Sacroiliac joint fusion navigation: how accurate is pin placement?

OBJECTIVE: Sacroiliac joint (SIJ) fusion utilizing intraoperative navigation requires a standard reference frame, which is often placed using a percutaneous pin. Proper placement ensures the correct positioning of SIJ fusion implants. There is currently no grading scheme for evaluation of pin placement into the pelvis. The purpose of this study was to evaluate the occurrence of ideal percutaneous pin placement into the posterior ilium during navigated SIJ fusion. METHODS: After IRB approval was obtained, electronic medical records and intraoperative computed tomography images of patients who underwent navigated SIJ fusion by the senior author between October 2013 and January 2020 were reviewed. A pin placement grading scheme and the definition of "ideal" placement were developed by the authors and deemed acceptable by fellow attending surgeons. Six attending surgeons completed two rounds of pin placement grading, and statistical analysis was conducted. RESULTS: Of 90 eligible patients, 73.3% had ideal pin placement, 17.8% medial/lateral breach, and 8.9% complete miss. Male patients were 3.7 times more likely to have ideal placement than females (p < 0.05). There was no relationship between BMI, SIJ fusion laterality, or pin placement laterality and ideal placement. Interobserver reliability was 0.72 and 0.70 in the first and second rounds, respectively, and defined as "substantial agreement." Intraobserver reliability ranged from 0.74 (substantial agreement) to 0.92 (almost perfect agreement). CONCLUSIONS: Nonideal pin placement occurred in 26.7% of cases, but a true "miss" into the sacrum was rare. Ideal pin placement was more likely in males and was not associated with BMI, SIJ fusion laterality, or pin placement laterality. The grading scheme developed has high intraobserver and interobserver reliability, indicating that it is reproducible and can be used for future studies. When placing percutaneous pins, surgeons must be aware of factors that can decrease placement accuracy, regardless of location.

Phosphaturic Mesenchymal Tumor: An Unusual Cause of Stress Fractures Presenting to Sports Medicine.

Phosphaturic mesenchymal tumors (PMT) are a rare neoplasm oftentimes associated with tumor-induced osteomalacia (TIO). The non-specific presentation and symptoms of these pathologies make them difficult to diagnose. We report a case of a 52-year-old patient with an intermetatarsal phosphaturic mesenchymal tumor who presented to the orthopedic sports medicine clinic with metabolic deficiencies and bilateral subtrochanteric cortical stress fractures indicative of osteomalacia. The tumor was entirely resected within nine months of symptom onset and has shown no recurrence at the one-year follow-up. This case report characterizes an unusual cause of stress fractures presenting to orthopedic sports medicine clinics and the variability in the presentation of phosphaturic mesenchymal tumors.

Safety of a Noninvasive Expandable Electromagnetic Prosthesis with an In Situ Ventricular Assist Device: A Case Report.

CASE: An 8-year-old girl was diagnosed with osteosarcoma of the distal femur. She underwent chemotherapy and wide resection with implantation of a noninvasive electromagnetic expandable distal femur prosthesis. Ninety-three days after chemotherapy, she developed anthracycline-induced cardiomyopathy with heart failure for which a ventricular assist device was placed. Device compatibility was tested, and she was successfully lengthened. CONCLUSION: Expandable prostheses allow limb length maintenance in skeletally immature patients who undergo limb salvage. Chemotherapy for osteosarcoma involves anthracyclines with a dose-dependent side effect of cardiotoxicity. Patients can be successfully and safely lengthened with expandable electromagnetic prostheses with in situ ventricular assist devices.

Reconstruction of the Shoulder and Humerus in Metastatic Bone Disease.

Metastatic disease involving the skeleton most often affects the spine, pelvis, and proximal long bones of the extremities. In the upper extremity, the proximal humerus is frequently affected. Although many of the principles of managing metastatic bone disease are similar, regardless of the metastatic site, the upper extremity has some unique anatomic and functional traits that warrant consideration when making management decisions. The main anatomic differences from the lower extremity pertain to the smaller bone size, rotator cuff function, and proximity to major neurologic structures, and the important functional differences that relate to activities of daily living have a greater dependence on the upper, rather than lower, extremity; greater range of motion of the shoulder; side dominance; limited weight-bearing function; and marked propensity of the elbow to develop stiffness. Clinicians should consider aspects of the shoulder and humerus as they relate to the overall management of metastatic bone disease, either monostotic or polyostotic, when evaluating and managing metastatic lesions at this site.

Vascular endothelial growth factor improves bone repair in a murine nonunion model.

