New method of local adjuvant therapy with bicarbonate Ringer's solution for tumoral calcinosis: A case report.

BACKGROUND: Tumoral calcinosis is a condition characterized by deposits of calcium phosphate crystals in extra-articular soft tissues, occurring in hemodialysis patients. Calcium phosphate crystals are mainly composed of hydroxyapatite, which is highly infiltrative to tissues, thus making complete resection difficult. An adjuvant method to remove or resolve the residual crystals during the operation is necessary. CASE SUMMARY: A bicarbonate Ringer's solution with bicarbonate ions (28 mEq/L) was used as the adjuvant. After resecting calcium phosphate deposits of tumoral calcinosis as much as possible, while filling with the solution, residual calcium phosphate deposits at the pseudocyst wall can be gently scraped by fingers or gauze in the operative field. A 49-year-old female undergoing hemodialysis for 15 years had swelling with calcium deposition for 2 years in the shoulders, bilateral hip joints, and the right foot. A shoulder lesion was resected, but the calcification remained and early re-deposition was observed. Considering the difficulty of a complete rection, we devised a bicarbonate dissolution method and excised the foot lesion. After resection of the calcified material, the residual calcified material was washed away with bicarbonate Ringer's solution. CONCLUSION: The bicarbonate dissolution method is a new, simple, and effective treatment for tumoral calcinosis in hemodialysis patients.

Recycled bone grafts treated with extracorporeal irradiation or liquid nitrogen freezing after malignant tumor resection.

INTRODUCTION: Recycled bone autografts prepared using extracorporeal irradiation (ECIR) or liquid nitrogen freezing (LNF) methods have been used for the reconstruction of skeletal elements after wide resection of sarcomas involving bone tissues. Few reports include long-term follow-up data for histological analyses of recycled autografts, particularly in the case of ECIR autografts. MATERIALS: A total of 34 malignant bone and soft tissue tumors were resected and reconstructed using 11 ECIR- and 23 LNF-recycled autografts; the mean postoperative follow-ups were 14 and 8 years, respectively. ECIR was used for either osteosarcomas or Ewing sarcomas, whereas in addition to these tumors LNF was used for chondrosarcomas and soft tissue sarcomas involving bone tissues. Recycled bone was implanted as total bone, osteoarticular, or intercalary grafts, with or without prosthesis or vascularized fibular grafts. RESULTS: The 10-year graft survival rate was similar between groups, 81.8% using ECIR and 70.2% using LNF. There were no autograft-related tumor recurrences in either group. Graft survival was unrelated to type of graft or additional procedures. Complication rates tended to be higher using ECIR (64%) compared with LNF (52%) and the infection rate was significantly higher with ECIR (27%) versus LNF (0%). At the final assessment, plain radiographs revealed original recycled bone was present in 7 of 11 ECIR cases and in zero cases treated with LNF autografts, indicating that recycled bone treated with LNF autografts was remodeled into new bone. Histological examination of ECIR-treated bones revealed a delayed and incomplete endochondral ossification process, necrosis and empty lacunae. Conversely, LNF autografts showed remodeled bones with normal trabecular structures. CONCLUSIONS: ECIR and LNF treatment of autografts provided adequate tumor control with acceptable clinical results as a reconstruction method.

Minimally Invasive Resection of a Large Subcutaneous Lipoma: The 2.5-cm (1-inch) Method.

