What Determines the Success of Closed-Wedge High Tibial Osteotomy: Severity of Malalignment, Obesity, Follow-up Period, or Age?

OBJECTIVES: High tibial osteotomy (HTO) is a well-established procedure for the treatment of medial knee osteoarthritis originating from malalignment of the lower extremity. The current study was designed to evaluate the clinical and radiographic results of closed-wedge HTO for the treatment of medial knee osteoarthritis and to reveal factors affecting the outcome. METHODS: A retrospective study was conducted with 138 patients who were operated on for medial knee osteoarthritis between 2000 and 2007 using closed-wedge HTO. Preoperative and follow-up physical examination findings, body mass index (BMI) values, and Hospital for Special Surgery (HSS) and Lysholm knee scores were reviewed. Radiographic evaluation included measurement of the mechanical axis preoperatively and the most recent follow-up orthoroentgenograms. The follow-up knee scores were evaluated according to preoperative mechanical axis, obesity, age, follow-up period, and gender of the patient. The mechanical axis measurement was assessed based on obesity, age, and follow-up period. RESULTS: The mean preoperative and latest follow-up mechanical axis was 4.92o±4.24o varus and 3.43o±3.74o valgus, respectively (p=0.0001). Improvement in the Lysholm (p=0.0001) and HSS (p=0.0001) knee scores was significant. The preoperative mechanical axis, obesity, follow-up period, and gender had no negative effect on the follow-up knee scores, whereas a preoperative age over 50 years had a negative effect on the follow-up knee score. Obesity and the length of the postoperative follow-up period did not have a negative effect on the postoperative mechanical axis, whereas a preoperative age over 50 had a negative effect on the postoperative mechanical axis. CONCLUSION: The results of this study suggest that medial knee osteoarthritis may be treated successfully with closed-wedge HTO. The analysis indicated that factors such as obesity, the degree of preoperative deformity, and gender do not adversely affect the success of treatment. However, a preoperative age over 50 adversely affected the outcome.

Tibiofemoral Instability After Primary Total Knee Arthroplasty: Posterior-Stabilized Implants for Obese Patients.

Tibiofemoral instability is a common complication after total knee arthroplasty (TKA), accounting for up to 22% of all revision procedures. Instability is the second most common cause of revision in the first 5 years after primary TKA. In this study, 13 knees with tibiofemoral instability after TKA were identified among 693 consecutive primary TKA procedures. Patient demographics, body mass index, clinical symptoms, previous deformity, previous knee surgery, complications, interval between index TKA and first tibiofemoral instability, causes of instability, and interval between index TKA and revision TKA were retrospectively reviewed. Clinical outcomes were assessed with the Lysholm Knee Scoring Scale. All patients were women, and mean body mass index was 37.7 kg/m2 (range, 27.2-52.6 kg/m2). Mean interval between index TKA and first tibiofemoral instability was 23.4 months (range, 9-45 months), and mean interval between index TKA and revision TKA was 25.6 months (range, 14-48 months). All patients had posterior cruciate ligament-retaining implants. Of the 13 knees, 11 had flexion instability and 2 had global instability. In all patients, instability was caused by incompetence of the posterior cruciate ligament; additionally, 1 patient had undersized and malpositioned implants. In 4 knees, the polyethylene insert was broken as well. All patients underwent revision TKA. Lysholm Knee Scoring Scale score had improved from a mean of 35.8 (range, 30-46) to a mean of 68.3 (range, 66-76). All patients included in this study were female and obese. The main cause of instability was secondary posterior cruciate ligament rupture and incompetence. The use of posterior-stabilized implants for primary TKA may prevent secondary instability in obese patients. [Orthopedics. 2017; 40(5):e812-e819.].

Total knee arthroplasty after osseous ankylosis of the knee joint.

OBJECTIVE: A knee fusion is associated with considerable restrictions, including the inability to sit properly, use public transportation, and climb stairs. The purpose of this study is to report and discuss our cases of spontaneous ankylosed knees which were taken down and underwent total knee arthroplasty (TKA). METHODS: Six patients who experienced spontaneous ankylosis of the knee undergoing conversion to TKA between 2003-2012 were enrolled retrospectively in this study. The etiology was childhood pyogenic arthritis in 2 patients, intraarticular fractures in 2, gunshot in 1, and juvenile rheumatoid arthritis in 1. The clinical data were recorded with the use of the Hospital for Special Surgery (HSS) knee rating system, Western Ontario and McMaster Questionnaire (WOMAC), and Visual Analog Scale (VAS), preoperatively and postoperatively at final follow-up. RESULTS: The average follow-up time was 86 months (range: 22-126 months). At the final follow-up, the average range of active flexion was 85° (range: 75-95°). Postoperative average HSS knee rating system was improved from 19.5 (range: 18-22) to 57.49 (range: 46-80), WOMAC was improved from 39.75 (range: 36.4-43) to 62.41 (range: 50.8-74.5). VAS was improved from 9.5 (range: 7-9) to 2.8 (range: 2-4). A pyogenic infection developed in 2 patients; 1 was managed by debridement, and 1 was managed by arthrodesis 2 years later. CONCLUSION: The ability to walk and sit in a normal fashion is of great importance for patients. With good preoperative planning and careful handling, gratifying results are possible with TKA.