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Objectives:To observe the anatomical location and mechanism of axis ring fractures (ARF) using 3-D CT scans, and propose a new classification for such fractures.Methods:By reviewing prospectively maintained database collecting ARF from 7 medical centers in China, 202 patients were included in this study. According to anatomical location, ARFs were classified into axis arthrosis fracture (AAF) and axis bony damage (ABD). The axis ring was divided into anterior, middle, and posterior rings, based on the border of the pars interarticularis (or pedicle) of axis. According to the features of ARF and previous study, a new classification was proposed based on the anatomical features of different fracture patterns, which was divided into three types and six subtypes (A1, A2, B1, B2, C1 and C2). The incidence of AAF and ABD and their distribution in different location of axis ring and the new classification, were observed.Results:In 202 patients with ARF, 501 anatomical structures were involved. 288 AAFs were found in 178 patients (288/501, 57%), while 213 ABDs were found in 149 patients (213/501, 43%). In anterior ring, 304 structures (304/501, 61%) were involved in injury, with 225 AAF and 79 ABD. In middle ring, 99 structures (99/501, 20%) were involved in injury, and all of them were ABD. In posterior ring, 98 structures (98/501, 19%) were involved in injury, with 63 AAF and 35 ABD. The anterior ring injuries (61%) were more common than middle (20%) or posterior ring (19%). In anterior ring, AAF (84%) were morecommon than ABD (16%); In middle ring, all the injuries were ABD; In posterior ring, AAFs (64%) were more common than ABD (36%). Type A fractures were featured with pedicle fractures and were identified in 30 patients (30/202, 15%). Type A1 fractures were bilateral pedicle fracture lines symmetrically or asymmetrically and identified in 12 (6%) patients; Type A2 fractures were pedicle fracture lineson one side and inferior articular facet injuries or lamina fractures on the otherside and identified in 18 (9%) patients. Type B fractures were featured with superior articular facet injuries or posterior wall of C2 body fractures on one side and identified in 136 patients (67%). Type B1 fractures were superior articular facet injuries or posterior wall of C2 body fractures on one side and pedicle fracture on the other side and identified in 57 (28%) patients; Type B2 fractures were superior articular facet injuries or posterior wall of C2 body fractures on one side and inferior articular facet injuries or lamina fractures on the otherside and identified in 79 (39%) patients. Type C fractures were featured with bilateral superior articular facet injuries or posterior wall of C2 body fractures and identified in 36 patients (18%). Type C1 fractures were bilateral superior articular facet injuries or posterior wall of C2 body fractures symmetrically and identified in 22 (11%) patients; Type C2 fractures were bilateral superior articular facet injuries or posterior wall of C2 body fractures asymmetrically and identified in 14 (7%) patients.Conclusion:ARF could occur in different anatomical locations, and most of these fractures were caused by hyperextension and axial load on superior articular facet on one or two sides. The new CT classification of ARF with three types and six subtypes might provide all fracture patterns, which could be useful for the choice of proper diagnosis and treatment for such fractures.
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Objective To investigate the guidance value of TOI classification in treating traumatic T-type atlantoaxial dislocation (ADD).Methods A retrospective case series study was made on 32 cases of traumatic TOI T-type ADD treated between January 2012 and December 2015.There were 19 males and 13 females,aged (38.4 ± 14.7) years.Fifteen cases of T1-type underwent external fixation or internal fixation without fusion,while 17 cases of T2-type underwent internal fixation with fusion.Symon-Lavender clinical standard,Japanese orthopedic association score (JOA),visual analogue scale (VAS),atlas-dens interval (ADI) and space available for the cord (SAC) were used to evaluate the therapeutic effect.Results Patients were followed up for 6-54 months (mean,32.4 months).At final follow-up,ADI was decreased to (2.3 ± 1.4) mm from preoperative (5.6 ± 1.6) mm,but SAC was increased to (15.4 ± 1.9) mm from preoperative (12.0 ± 2.9) mm(P ＜ 0.01).At final follow-up,cervical axial rotation range of motion was 102°-154° in T1-type cases and 57°-93° in T2-type cases.Range of motion for atlantoaxial joint was preserved in T1-type cases,but lost in T2-type cases.According to the Symon-Lavender clinical standard,there were 14 cases of mild disability,nine moderate disability,eight severe disability and one extremely severe disability before operation;there were 21 cases of mild disability,nine moderate disability and two severe disability at last follow-up.Significant difference was observed in the grades according to the Symon-Lavender clinical standard before operation and at last follow-up (P ＜0.05).At last follow-up,JOA score was increased to (14.6 ± 2.9) points from preoperative (9.9± 3.2) points,and VAS was decreased to (2.7 ± 1.3)points from preoperative (6.0 ± 1.6)points (P ＜ 0.01).Conclusions By using TOI classification,reconstruction of stability and improved neurological function can be achieved in treatment of traumatic T-type atlantoaxial dislocation.Non-fusion treatment of T1-type atlantoaxial dislocation can preserve range of motion for atlantoaxial joint.
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[Objective]To discuss the efficacy of medial wedged proximal tibial osteotomy for treating genu varus deformity.[Methods]From July 1998 to October 2007,49 patients with genu varus deformity were treated by medial wedged proximal tibial osteotomy combined with internal fixation.Full-length anterior-posterior radiographs were taken preoperatively at 8 weeks and 1.5 years postoperatively.The parameters including the femorotibial angle and the medial joint space were measured on the radiographs.The pre-and postoperative function of knee were evaluated according to the HSS score system of the knee.[Results]All the 49 patients were followed up from 18 to 128 months.The mean postoperative femorotibial angle decreaced from 187.5??5.3? to 172.6??3.6?.The mean postoperative HSS score significantly improved from 83.2?15.3 to 47.2?17.6 points after 1.5 years of operation.The medial joint space increased from(2.4?1.2) mm to(4.3?1.2) mm.There were complications in 5 cases: 3 cases of intra-articular fracture during operation and 2 of postoperative superficial wound infections.There were no delayed union,no recurrence of varus deformity,and no blood vessels or nerves injury in all cases.The pain relieved and walking function improved significantly postoperativly.[Conclusion]Medial wedged proximal tibial osteotomy combined with internal fixation is an effect approach to treat genu varus deformity.
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[Objective]To assess the success of hallux valgus surgery of oblique and impaction osteotomy of first metatarsal neck.[Method]The outcome of 36 patients(45 feet)treated by this technique for symptomatic hallux valgus deformity was reviewed.The follow-up was two years.Lateral and AP radiographs were taken in a standing position pre-and postoperativly and hallux valgus angle(HV angle)and intermetatarsal angle(IM 1~2 angle)were measured accordingly.The efficacy of the surgery was evaluated by JOA scoring for foot disorders.[Result]The fracture healing was excellent.There was no case of delay union and nonunion.Two cases(three feet)were found to have superficial infection.The mean HV angle and IM 1~2 angle was revised by 15.6? and 4.2? respectively.JOA score was elevated for 29.6 points.[Conclusion]Hallux valgus can be corrected in three-dimension by the technique of first metatarsal neck osteotomy and inverted impaction fixation.