Axial-Plane Biomechanical Evaluation of 2 Suspensory Cortical Button Fixation Constructs for Acromioclavicular Joint Reconstruction

Surgical management of acute, high-grade acromioclavicular joint separations: a systematic review

Background

While a number of treatment options exist for repair of acute, high-grade acromioclavicular joint (ACJ) separation, none have emerged as the standard of care. The purpose of this study was to systematically review the literature on surgical treatment of acute, high-grade (Rockwood grades III-V) ACJ separations in order to compare outcomes between direct fixation and tendon graft ligament reconstruction.

Methods

A systematic review of the literature evaluating outcomes for acute ACJ separation treatment with direct fixation or free biologic tendon graft reconstruction was performed. The following databases were examined: the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (1980-2021), and Embase (1980-2021). Studies were included if they reported a mean time to surgery as <6 weeks, contained >10 patients with a minimum 1-year follow-up, and reported clinical or radiographic outcomes.

Results

A total of 52 studies met the inclusion criteria. Seven studies reported outcomes following tendon graft ligament reconstruction (n = 128 patients). There were multiple methods of direct fixation. Thirty-three studies utilized suture button constructs (n = 1138), 16 studies used hook plates (n = 567), 2 studies used coracoclavicular screws (n = 94), 2 studies used suture fixation (n = 93), 2 studies used suture anchor (n = 55), 2 studies used suture cerclage fixation (n = 87), 1 used single multistrand titanium cable (n = 24), and 1 used K wire (n = 11). The mean follow-up Constant scores ranged from 77.5 to 97.1 in the fixation group compared to 90.3-96.6 in the tendon graft group. The mean visual analog scale scores ranged from 0 to 4.5 in the fixation group and 0.1-1 in the tendon graft group. Net CC distance ranged from 17.5 to 3.6 mm in the fixation group and 7.4-4 mm in the tendon graft group. The revision rates ranged from 0.0% to 18.18% in the direct fixation group and 5.88%-17% in the tendon graft group.

Conclusion

Direct fixation and tendon graft reconstruction for management of acute, high-grade ACJ separations have similar patient subjective and radiographic outcomes, as well as complication and revision rates at a minimum 1-year follow-up.

Arthroscopic-Assisted Double-Bundle Coracoclavicular Ligament Reconstruction Using Cortical Fixation Buttons With Suture Tape Provides Superior Vertical Stability Than the Single-Bundle Reconstruction for Acute Acromioclavicular Joint Dislocation

PURPOSE

This study aimed to compare clinical and radiologic outcomes between single- and double-bundle arthroscopic-assisted coracoclavicular (CC) ligament reconstruction using cortical fixation buttons with suture tapes for acute acromioclavicular (AC) joint dislocation.

METHODS

Patients who underwent arthroscopic-assisted CC ligament reconstruction using cortical fixation buttons with suture tapes for acute AC joint dislocation from July 2014 to March 2019 were identified. This study included patients treated for acute AC joint dislocation within 2 weeks after an injury, with a Rockwood classification of III or V and at least 2 years of follow-up. Patients were divided into 2 groups based on the reconstruction technique: group I (single-bundle technique) and group II (double-bundle technique). The clinical outcomes were compared using the American Shoulder Elbow Surgeons (ASES) score, Constant score, and visual analog scale for pain score between the 2 groups. On the plain radiograph, the CC interval ratio (CCIR) was measured to evaluate maintenance of CC interval fixation. Postoperative complications, including reduction failure, were also documented.

