In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation...In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation stability comparable to those of anterograde intramedullary nailing and locking plate which achieve clinically favorable outcomes. In retrograde intramedullary nailing, a nail entry point is made in the diaphysis, for which reduction of stiffness of the humerus is of concern. Thus, we investigated the influence of a nail entry point made in the diaphysis on humeral strength. Retrograde intramedullary nailing had fixation stability against bending and a force loaded in the rotation direction comparable to those of anterograde intramedullary nail and locking plate. Displacement by the main external force loaded on the humerus, compressive load, was less than half in the bone fixed by retrograde intramedullary nailing compared with that in the bone fixed with a locking plate, showing favorable fixation stability. It was clarified that stiffness of the humerus against rotation and a load in the compression direction is not reduced by a nail entry point made by retrograde intramedullary nailing.展开更多
Background： Technical aspects of the correct placement of medial support locking screws in the locking plate for proximal humerus fractures remain incompletely understood. This study was to evaluate the clinical rela...Background： Technical aspects of the correct placement of medial support locking screws in the locking plate for proximal humerus fractures remain incompletely understood. This study was to evaluate the clinical relationship between the number of medial support screws and the maintenance of fracture reduction after locked plating of proximal humerus fractures. Methods： We retrospectively evaluated 181 patients who had been surgically treated for proximal humeral fractures （PHFs） with a locking plate between September 2007 and June 2013. All cases were then subdivided into one of four groups as follows： 75 patients in the medial cortical support （MCS） group, 26 patients in the medial multiscrew support （MMSS） group, 29 patients in the medial single screw support （MSSS） group, and 51 patients in the 11o medial support （NMS） group. Clinical and radiographic evaluations included the Constant-Murley score （CM）, visual analogue scale （VAS）, complications, and revision surgeries. The neck-shaft angle （NSA） was measured in a true anteroposterior radiograph immediately postoperation and at final follow-up. One-way analysis of variance or KruskaI-Wallis test was used for statistical analysis of measurement data, and Chi-square test or Fisher＇s exact test was used for categorical data. Results： The mean postoperative NSAs were 133.46°± 6.01°, 132.39° ± 7.77°. 135.17° ± 10.15°, and 132.41° ± 7.16° in the MCS, MMSS, MSSS, and NMS groups, respectively, and no significant differences were found （F = 1.02, P= 0.387）. In the final follow-up, the NSAs were 132.79° ±6.02°, 130.19° ± 9.25°, 131.28° ± 12.85°, and 127.35° ± 8.50° in the MCS, MMSS, MSSS, and NMS groups, respectively （F = 4.40, P = 0.008）. There were marked differences in the NSA at the final follow-up between the MCS and NMS groups （P = 0.004）. The median （interquartile range [IQR]） NSA losses were 0.0° （0.0-1.0）°, 1.3° （0.0-3.1）°, 1.5° （ 1.0-5.2）°, and 4.0° （ 1.2 -7.1 ）° in the MCS, MMSS, MSSS, and NMS groups, respectively （H = 60.66, P 〈 0.001 ）. There were marked differences in NSA loss between the MCS and the other three groups （MCS vs. MMSS, Z = 3.16, P = 0.002; MCS vs. MSSS, Z = 4.78, P 〈 0.001; and MCS vs. NMS, Z = 7.34, P 〈 0.001）. There was also significantly less NSA loss observed in the MMSS group compared to the NMS group （Z = -3.16, P = 0.002）. However, there were no significant differences between the MMSS and MSSS groups （Z = -1.65, P = 0.225） or the MSSS and NMS groups （Z =- 1.21, P = 0.099）. The average CM scores were 81.35 ± 9.79, 78.04± 8.97, 72.76 ± 10.98, and 67.33 ± 12.31 points in the MCS, MMSS, MSSS, and NMS groups, respectively （F = 18.68, P 〈 0.001）. The rates of excellent and good CM scores were 86.67%, 80.77%, 65.52%, and 43.14% in the MCS, MMSS, MSSS, and NMS groups, respectively （ X^2 = 29.25, P 〈 0.001 ）. The median （IQR） VAS scores were 1 （0-2）, l （0 2）,2 （ 1-3）, and 3 （1-5） points in the MCS, MMSS, MSSS, and NMS groups, respectively （H = 27.80, P 〈 0.001）. Functional recovery was markedly better and VAS values were lower in the MCS and MMSS groups （for CM scores： MCS vs. MSSS, P 〈 0.001 ; MCS vs. N MS. P 〈 0.001; MMSS vs. MSSS, P= 0.031 and MMSS vs. NMS, P 〈 0.001 and for VAS values： MCS vs. MSSS, Z=3.31, P = 0.001： MCS vs. NMS, Z = 4.64, P 〈 0.001; MMSS vs. MSSS, Z = -2.09, P = 0.037： and MMSS vs. NMS, Z=-3.16, P = 0.003）.Conclusions： Medial support screws might help enhance mechanical stability and maintain fracture reduction when used to treat PHFs with medial metaphyseal comminution or malreduction.展开更多
文摘In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation stability comparable to those of anterograde intramedullary nailing and locking plate which achieve clinically favorable outcomes. In retrograde intramedullary nailing, a nail entry point is made in the diaphysis, for which reduction of stiffness of the humerus is of concern. Thus, we investigated the influence of a nail entry point made in the diaphysis on humeral strength. Retrograde intramedullary nailing had fixation stability against bending and a force loaded in the rotation direction comparable to those of anterograde intramedullary nail and locking plate. Displacement by the main external force loaded on the humerus, compressive load, was less than half in the bone fixed by retrograde intramedullary nailing compared with that in the bone fixed with a locking plate, showing favorable fixation stability. It was clarified that stiffness of the humerus against rotation and a load in the compression direction is not reduced by a nail entry point made by retrograde intramedullary nailing.
