An Algorithmic, Pie-Crusting Medial Soft Tissue Release Reduces the Need for Constrained Inserts Patients With Severe Varus Deformity Undergoing Total Knee Arthroplasty.

BACKGROUND: We studied the need to use a constrained insert for residual intraoperative instability and the 1-year result of patients undergoing total knee arthroplasty (TKA) for a varus deformity. In a control group, a "classic" subperiosteal release of the medial soft tissue sleeve was performed as popularized by pioneers of TKA. In the study group, an algorithmic approach that selectively releases and pie-crusts posteromedial structures in extension and anteromedial structures in flexion was used. METHODS: All surgeries were performed by a single surgeon using measured resection technique, and posterior-stabilized, cemented implants. There were 228 TKAs in the control group and 188 in the study group. Outcome variables included the use of a constrained insert, and the Knee Society Score at 6 weeks, 4 months, and 1 year postoperatively. The effect of the release technique on use of constrained inserts and clinical outcomes were analyzed in a multivariate model controlling for age, sex, body mass index, and severity of deformity. RESULTS: The use of constrained inserts was significantly lower in study than in control patients (8% vs 18%; P = .002). There was no difference in the Knee Society Score and range of motion between the groups at last follow-up. No patient developed postoperative medial instability. CONCLUSION: This algorithmic, pie-crusting release technique resulted in a significant reduction in the use of constrained inserts with no detrimental effects in clinical results, joint function, and stability. As constrained TKA implants are more costly than nonconstrained ones, if the adopted technique proves to be safe in the long term, it may cause a positive shift in value for hospitals and cost savings in the health care system.

Topical Tranexamic Acid May Improve Early Functional Outcomes of Primary Total Knee Arthroplasty.

INTRODUCTION: The use of tranexamic acid (TXA) reduces postoperative anemia and blood transfusion requirements. We investigated if these beneficial effects improve the early outcomes of primary total knee arthroplasty (TKA). METHODS: We retrospectively studied 166 consecutive patients (179 TKAs) who received topical TXA (3 g before tourniquet deflation). This "study group" was compared with a "control group" of 197 consecutive patients (209 TKAs) in whom no TXA was used. We captured outcomes during the first 4 postoperative months. Knee Society score (KSS) was determined preoperatively, 6 weeks, and 4 months postoperatively. The outcomes were compared using univariate analysis. Multiple logistic regressions were calculated to assess differences between groups in KSS at 6 weeks and 4 months, controlling for age, sex, body mass index, and preoperative KSS. RESULTS: Postoperative hemoglobin was significantly higher in the study than that in the control group on day 1, day 2, and at discharge (P < .0001). Blood transfusions were required in 5% and 22% of patients (P < .001), respectively. Six weeks postoperatively, the functional KSS and its 5 categories (ability to walk, negotiate stairs up and down, stand up from a chair, and the use of support) were significantly higher in the study than those in the control group (P ≤ .001). Four months postoperatively, there was no difference in the KSS between the groups. DISCUSSION: Our study suggests that the clinical benefit of topical TXA administration extends beyond the hospitalization period. Its use may improve knee function during the first 6 postoperative weeks. This beneficial clinical effect seems to be negligible afterward.

A critical analysis of radiographic factors in patients who develop dislocation after elective primary total hip arthroplasty.

PURPOSE: In order to diminish total hip arthroplasty (THA) dislocation rate, surgeons strive to achieve adequate component orientation, offset and limb length. In addition, dislocation rate can theoretically be reduced by increasing head diameter and by choosing implants with favorable head-to-neck and cup-to head ratios. We assessed nine radiographic and implant-related parameters associated with an increased risk of dislocation in patients who sustained a dislocation and in those with a stable arthroplasty. METHODS: A total of 1,487 consecutive elective primary THAs performed by a single surgeon, using a posterolateral approach were reviewed at an average follow-up of 18 months (range, 1-112). Fixation was hybrid in 85 % of hips and non-cemented in 15 %. Thirty-eight patients (38 hips, 2.5 %) sustained at least one dislocation. Thirty-seven patients with good quality, standardized anteroposterior radiographs were selected as a "study group". The study group was matched-paired (1:3) with patients who had a stable arthroplasty based on gender, age, BMI, diagnosis and follow-up. Variables compared between the groups included: head size, cup size, head-to-neck ratio, cup-to-head ratio, leg-length discrepancy, offset, cup inclination, cup version and cup orientation based on the safe zone defined by Lewinnek et al. RESULTS: None of the nine parameters showed a statistically significant difference between the groups. DISCUSSION: In this study, 90 % of patients who developed a dislocation had properly positioned acetabular components. In addition, the vast majority of patients in the study group had adequate restoration of limb length and offset. The results of our study may be useful for the orthopedic surgeons who discuss instability following THA surgery, particularly in patients with radiographically sound reconstructions.