Anatomic ligament consolidation of the superior acromioclavicular ligament and the coracoclavicular ligament complex after acute arthroscopically assisted double coracoclavicular bundle stabilization

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.

Clavicular Tunnel Widening After Acromioclavicular Stabilization Shows Implant-Dependent Correlation With Postoperative Loss of Reduction

PURPOSE

To radiographically describe, quantify, and compare clavicular tunnel widening (cTW) of 2 different types of stabilization devices and investigate a possible correlation between cTW and loss of reduction.

METHODS

In a retrospective analysis of single-center registry data, we compared patients who were treated for an acute AC dislocation (Rockwood types III to V) with either the AC Dog Bone (DB) or low-profile AC (LP) repair systems. On 6-week and 6-month postoperative radiographs, we measured clavicle height and tunnel diameter. We calculated the button/clavicle filling (B/C) ratio to quantify how much of the clavicular tunnel height is covered by the low-profile inlet. The association between B/C ratio and the extent of cTW was defined, and we also compared cTW between treatment groups. Reduction of the AC joint was graded as either stable, partially dislocated or dislocated depending on the AC ratio. A 2-sample t-test was used for comparing cTW progression between the 2 groups. For continuous variables between more than 2 groups, the Kruskal-Wallis test was used.

RESULTS

Of 65 eligible patients, there were 37 and 28 included in the DB and LP groups, respectively. Overall, cTW was conically shaped with transclavicular widening noted in the DB group and cTW developing strictly inferior to the button in the LP group. For both implants, mean maximal cTW was 7.1 mm and located at the inferior cortex; the B/C ratio was not associated with increased inferior cTW (r = -0.23, P = .248). Only LP patients with complete loss of reduction had significantly increased cTW (P = .049).

CONCLUSIONS

Conical-shaped cTW is a common implant-independent phenomenon after AC stabilization using suture-button devices. It occurs only at the suture-bone interface and is less excessive for the LP implant. There is an association between increased cTW and loss of reduction specific to the LP implant only.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Morphology of the Acromioclavicular Joint Does Not Influence the Postoperative Outcome Following Acute Stabilization—A Case Series of 81 Patients

Purpose

To specifically evaluate the influence of the acromioclavicular (AC)-joint morphology on the outcome after arthroscopically assisted coracoclavicular (CC) stabilization surgery with suspensory fixation systems and to investigate whether an additional open AC-joint reduction and AC cerclage improves the clinical outcome for patients with certain morphologic AC-joint subtypes.

Methods

Patients with an acute acromioclavicular joint injury, who underwent arthroscopically assisted CC stabilization with suspensory fixation systems with or without concomitant AC cerclage between January 2009 and June 2017 were identified and included in this retrospective cohort analysis. AC-joint morphology was assessed on preoperative radiographs and categorized as “flat” or “non-flat” (“oblique”/“curved”) subtypes. After a minimum of 2 years of follow-up, postoperative Single Assessment Numeric Evaluation (SANE), American Shoulder and Elbow Surgeons (ASES), and visual analog scale (VAS) scores for pain were collected. A subgroup analysis of clinical outcomes depending on the surgical technique and morphological subtype of the AC joint was performed.

Results

Eighty-one patients (95% male, mean age 35 ± 12 years) could be included at a mean follow-up of 57 ± 14 months. Radiographic assessment of AC-joint morphology showed 24 (30%) cases of flat type, 38 (47%) cases of curved type, and 19 (23%) cases of oblique morphology. Postoperatively, no clinically significant difference could be detected after the treatment of AC joint injury via CC stabilization with or without concomitant AC cerclage (VAS_rest: P = .067; VAS_max: P = .144, ASES: P = .548; SANE: P = .045). No clinically significant differences were found between the surgical techniques for the flat morphologic subtype (VAS_rest: P = .820; VAS_max: P = .251; SANE: P = .104; ASES: P = .343) or the non-flat subtype (VAS_res: P = .021; VAS_max: P = .488; SANE: P = .243, ASES: P = .843).

