Explore the vast range of titles available.

PurposeThe two-dimensional fluoroscopic method of percutaneous pedicle screw instrumentation has been clinically described as reliable method in the caudal thoracic and lumbosacral spine. Its accuracy has not been clearly reported in the cranial thoracic spine. The aim of this in vitro study was to investigate percutaneous pedicle screw placement accuracy according to pedicle dimensions and vertebral levels.MethodsSix fresh-frozen human specimens were instrumented with 216 screws from T1 to S1. Pedicle isthmus widths, heights, transversal pedicles and screws were measured on computed tomography. Pedicle cortex violation ≥ 2 mm was defined as screw malposition.ResultsThe narrowest pedicles were at T3–T5. A large variability between transversal pedicle axes and percutaneous pedicle screw was present, depending on the spinal level. Screw malposition rates were 36.1% in the cranial thoracic spine (T1–T6), 16.7% in the caudal thoracic spine (T7–T12), and 6.9% in the lumbosacral spine (L1–S1). The risk for screw malposition was significantly higher at cranial thoracic levels compared to caudal thoracic (p = 0.006) and lumbosacral (p < 0.0001) levels. Cortex violation ≥ 2 mm was constantly present if the pedicle width was < 4.8 mm.ConclusionPercutaneous pedicle screw placement appears safe in the caudal thoracic and lumbosacral spine. The two-dimensional fluoroscopic method has a limited reliability above T7 because of smaller pedicle dimensions, difficulties in visualizing radiographic pedicle landmarks and kyphosis.

Background Terrible triad of the elbow (TTE) is a complex dislocation associating radial head (RH) and coronoid process (CP) fractures. There is at present no reproducible anatomic model for TTE, and pathophysiology is unclear. The main aim of the present study was to create and validate an anatomic model of TTE. Secondary objectives were to assess breaking forces and relative forearm rotation with respect to the humerus before dislocation. Methods An experimental comparative study was conducted on 5 fresh human specimens aged 87.4 ± 8.6 years, testing 10 upper limbs. After dissection conserving the medial and lateral ligaments, interosseous membrane and joint capsule, elbows were reproducibly positioned in maximal pronation and 15° flexion, for axial compression on a rapid (100 mm/min) or slow (10 mm/min) protocol, applied by randomization between the two elbows of a given cadaver, measuring breaking forces and relative forearm rotation with respect to the humerus before dislocation. Results The rapid protocol reproduced 4 posterolateral and 1 divergent anteroposterior TTE, and the slow protocol 5 posterolateral TTE. Mean breaking forces were 3,126 ± 1,066 N for the lateral collateral ligament (LCL), 3,026 ± 1,308 N for the RH and 2,613 ± 1,120 N for the CP. Comparing mean breaking forces for all injured structures in a given elbow on the rapid protocol found a p-value of 0.033. Comparison of difference in breaking forces in the three structures (LCL, RH and CP) between the slow and rapid protocols found a mean difference of -4%. Mean relative forearm rotation with respect to the humerus before dislocation was 1.6 ± 1.2° in external rotation. Conclusions We create and validate an anatomic model of TTE by exerting axial compression on an elbow in 15° flexion and maximal pronation at speeds of 100 and 10 mm/min.

