Demetris Delos

The Effect of Platelet-Rich Fibrin Matrix on Rotator Cuff Tendon Healing: A Prospective, Randomized Clinical Study

Background: There is a strong need for methods to improve the biological potential of rotator cuff tendon healing. Platelet-rich fibrin matrix (PRFM) allows delivery of autologous cytokines to healing tissue, and limited evidence suggests a positive effect of platelet-rich plasma on tendon biology. Purpose: To evaluate the effect of platelet-rich fibrin matrix on rotator cuff tendon healing. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: Seventy-nine patients undergoing arthroscopic rotator cuff tendon repair were randomized intraoperatively to either receive PRFM at the tendon-bone interface (n = 40) or standard repair with no PRFM (n = 39). Standardized repair techniques were used for all patients. The postoperative rehabilitation protocol was the same in both groups. The primary outcome was tendon healing evaluated by ultrasound (intact vs defect at repair site) at 6 and 12 weeks. Power Doppler ultrasound was also used to evaluate vascularity in the peribursal, peritendinous, and musculotendinous and insertion site areas of the tendon and bone anchor site. Secondary outcomes included standardized shoulder outcome scales (American Shoulder and Elbow Surgeons [ASES] and L’Insalata) and strength measurements using a handheld dynamometer. Patients and the evaluator were blinded to treatment group. All patients were evaluated at minimum 1-year follow-up. A logistic regression model was used to predict outcome (healed vs defect) based on tear severity, repair type, treatment type (PRFM or control), and platelet count. Results: Overall, there were no differences in tendon-to-bone healing between the PRFM and control groups. Complete tendon-to-bone healing (intact repair) was found in 24 of 36 (67%) in the PRFM group and 25 of 31 (81%) in the control group (P = .20). There were no significant differences in healing by ultrasound between 6 and 12 weeks. There were gradual increases in ASES and L’Insalata scores over time in both groups, but there were no differences in scores between the groups. We also found no difference in vascularity in the peribursal, peritendinous, and musculotendinous areas of the tendon between groups. There were no differences in strength between groups. Platelet count had no effect on healing. Logistic regression analysis demonstrated that PRFM was a significant predictor (P = .037) for a tendon defect at 12 weeks, with an odds ratio of 5.8. Conclusion: Platelet-rich fibrin matrix applied to the tendon-bone interface at the time of rotator cuff repair had no demonstrable effect on tendon healing, tendon vascularity, manual muscle strength, or clinical rating scales. In fact, the regression analysis suggests that PRFM may have a negative effect on healing. Further study is required to evaluate the role of PRFM in rotator cuff repair.

Tibial and Femoral Tunnel Changes After ACL Reconstruction A Prospective 2-Year Longitudinal MRI Study

Background: Tunnel widening after anterior cruciate ligament reconstruction (ACL-R) is a well-accepted and frequent phenomenon, yet little is known regarding its origin or natural history. Purpose: To prospectively evaluate the cross-sectional area (CSA) changes in tibial and femoral bone tunnels after ACL-R with serial MRI. Study Design: Case series; Level of evidence, 4. Methods: Patients underwent arthroscopic ACL-R with the same surgeon, surgical technique, and rehabilitation protocol. Each patient underwent preoperative dual-energy x-ray absorptiometry and clinical evaluation, as well as postoperative time zero MRI followed by subsequent MRI and clinical examination, including functional and subjective outcome tests, at 6, 12, 24, 52, and 104 weeks. Tibial and femoral tunnel CSA was measured on each MRI at tunnel aperture (ttA and ftA), midsection (ttM and ftM), and exit (ttE and ftE). Logistic regression modeling was used to examine the predictive value of demographic data and preoperative bone quality (as measured by dual-energy x-ray absorptiometry) on functional outcome scores, manual and instrumented laxity measurements, and changes in tunnel area over time. Results: Eighteen patients (including 12 men), mean age 35.5 ± 8.7 years, underwent ACL-R. There was significant tunnel expansion at ttA and ftA sites 6 weeks postoperatively (P = .024 and .0045, respectively). Expansion continued for 24 weeks, with progressive tunnel narrowing thereafter. Average ttA CSA was significantly larger than ftA CSA at all times. The ttM significantly expanded after 6 weeks (P = .06); continued expansion to week 12 was followed by 21 months of reduction in tunnel diameter. The ftM and both ttE and ftE sites decreased in CSA over the 2 years. Median Lysholm and International Knee Documentation Committee scores significantly improved at final follow-up (P = .0083 and <.0001, respectively), and patients returned to preoperative activity levels. Pivot shift significantly decreased (P < .0001). Younger age (<30 years), male sex, and delayed ACL-R (>1 year from time of injury) predicted increased tunnel widening and accelerated expansion in CSA (P < .005). Conclusion: Tunnel expansion after ACL-R occurs early and primarily at the tunnel apertures. Expansion may not affect clinical outcome. Younger age, male sex, and delay from injury to ACL-R may be potential risks for enlargement.