Background: Lipomas are benign and are usually located in subcutaneous tissues. Surgical excision frequently requires an incision equal to the diameter of the lipoma. However, small incisions are more cosmetically pleasing and decrease pain and/or hypoesthesia at the incision. A "fibrous structure" occurs inside the lipoma and is characterized by a low-intensity signal on T1-weighted magnetic resonance images. The "fibrous structure" is actually retaining ligaments with a normal structure that intrudes from the periphery1. Retaining ligaments are fibrous structures that are perpendicular to the skin and tether it to underlying muscle fascia. Description: The peripheral border of the tumor is marked with a surgical pen preoperatively. Under general anesthesia, a 2.5-cm (1-inch) incision is made with a surgical knife, cutting into the tumor through the capsule-like structure. Distinguishing the tumor from the overlying adipose tissue can be difficult. Use of only local anesthesia may be possible when the number of retaining ligaments is low, such as for lesions involving the upper arm. A central incision is preferred; a peripheral incision is possible but can make the procedure more difficult. Detachment of the lipoma from the retaining ligaments is performed bluntly with a finger, which allows pulling the tumor out between the retaining ligaments. We use hemostat forceps (Pean [or Kelly] forceps) to facilitate blunt dissection. Hemostat forceps are usually utilized for soft-tissue dissection and for clamping and grasping blood vessels. Prior to blunt dissection, dissection with Pean forceps can be performed over the surface of the tumor, but tearing the tumor apart can also be useful to allow subsequent finger dissection of the lipoma from the retaining ligament not only from outside but also from inside the lipoma. The released lipoma is extracted in a piecemeal fashion with Pean forceps or by squeezing the location to cause the lipoma to extrude through the incision. The retaining ligament is preserved as much as possible, but lipomas are sometimes completely trapped by the retaining ligament. In such cases, partially cutting the ligament with scissors to release the tumor can be useful during extraction. Detachment and extraction are repeated until the tumor is completely resected, which can be confirmed visually through the incision because of the resulting skin laxity. Remaining portions of a single lipoma are removed with Pean forceps. The residual lipomas may be located deep to the retaining ligament. Adequate lighting and visualization through a small incision is useful. After the skin is sutured, a Penrose drain is optional. Alternatives: The squeeze technique utilizing a small incision over the lipoma is a well-described technique for forearm or leg lipomas, but is often not successful for large lipomas, especially those in the shoulder. The squeeze technique is not always successful in these cases because of the fibrous structure, which is actually retaining ligaments1. Liposuction has also been reported as a minimally invasive treatment; however, long-term results of liposuction are disappointing with respect to the completeness of the resection and frequency of side effects, especially when the lipoma is fibrous. Rationale: The retaining ligaments are not truly linear but rather membranous, continuous with the surrounding normal tissues, and located at the periphery of the lipoma. Detachment of the lipoma from the retaining ligaments with a finger allows for extraction of the lipoma in a piecemeal fashion or via the squeeze technique through a small incision. Subcutaneous fibrous structures are reportedly highest in concentration for lateral and posterior lesions, with the density gradually increasing as lesions move posteriorly2. The operative time for the 1-inch method is longer for lipomas of the torso than those of the shoulder or extremities because the number of retaining ligaments is higher in the back. We assessed 25 patients with large lipomas, defined as a tumor diameter >5 cm. The mean operative time for all lesions was 28 minutes, with a mean time of 26 minutes for lipomas at the shoulder, 22 minutes for the extremities, and 47 minutes for the torso3. Expected Outcomes: The blunt procedure may cause dull pain at the tumor site for approximately 1 week. The skin-retaining ligaments at the periphery of the lipoma may serve to warn of the locations of peripheral nerve branches. Preserving the retaining ligaments decreases the possibility of hypoesthesia or permanent chronic pain at the incision site1. The 1-inch method is indicated in cases with a large subcutaneous lipoma. The maximum lipoma size for this procedure has not been established; however, because of skin laxity, we have not had difficulty reaching the peripheral parts of a lipoma, even if it is >10 cm in diameter, with use of the 1-inch method. Important Tips: Lipomas involving the back take more time than shoulder or extremity lipomas.The peripheral border of the tumor is marked.The incision is made with a surgical knife from the skin to the inside of the tumor.The lipoma is detached from the retaining ligaments with a finger, and the tumor is pulled between the retaining ligaments.The lipoma is extracted in a piecemeal fashion or using the squeeze technique.Complete resection is confirmed visually through the incision, which is possible because of the skin laxity. Acronyms and Abbreviations: MRI = magnetic resonance imagingSTIR = short-tau inversion recovery.

