Limited Revision with a Newly Designed Hinge Device for the Treatment of Mega-Prosthesis Hinge Failure: Two Case Reports.

BACKGROUND: Surgical treatment for hinge failure in mega-prosthesis continues to be a challenge. This study introduces a new method for treating hinge failure by using a unilateral prosthesis and hinge revision. CASE PRESENTATION: We here present two patients who underwent mega-prosthesis reconstruction after resection of osteosarcoma in the distal femur. To address the issue of knee hyperextension after mega-prosthesis reconstruction, one patient underwent three revision surgeries, two surgeries were performed using the original hinge, and one surgery involved a newly designed hinge. To resolve the problem of dislocation, one patient underwent three revisions, with the first two revisions not involving hinge replacement and the third revision involving a newly designed hinge. Two replacements of unilateral prosthesis and hinge renovations were successful. CONCLUSIONS: Unilateral prosthesis and newly designed hinge device revision are effective in treating the failure of old-fashioned mega-prosthesis hinges.

Using 3D Printing Technology to Design Split-Piece Sleeve Prosthesis in the Revision Surgery of Tumor-Type Total Elbow Prosthetic Fractures: A Case Report.

BACKGROUND: Revision of tumor-type prosthetic fractures is very challenging in clinical work. Traditional repair methods may not be able to meet the needs of complex cases or cause greater bone damage. Therefore, more effective and reliable solutions need to be found. CASE PRESENTATION: This study presents a novel revision technique for managing fractures of tumor-type total elbow prostheses. A 57-year-old female patient was diagnosed with a left distal humeral bone tumor accompanied by pathological fracture and underwent customized tumor-type total elbow prosthesis arthroplasty. After 5 years, she experienced pain and encountered difficulty in flexing the left elbow while lifting heavy objects. The X-ray examination revealed a fracture of the distal humeral prosthesis. As a response, the elbow joint was initially explored, and the damaged component of the prosthesis was extracted. Subsequently, we utilized 3D printing technology to design a split-piece sleeve prosthesis and effectively restored the fractured left distal humerus implant. During the 2-year follow-up, The X-ray demonstrated satisfactory positioning of the prosthesis, which remained securely affixed without any indications of loosening. The Mayo Elbow Performance Score (MEPS) reached 80 points, the Musculoskeletal Tumor Society (MSTS) attained a score of 28 points, and the range of motion of the elbow was measured between 25° and 110°, revealing favorable functional outcomes. CONCLUSION: The utilization of a 3D printed split-piece sleeve prosthesis presents a viable clinical treatment strategy for addressing fractures in tumor-type elbow prostheses.

Using 3D Printing Technology to Manufacture Personalized Bone Cement Placeholder Mold for Bone Defect Repair and Reconstruction with Infection: A Case Report.

BACKGROUND: Limb salvage surgery is the preferred treatment for most malignant bone tumors, but postoperative infection treatment is very challenging. Simultaneously controlling infection and solving bone defects are clinical treatment challenges. CASE PRESENTATION: Here we describe a new technique for treating bone defect infection after bone tumor surgery. An 8-year-old patient suffered an incision infection after osteosarcoma resection and bone defect reconstruction. In response, we designed her a personalized, anatomically matched, antibiotic-loaded, bone cement spacer mold using 3D printing technology. The patient's infection was cured, and limb salvage was successful. In follow-up, the patient had returned to normal postoperative chemotherapy and was able to walk with the help of a cane. There was no obvious pain in the knee joint. At 3 months after operation, the range of motion of the knee joint was 0°-60°. CONCLUSION: The 3D printing spacer mold is an effective solution for treating the infection with large bone defect.

Conservative surgery with microwave ablation for recurrent bone tumor in the extremities: a single-center study.

