Comparison of tumor curettage and resection for treatment of giant cell tumor of the bone around the knee joint

The Role of Bone Grafting vs. Bone Cement in the Treatment of Giant Cell Tumor of Bone: A Systematic Review and Meta-Analysis on the Risk of Recurrence in 1,454 Patients

BACKGROUND

Giant cell tumor of bone (GCTB) presents a challenge in management due to its invasive nature and propensity for local recurrence. While either bone grafting (BG) or bone cement (BC) can be utilized to fill defects after intralesional curettage, the optimal treatment remains contested. The purpose of this study was to examine the impact of defect filling with BC compared with BG on recurrence rates in patients with GCTB following intralesional curettage.

METHODS

A random-effects model binary outcome meta-analysis was performed utilizing recurrence rate for the BC and BG groups to evaluate the risk ratio (p < 0.05 considered significant). There were 1,454 patients included.

RESULTS

Intralesional curettage with BG had a recurrence risk ratio of 1.68 (95% confidence interval [CI], 1.22-2.31, p = 0.001) when compared with BC. The overall rate of recurrence for GCTB after intralesional curettage with BC was 20.05% vs. 29.74% with BG (95% CI, 0.17-0.23 vs. 0.26-0.33, p < 0.001).

CONCLUSION

Intralesional curettage with BC for the treatment of GCTB demonstrated lower recurrence rates than intralesional curettage with BG. However, the rates of recurrence remain substantial for both groups, necessitating careful consideration of the benefits and potential pitfalls associated with BC vs. BG when considering salvage options after recurrences.

LEVEL OF EVIDENCE

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

Micro-CT, Mechanical, and Histological Examination of the Effect of Local Adjuvants on Porcine Cortical Bone Following Intralesional Curettage of Bone Tumors

BACKGROUND AND OBJECTIVES

Curettage is the removal of a tumor from the bone while preserving the surrounding healthy cortical bone, and is associated with higher rates of local recurrence. To lower these rates, curettage should be combined with local adjuvants, although their use is associated with damage to nearby healthy bone.

OBJECTIVE

The purpose of this analysis is to determine the effect of local adjuvants on cortical porcine bone by using micro-computed tomography (micro-CT) along with histological and mechanical examination.

METHODS

Local adjuvants were applied to porcine specimens under defined conditions. To assess changes in bone mineral density (BMD), a micro-CT scan was used. The pixel gray values of the volume of interest (VOI) were evaluated per specimen and converted to BMD values. The Vickers hardness test was employed to assess bone hardness (HV). The depth of necrosis was measured histologically using hematoxylin and eosin-stained tissue sections.

RESULTS

A noticeable change in BMD was observed on the argon beam coagulation (ABC) sample. Comparable hardness values were measured on samples following electrocautery and ABC, and lowering of bone hardness was obtained in the case of liquid nitrogen. Extensive induced depth of necrosis was registered in the specimen treated with liquid nitrogen.

CONCLUSION

This study determined the effect of local adjuvants on cortical bone by using micro-CT along with histological and mechanical examination. Phenolization and liquid nitrogen application caused a decrease in bone hardness. The bone density was affected in the range of single-digit percentage values. Liquid nitrogen induced extensive depth of necrosis with a wide variance of values.

Treatment of Recurrent Giant Cell Tumor of Bones: A Systematic Review

The giant cell tumor of bones (GCTB) is a benign bone tumor with high postoperative recurrence potential. No specific treatment protocol has been developed to date in case of tumor recurrence, and the kind of re-operative surgery depends upon the surgeon's preferences. The aim of this systematic review is to determine the second recurrence rate and the respective functional results of the available treatment options applied to recurrent GCTB. Medline/PubMed and Scopus were searched to identify articles published until March 2023. Twelve studies fulfilled the inclusion criteria, comprising 458 patients suffering from recurrent GCTB. The overall incidence of second recurrence was 20.5%, at a mean interval of 28.8 months after the first surgery, and it was more evident after intralesional curettage (IC) surgery than en-bloc resection (EBR) (p = 0.012). In the IC group of patients, the second recurrence rate was lower and the functional outcome was greater when polymethylmethacrylate cement (PMMAc) was used as an adjuvant instead of bone grafting (p < 0.001 for both parameters). Reconstruction of the created bone defect after EBR with a structural allograft provided a better outcome than prosthesis (p = 0.028). According to this systematic review, EBR (first choice) and IC with PMMAc (second choice) are the best treatment options for recurrent GCTB.

