Single-Molecule Imaging Reveals that Rad4 Employs a Dynamic DNA Damage Recognition Process.

Nucleotide excision repair (NER) is an evolutionarily conserved mechanism that processes helix-destabilizing and/or -distorting DNA lesions, such as UV-induced photoproducts. Here, we investigate the dynamic protein-DNA interactions during the damage recognition step using single-molecule fluorescence microscopy. Quantum dot-labeled Rad4-Rad23 (yeast XPC-RAD23B ortholog) forms non-motile complexes or conducts a one-dimensional search via either random diffusion or constrained motion. Atomic force microcopy analysis of Rad4 with the ß-hairpin domain 3 (BHD3) deleted reveals that this motif is non-essential for damage-specific binding and DNA bending. Furthermore, we find that deletion of seven residues in the tip of ß-hairpin in BHD3 increases Rad4-Rad23 constrained motion at the expense of stable binding at sites of DNA lesions, without diminishing cellular UV resistance or photoproduct repair in vivo. These results suggest a distinct intermediate in the damage recognition process during NER, allowing dynamic DNA damage detection at a distance.

Surgical treatment of acromioclavicular joint dislocation of Rockwood III/IV: a retrospective study on clavicular hook plate versus arthroscopic TightRope loop titanium button.

PURPOSE: To compare the clinical efficacy of arthroscopic TightRope loop titanium button and clavicular hook plate in the treatment of acromioclavicular joint (ACJ) dislocation of Rockwood III/IV. METHODS: A retrospective analysis of patients with ACJ dislocation in our hospital from January 2018 to December 2020 was conducted. The patients were assigned to be treated with arthroscopic TightRope loop titanium button (TR group) or clavicular hook plate (HP group). The preoperative, intraoperative and postoperative data and imaging findings of the two groups were compared. RESULTS: A total of 58 eligible patients were enrolled in this study. Compared with HP group, TR group had shorter incision length and less blood loss during operation. Postoperative follow-up ranged from 12 to 24 months (mean 15.4 months). At 6 months and 12months postoperatively, compared with HP group, TR group had lower VAS and higher CMS, and the difference was statistically significant. At 12 months postoperatively, compared with HP group, TR group had lower ACJ gap and coracoclavicular joint(CCJ) distance, and the difference was statistically significant.In HP group, there were 3 cases of subacromial impact, 1 case of redislocation, 2 cases of traumatic arthritis and 2 cases of wound infection. There was 1 case of redislocation in TR group. CONCLUSIONS: Compared with clavicular hook plate, arthroscopic TightRope loop titanium button is minimally invasive, safe and effective in the treatment of ACJ dislocation, and has a good trend in clinical application.

The TightRope study: a cadaveric, biomechanical comparison of generations of suspensory fixation with internal brace for Rockwood grade V acromioclavicular joint injuries.

BACKGROUND: Surgical treatment of Rockwood grade V acromioclavicular (AC) joint injuries remains varied. We hypothesized that the addition of a second suspensory device between the clavicle and coracoid would yield superior biomechanical results over a single device. We also hypothesized that the addition of an internal brace across the AC joint to a suspensory device would yield superior results over the suspensory device in isolation. METHODS: A total of 24 cadaveric shoulders were dissected and randomized to 4 groups with 4 different constructs implanted: group A, single AC TightRope (Arthrex Inc.); group B, double AC TightRope; group C, single Knotless AC TightRope (Arthrex Inc.); group D: single Knotless AC TightRope with AC InternalBrace ligament augmentation (Arthrex Inc.). These were then loaded in a robotic arm (SIMVITRO), where 250 cycles of 50 N of force in the superior plane was applied. Dynamic creep, displacement, translation, and stiffness were assessed. RESULTS: Testing was successfully completed for all specimens. There were no failures due to fracture or translation of the clavicle >5 mm from the starting position. Reduction was maintained with a mean superior displacement of 1.7 mm (±1.4 mm). The mean peak-to-peak displacement, superior and posterior translation, dynamic creep, and stiffness did not differ significantly between the construct groups. CONCLUSION: This study did not demonstrate any significant biomechanical differences between groups in terms of displacement, translation, creep, or stiffness.