RESULTS

Fifty-eight patients (26 in group I, 32 in group II) were enrolled. There were no significant differences in CCIR between the 2 groups preoperatively and 3 months postoperatively. However, the CCIR of group I was significantly greater than that of group II 6 months postoperatively (group I: 160.5% ± 48.5%, group II: 125.4% ± 38.9% at 6 months postoperatively, P = .01; group I: 164.0% ± 57.3%, group II: 123.2% ± 35.9% at the last visit, P = .01). Despite radiologic differences, the clinical outcomes demonstrated no significant differences between 2 the groups (ASES score: 93.5 ± 5.2 in group I, 94.4 ± 4.5 in group II, P = .54; Constant score: 92.9 ± 5.3 in group I, 94.8 ± 4.3 in group II, P = .16). Reduction failure occurred in 4 patients (15.3%) in group I and in 1 patient (3.2%) in group II (P = .16).

CONCLUSIONS

Arthroscopic-assisted double-bundle CC ligament reconstruction using cortical fixation buttons with suture tapes provided superior vertical stability than the single-bundle technique.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Evaluation of the coracoid bone tunnel placement on Dog Bone™ button fixation for acromioclavicular joint dislocation: a cadaver study combined with finite element analysis

BACKGROUND

Dog Bone™ button fixation is frequently used to treat acromioclavicular joint (ACJ) dislocation. However, various studies have reported complications after fixation.

OBJECTIVE

To investigate the effect of the coracoid bone tunnel location on the treatment of ACJ dislocation through single-tunnel coracoclavicular (CC) ligament fixation with the Dog Bone™ button.

METHODS

Six cadaveric shoulders were used. Each specimen was subjected to five testing conditions in the following order: (1) normal ACJ (Gn); (2) acromioclavicular and CC ligaments were removed (G0); (3) CC ligament reconstruction was performed using the Dog Bone™ technique, and the coracoid bone tunnel was at the center of the coracoid base (G1); (4) reconstruction was performed at 5 mm distal from the G1 site, along the axis of the coracoid (G2); (5) reconstruction was performed at 10 mm distal from the G1 site, along the axis of the coracoid (G3). The angles of pronation and supination of the clavicle under the same load (30 N) were measured. Next, a finite element (FE) model was created using computed tomography (CT) images of the normal shoulder. Model 1 (M1), model 2 (M2), and model 3 (M3) correspond to G1, G2, and G3, respectively. A force of 70 N was applied as a vertical upward load to the distal clavicle. Subsequently, the von Mises stress, the strain LE along the FiberWire, and the displacement nephogram of the three models were obtained.

RESULTS

After single-tunnel CC ligament fixation using the Dog Bone™ technique, the clavicle in the G2 group (20.50 (19.50, 21.25) °, 20.00 (18.75, 21.25) °) had the best rotational stability. The peak von Mises stress, the strain LE along the FiberWire, and the maximum displacement were smaller in M2 than in M1 and M3.

CONCLUSIONS

When the coracoid bone tunnel was located 5 mm anterior to the center of the coracoid base (along the axis of the coracoid), the clavicle showed greater rotational stability.

Comparing the Anatomical Landmarks Versus the Coracoid-Based Landmarks Techniques for Coracoclavicular Stabilization After High-Grade Acromioclavicular Injury: A Biomechanical Study

BACKGROUND

In acute high-grade acromioclavicular (AC) joint injuries, the aim of treatment is robust reduction and stabilization of the joint. The anatomical landmarks method is most commonly used for stabilization, but loss of reduction often occurs because of the suture tunnels.

PURPOSE/HYPOTHESIS

The purpose was to evaluate and compare the stability of coracoclavicular (CC) stabilization using the anatomical landmarks and coracoid-based landmarks techniques in treating a high-grade AC joint injury. It was hypothesized that stabilization using coracoid-based landmarks would provide better stability.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty fresh-frozen cadaveric shoulders (8 male and 2 female pairs) were randomized into 2 operative technique groups: 10 shoulders in the anatomical landmarks group and 10 shoulders in the coracoid-based landmarks group. The CC ligaments and AC capsule were cut at the midlevel, and CC stabilization and AC capsule repair were performed. For the anatomical landmarks technique, two 2.5-mm clavicular tunnels were created at 25 and 45 mm from the AC joint, while for the coracoid-based landmarks technique, two 2.5-mm clavicular tunnels were drilled using the medial and lateral borders of the coracoid base to choose the tunnel sites. Before injury creation and after stabilization, each shoulder underwent a loading force of 70 N in the superior and anteroposterior directions, and the displacement distance and stiffness were compared between the 2 techniques using the paired t test.

