Giant cell tumour of the distal radius/ulna: response to pre-operative treatment with short-term denosumab

Establishment and characterization of NCC-GCTB14-C1 and NCC-GCTB15-C1: two novel patient-derived cell lines of giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare bone tumor that is genetically characterized by a unique mutation in the H3-3A gene. Curative surgical resection is the standard treatment. Unfortunately, a considerable proportion of patients with GCTB have local recurrence and pulmonary metastasis after surgical treatment, and current chemotherapy treatments have shown non-effective. Considering the heterogeneity of the disease, patient-derived cancer models established from multiple cases are required. Therefore, we aimed to establish novel GCTB cell lines for use in preclinical studies. In this study, we successfully established two GCTB cell lines, NCC-GCTB14-C1 and NCC-GCTB15-C1. Both cell lines retained the genetic characteristics of the original tumors, constantly proliferated, and exhibited migratory activity. These cells formed spheroids with morphologically variable phenotypes. We found that they were compatible with chemosensitivity assays, and drug screening using these cell lines led to the identification of potential therapeutic candidates for GCTB. Therefore, NCC-GCTB14-C1 and NCC-GCTB15-C1 may be useful for elucidating the pathogenesis of and developing novel treatments for GCTB.

Performance parametric formulation of carbon fiber-reinforced composite locking bone implant plates based on finite-element analysis

The treatment of Giant Cell Tumor (GCT) in the distal radius poses challenges due to the intricate anatomical features of the bone. It often necessitates the use of long implant plates or the interconnection of multiple short plates after tumor excision. However, the deployment of metal plates may increase the risk of screw loosening and various complications. To address these challenges, this study proposes the adoption of carbon fiber-reinforced PEEK (CFRP) as the base material. As a unique strategy, performance parameters (PP) were developed to compare CFRP implant plates with a Ti-6Al-4V plate using the Finite-element Method. The focus was on four elements: the screw axial force, bone growth, callus formation, and bone resorption. The investigation into the screw axial force involved analyzing the internal force of the screw. The remaining parameters were evaluated using the stress, strain, or elastic energy induced in the bones. The findings showed that the second screw endured the largest screw axial force, measuring 10.16 N under a 90-degree 10-N loading at the translocated bone. The model without a callus exerted a significantly greater force on the screw than the model with a callus, leading to screw loosening in the early stage of treatment. The maximum PP, reached 1.62, was achieved with an angle-ply [456/-456] laminate, featuring a weighting fraction of 0.7 for bone growth and 0.1 for the other parameters. This study provides a generalized methodology for assessing the performances of CFRP implants and offers guidelines for future development in composite implant plate technology.

Denosumab for giant cell tumors of bone from 2010 to 2022: a bibliometric analysis

Giant cell tumors of the bone (GCTB) are considered moderately malignant bone tumors. Denosumab, as a neoadjuvant therapy, provides new possibilities for treating GCTB. However, even after multiple studies and long-term clinical trials, there are limitations in the treatment process. Research data and Medical Subject Headings terms related to denosumab and GCTB were collected from January 2010 to October 2022 using the Web of Science and MeSH ( https://meshb.nlm.nih.gov ) browsers. These data were imported into CiteSpace and VOSviewer softwares for bibliometric analysis. Overall, 445 publications on denosumab and GCTB were identified. Over the last 12 years, the growth rate of the total number of publications has remained relatively stable. The USA published the highest number of articles (83) and had the highest centrality (0.42). Amgen Inc. and Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) First Ortoped Rizzoli were identified as the most influential institutions. Many authors have made outstanding contributions to this field. Lancet Oncology had the highest journal impact factor (54.433). Local recurrence and drug dosage are current research hotspots, and future development trends will mainly focus on prognostic markers of GCTB and the development of new therapies. Further research is required to analyze denosumab's safety and efficacy and understand its local recurrence of GCTB, to identify the optimal dose. Future progress in this field will likely focus on exploring new diagnostic and recurrence markers to monitor disease progression and examine new therapeutic targets and treatment strategies.

Management of giant cell tumors of the distal radius

Background

The distal radius is the most common location for giant cell tumors (GCT) in the upper extremity. Treatment should balance the goals of maximizing function and minimizing recurrence and other complications. Given the complexity in surgical treatment, various techniques have been described without clear standards of treatment.