OBJECTIVES: Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that plays an important role during skeletal development and fracture healing. Previous experimental studies have shown that VEGF applied immediately after injury can stimulate bone repair in animal fracture nonunion models. However, the effectiveness of VEGF on an established fracture non-union has not been determined. the goal of this work was to test the ability of VEGF applied at a later stage on the healing of fracture nonunions. METHODS: In this study, a murine non-union model was induced by rapid distraction of a tibia osteotomy. this model exhibits radiological and histological evidence of impaired fracture healing at 7 days after the completion of distraction. VEGF (10 µg in 20 µl Pbs/day, n=10) or control (20 µl Pbs/day, n=10) was injected directly into the distraction gap through the posterior musculature on three consecutive days (7, 8, and 9 days after completing distraction). A third group of animals (n=10) with rapid distraction, but no injections, served as non-treated controls. Fracture healing was analyzed by x-ray, histology, and histomorphometry at 27 days after the last round of distraction. RESULTS: radiographs showed that half of the VEGF treated animals (5/10) achieved bony healing whereas the majority of Pbs treated (7/10) and non-treated controls (8/10) did not exhibit bone bridging. Histological and histomorphometric analyses demonstrated that VEGF increased, but not significantly, the amount of bone formed in the distraction gap (1.35 ± 0.35 mm(3)), compared to the saline treated (0.77 ± 0.25 mm(3), p=0.19) and non-treated animals (0.79 ± 0.23mm(3), p=0.12). CONCLUSIONS: Results from this study demonstrate that VEGF potentially promotes bone repair, warranting further research in this direction.

Surgical complications associated with extensive tumoral calcinosis.

In this article, we describe the presenting features, radiographic appearance, and proposed pathogenesis of tumoral calcinosis; highlight the surgical complications we have encountered with the syndrome; and review the complications reported in the literature.

When should we biopsy a solitary central cartilaginous tumor of long bones? Literature review and management proposal.

Differentiation between benign and low-grade malignant cartilaginous tumors is a radiological and pathological challenge. Based on a literature review, we propose the following guidelines for the management of a solitary central cartilaginous tumor of long bones distinguishing three situations: 1. The tumor is considered to be aggressive and requires surgery if one of the following criteria is present: cortical destruction, Moth-eaten or permeative osteolysis, spontaneous pathologic fracture, periosteal reaction, edema surrounding the tumor on MR images, and soft tissue mass. Tumor biopsy followed by complete intralesional treatment is indicated. 2. The tumor is classified as active if two of the following active criteria are present: pain related to the tumor, endosteal scalloping superior to two-thirds of the cortical thickness, extent of endosteal scalloping superior to two-thirds of the lesion length, cortical thickening and enlargement of the medullary cavity. Tumor biopsy or excision is indicated. 3. The tumor is classified as possibly active if one of the previous active criteria is present. In such cases, bone scintigraphy and dynamic-enhanced MR imaging should be obtained. Radionuclide uptake superior to the anterior iliac crest at bone scintigraphy and early and exponential enhancement at dynamic-enhanced MR are considered as two additional active criteria. After these two examinations, if only one criterion is still present, the lesion can be regarded as possibly quiescent, and the following monitoring is suggested: first follow-up at three to six months and then once a year. Otherwise, if two or more active criteria are present, biopsy is recommended. 4. The tumor is considered quiescent and does not require surgery if no active or aggressive criterion is present. A radiological follow-up can be proposed.

Early outcomes for malignant peripheral nerve sheath tumor treated with chemotherapy.

OBJECTIVES: Malignant peripheral nerve sheath tumors (MPNST) are rare soft-tissue sarcomas with a tendency for recurrence and metastasis. Treatment using chemotherapy is controversial, but benefit with some agents has been described. This study aimed to analyze early survival outcomes using doxorubicin and ifosfamide chemotherapy for MPNST. METHODS: Pathology records at our musculoskeletal tumor center were searched for patients with a new diagnosis of MPNST between 2003 and 2008. Treatment involved surgical resection, radiation, and chemotherapy with doxorubicin and ifosfamide. Ten patients met inclusion criteria, with mean age 40 years (range, 20-70). Four patients had metastatic disease on presentation. Four patients had neurofibromatosis type I (NF1). RESULTS: Of 6 patients with nonmetastatic disease on presentation, 5 had no evidence of disease post-treatment. The sixth had positive margins after surgery and initially received no further treatment due to noncompliance. Three from this subgroup developed local recurrence, but none developed distant metastases and 1 died of disease at last follow-up. One- and 2-year disease-free survival (DFS) for this subgroup was 80% and 60%, respectively. One- and 2-year overall survival (OS) for the subgroup was 100%. Of 4 patients with metastatic disease on presentation, 2 had no evidence of disease post-treatment. One of these 2 developed local recurrence, but none from the subgroup developed new metastatic disease. Two of these 4 died of disease at last follow-up. One- and 2-year DFS for this subgroup was 100% and 50%, respectively. One- and 2-year OS was 75% and 50%, respectively. Two of the 4 patients presenting with metastatic disease had NF1. All 3 local recurrences and 2 of the 3 deaths in this study occurred in NF1 patients. CONCLUSIONS: For all patients, when combined with surgery and radiation, chemotherapy using doxorubicin and ifosfamide yielded 57% DFS and 80% OS at 2 years. NF1 patients appeared to have worse outcomes, with a statistically significantly lower DFS than non-NF1 patients. Limitations of this study include a small sample size, retrospective design, and use of different chemotherapy regimens.

