Giant Cell Tumor (GCT) is a common primary bone tumor, accounting for about 5% of primary bone tumors, and is aggressive and recurrent. The local recurrence rate is high with lesion scraping alone, and low with resection of tumor segments and reconstruction of artificial joints or large segments of allograft bone, but the patient’s own joint function (Native joint function) is significantly impaired. With the increasing understanding of the biological behavior of tumors and the improvement of surgical techniques, lesion curettage has been transformed into Aggressive curettage [1]. This means that a high-speed grinding drill is used to grind the tumor wall to enlarge the incision and scraping area, and then the bone cavity is treated with pulse pressure irrigation and chemical agents (phenol, alcohol and bone cement) to obtain a marginal resection. We followed up 16 cases of adjacent knee GCT treated in our department from January 2008 to October 2010, and all of them were treated with expanded scraping of the tumor in the lesion, bone cement filling and plate internal fixation combined with diphosphonates to observe the recurrence status of the tumor and joint function and evaluate their recent treatment results. Yu Xiuchun, Department of Orthopedics, General Hospital of Jinan Military Region
1 Materials and methods
1.1 Clinical data
The 16 patients in this group were complete cases admitted from January 2008 to October 2010, 7 males and 9 females, age 27-78 years old, average 38 years old. Site of lesion: 10 cases of distal femur and 6 cases of proximal tibia. There were 12 cases of primary giant cell tumor of bone and 4 cases of recurrent cases.
1.2 Clinical diagnosis and staging.
Clinical and imaging assessments were performed using X-ray radiographs, CT, MRI and other imaging examinations. All primary cases underwent preoperative lesion puncture biopsy to clarify the diagnosis of giant cell tumor of bone and determine Campanacci typing, including 2 cases of type I, 11 cases of type II and 3 cases of type III.
1.3 Surgical method and adjuvant treatment
According to the location of the lesion, the surgical approach was determined, the outer wall of the lesion was fully exposed according to the principle of tumor-free operation, the surrounding soft tissues were protected, a large bone window was opened as far as possible from the edge of the lesion, the tumor tissue was scraped away with a scraping spoon, the resection area was enlarged with a high-speed grinding drill, the cortical bone of the tumor wall was abraded until smooth, the cancellous bone was enlarged and abraded by 0.5~1.0 cm, and the tumor wall was cauterized with an electric knife, and the lesion was flushed with a large amount of distilled water under pulse pressure. A suitable anatomical steel plate was selected, drilled and tapped in the normal bone stem and tumor wall, a screw of suitable length was selected and temporarily screwed in, and the screw was screwed out after mastering the angle of nail entry, and only one temporary fixed steel plate was used; the steel plate was lifted, filled with bone cement, and the screw was quickly tightened along the original nail path (Figure 1).
All patients were given 10 mg/day of alendronate tablets orally for 2 months after surgery, followed by 1 month of rest for 1 year.
1.4 Postoperative review follow-up
Postoperative follow-up was obtained for all patients. The follow-up period was 2-36 months (as of January 2011), with a median follow-up time of 15 months. Review method: X-ray was taken every 3 months for 2 years after surgery and every 6 months after 2 years. Pulmonary CT was performed every 6 months. At the same time of review, a functional score was given according to the Enneking Limb Functional Reconstruction Scale [2].
2 Results
2.1 Oncological follow-up results
All patients in this group were followed up for 2-36 months (as of January 2011), with a median follow-up time of 15 months, and no local recurrence or metastasis has occurred.
2.2 Limb function
All patients had one-stage healing of the incision, and functional exercises of the affected knee started 3-5 days after surgery, and weight-bearing activities started on day 14. The limb function basically recovered 1 month after surgery. Only one patient had pain during knee flexion due to a screw that was too long, and the screw was removed by surgery again. Referring to the Enneking Limb Function Scale, the average score of this group of patients was 29 (27-30 ) as of January 2011 (Figure 1).
Figure 2 Male, 41 years old, recurrent postoperative giant cell tumor of the right distal femur. a 1 year after tumor scraping and bone grafting on 2009-3-26, the radiograph showed osteolytic destruction and cortical thinning at the medial condyle. b, c MR showed high and low mixed signal at the distal femur on T2-weighted image, and the tumor was seen to break through the posterior lateral cortex in transverse view. d 4 days after reoperation on 2009-4-14, satisfactory bone cement filling and firm internal fixation were seen. e 2010-10-11 22 months after surgery On 2010-10-11, 22 months after surgery, the joint space was normal, there was no translucent zone around the bone cement, and the internal fixation was firm; f On 2010-10-11, 22 months after surgery, the joint function was normal.
