Long-term clinical outcomes, motion, strength, and function after total claviculectomy.

BACKGROUND: Total excision of the clavicle is rarely performed. No previous study has documented long-term outcomes with objective measurements of strength, motion, and patient-centered outcomes. We present the long-term consequences of total claviculectomy on shoulder girdle function, global upper extremity function, and overall general health. METHODS: Five total claviculectomy patients were evaluated at 2 time points (2005 and 2010, mean 4.8 and 9.4 years postoperatively) by use of the DASH, SF-36, Simple Shoulder Test, ASES, UCLA, HSS, and Constant shoulder scores. Isokinetic strength, clinical range of motion, and kinematic analysis were performed on each limb pair. RESULTS: All clinical scores allowing side-to-side comparison were poorer for the aclaviculate side, with significance reached for 2005 ASES scores and 2010 ASES, UCLA, HSS, and Constant scores. DASH scores and SF-36 scores were not significantly inferior to age- and sex-matched population norms. Deficits in strength were present in the aclaviculate limbs, with significance reached for adduction in 2005 and for forward flexion and external rotation in 2010. Kinematic and clinical range of motion analysis revealed scapular dyskinesis and significant deficits in external rotation in the aclaviculate limb. CONCLUSIONS: We found that the clavicle contributes to the strength, coordinated scapulohumeral rhythm, and overall range of motion of the shoulder girdle. Patients compensate for loss of the clavicle with minimal functional deficit. With time, patients gradually lose some compensatory ability as evidenced by deteriorating limb-specific, patient-centered outcome measures, diminished strength in certain planes of shoulder motion, and scapular dyskinesis at long-term follow-up. Despite objective deficits, these patients continue to have normal self-perceptions of overall health and global upper extremity function.

'In need of further tuning': using a US patient satisfaction with chaplaincy instrument in a UK multi-faith setting, including the bereaved.

Healthcare chaplaincy research seems further advanced in the USA. Here a US patient satisfaction with chaplaincy instrument (PSI-C-R) was used in a London NHS foundation hospital with a multi-faith chaplaincy team and population. A version of the instrument was also generated for the bereaved. PSI-C-R had not been subjected to test-retest to confirm its reliability so this was done at the pilot stage. It proved only partly reliable, but in three separate surveys a cluster of highly rated factors emerged, as in earlier studies: chaplains' prayer, competence, listening skills and spiritual sensitivity. Low-rated factors and qualitative data highlighted areas for improvement. Disappointing response rates arose from patient acuity, ethical concerns about standard follow-up protocols, and the Western Christian origins of the instrument which requires further revision for multi-faith settings, or the design of new instruments.

The effect of coordinate system choice and segment reference on RSA-based knee translation measures.

Roentgen stereophotogrammetric analysis (RSA) can be utilized to accurately describe joint kinematics, but even when measuring small displacements within radiographically discernible structures, standardized reference frames are imperative for useful comparison across patients and across studies. In the current paper, accurately controlled laboratory models demonstrated the considerable influence that a mere 1.9-cm offset of the origin of the coordinate system from the rotation axes could exert on translation measures when rotations were occurring. In addition, the use of two different coordinate systems to gauge translation on a radiographic anterior-posterior (A-P) knee laxity exam resulted in a significant correlation (R(2)=0.562) between the two systems; however, differences of up 9.28 mm were found between corresponding measurements. This implies that clinical conclusions can potentially be upheld or refuted, based on the same data set, subject to coordinate system definition. Although the data analyzed presently involved the knee joint, similar issues surround the RSA motion analysis of other joints as well.

Interfragmentary surface area as an index of comminution severity in cortical bone impact.

A monotonic relationship is expected between energy absorption and fracture surface area generation for brittle solids, based on fracture mechanics principles. It was hypothesized that this relationship is demonstrable in bone, to the point that on a continuous scale, comminuted fractures created with specific levels of energy delivery could be discriminated from one another. Using bovine cortical bone segments in conjunction with digital image analysis of CT fracture data, the surface area freed by controlled impact fracture events was measured. The results demonstrated a statistically significant (p < 0.0001) difference in measured de novo surface area between three specimen groups, over a range of input energies from 0.423 to 0.702 J/g. Local material properties were also incorporated into these measurements via CT Hounsfield intensities. This study confirms that comminution severity of bone fractures can indeed be measured on a continuous scale, based on energy absorption. This lays a foundation for similar assessments in human injuries.

Interfragmentary surface area as an index of comminution energy: proof of concept in a bone fracture surrogate.

