Scientific Program

Day 1 :

Keynote Forum

Monika Jenko

Institute of Metals and Technology

Keynote: Premature fracture of a Modular Femoral Neck after Total Hip Arthroplasty: Comparison of Two Different Stem-Neck Alloys

Time : 10:00 AM to 10:40 AM

Biography:

Dr Monika Jenko  accomplished her PhD studies of material science at the University of Ljubljana. She was 11 years director of the public research Institute of Metals and Technologies (IMT) and initiator that institute has joined to Jozef Stefan International postgraduate School with Advanced Metallic Materials in the frame of the Nanoscience and nanotechnology study program. She introduced the surface analysis in Slovenia into metallurgy as well as the integrated electron spectroscopy techniques. She has worked in different national and international projects in the field of Material Science, Applied Surface Science, Surface Engineering, Nanoscience and last ten years she is very active in biocompatible materials . She is author of several papers published in reputed journals and is a member of different international working groups

Abstract:

Statement of the Problem: An alarmingly large number of femoral modular stems of titanium alloy neck suffer from premature fractures. The cobalt-chromium neck was introduced for its better wear and mechanical properties, although it fails even earlier. Until now there were no direct comparisons between two different femoral modular necks for the same type of stem implant.  Experts from orthopaedic surgery and metallurgy have combined their research efforts to compare the femoral modular stem-necks of similar titanium and dissimilar titanium/cobalt-chromium alloy  systems from the clinical and metallurgical points of view.    

Orientation: Two  premature  fractured modular neck Hip endprostheses of  similar and dissimilar metals systems were investigated. Multivariate analyses were performed to assess the differences in the fretting, corrosion and fatigue of similar alloys and dissimilar alloys modular joints. Patient’s demographic information was collected from medical records.

Findings: Similar stem-neck metals of hip endoprostheses failed due to continuous dynamic micro-motions, crevice corrosion, fretting and fatigue, as well as improper neck dimensions.   The mechanism of  titanium alloy modular neck fracture is shown in Figure 1. The dissimilar metals stem-neck fractured due to continuous dynamic micro-motions, selective leaching of cobalt ions from the cobalt-chromium-molybdenum alloy and formation of titan-chromium-molybdenum interfacial phase and severe crevice corrosion. The mechanism  of cobalt-chromium-molybdenum alloy modular neck fracture is shown in Figure 2  The dissimilar joints suffered more corrosion than the similar joints due to additional galvanic corrosion.

Conclusions: Fretting, corrosion and fatigue occurred on both neck-stem retrievals of the similar and dissimilar metals. Both metal-alloy systems used in this application are known to be highly corrosion resistant and giving rise to the bio-tribo-corrosion processes needs to be understood and characterized so that appropriate changes in design and materials can be upgrade.  

 

Keynote Forum

Rashid Ganji

Sina Hospital, Iran

Keynote: New Concepts In Medial Release Based On Experience With Varus Total Knee Arthroplasty

Time : 10:40 AM to 11:20 AM

Biography:

Dr. Ganji is that he specializes and focuses solely on total knee replacements. By using up-to-date and proven techniques, he is a leader in the field. He has been specialized in the field since 1997 and completed his residency in Mashhad (2nd largest city in Iran). He is certified by the Iran Orthopedic Surgery Organization. Furthermore, he has continued his education and has earned various certifications in USA, Germany, Italy, and Belgium.Dr. Ganji is currently associated with The Iranian Orthopedic Society, The Iranian Society of Knee Surgery as well as America Association of Hip and Knee Surgeons. His areas of research include long-term follow-up studies associated with total knee replacement, especially in severe deformities and revisions.He is commonly invited to give lectures world-wide on total knee replacements & various special cases, Dr. Ganji is considered as an expert in the field Orthopedics, specifically total knee replacement, by his respected peers.

Abstract:

Background: Patients with severe Varus knees is common in developing countries (i.e. Middle East) where Total Knee Arthroplasty (TKA) can effectively resolve this issue. There are many methods to perform this medial release. However, each technique may have implied disadvantages. For this reason, many surgeons are unable to avoid instability and stop using semi-constrained prosthesis in this group of patients indeterminately. We have developed a new concept for this release based on our experience in performing over 5000 surgical cases to decrease subtle instability and reach nearly 0% use of semi-constrained prosthesis.

