John D. MacGillivray

Biomechanical evaluation of arthroscopic rotator cuff stitches

BACKGROUND The suture configurations in arthroscopic rotator cuff repairs have been limited to simple and horizontal stitches. Recent objective evaluations have demonstrated high failure rates of arthroscopic repairs of rotator cuff tears. A novel stitch for arthroscopic repair of the rotator cuff, the massive cuff stitch, was developed to increase the strength of the suture-tendon interface. The goal of this study was to determine the biomechanical properties of the massive cuff stitch and to compare it with other stitches commonly used for rotator cuff repair. METHODS Eight pairs of sheep infraspinatus tendons were harvested and split in half to yield a set of four tendon specimens from each animal. Four stitch configurations (simple, horizontal, massive cuff, and modified Mason-Allen) were randomized and biomechanically tested in each set of tendon specimens. Each specimen was first cyclically loaded on an MTS uniaxial load frame under force control from 5 to 30 N at 0.25 Hz for twenty cycles. Each specimen was then loaded to failure under displacement control at a rate of 1 mm/sec. Cyclic elongation, peak-to-peak displacement, ultimate tensile load, and stiffness were measured with use of an optical motion analysis system and load-cell output. The type of failure (suture breakage or pull-out) was also recorded. A repeated-measures analysis of variance was performed on the results, with the alpha level of significance set at p < 0.05. RESULTS There was no difference in cyclic elongation or peak-to-peak displacement among the four stitches. Ultimate tensile load was significantly higher (p < 0.05) for the massive cuff stitch (233 +/- 40 N) and the modified Mason-Allen stitch (246 +/- 40 N) than it was for either the simple stitch (72 +/- 18 N) or the horizontal stitch (77 +/- 15 N). There was no significant difference in the ultimate load between the massive cuff and modified Mason-Allen stitches. There was also no difference in stiffness among the four stitches. The simple and horizontal stitches failed by tissue pull-out, whereas the massive cuff and Mason-Allen stitches failed by a mixture of suture breakage and pull-out. CONCLUSIONS The massive cuff stitch provides strength comparable with that of the modified Mason-Allen stitch commonly used in open rotator cuff repair. The ultimate tensile load before failure of the massive cuff stitch was significantly higher (p < 0.05) than that of the simple and horizontal stitches.

Management of proximal humeral fractures based on current literature

Proximal humeral fractures are the second most common upper-extremity fracture and the third most common fracture, after hip fractures and distal radial fractures, in patients who are older than sixty-five years of age1. Although the overwhelming majority of proximal humeral fractures are either nondisplaced or minimally displaced and can be treated with sling immobilization and physical therapy, approximately 20% of displaced proximal humeral fractures may benefit from operative treatment. Many surgical techniques have been described, but no single approach is considered to be the standard of care. Surgeons who treat proximal humeral fractures should be able to identify the fracture pattern and select an appropriate treatment on the basis of this pattern and the underlying quality of the bone. Orthopaedic surgeons should have experience with a broad range of techniques, including transosseous suture fixation, closed reduction and percutaneous fixation, open reduction and internal fixation with conventional and locked-plate fixation, and hemiarthroplasty. In the future, locked-plate technology and the use of osteobiologics may play an increasingly important role in the treatment of displaced proximal humeral fractures, facilitating preservation of the humeral head in appropriately selected patients. The goals of this article are to enable the reader to: (1) become familiar with the recent literature on the classification of and treatment options for proximal humeral fractures, and (2) better identify fracture characteristics and devise an appropriate treatment plan. ### Transosseous Suture Fixation #### Surgical Technique Park et al.2 described different operative approaches for each fracture pattern described by Neer 3. For two-part greater tuberosity fractures, an anterosuperior approach along the Langer lines extending from the lateral aspect of the acromion toward the lateral tip of the coracoid is used. The split occurs in the anterolateral raphe and allows exposure of the displaced greater tuberosity fracture. When a surgical neck fracture exists, Park et al.2 …

Rotator Cuff Degeneration: Etiology and Pathogenesis

By virtue of its anatomy and function, the rotator cuff is vulnerable to considerable morbidity, often necessitating surgical intervention. How we intervene is governed by our understanding of the pathological mechanisms in cuff disease. These factors can be divided into those extrinsic to the rotator cuff (impingement, demographic factors) and those intrinsic to the cuff (age-related degeneration, hypovascularity, inflammation, and oxidative stress, among others). In an era where biologic interventions are increasingly being investigated, our understanding of these mechanisms is likely to become more important in designing effective new interventions. Here we present a literature review summarizing our current understanding of the pathophysiological mechanisms underlying rotator cuff degeneration.

