Anatomy of the clavicle and coracoid process for reconstruction of the coracoclavicular ligaments

Coracoclavicular ligament reconstruction: coracoid tunnel diameter correlates with failure risk

The current study compared tunnel diameter as an independent risk factor for fixation failure from the coracoid after transcoracoid coracoclavicular reconstruction. The effect of variation in coracoid size and scapular bone density on fixation failure was also studied. Sixty-two cadaveric scapulae were randomized into 1 of 4 groups: a control group with no coracoid hole, a group with a 4-mm transcoracoid tunnel, a group with a 6-mm transcoracoid tunnel, and a group with a socket technique using a 6-mm hole superiorly with a 4-mm hole inferiorly. Bone density measures for all specimens were performed. Coracoid dimensions were quantified. Using a cortical button device, all specimens were loaded to failure with an Instron servohydraulic testing machine (Instron Corp, Canton, Massachusetts). All drilled specimens failed by button pullout, and all control specimens failed by coracoid fracture. Average pullout strength for each tunnel subgroup was as follows: 4 mm, 296.9 N; 6 mm, 146.2 N; 6-4 socket, 261.8 N; control, 762.9 N. No difference was found with respect to tunnel subgroups in base height (P=.25) or bone density (P=.44). Load to failure for the control group was significantly higher than for the other 3 techniques. The 4-mm tunnel load to failure was significantly higher than that for the 6-mm tunnel (P=.006). No difference was found between the 4-mm tunnel and the 6-4 socket technique (P=.853). Although it was not statistically significant, a very strong trend was seen toward increased strength of the 6-4 socket over the 6-mm tunnel (P=.051). The study results show that when employing a transcoracoid reconstruction technique, a 4-mm tunnel technique is significantly stronger than a 6-mm tunnel technique. None of the coracoids drilled with the various tunnels approached the strength of the native coracoid controls using a looped wire technique.

Coracoclavicular ligaments anatomical reconstruction: a feasibility study

BACKGROUND

This study assessed the feasibility of anatomical coracoclavicular (CC) ligaments reconstruction, using three-dimensional (3D) measurement and virtual drilling.

METHODS

One-hundred-and-five 3D shoulder models were constructed using SuperImage software, based on computed tomography (CT) scan data. For each model the attachment sites and footprint dimensions of the CC ligaments were defined and adjusted according to constant anatomical ratios and individual measurement results. Different drilling techniques and 3D measurements were carried out separately on each model.

RESULTS

The collinear drilling technique with one bundle was used to breach the clavicle and/or coracoid process bone cortex in 38 of 105 models (36.2%); the percentage with two bundles was 90.5% (95/105). No cortical breach was observed using the non-collinear drilling technique.

CONCLUSIONS

The non-collinear drilling technique provides the capability to prepare bony tunnels without any risk of cortical breach.

Acromioclavicular reconstruction using hook plate and anterior tibial tendon allograft with triple tunnel: The early results of revision surgery using a novel surgical technique

In this study, a new modified surgical technique is presented for anatomic acromioclavicular (AC) joint reconstruction made by the application of anterior tibialis tendon autograft, three-way tunnel (two clavicular and one coracoid) and hook plate. The study is aimed to evaluate the post-operative short-term results of patients who underwent this treatment. A total of 11 patients underwent AC joint reconstruction because of persistent AC subluxation. In this reconstruction, a triple tunnel was made between the coracoid and the clavicle to anatomically restore the coracoclavicular (CC) ligament and an allograft was passed through the tunnels resembling conoid and trapezoid ligaments. The tendon had to be non-weight bearing at the appropriate tension to provide rapid and appropriate integration of the tendon in the tunnel. This was maintained by applying a hook plate. The hook plate method was used to protect the reconstructed ligament during the healing process as it has a similar hardness to that of the natural AC joint and provides rigid fixation. For a more comprehensive description of the technique, a cadaver demonstration was also performed. The mean follow-up period was 25.3 months (range: 18-34 month). None of the patients had a loss of reduction at the final follow-up. When the constant scores were examined, of the total 11 patients, 2 (18.2%) 38,39 had excellent results, 6 (54.5%) had good results and 3 (27.3%) had fair results. It can be seen that this newly described reconstruction technique has successful short-term results as an anatomic method and can be used effectively in revision cases. However, there is a need for further biomechanical and clinical studies to make comparisons with other techniques.

Management of acromioclavicular joint injuries

Acromioclavicular joint injuries are among the most common shoulder girdle injuries in athletes and most commonly result from a direct force to the acromion with the arm in an adducted position. Acromioclavicular joint injuries often present with associated injuries to the glenohumeral joint, including an increased incidence of superior labrum anterior posterior (SLAP) tears that may warrant further evaluation and treatment. Anteroposterior stability of the acromioclavicular joint is conferred by the capsule and acromioclavicular ligaments, of which the posterior and superior ligaments are the strongest. Superior-inferior stability is maintained by the coracoclavicular (conoid and trapezoid) ligaments. Type-I or type-II acromioclavicular joint injuries have been treated with sling immobilization, early shoulder motion, and physical therapy, with favorable outcomes. Return to activity can occur when normal shoulder motion and strength are obtained and the shoulder is asymptomatic as compared with the contralateral normal extremity. The management of type-III injuries remains controversial and is individualized. While a return to the previous level of functional activity with nonsurgical treatment has been documented in a number of case series, surgical reduction and coracoclavicular ligament reconstruction has been associated with a favorable outcome and can be considered in patients who place high functional demands on their shoulders or in athletes who participate in overhead sports. Surgical management is indicated for high-grade (≥type IV) acromioclavicular joint injuries to achieve anatomic reduction of the acromioclavicular joint, reconstruction of the coracoclavicular ligaments, and repair of the deltotrapezial fascia. Outcomes after surgical reconstruction of the coracoclavicular ligaments have been satisfactory with regard to achieving pain relief and return to functional activities, but further improvements in the biomechanical strength of these constructs are necessary to avoid loss of reduction and creep with cyclic loading.

A novel radiographic index for the diagnosis of posterior acromioclavicular joint dislocations

BACKGROUND

Posterior acromioclavicular (AC) joint dislocations are frequently misclassified because posterior translation of the clavicle is difficult to evaluate in Zanca radiograph views. A novel radiographic index was used in this study to accurately diagnose posterior dislocations of the AC joint.

HYPOTHESIS

This novel index has a high degree of accuracy for the diagnosis of posterior AC joint dislocations.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

This was an analytic, descriptive study of 150 patients with different grades of AC injuries according to the Rockwood classification (30 patients for each grade of injury: I, II, III, IV, and V). The diagnosis of an AC injury was made both clinically and radiographically by using comparative Zanca and axillary views. Two measurements were performed in Zanca views: the coracoclavicular distance and the AC width distance. A width index was calculated for each patient. The Student t test, Bonferroni test, logistic regression, linear regression, and receiver operating characteristic (ROC) curves were used for statistical analysis. Forty cases were impartially selected to obtain a κ concordance value.

RESULTS

The average value of the AC width index per group (according to the Rockwood classification) was as follows: type I, 2.1% (range, -12% to 25%); type II, 4.2% (range, -19% to 29%); type III, 19.1% (range, -59% to 91%); type IV, 110.3% (range, 47% to 181%); and type V, -3.8% (range, -71% to 62%). There was a significant difference between the average width index in the patients with type IV injuries and those in the remaining groups (P < .05). The ROC curve showed that a width index of 60% has a sensitivity of 95.7% and specificity of 97.5%, with a positive predictive value of 96.7% and negative predictive value of 95.6% to predict a type IV injury. Intraobserver reliability was rated as substantial agreement for each of 3 observers; the interobserver reliability of the 3 independent raters was almost perfect.

CONCLUSION

An AC width index of ≥60% is highly accurate for the diagnosis of a posterior AC joint dislocation, with high intraobserver and interobserver concordance.

Evaluation of coracoclavicular stabilization of acute acromioclavicular joint dislocation with multistrand titanium cables

PURPOSE

The aim of this study was to evaluate the outcome of surgical treatment of acute acromioclavicular (AC) joint dislocation with multistrand titanium cables for coracoclavicular (CC) stabilization.

METHODS

Forty-two patients with acute AC joint dislocation, including Rockwood type III 14 cases, type IV 2 cases and type V 26 cases, were operated with CC stabilization using multistrand titanium cables. The cables were removed 3-12 months after surgery. The function outcome was evaluated by Constant scores and visual analog scale (VAS) scores. Radiological examination included bilateral antero-posterior and axillary radiography.

RESULTS

Three patients were lost to follow-up. Thirty-nine patients had an average follow-up time of 42 months (range 34-60). The Constant scores were 95.3 ± 9.3 at final evaluation. Preoperative and final follow-up VAS scores were 5.6 ± 1.5 and 0.4 ± 1.2, respectively (P < 0.05). Radiographs showed anatomical reduction in 32 patients. Cables breakage occurred in two patients.

CONCLUSIONS

CC stabilization with multistrand titanium cables was an effective and safe alternative to other procedures for the treatment of acute high-grade AC joint dislocations. It can provide immediate joint stabilization and allow early mobilization of limb with satisfied functional recovery.

[Arthroscopically assisted reduction of acute acromioclavicular joint separations: comparison of clinical and radiological results of single versus double TightRope™ technique]

BACKGROUND

The aim of this study was to compare the results of the single (STR) versus double TightRope™ (DTR) technique for stabilisation of acute separations of the AC joint with the hypothesis that DTR achieves lower CC distance.

