Ashish Mahendra

Prediction of pathologic fracture risk of the femur after combined modality treatment of soft tissue sarcoma of the thigh

The objective of the current study was to formulate a scoring system to enable decision making for prophylactic stabilization of the femur after surgical resection of a soft tissue sarcoma (STS) of the thigh.

THE EVOLVING ROLE OF COMPUTER ASSISTED NAVIGATION IN MUSCULOSKELETAL ONCOLOGY

We report our experience of using a computer navigation system to aid resection of malignant musculoskeletal tumours of the pelvis and limbs and, where appropriate, their subsequent reconstruction. We also highlight circumstances in which navigation should be used with caution. We resected a musculoskeletal tumour from 18 patients (15 male, three female, mean age of 30 years (13 to 75) using commercially available computer navigation software (Orthomap 3D) and assessed its impact on the accuracy of our surgery. Of nine pelvic tumours, three had a biological reconstruction with extracorporeal irradiation, four underwent endoprosthetic replacement (EPR) and two required no bony reconstruction. There were eight tumours of the bones of the limbs. Four diaphyseal tumours underwent biological reconstruction. Two patients with a sarcoma of the proximal femur and two with a sarcoma of the proximal humerus underwent extra-articular resection and, where appropriate, EPR. One soft-tissue sarcoma of the adductor compartment which involved the femur was resected and reconstructed using an EPR. Computer navigation was used to aid reconstruction in eight patients. Histological examination of the resected specimens revealed tumour-free margins in all patients. Post-operative radiographs and CT showed that the resection and reconstruction had been carried out as planned in all patients where navigation was used. In two patients, computer navigation had to be abandoned and the operation was completed under CT and radiological control. The use of computer navigation in musculoskeletal oncology allows accurate identification of the local anatomy and can define the extent of the tumour and proposed resection margins. Furthermore, it helps in reconstruction of limb length, rotation and overall alignment after resection of an appendicular tumour.

Management of Vascular Involvement in Extremity Soft Tissue Sarcoma

Advances in adjuvant treatment protocols and improvements in imaging techniques have helped improve the limb-salvage rate for extremity soft tissue sarcomas to approximately 95%. Moreover, improvements in operative techniques have enabled successful limb-salvage surgery to be performed even in the face of vascular invasion or encasement by tumor. En bloc resection of major vascular structures with the tumor and reconstruction with reversed saphenous vein grafts, femoral venous grafts, or synthetic grafts has proved to be a feasible option in limb-salvage surgery. However, the surgical oncologist and patient should be aware that although overall function is only slightly worse after these procedures, individual functional results are less predictable. In addition, procedures requiring vascular resection and reconstruction are associated with an increased risk of complications, including amputation.

Primary Osseous Tumors of the Hindfoot: Why the Delay in Diagnosis and Should We Be Concerned?

BackgroundBony tumors of the foot account for approximately 3% of all osseous tumors. Diagnosis is frequently delayed as a result of lack of clinician familiarity and as a result of their rarity. The reasons for the delays, however, are unclear.Questions/purposesWe therefore determined (1) how hindfoot tumors present and the specific reasons for delay in diagnosis; (2) whether the spectrum of disease varies between the talus and calcaneus; and (3) how these patients were treated.MethodsWe retrospectively reviewed the medical notes and imaging for all patients with 34 calcaneal and 23 talar tumors recorded in the Scottish Bone Tumour Registry. Demographics, presentation, investigation, histology, management, recurrence, and mortality were recorded.ResultsHindfoot tumors present with pain and often swelling around the heel (calcaneus) or ankle (talus), most often misdiagnosed as soft tissue injury. Calcaneal lesions were more likely to be malignant than talar lesions: 13 of 34 versus three of 23.ConclusionsClinicians should be aware that hindfoot tumors can be initially misdiagnosed as soft tissue injuries and suspicion of a tumor should be raised in the absence of trauma or persistent symptoms. Lesions affecting the calcaneus are more likely to be malignant. Early diagnosis and adjuvant therapy are important.Level of EvidenceLevel IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Computer assisted navigation in total knee and hip arthroplasty

Introduction: Computer assisted surgery was pioneered in early 1990s. The first computer assisted surgery (CAS) total knee replacement with an imageless system was carried out in 1997. In the past 25 years, CAS has progressed from experimental in vitro studies to established in vivo surgical procedures. Methods: A comprehensive body of evidence establishing the advantages of computer assisted surgery in knee and hip arthroplasty is available. Established benefits have been demonstrated including its role as an excellent research tool. Its advantages include dynamic pre-operative and per-operative assessment, increased accuracy in correction of deformities, kinematics and mechanical axis, a better alignment of components, better survival rates of prostheses and a better functional outcome. Adoption of computer navigation in the hip arthroplasty is still at an early stage compared to knee arthroplasty, though the results are well documented. Evidence suggests improved accuracy in acetabular orientation, positioning, hip offset and leg length correction. Results: Among the orthopaedic surgeons, navigated knee arthroplasty is gaining popularity though slowly. The uptake rates vary from country to country. The Australian joint registry data shows increased navigated knee arthroplasty from 2.4% in 2003 to 28.6% in 2015 and decreased revision rates with navigated knee arthroplasty in comparison with traditional instrumented knee arthroplasty in patient cohort under the age of 55 years. Conclusion: Any new technology has a learning curve and with practice the navigation assisted knee and hip arthroplasty becomes easy. We have actively followed the evidence of CAS in orthopaedics and have successfully adopted it in our routine practice over the last decades. Despite the cautious inertia of orthopaedic surgeons to embrace CAS more readily; we are certain that computer technology has a pivotal role in lower limb arthroplasty. It will evolve to become a standard practice in the future in various forms like navigation or robotics.

