The Relationship of Olecranon Apophyseal Ossification and Sanders Hand Scores with the Timing of Peak Height Velocity in Adolescents.

BACKGROUND: The onset of peak height velocity (PHV) guides the timing of interventions in the growing child. The purpose of the present study was to validate the Diméglio olecranon grading system and to compare these scores with the Risser/triradiate closure (TRC), proximal humerus, and Sanders hand scores. METHODS: Eighty children with annual serial radiographs were selected from the Bolton-Brush collection. The olecranon apophysis was graded with use of lateral radiographs of the elbow. The mean age to PHV was determined for each stage, and reliability was calculated with use of an intraclass correlation coefficient (ICC). Olecranon stage was combined with age, sex, and height in a generalized estimating equation (GEE) model to predict PHV. Predictive performance of this model was evaluated with use of tenfold cross-validation such that the model was trained on 90% of the radiographs and was asked to predict the PHV of the remaining 10%. RESULTS: PHV is closely associated with olecranon stage, with stage 1 occurring 3.0 years before PHV and stage 7 occurring 3.4 years after PHV. Stage 5 was found to occur at PHV. Scoring system reliability was high across an array of observers (ICC = 0.85 ± 0.07). The GEE model showed that this olecranon system outperforms the Risser/TRC system in predicting PHV and is comparable with the humerus and Sanders hand systems. When combined with age and sex, the olecranon system successfully predicted PHV such that 62% of PHV predictions were accurate within 6 months and 90% of PHV predictions were accurate within a year. CONCLUSIONS: Our data show that stage 5 occurs at PHV, contrary to previously published data. When combined with age and sex, the olecranon system successfully predicts PHV within a year in 90% of cases, establishing a single lateral view of the olecranon as a simple alternative to more complex grading systems. Last, we describe novel 3 variations in olecranon morphology and provide a guide for accurate olecranon staging. CLINICAL RELEVANCE: Understanding PHV is critical in the treatment of many pediatric orthopaedic disorders. The revised olecranon staging system will allow for more accurate determination of this variable.

The smartphone inclinometer: A new tool to determine elbow range of motion?

BACKGROUND: There are easily accessible tools on smartphones (APP) for measuring elbow range of motion (ROM). The purpose of this study is to evaluate the validity of a particular APP in determining elbow ROM in comparison with the commonly used goniometer (GON), surgeon estimation of range (EST) and measurement on X-ray (XR). METHODS: The study included 20 patients (40 elbows). Flexion, extension, pronation and supination were measured using three different methods: EST, GON and APP. Radiographic measurements were taken using the average humeral diaphysis axis and dorsal midthird of ulna in flexion and extension. RESULTS: The accuracy of the three different methods has been compared to GON using statistical analysis (ANOVA and paired samples test). There was no statistically significant difference for XR flexion measurement (mean of 2.8° ± 1.5°). The APP overestimated flexion (mean of 6.4° ± 1.0°), and EST underestimated it (mean of - 7.9° ± 1.1°). For extension, the mean difference was 2.8° ± 0.7° for EST and - 26.8° ± 3.1° for XR. The APP method did not significantly differ from GON. Supination accuracy was greater with EST (2.7° ± 1.7°) than with APP (5.9° ± 1.9°). There was no difference for pronation measurement with both EST and APP. CONCLUSIONS: This study is the first comparing four measurement techniques of elbow ROM. Our results showed that EST was only accurate for forearm rotation. The XR scored the best for flexion but is less reliable for extension. Surprisingly, compared to GON, APP did not correlate as we expected for flexion and supination, but the other methods were also inaccurate. We found APP to be very useful to measure complete arc of motion (difference between maximal flexion and maximal extension). LEVEL OF EVIDENCE: III, Retrospective review of a prospective cohort of elbow fracture patients: Diagnostic Study.

Surgical techniques of olecranon fractures.

Olecranon fractures are common upper extremity injuries. The vast majority are treated with operative fixation. Many treatment techniques have been described including tension band and plating. This review covers the most commonly used fixation techniques in detail, including pearls and pitfalls with case examples of both successful treatments and potential complications.

A correlation of peak height velocity and olecranon apophysis ossification assessed by ultrasound.

