AC dysjunction, fixation with the ZipTight Device, experiences with the new method

Overview

Purpose of the study:
To present the ZipTight (Biomet, Inc.) technique and its results in the stabilization of acromioclavicular joint dislocation performed out at our department.

Material and methods:
From 1. 3. 2012 to 30. 8. 2013, we provided care for 26 patients with the diagnosis of AC joint dislocation (Group I). Acute surgical stabilization was performed in 16 patients, secondary surgery was performed in 2 patients (one for late diagnosis, one for additional injuries). Eight patients were treated conservatively. Patients with Tossy type III and coracoclavicular dissociation more than 10mm were indicated for surgery. In the surgically treated group there were 14 male and 4 female pa-tients, with an average age of 33.8 years. In the comparative patient group (Group II) from 1. 11. 2011 to 28. 2. 2012, there were 21 patients treated for AC-joint dislocation. Acute surgery (joint stabilization with 2 K-wires + steel wire loop) was performed in 16 patients, secondary surgery was not performed. Five patients were treated conservatively.

Results:
All 18 patients of Group I returned to their pre-operative activities without any problems or pain within 12.5 weeks after surgery. Radiographic evidence of loss of reduction, with no effect on the clinical outcome, was recorded in 3 patients (17%) during post-operative controls on 3rd, 6th and 12th week after surgery. In two patients, post-operative pull-out of the implant from the coracoid was seen, one patient sustained pathological fracture of clavicle in between two drill holes, when a second canal was needed because of malposition of the first canal. We did not observe any cases of deep wound infection. In Group II all 16 patiens returned to their pre-operative activities without complaints or pain within 14 weeks post surgery. We did not observe radiographic evidence of loss of reduction. We noticed 3 patients with wound infection, all healed after the implant removal.

Discussion:
The revision of AC-joint and revision of the injured disc can/should be discussed. At classical open surgery we performed joint revision with excision of the damaged disc and reduced the lateral end of the clavicle to the acromion. In the new method we do closed reduction, without AC-joint revision. The degree of AC-joint injury could be examined manually before operation: if the clavicle could be easily reduced in the AC-joint, than the joint revision is not necessary; if reduction is not possible, than the joint revision is indicated. This is usually the case in injuries older, than 4weeks. Another question is the price of the implant, which is doubtlessly higher than that of 2 K-wires and a steel wire loop, but the cost of treatment is lower: there is no need of second surgery for implant removal. Also the number of ambulatory controls is lower and, due to shorter rehabilitation, recovery and return to sports activities is earlier. Disadvantage is the need to use image intensifier, which was not the case during classic surgery. Anchoring of distal component is more demanding on surgeons skills.

Conclusions:
Stabilization of AC-joint dislocation with Zip Loop implant is a less invasive procedure leading to restoration of the coracoclavicular ligament complex with dynamic stability. In comparison with open procedures, it allows the patients to return earlier to daily activities and eliminates the necessity of secondary operation for implant removal. The loss of full reduction in three cases, as observed on radiographs during the controls, was not accompanied by any clinical problems and is in concordance with the findings of other authors.

Key words:
Acromioclavicular instability, shortening of rehabilitation, ZipTight technique.