[A clinical study of HoloSight Orthopaedic Trauma Surgery Robot-assisted infra-acetabular screw placement for acetabular fractures].

Objective: To investigate the effectiveness of HoloSight Orthopaedic Trauma Surgery Robot-assisted infra-acetabular screw placement for treatment of acetabular fractures. Methods: The clinical data of 23 patients with acetabular fractures treated with open reduction and internal fixation and infra-acetabular screw placement in two medical centers between June 2022 and October 2023 were retrospectively analyzed. According to the the method of infra-acetabular screw placement, the patients were divided into navigation group (10 cases, using HoloSight Orthopaedic Trauma Surgery Robot-assisted screw placement) and freehand group (13 cases, using traditional X-ray fluoroscopy to guide screw placement). There was no significant difference in gender, age, body mass index, cause of injury, time from injury to operation, and Judet-Letournel classification between the two groups ( P>0.05). The time of infra-acetabular screw placement, the fluoroscopy frequency, the guide pin adjustment times, the quality of screw placement, the quality of fracture reduction, and the function of hip joint were compared between the two groups. Results: All patients completed the operation successfully. The time of screw placement, the fluoroscopy frequency, and guide pin adjustment times in the navigation group were significantly less than those in the freehand group ( P<0.05). The quality of screw placement in the navigation group was significantly better than that in the freehand group ( P<0.05). Patients in both groups were followed up 6-11 months, with an average of 7.7 months. There were 9 and 9 cases in the navigation group and the freehand group who achieved excellent and good fracture reduction quality at 1 week after operation, and 12 and 12 cases with excellent and good hip joint function at last follow-up, respectively, and there was no significant difference between the two groups ( P>0.05). The fractures in both groups healed well, and there was no significant difference in healing time ( P>0.05). During the follow-up, there was no complication related to screw placement, such as failure of internal fixation, vascular and nerve injury, incisional hernia. Conclusion: In the treatment of acetabular fractures, compared with the traditional freehand screw placement, the HoloSight Orthopaedic Trauma Surgery Robot-assisted screw placement can reduce the time of screw placement, improve the accuracy of screw placement, and reduce the amount of radiation, which is an efficient, accurate, and safe surgical method.

Biomechanical evaluation of novel intra- and extramedullary assembly fixation for proximal humerus fractures in the elderly.

Purpose: A novel intra- and extramedullary assembly fixation method was introduced, which achieved good clinical results in complex proximal humeral fractures; however, evidence of its comparability with traditional fixation is lacking. This biomechanical study aimed to compare it with traditional fixation devices in osteoporotic proximal humeral fractures. Methods: Three-part proximal humeral fractures with osteopenia were created on 12 pairs of fresh frozen humerus specimens and allocated to three groups: 1) lateral locking plate, 2) intramedullary nail, and 3) intra- and extramedullary assembly fixation. The specimens were loaded to simulate the force at 25° abduction. Thereafter, an axial stiffness test and a compound cyclic load to failure test were applied. Structural stiffness, number of cycles loaded to failure, and relative displacement values at predetermined measurement points were recorded using a testing machine and a synchronized 3D video tracking system. Results: In terms of initial stiffness and the number of cycles loaded to failure, the intra- and extramedullary assembly fixation group showed notable improvements compared to the other groups (p <0.017). The mean relative displacement value of measurement points in the intra- and extramedullary assembly fixation group was smaller than that in the other two groups. However, there was no significant difference until 10,000 cycles. The mean relative displacement of the intramedullary nail group (3.136 mm) exceeded 3 mm at 7,500 cycles of loading. Conclusion: In this test model, axial fixation can provide better mechanical stability than non-axial fixation. The intra- and extramedullary assembly fixation is better able to prevent the varus collapse for elderly proximal humeral fractures with posteromedial comminution.

[Effectiveness of three-dimensional visible technique without fluoroscopy versus two-dimensional fluoroscopy in reduction of unstable pelvic fractures].

