Varus Knee Deformity Classification Based on Degree and Extra- or Intra-Articular Location of Coronal Deformity and Osteoarthritis Grade.

BACKGROUND: Medial coronal plane malalignment, also known as varus alignment, is commonly reported in osteoarthritic knees. Although the degree of deformity provides some insight regarding the severity of the disease, it does not always reflect the potential complexity of the surgical treatment. METHODS: This prospective observational study was conducted by analyzing the radiographs of 100 consecutive knees in patients undergoing total knee arthroplasty. For each knee, coronal alignment, expressed as the hip-knee-ankle angle, was measured on a full-leg standing radiograph and classified in 3 stages. The primary location of the varus deformity was identified as intra-articular and/or extra-articular. Additionally, knees were evaluated to assess for 10 radiographic features of varus deformity and then classified in 3 grades of osteoarthritis severity. RESULTS: The mean (and standard deviation) preoperative varus deformity was 11° ± 6° of varus (hip-knee-ankle, 169°), as measured on standardized full-leg radiographs. Extra-articular varus deformity was observed in 14% of patients. A higher number of radiographic features of varus severity corresponded with higher degrees of deformity. Varus grade correlated strongly with stage of varus deformity. Twenty-three (100%) of 23 stage-III deformities had grade-C features; however, 13 (48%) of 27 stage-I patients also had grade-C disease. CONCLUSIONS: One of every 7 osteoarthritis patients with varus deformity had an extra-articular deformity, and 1 of 2 of these patients had severe intra-articular disease (grade C) despite limited coronal deformity (stage I). These findings reconfirm the need for individual deformity analysis that accounts for the degree, location, and severity of the varus deformity. This insight may help to formulate an algorithmic treatment approach specific to the epiphyseal knee anatomy of the patient and according to the surgical preferences of the surgeon. CLINICAL RELEVANCE: Knee surgeons tend to consider knees with higher degrees of coronal deformity as more technically difficult, but the present study shows that knees with less deformity can still present with severe grades of osteoarthritis inside the knee, leading to more challenging joint reconstruction.

The feasibility of direct adductor canal block (DACB) as a part of periarticular injection in total knee arthroplasty.

BACKGROUND: Adductor canal block (ACB) is one of the preferred methods of analgesia in total knee arthroplasty (TKA). However, conventionally its use is time-consuming, requires ultrasound guidance, a trained anaesthesia team and adherence to strict asepsis by members of the allied teams. This study was done to assess the feasibility and safety of direct adductor canal block (DACB) as a part of surgeon-administered periarticular infiltration. MATERIALS AND METHODS: Thirty computed tomography (CT) angiography films of the patients were retrospectively reviewed. The trajectory of the needle placement for a DACB in relation to the target region of the adductor block was determined. Fourteen knees in seven cadavers, were dissected through a medial parapatellar approach to perform TKA. After administering the DACB using the technique based on CT data, dissection was carried out to ascertain the correct placement of the dye by visualising the stained areas. RESULTS: The angle of approach in the coronal plane from the entry point to the medial high point and to the adductor hiatus was 10.2° (8-14°) and 6° (3.8-11°), respectively. The angle of approach in the sagittal plane from the entry point to the medial high point and to the adductor hiatus was 7° (5-10.5°) and 29° (19-43°), respectively. In all the 14 cadaveric knees, we confirmed the correct placement of the methylene blue dye as demonstrated by the staining of the adductor canal. CONCLUSION: The study demonstrates the feasibility of the DACB. This surgeon-driven technique is likely to reduce the cost of the procedure, reduce operating room time and also eliminate the risks of surgical-site contamination.