Novel 3-point positioning technique combined with the TightRope system for treating acute Rockwood type III acromioclavicular joint dislocation

Abstract

BACKGROUND

The TightRope system is a common strategy for treating acute Rockwood type III acromioclavicular joint dislocation (ACJD). However, it requires frequent intraoperative fluoroscopy, which poses potential risks to both patients and operators. A novel 3-point positioning technique was developed to reduce intraoperative fluoroscopy time.

AIM

To evaluate the efficacy of the 3-point positioning technique combined with the TightRope system in acute Rockwood type III ACJD.

METHODS

Between January 2024 and October 2024, 26 patients with acute Rockwood type III ACJD underwent treatment via the 3-point positioning technique combined with the TightRope system. Demographic characteristics, operative parameters, and follow-up data were recorded. Preoperative and postoperative clinical evaluations were performed and compared.

RESULTS

The study included 26 patients, 19 males and 7 females, with a mean age of 41.04 ± 12.93 years. The average intraoperative fluoroscopy time was 8.31 ± 1.54 seconds, and the median follow-up period was 13 months. At the final follow-up, significant improvements in the scores were observed relative to preoperative measurements, with all comparisons yielding statistical significance (P < 0.05). The overall complication rate was 3.85%.

CONCLUSION

The 3-point positioning technique combined with the TightRope system reduces intraoperative fluoroscopy time and provides a safe and effective treatment option for patients with acute Rockwood type III ACJD.

Key Words: Acromioclavicular joint dislocation; 3-point positioning technique; TightRope system; Minimally invasive; Fluoroscopy

Core Tip: The TightRope system is a common treatment strategy for acute Rockwood type III acromioclavicular joint dislocation. Conventional surgery requires frequent intraoperative fluoroscopy, which poses potential risks to both patients and operating personnel. We developed a 3-point positioning technique to reduce intraoperative fluoroscopy time. This method uses a Kirschner wire and surface markings to establish a stable trajectory under fluoroscopic guidance by aligning the Kirschner wire, clavicular tunnel position, and the guidewire in a straight line. This technique facilitates rapid, accurate drilling and implant placement while significantly reducing fluoroscopic time.

INTRODUCTION

Acute acromioclavicular joint dislocation (ACJD) is one of the most common shoulder girdle injuries, primarily affecting young males; it accounts for more than 50% of injuries in this region[1]. The Rockwood classification categorizes acute lesions into six severity grades and remains the most widely adopted system for directing treatment decisions[2]. Typically, mild dislocations (types I and II) undergo conservative management, while severe dislocations (types IV to VI) require surgical intervention[3]. Despite extensive research, no universal consensus exists on the clinical management of grade III lesions, with some authors recommending nonoperative treatment and others favoring surgery[4-6]. While conservative approaches may achieve satisfactory results, they carry risks of persistent shoulder discomfort and unacceptable deformities in certain patients[7]. Conversely, surgical interventions may improve joint stability and shoulder function[8,9]. Several surgical approaches have been developed for stabilizing and reconstructing the acromioclavicular joint; nonetheless, no gold-standard method has yet been established[8,10].

The TightRope system, a commonly used surgical technique, has exhibited favorable clinical and imaging outcomes in the treatment of ACJD[11,12]. This microinvasive method achieves acromioclavicular joint stabilization and augments the coracoclavicular complex via high-strength sutures[13,14]. However, previous studies have shown that the conventional TightRope system often requires prolonged intraoperative fluoroscopic imaging during surgery[15]. Extended and repeated use of intraoperative fluoroscopy increases the risk of excessive radiation exposure and poses potential harm to both patients and the surgical team. While alternative strategies, such as navigation systems and specific drill guides, have been explored to reduce radiation and fluoroscopy time, they may increase procedural complexity or procurement costs. To minimize intraoperative fluoroscopy time, we propose a novel 3-point positioning technique that assists with drilling and precise TightRope placement by determining the orientation of the Kirschner wire (K-wire), the clavicular tunnel position, and the guidewire position. This study aimed to assess the clinical efficacy and associated complications in 26 consecutive patients who received this innovative intervention.