3D C-arm navigated acromioclavicular joint stabilization.

INTRODUCTION: Surgical treatment options for acromioclavicular joint separations are varied. Frequently, suspension devices (SD) are inserted for stabilization under arthroscopic view. This study investigates the feasibility and accuracy of three-dimensional (3D) digital-volume-tomography (DVT) C-arm navigated implantation with regard to the general trend toward increasingly minimally invasive procedures. MATERIALS AND METHODS: The implantation of a TightRope® suture button system (SD) via a navigated vertical drill channel through the clavicle and coracoid was investigated in 10 synthetic shoulder models with a mobile isocentric C-arm image intensifier setup in the usual parasagittal position. Thereby, in addition the placement of an additive horizontal suture cerclage via a navigated drill channel through the acromion was assessed. RESULTS: All vertical drill channels in the Coracoclavicular (CC) direction could be placed in a line centrally through the clavicle and the coracoid base. The horizontal drill channels in the Acromioclavicular (AC) direction ran strictly in the acromion, without affecting the AC joint or lateral clavicle. All SD could be well inserted and anchored. After tensioning and knotting of the system, the application of the horizontal AC cerclage was easily possible. The image quality was good and all relevant structures could be assessed well. CONCLUSION: Intraoperative 3D DVT imaging of the shoulder joint using a mobile isocentric C-arm in the usual parasagittal position to the patient is possible. Likewise, DVT navigated SD implantation at the AC joint in CC and AC direction on a synthetic shoulder model. By combining both methods, the application in vivo could be possible. Further clinical studies on feasibility and comparison with established methods should be performed.

Differences in gait analysis and clinical outcome after dynamic fixation or screw fixation in acute syndesmosis tear: a prospective randomized pilot study.

INTRODUCTION: Acute syndesmosis tears can be treated by static screw or dynamic fixation. Various studies have compared these techniques regarding postoperative outcome. However, to our knowledge, no study has used 3D-instrumented gait analysis (IGA). We hypothesized that a dynamic fixation would perform non-inferior to screw fixation in terms of biomechanical and clinical outcomes. MATERIALS AND METHODS: Patients were prospectively randomized to both groups. All patients received the same follow-up rehabilitation and consultations (6 and 12 weeks; 6 and 12 months) postoperatively. Standardized questionnaires were used to objectify pain and ankle function. At 6 months follow-up, IGA was conducted additionally to objectify the biomechanical outcome. RESULTS: Twenty-five patients in the dynamic fixation (DF) group using TightRope® and twenty-five in the screw fixation group (SF) completed gait analysis. The DF group showed significantly higher mean values for maximum moment in the affected ankle joint (DF: 1.40 ± 0.21 Nm, SF: 1.23 ± 0.30 Nm; p = 0.023) and the unaffected ankle joint (DF: 1.52 ± 0.20 Nm, SF: 1.37 ± 0.27 Nm; p = 0.035). The difference between the affected and unaffected ankle joint was significantly higher in the SF group for active plantarflexion (DF: 1.52 ± 0.20°, SF: 1.37 ± 0.27°; p = 0.035). Both dynamic and screw fixation groups exhibited significantly reduced plantarflexion during the push-off and early swing phase, with moments and powers in the ankle joint also significantly impaired. CONCLUSIONS: Our study demonstrated that dynamic fixation has better or similar biomechanical and clinical outcomes compared to screw fixation. Future research should focus on biomechanical differences during gait as well as clinical outcomes in case of earlier weight-bearing after dynamic fixation. TRIAL REGISTRATION NUMBER (TRN): DRKS00013562 Date of Registration: 07/12/2017.

No correlation exists between coracoid tunnel widening and loss of reduction after arthroscopic acromioclavicular fixation using tightrope system.

