Morrey, B.F.

Abstract The stress environment of the extracellular matrix of the supraspinatus tendon, including the stress distribution and concentration, was evaluated by using a finite element model. Stress riser was found around the insertion at the articular side of the tendon. Compressive and shear stresses were observed at the articular side which corresponded to the region associated with fibrocartilaginous matrix. This area corresponded well with the critical zone of potential tear observed clinically.

Diabetic foot ulcers (DFUs) are common complications of suboptimally controlled diabetes, characterised by non-healing, high morbidity, infection, recurrence (40–50%) and mortality. Ultrasonic debridement technology has been used for >30 years to treat cataracts safely and effectively, and animal studies have suggested that ultrasound debridement stimulates collagen turnover. This technology was applied in developing a system for soft tissue removal in tendons and elsewhere, with intended use in the elbow, knee, ankle, foot and shoulder. It was then modified for the treatment of DFUs. In this study, the rationale behind using this technology is discussed, the procedural technique is described, and photographic examples of treatment outcomes presented.

Abstract An efficient 2-D continuum finite element method (FEM), including the rigid body algorithm and our previously developed contact element, was formulated for the contact stress analysis of articular joints. This FEM can calculate the contact pressure distribution on articular surfaces and stress distribution inside of cartilage. This method can model geometric and material nonlinearities for both the static and dynamic situations. The major advantage of this method is that only the soft cartilage requires finite element (FE) mesh, while the bony structure can be modeled as a rigid body due to its relatively rigid nature. Since much less degrees of freedom are now required in FEM, much faster computing speed can be achieved.

Abstract The prevalence of rotator cuff disease among the elderly population and the greatest incidence of acute dislocations will continue to provide challenging patient management decisions. Stability of the shoulder is critical to successful upper extremity function. The GH joint is stabilized by passive capsuloligamentous restraints as well as by active dynamic stabilizers through concavity compression. The compression of the convex humeral head (HH) into the concave glenoid fossa (GF) counteracts against translational shear forces (Matsen et. al 1994). The major compressive load across the joint is provided by the action of the surrounding musculature, especially the rotator cuff. The muscles may generate both compressive and shear force components as well as moments. The purpose of this study is to describe a new testing methodology of how to estimate the contribution of individual rotator cuff muscles to the dynamic stability of the GH joint at a given joint position.

Background: In a study from our institution, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon for recalcitrant lateral elbow tendinopathy showed excellent safety profiles, high tolerability, efficiency, sustained pain relief, functional improvement, and sonographic evidence of tissue healing in 20 patients at 3 years’ follow-up. Purpose: To explore the long-term clinical and sonographic results of ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon. Study Design: Case series; Level of evidence, 4. Methods: The same cohort of 20 patients was recalled after 7 years, and visual analog scale (VAS) for pain and Disabilities of the Arm, Shoulder and Hand (DASH) scores, need for secondary intervention, and overall satisfaction were assessed. They were also reassessed using ultrasound imaging of the brevis and the common extensor tendon to evaluate tendon hypervascularity, tendon thickness, and the progress or the recurrence of the hypoechoic scar tissue. Results: We successfully scored 19 patients and performed ultrasound on 16 patients with a median follow-up of 90 months (range, 86-102 months). There were no adverse outcomes and satisfaction remained at 100% (6 patients, satisfied; 13 patients, very satisfied). No patient developed a recurrence of symptoms and signs of lateral elbow tendinopathy, and therefore no secondary intervention was required. The improvement from baseline and early term scores was sustained ( P < .001 for all). At 90 months, there was a significant improvement in VAS scores and DASH–Compulsory scores compared with preprocedure scores and all follow-up times until 3 months. There was no difference in VAS scores and DASH–Compulsory scores at 90 months compared with 6 and 36 months. For DASH–Work scores, there was a significant improvement at 90 months compared with preprocedure scores, but there was no difference between DASH–Work scores at 90 months and scores at all other points of follow-up. At 90 months, hypervascularity remained resolved in 79% of patients, while all patients had reduced tendon swelling and sustained resolution or reduction of the hypoechoic lesion. Conclusion: At the long-term follow-up of 90 months, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon, previously shown to enhance recovery of lateral elbow tendinopathy, demonstrated good durability of pain relief and functional recovery that was previously achieved. This was accompanied by sustained sonographic tissue healing with no significant deterioration.