Extending the usefulness of the Stryker Growing Prosthesis in pediatric patients.

Osteosarcoma is a highly invasive primary bone tumor that predominantly occurs in childhood and adolescence. The Stryker Growing Prosthesis provides a means of reconstructing large bone defects resulting from bone resection in skeletally immature patients. This device can be expanded as the patient grows. The possible length of extension depends on the length of the prosthesis. Because further expansion was not possible, by turning the adjustable part of the extension back to zero and adding a new permanent extension allow the prosthesis to be further adjusted as growth ensues. Using this method/device only, a separate endoprosthesis was required to be attached onto the extension. Therefore, the applicable cases are limited, because of the fact that extensive resection usually means total femoral replacement is best indicated. However, this method is still useful for reducing the number of revision surgeries in such cases. This reduces costs and increases savings for insurers/countries.

Golden Ratio Flap Designed Using the Golden Ratio Rectangle.

Background: Rotation flaps are arcuate repairs that redistribute tension vectors and recruit adjacent and/or distant tissue laxity. The incision curve could be a logarithmic spiral curve to reduce the length of an incision. We propose a rotation flap-the golden ratio flap-designed using a golden rectangle. Methods: The flap incision is an arc though the major square which is beside the minor square of a golden rectangle. The defect is attached to the line of another minor square and diagonal to the major square. The bottom line runs from the incision end to the tangent point of the circle or the oval, and the perpendicular height line runs from the bottom line to the cross point of the flap incision. These parameters were analyzed retrospectively for four superficial sarcomas that were treated using a rotation flap with an incision approximating the logarithmic spiral curve. Results: The ratio of height to bottom of the golden ratio flap design was highly similar to the preoperative flap design in the four cases assessed. With the new design, the ratio of bottom to the defect diameter (minor axis in the oval defect) was 1.3, and for the height, it was 1.4. Conclusions: The golden ratio flap, designed using the golden rectangle, is reproducible. The parameters of height and bottom approximate the flap shape, or the length and width, respectively. For clinical applications, step-by-step guidance for drawing the new flap are also proposed.

System describing surgical field extension associated with flap reconstruction after resection of a superficial malignant soft tissue tumor.

BACKGROUND: Flap reconstruction after resection of a superficial malignant soft tissue tumor extends the surgical field and is an indicator for potential recurrence sites. AIM: To describe a grading system for surgical field extension of soft tissue sarcomas. METHODS: Grading system: CD-grading is a description system consisting of C and D values in the surgical field extension, which are related to the compartmental position of the flap beyond the nearby large joint and deeper extension for the pedicle, respectively. C1/D1 are positive values and C0/D0 are negative. With a known location, 1/0 values can be "p" (proximal), "d" (distal), and "b" (in the tumor bed), and the description method is as follows: flap type, CxDx [x = 0, 1, p, d or b]. RESULTS: Four representative patients with subcutaneous sarcomas who underwent reconstruction using fasciocutaneous flaps are presented. The cases involved a distal upper arm (elbow) synovial sarcoma reconstructed using a pedicled latissimus dorsi (pedicled flap: CpDp); a distal upper arm (elbow) pleomorphic rhabdomyosarcoma reconstructed using a transpositional flap from the forearm (transpositional flap: CdD0); an undifferentiated pleomorphic sarcoma in the buttocks reconstructed using a transpositional flap (transpositional flap: C0D0); and a myxofibrosarcoma in the buttocks reconstructed using a propeller flap from the thigh (pedicled flap: CdDd). CONCLUSION: The reconstruction method is chosen by the surgeon based on size, location, and other tumor characteristics; however, the final surgical field cannot be determined based on preoperative images alone. CD-grading is a description system consisting of C and D values in the surgical field extension that are related to the compartmental position of the flap beyond the nearby large joint and deeper extension for the pedicle, respectively. The CD-grading system gives a new perspective to the flap reconstruction classification. The CD-grading system also provides important information for follow-up imaging of a possible recurrence.

