Bryan S. Moon

Surgical management of appendicular skeletal metastases in thyroid carcinoma

Background. Bone is a frequent site of metastasis from thyroid carcinoma, but prognostic factors for patients who have surgery for thyroid carcinoma bone metastases are poorly understood. Methods. A retrospective review at a single institution identified 41 patients that underwent surgery in the appendicular skeleton for thyroid carcinoma bone metastasis from 1988 to 2011. Results. Overall patient survival probability by Kaplan-Meier analysis after surgery for bone metastasis was 72% at 1 year, 29% at 5 years, and 20% at 8 years. Patients who had their tumor excised (P = 0.001) or presented with solitary bone involvement had a lower risk of death following surgery adjusting for age and gender. Disease progression at the surgery site occurred more frequently with a histological diagnosis of follicular carcinoma compared with other subtypes (P = 0.023). Multivariate analysis showed that tumor subtype, chemotherapy, and preoperative radiation treatment had no effect on survival after surgery. Patients treated with radioactive iodine had better survival following thyroidectomy, but not following surgery for bone metastases. Conclusions. For patients undergoing surgery for thyroid cancer bone metastasis, resection of the bone metastasis, if possible, has a survival benefit.

Intramedullary nailing of femoral diaphyseal metastases: is it necessary to protect the femoral neck?

BackgroundIntramedullary nailing is the accepted form of treatment for impending or pathologic fractures of the femoral diaphysis. Traditional teaching promotes the use of a cephalomedullary nail so that stabilization is provided for the femoral neck in the event that a future femoral neck metastasis develops. However, that approach may add cost, surgical time, blood loss, and added radiation exposure to staff members, and there is limited evidence in the literature that supports this practice.Questions/purposesThe purpose of our study was to evaluate the incidence of femoral neck metastases in patients who underwent femoral nailing of diaphyseal metastases.Patients and MethodsRetrospective analysis of our Musculoskeletal Oncology database identified 145 femoral nailings performed for metastatic disease, myeloma, or lymphoma of the femoral diaphysis between 2001 and 2011. Average patient age was 59 years. One hundred forty-one patients underwent 145 femoral nailings (four were bilateral). One hundred forty-four of the nails used were cephalomedullary implants and one was a flexible nail. Thirty-six (25%) femurs had sustained a pathologic fracture and 109 (75%) femurs were treated as impending fractures. Eighty-four patients received either preoperative or postoperative radiation therapy. Average radiographic followup was 13 months and average postoperative survival was 16 months. Of the 141 patients in this series, 121 (86%) are known to have died at a median of 9 months (range, 0.1–133 months) after surgery. The latest followup radiographs were obtained at a median of 5 months after the femoral nailing (range, 0–119 months). Of the 90 patients with documented dates of death and radiographic followup greater than zero months, 76 (84%) had radiographs available within a year of death. Thirty-one patients had zero months radiographic followup. The median survival for this group of patients was only 0.9 months (range, 0.1–12 months).ResultsNo patients (0%) in this series had femoral neck metastases develop postoperatively.ConclusionDespite traditional teaching that supports the use of cephalomedullary implants when treating metastatic disease of the femur, we were unable to identify a single patient who had femoral neck metastasis after surgery on the femur. Our findings do not support the use of cephalomedullary implants in this patient population for the sole purpose of prophylactic femoral neck stabilization; however, this series was relatively small, and the experiences of other centers will be needed to come to a more-complete sense of the frequency of what in all likelihood is a rare event.Level of EvidenceLevel IV, therapeutic study.

Tibial Growth Disturbance Following Distal Femoral Resection and Expandable Endoprosthetic Reconstruction

BACKGROUND In growing children, an expandable endoprosthesis is commonly used after distal femoral resection to compensate for loss of the distal femoral physis. Our hypothesis was that such prostheses can affect proximal tibial growth, which would contribute to an overall leg-length discrepancy and cause angular deformity. METHODS Twenty-three skeletally immature patients underwent the placement of a distal femoral expandable endoprosthesis between 1994 and 2012. Tibial length, femoral length, and mechanical axis were measured radiographically to determine the growth rate. RESULTS No patient had radiographic evidence of injury to the proximal tibial physis at the time of surgery other than insertion of the tibial stem. Fifteen (65%) of the patients experienced less proximal tibial growth in the operative compared with the contralateral limb. In ten (43%) of the patients, the discrepancy progressively worsened, whereas in five (22%) of the patients, the discrepancy stabilized. Seven patients did not develop tibial length discrepancy, and one patient had overgrowth of the tibia. For the ten patients with progressive shortening, the proximal tibial physis grew an average of 4.0 mm less per year in the operative limb. Five (22%) of the patients had ≥ 20 mm of tibial length discrepancy at last follow-up. Three of these patients underwent contralateral tibial epiphysiodesis. Three patients required corrective surgery for angular deformity. CONCLUSIONS The tibial growth plate may not resume normal growth after implantation of a distal femoral prosthesis. Physeal bar resection, prosthesis revision, and contralateral tibial epiphysiodesis may be needed to address tibial growth abnormalities.

