Mid-term outcome after curettage with polymethylmethacrylate for giant cell tumor around the knee: higher risk of radiographic osteoarthritis?

Balancing Tumor Control and Cartilage Preservation for Patients with Giant Cell Tumor of Bone Around the Knee: A Clinical Report from a Single Institute

BACKGROUND

When managing aggressive giant cell tumor of bone (GCTB) around the knee joint, surgeons are often caught in a dilemma when determining whether to perform marginal excision or intralesional curettage. The purpose of this study was to report the long-term results of different treatment strategies in our institute.

METHODS

We retrospectively reviewed 64 eligible cases (34 female and 30 male) with a GCTB (37 in the distal femur, 27 in the proximal tibia) treated from 2002 to 2013. Forty patients received intralesional curettage (group A). Twenty-four received marginal excision of the tumor, with 18 of them undergoing reconstruction with unicondylar osteoarticular allograft (UOA) (group B) and 6 receiving arthroplasty reconstruction (group C). The minimum follow-up was 8 years, and the oncological status, clinical outcomes, and cartilage condition were analyzed.

RESULTS

Tumor recurrence was most common in group A (10 of 40, 25.0%), followed by group B (1 of 18, 5.6%) and group C (0 of 6). Eleven patients in group A (27.5%) and 6 in group B (33.3%) developed osteoarthritis (Kellgren-Lawrence grade 3 or 4). Five patients in group A (12.5%) and 3 patients in group B (16.7%) received total knee arthroplasty. Risk factors for the development of osteoarthritis in group A included a centrally located tumor, tumor length of >6 cm, a tumor-cartilage distance of ≤3 mm, and >50% subchondral bone involvement. In group B, osteoarthritis mostly resulted from postoperative complications. The mean Musculoskeletal Tumor Society (MSTS) score was 87.9 in group A, 84.8 in group B, and 93.3 in group C.

CONCLUSIONS

Although intralesional curettage preserved cartilage and resulted in better function, it was associated with a higher tumor recurrence rate in our series. For advanced tumors close to the articular cartilage with significant subchondral bone involvement, marginal excision with UOA reconstruction might be a viable alternative. Arthroplasty should be reserved for patients who have bicondylar involvement with severe bone and cartilage loss making cartilage preservation impossible.

LEVEL OF EVIDENCE

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

Clinical results of knee juxta-articular giant-cell tumors treated with bone cement filling and internal fixation after extensive curettage

OBJECTIVES

This study was to evaluate the radiological and clinical outcomes of patients with juxta-articular giant-cell tumors (GCTs) around the knee treated with bone cement filling and internal fixation after extensive curettage.

PATIENTS AND METHODS

A total of 15 patients (6 males, 9 females; mean age: 35.3±8.4 years; range, 24 to 53 years) with juxta-articular GCTs around the knee were retrospectively reviewed between January 2010 and June 2020. Wound healing, functional status as assessed by the Musculoskeletal Tumor Society (MSTS) scores, local recurrence, metastasis, and complications were evaluated.

RESULTS

The mean follow-up was 41.3±9.9 (range, 24 to 69) months with an overall survival of 93.3%. The mean distance between tumor and cartilage was 6.29±3.73 mm. Five patients underwent reconstruction with cancellous allografts and the mean distance between tumor and cartilage was 2.20±1.48 mm in these patients. At the final follow-up, three patients had Kellgren-Lawrence Grade 2 tibiofemoral osteoarthritis in the operated knee. Lucent zones around the bone cement with no further progression were found in five patients. One patient experienced recurrence 17 months after surgery and was treated by en-bloc resection and reconstructed with a tumor endoprosthesis. The remaining 14 patients had a mean MSTS score of 26.86±2.11 (range, 23 to 30) at the final follow-up. The mean overall range of motion at the final follow-up was 109.20±14.20° (range, 85 to 130°).

CONCLUSION

Bone cement filling and internal fixation after extensive curettage is a viable strategy for accessing juxta-articular GCTs around the knee. The choice of local adjuvants, subchondral bone grafting, and the thickness of subchondral bone require more attention to preserve the continuity of articular cartilage.

Subchondral curettage cement packing in the distal radius causes wrist joint degeneration: long-term evaluation of distal radius giant-cell bone tumour

INTRODUCTION

This study investigated wrist joint degeneration after curettage and PMMA treatment for giant cell bone tumours (GCBT) at the distal radius.

METHODS

We performed a retrospective single-centre study, which included 23 patients with GCBT at distal radius treated with curettage and PMMA between 2001 and 2021. The progression of wrist joint degeneration was assessed through radiographic evidence, comparing the postoperative grade with both the preoperative grade and the grade of the contralateral wrist at the latest follow-up. We also analyzed the influence of age, sex, tumour distance of the joint, subchondral bone involvement, tumour size and body mass index.

RESULTS

The study included 23 patients with a mean age of 32.1 ± 13.3 years. The average duration of follow-up was 96.4 ± 69 months (range, 24-265 months). The mean tumour-cartilage distance was 1.79 ± 2.4 mm (range, 0-10 mm) and the mean BMI was 23.5 ± 3.8 kg/m2. Degeneration of the wrist joint was evident in 16 patients (69.6%) at the final assessment, however, 10 patients (43.4%) were identified as having a progression of joint degeneration secondary to the surgical procedure among the 16 patients with wrist joint degeneration at the final control view. Age, gender, dominance, tumour-cartilage distance, subchondral bone involvement, tumour size, patient height, weight, and BMI were not associated with secondary joint degeneration.

CONCLUSIONS

Ten of 23 patients developed wrist joint degeneration over an average follow-up period of 8 years, and no particular factors associated with the degeneration were identified.

Differential diagnoses and therapeutic features of giant cell tumor of the bone in an elderly patient: A case report

INTRODUCTION

Giant cells tumor (GCT) of the bone is usually seen in young adults between the ages of 20 and 40. When occurring in older patients, diagnosis and therapeutic specific feature are to be considered. We underline those aspects through this case report.

CASE PRESENTATION

We report the case of a 73-year-old man presenting with a painful swelling knee. The diagnosis of GCT of proximal tibia was retained and the patient underwent extensive curettage, subchondral bone grafting and cementation of the residual cavity. The long-term results show a good functional outcome and no recurrence.

DISCUSSION

In this age group, other lesions have similar clinical and radiological presentations as GCT of bone. The diagnosis of a metastatic carcinoma is to be carefully ruled-out in this situation. While the option of large resection with joint arthroplasty is better accepted in ageing patients as a treatment of GCT of bone, this case suggests that jointpreserving methods should also be considered especially when there are no signs of osteoarthritis. While polymethylmethacrylate cementation is an efficient adjuvant in order to reduce recurrences, it may cause secondary osteoarthritis. Subchondral grafting seems to be a good alternative to prevent this complication.

