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BACKGROUND: A combined regimen of adductor canal block (ACB) and multimodal periarticular infiltration (MPI) with local anesthetic (ropivacaine) is a known effective method of controlling pain in the first 6-8 h after total knee arthroplasty (TKA); however, managing breakthrough pain after their combined effect wears off can be challenging. We hypothesized that, by additionally leaving an intra-articular epidural catheter (IAEC) inside the knee with intermittent infiltration of local anesthetic in conjunction with ACB and MPI, it would help manage the breakthrough pain when their combined effect wears off. METHODS: We did a prospective study in our institution between December 2015 and August 2016 on a total of 206 patients undergoing primary unilateral TKA. The initial consecutive 106 patients received ACB + MPI (Group 1, n = 106), and the subsequent 100 patients received ACB + MPI + IAEC (Group 2, n = 100). The primary outcome measure was pain using visual analogue scale (VAS) recorded at 6, 12, 24 and 48 h, and the secondary outcome measures were requirement for rescue analgesics and repeat adductor canal block and length of hospital stay. RESULTS: There was no statistically significant difference in VAS scores between the two groups at 6 h but at 12, 24 and 48 h; there was a statistically significant difference between the two groups in terms of VAS scores, rescue analgesic requirements, repeat adductor canal block and shorter hospital stay favoring the ACB + MPI + IAEC group. CONCLUSION: Intermittent knee infiltration with ropivacaine is a safe, reproducible and effective method to control pain in the first 48 h postoperative period after TKA.

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BACKGROUND: Blood loss in total knee arthroplasty (TKA) is an area of significant concern as it has an effect on patient morbidity and hospital stay. Among many different modalities to reduce blood loss, the use of Tranexamic acid has become a standard procedure nowadays. The aim of our study was to determine if Tranexamic acid alone decreases blood loss as an independent variable irrespective of other blood loss preserving measures. METHOD: This prospective non-randomized study included patients undergoing unilateral TKA by conventional method (Group 1) and computer-assisted TKA (Group 2). All the patients in both groups received Tranexamic acid in a dose of 10 mg/kg body weight prior to inflation of tourniquet. Blood loss in both the groups was calculated using Nadler's formula, and haemoglobin (Hb) level was calculated on day one and day three after surgery. RESULTS: The mean drop of Hb in Group 1 was 1.608 and 1.56 g/dl in Group 2 which was statistically significant (p < 0.001); however, none of the patients in either of the groups actually required any blood transfusion postoperatively. Although there was a significant drop in haemoglobin and haematocrit in both the groups, on comparison, there was no significant difference in blood loss and fall in Hb levels between the groups (p > 0.001). CONCLUSION: Tranexamic acid decreases blood loss in patients undergoing TKA independent of all the other blood conserving procedures.

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The restoration of knee alignment is an important goal during total knee arthroplasty (TKA). In the past surgeons aimed to restore neutral limb alignment during surgery. However, previous studies have demonstrated alignment to be dynamic, varying depending on the position of the limb and the degree of weight-bearing, and between patients. We used a validated computer navigation system to measure the femorotibial mechanical angle (FTMA) in 264 knees in 77 male and 55 female healthy volunteers aged 18 to 35 years (mean 26.2). We found the mean supine alignment to be a varus angle of 1.2° (standard deviation (sd) 4), with few patients having neutral alignment. FTMA differs significantly between males and females (with a mean varus of 1.7° (sd 4) and 0.4° (sd 3.9), respectively; p = 0.008). It changes significantly with posture, the knee hyperextending by a mean of 5.6°, and coronal plane alignment becoming more varus by 2.2° (sd 3.6) on standing compared with supine. Knee alignment is different in different individuals and is dynamic in nature, changing with different postures. This may have implications for the assessment of alignment in TKA, which is achieved in non-weight-bearing conditions and which may not represent the situation observed during weight-bearing.

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Posterolateral corner injuries of the knee are usually associated with injuries to other structures of the knee. It is not unusual to miss this injury during the initial assessment. Undiagnosed and untreated posterolateral corner knee injury leads to significant morbidity including early osteo-arthritis of the knee. Failure to recognise and reconstruct posterolateral corner injuries is one of the important reasons for the failure of cruciate ligament reconstruction surgery. In this article we have reviewed the literature regarding anatomy, biomechanics, clinical features and treatment of the posterolateral corner injuries of the knee.

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Although many PCL injuries are in combination with posterolateral corner (PLC) injuries, there has been little work done on combined injury reconstruction; the literature includes differing recommendations. It was hypothesised that a double-bundle PCL reconstruction would restore both posterior drawer and external rotation laxities closer to normal than an isolated single-bundle reconstruction in combined PCL plus PLC-deficient knees. However, it was also hypothesised that an isolated PCL reconstruction would still leave abnormal rotation laxity. In this controlled laboratory study, cadaver knee kinematics were measured electromagnetically with posterior drawer, external rotation, varus rotation loads applied, at sequential stages: intact; PCL-deficient; PCL plus PLC-deficient; double-bundle PCL reconstruction; single-bundle PCL reconstruction. The grafts were tensed using a posterior drawer laxity matching protocol. There was no significant difference between single- and double-bundle PCL reconstructions at any angle of flexion: both reconstructions restored posterior drawer to normal; neither reconstruction restored external rotation or varus laxity to normal. We concluded that, in combined PCL plus PLC deficiency, isolated PCL reconstruction only controls tibial posterior drawer, but is not sufficient to restore rotational laxity to normal. Double-bundle PCL reconstruction was not better than single-bundle, so the added complexity of double-bundle reconstruction does not seem to be justified by these results.

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