Curettage and graft alleviates athletic-limiting pain in benign lytic bone lesions.

BACKGROUND: Solitary bone cysts (SBC), nonossifying fibromas (NOF), and fibrous dysplasia (FD) create benign intramedullary lytic bone lesions. They are typically asymptomatic and treated conservatively. We present a series of lesions that caused performance-limiting pain in young athletes, a symptom phenomenon and possible treatment indication that has been poorly described in the literature. QUESTIONS/PURPOSES: We asked whether intralesional curettage and defect grafting of these lesions would alleviate pain in young athletes and permit their return to unrestricted athletic activities. PATIENTS AND METHODS: We retrospectively identified 29 patients (30 lesions) who underwent curettage and grafting for SBC (12 patients), NOF (nine), or FD (eight). All patients had pain predominantly with athletic involvement. The mean age of the patients was 18 years (range, 12-31 years). Tumor locations were the femur (eight lesions), humerus (seven), tibia (six), fibula (five), pubic ramus (two), ulna (one), and calcaneus (one). Signs/symptoms were pain alone (24 patients) and pain plus fracture (five). Surgery involved curettage and packing with allograft cancellous chips, bone substitute, or demineralized bone matrix. Two patients required internal fixation. The mean followup was 21 months (range, 2-114 months). RESULTS: Twenty-four patients had no pain and five had occasional mild pain at last followup. All patients resumed full activity at a mean of 3.3 months (range, 1.5-8.3 months), excluding two who required repeat surgery. CONCLUSIONS: Our observations suggest curettage and packing with bone graft/substitute can provide pain relief and allow full athletic recovery for young athletes with benign lytic bone lesions. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Primary musculoskeletal sarcoidosis.

Sarcoidosis is a well-described clinical entity with several types of presentation among different organ systems. However, primary musculoskeletal manifestation is a rare and seldom-described manifestation. A retrospective review of patients seen at our institution from 1999 to 2009 was performed to identify patients with such presentation. Eleven patients with musculoskeletal sarcoidosis were identified. Seven patients presented with solitary lesions, while 4 presented with multiple foci of disease. Histologically, all lesions revealed granulomatous inflammation consistent with sarcoidosis. Cultures and gram stain were negative in all patients. One patient was found to have evidence of pulmonary sarcoidosis after diagnosis of musculoskeletal sarcoidosis. Eight patients had primarily soft tissue involvement with visible masses, while 3 patients had primarily osseous involvement with no mass. Pain was reported by 9 of 11 patients. On magnetic resonance imaging, all lesions were dark on T1, bright on T2, and poorly marginated. Magnetic resonance imaging was noted to be more accurate in revealing the pathology than radiographic imaging. Four patients underwent complete excision and 1 received a steroid injection. The remaining patients required no further treatment after diagnosis. Musculoskeletal sarcoidosis is rare and can present as single or multiple lesions. Definitive diagnosis is made by biopsy. The decision to operate should be based on symptoms, issues with cosmesis, impending fractures, growth, and/or involvement of neuro-vascular structures. Patients should be evaluated for pulmonary involvement.

Case report: hemosiderotic fibrohistiocytic lipomatous lesion: a clinicopathologic characterization.