CONCLUSION

Malignancies should be ruled-out before retaining the diagnosis of GCT of the bone after the age of 50. Conservative surgical treatment is always an option in this age group.

Giant cell tumor of bone and secondary osteoarthritis

Giant cell tumor of bone is a commonly encountered aggressive epiphyseal bone tumor, most often treated surgically. The natural history and presentation are classically described but the histopathology is poorly understood. Intralesional curettage is the mainstay of treatment, but there is significant variation in the use of adjuvant and cavity filling modalities. No gold standard has been agreed upon for treatment, and a variety of techniques are currently in use. Given its location, secondary osteoarthritis is a known long-term complication. This review examines the natural history of giant cell tumors, treatment options and complications, and subsequent development of osteoarthritis. Arthroplasty is usually indicated for secondary osteoarthritis although data is limited on its efficacy. Further directions will likely center on improved pharmacological treatments as well as improved arthroplasty techniques.

Time to full weight-bearing with the use of a calcium sulfate-calcium phosphate bone substitute as a bone void filler following extended curettage in the treatment of primary benign bone tumours

PURPOSE

The primary objective of this study was to determine time to full weight-bearing after the use of a calcium-sulfate-calcium phosphate bone substitute (CaSO4/CaPO4) as a bone void filler in the treatment of primary benign bone tumours following intralesional curettage. The secondary objectives were to determine surgical complications and recurrence rates.

METHODS

Retrospective review of patients identified from a surgeon-specific orthopaedic oncology database, who underwent curettage of benign bone tumours and subsequent bone void filling with CaSO4/CaPO4.

RESULTS

A total of 39 patients (20 males, 19 females) met inclusion criteria with an average age of 31 years (range: 13 to 62 years), a median follow-up of 3.7 years, and a maximum follow-up of 11 years. The most common tumour diagnosis was giant cell tumour of bone (GCT) (n = 19), and the most common location was the proximal tibia (n = 9). The mean volume of tumour excised was 74.1 cm3 including extraosseous bone expansion due to tumour growth, with a mean of volume of 21.4 mL of CaSO4/CaPO4 used to fill the intraosseous cavitary defects to restore normal bone anatomy. None of the lesions required additional internal fixation. The primary outcome measure, average time to full weight-bearing/full range of motion, was 11 weeks and 6 weeks for upper and lower extremity lesions, respectively. Secondary outcomes included tumour recurrence requiring reoperation in five patients and infection requiring reoperation in two patients.

CONCLUSION

This study demonstrates that CaSO4/CaPO4 is a viable option as a bone void filler in the reconstruction of cavitary defects following removal of primary benign bone tumours. CaSO4/CaPO4 provides sufficient bone regeneration early in the post-operative period to allow progression to full weight-bearing within weeks without the need for internal fixation. There were no graft-specific complications noted.

Current Concepts in the Treatment of Giant Cell Tumor of Bone: An Update

Curettage is recommended for the treatment of Campanacci stages 1-2 giant cell tumor of bone (GCTB) in the extremities, pelvis, sacrum, and spine, without preoperative denosumab treatment. In the distal femur, bone chips and plate fixation are utilized to reduce damage to the subchondral bone and prevent pathological fracture, respectively. For local recurrence, re-curettage may be utilized when feasible. En bloc resection is an option for very aggressive Campanacci stage 3 GCTB in the extremities, pelvis, sacrum, and spine, combined with 1-3 doses of preoperative denosumab treatment. Denosumab monotherapy once every 3 months is currently the standard strategy for inoperable patients and those with metastatic GCTB. However, in case of tumor growth, a possible malignant transformation should be considered. Zoledronic acid appears to be as effective as denosumab; nevertheless, it is a more cost-effective option. Therefore, zoledronic acid may be an alternative treatment option, particularly in developing countries. Surgery is the mainstay treatment for malignant GCTB.

A new joint reconstruction technique in the treatment of giant cell tumors around the knee: Structural allograft and unicompartmental arthroplasty

OBJECTIVE

The long-term prognosis of patients who underwent unicompartmental knee arthroplasty (UKA) with a structural allograft or hemiarticular allograft transplantation to treat giant cell tumors (GCTs) around the knee and the prosthesis survival rate were analyzed.

METHODS

We retrospectively reviewed 73 patients who were diagnosed with GCTs around the knee and underwent surgery to restore joint function from 2000 to 2015. Patients were divided into two groups according to the surgical procedure used for functional knee reconstruction: hemiarticular allograft transplantation or structural allograft and UKA. The Knee Society Score (KSS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were used to analyze postoperative knee function between the two groups. The Kellgren-Lawrence (K-L) classification system was used to evaluate the progression of osteoarthritis. The incidence of complications and the prosthesis survival rate were also investigated.

RESULTS

Patients who underwent UKA to treat GCT demonstrated significantly improved knee function. The rate of an excellent or good KSS was significantly different between the two groups (p = 0.041 at the 1-year follow-up, p = 0.033 at the last follow-up). The proportion of severe cases according to WOMAC in the two groups was also different (p = 0.030 at the 1-year follow-up, p = 0.021 at the last follow-up). According to the K-L grade of unaffected compartments, UKA better prevented the progression of osteoarthritis (p = 0.034).

CONCLUSIONS

Patients with GCTs around the knee could benefit from UKA. In addition to providing better knee function and range of motion, UKA could also slow the progression of osteoarthritis in the knee joint. This new surgical method could meet the needs of patients wishing to preserve joint integrity and favorable joint function.

Is higher body mass index associated with secondary osteoarthritis in patients treated with bone cement for benign aggressive bone tumors? Long-term evaluation of 43 patients

BACKGROUND

This study was designed to investigate the secondary osteoarthritis rate in patients with benign aggressive bone tumors treated with curettage and cementing at long-term follow up.

METHODS

Patients diagnosed with benign aggressive bone tumor (giant cell or aneurysmal bone cyst), treated with extended curettage and cementation with polymethylmethacrylate, who had a minimum of 60 months of follow up after surgery were included in this study. After definitive diagnoses were confirmed by a histopathologist, we decided to perform standard surgical management. Osteoarthritis was staged radiologically using the Kellgren-Lawrence scoring system, and the contralateral knees of the patients were used as the control group. Based on the Kellgren-Lawrence classification system, stages 3 and 4 were accepted as the existence of osteoarthritis. Body mass index, the distance to the subchondral joint line, tumor mass volume, the location of the tumor (i.e., femur, tibia, medial condyle, or lateral condyle), age, and sex were also investigated, all of which are factors that can affect the occurrence of osteoarthritis.