RESULTS

The mean difference in displacement before and after stabilization was higher in the anatomical landmarks technique than the coracoid-based landmarks technique (1.82 ± 3.52 vs -0.18 ± 4.78 mm in the superior direction and 7.47 ± 9.35 vs 1.76 ± 3.91 mm in the anteroposterior direction), but none of the differences in displacement or stiffness were statistically significant between the groups.

CONCLUSION

No significant biomechanical differences in displacement or stiffness were seen between the anatomical landmarks technique and the coracoid-based landmarks technique.

CLINICAL RELEVANCE

Either stabilization technique can be utilized for repair of the CC ligaments in an acute AC injury setting.

Biomechanical testing of three coracoclavicular ligament reconstruction techniques with a 3D printing navigation template for clavicle-coracoid drilling

Background

The identification and precise clavicle-coracoid drilling during coracoclavicular (CC) ligament reconstruction for acromioclavicular (AC) joint dislocation require a high level of experience and surgical skills. Furthermore, the improvement of flexible fixation, such as Endobutton techniques for CC ligament reconstructions is ongoing. We have developed a 3D printing technique navigation template for clavicle-coracoid drilling and a novel implant for the reconstruction. This study aimed to determine the efficiency of the navigation template for clavicle-coracoid drilling and to evaluate the biomechanical performance of the novel CC ligament reconstruction technique.

Methods

A total of 24 fresh-frozen human cadaveric shoulders were randomly assigned to 1 of 3 reconstruction groups or a control group: TightRope, Triple Endobutton, and the Adjustable Closed-Loop Double Endobutton technique. Computed tomography scans, navigation template designs, and 3D printing were performed for the shoulders. Then, AC joint dislocation was simulated in the reconstruction groups, and 3 CC ligament reconstruction techniques were operated via the 3D printing template separately. Furthermore, biomechanical protocols including the translation test (load from 5 to 70 N) and the load-to-failure test were performed to characterize the behaviors and strengths. One-way ANOVA test analyzed differences in displacement under the translation load and the load at failure.

Results

CC ligament reconstructions were performed successfully along with the 3D printing navigation template in the 3 reconstruction groups. During the translation test, no significant difference was found in displacements among the 4 groups. Meanwhile, the mean load of all reconstruction groups at failure (Adjustable Closed-Loop Double Endobutton, 722.1620 N; TightRope, 680.4020 N; Triple Endobutton, 868.5762 N) was significantly larger than the control group (564.6264 N, P<0.05). The Triple Endobutton group had the maximum load at failure (P<0.05), however, no significant difference was noticed between the other 2 reconstruction groups (P>0.05).

Conclusions

The 3D printing navigation template may become helpful and reliable for AC joint dislocation surgery. Among the 3 CC ligament reconstruction techniques, the Triple Endobutton technique has the best strength in terms of biomechanics, while the biomechanical strength of the Adjustable Closed-Loop Double Endobutton technique is reliable in comparison with the TightRope technique.

[Arthroscopically-assisted treatment of acute and chronic dislocations of the acromioclavicular joint : A prospective clinical trial]

BACKGROUND

Injuries of the acromioclavicular joint (ACJ) are frequent and often occur during sports. While arthroscopically-assisted stabilization of acute injuries of the ACJ is a well-established procedure, there is not much data available for arthroscopically-assisted stabilization of chronic injuries of the ACJ.

OBJECTIVES

This study assesses clinical and radiological results of arthroscopically-assisted stabilization of acute and chronic injuries of the ACJ.

