Efficacy and safety of a 3D-printed arthrodesis prosthesis for reconstruction after resection of the proximal humerus: preliminary outcomes with a minimum 2-year follow-up

The Role of 3D Custom Implants in Upper Extremity Surgery

SUMMARY

As the technology of three-dimensional (3D) printing becomes more refined and accessible, multiple applications of its use are becoming more commonplace in upper extremity surgery. 3D-printed models have been beneficial in preoperative planning of complex cases of acute trauma or malunions, contributing to spatial understanding or even contouring of implants. Custom guides can also be created to assist intraoperatively with precise placement of osteotomies or arthroplasty implants. Finally, custom 3D implants have been described for cases of bone loss in the upper extremity. This can be for relatively small gaps after malunion correction or extensive defects, typically for trauma or tumor. Articular defects can also be addressed with this technology, although special considerations should be given to the implant design and longevity in these situations. Because of the relatively recent nature of 3D implants, long-term data are lacking. However, they show great promise in an expanding range of challenging clinical indications.

Computer-aided Design and 3D-printed Personalized Stem-plate Composite for Precision Revision of the Proximal Humerus Endoprosthetic Replacement: A Technique Note

BACKGROUND

Aseptic loosening is considered to be a rather uncommon complication in proximal humerus endoprosthetic replacement (PHER). However, patients with aseptic loosening often suffer severe bone loss, which poses a great challenge in following revision. Under this situation, a standard stemmed endoprosthesis is unavailable for revision limb salvage. Computer-aided design and 3D-printed personalized implants are an emerging solution for reconstructing complex bone defects.

CASE PRESENTATION

Here, we present a 67-year-old male who underwent PHER after tumor resection and developed aseptic loosening with severe periprosthetic osteolysis around the stem. Computer-aided design and 3D-printed personalized stem-plate composite was used for the precision revision of this patient. During the follow-up, encouraging results were observed, with good endoprosthetic stability and satisfactory limb function.

CONCLUSION

Computer-aid design and 3D-printed personalized stem-plate composite used in the present case could help to achieve good endoprosthetic stability and satisfactory limb function. This 3D-printed personalized stem-plate composite seems to be an effective method for the precise revision of PHER in patients with severe periprosthetic osteolysis. In addition, it also provides a novel method for similar revision surgery of other joints or primary endoprosthetic replacement with severe bone defects.

An overview of 3D printed metal implants in orthopedic applications: Present and future perspectives

With the ability to produce components with complex and precise structures, additive manufacturing or 3D printing techniques are now widely applied in both industry and consumer markets. The emergence of tissue engineering has facilitated the application of 3D printing in the field of biomedical implants. 3D printed implants with proper structural design can not only eliminate the stress shielding effect but also improve in vivo biocompatibility and functionality. By combining medical images derived from technologies such as X-ray scanning, CT, MRI, or ultrasonic scanning, 3D printing can be used to create patient-specific implants with almost the same anatomical structures as the injured tissues. Numerous clinical trials have already been conducted with customized implants. However, the limited availability of raw materials for printing and a lack of guidance from related regulations or laws may impede the development of 3D printing in medical implants. This review provides information on the current state of 3D printing techniques in orthopedic implant applications. The current challenges and future perspectives are also included.

Customized three dimensional printed prosthesis as a novel intercalary reconstruction for resection of extremity bone tumours: a retrospective cohort study

AIMS

The 3D-printed prosthesis (3DP) is a novel treatment for massive bone defect reconstruction after tumor resection. This study was aiming to explore the clinical efficacy of customized 3DP for intercalary reconstruction by comparing the clinical outcomes after implanting customized 3DP or conventional allograft in limb salvage surgery.

METHODS

A total of 28 patients with extremity bone tumors who underwent customized 3DP or conventional allograft reconstruction between 2011 and 2018 at our institution were analyzed retrospectively. Among them, 14 cases received customized 3DP reconstruction (3DP group), and 14 cases received conventional allograft reconstruction (control group). Demographics, surgical outcomes, radiographical assessments, limb functions, and post-operative complications between these two groups were collected to evaluate clinical outcomes.

RESULTS

No significant difference was observed in the demographics, mean intra-operative blood loss, MOSI scores, and MSTS scores between the two groups. Patients in 3DP group had a shorter operative time (157.9 vs 199.6 min, p = 0.03) and lesser number of fluoroscopy (4.1 vs 8.1, p < 0.001) compared to control group. The mean time to osseointegration at bone-implant interfaces in 3DP group was significantly earlier than that in control group (6.1 vs 12.2 months, p < 0.001). Moreover, the 3DP group had a significantly lower post-operative complication rate than the control group (7% vs 50%, p = 0.03).

CONCLUSIONS

The customized 3DP might provide a promising strategy for intercalary reconstruction in limb salvage surgery with more precise reconstruction, higher surgical efficiency, and comparable satisfactory clinical outcomes.