Conclusions

In arthroscopically assisted AC stabilization surgery with suspensory fixation systems for acute AC-joint injury, the AC-joint morphology did not influence the postoperative outcome, independent of the surgical technique. No clinical benefit of performing an additional horizontal stabilization could be detected in our collective at mid-term follow-up.

Level of Evidence

Level IV, therapeutic case series.

Is coracoclavicular ossification a complication or a good prognostic factor after surgical treatment of acromioclavicular joint injury?

Background

The purpose of this study was to investigate whether heterotopic ossification (HO) in the coracoclavicular (CC) space after surgical treatment of acromioclavicular joint (ACJ) injury is a complication or a sign of good prognosis.

Methods

Fifty-nine consecutive patients who underwent CC reconstruction with or without augmentation of the ACJ for acute ACJ injuries were analyzed. Postoperative American Shoulder and Elbow Surgeons (ASES) score, Constant score (CS), subjective shoulder value (SSV), and visual analog scale (VAS) results were evaluated. For radiological evaluation, HO was evaluated, and CC distances were measured.

Results

Fifty-one patients (11 women and 40 men; mean age, 36 years [range, 17-68 years]) were evaluated after a mean follow-up of 3 years (range, 2-8 years). The mean ASES score at the follow-up was 82.73 (range, 51.6-100), mean CS was 85 (range, 50-100), mean SSV was 80 (range, 40-100), and mean VAS was 1.9 (range, 0-5). It was observed that the clinical outcomes (ASES, CS, SSV, VAS) of patients who developed ossification in the CC space were better than those who did not although it was not statistically significant. No statistically significant differences were found in the clinical outcomes (ASES, CS, SSV, VAS) between patients who underwent CC reconstruction without augmentation of the ACJ and those who were combined (P > .05).

Conclusion

HO in the CC space is a common finding following AC joint fixation injury. We suggest that HO is not a complication and might possibly have positive effects on clinical outcomes.

Ligamentous healing potential of the acromioclavicular ligament following acute anatomical reconstruction

BACKGROUND

Horizontal instability following acute acromioclavicular joint (ACJ) reconstruction still occurs with a high prevalence. Although the human acromioclavicular ligament complex (ACLC) represents the major horizontal ACJ stabilizer, experimental studies on healing characteristics are lacking. Therefore, the purpose of this histological study was to investigate the healing potential of the ACLC following acute anatomical reconstruction METHODS: In this prospective clinical-experimental study, 28 ACLC biopsies were performed in patients with complete ACJ dislocations (Rockwood type 4 or 5) during acute hook plate stabilization (IG: implantation group; n = 14) and hook plate removal (EG: explantation group; n = 14). Histological analyses included Giemsa staining, polarized light microscopy and immunostaining against CD68, αSMA and collagen type I and type III. Histomorphological evaluation entailed cell counts, collagen expression score, ligament tissue maturity index (LTMI) and descriptive analysis of specific ligamentous structures. Statistics consisted of nonparametric Mann-Whitney U tests and a level of significance of P < .05.

RESULTS

Total cell counts (cells/mm² 1491 ± 296 vs. 635 ± 430; P < 0.001) and collagen III expression (3.22 ± 0.22 vs. 1.78 ± 0.41; P < 0.001) were higher in EG compared to IG. Inversely αSMA + (11 ± 9 vs. 179 ± 186; P < 0.001) and CD68 + cell counts (56 ± 20 vs. 100 ± 57; P 0.009) were significantly lower in the EG. The EG revealed a comparable reorientation of ligamentous structures. Consistently, ACLC samples of the EG (21.6 ± 2.4) displayed a high total but differently composed LTMI score (IG: 24.5 ± 1.2; P < 0.001).

CONCLUSIONS

This experimental study proved the ligamentous healing potential of the human ACLC following acute anatomical reconstruction. Histomorphologically, the ACLC reliably showed a ligamentous state of healing at a mean of about 12 weeks after surgery. However, processes of ligamentous remodeling were still evident. These experimental findings support recent clinical data showing superior horizontal ACJ stability with additional AC stabilization in the context of acute ACJ reconstruction. Though, prospective clinical and biomechanical studies are warranted to evaluate influencing factors on ACLC healing and potential impacts of acute ACLC repair on clinical outcome.