MATERIALS AND METHODS

Thirty-six patients with acute and chronic injuries of the ACJ were assessed in a prospective clinical trial. Twenty-five patients with acute injuries (group A) and eleven patients with chronic injuries (group B) were included in this study. Patients of group A were operated using two suture-button systems, while patients of group B received one suture-button system and an autologous gracilis tendon graft.

RESULTS

In group A, the mean preoperative Constant score rated 38, and the ASES score rated 34. At follow-up the Constant score (92) and the ASES score (89) had improved. Panorama views revealed an increased coracoclavicular distance of the affected shoulder (15.8 mm) in comparison to the contralateral shoulder (10.9 mm). In group B, the preoperative Constant score measured 57. It improved to 72 points at follow-up. The ASES score improved from 39 to 72 points in the same period. Panorama views revealed an increased coracoclavicular distance of the affected shoulder (18.9 mm) in comparison to the contralateral shoulder (12.4 mm).

CONCLUSIONS

Stabilization of acute injuries of the ACJ with two suture-button systems is related to very good shoulder function after one year. The native coracoclavicular distance cannot be restored with this procedure. Stabilization of chronic injuries of the ACJ with a suture-button system and an autologous gracilis tendon graft is related to improved shoulder function after one year. However, shoulder function cannot be fully restored with the stabilization technique presented.

Nonanatomic and Suture-Based Coracoclavicular Joint Stabilization Techniques Provide Adequate Stability at a Lower Cost of Implants in Biomechanical Studies When Compared With Anatomic Techniques: A Systematic Review and Meta-Analysis

Purpose

To compare the stability and cost of the used implants in nonanatomic and anatomic acromioclavicular joint repair/reconstruction (ACCR) techniques tested in cadaveric shoulder biomechanical studies during the last decade.

Methods

A systematic review and meta-analysis were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and prospectively registered in PROSPERO. Two independent reviewers searched PubMed, Embase, and Virtual Health Library databases. Studies evaluating 3-direction stability under 70-N loads and load-to-failure protocols with servohydraulic testing systems were included. A meta-analysis of the mean differences of anterior, posterior, and superior direction; relative stability value in 3 directions; superior direction load-to-failure; stability/cost index; and load-to-failure/cost index was performed using a continuous random-effects model and 95% confidence interval.

Results

Eighteen articles were included. Both non-ACCR and ACCR techniques exceeded the minimum acceptable threshold of stability and load-to-failure. ACCR techniques were biomechanically better in terms of anterior stability (P = .04) and relative stability value (mean difference 64.08%, P = .015). However, supraphysiological stability and failure loads were achieved with non-ACCR techniques at a lower cost of implants. Techniques combining 2 clavicular tunnels separated by at least 10 mm, a mean of 2 sutures, and/or suture tapes had the greatest stability/cost index and load-to-failure/cost index among the included techniques (confidence interval 99%).

Conclusions

Non-ACCR and ACCR techniques exceeded the minimum acceptable threshold of stability and failure loads in controlled biomechanical testing. However, non-ACCR and techniques combining 2 clavicular tunnels separated by at least 10 mm, a mean of 2 sutures, and/or suture tapes provide supraphysiologic stability and failure loads at a lower cost of implants.

Clinical Relevance

Non-ACCR and suture-based techniques may provide more cost-effective and greater value treatment for acromioclavicular joint injury and could be considered in the surgical management of normal activity individuals and cost-sensitive populations.

Arthroscopic treatment of tibial eminence fractures using double-loop endobutton device: Surgical technique and short-term treatment outcomes

Objectives

This study aims to explain the arthroscopic surgical technique of double-loop endobutton device for tibial eminence fractures and share the outcomes of this treatment method.

Patients and methods

Thirteen patients (10 males, 3 females; mean age 19.9±5.6 years; range, 14 to 34 years) with tibial eminence fractures type II, IIIa, and IIIb were analyzed retrospectively between March 2017 and March 2019. Knee laxity, Tegner Lysholm knee scores, the International Knee Documentation Committee (IKDC) scores, knee mobility, Lachman test, and bone union were analyzed after the arthroscopic fracture fixation with double-loop endobutton device at first and sixth months after surgery.

