Does It Matter: Total Hip Arthroplasty or Lumbar Spinal Fusion First? Preoperative Sagittal Spinopelvic Measurements Guide Patient-Specific Surgical Strategies in Patients Requiring Both.

Background: In patients requiring both total hip arthroplasty (THA) and lumbar spinal fusion (LSF), consideration of preoperative sagittal spinopelvic measurements can aid in the prediction of postfusion compensatory changes in pelvic tilt (PT) and inform adjustments to traditional THA cup anteversion. This study aims to identify relationships between spinopelvic measurements and post-THA hip instability and to determine if procedure order reveals a difference in hip dislocation rate.

Methods: Patients at a single practice site who received both THA and LSF between 2005 and 2015 (292: 158 = LSF prior to THA, 134 = THA prior to LSF) were retrospectively reviewed for incidents of THA instability.

Survivorship of the Modular Femoral Revision Stem.

The geriatric population represents a rapidly growing segment of society with prolonged life expectancies and more active lifestyles. Many of these patients have already undergone primary total hip arthroplasty (THA) and are presenting with aseptic loosening, polyethylene wear, osteolysis, or periprosthetic fractures. Therefore, the demand for hip revision procedures is expected to grow.

Aspirin Alone Is Not Enough to Prevent Deep Venous Thrombosis After Total Joint Arthroplasty.

Thromboembolic events after total joint arthroplasty are potentially devastating complications. This study evaluated the efficacy of 4 different anticoagulants in preventing deep venous thrombosis and pulmonary embolism after total joint arthroplasty. The demographics and anticoagulant use (warfarin, enoxaparin, and aspirin with and without outpatient mechanical pumps) for patients who underwent primary unilateral total joint arthroplasties performed by a single surgeon from January 2013 to October 2014 were retrospectively reviewed.

Alarmingly High Rate of Implant Fractures in One Modular Femoral Stem Design: A Comparison of Two Implants.

Background: Reports of implant fracture at the modular junction have been seen in modular neck designs, stem-sleeve modular femoral stems, and diaphyseal engaging bi-body modular stems. To date, however, there has never been a direct comparison between 2 different implant designs from the same modular family. The purpose of this study is to compare the rate of implant failure of 2 such stem-sleeve modular femoral stem designs, the S-ROM and Emperion, to further identify factors which increase the risk of this mode of failure.

Total Knee Arthroplasty in Obesity: In-Hospital Outcomes and National Trends.

Background: Both the prevalence of obesity and the utilization rate of total knee arthroplasty are increasing. The rate and proportion of total knee arthroplasty (TKA) performed in the setting of obesity/morbid obesity is increasing significantly over time.

Methods: Using International Classification of Diseases-Ninth Revision codes, we searched the National Hospitals Discharge Survey national database for patients admitted for primary TKA between 2001 and 2010.

National trends and in hospital outcomes for total hip arthroplasty in avascular necrosis in the United States.

Purpose: While a majority of total hip arthroplasty (THA) is performed for osteoarthritis (OA), a significant portion is performed in the setting of avascular necrosis (AVN). The purpose of this study is to evaluate recent trends, patient demographics, and in hospital outcomes for primary THA in the setting of AVN in the United States.

Methods: The National Hospital Discharge Survey database was searched for patients admitted to US hospitals after a primary THA for the years 2001-2010.

Factors influencing initial cup stability in total hip arthroplasty.

Background: One of the main goals in total hip replacement is to preserve the integrity of the hip kinematics, by well positioning the cup and to make sure its initial stability is congruent and attained. Achieving the latter is not trivial.

Methods: A finite element model of the cup-bone interface simulating a realistic insertion and analysis of different scenarios of cup penetration, insertion, under-reaming and loading is investigated to determine certain measurable factors sensitivity to stress-strain outcome.

Perioperative differences in conventional and computer-assisted surgery in bilateral total knee arthroplasty.

Performing bilateral total knee arthroplasties (bTKAs), sequential or staged, is a topic of debate among surgeons. To our knowledge, no studies have compared computer-assisted surgery (CAS) and conventional (CON) procedures for sequential bTKAs. We retrospectively reviewed 124 (62 CAS, 62 CON) sequential bTKAs.

Finite element analysis of resurfacing depth and obliquity on patella stress and stability in TKA.

Patella resurfacing in total knee arthroplasty (TKA) reduces postoperative complications and revisions; however, the optimal cutting depth and angle that minimize patellar strain and fracture remain unclear. We performed three-dimensional finite element analysis (FEA) of resurfacing cutting depth and obliquity to assess the stresses in each component of the knee joint, and fatigue testing to determine cyclic loading conditions over the expected life span of the implant. Maximum stress on the patella increased as cutting depth increased up to 8mm; peak stresses on the idealized button further increased at 10-mm depth.