文摘Background： Technical aspects of the correct placement of medial support locking screws in the locking plate for proximal humerus fractures remain incompletely understood. This study was to evaluate the clinical relationship between the number of medial support screws and the maintenance of fracture reduction after locked plating of proximal humerus fractures. Methods： We retrospectively evaluated 181 patients who had been surgically treated for proximal humeral fractures （PHFs） with a locking plate between September 2007 and June 2013. All cases were then subdivided into one of four groups as follows： 75 patients in the medial cortical support （MCS） group, 26 patients in the medial multiscrew support （MMSS） group, 29 patients in the medial single screw support （MSSS） group, and 51 patients in the 11o medial support （NMS） group. Clinical and radiographic evaluations included the Constant-Murley score （CM）, visual analogue scale （VAS）, complications, and revision surgeries. The neck-shaft angle （NSA） was measured in a true anteroposterior radiograph immediately postoperation and at final follow-up. One-way analysis of variance or KruskaI-Wallis test was used for statistical analysis of measurement data, and Chi-square test or Fisher＇s exact test was used for categorical data. Results： The mean postoperative NSAs were 133.46°± 6.01°, 132.39° ± 7.77°. 135.17° ± 10.15°, and 132.41° ± 7.16° in the MCS, MMSS, MSSS, and NMS groups, respectively, and no significant differences were found （F = 1.02, P= 0.387）. In the final follow-up, the NSAs were 132.79° ±6.02°, 130.19° ± 9.25°, 131.28° ± 12.85°, and 127.35° ± 8.50° in the MCS, MMSS, MSSS, and NMS groups, respectively （F = 4.40, P = 0.008）. There were marked differences in the NSA at the final follow-up between the MCS and NMS groups （P = 0.004）. The median （interquartile range [IQR]） NSA losses were 0.0° （0.0-1.0）°, 1.3° （0.0-3.1）°, 1.5° （ 1.0-5.2）°, and 4.0° （ 1.2 -7.1 ）° in the MCS, MMSS, MSSS, and NMS groups, respectively （H = 60.66, P 〈 0.001 ）. There were marked differences in NSA loss between the MCS and the other three groups （MCS vs. MMSS, Z = 3.16, P = 0.002; MCS vs. MSSS, Z = 4.78, P 〈 0.001; and MCS vs. NMS, Z = 7.34, P 〈 0.001）. There was also significantly less NSA loss observed in the MMSS group compared to the NMS group （Z = -3.16, P = 0.002）. However, there were no significant differences between the MMSS and MSSS groups （Z = -1.65, P = 0.225） or the MSSS and NMS groups （Z =- 1.21, P = 0.099）. The average CM scores were 81.35 ± 9.79, 78.04± 8.97, 72.76 ± 10.98, and 67.33 ± 12.31 points in the MCS, MMSS, MSSS, and NMS groups, respectively （F = 18.68, P 〈 0.001）. The rates of excellent and good CM scores were 86.67%, 80.77%, 65.52%, and 43.14% in the MCS, MMSS, MSSS, and NMS groups, respectively （ X^2 = 29.25, P 〈 0.001 ）. The median （IQR） VAS scores were 1 （0-2）, l （0 2）,2 （ 1-3）, and 3 （1-5） points in the MCS, MMSS, MSSS, and NMS groups, respectively （H = 27.80, P 〈 0.001）. Functional recovery was markedly better and VAS values were lower in the MCS and MMSS groups （for CM scores： MCS vs. MSSS, P 〈 0.001 ; MCS vs. N MS. P 〈 0.001; MMSS vs. MSSS, P= 0.031 and MMSS vs. NMS, P 〈 0.001 and for VAS values： MCS vs. MSSS, Z=3.31, P = 0.001： MCS vs. NMS, Z = 4.64, P 〈 0.001; MMSS vs. MSSS, Z = -2.09, P = 0.037： and MMSS vs. NMS, Z=-3.16, P = 0.003）.Conclusions： Medial support screws might help enhance mechanical stability and maintain fracture reduction when used to treat PHFs with medial metaphyseal comminution or malreduction.
