Adam Brekke

Development of a New Knee Society Scoring System

BackgroundThe 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/purposesWe developed and validated a new Knee Society Scoring System.MethodsWe 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.ResultsWe 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.ConclusionsThe 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.

The Effect on External Rotation of an Anchor Placed Anterior to the Biceps in Type 2 SLAP Repairs in a Cadaveric Throwing Model

PURPOSE This study examined whether there is a difference in external rotation (ER) between type 2 SLAP repairs consisting of anchors placed only posterior to the biceps insertion compared with repairs with an additional anchor placed anterior to the biceps. METHODS Seven cadaveric shoulders from donors with a mean age of 39.4 years were tested. Type 2 SLAP lesions were created, followed by a 3-anchor repair: a standard repair with 2 anchors posterior to the biceps plus an additional anchor anterior to the biceps. The specimens were placed on a material testing system machine and rotation was measured under a constant torque. The sutures were then removed sequentially from anterior to posterior during testing. RESULTS The average ER of the intact shoulder was 115.7° ± 2.6°. After SLAP tear creation and cyclic loading, the ER was 118.5° ± 2.6°, which decreased to 116.5° ± 2.6° after repair. This corresponds to a reduction of 2.0° of ER (P < .0001) with the repair. After release of the anterior anchor, the ER increased to 117.9° ± 2.6°, which corresponds to an increase in shoulder motion of 1.4° of ER (P = .0011). Additional release of the middle anchor, leaving only the posterior anchor intact, resulted in 118.0° ± 2.7° of ER, which corresponds to an increase of only 0.1° of ER (P = .7667). CONCLUSIONS Following type 2 SLAP repair in the cadaveric shoulder, removing the effect of the anchor anterior to the biceps resulted in a small but statistically significant increase in ER. The anterior anchor had the greatest effect on ER. The presence of 1 or 2 anchors posterior to the biceps did not have a significant effect on rotation. CLINICAL RELEVANCE When performing SLAP repairs on those in whom even a small loss of ER would be detrimental, such as baseball pitchers, avoidance of the use of an anchor anterior to the biceps should be considered.

The Financial Impact of Joint Registries in Identifying Poorly Performing Implants

We analyzed the effect of the Australian National Joint Registry on the cost of joint arthroplasty through identification of implants with higher than expected failure rates. From 2003 to 2007, 242,454 primary joint arthroplasties were performed in Australia at a total cost of

Commonalities, differences, and challenges with patient-derived outcome measurement tools: function/activity scales.

4.1 billion. Of these cases, 19,224 were performed using components identified by the Registry as poorly performing. If all of these cases were performed using average-performing designs, the number of revisions would have dropped by 28.6%. We also predicted that over a 5-year period after Registry identification, 32,807 primary procedures would be performed using poorly performing implants. If implants of average longevity were selected instead, we predict that 25.8% fewer revision procedures would be needed, ranging from 7% in unicompartmental knee replacement to 47% in total hip arthroplasty. This change in practice is expected to save 10.2% of direct costs, corresponding to

Influence of Gender on Age of Treatment with TKA and Functional Outcome

14 million over a 5-year period.

Scoring Systems and Their Validation for the Arthritic Knee

BackgroundThere is a critical need to evaluate the success of orthopaedic treatments through valid outcome measures. Previous attempts to express patient outcomes using a single aggregate score led to scores that were ambiguous, often insensitive to change, and poorly correlated with the patient’s assessment of the outcome of surgical procedures.Where Are We Now?Numerous patient-reported outcome measurement tools have been developed for assessment of patients’ level of activity and functional status, especially after joint arthroplasty. However, most tools assume an idealized set of prescribed activities independent of the age, activity level, and lifestyle of each individual. Few instruments are designed to capture the priorities of individual patients, especially those involved in high-demand sporting and recreational activities.Where Do We Need to Go?We need valid outcome measures that provide a meaningful, individualized assessment of the functional status of each patient, taking into account the lifestyle and expectation of each individual. This advance in outcome measurement will allow clinicians to individualize treatment and provide patients with an accurate estimate of the outcome of alternative treatments and procedures.How Do We Get There?Much more comprehensive information is needed to characterize the activities, abilities, and physical aspirations of individual patients. This could form a database for the development of predictive models relating individual characteristics to functional outcomes. Statistical tools are needed to minimize the burden on patients in completing questionnaires to access predictive data and to ensure that all outcome assessments are psychometrically valid.