The Knee Society Short Form Reduces Respondent Burden in the Assessment of Patient-reported Outcomes.

BACKGROUND: The patient's own evaluation of function and satisfaction is a fundamental component of assessing outcomes after total knee arthroplasty (TKA). The new Knee Society Knee Score was introduced in 2012 and has been shown to be a valid and reliable instrument for measuring the outcome of TKA. This score combines an objective, physician-derived component and a patient-reported component to characterize the expectations, satisfaction, and functional activities of diverse lifestyles of contemporary patients undergoing TKA. However, in the routine clinical setting, the administration and scoring of outcome measures is often resource-intensive, as the expenditure of time and budget for outcome measurement increase with the length and complexity of the instrument used, and so a short-form assessment can help to reduce the burden the assessment of outcomes. QUESTIONS/PURPOSES: The purposes of this study were (1) to develop a short-form version of the new Knee Society Knee Score; (2) to validate the short form against the full Knee Society Knee Score; and (3) to evaluate the responsiveness to treatment (TKA) of the new Knee Society short-form assessment. METHODS: To develop the short form, data from the sample of 497 patients recruited during validation of the original long form the new Knee Society Knee Score were used. The multicenter study was approved by the institutional review boards at 15 participating medical institutions within the United States and Canada. An analytic item reduction approach was applied simultaneously but separately to preoperative and postoperative patient-reported data to select a subset of items from the original form that had good measurement properties and closely reflected the scores obtained using the original form. RESULTS: Expectations and satisfaction were reflected by a single item in the newly developed short form compared with a total of five satisfaction and three expectation items in the long form. The functional activities subscale was reduced from 17 to six items. An excellent correlation was demonstrated between function scores derived from the functional activities subscale of the original long-form score (17 items) and the six-item short form (r = 0.97; p < 0.01). The sample mean difference between the two scores was less than 4 points with a SD of 6.7 points. The short form was capable of discriminating clinically different groups of patients before and after TKA with virtually the same estimated effect size as the original functional activities subscale of the new Knee Society Knee Score. CONCLUSIONS: The Knee Society Knee Score long form is still recommended for research studies and for more sensitive measurement of the outcomes of individual patients. However, for general clinical use with large patient populations, the short form is expected to improve the rate of patient completion while also being easier to administer. In this study, we found the short-form version of the Knee Society Knee Score to be practical, valid, reliable, and responsive for assessing the functional outcome of TKA.

Are Routine Blood Salvage/Preservation Measures Justified in All Patients Undergoing Primary TKA and THA?

A sequential series of 366 primary total knee arthroplasties and 320 total hip arthroplasties was reviewed to determine the incidence of allogeneic transfusion. Surgery was performed under regional anesthesia and all patients had a hemovac drain for 24°. Tourniquet hemostasis in TKA was maintained through wound closure. Coumadin, SCD and TED hose were utilized for DVT prophylaxis. No additional blood conservation measures were employed. The transfusion incidence in primary TKA was 2.2% (males .6%/females 3.5%). The transfusion incidence in THA was 1.9%, (males .8%/females 2.6%). The low incidence of allogeneic transfusion in a contemporary series of primary TKA and THA, especially in males, would question the need for routine blood preservation techniques in this group of patients.

Development of a new Knee Society scoring system.

BACKGROUND: The Knee Society Clinical Rating System was developed in 1989 and has been widely adopted. However, with the increased demand for TKA, there is a need for a new, validated scoring system to better characterize the expectations, satisfaction, and physical activities of the younger, more diverse population of TKA patients. QUESTIONS/PURPOSES: We developed and validated a new Knee Society Scoring System. METHODS: We developed the new knee scoring system in two stages. Initially, a comprehensive survey of activities was developed and administered to 101 unilateral TKA patients (53 women, 48 men). A prototype knee scoring instrument was developed from the responses to the survey and administered to 497 patients (204 men, 293 women; 243 postoperatively, 254 preoperatively) at 15 medical institutions within the United States and Canada. Objective and subjective data were analyzed using standard statistical and psychometric procedures and compared to the Knee Injury and Osteoarthritis Score and SF-12 scores for validation. Based on this analysis, minor modifications led to the new Knee Society Scoring System. RESULTS: We found the new Knee Society Scoring System to be broadly applicable and to accurately characterize patient outcomes after TKA. Statistical analysis confirmed the internal consistency, construct and convergent validity, and reliability of the separate subscale measures. CONCLUSIONS: The new Knee Society Scoring System is a validated instrument based on surgeon- and patient-generated data, adapted to the diverse lifestyles and activities of contemporary patients with TKA. This assessment tool allows surgeons to appreciate differences in the priorities of individual patients and the interplay among function, expectation, symptoms, and satisfaction after TKA.