Preoperative Mohs Paste Treatment for a Subcutaneous Sarcoma and a Skin Ulcer to Prevent Intraoperative Bleeding.

Introduction: Mohs paste has a zinc chloride component and the ability to coagulate tissue. Mohs chemosurgery or surgery is a method by which coagulated tissue is removed and can be repeated until the tumor disappears. The palliative purpose of Mohs chemosurgery or surgery is to control bleeding or exudate from a malignancy with a skin ulcer. In the current report, a single application of Mohs paste as a pre-operative treatment for a superficial sarcoma with a skin ulcer prevented intra-operative bleeding. Case Report: Two metastatic sarcomas are described: one in the scalp originating from a rectoperineal dedifferentiated liposarcoma and one in the elbow originating from a humeral telangiectatic osteosarcoma. Mohs paste treatment was performed the day before surgical resection. The Mohs paste procedure successfully prevented intra-operative bleeding from the tumor, leading to easy removal of the tumors with appropriate tumor-free margins. Conclusion: Preoperative Mohs paste treatment is a simple and reliable method. Intra-operative neoplastic bleeding may contaminate the tumor cells within the surgical field; thus the prevention of bleeding with Mohs paste treatment may lead to a decrease in the tumor recurrence rate.

Anatomic variations in retaining ligaments during minimally invasive resection of subcutaneous lipomas.

Objective: Lipomas are common, benign tumors usually located in the subcutaneous tissue. The "one-inch method" is a minimally invasive technique for resecting large subcutaneous lipomas through a one-inch incision after blunt dissection of the lipoma from its peripheral retaining ligaments. The limitations of this method are currently unclear. Materials and methods: We assessed twenty-five patients with large lipomas, defined as a tumor diameter greater than 5 cm. The location of the lipoma was at the shoulder in fifteen patients, the extremity in six patients, and the torso in four patients. Results: The mean operative time for all lesions was 28.3 minutes, with a mean time of 25.9 minutes for lipomas at the shoulder, 21.8 minutes for the extremities, and 47.0 minutes for the torso. We classified patients into three groups according to operative time: the short group (10-29 min), middle group (30-49 min), and long group (50-70 min). For lipomas of the shoulder, there were eleven patients (73%) in the short group, three patients (20%) in the middle group, and one patient (7%) in the long group. For lipomas of the extremity, the groups contained five patients (83%), one patient (17%), and no patients (0%), respectively. For lipomas of the torso, the groups contained one patient (25%), no patients (0%), and three patients (75%), respectively. Conclusions: Lipomas of the torso require a longer operative time than those of the shoulder or extremity; this difference could be due to the number of retaining ligaments present, which is reportedly higher in the back than in the anterior or side body. Lipomas of the back are less amenable to the one-inch method, and posterior shoulder lipomas may take more time than those at other parts of the shoulder or at the extremities.

T2-star (T2*)-weighted magnetic resonance imaging of tenosynovial giant cell tumors.

Purpose: Tenosynovial giant cell tumors (TSGCTs) are benign but aggressive lesions, and the treatment is resection. A low to intermediate signal intensity on both T1- and T2-weighted images of magnetic resonance imaging (MRI) is characteristic, which is similar to the signal intensity of muscle, and therefore can be challenging for lesion detection. T2-star (T2*)-weighted MR images reflect paramagnetic deoxyhemoglobin, methemoglobin, or hemosiderin. Methods: In 23 TSGCT patients (6 male and 17 females), the T2*MRI findings were analyzed. The tumor locations involved 10 large joints including nine knees and one ankle, 10 small joints including six fingers and four toes, as well as three wrists/hands. Results: Ten diffuse and 13 localized tumors were predominantly located in the large joints and small joints, respectively. The T2*-weighted images indicated three signal patterns of low, iso and high signal intensity compared to muscle. Low-, iso- and high-signal intensities were seen in 22 (96 %), 23 (100 %) and 12 (52 %) of the locations, respectively. To distinguish TSGCTs from the surrounding tissue, the low intensity T2*-weighted images and low to intermediate intensity T1-weighted images when compared to muscle and fluid, respectively were useful for the large joints. Low to intermediate intensity on T1- or T2-weighted images was useful to distinguish TSGCTs from subcutaneous tissue in the small joints. Conclusions: MRI using T2*-, as well as T1- and T2-weighted images, may be useful to detect lesions and assess the extent of TSGCTs in a tissue-specific manner, which is important for surgical planning.

