A modified single-endobutton technique combined with nice knot for treatment of Rockwood type III or V acromioclavicular joint dislocation

The effect of number of knots per throw, knot technique, and suture type on strength properties of suspensory fixation button surgical procedures

Background

Previous studies of the cortical suspensory button (CSB) implant have analyzed fixation strength as a function of suture type and surgical technique, but knot configuration remains an area of interest. This study investigates 4-strand knot configurations in CSB suspensory fixation, specifically comparing the use of 2 separate knots with a single knot. We hypothesize that using 2 knots on the distal side of the CSB with #2 suture will yield the strongest and stiffest suspensory fixation.

Methods

Two types of knot configurations were compared: a single knot with all 4 suture strands versus 2 independent knots with 2 suture strands each (1 knot from inner strands and 1 knot from outer strands). They were tested using #2 or 2-0 suture, and at distal (on top of the button) or proximal (underneath the button) knot positions. Mechanical testing on the Instron measured ultimate failure load, elongation at failure, and stiffness. Statistical analyses (Shapiro-Wilk, unpaired Student's t-tests, and Chi-square tests) assessed differences in strength, stiffness, elongation, and failure mode between knot configurations within each CSB construct combination.

Results

With #2 suture, 2 knots across the CSB resulted in higher load to failure compared to 1 knot in both proximal (467.00 N vs. 554.66 N, P = .026) and distal (395.18 N vs. 526.51 N, P < .001) locations. Furthermore, 2 knots provided higher stiffness than 1 knot in both proximal (53.24 N/mm vs. 67.89 N/mm, P < .001) and distal (47.08 N/mm vs. 56.73 N/mm, P = .041) knot locations. However, using 2-0 suture showed no significant differences in failure load and stiffness regardless of knot location.

Conclusion

Using #2 suture and tying 2 independent knots across the CSB increased load to failure and stiffness compared to using only 1 knot regardless of knot position. Thus, if using #2 suture, it is recommended to tie 2 knots to enhance construct strength. However, with 2-0 suture, the number of knots did not impact construct strength. Therefore, if using 2-0 suture, 1 knot can be used to save time. Knot position did not significantly affect the strength or stiffness of the CSB construct, emphasizing the importance of considering knot prominence and surgical approach for determining knot location.

A Self-Designed Endobutton Installation Device for Coracoclavicular Stabilization in Acute Rockwood Type III Acromioclavicular Joint Dislocation

OBJECTIVE

Endobutton technique could provide flexible coracoclavicular (CC) stabilization for acromioclavicular joint (ACJ) dislocation and achieved good clinical outcomes. However, the difficult part of this technique was placement of the Endobutton to the coracoid base. In this study, we designed an Endobutton installation device to place the Endobutton at the coracoid base. And we examined the clinical and radiographic outcomes of patients with acute Rockwood type III ACJ dislocation repaired with Endobutton using this device.

METHODS

We designed an Endobutton installation device to place the Endobutton at the coracoid base to achieve CC stabilization. We retrospectively reviewed 42 patients with acute Rockwood type III ACJ dislocation who underwent CC stabilization with Endobuttons placed either using this novel device (group I, n = 19) or the traditional technique (CC stabilization without using special device, group II, n = 23) from January 2015 to April 2020. The two groups were compared regarding the operative time, intraoperative blood loss, and clinical and radiologic outcomes at final follow-up. The operation-related complications were also evaluated. The Student's t test and the Mann-Whitney U-test were used to compare differences in continuous variables. Differences in categorical variables were assessed with either the Pearson's chi-squared test or Fisher's exact test.

RESULTS

Forty-two patients were clinically followed up for a minimum of 12 months. Compared with group II, group I had a significantly shorter mean operative time (56.05 ± 7.82 min vs. 65.87 ± 7.43 min, p < 0.01) and significantly lesser mean intraoperative blood loss (67.89 ± 14.75 mL vs. 94.78 ± 25.01 mL, p < 0.01). At final follow-up, there were no significant differences between the two groups in the visual analog scale score for pain, Oxford Shoulder Score, Disabilities of the Arm, Shoulder, and Hand score, and postoperative CC distance of the affected side. Loss of reduction occurred in four patients in group I and three patients in group II (p = 0.68); there were no other operation-related complications in either group.

CONCLUSIONS

The Endobutton installation device makes placement of the Endobutton at the coracoid base easier and achieves satisfactory clinical and radiologic outcomes without additional complications in acute Rockwood type III ACJ dislocation.

[Application of Nice knot technique in wound closure of Gustilo type A and B open tibial fractures]

Objective

To explore the effectiveness of Nice knot technique for wound closure in Gustilo type ⅢA and ⅢB open tibial fractures.

Methods

A retrospective study was performed on 22 patients with Gustilo type ⅢA and ⅢB open tibial fractures, who underwent wound closure using the Nice knot technique and were admitted between June 2021 and June 2022. There were 15 males and 7 females. The age ranged from 18 to 67 years, with an average of 41.9 years. The causes of injury included traffic accident in 11 cases, falling from height in 7 cases, and heavy object injuries in 4 cases. Fractures were located on the left side in 9 cases and on the right side in 13 cases. And 9 cases were type ⅢA fractures and 13 were type ⅢB fractures according to Gustilo classification. All patients had extensive soft tissue injuries, and no vascular or neurological damage was observed. The time from injury to debridement was 3-8 hours (mean, 6.5 hours). The sizes of wounds before operation and at 2 weeks after operation were measured and wound healing rate at 2 weeks after operation were calculated. The wound healing time and wound healing grading were recorded. The Vancouver Scar Scale (VSS) score was used to assess the wound scar after wound healed and the excellent and good rate was calculated.

