Mean Musculoskeletal Tumor Society Research Articles

Patient survival after surgical resection of pelvic bone sarcomas: A nationwide cohort study

Background: Pelvic bone sarcomas are extremely rare malignant tumours. Patients require a multidisciplinary approach to plan the treatment and complex surgical resections and limb-sparing reconstructions associated with complications, revisions, and functional limitations. The presented nationwide study in the Republic of Slovenia aims to analyse the oncological survival and functional outcomes of patients after primary resection of pelvic bone sarcomas.
 Methods: The retrospective observational cohort included 21 consecutive patients who underwent limb-sparing pelvic resection at a specialized orthopaedic oncology centre in the Republic of Slovenia between 2004-2022. Patient survival, complication rates, and functional outcomes were analysed according to to the primary diagnosis.
 Results: Wide margins with R0 resection were achieved in 16 (76%) cases. After a median follow-up of 5.7 (0.6-18.1) years, 7 (33%) patients died of oncological disease, 3 (14%) patients were alive with oncological disease, and 11 (53%) patients were alive with no evidence of disease. The estimated Kaplan-Meier survival probability at 2 years, 5 years, and 10 years after pelvic resection was 85%, 73%, and 45%, respectively. The major complication rate was 29%. The mean Musculoskeletal Tumour Society Score was 17.5 (range 2-29).
 Conclusions: Patient survival after resection of pelvic bone sarcomas in Slovenia between 2004-2022 is comparable to previously published reports of European and North American countries. Wide resection of tumours with reconstruction provides a relatively good survival rate, although complications are common and functional outcomes are often poor.

Intercalary frozen autografts for reconstruction of bone defects following meta-/diaphyseal tumor resection at the extremities

BackgroundFor patients with malignant limb tumors, salvage surgery can be achieved using endoprosthesis or biological reconstructions like allograft or autograft. In carefully selected patients, resected bone can be recycled after sterilization using methods like autoclaving, irradiation, pasteurization or freezing with liquid nitrogen. We evaluated the clinical outcome and complications of malignant limb tumors treated with intercalary resection and frozen autograft reconstruction.MethodsWe reviewed 33 patients whose malignant bone tumors were treated by wide resection and reconstruction with recycling liquid nitrogen-treated autografts between 2006 and 2017. Limb function, bone union at the osteotomy site and complications were evaluated. Functional outcome was assessed using the Musculoskeletal Tumor Society (MSTS) scoring system.ResultsThe cohort comprised 16 males and 17 females, with a mean age of 35.4 years (14–76 years). The most common tumor was osteosarcoma (7 cases). Tumors were located in the humerus (5), ulna (1), femur (10) and tibia (17). The mean follow-up was 49.9 months (range 12–127 months). Of the 33 patients, 16 remained disease-free, and 3 were alive with disease. The mean size of the defect after tumor resection was 11.6 cm (range 6–25 cm). Bone union was achieved in 32 patients, with a mean union time of 8.8 months (range 4–18 months). Complications included 1 graft nonunion, 2 infections (1 superficial, 1 deep infection), 1 leg length discrepancy, 2 graft fractures and 3 local recurrences. The mean MSTS score was 87.2% (range 70–100%).ConclusionLiquid nitrogen-treated tumor-bearing autograft is an effective option for biological reconstruction after meta-/diaphyseal tumor resection of long bones. This method has excellent clinical outcomes and is especially recommended for patients with no severe osteolytic bone tumors.

A Retrospective Cohort Analysis of Limb Salvage Surgery Using Mega Prosthesis in Bone Tumours at a Tertiary Care Centre in Eastern India.