Non-radiographic Risk Factors Differentiating Atypical Lipomatous Tumors From Lipomas

Purpose To determine non-radiographic risk factors differentiating atypical lipomatous tumors (ALTs) from lipomas. Methods All patients with deep-seated lipomatous tumors of the extremities treated from January 2000 to October 2010 were retrospectively reviewed. Factors reviewed included age, gender, tumor location, size, histology, local recurrence, dedifferentiation, and metastasis. Multivariate logistic regression models were used to evaluate the effects of patient characteristics on ALT status. Results Ninety-four lipomas and 46 ALTs were included. Patients with an ALT were older (median: 60.5 vs. 55 years). Lipomas were evenly distributed between upper (48.9%) and lower extremities (51.1%), whereas ALTs predominately involved the lower extremities (91.3%). Median ALT size (22 cm) was greater than lipomas (10 cm), p < 0.0001. One lipoma (1.04%) recurred at 77 months and five ALTs (10.9%) recurred at an average of 39 months (19–64 months). Two ALTs originally treated with wide resection recurred with a dedifferentiated component and were treated with wide re-excision and chemotherapy. No metastases or tumor-related deaths occurred in either group at the time of last follow-up. Patients older than 60 years, tumors greater than 10 cm, or thigh location, were more likely to be diagnosed with an ALT (p < 0.05). Conclusion Lipomatous tumors were more likely to be ALTs when the tumor was at least 10 cm in size, located in the thigh, or found in patients that were 60 years of age or older. These risk factors may be used to guide management and surveillance strategies, when lipomatous tumors do not display characteristic radiographic features.

Distal Femur Allograft Prosthetic Composite Reconstruction for Short Proximal Femur Segments following Tumor Resection

Short metaphyseal segments remaining after distal femoral tumor resection pose a unique challenge. Limb sparing options include a short stemmed modular prosthesis, total endoprosthetic replacement, cross-pin fixation to a custom implant, and allograft prosthetic composite reconstruction (APC). A series of patients with APC reconstruction were evaluated to determine functional and radiologic outcome and complication rates. Twelve patients were retrospectively identified who had a distal femoral APC reconstruction between 1994 and 2007 to salvage an extremity with a segment of remaining bone that was less than 20 centimeters in length. Seventeen APC reconstructions were performed in twelve patients. Eight were primary procedures and nine were revision procedures. Average f/u was 89 months. Twelve APC reconstructions (71%) united and five (29%) were persistent nonunions. At most recent followup 10 patients (83%) had a healed APC which allowed WBAT. One pt (8%) had an amputation and one pt (8%) died prior to union. Average time to union was 19 months. Four pts (33%) or five APC reconstructions (29%) required further surgery to obtain a united reconstruction. Although Distal Femoral APC reconstruction has a high complication rate, a stable reconstruction was obtained in 83% of patients.

Total Humeral Endoprosthetic Replacement following Excision of Malignant Bone Tumors

Humerus is a common site for malignant tumors. Advances in adjuvant therapies and reconstructive methods provide salvage of the upper limb with improved outcomes. Reports of limb salvage with total humeral replacement in extensive humeral tumors are sparse. We undertook a retrospective study of 20 patients who underwent total humeral endoprosthetic replacement as limb salvage following excision of extensile malignant tumor from 1990 to 2011. With an average followup of 42.9, functional and oncological outcomes were analyzed. Ten patients were still alive at the time of review. Mean estimated blood loss was 1131 mL and duration of surgery was 314 minutes. Deep infection was encountered in one patient requiring debridement while mechanical loosening of ulnar component was identified in one patient. Subluxation of prosthetic humeral head was noted in 3 patients. Mean active shoulder abduction was 12.5° and active flexion was 15°. Incompetence of abduction mechanism was the major determinant of poor active functional outcome. Mean elbow flexion was 103.5° with 30.5° flexion contracture in 10 patients with good and useful hand function. Average MSTS score was 71.5%. Total humeral replacement is a reliable treatment option in restoring mechanical stability and reasonable functional results without compromising patient survival, with low complication rate.

Treatment-related fractures after combined modality therapy for soft tissue sarcomas of the proximal lower extremity: Can the risk be mitigated?

