A Medial Subvastus Approach for Lateral Unicompartmental Knee Arthroplasty: Technique Description and Early Outcome Results.

Background: Unicompartmental knee arthroplasty (UKA) treats arthritis involving only one compartment of the knee. Lateral UKA is mainly performed through medial parapatellar or lateral parapatellar approaches to the knee. This technique article introduces a medial subvastus approach to lateral UKA, discusses the clinical rationale behind its use, and offers a preliminary retrospective study on short-term outcomes of lateral UKAs using the lateral vs medial subvastus approaches.

Prevalence of Postoperative Periprosthetic Femur Fractures Between Two Different Femoral Component Designs Used in Direct Anterior Total Hip Arthroplasty.

Background: Periprosthetic femur fractures are a well-documented complication following direct anterior uncemented total hip arthroplasty. The purpose of this study is to compare the prevalence of postoperative periprosthetic femur fractures between 2 different femoral component designs used in direct anterior total hip arthroplasty.

Methods: Beginning in February 2015, a single fellowship-trained adult reconstruction surgeon performed 361 consecutive direct anterior total hip replacements using a flat, single-taper, wedged femoral implant.

Is Physician Quality Reporting System Worth the Cost to Report to Center for Medicare and Medicaid Services?

Background: The Center for Medicare and Medicaid Services (CMS) has proposed a move to payment based on patient-reported outcomes (PROs), and failure to report on PROs will result in a penalty of 2% in 2016. However, the cost to the physician to collect PROs is not known.

Methods: Using data from the 2013 Medical Group Management Association Compensation and Financial survey and Center for Medicare and Medicaid Services reimbursement, a calculation was performed to determine the cost to the physician to report on PROs for patients undergoing total knee arthroplasty and total hip arthroplasty.

The Location and Severity of Preoperative Subchondral Bone Marrow Lesions Were Not Associated With Inferior Postoperative Outcomes After Medial Unicompartmental Knee Arthroplasty or Total Knee Arthroplasty.

Background: Inferior outcomes for medial unicompartmental knee arthroplasty (UKA) patients with preoperative medial tibial bone marrow lesions (BMLs) were recently reported. The purpose of this study was to compare the location and severity of BML on postoperative outcomes after medial UKA and TKA using a larger sample size and more rigorous magnetic resonance imaging (MRI) evaluation.

Methods: BML were graded on preoperative MRIs from 174 UKAs performed between 2009 and 2013 using the MRI Osteoarthritis Knee Score criteria.

Greater Medial Compartment Forces During Total Knee Arthroplasty Associated With Improved Patient Satisfaction and Ability to Navigate Stairs.

Background: The purpose of this study was to determine if postoperative patient satisfaction, subjective outcomes, and functional force testing differed between those with symmetric or asymmetric intraoperative mediolateral (ML) compressive forces. We hypothesized that the threshold would be similar to the previously reported valued of 15 lbf and that a significantly greater proportion of those with more symmetrical medial and lateral compressive forces would be satisfied with their total knee arthroplasty.

Methods: A commercially available instrumented trial tibial liner was used to measure ML compressive force differences with the knee at 0°, 20°, and 90°.

An Intact Anterior Cruciate Ligament at the Time of Posterior Cruciate Ligament-Retaining Total Knee Arthroplasty Was Associated With Reduced Patient Satisfaction and Inferior Pain and Stair Function.

Background: Patients with an intact anterior cruciate ligament (ACL) at the time of ACL-sacrificing total knee arthroplasty (TKA) have been suggested to have inferior outcomes compared with those with a dysfunctional ACL. However, to date, no published clinical studies have evaluated the potential link between the condition of the ACL at the time of posterior cruciate ligament-retaining TKA and postoperative pain, function, and satisfaction. As such, the purpose of this study was to compare subjective function, movement-elicited pain, pain at rest, and patient satisfaction between those with an intact or dysfunctional ACL.

Subchondral Bone Marrow Edema Had Greater Effect on Postoperative Pain After Medial Unicompartmental Knee Arthroplasty Than Total Knee Arthroplasty.

Background: Although the relationship between pain and bone marrow edema (BME) in the osteoarthritic knee has been established, little is known about the effect of preoperative BME on postoperative outcomes after knee arthroplasty or if the influence of BME on postoperative outcomes differs between medial unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). The purpose of this study was to compare pain, patient satisfaction, and revision rates between medial UKA and TKA patients with and without magnetic resonance imaging evidence of BME in the proximal tibia.

