Acromioclavicular (AC) joint injuries are among the most frequent shoulder girdle disruptions, representing nearly 9% of all shoulder injuries encountered in clinical practice [1]. The AC joint is biomechanically complex, stabilized by a coordinated system of capsular ligaments and the coracoclavicular (CC) ligaments, which together maintain vertical and horizontal stability. Disruption of these ligamentous structures leads to instability, pain, restricted motion, and compromised functional performance, particularly in young and active adults who constitute the majority of affected patients [1–3]. While low-grade injuries (Rockwood types I–II) generally respond well to conservative management, high-grade injuries (Rockwood types IV–VI) are widely recognized to require surgical intervention due to the severity of displacement and soft-tissue disruption [4]. Historically, various operative strategies—including fixation with pins, screws, hook plates, ligament transfers, and biologic graft reconstructions—have been described with varying outcomes [5]. However, many traditional methods are associated with complications such as implant migration, coracoid or clavicular fractures, subacromial impingement, and the frequent need for secondary implant removal [6]. The introduction of suture-based suspensory devices, particularly double-button constructs, has marked a significant advancement in AC joint stabilization. These devices aim to replicate the physiological behavior of the CC ligament complex while avoiding the rigidity and stress concentration associated with metallic hardware. The double-endobutton technique provides strong vertical stabilization, allows controlled micromotion conducive to ligamentous healing, and minimizes soft-tissue disruption due to its minimally invasive nature [4,6]. Furthermore, the use of high-strength fiber tape enhances load-sharing capacity and reduces the likelihood of early failure. Existing literature demonstrates encouraging outcomes with this technique. Beris et al. reported excellent postoperative function and early return to activity following double-button fixation of acute AC dislocations [4]. Likewise, Issa et al. documented favorable radiological and functional recovery with single double-button constructs for acute AC separation, noting satisfactory mid-term outcomes and low complication rates [2]. Nonetheless, despite growing enthusiasm, the optimal method of fixation and the superiority of double-button constructs over other modalities remain subjects of debate. Given the increasing adoption of suspensory devices, further evidence is required to establish their functional benefits and complication profiles in high-grade AC injuries. Additionally, data from Indian tertiary-care orthopedic centers remain limited. Therefore, the present study aimed to prospectively evaluate the functional outcomes, complication rates, and radiological stability in patients with Rockwood type IV and V acute AC joint dislocations treated with double-endobutton fixation combined with fiber tape augmentation. This research intends to contribute contemporary clinical evidence on the effectiveness of this technique and its applicability in operating environments similar to the Indian healthcare setting.

This prospective observational study was conducted in the Department of Orthopaedics, King George Hospital, Andhra Medical College, Visakhapatnam, between July 2023 and December 2024. All patients presenting with acute Rockwood type IV or V AC joint dislocations were screened for eligibility. Written informed consent was obtained from each participant. Study Population Patients aged 18–60 years with acute, closed AC joint disruptions classified as Rockwood IV or V were included. Exclusion criteria comprised chronic injuries, compound injuries, elderly patients, and cases with associated polytrauma requiring staged intervention. A total of 22 patients meeting these criteria were enrolled consecutively. Clinical and Radiological Assessment A detailed history documenting the mechanism of trauma, symptom duration, and prior treatments was obtained. Physical examination assessed deformity, swelling, skin tenting, tenderness, and range of motion. Radiological evaluation included anteroposterior, axial, and Zanca views of the shoulder. CT was utilized selectively when coracoid fractures or occult displacement were suspected. Surgical Technique All procedures were performed under general anesthesia with patients positioned in the beach-chair position. Through a limited open approach, the base of the coracoid was exposed, and a 2.7-mm drill was used to create a tunnel for suspensory fixation. Two clavicular tunnels spaced 1.5 cm apart were created, ensuring appropriate alignment and minimizing fracture risk. A double-endobutton device with fiber tape was shuttled through the tunnels, the inferior endobutton flipped beneath the coracoid, and the superior button secured over the clavicle with the shoulder held in anatomical reduction confirmed using an image intensifier. Figure 1,2 Figure 1: Tying of ends of fiber tape over clavicle using AC button while simultaneously applying manual pressure over lateral end of clavicle to maintain reduction of AC joint. Figure 2: Confirming reduction on image intensifier. Postoperative Protocol Intravenous antibiotics were administered for 72 hours, followed by oral antibiotics. Shoulder immobilization was maintained for two weeks, after which pendulum exercises were initiated. Active-assisted mobilization began at three weeks, and full range-of-motion exercises commenced by the sixth postoperative week. Strengthening exercises were implemented after radiological confirmation of maintained reduction. Outcome Measures Functional outcomes were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) score and the Constant–Murley score at 6 weeks, 3 months, and 6 months. Radiographs at each follow-up evaluated maintenance of reduction, implant integrity, and CC distance restoration. Data Analysis All data were entered into Microsoft Excel and analyzed using SPSS version 20. Quantitative variables were expressed as mean ± SD. Repeated-measures analysis using the Friedman test evaluated changes in functional scores over time. A p-value <0.05 was considered statistically significant.