IntroductionThe medial head of the triceps brachii flap is already described as a local muscular or as a free flap. It allows coverage of defects of the posterior cubital region. The aim of this study was to describe the vascular anatomy of the musculocutaneous medial triceps brachii pedicled flap.MethodsEleven fresh–frozen upper limbs (6 come from women and 5 from men) were proximally injected with Indian ink agar solution. The medial head of the triceps brachii muscle was dissected and the superior ulnar collateral artery (SUCA) was isolated with its collaterals. The collateral arteries were dissected to determine whether there were septocutaneous or musculocutaneous arteries for vascularization of the skin in front of the medial head. Lengths of those collaterals arteries were measured.ResultsThe average number of collaterals arteries from the SUCA supplying the medial head of the triceps brachii is 4.5 (from 3 to 6 arteries). Among these collaterals’ arteries, there are one average 1.5 (0.6–4.5) septocutaneous arteries and 3 (1–4.8) musculocutaneous arteries.Discussion and conclusionA musculocutaneous flap with the medial head of the triceps brachii muscle can be described with the muscle. The SUCA gives perforator arteries musculocutaneous and septocutaneous for the vascularization of the triceps brachii medial head. The use of local pedicled flap with similar tissue maximizes healing with a minimal morbidity of the donor site. This study demonstrated the feasibility of the medial head triceps brachii musculocutaneous flap to cover defect of the posterior aspect of the elbow.

Purpose Despite their functional importance, the infraspinatus (ISP) and teres minor (TM) muscles have been little investigated. This study aimed to describe the macroscopic morphology, innervation, and inter-relations of the ISP and TM muscles. Methods Forty fresh cadaver dissections and histologic analysis were performed. Three groups of specimens were distinguished according to the rotator cuff tendon status: (1) intact rotator cuff; (2) supraspinatus tendon tears with intact ISP tendon; and (3) both supraspinatus and ISP tendons torn. Muscle fiber organization and muscle and tendon length were recorded. ISP and TM innervation and fiber structure were studied. Results ISP muscles were composed of three groups of fiber organized in two planes: two superficial groups, with mean pennation angles of, respectively, 27° ± 4° and 23° ± 3° with respect to the axis of the central tendon of the underlying group. TMs were thick fusiform muscles showing a parallel organization; 26 specimens (67 %) had aponeuroses isolating the TM, with a mean length of 5.2 ± 2.7 cm. Rotator cuff lesions were associated with relatively greater ISP tendon than muscle length. Innervation of the ISP muscle comprised 2–4 main branches from the suprascapular nerve and that of the TM 1 branch from the axillary nerve. Conclusion ISP muscle body morphology derives from three groups of fibers in two planes. The TM has a parallel organization. Several nerve branches innervate the ISP muscle, whereas only one supplies the TM. The limits between the two muscles bodies consist of an aponeurotic fascia in two-thirds of cases.

Background There is little data in the literature regarding the preparation methods of the intra-articular portion of quadruple hamstring-tendon grafts for anterior cruciate ligament (ACL) reconstruction. The aim of this study was to compare the biomechanical properties of a sutured transplant to that of a non-sutured transplant. The hypothesis was that adding stitches to the intra-articular portion of the graft increased its resistance. Method A comparative cadaveric study was carried out on five pairs of knees. The average age of the cadavers was 68 years. The exclusion criterion was past knee surgery. In the Sutured Group (SG) two stitches were made on the grafts. No stitches were made on the grafts of the Non-sutured Group (NSG). A tensile failure test was carried out using an Instron® loading machine. The maximal load to failure and stiffness were recorded and we observed the mode of failure for each graft. Statistical analysis was performed using the Wilcoxon rank sum test. Level of significance was set at p  < 0.05. Results The hypothesis proposed was not confirmed; adding stitches to the intra-articular portion of the four-strand hamstring-tendon graft does not increase its biomechanical properties. The maximal load to failure was 233.5 N ± 40.6 (186.7–274.5 N) for the NSG, 19.6% higher than for the SG which was 195.2 N ± 42.9 (139.0–238.2 N). Nevertheless, the difference observed was not statistically significant ( p  = 0.188). The stiffness of the grafts for the NSG was 23.5 N/mm ± 5.3 (17.8–29 N/mm) and 19.7 N/mm ± 5.5 (13.2–24.7 N/mm) for the SG grafts. Overall stiffness values for the NSG were 19% higher than those of the SG; however, the results were not statistically significant ( p  = 0.438). The failure mode was a rupture at the fixation point except for one sample from the SG which failed at an intra-articular stitch. Conclusion Whilst the initial hypothesis was not verified, nevertheless, the maximal loads to failure and stiffness were approximately 20% higher when there were no intra-articular stitches compared to the situation where stitches were added to the intra-articular portion of the graft. This was a cadaveric pilot study and, therefore, whilst we are not able to extend our results to clinical practice, the outcomes would indicate the need for further development of this and related protocols deriving from the question of whether there is weakening the graft when adding stitches to its mid-substance. These results remain to be confirmed by further research.