RESULTS

Forty-three patients, 24 male (56%) and 19 female (44%), were included in the study. The mean age of the patients was 29.5 ± 10 years, and mean follow up duration was 128.7 months. Tumor localization was the distal femur in 20 patients (46.5%) and the proximal tibia in 23 patients (53.5%). The mean tumor mass volume was 77.84 cm3 and the distance to the knee joint subchondral line was 3.2 ± 2 mm. According to this scoring system, 14 patients were at stage 0, 10 patients were at stage 1, 10 patients were at stage 2, four patients were at stage 3, and five patients were at stage 4. When we compared osteoarthritis development, the affected knee had a significantly higher rate of osteoarthritis development than the contralateral knee. A univariate analysis demonstrated that age (P = 0.002) and body mass index (P = 0.045) were associated with secondary osteoarthritis. Moreover, multivariate analysis demonstrated that none of the variables were independently associated with secondary osteoarthritis.

CONCLUSION

Patients with contralateral osteoarthritis had bilateral knee osteoarthritis, indicating that primary osteoarthritis progressed in both knees. Seven of the 43 patients (16.2%) showed secondary osteoarthritis. Although age and body mass index were associated with secondary osteoarthritis in univariate analysis, none of the variables were independently associated with secondary osteoarthritis in the multivariate analysis.

Comprehensive evaluation and advanced modification of polymethylmethacrylate cement in bone tumor treatment

Bone tumors are invasive diseases with a tendency toward recurrence, disability, and high mortality rates due to their grievous complications. As a commercial polymeric biomaterial, polymethylmethacrylate (PMMA) cement possesses remarkable mechanical properties, injectability, and plasticity and is, therefore, frequently applied in bone tissue engineering. Numerous positive effects in bone tumor treatment have been demonstrated, including biomechanical stabilization, analgesic effects, and tumor recurrence prevention. However, to our knowledge, a comprehensive evaluation of the application of the PMMA cement in bone tumor treatment has not yet been reported. This review comprehensively evaluates the efficiency and complications of the PMMA cement in bone tumor treatment, for the first time, and introduces advanced modification strategies, providing an objective and reliable reference for the application of the PMMA cement in treating bone tumors. We have also summarized the current research on modifications to enhance the anti-tumor efficacy of the PMMA cement, such as drug carriers and magnetic hyperthermia.

Total Knee Arthroplasty for Osteoarthritis Is Uncommon after Intralesional Curettage in Giant Cell Tumor of Bone

Giant cell tumor of bone (GCTB) is most often treated with intralesional curettage; however, periarticular lesions have been shown to increase risk for osteoarthritis. Additionally, the location of these lesions may occasionally preclude a joint-sparing procedure in recurrent tumors. This study sought to investigate rates of secondary arthroplasty in long-term follow-up of knee GCTB. Cases of knee GCTB treated at our institution were reviewed. Rates of recurrence and secondary arthroplasty were recorded, and Kaplan-Meier survival analyses were performed. The records of 40 patients were reviewed. Local recurrence occurred in 25% of patients. The 1-, 5-, and 10-year recurrence-free survival (RFS) probability was 87.4% (95% CI, 77.0-97.7), 72.4% (95% CI, 57.6-87.2), and 72.4% (95% CI, 57.6-87.2), respectively. Function improved after surgery with a mean preoperative MSTS score of 14.9 (standard deviation [SD] 8.4) and mean postoperative MSTS score of 25.1 (SD 5.6) (p <0.001). Three patients had evidence of radiographic osteoarthritis at the last follow-up though they did not require arthroplasty. Arthroplasty was performed as a secondary procedure in six patients. Five patients underwent arthroplasty for recurrent tumors after initial treatment with curettage and one patient underwent patellar arthroplasty for osteoarthritis after initial treatment with an allograft composite arthroplasty. Arthroplasty is performed as a secondary procedure in patients with GCTB at a relatively infrequent rate and more often for cases of recurrent disease than for osteoarthritis. Overall, patients treated for GCTB have improved functional outcomes after surgery than before. Large, multi-institutional studies may be required to assess the incidence of secondary osteoarthritis requiring arthroplasty as this was an infrequent finding in our cohort.

Microwave in situ inactivation in the treatment of bone giant cell tumor: a mid-term descriptive study

AIM

To evaluate the mid-term clinical efficacy of microwave in situ inactivation combined with bone grafting or polymethyl methacrylate (PMMA) filling in the treatment of giant cell tumor of bone (GCTB).

METHODS

This is a retrospective, descriptive, and analytical study. A total of 30 GCTB patients received microwave in situ inactivation from January 2012 to January 2020, whose clinical recurrence rate was evaluated at the last follow-up after microwave in situ inactivation surgery. The Musculoskeletal Tumor Society (MSTS) function score was used to evaluate the postoperative clinical panoramic results.

RESULTS

All patients were followed up for 21 to 110 months, with an average of 63.79 months. Distal femur (40%) and proximal tibia (28%) had a higher rate of GCTB incidence. Seventeen percent of tumor patients suffered from associated pathologic fracture. The rate of Campanacci classification stage III was 60%. The average MSTS score was evaluated as 27.53 points overall at the last follow-up. In terms of complications, three, two, two and one cases developed fat liquefaction, controllable tissue rejection reaction, incision infection and degenerative changes around lesion joint, respectively, without in situ recurrences and reoperation as well as distant lung metastasis.

CONCLUSIONS

The method of microwave in situ inactivation combined with bone grafting or PMMA filling is prudently recommended as one of the options for the limb salvage treatment of giant cell tumor of long and periarticular bone.

LEVEL OF EVIDENCE

IV: case series.

Incidence and progression of osteoarthritis following curettage and cementation of giant cell tumor of bone around the knee: long-term follow-up

BACKGROUND

Giant cell tumor of bone (GCTB) is a benign locally aggressive tumor frequently treated with intralesional curettage and cementation. The aim of this study was to investigate the long-term incidence of arthritic changes following curettage and cementation of GCTB around the knee.

MATERIALS AND METHODS

This study was a retrospective review of patients with GCTB around the knee treated with curettage and cementation with a minimum follow-up of 10 years. The functional results were assessed using the Musculoskeletal Tumor Society (MSTS) score. The arthritic changes were classified using the Kellgren-Lawrence (KL) classification system of osteoarthritis.