BACKGROUND: A hemosiderotic fibrohistiocytic lipomatous lesion, also called hemosiderotic fibrolipomatous tumor, is a rare and recently described fibrolipomatous entity. Initially considered the result of a reactive inflammatory process from trauma or vascular disease, newer evidence suggests it may be neoplastic in origin. CASE REPORT: We report the case of a 56-year-old woman with a painful mass in the dorsal aspect of the foot diagnosed as a hemosiderotic fibrohistiocytic lipomatous lesion. LITERATURE REVIEW: We reviewed all 31 published cases of hemosiderotic fibrohistiocytic lipomatous lesions looking for common clinical, imaging, and histologic patterns. Hemosiderotic fibrohistiocytic lipomatous lesions occur predominantly in the fifth and sixth decades of life (average age, 49.5 years; range, 0.67-74 years). Females predominate 22 to 9. Thirteen of 28 patients had histories of trauma or vasculopathy. Twenty-six of 31 lesions were in the foot. The MRI signal of a hemosiderotic fibrohistiocytic lipomatous lesion follows fat in all sequences. Stranding or septations also frequently are seen. Histologically, the lesions are composed of three main elements in varying proportions: mature adipocytes, spindle cells, and hemosiderin pigment. Ten of 27 resected lesions recurred. Resection types are not reported in many cases. Four of 15 lesions recurred after marginal/intralesional excision, whereas none of three lesions treated by wide excision recurred. PURPOSE AND CLINICAL RELEVANCE: The high recurrence rate may be related to the difficulty in determining intraoperatively that a resection is complete, secondary to the lack of anatomic boundaries such as a pseudocapsule. Any attempt at wide resection must weigh the morbidity of this surgery against that of a recurrence after a resection which seemed complete intraoperatively. There have been no reports of metastasis.

Treatment of adult rhabdomyosarcoma.

OBJECTIVES: Rhabdomyosarcoma is an exceedingly rare tumor in adults, and standard chemotherapy used for children is much less effective in adults. This study examines short-term outcomes using doxorubicin, ifosfamide, and vincristine for adult rhabdomyosarcoma. METHODS: Pathology records were searched for adults (age, >18) with rhabdomyosarcoma treated at our musculoskeletal tumor center. Treatment involved surgical resection, radiation therapy, and chemotherapy with doxorubicin, ifosfamide, and vincristine. Eleven met inclusion criteria. Mean age was 49 (range: 19-72). Tumors sites included upper extremity (4 patients), lower extremity (6), and cervix (1). Subtypes were pleomorphic (7), alveolar (1), embryonal (1), and mixed alveolar/embryonal (2). RESULTS: Of the 7 patients with nonmetastatic disease, 6 had no evidence of disease posttreatment, but 1 died of myelodysplastic syndrome after 51 months. Three patients who received neoadjuvant chemotherapy had 100% tumor necrosis. One patient with positive margins scheduled for adjuvant chemotherapy had local recurrence and metastasis within 2 weeks and died 5 months later. Of the 4 patients with metastatic disease on presentation, 1 had complete response, 2 had partial response with later progression and death at 8 and 24 months, and 1 had immediate progression and died at 12 months. Mean overall survival was 24 months with 6 of 11 (55%) alive at last follow-up. Mean disease-free survival was 17 months for all patients and 23 months for the 7 patients who had remission of all disease. CONCLUSIONS: When combined with surgery and radiation therapy, chemotherapy using doxorubicin, ifosfamide, and vincristine yielded 55% overall and 64% disease-free survival at 2 years.

Symptomatic fat necrosis and lipoatrophy of the posterior pelvis following trauma.

Posttraumatic fat necrosis and lipoatrophy can occur in the subcutaneous fat following falls, blunt injury, surgery, and minor procedures or injections. While these processes have no inherent serious medical consequences, they occasionally require treatment due to severe or concerning symptoms. Three patients (all women; average age, 47 years) who sustained blunt trauma to the pelvis and were diagnosed with posttraumatic fat necrosis or lipoatrophy were retrospectively identified from our orthopedic oncology records. All patients recalled blunt trauma to the posterior pelvis just prior to symptom onset; 2 patients fell down stairs and 1 fell from a bed. Chief symptoms were a painful mass, a painless mass, and chronic pain in the injured area. Magnetic resonance imaging (MRI) revealed atrophy of the subcutaneous fat in all cases and a small mass in 1 patient. A bright linear signal was seen on T2-weighted, fat-saturated images in 2 cases, likely representing scar tissue. One patient with chronic pain underwent surgery to provide better soft tissue coverage in the area of atrophic fat. The other 2 patients did not undergo surgical treatment: 1 was treated at a pain center for reflex sympathetic dystropy-type pain, and 1 remained pain free. Blunt trauma with subsequent fat atrophy and necrosis manifests as a mass, a subcutaneous fat defect, and even as chronic pain. Characteristic MRI findings are often sufficient for diagnosis, but any indeterminate masses should be further evaluated to rule out aggressive or malignant neoplasms. Chronic unrelenting pain despite treatment may be related to posttraumatic reflex sympathetic dystropy-like symptoms.