BACKGROUND: Surgical treatment for recurrent bone tumors in the extremities still presents a challenge. This study was designed to evaluate the clinical value of microwave ablation in the treatment of recurrent bone tumors. METHODS: We present 15 patients who underwent microwave ablation for recurrent bone tumors during the last 7 years. The following parameters were analyzed for outcome evaluation: general condition, surgical complications, local disease control, overall survival, and functional score measured using the Musculoskeletal Tumor Society (MSTS) 93 scoring system. RESULTS: Percutaneous microwave ablation in one patient with osteoid osteoma and another with bone metastasis resulted in postoperative pain relief. Thirteen patients received intraoperative microwave ablation before curettage or resection, including those with giant cell tumors of bone (6), chondroblastoma (2), osteosarcoma (2), undifferentiated sarcoma (1), and bone metastases (2). All patients achieved reasonable local tumor control in the mean follow-up of 29.9 months. The functional score was 24.1 for the 15 patients 6 months after the operation. Four patients had tumor metastasis and died, whereas 3 patients with tumors survived, and the remaining 8 patients without the disease survived. CONCLUSIONS: Microwave ablation represents an optional method for local control in treating recurrent bone tumors in the extremities.

Classification and reconstruction of femoral bone defect in the revision of aseptic loosening of distal femoral endoprostheses: a 10-year multicenter retrospective analysis.

OBJECTIVE: This study proposes a system for classifying the aseptic loosening of distal femoral endoprostheses and discusses reconstruction methods for revision surgery, based on different classification types. METHODS: We retrospectively analyzed the data of patients who received revision surgery for aseptic loosening in distal femoral tumor endoprosthesis from January 2008 to December 2020 at 3 bone tumor treatment centers in China. Based on the patient imaging data, we proposed a classification system for the aseptic loosening of distal femoral endoprostheses and discussed its revision surgery strategy for various bone defects. RESULTS: A total of 31 patients were included in this study, including 21 males and 10 females aged 15-75 y (average: 44.3 y). First-revision surgery was performed on 24 patients, whereas second-revision surgery was conducted on 7 patients. The 31 patients were classified into different types based on the degree of aseptic loosening: Type I, 12 patients (38.7%); Type IIa, 7 patients (22.5%); Type IIb, 7 patients (22.5%); Type III, 4 patient (12.9%); and Type IV, 1 patient (3.2%). For type I, 11 patients underwent revisions with standard longer-stem prostheses (one with the original prosthesis), and one patient had the original prosthesis plus cortical allograft strut. For type II (a and b), 10 patients underwent revisions with original prosthesis or longer-stem prosthesis and 4 patients combined with cortical allograft strut. For type III, one patient underwent revision with a longer-stem prosthesis and the other 3 patients with a custom short-stem prosthesis. For type IV, only one patient underwent revision with a custom short-stem prosthesis. CONCLUSIONS: Aseptic loosening of the distal femoral prosthesis can be divided into 4 types: type I, type II (a, b), type III and type IV. The reconstruction methods of our centers for different types of bone defects can offer some reference value in the revision of aseptic loosening.

Radiographic Assessment of Aseptic Loosening of Tumor-Type Knee Prosthesis in Distal Femur.

OBJECTIVE: To measure the full-length anteroposterior and lateral radiographs of lower limbs after the resection of a tumor in the distal femur and tumor-type knee prosthesis replacement and to analyze the factors leading to aseptic loosening of the prosthesis. METHODS: A total of 26 cases of tumor-type knee prosthesis replacement or revision due to the distal femoral tumor at our hospital from January 2007 to December 2019 were retrospectively analyzed. The patients were divided into the loosening and unloosening groups depending on whether aseptic loosening occurred after surgery. Full-length anteroposterior and lateral radiographs of lower limbs were used to measure bone resection length, length of prosthesis, distance of proximal apex of the medullary stem of the femoral prosthesis from the maximum arc of the anterior femoral arch, diameter of the medullary stem, etc. Data were analyzed, and the risk factors for aseptic loosening of the prosthesis were explored. RESULTS: The ratio of the prosthetic length to the femoral length (63.72 ± 5.21) and the ratio of the femoral medullary stem diameter to the femoral diameter (26.03 ± 8.45) were smaller in the loosening group than in the unloosening group. The difference was statistically significant (p < 0.05). The distance between the apex of the medullary stem and the maximum arc of the anterior femoral arch was significantly shorter in the loosening group (3.47 ± 2.96) than in the unloosening group, and the difference was statistically significant (p < 0.05). The measurement of the lower limb alignment showed significant differences between the loosening and unloosening groups in terms of HKAA, mLDFA, and distance between the lower limb alignment and the center of the knee joint (p < 0.05). The logistic regression analysis showed that less than 30% ratio between the medullary stem diameter and the femoral diameter, less than 3 cm distance between the apex of the medullary stem and the maximum curvature of the anterior arch of the femur, distance between the lower limb alignment and the center of the knee joint, and presence of varus knee and valgus knee after the surgery were the risk factors for aseptic loosening of the prosthesis. CONCLUSIONS: The diameter of the femoral medullary stem of the prosthesis, the apex position of the prosthetic stem, and the lower limb alignment are the risk factors for aseptic loosening of the prosthesis.