RESULTS

This study included 119 patients, 54 males and 65 females, with a mean age of 29.4 ± 9.2 years. There were 35 (29.4%) patients with pathological fractures. There were 84 (70.6%) patients with de novo lesions and 35 (29.4%) with recurrent lesions. The mean follow-up period was 13.2 ± 3.16 years. The mean MSTS score was 28.5 ± 1.9. Overall, 25 (21%) patients developed variable degrees of arthritis of KL grade 1 (n = 7), KL grade 2 (n = 11), KL grade 3 (n = 4), and KL grade 4 (n = 3). Ten patients showed progression of arthritis during the follow-up period. Age at presentation, gender, presence of pathological fracture, whether the tumor was de novo or recurrent, and tumor location were not associated with arthritis incidence.

CONCLUSIONS

Curettage and cementation can be used safely to treat GCTB around the knee. Arthritis of the knee is a possible complication, but mild grades are expected in most cases. There was no association between arthritis incidence and age, gender, pathological fractures, tumor location, or recurrent tumors.

LEVEL OF EVIDENCE

Level IV.

Is three-dimension-printed mesh scaffold an alternative to reconstruct cavity bone defects near joints?

PURPOSE

Reconstruction of cavity bone defects after curettage of benign bone tumours around the joint remains challenging. We designed a novel 3D-printed mesh scaffold as a substitute for bone cement, aiming to support the articular surface, protect the subchondral bone, and reduce complication rates.

METHODS

We retrospectively analyzed seven patients who received curettage and reconstruction using a 3D-printed mesh scaffold between January 2020 and June 2021. Pain and function were evaluated using the 10-cm Visual Analogue Scale (VAS) score and the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score. Radiographs were used to evaluate articular surface supporting, subchondral bone protection, and complications.

RESULTS

The median functional MSTS-93 and VAS scores were both improved after surgery, and the median 3D-printed mesh scaffold volume was smaller than the median defect volume. Articular surface supporting, subchondral bone preservation, and osteogenesis were observed post-operatively. No related complications were observed during the last follow-up.

CONCLUSIONS

The 3D-printed mesh scaffold provided sufficient mechanical support for the articular surface and protected the subchondral bone. We recommended the 3D-printed mesh structure as an alternative to repair cavity bone defects around joints.

Posterior ankle arthroscopic treatment of a talar chondroblastoma with allograft and a platelet-rich plasma-fibrin glue: A case report and literature review

Talar chondroblastoma, which is a benign tumor of immature cartilage cells, is an uncommon but easily missed diagnosis of foot pain. Arthroscopic treatment for this condition is a safe, powerful, and promising technique with definitive advantages of visualization and minimal invasion. Here, we report a case of a talar chondroblastoma treated by posterior ankle arthroscopic curettage, allograft bone graft, and platelet-rich plasma-fibrin glue (PRP-FG) application.

Level of evidence

Case Report. Level IV.

Risk factors of fracture following curettage for bone giant cell tumors of the extremities

BACKGROUND

Following curettage of giant cell tumor of bone (GCTB), it is common to fill the cavity with polymethylmethacrylate (PMMA) bone cement, bone allograft, or artificial bone to maintain bone strength; however, there is a 2-14% risk of postoperative fractures. We conducted this retrospective study to clarify the risk factors for fractures after curettage for GCTB of the extremities.

METHODS

This study included 284 patients with GCTBs of the extremities who underwent curettage at our institutions between 1980 and 2018 after excluding patients whose cavities were not filled with anything or who had additional plate fixation. The tumor cavity was filled with PMMA bone cement alone (n = 124), PMMA bone cement and bone allograft (n = 81), bone allograft alone (n = 63), or hydroxyapatite graft alone (n = 16).

RESULTS

Fractures after curettage occurred in 10 (3.5%) patients, and the median time from the curettage to fracture was 3.5 months (interquartile range [IQR], 1.8-8.3 months). The median postoperative follow-up period was 86.5 months (IQR, 50.3-118.8 months). On univariate analysis, patients who had GCTB of the proximal or distal femur (1-year fracture-free survival, 92.5%; 95% confidence interval [CI]: 85.8-96.2) presented a higher risk for postoperative fracture than those who had GCTB at another site (100%; p = 0.0005). Patients with a pathological fracture at presentation (1-year fracture-free survival, 88.2%; 95% CI: 63.2-97.0) presented a higher risk for postoperative fracture than those without a pathological fracture at presentation (97.8%; 95% CI: 95.1-99.0; p = 0.048). Patients who received bone grafting (1-year fracture-free survival, 99.4%; 95% CI: 95.7-99.9) had a lower risk of postoperative fracture than those who did not receive bone grafting (94.4%; 95% CI: 88.7-97.3; p = 0.003).

CONCLUSIONS

For GCTBs of the femur, especially those with pathological fracture at presentation, bone grafting after curettage is recommended to reduce the risk of postoperative fracture. Additional plate fixation should be considered when curettage and cement filling without bone grafting are performed in patients with GCTB of the femur. This should be specially performed for those patients with a pathological fracture at presentation.

Complications of surgery for giant cell tumor of bone in the extremities: Incidence, risk factors, management modality, and impact on functional and oncological outcomes

BACKGROUND

Due to the wide variations in location, size, local invasiveness, and treatment options, the complications associated with surgery for giant cell tumor of bone have been sporadically reported. For quality assessment, fundamental data based on large-scale surveys of complications under a universal evaluation system is needed. The Dindo-Clavien classification is an evaluation system for complications based on severity and required intervention type and is suitable for the evaluation of surgery in a heterogeneous cohort.

METHODS

A multi-institutional retrospective survey of 141 patients who underwent surgery for giant cell tumor of bone in the extremity was performed. The incidence and risk factors of complications, type of intervention for complication control, and impact of complications on functional and oncological outcomes were analyzed using the Dindo-Clavien classification.

RESULTS

Forty-six cases (32.6%) had one or more complications. Of them, 18 (12.8%), 11 (7.8%), and 17 (12.1%) cases were classified as Dindo-Clavien classification grade I, II, and III complications, respectively. There were no cases with grade IV or V complications. Progression in Campanacci grading (p = 0.04), resection (over curettage, p < 0.0001), reconstruction with prosthesis (p = 0.0007), and prolonged operative duration (p = 0.0002) were significant risk factors for complications. Complications had a significant impact on function (p < 0.0001). Differences in the impact of complication types and tumor location on function were confirmed. Complications had no impact on local recurrence and metastasis development.

CONCLUSION

The Dindo-Clavien classification could provide fundamental information, under a uniform definition and classification system, on postoperative complications in patients with giant cell tumor of bone in terms of incidence, type of intervention for complication control, risk factors, and impact on functional outcome. The data are useful not only for preoperative evaluation for the risk of complications under specific conditions but also for quality assessment of surgery for giant cell tumor of bone.

