Julien Chapleau

Validity of Goniometric Elbow Measurements: Comparative Study with a Radiographic Method

BackgroundA universal goniometer is commonly used to measure the elbow’s ROM and carrying angle; however, some authors question its poor intertester reliability.Questions/purposesWe (1) assessed the validity of goniometric measurements as compared with radiographic measurements in the evaluation of ROM of the elbow and (2) determined the reliability of both.MethodsThe ROM and carrying angle of 51 healthy subjects (102 elbows) were measured using two methods: with a universal goniometer by one observer three times and on radiographs by two independent examiners. Paired t-test and Pearson’s correlation were used to compare and detect the relationship between mean ROM. The maximal error was calculated according to the Bland and Altman method.ResultsThe intraclass correlation coefficients (ICC) ranged from 0.945 to 0.973 for the goniometric measurements and from 0.980 to 0.991 for the radiographic measurements. The two methods correlated when measuring the total ROM in flexion and extension. The maximal errors of the goniometric measurement were 10.3° for extension, 7.0° for flexion, and 6.5° for carrying angle 95% of the time. We observed differences for maximum flexion, maximal extension, and carrying angle between the methods.ConclusionBoth measurement methods differ but they correlate. When measured with a goniometer, the elbow ROM shows a maximal error of approximately 10°.Clinical RelevanceThe goniometer is a reasonable and simple clinical tool, but for research protocols, we suggest using the radiographic method because of the higher level of precision required.

The influence of proximal ulnar morphology on elbow range of motion

BACKGROUND Physiologic dorsal apex angulation of the proximal ulna is present in 96% of the population. We hypothesize that a correlation exists between the physiologic dorsal ulnar angulation and elbow range of motion (ROM). METHODS Fifty healthy adults underwent bilateral lateral elbow radiographs in neutral forearm rotation in the following positions: terminal flexion (TF), 90° of flexion, and terminal extension (TE). The proximal ulna dorsal angulation (PUDA), TF, and TE were measured on the digital lateral radiographs by 2 independent observers. ROM was calculated as the difference between TF and TE measurements. Subjects were divided into 2 groups: those with PUDA measurements less than the median and those with PUDA measurements equal to or greater than the median. The relationship between the PUDA and TE, TF, and ROM was evaluated by use of Pearson correlation coefficients. RESULTS The mean age of the cohort was 31 ± 9 years, and there were 30 women among the 50 volunteers. The sample of 100 elbow radiographs had a mean TF of 150.8° ± 4.5°, a mean TE (ie, flexion contracture) of 11.5° ± 7.3°, and a mean ROM of 139.3° ± 8.4°. The mean PUDA was 5.2° ± 2.8°. Elbows with a greater PUDA had significantly less TE (r = 0.381, P ≤ .001) and ROM (r = -0.351, P ≤ .001). The group of elbows with a lesser PUDA had better TE (9.4° vs 13.6°, P = .004) and ROM (142.0° vs 136.7°, P = .001) than elbows with a greater PUDA. CONCLUSION The increasing magnitude of the PUDA is associated with decreased maximal elbow extension and global elbow ROM.

Demographic and anthropometric factors affecting elbow range of motion in healthy adults

BACKGROUND To use elbow range of motion routinely as a diagnostic index, it is important to explain the normal variability among the population. Consequently, this study assessed the possible associations between age, sex, laterality, body mass index, joint laxity, level of physical activities, upper limb dimensions, and the elbow range of motion in flexion/extension. MATERIALS AND METHODS Maximal flexion and extension were measured on the lateral radiographs of 102 elbows of 51 volunteers. The difference of range of motion regarding sex and laterality was assessed with Student t tests. The Pearson correlation coefficient was used to evaluate the relationship between elbow mobility and the other factors, and a stepwise multiple regression analysis was performed. RESULTS Among the 51 volunteers, a correlation was found between flexion and body mass index, age, and midbrachial and forearm circumferences (r = -0.234 to -0.594). Age (r = 0.268) and hyperlaxity (r = -0.323) were the only factors associated with a change in elbow extension. No correlation was found between the level of physical activity or with the laterality and changes in elbow mobility. Finally, women presented with more flexion and total elbow range of motion than men. CONCLUSIONS This study confirms the association between various demographic and anthropometric factors and elbow range of motion in healthy adults. Among these, the body mass index and forearm circumference are the most likely responsible for mobility variations among the population.

Impact of olecranon fracture malunion: Study on the importance of PUDA (Proximal Ulna Dorsal Angulation).