BackgroundThe method known as "limb salvage surgery" (LSS) aids in the removal of extremity tumours, and reconstruction is completed with satisfactory oncologic, functional, and cosmetic outcomes. Oncologic clearance is given first priority, followed by functional outcomes. Worldwide, the trend has already shifted away from amputations and toward limb salvage surgery for eligible patients due to efficient chemotherapy regimens, improved imaging techniques, precise administration of enhanced radiation, better reconstructive choices, and developments in bio-engineering. The purpose of the present study was to determine the clinicopathological characteristics, surgical techniques, functional outcome, and prognostic factors of limb salvage surgery performed using mega prosthesis in primary malignant or benign resectable tumours.MethodsOur retrospective cohort study was carried out over a period of two years and included 28 patients who received care for bone tumours. The data gathered comprised the demographic profile, clinical characteristics, histological characteristics, treatments given, functional results, and survival. LSS was performed on all patients by orthopaedics oncologists trained in the surgical oncology department. Following surgery, during the first two years, patients were examined at every three-month interval, then every six months until the fifth year, and then once a year after that. The Kaplan-Meier method was utilized to determine the median follow-up and recurrence-free survival (RFS).ResultsIn our study, the mean age of study subjects was 30.0±10.9 years. Almost all of the subjects included in the study had lower limb bone tumours (96.4%). The most common site for the tumour was the distal femur (57.1%) followed by the proximal femur (32.2%). The most common type of benign tumour was giant cell tumour (GCT) (53.6%), including recurrences of giant cell tumour (GCT), and among malignant tumours, osteosarcoma was the most common (25.0%). The mean surgical resection of bone in limb salvage surgery was 125.2±24.2 mm. The most common post-operative complication was leg length discrepancy (LLD) among 25.0% of subjects, which was managed by shoe raise. The overall mean musculoskeletal tumour society (MTSS) score after LSS was 25.0±4.3. Using the Kaplan-Meier method analysis, we found that relapse-free survival was 83.7% among enrolled subjects at a median follow-up period of 80 months.ConclusionIt can be difficult to surgically treat patients who have malignant bone tumours. In limb-sparing surgery for bone tumours, the modular segmental-replacement system prosthesis that we preferred produced satisfactory results in terms of tumour control and limb function. To get good long-term results, the case selection must be appropriate.

Role of impaction bone grafting of allografts in the management of benign lesions of the proximal femur

Purpose of studyThe use of allografts to reconstruct benign lesions of the proximal femur after curettage has seldom been reported. We report our experience of impaction bone grafting of only allografts combined with osteosynthesis to manage benign lesions involving the proximal femur. Materials and methodsBetween 2013 and 2019, 35 patients of a mean age of 23.8 years (14–41) who had a biopsy proven benign pathology and a median pre-operative Mirels’ score of 9 (8–11) were managed using extended curettage, impaction bone grafting of allografts combined with osteosynthesis through a lateral approach. Radiographs were assessed to see for any recurrence at follow-ups, and functional outcomes were assessed using Musculoskeletal Tumour Society (MSTS) score and Harris hip score (HHS). ResultsAt a mean follow-up was 41.5 months (23–80), patients demonstrated favorable functional outcomes with a mean MSTS of 28.3 (18–30) and a mean HHS of 94.3 (66–100) at the last follow-up. Two cases (GCT = 1; fibrous dysplasia = 1) had a recurrence of disease. Allografts demonstrated a particular integration pattern on radiographs that involved an intermediate period of lucency followed by consolidation and integration with the parent bone. ConclusionImpaction grafting of allografts in benign lesions of the proximal femur allows adequate bony consolidation of the cavity after extended curettage and can be effectively used as a permanent solution to manage such lesions in most cases. The intermediate period of lucency seen on radiographs must not be confused for recurrence, and patients must be followed up continuously. Study designRetrospective Case Series. Level of evidenceLevel IV.

Allograft versus autograft for reconstruction after resection of primary bone tumors: a comparative study of long-term clinical outcomes and risk factors for failure of reconstruction