STUDY TYPE

Controlled Laboratory Study.

Comparison of single versus double TightRope system in the treatment of acute acromioclavicular joint dislocation

BACKGROUND

Reconstruction of the coracoclavicular (CC) ligament using a single TightRope (ST) system has some complications. We attempted to use a double TightRope (DT) system to reduce complications and obtain the ideal therapeutic effect.

PURPOSE

This investigation aimed to compare the ST and DT systems in terms of efficacy and safety in treating acromioclavicular (AC) joint dislocation.

METHODS

Sixty-six cases of acute AC joint dislocation between January 2013 and January 2018 were retrospectively reviewed. All patients were divided into 2 groups based on treatment with the ST or DT system. Patients were evaluated radiologically and clinically using the Disability of Arm, Shoulder, and Hand, Constant, and visual analog scale scores as clinical outcome measures at 1 day, 3 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years after surgery. The CC distance and displacement ratio were assessed radiologically.

RESULTS

The mean follow-up period was 49 months. Satisfactory clinical outcomes were obtained after CC fixation in both groups. No intergroup difference was found regarding the visual analog scale (P = .80), Disability of Arm, Shoulder, and Hand (P = .42), or Constant score (P = .28) at 2 years. However, there was a significant difference in the displacement ratio at 6 weeks (P < .0001), 3 months (P < .0001), 6 months (P < .0001), 1 year (P < .0001), and 2 years (P < .0001) postoperatively between the 2 groups. There were 3 complications in the ST group, including 1 case of secondary coracoid fracture, 1 case of AC joint arthrosis combined with ossification of the CC ligaments, and 1 case of clavicular erosion. All complications occurred in the ST group.

CONCLUSIONS

Both surgical methods are effective in treating AC joint dislocation, but the DT system is more reliable for reduction maintenance.

The prevalence of intraarticular associated lesions after acute acromioclavicular joint injuries is 20%. A systematic review and meta-analysis

PURPOSE

To synthesise the evidence on the prevalence of associated intraarticular lesions in subjects with acute acromioclavicular joint (ACJ) dislocations.

METHODS

A search in two electronic databases (PUMBMED and EMBASE) was performed from 1985 to 2019. Two independent reviewers selected studies that complied with the following inclusion criteria: (1) the study included data on surgically treated ACJ dislocation grade III-V in the Rockwood classification, (2) the ACJ injuries were acute (the surgery was performed less than 6 weeks after injury), (3) an arthroscopic evaluation of the glenohumeral joint was performed during surgery. The quality of the studies included was assessed using the tool of the Joanna Briggs Institute.

RESULTS

A total of 47 studies with acute ACJ injuries met the initial inclusion criteria. Of these, 21 studies (9 retrospective case series, 9 prospective case series and 3 retrospective cohort studies) presented data on associated intraarticular lesions amenable for use in the meta-analysis. The meta-analysed studies included a total of 860 subjects with acute ACJ dislocations with a male/female ratio of 6.5 and a mean age of 32 years. The meta-analysis showed a prevalence of associated intraarticular lesions in subjects with acute ACJ of 19.9% (95% confidence interval [CI] 14.0-26.4%; 21 studies, 860 analysed participants; P = 0.000; I²: 74.5% random-effects model; low risk of bias).

CONCLUSION

One in five subjects with surgically treated acute ACJ dislocations will have an associated intraarticular lesion that requires further intervention. The case for a customary arthroscopic evaluation of the joint, even when an open procedure is performed to deal with the ACJ dislocation, is strong. Level of evidence IV Trial registry Systematic review registration number: PROSPERO CRD42018090609.

Comparison of Hook Plate Fixation Versus Arthroscopic Coracoclavicular Fixation Using Multiple Soft Anchor Knots for the Treatment of Acute High-Grade Acromioclavicular Joint Dislocations

PURPOSE

To compare the clinical and radiologic outcomes of arthroscopically assisted coracoclavicular (CC) fixation using multiple soft anchor knots versus hook plate fixation in patients with acute high-grade Rockwood type III and V acromioclavicular (AC) joint dislocations.