Establishment and characterization of the NCC-GCTB4-C1 cell line: a novel patient-derived cell line from giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare osteolytic intermediate bone tumor that harbors a pathogenic H3F3A gene mutation and exhibits characteristic histology. The standard curative treatment for GCTB is complete surgical resection, but it frequently results in local recurrence and, more rarely, metastasis. Therefore, effective multidisciplinary treatment is needed. Although patient-derived tumor cell lines are promising tools for preclinical and basic research, there are only four available cell lines for GCTB in public cell banks. Thus, the aim of this study was to establish a novel GCTB cell line. Using surgically resected tumor tissues from a patient with GCTB, we established a cell line named NCC-GCTB4-C1. The cells harbored the typical H3F3A gene mutation and exhibited constant proliferation and invasive capabilities. After characterizing NCC-GCTB4-C1 cell behaviors, we conducted high-throughput screening of 214 anti-tumor drugs and identified seven effective drugs. Comparing the results of high-throughput screening using NCC-GCTB4-C1 cell line with the results using NCC-GCTB1-C1, NCC-GCTB2-C1, and NCC-GCTB3-C1 cell lines that we previously established, four drugs were in common effective. This study showed potential drugs for the treatment of GCTB. These data indicate that NCC-GCTB4-C1 has the potential to be a powerful tool in preclinical and basic research on GCTB.

Extended Curettage for Giant Cell Tumors of Bone: A Surgeon's View

The key to intralesional surgical treatment of giant cell tumor of bone (GCTB) is extended curettage. As GCTB is locally aggressive with a high propensity for local recurrence, a primary factor of surgical treatment is the ability to achieve local tumor clearance. GCTB commonly affects the epimetaphyseal region of the bone, which may compromise the integrity of the articular surface. With the exception of expendable bone that may be considered for resection without the challenge of reconstruction (e.g., the proximal aspect of the fibula or the distal aspect of the ulna), a large majority of cases of GCTB can be treated with joint-preserving techniques. In the present article, we share a video demonstration including the surgeon view of intralesional surgery for GCTB, with emphasis on the 360° visualization of the tumor cavity, dilemmas regarding use of adjuvants for extended curettage, and options in cavity reconstruction.

Description

The surgical procedure involves 4 essential components.(1) Surgical exposure and isolation of the soft tissues. The technique begins with a complete exposure that allows visualization of the entire tumor cavity. The initial part of the exposure involves getting to the bone and to the soft-tissue mass outside the bone, when present. The muscles are separated from the bone and retracted away from the soft-tissue component of the tumor. Soft tissue is adequately retracted to allow complete visualization of the tumor cavity. The tissues around the cavity are protected by placing hydrogen peroxide-soaked mops around the tumor cavity. The aim is to isolate the bone opening and avoid any contamination of soft tissue by the tumor, as hydrogen peroxide kills GCTB cells on contact¹. The soft-tissue mass of the tumor is removed en bloc with a cover of normal tissue in order to prevent spillage into uninvolved tissues. Ward and Li advise the use of cautery for this part of the exposure in order to minimize contamination because high-temperature cautery kills the tumor². The initial opening into the osseous tumor cavity is made smaller in order to control the tumor spillage, and then enlarged in order to gain complete visualization.(2) Curetting and burring for tumor clearance. The walls are curetted, using the sharp edges of the curet. Good visualization is the key to meticulous and complete curetting. We recommend the use of a surgical loupe and headlight for adequate visualization¹. Tumor cavities often have overhanging osseous ridges with tumor hidden behind them. A curet may not be useful for breaking these hard osseous ridges; a burr is best utilized for this task. In addition to breaking the ridges, a high-speed burr helps to extend the curettage for a few millimeters beyond the grossly visible tumor margin^3,4.(3) Use of adjuvants to achieve extended curettage. Various physical and chemical agents have been utilized to control the microscopic disease remaining in the walls following a thorough curettage. Liquid nitrogen, phenol, hydrogen peroxide, alcohol, electrocautery, bone cement, and argon plasma cautery have been utilized as adjuvants. Balke et al. showed that the rate of recurrence decreases with use of more adjuvants, with high-speed burring having the greatest effect on the rate of recurrence, likely as a result of the larger resection and the thermal effect of the burring⁵. We suggest a case-by-case use of specific adjuvants, but in our experience, a high-speed burr is always utilized, hydrogen peroxide is utilized commonly when safe, and argon-plasma cautery is utilized judiciously.(4) Reconstruction of the cavity. The defect may be filled with bone, cement, or a combination of both. We suggest an individual, case-by-case approach to the reconstruction. In cases in which >25% of the articular surface is undermined², subchondral bone grafting is recommended prior to cementing (i.e., a sandwich procedure).

