[Irreparable rotator cuff tear-reverse shoulder arthroplasty and alternative procedures]. / Irreparable Rotatorenmanschettenruptur ­ inverse Prothese und Alternativverfahren.

Irreparable rotator cuff tears represent a significant everyday clinical challenge. A high degree of tendon retraction and muscle degeneration means that a direct reconstruction is impossible. Patients often suffer from pain and pseudoparalysis. In older patients this can reliably be resolved by the implantation of a semiconstrained inverse shoulder prosthesis; however, for younger patients joint-preserving techniques should be employed. Furthermore, for frail older patients who may not be suitable for a joint replacement operation, alternative treatment strategies are required. Management options include physiotherapy and pain relieving or reconstructive operations. Minimally invasive arthroscopic treatment approaches can lead to pain relief and slight functional improvements in selected patients; however, to restore the active movement of the joint a partial cuff repair, augmentation with a graft or replacement with muscle transfer is necessary. This article presents the various treatment options and the results reported in the literature. Through this a treatment algorithm is suggested in order to facilitate management decisions.

[Clinical results after refixation of proximal hamstring tendon ruptures comparing different anchor systems]. / Klinische Ergebnisse nach Refixation proximaler Hamstring-Sehnen-Rupturen unter Berücksichtigung verschiedener Ankersysteme.

BACKGROUND: Injuries to the hamstring muscles and tendon complex are among the most frequent muscular injuries with proximal hamstring tendon avulsion being a particularly severe form. The surgical treatment of these injuries is superior to conservative management with respect to patient satisfaction, recovery of muscle strength and function as well as return to sport rates. It is therefore the method of choice. OBJECTIVE: Presentation and comparison of the surgical results after treatment with titanium, polyether ether ketone (PEEK) and all suture anchors. MATERIAL AND METHODS: A systematic search was carried out in the PubMed medical database and the results are summarized. RESULTS: All systems exhibit comparable biomechanical properties regarding elongation and ultimate failure load. Tendon repair with these anchors results in good to excellent clinical outcomes and shows high return to sport and low complication rates. Patient satisfaction after hamstring tendon repair is reported to be over 90% and return to sport rate is 80-100%. The muscle strength recovers to 80-90% in comparison to the contralateral side. CONCLUSION: All available anchors systems provide good to excellent clinical outcomes and an explicit advantage for one anchor system could so far not be shown.

[Diagnosis and therapy of chronic patellofemoral instability]. / Diagnostik und Therapie der chronischen patellofemoralen Instabilität.

The chronic patellofemoral instability is a multifactorial disease, which is mostly congenital. Luxation of the patella is mainly atraumatic. Sole conservative treatment is often unsuccessful. Surgical treatment is needed in most cases and requires consideration of all pathologic changes of the patella-stabilizing anatomic structures. Rupture of the medial patellofemoral ligament is almost pathognomonic. In addition, the frontal mechanical axis, rotation of femur and tibia, the trochlear shape, the distance from the tibial tuberosity to the trochlear sulcus and the patellar height play an important role. Often, in addition to soft tissue reconstruction, the bony alignment needs to be corrected. Consideration of risk factors in both adult and adolescent patients is needed to avoid recurrent instability.

T2-relaxation time of cartilage repair tissue is associated with bone remodeling after spongiosa-augmented matrix-associated autologous chondrocyte implantation.

OBJECTIVE: To investigate whether T2 relaxation time measurements of cartilage repair tissue and structural changes of the knee joint are associated with subchondral bone architecture after spongiosa-augmented matrix-associated autologous chondrocyte implantation (MACI). DESIGN: Both knees of 25 patients (25.5 ± 7.8y; 10 women) were examined preoperatively and 2.7 years after unilateral spongiosa-augmented MACI with 3T magnetic resonance (MR) imaging. Cartilage composition was assessed using T2 relaxation time measurements, subchondral trabecular bone microstructure was quantified using a 3D phase-cycled balanced steady state free-precision sequence. Structural knee joint changes were assessed using the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score was used for the postoperative description of the area that underwent MACI. Correlations were assessed using Spearman's rank correlation coefficients. RESULTS: Hypertrophy of the cartilage repair tissue was found in 2 of 25 patients, both after a MACI procedure at the patella, 21 patients showed congruent filling. In subchondral bone of the cartilage repair compartment, apparent trabecular thickness was significantly higher in compartments with elevated cartilage T2 (n = 17; 0.37 ± 0.05 mm) compared to those showing no difference in cartilage T2 compared to the same compartment in the contralateral knee (n = 8; 0.27 ± 0.05 mm; P = 0.042). Significant correlations were found between the overall progression of WORMS and the ipsilateral vs contralateral ratio of average trabecular thickness (r = 0.48, P = 0.031) and bone fraction (r = 0.57, P = 0.007). CONCLUSIONS: After spongiosa-augmented MACI, T2 values of cartilage repair tissue and structural knee joint changes correlated with the quality of the underlying trabecular bone.