A New Simple and Practical Clinical Classification for Tenosynovial Giant Cell Tumors of the Knee.

OBJECTIVE: To propose a simple and practical clinical classification for tenosynovial giant cell tumor (TGCT) of the knee. METHODS: A retrospective study was conducted to verify the value and significance of this clinical classification. TGCT growth patterns, knee joint capsule, and bone erosion were applied to establish this novel clinical classification. Seventy-eight patients who underwent surgery for TGCT from 2008 to 2016 were identified. This novel clinical classification was retrospectively applied to patients' existing classification, and patients with different TGCT types were statistically compared to verify the significance of the clinical classification. RESULTS: The clinical classification included three types and four subtypes. Type 1: localized TGCT, Subtype 1a: localized intra-articular TGCT, Subtype 1b: localized extra-articular TGCT. Type 2: diffuse TGCT, Subtype 2a: diffuse intra-articular TGCT with bone normal, Subtype 2b: diffuse intra-articular TGCT with bone destruction. Type 3: diffuse TGCT across the knee joint capsule. The mean follow-up time for the 78 patients was 59.6 months. Twenty-one patients were in Subtype 1a, four were Subtype 1b, 38 were Subtype 2a, seven were Subtype 2b, and eight were Type 3. Oncological results and surgical complications differed significantly (P = 0.000, P = 0.000). The mean Musculoskeletal Tumor Society functional scores differed significantly at 27.8 for Type 1 patients, 22.9 for Type 2 patients, and 17.0 for Type 3 patients (P = 0.000). CONCLUSIONS: This clinical classification can be easily used to evaluate TGCT of all knees prior to surgery or other treatments and can help determine surgical options.

Guideline for Limb-Salvage Treatment of Osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumor, occurring mainly in children and adolescents, and the limbs are the main affected sites. At present, limb-salvage treatment is considered as an effective basic standard treatment for osteosarcoma of the limb. China has a vast territory, but the development of technology is not balanced,which requires sufficient theoretical coverage, strong technical guidance and the application of limb-salvage treatment guidelines to the treatment of osteosarcoma. Therefore, to standardize and promote the development of limb-salvage surgery technology and improve the success rate of limb-salvage treatment, this guide systematically introduces limb-salvage techniques for the treatment of patients with limb osteosarcoma through definition of limb-salvage treatment, surgical methods, efficacy evaluation, postoperative treatment and prevention of complications, rehabilitation guidance, and follow-up advice.

Influence of Congruency Design on the Contact Stress of a Novel Hinged Knee Prosthesis Using Finite Element Analysis.

OBJECTIVES: To investigate the contact stress and the contact area o tibial inserts and bushings with respect to different congruency designs in a spherical center axis and rotating bearing hinge knee prosthesis under gait cycle loading conditions using finite element analysis. METHODS: Nine prostheses with different congruency (different degrees of tibiofemoral conformity and different distances between the spherical center and the bushing) designs were developed with the same femoral and tibial components. The models were transferred to finite element software. The peak contact stresses and contact areas on tibial inserts and bushings under the gait cycle loading conditions were investigated and compared. RESULTS: For tibial insert, the peak contact stress was the highest in the low conformity-long group (61.4486 MPa), and it was 1.88 times higher than that in the group with the lowest stress (moderate conformity-short group, 32.754 MPa). The contact area was the largest in the low conformity-long group (420.485 mm2 ), and it was 1.19 times larger than that in the group with the smallest area (moderate conformity-middle group, 352.332 mm2 ). For bushing, the peak contact stress was the highest in the high conformity-long group (72.8093 MPa), and it was 3.21 times higher than that in the group with the lowest stress (high conformity-short group, 22.6928 MPa). The contact area was the largest in the low conformity-short group (2.41 mm2 ), and it was 2.27 times larger than that in the group with the smallest area (high conformity-middle group, 1.063 mm2 ). CONCLUSION: The results of our study showed that the congruency of the tibiofemoral surface and bushing surface should be considered carefully in the design of the spherical center axis and rotating bearing hinge knee prosthesis. Different levels of contact performance were observed with different congruency designs. In addition, the influence of contact stress and contact area on the polyethylene wear of rotating hinge knee prostheses should be confirmed with additional laboratory tests.