PurposeIn the case of reverse shoulder arthroplasty (RSA) for proximal humeral fractures (PHFs) with tuberosity reconstruction, it is unclear whether the supraspinatus tendon continues to play a role. The aim of this study was to evaluate the clinical and radiological outcomes of RSA for PHFs in a large cohort of elderly patients and compare the results in the case of supraspinatus excision or preservation.MethodsIn this retrospective multicentre study, 150 patients (mean age 77 years, 93% female) were reviewed and radiographed with a minimum follow-up of 24 months. The same Grammont prosthetic design was used in all cases (inclination angle 155°, non-lateralised glenosphere). Patients were divided into two groups: Group A (n = 117) underwent supraspinatus excision and Group B supraspinatus preservation (n = 33). Complications were recorded, and shoulder function, active mobility and subjective results were assessed.ResultsAt a mean follow-up of 59 months, there was no statistical difference in the complication rate (6% vs. 6.8%, p = 1), mean Constant score (61 points vs. 59 points, p = 0.52), simple shoulder value (74% vs. 73.9%, p = 0.9), active anterior elevation (125° vs. 128°, p = 0.45) and internal rotation (4.9 points vs. 4.1 points, p = 0.2). However, mean active external rotation was better in Group A (22° vs. 13°, p = 0.01). The greater tuberosity healing rate in satisfactory position did not differ statistically between the groups (68% vs. 55%, p = 0.14).ConclusionIn the case of RSA with tuberosity reconstruction for acute PHFs, there is no clear evidence that supraspinatus preservation is advantageous.

Knee laxity may be impacted by rupture of the anterolateral knee ligament (ALL). The goal of this study was to measure tibial translation and rotation as a function of the status of the ALL and the anterior cruciate ligament (ACL). Five pairs of fresh frozen cadaver specimens were analyzed. The knee was positioned in 20° flexion. Calibrated posteroanterior forces and internal/external torques were successively applied. Anterior tibial translation and total internal/external tibial rotation were measured with a navigation system. Three conditions were used in each knee: intact ACL and ALL, transection of ACL or ALL (randomly assigned to each knee of a pair), and transection of both ligaments. The primary outcome criterion was the increase in tibial rotation at 8 Nm. The mean increase in tibial rotation at 8 Nm was 0.8° after transecting the ALL only, 1.2° after transecting the ACL only, and 0.8° after transecting both ligaments. The mean increase in anterior tibial translation at 250 N was 1.2 mm after transecting the ALL only, 9.0 mm after transecting the ACL only, and 6.1 mm after transecting both ligaments. There was no significant increase in the tibial rotation or anterior tibial translation after transecting the ALL only or after transecting the ALL in ACL-deficient knees. The expected role of ALL in controlling anterior or rotational tibia motion could not be confirmed.