Objectives

The purpose of this review is to provide an overview of evaluation of patients presenting with GCT of the distal radius, discuss management, and provide an updated summary on outcomes of treatment options.

Conclusion

Surgical treatment should consider tumor Grade, involvement of the articular surface, and patient-specific factors. Options include intralesional curettage and en bloc resection with reconstruction. Within reconstruction techniques, radiocarpal joint preserving and sparing procedures can be considered. Campanacci Grade 1 tumors can be successfully treated with joint preserving procedures, whereas for Campanacci Grade 3 tumors consideration should be given to joint resection to prevent recurrence. Treatment of Campanacci Grade 2 tumors is debated in the literature. Intralesional curettage and adjuvants can successfully treat cases where the articular surface can be preserved, while en-bloc resection should be used in cases where the articular surface cannot undergo aggressive curettage. A variety of reconstructive techniques are used for cases needing resection, with no clear gold standard. Joint sparing procedures preserve motion at the wrist joint, whereas joint sacrificing procedures preserve grip strength. Choice of reconstructive procedure should be made based on patient-specific factors, considering relative functional outcomes, complications, and recurrence rates.

Resection and reconstruction with and without neoadjuvant denosumab in campanacci grade III giant cell tumors of proximal humerus: a retrospective comparative study

BACKGROUND

Giant cell tumors (GCT) of the proximal humerus are rarely reported case that requires complex surgeries due to involvement of the shoulder joint. Therefore, we report the first retrospective comparative study where the postoperative functional outcomes, recurrence rate and complications in patients who underwent arthrodesis of shoulder after resection of grade III GCT with and without neoadjuvant denosumab are compared.

METHODS

A retrospective review of eight cases of grade III GCT of proximal humerus receiving resection and fibular strut graft and arthrodesis between January 2014 and December 2019 is performed. They were stratified into two groups: one group of four patients received once-weekly denosumab 120 mg for 4-weeks before resection and reconstruction, while the other group of four patients did not receive denosumab before surgery. Primary outcomes included the functional outcomes assessed by revised Musculoskeletal tumor society (MSTS) score and shoulder pain and disability index (SPDI) at 6-weeks and 12-months postoperatively while secondary outcomes included complications and recurrences.

RESULTS

There was no significant difference in terms of SPDI at 6 weeks and 12 months, MSTS at 12 months, complications, recurrence among denosumab and non-denosumab groups. At 6-weeks follow-up, a significantly better pain score in SPDI and MSTS was acquired in the denosumab group.

CONCLUSIONS

Resection and reconstruction with or without neoadjuvant denosumab for Grade III GCT of proximal humerus had similar functional outcomes and with no major differences in recurrence and complications. Hence, postoperative pain relief while long-term benefits were not discovered with the use of neoadjuvant denosumab.

A rare case of sphenoid giant cell tumor: Case report & review of imaging features post short-term denosumab treatment

Background: Giant cell tumors (GCTs) are locally aggressive but rarely malignant bone neoplasms that uncommonly involve the skull. In this report, we describe a tumor of the sphenoid sinus. Case presentation: A 51-year-old female was presented with headache, and bilateral decreased visual acuity, CT scan, and brain MRI revealed an infra-sellar enhancing tumor expanding to the sellar and supra-sellar region which proved to be a GCT. the patient had received 03 months of preoperative denosumab-based treatment and imaging follow-up showed regression in size and morphology modifications of tumor tissue. Conclusion: This is one of few reports to describe the appearance of sphenoid bone GCT, and the first report to highlight the effects of short-term denosumab treatment in GCTb in such a location.

Surgical challenges, novel techniques, and systemic treatment of giant cell tumour of bone of the distal radius

Aims

Giant cell tumour of bone (GCTB) treatment changed since the introduction of denosumab from purely surgical towards a multidisciplinary approach, with recent concerns of higher recurrence rates after denosumab. We evaluated oncological, surgical, and functional outcomes for distal radius GCTB, with a critically appraised systematic literature review.

Methods

We included 76 patients with distal radius GCTB in three sarcoma centres (1990 to 2019). Median follow-up was 8.8 years (2 to 23). Seven patients underwent curettage, 38 curettage with adjuvants, and 31 resection; 20 had denosumab.