2.3 Imaging results
All patients took X-ray films every 3 months within 2 years after surgery and every 6 months after 2 years. As of January 2011, all patients in this group had secure internal fixation and no subchondral bone fractures. Four patients had translucent bands at an average follow-up of 8 months (4-13 months), all located around the bone cement, evenly distributed, and surrounded by a sclerotic border (Figure 2), which were found not to have progressed through follow-up.
Figure 3 Female, 30 years old, giant cell tumor of the left proximal tibia. a On 2009-1-4, 4 days after surgery, the radiograph showed satisfactory cement filling and firm internal fixation. b On 2010-11-16, 23 months after surgery, a translucent band around the cement with sclerotic edges was seen. The joint gap was normal and the internal fixation was firm.
3 Discussion
Giant cell tumor of bone is a more common primary bone tumor in clinical practice, and although it is benign, it is prone to recurrence after surgery because of its strong local aggressiveness. Currently, two types of surgical procedures, intra-focal scraping and whole-block resection, are usually adopted in clinical practice. The recurrence rate of intra-focal surgery alone is high. Early literature reported that the recurrence rate after intra-focal scraping and bone grafting for giant cell tumor of bone is about 29%-75%. Whole resection has a low recurrence rate, but destroys its own joint function and requires the application of artificial joints or large segments of allograft bone for reconstruction, which inevitably leads to various complications and poor long-term results in the case of long-term survival.
With the increasing awareness of local aggressiveness of giant cell tumor of bone and the continuous improvement of surgical techniques, some scholars at home and abroad have proposed the concept of Aggressive curettage. Algawahmed et al [3] performed a Meta-analysis of 13 articles on the application of high-speed abrasive drilling with or without other adjuvant methods in giant cell tumor lesions, and concluded that in the application of high-speed abrasive drilling with or without other adjuvant methods Of the 323 patients who applied high-speed abrasive drilling in combination with other adjuvant methods, 66 recurred (20%); of the 64 patients treated with high-speed abrasive drilling alone, 15 recurred (23%). The authors noted that the use of high-speed grinding drills was the most important method to reduce the local recurrence rate. Expanded resection for limb bone giant cell tumors greatly preserves the function of the limb and reduces the recurrence rate of the tumor. There is no uniform standard for the surgical indications of extended curettage, and we believe that a comprehensive assessment of the biological behavior of giant cell tumor of bone should be performed preoperatively, including tumor growth, clinical progression process, pathology and imaging seen. For giant cell tumor of the limb without pathologic fracture, the location and scope of the tumor are relatively limited, and the imaging Campanacci grade III is not a contraindication for focal scraping.
Giant cell tumors of the limb often occur near the knee joint, and because the age of onset is mostly in middle age, patients have a long survival time and high functional demands on the limb. If intra-lesion scraping and bone grafting is used alone, sometimes a large amount of bone is required, and if the bone graft is resorbed, it is difficult to distinguish from recurrence, and protective weight-bearing is required until the bone heals, which affects the recovery of joint function. Bone cement has long been used as a filling material for filling lesions in giant cell tumors of bone, and it has the following advantages: 1. immediate reconstruction of the bone defect, restoration of bone continuity, and early postoperative weight bearing; Frassica et al [4] confirmed through biomechanical studies that the application of bone cement to reconstruct bone defects can restore 98% of mechanical strength. 2. the heat released during cement polymerization can form a high temperature on the edge of the lesion Kivioja et al [5] followed 147 patients with intra-lesion scraping and cement filling, and the postoperative recurrence rate was 22%, while 47 patients with scraping and bone grafting had a 52% postoperative recurrence rate. kafchitsas et al [6] performed scraping in 38 patients with giant cell tumor of bone, and 21 of them applied bone cement filling, and their recurrence rate was 23.8%, while the other 17 patients who underwent bone grafting had a postoperative recurrence rate of 52.9%.3. Patients with recurrence can be detected early from radiographs.Kafchitsas et al [6] performed imaging follow-up of 21 patients who applied bone cement filling and found a progressive translucent band between the bone cement and bone in four of the five patients with recurrence, and the authors concluded that this phenomenon could be a The authors concluded that this phenomenon could be a reliable indicator of tumor recurrence. The authors also found a translucent band averaging 1.4 mm with a sclerotic border for the first 6 months postoperatively in cement-filled patients, which usually did not progress and did not interfere with internal fixation. The width of the translucent band was found to be related to the size of the cement volume, and it is believed that thermal cautery and micromovement of the cement are responsible for the translucent band, and the progressive translucent band suggests tumor recurrence. In our group, four patients showed a uniformly distributed translucent zone around the bone cement with a sclerotic border at an average follow-up of 8 months (4-13 months), which may be related to the thermal burn of the bone cement.