Establishment and validation of a nomogram model for periprosthetic infection after megaprosthetic replacement around the knee following bone tumor resection: A retrospective analysis.

BACKGROUND: Due to the particularity of patients with bone tumors, the risk of periprosthetic infection following megaprosthetic replacement is much higher than that of traditional total knee arthroplasty. Unfortunately, few studies specifically reported the risk factors for periprosthetic infection following megaprosthetic replacement. The purposes of the study were to (1) establish a nomogram model, which can provide a reference for clinicians, and patients to reduce the occurrence of periprosthetic infection (2) explore the risk factors for deep infection of megaprosthesis. HYPOTHESIS: A prediction model can be established and has favorable predictive accuracy. PATIENTS AND METHODS: One hundred and seventy-seven megaprostheses were identified. There were 61 female patients and 116 male patients with a mean age of 35 years. The following risk factors were analyzed: tumor site, sex, age, material for prosthetic stem, tumor type, smoking, diabetes, length of bone resection, operation time, chemotherapy, BMI, malignant tumor staging and hematoma formation. Finally, based on the multivariate analysis, the independent risk factors were used to develop a nomogram model. RESULTS: Univariate Cox regression analysis showed that the chemotherapy, longer operation time and hematoma formation were risk factors for periprosthetic infection. Multivariate Cox regression analysis showed that the chemotherapy, longer operation time and hematoma formation were significant risk factors for periprosthetic infection. The nomogram model was established using these significant risk factors, with a C-index of 0.766 and an acceptable consistency according to the internal validation, indicating that the prediction model had favorable predictive accuracy. DISCUSSION: This study has important implications for the future investigations of prevention of periprosthetic infection. The nomogram model identifies high-risk patients for whom attached prophylaxis measures are required. Future studies regarding reduction of incidence of periprosthetic infection should pay close attention to these high-risk patients. LEVEL OF EVIDENCE: IV, retrospective, cohort study.

Surgical Outcomes and Prognostic Factors of Myxoid Liposarcoma in Extremities: A Retrospective Study.

OBJECTIVES: To evaluate treatments and prognostic factors for the myxoid liposarcoma in extremities. METHODS: We retrospectively reviewed 34 patients histologically diagnosed with myxoid liposarcoma arising in the extremities, treated in our hospital from 2010 to 2017. We recorded tumor locations, max diameter, operations, complications, radiation, chemotherapy, survival, recrudescence, and metastases. Overall survival, treatments, and prognostic factors were subsequently analyzed. RESULTS: The mean age of 34 patients with myxoid liposarcoma in extremities was 49.1 years, and the mean follow-up period was 65.1 months. The median survival time was 190 months. Five of 14 patients accepted recrudescence resection and two patients of 20 patients who underwent primary tumor resection or unplanned operation died of tumor progression. Although no statistical difference was found (X 2 = 3.331, P = 0.068), the lower mortality was confirmed in the patients who accepted primary tumor resection or unplanned operation. Eleven patients with a tumor diameter of 8.6 ± 4.7 cm accepted wide resection, while 23 patients with 17.2 ± 8.8 cm tumors accepted marginal resection. Statistical difference was found between the size of tumors with relatively wide resection and those with relatively marginal resection (F = 9.130, P = 0.005). No recurrence or metastasis occurred in patients who accepted wide resection, while 14 patients presented with local recurrence and 8 patients developed distant metastases among the 23 patients with marginal resection. Seven patients died of metastases, while one patient lived with metastases. No significant difference in survival was found between different surgical methods (X 2 = 0.9460, P = 0.3307). The average diameter of eight patients with distant metastases was 21.7 cm, which was considerable larger than the 12.1 cm of patients without metastasis. This difference was proven significant upon the statistical analysis (F = 9.412, P = 0.004). CONCLUSIONS: Wide resection achieved good local control but was not unambiguously superior in long-term survival. Myxoid liposarcoma tumors with larger diameters were more difficult to be submitted to wide resection and were more likely to present with distant metastasis.