PATIENTS AND METHODS

A total of 29 consecutive patients treated operatively with the TR technique (mean age 38.1 years, n=26 male) were analysed in a cohort study with a mean follow-up of 13.3 months (12.0-21.7). Acute AC joint separations types III and V according to Rockwood (R) were included; R types I, II, IV and VI were excluded. The prospective scores determined pre-op and 3, 6 and 12 months post-op and X-rays were evaluated.

RESULTS

Of the patients 12 suffered an R type III and 17 an R V separation; 14 were treated with STR and 15 with DTR. With STR, 8 R III and 6 R V injuries and with DTR 4 R III and 11 R V injuries were treated arthroscopically. STR achieved an increased CC distance >125% compared to the contralateral AC joint in five cases (36%). Two of them occurred as R V and three as R III injury. DTR achieved a CC distance >125% in two cases of an R V injury (13%).

CONCLUSION

The DTR technique provides lower CC distance compared to the STR technique, without a significant difference of CC distance and scores.

Complications after anatomic fixation and reconstruction of the coracoclavicular ligaments

BACKGROUND

Reconstruction of the disrupted acromioclavicular (AC) joint has historically resulted in high complication rates. As a result, there has been a move toward anatomic coracoclavicular (CC) ligament fixation and reconstruction, owing to its numerous biomechanical advantages and perceived clinical advantages.

PURPOSE

To report and analyze the unique complications associated with these anatomic CC ligament procedures using either cortical fixation buttons (CFBs) or tendon grafts (TGs) and to evaluate the effect that these complications have on patient outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From January 2006 until May 2011, a total of 59 primary anatomic CC ligament procedures were performed using either CFBs or TGs. Demographic, surgical, subjective (including the American Shoulder and Elbow Surgeons [ASES], quick Disabilities of the Arm, Shoulder and Hand [QuickDASH], Short Form-12 [SF-12], and Single Assessment Numeric Evaluation [SANE] scores), and radiographic data along with surgical complications were prospectively collected and retrospectively analyzed. Construct survivorship, defined as the maintenance of reduction of the AC joint, was calculated using the Kaplan-Meier method at 12- and 24-month intervals.

RESULTS

Surgical treatment for AC joint dislocations was performed in 3 women (4 shoulders) and 52 men (55 shoulders) with a mean age of 43.6 years (range, 18-71 years); 13 shoulders (22.0%) underwent fixation using the CFB technique, and 46 shoulders (78.0%) underwent reconstruction using the TG technique. The overall complication rate was 27.1% (16/59) in this study. There were 3 complications (23.1%) in the CFB group, including 1 coracoid fracture and 2 cases of hardware failure resulting in a loss of reduction. There were 13 complications (28.2%) in the TG group, including 4 graft ruptures, 2 clavicle fractures, 1 case of hardware failure, 1 hypertrophic distal clavicle, 2 cases of hardware pain, 1 suture granuloma, 1 case of adhesive capsulitis, and 1 case of axillary neuropathy. Twelve- and 24-month construct survivorship was calculated to be 86.2% and 83.2%, respectively. Of the 43 shoulders that did not have a complication, mean ASES scores significantly improved from 57.5 (range, 0-97) to 91 (range, 63-100) (P < .001), and mean SF-12 physical component summary scores significantly improved from 45 (range, 25-58) to 56 (range, 43-65.8) (P < .001) after a mean 2.4-year follow-up (range, 1.0-5.7 years). There were no significant differences in outcomes between those that did and did not experience a complication, with the exception that those with complications had significantly decreased median patient satisfaction compared with those without complications (3.5 vs 9, respectively; P = .049).

CONCLUSION

Anatomic procedures to treat disrupted CC ligaments using either CFBs or TGs resulted in an overall complication rate of 27.1% (16/59). Construct survivorship was calculated to be 86.2% at 12 months and 83.2% at 24 months. Good to excellent outcomes could only be reported in those patients who did not have a complication.

[Arthroscopically assisted stabilization of acute injury to the acromioclavicular joint with the double TightRope™ technique: one-year results]

BACKGROUND

The aim of this study was to evaluate the clinical and radiological results of 37 consecutive patients (Ø age 37.9; 4♀, 33♂) following arthroscopically assisted and image intensifier-controlled AC joint reconstruction using the double TightRope™ technique for acute AC joint separations grade V according to Rockwood.

MATERIAL AND METHODS

After 12 months 30 patients with a mean age of 38.8 years (range 18.6-65.8 years) could be included. The postoperative assessment included the Subjective Shoulder Value (SSV), Constant Score (CS), and Taft Score (TF) as well as radiological evaluation using bilateral stress views and bilateral Alexander views for determining vertical and horizontal AC joint instability.

RESULTS

The clinical scores reached 91.4±9.8% for SSV, 87.8±5.2 for CS, and 10.1±2.1 points for TF. The initial coracoclavicular distance (CCD) was 22.1±5.6 mm and could be reduced to 8.6±2.8 mm postoperatively (p<0.05). The CCD increased at final follow-up to 12.8±2.4 mm. The difference of the CCD compared to the contralateral side was initially 13.7±4.8 mm; postoperatively it was 0.3±3.0 mm with an increase at final follow-up to 3.6±3.5 mm. A posterior instability on the Alexander view occurred in 53.3% of patients. A correlation between inferior clinical results and horizontal instability could be detected. Only one patient was slightly tender to palpation at the AC joint.

CONCLUSION

Following arthroscopic AC joint stabilization using the double TightRope™ technique, despite partial recurrent instability, favorable clinical results can be expected.

Analysis of neurovascular safety between superior and anterior plating techniques of clavicle fractures

OBJECTIVES

Clavicle fractures are commonly plated as a method of fixation, with superior and anterior techniques described. Although advantages and disadvantages have been attributed to both, it is unclear if one approach provides a lower risk of neurovascular injury. The aim of this study was to compare the potential for neurovascular injury between these 2 plate locations in a cadaveric model.

METHODS

Seventeen adult fresh frozen cadavers underwent bilateral dissections exposing the clavicle and underlying neurovasculature. After taking baseline anatomical measurements, a superior and anterior clavicle plate was applied, removed and measurements were taken from the nearest screw exit site to the underlying subclavian vein/artery and brachial plexus. The differences between superior and anterior measurements were compared based on proximity with the neurovasculature.

RESULTS

Distance to the vessels were unobtainable in 6 specimens (35%) plated with the anterior technique due to the trajectory of the screws projecting cephalad to the vessels. In the remaining specimens, there was no significant difference in the distance to the subclavian vein/artery and brachial plexus in the superior plate position (9.2 ± 4.6, 12.2 ± 5.8, and 9.8 ± 5.2 mm, respectively) compared with the anterior plate position (8.3 ± 3.5, 12.2 ± 6.5, and 9.7 ± 5.3 mm, respectively). In addition, no significant difference in potential neurovascular injury with regard to body size or gender was found.

CONCLUSIONS

The majority of our specimens showed no significant difference between superior and anterior plating in regard to potential risk for injury to the underlying neurovasculature. However, there appears to be a subset of the population with a more caudal position of the neurovascular structures in which anterior plating may be potentially safer.

Arthroscopically assisted stabilization of acute high-grade acromioclavicular joint separations in a coracoclavicular Double-TightRope technique: V-shaped versus parallel drill hole orientation

BACKGROUND

The arthroscopically assisted Double-TightRope technique has recently been reported to yield good to excellent clinical results in the treatment of acute, high-grade acromioclavicular dislocation. However, the orientation of the transclavicular-transcoracoidal drill holes remains a matter of debate.

HYPOTHESIS

A V-shaped drill hole orientation leads to better clinical and radiologic results and provides a higher vertical and horizontal stability compared to parallel drill hole placement.

STUDY DESIGN

This was a cohort study; level of evidence, 2b.

METHODS

Two groups of patients with acute high-grade acromioclavicular joint instability (Rockwood type V) were included in this prospective, non-randomized cohort study. 15 patients (1 female/14 male) with a mean age of 37.7 (18-66) years were treated with a Double-TightRope technique using a V-shaped orientation of the drill holes (group 1). 13 patients (1 female/12 male) with a mean age of 40.9 (21-59) years were treated with a Double-TightRope technique with a parallel drill hole placement (group 2). After 2 years, the final evaluation consisted of a complete physical examination of both shoulders, evaluation of the Subjective Shoulder Value (SSV), Constant Score (CS), Taft Score (TF) and Acromioclavicular Joint Instability Score (ACJI) as well as a radiologic examination including bilateral anteroposterior stress views and bilateral Alexander views.

RESULTS

After a mean follow-up of 2 years, all patients were free of shoulder pain at rest and during daily activities. Range of motion did not differ significantly between both groups (p > 0.05). Patients in group 1 reached on average 92.4 points in the CS, 96.2 % in the SSV, 10.5 points in the TF and 75.9 points in the ACJI. Patients in group 2 scored 90.5 points in the CS, 93.9 % in the SSV, 10.5 points in the TF and 84.5 points in the ACJI (p > 0.05). Radiographically, the coracoclavicular distance was found to be 13.9 mm (group 1) and 13.4 mm (group 2) on the affected side and 9.3 mm (group 1) and 9.4 mm (group 2) on the contralateral side. The distance of neither the affected side nor the contralateral side differed significantly between both groups (p > 0.05). In group 1, eight patients (53 %) and in group 2 four patients (31 %) revealed signs of dynamic posterior instability (p > 0.05). Clavicular drill hole enlargement was found to be equally distributed in group 1, whereas group 2 displayed a cone-shaped form.