Primary total knee arthroplasty assisted by computed tomography-free navigation for secondary knee osteoarthritis following massive calcium phosphate cement packing for distal femoral giant-cell bone tumor treatment: a case report

BACKGROUND

Giant cell tumor of bone (GCTB) is an intermediate tumor commonly arising from the epiphysis of the distal femur and proximal tibia. Standard GCTB treatment is joint-preserving surgery performed using thorough curettage and the filling of the cavity with allo-, auto-, polymethyl methacrylate (PMMA), or synthetic bone graft. Calcium phosphate cement (CPC) is an artificial bone substitute, which has the benefit of being able to adjust defects, consequently inducing immediate mechanical strength, and promoting biological healing. Secondary osteoarthritis may occur following GCTB treatment and may need additional surgery if severe. However, details regarding surgery for secondary osteoarthritis have not been fully elucidated. There are no reports on the use of total knee arthroplasty (TKA) for the treatment of secondary osteoarthritis following CPC packing. The insertion of an alignment rod is a standard procedure in TKA; however, it was difficult to perform in this case due to CPC. Therefore, we used a computed tomography (CT)-free navigation system to assist the distal femur cut. This study presents a knee joint secondary osteoarthritis case following CPC packing for GCTB curettage that was treated with standard TKA.

CASE PRESENTATION

A 67-year-old Japanese woman, who was previously diagnosed with left distal femur GCTB and was treated by curettage and CPC packing 7 years ago, complained of severe knee pain. Left knee joint plain radiography revealed Kellgren and Lawrence (K-L) grade 4 osteoarthritis without evidence of tumor recurrence. Therefore, she was scheduled for TKA. There are no reports on the cutting of a femoral condyle surface with massive CPC with accurate alignment. Because it is difficult to insert the alignment rod intramedullary and cut the femoral condyle with CPC, we planned CT-free navigation-guided surgery for accurate bone cutting using an oscillating tip saw system to prevent CPC cracks. We performed standard TKA without complications, as planned. Postoperative X-ray showed normal alignment. Knee Society Knee Score (KSKS) and Knee Society Function Score (KSFS) ameliorated from 27 and 29 to 64 and 68, respectively The patient can walk without a cane postoperatively.

CONCLUSION

There was no report about the surface TKA guided by CT-free navigation after primary GCT surgery with CPC. We believe that this case report will help in planning salvage surgery for secondary osteoarthritis after CPC packing.

Fibular strut allograft or bone cement for reconstruction after curettage of a giant cell tumour of the proximal femur : a retrospective cohort study

AIMS

Giant cell tumours (GCTs) of the proximal femur are rare, and there is no consensus about the best method of filling the defect left by curettage. In this study, we compared the outcome of using a fibular strut allograft and bone cement to reconstruct the bone defect after extended curettage of a GCT of the proximal femur.

METHODS

In a retrospective study, we reviewed 26 patients with a GCT of the proximal femur in whom the bone defect had been filled with either a fibular strut allograft (n = 12) or bone cement (n = 14). Their demographic details and oncological and nononcological complications were retrieved from their medical records. Limb function was assessed using the Musculoskeletal Tumor Society (MSTS) score.

RESULTS

Mean follow-up was 116 months (SD 59.2; 48 to 240) for the fibular strut allograft group and 113 months (SD 43.7; 60 to 192) for the bone cement group (p = 0.391). The rate of recurrence was not significantly different between the two groups (25% vs 21.4%). The rate of nononcological complications was 16.7% in the strut allograft group and 42.8% in the bone cement group. Degenerative joint disease was the most frequent nononcological complication in the cement group. The mean MSTS score of the patients was 92.4% (SD 11.5%; 73.3% to 100.0%) in the fibular strut allograft group and 74.2% (SD 10.5%; 66.7% to 96.7%) in the bone cement group (p < 0.001).

CONCLUSION

Given the similar rate of recurrence and a lower rate of nononcological complications, fibular strut grafting could be recommended as a method of reconstructing the bone defect left by curettage of a GCT of the proximal femur. Cite this article: Bone Joint J 2022;104-B(2):297-301.

Joint Salvage and Biological Repair of Massive-Cavity Bone Defects After Extensive Curettage of Campanacci Grade II or III Giant Cell Tumor Around the Knee With Vascularized Fibular Autograft and Cancellous Allograft

OBJECTIVE

The aim of the study was to report the clinical outcomes of repair of massive-cavity bone defects after extensive curettage of Campanacci grade II or III giant cell tumor (GCT) around knee with vascularized fibular autograft and cancellous allograft.

METHODS

There were 12 consecutive patients with Campanacci grade II or III GCT around knee treated in our department between 2004 and 2016. All the patients underwent clinical evaluation, plain radiography, and/or magnetic resonance imaging of the knee right after admission. To preserve their knee function, we repaired the massive-cavity bone defects after extensive curettage of GCT by vascularized fibular autografts and cancellous allograft. All the patients were evaluated through clinical examinations, plain radiography of the knee and chest, and Musculoskeletal Tumor Society (MSTS) scores of the lower extremity in the follow-ups.

RESULTS

The follow-up ranged from 1.5 to 12.0 years (mean, 4.2 years). There were no local recurrences or lung metastasis in any of the 12 patients at the last follow-up. Ten patients had no pain or experienced occasional pain, and 9 were able to resume their previous work. The mean range of motion of knee flexion was 117 degrees, and the extension was -6 degrees. The mean MSTS score was 24.7, and a total of 10 patients had excellent or good MSTS scores.

CONCLUSIONS

It is reliable to achieve knee joint salvage and repair massive-cavity bone defects after extensive curettage with vascularized fibular autograft and cancellous allograft in patients with Campanacci grade II or III GCT around the knee.

Imaging following surgery for primary appendicular bone tumours

Primary bone tumours are uncommon, with sarcomas accounting for < 0.2% of all malignancies. The survival rate of primary bone sarcomas has significantly improved due to (neo)adjuvant therapy, while improved surgical techniques and development of new prostheses have shifted the surgical focus from amputation to limb preservation in the vast majority of patients. A wide variety of surgical options are available for the treatment of primary bone tumours which depend upon histological diagnosis, their appearance at the time of presentation and response to any (neo)adjuvant therapy as required. This review is intended to help radiologists familiarise themselves with the management of primary appendicular bone tumours and expected normal postoperative appearances for the various surgical techniques, and to recognise potential complications.

