Thesis (doctoral)--Freie Universität Berlin, 1979.

Humeral fractures in veterinary patients are challenging to stabilize. This study is a biomechanical in vitro comparison of the performance of two locking plate constructs used to stabilize a canine distal humeral metaphyseal gap model. Two groups of canine cadaveric humeri were prepared. One group consisted of a unilateral medially placed locking plate (UNI). The second group consisted of bilateral locking plates (BI). Constructs were tested in torsion and axial compression. The UNI constructs had significantly lower stiffness in torsion and axial compression than the BI group. However, UNI constructs had a significantly higher ultimate strength than BI constructs. All UNI constructs failed by bending of the transcondylar screw and SOP plate. All BI constructs failed by axial pullout of the distal most screws. The clinical significance is that in stabilizing canine supracondylar humeral fractures as modeled here, both the UNI model and the BI model demonstrated biomechanical advantages.

No description available.

This dissertation discusses distal humeral epiphyseal injuries in children, i.e. lateral condylar fractures, medial condylar fractures, fracture-separation of the distal humeral epiphysis and T-condylar fractures. Medial and lateral epicondylar fractures, being apophyseal, are excluded. The research was done at the Red Cross Children's Hospital Trauma Unit. It was based on two clinical retrospective studies and one case report: a: 60 lateral condylar fractures presenting from 1984 to 1987 -were reviewed. b: 12 fracture-separations of the distal humeral epiphysis presenting from 1984 to 1989 were reviewed. c: One case report of a medial condylar fracture with associated elbow dislocation The distal humeral epiphysis is the second most commonly injured epiphysis in the body, after that of the distal radius (Peterson 1972). Supracondylar fractures are the most common fractures around the elbow in children, making up 65% of the total (Canale 1987). Lateral condyle fractures have an incidence of 17.4%, compared to 3.2% for medial condylar fractures and 0.8% for T-condylar fractures (Canale 1987). At the Red Cross Children's Hospital, 60 displaced supracondylar fractures, 20 lateral condylar fractures and 2 to 3 fracture-separations of the distal humeral epiphysis are seen every year. Medial condylar fractures are rare.

Fractures of proximal humerus and humeral shaft are two clinical problems that have many differences and different treatment. The aim was to compare these differences in a retrospective epidemiological study. At the beginning is an overview of anatomy, classification and treatment of humerus fractures. The point of the study was the evidence of patients, who were treated in Orthopedic - traumatological clinic of FNKV. In years 2000-2008 there were 1891 patients treated for proximal humerus fracture and 223 patients treated for humeral shaft fracture. The result of the work is an overview of incidence, sex and average age of the monitored patients, Neer's and AO classification overview and comparison of surgical and conservative treatment and the progression in time.

Background: Baseball players exhibit a more posteriorly oriented humeral head or humeral retrotorsion (HRT) in the dominant arm, likely representing an adaptive response to the stress of throwing. This adaptation is thought to occur while skeletally immature, however there is limited research detailing how throwing while young influences the development HRT. In addition, it is currently unclear how this changing osseous orientation influences shoulder motion within young athletes. Purpose: To determine the influence of throwing and age on the development of asymmetry in HRT and shoulder range of motion (ROM); and analyze the relationship between HRT and ROM. Study Design: Cross-sectional age matched study Methods: Healthy athletes (8-14 years-old) were categorized into two groups based upon sports participation; throwing group (n=85) and non-throwing group (n=68). Bilateral measurements of HRT, shoulder external (ER), internal rotation (IR) and total range of motion (TROM) at 90° were performed using diagnostic ultrasound and digital inclinometer. A two-way analysis of variance was performed with throwing status (yes/no) and age group (youth (8-10.5), junior (10.51-12) and senior (12.01-13.99)) as primary factors. Dependent variables were asymmetry (dominant-non-dominant) in HRT,ER, IR and TROM. The relationship between ROM and HRT was analyzed using Pearson correlation coefficients. Results: Throwing athletes demonstrated a larger degree of HRT on the dominant side, resulting in greater asymmetry (8.7° versus 4.6°). Throwing athletes demonstrated a gain of ER (5.2°), a loss of IR (6.0°) and no change in TROM when compared to the non-dominant shoulder. Pairwise comparisons identified altered HRT and shoulder ROM in all age groups of throwers. A significant but weak relationship between HRT and shoulder ROM existed. Conclusion: Throwing causes adaptive changes in HRT and shoulder ROM in youth baseball players at a very young age. Other factors in addition to HRT influence shoulder motion within this population. Clinical Relevance: In baseball players, an altered arc of motion can be expected at a young age. This adaptation is in part due to changes in osseous structures, however a larger component of change is likely due to other factors.