Peak height velocity (PHV) is defined as the period of the fastest growth during puberty. An ability to predict annual growth and the timing of PHV may provide an opportunity to modify treatment of many diseases and conditions of the skeletal system such as scoliosis and kyphosis, slipped capital femoral epiphysis, leg length inequality and adolescent Blount's disease. There is a good correlation of peak height velocity and skeletal age determined from the radiographic assessment ofolecranon. To avoid radiation, we tested value of olecranon ultrasound in prediction of annual growth and peak height velocity. In present study, using ultrasound, we made a classification of olecranon apophysis in 7 levels (0-6) according to the amount of cartilage left unossified. In 134 healthy children, aged from 10 to 15, evaluation of olecranon sonographs and staging was done by two observers in two spaced time intervals. Calculation of intra-examiner and inter-examiner agreement presented satisfactory reliability (intraclass correlation coefficient for Rater 1 = 0.967 and Rater 2 = 0.836) and very good reproduciblity (Cohen's Kappa 0.85). We measured increase in height, during six month period, for 54 children, who were classified by ultrasound in levels from 0 to 6. The greatest growth was noted in children classified as level 4. Olecranon apophysis maturity level 4, assessed by ultrasound could correspodent to peak height velocity.

Contribution of the olecranon to elbow stability: an in vitro biomechanical study.

BACKGROUND: The amount of the olecranon that can be removed without substantially affecting the kinematics and stability of the elbow is controversial. The purpose of this study was to determine the effect of serial resections of the olecranon on elbow kinematics and stability. METHODS: Eight fresh, previously frozen cadaver arms were mounted in an in vitro motion simulator, and kinematic data were obtained with use of an electromagnetic tracking system for active and passive motion. Flexion was studied in the varus, valgus, horizontal, and dependent positions. Custom-written three-dimensional computer navigation software was utilized to guide serial resection of the olecranon in 12.5% increments from 0% to 100%. A traditional triceps advancement repair was performed following each resection. Flexion angle, amount of olecranon resection, and active and passive motion measurements were compared. RESULTS: Serial resection of the olecranon resulted in a significant increase in varus-valgus angulation with the arm in the varus (p < 0.04) and valgus (p = 0.01) orientations. Ulnohumeral rotation significantly increased in the varus (p < 0.001) and valgus (p < 0.007) orientations. Angular (p = 0.02) and rotational (p < 0.001) kinematics were greater with passive compared with active motion. There was no difference in elbow kinematics following olecranon resection with the arm positioned in the horizontal and dependent positions. CONCLUSIONS: Valgus-varus angulation and ulnohumeral rotation progressively increase with sequential excision of up to 75% of the olecranon. Elbow stability is progressively lost with sequential excision, with gross instability noted at resection of > or = 87.5% of the olecranon.

Olecranon orientation as an indicator of elbow joint angle in the stance phase, and estimation of forelimb posture in extinct quadruped animals.

Reconstruction of limb posture is a challenging task in assessing functional morphology and biomechanics of extinct tetrapods, mainly because of the wide range of motions possible at each limb joint and because of our poor knowledge of the relationship between posture and musculoskeletal structure, even in the extant taxa. This is especially true for extinct mammals such as the desmostylian taxa Desmostylus and Paleoparadoxia. This study presents a procedure that how the elbow joint angles of extinct quadruped mammals can be inferred from osteological characteristics. A survey of 67 dried skeletons and 113 step cycles of 32 extant genera, representing 25 families and 13 orders, showed that the olecranon of the ulna and the shaft of the humerus were oriented approximately perpendicular to each other during the stance phase. At this angle, the major extensor muscles maximize their torque at the elbow joint. Based on this survey, I suggest that olecranon orientation can be used for inferring the elbow joint angles of quadruped mammals with prominent olecranons, regardless of taxon, body size, and locomotor guild. By estimating the elbow joint angle, it is inferred that Desmostylus would have had more upright forelimbs than Paleoparadoxia, because their elbow joint angles during the stance phase were approximately 165 degrees and 130 degrees , respectively. Difference in elbow joint angles between these two genera suggests possible differences in stance and gait of these two mammals.