Protocol for the 2ND-STEP study, Japan Clinical Oncology Group study JCOG1802: a randomized phase II trial of second-line treatment for advanced soft tissue sarcoma comparing trabectedin, eribulin and pazopanib.

BACKGROUND: Soft tissue sarcomas (STS) are a rare type of malignancy comprising a variety of histological diagnoses. Chemotherapy constitutes the standard treatment for advanced STS. Doxorubicin-based regimens, which include the administration of doxorubicin alone or in combination with ifosfamide or dacarbazine, are widely accepted as first-line chemotherapy for advanced STS. Trabectedin, eribulin, pazopanib, and gemcitabine plus docetaxel (GD), which is the empirical standard therapy in Japan, are major candidates for second-line chemotherapy for advanced STS, although clear evidence of the superiority of any one regimen is lacking. The Bone and Soft Tissue Tumor Study Group of the Japan Clinical Oncology Group (JCOG) conducts this trial to select the most promising regimen among trabectedin, eribulin, and pazopanib for comparison with GD as the test arm regimen in a future phase III trial of second-line treatment for patients with advanced STS. METHODS: The JCOG1802 study is a multicenter, selection design, randomized phase II trial comparing trabectedin (1.2 mg/m2 intravenously, every 3 weeks), eribulin (1.4 mg/m2 intravenously, days 1 and 8, every 3 weeks), and pazopanib (800 mg orally, every day) in patients with unresectable or metastatic STS refractory to doxorubicin-based first-line chemotherapy. The principal eligibility criteria are patients aged 16 years or above; unresectable and/or metastatic STS; exacerbation within 6 months prior to registration; histopathological diagnosis of STS other than Ewing sarcoma, embryonal/alveolar rhabdomyosarcoma, well-differentiated liposarcoma and myxoid liposarcoma; prior doxorubicin-based chemotherapy for STS, and Eastern Cooperative Oncology Group performance status 0 to 2. The primary endpoint is progression-free survival, and the secondary endpoints include overall survival, disease-control rate, response rate, and adverse events. The total planned sample size to correctly select the most promising regimen with a probability of > 80% is 120. Thirty-seven institutions in Japan will participate at the start of this trial. DISCUSSION: This is the first randomized trial to evaluate trabectedin, eribulin, and pazopanib as second-line therapies for advanced STS. We endeavor to perform a subsequent phase III trial comparing the best regimen selected by this study (JCOG1802) with GD. TRIAL REGISTRATION: This study was registered with the Japan Registry of Clinical Trials ( jRCTs031190152 ) on December 5, 2019.

Inhibition of RANKL Expression in Osteocyte-like Differentiated Tumor Cells in Giant Cell Tumor of Bone After Denosumab Treatment.