Abnormal Mineral-Matrix Interactions Are a Significant Contributor to Fragility in oim/oim Bone

The presence of abnormal type I collagen underlies the tissue fragility in the heritable disease osteogenesis imperfecta (OI), though the specific mechanism remains ill-defined. The current study addressed the question of how an abnormal collagen-based matrix contributes to reduced bone strength in OI by comparing the material properties of mineralized and demineralized bone from the oim/oim mouse, a model of OI that contains homotrimeric (α13(I)) type I collagen, with the properties of bone from wildtype (+/+) mice. Femoral three-point bend tests combined with geometric analyses were conducted on intact (mineralized) 14-week-old oim/oim and +/+ mice. To investigate the bone matrix properties, tensile tests combined with geometric analyses were conducted on demineralized femora. The majority of the properties of the mineralized oim/oim bone were inferior to those of the +/+ bone, including greater brittleness (+78.6%) and lower toughness (–69.2%). In contrast, tensile measurements on the demineralized bone revealed no significant differences between the oim/oim and +/+ bone, indicating that the matrix itself was not brittle. These results support the concept that deficient material properties of the demineralized bone matrix itself are not the principal cause of the severe fragility in this model of OI. It is likely the abnormal collagen scaffold serves as a template for abnormal mineral deposition, resulting in an incompetent mineral-matrix interaction that contributes significantly to the inferior material properties of bone in oim/oim mice.

The Effect of Platelet-Rich Plasma on Muscle Contusion Healing in a Rat Model

Background: Current therapy for muscle contusions is usually limited to nonsteroidal anti-inflammatory drugs and/or use of the RICE principle (rest, ice, compression, elevation); thus, other forms of treatment that can potentially accelerate the rate of healing are desirable. Hypotheses: A local injection of platelet-rich plasma (PRP) would lead to accelerated healing rates compared with controls; also, delayed administration of PRP would lead to a blunted response compared with immediate treatment. Study Design: Controlled laboratory study. Methods: Forty-six male Lewis rats each underwent a single blunt, nonpenetrating impact to the gastrocnemius muscle via a drop-mass technique and subsequently received either a single injection of saline into the area of injury immediately after injury (controls, n = 11) or rat PRP (either immediately after injury [PRP day 0, n = 12], the first day after injury [PRP day 1, n = 12], or the third day after injury [PRP day 3, n = 11]). The primary outcome was maximal isometric torque strength of the injured muscle, which was assessed before injury as well as on postinjury days 1, 4, 7, 10, and 14. All animals were sacrificed on postinjury day 15. Histological and immunohistochemical analyses were performed on 6 specimens from each group after sacrifice. Results: The mean platelet concentration in the PRP was 2.19 × 106 (±2.69 × 105)/μL. The mean white blood cell count in the PRP was 22.54 × 103/μL. Each group demonstrated statistically significant decreases in maximal isometric torque strength after injury when compared with preinjury levels, followed by significant increases back toward baseline values by postinjury day 14 (controls, 90.6% ± 7.90%; PRP day 0, 105.0% ± 7.60%; PRP day 1, 92.4% ± 7.60%; PRP day 3, 77.8% ± 7.90%) (P = .121). There were no statistically significant differences between the treatment and control groups at any of the time points. There were also no statistically significant differences between any of the groups in the percentage of centronucleated fibers (controls, 3.31% ± 5.10%; PRP day 0, 0.62% ± 1.59%; PRP day 1, 3.24% ± 5.77%; PRP day 3, 2.13% ± 3.26%) (P = .211) or the presence of inflammatory cells and macrophages. Conclusion: In this rat contusion model, a local injection of PRP into the injured gastrocnemius muscle resulted in no significant differences in functional or histological outcomes, indicating no likely benefit to healing. Additionally, there was no significant difference between immediate or delayed administration of PRP. Clinical Relevance: Before PRP can be recommended for the treatment of muscle contusion injuries, further translational and clinical investigations need to be performed.