En Bloc Resection and Pelvic Ring Reconstruction for Primary Malignant Bone Tumors Involving Sacroiliac Joint.

OBJECTIVE: To observe the process of sacroiliac joint invasion by primary malignant tumors of sacrum and iliac bone, and to explore the methods of surgical resection and reconstruction. METHODS: From January 2009 to November 2017, there were nine patients with primary malignant bone tumors involving sacroiliac joints, five males and four females, aged from 16 to 63 years, with an average age of 35 years. Of these there were three cases of primitive neuroectodermal tumors, three cases of chondrosarcoma, and three cases of osteosarcoma. Pelvic ring reconstruction was performed with longitudinal half sacrum, sacroiliac joint and partial iliac bone block excision and screw-rod system combined with bone grafting. RESULTS: The operation time was 155-310 min, with an average of 245 ± 55 min, and the bleeding volume was 1400-8500 ml, with an average of 3111 ± 2189 ml. Follow-up ranged from 5 to 108 months, with a median follow-up of 24 months. Three patients (33.3%) had local recurrence, three patients (33.3%) survived without tumors, and one patient had lung metastasis 2 years after operation, and survived with tumors. Five patients (55.6%) died, of which four died of lung metastasis and one died of brain metastasis. Survival analysis showed that the 3-year overall survival rate was 57%. Bone grafts did not heal in four patients, and bone grafts healed in five patients. The healing time ranged from 5 to 7 months, with an average of 6.2 months. COMPLICATIONS: one patient developed deep infection 2 months after operation; one patient had skin edge necrosis; titanium rod loosening and displacement were found in two patients with nonunion of bone graft, and no fracture of nail rod was found. The MSTS 93 functional score of nine patients ranged from 20% to 50%, with an average of 34%. CONCLUSION: The tumors around the sacroiliac joint often invade the contralateral bone by ligament, and the en bloc resection and pelvic ring reconstruction for primary malignant bone tumors involving sacroiliac joint was feasible.

Establishment and validation of a nomogram model for aseptic loosening after tumor prosthetic replacement around the knee: a retrospective analysis.

BACKGROUND: Aseptic loosening has become the main cause of prosthetic failure in medium- to long-term follow-up. The objective of this study was to establish and validate a nomogram model for aseptic loosening after tumor prosthetic replacement around knee. METHODS: We collected data on patients who underwent tumor prosthetic replacements. The following risk factors were analyzed: tumor site, stem length, resection length, prosthetic motion mode, sex, age, extra-cortical grafting, custom or modular, stem diameter, stem material, tumor type, activity intensity, and BMI. We used univariate and multivariate Cox regression for analysis. Finally, the significant risk factors were used to establish the nomogram model. RESULTS: The stem length, resection length, tumor site, and prosthetic motion mode showed a tendency to be related to aseptic loosening, according to the univariate analysis. Multivariate analysis showed that the tumor site, stem length, and prosthetic motion mode were independent risk factors. The internal validation indicated that the nomogram model had acceptable predictive accuracy. CONCLUSIONS: A nomogram model was developed for predicting the prosthetic survival rate without aseptic loosening. Patients with distal femoral tumors and those who are applied with fixed hinge and short-stem prostheses are more likely to be exposed to aseptic loosening.

Efficacy of a Modified Scoring System to Facilitate Surgical Decision-making for Diaphyseal Malignancies: When is Devitalized Tumor-bearing Autograft of Value?