Bone marrow edema pattern in advanced hip osteoarthritis: quantitative assessment with magnetic resonance imaging and correlation with clinical examination, radiographic findings, and histopathology.

OBJECTIVE: To correlate the amount of bone marrow edema (BME) calculated by magnetic resonance imaging(MRI) with clinical findings, histopathology, and radiographic findings, in patients with advanced hip osteoarthritis(OA). MATERIALS AND METHODS: The study was approved by The Institutional Human Subject Protection Committee. Coronal MRI of hips was acquired in 19 patients who underwent hip replacement. A spin echo (SE) sequence with four echoes and separate fast spin echo (FSE) proton density (PD)-weighted SE sequences of fat (F) and water (W) were acquired with water and fat suppression, respectively. T2 and water:fat ratio calculations were made for the outlined regions of interest. The calculated MRI values were correlated with the clinical, radiographic, and histopathologic findings. RESULTS: Analyses of variance were done on the MRI data for W/(W + F) and for T2 values (total and focal values) for the symptomatic and contralateral hips. The values were significantly higher in the study group. Statistically significant correlations were found between pain and total W/(W + F), pain and focal T2 values, and the number of microfractures and calculated BME for the focal W/(W + F) in the proximal femora. Statistically significant correlations were found between the radiographic findings and MRI values for total W/(W + F), focal W/(W + F) and focal T2 and among the radiographic findings, pain, and hip movement. On histopathology, only a small amount of BME was seen in eight proximal femora. CONCLUSION: The amount of BME in the OA hip, as measured by MRI, correlates with the severity of pain, radiographic findings, and number of microfractures.

Fracture fixation.

The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of the injured bone, and to return early mobility and full function of the injured extremity. Fractures can be treated conservatively or with external and internal fixation. Conservative fracture treatment consists of closed reduction to restore the bone alignment. Subsequent stabilization is then achieved with traction or external splinting by slings, splints, or casts. Braces are used to limit range of motion of a joint. External fixators provide fracture fixation based on the principle of splinting. There are three basic types of external fixators: standard uniplanar fixator, ring fixator, and hybrid fixator. The numerous devices used for internal fixation are roughly divided into a few major categories: wires, pins and screws, plates, and intramedullary nails or rods. Staples and clamps are also used occasionally for osteotomy or fracture fixation. Autogenous bone grafts, allografts, and bone graft substitutes are frequently used for the treatment of bone defects of various causes. For infected fractures as well as for treatment of bone infections, antibiotic beads are frequently used.

Joint arthroplasties and prostheses.

Joint arthroplasty is the most frequently performed orthopedic procedure after fracture fixation. The major indications for any joint replacement are degenerative joint disease, inflammatory arthropathy, avascular necrosis, and complicated fractures. The major contraindications for any joint arthroplasty are systemic and joint infection and a neuropathic joint. The interpretation of radiographs in cases of joint arthroplasty is a significant part of many radiology practices, and correct recognition of the prosthetic devices and their complications by the radiologist is important. The article reviews the most common types of joint arthroplasties and prostheses of the upper and lower extremities and discusses the most frequent complications associated with their placement.

The effect of implant constraint on results of conversion of unicompartmental knee arthroplasty to total knee arthroplasty.

A series of unicompartmental knee arthroplasty (UKA) revision to total knee arthroplasty (TKA) was compared to a group of primary TKAs performed at the same institution. The UKA revision group had a higher incidence of local wound complications and inferior clinical results as measured by Knee Society scores. When the revisions were stratified by the degree of interface constraint, knees revised with posterior cruciate ligament (PCL) substituting designs had superior knee scores that were comparable to the primary group. The use of a PCL-substituting knee design is recommended when converting a UKA to TKA.