Ethanol sclerotherapy reduces pain in symptomatic musculoskeletal hemangiomas.

UNLABELLED: Hemangiomas, benign vascular lesions, require intervention if causing pain or functional limitations. Functional deficits are common after excision, favoring minimally invasive treatments. To determine whether ethanol sclerotherapy reduces pain and lesion size and to assess complications in symptomatic musculoskeletal hemangiomas, we retrospectively reviewed 19 patients (six males, 13 females; mean age, 34 years) meeting criteria of confirmed hemangioma, treatment with ethanol sclerotherapy, and minimum of 6 weeks of followup. Fourteen were primary lesions and five were recurrent; all were painful. Thirty-eight sclerotherapy procedures were performed, with each patient undergoing a maximum of three procedures. Mean followup was 24 months (range, 2-95 months). Four patients reported full pain relief, 11 had partial relief, and four had no relief. With recurrent lesions, one patient had full pain relief, one had partial relief, and three had no relief. For patients with lesions larger than 5 cm, two had full relief, six had partial relief, and three had no relief. Lesion shrinkage occurred in 12 patients. Temporary complications included paresthesiae (three), tendon contracture (one), skin breakdown (one), and deep vein thrombosis (one). Ethanol sclerotherapy afforded prompt pain relief in 15 of 19 patients with hemangioma, making it a reasonable option for initially avoiding surgical excision. However, the short followup of our patients requires additional long-term studies to assess the duration of the results. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Early outcomes of soft tissue sarcomas presenting with metastases and treated with chemotherapy.

OBJECTIVES: The purpose of this study is to describe outcomes for patients with metastatic soft tissue sarcoma treated with chemotherapy. METHODS: We retrospectively reviewed the records of 383 soft tissue sarcoma patients treated at our institution from 1997 to 2006. Thirty-five patients met the inclusion criteria-metastatic disease on presentation; primary tumor outside the abdomen; treatment with chemotherapy; and minimum follow-up of 3 months. Treatments were individualized and determined by a multidisciplinary oncology team. Patient survival was calculated from the diagnostic biopsy to the date of death or last follow-up using the Kaplan-Meier method. RESULTS: Mean age was 47 years (range 17-74 years). Most common tumors involved were MFH and leiomyosarcoma. Sixteen of 35 (46%) patients had died at last follow-up. Mean patient survival was 24 months (range 4-102). The 2-year and 5-year survival rates were 64% and 24%, respectively. Twenty-nine patients (83%) presented with pulmonary metastasis, 6 with bone metastases (17%), 4 with regional node metastases (11%), and 4 with soft tissue metastases (11%). Survival was the same for those with pulmonary and only extrapulmonary metastases. The 10 patients with complete resection or complete chemotherapy response of all detectable lesions had longer mean survival (34 months) than the 25 patients who had partial/no resection or response (20 months) (P = 0.02). CONCLUSIONS: Soft tissue sarcoma patients presenting with metastatic disease have a low survival rate, but complete eradication of tumor correlated with longer survival. Longer-term studies especially those tracking the outcome of complete responders and those completely resected will help determine the efficacy of chemotherapy.

Chondromyxoid fibroma involving the metacarpophalangeal joint.

Chondromyxoid fibroma is a rare benign bony tumor classically occurring in the metaphyseal region of the long bones surrounding the knee, but also found with relative frequency in other long bones, the pelvis, ribs, and small foot bones. The small bones of the hand, however, are rarely involved. The tumor is considered a physeal plate remnant and may involve the epiphysis, diaphysis, or both along with its metaphyseal origin. It may cause cortical expansion and destruction, but consistently respects the periosteal boundary. We report a case of histopathologically confirmed chondromyxoid fibroma involving a metacarpal, proximal phalanx, and synovial tissues of the metacarpophalangeal joint. A 29-year-old woman presented with pain, weakness, and a mass of the right ring finger metacarpophalangeal joint that had persisted since prior surgery to remove an extraosseous chondroma. Prominent soft tissue swelling and limited range of motion were noted, corresponding to magnetic resonance imaging findings of lytic changes in the right ring finger metacarpal and proximal phalanx, surrounded by an irregularly enhancing mass with soft tissue extension. Open biopsy revealed calcified cartilaginous synovial deposits suspicious for synovial chondromatosis, with erosion into surrounding bones. Histologic examination revealed an unusual chondromyxoid fibroma with joint involvement. The patient is >15 months out from synovectomy, intralesional curettage, and placement of demineralized bone matrix and allograft cancellous chips, and is without signs of recurrence. This benign, curable lesion should be included in the differential diagnosis of a bony lesion, even when a joint and adjacent bones are involved.