Primary bone tumours of the talus: The Scottish Bone Tumour Registry experience

BACKGROUND Primary bone tumours of the talus are rare and the existing literature is limited. The aim of this study was to investigate the epidemiology of primary bone tumours affecting this uncommon site and suggest a management protocol for these tumours. METHODS We retrospectively reviewed the Scottish Bone Tumour Register from January 1954 to May 2010 and included all primary bone tumours of the talus. RESULTS We identified only twenty three bone tumours over fifty six years highlighting the rarity of these tumours. There were twenty benign and three malignant tumours with a mean age of twenty eight years. A delay in presentation was common with a mean time from onset of symptoms to diagnosis of ten months. CONCLUSIONS Tumour types identified were consistent with previous literature. We identified cases of desmoplastic fibroma and intraosseous lipodystrophy described for the first time. We suggest an investigatory and treatment protocol for patients with a suspected primary bone tumour of the talus.

Outcome of image-guided biopsies: Retrospective review of the West of Scotland musculoskeletal oncology service

INTRODUCTION Image-guided needle biopsy of a suspected musculoskeletal malignancy has become increasingly popular as an effective modality for diagnosis. Our aim was to determine accuracy and success rates of the image guided biopsies performed by our service. METHODS A retrospective review of the Bone and Soft Tissue Sarcoma service database was performed to identify all patients who underwent image guided biopsy and to identify the results of such investigations. Patients who had an open biopsy or a biopsy performed at another institution were excluded from this review. A biopsy was deemed successful if a sample of the target lesion was sampled at the time of biopsy. The successful biopsies were then classified as diagnostic or non-diagnostic depending on whether the diagnosis was established from the sampled tissue. RESULTS 465 of the 1181 new referrals to the Bone and Soft Tissue Sarcoma service in a 4 year period underwent biopsy. 75% (350) were image guided biopsies - 60% (281) ultrasound and 15% (69) CT guided. The rate of successful ultrasound guided biopsy was 94.7% and the rate of a successful diagnostic biopsy was 93.6%. CT guided biopsies were successful in 95.7% and were both successful and diagnostic in 79.7%. DISCUSSION The rate of a successful diagnostic ultrasound biopsy within our institution reflects the reported rate within the literature. The rate of a successful diagnostic CT guided biopsy is lower however is also consistent with that reported within the literature. Low grade lipomatous lesions and chondroid lesions of undetermined malignant potential (CLUMP) are associated with a more difficult histological diagnosis on biopsy alone which is consistent with our findings. For this reason our institution has stopped performing routine image guided biopsies on these lesions. Radiological low grade lipomatous lesions are treated with marginal excision and all CLUMP lesions undergo open biopsy.

Tophaceous gout of the patella: a report of two cases.

Introduction. Tophaceous gout of the patella is rare and may masquerade as a tumour or tumour-like condition. Cases. We report two patients with gout involving the patella, one complicated by a pathological fracture and the other occurring in a bipartite patella in a young adult. Discussion. Typical imaging appearances and measurement of serum urate will usually confirm the diagnosis but, occasionally, the serum urate level may be normal in active gout and in such cases, a biopsy will be required. Conclusion. Gout of the patella may masquerade as a tumour or tumour-like condition and it is important to consider gout in the differential diagnosis.

Negative Pressure Wound Therapy for Closed Surgical Wounds in Musculoskeletal Oncology Patients - A Case-Control Trial

Following excision of musculoskeletal tumours, patients are at high risk of wound issues such as infection, dehiscence and delayed healing. This is due to a multitude of factors including the invasive nature of the disease, extensive soft tissue dissection, disruption to blood and lymphatic drainage, residual cavity and adjuvant therapies. The use of negative pressure wound therapy (NPWT) has a growing body of evidence on its beneficial effect of wound healing such as promoting cell differentiation, minimising oedema and thermoregulation. Traditionally, these dressings have been used for open or dehisced wounds; however recent research has investigated its role in closed wounds. Aim: To evaluate the effect of NPWT in patients with closed wounds, either primarily or with flap coverage, in our high risk group. Consecutive patients who had a NPWT dressing applied were selected, and a control group was established by a blinded researcher with matching for tissue diagnosis, surgical site, gender and age. The primary outcome measured was documented for wound complications, with secondary data collected on radiotherapy and wound drainage. Results: Patients were well matched between the intervention (n=9) and control (n=9) groups for gender, age and tissue diagnosis. Both groups had 1 patient who underwent preoperative radiotherapy. A total of 3 wound infections occurred in the control group and none in the NPWT group. Overall there was a trend towards lower drain output and statistically significantly reduced infection rate in the NPWT group. Conclusion: In this short series, despite the NPWT patients having more additional risk factors for wound issues, they resulted in fewer infections. The sample size is not sufficient to have statistically significant reduction. Further evaluation on the value of NPWT in this patient group should be prospectively evaluated.

A Novel Antibiotic Spacer for Significant Proximal Femoral Loss - Surgical Technique

Background: Infections of proximal femora with prosthetic implants in situ have long been a major concern in orthopedic surgery. The gold standard in the management of infected proximal femurs in the presence of prosthetic implants has traditionally been a two-stage revision. However, this is challenging in the setting of extensive bone loss. Methods: A 3 case series of such infections leading to extensive loss of the proximal femur is presented. We specifically describe our technique of debriding the infected segments as well as utilization of a trochanteric slide osteotomy to resect the femur.We also demonstrate preparation of the “pseudoacetabulum” and femoral component with an antibiotic spacer. Conclusion: The high cost of such a procedure is offset by reduction in time spent in hospital. The spacer also helps to allow mobilization by partial weight bearing on a stable femoral component and provide pain control which improves quality of life as compared to prolonged intravenous antimicrobial therapy.