Methods: Surgical procedures were accomplished by the same surgeon with measured resection technique, and cemented posterior-stabilized prosthesis. 250 TKAs were in this study and divided them into 3 groups. First group of patients had varus deformity up to 15 degrees, second group 15-25 degrees, and the third group over 25 degrees. The medial soft tissue release was distinctive for each group by only releasing the deep MCL and capsule for the first group. We evaluated our outcome based on the Knee Society Score at 2 and 6 months, and 1 year postoperatively.

Results: Results showed that in mild deformity, there was no need for considerable release. Even in moderate deformity with little extension release to the posteromedial corner, we can obtain good balancing. For severe deformity, the main objective was to retain the superficial MCL as much as possible even by accepting some lateral widening of the joint. No patient developed postoperative medial instability.

Conclusion: This approach, considering sex, body mass index, and different soft tissue quality, as one of the alternatives in soft tissue balancing resulted in nearly 0% use of semi-constrained prosthesis and even avoidance of subtle instability in severe varus deformity cases (+25 degrees).

  • Knee Arthroplasty
Speaker
Biography:

Dr Yoon has his expertise in knee arthroplasty and arthroscopy. He has finished residency at Seoul National University Hospital, department of orthopaedic surgery, and specialized in knee arthroplasty and arthroscopy during his fellowship at Seoul Metropolitan Government Boramae Medical Center. He is currently working as a orthopaedic surgical staff at Seoul Bumin Hospital. He has special interest in total and partial knee arthroplasty.

Abstract:

Introduction: The role of Unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) remains controversial, even though SONK involves only one compartment of the knee joint. We aimed to compare the survival rate and clinical outcomes of UKA in SONK and medial compartment osteoarthritis (MOA) via a meta-analysis of previous studies.

Materials and Methods: MEDLINE, Embase, and Cochrane Library were searched up to January 2018 with keywords related to SONK and knee arthroplasty. Studies were selected with predetermined inclusion criteria: (1) medial UKA as the primary procedure, (2) reporting implant survival or clinical outcomes of osteonecrosis and osteoarthritis, and (3) follow-up period > 1 year. Quality assessment was performed using the risk of bias assessment tool for non-randomized studies. A random-effects model was used to estimate the pooled relative risk (RR) and standardized mean difference.

Results: The incidence of UKA revision for any reason was significantly higher in SONK than in MOA group (pooled RR=1.83, p=0.009). However, the risk of revision due to aseptic loosening was not significantly different between the groups (Figure 1). Moreover, when stratified by the study quality, high quality studies showed similar risk of overall revision in SONK and MOA (p=0.71). Subgroup analysis revealed no significant difference in failure between SONK and MOA after cemented mobile and fixed bearing UKA. Results of uncemented UKA was reported only in one study, which showed higher failure of SONK compared to MOA. Clinical outcomes after UKA were similar between SONK and MOA (p=0.66).

Conclusions: Cemented UKA has similar survival and clinical outcomes in SONK and MOA.  Prospective studies designed specifically to compare the UKA outcomes in SONK and MOA are necessary.

 

Speaker
Biography:

Dr Navneeth Kumar.G.K- completed my post-graduation in MS Orthopaedics, from the prestigious Bangalore Medical College and Research Institute, India under the guidance and mentorship of Dr. Purushotham V.J (Professor and Unit Chief) in BMCRI. Due to my fond interest in arthroplasty, I pursed my fellowship in arthroplasty at Sparsh Hospital Bangalore, under the esteemed guidance of Dr. Sharan Shivraj Patil. This study on efficacy of  PRP vs HA injections in OA knee, was under taken to primarily explore the non-operative solutions in the management of early antero-medial osteoarthritis of knee, which is a rising health problem in a developing country like India. The results of the study attempts to establish a protocol for intra-articular injectons in OA knee.

 

Abstract:

Introduction & aim: Osteoarthritis (OA) is the most prevalent form of arthritis in the world. OA incidence increases steadily with age, affecting 12.1% of the population from 25 to 74 years old, and it is the leading cause of physical disability in people older than 65 years. The primary objective of this study was t to assess and compare the Clinical Outcomes of Patients with Primary Osteoarthritis of Knee receiving Intra-articular injections of Platelet Rich Plasma and High Molecular Weight Hyaluronic Acid

Materials and Methods: 44 Patients with primary OA of knee, were divided into two groups of 22 each. Group A was administered intra-articular injections of PRP (prepared using single spin technique) and Group B was administered intra-articular injections of Hyaluronic Acid. The functional outcome was assessed before administration of injection and at 6 months follow-up using subjective questionnaire scoring systems i.e. WOMAC, IKDC and VAS indices.

