A graphic guide to the percutaneous tripod acetabular reconstruction for metastatic cancer

Artificial intelligence assisted preoperative planning and 3D-printing guiding frame for percutaneous screw reconstruction in periacetabular metastatic cancer patients

Background

The percutaneous screw reconstruction technique, known as the "Tripod Technique," has demonstrated favorable clinical outcomes in the management of metastatic periacetabular lesions, as evidenced by our prior investigations and corroborated by independent studies. Nevertheless, there is a steep learning curve in handling this technique, with possible complications such as intraarticular screw placement.

Methods

Preoperative pelvic CT scans were acquired before surgery and utilized for the guiding frame design. A convolutional neural network model was trained with annotated data to identify the starting point and trajectory of each potential screw. A model boundary intersection detection technology was used to determine the optimal diameter and length of each screw. A non-rigid registration technology was matched with a prefabricated model of the body surface to design personalized anchoring skin pads. Finally, a polylactic acid-based guiding frame for intraoperative was custom-made with a 3D printer.

Results

12 patients underwent a guiding frame-assisted Tripod procedure for treatment of periacetabular metastatic lesions. An intraoperative CT scan was performed in all cases to confirm screw trajectories. Among 36 screws that were implanted, 26 screws were implanted as designed. The remaining ten screws drifted, but all remained within the intra-osseous conduit without any complications. The mean surgical time was 1.22 h with the guiding frame compared with 2.3 h without the guiding frame. Following the surgical procedure, a noteworthy enhancement in pain management, as evidenced by a reduction in scores on the visual analog scale (p < 0.01), and an improvement in functional status, as assessed through the Eastern Cooperative Oncology Group score (p < 0.01), were observed when compared to the patient's pre-operative condition.

Conclusion

This proof-of-concept investigation demonstrates that the amalgamation of AI-assisted surgical planning and additive manufacturing can improve surgical accuracy and shorten surgical duration. While access to this technology is currently constrained during its early stages of development, it is anticipated that these limitations will diminish as the potential of AI and additive manufacturing in facilitating complex orthopedic procedures becomes more evident, leading to a surge in interest and adoption of this approach.

Percutaneous Fixation with Internal Cemented Screws for Iliac Lytic Bone Metastases: Assessment of Pain and Quality of Life on Long Term Follow-up

PURPOSE

To assess effectiveness on pain, quality of life and late adverse events of percutaneous fixation with internal cemented screw (FICS) among patients with iliac lytic bone metastases with or without pathological fractures.

MATERIALS AND METHODS

This retrospective exploratory study analyzed FICS procedures on iliac osteolytic bone lesions with and without pathological fracture performed from July 2019 to January 2022 in one tertiary level university hospital. The procedure were performed under general anesthesia, and were CT and fluoroscopically guided. Numerical Pain Rate Score (NPRS), mean EuroQol visual analogue scale (EQ VAS), morphine consumption, walking ability, walking perimeter and presence of walking aids and the appearance of complications were evaluated.

RESULTS

Nineteen procedures among 18 patients were carried out with a mean follow up time of 243.3 ± 243.2 days. The mean of the maximum NPRS decreased from 8.4 ± 1.3 to 2.2 ± 3.1 at 1 month (p < 0.01) and remained between 1.3 and 4.1 during a follow-up consultation period of 3-24 months. The mean EQ VAS rose from 42.0 ± 12.5 to 57.3 ± 13.9 at 1 month (p < 0.01) follow-up and remained between 55.8 and 62.5 thereafter. No patient scores returned to pre-procedure levels during follow-up. Mean morphine use decreased from 111.1 ± 118.1 to 57.8 ± 70.3 mg/d at 1 month (p > 0.05) follow-up. No late adverse events were reported.

CONCLUSION

Percutaneous FICS is a safe procedure with fast and long-standing effect on pain, mobility and quality of life. It can be used as a complement to the known analgesic therapeutic arsenal for bone metastases.

Antegrade anterior column acetabulum fracture fixation with cannulated compression headless screws-A biomechanical study on standardized osteoporotic artificial bone

PURPOSE

Due to the increase in life expectancy and high-energy traumas, anterior column acetabular fractures (ACFs) are also increasing. While open reduction and internal fixation (ORIF) is still the standard surgical procedure, minimally invasive, percutaneous fixation of osteoporotic acetabulum fractures (AF) are growing in popularity. The aim of this biomechanical study was to evaluate the biomechanical competence following antegrade fixation with a standard screw versus a cannulated compression headless screw.

METHODS

Eight anatomical osteoporotic composite pelvises were given an anterior column fracture. Two groups of eight specimens each (n = 8) for fixation with either a 6.5 mm cannulated compression headless screw in group Anterior Acetabulum Canulated Compression Headless Screw (AACCH), or with a 6.5 mm partially threaded cannulated screw in group Anterior Acetabulum Standard Screw (AASS) where compared. Each specimen was biomechanically loaded cyclically at a rate of 2 Hz with monotonically increasing compressive load until failure. Motions were assessed by means of optical motion tracking.

RESULTS

Initial construct stiffness trended higher in group AACCH at 152.4 ± 23.1 N/mm compared to group AASS at 118.5 ± 34.3 N/mm, p = 0.051. Numbers of cycles and corresponding peak load at failure, were significantly higher in group AACCH at 6734 ± 1669 cycles and 873.4 ± 166.9 N versus group AASS at 4440 ± 2063 cycles and 644.0 ± 206.3 N, p = 0.041. Failure modes were breakout of the screws around the proximal entry point.

CONCLUSION

From a biomechanical perspective, group AACCH was associated with superior biomechanical competence compared to standard partially threaded cannulated screws and could therefore be considered as valid alternative for fixation of anterior acetabulum fractures.

