Skeletal Muscle Measurements in Pediatric Hematology and Oncology: Essential Components to a Comprehensive Assessment.

Children with hematologic and oncologic health conditions are at risk of impaired skeletal muscle strength, size, and neuromuscular activation that may limit gross motor performance. A comprehensive assessment of neuromuscular function of these children is essential to identify the trajectory of changes in skeletal muscle and to prescribe therapeutic exercise and monitor its impact. Therefore, this review aims to (a) define fundamental properties of skeletal muscle; (b) highlight methods to quantify muscle strength, size, and neuromuscular activation; (c) describe mechanisms that contribute to muscle strength and gross motor performance in children; (d) recommend clinical assessment measures; and (e) illustrate comprehensive muscle assessment in children using examples of sickle cell disease and musculoskeletal sarcoma.

Quantifying muscle strength, size, and neuromuscular activation in adolescent and young adult survivors of musculoskeletal sarcoma: Identifying correlates and responses to functional strengthening.

BACKGROUND: Medical and surgical treatment for musculoskeletal sarcoma (MSS) place survivors at risk for impairments in muscle properties including muscle strength, muscle size, and neuromuscular activation. The purpose of this study was to explore muscle properties, gross motor performance, and quality of life (QoL) and the changes in response to a 6-week functional strengthening intervention (PT-STRONG) in MSS survivors of childhood cancer (CCS). METHODS: Eight lower extremity MSS CCS (13-23 years old) performed baseline testing and three completed PT-STRONG. Participants completed measurements of knee extension strength using handheld dynamometry, vastus lateralis (VL) and rectus femoris (RF) muscle thickness using ultrasonography at rest, and neuromuscular activation using electromyography during strength testing and a step-up task. Participants also completed gross motor and QoL assessments. RESULTS: Compared with the non-surgical limb, MSS CCS had lower surgical limb knee extension strength, VL muscle thickness, and RF step-up muscle rate of activation (RoA). Compared with normative values, MSS CCS had decreased bilateral knee extension strength, gross motor performance, and physical QoL. Positive correlations among muscle strength, muscle thickness, and gross motor performance were identified. After PT-STRONG, MSS CCS had improvements in VL muscle thickness, VL and RF RoA duing step-up, gross motor performance, and physical QoL. CONCLUSIONS: Positive association between larger muscle thickness with greater knee extension strength, and higher knee extension strength with better gross motor performance indicate that comprehensive physical therapy assessment and interventions that identify and target impairments in muscle properties to guide clinical decision making should be considered for MSS CCS into survivorship.

Can low-grade chondrosarcoma in flat bones be treated with intralesional curettage and cryotherapy?

BACKGROUND AND OBJECTIVES: Chondrosarcomas in flat bones are thought to be more aggressive in their behavior, and little is known about intralesional treatment outcomes of low-grade chondrosarcoma in these locations. We tried to find the differences between patients who had low-grade chondrosarcoma in their flat bones versus those with long bone involvement with regard to (1) disease outcome, (2) functional outcome, and (3) treatment complications. METHODS: We retrospectively reviewed 44 patients with primary low-grade chondrosarcoma who were treated with intralesional curettage and cryotherapy. The patients were divided by location of tumor, group I (flat bones, seven patients) and group II (long bones, 37 patients). RESULTS: The local recurrence rate was higher in group I with 5 years disease-free survival of 80.0% in group I and 97.0% in group II (p = 0.001). All recurrent cases were noted to have initially presented with soft tissue extension (Enneking stage IB). The mean Musculoskeletal Tumor Society score at the last follow-up was 21.7 in group I and 27.9 in group II (p = 0.045). CONCLUSIONS: Intralesional curettage and cryotherapy for low-grade chondrosarcoma appear to be a safe and reasonable surgical option for patients with lesions confined to bone (Enneking stage IA). LEVEL OF EVIDENCE: Level III, retrospective cohort study. See the Guidelines for Authors for a complete description of levels of evidence.

Radiolucent Implants for Fixation of Impending and Pathologic Fractures.