CONCLUSION

The Double-TightRope technique yields good to excellent clinical results in both V-shaped and parallel drill hole placement. Partial recurrent vertical and horizontal instability represents a problem in both techniques. So far, no significant differences regarding clinical or radiologic results have been found. Long-term results are needed to reveal possible advantages in terms of clinical and radiologic acromioclavicular stability.

Sex assessment using clavicle measurements: inter- and intra-population comparisons

We studied sexual dimorphism of the human clavicle in order to describe size variation and create population-specific discriminant tools for morphometric sex assessment. The studied sample consisted of 200 skeletons of adult individuals obtained from the University of Athens Human Skeletal Reference Collection, Athens, Greece. The specimens were well-documented and represented a modern population from cemeteries in the Athens area. Six dimensions typically used for clavicle measurements were recorded. For sexing clavicles, we used both traditional univariate (limiting, demarking and sectioning points) and multivariate discriminant function analysis. The accuracy of the best five classification equations/functions ranged from 91.62% to 92.55% of correctly assigned specimens. By testing new and previously published sexing functions (Greeks, Polynesians, Guatemalans) on four available population samples (English, Indians from Amritsar, Indians from Varanasi, and data from the present study) we found that, for some combinations of tested and reference samples, the accuracy of the sex assessment may decrease even below the probability given by random sex assignment. Therefore, measurements of the clavicle should not be used for sex assessment of individual cases (both forensic and archeological) whose population origin is unknown. However, significant metric differences were also recorded among three different Greek samples (i.e. within a population). As a consequence, application of a sexing method generated from one Greek sample and applied to another Greek sample led to negligible reduction in the success of sex assessment, despite general similarities in ethnic origin (Greeks), generation structure and presumed social background of the samples. Therefore, we believe that future studies should focus on understanding the nature of the differences among within-population reference samples.

Clavicle and coracoid process drilling technique for truly anatomic coracoclavicular ligament reconstruction

BACKGROUND

High-grade acromioclavicular (AC) joint separations require surgical treatment, as conservative treatment may result in functional decline or persistent pain. Although many surgical techniques have been described in the literature, there is still no non-controversial gold standard procedure for AC joint dislocation. The different orientation of the two components of the coracoclavicular (CC) ligaments has been proven to account for different functions. However, the majority of the techniques reconstruct the CC ligaments with a single structure. The purposes of this study were to assess the feasibility of truly anatomic coracoclavicular ligament reconstruction (TACCR) and to determine the corresponding drilling parameter.

METHODS

We constructed virtual three-dimensional (3D) models of 105 shoulders from computed tomography (CT) scan data by using SuperImage software. For each model, the attachment sites and footprint dimensions of the conoid and trapezoid ligaments were defined and adjusted according to previously defined anatomic parameters and individual measurement results. Virtual drilling and 3D measurement were carried out in each model separately. Guided by the drilling parameter, we performed TACCR on 24 shoulders from 12 whole cadavers after transecting the AC and CC ligaments.

RESULTS

The collinear drilling technique was noted to breach the bone cortex of the clavicle and/or the coracoid process in 95 of 105 virtual models (90.5%). No cortical breach was observed using a non-collinear drilling technique. The anteversion angulation of the conoid-coracoid tunnel ranged from 10° to 15° (mean value 12.4°). The extraversion angulation of the conoid-coracoid tunnel varied from 5° to 10° (mean value 6.8°). The anteversion angulation of the trapezoid-coracoid tunnel ranged from 20° to 30° (mean value 25.2°). There were no failures when performing the non-collinear drilling technique on cadaver models.

CONCLUSIONS

The collinear drilling technique is not technically feasible for TACCR. For this reason, we recommend the non-collinear drilling technique, which provides the ability to prepare bony tunnels without any risk of cortical breach.

CLINICAL RELEVANCE

Based on this computer and cadaver model study, we have devised a novel drilling technique to restore the CC ligaments anatomically.

Arthroscopic anatomy of the subdeltoid space

From the first shoulder arthroscopy performed on a cadaver in 1931, shoulder arthroscopy has grown tremendously in its ability to diagnose and treat pathologic conditions about the shoulder. Despite improvements in arthroscopic techniques and instrumentation, it is only recently that arthroscopists have begun to explore precise anatomical structures within the subdeltoid space. By way of a thorough bursectomy of the subdeltoid region, meticulous hemostasis, and the reciprocal use of posterior and lateral viewing portals, one can identify a myriad of pertinent ligamentous, musculotendinous, osseous, and neurovascular structures. For the purposes of this review, the subdeltoid space has been compartmentalized into lateral, medial, anterior, and posterior regions. Being able to identify pertinent structures in the subdeltoid space will provide shoulder arthroscopists with the requisite foundation in core anatomy that will be required for challenging procedures such as arthroscopic subscapularis mobilization and repair, biceps tenodesis, subcoracoid decompression, suprascapular nerve decompression, quadrangular space decompression and repair of massive rotator cuff tears.

Biomechanical evaluation of anatomical double-bundle coracoclavicular ligament reconstruction secured with knot fixation versus screw fixation

Methods to reconstruct the coracoclavicular ligaments anatomically have been described. No clear advantage of 1 technique has been elucidated. The authors' hypothesis was that the biomechanical properties of a modified knot fixation technique would be similar to the anatomical double-bundle technique. Sixteen matched cadaveric shoulders were used for this study, and 1 additional shoulder was used in the knot fixation group only. Shoulders were randomly assigned to the anatomical double-bundle coracoclavicular ligament reconstruction technique (n=8) or a knot fixation technique (n=9). The intact coracoclavicular ligaments were tested to failure with superior displacement at a rate of 2 mm/s. Reconstruction was performed using a semitendinosus tendon allograft, and load to failure was repeated for each construct. Ultimate failure load, stiffness, and failure mode were compared using a paired t test (P<.05). No significant difference existed in load to failure between native and reconstructed ligaments or between reconstruction techniques. Stiffness decreased significantly after reconstruction in the double-bundle group (from 32.5 to 22.5 N/mm; P=.035) and in the modified knot fixation group (from 35.5 to 21.9 N/mm; P=.043). No significant difference existed in stiffness between the 2 reconstruction groups. A significant difference (P=.003) existed between failure modes between the 2 reconstruction techniques. Although less stiff than the native ligament, either technique used to reconstruct the coracoclavicular ligament can be performed to yield a load to failure similar to the intact ligament. The majority of failures in the double-bundle group were by means of the graft slipping at the screw-tendon interface at 1 of the clavicular drill holes. The modified knot fixation technique failed the majority of the time by graft elongation.

Biomechanical evaluation of a coracoclavicular and acromioclacicular ligament reconstruction technique utilizing a single continuous intramedullary free tendon graft

BACKGROUND

Reconstruction of only the coracoclavicular (CC) ligaments may restore superior-inferior (S-I) but not anterior-posterior (A-P) stability of the acromioclavicular (AC) joint. Concomitant reconstruction of both the AC and CC ligaments may more reliably restore intact biomechanical characteristics of the AC joint.

METHODS

Ten matched pairs of shoulders were utilized. Five specimens underwent CC ligament reconstruction while an equal number underwent combined AC and CC ligament reconstruction utilizing an intramedullary tendon graft. Each of the reconstructions was compared with the intact contralateral control. Translational and load to failure characteristics were compared between groups.

RESULTS

No difference was found in S-I translation between intact specimens and CC-only reconstructions (P = .20) nor between intact specimens and AC/CC reconstructions (P = .33) at 10 Newton (N) loads. Significant differences were noted in A-P translation between intact specimens and CC-only reconstructions (P < .001) but no difference in A-P translation between intact specimens and AC/CC reconstructions (P = .34).

CONCLUSION

The A-P and S-I translational biomechanical characteristics of the AC joint were restored using the new technique described. Reconstruction of the CC ligaments only (versus AC/CC combined) led to significantly increased translational motion in the A-P plane as compared to intact control specimens.

Navigated vs arthroscopic-guided drilling for reconstruction of acromioclavicular joint injuries: accuracy and feasibility

BACKGROUND

Anatomical reconstruction of the coracoclavicular ligaments is a relatively new technique for acromioclavicular (AC) joint injuries.

METHODS

Eighteen procedures (nine non-navigated, nine navigated) of anatomical reconstruction were performed minimally invasively, using the Tight Rope system, on cadaveric shoulders. Two Kirschner wires were placed, freehand under fluoroscopic control (non-navigated) or 3D C-arm navigated. The insertion point on the clavicle as well as the position of the K-wire in the coracoid were measured in the axial and coronal planes; points were assigned for different zones. For statistical analysis, the significance level was set to p = 0.05.

RESULTS

The accuracy of the entry point in the clavicle was significantly more accurate for the conoidal (p = 0.022) and trapezoidal ( p = 0.0062) drillings. The positioning in the coronal (p = 0.037) and axial (p = 0.0416) planes also showed higher accuracy for the navigated procedures.

CONCLUSION

The accuracy of anatomical AC joint reconstruction can be improved using 3D C-arm flat detector navigation.