A total of 22 patients with acute Rockwood type IV and V acromioclavicular (AC) joint dislocations underwent double-endobutton fixation with fiber tape. The mean age of the cohort was 34.2 ± 8.1 years, with a predominance of young adults. Males constituted the majority of the study population (86.36%), reflecting the higher exposure of this group to high-energy trauma. Table 1. Age-wise Distribution of Patients Age (Years) No. of Patients Percentage (%) < 30 8 36.36 30–39 7 31.81 40–49 5 22.72 ≥ 50 2 9.09 Total 22 100 Most patients (68.17%) were younger than 40 years, aligning with the known epidemiology of high-grade AC joint injuries occurring predominantly in active individuals. Table 1 Table 2. Distribution According to Mode of Injury Mode of Injury No. of Patients Percentage (%) Road Traffic Accident (RTA) 18 81.81 Fall from Height 2 9.09 Slip Injury 2 9.09 Total 22 100 Road traffic accidents constituted the most common mechanism of trauma (81.81%), highlighting the high-energy nature of injuries associated with Rockwood IV–V dislocations. Table 2 Functional Outcomes Significant improvements were noted in functional outcome scores across all follow-up intervals. Table 3. Comparison of DASH Scores Over Time Time Point Mean DASH Score SD Pre-operative 48.97 4.808 Post-op 6 weeks 37.83 3.723 Post-op 3 months 18.81 2.816 Post-op 6 months 5.33 2.165 The decrease in DASH scores was statistically significant (Friedman test p = 0.0001), demonstrating progressive reduction of disability. By six months, most patients achieved near-normal functional status, with a mean DASH score of 5.33, indicating minimal residual impairment. Table 3 Table 4. Comparison of Constant–Murley Scores Over Time Time Point Mean Constant Score SD Pre-operative 33.67 4.276 Post-op 6 weeks 53.72 3.997 Post-op 3 months 75.19 3.740 Post-op 6 months 95.11 2.327 Constant scores improved significantly (p = 0.0001) at each follow-up stage. By six months, the mean score of 95.11 reflected restoration of near-normal shoulder function, with improvements noted in pain, strength, and range of motion domains. Table 4

The present study demonstrated that double-endobutton fixation with fiber tape provides excellent functional recovery in patients with Rockwood type IV and V acromioclavicular (AC) joint dislocations. The improvement observed in DASH and Constant–Murley scores over the six-month follow-up period reflects the biomechanical stability offered by this suspensory construct and is consistent with previously published reports. Early literature noted limitations of traditional methods such as pins, screws, and hook plates, including migration, breakage, and the need for secondary removal procedures [11]. These shortcomings prompted the shift toward dynamic suspension systems that more closely reproduce native coracoclavicular biomechanics. Biomechanical and clinical studies have shown that double-button devices provide superior load-to-failure characteristics and reduce postoperative discomfort by minimizing soft-tissue disruption [12]. Arthroscopically assisted and mini-open approaches have also been reported to enhance cosmetic outcomes and reduce operative morbidity [13]. In the present series, the use of a limited-incision open technique with a 2.7-mm tunnel avoided iatrogenic fractures, a complication noted in earlier reconstructions involving larger drill holes and allograft tunnels [14]. Similarly, the low infection rate in this study compares favorably with published reports, where synthetic tapes and nonabsorbable sutures have occasionally been associated with late infections and soft-tissue irritation [15]. Clinical comparisons between hook plates and double-button constructs in the literature consistently show superior patient-reported outcomes for the latter, particularly due to elimination of subacromial impingement and avoidance of implant removal [16]. Stein et al. demonstrated significantly better functional scores with the double-button technique in high-grade injuries, supporting the findings of the present study [17]. Other authors, including Beris et al., highlighted the rapid return to activity and high satisfaction rates following modern suspensory techniques, findings echoed in our functional outcomes [18]. The evolution from Weaver–Dunn and its modifications toward anatomical coracoclavicular reconstruction underscores the importance of restoring vertical and horizontal stability. Long-term studies have shown that anatomic reconstruction using suspensory devices yields durable stability with low rates of recurrent displacement [19]. The absence of radiographic loss of reduction in our cohort reinforces this concept. Additionally, minimal postoperative stiffness and restoration of full range of motion by six months align with recent mid-term analyses reporting predictable rehabilitation trajectories after double-button fixation [20]. The study was limited by its single-centre design and relatively small sample size, a constraint also observed in comparable clinical investigations [21,22]. The absence of a comparative control arm restricted the ability to evaluate differences between fixation methods, a limitation similarly noted in prior observational reports [23]. The short follow-up duration may not adequately reflect long-term biomechanical behavior or late complications, consistent with limitations described in earlier short-term outcome studies [24]. Furthermore, reliance on standard radiographs rather than advanced imaging may have reduced diagnostic sensitivity for subtle postoperative changes, as highlighted in previous radiographic-accuracy assessments [25]. Overall, this study adds to the growing evidence supporting double-endobutton constructs as a reliable option for high-grade AC dislocations, providing stable fixation, low complication rates, and excellent functional outcomes.

Double-endobutton fixation with fiber tape provides a stable, anatomical, and minimally invasive solution for managing Rockwood type IV and V acute acromioclavicular joint dislocations. In this prospective cohort of 22 patients, significant improvements in DASH and Constant–Murley scores were observed at each follow-up interval, with most patients achieving near-normal shoulder function by six months. Complications were minimal and manageable, and no cases of implant migration or loss of reduction were identified. The technique allowed early mobilization, predictable healing, and restoration of shoulder biomechanics. These findings support the growing preference for suspensory fixation systems over traditional rigid implants, offering superior clinical outcomes and reducing the need for secondary surgical interventions. Larger, long-term comparative studies would further strengthen the evidence for adopting this technique as a standard operative approach for high-grade AC joint injuries.

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