Radiolucent implants offer theoretical advantages of increased ability to evaluate the fracture site for healing and recurrence and potentially less effect on radiation treatment, avoiding scatter. Their clinical utility and outcomes have yet to be proven in a well-designed randomized trial or large cohort study, although studies based on other indications have shown relative safety and they are approved by the US Food and Drug Administration for treatment of pathologic fractures. Further research is necessary to better understand when and how these implants should be implemented in practice. [Orthopedics. 2022;45(3):e115-e121.].

Metastatic prostate carcinoma: A rare presentation initially misdiagnosed as a rib fracture.

Metastatic prostate carcinoma mainly occurs in bone as an osteoblastic lesion or lesions in the pelvis, spine, or chest wall. We present a unique case of a singular metastatic osteolytic lesion in the rib initially misdiagnosed as a fracture in a 61-year-old male. A single rib fracture in a patient with no history of trauma should raise suspicion for metastatic disease. We would encourage prostate cancer to be included in the differential diagnosis for an osteolytic lesion in a male over the age of 40. We review the current literature on this rare presentation of bone metastasis as well as the pathogenesis of metastatic prostate carcinoma as it relates to a solitary metastatic osteolytic lesion.

Alterations in Muscle Architecture: A Review of the Relevance to Individuals After Limb Salvage Surgery for Bone Sarcoma.

Osteosarcoma and Ewing's sarcoma are the most common primary bone malignancies affecting children and adolescents. Optimal treatment requires a combination of chemotherapy and/or radiation along with surgical removal when feasible. Advances in multiple aspects of surgical management have allowed limb salvage surgery (LSS) to supplant amputation as the most common procedure for these tumors. However, individuals may experience significant impairment after LSS, including deficits in range of motion and strength that limit function and impact participation in work, school, and the community, ultimately affecting quality of life. Muscle force and speed of contraction are important contributors to normal function during activities such as gait, stairs, and other functional tasks. Muscle architecture is the primary contributor to muscle function and adapts to various stimuli, including periods of immobilization-protected weightbearing after surgery. The impacts of LSS on muscle architecture and how adaptations may impact deficits within the rehabilitation period and into long-term survivorship is not well-studied. The purpose of this paper is to [1] provide relevant background on bone sarcomas and LSS, [2] highlight the importance of muscle architecture, its measurement, and alterations as seen in other relevant populations and [3] discuss the clinical relevance of muscle architectural changes and the impact on muscle dysfunction in this population. Understanding the changes that occur in muscle architecture and its impact on long-term impairments in bone sarcoma survivors is important in developing new rehabilitation treatments that optimize functional outcomes.

Cytogenetic Single-Institution Analysis: 101 Consecutive Cases of Soft-Tissue Tumors of the Extremities.

We summarize the results and clinical usefulness of cytogenetic analysis that is routinely performed for musculoskeletal tumors. We performed cytogenetic analysis and traditional histologic evaluation on 101 (51 malignant/ 50 benign) consecutive tumors that were surgically excised. The successful culture rate for cytogenetic analysis was 86% (87/101). Fifty-four percent (25/46) of clearly malignant tumors that were successfully cultured demonstrated significant clonal abnormalities. Fifty-one percent (21/41) of benign tumors that were cultured had significant cytogenetic clonal aberrations. Increased cellular ploidy (> 50 chromosomes/cell) was demonstrated in 14/46 malignant and 1/41 benign tumors that were successfully cultured. Hyperploidy was highly correlated with malignancy (p < 0.001); the only "benign" tumor was a multiply recurrent and giant cell, demonstrating histologic changes consistent with early sarcomatous transformation. As expected, cytogenetic abnormalities frequently occurred in malignant tumors. Surprisingly, almost half of the benign tumors had significant clonal cytogenetic aberrations. Consistent findings of extra chromosomes 5 and 7 in samples of pigmented villonodular synovitis strongly favored a neoplastic origin for this condition. Although the presence or absence of cytogenetic aberrations cannot be used to determine malignant potential, increased cellular ploidy is highly indicative of malignancy. Modern molecular genetics have become more popular, but cytogenetic analysis can be useful for classifying the malignant potential of recurrent and difficult to diagnose tumors of the musculoskeletal system.

Plantar Fibromatosis: Pathophysiology, Surgical and Nonsurgical Therapies: An Evidence-Based Review.

