Primary Intraosseous Malignant Peripheral Nerve Sheath Tumor of the Medial Cuneiform: A Case Report and Review of the Literature.

Peripheral nerve sheath tumors (benign and malignant) usually arise in the soft tissues and are unusual in bone. Intraosseous peripheral nerve sheath tumors are usually benign and constitute approximately 0.2% of all bone tumors. Intraosseous malignant peripheral nerve sheath tumors (MPNSTs) are uncommon and usually result from secondary invasion. Only a few cases of primary intraosseous MPNSTs have been reported in published studies, and these were localized mostly in the mandible (approximately 50%) or maxilla, spine, and, occasionally, in the appendicular skeleton. To the best of our knowledge, we report the first case of primary intraosseous MPNST involving a midtarsal bone (medial cuneiform). The patient was a 62-year-old female who presented with pain and tenderness but without swelling. Imaging revealed nonspecific findings, and the preoperative computed tomography-guided biopsy findings were consistent with MPNST. The patient was treated with neoadjuvant radiotherapy, followed by wide local excision and allograft reconstruction. At the final follow-up examination (24 months), the graft had been incorporated without evidence of local recurrence or distant disease. The patient with primary intraosseous MPNST of the medial cuneiform described in the present report presented with nonspecific clinical and radiologic findings. Thus, a high index of suspicion and histopathologic examination, including immunohistochemistry, are necessary for an accurate diagnosis.

The use of blocking screws with internal lengthening nail and reverse rule of thumb for blocking screws in limb lengthening and deformity correction surgery.

Internal lengthening nail (ILN) is a recent development in limb lengthening and deformity correction specialty. The ILN has the distinct advantage of combining acute deformity correction with gradual lengthening of bone. While using ILN, the short metaphyseal bone fragment may develop a deformity at the time of osteotomy and nail insertion or during bone lengthening because of the wide medullary canal. These deformities are typically predictable, and blocking screws (Poller screws) are helpful in these situations. This manuscript describes the common deformities that occur in femur and tibia with osteotomies at different locations while using ILN in antegrade and retrograde nailing technique. Also, a systematic approach to the appropriate use of blocking screws in these deformities is described. In addition, the "reverse rule of thumb" is introduced as a quick reference to determine the ideal location(s) and number of blocking screws. These principles are applicable to limb lengthening and deformity correction as well as fracture fixation using intramedullary nails.

Locally aggressive fibrous dysplasia mimicking malignancy: a report of four cases and review of the literature.

BACKGROUND: Fibrous dysplasia is a benign fibroosseous bone tumor that accounts for 5% to 10% of benign bone tumors. It can present as monostotic fibrous dysplasia (70% to 80%), polyostotic fibrous dysplasia (20% to 30%), McCune-Albright syndrome (2% to 3%), or Mazabraud's syndrome in rare cases. Bone lesions in fibrous dysplasia arise in the medullary canal and usually are confined to the bone. Cortical destruction and extension into soft tissue usually indicates malignant transformation or secondary aneurysmal bone cyst formation. Locally aggressive fibrous dysplasia with cortical destruction and extension into soft tissue in the absence of these two possibilities is extremely rare. It is important for the treating physician to distinguish this entity from more aggressive or malignant tumors to avoid overtreating the patient for a benign condition or inattention to a malignant tumor. CASE DESCRIPTIONS: We report four unusual cases of fibrous dysplasia with an aggressive radiographic appearance. They occurred in the rib (1), ilium (2), and distal femur (1). Two patients had pain and two had swelling. Radiologically, all were associated with cortical destruction and an associated soft tissue mass, and initially they were interpreted as potentially malignant. Three patients underwent biopsy and one patient did not have a biopsy. Histopathologic analysis by an experienced bone pathologist confirmed fibrous dysplasia in all patients. Two patients were treated surgically; one patient with zoledronic acid and one patient currently is being followed by observation alone. LITERATURE REVIEW: There are only a few reports in the literature that describe the locally aggressive variant of fibrous dysplasia that presents with pain and progressive swelling clinically and with cortical destruction and soft tissue extension on imaging which suggest malignancy. We could not find any article that describes the use of bisphosphonates in such lesions or the response to bisphosphonates clinically, on laboratory parameters or imaging. To our knowledge, this is the largest case report published regarding locally aggressive fibrous dysplasia arising outside the craniofacial skeleton. CLINICAL RELEVANCE: The locally aggressive variant of fibrous dysplasia may be confused with a malignant tumor or malignant degeneration of fibrous dysplasia. It is important to properly evaluate these lesions to ensure that a proper diagnosis is made, especially with respect to a malignant versus benign mass.

