Glomus Tumor of the Lower Extremity Previously Misdiagnosed as Complex Regional Pain Syndrome in Close Proximity to a Myxofibrosarcoma: A Case Report.

Complex regional pain syndrome (CRPS) is a potentially devastating condition that can result in severe psychological and social morbidity. It is a diagnosis of exclusion, and other pathologic entities must be ruled out first. Glomus tumors are exquisitely painful benign vascular tumors that are most common in the hand and are rarely found in the lower extremity. Here, we present a case of a patient who developed a focus of severe anterior knee pain and tenderness a few months after a car accident that had been misdiagnosed as CRPS for 15 years. She coincidentally developed a sarcoma of her ipsilateral leg distal to this site. Magnetic resonance imaging of the sarcoma included the area of knee pain where, interestingly, it identified a separate small soft-tissue mass. A glomus tumor was diagnosed histologically in a needle biopsy specimen from this mass, which was resected along with the sarcoma. For the first time in 15 years, despite the additional sarcoma surgery, she reported relief of her pain and complete resolution of her "CRPS."

Negative-Pressure Wound Therapy versus Standard Surgical Dressings after Malignant Tumor Resection: A Systematic Review and Meta-Analysis.

BACKGROUND: Negative-pressure wound therapy offers many advantages over standard surgical dressings in the treatment of open wounds, including accelerated wound healing, cost savings, and reduced complication rates. Although contraindicated by device manufacturers in malignancy-resected wounds because of hypothesized risk of tumor recurrence, negative-pressure wound therapy is still applied postoperatively because of limited clinical support. The authors performed a systematic review with meta-analysis to compare negative-pressure wound therapy outcomes with those of standard surgical dressings on open wounds, with their null hypothesis stating there would be no outcome differences. METHODS: A systematic review of the literature on negative-pressure wound therapy and standard surgical dressings on malignancy-resected wounds was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using PubMed, Embase, CINAHL, and Cochrane Central databases. Meta-analysis compared group outcomes, including malignancy recurrence, wound complication, and surgical site infection rates, with a random effects model. RESULTS: A total of 1634 studies were identified and 27 met eligibility criteria, including four randomized controlled trials, four prospective cohort studies, and 19 retrospective reviews. Eighty-one percent of articles ( n = 22) recommended negative-pressure wound therapy in malignancy-resected wounds. Meta-analysis determined that the treatment yielded significantly lower overall surgical site infection ( p = 0.004) and wound complication ( p = 0.01) rates than standard surgical dressings; however, there were no statistically significant differences found for other outcomes between the two groups. CONCLUSIONS: This review demonstrates favorable outcomes of negative-pressure wound therapy over standard surgical dressings for malignancy-resected wounds without an increased risk of malignancy recurrence. However, because limited randomized controlled trials (detailing only incisional wounds for limited malignancies and anatomic regions) are available, additional high-power randomized controlled trials are recommended.

A novel intraoperative method to project osteotomy lines for accurate resection of primary bone sarcomas.

Background: Accurate reproduction of a preoperative plan is critical in wide resection of bone sarcomas. Recent advances in computer navigation and 3D-custom jigs have increased resection accuracy, although with certain practical drawbacks. Methods: We developed a novel "projector method" that projects the preoperative osteotomy lines onto the bone. A sawbone study was conducted to evaluate accuracy in reproducing preoperative resection plans. An additional cadaver experiment was conducted to evaluate feasibility in a more realistic operating room setting. Results: Based on the results of experiments conducted on sawbones, the proposed light projector method was more accurate at depicting desired osteotomy lines than a traditional manual method, reducing the corner deviation from 2.53 mm to 0.35 mm, angular deviation from 2.10° to 0.31°, and point deviation from 4.66 mm to 0.48 mm (p < 0.001). Results of the cadaver experiment were consistent with those of sawbone experiments. Conclusions: The new projector method can accurately assist surgeons in visualizing the preoperative plan of osteotomy lines accurately in surgery.

A Novel 3D Light Assisted Drawing (3D-LAD) Method to Aid Intraoperative Reproduction of Osteotomy Lines Surrounding a Bone Tumor During Wide Resection: An Experimental Study.