Results

Recurrence rate was 71% (5/7) after curettage, 32% (12/38) after curettage with adjuvants, and 6% (2/31) after resection. Median time to recurrence was 17 months (4 to 77). Recurrences were treated with curettage with adjuvants (11), resection (six), or curettage (two). Overall, 84% (38/45) was cured after one to thee intralesional procedures. Seven patients had 12 months neoadjuvant denosumab (5 to 15) and sixmonths adjuvant denosumab; two recurred (29%). Twelve patients had six months neoadjuvant denosumab (4 to 10); five recurred (42%). Two had pulmonary metastases (2.6%), both stable after denosumab. Complication rate was 18% (14/76, with 11 requiring surgery). At follow-up, median MusculoSkeletal Tumour Society score was 28 (18 to 30), median Short Form-36 Health Survey was 86 (41 to 95), and median Disability of Arm, Shoulder, and Hand was 7.8 (0 to 58).

Conclusion

Distal radius GCTB treatment might deviate from general GCTB treatment because of complexity of wrist anatomy and function. Novel insights on surgical treatment are presented in this multicentre study and systematic review. Intralesional surgery resulted in high recurrence-rate for distal radius GCTB, also with additional denosumab. The large majority of patients however, were cured after repeated curettage. Cite this article: Bone Jt Open 2022;3(7):515–528.

Malignant Transformation of Giant Cell Tumor of Bone and the Association with Denosumab Treatment: A Radiology and Pathology Perspective

Objective

Malignancy in giant cell tumor of bone (mGCTB) is categorized as primary (concomitantly with conventional GCTB) or secondary (after radiotherapy or other treatment). Denosumab therapy has been suggested to play a role in the etiology of secondary mGCTB. In this case series from a tertiary referral sarcoma center, we aimed to find distinctive features for malignant transformation in GCTB on different imaging modalities. Furthermore, we assessed the duration of denosumab treatment and lag time to the development of malignancy.

Methods

From a histopathology database search, 6 patients were pathologically confirmed as having initial conventional GCTB and subsequently with secondary mGCTB.

Results

At the time of mGCTB diagnosis, 2 cases were treated with denosumab only, 2 with denosumab and surgery, 1 with multiple curettages and radiotherapy, and 1 with surgery only. In the 4 denosumab treated patients, the mean lag time to malignant transformation was 7 months (range 2–11 months). Imaging findings suspicious of malignant transformation related to denosumab therapy are the absence of fibro-osseous matrix formation and absent neocortex formation on CT, and stable or even increased size of the soft tissue component.

Conclusion

In 4 patients treated with denosumab, secondary mGCTB occurred within the first year after initiation of treatment. Radiotherapy-associated mGCTB has a longer lag time than denosumab-associated mGCTB. Close clinical and imaging follow-up during the first months of denosumab therapy is key, as mGCTB tends to have rapid aggressive behavior, similar to other high-grade sarcomas. Nonresponders should be (re) evaluated for their primary diagnosis of conventional GCTB.

Denosumab in Giant Cell Tumor of Bone: Multidisciplinary Medical Management Based on Pathophysiological Mechanisms and Real-World Evidence

Simple Summary

The widely accepted local therapy in extremity giant cell tumor of bone (GCTB) is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. Most GCTB patients with localized disease can be successfully treated with surgical curettage; patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Abstract

(1) Despite the benign nature of the giant cell tumor of bone (GCTB), it shows a local recurrence rate of up to 50% and a chance of malignant transformation. The widely accepted local therapy in extremity GCTB is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab, a human monoclonal antibody directed against the RANKL and associated inhibition of the RANKL pathway, is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. (2) The literature review of patients with GCTB treated with denosumab is performed via PubMed, using suitable keywords from January 2009 to January 2021. (3) Current indications for denosumab use are not definitively clear and unambiguous. Most GCTB patients with localized disease can be successfully treated with surgical curettage, and the role of denosumab in preoperative therapy in this patient population remains unclear. (4) However, patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Clinical and pathological analysis of giant cell tumor of bone with denosumab treatment and local recurrence

BACKGROUND

Giant cell tumor of bone (GCTB) is a primary bone tumor which comprises giant cells and two types of stromal cells. Recent studies have suggested therapeutic risks of denosumab. No previous studies have reported changes in serum TRACP-5b and SUVmax of ¹⁸F-FDG-PET/CT in recurred GCTB after denosumab treatment. Therefore, we assessed the relationship between clinical and pathological features of GCTB which recurred after denosumab treatment.