Results:

Out of 44 patients, 33 were females, and 11 males. The average age in Group A was 51.55±6.93 years and 53.27±7.73 years in Group B. 68.2% of patients in the study had bilateral affection. The Improvement in functional outcome scores in Group A (WOMAC=12.980, P <0.001; IKDC=11.680, P<0.001; VAS=2.773, P<0.001) were significantly better than that of Group B (WOMAC= 6.685, P <0.001; IKDC=8.501, P<0.001; VAS= 1.773, P<0.001)

Discussion & Conclusion: The results obtained in our study compare well with other studies undertaken in the past. Patients of both groups showed statistically significant improvement in functional outcome at 6months follow-up. The functional outcome of patients receiving Platelet Rich Plasma was significantly better than those receiving Hyaluronic Acid. Therefore intra-articular PRP is superior to HA in alleviating symptoms and improving short term outcome of early OA Knee and can be considered a safe, simple and efficacious option over that of Hyaluronic Acid.

  • Hip Arthroplasty
Speaker
Biography:

Dr Haytham Abdelazim is an assistant professor of orthopedic surgery in Ain Shams University Faculty of medicine. He has his expertise in joint replacement surgeries. He has years of experience in research, teaching and administration  both in hospital and education institutions..

 

Abstract:

Statement of the Problem: Total hip replacement in patients with a dysplastic hip is challenging. The normal anatomy about the hip joint is distorted in the presence of congenital hip dislocation and proximal migration of the femur. It is a technically demanding procedure in which several problems and complications can be encountered. Restoring the anatomic center of hip rotation may require femoral osteotomy.

Methodology & Theoretical Orientation: The aim of this study was to determine the rate of union, complications and functional results in a series of patients with Crowe III and IV dysplastic hips who underwent single stage THA with or without simultaneous subtrochanteric femoral shortening osteotomy. A retrospective study was designed in a series of 20 patients (20hips). Patients were reviewed clinically and radiographically with a minimum follow-up of one year. Harris Hip Score (HHS) was recorded pre-operatively and at six weeks, six months and 12 months postoperatively. Results: Hip center was restored at the anatomic center in 95% and near anatomic center in 5% of cases, subtrochanteric femoral osteotomy was needed in 11 cases (55%), intraoperative femoral cracks were encountered in 3 cases (15%), union occurred in all cases with subtrochanteric shortening (100%) Mean HHS improved from 36.31 preoperatively to 87.13 at 6 months and 88.60 at 12 months. Infection and dislocation occurred in 1 case (5%) and sciatic nerve injury occurred in 1 case (5%). No cases required revision till last follow up and no patients encountered postoperative DVT or aseptic loosening.

Conclusion & Significance: Single stage THA for dysplastic hip Crowe III or IV is technically demanding and proved to be safe and effective with or without subtrochanteric femoral shortening osteotomy with restoration of anatomic hip center.

 

Speaker
Biography:

A dedicated professional, benefiting from experience working effectively as part of a multi-disciplinary team in the civil hospital karachi and within other systems and administrations, gaining a good understanding of cultural and social issues. Possessing a developed empathic, patient-centered philosophy of care with practical clinical skills.

Abstract:

Object:  The objective of this study was to assess the mid term clinical & radiological outcome of hip revision hip replacement & complex primary arthroplasty by using modular cementless femoral stem in our local population

Method: This study was conducted in Liaquat National Hospital, Orthopedic department from June 2017 to Jan 2019. Patients with Primary & Revised hip arthroplasty were included in the study in which modular femoral stem with sleeve were used with a minimum 15 months of follow up. Patients were assessed clinically & radiological at 3 months, 6 months, 9 months , 12 months & 15 months. Antero posterior & lateral radiograph of replaced hip were taken in every follow up visit. Follow up x-rays were compared with immediate postoperative x-rays for pedestal formation, endosteal spot welds, stress shielding, migration & cortical hypertrophy.

Result: Total 32 patients underwent hip arthroplasty with modular femoral stem during the specified period. 29 patients met the criteria for inclusion in the study. Gait improved substantially after revision hip replacement by modular femoral stem femoral stem. Harris hip score was also improved substantially after hip replacement & value increased from 40.2 to 79.7. The Merle D Aubigne score indicated a mark reduction in pain. According to Engh et al osteointegration were present in 23(79.3%) stem.