There have been no studies comparing the outcomes of nonvascularized autograft (NA) and allograft after resection of primary bone tumors. This study compares the clinical, functional outcomes of NA and allograft reconstruction and analyzes the risk factors for failure after these procedures. A retrospective study of patients with primary bone tumors of the extremities who underwent NA (n = 50) and allograft reconstruction (n = 47). The minimum follow up time was 24 months. The mean time to union for the NA and allograft group was 9.8 ± 2.9 months and 11.5 ± 2.8 months, respectively (p = 0.002). Reconstruction failure in the NA and allograft group was 19 (38%) and 26 (55.3%), respectively. Nonunion (30%) was the most common complication found in the NA group, while structural failure (29.8%) was the most common in the allograft group. There was no significant difference in functional outcome in terms of the mean Musculoskeletal Tumor Society score between the NA and allograft groups (23.5 ± 2.8 and 23.9 ± 2.1, respectively, p = 0.42). Age, sex, tumor location, graft length, method of reconstruction did not significantly influence failure of reconstruction. Chemotherapy was the only significant risk factor affecting outcomes (HR = 3.49, 95% CI = 1.59–7.63, p = 0.002). In the subgroup analysis, the use of chemotherapy affected graft-host nonunion (p < 0.001) and structural failure in both the NA and allograft groups (p = 0.02). Both NA and allograft reconstruction methods provide acceptable clinical and functional outcomes. Chemotherapy is a risk factor for failure of both reconstructions, particularly graft-host nonunion and structural failure.

Computer-Aided Design and 3D Printing of Hemipelvic Endoprosthesis for Personalized Limb-Salvage Reconstruction after Periacetabular Tumor Resection.

3D-printed hemipelvic endoprosthesis is an emerging solution for personalized limb-salvage reconstruction after periacetabular tumor resection. Further clinical studies are still required to report its surgical characteristics, outcomes, benefits and drawbacks. Sixteen consecutive patients underwent periacetabular tumor wide resection and pelvic reconstruction with a 3D-printed hemipelvic endoprosthesis from 2018 to 2021. The surgical characteristics and outcomes are described. The mean follow-up duration was 17.75 months (range, 6 to 46 months). Five patients underwent surgery for type I + II resection and reconstruction, seven for type II + III resection and reconstruction, three for type II resection and reconstruction, and one for type I + II + IV resection and reconstruction. The incidence of postoperative complication was 12.5% (2/16) for deep venous thrombosis (DVT), 12.5% (2/16) for pneumonia, and 12.5% (2/16) for would deep or superficial infection. During follow-up, two patients (12.5%) suffered hip dislocation and underwent revision surgery. CT demonstrated an obvious prosthetic porous structure–bone fusion after follow-up of at least 6 months. At the final follow-up, 12 lived with no evidence of disease while four lived with disease; no patients experienced pain; and 15 had independent ambulation, with a mean Musculoskeletal Tumor Society (MSTS) score of 85.8% (range, 26.7% to 100%). 3D-printed hemipelvic endoprosthesis facilitates wide resection of periacetabular tumor and limb-salvage reconstruction, thus resulting in good oncological and functional outcomes. The custom-made nature is able to well mimic the skeletal anatomy and microstructure and promote osseointegration. Perioperative complications and rehabilitation exercise still need to be stressed for this engineering technology-assisted major orthopedic surgery.

Outcomes of distal radial endoprostheses for tumour reconstruction: a single centre experience over 15 years.

We report a retrospective study over a 15-year period, between 2005 and 2020, evaluating clinical and functional outcomes in patients who underwent reconstruction of the distal radius with an endoprosthetic replacement following excision of both malignant and aggressive benign bone tumours. Data was collected retrospectively from a prospectively maintained electronic database, and prospectively via telephone patient consultation. Musculoskeletal Tumour Society and patient-rated wrist evaluation scores were assessed at a minimum of 1 year postoperatively. Of nine implants, five were arthrodeses and four were arthroplasties. One patient required amputation within 6 months for proximal metastatic disease. At last follow-up, eight patients subjectively reported good function. Five patients returned to high functionally demanding jobs. Mean Musculoskeletal Tumour Society and patient-rated wrist evaluation scores were 72% and 50/100, respectively. We conclude that distal radius endoprosthetic replacements offer acceptable functional outcomes and remain a viable option when biological reconstruction is not possible.Level of evidence: IV.

Campanacci Grade III Giant Cell Tumors of Distal End Radius Treated With Wide Excision and Reconstruction: A Retrospective Case Series.