METHODS

We retrospectively reviewed the medical records of 26 patients with GCTB who underwent curettage between 2010 and 2018. Fourteen patients treated with denosumab were defined as the denosumab group. We evaluated TRACP-5b and SUVmax values in the denosumab group. H&E staining and immunohistochemistry for H3.3 G34W were performed for pathological assessment. Twelve patients treated without denosumab were defined as the non-denosumab group and compared with denosumab group.

RESULTS

The local recurrence rate in the denosumab group was 57.4%. The mean TRACP-5b and SUVmax values were significantly decreased after denosumab therapy (P < 0.001, 1077 ± 161 to 74 ± 9 mU/dL and 8.88 ± 0.40 to 3.79 ± 0.56, respectively). Both parameters significantly increased with local recurrence. H&E staining after denosumab treatment revealed the disappearance of giant cells and histological changes in stromal cells. Specimens of local recurrence subjected to H&E staining and immunohistochemistry for H3.3 G34W demonstrated almost identical features to those in the first biopsy.

CONCLUSION

Although denosumab can prevent GCTB from osteolysis, local recurrence cannot be reduced by denosumab treatment. The clinical and pathological results were almost the same as those before denosumab treatment, suggesting that the changes of GCTB by denosumab are reversible.

Recurrent giant cell tumour of the distal ulna after en bloc resection with preoperative denosumab use

In recent years, denosumab has been used to treat giant cell tumour of bone (GCTB) not only in cases where surgery is complicated but also preoperatively to decrease the preoperative grade or to facilitate surgery for Campanacci grade II and III cases. However, there are no clear protocols regarding the preoperative use of denosumab before en bloc resection. There are a few reports of recurrent cases after en bloc resection; however, the association with the use of denosumab is unknown. We present the clinical, radiological and histopathological findings of a case of Campanacci grade III GCTB at the distal end of the ulna, which resulted in soft tissue recurrence after en bloc resection with the preoperative use of denosumab.

Denosumab for Effective Tumor Size Reduction in Patients With Giant Cell Tumors of the Bone: A Systematic Review and Meta-Analysis

BACKGROUND

Denosumab is a human monoclonal antibody that has been used successfully in the treatment of giant cell tumors of bone. These tumors are rare and, in principle, benign, but they are highly aggressive, locally advanced, osteolytic bone tumors that can metastasize to the lungs. Denosumab is an effective treatment when these tumors cannot be surgically removed or when surgical resection is likely to lead to severe morbidity (eg, loss of limbs or joints). The aim of this systematic review and meta-analysis was to investigate patients with giant cell tumors of bone who experienced tumor progression during treatment with denosumab and to compare them with patients who experienced reduction of their giant cell tumors of bone during treatment with denosumab.

METHODS

Embase, Cochrane Library, and MEDLINE/PubMed databases were searched for trials submitted by January 7, 2020, that reported the efficacy and safety of denosumab in patients with giant cell tumors of bone.

RESULTS

Sixty studies were reviewed, involving a total of 1074 patients who had giant cell tumors of bone and were treated with denosumab. Of the 60 studies, 58% of the patients were from case series studies, 39% from open-label phase II studies, and 3% from case reports. The response rate for denosumab as a treatment for giant cell tumors of bone was 97.5%, with statistical significance (P < .0001). Pain in the limbs was statistically the most common adverse event for denosumab treatment in case series studies (P < .0001). No treatment-related deaths occurred in the reviewed studies.

CONCLUSION

Cumulative evidence supports the addition of surgery to optimal medical therapy with denosumab to reduce tumor size, clinical symptoms, and mortality among patients with giant cell tumors of bone.

Is a Short-course of Preoperative Denosumab as Effective as Prolonged Therapy for Giant Cell Tumor of Bone?

BACKGROUND

Denosumab is an inhibitor of monoclonal receptor activator of nuclear factor-ĸB ligand, approved to treat giant cell tumors of bone (GCTB). It is commonly used for unresectable tumors and for downstaging the tumor to perform less-morbid procedures. Although denosumab has been used extensively for GCTBs, there are no recommendations regarding the duration of therapy. The risk factors associated with local recurrence (LR) in patients receiving preoperative denosumab for GCTB also are unknown.

QUESTIONS/PURPOSES

(1) Is short-course (three doses or fewer) preoperative denosumab treatment as effective as longer course (more than three doses) of treatment in terms of achieving a clinical, radiologic, and histologic response in patients with GCTB? (2) Is there an increased risk of LR after short-course denosumab therapy compared with long-course denosumab therapy; and after controlling for confounding variables, what factors were associated with LR after surgery for GCTB in patients receiving preoperative denosumab?