Rotator cuff repair augmentation using a novel polycarbonate polyurethane patch: preliminary results at 12 months’ follow-up

BACKGROUND Preventing anatomic failure after rotator cuff repair (RCR) remains a challenge. Augmentation with a surgical mesh may permanently reinforce the repair and decrease failure rates. The purpose of this study is to assess the postoperative outcomes of open RCR augmented with a novel reticulated polycarbonate polyurethane patch. MATERIALS AND METHODS Ten patients with supraspinatus tendon tears underwent open RCR augmented with a polycarbonate polyurethane patch secured in a 6-point fixation construct placed over the repaired tendon. Patients were evaluated with preoperative and postoperative outcome measures, including the Simple Shoulder Test, visual analog pain scale, American Shoulder and Elbow Surgeons shoulder score, Cumulative Activities of Daily Living score, and University of California, Los Angeles shoulder scale, as well as range of motion. Postoperative magnetic resonance imaging was used to evaluate repair status. RESULTS Patients showed significant improvements in visual analog pain scale, Simple Shoulder Test, and American Shoulder and Elbow Surgeons shoulder scores at both 6 and 12 months postoperatively (P < .05 and P < .01, respectively). The University of California, Los Angeles postoperative score was good to excellent in 7 patients at 6 months and in 8 patients at 12 months. Range of motion in forward flexion, abduction, internal rotation, and external rotation was significantly improved at both 6 and 12 months postoperatively (P < .05 and P < .01, respectively). Magnetic resonance imaging at 12 months showed healing in 90%; one patient had a definitive persistent tear. We found no adverse events associated with the patch, including the absence of fibrosis, mechanical symptoms, or visible subacromial adhesions. DISCUSSION The polycarbonate polyurethane patch was designed to support tissue in growth and enhance healing as shown by preclinical animal studies. Clinically, the patch is well tolerated and shows promising efficacy, with a 10% retear rate at the 12-month time point.

Systematic review of arthroscopic rotator cuff repair and mini-open rotator cuff repair.

Rotator cuff repair is one of the most common surgical procedures performed in the shoulder, and the benefit of repair is well known1-5. Over the past decade, the treatment of rotator cuff tears has evolved from an open procedure to an arthroscopic-assisted (mini-open) technique to an all-arthroscopic technique. Traditional open rotator cuff repairs produce satisfactory results when used for the treatment of nonmassive tears (<5 cm). However, this procedure has been associated with morbidity such as severe early postoperative pain, deltoid detachment and/or weakness, and arthrofibrosis6-8. Mini-open repairs were developed because they had the potential advantage of less deltoid morbidity, and they have demonstrated results that have been similar to those of open repairs (Figs. 1-A through 1-D)9-14. With recent advances in arthroscopic techniques, many surgeons are now performing complete arthroscopic repairs. The potential advantages of this procedure include less pain, more rapid rehabilitation, the ability to treat intra-articular lesions, smaller skin incisions, less soft-tissue dissection, and an extremely low risk of deltoid detachment (Figs. 2-A through 2-E). In the short and long term, the arthroscopic approach has shown promising results3,7,15-27. Despite these advantages, the use of the complete arthroscopic repair is technically demanding and requires a large-volume practice in order for a surgeon to obtain proficiency in this procedure28. Because of the technical demands of this procedure, many orthopaedic surgeons still consider the mini-open repair to be the gold standard for rotator cuff repair29. We hypothesized that arthroscopic rotator cuff repair produces clinical results comparable with those of mini-open rotator cuff repair, with fewer complications. In order to compare the mini-open and all-arthroscopic techniques, we performed a qualitative systematic review with use of a …

Innovations in the Management of Displaced Proximal Humerus Fractures

Abstract The management of displaced proximal humerus fractures has evolved toward humeral head preservation, with treatment decisions based on careful assessment of vascular status, bone quality, fracture pattern, degree of displacement, and patient age and activity level. The AO/ASIF fracture classification is helpful in guiding treatment and in stratifying the risk for associated disruption of the humeral head blood supply. Nonsurgical treatment consists of sling immobilization. For patients requiring surgery, options include closed reduction and percutaneous fixation; transosseous suture fixation; open reduction and internal fixation, with either conventional or locking plate fixation; bone graft; and hemiarthroplasty. Proximal humerus fractures must be evaluated on an individual basis, with treatment tailored according to patient and fracture characteristics.

Anterior cruciate ligament reconstruction with allograft tendons

Allograft tissue allows reconstruction of the ACL without the donor site morbidity that can be caused by autograft harvesting. Patients who must kneel as a part of their occupation or chosen sport are particularly good candidates for allograft reconstruction. Patients over 45 years of age and those requiring revision ACL surgery can also benefit from the use and availability of allograft tendons. In some cases, patients or surgeons may opt for allograft tendons to maximize the result or morbidity ratio. Despite advances in cadaver screening and graft preparation, there remain risks of disease transmission and joint infection after allograft implantation. Detailed explanation and informed consent is vitally important in cases in which allograft tissue is used.