PURPOSE: To detect the widening of the tunnel of the coracoid process after arthroscopic fixation of acute acromioclavicular joint (ACJ) dislocation using the TightRope system and its correlation with loss of reduction and functional scores. METHODS: From 2016 to 2018, a prospective study was performed on twenty-three patients with acute grade III-V ACJ dislocation. Arthroscopic TightRope repair of the ACJ was performed. Coracoid tunnel widening was measured by CT, and the coracoclavicular distance was measured on the radiographs immediately postoperatively and at 12 months. The Constant Shoulder Score, Oxford Shoulder Score, Nottingham Clavicle Score and Visual analog scale were used as outcome measures at 12 months. RESULTS: The coracoid tunnel diameter to horizontal coracoid diameter ratio increased from 22.8 ± 3.7% immediately postoperatively to 38.5 ± 5.5% at 12 months (p < 0.001). The coracoclavicular (CC) distance showed an increase from a mean of 10.8 ± 1.7 mm to a mean of 11.8 ± 2.5 at 12 months (p < 0.001). There was no correlation between the increase in the coracoclavicular distance and the patients' functional clinical scores or coracoid tunnel widening. CONCLUSION: Coracoid tunnel widening and radiological loss of reduction occur after arthroscopic fixation of acute ACJ dislocation with the TightRope system. However, they do not correlate with each other or with the functional scores of the patient. LEVEL OF EVIDENCE: Level IV.

Treatment options for acute Rockwood type III-V acromioclavicular dislocations: a network meta-analysis of randomized controlled trials.

BACKGROUND: Acute Rockwood type III-V acromioclavicular (AC) dislocations have been treated with numerous surgical techniques over the years. The purpose of this study was to perform a network meta-analysis (NMA) of randomized controlled trials to quantitatively define the optimal treatment for AC dislocations requiring operative treatment. METHODS: A literature search of 3 databases was performed based on Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Randomized controlled trials comparing 1 of 10 treatments for acute Rockwood type III-V AC dislocations-nonoperative treatment, Kirschner wire fixation (KW), coracoclavicular screw fixation (Scr), hook plate (HP), open coracoclavicular cortical button (CBO), arthroscopic coracoclavicular cortical button (CBA), ≥2 coracoclavicular cortical buttons (CB2), isolated graft reconstruction (GR), cortical button with graft augmentation (CB-GR), and coracoclavicular and acromioclavicular fixation (AC)-were included. Clinical outcomes were compared using a frequentist approach to NMA, with statistical analysis performed using the R program. Treatment options were ranked using the P-score, which estimates the likelihood that the investigated treatment is the ideal method for an optimal result in each outcome measure on a scale from 0 to 1. RESULTS: Of 5362 reviewed studies, 26 met the inclusion criteria, with a total of 1581 patients included in the NMA. AC, CB-GR, GR, CB2, CBA, and CBO demonstrated superiority over HP, Scr, KW, and nonoperative treatment at final follow-up for the Constant-Murley score and Disabilities of the Arm, Shoulder and Hand score, with AC and CB-GR showing the highest P-scores for the Constant-Murley score (0.957 and 0.781, respectively) and GR and CBO showing the highest P-scores for the Disabilities of the Arm, Shoulder and Hand score (0.896 and 0.750, respectively). GR had the highest P-score for the visual analog scale score (0.986). HP, CB2, CB-GR, AC, CBA, and CBO demonstrated superiority in the coracoclavicular distance (CCD) and recurrence at final follow-up, with HP and CB2 having the highest P-scores for the CCD (0.798 and 0.757, respectively) and with GR and CB-GR having the highest P-scores for recurrence (0.880 and 0.855, respectively). KW and Scr showed the shortest operative times (P-scores of 0.917 and 0.810, respectively), whereas GR and CBA showed the longest operative times (P-scores of 0.120 and 0.097, respectively). CONCLUSIONS: Although there are multiple fixation options for acute Rockwood type III-V AC dislocations, adding AC fixation or graft augmentation likely improves functional outcomes and decreases the CCD and recurrence rate at final follow-up-at the expense of longer operative times.

Suspension arthroplasty using the palmaris longus tendon with a suture button for thumb trapeziometacarpal arthritis: a retrospective observational study.

