John Apostolakos

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.

Rotational and Translational Stability of Different Methods for Direct Acromioclavicular Ligament Repair in Anatomic Acromioclavicular Joint Reconstruction

Background: Many reconstructions of acromioclavicular (AC) joint dislocations have focused on the coracoclavicular (CC) ligaments and neglected the functional contribution of the AC ligaments and the deltotrapezial fascia. Purpose: To compare the modifications of previously published methods for direct AC reconstruction in addition to a CC reconstruction. The hypothesis was that there would be significant differences within the variations of surgical reconstructions. Study Design: Controlled laboratory study. Methods: A total of 24 cadaveric shoulders were tested with a servohydraulic testing system. Two digitizing cameras evaluated the 3-dimensional movement. All reconstructions were based on a CC reconstruction using 2 clavicle tunnels and a tendon graft. The following techniques were used to reconstruct the AC ligaments: a graft was shuttled underneath the AC joint back from anterior and again sutured to the acromial side of the joint (group 1), a graft was fixed intramedullary in the acromion and distal clavicle (group 2), a graft was passed over the acromion and into an acromial tunnel (group 3), and a FiberTape was fixed in a cruciate configuration (group 4). Anterior, posterior, and superior translation, as well as anterior and posterior rotation, were tested. Results: Group 1 showed significantly less posterior translation compared with the 3 other groups (P < .05) but did not show significant differences compared with the native joint. Groups 3 and 4 demonstrated significantly more posterior translation than the native joint. Group 1 showed significantly less anterior translation compared with groups 2 and 3. Group 3 demonstrated significantly more anterior translation than the native joint. Group 1 demonstrated significantly less superior translation compared with the other groups and with the native joint. The AC joint of group 1 was pulled apart less compared with all other reconstructions. Only group 1 reproduced the native joint for the anterior rotation at the posterior marker. Group 4 showed significantly increased distances for all 3 measure points when the clavicle was rotated posteriorly. Conclusion: Reconstruction of the AC ligament by direct wrapping and suturing of the remaining graft around the AC joint (group 1) was the most stable method and was the only one to show anterior rotation comparable with the native joint. In contrast, the transacromial technique (group 3) showed the most translation and rotation. Clinical Relevance: An anatomic repair should address both the CC ligaments and the AC ligaments to control the optimal physiologic function (translation and rotation).

Material Properties and Composition of Soft-Tissue Fixation

Surgical interference screws and suture anchors for attaching soft tissue, such as ligaments and tendons, to bone are routinely used in arthroscopic surgery and sports medicine. Interference screw fixation provides a press fit between bone, graft/tendon, and screw and is frequently used to attach replacement ligaments in tunnels drilled for anterior and posterior cruciate ligament reconstruction. Suture anchors are used in surgical procedures wherein it is necessary for a surgeon to attach (tie) tissue to the surface of the bone, for example, during joint reconstruction and ligament repair or replacement. The composition of these implants ranges from metals to polymers and composites. Typically, because of the relatively large amount of torque that must be applied during insertion, these screws are constructed from metal. However, interference screws and suture anchors have also been constructed from bioabsorbable polymers and composites. The ideal material would (1) provide adequate mechanical fixation, (2) completely degrade once no longer needed, and (3) be completely replaced by bone. Because no material has been shown to be superior for all applications, the surgeon must weigh the advantages and disadvantages of each to evaluate the optimum material for a given application and patient. The purpose of this article is to present a comprehensive review of the commercially available interference screws and suture anchors, with an emphasis on implant composition, interaction, and design. This article provides the orthopaedic surgeon with a background on biomaterials, specifically those used in interference screws and suture anchors. Because there is no material that is perfect for all surgical situations, this review can be used to make educated decisions on a case-by-case basis.

Biomechanical evaluation of classic solid and novel all-soft suture anchors for glenoid labral repair.

PURPOSE To evaluate the biomechanical performance of an all-soft suture anchor (JuggerKnot; Biomet, Warsaw, IN) in comparison with a classic solid suture anchor (2.4-mm biocomposite SutureTak; Arthrex, Naples, FL) in an in vitro labral repair model. METHODS We dissected 12 cadaveric shoulders (mean age, 61 ± 9.4 years), leaving the labrum intact, and bone mineral density was obtained (mean, 0.375 ± 0.06 g/cm(3)). Simulated labral tears were made at the anteroinferior and posteroinferior edges of the labrum. Repairs used 2 all-soft suture anchors (JuggerKnot) or 2 solid anchors with free, high-strength No. 2 suture (FiberWire; Arthrex) spanning the operative construct to load the repair. Differential variable reluctance transducers were used to measure labral displacement for each specimen. The testing protocol consisted of a preconditioning phase at 10 N for 10 cycles (1 Hz) and then a final load-to-failure testing at a rate of 3 mm/min. Labral displacement of 2 mm was determined as the primary outcome. RESULTS There was no statistical difference (P = .22) in ultimate load to failure and displacement at ultimate failure (anchor pullout) between the all-soft JuggerKnot (146.0 ± 43.0 N and 19.8 ± 5.4 mm, respectively) and the solid SutureTak (171.9 ± 52.6 N and 22.3 ± 6.8 mm, respectively). The solid anchor had a significantly higher ultimate load at 2 mm of labral displacement than the all-soft suture anchor (84.1 ± 19.0 N and 39.2 ± 10.6 N, respectively; P < .001). CONCLUSIONS Whereas both the solid SutureTak and the all-soft JuggerKnot displayed similar results on ultimate load-to-failure testing, the solid anchor required significantly greater load for 2 mm of labral displacement than the all-soft anchor. CLINICAL RELEVANCE The all-soft anchor (JuggerKnot) is similar in biomechanical performance to the classic solid anchor (SutureTak) with the exception of load at 2 mm of labral displacement, suggesting micromotion of the device.

