Lateral Patellar Facet Impingement After Primary Total Knee Arthroplasty: It Does Exist

The existence of the diagnosis “lateral patellar facet impingement” (LPFI) is controversial and the outcomes for surgical revision for symptomatic LPFI uncertain. We found that of the 3361 index knee revisions performed at our institution from 1995 to 2008, eleven were done for symptomatic LPFI. Their clinical histories and radiographic imaging were reviewed before and after revision TKA and were also compared to a group of control patients. We found no statistically significant differences between the groups in preoperative KS pain and function scores or radiographic features. However, the combined findings of pain in the subpatellar/lateral aspect of the knee post TKA and radiographic lateral facet contact were significantly associated with revision due to LPFI. Surgical revision results were variable, but ~ 2/3 of the patients were satisfied with the operation and had a significant improvement in KS function scores.     

A Comparison of Patient-Reported and Measured Range of Motion in a Cohort of Total Knee Arthroplasty Patients

Range of motion (ROM) is an important component of the assessment of total knee arthroplasty (TKA) outcome. We compared patient-reported versus clinically observed ROM in a prospective cohort. Clinically observed ROM was measured using a goniometer by a trained research assistant. Self-reported ROM was estimated using a set of lateral knee photographs depicting varying levels of flexion and extension. All measures were taken pre-operatively, three, and six months postoperatively. We found statistically significant associations between self-reported ROM and clinically observed ROM for flexion and extension (all P < 0.001). We dichotomized flexion at 90° and found that self-report had a specificity of 94% and sensitivity of 65%. We conclude that patient-reported ROM may be a useful outcome measure for TKA.     

Total Hip Arthroplasty Using Large-Diameter Metal-On-Metal Articulation in Patients With Neuromuscular Weakness

The purpose of this prospective study was to evaluate the clinical and functional outcomes of THA using large-diameter metal-on-metal articulation in patients with neuromuscular weakness. Nineteen consecutive patients (19 hips) with neuromuscular weakness and displaced femoral neck fractures were enrolled. Functional improvement and recovery, radiological evaluation of THA and surgical morbidity were assessed. Mean Harris hip and WOMAC scores at final follow-up were 81.0 and 42.9, respectively. At final follow-up, no dislocation, metal hypersensitivity, or osteolysis was observed and no patient required revision of THA. The findings of this study indicate that the functional results of THA using large-diameter metal-on-metal articulation in patients with neuromuscular weakness can produce satisfactory outcomes with early functional recovery and a low dislocation rate.     

Plain Radiographs Fail to Reflect Femoral Offset in Total Hip Arthroplasty

Successful biomechanical reconstruction is a major goal in total hip arthroplasty (THA). We measured leg length (LL), global (GO) and femoral offset (FO) change on anteroposterior pelvis radiographs and on three-dimensional computed-tomography (3D-CT) with fiducial landmarks after cementless THA on 18 hips of cadaveric specimens. Measurements on radiographs were performed twice by four examiners and showed high interobserver (mean CCC ≥ 0.79) and intraobserver agreements (mean ICC ≥ 0.88). Mean differences between radiographic and 3D-CT measurements were 1.0 (SD 2.0) mm for LL, 0.6 (SD 3.6) mm for GO and 1.4 (SD 5.2) mm for FO. 1% of radiographic LL-, 15% of GO- and 35% of FO measurements were outside a tolerance limit of 5 mm. Radiographs seem acceptable for measuring LL/GO change but fail to reflect FO change in THA.     

Can Total Knee Arthroplasty Be Safely Performed Among Nonagenarians? An Evaluation of Morbidity and Mortality Within a Total Joint Replacement Registry

As the nonagenarian patient population continues to grow, more patients aged 90 and over will become candidates for total knee arthroplasty (TKA). This study evaluated the patient characteristics and incidence of postoperative morbidity and mortality of 216 nonagenarian TKA patients among 81,835 primary TKA patients followed by a total joint replacement registry. Nonagenarians had a greater number of comorbidities preoperatively, experienced a higher rate of deep vein thrombosis and 30 day mortality, and had a longer hospital length of stay. However, nonagenarians did not have an increased risk of infection nor pulmonary embolism and postoperative mortality was within expected rates for individuals 90 years and older. Higher readmission rates, however, highlight the benefits of close follow up during a prolonged postoperative period.     