BACKGROUND: This study was performed to assess the clinical and radiographic results at a minimum of 2 years after ligament reconstruction suspension arthroplasty (LRSA) that comprised full trapeziectomy and suspensionplasty using the palmaris longus tendon and the Mini TightRope (Arthrex, Naples, FL) for advanced thumb carpometacarpal arthritis. METHODS: We clinically and radiographically evaluated 26 thumbs in 26 patients who had undergone LRSA at least 2 years previously. The mean follow-up period was 35.9 months. We evaluated the subjective clinical outcomes (visual analogue scale and Quick Disabilities of the Arm, Shoulder, and Hand scores) and objective clinical outcomes (range of motion, pinch strength, grip strength, and trapezial space height ratio). RESULTS: At the final follow-up evaluation, the mean visual analogue scale score was 11.1 (standard deviation (SD) 13.4) and the mean Quick Disabilities of the Arm, Shoulder, and Hand questionnaire score was 9.39 (SD 10.1). The mean palmar and radial abduction were 62.3° (SD 11.8°) and 63.8° (SD 9.09°), respectively. The mean key pinch and grip strength were 3.92 (SD 1.07) kg and 19.7 (SD 7.77) kg, respectively. The mean trapezial space ratio was 0.21 (SD 0.10). The subjective clinical outcomes, range of motion, and pinch strength were significantly improved compared with preoperatively. CONCLUSIONS: LRSA for advanced-stage thumb carpometacarpal osteoarthritis relieves pain, improves range of motion and strength, and obtains favourable subjective patient-reported clinical outcomes.

Open coraco-clavicular ligament reconstruction (CCLR) in treatment of displaced distal clavicle fractures has low complication rate and excellent union rate: a systematic review.

BACKGROUND: It is well established that non-operative treatment of displaced distal clavicle fractures (DDCF) leads to a high non-union rate. A number of open surgical treatments in the past have shown good to excellent outcomes including shoulder function and union rate. Despite this there is no consensus on the outcome of open coraco-clavicular ligament reconstruction (CCLR). The aim of this systematic review was to assess the union rate, complications and shoulder function of open CCLR techniques in the treatment of DDCF. PATIENTS AND METHODS: A review of the online databases MEDLINE and Embase was conducted on 1 January 2021 according to PRISMA guidelines. The review was registered prospectively in the PROSPERO database. Clinical studies reporting union rate, complications and shoulder function were included. The studies were appraised using the Methodological Index for Non-Randomized Studies (MINORS) tool. RESULTS: The search strategy identified 18 studies eligible for inclusion with a total of 330 patients. These included 12 retrospective case series and 5 nonrandomized retrospective comparative studies and one RCT. All but one study reported on shoulder function, while all the studies reported on union rate and complications. The overall shoulder function was good to excellent using Constant-Murley score. The overall union rate was 97.6% and complication rate was 7.6%. CONCLUSION: Open CCLR for displaced distal clavicle fractures that have a disruption of CC ligament, is a reliable treatment with excellent union rate and good to excellent shoulder functional scores. LEVEL OF EVIDENCE: IV; Systematic review.

Mid-term outcome of arthroscopic TightRope fixation of displaced lateral end clavicular fractures: Average follow-up of 6.1 years.

PURPOSE: Various surgical modalities are available to treat Neer types 2 and 5 unstable fractures of lateral end clavicle but none of them are standardized. Arthroscopic fixation of the displaced lateral end clavicle fractures provides good short-term results but mid- to long-term outcomes are not available. The purpose of this study was to show the mid- to long-term radiological and functional outcomes of these fractures treated arthroscopically by a TightRope device, and to show the complications associated with this procedure. METHODS: A retrospective study was conducted over 2 years from January 2014 to December 2015 with a minimum 5-year follow-up. Active patients aged 18-50 years with acute (less than 3 weeks) displaced fracture of lateral end of the clavicle, with a minimum 5-year follow-up were included in the study. Patients with associated fractures of the proximal humerus, glenoid, scapula and acromioclavicular joint injuries were excluded from the study along with open fractures and neurovascular injuries. The outcomes were assessed by objective (complications and radiographic examination) and subjective criteria (quick disabilities of the arm, shoulder and hand score, the Constant-Murley score and the visual pain analogue scale). The data were analyzed by SPSS version 21.0. RESULTS: Totally, 42 patients were operated during the study period and 37 were available with a minimum 5-year follow-up. Thirty were male and 7 were female with a mean age of 29.5 years and a mean follow-up of 6.1 years. The mean quick disabilities of the arm, shoulder and hand score was 68.2 ± 4.6 preoperatively and 1.27 ± 2.32 at final follow-up (p < 0.001); the mean visual pain analogue scale score was 6.85 ± 2.2 preoperatively and 0.86 ± 1.60 at final follow-up (p < 0.001). The average Constant-Murley score was 93.38 ± 3.25 at the end of the follow-up. There were 2 fixation failures, with established non-union and 3 patients developed radiographic acromioclavicular joint arthritis. CONCLUSIONS: Arthroscopic TightRope fixation of displaced lateral end clavicular fractures provides good radiological and functional outcomes at mid- to long-term follow-up. With the low complication rates and high patient satisfaction, this technique can be considered as a primary option in the surgical treatment of these fractures.