Variability of platelet-rich plasma preparations.

Platelet-rich plasma (PRP) as a clinical treatment for bone, muscle, tendon, and cartilage injury has gained popularity in the field of orthopedic sports medicine. The use of a patient’s own blood is an appealing aspect of PRP treatment, as the resulting plasma preparation is considered relatively benign in comparison with more common, potentially caustic treatments such as corticosteroids and anesthetics. Although appealing, the autologous nature of PRP introduces variability to plasma preparations, creating challenges for both the researcher and the clinician. Differences in patients at the time of blood draw result in plasma preparations that vary within as well as between patients. This variability is compounded by the multitude of protocols and devices available for procuring PRP. The variability of components and its effects on dosage should be considered in single or consecutive treatments of PRP.

An In Vitro Evaluation of the Anti-Inflammatory Effects of Platelet-Rich Plasma, Ketorolac, and Methylprednisolone

PURPOSE The purpose of this study was to quantify the extent of the anti-inflammatory effect of platelet-rich plasma (PRP) in a controlled in vitro environment. METHODS Through the stimulation of human umbilical vein endothelial cells with inflammatory cytokines (tumor necrosis factor α and interferon γ), cell adhesion molecule expression (E-selectin, vascular cell adhesion molecule, and human leukocyte antigen DR) and PRPs anti-inflammatory effect can be measured. PRP was produced from 3 individuals using a single-spin (PRPLP) process. Treatment groups include negative (unstimulated) controls, positive (stimulated) controls, ketorolac tromethamine, methylprednisolone, PRP, ketorolac-PRP, and methylprednisolone-PRP. A fluorescence assay of the cellular inflammation markers was measured by the BioTek Synergy HT plate reader (BioTek Instruments, Winooski, VT) at 0, 1, 2, and 5 days. RESULTS At days 2 and 5, methylprednisolone treatment showed a 2.1- to 5.8-fold reduction (P < .05) in inflammation markers over PRP. In addition, PRP and ketorolac showed a 1.4- to 2.5-fold reduction (P < .05) in cellular inflammation markers over the control. There was no statistically significant difference between ketorolac and PRP. CONCLUSIONS Although PRP and ketorolac reduced cellular inflammation markers (E-selectin, vascular cell adhesion molecule, and human leukocyte antigen DR) compared with control, neither caused as great a reduction as methylprednisolone. CLINICAL RELEVANCE Although PRP and ketorolac did not produce as significant a reduction in cellular inflammation markers as methylprednisolone, they reduced cellular inflammation compared with the control. These agents may have clinical application as injectable anti-inflammatory medications.

The Future Role of Mesenchymal Stem Cells in the Management of Shoulder Disorders

PURPOSE Biologics may help to optimize the healing environment after rotator cuff repair. Mesenchymal stem cells (MSCs) may have the potential to regenerate a physiological enthesis, thereby improving healing at the repair site after rotator cuff repair. METHODS The PubMed database was searched in May 2013. Only in vivo and in vitro studies reporting on stem cell use in the rotator cuff of humans or animals were included. Exclusion criteria consisted of the following: Level V evidence, systematic reviews, and studies reporting preliminary results. RESULTS This query resulted in 141 citations. Of these, 90 were excluded based on the title of the study. A final group of 17 studies was included in this review (9 in vivo animal studies, 5 in vitro human studies, 1 in vitro animal study, 1 study reporting in vitro human and in vivo animal results, and 1 study reporting on clinical outcomes of human patients). CONCLUSIONS The current literature regarding therapeutic use of MSCs in shoulder surgery is limited. Although in vivo animal studies have shown some promising approaches to enhance tendon-to-bone healing, the use of MSCs for shoulder surgery should still be regarded as an experimental technique. Further basic and clinical research is needed until a procedure can be defined for the routine use of these cells in shoulder surgery.

