Security Comparison of Various Surgical Knots Using Nylon Suture.

OBJECTIVE: To evaluate the strengths of various surgical knot techniques, including square knot, surgeon's knot, granny knot, and random knot with the same three throws. METHODS: The authors tested each of the four knot techniques using four different gauges of nylon (polyamide [Ethicon]): 4-0, 5-0, 6-0, and 7-0. Each knot type was tested 20 times per nylon gauge, for a total of 320 knots tested. The authors used a static pull machine to measure elongation at yield and maximal force to break. RESULTS: A comparison of elongation at yield revealed that the surgeon's knot was superior to the square knot, granny knot, and random knots across all gauges of nylons. Further, a comparison of maximal force to break revealed that the surgeon's knot was superior to the square knot, granny knot, and random knots when using 4-0, 5-0, and 6-0 nylon but not when using 7-0 nylon. CONCLUSIONS: The surgeon's knot was the strongest, and random knot was the weakest when the authors used nylon 4-0, 5-0, and 6-0. While handling fine suture materials such as 7-0 nylon, knot failure appears to be unrelated to the knot technique used. This study provides not only fundamental guidance for tying surgical knots using nylon, but also a rational basis for an adequately strong knot choice in various fields of surgery.

Versatility of the Posterior Interosseous Artery Flap: Emphasis on Powering Up the Toe Transfer.

BACKGROUND: Reverse-flow posterior interosseous artery (rPIA) flap is an excellent tool for restoration of defects in the hand and upper extremity, sparing the main arteries to the hand. Its reliability has been well established. MATERIALS AND METHODS: Fifty-one cases of rPIA flap involving 49 patients were retrospectively reviewed. The inclusion criteria were age, sex, etiology, size and location of the defect, flap size, number of perforators included, pedicle length, flap inset, donor site coverage, complications, and ancillary procedures. RESULTS: This study included 44 men and 5 women, ranging in age between 10 and 73 years. The subjects had soft tissue defects of the hand and upper extremity mainly due to traumatic injuries, including scar contractures of the first web space in 18 cases, thumb amputations in 6 cases, and congenital defects in 1 case. Among the 51 rPIA flap elevations, 3 cases involved flap failure due to the absence of proper pedicle. A fasciocutaneous pattern was observed in 45 cases and a myocutaneous pattern in 3 cases. In 5 cases of unplantable thumb amputations, the rPIA flap was performed for arterial inflow to the secondary toe-to-thumb transfer. Venous congestion of varying degrees was noted in 7 cases involving partial necrosis in 2 cases. During the mean 17 months of follow-up, patients were generally satisfied with the final outcomes. CONCLUSION: The rPIA flap can be used not only for soft tissue coverage of the hand and upper extremity but also as a recipient arterial pedicle for a secondary toe-to thumb transfer.

An Anatomical Study of the Palmaris Brevis, Transverse Carpal Ligament, and the Recurrent Motor Branch of the Median Nerve.

Background: The anatomical structures in relation to the carpal tunnel release are the palmaris brevis muscle (PBM), transverse carpal ligament (TCL), and the recurrent motor branch of the median nerve (RMBMN). Our aim is to describe the gross morphology in the Korean population of the PBM, TCL, and RMBMN specifically looking for anomalies, and to determine the muscles encountered during a standard carpal tunnel release. Material and Methods: A total of 30 cadaveric hands were dissected. A longitudinal line drawn from the third web space to the midpoint of the distal wrist crease served as the reference line (RL). The PBM and TCL were classified according to its shape and location. The length, width, and thickness of the TCL were measured. The ratio of the lengths of PBM and TCL to RL was calculated. The course of the RMBMN was dissected specifically looking for anomalies. We also looked at the muscle fibers encountered during a standard carpal tunnel release to identify the muscle. Results: PBM was classified into three different types based on the shape. The average thickness of the PBM and TCL were 0.89 ± 0.16 mm and 1.43 ± 0.40 mm, respectively. The distal border of the TCL was thicker than the proximal border. The average ratio of the length of the PBM to the RL was 25.65 ± 8.62% and TCL to the RL was 24.00 ± 3.37%. The distribution of the RMBMN was classified into three different types. A few accessory branches of the RMBMN were also noted. And 36 muscle fibers were noted within the TCL in line with the RL. Conclusion: We clarified findings and added quantitative information about the anatomical structures surrounding carpal tunnel. A thorough knowledge of the anatomy and anomalies around the carpal tunnel is helpful for surgeons to ensure optimal surgical results.