Hyperextension following two different designs of fixed-bearing posterior-stabilized total knee arthroplasty.

PURPOSE: Hyperextension after total knee arthroplasty (TKA) is related to worse functional outcomes. Among the reported predictive factors, it is unclear whether prosthesis design affects postoperative hyperextension. Hence, our objectives were to (1) compare time-dependent changes of the extension angle following multi-radius (MR) and single-radius (SR) TKA and (2) assess predictive factors for the hyperextension. METHODS: In this study, consecutive 136 MR TKAs and consecutive 71 SR TKAs performed by a single surgeon were reviewed. The extension angle was evaluated by digitized full-extension lateral radiographs at preoperative, 3 months and at 1 and 2 years after TKA. A positive value was defined as hyperextension. A multiple regression analysis was used to determine predictive factors for the extension angle and the risk of hyperextension > 5°. RESULTS: The postoperative extension angle of both groups gradually increased during the first 2 years and the SR group finally progressed with 4.04° greater extension than the MR group (p < 0.01). The incidence of hyperextension > 5° in the SR group was 18.3% and for the MR group, 7.4% (p = 0.02). However, the Oxford knee scores was nonsignificant different between the groups (p = 0.15). Preoperative extension angle, sagittal femoral component angle (SFA) and SR prosthesis were predictive factors for the extension angle at 2 years after TKA and were also associated with hyperextension > 5°. CONCLUSIONS: The extension angle of the SR group became significantly more extended than that of the MR group during the first two years after TKA. Hence, ideal extension position immediately after SR TKA may be different from that of the MR TKA prosthesis. The preoperative extension angle, SFA and SR prosthesis were factors that were associated with postoperative hyperextension.

Contamination Rate of Burnt Necrotic Tissue after Electrocoagulation in Total Knee Arthroplasty.

BACKGROUND: Periprosthetic joint infection (PJI) is one of the commonly found catastrophic complications after total knee arthroplasty (TKA). Preoperative antibiotic prophylaxis, proper skin cleansing, shortened operative time, and sterility of surgical field and equipment are essential to minimize the risk of PJI. Although bacterial contamination of electrocautery tips has been reported, contamination of residual product of electrocoagulation, burnt necrotic tissue (BNT), is not well known. Therefore, we aimed to assess the contamination rate of BNT and association between contaminated BNT and PJI, and risk factors. METHODS: BNTs from 183 patients who had undergone unilateral primary TKA at our institution were retrospectively analyzed. In each patient, three to five specimens of BNT were routinely collected in the operative field of primary TKA. Collecting time was defined as the duration from start of using the electrocautery device to the first collection of BNT. RESULTS: Culture was positive in eight of 183 patients (4.4%; contaminated BNT group), and the most commonly isolated organism was coagulase-negative Staphylococcus (62.5%). The average operative time was 103.1 ± 44.2 minutes in the contaminated BNT group and 79.0 ± 16.7 minutes in the non-contaminated BNT group (p = 0.17), and collecting time was 48.0 ± 44.3 minutes and 29.7 ± 17.0 minutes (p = 0.28), respectively. None of the patients with contaminated BNT developed PJI, whereas four patients with culture-negative BNT developed PJI within 2 postoperative years. CONCLUSIONS: BNT in surgical field can become a reservoir of contaminating bacteria. However, contamination of BNT was not associated with PJI. Therefore, routine removal of all BNTs may be unnecessary.

Blood loss reduction: effect of different knee prosthesis designs and use of tranexamic acid-a randomized controlled trial.

PURPOSE: In regard to blood loss in total knee arthroplasty (TKA), the effect of either knee prosthesis designs or bone preparation is still unclear. While the benefit of using tranexamic acid (TXA) is well demonstrated, our study aims to determine the effect of different knee prosthesis designs uses and efficacy of blood loss reduction by different routes of TXA administration. METHODS: The 228 patients undergone primary TKA were randomized to determine between open-box and closed-box prosthesis. Among each group, a second randomization was applied to categorize the patients into (1) no use of TXA (No-TXA), (2) intra-articular TXA use (IA-TXA) and (3) intravenous TXA use (IV-TXA). The calculated blood loss (CBL), drain volume (DV) and an average number of units of blood transfused (ANUBT) were blindly evaluated. RESULTS: The open-box TKA had 85.60 and 63.29 ml (p = 0.02 and p < 0.01) more CBL and DV compared to closed-box TKA. The IA-TXA and IV-TXA significantly reduced CBL by 190.75 and 162.01 ml (p < 0.01 and p < 0.01) and reduced DV by 129.07 and 61.04 ml (p < 0.01 and p = 0.01), respectively, when compared to No-TXA. Patients who received IA and IV-TXA had ANUBT of 0.21 and 0.23 unit, which was significantly lower than 0.42 unit of No-TXA group (p = 0.03). CONCLUSIONS: Use of the different prosthesis designs could significantly affect CBL and DV following TKA. However, the use of either design resulted in a comparable ANUBT. Regardless of prosthetic type, either IA- or IV-TXA could significantly reduce the CBL and ANUBT when compared to No-TXA.

Intra-Articular Tranexamic Acid Mitigates Blood Loss and Morphine Use After Total Knee Arthroplasty. A Randomized Controlled Trial.