Functional outcomes after open reconstruction or nonoperative management of 81 pathologic acetabular fractures from metastatic bone disease

Background

Pathologic acetabular fracture secondary to skeletal metastasis may result in debilitating pain, inability to ambulate, and impaired quality of life, which may mark the first period of dependent care in cancer patients. Acetabular reconstruction may involve morbid procedures with increased complication rates. This study aimed to evaluate the evolution of pain, performance status, and ambulation following nonoperative management or open reconstruction of pathologic acetabular fractures.

Methods

A retrospective cohort of 2630 adult patients with osseous metastatic disease treated at a high-volume cancer center between 2005 and 2021 was screened for pathologic fractures of the acetabulum. The study outcomes were pain, performance status, and the ability to ambulate. We identified 78 patients (median age, 60 years; 37 female patients [46%]) with 81 fractures. Of these, treatment consisted of open reconstruction (n = 34) or nonoperative management alone (n = 47). The mean follow-up in surviving patients was 3.4 years.

Results

Open reconstruction was performed more frequently for displaced fractures (P < 0.01), Harrington class III or IV acetabula (P < 0.01), and patients with a performance status ≥3 at hospitalization (P = 0.00). Open reconstruction was associated with clinically meaningful improvements in pain (adjusted odds ratio [aOR], 8.3; 95% CI, 1.4-50.6; P = 0.02) and performance status (aOR, 10.9; 95% CI, 1.7-71.0; P = 0.01) at discharge and a restoration of ambulation (aOR, 7.5; 95% CI, 1.9-29.8; P < 0.01) at final follow-up.

Conclusions

In patients with pathologic acetabular fracture due to osseous metastatic disease, functional improvements in pain, performance status, and ambulation were observed following open acetabular reconstruction in carefully selected patients, with no impact on survival, while noninferior improvements were observed in patients receiving nonoperative management when considering their larger clinical context.

Level of evidence

Level III, therapeutic study.

Surgical robot-assisted tripod percutaneous reconstruction technique combined with bone cement filling technique for the treatment of acetabular metastasis

Background: Acetabular metastasis is a type of metastatic bone cancer, and it mainly metastasizes from cancers such as lung cancer, breast cancer, and renal carcinoma. Acetabular metastasis often causes severe pain, pathological fractures, and hypercalcemia which may seriously affect the quality of life of acetabular metastasis patients. Due to the characteristics of acetabular metastasis, there is no most suitable treatment to address it. Therefore, our study aimed to investigate a novel treatment technique to relieve these symptoms. Methods: Our study explored a novel technique to reconstruct the stability of the acetabular structure. A surgical robot was used for accurate positioning and larger-bore cannulated screws were accurately inserted under the robot's guidance. Then, the lesion was curetted and bone cement was injected through a screw channel to further strengthen the structure and kill tumor cells. Results: A total of five acetabular metastasis patients received this novel treatment technique. The data relating to surgery were collected and analyzed. The results found that this novel technique can significantly reduce operation time, intraoperative bleeding, visual analogue score scores, Eastern Cooperative Oncology Group scores, and postoperative complications (e.g., infection, implant loosening, hip dislocation) after treatment. Follow-up time ranged from 3 months to 6 months, and the most recent follow-up results showed that all patients survived and no acetabular metastasis progressed in any of the patients after surgery. Conclusion: Surgical robot-assisted tripod percutaneous reconstruction combined with the bone cement filling technique may be a novel and suitable treatment in acetabular metastasis patients. Our study may provide new insights into the treatment of acetabular metastasis.

Percutaneous Screw Stabilization of Non-Periacetabular Pelvic Lesions Caused by Metastatic Cancer and Multiple Myeloma

BACKGROUND

The pelvis is one of the most common locations for metastatic bone disease. While many of the publications that describe surgical treatments focus on periacetabular lesions (Enneking zone II), there is a lack of investigation into lesions in the non-periacetabular areas (zones I, III, and IV). We recently described a minimally invasive percutaneous screw application for metastatic zone-II lesions with excellent results. In the present study, we aimed to extend this approach to the other pelvic areas.

METHODS

Twenty-two consecutive patients with painful non-periacetabular pelvic metastatic cancer were included based on retrospective chart review. There were 16 women and 6 men with an average age of 60 years (range, 36 to 81 years). The most common primary cancers were multiple myeloma (7 cases) and breast (5 cases). The most common locations were the sacrum and the ilium. A pathologic fracture was identified in 15 patients. Most of the lesions were treated with multiple large-diameter screws, except for the isolated zone-III lesions. All of the procedures were completed in a standard operating room without the need for special instruments. Radiation therapy was given to 19 patients; the average dose was 15 Gy. The studied outcomes were pain and functionality as assessed by a visual analog scale (VAS) score and the Eastern Cooperative Oncology Group score (ECOG), respectively.

RESULTS

There were no surgical complications and no need for blood transfusion. The average follow-up time was 7 months (range, 0.3 to 34.0 months). Two patients died within 4 weeks of surgery due to COVID-19 infection. There was significant improvement in the postoperative VAS pain score (p < 0.0001) and the ECOG score (p < 0.05) when compared with the preoperative scores. There was no implant failure or revision surgery. Local bone-healing was observed in 12 of 14 patients (86%) who survived for >3 months after surgery.

CONCLUSIONS

Percutaneous screw application is safe and effective in the treatment of metastatic non-periacetabular pelvic lesions. Given the simplicity of the technique and the instrumentation and the tolerance for concomitant treatments, this approach is worthy of broader consideration.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.