Giant cell tumors of bone (GCTBs) are locally aggressive tumors with the histological features of giant cells and stromal cells. Denosumab is a human monoclonal antibody that binds to the cytokine receptor activator of nuclear factor-kappa B ligand (RANKL). RANKL inhibition blocks tumor-induced osteoclastogenesis, and survival, and is used to treat unresectable GCTBs. Denosumab treatment induces osteogenic differentiation of GCTB cells. In this study, the expression of RANKL, special AT-rich sequence-binding protein 2 (SATB2, a marker of osteoblast differentiation), and sclerostin/SOST (a marker of mature osteocytes) was analyzed before and after treatment with denosumab in six cases of GCTB. Denosumab therapy was administered a mean of five times over a mean 93.5-day period. Before denosumab treatment, RANKL expression was observed in one of six cases. After denosumab therapy, spindle-like cells devoid of giant cell aggregation were RANKL-positive in four of six cases. Bone matrix-embedded osteocyte markers were observed, although RANKL was not expressed. Osteocyte-like cells were confirmed to have mutations, as identified using mutation-specific antibodies. Our study results suggest that treatment of GCTBs with denosumab results in osteoblast-osteocyte differentiation. Denosumab played a role in the suppression of tumor activity via inhibition of the RANK-RANKL pathway, which triggers osteoclast precursors to differentiate into osteoclasts.

Combined latissimus dorsi and scapular flaps for reconstruction of a large defect after a shoulder sarcoma resection.

Reconstruction with a pedicled latissimus dorsi flap is used for a large defect after resection of soft tissue sarcoma of the shoulder. Primary donor site closure is sometimes difficult and a skin graft is necessary, possibly delaying postoperative chemotherapy. Combined latissimus dorsi and scapular flaps are used for free flaps in head and neck reconstruction. Myxofibrosarcoma resection in the shoulder of a 76-year-old man resulted in a 16 cm diameter skin resection. The defect was reconstructed with a scapular flap (width = 5 cm) for the distal defect and a pedicled latissimus dorsi muscle flap (flap size, 10 × 7 cm) for the proximal defect. Primary closure of the donor site in the latissimus dorsi flap was easy. By adding a scapular flap to the latissimus dorsi flap, the latissimus dorsi flap area can be reduced, making it easy for primary suture and contributing to less invasive surgery.

Old Surgical Scar at the Ankle Causing Referred Sciatica-Like Pain Treated With a Scar-Fascial Release Technique.

A surgical scar with adhesions to the underlying fascia and periosteum caused radiating pain to different parts of the scar. Abdominal pain is a common complication of surgical scars, but surgical scar associated with extremity pain is rare. A 75-year-old man had a gait disturbance due to right sciatica-like pain from the thigh to the lower leg for >10 years. He also had mild ankle pain due to osteoarthrosis. The medical history was significant for an ankle injury diagnosed as a sprain and intra-articular small fracture, for which he underwent resection of the bone fragment from the anterior aspect 14 years ago. The surgical scar was adherent to the underlying fascia. The surgical scar was shown to be involved in sciatica-like pain. For the adhesive scar, the scar-fascial release technique was performed by stretching in the direction of the palpated restriction. The sciatica-like pain and gait disturbance resolved one month after the procedure, while the ankle pain remained mild. The current case is a rare case of an adhesive ankle scar causing sciatica-like pain and gait disturbance. The sciatica-like pain involving the proximal lower extremity caused by the ankle scar supports the myofascial meridian concept.

Muscle Grafts with Doxorubicin Pretreatment Produce "Empty Tubes" in the Basal Laminae, Promote Contentious Maturation of the Regenerated Axons, and Bridge 20-mm Sciatic Nerve Defects in Rats.