OBJECTIVES: To evaluate the validity of a modified scoring system (MSS) for inferring the bony quality of tumor-bearing diaphyses and predicting the risk of reconstructive failure after devitalized bone replantation (DBR). METHODS: In this retrospective cohort study, we reviewed the records of 30 patients surgically treated for diaphyseal malignancies between 1996 and 2015. There were 18 male and 12 female subjects; the average age was 34.0 ± 24.5 years (8-82 years). Tumor locations comprised the femur (21), the humerus (4), the tibia (3), the radius (1), and the fibula (1). Histological diagnoses included osteosarcoma (13), metastases (4), Ewing sarcoma (3), chondrosarcoma (3), malignant fibrohistiocytoma (2), periosteal osteosarcoma (1), Langerhans cell sarcoma (1), lymphoma (1), rhabdomyosarcoma (1), and malignant giant cell tumor (1). All primary tumors were rated as stage IIB. Twenty patients underwent DBR. Prosthetic procedures and segmental autografting/allografting were performed in 7 and 3 cases, respectively. MSS (comprising 5 elements: pain, tumor location, bone destruction, localized dimension, and longitudinal dimension) for each patient was calculated in accordance with their preoperative presentations. Outcome measurements included oncological results, outcomes of reconstructions, complications, and functional preservation, presented using the musculoskeletal tumor society (MSTS) scale. RESULTS: Follow up was available in 29 cases for an average duration of 61.0 ± 49.9 months (12-152 months). Infection occurred in 2 patients (6.9%), primary nonunion in 6 (27.3%), metastases in 9 (31.9%), recurrences in 4 (13.8%), and deaths in 7 (24.1%); 1 subject underwent amputation due to recurrence following endoprosthetic replacement (3.4%). In the DBR group, fractures occurred in 4 cases (21.1%) and nonunion in 5 (25%); internal fixation was related to nonunion (nails, 44.4% vs plates, 9.1%, P = 0.02). MSS was associated with fractures of devitalized autografts (11.0 ± 1.2 vs 8.3 ± 1.8, P = 0.01); the system was efficacious in predicting chances of fractures of these grafts (P = 0.02). MSS ≥ 10 (with false positive rate ≤ 6.7%) suggested increased fracture probability (≥22.7%) after DBR; therefore, 10 was considered a cutoff value. CONCLUSIONS: Diaphyseal malignancies with MSS ≥10 may contraindicate DBR for increased chances of reconstructive failure. In this situation, alternative procedures are advisable. Further investigations are warranted to assess the efficacy of MSS in implying the validity of DBR for diaphyseal malignancies.

Comparison of outcomes of 2 surgical treatments for proximal humerus giant cell tumors: a multicenter retrospective study.

BACKGROUND: The incidence of giant cell tumors in the proximal humerus is low. We evaluated 2 surgical treatments for giant cell tumors of the proximal humerus and postoperative upper-extremity function. METHODS: This study retrospectively analyzed the clinical data of 27 cases of giant cell tumors of the proximal humerus at 4 Chinese medical centers specializing in bone oncology collected between January 2002 and June 2015. All patients were followed up for more than 2 years. The surgical procedures performed for treatment included curettage in 14 patients and segmental resection in 13. The Campanacci grade, occurrence of pathologic fracture, surgical method, complications, and Musculoskeletal Tumor Society score were recorded for each cohort. RESULTS: The recurrence rate was 7.1% in the curettage group and 15.4% in the segmental resection group. Other postoperative complications occurred in 4 patients with segmental resection, including resorption of the osteoarticular allograft in 2, subluxation of the glenohumeral joint in 1, and prosthetic loosening and exposure in 1. A significant difference in postoperative upper-extremity function was noted between the 2 groups (P < .001). CONCLUSIONS: Postoperative upper-extremity function in the curettage group was significantly better than that in the segmental resection group. Segmental resection and reconstruction with a large segmental osteoarticular allograft were considered unadvisable. We suggest that extensive curettage should be selected to treat proximal humerus giant cell tumors as much as possible.

Outcome of segmental prosthesis reconstruction for diaphyseal bone tumors: a multi-center retrospective study.

