Locking compression plate in musculoskeletal oncology 'a friend in need'

Fixation Principles for Pathologic Fractures in Metasatic Disease

The management of pathologic fractures differs from nonpathologic fractures with respect to preoperative evaluation, surgical strategies, adjuvant therapies, and complication rates. These issues must be understood to provide appropriate musculoskeletal care for patients with metastatic disease.

Management of Pathologic Fractures around the Knee: Part 1-Distal Femur

Pathologic fractures secondary to metastatic disease are an increasingly prevalent problem. Such patients require multidisciplinary collaboration to optimize clinical outcomes. An established algorithm for clinical, laboratory, and radiographic work-up will ensure that each patient achieves the best outcome while avoiding catastrophic complications. Metastatic disease to the region of the knee is less commonly encountered than in other regions of the body, but it presents unique difficulties that merit discussion. Part one of this two-part article series will discuss the appropriate work-up of patients with suspected or impending pathologic fracture of the distal femur, highlight biopsy principles, address perioperative nonsurgical treatments that will optimize patient outcomes, and discuss available surgical treatment modalities.

Screw stripping and its prevention in the hexagonal socket of 3.5-mm titanium locking screws

There have been several reports about the difficulties in removing 3.5-mm titanium locking screws from plates due to the stripping or rounding of the hexagonal screw socket. We investigated whether stripping the locking screw sockets can be prevented by using different screwdrivers or interposing materials into the socket during removal. We overtightened 120 3.5-mm titanium locking screws (Depuy Synthes, Paoli, PA) equally into locking plates on sawbone tibia models, applying a uniform torque of 4.5 Nm, exceeding the recommended torque of 1.5 Nm. Twenty screws each were removed using a straight-handle 2.5-mm screwdriver, T-handle screwdriver, hex key wrench, and straight-handle screwdriver with a non-dominant hand. In addition, 20 screws were removed using foil from a suture packet inserted into the screw socket or using parts of a latex glove inserted into the screw socket. The incidence rates of screw stripping using the straight-handle screwdriver, T-handle screwdriver, hex key wrench, non-dominant hand, foil interposition, and latex glove interposition were 75%, 40%, 35%, 90%, 60%, and 70%, respectively. When a T-handle screwdriver or hex key wrench was used, the probability of screw stripping was 4.50 times (odds ratio = 4.50, 95% confidence interval = 1.17 to 17.37, p = 0.03) and 5.57 times (odds ratio = 5.57, 95% confidence interval = 1.42 to 21.56, p = 0.01) lower than that with the straight-handle screwdriver, respectively. Foil or latex glove interpositions did not prevent screw stripping. Thus, in the current experimental study, T-handle screwdriver or hex key wrench usage decreased the incidence rate of screw stripping during removal compared to straight-handle screwdriver use.

Multiple calcaneal fibrous dysplasia: A case report

RATIONALE

Fibrous dysplasia (FD) is a benign bone tumor due to developmental failure in the process of primitive bone remodeling to mature lamellar bone. The most common locations of monostotic FD of the extremity bones are the proximal femur, tibia, humerus and the radius. FD in the calcaneus is extremely rare and usually manifests clinically as a single bone lesion. Moreover, no research has reported on multiple lesions in calcaneal FD.

PATIENT CONCERNS

We report a 21-year-old man presented to our institution with pain upon walking for 2 months.

DIAGNOSES

We diagnosed the patient with multiple calcaneal FD through histologic examination of the excised biopsy that revealed cellular, spindly stroma and woven bone without osteoblastic rimming resembling Chinese characters INTERVENTIONS:: Plain X-ray, computed tomography, magnetic resonance imaging and histologic examination. An excisional biopsy with extended curettage and bone grafting with allogenous bone and autogenous bone marrow aspirate concentrate were performed.

OUTCOMES

No complications developed after surgery and during serial follow-ups at 3, 6 and 12 months. At a postoperative 12-month follow-up, a plain radiogram showed a well-consolidated bone graft in the lesions.

LESSONS

Calcaneal FD is rare disease entity. This case can help guide clinical decision-making in the future.

Malignant distal femur tumors management in children, low cost innovations with affordable care in a tertiary care hospital, a cross sectional study

INTRODUCTION

Malignant musculoskeletal tumors in children are mostly comprised of Osteosarcoma and Ewing's sarcoma and distal femur is the most common site for primary bone tumors. This study examined the surgical management outcomes of pediatric patients (<18 years) presented in our setup with malignant distal femur tumors.

METHODOLOGY

We retrospectively reviewed the medical records of patients diagnosed with malignant sarcomas of distal femur and younger than 18 years of age who underwent limb salvage surgery during June 2009-June2017.