BACKGROUND: Tranexamic acid (TXA) has been widely used in total knee arthroplasty (TKA) for blood loss reduction. Given limited evidence on potential relationship between the TXA and improvement of pain control and functional outcome after TKA, this study aimed at comparing the blood loss, pain scores, morphine consumption, and knee flexion across the TXA administration routes. METHODS: The 228 primary TKA were randomized into no TXA use (No-TXA), intra-articular TXA (15 mg/kg) use (IA-TXA), and intravenous TXA (10 mg/kg) use (IV-TXA). A multivariate regression analysis was used for comparing perioperative blood loss (PBL), drain output, average number of units of blood transfused (ANUBT), visual analogue scales (VAS) for pain, amount of morphine consumption, and knee flexion angle. RESULTS: The IA-TXA and IV-TXA group had 193.26 (P < .01) and 160.30 mL (P < .01) less PBL than No-TXA, respectively. No-TXA significantly required higher ANUBT than IA-TXA and IV-TXA (P = .03). The IA-TXA group had lower VAS at 6 (P = .04), 12 (P = .03), and 24 hours (P = .02) postoperative when compared to No-TXA, while IV-TXA had no effect. The IA-TXA required 18.26 mg less total morphine at 48 hours than No-TXA (P = .02), whereas IV-TXA used insignificantly (5.31 mg; P = .31) less total morphine at 48 hours than No-TXA. Both TXA routes tended to improve knee flexion, but not statistically significant. CONCLUSION: Both IA-TXA and IV-TXA could significantly reduce PBL and ANUBT. The IA-TXA could significantly mitigate VAS and morphine use after TKA. Hence, IA-TXA could minimize blood loss and may be considered as an adjunct to pain control following TKA.

Anterior vs Posterior Periarticular Multimodal Drug Injections: A Randomized, Controlled Trial in Simultaneous Bilateral Total Knee Arthroplasty.

BACKGROUND: Currently, various techniques are used to overcome postoperative pain after total knee arthroplasty. A local analgesic infiltration with periarticular multimodal drug injection (PMDI) is favorable because of its simplicity, safety, and efficacy. The present study compared the efficacy of a PMDI at the anterior vs posterior compartments. METHODS: Forty-six patients were randomized to receive the PMDI at either the anterior or posterior compartment, with the contralateral knee receiving the PMDI at the opposite compartment. The PMDI injected to the posterior capsule, medial and lateral meniscal remnant, was defined as the posterior compartment injection, whereas the injection to the medial retinaculum, quadriceps muscle, pes anserinus, and retropatellar fat pad was defined as the anterior compartment injection. Pain scores at rest, knee flexion angle, quadriceps function, and drainage blood loss were evaluated in both groups. RESULTS: The anterior PMDI group had significantly lower pain scores at rest during 96 hours postoperatively. On the day of discharge, 19 patients (41.3%) favored the knee with the anterior PMDI, which was superior to 9 patients (19.6%) who favored the knee with the posterior PMDI. The anterior PMDI demonstrated a superior recovery of quadriceps function during the same period, but there was no significant difference in terms of other parameters. CONCLUSION: The PMDI at the anterior compartment can reduce pain after total knee arthroplasty with potentially better quadriceps function compared with that in the PMDI at the posterior compartment. We recommend infiltrating the anterior compartment with a greater amount of PMDI than the posterior compartment.

Randomized controlled trial local injection for treatment of lateral epicondylitis, 5 and 10 mg triamcinolone compared.

OBJECTIVE: To compare the efficacy and adverse effects between 5 and 10 mg triamcinolone local injection for treatment of the lateral epicondylitis. The primary outcome was the improvement of pain after 12 weeks of treatment. The secondary outcome was the adverse effects rate. MATERIAL AND METHOD: One hundred and four patients with lateral epicondylitis were randomly allocated into 2 groups. Group A were injected with 5 mg triamcinolone and group B were injected with 10 mg triamcinolone at the maximum tenderness point at the lateral aspect of the elbow. All the patients were followed-up to 12 weeks. Patient satisfaction, pain score (VAS), degree of tenderness, pain on wrist extension against resistance, grip strength and adverse effects were recorded at 12 weeks after the injection. RESULTS: Group A (n = 51) had excellent result 80.39%, good 11.76%, slightly improved 1.96% and not improved 5.88%. Group B (n = 53) had excellent result 73.58%, good 16.98%, slightly improved 3.77% and not improved 5.66%. The adverse effects rate were 9.8% in group A and 13.2% in group B. There were no statistically significant in terms of patient satisfaction, pain score, tenderness at lateral epicondyle, grip strength and adverse effect rate. CONCLUSION: The use of 5 mg triamcinolone was comparable to 10 mg triamcinolone injected locally to treatment of lateral epicondylitis.

Result of arthroscopic removal of an enchondroma at the talar dome: a case report.

Enchondroma is a benign tumor that is generally asymptomatic and rarely found in the talus. A forty-nine-year-old man, had a chronic left ankle pain which related to moderate to heavy activity. A plain radiograph and magnetic resonance imaging (MRI) revealed a 1.3 cm benign lobulated intramedullary lesion at the middle 1/3 of medial part of talar dome with sclerotic rim. An arthroscopic intralesional curettage of the ankle joint was performed without bone grafting. Histologic examination was consistent with the diagnosis of an enchondroma. The patient was asymptomatic and without restriction on his job at 6 months. At 1 year of follow-up, the CT scan and MRI demonstrated no recurrence of the tumor but the defect was not filled up.