Results

First month mean IKDC scores were 38.0±7.0 and mean Tegner Lysholm scores were 50.3±5.8. Sixth month mean IKDC scores were 80.2±4.0 and mean Tegner Lysholm scores were 87.1±5.4. All patients showed negative Lachman test and negative pivot-shift test at final follow-up. Radiological bone union without reduction loss was also seen in all patients.

Conclusion

Using double-loop endobutton device provides successful results to fix tibial eminence fractures.

Sagittal orientation of coracoclavicular ligament reconstruction affects the stability of surgical repair

BACKGROUND

The variation in the anatomic relationship between the coracoid and the clavicle affects the biomechanical stability of coracoclavicular ligament reconstruction (CCLR).

METHODS

Three-dimensional computed tomography reconstruction of 85 patients was analyzed. Anatomic landmarks were used to derive the coracoclavicular sagittal reconstruction angle (sRA). The lateral concave angle, which indicated the shape of the distal clavicle, and the offsets between the clavicle and coracoid were also measured. To investigate the biomechanical effects of the sRA on CCLR, 7 computed tomography scans with different sRAs were 3D printed. Two reconstructions, a single trans-coracoclavicular tunnel and a looped reconstruction technique, were performed sequentially. Models were cyclically loaded at 70 N in the anterior, posterior, and superior directions.

RESULTS

The mean sRA was 68° ± 9.3° (range, 47°-85°). The superoinferior offset between the clavicle and the coracoid and the lateral concave angle positively correlated with the sRA (r = 0.359 and 0.837, respectively; P ≤ .001), whereas the anteroposterior offset had a negative correlation (r = -0.925; P < .001). The sRA had a negative correlation with the anterior displacement of the clavicle (rho = -0.96; P < .001) and a positive correlation with the posterior displacement for both surgical techniques (rho = 1.0; P < .001).

CONCLUSION

The anatomic orientation of the native coracoclavicular ligaments is highly variable in the sagittal plane. Low sagittal angles can reduce anterior stability, whereas high sagittal angles can reduce posterior stability of CCLR.

Novel Double Endobutton Technique Combined with Three-Dimensional Printing: A Biomechanical Study of Reconstruction in Acromioclavicular Joint Dislocation

Objective

To reconstruct the acromioclavicular (AC) joint using an adjusted closed‐loop double Endobutton technique via a guiding locator that was applied using three‐dimensional (3D) printing technology. At the same time, the reliability and safety of the novel double Endobutton (NDE) were tested by comparing the biomechanics of this technique with the TightRope (TR) approach.

Methods

This retrospective study was conducted between January 2017 and January 2019. The Department of Anatomy at Southern Medical University obtained 18 fresh‐frozen specimens (8 left and 10 right; 12 men and 6 women). First, the guiding locators were applied using 3D printing technology. After preparation of materials, specimens were divided into an NDE group, a TR group, and a normal group. In the NDE and TR groups, the navigation module was used to locate and establish the bone tunnels; after that, the NDE or TR was implanted. However, the Endobuttons were fixed while pressing the distal clavicle downwards and the length of the loop could be adjusted by changing the upper Endobutton in the NDE group while the suture button construct was tensioned and knotted after pressing down the distal clavicle in the TR. Finally, load testing in anterior–posterior (AP), superior–inferior (SI), and medial–lateral (ML) directions as well as load‐to‐failure testing in the SI direction were undertaken to verify whether the NDE or TR had better biomechanics.