Distal-third clavicle fracture fixation: a biomechanical evaluation of fixation

BACKGROUND

Approximately 25% of distal clavicle fractures are unstable. Unstable patterns have longer times to union and higher nonunion rates. Stable restoration of the distal clavicle is important in decreasing the nonunion rate in distal clavicle fractures. The purpose of this study was to biomechanically compare operative constructs for the treatment of unstable, comminuted distal-third clavicle fractures in a cadaveric model using a locking plate and coracoclavicular reconstruction. We hypothesized that the combination of coracoclavicular reconstruction and a distal clavicle locking plate is biomechanically superior to either construct used individually.

MATERIALS AND METHODS

An unstable distal clavicle fracture was created in 21 thawed fresh-frozen cadaveric specimens. The 21 specimens were divided into 3 treatment groups of 7: distal-third locking plate, acromioclavicular (AC) TightRope (Arthrex, Naples, FL, USA), and distal-third locking plate and AC TightRope together. After fixation, each specimen was cyclically tested with recording of displacement to determine the stiffness and stability of each construct, followed by load-to-failure testing in tension and compression to determine the maximum load.

RESULTS

The combined construct of the locking distal clavicle plate and coracoclavicular reconstruction resulted in increased stiffness, maximum resistance to compression, and decreased displacement compared with either construct alone.

CONCLUSION

Greater fracture stability was achieved with the combination of the AC TightRope and locking clavicle plate construct than with either alone, suggesting a possibility for increased fracture-healing rates.

Biomechanical evaluation of 3 stabilization methods on acromioclavicular joint dislocations

BACKGROUND

Traumatic acromioclavicular (AC) joint dislocations can be addressed with several surgical stabilization techniques. The aim of this in vitro study was to evaluate biomechanical features of the native joint compared with 3 different stabilization methods: locking hook plate (HP), TightRope (TR), and bone anchor system (AS).

HYPOTHESIS

The HP provides higher stiffness than the anatomic reconstruction techniques.

STUDY DESIGN

Controlled laboratory study.

METHODS

A new biomechanical in vitro model of the AC joint was used to analyze joint stability after surgical repair (HP, TR, and AS). Eighteen cadaveric specimens were randomized for bone density and diameter in the midclavicle section. Joint stiffness was measured by applying an axial load and a defined physiological range of motion for internal and external rotations and upward and downward rotations. Data were recorded at 3 stages: for the native joint after dissecting the AC ligaments, directly after repair, and after axial cyclic loading (1000 cycles with 20 and 70 N at 1 Hz). To evaluate which implant mimics physiological joint properties best, axial stiffness of vertical stability was assessed in combination with rotation. Finally, static loading in the superior direction was applied until failure of the joints occurred.

RESULTS

Axial stiffness of the TR and AS groups was 2-fold higher than for the HP group and the native joint (67.1, 66.1, and 22.5 N/mm, respectively; P < .004). Decreased load-to-failure rates were recorded in the HP group compared with the TR and AS groups (248.9 ± 72.7, 832.0 ± 401.4, and 538.0 ± 166.1 N, respectively). The stiffness of the rotations was not significantly different between the treatment methods but was lower in horizontal and downward rotations compared with the native state. Thus, native AC ligaments contributed a significant share to joint stiffness.

CONCLUSION

The TR and AS groups demonstrated higher vertical load capacity. Compared with the TR and AS, the HP demonstrated an axial stiffness closest to the native joint. For restoring physiological properties, reconstruction of the AC ligaments may be necessary.

CLINICAL RELEVANCE

The results show different biomechanical properties of the HP and anatomic reconstructions.

Coracoclavicular ligament attachment regions of the Chinese population: a quantitative anatomic study

It is reported that the coracoclavicular (CC) ligaments arise at a constant region, which is proportional to the size of the clavicle and the coracoid process. However, all cadavers in those studies were from whites or African-Americans. The aim of this study was to evaluate dimension and orientation of CC footprints in Chinese cadavers and to determine whether race-dependent differences in these measurements exist. A total of 172 shoulders from 87 Chinese cadavers were used in this study, and the CC ligaments including the coracoid and the lateral clavicle were exposed. After measurement of the length of the CC ligaments, the ligaments were dissected and the insertion sites as well as the footprint centers were identified and marked. Each CC insertion dimension and its distance to the bony landmarks were recorded. Ratios representing the distance from the clavicular landmarks to each footprint center divided by clavicular length and clavicular width were calculated. These ratios were calculated for the coracoid process as well. The mean length of the clavicle and the coracoid process was 139.9 ± 9.4 and 40.5 ± 4.0 mm. The distance from the lateral edge of the clavicle to the conoidal center and to the trapezoidal center was 35.7 ± 3.4 and 21.8 ± 2.7 mm, respectively. The distance from the tip of the coracoid to the conoidal center and to the trapezoidal center was 35.1 ± 3.2 and 29.7 ± 2.9 mm, respectively. The ratios of the distance to the conoidal center and to the trapezoidal center divided by clavicular length and coracoidal length were 25.5, 15.6, 86.8 and 73.4 %, respectively. While absolute differences in the origin of the CC ligaments exist between different races, the ratio of these origins to the size of the clavicle and the coracoid process is constant.

Biomechanics of a new technique for minimal-invasive coracoclavicular ligament reconstruction

PURPOSE

To evaluate the biomechanical properties of a new coracoclavicular (CC) ligament reconstruction using a subcoracoidal flip button and a tendon graft compared to an augmented tendon loop and a synthetic coracoclavicular ligament reconstruction.

METHODS

A porcine metatarsalia model was used to assess supero-inferior fixation strength of (1) a new technique using an augmented tendon graft and a subcoracoidal flip button in a lifting block fashion, (2) an augmented tendon loop around the coracoid base and (3) a synthetic coracoclavicular ligament augmentation technique. Cyclic loading from 20 to 70 N for 1,000 cycles was performed, followed by a load-to-failure protocol.

RESULTS

All specimens of the three different groups survived the cyclic loading protocol. The maximum loads to failure under superior loading conditions were 760 ± 78 N for group 1, 702 ± 48 N for group 2 and 1117 ± 91 N for group 3. The synthetic coracoclavicular ligament augmentation technique revealed significantly higher maximum loads compared to the other groups (p < 0.001). The augmented tendon graft/flip button construct had higher maximum loads than the augmented tendon loop (n.s.). No significant differences were found for stiffness and elongation behaviour among the 3 tested groups.

CONCLUSION

The results suggest that the described technique is an alternative option to reconstruct the CC ligaments in AC joint instability in a minimal-invasive technique. Under superior loading conditions, the biomechanical properties exhibited by this novel technique were comparable to those of the tendon loop around the coracoid base.

Coracoid graft dimensions after harvesting for the open Latarjet procedure

BACKGROUND

Recent studies have reported the theoretic amount of coracoid graft available for harvesting with the Latarjet procedure. Our aim was to investigate the actual dimensions of coracoid grafts harvested using a standardized technique. We also hoped to confirm previous recommendations regarding placement of the inferior glenoid drill hole to avoid lateral overhang of the graft.

MATERIALS AND METHODS

Intraoperative measurements were taken after coracoid graft harvesting and preparation during the Latarjet procedure. Specifically, we measured the length of coracoid, thickness of coracoid, distance from the inferior drill hole to the lateral margin of the graft, distance between drill holes, width at the level of the superior drill hole, and width at the level of the inferior drill hole.

RESULTS

Data were collected from 76 Latarjet procedures (67 men, 9 women). Patients were an average age of 28.7 years (range 16-67 years). Mean measurements were length of coracoid graft, 26.4 ± 2.9 mm; thickness, 9.3 ± 1.4 mm; distance from the edge of the inferior drill hole to the lateral margin of the graft, 5.7 ± 1.1 mm; distance between drill holes, 7.8 ± 1.9 mm; width at the level of the superior drill hole, 14.1 ± 1.8 mm; and width at the level of the inferior drill hole, 13.3 ± 1.8 mm.

CONCLUSIONS

Using a standardized surgical technique that does not violate the coracoclavicular ligaments, a coracoid graft greater than 25 mm can routinely be harvested for the Latarjet procedure. The inferior glenoid drill hole should typically be placed at least 7 mm from the glenoid margin to avoid lateral overhang.

Management of acute acromioclavicular joint dislocation with a double-button fixation system

INTRODUCTION

Numerous static and dynamic techniques have been described for the management of acute acromioclavicular (AC) joint dislocation. To date, no standard technique has been established and several complications have been described for each of these techniques. The purpose of the present study was to evaluate the functional and radiographic outcomes of acute AC joint reconstruction after a mini-open technique using the double-button fixation system.

PATIENTS AND METHODS

Twelve patients with acute AC joint dislocation treated with the double-button fixation system by one surgeon were retrospectively reviewed. Functional assessment was performed by an independent reviewer using the DASH, Constant and the VAS scores. The coracoclavicular (CC) distance of the affected shoulder was assessed on a standard radiograph and compared with the contralateral normal one.

RESULTS

Eight patients were operated on for grade III AC joint dislocation and 4 for grade IV. The mean age of the patients at the time of surgery was 27.5 years. The mean follow-up was 18.25 months (range: 12-30 months). At the most recent follow-up, the mean Constant score was 94.8 (range: 84-100) showing a significant increase compared with the mean pre-operative value of 34.4 (range: 25-52) (p<0.001). The mean DASH score was significantly decreased from 19.6 (range: 14-28) preoperatively to 0.25 (range: 0-3) at the last follow-up (p<0.001). The mean VAS score showed a significant decrease from 5.75 (range: 4-7) to 0.2 (range: 0-2) (p<0.001). The mean CC distance on the operated shoulder was found to have no significant difference from the CC distance on the contralateral normal side (10.5 vs. 10mm) (p>0.05). There was no evidence of AC joint osteoarthrosis, CC calcification or osteolysis of the distal clavicle or the coracoid process.

