tumour resection, repair, and reconstruction, as well as preoperative planning and design, enables more accurate tumour resections and better prosthesis-patient matchings, possibly reducing surgical trauma, shortening the duration of surgery, and promoting the functional recovery of patients postoperatively.

The Translation Potential of this Article

Contrary to existing studies on 3D printed personalised prostheses, this study reports the clinical efficacy of the aforementioned technology in treating bone defects in a series of patients who underwent pelvic tumour resection. Moreover, it presents a comprehensive comparison of this technology with conventional procedures, thus strengthening its importance in treatment regimens for reconstructing bone defects.

An Efficient Method for Aneurysm Volume Quantification Applicable in Any Shape and Modalities

Objective

Aneurysm volume quantification (AVQ) using the equation of ellipsoid volume is widely used although it is inaccurate. Furthermore, AVQ with 3-dimensional (3D) rendered data has limitations in general use. A novel universal method for AVQ is introduced for any diagnostic modality and application to any shape of aneurysms.

Methods

Relevant AVQ studies published from January 1997 to June 2019 were identified to determine common methods of AVQ. The basic idea is to eliminate the normal artery volume from 3D model with the aneurysm. After Digital Imaging and Communications in Medicine (DICOM) data is converted and exported to stereolithography (STL) file format, the 3D STL model is modified to remove the aneurysm and the volume difference between the 3D model with/without the aneurysm is defined as the aneurysm volume. Fifty randomly selected aneurysms from DICOM database were used to validate the different AVQ methods.

Results

We reviewed and categorized AVQ methods in 121 studies. Approximately 60% used the ellipsoid method, while 24% used the 3D model. For 50 randomly selected aneurysms, volumes were measured using 3D Slicer, RadiAnt, and ellipsoid method. Using 3D Slicer as the reference, the ratios of mean difference to mean volume obtained by RadiAnt and ellipsoid method were -1.21±7.46% and 4.04±30.54%, respectively. The deviations between RadiAnt and 3D Slicer were small despite of aneurysm shapes, but those of ellipsoid method and 3D Slicer were large.

Conclusion

In spite of inaccuracy, ellipsoid method is still mostly used. We propose a novel universal method for AVQ that is valid, low cost, and easy to use.

Personalized three-dimensional printed polyether-ether-ketone prosthesis for reconstruction after subtotal removal of chronic clavicle osteomyelitis: A case report

RATIONALE

Three-dimensional (3D) printing has attracted wide attention for its potential and abilities in the assistance of surgical planning and the development of personalized prostheses. We herewith report a unique case of chronic clavicle osteomyelitis treated with a two-stage subtotal clavicle reconstruction using a 3D printed polyether-ether-ketone (PEEK) prosthesis.

PATIENT CONCERNS

A 23-year-old Chinese female presented to our clinic complaining about a progressive pain of her right clavicle for about 1 year.

DIAGNOSES

Chronic clavicle osteomyelitis confirmed by percutaneous biopsy and lesion biopsy.

INTERVENTIONS

This patient accepted a long-term conservative treatment, which did not gain satisfactory outcomes. Thus, a subtotal removal and two-stage reconstruction of the right clavicle with a 3D-printed polyether-ether-ketone prosthesis stabilized by screw fixation system was performed.

OUTCOMES

At 2-year follow-up, complete pain relief and satisfactory functional recovery of her right shoulder were observed.

LESSONS

Personalized 3D printed prosthesis is an effective and feasible method for reconstruction of complex bone defects.

Periprosthetic femoral fractures around tumor endoprostheses treated with limited revision surgery combined with allograft: A case report

RATIONALE

Old periprosthetic femoral fractures (OPFFs) around a tumor prosthesis of the knee present formidable problems for orthopedic oncologists; large bone defects and inappropriate biomechanics of the revision implant design can impair successful reconstruction. Limited literature is available on the reconstruction of OPFFs using revision combined with massive allograft following resection of a bone tumor around the knee joint. In this study, we present the first reported case in the English literature of a limited revision followed by several segmental allografts for the reconstruction of the knee joint.

PATIENT CONCERNS

This case involved a 45-year-old female who was treated for a malignant fibrous histiocytoma (MFH) of the knee joint with surgical excision of the lesion and replacement of the defect using endoprosthetic reconstruction when she was 25 years old. Her surgical history was remarkable for a left tumoral knee prosthesis implanted 20 years ago. Nine years before revision, the patient had fall damage; however, she was able to walk independently and with moderate pain. In the 9-year period, prosthesis malfunction caused progressive left lower extremity shortening and a persistent swelling pain in the left thigh.

DIAGNOSES

According to her clinical history, imaging results and physical examination, we confirmed the diagnosis of OPFFs potentially due to aseptic loosening and trauma injury.

INTERVENTIONS

In this study, we present the first case of OPFFs around a tumor endoprosthesis that was successfully treated using limited revision combined with a massive allograft.

OUTCOMES

At 80 months after revision surgery, the patient had made a sufficient recovery from her symptoms. The bone union was complete without tumor recurrence or implant failure.

LESSONS

We propose that if prosthesis fracture is detected, revision surgery should be attempted as early as possible, and for patients with OPFFs, the use of limited revision combined with massive allografts may be useful for safely and adequately reconstructing OPFFs around the knee joint. However, patients should be followed-up closely after surgical treatment because of the high risk of revision.

Correlation Between Conditional Approval and Customized Bone Implant Devices

This report aims to summarize key concerns regarding customized devices and conditional approval during the premarket evaluation of bone implants, and to explore the correlation between them. Based on the experience of approval of the first domestic custom-designed bone implant, we consider the process of gaining conditional approval for urgently-needed medical devices and medical devices for rare diseases, as well as the guidance available for clinical investigation. We also streamlined the scientifically administrative concept of this unique device, from the design and development of premarket technical evaluation to continuous post-market study. The present study found that those two aspects have certain connections, but they are not directly correlated to each other. In contrast to the USA, Canada, Australia and the EU, where regulations and guidelines have been established for the use of customized devices, in this regard, China is still it its infancy. Thus, there is considerable potential for China to develop and perfect the policies relating to customized devices and to develop relevant strategies to ensure their efficacy with the aid of conditional approval. Appropriate scientific conditional approval for mass production of individualized anatomy-matching bone implants could become a valuable approach for precision medicine.