Introduction: Computer navigation and customized 3D-printed jigs improve accuracy during bone tumor resection, but such technologies can be bulky, costly, and require intraoperative radiation, or long lead time to be ready in OR. Methods: We developed a method utilizing a compact, inexpensive, non-X-ray based 3D surface light scanner to provide a visual aid that helps surgeons accurately draw osteotomy lines on the surface of exposed bone to reproduce a well-defined preoperative bone resection plan. We tested the accuracy of the method on 18 sawbones using a distal femur hemimetaphyseal resection model and compared it with a traditional, freehand method. Results: The method significantly reduces the positional error from 2.53 (±1.13) mm to 1.04 (±0.43) mm (p<0.001), and angular error of the front angle from 2.10° (±0.83°) to 0.80° (±0.66°) (p=0.001). The method also reduces the mean maximum deviation of the bone resection, with respect to the preoperative path, from 3.75mm to 2.69mm (p=0.003). However, no increased accuracy was observed at the back side of the bone surface where this method would not be expected to provide information. Discussion: In summary, we developed a novel 3D-LAD navigation technology. From the experimental study, we demonstrated that the method can improve the ability of surgeons to accurately draw the preoperative osteotomy lines and perform resection of a primary bone sarcoma, with comparison to traditional methods, using 18 sawbones.

A novel method of light projection and modular jigs to improve accuracy in bone sarcoma resection.

We developed a novel method using a combined light-registration/light-projection system along with an off-the-shelf, instant-assembly modular jig construct that could help surgeons improve bone resection accuracy during sarcoma surgery without many of the associated drawbacks of 3D printed custom jigs or computer navigation. In the novel method, the surgeon uses a light projection system to precisely align the assembled modular jig construct on the bone. In a distal femur resection model, 36 sawbones were evenly divided into 3 groups: manual-resection (MR), conventional 3D-printed custom jig resection (3DCJ), and the novel projector/modular jig (PMJ) resection. In addition to sawbones, a single cadaver experiment was also conducted to confirm feasibility of the PMJ method in a realistic operative setting. The PMJ method improved resection accuracy when compared to MR and 3DCJ, respectively: 0.98 mm versus 7.48 mm (p < 0.001) and 3.72 mm (p < 0.001) in mean corner position error; 1.66 mm versus 9.70 mm (p < 0.001) and 4.32 mm (p = 0.060) in mean maximum deviation error; 0.79°-4.78° (p < 0.001) and 1.26° (p > 0.999) in mean depth angle error. The PMJ method reduced the mean front angle error from 1.72° to 1.07° (p = 0.507) when compared to MR but was slightly worse compared to 0.61° (p = 0.013) in 3DCJ. The PMJ method never showed an error greater than 3 mm, while the maximum error of other two control groups were almost 14 mm. Similar accuracy was found with the PMJ method on the cadaver. A novel method using a light projector with modular jigs can achieve high levels of bone resection accuracy, but without many of the associated drawbacks of 3D printed jigs or computer navigation technology.

A novel bone registration method using impression molding and structured-light 3D scanning technology.

Accurate bone registration is critical for computer navigation and robotic surgery. Existing registration systems are expensive, cumbersome, limited in accuracy and/or require intraoperative radiation. We recently reported a novel method of registration utilizing an inexpensive, compact, and X-ray-free structured-light 3D scanner. However, this technique is not always practical in a real surgical setting where soft tissue and blood can obstruct the continuous line-of-sight required for structured-light technology. We sought to remedy these limitations using a novel technique using rapid-setting impression molding to capture bone surface features and scan the undersurface of the mold with a structured-light scanner. The photonegative of this mold is compared to the preoperative computed tomography (CT)-scan to register the bone. A registration accuracy study was conducted on 36 CT-scanned femur sawbones, simulating typical exposure in hip/knee arthroplasty and bone tumor surgery. A cadaver experiment was also conducted to evaluate the feasibility of using the impression molding in a more realistic operating room setting. The registration accuracy of the proposed technique was 0.50 ± 0.19 mm. This was close to the reported accuracy of 0.43 ± 0.18 mm using a structured-light scanner without impression molding (p = 0.085). In comparison, historical values for "paired-point" and intraoperative CT image-based registration methods currently used in modern robotic/computer-navigation systems were 0.68 ± 0.14 mm (p = 0.004) and 0.86 ± 0.38 mm, respectively. The registration accuracy of the cadaver experiment was consistent with that of sawbone experiments. Although future studies are needed to extend to human subjects, this study shows that the impression molding method can produce comparable or better registration accuracy than the existing techniques.

Report on a novel bone registration method: A rapid, accurate, and radiation-free technique for computer- and robotic-assisted orthopedic surgeries.