Multiplanar Analysis of Acromion Morphology

To more completely describe acromion morphology and its relationship to impingement syndrome, we performed three-dimensional magnetic resonance imaging (N 111) or computed tomography (N 27) on 132 symptomatic shoulders. The mean patient age was 46.2 years (range, 14 to 86). Four parameters were evaluated: the angle of anterior slope of the acromion in the midsagittal and lateral-sagittal planes, lateral acromial angulation in the coronal plane, and the presence or absence of medial encroachment in the acromioclavicular joint. Twenty-five asymptomatic, age-matched shoulders were used as controls. All imaging data were combined because no significant differences existed between the two imaging techniques. The mean acromion angle was 19.4° in the midsagittal plane and 20° in the lateral-sagittal plane. In the coronal plane, 97 (73%) acromions were neutral and 35 (27%) were downward sloping. Medial encroachment was present in 31 (24%) shoulders. Age distribution from the 2nd to 8th decade demonstrated a consistent and gradual transition from a flat acromion in the younger decades to a more hooked acromion in the older decades that was significant in both the midsagittal and lateral-sagittal planes. Furthermore, a greater percentage of patients were found to have downward angulating acromions with increasing age. Ninety-eight patients (74%) had stage II or III impingement. Of these shoulders, 39 (40%) had type I acromions, 51 (52%) type II, and 8 (8%) type III. Twenty-eight of 33 acromions with coronal lateral downward sloping had impingement, and all 31 shoulders with medial encroachment had impingement.

Traumatic shoulder dislocation in the adolescent athlete: advances in surgical treatment

Purpose of review The shoulder joint has the greatest range of motion of any joint in the body and as a result is particularly susceptible to dislocation and subluxation. Recurrent instability is a common complication after traumatic shoulder dislocation in young people, with rates as high as 100% in skeletally immature patients and 96% in for adolescents. Treatment for shoulder dislocation has traditionally involved immobilization followed by a rehabilitation program. Recent studies have reported decreased rates of recurrent instability and improved outcomes in patients treated with surgical stabilization of acute, traumatic shoulder dislocation. The purpose of this review is to review recent publications concerning the treatment of traumatic shoulder dislocations in adolescents. Recent findings Lawton et al. retrospectively reviewed 70 shoulders in 66 patients 16 years old or younger treated for shoulder instability with follow-up more than 2 years. Forty-two shoulders were successfully treated with physical therapy, whereas 28 eventually required surgery. Subsequently, Deitch et al. retrospectively identified 32 patients between 11 and 18 years of age with radiographically documented traumatic anterior shoulder dislocation. Instability recurred in 75% of patients and 50% eventually required surgical stabilization. Bottoni et al. reported results of a prospective randomized trial comparing arthroscopic stabilization to nonoperative treatment of acute, traumatic shoulder dislocations in patients aged 18 to 26 years. Recurrent instability developed in 75% of patients treated conservatively versus 11% in those treated with surgery. DeBerardino et al. prospectively evaluated arthroscopic stabilization of acute shoulder dislocations in 48 young athletes with an average follow-up of 37 months and reported a 12% rate of recurrent instability. All patients with stable shoulders were able to return to their previous levels of activity. Summary Conservative management of traumatic shoulder dislocations in young patients is associated with high rates of recurrent instability. Recent studies have demonstrated improved results and significant reduction in recurrent instability in patients treated with surgical stabilization when compared with nonoperative treatment.

Biomechanical Analysis of an Ovine Rotator Cuff Repair via Porous Patch Augmentation in a Chronic Rupture Model

Background Rotator cuff repair is a commonly performed procedure, but many of these repairs fail in the postoperative term. Despite advances in surgical methods to optimize the repair, failure rates still persist clinically, thereby suggesting the need for novel mechanical or biological augmentation strategies. Nonresorbable implants provide an appealing approach because patch materials may confer acute mechanical stability and act as a conductive scaffold for tissue ingrowth at the site of the tendon insertion. Hypothesis The polyurethane scaffold mesh will confer greater biomechanical function relative to a nonaugmented repair after 12 weeks in vivo using a chronic ovine model of rotator cuff repair. Study Design Controlled laboratory study. Methods After development of the chronic rupture model, the tensile failure properties of the nonresorbable mesh-augmented repair (n, 9) were compared with those of a surgical control in an ovine model (n, 8). Results Rotator cuff repair with the scaffold mesh in the chronic model resulted in a significant 74.2% increase in force at failure relative to the nonaugmented surgical control (P = .021). Apparent increases in stiffness (55.4%) and global displacement at failure (21.4%) in the mesh-augmented group relative to nonaugmented controls were not significant (P = .126 and P = .123, respectively). At the study endpoint, the augmented shoulders recovered 37.8% and 40.7% of the force at failure and stiffness, respectively, of intact, nonoperated controls. Conclusion Using the previously described chronic rupture model, this study demonstrated that repair of a chronic tendon tear with the polyurethane scaffold mesh provides greater mechanical strength in the critical healing period than that of traditional suture anchor repair. Clinical Relevance This device could be used to enhance the surgical repair of the rotator cuff and consequently improve long-term clinical outcome.