No healing improvement after rotator cuff reconstruction augmented with an autologous periosteal flap.

PURPOSE: To show descriptive clinical and magnetic resonance (MR) imaging results after an additional periosteal flap augmentation in mini-open rotator cuff reconstruction and to evaluate potential healing improvement at long-term follow-up. METHODS: Twenty-three patients with degenerative rotator cuff tears were followed after receiving a mini-open single-row repair with a subtendinous periosteal flap augmentation. Data were collected preoperatively, after 12 months and after 11 years. Clinical examination, simple shoulder test (SST), Constant-Murley Score (CS), ultrasonography examination and 3T MR imaging were performed. RESULTS: Out of 23 patients, 20 were available for short-term and 19 for final follow-up at a median of 11.5 years (range 10.4-13.0). Questions answered with "yes" in SST improved from baseline 5.0 (range 1.0-8.0) to short 10.5 (range 8.0-12.0) and final follow-up 12.0 (range 7.0-12.0). CS improved from 53.5 (range 25.0-66.0) to 80.8 (range 75.9-89.3) and finally to 79.8 points (range 42.3-95.4). Improvement was highly significant (p < 0.05). Severe retears were found in 9/19 patients. Ossifications along the refixed tendon were noticed in 8/19 cases. Ossifications did not correlate with clinical outcome. At final follow-up, patients with retears seemed likely to have lower strength values in CS (mean ± SD) than patients without retears (7.3 ± 4.1 vs. 12.8 ± 5.3; p < 0.05). CONCLUSION: No positive effect on improving healing response in rotator cuff refixation with a periosteal flap augmentation could be found. Retear rate is comparable to that of conventional rotator cuff refixation in the published literature. Ossifications along the tendon, without negatively affecting the clinical outcome, were seen. This invasive technique cannot be advised and should not be used anymore. LEVEL OF EVIDENCE: IV.

Degenerative isolated cartilage defects of the patellofemoral joint are associated with more severe symptoms compared to trauma-related defects: results of the German Cartilage Registry (KnorpelRegister DGOU).

PURPOSE: The purpose of this study was to utilize data from the German Cartilage Registry (KnorpelRegister DGOU) to examine the hypothesis that degenerative cartilage defects of the patellofemoral joint are associated with more severe clinical symptoms compared to trauma-related defects. METHODS: All patients with isolated focal cartilage defects of the patellofemoral joint registered in the German Cartilage Registry until May 2017 were included in the study. Patients with previous surgery of the ipsilateral knee were excluded. Baseline data including etiology (traumatic, degenerative), size, location and ICRS grade of the cartilage defects as well as the duration of symptoms were analyzed. Clinical symptoms were evaluated by means of the numeric analog scale (NAS) for pain and the Knee injury and Osteoarthritis Outcome Score (KOOS). Group comparisons were performed using the Mann-Whitney-U test along with the Chi-squared test and Fisher's exact test. A bivariate correlation analysis and a multivariable linear regression analysis were performed to investigate the association between the defect characteristics and the clinical scores. RESULTS: A total of 423 patients (203 traumatic and 220 degenerative defects) were included. Isolated degenerative cartilage defects were found to have significantly more trochlear locations (28% vs. 18%; p = 0.006), significantly less ICRS grade 4 lesions (50% vs. 73%; p = 0.002) and a significantly smaller defect size [median 300 (IQR 105-400) vs. 300 (200-400) mm2] when compared to those from traumatic etiology. Traumatic defects showed significantly better KOOS-ADL [77 (60-90) vs. 69 (56-82); p = 0.005], KOOS-pain [69 (56-81) vs. 61 (47-75); p = 0.001] and NAS [2 (1-5) vs. 4 (1-6); p = 0.005] scores compared to degenerative defects. The correlation analysis revealed only weak correlations between the quantitative defect characteristics and clinical scores. CONCLUSIONS: Degenerative isolated cartilage defects in the patellofemoral joint are associated with more severe clinical symptoms in comparison to trauma-related defects. Additionally, they show a larger variance regarding their location with more trochlear defects. LEVEL OF EVIDENCE: III.