PURPOSE The Proximal Ulna Dorsal Angulation (PUDA) is part of the proximal ulnas normal anatomy. The importance of restoring ulnar anatomy characteristics precisely after olecranon fracture is not known, however, failure to recreate the PUDA after surgery may result in poorer functional outcomes. The purpose of this study is to evaluate the impact of minimal proximal ulna malunion on elbow ROM and function at least one year after olecranon ORIF. METHOD A retrospective comparative cohort study took place in three level-1 trauma centers. Forty-nine adult volunteers who underwent ORIF for olecranon fracture were included. Patients were separated into two groups according to PUDA malreduction-defined as more than 5° of difference between the fractured and the contralateral elbow. OUTCOME MEASUREMENTS Radiographic ROM measurement, demographic data and quality of life questionnaires were recorded (PREE, MEPS, Q-DASH, SF12, VAS). RESULTS The mean follow up was 3 years and 9 months (1-7 years). There was no difference in terms of outcome, quality of reduction or range of motion between patients treated with plate or tension band. The mean PUDA on the fracture side was different from the normal side (2.20 vs 4.90, p<0.001). Fourteen patients (29%) had PUDA malunion. Those patients had decreased elbow flexion (-7°, p=0.011), extension (-11.2°, p=0.013) and total ROM (-18.6°, p=0.006) as opposed to the control group. Both groups had comparable quality of life questionnaire scores. Alcohol consumption was the only risk factor associated with worse scores. CONCLUSION Incidence of olecranon malunion-as defined by PUDA measurement - was 29% and it was associated with decreased elbow range of motion. Alcohol consumption was correlated with a worse prognosis in our series of patients. Tension band and plate fixation can maintain a good reduction in terms of PUDA and the choice of fixation method does not influence outcome. LEVEL OF EVIDENCE III Therapeutic study.

Does malpositioning of the arm influence radiographic range of motion measurement

Purpose: Radiographic range of motion measurement of the elbow has been shown to be both precise and reliable. For this method to be used routinely in research studies, it is important to describe its limits regarding: (1) rotation of the arm from the perfect lateral position and (2) the length of humerus and ulna visible on the radiograph. Material and Methods: A 3D bone reconstruction was performed from an upper limb CT scan. Planar radiographs were simulated for rotations of the elbow within a range of ±30o from the perfect lateral position. The field of view was modified, ranging from five visible centimeters of diaphysis on the radiograph to full visibility of the upper limb. Results: The disparity was less than 2.5° (mean=0.68°, SD=0.43°) when the flexed arm was rotated between -30.0° (external rotation, ER) and + 18.0° (internal rotation, IR). When considering the extended arm, measured angles differed by less than 2.5° (mean=0.79°, SD=0.57°) within a range of -15.0° (ER) to +30.0° (IR). When a minimum of 12 cm of humerus and ulna, from the capitellum, were visible on the radiograph measured angles varied very slightly (mean disparity of 0.71°, SD= 0.71°). Finally a qualitative description of the appearance of the radiographs was included to help surgeons estimate acceptable degrees of rotation. Conclusion: Range of motion (ROM) measurement shows consistent results, despite 15 to 30 degrees of internal or external rotation. The middle third of the humeral and ulnar diaphyses should be visible on the radiographs to ensure the validity of measurement. Radiographic ROM measurement is still recommended over the goniometer for research purposes because of its high reliability and precision. Moreover, malpositioning of the elbow should not jeopardize results since it will most likely be an angle measurement variation of less than 2.5°.

Involvement of the proximal radial ulnar joint in partial radial head fractures: a novel three-dimensional computed tomography scan evaluation method

Background Partial radial head fractures (PRHF) can involve the proximal radioulnar joint (PRUJ) or be restricted to the ‘safe zone’ (SZ) during forearm rotation. The objective of the present study was to develop an assessment method for PRUJ involvement in radial head fractures using axial computed tomography (CT) scans. Methods The area of the radial head in contact with the PRUJ zone was identified, and defined on 18 cadaveric elbows CT scans; the quantitative relationship between PRUJ zone and radial tuberosity was established. Then, four evaluators validated it on PRHF CT scan axial views, classifying the fractures as involving the PRUJ or not. Results Using the radial tuberosity as the 0° of a 360° circle, the SZ was within 108° to 212° clockwise for a right elbow and counter clockwise for the left elbow. Fifty-five consecutive (30 men, 25 women, mean age of 49 years) partial radial head fracture CT scans were classified: four in the SZ only, three in the PRUJ zone and 48 in both the PRUJ and SZ. The kappa for the inter- and intra-observer agreement was 0.517 and 0.881, respectively. Conclusions Ninety-three percent of partial radial head fractures will involve the PRUJ and the geometric model developed allows their classification, potentially helping surgeons decide on optimal treatment. Level of evidence Retrospective basic science study. Level III: anatomic study, imaging