Plantar fibromatosis (morbus Ledderhose), an extra-abdominal desmoid tumor of the plantar foot, is a rare benign hyperproliferative disorder of the plantar fascia with an unknown etiology. The main clinical characteristics include slow growing nodules on the medial and central bands of the plantar fascia, which may become painful and negatively affect ambulation. Most established conservative therapies today target symptomatic relief. As symptoms progress, therapies such as injections, shockwave ablation, radiation, and/or surgery may be required. This review aims to provide insight into the pathophysiology of this condition in addition to detailing current and investigational therapies for this disorder. Many therapies have been proven in similar conditions, which could lead to promising treatment options for plantar fibromatosis. LEVELS OF EVIDENCE: Level V: Expert opinion.

Glomus Tumor of the Sciatic Nerve: An Extraspinal Cause of Sciatica.

Glomus tumors are small, benign tumors that arise from glomus bodies, structures found normally within the dermis that assist in temperature regulation via their vasoconstrictive response to sympathetic stimuli. Glomus tumors are found typically in the hand and are classically a cause of focal pain and temperature sensitivity. They often present as a small blue lesion seen under the nail bed of a finger or a toe and cause point tenderness. Glomus tumors of peripheral nerves are exceedingly rare and can lead to disability akin to compressive neuropathy when present. This case report explores the unusual presentation of a rare and large glomus tumor of the sciatic nerve. The patient presented with symptoms such as those mentioned above and was assumed to have sciatica emanating from spinal and neuroforaminal stenosis. Although she repeatedly and appropriately sought medical attention for her condition, she was improperly diagnosed and ultimately experienced a significant deterioration of her function, eventually undergoing an unnecessary surgical procedure. On referral to the authors' institution, the patient was evaluated and found to have a glomus tumor involving the sciatic nerve. This is the largest glomus tumor of a peripheral nerve that has been reported to date. Although the patient's presentation was insidious and her diagnosis was uncommon, this underscores the importance of developing a differential diagnosis based primarily on a thorough physical examination and, only then, correlating imaging to clinical findings. Additionally, given the atypical presentation and intractable course of this patient's condition, the examiner must consider neoplastic entities and space-occupying lesions as part of the differential diagnosis. [Orthopedics. 2018; 41(1):e151-e153.].

Long-term Results of Intercalary Endoprosthetic Short Segment Fixation Following Extended Diaphysectomy.

Intercalary endoprosthetic reconstruction following diaphyseal resection of osseous tumors offers functional advantages through preservation of native joints adjacent to the resected defect. Use of such implants is restricted by the amount of bone available for stem fixation adjacent to the defect. This study aimed to determine whether short osseous segment fixation with acceptable outcomes and complication rate can be reliably achieved with a customized intercalary endoprosthesis following extended diaphysectomy. A retrospective review of prospectively collected data was performed on 6 patients receiving customized anchor plugs for short segment fixation with a double compressive osseointegration intercalary implant to reconstruct segmental defects. Five of the implants were augmented with cement to support fixation in metaphyseal bone. Patient age at surgery ranged from 12 to 86 years. At mean follow-up of 39 months, mean Musculoskeletal Tumor Society functional score was 26.3, with 5 of 6 patients achieving scores of 27 or greater. Stable fixation was achieved in all patients, with the shortest segment of bone 3.7 cm in length. Three mechanical implant failures requiring revision surgery occurred. No patient required revision of the entire implant, secondary adjacent joint replacement, or secondary amputation. No patient exhibited aseptic loosening, and no case was complicated by infection. Excellent functional outcomes were seen with follow-up out to 9 years. This suggests that cement-augmented double compressive osseointegration intercalary endoprosthetic reconstruction can extend the benefits of intercalary replacement to many patients who otherwise might require adjacent joint or physeal sacrifice. However, patients should be counseled on the high risk of implant failure with subsequent need for revision surgery. [Orthopedics. 2017; 40(6):e964-e970.].

Unplanned Resection of Sarcoma.