The Integrity of the Acromioclavicular Capsule Ensures Physiological Centering of the Acromioclavicular Joint Under Rotational Loading

Background: The acromioclavicular (AC) capsule is an important stabilizer against horizontal translation and also contributes to the strut function of the clavicle, which guides rotation of the scapula. To best reproduce the biomechanical properties and the complex 3-dimensional (3D) guidance of the AC joint, detailed knowledge of the contribution of each of the distinctive capsular structures is needed. Purpose/Hypothesis: To perform a detailed biomechanical evaluation of the specific capsular structures of the AC joint and their contribution to translational and rotational stability. The hypothesis was that successive cutting of each quadrant of the AC capsule would result in increased instability and increased amplitude of the clavicle’s motion in relation to the acromion. Study Design: Controlled laboratory study. Methods: Thirty-two fresh-frozen human cadaveric shoulders were used. Each scapula was fixed to a swivel fixture of a servohydraulic materials testing system. The AC capsule was dissected in serial steps with immediate rotational and horizontal testing after each cut. A 3D optical measuring system was used to evaluate 3D movement. Posterior translation, rotation, and displacement of the lateral clavicle in relation to the center of rotation were measured. Torques and axial forces required to rotate and translate the clavicle were recorded. Results: When posterior translational force was applied, all specimens with a completely cut AC capsule demonstrated a significant loss of resistance force against the translational motion when compared with the native state (P < .05). The resistance force against posterior translation was reduced to less than 27% of the native state for all specimens. Sequential cutting of the AC capsule resulted in a significant reduction of resistance torque against anterior rotation for all specimens with less than 22% of resistance force compared with the native state. Cutting 50% of the capsule reduced the resistance torque for all segments and all testing modalities (posterior translation as well as anterior and posterior rotation) significantly compared with the native state (P < .05). Cutting the entire AC capsule resulted in a significant increase in motion within the joint as a sign of decentering of the AC joint when torque was applied. All groups demonstrated a significant increase of motion in all directions when the AC capsule was cut by 50%. Conclusion: Cutting the entire capsule (with intact coracoclavicular [CC] ligaments) reduced the resistance force to less than 25% compared with the native state during translational testing and less than 10% compared with the native state during rotational testing. However, the anterior segments of the capsule provided the greatest stability under rotational loading. Second, the amplitude of the joint’s motion significantly increased under rotational stress, indicating increased amplitude of the clavicle’s motion in relation to the acromion when the ligamentous structures of the AC capsule are dissected. Clinical Relevance: To best restore stability to the AC joint, the relevance and function of each section of the circumferential AC capsule need to be understood. Our findings support the synergistic contribution of the CC ligaments and AC capsular structures to AC joint stability. This synergy supports the need to address both structures to achieve anatomic reconstruction.

Operative and Nonoperative Treatment of Acromioclavicular Dislocation: A Critical Analysis Review.

Acromioclavicular joint injury is a common contact sports-related injury in the upper extremity1. These injuries range from a simple sprain of the acromioclavicular ligament to a complete dislocation (complete separation) of the joint, which involves disruption of the acromioclavicular and coracoclavicular ligaments and varying degrees of injury to the deltoid and trapezius muscles and fascia. Rockwood et al.2 classified acromioclavicular joint injuries on the basis of the number of ligaments involved, the severity of injury, radiographic findings (including the position of the clavicle relative to the acromion), and reducibility of the acromioclavicular joint with shoulder shrugging (Table I). The Upper Extremity Committee of ISAKOS (International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine) recently proposed a subclassification of the original Rockwood type-III dislocation into …

Lateral clavicle fracture with coracoclavicular ligament injury: a biomechanical study of 4 different repair techniques

PurposeTo investigate the biomechanical performance of four different methods used for coracoclavicular (CC) ligament reconstruction in a lateral clavicle fracture repair.MethodsNative displacement, translation, and rotation at the acromioclavicular joint of 24 fresh-frozen cadaveric shoulders were tested. A reproducible fracture in the lateral third of the clavicle was created by dissecting both CC ligaments. Each specimen was then repaired with plate fixation of the fracture and the following CC repair technique: (1) Cortical button. (2) Suture anchor and plate button. (3) Suture anchor no plate button, and (4) Suture around coracoid. All reconstructed specimens were then re-tested for displacement, translation, and load to failure, and compared to their native results. Groups 1 and 3 were investigated for rotational load.ResultsThere was no difference in load to failure between the repaired groups (p: ns). Group 1 showed less superior and anterior translations (p < 0.05). Group 2 showed significantly less superior translation (p = 0.003), but no significance with anterior and posterior translations to the native joint. Group 3 showed less superior and posterior translations (p = 0.005 and p = 0.039). Anterior and posterior translations were increased in group 4 (p < 0.05).ConclusionThe biomechanical analyses did not show any significance in load to failure or displacement after cyclic loading among the study groups. All repairs were effective in preventing superior translation. Groups 1 and 2 demonstrated increased horizontal stability compared to the native state. All 4 methods are clinically viable options for CC ligament repair.