Results

In the load testing, the displacements of the NDE and TR groups in the AP, SI, and ML direction were significantly shorter than those of the normal group (P < 0.05). In the load‐to‐failure testing, the ultimate load of the NDE and TR groups had significantly higher increases than the normal group (722.16 ± 92.04 vs 564.63 ± 63.05, P < 0.05; 680.20 ± 110.29 vs 564.63 ± 63.05, P < 0.05). However, there was no statistically significant difference between the two techniques for these two tests (P > 0.05). In the NDE group, four of six failures were a result of tunnel fractures of the coracoid, while two of six were due to suture breakage. In the TR, three failures were due to coracoid tunnel fractures, one was a result of a clavicle tunnel fracture, and the rest were due to suture breakage. In the normal group, half of the failures were a result of avulsion fractures of the conical ligament at the point of the coracoid process, and the other three were due to rupture of the conical ligament, fracture of the distal clavicle, and fracture of the scapular body.

Conclusion

As for the TR technique, the stability and strength of the AC joint were better in patients who underwent reconstruction using the NDE technique than in the intact state.

Synthetic coracoclavicular ligament vs. coracoclavicular suspensory construct for treatment of acromioclavicular dislocation: a biomechanical study

BACKGROUND

A synthetic ligament (LockDown, Worcestershire, England) has become available to treat complete acromioclavicular dislocation with promising clinical results and potential benefit to avoid postoperative loss of reduction. We investigated the biomechanics of this synthetic ligament in a simulated immediate postoperative rehabilitation setting, hypothesizing that the synthetic ligament would demonstrate less superior coracoclavicular displacement to cyclic loading and higher ultimate load-to-failure values than a coracoclavicular suspensory construct.

METHODS

Seven matched-pair cadaveric shoulders (mean age at time of death, 79 years) were loaded cyclically and to failure. One specimen in each pair was randomly assigned to the synthetic ligament or coracoclavicular suspensory construct. Superiorly directed 70-N cyclic loading for 3000 cycles at 1.0 Hz was applied through the clavicle in a fixed scapula simulating physiologic states during immediate postoperative rehabilitation, followed by a load-to-failure test at 120 mm/min.

RESULTS

After 3000 cycles, the superior displacement of the clavicle in the synthetic ligament (9.2 ± 1.1 mm) was 225% greater than in the coracoclavicular suspensory construct (2.8 ± 0.4 mm, 95% confidence interval [CI] 3.4, 8.3; P < .001). Average stiffness of the synthetic ligament (32.8 N/mm) was 60% lower than that of the coracoclavicular suspensory construct (81.9 N/mm, 95% CI 43.3, 54.9; P < .001). Ultimate load-to-failure of the synthetic ligament was 23% (95% CI 37.9, 301.5; P = .016) lower than the coracoclavicular suspensory construct (580.5 ± 85.1 N and 750.2 ± 135.5 N, respectively).

CONCLUSION

In a simulated immediate postoperative cadaveric model, the synthetic ligament demonstrated poorer biomechanics than the coracoclavicular suspensory construct. These findings suggest that a coracoclavicular suspensory construct may be preferable to a synthetic ligament if early rehabilitation is intended.

Vertical and Rotational Stiffness of Coracoclavicular Ligament Reconstruction: A Biomechanical Study of 3 Different Techniques

PURPOSE

To compare the biomechanical stability of 3 different coracoclavicular reconstruction techniques under rotational and vertical loading using a cadaveric model.

METHODS

In total, 12 cadaveric shoulders were used for testing. The native state was first tested then followed by 3 different reconstruction configurations using suture tapes and cortical buttons: coracoid loop (CL), single-bundle (SB), and double-bundle (DB). Superior displacement was measured by cycling an inferiorly directed force of 70 N to the scapula. The rotational stiffness of the scapula was determined by cycling the scapula in rotational displacement control between 15° of internal and external rotation. The rotational stiffness of the clavicle was determined by rotating the clavicle around its long axis 20° anteriorly and 30° posteriorly in rotational displacement control. All measurements were captured over 10 cycles at a rate of 200 Hz.