CONCLUSIONS

The proposed mini-open technique provides adequate exposure of the base of the coracoid with minimal damage to the soft tissues surrounding the CC ligaments while ensures an excellent cosmetic result. We recommend this fast and relatively simple technique for all type IV injuries and for type III injuries in heavy manual workers and high-demand upper extremities athletes.

Graft fixation is highest with anatomic tunnel positioning in acromioclavicular reconstruction

PURPOSE

The purposes were to determine the bone density at specific bone tunnel locations in the clavicle and to determine ultimate load to failure of a graft fixed with an interference screw at specific areas.

METHODS

Bone mass densitometry was tested at 5-mm intervals from the lateral to the medial end of 11 clavicles (mean age, 70.0 ± 17.7 years). Tunnels were drilled in 10-mm increments from the lateral edge, and tenodesis screws were used to fix semitendinosus grafts in the tunnel. Grafts were cyclically loaded, followed by load to failure.

RESULTS

The bone mineral density (BMD) of the cadaveric clavicles increased from lateral (0.304 ± 0.078 g/cm(2) at 10 mm) to medial (0.760 ± 0.103 g/cm(2) at 50 mm). Load to failure increased from lateral to medial, and most specimens failed by tendon pullout. The load was 125.3 ± 42.5 N at the most lateral tunnel and 349.3 ± 120.3 N at the most medial tunnel. The Pearson correlation coefficient was 0.653 between tunnel position and load to failure, 0.659 between bone density and load to failure, and 0.803 between tunnel position and bone density. These all showed strong correlation.

CONCLUSIONS

BMD shows that optimal bone density is found in the anatomic insertion area of the coracoclavicular ligaments between 20 mm and 50 mm from the lateral end of the clavicle. Low BMD correlated with decreased load to failure.

CLINICAL RELEVANCE

Failure at the lateral bone tunnel in coracoclavicular ligament reconstruction may be a result of poor bone quality. When one is drilling bone tunnels for this surgery, consideration should be given to both anatomic position and bone quality.

Arthroscopically assisted 2-bundle anatomic reduction of acute acromioclavicular joint separations: 58-month findings

BACKGROUND

Currently, no clinical midterm results have been reported on arthroscopically assisted reduction of the acutely dislocated acromioclavicular (AC) joint using suture-button devices for fixation.

HYPOTHESIS

Athroscopically assisted reduction of the acutely dislocated AC joint yields satisfactory clinical outcomes without loss of reduction, clavicle migration, or AC joint degeneration at midterm follow-up evaluation.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The clinical and radiographic outcomes of 23 of 30 consecutive patients (21 men, 2 women) who underwent anatomic reduction for acute AC joint dislocation using 2 suture-button devices between 2006 and 2007 were reviewed. Radiographic evaluation was performed by measurement of coracoclavicular (CC) distance and AC displacement. Clinical evaluation included a visual analog scale (VAS) for pain, the Constant score, the simple shoulder test, and the Short Form-36. Previously, this same patient collective was reviewed after 2 years of follow-up using similar methods.

RESULTS

All 23 patients were available for midterm follow-up examination 58 months postoperatively. There were 3 Rockwood type III, 3 type IV, and 17 type V acromioclavicular joint separations. Mean ± SD follow-up was 58 ± 5.6 months (range, 51-67 months). Most patients (96%) remained very satisfied or satisfied with the procedure outcome. The VAS and Constant score improved significantly when compared with baseline (0.3 ± 0.6 and 91.5 ± 4.7 at 58 months postoperatively vs 4.5 ± 1.9 and 34.5 ± 6.9 at baseline) and remained essentially unchanged when compared with the 2-year outcome scores (0.3 ± 0.6 and 91.5 ± 4.7 at 58 months postoperatively vs 0.25 ± 0.5 and 94.3 ± 3.2 at 2 years). Radiographs showed 8 radiographic failures (undercorrection, posterior displacement, or both) and 4 additional overcorrections of the CC distance. When comparing with 24-month data, 17 of 20 radiographs remained unchanged; 1 case of previous overcorrection drifted into normal AC alignment and 2 cases increased in posterior subluxation of the clavicle.

CONCLUSION

Arthroscopically assisted reduction of the acutely dislocated AC joint provides satisfactory clinical results 58 months after surgery. Compared with the baseline, all patients improved significantly. Two of 23 patients revealed an increased posterior dislocation compared with evaluation 24 months after surgery. No further migration of the clavicle or AC joint degeneration was observed.

Acromioclavicular joint separations

Acromioclavicular (AC) joint separations are common injuries of the shoulder girdle, especially in the young and active population. Typically the mechanism of this injury is a direct force against the lateral aspect of the adducted shoulder, the magnitude of which affects injury severity. While low-grade injuries are frequently managed successfully using non-surgical measures, high-grade injuries frequently warrant surgical intervention to minimize pain and maximize shoulder function. Factors such as duration of injury and activity level should also be taken into account in an effort to individualize each patient's treatment. A number of surgical techniques have been introduced to manage symptomatic, high-grade injuries. The purpose of this article is to review the important anatomy, biomechanical background, and clinical management of this entity.

Acromioclavicular and coracoclavicular PDS augmentation for complete AC joint dislocation showed insufficient properties in a cadaver model

PURPOSE

Optimal surgical treatment of high-grade acromioclavicular joint dislocations is still controversially discussed. The purpose of the present controlled laboratory study was to evaluate whether a polydioxansulfate (PDS(®)) cord augmentation with separate reconstruction of the coracoclavicular (CC) ligaments and the acromioclavicular (AC) complex provides sufficient vertical stability in a biomechanical cadaver model.

METHODS

Twenty-four shoulders of fresh-frozen cadaveric specimen were tested. Cyclic loading and load to failure protocol was performed in vertical direction on 12 native AC joints and repeated after reconstruction. The reconstruction of the coracoclavicular ligament was performed using two CC PDS cerclages and an additional AC PDS cerclage.

RESULTS

In static load testing for vertical force, the native AC joint complex measured 590.1 N (±95.8 N), elongation 13.4 mm (±2.1 mm) and stiffness 48.7 N/mm (±12.0 N/mm). The mean maximum load to failure in the reconstructed joints was 569.9 N (±97.9 N), elongation 18.8 mm (±4.7 mm) and stiffness 37.9 N/mm (±8.0 N/mm). During dynamic testing of the reconstructed AC joints, all specimens reached the critical elongation of 12.0 mm, defined as clinical failure between 200 and 300 N. The mean amount of repetitions at clinical failure was 305. A plastic deformation of the reconstructed specimens throughout cyclic loading could not be detected.

CONCLUSION

The AC joint reconstruction with acromioclavicular and coracoclavicular PDS cord cerclages did not provide the aspired vertical stability in a cadaver model.

LEVEL OF EVIDENCE

Basic Science Study.

Current concepts in the treatment of acromioclavicular joint dislocations

PURPOSE

To conduct a systematic review of the literature in relation to 3 considerations in determining treatment options for patients with acromioclavicular (AC) joint dislocations: (1) operative versus nonoperative management, (2) early versus delayed surgical intervention, and (3) anatomic versus nonanatomic techniques.

METHODS

The PubMed database was searched in October 2011 using the single term acromioclavicular and the following search limits: any date, humans, English, and all adult (19+). Studies were included if they compared operative with nonoperative treatment, early with delayed surgical intervention, or anatomic with nonanatomic surgical techniques. Exclusion criteria consisted of the following: Level V evidence, laboratory studies, radiographic studies, biomechanical studies, fractures or revisions, meta-analyses, and studies reporting preliminary results.

RESULTS

This query resulted in 821 citations. Of these, 617 were excluded based on the title of the study. The abstracts and articles were reviewed, which resulted in the final group of 20 studies that consisted of 14 comparing operative with nonoperative treatment, 4 comparing early with delayed surgical intervention, and 2 comparing anatomic with nonanatomic surgical techniques. The lack of higher level evidence prompted review of previously excluded studies in an effort to explore patterns of publication related to operative treatment of the AC joint. This review identified 120 studies describing 162 techniques for operative reconstruction of the AC joint.

CONCLUSIONS

There is a lack of evidence to support treatment options for patients with AC joint dislocations. Although there is a general consensus for nonoperative treatment of Rockwood type I and II lesions, initial nonsurgical treatment of type III lesions, and operative intervention for Rockwood type IV to VI lesions, further research is needed to determine if differences exist regarding early versus delayed surgical intervention and anatomic versus nonanatomic surgical techniques in the treatment of patients with AC joint dislocations.

LEVEL OF EVIDENCE

Level III, systematic review of Level II and Level III studies and one case series.

Anatomic considerations of transclavicular-transcoracoid drilling for coracoclavicular ligament reconstruction

HYPOTHESIS

Acromioclavicular (AC) joint injuries vary in severity and damage to the AC and coracoclavicular (CC) ligaments. We hypothesized that transclavicular-transcoracoid drilling techniques, which allow for arthroscopic passage and fixation of tendon grafts in bone sockets to replace the insufficient conoid and trapezoid ligaments, cannot restore the footprints of the conoid and trapezoid ligaments without significant risk of cortical breach and coracoid fracture.

MATERIALS AND METHODS

Data from a prospective computed tomography shoulder registry were used to create 23 distinct shoulders. Three-dimensional models were constructed the shoulders in which virtual CC ligament reconstruction tunnels were superimposed using previously described anatomic distances and landmarks.