MATERIALS AND METHODS

Subject screening

This study was reviewed and approved by the Ethics Committee of Luoyang Orthopedic-Traumatological Hospital of Henan Province: Henan Provincial Orthopedic Hospital (No. 2024KYKT0032-01), and written informed consent was obtained from all patients. The clinical records of 26 patients diagnosed with acute Rockwood type III ACJD who received treatment using the TightRope system with the novel 3-point positioning technique between January 2024 and October 2024 were reviewed.

The inclusion criteria were as follows: (1) Patients aged 18 years or above; (2) Confirmed diagnosis of isolated, acute Rockwood type III ACJD with a duration of less than 3 weeks; (3) Treated with the TightRope system using the novel 3-point positioning technique; (4) Provided written informed consent; and (5) Had at least one year of follow-up.

The exclusion criteria were as follows: (1) Open injuries; (2) Chronic injuries; (3) Concurrent rotator cuff injuries or other shoulder joint trauma; (4) Prior history of shoulder dysfunction on the affected side or severe systemic illnesses that contraindicate surgical intervention; (5) Significant comorbidities preventing tolerance of anesthesia and surgery, including osteoporosis; and (6) Incomplete or fragmented follow-up records, a follow-up period of less than 12 months, or poor patient compliance.

Preoperative clinical assessment

Clinical and demographic data were collected from medical records. These demographic variables included sex, age, body mass index, injury mechanism, injured side, Rockwood classification, and time from injury to surgery. Clinical evaluation was performed preoperatively in all patients and included the American Shoulder and Elbow Surgeons (ASES) score, University of California, Los Angeles (UCLA) score, Disabilities of the Arm, Shoulder and Elbow (DASH) score, Constant-Murley score (CMS), Shoulder Pain and Disability Index (SPADI) score, and Visual Analog Scale (VAS) score.

Operative procedure and 3-point positioning technique

All surgeries were performed by the same surgical team. Patients were placed under general anesthesia in the beach chair position, with the injured limb freely mobile. A 1.0-2.0 cm horizontal skin incision was made, beginning 3.0 cm medial to the acromioclavicular joint. A 2.0 mm K-wire was temporarily inserted to maintain the reduction. The clavicular tunnel was positioned approximately 3.5 cm medial to the acromioclavicular joint. Under fluoroscopic guidance, a second 2.0 mm K-wire was temporarily placed on the skin surface to establish the guideline from the clavicular tunnel site to the coracoid process center. The skin along both sides of this K-wire was then marked using a sterile surgical marking pen. These surface marks served as a visual reference to ensure the K-wire remained stable throughout the subsequent procedure without requiring additional fluoroscopy.

Subsequently, the 3-point positioning technique was applied. The assistant, standing on the patient’s affected side, adjusted their viewing position directly above the surgical field to obtain a bird’s-eye view. This vantage point provides the optimal visual axis for aligning the previously placed K-wire, the clavicular tunnel position, and the guidewire. From this perspective, the assistant verifies that these three points are collinear (Figure 1). The guidewire was then advanced slowly along this line. The clavicular and coracoid tunnels were drilled with a 4.0 mm cannulated drill guided along the guide pin.

Figure 1 Schematic diagram of the three-point positioning technique.

Under the assistant’s guidance, an oblong coracoid button was advanced from the clavicle through the coracoid tunnel. After placing the second button on the superior surface of the clavicle, the TightRope system was tensioned, and the temporary K-wire was removed. Fluoroscopy imaging was employed to verify that the acromioclavicular joint had achieved anatomical reduction. Operative time, fluoroscopy time, and intraoperative blood loss were recorded. From skin incision to wound closure, the surgical time (minutes) was documented. In addition, fluoroscopy time (seconds), intraoperative blood loss (mL), and postoperative complications were also recorded.