RESULTS

Both the CL and SB techniques demonstrated significantly less internal scapular rotation stiffness. (intact: 19.70 ± 9.07 cNm/deg, CL: 3.70 ± 2.63 cNm/deg, SB:4.30 ± 2.66 cNm/deg, P <.001) External scapular rotation stiffness was significantly decreased in all techniques (intact: 17.70 ± 4.43 cNm/deg, CL: 3.30 ± 1.37 cNm/deg, SB: 4.50 ± 1.56 cNm/deg, DB: 4.67 ± 1.99 cNm/deg, P < .001). The CL and SB reconstructions were significantly less stiff with regards to posterior rotation of the clavicle (intact: 5.60 ± 1.80 cNm/deg, CL: 2.90 ± 1.10 cNm/deg, SB: 1.40 ± 0.65 cNm/deg, P < .001). Anterior rotation stiffness of the clavicle was significantly lower in all of the reconstructions (intact: 6.95 ± 1.90 cNm/deg, CL: 3.08 ± 0.84 cNm/deg, SB: 3.64 ± 0.93 cNm/deg, DB: 4.48 ± 1.21 cNm/deg, P < .001).

CONCLUSIONS

None of the described techniques provided equivalent rotational stability in all planes compared with the native state. DB reconstruction presented stiffness characteristics closest to the native state under cyclic loading during internal scapular and posterior clavicular rotation.

CLINICAL RELEVANCE

Additional procedures such as tendon grafting or acromioclavicular ligament reconstruction may be required to control rotational stability.

Open Reduction and Tunneled Suspensory Device Fixation Compared with Nonoperative Treatment for Type-III and Type-IV Acromioclavicular Joint Dislocations: The ACORN Prospective, Randomized Controlled Trial

BACKGROUND

Nonoperative management of complete acromioclavicular (AC) joint dislocation has yielded reasonable results, although patients may report dissatisfaction with the outcome. The purpose of this prospective, randomized, controlled trial was to compare patient outcome following nonoperative care versus operative treatment with open reduction and tunneled suspension device (ORTSD) fixation for acute, type-III or IV disruptions of the AC joint.

METHODS

Sixty patients aged 16 to 35 years with an acute type-III or IV disruption of the AC joint were randomized to receive ORTSD fixation or nonoperative treatment, following a power analysis to determine sample size. Functional outcomes were assessed with use of the Disabilities of the Arm, Shoulder and Hand (DASH) as the primary outcome measure and the Oxford Shoulder Scores (OSS) and Short Form (SF-12) as secondary outcome measures at 6 weeks, 3 months, 6 months, and 1 year after treatment. Reduction was evaluated with use of radiographs. Any complications were noted at each assessment. The economic implication of each treatment was evaluated.

RESULTS

ORTSD and nonoperative groups were similar with regard to demographics at baseline. The mean degree of radiographic displacement was significantly less in patients following ORTSD fixation (1.75 mm) compared with patients who received nonoperative treatment (10.61 mm, p < 0.0001). At 1 year postoperatively, the mean DASH score was 4.67 in the nonoperative treatment group and 5.63 in the ORTSD group, and the mean OSS was 45.72 and 45.63, respectively. Patients managed with ORTSD fixation had inferior DASH scores at 6 weeks (p < 0.01). There were 5 patients who experienced failed nonoperative treatment and subsequently underwent a surgical procedure. ORTSD fixation (£3,359.73) was associated with significantly higher costs than nonoperative treatment (£796.22, p < 0.0001).

CONCLUSIONS

ORTSD fixation confers no functional benefit over nonoperative treatment at 1 year following type-III or IV disruptions of the AC joint. Although patients managed nonoperatively generally recovered faster, a substantial group of patients remained dissatisfied following nonoperative treatment and required delayed surgical reconstruction. We were unable to identify any demographic or injury-related factors that predicted a poorer outcome in these patients.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical Analysis of Single-, Double-, and Triple-Bundle Configurations for Coracoclavicular Ligament Reconstruction Using Cortical Fixation Buttons With Suture Tapes: A Cadaveric Study

PURPOSE

To compare the acromioclavicular (AC) joint stability of single-bundle (SB), double-bundle with an anterolateral limb (DBa), double-bundle with a posterolateral limb (DBp), and triple-bundle (TB) coracoclavicular (CC) ligament reconstructions using cortical fixation buttons with suture tapes.