Results

The wound area was 21.0-180.0 cm 2 (mean, 57.82 cm 2) before operation, and it was 1.2-27.0 cm 2 (mean, 6.57 cm 2) at 2 weeks after operation. The wound healing rate at 2 weeks after operation was 76%-98% (mean, 88.6%). After operation, 2 cases needed to adjust Nice knot due to skin cutting and 1 case occurred soft tissue infection on the wound. The other patient's wounds healed. The average wound healing time was 27.8 days (range, 18-44 days). And the wound healing were grade A in 13 cases and grade B in 9 cases. VSS score was 2-9, with an average of 4.1; 10 cases were rated as excellent, 10 as good, and 2 as poor, with an excellent and good rate of 90.9%. All patients were followed up 9-24 months (mean, 14.6 months). During follow-up, no deep infection or osteomyelitis occurred. Two cases experienced fracture non-union, and were treated with compression fixation and bone grafting. The fractures of the other patients all healed, with a healing time of 85-190 days (mean, 148.2 days).

Conclusion

Nice knot technique can be used in wound closure of Gustilo type ⅢA and ⅢB open tibial fractures effectively, which is easy to operate.

Biomechanical study of posterior cruciate ligament tibial arrest avulsion fracture fixation with triple tibial channel net sutures

To investigate the biomechanical properties of posterior cruciate ligament avulsion fractures of the tibia fixed using four different methods, including triple tibial channel net suture fixation. In 40 porcine knees, a standardized bony avulsion of the posterior cruciate ligament was generated. Double tibial bone channel suture fixation was performed in group A, double-head hollow compression screw fixation was performed in group B, triple tibial bone channel net suture fixation was performed in group C, and cortical suspension EndoButton fixation was performed in group D. The constructs were cyclically loaded 500 times (10 to 100 N) to measure the initial displacement and stiffness values. Subsequently, loading to failure was performed, and the yield load and peak load were measured. The results were analysed by one-way ANOVA, with significance set at P < 0.05. The initial displacement in group D (1.00 ± 0.20 mm) was lower than that in group C (1.46 ± 0.33 mm, P = 0.000), group B (1.91 ± 1.71 mm, P = 0.000) and group A (3.91 ± 0.79 mm, P = 0.000), but there was no significant difference between groups B and C (P = 0.055). The initial stiffness in group A (50.59 ± 6.89 N/mm) was lower than that in group C (67.21 ± 12.80 N/mm, P = 0.001), group D (71.18 ± 9.20 N/mm, P = 0.000) and group B (78.67 ± 5.91 N/mm, P = 0.000). However, there was no significant difference between groups B and D or between groups C and D (P = 0.111 and P = 0.391). The yield load in group A (554.86 ± 71.43 N) was lower than that in group C (767.00 ± 34.53 N, P = 0.000), group D (777.62 ± 73.03 N, P = 0.000) and group B (837.50 ± 55.73 N, P = 0.000). There was no significant difference between groups C and D (P = 0.729). The peak load in group A (667.38 ± 61.54 N) was lower than that in group C (842.00 ± 26.20 N, P = 0.000), group D (867.63 ± 63.42 N, P = 0.000) and group B (901.25 ± 54.38 N, P = 0.000). There was no significant difference between groups C and D (P = 0.346). Different failure modes were found among the four groups. The triple tibial bone channel suture fixation group showed better initial stability and fixation strength, which was comparable to that in the cortical suspension EndoButton fixation group and double-head hollow compression screw fixation group and significantly stronger than that in the double tibial bone channel suture fixation group. This study analysed the dynamic and static indexes of posterior cruciate ligament tibial avulsion fractures fixed by four different fixation methods under cyclic loading tests and single failure loading tests, providing a theoretical basis for clinical treatment.

A double-suture cerclage reduction technique with Nice knots for comminuted patella fractures (AO/OTA 34-C3)

BACKGROUND

Comminuted patella fractures place high demands on surgeons' surgical skills. We used a double-suture cerclage reduction with Nice knots as an intra-operative reduction technique to displaced comminuted patella fractures.

METHODS

Patients were divided into two groups by whether or not an intra-operative suture cerclage reduction technique was used. Fragments count, surgical time, quality of the reduction, and fracture healing time were recorded. The postoperative function was assessed by Böstman score and range of motion.

RESULTS

With the inclusion and exclusion criteria, 48 patients we included in the cohort between Sept. 2016 and Oct. 2021. The double-suture cerclage reduction technique with a Nice knot achieved a satisfactory reduction. When the number of fragments was over 5, this technique showed significant advantages in saving surgery time.

CONCLUSIONS

In this study, the double-suture cerclage reduction technique combined with the Nice knot shows significant advantages for displaced highly comminuted patella fractures. This technique simplifies the operation and saves surgical time, which is helpful for clinical practice.