Rotating platform revision total knee arthroplasty.

Although revision total knee arthroplasty (TKA) procedures are successful in relieving pain and restoring function in failed knees, long-term results are inferior to primary procedures. Mobile bearing (MB) revision knees can potentially improve functional performance. Clinical results of 44 MB rotating platform (RP) revision TKAs demonstrated mean knee injury and osteoarthritis outcome score (KOOS) activity of daily living score of 77 2 years postoperatively.

Mid-term survivorship results for a rotating-platform knee prosthesis.

Interest in mobile-bearing knee prostheses is increasing in the US market. We studied results at 2 to 5 years with a mobile-bearing system that includes a cobalt-chrome tibial tray and femoral component with a polyethylene cruciate-retaining tibial component insert that allows rotation around a central axis and can be used with cruciate-retaining or posterior-stabilized femoral components. The inserts used in this study were cruciate retaining and did not include the posterior-stabilized design.

Unilateral vs bilateral total knee arthroplasty risk factors increasing morbidity.

Because surgeons are electing to perform simultaneous bilateral total knee arthroplasty (TKA), it is important to identify which patients are at increased risk. We performed a retrospective cohort analysis of 150 patients with unilateral TKA vs 150 patients with simultaneous bilateral TKA. The bilateral group demonstrated a 2.

Acetabular cup revision with the use of the medial protrusio technique at an average follow-up of 6.6 years.

A significant rim defect encountered during revision surgery can make stable cementless cup fixation difficult. One approach to this problem is to medialize the acetabular cup to improve the degree of rim contact. In this study, we investigate this technique, termed the medial protrusio technique, for acetabular fixation in revision hip arthroplasty.

Comparison of patient satisfaction with incision cosmesis after standard and minimally invasive total hip arthroplasty.

This study evaluated patient assessments and attitudes regarding incision cosmesis following standard and minimally invasive total hip arthroplasty 1 to 3 years postoperatively. A cosmesis questionnaire designed to elicit a score evaluating scar satisfaction was mailed to patients. Although the difference in total cosmesis score between the standard and minimally invasive groups was not statistically significant, patients with a standard incision had better scores at <1 year.

Optimisation of the posterior stabilised tibial post for greater femoral rollback after total knee arthroplasty--a finite element analysis.

Femoral rollback after total knee arthroplasty (TKA) is necessary for flexion beyond 90-100 degrees. Femoral rollback in posterior cruciate substituting TKA occurs as a result of the interaction between the femoral cam and tibial post. The geometric design of the cam post mechanism determines the kinematics of rollback.

Dislocation of an S-ROM total hip arthroplasty secondary to traumatic femoral stem dissociation from the metaphyseal sleeve.

Modular total hip arthroplasty component dissociation has been reported. We describe a case of recurrent instability secondary to femoral stem dissociation from the proximal metaphyseal sleeve and resultant traumatic retroversion of the neck. Femoral stem revision was necessary for treatment of this rare complication.

Optimizing range of motion in cruciate-retaining mobile-bearing tka: experience with 2000 cases.

We describe experience with 2000 cruciate-retaining Sigma RP total knee arthroplasties performed between September 2000 to January 2006. All procedures were performed with a midvastus arthrotomy, medioposterior release, and posterior condylar clean-out technique. This implant design uses a congruent polyethylene bearing to diminish contact stress while allowing rotation between the polyethylene bearing surface and tibial tray.

Implant sizing of the P.F.C. sigma rotating-platform total knee system.

We studied the P.F.C.

Modular femoral component for conversion of previous hip surgery in total hip arthroplasty.

The conversion of previous hip surgery to total hip arthroplasty creates a durable construct that is anatomically accurate. Most femoral components with either cemented or cementless design have a fixed tapered proximal shape. The proximal femoral anatomy is changed due to previous hip surgery for fixation of an intertrochanteric hip fracture, proximal femoral osteotomy, or a fibular allograft for avascular necrosis.

Leg length inequality in total hip arthroplasty.

Postoperative leg length inequality after total hip arthroplasty frequently leads to medical liability issues because no standard exists regarding the acceptable disparity. Modular stems allow control of offset, independent sizing of the distal femoral anatomy, as well as proximal medullary sizing. The authors compared the restoration of leg length in two cohort protocols.

Posterior-lateral approach to minimal incision total hip arthroplasty.

As surgeons learn to perform minimally invasive hip arthroplasty procedures, the various techniques will evolve and one or two approaches may eventually become the standard. Currently, most of these procedures are reserved for the nonmorbidly obese patients; however, as techniques are perfected and surgeons gain experience, this patient population may eventually be served. Surgeons must present information to patients in a responsible manner and clarify the actual versus perceived advantages of the MITH.