Objective To explore the anatomical characteristic of the third palmar interosseous mus- cle as well its dominate nerve,and to investigate the anatomical basis of difficult recovery of digitus minimus adduction.Methods Twenty aduh fresh hands without deformity and trauma were obtained.Dissect and observe the third palmar interosseous muscle and its dominate nerve and adjacent structure under surgical mi- croseope,measure the size of the third pahnar interosseous muscle and its dominate nerve,the data were pro- cessed by stastistics method.Results Among palmar interosseous muscles and its dominate nerves,the third palmar interosseous muscle and its dominate nerve is the smallest.There are conspicuous tendon bundle on the surface of the third palmar interosseous muscle partly,which have a potential compression on the third palmar interosseous muscle dominting nerve.Conclusion The third palmar interosseous muscle is the smal- lest among palmar interusseous muscles and it is the only digitus minimus adduction muscle.The sominating nerve of the third palmar interosseous muscle is small anti the tendon bundle of the third palmar interosseous muscle have a potential compression.All these can cast light on diffcult recovery of digitus minimus adduction.

BACKGROUND: In clinical practice, inducible grafting from trimmed spinous process of hinge groove combined with different internal fixators is primarily applied to prevent postoperative axial pain after unilateral open-door cervical expansive laminoplasty. OBJECTIVE: To investigate the influence of autologous grafting of hinge groove combined with two internal fixators on postoperative axial pain after unilateral open-door cervical expansive laminoplasty. METHODS: We retrospectively reviewed 106 patients with multilevel ossification of cervical posterior longitudinal ligament who had underwent unilateral open-door cervical expansive laminoplasty with pedicle screw fixation (n=52, including grafting in 24 cases and non-grafting in 28 cases) or with mini-plate fixation (n=54, including grafting in 37 cases and non-grafting in 17 cases). Fusion rate of hinge groove, characteristics of postoperative axial pain and postoperative efficacy were evaluated by means of imaging methods. RESULTS AND CONCLUSION: All the 106 patients were followed up for 3.2-5.9 years, with no appearance of breaking or loosening of fixed appliances, disruption of the interior cortex of hinge groove. The 19 of 106 cases appeared to have postoperative axial pain, including 9 cases in the pedicle screw group (grafting: 4 cases, non-grafting: 5 cases) and 10 cases in the mini-plate group (grafting: 3 cases, non-grafting: 7 cases). Under the condition of pedicle screw fixation, there were no significant differences in the fusion rate at 3 months postoperatively and improvement rate of Japanese Orthopaedic Association Scale (JOA) score at final follow-up between the grating and non-grafting groups. After the implementation of mini-plate fixation, there was also no difference in JOA improvement rate at final follow-up between the grafting and non-grafting groups, but the fusion rate in the grafting group was significantly higher than that in the non-grafting group at 3 months postoperatively (P < 0.05). After pedicle screw fixation, there was no significant difference in incidence, onset time and severity of initial onset, duration, pain improvement between grafting and non-grafting groups. When fixed by mini-plates, pain duration and pain improvement were better in the grafting group than the non-grafting group (P < 0.05), and there were still no significant differences in the other indices between the two groups. To conclude, hinge grafting combined with pedicle screw fixation cannot affect onset characteristics of postoperative axial pain, while hinge grafting combined with mini-plate fixation can reduce duration of postoperative axial pain, improve prognosis, promote definite fusion of hinge groove, thereby remodeling alignment balance and biomechanical stability as soon as possible.

Objective To observe the influence of preoperatively physical curvature abnormality and different fixation systems on postoperative axial symptom (PAS) and union rate of hinge groove after unilateral expansive laminoplasty for the patient with cervical spondylotic myelopathy (CSM).Methods The study reviewed 106 CSM patients who underwent unilateral laminoplasty supplemented by lateral mass or pedicle screw/rod fixation with a minimum of 36 months of follow-up.According to being complicated with physical curvature abnormality or not,the incidence,initial onset,severity,duration of PAS and union rate of hinge groove at postoperative 6 months were respectively compared to analyze the influences of two internal methods on the features of PAS.Results For 50 cases without physical curvature abnormality,fusion rates of hinge groove in pedicle placement group was higher than that in lateral mass fixation group,the P value reached statistical difference (t=142.2,P=0.032).Duration of PAS in pedicle group was shorter than that in lateral mass group,the difference reached statistic significance (t=147.2,P=0.019).For 56 cases of with physical curvature abnormality,incidence of PAS in pedicle group presented was lower than that in lateral mass group,the difference achieved statistic significance (x2=3.89,P=-0.042).Conclusion Whether concomitant with physical curvature abnormality or not,pedicle fixation would be beneficial to promoting bony fusion of hinge groove,shortening duration of PAS and reducing incidence of PAS in contrast to lateral mass fixation to some extent after unilateral laminoplasty for treating CSM patients.