BACKGROUND: We newly developed a muscle graft that employs a doxorubicin pretreatment technique. The aims of this study were to reveal the biological and morphological features of the muscle tissue in the second week (Study I), to reveal the regeneration outcomes of functional and kinematic assessments of longer-term follow-up (16 weeks, Study II), and to make assessments of the muscle graft with doxorubicin pretreatment in the critical-sized nerve defect model (20 mm, Study III). METHODS: A total of 26 adult rats were used in this study. Doxorubicin treatment was accomplished by immersion in a doxorubicin solution for 10 minutes followed by a rinsing procedure. The rats were divided into three groups: the muscle graft with and without doxorubicin pretreatment (M-graft-w-Dox and M-graft-w/o-Dox) groups and the autologous nerve graft (N-graft) group. Assays of apoptosis, immunofluorescent histochemistry including CD68 (macrophage marker), scanning electron microscopy (SEM), morphometrical studies of the regenerated axons, nerve conduction studies, and kinematic studies were performed. RESULTS: The M-graft-w-Dox group contained significantly larger numbers of apoptotic cells and CD68-positive cells. SEM revealed the existence of the basal lamina, so called "empty tubes," in the M-graft-w-Dox group. Study II showed contentious maturation of the regenerated axons, especially in the compound muscle action potentials. Study III showed that even at 20 mm, the M-graft-w-Dox group promoted axonal regeneration and functional regeneration. CONCLUSION: The M-graft-w-Dox group showed superior regeneration results, and this easy and short-term procedure can expand the muscle graft clinical indication for the treatment of peripheral nerve defects.

Clinical Outcomes of Patients With Osteosarcoma Experiencing Relapse or Progression: A Single-institute Experience.

BACKGROUND: Patients with osteosarcoma who experience relapse or progression [R/P] have a poor prognosis. METHODS: Data from 30 patients who experienced R/P among 59 with a diagnosis of high-grade osteosarcoma, who were younger than 40 years old between 2000 and 2019, were retrospectively analyzed to identify prognostic and therapeutic factors influencing their outcomes. RESULTS: The 5-year overall survival [OS] rates after the last R/P of patients experiencing first [n=30], second [n=14], and third [n=9] R/P were 50.3%, 51.3%, and 46.7%, respectively. Multivariate analysis did not identify any independent risk factors affecting OS. The 5-year PFS rate of the 30 patients after first R/P was 22.4%, and multivariate analysis identified histologic subtype and curative local surgery as independent risk factors influencing PFS. Long [>6 mo] partial response was observed in three patients treated using temozolomide+etoposide, irinotecan+carboplatin, or regorafenib. CONCLUSIONS: OS rate in the patients with osteosarcoma experiencing R/P included in this study was markedly higher than that reported previously, mainly due to the surgical total removal of tumors, even after subsequent R/P. The recent establishment of salvage chemotherapy or molecular targeted therapy may also increase survival rates in a subgroup of patients.

Stress Fractures of the First Rib Related to Soft Tennis, Associated with the Tennis Ground Stroke.

Stress fractures of the first rib are uncommon and thought to be associated with overhead-throwing athletes. Soft tennis is similar to regular tennis but uses a much softer rubber ball. In the current report, a 14-year-old girl suffered from shoulder girdle pain, especially at the end of her tennis ground stroke. Plain radiographs showed overgrowth of bone with a fracture line on the first rib, and a diagnosis of stress fracture was made. She was advised to amend her stroke form to reduce force to the shoulder and was able to continue sports activity without pain 10 months after the appearance of her symptoms and before confirmation of bone healing. The current case is not associated with overhead-throwing, but possibly with repetitive exercises of her tennis ground strokes. Conservative medical follow-up with proper sport-specific professional advice allows continuation of the sport.

Reconstruction using low-porosity ß-tricalcium phosphate for a chondroblastoma in the proximal humeral epiphysis.

Chondroblastoma is a locally aggressive tumor, commonly occurring in the epiphysis of long bones. Damage after curettage at the joint surface can occur. Low porosity ß-tricalcium phosphate (ß-TCP) blocks are characterized by their high compression resistance. Reconstruction in which low-porosity ß-TCP blocks are used as a strut have been reported for bone tumors around the knee. In the current report, a 13-year-old female with a chondroblastoma that extended to the subchondral bone of the proximal humeral epiphysis was treated with curettage and strut reconstruction using low-porosity ß-TCP blocks. The implanted ß-TCP blocks were incorporated without damage or shoulder dysfunction. Application of the strut reconstruction method using low-porosity ß-TCP blocks is suitable for a chondroblastoma of the epiphysis in the humerus.