Abstract Guidelines for using finite element to model cortical defects were established by determining the consequences for solution accuracy of various modeling strategies. Solution accuracy was established by comparing finite element results to an existing experimental benchmark for the torsion of circular tubes that contained transverse through circular holes. A new automated modeling approach was developed that could be used to support clinical modeling of cortical defects.

Background Despite good reported outcomes with open reduction and internal fixation of intra-articular distal humerus fractures, complication rates remain high. The objective of this work is to identify factors associated with reoperation. Methods Sixty-three patients treated with open reduction and internal fixation for intra-articular ( Arbeitsgemeinschaft für Osteosynthesefragen type C) distal humerus fractures between 2004 and 2010 were identified using an institutional trauma registry, 62 of which were followed for a minimum of six months. Age, gender, fracture subclassification, open fracture presence, Injury Severity Score, time to definitive surgery, length of postoperative immobilization, and type of approach were recorded. Multivariate analysis was utilized to identify factors independently associated with reoperation. Results Complications requiring reoperation developed in 25 (40.3%) elbows. The most common reasons were wound dehiscence or infection in nine elbows (14.5%) and symptomatic hardware in six (9.6%). During multivariate analysis, only olecranon osteotomy remained an independent predictor for reoperation ( P = 0.043). Discussion Despite improved internal fixation techniques, a high proportion of elbows require reoperation after open reduction and internal fixation for distal humerus fractures. Higher complication rates in fractures fixed through an olecranon osteotomy may reflect additional reoperations due to nonunion of the osteotomy or need to remove hardware from the ulna. Level of evidence Prognostic Level III.

Posttraumatic elbow arthritis presents a difficult problem in young patients. Total elbow arthroplasty may not be suited to the functional demands placed on the prosthesis in younger, more active individuals. Interposition arthroplasty is a useful nonprosthetic alternative in these patients. Various biologic materials have been employed as an interpositional graft, with Achilles tendon allograft being the preferred material. Successful outcomes have been reported in 26% to 94% cases, with the best results in patients with posttraumatic arthritis with stiffness and no underlying instability. Poor prognostic factors associated with this procedure include malalignment and pre- and postoperative instability. Use of a hinged-distraction device to allow immediate postoperative range of motion while protecting the graft may further improve results. In those patients where postoperative instability occurs or where results deteriorate with time, stability and pain relief can be salvaged by conversion to a semiconstrained total elbow arthroplasty.

We describe the intermediate results of lateral ligamentous repair or reconstruction for posterolateral rotatory instability of the elbow. Between 1986 and 1999, we performed 12 direct repairs and 33 ligament reconstructions with a tendon autograft. One patient was lost to follow-up and 44 were retrospectively studied at a mean of six years (2 to 15).Surgery restored stability in all except five patients. In two the elbow became stable after a second procedure. The mean post-operative Mayo elbow performance score was 85 points (60 to 100). The result was classified as excellent in 19, good in 13, fair in seven and poor in five patients. Thirty-eight patients (86%) were subjectively satisfied with the outcome of the operation. Better results were obtained in patients with a post-traumatic aetiology (p = 0.03), those with subjective symptoms of instability at presentation (p = 0.006) and those who had an augmented reconstruction using a tendon graft (p = 0.04).Reconstruction using a tendon graft seems to provide better results than ligament repair and the results do not seem to deteriorate with time. The outcome of this procedure is less predictable in patients with no subjective instability.