Periprosthetic osteomegaloblastic tumors tend to involve the subchondral bone and sometimes even adhere to the articular cartilage. Filling with bone cement can theoretically degenerate and fracture the cartilage due to thermal burn or micromovement of the bone cement, leading to the development of osteoarthritis. fraquet et al [7] performed tumor scraping bone cement filling in 30 patients with periosteal osteoblastoma, 73% of whom were close to the articular cartilage, and only 2 patients developed minor joint degeneration through a mean follow-up of 6.4 years. von Steyern et al [8] performed tumor scraping bone cement filling in 9 patients with periosteal osteoblastoma of the adjacent patients with osteomegaloblastoma of the knee with tumor scraping and bone cement filling, the distance between the bone cement and the articular cartilage ranged from 0 to 3.5 mm, with a mean of 1 mm, including 3 cases with 0 mm. Follow-up ranged from 6 to 16 years, with only one case showing narrowing of the medial joint space on postoperative weight-bearing radiographs, MR showing the presence of articular cartilage, and gadolinium contrast-enhanced and delayed-enhanced MR scans showing articular cartilage damage. The authors emphasized the need for preoperative articular cartilage continuity and pointed out that the strength of the subchondral filler is an important factor affecting articular cartilage degeneration, and it has been demonstrated in animal experiments that replacing subchondral bone with bone cement does not reduce its strength. In addition, articular cartilage relies mainly on synovial nutrition and less on blood supply. Therefore, the effect of bone cement filling on articular cartilage is not as severe as theoretically speculated. None of the 16 patients in this group showed clinical symptoms of osteoarthritis, and further observation is needed due to the short follow-up period.
There are few studies on when internal fixation is needed after cement filling, but we believe that internal fixation is very necessary. Fraquet et al [7] suggested that if internal fixation is not applied, the cement will produce a bead effect (Bead effect) due to stress that loosens the cement leading to resorption of the surrounding bone and pathological fracture of the subchondral bone (Figure 3). In contrast, the cement is locked into place with the bony shell by internal fixation, preventing loosening from occurring. This author performed internal fixation to strengthen 16 of 30 patients with osteomegaloblastic tumors of long bones, and no bead effect of bone cement was observed. Professor Yang Zhengming proposed [9] that surgical treatment of osteoblastic giant cell tumor of the adjacent knee can be based on CT cross-section, tumor destruction size, and the choice of surgery. Type I tumor destruction maximum diameter is less than 1/2 bone diameter, intra-focal surgery with autologous or allogeneic bone support bone graft or bone cement filling can be performed; (2) Type II tumor destruction maximum diameter is between 1/2 and 3/4, type I treatment is based on the addition of internal fixation; ( 3) Type III tumor destruction diameter > 3/4 bone diameter, allogeneic hemiarthroplasty or artificial joint replacement after whole block resection. We think it is a scientific method to choose the surgery by the area of tumor destruction, but we also need to consider the tumor invasion of subchondral bone, if the tumor is close to the cartilage surface, even type Ⅰ tumor needs internal fixation.
Bisphosphonates have significant therapeutic effects on osteoclast-mediated bone destruction such as bone metastases, and giant cell tumors of bone are also osteolytic lesions mediated by osteoclasts. There have been clinical studies of bisphosphonates as adjuvant therapy for giant cell tumor of bone, Tse et al [10] conducted a retrospective controlled study of 44 patients with giant cell tumor of bone, in which 24 patients were treated with disodium pamidophosphate or zoledronic acid in 2 preoperative and 3 postoperative courses, followed by oral administration of disodium clodronate for 3 months. After 48 to 115 months of follow-up, the recurrence rate was 4.2% (1/24) in the drug group and 30% (6/20) in the control group. However, due to the small sample of the study trial and the short follow-up period, as well as the many factors that influence the recurrence rate, it is not certain that bisphosphonates can reduce the recurrence rate of bone giant cell tumors.
In our group of 16 patients, we applied expanded scraping within the lesion, bone cement-filled plate internal fixation, and combined postoperative application of the diphosphonate drug alendronate sodium orally, and no recurrence cases have been found. In clinical treatment, we believe that this method has the advantages of simple operation, ideal recovery of limb function, low recent recurrence rate, and easy acceptance by patients. The median follow-up time of our group is 15 months, and we need to continue to increase the number of cases and follow-up time in future studies.