Clavicular Tunnel Complications after Coracoclavicular Reconstruction in Acute Acromioclavicular Dislocation: Coracoid Loop versus Coracoid Tunnel Fixation

Presurgical perspective and postsurgical evaluation of acromioclavicular joint instability

Acromioclavicular joint (ACJ) dislocations are a common cause of pain in patients of any age. Athletes who participate in contact sports, such as hockey, football, rugby, and soccer, are particularly susceptible to such injuries. The ACJ has an important role in the function of the upper limb, and its complexity of movement makes it susceptible to acute injuries and chronic dysfunction with debilitating effects that must be treated appropriately and promptly to preserve function. Recently, ACJ has received increasing attention due to the development of new surgical techniques for the restoration of normal function and stability. There is some agreement about the treatment of ACJ dislocations, but controversy remains about the treatment of Rockwood grade III dislocations, and a new approach to these injuries is suggested by ISAKOS. Overall, the paper summarizes new concepts in the anatomy of the ACJ and reviews the utility of imaging methods in ACJ dislocations as well as their treatment and complications.

Clavicular tunnel widening after coracoclavicular stabilization surgery: a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to (1) estimate the prevalence of clavicular tunnel widening (TW) after coracoclavicular stabilization surgery and its risk factors and (2) assess whether TW is correlated with clavicle fracture or loss of reduction of the acromioclavicular joint (ACJ).

METHODS

In January 2023, 3 electronic databases were searched to collect data on postoperative clavicular TW, its prevalence, magnitude, and correlation with fracture and ACJ loss of reduction. Studies were classified according to the time of surgical intervention, and the clavicular tunnels were categorized by their anatomic location. Mean differences were calculated using a DerSimonian-Laird random-effects model, while binomial outcomes were pooled using the Freeman-Tukey double arcsine transformation. Univariate and multivariate meta-regression analyses were performed to determine the effect of several variables on the proportion of cases with TW.

RESULTS

Fifteen studies (418 shoulders) were included. At the final follow-up, evidence of clavicular TW was found in 70% (95% confidence interval [CI]: 70%-87%; I2 = 89%) of 221 shoulders. Surgeries in acute cases had a lower prevalence of TW (52%) compared to chronic cases (71%) (P < .001). Significant TW was found in the central tunnel (3.2 mm; 95% CI: 1.8-4.6 mm; P < .001; I2 = 72%) for acute injuries and in the medial (1.2 mm; 95% CI: 0.7-1.7 mm; P < .001; I2 = 77%) and lateral (1.5 mm; 95% CI: 0.7-2.3 mm; P < .001; I2 = 77%) tunnels for chronic cases. Single central-tunnel techniques were positively associated with the prevalence of TW (P = .046), while biotenodesis screw fixation was associated with a lower prevalence (P = .004) in chronic cases. Reconstruction of the ACJ ligament complex with tendon grafts or sutures was associated with a higher prevalence of TW (P < .001). Drill sizes between 2.5 and 5 mm were significantly associated with a lower prevalence of TW, regardless of injury chronicity (P = .012). No correlation was found between TW and the loss of ACJ reduction or clavicle fractures.

CONCLUSIONS

This systematic review and meta-analysis explored TW occurrence following coracoclavicular stabilization surgery. TW was observed in 70% of patients at final follow-up, with a higher prevalence in chronic than in acute cases. Modifiable surgical variables, such as single-tunnel tendon graft constructs for acute or chronic injuries and knotted graft procedures for chronic injuries, were significantly associated with TW. Furthermore, the prevalence of TW increased with concomitant surgical treatment of the ACJ ligament complex, and decreased with drill sizes between 2.5 and 5 mm, regardless of lesion chronicity. These surgical variables should be considered when establishing transosseous tunnels for coracoclavicular stabilization. Clavicle fractures and TW mechanisms require further investigation.

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.