Post-operative management and follow-up

All patients underwent radiography on the first postoperative day. During the first four postoperative weeks, patients were immobilized with a shoulder sling. After four weeks, the range of motion was gradually increased as each patient’s healing progressed. Patients were advised to avoid sporting activities for the first three months. Follow-up visits were scheduled at 1, 3, 6, and 12 months postoperatively for clinical evaluation. At the final follow-up, functional assessment was performed by an independent reviewer using the ASES, DASH, UCLA, CMS, VAS, and SPADI scores. Patients were also asked to rate their satisfaction with the treatment outcome as “disappointed”, “not satisfied”, “satisfied”, or “very satisfied”[16].

Complications were categorized as postoperative adverse outcomes, including infection, hematoma, nerve injury, fracture, implant displacement, implant irritation, and persistent shoulder stiffness. Revision procedures were defined as reoperations linked to the initial surgery, including removal of the implant, arthrolysis, lavage, or management of chronic acromioclavicular joint instability. Acromioclavicular joint stabilization failure was categorized as either recurrent symptomatic instability corresponding to Rockwood type IIIB or V, or chronic instability that required surgical intervention.

Statistical analysis

Statistical analyses were carried out with Prism 8.0 (GraphPad Software Inc., San Diego, CA, United States). Continuous variables are presented as means ± SD; the Student’s t-test was applied to compare groups if the variables exhibited a normal distribution. Non-normally distributed variables are presented as medians (quartiles) and compared using the Mann-Whitney U test. Categorical variables are reported as counts and percentages. Statistical significance was set at P < 0.05. Biomedical graphics were created using the Generic Diagramming Platform (GDP, available from: https://BioGDP.com).

RESULTS

Clinical assessment of participants

Twenty-six patients were recruited for this study, and their clinical characteristics are detailed in Table 1. There were 19 males and 7 females, with a mean age of 41.04 ± 12.93 years. The mean body mass index was 21.97 ± 2.18 kg/m². The left shoulder was affected in six patients (23.08%) and the right shoulder in 20 patients (76.92%). The mean time from injury to surgery was 6.35 ± 2.12 days. The mechanisms of injury included traffic accidents in ten patients (38.46%), sports injuries in seven (26.92%), simple falls in three (11.54%), and work-related injuries in six (23.08%). The anesthesia record documented a mean operation time of 29.50 (25.75-32.50) minutes, and it also recorded a mean intraoperative blood loss of 27.50 (20.00-30.00) mL. The average fluoroscopy time was 8.31 ± 1.54 seconds (Table 1).

Table 1 Clinical assessment of the patients.

Variable	Value
Number of cases	26
Gender, M/F	19/7
Age, years, mean ± SD	41.04 ± 12.93
BMI, kg/m2, mean ± SD	21.97 ± 2.18
Left or right, L/R	6/20
Time from injury to surgery, days, mean ± SD	6.35 ± 2.12
Follow-up time, months, median (IQR)	13.00 (12.00, 13.00)
Injury mechanism
Traffic accident, n (%)	10 (38.46)
Sport injury, n (%)	7 (26.92)
Simple fall, n (%)	3 (11.54)
Work injury, n (%)	6 (23.08)
Operation related indexes
Operative time, min, median (IQR)	29.50 (25.75, 32.50)
Intraoperative bloods, mL, median (IQR)	27.50 (20.00, 30.00)
Fluoroscopy time, seconds, mean ± SD	8.31 ± 1.54

M/F: Male/female; BMI: Body mass index; IQR: Interquartile range.

Pre- and postoperative function of the shoulder

Significant improvements were demonstrated in all assessed functional scores (ASES, DASH, UCLA, CMS, VAS, and SPADI) at the final follow-up, relative to preoperative data (all P < 0.05) (Figure 2 and Table 2).