Secondary Osteoarthritis After Curettage and Calcium Phosphate Cementing for Giant-Cell Tumor of Bone Around the Knee Joint: Long-Term Follow-up

Giant-cell tumor of bone (GCTB) is a locally aggressive intermediate bone tumor with a rarely metastasizing disposition. Standard surgical treatment consists of curettage, adjuvant treatment, and augmentation with allograft, autograft, or synthetics. Polymethylmethacrylate (PMMA) has been widely used for augmentation of the bone defect; however, the hyperthermic polymerization of PMMA may cause damage to articular cartilage, and the stiffness of the material may decrease the ability of the joint to absorb shock. These properties were reported to result in secondary osteoarthritis. Calcium phosphate cement has a low degree of thermal reaction and a strength that is similar to cortical bone. The aim of the present study was to investigate the incidence of secondary osteoarthritis around the knee joint following augmentation with calcium phosphate cement.

Surgical Treatment Options for Giant Cell Tumors of Bone Around the Knee Joint: Extended Curettage or Segmental Resection?

Aims: This study aimed to compare and evaluate the oncological and functional prognosis of two surgical approaches for giant cell tumor of the bone (GCTB) around the knee joint and provide worthy suggestion for clinical treatment. Patients and Methods: This study included 93 patients, who were divided into the extended curettage (EC) group and segmental resection (SR) group. Relevant preoperative and postoperative data were collected, oncological and functional prognosis were evaluated, and postoperative complications of the two groups were analyzed. Local recurrence was assessed via clinical and radiological tests. Functional prognosis was evaluated using the Musculoskeletal tumor Society (MSTS) scoring system. Results: The EC group had 69 patients; it included 57 primary cases and 12 recurrent cases. The SR group had 24 patients (12 men and 12 women; mean age, 34.9 years), including 15 primary cases and 9 recurrent cases. In this study, six cases (6.5%; EC group, 5 cases; SR group 1 case) recurred within 18 months postoperatively. There was a significant difference in the mean MSTS score between the two groups (p < 0.001). Nononcologic complications occurred frequently in the EC group than in the SR group (28.0 vs. 16.7%), but no complications had serious consequences, and the functional prognosis was not affected. Conclusion: EC and SR for GCTB around the knee joint can achieve satisfactory oncological prognosis, but we should individually select the most suitable surgical method according to Campanacci grade, age, and long-term complications of patients and consider the functional prognosis to ensure excellent oncological prognosis.

Early postoperative compilations of bone filling in curettage defects

Background

Curettage is widely used in orthopedic oncology; the defect created frequently requires filling for mechanical and functional stability for the bones and adjacent joint. Allograft, bone graft substitute, and polymethyl methacrylate (PMMA) are the most common substances used each with their benefits and drawbacks. The aim of the study is to show that good functional result can be achieved with curettage and bone filler, regardless of type.

Methods

A series of 267 cases were reviewed between 1994 and 2015 who received curettage treatment and placement of a bone filler. Endpoints included fracture, infection, cellulitis, pulmonary embolism, and paresthesia. Complication rates at our single institution were compared against literature values for three study cohorts: allograft, bone graft substitute, and PMMA bone fillers. Friedman test, Wilcoxon test, and Z-score for two populations were used to compare our subset against literature values and between different bone filling types.

Results

Our cases included 18 autografts, 74 allografts, 121 bone graft substitute, and 54 PMMA of which the bulk of complications occurred. Our overall complication rate was 3.37%. Allograft has a complication rate of 1.35%, bone graft substitute of 4.13%, and PMMA of 5.56%. Other techniques did not yield any complications. Combination filling techniques PMMA + allograft and PMMA + bone graft substitute had sample sizes too small for statistical comparison. Statistical comparison yielded no significant difference between complications in any of the filling groups (P = 0.411).

Conclusions

Some has even argued that bone defects following curettage do not require bone filling for good outcome. However, many structural or biologic benefits that aid in earlier return to functionality can be conferred by filling large bone defects. There was no significant difference in postoperative complication rates between allograft, bone graft substitute, and PMMA when compared at our institution and with literature values. Nevertheless, one complication with a large defect filled with allograft, requiring a subsequent reconstruction using vascularized fibular graft. Taking everything into account, we see bone graft substitute as a suitable alternative to other bone filling modalities.

A novel subchondral bone-grafting procedure for the treatment of giant-cell tumor around the knee: A retrospective study of 27 cases

The vast majority of giant-cell tumors occur around the knee and characteristically affect the subchondral bone. Thermal damage to the articular cartilage arising from the application of polymethylmethacrylate (PMMA) or extensive intralesional curettage presents a challenging problem to orthopedic surgeons and patients due to compliance issues. For this reason, we developed a new subchondral bone-grafting procedure to restore massive bone defects and reduce degenerative changes in the knee.The aim of this study was to describe the novel subchondral bone-grafting procedure and evaluate clinical outcomes in patients with giant-cell tumors around the knee.This retrospective single-center study included a total of 27 patients with giant-cell tumors in the distal femur and proximal tibia admitted to our department from January 2012 to December 2015 and treated with aggressive intralesional curettage. Eleven males and 16 females were included. All cases underwent subchondral autograft bone grafting followed by bone cement reconstruction and instrument internal fixation. The Musculoskeletal Tumor Society (MSTS) score and short form-36 (SF-36) were applied to assess the functional outcome of the knee joint and quality of life. Tumor recurrence, Kellgren and Lawrence (KL) grade, and the distance of the cement to the articular surface were assessed throughout the sample.All cases were followed up after surgery for an average of 32.9 ± 7.1 months (range 25-57 months). At the end of the follow-up period, all patients were alive and free from pulmonary metastasis. Complications associated with this surgery occurred only in 1 patient (3.7%), who presented with an incision infection that resolved with regular dressing and antibiotics. No fractures, instrument breakage, or joint fluid leakage occurred. Local recurrence occurred in 1 case (3.7%) at the distal femur after 23 months and was treated by wide resection followed by prosthesis reconstruction. Twenty-four patients (89%) did not develop radiographic findings of osteoarthritis: at the final follow-up 2 patients (7.4%), had progressed to KL1 and 1 patient had progressed to KL2. According to the MSTS scoring system, the functional score of the affected knee joint at the last follow-up ranged from 80% to 97%, with an average of 87.3%. The quality of life parameters assessed by the SF-36 survey at the last follow-up ranged from 47 to 96, with an average of 77.For patients with giant-cell tumor of bone near the knee, subchondral bone grafting combined with bone cement reconstruction is recommended as a feasible and effective treatment modality.

Giant cell tumor of the distal femur: Outcome beyond 20 years of follow-up after curettage with polymethylmethacrylate

BACKGROUND

Polymethymethacrylate (PMMA) is often used to reconstruct defects after curettage of Giant Cell Tumors (GCT). While GCTs usually originate in the epiphysis, the use of PMMA in distal femoral lesions may induce the risk of degenerative osteoarthritis (OA). We investigated the limb function of patients after curettage with PMMA beyond 20 years of follow-up.