M.Med., Orthopaedic Surgery, Faculty of Health Sciences, University of the Witwatersrand, 2010

Undesirable work factors, such as awkward upper body postures and repetitive arm motion, in the workplace can lead to upper extremity pain. Research suggests that these work-related factors, and subsequent rotator cuff fatigue, may cause the subacromial space (the space between the inferior acromion surface and superior humerus) of the shoulder to decrease. Reducing this space can create impingement of the interposed tissues, which causes shoulder pain. The aim of this study was to examine superior humeral head excursion and changes in the width of the subacromial space (acromio-humeral interval) after fatiguing the rotator cuff musculature. Four anterior-posterior radiographs of the glenohumeral joint at arm abduction angles of 0˚, 45˚, 90˚ and 135˚ were taken before and after a fatiguing task. The fatiguing task was a simulated job task requiring shoulder flexion/abduction and internal/external rotation, with the intention of exhausting the entire rotator cuff. The position of the humeral head with respect to the glenoid cavity was significantly affected both by arm angle and fatigue state; the mean humeral superior excursion following fatigue was 0.63±1.76mm. In the pre-fatigued state, increasing arm angle was related to superior translation until 90˚, after which the humeral head moved inferiorly to a more central position. In the post-fatigued state, the inability of the rotator cuff to centralize the humeral head led to increasing translations with higher elevations. Although the magnitude of translation in this study was smaller than seen in patients with rotator cuff tears, continuous overhead work demonstrably created rotator cuff fatigue, which apparently inhibited the ability of the shoulder musculature to resist upward translation of the humerus. Therefore, jobs that require overhead and repetitive work arguably put the worker at greater risk for superior translation of the humerus and subsequent related tissue damage.

Undesirable work factors, such as awkward upper body postures and repetitive arm motion, in the workplace can lead to upper extremity pain. Research suggests that these work-related factors, and subsequent rotator cuff fatigue, may cause the subacromial space (the space between the inferior acromion surface and superior humerus) of the shoulder to decrease. Reducing this space can create impingement of the interposed tissues, which causes shoulder pain. The aim of this study was to examine superior humeral head excursion and changes in the width of the subacromial space (acromio-humeral interval) after fatiguing the rotator cuff musculature. Four anterior-posterior radiographs of the glenohumeral joint at arm abduction angles of 0˚, 45˚, 90˚ and 135˚ were taken before and after a fatiguing task. The fatiguing task was a simulated job task requiring shoulder flexion/abduction and internal/external rotation, with the intention of exhausting the entire rotator cuff. The position of the humeral head with respect to the glenoid cavity was significantly affected both by arm angle and fatigue state; the mean humeral superior excursion following fatigue was 0.63±1.76mm. In the pre-fatigued state, increasing arm angle was related to superior translation until 90˚, after which the humeral head moved inferiorly to a more central position. In the post-fatigued state, the inability of the rotator cuff to centralize the humeral head led to increasing translations with higher elevations. Although the magnitude of translation in this study was smaller than seen in patients with rotator cuff tears, continuous overhead work demonstrably created rotator cuff fatigue, which apparently inhibited the ability of the shoulder musculature to resist upward translation of the humerus. Therefore, jobs that require overhead and repetitive work arguably put the worker at greater risk for superior translation of the humerus and subsequent related tissue damage.

No description available.