Methods: We identified 71 patients (72 knees) from our prospective outcomes database with magnetic resonance images taken before undergoing either medial UKA or TKA and recorded the absence or presence of tibial BME.

Comparison of Patient Function during the First Six Weeks after Direct Anterior or Posterior Total Hip Arthroplasty (THA): A Randomized Study.

The purpose of this single-surgeon randomized study was to determine if functional recovery during the early postoperative period differs between the direct anterior (DAA) and posterior approaches (PA). An a priori power analysis indicated that 26 patients per group were needed, and 6-week follow-up data were available for 51 THAs to date. Hospitals stays were significantly shorter for the DAA group (1.

Patients with Pain 60 to 120 Days after Total Knee Arthroplasty More Likely to be Dissatisfied at Mid-Term Follow-Up.

The purpose of this study was to determine if TKA patients with pain between 60 and 120 days are more likely to be dissatisfied at mid-term follow-up. At the 60-120 day follow-up, moderate to severe movement-elicited pain (MEP) and pain at rest (PAR) were reported by 25/316 TKAs (7.9%) and 44/316 TKAs (13.

Chronic Non-Orthopedic Conditions More Common in Patients with Less Severe Degenerative Changes That Have Elected to Undergo Total Knee Arthroplasty.

The purpose of this study was to determine whether the prevalence of chronic non-orthopedic conditions that may play a role in an abnormal pain response differs between patients based on the severity of degenerative changes at the time of surgery. Of 1020 OA knees that had undergone primary TKA with a minimum 2year follow-up, we identified 117 (11.5%) that had less severe degenerative changes.

Assessing the utility of routine first annual follow-up visits after primary total knee arthroplasty.

The combination of increased TKA utilization and a decreased number of arthroplasty specialists has resulted in a growing need to maximize efficiency without sacrificing the level of care being provided. The purpose of this study was to evaluate the utility of routine first annual follow-up visits for patients that have undergone primary TKA. Of 339 TKAs performed by a single surgeon in 2012, 23% failed to attend scheduled first annual visits.

Greater prevalence of wound complications requiring reoperation with direct anterior approach total hip arthroplasty.

The purpose of this retrospective study was to compare wound complication rates between primary THAs performed via a posterior or direct anterior approach. From our prospective outcomes registry, we identified 1288 primary THAs performed via a posterior approach and 505 via a direct anterior approach. The direct anterior approach resulted in a significantly greater number of wound complications that required reoperation than the posterior approach (7/505 (1.

Patient and intraoperative factors influencing satisfaction two to five years after primary total knee arthroplasty.

The purpose of this study was to compare patient demographics and factors recorded at the time of surgery between patients that were either satisfied or dissatisfied with their TKA at mid-term follow-up. From our prospective outcomes database, 989 primary TKAs with complete preoperative and intraoperative data were identified. At mean follow-up of 3.

Clinical comparison of THA with a standard-length or short femoral component.

The purposes of this 2-part study were to determine whether reduced distal femoral component geometry allows for routinely larger component sizes to be used and whether clinical or radiographic outcomes differ between total hip arthroplasty (THA) patients treated with either standard-length or short femoral components. Femoral component size and ongrowth surface area were retrospectively compared in a group of bilateral THA patients that had both a standard-length component and a contralateral short component. Then, clinical and radiographic outcomes were compared between matched groups of THA patients that had either a standard-length or short femoral component.

Factors influencing patient satisfaction two to five years after primary total knee arthroplasty.

Between 15% and 20% of primary total knee arthroplasty (TKA) patients have been reported to be dissatisfied with the procedure. With 2 to 5 year follow-up of 768/959 (80%) cruciate-retaining TKAs performed by a single surgeon, we evaluated the prevalence of dissatisfied patients and determined which factors were most related to patient satisfaction. Of the 768 TKAs, 80 were dissatisfied with their procedure (10.

The natural progression of synovial fluid white blood-cell counts and the percentage of polymorphonuclear cells after primary total knee arthroplasty: a multicenter study.

Background: Assessments of the synovial fluid white blood-cell (WBC) count and percentage of polymorphonuclear cells (PMNs) have been reported to be useful in the diagnosis of periprosthetic joint infection. The purpose of this multicenter retrospective study was to evaluate the natural progression of the synovial fluid WBC count, PMN percentage, and total neutrophil count in patients who underwent knee aspiration during the first two years after primary total knee arthroplasty and had no evidence of periprosthetic joint infection.