METHODS

Patients with more than 20 years of follow-up who underwent curettage with PMMA for distal femoral GCTs were observed. We retrospectively investigated the radiographic assessment of OA and functional assessment of the limb. The Kellgren and Lawrence (KL) grading system was used for radiographic evaluation.

RESULTS

Five patients were included in this study. The mean age was 33 years, and the mean period from application of PMMA to final follow-up observation was 28.1 years. Four lesions were primary, and one lesion was recurrent. There were no patients with postoperative recurrence. There were no OA changes in preoperative radiographs. The shortest mean distance from PMMA to the articular cartilage was 4.6 mm on radiographs immediately after surgery. On radiographs at final follow-up observation, the KL grading were as follows: grade 1, 2 patients; grade 2, 1 patient; grade 3, 2 patients. All patients were able to independently ambulate without a crutch, and there was not enough pain to require nonsteroidal anti-inflammatory drugs. The mean flexion of the knee joint was 116°.

CONCLUSIONS

Although PMMA used for distal femoral GCTs exhibited OA changes beyond a 20 year follow-up period, there were no cases requiring artificial joints, and the affected limbs demonstrated good function.

A safety comparative study between freezing nitrogen ethanol composite and liquid nitrogen for cryotherapy of musculoskeletal tumors

Freezing nitrogen ethanol composite (FNEC) showed effective cryoablative ability for bone tumor ex vivo and in vivo comparable to liquid nitrogen (LN). We therefore wished to compare the radiant cooling damage of the surrounding tissue between FNEC and LN. The evaluation of the radiant cooling damage was demonstrated human bone xenograft transplantation (HXT) in a mouse model. Characterizations and quantifications of the damaging effects on morphologic features and apoptosis of the cryoablative surrounding bone tissue, muscle and epidermal layer of skin were compared. The radiant cooled damaging effects including epidermal rupture, hair follicle atrophy, dermis and subcutaneous crystal vacuolation of skin were significantly greater in LN than FNEC. Muscular apoptosis, structural shrinkage and bone cellular apoptosis were supposedly 15%-33% destroying degrees of LN more than FNEC. We concluded that FNEC is an innovative cryogenic material, and it could cause less cryoablative damage to surrounding normal tissue than LN. The findings might support the safety of FNEC being applied in clinical cryoablation therapy.

Mid- to long-term clinical outcome of giant cell tumor of bone treated with calcium phosphate cement following thorough curettage and phenolization

BACKGROUND AND OBJECTIVES

Giant cell tumors of bone (GCTB) are intermediate and locally aggressive bone tumor. Calcium phosphate cement (CPC) is a bone void filler used in orthopaedic surgery. This study investigated the clinical outcome of GCTB treated with thorough curettage, phenolization, and CPC.

METHODS

We investigated 26 patients with at least 36 months of follow-up. The mean age and follow-up were 37 years (range: 19-63) and 87 months (range: 38-169), respectively. Radiological outcomes including consolidation of CPC to the surrounding bone, cortical bone defect remodeling, and clinical outcomes were investigated.

RESULTS

The consolidation of CPC to the surrounding bone was excellent in 22 cases (84.6%), good in three (11.5%), and acceptable in one (3.8%). Local recurrence occurred in three cases (11.5%). Pulmonary metastasis occurred in one case (3.8%). Cortical bone defect remodeling appeared in 22 cases (84.6%). The mean Musculoskeletal Tumour Society score was 28.7 (95.7%). Osteoarthritis, chronic synovitis, and fracture were observed in one case each (3.8%), which were managed conservatively.

CONCLUSIONS

Phenolization did not prevent the consolidation of CPC to the bone. CPC provided biological interface and long lasting stability without internal fixation, with comparable complication rates to other published series.

Does curettage-cement packing for treating giant cell tumors at the knee lead to osteoarthritis?

INTRODUCTION

Giant cell tumors (GCTs) make up 15 to 20% of bone-related tumors in adults. They are often found around the knee in the metaphysis and epiphysis area, contacting the joint cartilage. The aims of our study were to evaluate the presence of early knee osteoarthritis (OA) in patients with GCTs in the knee area treated by curettage-cement packing, and to evaluate whether replacing subchondral bone with acrylic cement has an effect on the functional outcomes and quality of life.

MATERIAL AND METHODS

This was a retrospective study of all patients operated between 2000 and 2010 by the same specialized surgical team. Functional outcomes and quality of life were evaluated in each patient using the Knee Injury and Osteoarthritis Outcome (KOOS), the Musculoskeletal Tumor Society Score (MSTS) and the Short Form-36 (SF-36). The presence of OA was evaluated in a full radiological work-up comparing the operated knee with the healthy contralateral knee. Knee OA was defined as grade 3 or grade 4 radiographic findings based on the Kellgren and Lawrence classification, and a significant difference between the operated and contralateral knee.

RESULTS

Nineteen patients were included in this study. The average follow-up was 120 months (range 60-180). Four patients (21%) had radiographic KL-3 and one patient (5%) had KL-4. Eight patients (42%) had recurrence of the GCT. The distance between the tumor and cartilage, and the area of the subchondral bone invaded by the tumor appeared to contribute to OA progression.

DISCUSSION

Resection of GCTs around the knee by curettage-cement packing did not have an effect on development of OA. In the four patients who developed knee OA, the tumor was located less than 3mm from the joint cartilage and took up more than 90% of the epiphysis. Based on these observations, there seems to be a strong correlation between the development of knee OA and the small quantity of subchondral bone left after curettage. The functional outcomes and quality of life were similar no matter the knee OA grade in patients. Replacing subchondral bone by cement had no effect on quality of life in this study.

LEVEL OF EVIDENCE

IV (retrospective study).

Supplemental Bone Grafting in Giant Cell Tumor of the Extremity Reduces Nononcologic Complications

BACKGROUND

Giant cell tumors (GCTs) are treated with resection curettage and adjuvants followed by stabilization. Complications include recurrence, fracture, and joint degeneration. Studies have shown treatment with polymethylmethacrylate (PMMA) may increase the risk of joint degeneration and fracture. Other studies have suggested that subchondral bone grafting may reduce these risks.

QUESTIONS/PURPOSES

Following standard intralesional resection-curettage and adjuvant treatment, is the use of bone graft, with or without supplemental PMMA, (1) associated with fewer nononcologic complications; (2) associated with differences in tumor recurrence between patients treated with versus those treated without bone grafting for GCT; and (3) associated with differences in Musculoskeletal Tumor Society (MSTS) scores?