METHODS

Eight cadaveric shoulders were used. AC joint translation and rotational stability were tested for intact and following 4 different CC reconstruction techniques: SB, DBa, DBp, and TB configurations using cortical fixation buttons with suture tapes. For each reconstruction and native AC joint as control, anteroposterior (AP) and superoinferior translations were quantified using 10- and 15-N translational loads and anterior and posterior rotations were measured using 0.16- and 0.32-Nm rotational torque.

RESULTS

DBp reconstruction showed significantly better AP stability compared with SB and DBa reconstruction at 10 and 15 N (DBp: 4.1 ± 0.6 mm, SB: 7.8 ± 1.1 mm, P < .001; DBa: 6.5 ± 0.7 mm, P = .02 at 10 N; DBp: 5.5 ± 0.8 mm, SB: 10.1 ± 1.0 mm, P = .003; DBa: 9.1 ± 0.7 mm, P = .02 at 15 N). The degree of total rotation showed tendency to decrease according to increasing number of bundles; however, there were no significant differences (SB: 43.1 ± 9.2°, DBa: 37.9 ± 7.3°, DBp: 33.9 ± 6.8°, TB: 32.2 ± 6.6°, P = .37 at 0.32 Nm).

CONCLUSIONS

An additional posterolateral clavicular hole for CC ligament reconstruction using cortical fixation buttons with suture tapes resulted in better AP stability compared with SB reconstruction, whereas use of additional anterolateral clavicular hole did not show any improvement compared with SB reconstruction. Reconstruction using both anterolateral and posterolateral clavicular holes did not guarantee better stability compared with SB reconstruction. There was an increasing tendency of rotational stability with number of bundle increases, although they did not reach statistical difference.

CLINICAL RELEVANCE

When surgeons consider double-bundle CC ligament reconstruction using cortical fixation buttons with suture tapes, it is better to position the lateral clavicular hole posteriorly to restore AP stability.

Modified closed-loop double-endobutton technique for repair of rockwood type III acromioclavicular dislocation

Acromioclavicular dislocation (ACD) is a common injury. According to the Rockwood classification, ACD is classified into six types (type I–VI); however, for type III injuries, it remains controversial whether or not operative treatment should be applied. Numerous studies have advocated early surgical treatment to ensure early rehabilitation activities. Thus, the present study aimed to investigate a modified closed-loop double-endobutton technique (MCDT), that may be used to repair Rockwood type III ACD. In the current study, 61 patients with Rockwood type III ACD were enrolled during a period of 5 years at the Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University. Patients were divided into three groups according to the surgical method used, the MCDT group (n=20), the common closed-loop double-endobutton technique (CCDT) group (n=21), and the clavicular hook plate fixation (CHPF) group (n=20). Preoperative and intraoperative information were recorded. Furthermore, the functional scores of injured shoulder were evaluated prior to surgery and following surgery with a 1-year follow-up. Among the three groups, postoperative functional scores were significantly more improved compared with those prior to surgery (P<0.05), and no significant difference was observed regarding the coracoclavicular interval with the 1-year follow-up (P>0.05). Postoperative functional scores in the MCDT and CCDT groups were significantly more improved compared those in the CHPF group (P<0.05). In addition, the duration of surgery in the MCDT group was significantly shorter compared with that in the CCDT group (P<0.05). Furthermore, compared with the CHPF group, the incision length was significantly shorter with reduced hemorrhage in the MCDT group (P<0.05). In conclusion, the results of the current study suggest that MCDT is more simple, convenient and efficient compared with CCDT, and is worth popularizing.