Biomechanical evaluation of effect of coracoid tunnel placement on load to failure of fixation during repair of acromioclavicular joint dislocations

Accuracy analysis of a novel electromagnetic navigation procedure versus a standard minimally invasive method for arthroscopically assisted acromioclavicular joint reconstructions

PURPOSE

The aim of this cadaveric study was to evaluate the accuracy, feasibility, and operation time of a novel electromagnetic navigation system (ENS) and procedure for transclavicular-transcoracoid tunnel placement compared with a standard minimally invasive (SMI) reconstruction method for minimally invasive arthroscopically assisted anatomic acromioclavicular joint reconstruction.

METHODS

Ten arthroscopically assisted electromagnetic-navigated transclavicular-transcoracoid drilling procedures and 10 SMI procedures were performed on 10 human cadavers using 2 TightRope reconstructions (Arthrex, Naples, FL) for each site. Postoperative computed tomography scans were acquired to determine tunnel placement accuracy. Optimal coracoid tunnel placement was defined according to the anatomic insertions of the trapezoid and conoid ligaments with the oblong button placed in a center-base position at the coracoid undersurface without cortical breach or fracture. Both reconstruction procedures were performed without fluoroscopy.

RESULTS

Successful tunnel placement was accomplished in 98.8% using the ENS method and in 83.8% using the SMI procedure (P = .087). The mean overall operation time was 28.5 ± 6.6 minutes for the ENS method and 35.2 ± 3.9 minutes for the SMI method (P = .012). The ENS procedure required no directional readjustments or restarts. Drill misguidance with subsequent cortical breach occurred twice in the SMI group. In both groups no fractures were documented.

CONCLUSIONS

In this descriptive laboratory study, both the ENS and the SMI techniques achieved the desired anatomic reconstruction. Compared with the SMI method, the ENS procedure showed higher accuracy, required a shorter operation time, and was associated with no complications.

CLINICAL RELEVANCE

Length of surgery, drilling accuracy, and reduction of radiation exposure in acromioclavicular joint reconstruction procedures affect the safety of both patients and surgeons.

Acute lateral dislocated clavicular fractures: arthroscopic stabilization with TightRope

HYPOTHESIS

Type IIA, IIB, and V lateral clavicular fractures (Craig modification of the Neer classification) are characterized by a constant displacement and are associated with a high rate of nonunion. The aim of this study is to verify whether the reduction and arthroscopic stabilization of these clavicular fractures with coracoclavicular cerclage provide stable fixation to allow for bone healing. To date, the treatment of these fractures is still controversial in young active patients in whom functional requirements are to be met.

METHODS

Fourteen male patients, with type IIA, IIB, and V lateral clavicular fractures (2 type IIA, 10 type IIB, and 2 type V) had been treated arthroscopically with a TightRope (Arthrex, Naples, FL, USA) and had a radiologic/clinical follow-up of at least 2 years.

RESULTS

All fractures were confirmed to have healed without limitations in range of motion or loss of reduction. The acromioclavicular joint and the coracoclavicular interspace were restored to the level of the healthy site in all but 1 patient, in whom a reduction was observed because of hypercorrection of the fracture. The mean Constant score was 95, and all patients had a Simple Shoulder Test score of 12 points. Healing was delayed up to 20 days in 1 patient because of a skin infection, and the coracoid bone tunnel was too marginal in another patient, in whom the coracoid button broke the lateral side of the tunnel during fixation.

CONCLUSIONS

The arthroscopic procedure with the TightRope allows for fracture healing with no loss of reduction in the acromioclavicular joint and full return to everyday activities.

Complications after anatomic fixation and reconstruction of the coracoclavicular ligaments

BACKGROUND

Reconstruction of the disrupted acromioclavicular (AC) joint has historically resulted in high complication rates. As a result, there has been a move toward anatomic coracoclavicular (CC) ligament fixation and reconstruction, owing to its numerous biomechanical advantages and perceived clinical advantages.

PURPOSE

To report and analyze the unique complications associated with these anatomic CC ligament procedures using either cortical fixation buttons (CFBs) or tendon grafts (TGs) and to evaluate the effect that these complications have on patient outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From January 2006 until May 2011, a total of 59 primary anatomic CC ligament procedures were performed using either CFBs or TGs. Demographic, surgical, subjective (including the American Shoulder and Elbow Surgeons [ASES], quick Disabilities of the Arm, Shoulder and Hand [QuickDASH], Short Form-12 [SF-12], and Single Assessment Numeric Evaluation [SANE] scores), and radiographic data along with surgical complications were prospectively collected and retrospectively analyzed. Construct survivorship, defined as the maintenance of reduction of the AC joint, was calculated using the Kaplan-Meier method at 12- and 24-month intervals.

RESULTS

Surgical treatment for AC joint dislocations was performed in 3 women (4 shoulders) and 52 men (55 shoulders) with a mean age of 43.6 years (range, 18-71 years); 13 shoulders (22.0%) underwent fixation using the CFB technique, and 46 shoulders (78.0%) underwent reconstruction using the TG technique. The overall complication rate was 27.1% (16/59) in this study. There were 3 complications (23.1%) in the CFB group, including 1 coracoid fracture and 2 cases of hardware failure resulting in a loss of reduction. There were 13 complications (28.2%) in the TG group, including 4 graft ruptures, 2 clavicle fractures, 1 case of hardware failure, 1 hypertrophic distal clavicle, 2 cases of hardware pain, 1 suture granuloma, 1 case of adhesive capsulitis, and 1 case of axillary neuropathy. Twelve- and 24-month construct survivorship was calculated to be 86.2% and 83.2%, respectively. Of the 43 shoulders that did not have a complication, mean ASES scores significantly improved from 57.5 (range, 0-97) to 91 (range, 63-100) (P < .001), and mean SF-12 physical component summary scores significantly improved from 45 (range, 25-58) to 56 (range, 43-65.8) (P < .001) after a mean 2.4-year follow-up (range, 1.0-5.7 years). There were no significant differences in outcomes between those that did and did not experience a complication, with the exception that those with complications had significantly decreased median patient satisfaction compared with those without complications (3.5 vs 9, respectively; P = .049).

CONCLUSION

Anatomic procedures to treat disrupted CC ligaments using either CFBs or TGs resulted in an overall complication rate of 27.1% (16/59). Construct survivorship was calculated to be 86.2% at 12 months and 83.2% at 24 months. Good to excellent outcomes could only be reported in those patients who did not have a complication.