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.

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.

Background: This study was done to study the anthropometry of nonarthritic Asian knees; to determine the differences in morphology between knees of different ethnicities and to compare the knee anthropometry values with sizes of available knee implants. Methods: Magnetic resonance imaging scans of 100 nonarthritic Indian knees were analyzed. Anteroposterior (AP) length, mediolateral (ML) length, and aspect ratio of the distal femur and proximal tibia, patellar length, and patellar tendon length were measured. These values were compared with values of other ethnicities from literature. The values were also compared with sizes of available knee implants and evaluated for mismatch. Results: All the parameters of female knees were significantly smaller than those of male knees (p < 0.05). The distal femur of Indian knees resembled that of Chinese knees with similar AP and ML lengths and aspect ratio. The distal femur of Indian knees had a significantly smaller AP, ML, and aspect ratio than those of Hispanic knees did. In comparison to Caucasian distal femur, Indian knees had smaller AP and ML lengths and larger aspect ratio. In terms of the proximal tibia, the Indian knees were smaller than Chinese (only ML), Caucasian (AP and ML) and Hispanic (AP and ML) knees. On comparison with implant sizes, there was a mismatch between the distal femur morphology and the dimensions of all implants. For a given AP length, the ML dimensions of all implants were smaller than the measured ML length of the knee. However, the tibial components of all the studied implants correlated well with the tibial morphology. Conclusions Distinct anthropometric differences exist between knees of different ethnicities. The knees of females were smaller than the knees of males. In Indian knees, the ML-AP aspect ratio of the distal femur was higher than that of the currently available femoral components. These results suggest the need for race-specific knee implants.