METHODS

This retrospective study included 22 patients with acute Rockwood type III and V AC joint dislocations who underwent arthroscopic fixation or hook plate fixation surgery between February 2016 and March 2018. Patients were categorized into 2 groups: arthroscopically assisted CC fixation using multiple soft anchor knots group (AR, n = 12) and hook plate fixation group (HO, n = 10). We measured the CC distances (CCDs) and CCD ratio at 6 months, 1 year, and last follow-up postoperatively to compare the radiologic results between the groups. Clinical outcomes were assessed at 1 year postoperatively and at the last follow-up using the Visual Analog Scale, American Shoulder and Elbow Surgeons (ASES) scores, and Shoulder Pain and Disability Index (SPADI) scores, and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Magnetic resonance imaging after hook plate removal was used to evaluate the healing ligaments and tendon-bone interface.

RESULTS

The patients in the AR group had better ASES, SPADI, and Quick DASH scores than the patients in the HO group at 1 year postoperatively and at last follow-up. The CCD and CCD ratio were significantly better in the AR group than in the HO group at the last follow-up period (P = .007/0.029). Magnetic resonance imaging findings showed grade I in 60% of patients in the AR group and grade III in 60% of patients in the HO group. AC joint arthritic change was observed in 40% of the HO group.

CONCLUSIONS

The CC fixation method using multiple soft anchor knots showed satisfactory results and had superior CC ligament healing ability and maintenance of CCD than hook fixation.

LEVEL OF EVIDENCE

Level III, retrospective therapeutic comparative investigation.

The acromioclavicular ligament shows an early and dynamic healing response following acute traumatic rupture

Purpose

Symptomatic horizontal instability is clinically relevant following acute acromioclavicular joint dislocations. However, the intrinsic healing response is poorly understood. The present study sought to investigate time-dependent healing responses of the human acromioclavicular ligament following acute traumatic rupture.

Methods

Biopsies of the acromioclavicular ligament were obtained from patients undergoing surgical treatment for acute acromioclavicular joint dislocations. Specimens were stratified by time between trauma and surgery: group 1, 0–7 days (n = 5); group 2, 8–14 days (n = 6); and group 3, 15–21 days (n = 4). Time-dependent changes in cellularity, collagen (type 1 and 3) concentration, and histomorphological appearance were evaluated for the rupture and intact zone of the acromioclavicular ligament.

Results

Group 1 was characterized by cellular activation and early inflammatory response. The rupture zone exhibited a significantly higher count of CD68-positive cells than the intact zone (15.2 vs 7.4; P ≤ 0.05). Consistently, synovialization of the rupture end was observed. Within the second week, the rupture zone was subject to proliferation showing more fibroblast-like cells than the intact zone (66.8 vs 43.8; P ≤ 0.05) and a peak of collagen type 3 expression (group 1: 2.2 ± 0.38, group 2: 3.2 ± 0.18, group 3: 2.8 ± 0.57; P ≤ 0.05). Signs of consolidation and early remodeling were seen in the third week.

Conclusions

The acromioclavicular ligament exhibits early and dynamic healing responses following acute traumatic rupture. Our histological findings suggest that surgical treatment of acute ACJ dislocations should be performed as early as possible within a timeframe of 1 week after trauma to exploit the utmost biological healing potential. Prospective clinical studies are warranted to investigate whether early surgical treatment of ACJ dislocations translates into clinical benefits.

Editorial Commentary: Coracoclavicular Ligament Reconstruction. Double Up It Is?

More than 100 surgical techniques have been described for the reconstruction of the coracoclavicular ligament complex. None of the techniques appears superior, but double-button fixation for acute high-grade acromioclavicular dislocations has become an attractive option. The clinical outcomes are good to excellent, and the return to physical activity and sport is above 90%. However, complications such as loss of reduction and tunnel widening have been described and can reach up to 80%. The load to failure of the native coracoclavicular complex is more than 600 N, and any surgical technique must surpass this figure. Single-button and loop techniques do not always sufficiently stabilize the acromioclavicular joint. Even double- and triple-button techniques may not restore vertical and horizontal stability of the acromioclavicular joint to its native normal state. Double-button technique restores both scapula and clavicular rotation closest to the native state, but still has lower stiffness and results in higher superior-inferior translation, which could cause ongoing vertical instability.