RESULTS

Transclavicular-transcoracoid techniques resulted in mean remaining medial and lateral wall thicknesses before cortical breach of 7.3 ± 1.7 and 7.0 ± 1.6 mm, respectively. The distance from the entry point of this tunnel from the anatomic midpoint of the CC ligaments was 9.9 ± 2.2 mm. Attempts to recapitulate the CC ligament anatomy by using anatomic distances and landmarks with transcoracoid, transclavicular techniques resulted in medial cortical breach of the coracoid in 91.3% of the shoulders.

CONCLUSION

Transclavicular-transcoracoid reconstructive techniques cannot restore the footprints of the conoid and trapezoid ligaments without significant risk of cortical breach and fracture. Attempts to correct this nonanatomic configuration by creating a tunnel based on the anatomic footprints results in a nearly universal medial cortical breach of the coracoid process.

Clavicular bone tunnel malposition leads to early failures in coracoclavicular ligament reconstructions

BACKGROUND

Modern techniques for the treatment of acromioclavicular (AC) joint dislocations have largely centered on free tendon graft reconstructions. Recent biomechanical studies have demonstrated that an anatomic reconstruction with 2 clavicular bone tunnels more closely matches the properties of native coracoclavicular (CC) ligaments than more traditional techniques. No study has analyzed tunnel position in regard to risk of early failure.

PURPOSE

To evaluate the effect of clavicular tunnel position in CC ligament reconstruction as a risk of early failure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review was performed of a consecutive series of CC ligament reconstructions performed with 2 clavicular bone tunnels and a free tendon graft. The population was largely a young, active-duty military group of patients. Radiographs were analyzed for the maintenance of reduction and location of clavicular bone tunnels using a picture archiving and communication system. The distance from the lateral border of the clavicle to the center of each bone tunnel was divided by the total clavicular length to establish a ratio. Medical records were reviewed for operative details and functional outcome. Failure was defined as loss of intraoperative reduction.

RESULTS

The overall failure rate was 28.6% (8/28) at an average of 7.4 weeks postoperatively. Comparison of bone tunnel position showed that medialized bone tunnels were a significant predictor for early loss of reduction for the conoid (a ratio of 0.292 vs 0.248; P = .012) and trapezoid bone tunnels (a ratio of 0.171 vs 0.128; P = .004); this correlated to an average of 7 to 9 mm more medial in the reconstructions that failed. Reconstructions performed with a conoid ratio of ≥0.30 were significantly more likely to fail (5/5, 100%) than were those performed lateral to a ratio of 0.30 (3/23, 13.0%) (P < .01). There were no failures when the conoid ratio was <0.25 (0/10, 0%). Conoid tunnel placement was also statistically significant for predicting return to duty in our active-duty population.

CONCLUSION

Medial tunnel placement is a significant factor in risk for early failures when performing anatomic CC ligament reconstructions. Preoperative templating is recommended to evaluate optimal placement of the clavicular bone tunnels. Placement of the conoid tunnel at 25% of the clavicular length from the lateral border of the clavicle is associated with a lower rate of lost reduction and a higher rate of return to military duty.

Acute surgical treatment of acromioclavicular dislocation type V with a hook plate: superiority to late reconstruction

BACKGROUND

Outcomes for patients with acromioclavicular joint dislocation, Rockwood type V, treated with acute or delayed hook plate surgery were investigated.

MATERIALS AND METHODS

Patients treated with a hook plate for acromioclavicular joint dislocation, Rockwood type V, were retrospectively evaluated 1 to 8 years after the injury. Of 41 patients, 37 were re-evaluated, 32 in person and 5 by telephone or letter. The acute surgery group comprised 22 patients operated on with a hook plate within 4 weeks after the injury. The delayed surgery group comprised 15 patients, with unacceptable pain or functional disability after a minimum of 4 months of conservative treatment, who were operated on with modified Weaver-Dunn procedure augmented with a hook plate. The evaluation was based on radiographs, registration of activity level, and shoulder function.

RESULTS

The median Constant Score was 91 for the acute surgery group and 85 for the delayed surgery group (P = .097). The acutely treated patients had better outcomes according to the median Shoulder Pain and Disability Index (SPADI; P = .006), shortened version of the Disabilities of the Arm, Shoulder, and Hand (QuickDASH; P = .002), and Subjective Shoulder Value (P = .032). The acutely treated patients had less pain in their injured shoulder during rest (P = .014) and during movement (P = .005). There was a significant difference in subluxation between the groups in favor of the acute group, shown by weighted radiographs (P = .011), but no significant relation between subluxation on the weighted radiographs and the shoulder function according to Constant Score at follow-up (r(s) = .122, P = .619).

CONCLUSIONS

Patients treated with acute surgery had a more satisfactory outcome than those with late surgery after failed conservative treatment.

Anatomic study of the coracoid process: safety margin and practical implications

PURPOSE

The aim of this study was to define a safety margin for coracoid process osteotomy that does not compromise the coracoclavicular ligaments and that can be used in the coracoid transfer procedures.

METHODS

Thirty shoulders from 15 cadavers were dissected, exposing the coracoid process and attached anatomic structures. The distance of the insertion of these structures to the coracoid process apex was measured.

RESULTS

The average length of the coracoid process was 4.26 ± 0.26 cm. The average width and height at the tip were 2.11 ± 0.2 and 1.49 ± 0.12 cm, respectively. The average distance from the tip to the anterior and posterior margin of the pectoralis minor was 0.1 ± 1.17 and 1.59 ± 0.27 cm, respectively. The average distance from the tip to the posterior margin of the coracoacromial ligament was 2.79 ± 0.33 cm. The average distance from the apex to the most anterior part of the trapezoid ligament was 3.33 ± 0.38 cm. We obtained a constant value of 0.85 cm for this measure, and the value increased with each 1.0-cm increase in the distance from the tip to the posterior margin of the pectoralis minor. The safety margin for osteotomy (i.e., available bone distance for the coracoid process transfer) was 2.64 cm.

CONCLUSIONS

This study established a safety margin of 2.64 cm for the osteotomy of the coracoid process and its relation with the posterior margin of the pectoralis minor. The anatomic descriptions of bone and soft tissue, as well as a measure of correlation for the safety margin of the coracoid, provide tools for surgeons performing anatomic surgical procedures to correct glenohumeral instability with significant bone loss.

CLINICAL RELEVANCE

Knowing the safety margin allows the surgeon to perform a safe osteotomy without direct visualization of the coracoclavicular ligaments attachments, thereby making procedures more anatomic.

Reconstruction of displaced acromio-clavicular joint dislocations using a triple suture-cerclage: description of a safe and efficient surgical technique

Purpose

In this retrospective study we investigated the clinical and radiological outcome after operative treatment of acute Rockwood III-V injuries of the AC-joint using two acromioclavicular (AC) cerclages and one coracoclavicular (CC) cerclage with resorbable sutures.

Methods

Between 2007 and 2009 a total of 39 patients fit the inclusion criteria after operative treatment of acute AC joint dislocation. All patients underwent open reduction and anatomic reconstruction of the AC and CC-ligaments using PDS® sutures (Polydioxane, Ethicon, Norderstedt, Germany). Thirty-three patients could be investigated at a mean follow up of 32±9 months (range 24–56 months).

Results

The mean Constant score was 94.3±7.1 (range 73–100) with an age and gender correlated score of 104.2%±6.9 (88-123%). The DASH score (mean 3.46±6.6 points), the ASES score (94.6±9.7points) and the Visual Analogue Scale (mean 0.5±0,6) revealed a good to excellent clinical outcome. The difference in the coracoclavicular distance compared to the contralateral side was <5 mm for 28 patients, between 5-10 mm for 4 patients, and more than 10 mm for another patient. In the axial view, the anterior border of the clavicle was within 1 cm (ventral-dorsal direction) of the anterior rim of the acromion in 28 patients (85%). Re-dislocations occured in three patients (9%).

Conclusion

Open AC joint reconstruction using AC and CC PDS cerclages provides good to excellent clinical results in the majority of cases. However, radiographically, the CC distance increased significantly at final follow up, but neither the amount of re-dislocation nor calcifications of the CC ligaments or osteoarthritis of the AC joint had significant influence on the outcome.

Level of evidence

Case series, Level IV

Biomechanical properties of repairs for dislocated AC joints using suture button systems with integrated tendon augmentation

PURPOSE

To evaluate the biomechanical performance of different techniques for CC reconstruction using suture button systems with integrated tendon augmentation. Hypothesis was that (1) reconstructions using a cortical button combined with a biological augmentation (semitendinosus allograft) will demonstrate improved stability than a modified Weaver-Dunn procedure and (2) constructs using two tunnels at the clavicle for fixation will show superior horizontal stability than single-tunnel constructs.

METHODS

The acromioclavicular joints of 47 cadaveric shoulders were tested for anterior, posterior, and superior translations (70 N load) and maximal load to failure (superior). Shoulders were assigned to 4 groups: (1) native (n = 18) and after sectioning the AC and CC ligaments; (2) CC reconstruction with 1 clavicular and 1 coracoid tunnel (GR-ST) augmented with semitendinosus graft (n = 15); (3) CC reconstruction augmented with semitendinosus tendon (GR-DT) with 2 clavicular and 1 coracoid tunnel (n = 8); and (4) modified Weaver-Dunn reconstruction (n = 6).

