header advert
Results 1 - 11 of 11
Results per page:
Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 38 - 38
11 Apr 2023
Stewart M Nguyen J
Full Access

Osteoprogenitors on the inner layer of periosteum are the major cellular contributors to appositional bone growth and bone repair by callus formation. Previous work showed that periosteal-derived cells have little or no osteogenic activity under standard in vitro osteogenic culture conditions. This study was conducted to determine what growth factor(s) can activate periosteal osteogenic capacity.

This study was conducted with IACUC approval. Periosteum from five equine donors was digested in collagenase for 3-4 hours at 37C. Isolated periosteal cells were maintained in DMEM/10% FBS medium and exposed to PDGF, Prostaglandin E2, BMP-2 and TGF-b3 at a range of concentrations for 72 hours. Changes in osteogenic gene expression (Runx2, OSX and ALP) were measured by qPCR. Periosteal cells were pre-treated with TGF-b3 or maintained in control medium were transferred into basal or osteogenic medium. Osteogenic status was assessed by Alizarin Red staining for mineralized matrix, ALP enzymatic activity and induction of osteogenic genes.

PDGF, PgE2 and BMP-2 had little impact on expression of osteogenic markers by periosteal cells. In contrast, TGF-b3 stimulated significant increases in Osterix (over 100-fold) ALP expression (over 70-fold). Pre-treating periosteal cells with TGF-b3 for 72 hours stimulated rapid cell aggregation and aggregate mineralization once cells were transferred to osteogenic medium, while cells not exposed to TGF-b3 exhibited minimal evidence of osteogenic activity.

This study indicate that TGF-b signaling is vital for periosteal osteogenic activity. Transient ‘priming’ of periosteal cells through TGF-b exposure was sufficient to activate subsequent osteogenesis without requiring ongoing growth factor stimulation. TGF beta ligands are secreted by many cell types, including periosteal progenitors and osteocytes, providing opportunities for both autocrine and paracrine pathways to regulate periosteal bone formation under homeostatic and reparative conditions.


The Bone & Joint Journal
Vol. 102-B, Issue 9 | Pages 1151 - 1157
14 Sep 2020
Levack AE McLawhorn AS Dodwell E DelPizzo K Nguyen J Sink E

Aims

Tranexamic acid (TXA) has been shown to reduce blood loss and transfusion requirements in patients undergoing orthopaedic surgery. There remains a lack of prospective evidence for the use of TXA in patients undergoing periacetabular osteotomy (PAO). The purpose of this study was to determine if intravenous (IV) TXA is effective in reducing calculated blood loss and transfusions after PAO.

Methods

This was a single-centre prospective double-blind placebo-controlled randomized trial of 81 patients aged 12 to 45 years undergoing elective PAO by a single surgeon. The intervention group (n = 40) received two doses of IV TXA of a maximum 1 g in each dose; the control group (n = 41) received two doses of 50 ml 0.9% saline IV. The primary outcome was perioperative calculated blood loss. Secondary outcomes included allogenic transfusions and six-week postoperative complications.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 71 - 77
1 Jul 2020
Gonzalez Della Valle A Shanaghan KA Nguyen J Liu J Memtsoudis S Sharrock NE Salvati EA

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.

Methods

Between 2004 to 2018, 257 patients with a proven history of VTE underwent 277 primary elective THA procedures by two surgeons at a single institution. The patients had a history of deep vein thrombosis (DVT) (186, 67%), pulmonary embolism (PE) (43, 15.5%), or both (48, 17.5%). Chemoprophylaxis included aspirin (38 patients), anticoagulation (215 patients), or a combination of aspirin and anticoagulation (24 patients). A total of 50 patients (18%) had a vena cava filter in situ at the time of surgery. Patients were followed for 120 days to record complications, and for one year to record mortality.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 70 - 70
1 Oct 2019
Greenky M McGrath M Levicoff EA Good RP Nguyen J Makhdom AM Lonner JH
Full Access

Introduction

Controlling post-operative pain and reducing opioid requirements after total knee arthroplasty (TKA) remains a challenge, particularly in an era stressing rapid recovery protocols and early discharge. A single shot adductor canal block (ACB) has been shown to be effective in decreasing post-operative pain. This requires a specialty-trained Anesthesiologist skilled in ultrasound techniques, which imposes cost, time and skill barriers. Cadaveric studies and magnetic resonance imaging data have shown that access to the adductor canal is possible from within the joint, and thus the potential for intraoperative, intra-articular, surgeon administered ACB through a standard surgical approach is a feasible alternative to ultrasound guided ACB at the time of TKA. The purpose of the present study is to compare the efficacy of surgeon administered intraoperative ACB to anesthesiologist administered ACB.

