[Effectiveness analysis of three-dimensional printing assisted surgery for unstable pelvic fracture]

[The application of percutaneous retrograde pubic screw implantation assisted by hollow pedicle opener in treatment of pubic branch fracture]

OBJECTIVE

To evaluate the effectiveness of percutaneous retrograde pubic screw implantation assisted by hollow pedicle opener in pubic branch fractures.

METHODS

The clinical data of 42 patients with pubic branch fractures treated by hollow screw fixation between March 2008 and March 2019 were analyzed retrospectively. According to the operation method, they were divided into the traditional operation group (20 cases in group A, fixed with traditional retrograde pubic screws) and the modified operation group (22 cases in group B, fixed with percutaneous retrograde pubic screws assisted by hollow pedicle opener). There was no significant difference ( P>0.05) between the two groups in terms of gender, age, cause of injury, fracture classification, comorbidity, and time from injury to operation. The operation time, blood loss, incision length, screw length, and complications were recorded and compared between the two groups. The fracture reduction was evaluated according to Matta standard on the next day after operation, and the function was evaluated by Majeed score at 12 months after operation.

RESULTS

The operation was successfully completed in both groups. The operation time, blood loss, and incision length of group B were significantly less than those of group A ( P<0.05); there was no significant difference in screw length between the two groups ( t=0.793, P=0.437). All patients were followed up 8-24 months, with an average of 16.8 months. There was no complication in the two groups, such as injury of blood vessels and nerves, fracture of internal fixation, screw entering into joint cavity, and nonunion of fracture. There was no significant difference in the fracture healing time between the two groups ( t=-1.068, P=0.299). There were 2 cases of incision infection, 1 case of incision fat liquefaction, 2 cases of lower extremity deep vein thrombosis in group A, the incidence of complications was 25.0%; there was only 1 case of lower extremity deep vein thrombosis in group B, the incidence of complication was 4.5%, which was lower than that in group A, but the difference was not significant ( χ 2=2.104, P=0.147). In group A, 1 case was found to be dislocated, but in group B, there was no dislocated fracture. There was no significant difference between the two groups in the evaluation of Matta imaging on the next day after operation and the evaluation of Majeed function at 12 months after operation ( P>0.05).

CONCLUSION

Percutaneous retrograde pubic screw implantation assisted by hollow pedicle opener is effect for the pubic branch fractures with the advantage of smaller incision, shorter operation time, and less bleeding compared with traditional methods.

[Effectiveness of a modified posterior approach for arthroscopic resection on painful talocalcaneal coalition in adults]

OBJECTIVE

To investigate the effectiveness of arthroscopic talocalcaneal coalition resection in painful adults via a modified posterior approach.

METHODS

Between January 2015 and December 2017, 9 patients with painful talocalcaneal coalition accepted arthroscopic resection via the posterior malleolus high lateral observation approach combined with the lower medial operation approach. Of them, 6 were male and 3 were female, aged from 19 to 30 years (mean, 24 years). Among them, 2 cases had no definite local trauma and 7 cases had a history of sprain of foot and ankle. The disease duration ranged from 6 to 30 months, with a median of 12 months. Rozansky classification of talocalcaneal coalition for the 9 patients: 5 cases (5 feet) were type Ⅰ, 2 cases (2 feet) type Ⅱ, and 2 cases (2 feet) type Ⅲ. The patients had no sequelae of limb dysfunction and no limb joint surgery in the past. All the patients received anteroposterior and lateral X-ray films and CT scans of the ankle joint during follow-up. The visual analogue scale (VAS) score and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hind foot score were used to evaluate the effectiveness.

RESULTS

The operation time was 60-90 minutes (mean, 76 minutes). All patients were followed up 12-24 months (mean, 18 months). All the incisions healed by first intention, without infection, skin necrosis, lower extremity deep vein thrombosis, vascular nerve and tendon injury, bone bridge recurrence, and other complications. The ankle function recovered well and the pain was relieved obviously after operation, and the patients returned to work at 3-5 months after operation, with an average of 3.9 months. At last follow-up, the VAS score was 0.7±0.5, which was significantly improved ( t=20.239, P=0.000) when compared with preoperative score (4.2±0.5); the AOFAS ankle-hind foot score was 94±4, which was significantly improved ( t=-27.424, P=0.000) when compared with preoperative score (62±2). According to AOFAS ankle-hindfoot scoring system, the results were excellent in 7 cases and good in 2 cases at last follow-up.

CONCLUSION

It is more intuitive, more space, and more flexibility for operation via the modified posterior malleolus high lateral observation approach combined with the lower medial operation approach in talocalcaneal coalition. It is feasible to remove talocalcaneal coalition programmatically according to the specific anatomic signs during the operation.

[Application of individualized transiliac crest nail-grafting guide plate in deep pelvic external fixator implantation]

OBJECTIVE

To explore the application of individualized transiliac crest nail-grafting guide plate prepared by computer-aided design and three-dimensional (3D) printing technology in deep pelvic external fixator implantation.

METHODS

Five patients with pelvic fractures were collected between May 2017 and February 2018. There were 4 females and 1 male with an average age of 52 years (range, 29-68 years). Pelvic fractures were classified as type B in 3 cases and type C in 2 cases by Tile classification. The interval between injury and operation was 6-14 days (mean, 9 days). The preoperative CT images of pelvic fractures were collected. The data was reconstructed by 3D imaging reconstruction workstation. An individualized transiliac crest nail-grafting guide plate was designed on the virtual 3D model. The individualized transiliac crest nail-grafting guide plate and the solid pelvic model were produced with the 3D printing technology. The individualized transiliac crest nail-grafting guide plate was used for intraoperative deep pin position on iliac crest after the preoperative simulation. The follow-up CT scans were used to determine the differences in distance from anterior superior iliac spine, convergence angle, and caudal angle between the preoperative plan and postoperative measurement.

RESULTS

During the operation, the individualized transiliac crest nail-grafting guide plate was used to guide the placement of 20 pins. X-ray film and CT examination showed that all pins were well positioned. The average depth of pins was 83.16 mm (range, 70.13-100.53 mm). Fitted 3D reconstruction images showed that the entry point and orientation of the pins were all consistent with preoperative schemes. Compared with the planned nail path, there was no significant difference in the distance from anterior superior iliac spine, convergence angle, and caudal angle in the actual nail path ( P>0.05). No loosening and rupture of pin, no damage of blood vessels and nerve, and shallow or deep infection occurred during 3 months follow-up, and the incisions healed by first intention. All patients were satisfied with the treatment process. The ranges of motion of hip and knee were normal, and the visual analogue scale (VAS) score was 0-3 (mean, 0.5).

CONCLUSION

The individualized transiliac crest nail-grafting guide plate technique is the improvement of traditional technique. It can increase accuracy and effective depth of pin position, enable patients to obtain pelvic mechanical stability quickly after operation, and reduce the risk of complications related to nail path.