RESULTS

The Weaver-Dunn demonstrated statistically more translation than the native joint for posterior direction (P = 0.038). The GR-ST had significantly less translation than the Weaver-Dunn for anterior and posterior translations (P = 0.003, P = 0.004) and compared to the native for superior translation (P = 0.028). The GR-DT differed significantly in anterior and posterior translations compared to the Weaver-Dunn (P = 0.002, P = 0.001). The modified Weaver-Dunn failed at significantly less load to failure compared to all other groups (P = 0.002, P = 0.002, P = 0.005). There was no significant difference between the native and the other reconstructions.

CONCLUSION

The evaluated techniques for isolated CC ligament reconstruction (GR-ST) in AC joint dislocation showed biomechanical stability superior to the modified Weaver-Dunn procedure and obtained similar measures compared to the native control. A modified technique (GR-DT), which used two fixation points at the clavicle, did not result in decreased horizontal or vertical translation and therefore no superiority of the GR-DT technique could be shown compared to the GR-ST.

LEVEL OF EVIDENCE

Controlled laboratory study.

Biomechanical evaluation of effect of coracoid tunnel placement on load to failure of fixation during repair of acromioclavicular joint dislocations

PURPOSE

To evaluate the effect of entry and exit points of the coracoid tunnel on load to failure and mode of failure, to reduce the incidence of coracoid fractures and acromioclavicular joint repair failures.

METHODS

This study investigates 5 tunnel placements based on different entry and exit points in the coracoid process: center-center orientation represents perfect placement of the bone tunnel and served as perfect tunnel placement in our study. Four common errors in drilling were then tested and acted as the experimental groups in our study (medial-center, center-medial, lateral-center, and center-lateral). Using 35 cadaveric shoulders (mean age, 68.0 ± 13.0 years), we tested these 5 tunnel orientations using a single repair technique (cortical button) loaded to failure on an MTS 858 Servohydraulic test system (MTS Systems, Eden Prairie, MN). A control group of 7 cadaveric shoulders without the presence of a coracoid tunnel was also tested to determine the type of fracture pattern that occurred.

RESULTS

The coracoids without tunnel drilling fractured in patterns similar to traumatic coracoid injuries. With regard to the 5 tunnel groups, it was found that the loads to failure with center-center and medial-center tunnel placement were significantly higher than those with center-medial, center-lateral, and lateral-center tunnel placement. The failure modes of the former were primarily within the repair constructs, whereas those of the latter were primarily due to bony failure.

CONCLUSIONS

Our biomechanical results showed a higher peak load to failure with a center-center or medial-center tunnel orientation, which may lessen the risk of coracoid fracture during drilling with a 6-mm cannulated drill bit.

CLINICAL RELEVANCE

Proper trajectory of the drill during formation of a coracoid bone tunnel can help reduce the risk of coracoid process fracture and repair failure.

Midterm results of combined acromioclavicular and coracoclavicular reconstruction using nylon tape

PURPOSE

The purpose of this study was to evaluate the radiologic and functional outcomes of an anatomic reconstruction of both acromioclavicular (AC) and coracoclavicular (CC) ligaments in types III to V AC injuries using nylon tape and no metal hardware.

METHODS

A prospective case-series study was performed on 17 cases with types III to V AC injuries treated by anatomic reconstruction of the AC ligaments (anterior and superior) and CC ligaments (conoid and trapezoid) using nylon tape and no metal hardware. Clinical assessments, radiologic findings, and visual analog scale, American Shoulder and Elbow Surgeons, and Constant scores were recorded for all patients. After a minimum postoperative period of 2 years, all cases were re-evaluated and rescored.

RESULTS

The case-series study comprised 17 cases with types III to V AC injuries. After a mean follow-up period of 28 months (minimum, 24 months), the patients had a significantly improved mean visual analog scale score (from 6.4 to 2.4 points), American Shoulder and Elbow Surgeons score (from 25 to 81.7 points), and Constant score (from 21 to 85 points), with overall 88.2% satisfaction. Radiographic superior displacement showed reduction from 13 to 2 mm whereas posterior displacement showed reduction from 5 to 2 mm, and both were statistically significant (P < .05). The rate of return to the patients' preinjury jobs was 82.4%, and there was 1 case of recurrent subluxation.

CONCLUSIONS

Combined anatomic reconstruction of both AC and CC ligaments using nylon tape by the described technique provides overall 88.2% satisfaction, 94% radiologic reduction, and a low complication rate.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Prediction of coracoid thickness using a glenoid width-based model: implications for bone reconstruction procedures in chronic anterior shoulder instability

BACKGROUND

Chronic anterior shoulder instability with glenoid bone loss can be a very challenging clinical problem. Significant bone loss is commonly managed with the Latarjet procedure. However, in some cases with severe glenoid bone loss, iliac crest bone grafting is required to obtain a graft of adequate size. Iliac crest bone graft is associated with high rates of donor-site complications. Whereas glenoid dimensions can be determined by use of 3-dimensional computed tomography reconstructions, the thickness of the coracoid cannot be easily measured. This study aims to define a ratio between glenoid width and coracoid thickness that can be used in preoperative planning to determine whether coracoid transfer will yield adequate bone graft to restore glenoid contour or whether iliac crest bone graft must be taken.

METHODS

We studied 100 paired cadaveric scapulae (50 male and 50 female scapulae). The bony dimensions of the coracoid and glenoid were measured for each specimen.

RESULTS

Coracoid and glenoid dimensions are provided. The mean thickness of the male coracoid was 35.4% of the width of the glenoid. The mean female coracoid thickness was 34.4% of the glenoid width.

DISCUSSION

A new biomorphologic model is presented to predict coracoid thickness and the ability of the Latarjet procedure to restore stability to a given bone-deficient glenoid. This model may aid the shoulder surgeon in preoperative planning and help promote successful outcomes in glenoid reconstruction surgery by determining whether a Latarjet procedure or iliac crest bone graft is the most appropriate procedure given the predicted amount of coracoid bone graft available.

OSTEOTOMIES OF THE CORACOID PROCESS: AN ANATOMICAL STUDY

OBJECTIVE

Relate the main tendinous and ligamentous structures attached in the coracoid process, correlating it to several levels of osteotomy and describing the involved structures.

METHODS

Thirty shoulders were dissected. The coracoid process with mainly inserted anatomic structures was dissected, and five levels of osteotomy (1.0; 1.5; 2.0; 2.5; 3.0 cm) were made from the apex of the process and the mainly involved structures were recorded.

RESULTS

In osteotomies of 1.0 cm, in 100% of the cases only the conjoint tendon (CT). In osteotomies of 1.5 cm there were 63.33% of cases involved with the CT and the Pectoralis minor (PMi), in 20% of cases only the CT, and in 16.66% the CT, PMi, and the coracohumeral ligament (CUL). In osteotomies of 2.0 cm, in 80% of the shoulders, the osteotomies embraced the CT, PMi and the CUL, and in 20% only the CT and the PMi were involved. In the osteotomies of 2.5cm there was involvement of the CT, PMi and CUL in 100% of cases. In the osteotomies of 3.0cm, six cases (20%) have presented an injury on the trapezoid ligament, and in 100% of these osteotomies, the osteotomized distal fragment had embraced the CT, PMi, CUL.

CONCLUSION

The knowledge of anatomic structures inserted and involved in the osteotomies cuts of the coracoid process is very importan to lead with osteotomies performed in the treatment techniques of the coracoid process. Osteotomies of 3.0 cm can injure the trapezoid ligament.

In vivo analysis of coracoclavicular ligament kinematics during shoulder abduction

BACKGROUND

Anatomic reconstruction of the coracoclavicular ligaments for the treatment of acromioclavicular joint separations provides superior biomechanical stability compared with other procedures. Clavicular and coracoidal footprints of the conoid ligament (CL) and the trapezoid ligament (TL) are well described. So far, little is known about their kinematics and the changes of the coracoclavicular distance during shoulder abduction.

HYPOTHESIS

The coracoclavicular distance along the coracoclavicular ligaments changes significantly with shoulder abduction and weightbearing.

STUDY DESIGN

Descriptive laboratory study.

METHODS

With use of an open magnetic resonance imaging scanner, the shoulders of 13 healthy volunteers were examined in supine and sitting positions. Three-dimensional magnetic resonance images of the shoulders were obtained in 30° increments of abduction (0°-120°). A manual segmentation of the scapula, the clavicle, and the coracoclavicular ligaments was performed. The insertion points of the coracoclavicular ligaments were identified, and automated measures along the ligamentous course were carried out.

RESULTS

During transfer from the lying to sitting position, the coracoclavicular distance showed significant lengthening of 3 mm along the center of the CL, which significantly increased another 3 mm during shoulder abduction to a total lengthening of 6 mm. In the supine position, the coracoclavicular distance along the TL did not elongate significantly. In the sitting position, the distance along the medial portion of the TL shortened significantly, whereas the distance along the center portion did not elongate significantly during shoulder abduction.

CONCLUSION

The distances between the coracoclavicular insertion points depend on both patient and shoulder positioning. To prevent overconstraining of the graft, the CL should be fixated during 90° to 120° of shoulder abduction in a sitting position. Isometric reconstruction of the TL can be achieved if precise fixation of the graft at the centers of the conoidal and clavicular footprints is performed.

Biomechanical comparison of arthroscopic repairs for acromioclavicular joint instability: suture button systems without biological augmentation

BACKGROUND

Arthroscopic procedures for reconstruction of acromioclavicular (AC) joint separations are increasingly used in clinical practice. Multiple surgical techniques exist, but there are still few data on biomechanical performances of commonly used arthroscopic techniques and fixation methods.

