Preliminary proposal: a classification system for reconstruction with autologous femoral head after periacetabular tumors resection

Clinical efficacy of customized modular prosthesis in the treatment of femoral shaft metastases

Purpose

To examine clinical outcomes of a specialized modular prosthesis used to fill a bone deficiency following removal of femoral shaft metastases.

Methods

Eighteen patients with femoral shaft metastases who underwent en bloc resection and implantation of a personalized modular prosthesis between December 2014 and December 2019 were retrospectively analyzed. Pain, limb function, and quality of life were evaluated using the visual analog scale (VAS), Musculoskeletal Tumor Society (MSTS) scale, International Society of Limb Salvage (ISOLS) scoring system, Karnofsky Performance Status (KPS) scale, and Nottingham Health Profile (NHP) scale. The Kaplan–Meier technique was used to analyze patient survival.

Results

The operation duration was 90–150 min (mean, 115 min), and the osteotomy length was 9–16 cm (mean, 11.72 cm). The patients were followed for 12–62 months (mean, 25.28 months). The VAS and NHP ratings were lower at 3, 6, and 12 months after surgery than before surgery, while the MSTS, ISOLS, and KPS scores were higher after surgery than they had been before. These differences were statistically significant (P<0.05). The survival period was between 7 and 62 months (mean, 20.89 months), and the rates of survival at 1-year and 2-year were 72.22% and 27.78%, respectively. Except for two patients with aseptic prosthesis loosening during the follow-up period, there were no problems.

Conclusion

En bloc excision and implantation of a personalized modular prosthesis can reduce pain and improve the ability of patients with femoral shaft metastases to perform daily activities, thereby improving their quality of life.

Periacetabular Tumour Resection under Anterosuperior Iliac Spine Allows Better Alloprosthetic Reconstruction than Above: Bone Contact Matters

Background: Periacetabular resections are more affected by late complications than other pelvic resections. Reconstruction using bone allograft is considered a suitable solution. However, it is still not clear how the bone-allograft contact surface impacts on mechanical and functional outcome. Materials and methods: This paper presents the results of a retrospective analysis of 33 patients with resection of the entire acetabulum and reconstruction with an allograft-prosthetic composite for the period 1999 to 2010. Patients were divided in two groups, based on type of resection. In Group 1. patients had resections under anterosuperior iliac spine allowing the highest bone-allograft surface contact in reconstruction, while in Group 2 patients had resections over it. Results: Mechanical survival of the implant and Musculoskeletal Tumor Society functional score were calculated. Impact of age and artificial ligament were investigated as well. Patients in Group 1 had 38% mechanical failure rate of the implant while patients in Group 2 had 88%. Average functional score was higher in Group 1 compared with patients in Group 2. An artificial ligament was shown to have non-significant impact on survival of the reconstruction in Group 1, while significantly improving survival of reconstruction in Group 2. Conclusion: Bone-allograft contact matters: resection under anterosuperior iliac spine allows better mechanical survival and offers better reconstruction functional scores.

Clinical application of 3D-printed patient-specific guide plate combined with computer navigation in acetabular reconstruction following resection of periacetabular tumors

Background

The precise acetabular reconstruction has historically been a challenging procedure. 3D-printed patient-specific guide (PSG) and computer navigation (CN) technologies have been used to assist acetabular component positioning and pelvic reconstruction. This precise reconstruction approach may translate into clinical benefit.

Methods

The clinical data of 84 patients who underwent periacetabular malignant tumor resection and screw-rod-acetabular cage system reconstruction in our center from January 2013 to December 2020 were retrospectively analyzed. Patients were divided into four groups: free hand (FH) group, PSG group, CN group, and PSG combined with computer navigation (PSG + CN) group. The operation time, intraoperative blood loss, and number of fluoroscopy views were recorded. The oncological prognosis, radiographic measurements of the acetabulum, limb function data, and postoperative complications were compared among groups. And finally, we evaluated the risk factors for mechanical failure of the prosthesis.

Results

The postoperative X-ray and computed tomography (CT) scan revealed that the vertical offset discrepancy (VOD) between affected side and contralateral side was 8.4±1.9, 5.9±2.2, 4.1±1.3, and 2.4±1.2 mm in each groups; the horizontal offset discrepancy (HOD) was 9.0±1.9, 6.1±2.2, 3.2±1.3, and 2.1±1.2 mm, correspondingly; the abduction angle discrepancy (ABAD) was 8.6°±1.8°, 5.6°±2.0°, 2.5°±1.3°, and 1.8°±0.9°, respectively; the anteversion angle discrepancy (ANAD) was 5.9°±1.6°, 3.6°±1.7°, 2.9°±1.6°, and 1.9°±0.9°, correspondingly. Statistical results show that the PSG + CN group was superior to the FH group and the PSG group in terms of acetabular position and limb function (P<0.05). Body mass index (P=0.040) and resection type (P=0.042) were found to be the high-risk factors for mechanical failure of the prosthesis.

Conclusions

PSG + CN has potential advantages in improving the accuracy and safety of acetabular positioning and reconstruction.