Figure 2 Comparisons between preoperative and postoperative clinical evaluations. Comparisons between preoperative and postoperative scores. A: American Shoulder and Elbow Surgeons score; B: Shoulder and Elbow score; C: University of California, Los Angeles score; D: Constant-Murley score; E: Visual Analog Scale score; F: Shoulder Pain and Disability Index score. ^aP < 0.001, this shows that there was a significant difference before and after surgery using the Student’s t-test (P < 0.05); ^bP < 0.001, this shows that there was a significant difference before and after surgery using the Mann-Whitney U test (P < 0.05). ASES: The American Shoulder and Elbow Surgeons score; DASH: Shoulder and Elbow score; UCLA: University of California, Los Angeles score; CMS: Constant-Murley score; VAS: Visual Analog Scale score; SPADI: Shoulder Pain and Disability Index score.

Table 2 Comparison of functional assessment pre-operation and at the last follow-up.

Characteristic	Preoperation	Postoperation	P value
ASES score, mean ± SD	51.96 ± 4.17	94.15 ± 3.03	< 0.001a
DASH score, mean ± SD	83.88 ± 7.73	8.96 ± 2.54	< 0.001a
UCLA score, mean ± SD	9.15 ± 1.76	31.50 ± 1.97	< 0.001a
CMS, mean ± SD	35.19 ± 5.93	94.31 ± 2.56	< 0.001a
VAS score, median (IQR)	5.50 (4.00, 6.00)	1.00 (0, 2.00)	< 0.001b
SPADI score, mean ± SD	64.15 ± 4.91	8.00 ± 4.88	< 0.001a

^aP ≤ 0.05, Student’s t-test.

^bP ≤ 0.05, Mann-Whitney U test.

ASES: American Shoulder and Elbow Surgeons; DASH: Disability of the Arm, Shoulder and Hand; UCLA: University of California, Los Angeles; CMS: Constant-Murley score; VAS: Visual Analog Scale; SPADI: Shoulder Pain and Disability Index; IQR: Interquartile range.

Follow-up and complication

All patients completed follow-up. The median follow-up duration was 13 months. Satisfaction levels were high, with 21 patients (80.77%) reporting “satisfied” and five (19.23%) reporting “very satisfied”. Follow-up radiographs revealed no fixation failure or re-dislocation (Figure 3). No patients reported disappointment or dissatisfaction. One patient (3.85%) developed a local infection within seven days postoperatively, which resolved with oral antibiotics. No other complications, such as fracture, hematoma, nerve lesion, implant irritation, implant dislocation, or persistent shoulder stiffness, were observed. No failure of acromioclavicular joint stabilization or revision surgery occurred.

Figure 3 Serial radiographs of a 61-year-old man treated with the TightRope system using the novel 3-point positioning technique. A: Preoperative anteroposterior radiograph showing Rockwood type III acromioclavicular joint dislocation; B: 1-month postoperative plain radiograph; C: 12-month postoperative plain radiograph showing good maintenance of joint reduction with the TightRope system using the novel 3-point positioning technique.

DISCUSSION

In this study, we developed a novel 3-point positioning technique designed to assist in drilling and implanting the TightRope system. This method enables accurate localization while reducing fluoroscopy time during minimally invasive TightRope surgery, ensuring smooth progress and favorable therapeutic outcomes. The optimal therapeutic approach for acute Rockwood type III ACJD remains a matter of contention, with more than 150 treatment options proposed to date[17]. While conservative treatment has been reported to yield satisfactory functional outcomes for the shoulder, it is hindered by difficulty in achieving anatomical reduction of the acromioclavicular joint[18]. Moreover, residual deformities can result in cumulative alterations to the shoulder biomechanics, and many patients treated experience dissatisfaction conservatively, eventually requiring delayed surgical repair[18]. Conversely, surgical intervention is generally preferred for patients presenting with acute Rockwood type III ACJD. Among the available surgical methods, the TightRope system is one of the most widely used and has demonstrated favorable clinical outcomes. It provides better cosmetic results and faster functional recovery compared with traditional techniques[19]. However, it is technically demanding and requires frequent intraoperative fluoroscopic imaging. Therefore, we optimized TightRope system operations using the novel 3-point positioning technique, which effectively reduced intraoperative fluoroscopic frequency and yielded encouraging preliminary results.

