Clinical outcomes of bending versus non-bending of the plate hook in acromioclavicular joint dislocation

Abstract

Background: We aimed to assess the effect of plate hook bending in treatment of acromioclavicular (AC) dislocation by analyzing clinical and radiological results according to the angle of the plate hook (APH).Methods: This was a retrospective, observational, case-control study including 76 patients with acute AC joint dislocation that were divided into two groups according to treatment with bent or unbent plate hook. The visual analog scale (VAS), the American Shoulder and Elbow Surgeons (ASES) shoulder score, and range of motion (ROM) were evaluated as clinical outcomes. Comparative coracoclavicular distance (CCD) was measured to evaluate radiological outcomes.Results: While the VAS and ASES of the bending group at 4 months after surgery were significantly higher (P=0.021, P=0.019), the rest of those and ROM showed no significant difference. The initial CCD decreased from 183.2%±25.4% to 114.3%±18.9% at the final follow-up in the bending group and decreased from 188.2%±34.4% to 119.1%±16.7% in the non-bending group, with no statistical difference (P=0.613). The changes between the initial and post-metal removal CCD were 60.2%±11.2% and 57.3%±10.4%, respectively, with no statistical difference (P=0.241). The non-bending group showed greater subacromial osteolysis (odds ratio, 3.87). Pearson’s coefficients for the correlation between APH and VAS at 4 months after surgery and for that between APH and ASES at 4 months after surgery were 0.74 and –0.63 (P=0.027 and P=0.032), respectively.Conclusions: The APH was associated with improved postoperative pain and clinical outcomes before implant removal and with reduced complications; therefore, plate hook bending is more useful clinically during plate implantation.

Complications and Frequency of Surgical Treatment with AO-Type Hook Plate in Shoulder Trauma: A Retrospective Study

“…As part of this effort, studies have also been reported on whether the angle of the hook part is 90 degrees or whether a larger angle is appropriate. As a result, it was reported that a hook angle of 105 degrees or 110 degrees is appropriate to reduce the complications related to the hook [29][30][31]. Yoon et al reported that the hook made a pin-point contact with the undersurface of the acromion, and the force concentration phenomenon associated with the hook plate of existing designs results from cases of morphological mismatch, such as excessive inclination and improper occupation of the subacromial space [45].…”

“…In several previous studies, the authors emphasized the complications can be minimized by performing an anatomic fit of the plate during the procedure and found it necessary to bend the hook [14,27,28]. Precontouring of 20 degrees in the VariAx lateral hook plate is thought to be influenced or reflect these previous research results [29][30][31]. In order to match the hook part of the metal plate with the lower edge of the acromion as much as possible, the special fluoroscopic view technique we developed was utilized for the best fit between the hook and the acromion, which was helpful in reducing the inevitable acromial erosion [27].…”

Is Bending the Hook Plate Necessary in Acromioclavicular Joint Dislocation?

“…One of them is subacromial erosion/osteolysis due to use of a plate hook [4,5]. The study, "The clinical outcomes of bending versus non-bending of the plate hook in acromioclavicular joint dislocation, " by Joo et al [6] in the issue focuses on subacromial osteolysis of the hook plate and its associated deterioration of clinical outcomes. Several papers have demonstrated that friction pain and osteolysis are caused by compression of the subacromial area of the hook plate [7][8][9][10].…”

“…In a study by Joo et al [6], the hook plate was bent with the angle of the plate hook an average of 21°, and patient outcomes were compared with those of the non-bending group. The results showed that the incidence of subacromial osteolysis was significantly reduced, and the clinical outcome prior to plate removal had improved considerably.…”

“…In most cases, the hook plate is removed within a few months, and the induced complications do not worsen after removal, and the clinical results improve in most cases Many studies early removal of the hook plate to prevent complications and aggravation of clinical outcomes [8,19]. In a study of Joo et al [6], there was a significant difference in osteolysis between the bending and non-bending groups. However, the difference in clinical results was resolved after metal removal.…”