Objective: To compare the reduction qualities of three-dimensional visible technique without fluoroscopy and two-dimensional fluoroscopy for unstable pelvic fractures during operations. Methods: The clinical data of 40 patients with unstable pelvic fractures, who met the selection criteria in three clinical centers between June 2021 and September 2022, were retrospectively analyzed. According to the reduction methods, the patients were divided into two groups. Twenty patients in trial group were treated with unlocking closed reduction system combined with three-dimensional visible technique without fluoroscopy; 20 patients in control group with unlocking closed reduction system under two-dimensional fluoroscopy. There was no significant difference in the gender, age, injury mechanism, Tile type of fracture, Injury Severity Score (ISS), and the time between injury to operation between the two groups ( P>0.05). The qualities of fracture reduction according to the Matta criteria, operative time, intraoperative blood loss, fracture reduction time, times of fluoroscopy, and System Usability Scale (SUS) score were recorded and compared. Results: All operations were successfully completed in both groups. According to the Matta criteria, the qualities of fracture reduction were rated as excellent in 19 patients (95%) in trial group, which was better than that in the control group (13 cases, 65%), with a significant difference ( χ 2=3.906, P=0.048). The operative time and intraoperative blood loss had no significant differences between the two groups ( P>0.05). The fracture reduction time and times of fluoroscopy were significantly less in trial group than in control group ( P<0.05), and SUS score in trial group was significantly higher in trial group than in control group ( P<0.05). Conclusion: Compared to using unlocking closed reduction system under two-dimensional fluoroscopy, three-dimensional visible technique without fluoroscopy can significantly improve the reduction quality of unstable pelvic fractures without prolonging the operative time, and is valuable to reduce iatrogenic radiation exposure for patients and medical workers.

[Early effectiveness of computer navigation system-assisted transiliac-transsacral screws placement for posterior pelvic ring injuries].

Objective: To investigate the early effectiveness of transiliac-transsacral screws internal fixation assisted by augmented reality navigation system HoloSight (hereinafter referred to as "computer navigation system") in the treatment of posterior pelvic ring injuries. Methods: A retrospective analysis was made in the 41 patients with posterior pelvic ring injuries who had been treated surgically with transiliac-transsacral screws between June 2022 and June 2023. The patients were divided into navigation group (18 cases, using computer navigation system to assist screw implantation) and freehand group (23 cases, using C-arm X-ray fluoroscopy to guide screw implantation) according to the different methods of transiliac-transsacral screws placement. There was no significant difference in gender, age, body mass index, causes of injuries, Tile classification of pelvic fracture, days from injury to operation, usage of unlocking closed reduction technique between the two groups ( P>0.05). The time of screw implantation, the fluoroscopy times, the guide wire adjustment times of each screw, and the incidence of complications were recorded and compared between the two groups. The position of the transiliac-transsacral screw was scanned by CT within 2 days after operation, and the position of the screw was classified according to Gras standard. Results: The operation was successfully completed in both groups. The time of screw implantation, the fluoroscopy times, and the guide wire adjustment times of each screw in the navigation group were significantly less than those in the freehand group ( P<0.05). There were 2 cases of incision infection in the freehand group, and the incision healed by first intention after active dressing change; there was no screw-related complication in the navigation group during operation and early period after operation; the difference in incidence of complications between the two groups (8.7% vs. 0) was not significant ( P=0.495). According to the Gras standard, the screw position of the navigation group was significantly better than that of the freehand group ( P<0.05). Conclusion: Compared with the traditional freehand method, the computer navigation system assisted transiliac-transsacral screws internal fixation in the treatment of posterior pelvic ring injuries has advantages of improving the accuracy of screw implantation and reducing radiation damage and the time of screw implantation.

[A multicenter retrospective study assessing pelvic unlocking closed reduction device for reducing unstable pelvic posterior ring disruption].