Various Flexible Fixation Techniques Using Suture Button for Ligamentous Lisfranc Injuries: A Review of Surgical Options.

Contrary to Lisfranc joint fracture-dislocation, ligamentous Lisfranc injury can lead to additional instability and arthritis and is difficult to diagnose. Appropriate procedure selection is necessary for a better prognosis. Several surgical methods have recently been introduced. Here, we present three distinct surgical techniques for treating ligamentous Lisfranc employing flexible fixation. First is the "Single Tightrope procedure", which involves reduction and fixation between the second metatarsal base and the medial cuneiform via making a bone tunnel and inserting Tightrope. Second is the "Dual Tightrope Technique", which is similar to the "Single Tightrope technique", with additional fixation of an intercuneiform joint using one MiniLok Quick Anchor Plus. Last but not least, the "internal brace approach" uses the SwiveLock anchor, particularly when intercueniform instability is seen. Each approach has its own advantages and disadvantages in terms of surgical complexity and stability. These flexible fixation methods, on the other hand, are more physiologic and have the potential to lessen the difficulties that have been linked to the use of conventional screws in the past.

Comparative analysis of arthroscopic-assisted Tight-rope technique and clavicular hook plate fixation in the treatment of Neer type IIB distal clavicle fractures.

BACKGROUND: The aim of the present study was to compare the clinical efficacy of arthroscopic-assisted fixation using the Tight-rope system and clavicular hook plate fixation in the treatment of Neer IIB distal clavicle fractures. METHODS: We enrolled 48 consecutive patients with Neer IIB distal clavicle fractures who were treated at our institution from February 2016 and August 2020. These patients were divided into 2 groups based on the fixation method (16 cases with Tight-rope system and 32 cases with clavicular hook plate), and demographics and clinical characteristics of patients in different groups were compared. RESULTS: All 48 patients had functional outcome scores of the affected shoulder available at a mean of 23.8 ± 5.1 months, and there was a statistically significant improvement in the constant score, American shoulder and elbow surgeons (ASES) score, visual analogue scale (VAS) score at the end of follow-up (p < 0.001 respectively). However, the smaller length of skin incision, less estimated blood loss and shorter hospital stay were detected in the Tight-rope technique group patients than those of clavicular hook plate group patients (p < 0.001, respectively). Furthermore, the constant score, ASES score and VAS score were significantly improved in the Tight-rope technique group patients than those of clavicular hook plate group patients (p < 0.05, respectively). CONCLUSIONS: Both Tight-rope technique and clavicular hook plate fixation can provide satisfactory clinical and radiological results in the treatment of distal clavicular Neer IIB fracture. However, arthroscopic-assisted fixation using the Tight-rope technique showed better results in terms of length of hospital stay, surgical trauma, clinical scores, and diagnose and treat concomitant glenohumeral pathologies. LEVELS OF EVIDENCE: III, Case-control study Retrospective comparative study.

Comparison of open reduction and fixation with hook plate and modified closed reduction and fixation with tightrope loop plate for treatment of rockwood type III acromioclavicular joint dislocation.