Methods

Patients' undergoing primary TKA were prospectively randomized to receive either an Anesthesiologist administered (Group 1) or Surgeon administered (Group 2) ACB using 15 ml of Ropivacaine 0.5%, both in conjunction with spinal anesthesia. Perioperative multimodal anesthesia was standardized for the two groups. Primary outcomes were pain visual analogue scale (VAS), range of motion, and opioid consumption. Secondary outcomes were patient satisfaction scores and length of stay (LOS).


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 153 - 153
1 Jan 2016
Zuiderbaan H Khamaisy S Thein R Nawabi DH Chawla H Nguyen J Pearle A
Full Access

Introduction

There are several advantages of unicompartmental knee arthroplasty (UKA) in the treatment of isolated compartment osteoarthritis (OA) compared to the conventional total knee arthroplasty. Although various series report similar survivorship results, the national registries tend to show higher revision rates among the UKA. Persisting, unexplainable pain is a leading cause for UKA revision surgery. Therefore it is essential to investigate the various patient specific characteristics which might influence outcome following UKA in order to minimize revision rates and optimize clinical outcomes. The purpose of this study is to evaluate the influence of the various individual patient factors, including pre-operative radiographic parameters, on the outcome following UKA.

Methods

168 consecutive patients who underwent robot assisted UKA (MAKO Tactile Guidance System, MAKO Surgical Corporation, Ft. Lauderdale, FL, USA) were included. The investigated pre- and/or postoperative parameters included gender, BMI, age, type of tibial implant (inlay versus onlay), laterality, state of OA (i.e. Kellgren and Lawrence grade) of the operated and non-operated compartment and mechanical axis alignment.

Pre-operatively and at a minimum of 1 year (average 1.97 years, range 1 – 4.2 years) following surgery, patients were asked to complete the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire. It is subdivided in three separate scales (i.e. pain, stiffness and function). A score of 0 represents the best possible outcome and a score of 100 the worst. A p-value <0.05 was considered statistically significant.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 32 - 32
1 Jul 2014
Curry E Li X Buesser K Nguyen J Matzkin E
Full Access

Summary Statement

The purpose is to evaluate the effects of internet usage on new patient referral patterns to identify optimal patient recruitment and communication. Overall, social networking and internet may be an effective way for surgeons to recruit a wider patient population.

Introduction

Prior studies in other medical specialties have shown that social networking and internet usage has become an increasingly important means of patient communication and referral. However, this information is lacking in the orthopaedics literature. In this study, we evaluate the means by which new patients arrive at orthopaedic clinics in a major academic center. The purpose is to evaluate the effects of internet or social media usage on new patient referral patterns to identify avenues to optimise patient recruitment and communication.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 135 - 135
1 Dec 2013
Nam D Cody E Nguyen J Figgie MP Mayman DJ
Full Access

Background:

Conventional, extramedullary (EM) tibial alignment guides are only 65%–88% accurate in creating a tibial resection within 2° of perpendicular to the tibial mechanical axis in total knee arthroplasty (TKA). The purpose of this study was to compare the overall, tibial component alignment, and the surgeon's ability to achieve a specific, intraoperative goal for alignment between a portable, navigation system (KneeAlign™) and conventional, EM alignment guides.

Methods:

One hundred patients were enrolled in a prospective, randomized controlled study. Fifty patients received a TKA using the KneeAlign™ to perform the tibial resection, and 50 patients an EM alignment guide. Standing AP hip-to-ankle radiographs and lateral knee-to-ankle radiographs were obtained at the first, postoperative visit.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 240 - 240
1 Mar 2013
Li X Williams P Trivellas A Nguyen J Craig EV Warren R Gulotta L
Full Access

Introduction

There is a high prevalence of obesity in the United States and the numbers are increasing. These patients comprise a significant portion of the shoulder arthroplasty patient population. There are several reports of outcomes in the literature on obese patients after total knee or hip replacement, however, this data is lacking in the shoulder arthroplasty patient population. The purpose of this study is to compare the functional outcomes and complications of obese patients undergoing shoulder arthroplasty with the non-obese population.

Methods

Between 2009 to 2010, 76 patients that had a primary total shoulder replacement were grouped according to their Body Mass Index (BMI) and followed prospectively for 2 years. The groups were divided as normal (BMI <25, N=26), overweight (25 to 30 BMI, N=25), and obese (>30 BMI, N=25) according to the World Health Organization classifications. Preoperative demographics, age, comorbidities and postoperative complications were recorded. Perioperative operating room and hospital data were analyzed. Functional outcome measurements including ASES, SF-36 physical component (PC) scores, mental component (MC) scores and visual analog scale along with general health and fatigue were evaluated at the 0 and 2 year time period. Statistical analyses were performed.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 10 | Pages 1339 - 1343
1 Oct 2012
Cross MB Dolan MM Sidhu GS Nguyen J Mayman DJ Su EP