The novel 3-point positioning technique assists in accurate drilling and placement of the TightRope by determining the tunnel orientation of the clavicle and coracoid while minimizing fluoroscopy use. A previous study reported 80 patients with acute Rockwood type III/IV ACJD who underwent minimally invasive fixation with the TightRope system via mini-open or percutaneous stabilization with mean fluoroscopy times of 19.8 ± 5.8 seconds and 21.4 ± 7.5 seconds, respectively[20]. Yapici et al[21] reported a mean fluoroscopy time of 12.4 ± 0.7 seconds in 21 patients with Rockwood type III/V ACJD treated using the open double-button technique. Similarly, İğrek et al[15] reported a mean fluoroscopy time of 15.72 ± 3.95 seconds in 39 patients treated with a percutaneous endo-button procedure. In contrast, our study demonstrated a mean fluoroscopy time of 8.31 ± 1.54 seconds. We believe that this technique minimizes the need for repeated intraoperative imaging by establishing a precise K-wire guide from the clavicular tunnel site to the center of the coracoid process during the procedure. This provides a definitive spatial trajectory, eliminating much of the positional uncertainty. Consequently, it curtails the cycle of “trial-and-error” drilling and confirmation fluoroscopy. Therefore, the novel 3-point positioning technique can significantly reduce fluoroscopy time and radiation exposure, thereby enhancing intraoperative safety for both patients and surgical personnel.

Our study demonstrated that after surgery, the ASES, DASH, UCLA, CMS, VAS, and SPADI scores significantly improved, indicating that the TightRope system, combined with the novel 3-point positioning technique, achieved favorable therapeutic outcomes. In this study, the mean postoperative ASES scores were 94.15 ± 3.03, consistent with a previous report showing a mean ASES score of 95.5 ± 9.35 in ACJD patients who had previously undergone TightRope fixation[22]. The average postoperative UCLA, CMS, and VAS scores in our study were 31.50 ± 1.97, 94.31 ± 2.56, and 1.00 (0, 2.00), respectively. Similarly, a previous study reported 21 patients with acute Rockwood type III ACJD treated with minimally invasive TightRope fixation who had average postoperative UCLA, CMS, and VAS scores of 33.2 ± 1.5, 90.5 ± 9.6, and 0.8 ± 1.2, respectively[23]. These findings suggest that combining the TightRope system with the novel 3-point positioning technique yields excellent functional outcomes. Furthermore, this technique can shorten operative time while maintaining favorable therapeutic results. In our study, the median operative time was 29.5 minutes. A previous study reported that 80 patients with ACJD treated with Tightrope fixation via mini-open or percutaneous stabilization had mean operative times of 63.2 ± 9.6 minutes and 45.6 ± 7.1 minutes, respectively[20].

In this study, the novel 3-point positioning technique combined with the TightRope system proved to be a safe and reliable option for treating acute Rockwood type III ACJD. A wound infection occurred in one (3.85%) patient, and was successfully treated with daily dressing changes and antibiotics, resulting in complete healing without persistent infection or osteomyelitis. Liu et al[24] demonstrated a similar overall complication rate of 3.13% in 32 cases managed with a modified TightRope loop plate fixation.

Limitations

Several limitations should be acknowledged in this study. First, the retrospective design, small sample size, and single-center setting are associated with inherent selection bias, while limiting the generalizability of the findings. Second, this study lacked a control group receiving traditional surgery; thus, comparative studies will be needed in the future. Third, although the 13-month follow-up period in our study is not particularly long, the positive postoperative outcomes observed during this period indicate that this surgical approach is feasible and effective. Studies with longer follow-up periods will be conducted in the future.

CONCLUSION

The 3-point positioning technique employed for treating acute Rockwood type III ACJD in this study reduced intraoperative fluoroscopy time and achieved satisfactory clinical outcomes. Despite being grounded in a small sample size, this technological advancement merits additional optimization, research, and dissemination.