[Manual reduction combined with 3D printed small splint in treating humeral shaft fractures].

Objective: To analyze the clinical efficacy of manual reduction combined with 3D printing small splint external fixation and synchronous manual reduction combined with traditional small splint external fixation in the treatment of humeral shaft.

Methods: Between January 2021 and December 2022, 40 patients with humeral shaft fractures were treated with 3D printing small splints and traditional small splints. They were divided into 3D group and traditional group according to different fixation methods. Among them, there were 15 males and 5 females in the 3D group, aged from 20 to 52 years old with an average of (36.3±15.6) years old. In the traditional group there were 17 males and 3 females, aged from16 to 51 years old with an average of (32.9±17.2) years old. The occurrence of complications, duration of fracture healing, rate of fracture healing, subjective evaluation scores for brace comfort at 1 week and 4 weeks, as well as the Constant-Murley shoulder function score and Mayo elbow function score at 8 weeks and 16 weeks were compared between the two groups.

Results: All patients were followed up for 16 weeks. The 3D group did not experience any complications, while there were two cases of complications in the traditional group. However, this difference was not found to be statistically significant (χ²=2.105, P=0.146). The fracture healing time of the 3D group (90.1±4.5) days was significantly shorter compared to that of the traditional group (93.3±3.8) days (P<0.05). The subjective evaluation scores for brace comfort in the 3D group (53.7±2.3) points and (62.8±1.1) points were significantly higher than those in the traditional group (45.6±2.4) points and (52.3±1.4) points at 1 and 4 weeks after reduction (P<0.05). After 8 weeks of reduction, the Constant-Murley shoulder function score in the 3D group was(68.1±5.3) points, which demonstrated a statistically significant improvement compared to the traditional group(54.3±4.9) points (P<0.05). However, at 16 weeks post-reduction, there were no significant differences observed between the two groups (P>0.05). The Mayo elbow function score of the 3D group (84.1±7.5) points was significantly superior to that of the traditional group (79.5±6.8) points at 8 weeks post-reduction (P<0.05). However, there was no statistically significant difference between the two groups at 16 weeks post-reduction (P>0.05).

Conclusion: For humeral shaft fractures with conservative treatment indications, manual reduction combined with 3D printed small splints is a good choice for treatment. The patient's comfort level is higher, which can not only reduce the occurrence of complications, but also improve the fracture healing rate and joint function to a certain extent, and improve the patient's quality of life.