Unplanned resection is a common problem in the management of sarcoma. Because sarcomas are so rare, they may be misdiagnosed initially as more common benign lesions. When the treating surgeon is unaware of or does not adhere to proper surgical principles of orthopaedic oncology, an intralesional procedure may be performed without the requisite preoperative imaging, staging, or wide resection margins for optimal management of sarcoma. Studies show that oncologic outcomes after unplanned resections are mixed; however, surgical outcomes drastically deteriorate. Failure to adhere to oncologic principles accounts for increased morbidity and amputation rates with re-resection. No diagnostic modality has been proven to accurately predict residual disease in the resection bed following unplanned resection. Thus, repeat surgery with or without adjuvant treatment is usually offered to these patients, thereby adding considerable cost and morbidity. Medical malpractice litigation associated with unplanned sarcoma resection is common, with delayed diagnosis and unnecessary amputation most often cited in cases decided in favor of the plaintiff.

Near-complete Humerus Reconstruction in the Pediatric Patient with Vascularized Free Fibula Transfer.

Vascularized free fibula transfer remains the gold standard for reconstruction of large segmental diaphyseal defects of the upper extremity. In the pediatric patient, before skeletal maturity, free fibula transfer with the fibular head provides an active physis for growth and an articular interface for glenohumeral joint reconstruction. Clinical and cadaveric studies have demonstrated that the vascular supply to the fibular head originates, in most cases, from the anterior tibial system. However, anatomical variation exists, and we report a case in which a vascularized fibula autograft including the physis was transferred on the peroneal artery in a 5-year-old patient with Ewing's sarcoma. At 15-month follow-up, the patient has functional range of motion of the shoulder.

Implant Fracture after Long-Stemmed Cemented Hemiarthroplasty for Oncologic Indications.

Although a long-stemmed cemented hemiarthroplasty is frequently recommended for oncologic lesions of proximal femur, we have observed an alarming number of spontaneous stem fractures. The purpose of this retrospective study was to identify the associated risk factors for stem fractures in a study cohort of 60 (61 prostheses) during 1983-2007. At a mean follow-up of 41 months, 4/61 (6.6%) stems had fractured after a mean of 36 (12-92) months after surgery. All failed implants were Osteonics Omnifit (4/27; 14.8%) and multivariate analysis did not show any correlation with other studied variables. While the failures were successfully salvaged by conversion to a modular proximal femoral replacement, any implant failure in this population is devastating. Spontaneous onset of thigh pain in patients with long stems, particularly if associated with other risk factors, should raise suspicion of a fatigue fracture of the stem.

Surgical advances in bone and soft tissue sarcoma: 50 years of progress.

As the American Society of Clinical Oncology celebrates its 50th anniversary, physicians can appreciate the significant advances made in the treatment of patients with sarcoma. Historically, these rare tumors have garnered great interest in the medical profession, due to their ability to reach extraordinary size, resulting in substantial deformities and disabilities. Fortunately, advances in surgical management, which have occurred concurrently with advances in imaging, diagnostic techniques, and both local and systemic adjuvant treatments, offer patients diagnosed with sarcoma significant hope for successful treatment and the expectation of a meaningful quality of life.

Results of cement versus bone graft reconstruction after intralesional curettage of bone tumors in the skeletally immature patient.

BACKGROUND: Resection of periphyseal tumors in children presents several unique challenges and complications. Injury to the adjacent physis during resection and adjuvant application has been associated with adverse growth-related outcomes including angular deformities and physeal arrest. The appropriate method of reconstructing bone defects after resection is also controversial. To date there is scant literature on the use of polymethylmethacrylate (PMMA) bone cement as a method of reconstruction in children, and few long-term studies exist on the incidence of growth-related complications after reconstruction. The objective of this study is to evaluate the mechanical, oncological, and developmental outcomes of PMMA use in children. METHODS: The authors retrospectively reviewed the medical records and radiographs of 36 skeletally immature patients who underwent intralesional resections of locally aggressive bone tumors. These patients were divided into 17 patients who received reconstruction with PMMA cement, and 19 patients who were reconstructed with bone graft. Follow-up clinical and radiographic evaluations performed after skeletal maturity were reviewed to assess the structural durability, local tumor recurrence rates, reoperation rates, and the incidence of postoperative complications such as deformity, adjacent joint arthrosis, growth arrest, pain, and functional limitation. RESULTS: The average patient age at the time of surgery was 11.79 years (range, 6 to 15 y). The average length of patient follow-up was 5.3 years (range, 2 to 11.5 y). There were no statistically significant differences observed in the rates of reoperation, local tumor recurrence, growth-related complications, adjacent joint arthrosis, or postoperative pain between the 2 groups. There were no postoperative fractures in the cement group, compared to 3 fractures in the bone graft group, although this was not statistically significant. CONCLUSIONS: PMMA cement as a structural augment after resection may be used in the pediatric population for improving the mechanical stability of bone. Cement use is associated with complication rates of arthrosis, local recurrence, and growth complications comparable to those observed with bone grafting. LEVEL OF EVIDENCE: Level III: Retrospective comparison study.