HYPOTHESIS

Single and double clavicular tunnel reconstructions show comparable primary stability with a modified Weaver-Dunn procedure, and double tunnel constructs show superior horizontal stability.

STUDY DESIGN

Controlled laboratory study.

METHODS

The AC joints of 40 cadaveric shoulders were tested for anterior, posterior, and superior translation (70-N load) and maximal load to failure (superior) with the MTS 858 Bionix II Servohydraulic testing system. Shoulders were assigned to 4 groups: (1) native (n = 18), (2) coracoclavicular (CC) reconstruction with 1 clavicular and 1 coracoid tunnel (SCT) fixed with a suture pulley and 2 buttons (n = 8), (3) CC reconstruction with 2 clavicular and 1 coracoid tunnel (DCT) fixed with a suture pulley and 3 buttons (n = 8), and (4) modified Weaver-Dunn reconstruction (n = 6).

RESULTS

Native specimens showed a mean anterior translation of 7.92 mm (±1.69 mm), a mean posterior translation of 7.84 mm (±2.09 mm), and a superior translation of 4.28 mm (±1.81 mm). Maximal load to failure was 579.44 N (±148.01 N). The SCT technique showed a mean anterior translation of 5.81 mm (±1.16 mm), posterior translation of 8.30 mm (±1.94 mm), and a superior translation of 2.28 mm (±0.52 mm). The maximal load to failure was 591.35 N (±231.17 N). Anterior and superior translations were significantly less compared with the native specimen (P = .005 and P = .003). The DCT technique had an anterior translation of 4.68 mm (±0.6 mm), posterior translation of 6.85 mm (±0.83 mm), and superior translation of 2.09 mm (±0.86 mm). The mean maximal load to failure was 651.16 N (±226.93 N). Anterior and superior translations were significantly less compared with the native specimens (P = .000 and P = .001). No statistically significant differences were shown between SCT and DCT reconstruction for all measurements (P > .05). One reconstruction of the modified Weaver-Dunn procedure failed directly after mounting it into the testing device. The remaining 5 showed a mean anterior translation of 11.36 mm (±3.17 mm), a mean posterior translation of 13.51 mm (±2.21 mm), and a mean superior translation of 3.31 mm (±0.47 mm). Anterior and posterior translations were significantly increased compared with the native specimen (P = .019 and P = .000). The mean maximal load to failure measured 311.13 N (±52.2 N) and was significantly less compared with the native specimen (P = .000). The Weaver-Dunn technique showed significantly less maximal load to failure and more anterior and posterior translation compared with SCT and DCT (P ≤ .05).

CONCLUSION

Isolated reconstruction of the CC ligaments using single and double clavicular tunnel techniques results in a high load to failure for superior translation, which is equal to the native stability, and less translation in all 3 directions as well as higher superior stability when compared with the modified Weaver-Dunn procedure. A potential drawback is the risk of coracoid fracture, as the high load to failure of the device may exceed load to failure of cortical bone prior to device breakage.

CLINICAL RELEVANCE

Single clavicular tunnel arthroscopic reconstructions of the coracoacromial ligaments show good biomechanical results.

Conservative treatment of fractures of the clavicle

Background

In the treatment of clavicle fractures, the choice of procedure depends on the possibility of restoring the anatomical functional integrity of the shoulder.

Methods

We examined 71 patients (51 males and 20 females, mean age 38.9 years) who were affected by clavicle fracture sequelae. Demographic and clinical data and the site of the lesion were recorded for each partecipant. The dissatisfaction of the patient was determined by the presence of 1 or more affirmative answers on the Simple Shoulder Test. The Constant Shoulder Score was also included in the functional and clinical exams. We measured the length of the healthy clavicle and the previously fractured clavicle, and we expressed the difference in length in mm and in percentage shortening. We then examined the correlations between the shortening of the bone and the clinical and functional outcomes of the patients.

Results

Sixty patients had a lesion of the diaphysis, 8 patients had a lesion of the lateral third of the clavicle, and 3 patients had a lesion of the medial third of the clavicle. The mean Constant Shoulder Score was 77.9, and 51 of the 71 patients were satisfied with their treatment. Radiography showed a mean clavicle shortening of 10 mm (mean percentage 6.5%). In the 20 dissatisfied patients, the mean clavicle shortening was 15.2 mm (9.7%). In these patients, we found a highly significant association between dissatisfaction with treatment and the amount of bone shortening, (p < 0.0001), as well as with a diaphyseal location (p < 0.05) and with the female sex (p = 0.004). No other variable related to the patient, the type of treatment or the fracture characteristics correlated with the treatment outcome.

Conclusions

In the literature, measurements of the shortening of the bone segment following a fracture range between 15 and 23 mm, and marked shortening is correlated with the failure of conservative treatment. However, these data need to be reinterpreted in light of the physiological variability of the clavicle length, which ranges from 140 to 158 mm in the healthy population. Shortening of the bone by more than 9.7% should be the cut-off for predicting failure of conservative treatment.

Surgical outcome following arthroscopic fixation of acromioclavicular joint disruption with the tightrope device

The objective of this study was to evaluate the preliminary radiographic and clinical results of grade IV and V acromioclavicular joint disruption repair using the arthroscopic Arthrex acromioclavicular TightRope (Naples, Florida) fixation technique. Numerous procedures have been described for surgical management of acromioclavicular joint disruption. The TightRope device involves an arthroscopic technique that allows nonrigid anatomic fixation of the acromioclavicular joint. A cohort of 10 men and 2 women with a mean age of 43 years (range, 25-61 years) underwent the acromioclavicular joint TightRope procedure between April 2007 and October 2009. Eleven patients had either Rockwood grade IV or V disruptions and 1 sustained a distal third clavicle fracture with acromioclavicular joint disruption. Data was collected from a chart review. Patients were evaluated clinically, radiographically, by the simple shoulder test, and by overall satisfaction. There were 2 failures of reduction and 1 loss of reduction at final radiographic follow-up. The rate of fixation failure was 16.6%. All patients had >110° of total elevation. The majority of patients obtained satisfactory functional results according to the Simple Shoulder Test averaging 11 of 12 questions answered positively (range, 7-12; standard deviation, 1.50) and 11 of 12 patients were satisfied with the procedure. At final phone interview at approximately 2 years postoperatively, 6 patients were lost to follow-up. The remaining patients were all satisfied with the procedure and no patients reported subjective loss of reduction or deterioration of function. Simple Shoulder Test average was maintained with 11 of 12 positively answered questions (range, 7-12; standard deviation, 2.0) This case series revealed a high rate of fixation failure with the TightRope system. Still, most patients were satisfied with the procedure and achieved high functional shoulder results.

Arthroscopically assisted stabilization of acute high-grade acromioclavicular joint separations

BACKGROUND

The purpose of this study was to evaluate the clinical and radiological results after arthroscopically assisted and image intensifier--controlled stabilization of high-grade acromioclavicular (AC) joint separations using the double TightRope technique with the first-generation implant.

HYPOTHESIS

The double TightRope technique using the first-generation implant leads to good clinical and radiological results by re-creating the anatomy of the AC joint.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Thirty-seven consecutive patients (4 women and 33 men; mean age, 38.6 years) who sustained an acute AC joint dislocation grade V according to Rockwood were included in this prospective study. The Subjective Shoulder Value (SSV), the Constant Score (CS), the Taft Score (TS), and a newly developed Acromioclavicular Joint Instability Score (ACJI) were used for final follow-up. Bilateral stress views and bilateral Alexander views were taken to evaluate radiographic signs of recurrent vertical and horizontal AC joint instability.

RESULTS

Twenty-eight patients (2 women and 26 men; mean age, 38.8 years [range, 18-66 years]) could be evaluated after a mean follow-up of 26.5 months (range, 20.1-32.8 months). The interval from trauma to surgery averaged 7.3 days (range, 0-18 days). The mean SSV reached 95.1% (range, 85%-100%), the mean CS was 91.5 points (range, 84-100) (contralateral side: mean, 92.6 points), the mean TS was 10.5 points (range, 7-12), and the ACJI averaged 79.9 points (range, 45-100). The final coracoclavicular distance was 13.6 mm (range, 5-27 mm) on the operated versus 9.4 mm (range, 4-15 mm) on the contralateral side (P < .05). Radiographic signs of posterior instability were noted in 42.9% of cases. Patients with evidence of posterior instability had significantly inferior results in the TS and the ACJI (P < .05). Neither coracoid fractures nor early (within 6 weeks postoperatively) loss of reduction due to tunnel malpositioning or implant loosening was observed.

CONCLUSION

The combined arthroscopically assisted and image intensifier--controlled double TightRope technique using implants of the first-generation represents a safe technique and yields good to excellent early clinical results despite the presence of partial recurrent vertical and horizontal AC joint instability.

[Arthroscopic stabilization of acute acromioclavicular joint dislocation]

During the past few years arthroscopic and minimal invasive techniques for stabilization of acromioclavicular (AC) joint dislocations have gained increasing interest. Well established procedures for open surgery were modified and implemented to attain an arthroscopic level. Furthermore implants were developed which enable these reconstructive techniques to be performed arthroscopically without the disadvantages of open procedures. The short to mid-term results described so far concerning the clinical and radiological outcome of arthroscopic stabilization techniques show an at least equal outcome to those presented in open surgery.