Estimation of Minimum Biofilm Eradication Concentration (MBEC) on In Vivo Biofilm on Orthopedic Implants in a Rodent Femoral Infection Model.

The formation of a biofilm on the implant surface is a major cause of intractable implant-associated infection. To investigate the antibiotic concentration needed to eradicate the bacteria inside a biofilm, the minimum biofilm eradication concentration (MBEC) has been used, mostly against in vitro biofilms on plastic surfaces. To produce a more clinically relevant environment, an MBEC assay against biofilms on stainless-steel implants formed in a rat femoral infection model was developed. The rats were implanted with stainless steel screws contaminated by two Staphylococcus aureus strains (UAMS-1, methicillin-sensitive Staphylococcus aureus; USA300LAC, methicillin-resistant Staphylococcus aureus) and euthanized on days 3 and 14. Implants were harvested, washed, and incubated with various concentrations (64-4096 µg/mL) of gentamicin (GM), vancomycin (VA), or cefazolin (CZ) with or without an accompanying systemic treatment dose of VA (20 µg/mL) or rifampicin (RF) (1.5 µg/mL) for 24 h. The implant was vortexed and sonicated, the biofilm was removed, and the implant was re-incubated to determine bacterial recovery. MBEC on the removed biofilm and implant was defined as in vivo MBEC and in vivo implant MBEC, respectively, and the concentrations of 100% and 60% eradication were defined as MBEC100 and MBEC60, respectively. As for in vivo MBEC, MBEC100 of GM was 256-1024 µg/mL, but that of VA and CZ ranged from 2048-4096 µg/mL. Surprisingly, the in vivo implant MBEC was much higher, ranging from 2048 µg/mL to more than 4096 µg/mL. The addition of RF, not VA, as a secondary antibiotic was effective, and MBEC60 on day 3 USA300LAC biofilm was reduced from 1024 µg/mL with GM alone to 128 µg/mL in combination with RF and the MBEC60 on day 14 USA300LAC biofilm was reduced from 2048 µg/mL in GM alone to 256 µg/mL in combination with RF. In conclusion, a novel MBEC assay for in vivo biofilms on orthopedic implants was developed. GM was the most effective against both methicillin-sensitive and methicillin-resistant Staphylococcus aureus, in in vivo biofilms, and the addition of a systemic concentration of RF reduced MBEC of GM. Early initiation of treatment is desired because the required concentration of antibiotics increases with biofilm maturation.

A randomized phase III trial of denosumab before curettage for giant cell tumor of bone. JCOG1610.

OBJECTIVES: The aim of JCOG1610 (randomized controlled phase III trial) was to confirm the superiority of preoperative denosumab to curettage with adjuvant local therapy for patients with giant cell tumor of bone without possible post-operative large bone defect. METHODS: The primary endpoint was relapse-free survival and the total sample size was set at 106 patients. Patient accrual began in October 2017. However, the accrual was terminated in December 2020 due to a recommendation from the Data and Safety Monitoring Committee because of poor patient accrual. Now, we report the descriptive results obtained in this study. RESULTS: A total of 18 patients had been registered from 13 Japanese institutions at the time of termination on December 2020. Eleven patients were assigned to Arm A (curettage and adjuvant local therapy) and 7 to Arm B (preoperative denosumab, curettage and adjuvant local therapy). Median follow-up period was 1.6 (range: 0.5-2.8) years. Protocol treatment was completed in all but one patient in Arm A who had a pathological fracture before surgery. All patients in Arm B were treated with five courses of preoperative denosumab. Relapse-free survival proportions in Arm A and B were 90.0% (95% confidence interval: 47.3-98.5) and 100% (100-100) at 1 year, and 60.0% (19.0-85.5) and 62.5% (14.2-89.3) at 2 years, respectively [hazard ratio (95% confidence interval): 1.51 (0.24-9.41)]. CONCLUSION: In terms of relapse-free survival, the superiority of preoperative denosumab was not observed in patients with giant cell tumor of bone without possible post-operative large bone defect.