Muscle Injuries in Athletes: Enhancing Recovery Through Scientific Understanding and Novel Therapies

Context: Muscle injuries are extremely common in athletes and often produce pain, dysfunction, and the inability to return to practice or competition. Appropriate diagnosis and management can optimize recovery and minimize time to return to play. Evidence Acquisition: Contemporary papers, both basic science and clinical medicine, that investigate muscle healing were reviewed. A Medline/PubMed search inclusive of years 1948 to 2012 was performed. Results: Diagnosis can usually be made according to history and physical examination for most injuries. Although data are limited, initial conservative management emphasizing the RICE principles and immobilization of the extremity for several days for higher grade injuries are typically all that is required. Injection of corticosteroids may clinically enhance function after an acute muscle strain. Additional adjunctive treatments (nonsteroidal anti-inflammatory drugs, platelet-rich plasma, and others) to enhance muscle healing and limit scar formation show promise but need additional data to better define their roles. Conclusion: Conservative treatment recommendations will typically lead to successful outcomes after a muscle injury. There is limited evidence to support most adjunctive treatments.

The management of anterior glenohumeral instability with and without bone loss: AAOS exhibit selection.

Anterior glenohumeral instability is a common clinical entity with a reported prevalence of 2%1,2. Although the Bankart lesion, or anterior labral detachment, is the most commonly recognized pathologic lesion of traumatic anterior instability, associated osseous deficiencies are also common, particularly in patients with recurrent instability or those with unsuccessful surgical stabilization. Osseous lesions may be present in up to 89% of failed stabilizations3. In this review, we will provide a brief overview of anterior shoulder instability and discuss the implications of bone deficiency in recurrent shoulder instability. Given the increased recognition of these lesions and their contribution to glenohumeral instability, we highlight current treatment considerations relevant to diagnosis, quantification, and preoperative evaluation. Finally, we review the prevailing treatment options to address traumatic anterior glenohumeral instability with and without bone loss. ### Static Stabilizers The biomechanics of the glenohumeral joint are unique, allowing a very large arc of motion with little osseous constraint. Careful coordination of both static and dynamic stabilizers is necessary to maintain the humeral head on the glenoid surface. Important static restraints include the labrum, glenohumeral ligaments, rotator cuff interval, and glenohumeral articulation. The matching radii of curvature of the humeral head and the glenoid provide 25% to 30% surface contact4. The circumferential labrum serves to deepen the glenoid by 50%5. Overall, anteroposterior stability is increased by 20% by the functioning of the labrum6. For this reason, substantial loss of, or injury to, the anterior labrum can produce clinically important instability7. The glenohumeral ligament complex includes the superior glenohumeral ligament, middle glenohumeral ligament, and anterior and posterior bands of the inferior glenohumeral ligament. These ligaments act synergistically to stabilize the shoulder joint, especially at the end range of shoulder motion8. The superior glenohumeral ligament and …

Role of fatty infiltration in the pathophysiology and outcomes of rotator cuff tears

Rotator cuff (RC) pathology is a common and challenging musculoskeletal condition to manage. The prevalence of RC tears is estimated between 15% and 51%, with higher rates at age 50 years (1). While RC repair is an effective procedure for relieving pain and improving function, high retear and/or failure-to-heal rates persist despite technical improvements. Furthermore, poorer outcomes are associated with failures and recurrent defects compared to intact repairs, although some tears are painless and associated with good function (2). RC tendon research has primarily focused on changes at the tendon–bone interface. However, muscle physiology may require greater understanding, as the presence of fatty infiltration (FI) of the muscle following tears is also likely to influence the mechanics and biologic milieu of the RC tendons, and may predict and/or affect the results of RC repair. Fatty muscle infiltration influences several clinical parameters, as it is associated with higher failure rates and loss of muscle strength (3). Preoperative assessment of FI of any of the RC muscles, in addition to tear size and degree of retraction, may play an increasing role in planning surgical management and for counseling patient expectation. Both partialand full-thickness RC tears are associated with increased FI, which has been shown to be more extensive in larger tears (4). This review explores the prevalence, pathophysiology, and clinical implications of fatty changes of the RC. Muscle atrophy is an important related topic, but beyond the scope of this review. Pathophysiology of FI

Peripheral nerve injuries in sports-related surgery: presentation, evaluation, and management: AAOS exhibit selection.