Factors Predicting the Outcome After Arthroscopically Assisted Stabilization of Acute High-Grade Acromioclavicular Joint Dislocations

BACKGROUND

Factors influencing the outcome after arthroscopically assisted stabilization of acute high-grade acromioclavicular (AC) joint dislocations remain poorly investigated.

PURPOSE

To identify determinants of the radiological outcome and investigate associations between radiological and clinical outcome parameters.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The authors performed a retrospective analysis of patients who underwent arthroscopically assisted stabilization for acute high-grade AC joint dislocations. The following potential determinants of the radiological outcome were examined using univariable and multivariable regression analyses: timing of surgery, initial AC joint reduction, isolated coracoclavicular (CC) versus combined CC and AC stabilization, ossification of the CC ligaments, age, and overweight status. In addition, associations between radiological (ie, CC difference, dynamic posterior translation [DPT]) and clinical outcome parameters (Subjective Shoulder Value, Taft score [TS] subjective subcategory, and Acromioclavicular Joint Instability Score [ACJI] pain subitem) were evaluated using univariable analysis.

RESULTS

One hundred four patients with a mean (±SD) age of 38.1 ± 11.5 years were included in this study. The mean postoperative follow-up was 2.2 ± 0.9 years. Compared with patients with an overreduced AC joint after surgery, the CC difference was 4.3 mm (95% CI, 1.3-7.3; P = .006) higher in patients with incomplete reduction. Patients with anatomic reduction were 3.1 times (95% CI, 1.2-7.9; P = .017) more likely to develop DPT than those with an overreduced AC joint. An incompletely reduced AC joint was 5.3 times (95% CI, 2.1-13.4; P < .001) more likely to develop DPT versus an overreduced AC joint. Patients who underwent isolated CC stabilization were 4.8 times (95% CI, 1.1-21.0; P = .039) more likely to develop complete DPT than patients with additional AC stabilization. Significantly higher CC difference values were noted for patients who reported pain on the subjective TS (P = .025). Pain was encountered more commonly in patients with DPT (P_TS = .049; P_ACJI = .038).

CONCLUSION

Clinicians should consider overreduction of the AC joint because it may lead to favorable radiological results. Because of its association with superior radiographic outcomes, consideration should also be given to the use of additional AC cerclage.

Arthroscopic Coracoclavicular Fixation Technique Using Multiple All-Suture Anchors

Acromioclavicular (AC) joint dislocation is a common injury, particularly among active young individuals. Numerous surgical procedures for treating acute, high-grade AC joint dislocation have been reported. However, no standard surgical procedure that restores the normal kinematics of the AC joint is available. Among the available coracoclavicular (CC) fixation techniques, cortical button fixation was recently introduced, and it has had successful outcomes. Moreover, it is advantageous because it can be used in arthroscopic procedures. However, because of the limited number of fixation tools, a fundamental problem in terms of horizontal instability and gradual subsidence of cortical buttons has been observed, eventually leading to a threat to vertical stability. Therefore, we developed a unique CC fixation technique with multiple small tunnels using all-suture anchors, which may overcome potential complications caused by cortical buttons that require bone tunnels with relatively large diameters. This arthroscopic CC fixation technique was designed to achieve the ideal horizontal and vertical stability that may restore native AC kinematics.

Arthroscopic Coracoclavicular Fixation Using Multiple Low-Profile Devices in Acute Acromioclavicular Joint Dislocation

PURPOSE

To introduce an arthroscopically assisted coracoclavicular (CC) fixation technique using multiple low-profile devices to evaluate the clinical and radiologic outcomes in patients with acute high-grade acromioclavicular (AC) joint dislocation.

METHODS

Between July 2014 and September 2015, cases of AC joint dislocation that were treated with arthroscopic CC fixation using multiple low-profile devices with a minimum follow-up of 24 months were included. We measured the vertical coracoclavicular distance (CCD) on the anteroposterior view and the horizontal acromioclavicular distance on 3-dimensional computed tomography images to evaluate the changes in radiologic outcomes before and after surgery. We compared final radiologic outcomes between initial AC reduction groups based on hierarchical clustering. Clinical outcomes were evaluated using the Constant-Murley score.