Retrograde fixation of the lesser trochanter in the adolescent: new surgical technique and clinical results of two cases.

INTRODUCTION: Avulsions of the lesser femoral trochanter are rare injuries in the adolescent population. An acute avulsion causes severe functional impairment with compromised hip flexion. Recent literature reports the superiority of surgical treatment for apophyseal avulsion fractures of the pelvis in adolescents. Unfortunately, there are no guidelines for an evidence-based treatment of lesser trochanter avulsions established. We present the cases of two adolescent athletes treated operatively. MATERIALS AND METHODS: Two adolescent males, 12 and 16 years old, suffered an avulsion of the lesser trochanter during soccer. They reported immobilizing groin pain with subjective impairment in daily activities and inability to perform sports. Surgical treatment with a new retrograde technique by applying an adapted mini-open anterior approach was performed. Intraoperatively, both cases showed an intact musculo-tendinous unit attached to the avulsed fragment. RESULTS: Both patients showed excellent postoperative results and were satisfied with the clinical outcome. In the postoperative follow-up an adequate consolidation of the lesser trochanter was visible. No complications were postoperatively reported at final follow-up. CONCLUSIONS: The retrograde fixation technique has led to an excellent outcome without complications in two adolescents with acute lesser trochanter apophyseal avulsions. Further clinical use may support the value of this new surgical technique.

[Modern treatment strategies for the long head of the biceps tendon]. / Moderne Behandlungsstrategien der langen Bizepssehne.

The long head of the biceps and the biceps pulley sling are prone to acute or degenerative injury. As they both were identified as major pain generators, adequate diagnosis and treatment is vital for successful treatment of shoulder pain. Although the basic principles to address either pathology have not changed over the last decades, new trends have evolved to simplify surgical options. SLAP (superior labral tear from anterior to posterior) repair is seen more restrictive and is mostly performed in young individuals, whereas tenotomy or tenodesis are more often used in patients over 30. The long head of the biceps and pulley lesions are treated with either tenotomy or tenodesis. Surgical techniques for tenodesis are especially less invasive using current implants. Tenodesis is performed either intraarticular, supra- or subpectoral with tenodesis screws or suture anchors. Soft tissue tenodesis has become unpopular over the last decade. Surgical treatment of the long head of the biceps pathologies allows highly satisfying results if the indication is chosen thoroughly.

[Osteoarthritis of the shoulder: pathogenesis, diagnostics and conservative treatment options]. / Omarthrose: Pathogenese, Diagnostik und konservative Therapieoptionen.

PATHOGENESIS: Osteoarthritis of the shoulder is characterized by a progressive degenerative process, which is based on chronic inflammation with intra-articular release of different cytokines and proteolytic enzymes. The main predisposing factors are a history of trauma or surgery, as well as chronic overuse or instability of the glenohumeral joint. Affected patients especially suffer from impaired joint function and pain, which are often associated with cognitive and psychosocial restrictions. DIAGNOSTICS: Possible co-pathologies have to be evaluated carefully both clinically and radiologically as they must be taken into account in the therapeutic procedure. If arthroplasty of the shoulder is planned, a pre-operative CT scan is mandatory in order to evaluate the bone stock of the glenoid, which has a decisive influence on the choice of implant. TREATMENT: Conservative treatment options are oral pain medication, physical therapy, and intra-articular injections, whereby, in comparison to corticosteroids, hyaluronic acid seems to be advantageous especially with respect to the duration of a positive clinical effect.

[Recurrent instability and instability arthropathy]. / Rezidivinstabilität und Instabilitätsarthropathie.