METHODS

A retrospective study was performed using an institutional database of 161 skeletally mature patients with a histologic diagnosis of GCTB who received denosumab between November 2010 and July 2019 to downstage the tumor before surgery. In general, we used denosumab when we thought it would facilitate either resection or curettage (by formation of a sclerotic rim around the osteolytic lesion), when a less-morbid procedure than initially planned might be performed, and in patients with complex presentations like cortical breech and soft tissue extension, pathological fracture, thinning of more than three cortices of the extremity. From 2010 to late 2015, denosumab was administered for approximately 4 to 6 months; starting in late 2015 through 2020, the number of denosumab doses has been reduced. We divided patients into two groups: Those who received three or fewer doses of denosumab (short-course, n = 98) and those who received more than three doses of denosumab (long-course, n = 63). Comparing those in the long-course group with those in the short-course group whose procedures were performed at least 2 years ago, there were no differences in loss to follow-up before 2 years (3% [3 of 98] versus. 3% [2 of 63]). The mean patient age was 30 years (± 6.1) and the mean number of denosumab doses was 4.4 (range 1 to 14). Overall, 77% (37 of 48) of patients taking short-course denosumab and 75% (27 of 36) of patients on long-course denosumab underwent curettage, and the remaining patients with an inadequate bony shell around the tumor or destruction of articular cartilage in both groups underwent tumor resection. With the numbers available, the patients with short- and long-course denosumab were not different in terms of age, sex, MSTS score on presentation, lesion size, lesion location, Campanacci grade, presence of pathological fracture and pulmonary metastasis on presentation, and the type of surgery performed (curettage versus resection). We analyzed the change in the Musculoskeletal Tumor Society score, change in Campanacci grade, radiologic objective tumor response (defined as a partial or complete response, per the modified inverse Choi criteria), and histologic response (defined as reduction of more than 90% of osteoclast-like giant cells or a reduction of more than 50% of mesenchymal spindle-like stromal cells, along with evidence of lamellar or woven bone formation, when compared with the biopsy sample) between the two groups (short- and long-course denosumab). LR rates were compared between the two groups, and after controlling for confounding variables, factors associated with LR in all operated patients were analyzed with a Cox proportional hazards regression analysis.

RESULTS

With the numbers available, there was no difference between the short- and long-course denosumab groups in terms of mean percentage improvement in MSTS score (20 [± 18.5] versus 24 [± 12.6]; p = 0.37), radiologic objective tumor response (90% [43 of 48] versus 81% [29 of 36]; p = 0.24) and histologic response (79% [38 of 48] versus 83% [30 of 36]; p = 0.81). With the numbers available, there was no difference between the short- and long-course denosumab groups in terms of Kaplan-Meier survivorship free from LR at 5 years after surgery (73% [95% confidence interval, 68 to 76] versus 64% [95% CI 59 to 68]; log-rank p = 0.50). After controlling for potential confounding variables like age, sex, Campanacci grade and MSTS score on presentation, number of denosumab doses administered before surgery, clinical, radiologic and histologic response to denosumab, and time duration between denosumab therapy and surgery, we found that tumors involving the bones of the hand and the foot (hazard ratio 7.4 [95% CI 2.0 to 27.3]; p = 0.009) and curettage (HR 6.4 [95% CI 2.8 to 23.0]; p = 0.037) were independently associated with a higher risk of LR.

CONCLUSIONS

In this preliminary, single-center study, we found that a short-course of preoperative denosumab (three or fewer doses) was associated with no differences in clinical scores, histological and radiological response, or LR-free survivorship, compared with longer-course of denosumab (more than three doses). Fewer preoperative doses can reduce the complications and costs associated with more-prolonged therapy. Denosumab must be used cautiously before curettage for GCTB, and only if the benefit of joint salvage outweighs the possibility of LR. However, given the small number of patients, potentially clinically important differences might have been missed, and so our findings need to be confirmed by larger, multicenter, prospective trials.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Denosumab for Bone Giant Cell Tumor of the Distal Radius