Standardization of rehabilitation after limb salvage surgery for sarcomas improves patients' outcome.

BACKGROUND AND OBJECTIVE: The purpose of this study is to establish a standardized postoperative rehabilitation protocol following limb salvage surgery (LSS) in patients with primary bone sarcoma in five major anatomical locations: distal femur, proximal tibia, proximal and total femur, humerus and shoulder girdle and pelvic resections. SETTING AND DESIGN: Retrospective study. PATIENTS AND METHODS: All LSSs were performed by an orthopedic oncology surgeon, and rehabilitation of all patients was based on a devised standardized rehabilitation protocol. Patient outcomes were measured using the modified Musculoskeletal Tumor Society-International Symposium on the Limb Salvage (MSTS-ISOLS) scoring system. RESULTS: A total of 59 patients received LSS in the above mentioned locations; endoprostheses were used in 49, bone allograft in five, while no replacements were made in five patients. At a mean follow-up of 24 months, the mean modified MSTS-ISOLS score for all patients was 87% (95% CI; 0.85-0.89). The highest scores were encountered for patients with distal femur replacement: 93% (95% CI; 0.91-0.95). Seven patients had interruption of more than six weeks in their rehabilitation and had a mean score of 71% (95% CI; 0.64-0.82). CONCLUSION: The proposed rehabilitation protocol is a comprehensive, organized and applicable guideline to be used after performing LSS at the above mentioned anatomical locations. The use of standardized rehabilitation protocol resulted in improved patient functional outcome.

Long-term results of intralesional curettage and cryosurgery for treatment of low-grade chondrosarcoma.

BACKGROUND: Data regarding outcomes following intralesional curettage and cryosurgical treatment of low-grade chondrosarcoma of bone are limited. The aim of this study was to assess the long-term oncologic and functional outcomes of two different cryosurgery techniques. METHODS: Forty-three low-grade chondrosarcoma lesions (in forty-two patients) were treated with intralesional curettage and cryosurgery from June 1983 to October 2006. Eleven lesions were treated with cryoprobes and thirty-two were treated with the modified direct-pour Marcove technique. The mean patient age was 44.9 ± 11.3 years (range, 21.8 to 66.4 years), and the mean duration of follow-up was 10.2 ± 4.6 years (range, five to 22.5 years). Indications for treatment included a radiographic appearance consistent with a cartilage tumor with evidence of aggressive behavior. Pearson correlation and multivariate analyses were used to evaluate the relationships between predictive factors (including lesion size, soft-tissue extension, and location, patient age, cortical erosion, and presence of preoperative pain) and outcomes. RESULTS: The mean overall Musculoskeletal Tumor Society (MSTS) score was 26.5 ± 3.1 (range, 17 to 30). There were four local recurrences, all in patients who had had tumor extension out of the bone with soft-tissue involvement at initial presentation. The mean time to recurrence was 2.4 ± 2.3 years (range, 0.6 to 5.6 years). No patients developed metastatic disease during the follow-up period. There were no differences between the cryoprobe and Marcove techniques with respect to the MSTS score, fracture, or local recurrence. A significant correlation between tumor recurrence and soft-tissue extension was found (r = 0.79). Kaplan-Meier survivorship, with freedom from recurrence as the end point, was 90.7%. CONCLUSIONS: Intralesional curettage and cryosurgery for low-grade chondrosarcoma is safe and effective in selected patients. The presence of preoperative cortical breakthrough and soft-tissue extension was the strongest predictor of local recurrence following use of this technique. LEVEL OF EVIDENCE: Therapeutic level IV. See instructions for authors for a complete description of levels of evidence.