Conclusion: Mid term clinical & radiological outcome of femoral modular stem in revision hip arthroplasty & primary hip replacement with anatomical difficulties is good with Paprosky type II & III A bone loss. Femoral modular stem is our implant of choice in hip arthroplasty surgeries with proximal femoral bone loss

 

Speaker
Biography:

Daniel (Dan) Li has participated in a wide variety of both basic and clinical research regarding biomaterials in the context of orthopaedic applications, such as the use of hydrogels as a novel drug-eluting mechanism to combat osteomyelitis and tuberculosis infection. He has spent significant time overseas with the orthopaedics department at the 309th Hospital of the PLA in Beijing, China, working under the team of Dr. Yuanzheng Ma, as well as completing his undergraduate degree in Materials Science and Engineering at the University of Illinois. There, he conducted research under the John Rogers Research Group investigating novel biodegradable electronics. Currently, he is performing clinical outcomes research at Northwestern University regarding the evaluation of prosthetic joint infection.

 

Abstract:

Neck-stem corrosion has been associated with Adverse Local Tissue Reaction (ALTR) in dual-taper femoral stems.  In this study, we examine a single surgeon’s retrospective case series of 42 hips in 38 patients who underwent primary total hip arthroplasty (THA) with a dual-taper femoral component. Evaluation consists of clinical exam, labs including metal ion levels, and MARS MRI. We propose that hip aspiration would be a beneficial adjunct. Each hip aspirate was classified into Class 1, 2, or 3, based on qualitative variables. 19/42 hips were symptomatic, 38/42 had elevated Cobalt, and 23/42 had abnormal MRI findings. 40% of aspirates were Class I (benign), 17% Class 2, and 43% Class 3. Class 2 and 3 aspirates are associated with abnormal MRI Mid-term Outcomes and Evaluation Following Implantation with a Recalled Modular Neck Femoral Stem, elevated Cobalt, and a high rate of revision (71% and 72%, respectively). A small subset of patients (2/38) with symptoms, normal labs and MRI, had abnormal aspirates with extensive tissue necrosis at revision. A significant proportion of the aspirates were unable to complete a cell count due to cellular degradation or degeneration, or inability to process a thick fluid sample. For those samples that were processed, cells counts were variable in terms of the differential of neutrophils, lymphocytes, and monocytes. We noted a much higher percentage of patients with elevated Cobalt levels (90%) versus Chromium (22%), which appears to be consistent with contemporary literature. The utility of this diagnostic test may be apparent when looking more closely at select patients.  Within the patients who have been revised, there were 2 patients who were symptomatic, yet had normal cobalt and chromium labs, as well as a normal MARS MRI, yet had Class 3 aspirates, and were noted to have moderate to severe soft tissue necrosis at the time of revision surgery. These patients may potentially be overlooked for early revision.

 

 

  • Bones and Joints Infection
Biography:

Abstract:

Antibiotic Poly methyl-methacrylate bone cement (ABC) has a variety of surgical uses including primary and revision arthroplasty, dead space management in infection and structural support in bone tumors.  All of these indications rely on antibiotic elution to augment systemic antibiotic use.  However, in spite of years of research, ABC elutes only a small percentage of the total antibiotic incorporated. Several techniques and additives have been incorporated into ABC that improve elution, however this is accompanied by a considerable decrease in mechanical properties.  The present study investigates the additional of a lipid to ABC containing a hydrophilic and moderately lipophilic antibiotic, Gentamicin.

Olive oil was added by weight to Palacos MV + G bone cement (LL-ABC) which is known for its superior elution properties in 0, 10 and 20% w/w.  Cement was vacuum mixed and placed onto sterilized stainless-steel plates to create small cement dowels.  Antibiotic elution was determined at 4 hours, 1, 3, 7 and 28 days for each concentration.  Mechanical properties of the cement dowels were determined by compressive testing using MTS- bionix 858 with resultant determination of Young’s modulus and creation of load-deformation curves.

The cumulative antibiotic released (ug/mL) was proportionate to the % w/w of olive added. The cumulative antibiotic release from the 20% w/w LL-ABC was greater than the control at all time points.  At 28 days, 10% and 20% w/w LL-ABC had released 295% and 585 % more gentamicin than the control sample.  Compressive strength and young’s modulus were inversely related to the concentration of olive oil in the LL-ABC samples.  

The addition of olive oil to Gentamicin Palacos MV cement significantly increased the elution potential of the cement with minor compromise in the mechanical properties.  The recommended next step is evaluating whether the locally eluted antibiotic maintains therapeutic values above the minimal inhibitory concentration, and extending this in vitro study to an in vivo model.