OBJECTIVE: To compare the outcomes of open reduction and hook plate fixation (ORHPF) and modified TightRope loop plate fixation (MTRLPF) in the treatment of Rockwood type III acromioclavicular joint dislocation. METHODS: This was a retrospective study. Data on 71 patients with Rockwood type III acromioclavicular joint dislocation who underwent either ORHPF (n = 39) or MTRLPF (n = 32) between January 2016 and October 2019 were extracted and analyzed. Baseline data at injury were compared to evaluate the balance. The disabilities of the arm, shoulder, and hand (DASH) score, Constant-Murley score and visual analog scores (VAS) score at 1 month, 3 months, 6 months and 12 months after operation were compared; further, at 12 months coracoclavicular distance and related complications were evaluated and compared. RESULTS: Both groups did not differ for any baseline data. At 1 and 3 months after operation, MTRLPF group exhibited a significantly better performance than the ORHPF group in VAS (1 month: 2.4 ± 1.8 vs 3.0 ± 1.7; 3 months: 1.2 ± 1.4 vs 1.8 ± 1.6), Constant-Murley (1 month: 75.2 ± 11.2 vs 63.8 ± 13.7; 3 months: 81.4 ± 9.8 vs 75.8 ± 10.6), DASH (1 month: 33.6 ± 6.8 vs 40.6 ± 6.1; 3 months: 21.2 ± 7.4 vs 25.6 ± 6.6). At 6 months, only Constant-Murley remained marginally significant (p = 0.048). At 12 months, no statistical difference was observed for any outcome variable (all P > 0.05 for VAS, Constant-Murley and DASH), coracoclavicular distance (12.7 ± 1.6 mm vs 12.2 ± 1.6 mm; P = 0.374), or overall complication rate (P = 0.763). CONCLUSIONS: For Rockwood type III acromioclavicular joint dislocation, both methods can achieve satisfactory 1-year results, but modified minimally invasive TightRope treatment is more advantageous in early functional recovery at 1 and 3-month follow-ups.

Investigating the Radiological Outcomes of Syndesmosis Injuries in Ankle Fracture Patients After Suture Button Fixation.

Concomitant syndesmotic injury occurs in 10% of ankle fractures. Anatomic reduction and maintenance of this reduction is critical in ensuring ankle stability and preventing long-term complications. This is a retrospective cohort study aimed at evaluating the mid-term radiological outcomes of syndesmotic injuries in ankle fracture patients after surgical fixation with suture button device. The study group included 33 patients. Plain radiographs including anteroposterior, lateral and mortise views of the affected ankle were performed preoperatively, postoperatively and at 3-month follow-up. Anteroposterior views were used to measure the amount of tibiofibular overlap and tibiofibular clear space. Paired Student's t test and linear model regression were performed. Between the immediate postoperative and 3-month follow-up period, there was a mean decrease in tibiofibular overlap of 0.841 (±2.07) mm (p = .0259). There was a mean increase in tibiofibular clear space of 0.621 (±1.46) mm (p = .0201). In addition, we found significant correlation between fracture type and change in tibiofibular clear space (p = .047). Our study showed that there is statistically significant widening of the syndesmosis after suture button fixation at 3-month follow-up as evidenced by reduced tibiofibular overlap and increase in tibiofibular clear space. However, they remain within the maximum threshold for acceptable syndesmotic widening of 1.5 mm. Further correlation between radiological outcomes and patient function is needed to determine clinical significance of these changes.

Clinical outcomes of Tightrope system in the treatment of purely ligamentous Lisfranc injuries.

BACKGROUND: Purely ligamentous Lisfranc injuries are mainly caused by low energy damage and often require surgical treatment. There are several operative techniques for rigid fixation to solve this problem clinically. This study evaluated the effect of using the Tightrope system to reconstruct the Lisfranc ligament for elastic fixation. METHODS: We retrospectively analyzed 11 cases with purely ligamentous Lisfranc injuries treated with the Tightrope system from 2016 to 2019, including 8 male and 3 female. X-ray was performed regularly after operation to measure the distance between the first and second metatarsal joint and the visual analogue scale (VAS) score was used to evaluate pain relief. American orthopedic foot & ankle society (AOFAS) and Maryland foot score were recorded at the last follow-up. RESULTS: The average follow-up time was 20.5 months (range, 17-24). There was statistically significant difference in the distance between the first and second metatarsal joint and VAS score at 3 months, 6 months, and the last follow-up when compared with preoperative values (P < 0.05).Mean of postoperative AOFAS mid-foot scale and Maryland foot score were 92.4 ± 4.3, 94.1 ± 3.5, respectively. The Tightrope system was not removed and the foot obtained better biomechanical stability. No complications occurred during the operation. CONCLUSION: Tightrope system in the treatment of purely ligamentous Lisfranc injuries can stabilize the tarsometatarsal joint and achieve satisfactory effect.