IntroductionCampanacci Grade III Giant Cell tumors of the distal radius are difficult to manage as they are associated with a high recurrence rate. Wide excision of the distal radius and reconstruction with an ipsilateral proximal fibula or ulnar translocation reduces the recurrence rate significantly and gives acceptable function to the hand and wrist.Methods and materialsThis was a retrospective study of eight patients with Campanacci grade III giant cell tumors of distal radius treated with wide excision of distal radius followed by reconstruction at our institute. Four cases were operated on with ulnar translocation and four cases were operated on with ipsilateral proximal fibula grafting after wide excision of the distal radius. Patients were studied for the Musculoskeletal Tumor Society (MSTS) score and visual analogue scale (VAS) score for pain at one year, recurrence, and complications.ResultsThe mean MSTS score of the total series was 24.75 ± 1.6. The mean VAS score for the total series was 1.62 ± 0.4. Of the eight cases, two cases had a recurrence, one patient had persistent wrist paint, and two patients had wrist subluxation.ConclusionWide excision of the distal radius followed by reconstruction with a proximal fibula or ulnar translocation is a good option to avoid repeated surgeries in patients with Campanacci grade III giant cell tumors of the distal radius and achieve acceptable functional results for the wrist and hand.

Articular degeneration after subchondral cementation for giant cell tumors at the knee

PurposeTo quantify joint degeneration and the clinical outcome after curettage and cementation in subchondral giant cell tumors of the bone (GCTB) at the knee. MethodsWe conducted a retrospective analysis of 14 consecutive patients (seven female, seven male) with a mean age of 34 years (range 19–51) who underwent curettage and subchondral cementation for a biopsy-confirmed GCTB at the distal femur or the proximal tibia between August 2001 and August 2017, with a mean follow-up period of 54.6 months (range 16.1–156 months). The Whole-Organ Magnetic Resonance Imaging Score (WORMS), Kellgren-Lawrence (KL) classification, and Musculo-Skeletal Tumor Society (MSTS) score were assessed. ResultsRadiological degeneration progressed from preoperative to the latest follow-up, with a median WORMS from 2.0 to 4.0 (p = 0.006); meanwhile, the median KL score remained at 0 (p = 0.102). Progressive degeneration (WORMS) tended to be associated with the proximity of the tumor to the articular cartilage (mean 1.57 mm; range 0–12 mm) (p = 0.085). The most common degenerative findings were cartilage lesions (n = 11), synovitis (n = 5), and osteophytes (n = 4). Mean MSTS score increased from 23.1 (preoperatively) to 28.3 at the latest follow-up (p < 0.01).Seven patients (50%) were treated for a local recurrence, with six revision surgeries performed. Removal of the cement spacer and filling of the cavity with a cancellous autograft was performed in seven patients. Conversion to a total knee arthroplasty was performed in one patient for local tumor control. ConclusionsCementation following the curettage of GCTB around the knee is associated with slight degeneration at medium-term follow-up and leads to a significant reduction in pain. Removal of the cement and reconstruction with an autograft may be beneficial in the long term.

Recurrent Giant Cell Tumour of Distal End Radius: Treatment and Outcomes After Further Surgeries.

Introduction: Distal end radius is the second most common location for giant cell tumours (GCTs) followed by the knee. Like at any other location, they are treated with extended curettage or resection but reportedly have an increased propensity for recurrence. This study aims to treat the recurrent distal end radius GCTs and their outcome after further surgeries.Patients and methods: This study was conducted retrospectively from 2009 to 2021 and included 32 patients with recurrent distal end radius GCTs with a mean age of 29.53 years (range: 18-45 years). Twenty-five recurrences occurred after curettage and seven after resection. Twelve lesions were treated with further extended curettage. Nineteen recurrent lesions were treated with resection and arthrodesis. One out of two soft tissue recurrences was treated with en bloc resection. The mean follow-up period was 45.25 months (range: 24-120).Results: The patients with joint preservations treated with further curettage and those where resection of soft tissue recurrences was done with salvage of joint had better functional outcomes with a mean Musculoskeletal Tumor Society (MSTS) score of 26.53 (Range: 22-30). The cases with arthrodesis had an average score of 23.75 (Range: 20-26). The overall average MSTS score was 24.89.Conclusions: We conclude that local recurrence contained within the bone can be re-curetted. The isolated soft tissue recurrences can be re-excised. The bony lesions with extensive soft tissue extension should be treated with resection and reconstruction. The re-recurrence rate after further adequate treatment does not increase much.

Comparison of Reconstruction Techniques Following Sacroiliac Tumor Resection: A Systematic Review.