There are conflicting reports regarding the outcome and effect of denosumab for distal radius giant cell tumor of bone (GCTB). The authors performed this study to evaluate the behavior of distal radius GCTB in relation to the type of treatment and the administration of denosumab. The files of 72 patients with distal radius GCTB treated from 1984 to 2018 were reviewed. Fourteen patients were administered denosumab. Surgical treatment consisted of curettage (25 patients) or resection (47 patients) and allograft or vascularized fibular head graft reconstruction. Median follow-up was 63.1 months (interquartile range [IQR], 35.5-107.1 months). The authors evaluated local recurrences, metastasis, function, and complications. The local recurrence rate was 30.6% at a median of 14.0 months (IQR, 10-19 months), with no difference between curettage and resection. The local recurrence rate was significantly higher in the patients who received denosumab. The metastasis rate was 9.7% at a median of 41.0 months (IQR, 15-114 months), with no difference regarding denosumab administration. Function was significantly better in patients after curettage. The complication rate was 25%; vascularized fibular graft reconstruction was associated with fewer complications. This study found that denosumab increases the risk of local recurrence after curettage, function is better after curettage, and vascularized fibular graft is the optimal reconstruction after resection of distal radius GCTB. [Orthopedics. 2020;43(5):284-291.].

Radiological findings of denosumab treatment for giant cell tumours of bone

Giant cell tumours of bone (GCTB) are benign giant cell-rich tumours typically occurring in the epi-metaphysis of skeletally mature patients. Despite their benign classification, GCTB may be locally aggressive with local recurrence as a challenging issue. Denosumab is a human monoclonal antibody that inhibits osteolysis via the RANK-RANK ligand pathway. There is currently no consensus on optimal treatment duration or imaging modality for monitoring patients on denosumab therapy. This review illustrates the radiological findings of GCTB on denosumab treatment seen on plain radiographs, CT, MRI, PET-CT and DEXA, with reference to the current literature. Recognizing imaging features indicative of a positive response to denosumab is important for therapeutic decision-making. Imaging findings with respect to duration of denosumab treatment, tumour upregulation during treatment, tumour recurrence and malignant transformation are discussed. The development of a sclerotic neocortex and varying degrees of matrix osteosclerosis are seen on plain radiographs. Reconstitution of subarticular bone and articular surface irregularity are optimally evaluated on CT which can also quantify tumour density. MRI demonstrates heterogeneous low signal matrix and is useful to assess decrease in size of cystic and/or soft tissue components of GCTB. A fat-suppressed fluid-sensitive MR sequence is important to detect tumour reactivation. Reduction in 18F-FDG-PET avidity represents an early sensitive sign of response to denosumab treatment. Regardless of imaging modality, close follow-up in a specialist centre and careful evaluation of nonresponders is necessary as local recurrence after cessation of denosumab treatment and malignant transformation of GCTB have been described.

Vascularized Ulnar Transposition and Radioulnoscapholunate Fusion With Volar Locking Plate in a Dorsal Position Following Resection of Giant Cell Tumor of the Distal Radius

Giant cell tumor of the distal radius is a rare, locally destructive, and frequently recurrent tumor. We present a case of Campanacci Grade III giant cell tumor of the distal radius with pathologic fracture and cortical destruction which was treated with neoadjuvant denosumab. This facilitated en-bloc resection of the entire distal radius, including the articular surface, while minimizing tumor contamination. Reconstruction was accomplished using a vascularized ulnar transposition flap to facilitate radioulnoscapholunate fusion, which was fixated using a long-stem contralateral variable angle locking volar distal radius plate in a dorsal position. This case illustrates multidisciplinary management of a challenging reconstructive problem and demonstrates a novel strategy for fixation which repurposes familiar and readily available hardware to provide optimal osteosynthesis.

Functional outcome in giant cell tumor of distal radius treated with excision and fibular arthroplasty: a case series

INTRODUCTION

Giant cell tumor (GCT) of bone is a locally aggressive benign neoplasm that is associated with a wide spectrum of biological activity ranging from latent benign to highly recurrent and has occasional metastatic potential. It affects the meta-epiphyseal region of long bones of young adults with most common site involved is the distal femur, followed by the distal radius. Plain radiographs and contrast-enhanced magnetic resonance imaging are the imaging modalities widely used followed by definite histopathology for diagnosis. Surgical treatment with curettage is considered optimal for local tumor control. Tumor excision with tumor-free margins is associated with lesser recurrence rates; however, for periarticular lesions this is usually accompanied with a suboptimal functional outcome.