INTRODUCTION: Computer- and robotic-assisted technologies have recently been introduced into orthopedic surgery to improve accuracy. Each requires intraoperative "bone registration," but existing methods are time consuming, often inaccurate, and/or require bulky and costly equipment that produces substantial radiation. METHODS: We developed a novel method of bone registration using a compact 3D structured light surface scanner that can scan thousands of points simultaneously without any ionizing radiation.Visible light is projected in a specific pattern onto a 3 × 3 cm2 area of exposed bone, which deforms the pattern in a way determined by the local bone geometry. A quantitative analysis reconstructs this local geometry and compares it to the preoperative imaging, thereby effecting rapid bone registration.A registration accuracy study using our novel method was conducted on 24 CT-scanned femur Sawbones®. We simulated exposures typically seen during knee/hip arthroplasty and common bone tumor resections. The registration accuracy of our technique was quantified by measuring the discrepancy of known points (i.e., pre-drilled holes) on the bone. RESULTS: Our technique demonstrated a registration accuracy of 0.44 ± 0.22 mm. This compared favorably with literature-reported values of 0.68 ± 0.14 mm (p-value = 0.001) for the paired-point technique13 and 0.86 ± 0.38 mm for the intraoperative CT based techniques 14 (not enough reported data to calculate p-value). CONCLUSION: We have developed a novel method of bone registration for computer and robotic-assisted surgery using 3D surface scanning technology that is rapid, compact, and radiation-free. We have demonstrated increased accuracy compared to existing methods (using historical controls).

Hip disarticulation with pedicled total leg fillet flap for recurrent fungating sarcoma.

Soft tissue sarcomas may be treated with limb-sparing procedures in the majority of cases; however, certain cases involving significant tumor spread and fungation may call for amputation. In the thigh, hip disarticulation typically involves a pedicled gluteus maximus flap or a pedicled anterior quadriceps flap. In this case report, we describe a rare situation in which the anterior flap, posterior flap, and adductor flap musculature were contaminated with tumor; therefore, a hip disarticulation was performed applying a pedicled total leg fillet flap for closure. Eighteen months after treatment, the patient continues to have no local recurrence of disease, a stable flap site, and ambulates with a walker. We present this amputation and closure method as a potentially effective modality in treating extensive oncologic disease of the proximal lower extremity.

Management of an Unusual Periprosthetic Giant Cell Tumor of Bone of the Proximal Tibia.

Giant cell tumor of bone is a relatively rare type of bone tumor, accounting for approximately 4.9% to 9% of all primary osseous neoplasms.1 Management options include intralesional curettage, or more uncommonly, wide resection. This process is then followed by reconstruction with bone graft or bone cementation. We present a case of giant cell tumor of bone adjacent to the tibial component of a preexisting total knee arthroplasty, treated with extensive curettage, argon beam coagulation, polymethyl methacrylate cementation with strut reinforcement, and mesh reconstruction of the extensor mechanism. Twenty months after treatment, the patient was recurrence free with a stable prosthesis and had return to functional activity. We report this treatment modality as a potentially effective method of approaching this rare orthopaedic entity.

A Rare Incidence of Pigmented Villonodular Synovitis of the Ankle in an Adolescent.

Pigmented villonodular synovitis mostly affects the knee and other large joints such as the hip. Although the disease is most commonly found in adult patients aged 30 to 40 years, rare cases in children and the elderly have been reported. We present the case of an 11-year-old female who was found to have biopsy-proven pigmented villonodular synovitis in her subtalar joint in 2012. Five years after surgical excision, the patient has continued to be involved in competitive dancing and cheerleading without any pain in her ankle. Moreover, follow-up magnetic resonance imaging studies showed no evidence of recurrence. Our case report emphasizes that the disease should not be solely considered in the middle-age population but should be included in the differential diagnosis of the pediatric patient.

Surgical technique: Computer-generated custom jigs improve accuracy of wide resection of bone tumors.

BACKGROUND: Manual techniques of reproducing a preoperative plan for primary bone tumor resection using rudimentary devices and imprecise localization techniques can result in compromised margins or unnecessary removal of unaffected tissue. We examined whether a novel technique using computer-generated custom jigs more accurately reproduces a preoperative resection plan than a standard manual technique. DESCRIPTION OF TECHNIQUE: Using CT images and advanced imaging, reverse engineering, and computer-assisted design software, custom jigs were designed to precisely conform to a specific location on the surface of partially skeletonized cadaveric femurs. The jigs were used to perform a hemimetaphyseal resection. METHODS: We performed CT scans on six matched pairs of cadaveric femurs. Based on a primary bone sarcoma model, a joint-sparing, hemimetaphyseal wide resection was precisely outlined on each femur. For each pair, the resection was performed using the standard manual technique on one specimen and the custom jig-assisted technique on the other. Superimposition of preoperative and postresection images enabled quantitative analysis of resection accuracy. RESULTS: The mean maximum deviation from the preoperative plan was 9.0 mm for the manual group and 2.0 mm for the custom-jig group. The percentages of times the maximum deviation was greater than 3 mm and greater than 4 mm was 100% and 72% for the manual group and 5.6% and 0.0% for the custom-jig group, respectively. CONCLUSIONS: Our findings suggest that custom-jig technology substantially improves the accuracy of primary bone tumor resection, enabling a surgeon to reproduce a given preoperative plan reliably and consistently.