Although internal hemipelvectomies with sacroiliac resections are not traditionally reconstructed, surgeons are increasingly pursuing pelvic ring reconstruction to theoretically improve stability, function, and early ambulation. This study aims to systematically compare complications and functional and oncologic outcomes of sacroiliac resection with and without reconstruction. PubMed and MEDLINE were queried for studies published between January 1990 and October 2020 pertaining to sacroiliac neoplasm resection with subsequent reconstruction. Patient demographics, histopathologic diagnoses, reconstruction techniques, Musculoskeletal Tumor Society (MSTS) functional scores, and oncologic outcomes were pooled. Twenty-three studies (201 patients) were included for analysis. Reconstruction was performed in 79.1% of patients, most commonly with nonvascularized autografts (45.8%). The overall complication rate was54.8%; however, resection followed by reconstruction demonstrated significantly higher complication (62.3% versus 25.7%, p < 0.001) and infection rates (13.7% versus 0%, p = 0.020). Mean MSTS functional score trended higher in nonreconstructed patients (82% versus 71.6%). Reconstruction after sacroiliac resection produced higher complication rates and poorer physical recovery when compared with nonreconstructed resection. This systematic review suggests that patients without spinopelvic junction instability may experience superior outcomes without reconstruction. Ultimately, the need to reconstruct the pelvic girdle depends on tumor size, prognosis, and functional goals.

Outcome of Scapular Ewing Sarcoma.

Ewing sarcoma is a common primary bone tumor, often located in the distal femur or pelvis. Although the scapula is a flat bone similar to the pelvis, scapular Ewing sarcoma is rare. The aim of this study was to review our institution's experience with the management of scapular Ewing sarcomas. We reviewed 9 patients with an Ewing sarcoma of the scapula, which included 5 males and 4 females with a mean age of 19±6 years. All patients were treated with chemotherapy and local control. Local control included surgical resection (n=7) and definitive radiotherapy (n=2). Mean follow-up was 6 years. Prior to induction chemotherapy, the mean tumor size and volume were 10±2 cm and 181±112 cm3, respectively. Following induction chemotherapy, there was a reduction in the mean tumor size (6±3, p=0.02) and volume (20±12 cm3, p<0.01). The mean tumor necrosis in patients undergoing resection was 72±23%. The median survival was 30-months, and the 5-year disease specific survival was 38%. At most recent follow-up, the mean Musculoskeletal Tumor Society Score was 79±14%. Scapular Ewing sarcoma is a rare, aggressive tumor. Even with chemotherapy and local control with surgery or definitive radiotherapy, patient survival is poor.

Rotationplasty after failed limb salvage: an alternative to amputation.

Limb salvage procedures for musculoskeletal tumors have inherent complications. Though most complications can be managed with retention of the reconstructions, occasionally salvaging these reconstructions is not possible. We evaluated the outcomes of patients undergoing rotationplasty after multiple failed revisions of limb salvage surgery and document the success rate of this "salvage" technique and the subsequent functional outcome of these patients. Between January 1, 1999, and December 31, 2018, 14 patients (12 male and 2 female) with a median age of 24years (11-51years) underwent rotationplasty after multiple failed revisions of limb salvage surgery. Indication for rotationplasty was infection (10 patients), failed megaprosthesis (2 patients), unstable biological reconstruction (1 patient) and local recurrence (1 patient). The mean number of surgeries done before the patient underwent rotationplasty was 5 (range 2-7). One patient developed a vascular complication (venous congestion) immediately after rotationplasty and underwent an early amputation. The remaining 13 patients had no surgical complications. Mean Musculo Skeletal Tumor Society score in 13 evaluable patients was 26 (23-30). Our study demonstrates the utility of rotationplasty as a "salvage" procedure after multiple failed lower limb salvage surgeries. It offers good success rates, low rates of complications and good functional outcomes in carefully selected cases.

Clinical outcomes of tumors and tumor-like lesions located in the clavicle.