BACKGROUND: The optimal reconstructive method after diaphyseal malignant bone tumor resection remains controversial. This multicenter clinical study was designed to investigate the clinical value and complications of segmental prosthesis in the repair of diaphyseal defects. METHODS: We present 49 patients from three clinical centers treated with wide resection for primary or metastatic bone tumors involving the diaphysis of the femur, tibia, humerus, or ulna, followed by reconstruction using a modular intramedullary segmental prosthesis. RESULTS: Enrolled patients included 23 men and 26 women with a mean age of 63.3 years. Of these, seven patients had primary bone tumors and 42 patients had metastatic lesions. At the mean follow-up of 13.7 months, 17 patients were alive, 31 patients were deceased due to tumor progression, and one patient was dead of another reason. There were eight nononcologic complications (two with radial nerve injury, three with delayed incision healing, two with aseptic loosening in the proximal humerus prosthetic stem and one with structural failure) and three oncologic complications (three with primary tumor recurrence) among all patients. The incidence of complications in primary tumor patients (4/7, 57.1%) was higher than that in patients with metastatic tumors (7/42, 16.7%) (p = 0.036). Aseptic loosening and mechanical complications were not common for patients with primary tumors, although the reconstruction length difference was statistically significant (p = 0.023). No statistically significant differences were observed in limb function, while the mean musculoskeletal tumor society score was 21.2 in femora, 19.6 in humeri, and 17.8 in tibiae (p = 0.134). CONCLUSIONS: Segmental prostheses represent an optional method for the reconstruction of diaphyseal defects in patients with limited life expectancy. Segmental prostheses in the humerus experienced more complications than those used to treat lesions in the femur.

Prognostic Differences in Patients with Solitary and Multiple Spinal Metastases.

OBJECTIVES: To investigate the association between the number of metastases to the spine and survival in patients with metastatic spinal cord compression (MSCC), as well as the prognosis difference between patients with solitary spinal metastasis (SSM) and multiple spinal metastases (MSM). METHODS: Three institutional databases were searched to identify all patients who had undergone spinal surgery for metastatic spinal tumors between March 2002 and June 2010. As well as age and gender, preoperative medical conditions were collected from medical records, including primary tumor, preoperative Frankel score, other bone metastases, preoperative Karnofsky performance status (KPS), number of involved vertebrae, pathological fracture metastasis site, serum albumin, sphincter dysfunction and the time of developing motor deficits before surgery. Survival data were obtained from medical records or via telephone follow-ups. Univariate and multivariate predictors of overall survival for each group were assessed using the Cox proportional hazards model. RESULTS: The median postoperative survival time was 6.0 ± 0.6 months (95% confidence interval [CI] 4.8-7.2) in patients with SSM and 7.0 ± 1.0 months (95% CI 5.1-8.9) in patients with MSM (P = 0.238). The difference in survival was not significant between groups. Furthermore, univariate analysis showed that the number of spinal metastases had no significant association with survival (P = 0.075). Primary tumor (P = 0.004) and preoperative KPS (P < 0.001) were independent prognostic factors in the whole cohort; primary tumor (P = 0.020), time of developing motor deficit (P = 0.041) and preoperative KPS (P = 0.038) were independent prognostic factors in patients with SSM; while preoperative KPS (P = 0.001) and serum album level (P < 0.001) were independent prognostic factors in patients with MSM. CONCLUSION: The number of spinal metastases has not proven to be useful in predicting the prognosis for patients with MSCC. Consequently, more aggressive operations should be considered for patients with multiple spinal metastases.

Relationship Between Visceral Metastases and Survival in Patients with Metastasis-related Spinal Cord Compression.

OBJECTIVE: To investigate whether visceral metastases have a significant impact on survival in patients with metastasis-related spinal cord compression (MSCC), and to determine the difference in prognosis between patients with and without visceral metastases. METHODS: Three institutional databases were searched to identify all patients who had undergone spinal surgery for spinal metastases between March 2002 and June 2010. Data on patient characteristics including pre- and post-operative medical conditions, were collected from medical records or by telephone follow-up. Survival data were obtained either from medical records or by searching a governmental cancer registry. RESULTS: The mean age of study patients was 59.6 ± 10.5 years (range, 18-84 years), of whom 102 were male and 67 female. The median and mean postoperative survival times were 7.0 ± 0.5 (95% CI 6.0-8.0) months and 12.6 ± 1.2 (95% CI 10.1-15.0) months, respectively, in all patients, being 5.0 ± 0.5 (95% CI 4.0-6.0) months and 10.8 ± 2.4 (95% CI 6.1-15.5) months, respectively, for patients with visceral metastases and 7.0 ± 0.8 (95% CI 5.4-8.6) months and 13.0 ± 1.4 (95%CI 10.3-15.6) months, respectively, for patients without visceral metastases (P = 0.87). These survival times did not differ significantly between groups. Multivariate Cox proportional hazard regressions showed that visceral metastases had no statistically significant association with survival (P = 0.277), whereas rate of growth of primary tumor (P = 0.003), preoperative Karnofsky performance status (KPS) (P < 0.001), change in KPS (P < 0.001), and Frankel grade (P = 0.091) were independent prognostic factors in the whole cohort (P = 0.005). Changes in KPS (P = 0.001) and major complications (P = 0.003) were significantly associated with survival in patients with visceral metastases, whereas rate of growth of primary tumor (P = 0.016), change in KPS (P = 0.001), and preoperative KPS (P < 0.001) were significantly associated with survival in patients without visceral metastases. CONCLUSIONS: Visceral metastases do not appear to predict the prognosis of patients with MSCC; thus, more aggressive surgery should be considered in patients with MSCC who have visceral metastases. Additionally, prognostic factors differ according to visceral metastases status in these patients.