PURPOSE The purpose of this study was to investigate the incidence of and risk factors associated with femur fracture after combined modality therapy for soft tissue sarcomas (STS) of the proximal lower extremity. METHODS AND MATERIALS We reviewed the records of 596 patients with STS of the proximal lower extremity consecutively treated with surgery and radiation therapy (RT) from 1966 to 2012. One hundred ninety-seven patients (33%) received 50 Gy to the entire femur circumference (n = 197, 33%); 265 patients (45%) received perioperative chemotherapy, and during surgery, 155 patients (26%) had bone exposure, whereas 82 patients (14%) had the periosteum stripped. The Kaplan-Meier method was used to estimate actuarial outcome rates, and both Cox regression modeling and competing risk analyses using the method of Fine and Gray were performed. RESULTS Median follow-up time was 110 months (range, 6-470 months). The actuarial 10-year local control and overall survival rates were 88% (95% confidence interval [CI], 84%-90%) and 62% (95% CI, 57%-66%). Twelve patients had pathologic fractures, which were associated with 50 Gy to the entire bone circumference (P < .001), bone exposure (P < .001), and periosteal stripping during surgery (P < .001) and use of perioperative chemotherapy (P = .04). Using a competing risk model, bone exposure (P = .001; sub-hazard ratio [SHR], 9.13; 95% CI, 2.5-33.0), periosteal stripping (P < .001; SHR, 13.03; 95% CI, 4.0-43.0), and perioperative chemotherapy (P = .03; SHR, 4.03; 95% CI, 1.1-14.4) were significantly associated with fracture. The actuarial 10-year fracture rate was 2% (95% CI, 1%-3%) when the 50-Gy isodose line encompassed the entire bone circumference without the other risk factors, whereas it increased to 37% (95% CI, 12%-45%) when all 4 treatment-related factors were present. CONCLUSIONS Although femur fractures are rare, a component from each of the 3 therapeutic modalities contributes to the overall risk, and a multidisciplinary approach to mitigating fracture risk is needed. Although avoiding circumferential bone coverage with the 50-Gy isodose line may be a valuable dosimetric parameter, more rigorous dosimetric studies are required.

Patellar Resurfacing: Does It Affect Outcomes of Distal Femoral Replacement After Distal Femoral Resection?

BACKGROUND Patellar resurfacing after routine arthroplasty remains controversial. Few studies have specifically examined the effect of patellar resurfacing on outcomes after resection of the distal part of the femur and reconstruction with a megaprosthesis. Our objective was to compare the outcomes of megaprosthesis reconstructions of the distal part of the femur with and without patellar resurfacing after resection of a distal femoral tumor. METHODS We retrospectively reviewed the clinical records of patients with a femoral tumor who underwent resection of the distal part of the femur and endoprosthetic reconstruction between 1993 and 2013. We excluded patients who had had extra-articular knee resection, patellectomy, revision, reconstruction with an expandable prosthesis, or a proximal tibial replacement associated with the distal femoral replacement. We compared demographic characteristics, surgical variables, anterior knee pain, range of motion, extensor lag, Insall-Salvati ratio, Insall-Salvati patellar tendon insertion ratio, impingement, patellar degenerative disease, additional patellar procedures, complications, and Musculoskeletal Tumor Society (MSTS) score between the patellar resurfacing and nonresurfacing groups. RESULTS One hundred and eight patients--sixty without patellar resurfacing and forty-eight with patellar resurfacing--were included in the study. The mean age was 33.9 years (range, twelve to seventy-five years). There were fifty-four men and fifty-four women. The mean duration of follow-up was 4.5 years (range, 0.7 to twenty years). There was no significant difference in anterior knee pain between the groups (p = 0.51). Anterior knee pain did not significantly affect the range of motion, extensor lag, or reoperation or complication rate. Patellar degenerative disease occurred in 48% of the nonresurfaced knees but was not associated with focal pain. Complication rates were similar in the two groups, although peripatellar calcifications were significantly more common in the resurfacing group (19% versus 2%; p = 0.005). There was no significant difference in the mean MSTS score between the nonresurfacing (81%) and resurfacing (71%) groups (p = 0.34). CONCLUSIONS There were no differences in anterior knee pain, range of motion, extensor lag, or MSTS score between the patients with and those without patellar resurfacing. There were no cases of patellar component loosening or revision. In light of the similar outcomes in the two groups, the decision to resurface should be left up to the individual surgeon, who should take into account preoperative peripatellar pain and the status of the patella at the time of resection. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Single Case of Rosai–Dorfman Disease Marked by Pathologic Fractures, Kidney Failure, and Liver Cirrhosis Treated with Single-Agent Cladribine

Rosai–Dorfman disease (RDD) is a proliferative histiocytic disorder of unknown etiology, which is characterized by sinus histiocytosis with massive lymphadenopathy (1). In most cases, RDD has a benign course and treatment is not necessary. However, severe cases of RDD require treatment, and the treatment strategy is determined on the basis of the severity of the disease or the extranodal involvement of vital organs. We report a single case of RDD with atypical presentation of persistent constitutional symptoms, progressing pathologic fractures, and end-organ dysfunction, including acute kidney failure and liver cirrhosis with esophageal varices.

Posttraumatic intramedullary osteochondroma: Report of a case

We present a rare osteochondroma, which instead of being the usual exophytic growth outside bone, grew inward into the medullary cavity of distal femur in a patient with prior trauma to his knee. Except for its intramedullary location, the benign tumor had all the classic radiographic and pathologic features of typical osteochondroma.