Objectives The aim of this study was to examine the characterization of tumors and tumor-like lesions located in the clavicle and to present their clinical results.Patients and methods Between January 2006 and December 2018, a total of 44 patients (25 males, 19 females; mean age: 36.2±21.8 years; range, 2 to 87 years) who were operated in our clinic for a clavicular lesion were included. Among 4,856 extremity tumors operated in our clinic between these years, 44 cases (0.9%) located in the clavicle were eligible. Demographic data, tumor types, location, surgical method, metastasis, survival analyzes and clinical results of these patients were reviewed retrospectively. According to the clavicle location, the patients were divided into groups according to their involvement in proximal, middle, lateral and more than one region.Results The most frequently involved site was the lateral edge of the clavicle, and the most common tumor was aneurysmal bone cyst. The most common malignant tumor was Ewing sarcoma and plasmacytoma (13.6%) and the most common surgical method in the clavicle was wide resection with 34.1%. Of the 38 primary clavicle tumors remaining after the metastatic lesions were removed, 21 (55%) were benign, while 17 (45%) were malignant. Aneurysmal bone cyst was most common in the group under 30 years of age, osteochondroma was most common in the 30-50 age group, and plasmacytoma was most common in those over 50 years of age. The mean musculoskeletal tumor society (MSTS) score of 15 patients (34.1%) who underwent clavicle resection was 79.4±6.Conclusion We believe that a wide spectrum should be considered in the differential diagnosis of tumors located in the clavicle. Age is an important predictive factor for malignancy. We believe that resection should be applied without fear considering its effects on function and recurrence.

A novel limb-salvage reconstruction strategy with a custom hemipelvic endoprosthesis and preserved femoral head following the resection of periacetabular tumors: A preliminary study.

The treatment of periacetabular malignancy frequently challenges surgeons. To simplify the surgical procedure, we performed a novel reconstruction strategy preserving the femoral head for patients with periacetabular malignancies. We retrospectively reviewed 14 patients who underwent total en bloc resection of a periacetabular tumor and reconstruction of the hip joint with an individualized hemipelvic endoprosthesis and remaining femoral head from July 2015 to January 2019 at our center. Regions of pelvic resection: region II-4 (28.6%), region I + II-5 (35.7%), region II + III-2 (14.3%) and region I + II + III-3 (21.4%). The oncological outcomes were that 13 patients survived without disease and one patient survived with lung metastasis. None of the patients experienced local recurrence (range: 20-62 months; mean: 32 months). The incidence of postoperative complications was 35.7%, including delayed wound healing and deep venous thrombosis. No prosthesis-related complications occurred until the last follow-up in this study (range: 20-62 months; mean: 32 months). The mean Musculoskeletal Tumor Society functional outcome score was 23.2. The mean Toronto Extremity Salvage Score of the patients was 75.7 points, with a mean limb discrepancy of 1.51 cm (range: 0.5-3.2 cm). Reconstruction with preservation of the femoral head showed acceptable early functional and oncological outcomes, and it had an acceptable complication rate.

Oncological and Functional Outcomes after Hemicortical Resection and Biological Reconstruction Using Allograft for Parosteal Osteosarcoma of the Distal Femur

Background Parosteal osteosarcoma (PAOS) is a surface osteosarcoma. Treatment options include wide excision and endoprosthetic or allograft. However, due to the low local recurrence and metastasis rate, when it appears in the posterior surface of the distal femur, the lesion can be managed with hemicortical wide resection and biological reconstruction with hemicortical allograft. The purpose of this study is to evaluate the oncological and functional outcomes of patients with parosteal osteosarcoma (PAOS) of the posterior cortex of the distal femur who underwent biological reconstruction after hemicortical resection. Methods Eleven patients who underwent wide tumor resection and defect reconstruction of the posterior surface of the distal femur using hemicortical allograft were retrospectively studied. Local recurrence, metastasis, complications, and the functional outcome using the Musculoskeletal Tumor Society (MSTS) scoring system were evaluated. Results The average postoperative follow-up period was 53.64 months (range, 30 to 84 months). At the latest follow-up, all patients had no evidence of disease without metastases. One patient with local recurrence underwent revision surgery with fibula autograft reconstruction. The mean MSTS score was 93.45 ± 3.56. Conclusions Treatment of patients with PAOS of the posterior aspect of the distal femur with hemicortical resection and allograft reconstruction has satisfactory oncological and functional outcome and low complication rates.