Five polyostotic conditions that general orthopedic surgeons should recognize (or should not miss).

General orthopedic surgeons frequently encounter patients with conditions affecting multiple bones. It is important to recognize common polyostotic diseases. This article describes five polyostotic conditions: Multipe Enchondromatosis (Ollier Disease and Maffucci syndrome), Multiple Hereditary Exostosis (Diaphyseal Aclasis), Fibrous Dysplasia (McCune-Albright syndrome and Mazabraud syndrome), Paget's Disease of bone (Osteitis Deformans), and Skeletal Metastases. This is a survey of the clinical, pathologic and radiographic features that assist in diagnosing these conditions. Also, an overview of the laboratory findings, treatment, follow-up, and prognosis is presented. Recognizing these diseases will aid in prompt and accurate diagnosis and appropriate referral and therapy.

What risk factors predict usage of gastrocsoleus recession during tibial lengthening?

BACKGROUND: Tibial lengthening is frequently associated with gastrocsoleus contracture and some patients are treated surgically. However, the risk factors associated with gastrocsoleus contracture severe enough to warrant surgery during tibial lengthening and the consistency with which gastrocsoleus recession (GSR) results in a plantigrade foot in this setting have not been well defined. QUESTIONS/PURPOSES: We compared patients treated with or without GSR during tibial lengthening with respect to (1) clinical risk factors triggering GSR use, (2) ROM gains and patient-reported outcomes, and (3) complications after GSR. METHODS: Between 2002 and 2011, 95 patients underwent tibial lengthenings excluding those associated with bone loss; 82 (83%) were available for a minimum followup of 1 year. According to our clinical algorithm, we performed GSR when patients had equinus contractures of greater than 10° while lengthening or greater than 0° before or after lengthening. Forty-one patients underwent GSR and 41 did not. Univariate analysis was performed to assess independent associations between surgical characteristics and likelihood of undergoing GSR. A multivariate regression model and receiver operating characteristic curves were generated to adjust for confounders and to establish risk factors and any threshold for undergoing GSR. Chart review determined ROM, patient-reported outcomes, and complications. RESULTS: Amount and percentage of lengthening, age, and etiology were risk factors for GSR. Patients with lengthening of greater than 42 mm (odds ratio [OR]: 4.13; 95% CI: 1.82, 9.40; p = 0.001), lengthening of greater than 13% of lengthening (OR: 3.88; 95% CI: 1.66, 9.11; p = 0.001), and congenital etiology (OR: 1.90; 95% CI: 0.86, 4.15; p = 0.109) were more likely to undergo GSR. Adjusting for all other variables, increased amount lengthened (adjusted OR: 1.05; 95% CI: 1.02, 1.07; p < 0.001) and age (adjusted OR: 1.02; 95% CI: 0.99, 1.05; p = 0.131) were associated with undergoing GSR. Patients gained 24° of ankle dorsiflexion after GSR. Self-reported functional outcomes were similar between patients with or without GSR. Complications included stretch injury to the posterior tibial nerve leading to temporary and partial loss of plantar sensation in two patients. CONCLUSIONS: Dorsiflexion was maintained and/or restored similarly among patients with or without GSR when treated under our algorithm. Functional compromise was not seen after GSR. Identification of patients at risk will help surgeons indicate patients for surgery. Acute dorsiflexion should be avoided to minimize risk of injury to the posterior tibial nerve. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Distal tibial periarticular nonunions: ankle salvage with bone transport.

A nonunion of the distal tibial metaphysis in close proximity to the articular surface is a challenging clinical problem. Many of the commonly used techniques in a surgeon's treatment armamentarium can be ineffective because of the relative lack of distal bone stock. This study describes a technique of en bloc excision of all infected or nonunited distal tibial bone with an application of a circular external fixator and limb shortening. After treatment with parental antibiotics, when appropriate, and docking of the distal excision site, distraction osteogenesis of the proximal tibia is performed with a second circular frame.