Surgical technique: Porous tantalum reconstruction for destructive nonprimary periacetabular tumors.

BACKGROUND: Large bone loss and frequently irradiated existing bone make reconstructing metastatic and other nonprimary periacetabular tumors challenging. Although existing methods are initially successful, they may fail with time. Given the low failure rates of porous tantalum acetabular implants in other conditions with large bone loss or irradiated bone, we developed a technique to use these implants in these neoplastic cases where others might fail. DESCRIPTION OF TECHNIQUE: After local tumor curettage, a large uncemented tantalum shell (sometimes with tantalum augments) was fixed to remaining bone using numerous screws. When substantial medial bone loss was present, an antiprotrusio cage was placed over the top of the cup and secured to remaining ilium and ischium. PATIENTS AND METHODS: We retrospectively reviewed 20 patients who underwent THAs for neoplastic bone destruction with the described technique. Their mean age was 60 years (range, 22-80 years). We recorded pain and ambulatory status, pain medication use, and Harris hip scores. We assessed for progressive radiolucent lines and component migration on followup radiographs. Eleven of the 20 patients died at a mean of 17 months after surgery. The minimum followup for surviving patients was 26 months (mean, 56 months; range, 26-85 months). RESULTS: Harris hip scores improved from a mean 32 preoperatively to a mean 74 postoperatively. We observed no cases of progressive radiolucent lines or component migration. Complications included one perioperative death, two superficial infections, one deep vein thrombosis, and one dislocation. CONCLUSION: Our initial experience has made tantalum reconstruction our preferred method for dealing with major periacetabular neoplastic bone loss. Additional studies comparing this technique with alternatives are required. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Effect of local alignment on compartmental patterns of knee osteoarthritis.

BACKGROUND: Previous studies have shown that lower-extremity malalignment increases the risk and rate of progression of knee osteoarthritis. The authors of such studies have used full-length lower-extremity radiographs to quantify alignment. However, a radiograph that includes only the knee is commonly ordered for a patient with early symptoms of knee osteoarthritis. The purpose of this study was to investigate whether local malalignment, as determined with use of a standing short knee radiograph, is associated with an increased risk of having osteoarthritis and having more severe compartmental disease. METHODS: Short fluoroscopically guided standing anteroposterior knee radiographs of 306 patients (608 knees) with radiographic evidence of knee osteoarthritis were used to determine the compartment-specific Kellgren-Lawrence grade of osteoarthritis and the local (distal femoral to proximal tibial) knee alignment. The relationship between local alignment and compartmental patterns of osteoarthritis was assessed. RESULTS: Each degree of increase in the local varus angle was associated with a significantly increased risk of having predominantly medial compartment osteoarthritis, even when we adjusted for age, sex, and body mass index (odds ratio, 1.39; 95% confidence interval, 1.29 to 1.49; p < 0.001). A similar association was found between valgus angulation and lateral compartment osteoarthritis (odds ratio, 1.55; 95% confidence interval, 1.36 to 1.75; p < 0.001). Analysis of the 362 knees with predominantly medial compartment osteoarthritis showed that each degree of increase in the varus angle was associated with a significantly increased adjusted risk of having severe medial disease (odds ratio, 1.52, p < 0.001). In the forty-seven knees with predominantly lateral compartment osteoarthritis, a similar trend was found between an increase in the valgus angle and the severity of the lateral disease, with the results approaching but not reaching significance. CONCLUSIONS: In patients with early symptomatic knee osteoarthritis, there is a clear relationship between local knee alignment, as determined from short standing knee radiographs, and the compartmental pattern and severity of the knee osteoarthritis. This study provides data with which physicians can assess how knee alignment contributes to the observed patterns and severity of osteoarthritis in an individual patient.

Midfoot arthritis.

Foot and ankle complaints are commonly encountered in orthopedic practice. Midfoot arthritis has the potential to cause a significant amount of pain and disability. A variety of conditions can cause or lead to midfoot arthritis. Treatment consists of either conservative management or surgical arthrodesis of the painful joints. In this article, we review the midfoot (its basic anatomy and biomechanics) and midfoot arthritis (its clinical presentation and etiology, radiographic evaluation, and treatment options).