Methods: From April 1999 to March 2012, 571 patients who presented within the first two years after primary total knee arthroplasty underwent knee aspiration as part of an evaluation for periprosthetic joint infection.

Errors in visual estimation of flexion contractures during total knee arthroplasty.

Aim: To quantify and reduce the errors in visual estimation of knee flexion contractures during total knee arthroplasty (TKA).

Methods: This study was divided into two parts: Quantification of error and reduction of error. To quantify error, 3 orthopedic surgeons visually estimated preoperative knee flexion contractures from lateral digital images of 23 patients prior to and after surgical draping.

Soft tissue releases affect the femoral component rotation necessary to create a balanced flexion gap during total knee arthroplasty.

The structures that were released to balance the extension gap were recorded during 1500 consecutive TKA procedures, and the amount of femoral component external rotation (ER) necessary to balance the flexion gap was measured with a tensiometer. The amount of ER necessary to balance the flexion gap significantly decreased as more medial structures were released (1 structure=4.7°, 2=4.

Effect of periarticular corticosteroid injections during total knee arthroplasty. A double-blind randomized trial.

Background: Multimodal pain-control protocols that include periarticular injections have been reported to decrease pain and improve early outcomes following total knee arthroplasty. While injections containing a corticosteroid have been demonstrated to be safe and effective, we are not aware of any randomized trials in which the specific effect of the corticosteroid on early postoperative outcomes has been evaluated. The purpose of this double-blind study was to compare the clinical efficacy of periarticular injections consisting of bupivacaine, morphine, epinephrine, clonidine, and cefuroxime as well as a corticosteroid (methylprednisolone acetate) with the efficacy of periarticular injections consisting of the same agents but without the inclusion of a corticosteroid.

Static and mobile antibiotic-impregnated cement spacers for the management of prosthetic joint infection.

Two-stage treatment is currently the most common approach for management of an infected joint prosthesis in the United States. Static antibiotic-impregnated polymethylmethacrylate cement spacers have traditionally been used; increasingly, however, mobile or articulating spacers are being utilized. Advocates of mobile spacers have cited potential advantages, including more effective maintenance of the joint space, allowing for limited weight bearing and facilitating joint motion; possible reduction in bone loss; and local delivery of antibiotics.

Correlations between knee society function scores and functional force measures.

Subjective evaluations often are used after knee arthroplasty to quantify function; however, these scores may be influenced by pain and/or function of the nonoperated limb. Multiple influences increase variability of these scores, which in turn may result in a greater change in score required to be considered clinically important. We determined the relationships among the Knee Society pain and function scores, range of motion (ROM), and functional force measures of the surgically treated and nonoperated limbs.

Sport activity after total hip arthroplasty: changes in surgical technique, implant design, and rehabilitation.

Over the past 10-15 years, many aspects of total hip arthroplasty (THA) have changed. First and foremost, the patients themselves have changed. Since 1990, the age group that has demonstrated the greatest increase in THA was patients between the ages of 45 and 64.

Electromyographic analysis of hip abductor exercises performed by a sample of total hip arthroplasty patients.

Weakness of the hip abductors after total hip arthroplasty may result in pain and/or functional limitation. Non-weight-bearing (NWB) exercises are often performed to target the hip abductors; however, muscle activation of NWB exercises has not been compared to weight-bearing (WB) exercises. Our purpose was to evaluate gluteus medius activation during 2 WB and 2 NWB hip abductor strengthening exercises.

Progressive subsidence of a tapered, proximally coated femoral stem in total hip arthroplasty.

The purpose of this study was to determine if subsidence of a tapered, proximally porous- and hydroxyapatite-coated femoral implant with immediate postoperative weight-bearing differed between men and women. Modified Harris Hip Pain and Function Scores were collected preoperatively, and six weeks and one year postoperatively. Femoral subsidence was determined at six weeks and one year after surgery.

Clinical performance of highly cross-linked polyethylenes in total hip arthroplasty.

Aseptic loosening secondary to wear-debris-induced osteolysis has been identified as the leading cause of late failure of total hip arthroplasty. Highly cross-linked polyethylene acetabular liners were developed as one approach to reducing this wear. Preclinical laboratory wear testing showed a number of cross-linked polyethylenes to have dramatically less wear than the polyethylene that had been in use for several decades.