Fracture mechanics theory postulates a monotonic relationship between energy absorption and fracture surface generation. We hypothesized that this relationship was demonstrable to the point that, on a continuous scale, comminuted fractures created with disparate levels of energy delivery could be discriminated. Using a bone fracture surrogate in conjunction with digital image analysis of CT fracture data, we measured the surface area freed by controlled, discrete fracture simulations. Prior to these simulations, the reproducibility of the digital image analysis algorithm was validated with repeated measurements by two different operators. The parametric fracture series results showed a statistically significant difference in measured de novo surface area between four specimen groups, over a range of input energies from 1.4 x 10(10)-9.1 x 10(10)J/m(3) (or 12.5-80.2J/specimen). The results of this study provide confirmation that comminution severity can indeed be measured on a continuous scale, based on energy absorption (another clinically meaningful index).

A three-dimensional comparison of intramedullary nail constructs for osteopenic supracondylar femur fractures.

OBJECTIVES: This study developed a new 6 degree-of-freedom, unconstrained biomechanical model that replicated the in vivo loading environment of femoral fractures. The objective of this study was to determine whether various distal fixation strategies alter failure mechanisms and/or offer mechanical advantages when performing retrograde intramedullary nail (IMN) stabilization of supracondylar femur fractures in osteoporotic bone. METHODS: Forty fresh-frozen human femora were allocated into 2 groups of matched pairs: "locked" (fixed angle locking construct with both distal locking screws rigidly attached to the IMN) versus "unlocked" (conventional locking technique with 2 distal locking screws targeted through the distal locking screw holes of the IMN) and "locked" versus "washer" (fixed angle locking with the most distal screw exchanged for a bolt with condyle washers) distal fixation of a retrograde IM nails. A comminuted fracture (OTA 33-A3) was simulated with a wedge osteotomy. Bone density measurements were completed on all specimens before instrumentation. Instrumented femurs were loaded axially to failure, whereas 6 degree-of-freedom translations and angulations were measured using Roentgen stereophotogrammetric analysis. RESULTS: Mean (± SD) load born by "locked" specimens (1609 ± 667 N) at clinical failure was 38.1% greater (P = 0.09) than the corresponding mean load born by "unlocked" specimens (1165 ± 772 N). Clinical failure for the "washer" group (1738 ± 772 N) was 29.9% greater (P = 0.07) than the corresponding mean of the "locked" counterparts (1338 ± 822 N). Failure load was most clearly related to bone density in the "unlocked" fixation group. CONCLUSIONS: Predicting failure load based on bone density using a least squares estimate suggests that the washer construct provides superior fixation to other treatment techniques. The failure mechanism for a comminuted, supracondylar fracture cannot be analyzed accurately with a 1-dimensional measurement. The most common failure mechanism in this model was medial translation and varus angulation.

Analyzing glenohumeral torque-rotation response in vivo.

BACKGROUND: Because the human shoulder has many degrees of freedom that allow redundant means of producing the same net humerothoracic motion, there are many impediments to objective, repeatable assessment of shoulder function in vivo. Devices designed to date have suffered from poor reliability. In this study we introduce a new device and methods to evaluate human shoulder kinematics and evaluate its reproducibility from subject to subject and from day to day. METHODS: This was a controlled laboratory study. Using electromagnetic motion sensors to record the position and orientation of the thorax, scapula, and humerus, we quantified the kinematic response of twenty four normal shoulders in response to known internal-external torque application. A four-parameter logistic function was selected to characterize the strident features of the torque-rotation relationship. FINDINGS: Our analysis in conjunction with the measurement technique described herein, allowed the passive glenohumeral internal-external range of motion to be differentiated from other motion components and was determined to within 9.6% of full scale over three repeated trials. Range of motion was the most reliable biomechanical outcome, more so than computed indices of glenohumeral flexibility and hysteresis. The exact profile of the torque-rotation response, and therefore the repeatability of the calculated outcomes, was unique from shoulder to shoulder. INTERPRETATION: The development of the capacity for precise, non-invasive measurement of shoulder biomechanics over time is a requisite step towards optimizing treatment of shoulder injury and disease. Our current methods are superior to previous attempts at trying to non-invasively evaluate the biomechanics of the glenohumeral joint.

Quantifying comminution as a measurement of severity of articular injury.

The severity of articular injury caused by a fracture of periarticular bone impacts patient prognosis. There currently are not good, objective methods for grading articular injury severity. Quantification of bone comminution from fracture image data, which has been possible in laboratory studies, may be a promising route. We show that tibial pilon fractures can be discriminated on the basis of de novo surface-apparent energy absorption.