Peripheral nerve injuries during sports-related operative interventions are rare complications, but the associated morbidity can be substantial. Early diagnosis, efficient and effective evaluation, and appropriate management are crucial to maximizing the prognosis, and a clear and structured algorithm is therefore required. We describe the surgical conditions and interventions that are commonly associated with intraoperative peripheral nerve injuries. In addition, we review the common postoperative presentations of patients with these injuries as well as the anatomic structures that are directly injured or associated with these injuries during the operation. Some examples of peripheral nerve injuries incurred during sports-related surgery include ulnar nerve injury during ulnar collateral ligament reconstruction of the elbow and elbow arthroscopy, median nerve injury during ulnar collateral ligament reconstruction of the elbow, axillary nerve injury during Bankart repair and the Bristow transfer, and peroneal nerve injury during posterolateral corner reconstruction of the knee and arthroscopic lateral meniscal repair. We also detail the clinical and radiographic evaluation of these patients, including the utility and timing of radiographs, magnetic resonance imaging (MRI), ultrasonography, electromyography (EMG), and nonoperative or operative management. The diagnosis, evaluation, and management of peripheral nerve injuries incurred during sports-related surgical interventions are critical to minimizing patient morbidity and maximizing postoperative function. Although these injuries occur during a variety of procedures, common themes exist regarding evaluation techniques and treatment algorithms. Nonoperative treatment includes physical therapy and medical management. Operative treatments include neurolysis, transposition, neurorrhaphy, nerve transfer, and tendon transfer. This article provides orthopaedic surgeons with a simplified, literature-based algorithm for evaluation and management of peripheral nerve injuries associated with sports-related operative procedures.

Meniscectomy of the sternoclavicular joint: A report of two cases

The sternoclavicular joint (SCJ) is the only true articulation between the axial and appendicular skeleton. It is a saddle-type, diarthrodial joint where less than half of the clavicle articulates with the sternum; sprains, fractures, or dislocations, especially from indirect forces, are often attributed to this relatively bony incongruity. Its location close to the center of the body and its strong ligamentous restraints, however, limit the frequency of injury to this joint. Biomechanically, the SCJ is characterized by approximately 30 to 35 of forward elevation and 35 of flexion/extension during normal shoulder range of motion (ROM), with 4 of sternoclavicular motion for every 10 of shoulder elevation. Although injuries to the SCJ are rare, they can sometimes result in chronic pain and instability. Traumatic SCJ dislocation is most frequent after motor vehicle collision or sports-related injury, and it has been associated with chronic disability that may require operative intervention. Spontaneous dislocation has also been known to occur, though less frequently, in patients with generalized ligamentous laxity or congenital deformity. Injuries to the SCJ intra-articular disk (meniscal homologue) are common after trauma and may also play a role in chronic SCJ symptomatology. A recent magnetic resonance imaging (MRI) study from our institution found that 80% of patients with SCJ pain due to trauma had intra-articular disk injuries. The intra-articular disk has been described as

Arthroscopic Subscapularis Bankart Technique as a Salvage Procedure for Failed Anterior Shoulder Stabilization

BackgroundShoulder instability is a relatively common problem. Even with contemporary surgical techniques, instability can recur following both open and arthroscopic fixation. Surgical management of capsular insufficiency in anterior shoulder stabilization represents a significant challenge, particularly in young, active patients. There are a limited number of surgical treatment options. The Laterjet technique can present with a number of intraoperative challenges and postoperative complication.Description of TechniqueWe report an arthroscopic subscapularis tenodesis technique as a salvage procedure for challenging glenohumeral instability cases. Sutures are passed through the subscapularis tendon and capsule before they are tied as one in the subdeltoid psace. The rotator interval is closed with superior and medial advancement of anterior and inferior tissue. This technical note carefully describes this procedure with useful technical tips, illustrations, and diagrams.Patients and MethodsTwo clinical cases are described involving patients with recurrent instability following failed surgery who were successfully managed with this procedure.ResultsBoth cases described resulted in improved shoulder stability, range of motion, and function following management with this surgical technique. This arthroscopic subscapularis tenodesis procedure is proposed as a useful alternative repair technique for cases of recurrent instability after failed surgery with isolated capsular insufficiency.ConclusionIt is believed that this arthroscopic subscapularis tenodesis technique can potentially provide similar outcomes to open bone block stabilization procedures, while reducing the risks associated with those procedures.