Extensile posterior approach to the ankle with detachment of the achilles tendon for oncologic indications.

BACKGROUND: We describe an extensile posterior approach to the ankle with detachment of the Achilles tendon for resection of extensive tumors involving the posterior ankle. To the best of our knowledge, this approach and its results have not been reported for oncologic indications. METHODS: The surgical technique involved detachment of the Achilles tendon, tumor resection and reconstruction of the Achilles tendon with anchor sutures, and was used in six patients. The diagnosis was pigmented villonodular synovitis (5) and chondroblastoma (1). RESULTS: At a mean of 6 (range, 2 to 10) years followup, all patients were free from tumor. All patients could walk an unlimited amount without any support. There were no problems with Achilles incompetence. The mean Musculoskeletal Tumor Society score was 97 ± 4.2% (range, 90 to 100) and the mean Achilles Tendon Total Rupture Score was 95 ± 5.7 (range, 87 to 100). One patient with screwed suture anchors had backing out of two anchors along with deep infection, requiring surgical debridement and anchor removal. One other patient had a post-traumatic small wound dehiscence which responded to local wound care. CONCLUSION: Excellent exposure, tumor control and patient function were achieved by this approach in a select group of patients. The surgical technique described in this report offers another alternative for an extensile posterior approach to the ankle and/or subtalar joints.

Bilateral synchronous tibial periosteal osteosarcoma with familial incidence.

Multifocal or multicentric osteosarcoma (OS) has been described as tumor occurrence at two or more sites in a patient without visceral metastasis. These may be synchronous (more than one lesion at presentation) or metachronous (new tumor developing after the initial treatment). The incidence of multifocal OS has ranged from 1.5 to 5.4% in large series, with the synchronous type being rarer. Similarly, periosteal OS is another rare subtype of surface OS and constitutes less than 2% of all OS. An 11-year-old female was diagnosed with bilateral synchronous tibial periosteal OS, which were confirmed by CT-guided biopsies. After neoadjuvant chemotherapy, the patient underwent a staged wide local resection of the tumors. The defect was reconstructed with a proximal tibial replacement on the left side and autologous bone grafting on the right side. The patient did well after surgery and is free of disease at 5.5 years of follow-up. However, her brother also developed a right tibial periosteal osteosarcoma 4 years after her index surgery. Genetic analysis of blood sample from both patients showed a similar missense mutation in at least one allele of TP53 gene (exon 8). To the best of our knowledge, a case of bilateral 'synchronous' periosteal OS with a familial incidence has not been reported before.

Aseptic loosening rates in distal femoral endoprostheses: does stem size matter?

BACKGROUND: Long-term survival of distal femoral endoprosthetic replacements is largely affected by aseptic loosening. It is unclear whether and to what degree surgical technique and component selection influence the risk of loosening. QUESTIONS/PURPOSES: We (1) established the overall failure and aseptic loosening rates in a tumor population and asked (2) whether stem diameter and specifically the diaphysis-to-stem ratio predicts loosening, and (3) whether resection percentage correlates with failure. METHODS: We retrospectively reviewed the charts of all 93 patients in whom 104 distal femoral replacements had been performed from 1985 to 2008. We extracted the following data: age, need for revision surgeries, tumor diagnosis, adjunct treatment, and implant characteristics. We reviewed radiographs and determined stem size, bone diaphyseal width, and resection percentage of the femur. Kaplan-Meier survivorship was calculated for all implant failures and failures resulting from aseptic loosening. We evaluated radiolucent lines in patients with radiographic followup over 5 years. We identified independent risk factors for loosening. The minimum followup for radiographic evaluation was 5 years (mean, 12.7 years; range, 5.4-23.5 years). RESULTS: Overall implant survival for 104 stems in 93 patients was 73.3% at 10 years, 62.8% at 15 years, and 46.1% at 20 years. Survival from aseptic loosening was 94.6% at 10 and 15 years and 86.5% at 20 years. Of the variables analyzed, only bone:stem ratio independently predicted aseptic failure. Patients with stable implants had larger stem sizes and lower bone:stem ratios than those with loose implants (14.5 mm versus 10.7 mm and 2.02 versus 2.81, respectively). CONCLUSIONS: Our data suggest durability relates to selecting stems that fill the canal. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.