METHODS

Eleven eligible patients (all females, mean age 39.2 years) with Campanacci grade III GCT of the distal radius who were treated by en bloc resection and reconstruction with non-vascularized proximal fibular autografts at a single centre between July 2016 and December 2017 were included in the study. The patients had a clinical and radiographic review every month for the first 6 months, then biannually for minimum of 2 years. The functional, oncologic and radiological outcomes of the patients were analyzed and recorded.

RESULTS

The mean duration of follow-up was 31.9 months. Bony union was achieved in all cases. The mean VAS score at 6 months was 1.1 (range 0-2). The mean Mayo Wrist score was 66.36 (range 55-80) with mean MSTS score was 21.09 (range 18-24). The average range of motion of the wrist was: 37.3° ± 6.9° of flexion, 47.1° ± 7.5° of extension, 57.3° ± 7.8° of supination and 63.6° ± 6.4° of pronation. The average graft length used was 15.6 cm. The complications noted were lung metastases which developed preoperatively, local site recurrence, wrist joint subluxation, foot drop and wound complication.

DISCUSSION AND CONCLUSIONS

The primary aim of treating GCT distal radius is oncologically sound resection with good functional outcome and cosmesis being secondary. Reconstruction with a non-vascularized proximal fibular autograft is a reasonable option after en bloc resection of the distal radius for giant cell tumor of bone having comparable results with other treatment modalities.

Is Treatment with Denosumab Associated with Local Recurrence in Patients with Giant Cell Tumor of Bone Treated with Curettage? A Systematic Review

BACKGROUND

Denosumab, a monoclonal antibody that binds to receptor activation of nuclear factor-kappa ß ligand (RANKL), has been used as a drug to treat aggressive giant cell tumors of bone. It is unclear whether preoperative denosumab therapy is associated with the local recurrence risk in patients with giant cell tumors of bone treated with curettage. Early evidence suggests that denosumab treatment is associated with a reduction in local recurrence, but other studies have questioned that premise. Curettage after a short course of denosumab (3 to 4 months) has been recommended, especially for large, aggressive giant cell tumors in which complete curettage is difficult to achieve. No randomized studies have documented the benefit of this approach, and some investigators have reported higher local recurrence after denosumab treatment. Due to this confusion, we performed a systematic analysis of existing reports to attempt to answer this question and determine whether the appropriate preoperative denosumab therapy duration could be established.

QUESTIONS/PURPOSES

(1) Is the use of preoperative denosumab associated with local recurrence risk in patients with giant cell tumors of bone treated with curettage compared with those treated with curettage alone? (2) Is the preoperative denosumab therapy duration associated with local recurrence after curettage?

METHODS

We searched the PubMed, EMBASE, and CENTRAL databases on April 26, 2019 and included both randomized and non-randomized studies that compared local recurrence between patients who had giant cell tumors of bone and were treated with curettage after preoperative denosumab and patients treated with curettage alone. Two authors independently screened the studies. There were no randomized studies dealing with denosumab in giant cell tumors of bone, and generally, denosumab was used for more aggressive tumors. We assessed the quality of the included studies using the Risk of Bias Assessment tool for Non-randomized Studies, with a moderate overall risk of bias. We registered our protocol in PROSPERO (registration number CRD42019133288). We selected seven eligible studies involving 619 patients for the final analysis.

RESULTS

The proportion of patients with local recurrence ranged from 20% to 100% in the curettage with preoperative denosumab group and ranged from 0% to 50% in the curettage-alone group. The odds ratio of local recurrence ranged from 1.07 to 37.80 in no more than 6 months of preoperative denosumab duration group and ranged from 0.60 to 28.33 in more than 6 months of preoperative denosumab duration group.

CONCLUSIONS

The available evidence for the benefit of denosumab in more aggressive giant cell tumors is inconclusive, and denosumab treatment may even be associated with an increase in the proportion of patients experiencing local recurrence. Because there are no randomized studies and the existing studies are of poor quality due to indication bias (the most aggressive Campanacci 3 lesions or those where even a resection would be difficult and result in morbidity are generally the patients who are treated with denosumab), the evidence to suggest a disadvantage is weak. Denosumab treatment should be viewed with caution until more definitive, randomized studies documenting a benefit (or not) have been conducted. Furthermore, we could not find evidence to suggest an appropriate length of preoperative denosumab before curettage.