RESULTS

We enrolled 27 patients in total, and the mean follow-up period was 27.2 months. The mean CCD of the injured shoulder was 13.68 ± 3.98 mm preoperatively and decreased to 5.72 ± 1.68 mm immediately postoperatively but increased to 7.32 ± 2.29 mm at last follow-up (P = .07). Horizontal displacement of the distal clavicle was 1.1 ± 1.0 mm immediately postoperatively but decreased to 0.9 ± 0.6 mm at last follow-up (P < .05). In particular, in the 2 groups that were determined using the hierarchical cluster analysis, patients with excellent recovery of the initial CCD (20 patients) showed less of an increase in the CCD at last follow-up than did those in the other group (7 patients) (P < .001). The Constant-Murley score was 93.5 ± 2.7 points on the injured side at last follow-up (P = .074).

CONCLUSIONS

Our CC fixation technique with multiple low-profile devices exhibited satisfactory clinical and radiologic outcomes. In particular, ensuring good initial recovery of the CCD and the precise placement and location of the AC joints was important in maintaining the proper AC position at the final follow-up.

LEVEL OF EVIDENCE

Level IV, case series.

Stabilization of Acute High-Grade Acromioclavicular Joint Separation: A Prospective Assessment of the Clavicular Hook Plate Versus the Double Double-Button Suture Procedure

BACKGROUND

The stabilization strategy for acute high-grade acromioclavicular (AC) joint separations with AC-stabilizing clavicular hook plate (cHP) or coracoclavicular (CC)-stabilizing double double-button suture (dDBS) is still under consideration.

HYPOTHESIS

The CC-stabilizing dDBS is superior to the cHP according to an AC-specific radiologic assessment and score system.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Seventy-three consecutive patients with acute high-grade AC joint separation were prospectively followed in 2 treatment groups (64.4% randomized, 35.6% patient-selected treatment): open reduction and cHP (cHP group) or arthroscopically assisted dDBS (dDBS group) performed within 14 days of injury. Patients were prospectively analyzed by clinical scores (Taft, Constant score [CS], numeric analog scale for pain) and AC-specific radiographs (AC distance, CC distance [CCD], relative CCD [rCCD; 100 / AC distance × CCD]) at points of examination (preoperative and 6, 12, and 24 months). The minimal clinically important differences (MCIDs) were assessed by the anchor-based method.

RESULTS

Twenty-seven of 35 patients (mean age ± SD: 37.7 ± 9.7 years) after cHP implantation and 29 of 38 patients (34.2 ± 9.7 years) after dDBS implantation were continuously followed until the 24-month follow-up. All patients showed significantly increased scores after surgery as compared with preoperative status (all P < .05). As compared with GI, GII had significantly better outcomes at 24 months (Taft: cHP = 9.4 ± 1.7 vs dDBS = 10.9 ± 1.1, P < .05, MCID = 2.9; CS: cHP = 90.2 ± 7.8 vs dDBS = 95.3 ± 4.4, P < .02, MCID = 16.6) and at 24 months for Rockwood IV/V (Taft: cHP = 9.4 ± 1.7 vs dDBS = 11.1 ± 0.8, P < .0005; CS: cHP = 90.1 ± 7.7 vs dDBS = 95.5 ± 3.1, P < .04). Clinically assessed horizontal instability persisted in 18.52% (GI) and 6.89% (GII; P = .24). The rCCD showed equal loss of reduction at 24 months (GII = 130.7% [control = 111%] vs GI = 141.8% [control = 115%], MCID = 11.1%).

CONCLUSION

This prospective study showed significantly superior outcomes in all clinical scores between GII and GI. The subanalysis of the high-grade injury type (Rockwood IV/V) revealed that these patients showed significant benefits from the dDBS procedure in the clinical assessments. The cHP procedure resulted in good to excellent clinical outcome data and displayed an alternative procedure for patients needing less restrictive rehabilitation protocols.