Comparison of single versus double TightRope system in the treatment of acute acromioclavicular joint dislocation.

BACKGROUND: Reconstruction of the coracoclavicular (CC) ligament using a single TightRope (ST) system has some complications. We attempted to use a double TightRope (DT) system to reduce complications and obtain the ideal therapeutic effect. PURPOSE: This investigation aimed to compare the ST and DT systems in terms of efficacy and safety in treating acromioclavicular (AC) joint dislocation. METHODS: Sixty-six cases of acute AC joint dislocation between January 2013 and January 2018 were retrospectively reviewed. All patients were divided into 2 groups based on treatment with the ST or DT system. Patients were evaluated radiologically and clinically using the Disability of Arm, Shoulder, and Hand, Constant, and visual analog scale scores as clinical outcome measures at 1 day, 3 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years after surgery. The CC distance and displacement ratio were assessed radiologically. RESULTS: The mean follow-up period was 49 months. Satisfactory clinical outcomes were obtained after CC fixation in both groups. No intergroup difference was found regarding the visual analog scale (P = .80), Disability of Arm, Shoulder, and Hand (P = .42), or Constant score (P = .28) at 2 years. However, there was a significant difference in the displacement ratio at 6 weeks (P < .0001), 3 months (P < .0001), 6 months (P < .0001), 1 year (P < .0001), and 2 years (P < .0001) postoperatively between the 2 groups. There were 3 complications in the ST group, including 1 case of secondary coracoid fracture, 1 case of AC joint arthrosis combined with ossification of the CC ligaments, and 1 case of clavicular erosion. All complications occurred in the ST group. CONCLUSIONS: Both surgical methods are effective in treating AC joint dislocation, but the DT system is more reliable for reduction maintenance.

Syndesmotic Stabilization: Syndesmotic Screw Versus Flexible Fixation: A Systematic Review.

Syndesmotic injuries are common injuries that occur in isolation or associated with ankle fractures. The suture button device fixation (SBDF) has become increasingly attractive to orthopedic surgeons as an alternative to metallic screw fixation (MSF) for syndesmotic fixation. This review involved the highest-quality clinical biomechanical and cost analysis studies to provide a comprehensive review. A literature search in the electronic databases was conducted to identify clinical, biomechanical as well as cost analysis studies in which the MSF was compared to SBDF from 1990 to 2018. Only comparative clinical studies with a level of evidence I or II were included besides any comparative biomechanical or cost analysis study. The (PRISMA) guidelines were followed. Eight clinical, 11 biomechanical, and 3 cost analysis studies were included. The clinical studies consisted of 5 randomized controlled trials (RCTs) and 3 cohort studies. The average American Orthopaedic Foot and Ankle Society score for the SBDF group was (92.4) compared to (86.6) for the MSF group at 1 year follow-up. SBDF group showed a lower rate of malreduction, implant removal, implant failure, and complications. The biomechanical studies showed better reduction accuracy in the SBDF group. The reduction maintenance was comparable in the coronal plane but not in the sagittal plane. The cost-effectiveness of the SBDF was highly dependent on the difference in implant removal rate. In conclusion, the SBDF showed comparable to better outcomes compared to the MSF. It may be a better option for syndesmotic fixation.

Biomechanical comparison of suture-button, bioabsorbable screw, and metal screw for ankle syndesmotic repair: A meta-analysis.