RESULTS

There were 31 pediatric patients who had distal femur malignant tumors and out of them 20 patients were selected who underwent limb salvage as a primary surgery. The mean age (range) of patients was 11.90 (6-17) years. Seventeen had osteosarcoma and three had Ewing's sarcoma. In surgery all patients were offered reconstruction. Post-operative complications were observed in (50%) patients while other 50% patients had no complications. Wound infection, flap necrosis, broken plates with non-union and recurrence of disease were the reported complications. Revision surgery was performed in 10 patients out of 20 patients.

CONCLUSION

Salvage was the primary option in our surgery and revision surgery was performed in the cases due to complications. Small sample size was the limitation of the study.

Vascularized fibula with and without extracorporeal radiotherapy for limb salvage surgery in Indian patients

BACKGROUND

Reconstruction of segmental bone defects following resection of bone sarcomas is a challenging procedure. Vascularised fibula grafts alone or in combination with extracorporeal radiotherapy and reimplantation of tumor bone have long been established as a method of reconstruction of such defects, with satisfying results. Prompted by paucity of data on Indian patients, we report our experience with vascularised fibula graft for patients undergoing limb salvage surgery for sarcomas of bone.

MATERIAL AND METHODS

A total of 25 patients underwent the procedure from December 2008 to December 2014. Femur was the commonest site and osteosarcoma was the commonest diagnosis. Intercalary resection was done in 19 patients and arthrodesis in 6 patients. Vascularised fibula was used in combination with extra corporeally irradiated bone in eight patients, and alone in 17 patients.

RESULTS

All but one limb could be salvaged, and all but three patients had united at final follow up. Combination of extracorporeal radiotherapy and reimplantation with vascularised fibula fared better than vascularised fibula alone in terms of time to union (9.6 months vs 12.2 months) and rate of graft related complications (14.2% vs 62.5%).

CONCLUSION

Reconstruction with VFG with or without ECRT has a good and predictable functional outcome. Though manageable with active intervention, complications were more commonly seen with vascularised fibula alone than a combination of the two techniques.

Establishing musculoskeletal oncology service in resource constrained country: challenges and solutions

The burden of orthopedic tumor surgery in Pakistan is not known. Similarly the number of procedures being performed for bone and soft tissue surgery are not known. This is even becoming more challenging where the existence of rules and regulations in health care are next to minimal. Furthermore data recording in our country and case registries hardly exist. Despite the lack of information and resources, with high disease burden on community, various providers provide surgical interventions every day in our settings. A lot of tumor surgery is still being done by general surgeons and general orthopedic surgeons who have little knowledge and update about musculoskeletal oncology principles. Lack of subspecialized centers and the high cost of such centers force the patients to visit these surgeons for a highly sophisticated problem like a bone tumor which is the disease of young bones. In this article we will emphasize on the difficulty in establishing an orthopedic tumor service in our part of the world and the consequences including delay in diagnosis, faulty course of management and later decline in functionality, disease progression and increased mortality. We will highlight the principles and stepwise approach of orthopedic tumor surgery and explain the difficulty encountered if these principles are not followed.

A study on the mechanical characteristics of the EBM-printed Ti-6Al-4V LCP plates in vitro

Purpose

The electron beam melting (EBM) Ti-6Al-4V material technology has been developed over a short time period. It was introduced through a research to develop Ti-6Al-4V implants for patients, but EBM printed locking compression plates have not been used for clinical implants. The main purpose of this study is to find whether the EBM Ti-6Al-4V plate suit for clinical implants.

Methods

First, we scanned an AO-locking compression plate (LCP) and printed LCP samples using EBM. Next, we evaluated the EBM plate surface roughness through optical microscopy as well as the LCP and EBM plates’ mechanical characteristics using the ASTM standard, which is commonly used to test the mechanical properties of bone plates subject to bending. Each sample was examined using a single-cycle four-point bending test and hardness testing to acquire data on bending stiffness, bending strength, bending structural stiffness, and hardness.

Results

The results show significant differences in bending stiffness, bending strength, bending structural stiffness, and hardness between the samples using EBM and the original LCP plates. The EBM-printed samples’ surface roughness was 0.49 ± 0.02 μm. The mean hardness of the LCP sample was 266.67 HV10 ± 5.8, and the EBM-printed sample mean hardness was 341.1 HV10 ± 1.93. The EBM samples’ bending stiffness was 87.67%, which is greater than using the LCP plates’; and the bending strength was 190.7% greater, the bending structural stiffness was 73.2% greater, and the hardness was 27.9% greater.

Conclusions

The results show that the EBM plates’ general mechanical strength was significantly greater than the LCP plates. An EBM plate is advantageous for clinical implants because it can be customized with great potential for improvement.