Objective: To explore the application value and effectiveness of pelvic unlocking closed reduction device for the treatment of unstable pelvic posterior ring disruption. Methods: A retrospective analysis of clinical data of 243 cases of unstable pelvic posterior ring disruption treated with pelvic unlocking closed reduction device in 13 orthopaedic trauma centers across the country between December 2018 and June 2020 was performed. There were 139 males and 104 females; the age ranged from 18 to 92 years, with an average age of 48.5 years. The cause of injury included 132 cases of traffic accident injuries, 102 cases of falling from height, and 9 cases of crushing injuries. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 5 cases of type 61-B1, 13 cases of type 61-B2, 32 cases of type 61-C1.1, 47 cases of type 61-C1.2, 89 cases of type 61-C1.3, 35 cases of type 61-C2, and 22 cases of type 61-C3. The time from injury to operation was 2-121 days, with a median of 10 days. Preoperative preparation time, installation time of unlocking closed reduction device, fracture reduction time, intraoperative fluoroscopy times, intraoperative blood loss, and surgical complications were recorded, and Matta scoring standard was used to evaluate the quality of fracture reduction. According to Matta evaluation results, the patients were divided into two subgroups: excellent-good group and fair-poor group. The differences in gender, age, time from injury to operation, AO/OTA classification, and perioperative clinical indicators were compared between the two groups, and the effects of baseline data and perioperative indicators on the quality of fracture reduction were studied. Results: Pelvic unlocking closed reduction device did not interfere with the display of the pelvic structure and fracture displacement direction during the intraoperative fluoroscopy, effectively correcting the displacement of the pelvic ring. The preoperative preparation time was 17-60 minutes, with an average of 30 minutes; installation time of unlocking closed reduction device was 10-32 minutes, with an average of 21 minutes; intraoperative fracture reduction time was 15-205 minutes, with an average of 49.2 minutes; intraoperative fluoroscopy times were 41-420 times, with an average of 132 times; intraoperative blood loss was 40-1 500 mL, with an average of 71.5 mL. The reduction quality of pelvic fracture was evaluated according to Matta score immediately after operation. The results were excellent in 153 cases, good in 61 cases, fair in 24 cases, and poor in 5 cases. The excellent and good rate was 88.1%. Further subgroup analysis showed that there was no significant difference in other indexes ( P>0.05) between the excellent-good group and the fair-poor group except for the time from injury to operation and AO/OTA classification ( P<0.05). Among them, the excellent-good reduction rate was 92.2% (119/129) in patients with injury-to-operation time less than 10 days, and the fair-poor reduction rate was 25.7% (9/35) and 40.9% (9/22) in patients with AO/OTA 61-C2 and 61-C3 types, respectively. There was no surgery-related complication due to the application of the pelvic unlocked reduction device, no secondary iliac fractures, vascular, or nerve injuries, and postoperative CT showed that all channel screws were located in the osseous channel. Conclusion: The pelvic unlocking reduction device can effectively help to reduce the unstable pelvic posterior ring and maintain reduction, meet the needs of different projection angles of pelvic fracture with intraoperative C-arm fluoroscopy. The system facilitate the operation of pelvic reduction and precise fixation.

[Application of channel-assisted minimally invasive repair system in Myerson types â and â ¡ chronic Achilles tendon rupture].

OBJECTIVE: To investigate the effectiveness of channel-assisted minimally invasive repair system (CAMIR) in treatment of the Myerson types Ⅰ and Ⅱchronic Achilles tendon rupture. METHODS: Between May 2016 and August 2017, 19 patients with Myerson types Ⅰ and Ⅱchronic Achilles tendon ruptures were treated with CAMIR. There were 14 males and 5 females, aged from 21 to 48 years, with an average age of 34.5 years. The disease duration was 5-9 weeks (mean, 7.5 weeks). The preoperative Thompson tests of affected ankles showed positive. There were 11 cases of Myerson type Ⅰwith the gaps of Achilles tendon defect of 1-2 cm (mean, 1.58 cm), and 8 cases of Myerson type Ⅱwith the gaps of Achilles tendon defect of 2.5-4.0 cm (mean, 3.16 cm). The ankle dorsiflexion and plantarflexion range of motion were measured before and after operation; the American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score was used to assess the patients' ankle joint function. RESULTS: No major blood vessels, nerves, and other tissue structures were damaged during the operation; 3 cases of Myerson type Ⅰ were converted to Myerson type Ⅱ according to the gaps of the defect after the scar tissue was removed during the operation. After operation, the depressed part of the Achilles tendon disappeared, the continuity of the tendon was restored, and the Thompson tests were negative. All 19 patients were followed up 12-25 months, with an average of 14 months. All incisions healed by first intention, and no infection and skin necrosis occurred; all the pre-injury activities and exercise were restored at 6 months after operation. During the follow-up period, no heel pain or re-rupture occurred. At last follow-up, except that there was no significant difference in ankle dorsiflexion range of motion of Myerson type Ⅰ patients ( t=2.118, P=0.071), the AOFAS ankle and hindfoot score, ankle plantarflexion range of motion of Myerson types Ⅰ and Ⅱ patients, and ankle dorsiflexion range of motion of Myerson type Ⅱ patients were significantly improved when compared with preoperative values ( P<0.05). According to AOFAS ankle and hindfoot function score, the ankle joint function of type Ⅰ patients was excellent in 7 cases and good in 1 case, and of type Ⅱ patients were excellent in 8 cases, good in 2 cases, and fair in 1 case. CONCLUSION: CAMIR is safe and effective in the treatment of Myerson types Ⅰ and Ⅱ chronic Achilles tendon rupture with fewer complications and better functional recovery of ankle joint.

Comparison of channel-assisted minimally invasive repair and 3 common Achilles tendon restoration techniques.