BACKGROUND: To compare biomechanically metal screw fixation to suture-button or bioabsorbable screw fixation for ankle syndesmotic injuries. METHODS: A literature search of the comparison studies in Pubmed and Google Scholar was conducted. The biomechanical outcomes of interest were syndesmotic stability in the coronal, sagittal, and axial planes as well as torque and rotation at failure. RESULTS: A total of 11 cadaveric studies were included. In the suture-button group, coronal displacement (MD 1.72mm, p = 0.02) and sagittal displacement (MD 2.65mm, p = 0.0003) were increased relative to the metal screw group. In contrast, no difference was found with axial rotation (MD 0.35 degrees, p = 0.57). Bioabsorbable screws exhibited equivalent failure torque (MD -3.04Nm, p = 0.53) and rotation at failure (MD 3.77 degrees, p = 0.48) in comparison to metal screws. CONCLUSIONS: Suture-button provide less rigidity when compared to metal screw fixation. They afford flexible syndesmotic micromotion which may more closely resemble a physiological state and be helpful for ligament healing. Bioabsorbable screws demonstrate similar mechanical strength properties to metal screws.

Anatomic Risk to the Neurovascular Structures With a Medially Based All-Inside Syndesmosis Suture Button Technique.

Recent evidence suggests that the use of suture button devices for ankle syndesmosis fixation is increasing. Multiple studies have shown some concern about damaging the greater saphenous neurovasculature with placement of the anchor point on the medial tibial cortex. We hypothesized that an all-inside button deployment technique would allow for a low risk to medial soft tissue structures. A total of 40 syndesmosis suture buttons were placed into 10 separate cadaveric lower limbs, using the newly developed technique. Four suture buttons were sequentially placed from distal to proximal in each limb within the zone of typical syndesmosis fixation, using fluoroscopic guidance. A medial incision was then performed to evaluate the relationship of the suture buttons to the medial soft tissue structures and the medial malleolus. Thirteen of 40 suture buttons (32.5%) were placed anterior, 7 (17.5%) posterior, and 20 (50%) with a portion of the button directly deep to the saphenous vein. Two of 40 buttons (5%) were placed within the tibial periosteum, and 38 (95%) were subfascial and directly superficial to the periosteum. Four of 40 (10%) limbs revealed a perforation in the saphenous vein from the guidepin. In conclusion, risks to the medial neurovascular structures exist with the medial deployment technique, but they appear to be mitigated compared with previous publications. The necessity of a medial incision to evaluate for soft tissue entrapment may not be necessary in all patients, as this technique appears to be safe, accurate, and reproducible.

Biomechanical comparison of two biplanar and one monoplanar reconstruction techniques of the acromioclavicular joint.

INTRODUCTION: The purpose of this proof-of-concept study was to investigate the biomechanical performance of two surgical techniques, namely (1) the double Tight-Rope fixation with an additional acromioclavicular FiberTape fixation (DTRC) and (2) the fixation of the clavicle to the acromion and coracoid in a bipodal manner (Bipod) using a Poly-Tape and FiberTape. Both techniques intend to address vertical and horizontal instability after acromioclavicular dislocation. They were compared with the commonly used (3) double Tight-Rope (DTR) technique, which only stabilizes the clavicle to the coracoid. MATERIALS AND METHODS: The acromioclavicular joint (ACJ) of 18 composite Sawbone shoulder specimens (6 per reconstruction group) were tested for posterosuperior elongation (70N cyclical load, 1500 cycles), load-to-failure and stiffness. RESULTS: After 1500 cycles, the DTRC, Bipod and DTR group showed an elongation of 0.45 mm (SD 0.14 mm), 1.19 mm (SD 0.54 mm), and 0.46 mm (SD 0.15 mm), respectively. Although the elongation of the Bipod group was increased when compared to the other two groups (Bipod versus DTRC p = 0.008; Bipod versus DTR p = 0.006), the difference was less than 0.7 mm. The DTRC showed a higher load-to-failure of 656.1N (SD 58.1 N) compared to the Bipod [531.1 N (SD 108.2N) (p = 0.039)] and DTR group [522.8 N (SD 32.8 N) (p = 0.033)]. CONCLUSION: The DTRC and the DTR group resulted in similar low elongation, while the elongation in the Bipod technique was slightly higher. Even though this difference of 0.7 mm shows statistical significance, it most likely has no clinical relevance. When testing in posterosuperior direction, which is the clinically relevant load vector, an additional fixation of the clavicle to the acromion did not reduce elongation in this study. It is, furthermore, questionable if the benefit of an increased load-to-failure in combination with no improvement in elongation and stiffness as seen in the DTRC group outweighs the possible risks and increased costs coming with the DTRC refixation.