Long-term results of the Global Modular Replacement System tumor prosthesis for reconstruction after limb-sparing bone resections in orthopedic oncologic conditions: Results from a national cohort

Validity of the Musculoskeletal Tumor Society Score for lower extremity in patients with bone sarcoma or giant cell tumour of bone undergoing bone resection and reconstruction surgery in hip and knee

BACKGROUND

The Musculoskeletal Tumor Society Score (MSTS) is widely used to evaluate functioning following surgery for bone and soft-tissue sarcoma. However, concerns have been raised about its content validity due to the lack of patient involvement during item development. Additionally, literature reports inconsistent results regarding data quality and structural validity. This study aimed to evaluate content, structural and construct validity of the Danish version of the MSTS for lower extremity (MSTS-LE).

METHODS

The study included patients from three complete cohorts (n = 87) with bone sarcoma or giant cell tumour of bone who underwent bone resection and reconstruction surgery in hip and knee. Content validity was evaluated by linking MSTS items to frameworks of functioning, core outcome sets and semi-structured interviews. Data quality, internal consistency and factor analysis were used to assess the underlying structure of the MSTS. Construct validity was based on predefined hypotheses of correlation between the MSTS and concurrent measurements.

RESULTS

Content validity analysis revealed concerns regarding the MSTS. The MSTS did not sufficiently cover patient-important functions, the item Emotional acceptance could not be linked to the framework of functioning, the items Pain and Emotional acceptance pertained to domains beyond functioning and items' response options did not match items. A two-factor solution emerged, with the items Pain and Emotional acceptance loading highly on a second factor distinct from functioning. Internal consistency and construct validity showed values below accepted levels.

CONCLUSION

The Danish MSTS-LE demonstrated inadequate content validity, internal consistency, and construct validity. In addition, our analyses did not support unidimensionality of the MSTS. Consequently, the MSTS-LE is not a simple reflection of the construct of functioning and the interpretation of a sum score is problematic. Clinicians and researcher should exercise caution when relying solely on MSTS scores for assessing lower extremity function. Alternative outcome measurements of functioning should be considered for the evaluation of postoperative function in this patient group.

Bifunctional bone substitute materials for bone defect treatment after bone tumor resection

Aggressive benign, malignant and metastatic bone tumors can greatly decrease the quality of patients' lives and even lead to substantial mortality. Several clinical therapeutic strategies have been developed to treat bone tumors, including preoperative chemotherapy, surgical resection of the tumor tissue, and subsequent systemic chemo- or radiotherapy. However, those strategies are associated with inevitable drawbacks, such as severe side effects, substantial local tumor recurrence, and difficult-to-treat bone defects after tumor resection. To overcome these shortcomings and achieve satisfactory clinical outcomes, advanced bifunctional biomaterials which simultaneously promote bone regeneration and combat bone tumor growth are increasingly advocated. These bifunctional bone substitute materials fill bone defects following bone tumor resection and subsequently exert local anticancer effects. Here we describe various types of the most prevalent bone tumors and provide an overview of common treatment options. Subsequently, we review current progress regarding the development of bifunctional bone substitute materials combining osteogenic and anticancer efficacy. To this end, we categorize these biomaterials based on their anticancer mechanism deriving from i) intrinsic biomaterial properties, ii) local drug release of anticancer agents, and iii) oxidative stress-inducing and iv) hyperthermia-inducing biomaterials. Consequently, this review offers researchers, surgeons and oncologists an up-to-date overview of our current knowledge on bone tumors, their treatment options, and design of advanced bifunctional biomaterials with strong potential for clinical application in oncological orthopedics.

Application and Development of Megaprostheses in Limb Salvage for Bone Tumors Around the Knee Joint

In recent decades, limb-salvage surgery has replaced amputation as the first choice for the treatment of bone tumors around knee. After tumor resection, there are a variety of reconstruction methods for us to choose, including autograft or allograft, inactivation and reimplantation, artificial prosthesis replacement, and allograft-prosthesis compound reconstruction. Compared with other reconstruction methods, artificial prosthesis reconstruction has some advantages: relatively simple, early weight bearing, fewer early complications, and good function in the early and mid-term follow-up. After decades of continuous improvements, the design of tumor prosthesis has reached a relatively mature stage, and the failure rate of prosthesis has also been declining year by year. However, artificial prostheses also have multiple complications such as infection, aseptic loosening, prosthetic breakage, and patients sometimes face the risk of revision or amputation. Therefore, clinicians need to deeply understand the characteristics of related complications and the principles of treatment.

[Treatment of giant cell tumor of bone around knee joint with three-dimensional printing personalized prosthesis]

OBJECTIVE

To investigate the short-term effectiveness of three-dimensional (3D) printing personalized prosthesis in the treatment of giant cell tumor of bone around knee joint.

METHODS

A clinical data of 9 patients with giant cell tumor of bone around knee joints and met the inclusive criteria between May 2014 and August 2017 was retrospectively analysed. There were 4 males and 5 females, with an average age of 35.8 years (range, 24-50 years). The lesion located at the distal femur in 4 cases and at the proximal tibia in 5 cases. The disease duration was 5-25 months (mean, 12.9 months). According to Campanacci grading, there were 2 patients of grade Ⅰ and 7 of grade Ⅱ. The 3D printing personalized prosthesis was designed based on the CT scanning and 3D reconstruction prepared before operation. All patients were treated with the tumor resection and 3D printing personalized prosthesis reconstruction. The radiological examination was taken to observe the tumor recurrence and the Musculoskeletal Tumor Society 1993 (MSTS93) score was used to evaluate the knee function.

RESULTS

All operations were successful and all incisions healed by first intention without early complications. All patients were followed up 24-40 months (mean, 31.2 months). At last follow-up, no complication such as pain, pathological fracture, prosthesis loosening, or tumor recurrence occurred. The MSTS93 score was 20-29 (mean, 24.7). The knee function was rated as excellent in 6 cases and good in 3 cases, with the excellent and good rate of 100%.

CONCLUSION

For giant cell tumor of bone around knee joint, 3D printing personalized prosthesis has the advantages of bio-fusion with host bone, mechanical stability, good joint function, and ideal short-term effectiveness. But the middle- and long-term effectiveness still need to be further observed.