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.
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. 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).Introduction
Methods
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. 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.Introduction
Methods
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. 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.Summary Statement
Introduction
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. 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.Background:
Methods:
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. 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.Introduction
Methods
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. 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.Purpose
Methods