Capsulolabral reconstruction (Bankart repair) is recommended as the first line treatment in young and functionally demanding active patients with anteroinferior shoulder instability, due to the high tendency to recurrent dislocation. This has become established both for arthroscopic and open primary shoulder stabilization with good clinical outcome; nevertheless, recurrence of dislocation is reported in up to 25% of patients. Risk factors for failed surgery are patient (e.g. young age, male gender and contact sports) and surgery (e.g. primarily underestimated glenoid bone loss, Hill-Sachs lesion, non-treatment of bipolar defects or malpositioned anchors) related. In the management of recurrent instability, it is necessary to carry out a thorough clinical investigation in addition to extended diagnostics with X­ray and computed tomography. A second Bankart repair is only indicated in patients with low demands and without any glenoid bone loss. In the majority of patients, bony augmentation of the glenoid is necessary and realized by coracoid or iliac crest bone block transfer. The Latarjet procedure is biomechanically advantageous due to the additional sling effect of the conjoined tendons and both techniques show good clinical outcomes and a low recurrence rate. Furthermore, engaging Hill-Sachs lesions also require additional treatment. Remplissage of the infraspinatus muscle, iliac crest bone block transfer and partial joint replacement are viable options. A final consensus for treatment of Hill-Sachs lesions has yet to be defined. Dislocation arthropathy is an underestimated complication as a result of frequent recurrent dislocations. After development of dislocation arthropathy, patients reported a painful restriction of range of motion rather than instability. Arthroscopic arthrolysis and comprehensive arthroscopic management (CAM procedure) are possible joint-preserving treatment options.

[Paresis of the brachial plexus after anterior shoulder luxation : Traumatic damage or compression due to hematoma?] / Parese des Plexus brachialis nach vorderer Schulterluxation : Traumatische Schädigung oder hämatombedingte Kompression?

After traumatic anterior shoulder dislocation and self-reduction, the patient initially showed an inconspicuous clinical course. At the time of presentation in the emergency room the upper limb neurological status was reported to be normal. After discharge, paresis of the brachial plexus of the left arm occurred within 8 h. A subsequently performed computed tomography (CT) scan revealed a hematoma close to the brachial plexus, which was treated by surgical decompression and resulted in symptom relief. This case report describes a rare but significant complication after anterior shoulder dislocation, which should not be underestimated in the setting of a surgical emergency admission.

[Impingement syndromes of the shoulder]. / Impingement-Syndrome der Schulter.

In addition to tears of the rotator cuff, isolated impingement syndrome of the shoulder is the most common diagnosis in shoulder disorders. This is of high relevance in orthopedic sports medicine. In fact, impingement of the shoulder is not the diagnosis but rather a symptom of a functional or even a structural pathology. Detailed knowledge about the different types of impingement and the underlying causes is essential to provide adequate treatment. Primarily, impingement of the shoulder should be treated nonoperatively. However, if there is no clinical improve despite adequate conservative treatment, there is usually a structural pathology which cannot be adequately compensated for and surgical treatment may be necessary. In the case of severe structural pathologies, such as a full-thickness tear of the rotator cuff, a subsequent surgical treatment may be indicated.

[Sports activities after osteotomies around the knee]. / Sportfähigkeit nach kniegelenknaher Osteotomie.

In the current literature, the rate of return to sports following high tibial osteotomy is high. Patients are largely able to carry out the type of exercise done before the onset of symptoms and are satisfied with the clinical outcome. In general, however, a differentiated view of the sporting ability should be made, and the different requirements of the sport should be considered. A classification according to functional and biomechanical movement analysis seems to advisable. In addition, the recommendations of the treating physician seem to have a high impact on the postoperative level of the sports activities of the patients. A realistic assessment (by both the patient and the treating physician) that considers the sport, its requirements and the level of performance is necessary.

Stem cells and bFGF in tendon healing: Effects of lentiviral gene transfer and long-term follow-up in a rat Achilles tendon defect model.

BACKGROUND: The influence of stem cells and lentiviral expression of basic fibroblastic growth factor (bFGF) on tendon healing and remodelling was investigated in an in-vivo long-term (12 weeks) rat Achilles tendon defect model. METHODS: In sixty male Lewis rats, complete tendon defects (2.4 mm) were created and either left untreated (PBS) or treated by injection of stem cells lentivirally expressing the enhanced green fluorescence marker gene eGFP (MSC-LV-eGFP) or basic fibroblast growth factor bFGF (MSC-LV-bFGF). Tendons were harvested after 12 weeks and underwent biomechanical and (immuno)-histological analysis. RESULTS: After 12 weeks the mean ultimate load to failure ratio (treated side to contralateral side) in biomechanical testing reached 97 % in the bFGF-group, 103 % in the eGFP-group and 112 % in the PBS-group. Also in the stiffness testing both MSC groups did not reach the results of the PBS group. Histologically, the MSC groups did not show better results than the control group. There were clusters of ossifications found in all groups. In immunohistology, only the staining collagen-type-I was strongly increased in both MSC groups in comparison to PBS control group. However, there were no significant differences in the (immuno)-histological results between both stem cell groups. CONCLUSION: The biomechanical and (immuno)-histological results did not show positive effects of the MSC groups on tendon remodelling in a long-term follow-up. Interestingly, in later stages stem cells had hardly any effects on biomechanical results. This study inspires a critical and reflected use of stem cells in tendon healing.