The present study aimed to investigate the biomechanical comparison of channel-assisted minimally invasive restoration and three common Achilles tendon restoration techniques in an in vitro model via a progressive rehabilitation program. The 42 porcine tendons were randomly assigned to the following six groups of tendons (n=7/group): Achillon, percutaneous Achilles repair system (PARS), Krackow, channel-assisted minimally invasive repair (CAMIR), CAMIR augmentation (CAMIR+), CAMIR-5 (repair with No. 5 Ethibond suture). There was no significant difference in elongation among groups following the first 10 loading cycles, which consisted of 20-100 N at 1 Hz. The elongation of the CAMIR group (7.51±1.77 mm) was significantly longer than the Achillon group (3.19±0.57 mm) and PARS group (3.73±0.66 mm; P<0.05) following 1,000 cycles. However, the CAMIR group exhibited no significant difference vs. the Krackow (7.32±1.09 mm) and CAMIR+ groups (7.11±1.50 mm) following 1,000 cycles. Following 2,000 cycles, there was no significant difference between the CAMIR-5 (7.99±1.68 mm) group, and the Achillon (3.19±0.57 mm) and PARS groups (3.73±0.66 mm). At the point of restoration construct failure, the total cycles of the CAMIR group (median, 1,000; range, 1,000-1,000) were significantly less than the Achillon group (median, 2,000; range, 2,000-2,013) and PARS group (median, 2,000; range, 2,000-2,010; P<0.05), but had no significant difference compared with the Krackow group (median, 1,000; range, 1,000-1,000) and CAMIR+ group 1,000 (median, 1,000; range, 1,000-1,004). There was also no significant difference between the CAMIR-5 group (median, 2,000; range, 2,000-2,000), and the Achillon group (median, 2,000; range, 2,000-2,013) and PARS group (median, 2,000; range, 2,000-2,010). Restricted by the strength of suture, the one-suture CAMIR restoration technique was weaker than the three-suture Achillon and PARS restoration techniques, but there was no significant difference with the open Krackow restoration technique, which provides a reliable mechanical strength for repairing. CAMIR has an advantage of reducing the risk of suture reactivity.

[APPLICATION OF POSTEROLATERAL APPROACH FOR TREATMENT OF BIMALLEOLAR AND TRIMALLEOLAR FRACTURES].

OBJECTIVE: To evaluate the advantage of single posterolateral approach for exposing the fragments of lateral malleolus and posterior malleolus in treating bimalleolar and trimalleolar fractures. METHODS: Between January 2013 and June 2015, 47 patients with ankle fractures were treated. Of 47 cases, 16 were male and 31 were female with an average age of 47.7 years (range, 25-65 years); the locations were the left side in 21 cases and the right side in 26 cases. According to types system of Lauge-Hansen, 11 cases were rated as pronation-external rotation and 36 cases as supination-external rotation. There were 9 cases of bimalleolar fractures and 38 cases trimalleolar fractures. CT examination showed that posterior malleolus fracture involved more than 35% of the joint surface in 11 cases, and 9 cases had comminuted posterior malleolus fracture. Of 47 cases, 44 had fresh fractures with a mean disease course of 4 days (range, 8 hours to 7 days), and 3 had old fracture with the disease course of 43, 58, and 62 days respectively. Posterior malleolus fractures were fixed with T-type plates in 12 cases, one-third tubular plates in 10 cases, and cannulated screws in 25 cases. RESULTS: The operation time was 60-100 minutes (mean, 80 minutes); the bleeding volume was 50-100 mL (mean, 72 mL). Primary healing of incision was obtained in all patients, and no postoperative complications of infection, cutaneous necrosis, deep venous thrombosis, and sural nerve injury occurred. The CT examinations after operation showed anatomical reduction of fractures. All patients were followed up from 12 to 20 months (mean, 16 months). No fixation failure or reduction loss was found at last follow-up. All patients could walk normally. The active dorsiflexion of the affected ankles was within 5° less than normal side in 43 cases (91.5%) and 5-10° less than normal side in 4 cases (8.5%). The passive dorsiflexion of the affected ankles was within 5° less than normal side in 44 cases (93.6%) and 5-10° less than normal side in 3 cases (6.4%). According to the Olerud-Molander scoring system, the results were excellent in 40 cases, good in 5 cases, and fair in 2 cases; and the excellent and good rate was 95.7% at last follow-up. CONCLUSIONS: The single posterolateral approach could simultaneously expose the fragments of lateral malleolus and posterior malleolus, with less complication of the incision, short operation time, and clear exposure of posterior malleolus. The surgery could be performed under direct vision. It especially is suitable for bimalleolar and trimalleolar fractures with lateral malleolus and posterior malleolus.