Purpose Total shoulder arthroplasty planning requires a preoperative assessment of the glenoid version. This study aimed to determine the morphologic profile of the glenoid cavity and our null hypothesis was that age may affect the spiraling aspect. Method 114 CT arthrographies of patients from 15 to 78 years old were included. Four groups were defined according to age: 15–29, 30–44, 45–59 years old, and over 60. The version of the glenoid was measured in the axial plane according to the most common method: a line is drawn between the osseous anterior and posterior margins of the glenoid and the version corresponds to the angle between this line and the transverse axis of the glenoid. The transverse axis of the scapula is determined by a line drawn from the center of the glenoid fossa to the medial border of the scapula. The axial plane (perpendicular to the supero-inferior axis of the glenoid cavity) was defined by multiplanar reconstruction. The measurements were performed at three regions of interest: the level of the coracoid process (region A), the level of the notch on the anterior border of the glenoid (region B), and the region of the greater antero-posterior diameter (region C). Results 96 % of the glenoid cavities included were retroverted. The mean version in region A was 11.9° (0–24.3, S-D 5.2), in region B 6.85° (−5.2 to 12.1, S-D 4.13) and in region C 4.04° (−7.7 to 11.1, S-D 4.04). The difference between the mean version of region A and region B was 5.02° and the difference between the mean version of the region B and the mean version of the region C was 2.81°. When considering the rate of change of the mean version between two adjacent regions, no difference was observed between the four groups of age. Discussion The analysis showed the importance of the axial reconstruction plan chosen to allow interpretable and reproducible measures. A decreasing version of the glenoid superior-to-inferior was observed, presenting a spiraling twist as described in previous studies. The profile of variation does not change in the four groups of patients included. The reconstruction of an articular surface as close to the anatomy as possible would also participate in establishing the muscular balance and the constraints on implants. Up to now, implants do not take into account this cranio-caudal twisting.

Purpose The aim was to establish a functional MRI protocol for analyzing human stereoscopic vision in clinical practice. The feasibility was established in a cohort of 9 healthy subjects to determine the functional cortical areas responsible for virtually relief vision. Methods Nine healthy right-handed subjects underwent orthoptic examination and functional MRI. The activation paradigms used were based on a block sequence with the projection of static and dynamic 2D and 3D test patterns during three experiments. The test patterns were projected through two separate eyepieces to create stereoscopic vision. SPM software was used for post-processing and data analysis. Results Among the three different test patterns used, the second, which corresponded to a static high-relief image of a billiard, appeared to be significant for identifying cortical area activation during stereoscopy. In the group analysis, only areas V3A and V6 showed statistically significant activation. Individual analysis revealed activation of the rostral IPS and V5/MT+. Conclusion More data is needed to determine the precise cortical area of activation for stereoscopy. This study proposes a useful and accessible method for functional MRI analysis of stereoscopy.

Background. The indications for reverse shoulder arthroplasty (RSA) have been widely expanded, but only a few studies report the long-term survival of these implants. Our objective was to report the long-term survivorship of a large series of RSAs implanted for different etiologies. Methods. A retrospective multicenter study including all the RSAs was performed in six shoulder-specialized centers with at least 2 years of follow up. We reviewed 1611 RSAs, operated between 1993 and 2010, including 497 cuff-tear arthropathies (CTA), 239 revision RSAs, 188 massive cuff tears (MCT), 185 fracture sequelae (FS), 183 failed previous cuff repairs (FCR), and 142 primary osteoarthritis (POA). The mean follow-up was 5.6 ± 3.9 years (range 2–20). Results. Overall, 266 RSAs (16.5%) had at least one complication leading to 64 reoperations (4.0%) and 110 revision surgeries (6.8%). The most frequent complications were infection (3.8%), instability (2.8%), and humerus-related complications (2.8%). At 10 years, the survival without revision surgery was 91.0% in primary RSAs and 80.9% in revision RSAs for failed arthroplasty (p < 0.001). In the primary RSA group, MCT and FCR led to 10-year survivals for over 95% but fracture sequelae and tumors had the lowest 10-year survivals (83.9% and 53.1%). Younger patients had a lower 10-year survival. In revision RSAs, male patients had a significantly lower survival than females (72.3% vs. 84.5% at 10 years, p = 0.020). Discussion. Primary RSA for cuff-deficient shoulders or POA leads to a high 10-year survival, but revision RSA or primary RSA for FS and tumors are at high-risk for revision. Surgeons should be aware of high rates of complications and lower survival rates of RSA in younger patients, in males, and in RSAs for revision surgery.