Mid-term Functional Outcome and Return to Sports after Proximal Hamstring Tendon Repair.

Proximal hamstring tendon ruptures are commonly associated with a significant loss of function, and operative treatment is recommended in active patients. The objective was to evaluate objective/subjective functional results and return to sports following proximal hamstring tendon repair in the mid-term follow-up. 16 repairs of proximal hamstring ruptures were performed in 15 patients (9 males, 6 females). The average age at the time of injury was 47 years (range, 21-66). All patients were clinically examined at a mean follow-up of 56 months (range, 24-112 months). Validated patient-oriented assessment scores focussing on sports activity including the Lysholm Score, Tegner Activity Score, UCLA Activity Score, adapted WOMAC Score, and the VAS were evaluated as well as the return to sports. Isokinetic strength of both legs was tested using a rotational dynamometer. The Lysholm, Tegner, UCLA Activity Score and the adapted WOMAC demonstrated predominantly a return to a preinjury activity level at follow-up. Functional measurements of the operated leg showed similar results to the uninjured leg in knee extension and flexion strength (p>0.094). In return to sports, no signficant (p>0.05) differences concerning types or frequency were noted. The surgical repair of proximal hamstring tendon ruptures leads to constantly good functional results in the mid-term follow-up, where patients demonstrate similar isokinetic results in the healthy leg.

Pull-out stability of anchors for rotator cuff repair is also increased by bio-absorbable augmentation: a cadaver study.

INTRODUCTION: Osteoporosis is a highly focused issue in current scientific research and clinical treatment. Especially in rotator cuff repair, the low bone quality of patients suffering from osteoporosis is an important issue. In this context, non-biological solutions using PMMA for anchor augmentation have been developed in the recent past. The aim of this study was to evaluate whether augmentation of suture anchors using bio-absorbable osteoconductive fiber-reinforced calcium phosphate results in improved failure load of suture anchors as well. MATERIALS AND METHODS: Altogether 24 suture anchors (Corkscrew FT 1 Suture Anchors, Arthrex, Naples, FL, USA) were evaluated by applying traction until pullout in 12 paired fresh frozen human cadaver humeri using a servo-hydraulic testing machine. Inclusion criteria were an age of more than 64 years, a macroscopically intact RC and an intact bone. The anchors were evaluated at the anterolateral and posteromedial aspect of the greater tuberosity. 12 suture anchors were augmented and 12 suture anchors were conventionally inserted. RESULTS: The failure load was significantly enhanced by 66.8 % by the augmentation method. The fiber-reinforced calcium phosphate could be easily injected and applied. CONCLUSION: The bio-absorbable cement in this study could be a promising augmentation material for RC reconstructions, but further research is necessary-the material has to be evaluated in vivo.

[Post-traumatic osteoarthritis of the elbow joint : Endoprosthetic options in young patients]. / Sekundäre Arthrose des Ellenbogengelenkes : Endoprothetische Möglichkeiten beim jungen Patienten.

BACKGROUND: In young patients, post-traumatic osteoarthritis of the elbow is a rare condition. Whereas clinical manifestations often differ from radiological findings, pain and stiffness are variably combined in symptomatic forms. In deciding whether to perform surgery, the patient's age, activity level, and symptoms, as well as the location and severity of the osteoarthritis have to be taken into account. Elbow joint instability has to be identified to stop the post-traumatic osteoarthritic progress. If joint preserving surgical methods fail, diverse options for partial or total joint replacement are available. THERAPY: The treatment goal in young patients, therefore, is to reduce pain with a sufficient range of elbow motion.

Bilateral cartilage T2 mapping 9 years after Mega-OATS implantation at the knee: a quantitative 3T MRI study.

