BACKGROUND: The null hypothesis to be tested in this study is that the compression forces generated with a novel compressible intramedullary nail are not different from compression plating techniques. METHODS: A custom sensor was used to measure the compressive force at a transverse midshaft humeral sawbone osteotomy (OTA 12-A3.2) in four groups. The groups included: standard compression plating using a limited contact dynamic compression plate (LCDC) with eccentric screw placement (ED-LCDC), compression plating using an LCDC plate with an articulated tensioner and eccentric compression screw (AT-LCDC), locked humeral nail compressed using the manufacturer's long stainless steel screwdriver (T2-IMN), and locked humeral nail compressed using a short stainless steel AO screwdriver (SF-IMN). From continuous measurements recorded during osteotomy compression, the maximum force (CMax) and force at 60 seconds after the peak measurement (CMax +60) were analyzed. RESULTS: The mean CMax was 2043 N for SF-IMN, 1109 N for AT-LCDC, 799 N for T2-IMN, and 365 N for ED-LCDC. Mean CMax +60 was 1648 N for SF-IMN, 944 N for AT-LCDC, 650 N for T2-IMN, and 319 N for ED-LCDC. The difference in both CMax and CMax +60 was statistically significant between all groups (p < 0.002). CONCLUSION: A new humeral nail can generate higher compression than plating using eccentric drill holes or the articulated tensioner when used with a short stainless steel screwdriver shaft. Clinical studies are needed to analyze whether this compression could improve the union rate of humeral fractures and nonunions beyond those of standard nails.
BACKGROUND: The null hypothesis to be tested in this study is that the compression forces generated with a novel compressible intramedullary nail are not different from compression plating techniques. METHODS: A custom sensor was used to measure the compressive force at a transverse midshaft humeral sawbone osteotomy (OTA 12-A3.2) in four groups. The groups included: standard compression plating using a limited contact dynamic compression plate (LCDC) with eccentric screw placement (ED-LCDC), compression plating using an LCDC plate with an articulated tensioner and eccentric compression screw (AT-LCDC), locked humeral nail compressed using the manufacturer's long stainless steel screwdriver (T2-IMN), and locked humeral nail compressed using a short stainless steel AO screwdriver (SF-IMN). From continuous measurements recorded during osteotomy compression, the maximum force (CMax) and force at 60 seconds after the peak measurement (CMax +60) were analyzed. RESULTS: The mean CMax was 2043 N for SF-IMN, 1109 N for AT-LCDC, 799 N for T2-IMN, and 365 N for ED-LCDC. Mean CMax +60 was 1648 N for SF-IMN, 944 N for AT-LCDC, 650 N for T2-IMN, and 319 N for ED-LCDC. The difference in both CMax and CMax +60 was statistically significant between all groups (p < 0.002). CONCLUSION: A new humeral nail can generate higher compression than plating using eccentric drill holes or the articulated tensioner when used with a short stainless steel screwdriver shaft. Clinical studies are needed to analyze whether this compression could improve the union rate of humeral fractures and nonunions beyond those of standard nails.