METHODS

Between 1996 and 2014, 49 patients presented with GCT in the epiphysis of a long bone. Six patients were excluded, four who were lost to followup before 12 months and two because they presented with displaced, comminuted, intraarticular pathologic fractures with a nonreconstructable joint surface. The remaining 43 patients were included in our study at a mean followup of 59 months (range, 12-234 months). After resection-curettage, 21 patients were reconstructed using femoral head allograft with or without PMMA (JB) and 22 patients were reconstructed using PMMA alone (FRP, KSB); each surgeon used the same approach (that is, bone graft or no bone graft) throughout the period of study. The primary study comparison was between patients treated with bone graft (with or without PMMA) and those treated without bone graft.

RESULTS

Nononcologic complications occurred less frequently in patients treated with bone graft than those treated without (10% [two of 21] versus 55% [12 of 22]; odds ratio, 0.088; 95% confidence interval [CI], 0.02-0.47; p = 0.002). Patients with bone graft had increased nononcologic complication-free survival (hazard ratio, 4.59; 95% CI, 1.39-15.12; p = 0.012). With the numbers available, there was no difference in tumor recurrence between patients treated with bone graft versus without (29% [six of 21] versus 32% [seven of 22]; odds ratio, 0.70; 95% CI, 0.1936-2.531; p = 0.586) or in recurrence-free survival among patients with bone graft versus without (hazard ratio, 0.94; 95% CI, 0.30-2.98; p = 0.920). With the numbers available, there was no difference in mean MSTS scores between patients treated with bone graft versus without (92% ± 2% versus 93% ± 1.4%; mean difference 1.0%; 95% CI, -3.9% to 6.0%; p = 0.675).

CONCLUSIONS

Compared with PMMA alone, the use of periarticular bone graft constructs reduces postoperative complications apparently without increasing the likelihood of tumor recurrence.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Salvage of the proximal femur following pathological fractures involving benign bone tumors

BACKGROUND AND OBJECTIVES

To describe the surgical treatment of patients with a pathologic fracture through a benign tumor of the proximal femur to determine if there is a difference in local recurrence, complications or functional outcome compared to patients with tumors in the same location without pathologic fractures.

METHODS

From 1989-2010, of 97 patients, 29 presented with a pathologic fracture (PF) through a proximal femoral benign bone tumor and 68 presented without a pathologic fracture (NPF). Outcomes of the two groups were compared in terms of surgical management, postoperative complications, local recurrence and functional scores.

RESULTS

Fibrous dysplasia, giant cell tumor of bone and chondroblastoma were the most common subtypes. Most patients were managed with joint preservation in both PF (86.2%) and NPF (98.5%) groups (P = 0.03). Local recurrence risk was similar for patients in the PF (10.3%) and NPF (8.8%) groups. Mean follow-up was 105.7 months (P = 0.8). Functional outcome scores were high in both groups and not statistically significantly different.

CONCLUSIONS

The majority of pathologic fractures through a benign bone tumor of the proximal femur can be successfully treated with curettage, burring, bone grafting and internal fixation without increasing the risk of local recurrence or negatively impacting functional outcome.

Primary total knee arthroplasty twenty years after distal femoral cement augmentation of a giant cell tumor

We present a case of knee reconstruction 20 years after treatment of a giant cell tumor (GCT) with curettage and cementation. There is currently an ongoing debate whether cement or allograft bone is the preferred material for filling the void after GCT curettage. In this case we were able to readily implant a primary total knee replacement without disturbing the existing well-interdigitated large cement bolus and did not require any stems or augments for the reconstruction. Given the ease of TKR implantation in this patient, we feel that the use of cement following curettage of a GCT lesion is a better choice than allograft bone which may not provide enough structural support for the knee reconstruction and lead to a much more extensive procedure.

Does metaphyseal cement augmentation in fracture management influence the adjacent subchondral bone and joint cartilage?: an in vivo study in sheep stifle joints

Augmentation of implants with polymethylmethacrylate (PMMA) bone cement in osteoporotic fractures is a promising approach to increase implant purchase. Side effects of PMMA for the metaphyseal bone, particularly for the adjacent subchondral bone plate and joint cartilage, have not yet been studied. The following experimental study investigates whether subchondral PMMA injection compromises the homeostasis of the subchondral bone and/or the joint cartilage.Ten mature sheep were used to simulate subchondral PMMA injection. Follow-ups of 2 (4 animals) and 4 (6 animals) months were chosen to investigate possible cartilage damage and subchondral plate alterations in the knee. Evaluation was completed by means of high-resolution peripheral quantitative computed tomography (HRpQCT) imaging, histopathological osteoarthritis scoring, and determination of glycosaminoglycan content in the joint cartilage. Results were compared with the untreated contralateral knee and statistically analyzed using nonparametric tests.Evaluation of the histological osteoarthritis score revealed no obvious cartilage damage for the treated knee; median histological score after 2 months 0 (range 4), after 4 months 1 (range 5). There was no significant difference when compared with the untreated control site after 2 and 4 months (P = 0.23 and 0.76, respectively). HRpQCT imaging showed no damage to the metaphyseal trabeculae. Glycosaminoglycan measurements of the treated joint cartilage after 4 months revealed no significant difference compared with the untreated cartilage (P = 0.24).The findings of this study support initial clinical observation that PMMA implant augmentation of metaphyseal fractures appears to be a safe procedure for fixation without harming the subchondral bone plate and adjacent joint cartilage.

The clinical approach toward giant cell tumor of bone

We provide an overview of imaging, histopathology, genetics, and multidisciplinary treatment of giant cell tumor of bone (GCTB), an intermediate, locally aggressive but rarely metastasizing tumor. Overexpression of receptor activator of nuclear factor κB ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated giant cells. Conventional radiographs show a typical eccentric lytic lesion, mostly located in the meta-epiphyseal area of long bones. GCTB may also arise in the axial skeleton and very occasionally in the small bones of hands and feet. Magnetic resonance imaging is necessary to evaluate the extent of GCTB within bone and surrounding soft tissues to plan a surgical approach. Curettage with local adjuvants is the preferred treatment. Recurrence rates after curettage with phenol and polymethylmethacrylate (PMMA; 8%-27%) or cryosurgery and PMMA (0%-20%) are comparable. Resection is indicated when joint salvage is not feasible (e.g., intra-articular fracture with soft tissue component). Denosumab (RANKL inhibitor) blocks and bisphosphonates inhibit GCTB-derived osteoclast resorption. With bisphosphonates, stabilization of local and metastatic disease has been reported, although level of evidence was low. Denosumab has been studied to a larger extent and seems to be effective in facilitating intralesional surgery after therapy. Denosumab was recently registered for unresectable disease. Moderate-dose radiotherapy (40-55 Gy) is restricted to rare cases in which surgery would lead to unacceptable morbidity and RANKL inhibitors are contraindicated or unavailable.