Comparison of Intravenous versus Topical Tranexamic Acid in Total Knee Arthroplasty: A Prospective Randomized Study

The purpose of this study was to compare the efficacy of topical Tranexamic Acid (TXA) versus Intravenous (IV) Tranexamic Acid for reduction of blood loss following primary total knee arthroplasty (TKA). This prospective randomized study involved 89 patients comparing topical administration of 2.0 g TXA, versus IV administration of 10 mg/kg. There were no differences between the two groups with regard to patient demographics or perioperative function. The primary outcome measure, perioperative change in hemoglobin level, showed a decrease of 3.06 ± 1.02 in the IV group and 3.42 ± 1.07 in the topical group (P = 0.108). There were no statistical differences between the groups in preoperative hemoglobin level, lowest postoperative hemoglobin level, or total drain output. One patient in the topical group required blood transfusion (P = 0.342). Based on our study, topical Tranexamic Acid has similar efficacy to IV Tranexamic Acid for TKA patients.     

Outcomes of Total Hip Arthroplasty in Spastic Patients

Patients with spasticity and hip arthritis can present challenges to treatment. This investigation evaluated the effectiveness and safety of THA in patients with upper motor neuron disease. Twenty-seven consecutive patients with history of cerebral palsy (CP) or acquired spasticity (AS) underwent 30 THAs for treatment of hip arthritis. They were followed for an average 2.5 years (range 2.1–12.1). Patients with CP were more likely to require hip adductor release and hip flexor lengthening at the time of THA. Statistically significant improvements were made in Harris Hip Scores, pain scores, range of motion, ambulatory status, and the use ambulatory-assistive devices. There were no dislocations in this group. Patients with spasticity can benefit from THA in terms of pain relief and improved mobility with relatively low complications.     

Relationship Between Mechanical Axis-Derived and Anatomic Landmark-Derived Femoral Rotation in TKA: A Three-Dimensional CT Study

We sought to determine the relationship between the mechanical axis-derived and the anatomic landmark-derived femoral rotational axes using three dimensional computed tomographic images of 20 lower extremities. The mechanical axis-derived femoral rotational axis was created on the distal articular surface of the femur using coronal mechanical limb axis and the reconstructed images of the femur. Then, we measured the angular difference between mechanical axis-derived and anatomic landmark-derived femoral rotational axes. The mechanical axis-derived femoral rotational axis was externally rotated with a mean of 2.2° (range, 0 to 4.7°; SD, 1.0) compared with the surgical epicondylar axis. Our findings should be considered to obtain a proper femoral rotational axis in total knee arthroplasty.     

The Effect of Chronic Kidney Disease on Total Hip Arthroplasty

Patients with chronic kidney disease (CKD) undergoing total hip arthroplasty (THA) were evaluated for risk of revision, surgical site infection (SSI), thromboembolic events, mortality and readmission. 20,720 primary TKA cases were included (smaller sample for readmission evaluation, N = 9322). The prevalence of CKD among THA patients was 6.1% (N = 1269). After adjustment for age, gender, race, general health, and diabetes, CKD patients were at 1.4 (95% confidence interval 1.1–1.8) increased risk of readmission within 90 days. The adjusted risks for revision (overall, aseptic, and septic), SSI (deep and superficial), deep vein thrombosis, pulmonary embolism, and mortality (30-day, 90-day, ever) were not significantly different between patients with CKD and those without CKD. However, increased risk for 90-day readmission underscores that CKD patients are a fundamentally different population of patients.     

Are There Identifiable Risk Factors and Causes Associated with Unplanned Readmissions Following Total Knee Arthroplasty?

We conducted a retrospective review of 3218 primary total knee arthroplasties (TKA) performed over two years at an urban academic hospital network using clinical and administrative data. Increased length of stay (LOS) was associated with readmission (P < 0.001). Readmission was not associated with age (P = 0.100), gender (P = 0.608), body mass index (P = 0.329), or staged bilateral procedures (P = 0.420). The most common readmitting diagnoses were post-operative infection (22.5%), hematoma (10.1%), pulmonary embolus (7.9%) and deep vein thrombosis (5.6%). Of readmissions, 53.9% were for surgical reasons and 46.1% were for medical reasons. Certain interventions described in previous literature may be more successful in minimizing unplanned readmissions by focusing on patients with extended LOS, elevated infection risk and low socioeconomic status.