Alternatives

GCTB requires tumor clearance for local control. One alternative to intralesional surgical treatment performed around the knee is resection of the tumor-affected segment of bone and reconstruction with an endoprosthesis. This is a joint-sacrificing alternative and, in our experience, should be reserved for patients with joint involvement, multiply recurrent disease, or insufficient remaining wall to curet.

Rationale

When adequate tumor clearance is possible, joint-salvaging intralesional surgical treatment remains the superior option to achieve physiological joint function⁶. Indications for this procedure include maintained or restorable joint congruity and construct stability allowing early mobilization.

Expected Outcomes

The rate of local recurrence following intralesional surgical treatment ranges from 16% to 25%^1,7. The use of a high-speed burr is an essential part of the curettage⁵, and hydrogen peroxide is a safe choice for an adjuvant, if desired and when suitable, to provide greater local control⁸. Reconstruction with bone, cement, or both is acceptable, but we recommend building up a few millimeters of subchondral bone with bone graft before cement filling^1,9.

Important Tips

Illumination and magnification within the tumor cavity provide better visualization.Isolation of the soft tissue around the tumor with use of hydrogen peroxide-soaked mops can prevent seeding and contamination.Meticulous tumor clearance is more important to minimize recurrence than the use of adjuvants.Use of a C-arm helps to better guide extension of the curettage and avoid inadvertent joint penetration.Maintaining joint congruity is essential.

Measurement of morphological parameters of giant cell tumor of bone in the knee

The aim of the present study was to characterize the morphological parameters of giant cell tumor of bone (GCTB) in the knee. The imaging data of 250 patients with GCTB in the knee were retrospectively reviewed, and the morphological parameters were analyzed. The study included 137 cases with GCTB in the distal femur and 113 cases with GCTB in the proximal tibia. The maximal longitudinal diameter of the tumor was 6.616±2.322 cm in the femur group and 5.738±2.278 cm in the tibia group (P=0.003). The maximal transverse diameter in the two groups was 4.865±1.525 and 4.313±1.309 cm, respectively (P=0.003). The shortest distance from the articular surface (SDAS) in the two groups was 0.381±0.404 and 0.280±0.328 cm, respectively (P=0.035), whereas the longest distance from the articular surface in the two groups was 6.924±2.135 and 5.878±1.825 cm, respectively (P=0.001). There were statistically significant differences between the two groups in terms of the range of SDAS (P=0.043). Additionally, the incidence of pathological fractures in the femur was higher compared with that in the tibia (P=0.001), and the incidence of pathological fractures in the two groups gradually increased with the increase in lesion diameter. GCTB in the distal femur was larger compared with that in the proximal tibia, whereas GCTB in the tibia was closer to the articular surface compared with that in the femur. Furthermore, the incidence of pathological fractures in the femur was higher compared with that in the tibia.