Efficacy of intraarticular hyaluronic acid injections in knee osteoarthritis.

Intraarticular injections of hyaluronic acid have been advocated for treatment of symptomatic knee osteoarthritis. Appropriate indications and favorable patient response factors, such as radiographic disease severity and age, are not clearly defined for this therapy. The current review of 80 knees with symptomatic osteoarthritis treated with hyaluronic acid revealed that approximately 2/3 of treated knees received 2/3 relief of pain. Hyaluronic acid treatment is not appropriate for all patients with knee osteoarthritis. Overall, less than 50% of treated knees achieved satisfactory results, and only 35% reported increased activity. Twenty-two patients (28% of knees; 22 knees) underwent surgery within 7 months of their index injection, suggesting an inadequate response to treatment. The treatment is not without complication because 11 patients (15% of knees; 12 knees) experienced adverse reactions, including one case of septic arthritis. The authors recommend intraarticular hyaluronic acid only for patients with symptoms and significant surgical risk factors and for patients with mild radiographic disease in whom conservative treatment has failed (physical therapy, weight loss, nonsteroidal antiinflammatory medication, and intraarticular steroid injection). It is inadvisable to treat patients with a complete collapse of joint space or bone loss with intraarticular hyaluronic acid, given their poor clinical response.

Posterior stabilization in total knee arthroplasty with use of an ultracongruent polyethylene insert.

Fifty-three primary and 47 revision posterior cruciate ligament (PCL)-substituting total knee arthroplasties (TKAs) using a highly conforming (ultracongruent) polyethylene insert were retrospectively reviewed over a 48- to 106-month (mean, 60+/-11 months) follow-up period. These 100 knees were age and sex matched with another 100 TKAs performed using a PCL-sparing design. The ultracongruent design has an anterior buildup of 12.5 mm and a more conforming articular surface to match better the radius of the femoral component. In primary and revision TKAs, the average Hospital for Special Surgery knee score (P = .3) and range of motion (P = .43) were similar between the PCL-sparing and ultracongruent groups. In primary and revision TKAs, there were no revisions resulting from instability for patients receiving an ultracongruent insert versus 5 knees in the PCL-sparing control group secondary to subsequent postoperative anteroposterior instability and PCL insufficiency.

6- to 10-year experience using countersunk metal-backed patellas.

Three hundred two consecutive cementless total knee arthroplasties (Natural Knee, Intermedics Orthopedics, Inc., Austin, TX) were performed using a metal-backed, porous-coated patellar component. Fifty-nine patients died and 31 were lost to follow-up evaluation, resulting in 212 knees available for evaluation at 6 to 10 years. The mean follow-up period was 91 months. The mean modified Hospital for Special Surgery total knee score improved from 58 before surgery to 98 at the most recent follow-up visit. Mean patellar translation and tilt were 2.75 mm and 3.5 degrees, respectively. There were no patellar lucencies nor loosening. Eleven patients (5%) underwent revision of the patellar component. Overall patellar survivorship was 96%. Comparatively good results can be achieved with the use of a metal-backed patellar component if component design, surgical technique, and patellar alignment are properly addressed.

Patellar component medialization in total knee arthroplasty.

Intraoperative correction of patellar maltracking has traditionally involved the use of a lateral retinacular release. Problems, however, related to lateral retinacular release include increased postoperative pain and wound healing complications, compromised patellar blood flow, and longer rehabilitation. The purpose of this study was to assess the effect of patellar medialization in total knee arthroplasty. One hundred forty patients underwent total knee arthroplasty using the same components. Two groups of 70 patients each made up the study. Group 1 included patients whose patellar components were centralized on the patella, and group 2 consisted of patients in whom the patellar component was medialized to reproduce the patient's anatomic high point (ie, sagittal ridge). Lateral retinacular release was required in 45.5% of the patients in group 1 compared with 17% in group 2. The technique of patellar medialization is described.

Ideal thickness of Smith-Robinson graft for anterior cervical fusion. A cadaveric study with computed tomographic correlation.

To establish the optimal thickness for Smith-Robinson anterior cervical fusion grafts, anterior C4-5 discectomy and fusions were performed on six fresh, frozen cadavers. Plain radiographs and computed tomographic scans then were employed to correlate graft placement with changes in disc space height, foraminal height, and foraminal areas after 3-, 5-, 7-, and 9-mm interbody fusions. The ideal graft thickness appeared to be directly related to the preoperative baseline disc height. For a preoperative disc height of 3.5-6.0 mm, an interbody graft of 2 mm above baseline thickness was most appropriate. A thicker graft was required when the baseline disc height was smaller (2.0 mm) and a thinner graft when the disc height was larger (7.4 mm). No significant correlation was noted between disc space distraction at C4-5 and disc height, foraminal height, or foraminal area at adjacent levels.