OBJECTIVE: To evaluate morphological and quantitative MR findings 9 years after autograft transfer of the posterior femoral condyle (Mega-OATS) and to correlate these findings with clinical outcomes. Quantitative MR measurements were also obtained of the contralateral knee and the utility as reference standard was investigated. DESIGN: Both knees of 20 patients with Mega-OATS osteochondral repair at the medial femoral condyle (MFC) were studied using 3T MRI 9 years after the procedure. MR-sequences included morphological sequences and a 2D multislice multiecho (MSME) spin echo (SE) sequence for quantitative cartilage T2 mapping. Cartilage segmentation was performed at the cartilage repair site and six additional knee compartments. Semi-quantitative MR observation of cartilage repair tissue (MOCART) scores and clinical Lysholm scores were obtained. Paired t-tests and Spearman correlations were used for statistical analysis. RESULTS: Global T2-values were significantly higher at ipsilateral knees compared to contralateral knees (42.1 ± 3.0 ms vs 40.4 ± 2.6 ms, P = 0.018). T2-values of the Mega-OATS site correlated significantly with MOCART scores (R = -0.64, P = 0.006). The correlations between MOCART and Lysholm scores and between absolute T2-values and Lysholm scores were not significant (P > 0.05). However, higher T2 side-to-side differences at the femoral condyles correlated significantly with more severe clinical symptoms (medial, R = -0.53, P = 0.030; lateral, R = -0.51, P = 0.038). CONCLUSIONS: Despite long-term survival, 9 years after Mega-OATS procedures, T2-values of the grafts were increased compared to contralateral knees. Clinical scores correlated best with T2 side-to-side differences of the femoral condyles, indicating that intraindividual adjustment may be beneficial for outcome evaluation.

Treatment of osteochondral lesions in the elbow: results after autologous osteochondral transplantation.

BACKGROUND: Osteochondral lesions in the elbow still remain a challenging field of surgery. In recent years promising clinical results were described for the osteochondral transplantation technique. The aim of this retrospective study was to evaluate the clinical and radiological outcome in the mid-term follow-up of a large cohort of patients following osteochondral transplantation in the elbow. METHODS: 18 patients with advanced osteochondral lesions of the elbow treated by autologous osteochondral autograft cylinders and a minimum follow-up of 36 months were included in the study. The Broberg-Morrey score (BMS) and the American Shoulder and Elbow score (ASES) were used to assess elbow function and pain, respectively. The joint status was analyzed using plain radiographs and MRI scans taken from all patients at recent follow-up. In addition, the ipsilateral knee joint was examined for donor-site morbidity using the Lysholm knee score. RESULTS: 14 patients were evaluated with a mean follow-up of 7 years (range 3-14 years). The mean BMS was 95.1 (range 72-100) points. The ASES score also showed promising results: pain at worst 1.5 (range 0-5) points, pain at rest 0.4 (range 0-5) points, pain lifting loads 2.8 (range 0-8) points, repetitive movement pain 1.5 (range 0-8) points. The range of motion of the injured elbow was free and equal to the contralateral side. Signs of osteoarthritis could be found on plain radiographs in three patients. The MRIs at follow-up showed graft viability in all patients. However, a slight incongruency of the chondral surface could be detected in two patients. The average Lysholm score was 90.9 (range 0-70) points. CONCLUSIONS: Osteochondral transplantation in the elbow leads to both clinical and radiographic good-to-excellent mid-term results and therefore represents a reasonable treatment option for advanced osteochondral lesions in the elbow. LEVEL OF EVIDENCE: Retrospective study; Therapeutic Level IV.

[Arthroscopically assisted techniques for treatment of acute and chronic acromioclavicular joint injuries]. / Arthroskopisch gestützte Techniken zur Versorgung der akuten und chronischen AC-Gelenk-Verletzung.

Acute and chronic acromioclavicular (AC) joint dislocation is frequently encountered in the routine clinical practice. This injury can lead to significant impairment of shoulder girdle function. Therapy based on the severity of injury is recommended to re-establish correct shoulder function. The static radiographic Rockwood classification is used to define the degree of dislocation but the clinical aspects and functional x-ray imaging of horizontal AC joint instability should also be considered for selection of the appropriate procedure. Rockwood grades I and II injuries are treated non-operatively with early functional exercise. The approach for Rockwood grade III injuries should be individual and patient-specific, with non-surgical procedures for low functional requirement patients with a high risk for surgical interventions. For patients with high demands on shoulder function surgery is recommended. A detailed diagnostic assessment frequently reveals Rockwood grade III injuries to be type IV injuries. Rockwood types IV and V AC joint dislocations require surgery for sustained stability. Treatment of acute injuries is recommended within 1-3 weeks after trauma but there is no clear evidence of a cut-off for the presence of chronic injuries. Various surgical techniques have been described in the literature. This article presents an arthroscopically assisted technique that addresses both vertical and horizontal instability of the AC joint.