Intercalary prosthetic reconstruction for pathologic diaphyseal humeral fractures due to metastatic tumors: outcomes and improvements.

BACKGROUND: There is a high aseptic loosening rate for intercalary prosthetic reconstruction for malignant tumors. We evaluated outcomes and complications of intercalary prosthetic reconstruction for pathologic diaphyseal humeral fractures and report the application of an extracortical plate that can prevent early loosening. METHODS: We retrospectively analyzed 9 patients who underwent intercalary prosthetic reconstruction for pathologic diaphyseal humeral fractures secondary to metastatic diseases between March 2011 and September 2017. Procedures were intercalary prosthetic reconstruction in 4 patients (group A) and an implanted intercalary prosthesis with a plate in 5 patients (group B). Operative time, blood loss, complications, and functional score were noted. RESULTS: Mean operative time for group A and B was 80 ± 14 and 94 ± 5 minutes, respectively; blood loss was 115 ± 26 and 120 ± 31 mL respectively; and follow-up was 11.5 ± 10.1 and 6.2 ± 4.4 months, respectively. At final follow-up, all patients in group A had died, and 3 patients in group B had died; mean survival was 11.5 ± 10.1 and 9.3 ± 1.2 months, respectively. The mean postoperative Musculoskeletal Tumor Society score was 24.5 ± 2.4 and 26.2 ± 0.8, respectively. The mean postoperative American Shoulder and Elbow Surgeons score was 85.5 ± 4.20 and 87 ± 2.6, respectively. There were no significant differences between the 2 groups (P > .05). There was 1 aseptic loosening and 1 radial nerve injury in group A; there were no complications in group B. CONCLUSIONS: The intercalary prosthesis yielded satisfactory outcomes in patients with pathologic diaphyseal humeral fractures, and an extracortical plate can prevent early aseptic loosening.

Development and proposal of a scoring system for giant cell tumour of the bone around the knee.

PURPOSE: The purpose of this study was to provide the surgeons with effective and reliable guidelines for surgical decision-making by establishing a scoring system for giant cell tumour (GCTSS) based on evidence and expert opinion. METHODS: The modified Delphi technique and analytic hierarchy process were used to establish the GCTSS. The GCTSS was defined and classified based on different surgical methods using data from 207 patients collected retrospectively between October 2003 and December 2014. Finally, prospective data of 40 patients between December 2014 and October 2015 were used to analyze concordance between score categorization and experts' consensus on surgical procedure. RESULTS: A novel GCTSS included pathological fracture, cortical bone destruction, tumour size, and articular surface involved. The total scores ranged from 1 to 12 points. The strategy for each patient was decided: a total score of 1-4 suggested intralesional curettage alone for excellent post-operative function; 5-9 points indicated intralesional curettage with internal fixation for less surgery-related complications; and 10-12 points indicated prosthesis replacement for long-term local control. The κ-statistic for the predictive validity of total score was 0.611. The κ coefficient of each group represented moderate or substantial agreement, which was acceptable. The intraclass correlation coefficient for inter- and intra-observer reliability of total score was 0.831 and 0.740, respectively. CONCLUSIONS: The novel GCTSS is a comprehensive scoring system with content validity that can aid surgeons in assessing the aggressiveness or severity of giant cell tumour and might become a prognostic tool for surgical decision-making.