Randomized, placebo-controlled, double blind, phase II study of zaltoprofen for patients with diffuse-type and unresectable localized tenosynovial giant cell tumors.

11568 Background:A tenosynovial giant cell tumor (TGCT) is a locally aggressive benign neoplasm arising from intra- or extra-articular tissue, and categorized localized (L-TGCT) or diffuse-type (D-TGCT). D-TGCT most commonly develops in the knee or ankle. We revealed that zaltoprofen, a nonsteroidal anti-inflammatory drug possessing the ability to activate peroxisome proliferator-activated receptor gamma (PPARγ), can inhibit the proliferation of TGCT stromal cells via PPARγ. PPARγ is a ligand-activated transcription factor that belongs to the nuclear hormone receptor superfamily. Therefore, we conducted a randomized trial to evaluate whether zaltoprofen was effective for patients with TGCT. Methods:This study was a randomized, placebo-controlled, double-blind, multicenter trial to evaluate the safety and efficacy of zaltoprofen for patients with L-TGCT or D-TGCT. For the treatment group, zaltoprofen 480 mg/day was administered for 48 weeks. The primary outcome was the progression-free rate (PFR) at week 48 after treatment administration. Disease progression was defined as follows requiring surgical interventions: 1) repetitive joint swelling due to hemorrhage; 2) limited range of joint motion; 3) invasion of adjacent cartilage or bone; 4) severe joint space narrowing; or 5) increase in tumor size (target lesion). This study was registered at the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000025901). Results:We allocated forty-one patients to zaltoprofen (n = 21; Z) or placebo (n = 20; P) groups. The mean age was 44 years (range, 26 to 66) in the group Z and 47 years (range, 24 to 69) in the group P. TGCTs located at a knee in 26 patients and at an ankle in 15 patients. The primary outcome of PFR for the group Z was not higher than that for the group P at week 48 (84.0% vs. 90.0%; p = 0.619). The objective tumor response was graded as partial response (PR) in 1 patient, stable disease (SD) in 19, and progressive disease (PD) in 1 for the group Z, and SD in 17 and PD in 3 for the group P. The mean musculoskeletal tumor society scoring system for group Z was significantly improved from baseline to week 48 (83.8% vs. 93.0%, p = 0.02), whereas that for the group P was not significantly improved (82.2% vs. 86.8%; p = 0.167). During the study period, one severe adverse event was observed (grade 3 hypertension) in the group Z. Conclusions:To our knowledge, this was the first study to evaluate the efficacy of zaltoprofen in patients with TGCT. The TGCT patients in zaltoprofen group did not have higher PER compared with those in the placebo group at week 48. Zaltoprofen appeared to improve the limb-function. Both groups presented with a stable disease course for 48 weeks, therefore, the long-term clinical course of TGCT should be clarified. Further analysis with long-term administration of zaltoprofen is considered for the future study. Clinical trial information: UMIN000025901.

Elbow hemiarthroplasty with a 3D-printed megaprosthesis for defects of the distal humerus or proximal ulna after tumour resection

Aims The aim of this study was to investigate the feasibility of application of a 3D-printed megaprosthesis with hemiarthroplasty design for defects of the distal humerus or proximal ulna following tumour resection. Methods From June 2018 to January 2020, 13 patients with aggressive or malignant tumours involving the distal humerus (n = 8) or proximal ulna (n = 5) were treated by en bloc resection and reconstruction with a 3D-printed megaprosthesis with hemiarthroplasty, designed in our centre. In this paper, we summarize the baseline and operative data, oncological outcome, complication profiles, and functional status of these patients. Results Preparation of the prosthesis was a mean of 8.0 days (SD 1.5), during which time no patients experienced tumour progression. The mean operating time and intraoperative blood loss were 158.1 minutes (SD 67.6) and 176.9 ml (SD 187.8), respectively. All of the prostheses were implanted successfully. During a mean follow-up of 25.7 months (SD 7.8), no patients died, but four had complications (two superficial wound problems, one temporary palsy of radial nerve, and one dislocation). No aseptic loosening, structural failure, infection, heterotopic ossification, or degenerative arthritis was seen in this study. The mean flexion of the elbow was 119.6° (SD 15.9°) and the mean extension lag was 11.9° (SD 13.8°). The mean Musculoskeletal Tumor Society 93 score and Mayo Elbow Performance Score were 28.4 (SD 0.9) and 97.7 (SD 4.4), respectively. Conclusion The custom-made, 3D-printed megaprosthesis with hemiarthroplasty is a feasible option for functional reconstruction after resection of a tumour in the distal humerus or proximal ulna. Cite this article: Bone Joint J 2022;104-B(6):747–757.