The purpose of this study was to compare the amount of acetabular bone removed during hip resurfacing (HR) and cementless total hip replacement (THR), after controlling for the diameter of the patient’s native femoral head. Based on a power analysis, 64 consecutive patients (68 hips) undergoing HR or THR were prospectively enrolled in the study. The following data were recorded intra-operatively: the diameter of the native femoral head, the largest reamer used, the final size of the acetabular component, the size of the prosthetic femoral head and whether a decision was made to increase the size of the acetabular component in order to accommodate a larger prosthetic femoral head. Results were compared using two-sided, independent samples Student’s t-tests. A statistically significant difference was seen in the mean ratio of the size of the acetabular component to the diameter of the native femoral head (HR: 1.05 (sd 0.04) versus THR: 1.09 (sd 0.05); p <  0.001) and largest acetabular reamer used to the diameter of the native femoral head (HR: 1.03 (sd 0.04) versus THR: 1.09 (sd 0.05); p < 0.001). The ratios varied minimally when the groups were subdivided by gender, age and obesity. The decision to increase the size of the acetabular component to accommodate a larger femoral head occurred more often in the THR group (27% versus 9%). Despite the emphasis on avoiding damage to the femoral neck during HR, the ratio of the size of the acetabular component to the diameter of the native femoral head was larger in cementless THR than in HR.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XL | Pages 9 - 9
1 Sep 2012
Cross MB Plaskos C Nam D Egidy C Nguyen J Lyman S Pearle A Mayman DJ
Full Access

Purpose

Our aim was to compare the passive kinematics and coronal plane stability throughout flexion in the native and the replaced knee, using three different TKA designs: posterior stabilized (PS), bi-cruciate substituting (BCS), and ultracongruent (UC). Our hypotheses were: 1.) a guided motion knee replacement (BCS) offers the closest replication of native knee kinematics in terms of femoral rollback 2.) the replaced knee will be significantly more stable in the coronal plane than the native knee; 3.) No difference exists in coronal plane stability between the 3 implants/designs throughout flexion.

Methods

After IRB approval, two cadaveric specimens were used for a pilot study to determine sample size. Five fresh-frozen hip-to-toe cadaveric specimens then underwent TKA using an anatomic measured resection technique with a computer-navigated robotic femoral cutting-guide. The PS, BCS, and UC TKA designs were implanted in each knee using the same distal and posterior femoral cuts to standardize the position of the implants. Computer navigation was then utilized to record the varus/valgus laxity of each implant at 0°, 30°, 60° and 90° of flexion while applying a standardized 9.8Nm moment.

Passive tibiofemoral kinematics were measured in a continuous passive motion machine from 10° to 110°. Femoral rollback on the tibia was calculated for the native and replaced knees by measuring the closest point (CP) on the femoral condyle to a transverse plane perpendicular to the mechanical axis of the tibia at each flexion angle.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_I | Pages - 37
1 Mar 2002
Husson J Blond S Hieu PD Lazorthes Y Nguyen J Lapierre F Laugner B Djian M Bellow F
Full Access

Purpose: Since the introduction of spinal cord stimulation for the treatment of chronic neuropathies (Shealy, 1967), further development has identified indications. The objective of this prospective multicentric protocol was to quantify clinical and economical results in a homogeneous group of rigorously selected patients.

Material and methods: In 1999, nine university hospital centres recruited 43 patients (22 men, 21 women, mean age 50.8 years) with chronic postoperative neuropathic sciataligia insufficiently controlled by antiseizure and antidepressor (tricyclic) drugs. There were 34 unilateral cases and nine bilateral cases and 60% of the patients also had lombalgia. Diagnosis was established on the basis of history taking, clinical signs, and anatomic and electrophysiological findings. Indications for spinal cord stimulation were determined in a pluridisciplinary context including a psychological evaluation. A temporary test was made before implanting the programmable neurostimulator (Itrel®II or Itrel®3, Medtonic) in order to check that the induced paresthesia involved the painful territory. Included patients were assessed before implantation then at six (39 patients), 12 (30 patients) and 24 months after institution of the stimulation. At each follow-up visit, the clinical effect was assessed with validated pain scales (visual analogue scale, McGill Pain score, Oswestry incapacity score). Economical data were obtained from the medical file, patient interviews, and a specific therapeutic follow-up chart. Preliminary results (mean follow-up 10 months) are presented.

Results: Clinical scores improved 40 to 50% one year after implantation of the neurostimulator. There was significant relief of sciatalgia: on the visual analogue scale the mean pain score (7.8/10 before implantation) was 2.7/10 (p < 0.05) and 3.6/10 (p < 0.05) at six and 12 months after implantation. Drug prescriptions (antiseizure, antidepressors) were reduced by 70%. Residual treatments were prescribed for lumbalgia which was relieved little by stimulation. Annual expenditures (drugs + visits + non-drug treatments) was reduced by 1578 euros per patient (mean). Hospitalisation rate fell from 26% to 10% and the rate of resumed occupational activities was 11%

Discussion: Assessment of 24 patients after implantation of a neurostimulator will complete these early results.