Pain related to knee osteoarthritis (OA) is a complex phenomenon that cannot be fully explained by radiographic disease severity. We hypothesized that pain phenotypes are likely to be derived from a confluence of factors across multiple domains: knee OA pathology, psychology, and neurophysiological pain processing. The purpose of this study was to identify distinct phenotypes of knee OA, using measures from the proposed domains. Data from 3494 subjects participating in the Osteoarthritis Initiative (OAI) study was analyzed. Variables analyzed included: radiographic OA severity (Kellgren-Lawrence grade), isometric quadriceps strength, Body Mass Index (BMI), comorbidities, CES-D Depression subscale score, Coping Strategies Questionnaire Catastrophizing subscale score, number of pain sites, and knee tenderness on physical examination. Variables used for comparison across classes included pain severity, WOMAC disability score, sex and age. Latent Class Analysis was performed. Model solutions were evaluated using the Bayesian Information Criterion. One-way ANOVAs and post hoc least significance difference tests were used for comparison of classes.Introduction
Methods
Early postoperative strength loss is pronounced following total knee arthroplasty (TKA) and is largely the result of reduced muscular activation. High-intensity progressive rehabilitation may limit postoperative weakness and improve long-term outcomes, but no randomized controlled trials have examined its use after TKA. The purpose of this trial was to examine the efficacy of a high-intensity progressive rehabilitation protocol (HI) compared to a lower intensity (LI) rehabilitation protocol after TKA. One hundred and sixty-two subjects (aged 63±7 years, 89 females) were randomized to either the HI group or LI groups after TKA. The HI intervention consisted of an early initiation of intensive rehabilitation using progressive resistance exercise. The LI intervention was based on a synthesis of previously published standard TKA rehabilitation programs. Both groups were treated 2–3 times per week for 12 weeks. Outcomes included the stair climbing test, timed-up-and-go test, five-times sit-to-stand test, 6-minute walk test, isometric quadriceps and hamstring strength, quadriceps activation, surgical knee range of motion, and WOMAC. Secondary analysis evaluated whether outcomes differed depending on post-operative quadriceps activation. Outcomes were assessed preoperatively and at 1, 2, 3, 6, and 12 months postoperatively.INTRODUCTION
METHODS
Orthopaedic treatment of upper and lower extremities has traditionally been attended by specialists in specific areas of expertise; arthroscopy, biologic reconstruction, total joint replacement. In many specialty centers of the US and worldwide, procedures performed by specialists do not consistently coincide with subspecialty training. This is particularly true for hip surgery, where a majority of total hip arthroplasty (THA) procedures are performed by Orthopaedists that undertake less that 50 fifty such procedures annually. With advances in knowledge and technique, surgical hip treatments have significantly progressed in recent decades. By all estimates, there is a need for specialized surgical treatment in this area, as the demand for hip replacement and revision is likely to far outpace that of population growth in the coming decades. Discreet categories of replacement versus preservation have become less clear, thus paving the way for an emerging specialty of exclusive hip surgery. The scope of such surgery encompasses an age span from the adolescent at skeletal maturity to elderly. Advances in hip arthroscopy have improved outcomes for young patients. Progressive data and knowledge have fueled biologic non-arthroplasty solutions in the hip such as osteotomy and surgical hip dislocation for femoral acetabular impingement. Development of limited replacement options such as resurfacing have also broadened the spectrum of treatments and added to the level of complexity in hip surgery. Total hip arthroplasty and revision numbers continue to climb annually. Combining preservation procedures with options for replacement and resurfacing, the hip specialty creates a continuum of medical care that may redefine the joint care paradigm.