Computer Navigation-Aided Excision of Proximal Femoral Osteochondroma: Surgical Technique.

Purpose Symptomatic osteochondroma of the proximal femur necessitates a surgical excision. The purpose of this study was to describe a novel technique of computer navigation-aided excision for osteochondromata of the proximal femur. Outcomes of this technique are also presented. Methods A total of 13 patients underwent computer navigation-aided excision of osteochondromata of the proximal femur from February 2012 to August 2016 in our institution. They were enrolled in this study. OrthoMap 3D (Stryker Orthopaedics, Mahwah, NJ, USA), a commercially available navigation software system, was used to merge computed tomography images of the proximal femur with an osteochondromata with the image of a normal proximal femur. Using the normal proximal femur as a template, intended resection margins for the proximal femur with osteochondromata were planned and then executed using intraoperative navigation guidance. Patients were followed up clinically and radiographically. The physical and mental health of patients was assessed with the Musculoskeletal Tumor Society (MSTS) score. Results Eight patients had isolated exostoses. Five patients had tumors associated with multiple hereditary exostoses. For tumors projecting posteriorly or posteromedially, a posterolateral approach was used. For tumors projecting anteriorly or medially, an anterior approach was used. Prophylactic fixation was performed in four patients who required an anterior approach. The mean duration of the surgery was 189 minutes. There were no intraoperative fractures or postoperative complications. A secondary procedure was not needed for any case. The mean MSTS score at a mean follow-up of 17 months was 28.6 (maximum MSTS score: 30). Conclusions This is the first study to report a novel application of computer navigation for aiding the excision of osteochondromata of the proximal femur. It demonstrated favorable postoperative functional scores with a low rate of complications. The applicability, safety, and efficacy of this technique were demonstrated. It is particularly useful for resections involving large tumors that can obscure anatomical landmarks and for patients with associated proximal femoral deformity.

Effect of an Endoprosthetic Reconstruction Tube and Medial Gastrocnemius Flap on Extensor Mechanism Function After Oncologic Prosthesis Reconstruction of the Proximal Tibia

BackgroundExtensor mechanism reconstruction after the proximal tibial resection and implantation of a megaprosthesis is challenging. In this study, we evaluated the effectiveness of the Trevira tube and medial gastrocnemius flap in restoring extensor mechanism following the resection of proximal tibial tumor and implantation of megaprosthesis. MethodsForty patients who underwent endoprosthetic implantation following the resection of proximal tibial tumor and patellar tendon reconstruction with the Trevira tube and medial gastrocnemius flap were included. The outcome measures were knee range of motion, extensor mechanism function, patellar position, and limb function subjectively evaluated through Toronto Extremity Salvage Score and objectively through Musculoskeletal Tumor Society score. The mean follow-up of the patients was 6.1 years. ResultsThe patellar position was normal in 28 (70%) patients, patella baja in 3 (7.5%) patients, and patella alta in 9 (22.5%) patients. The mean active knee range of motion was 98.9 ± 17° (range: 85°-125°). Extension lag was present in 7 (17.5%) patients (range: 5°-20°). The mean Toronto Extremity Salvage Score of patients was 92.1 ± 6.9% (range: 85-100). The mean Musculoskeletal Tumor Society score of the patients was 87.7 ± 13 (range: 73.3-100). Postoperative complications included aseptic wound dehiscence (2 patients), aseptic loosening of the tibial component (1 patient), periprosthetic fracture in the femur (2 patients), and wound infection (1 patient). ConclusionTrevira tube combined with gastrocnemius flap augmentation is a suitable procedure for restoring extensor mechanism after proximal tibial resection and megaprosthesis implantation.