A new comprehensive ultrasonic diagnostic method for celiac artery compression syndrome that hybridizes “arterial compression hook sign” and peak systolic velocity

PurposeDiagnosing celiac artery compression syndrome (CACS) is based on an imaging finding of celiac artery compression (CAC), but the diagnostic criteria are inconsistent. The study aim was to devise an ultrasonographic screening method to effectively diagnose CAC in occult CACS.MethodsThe subjects were 61 patients with suspected CACS who underwent ultrasonography at our hospital from May 2017 to December 2019 and were divided into the following two groups: the “arterial compression hook sign”-positive group (n = 15, mean age: 26.6 ± 16.4 years, six males, nine females) and -negative group (n = 41, mean age: 32.5 ± 18.6 years, 12 males, 34 females). We used B-mode and advanced dynamic flow to detect arterial compression hook sign and pulse Doppler to measure expiration peak systolic velocity (EPSV) and inspiration PSV (IPSV).ResultsThe EPSV was significantly higher in the arterial compression hook sign-positive group (304.7 ± 47.4 cm/s) than in the -negative groups (158.2 ± 38.7 cm/s), (p < 0.001). Receiver operating characteristic curve analysis was performed to calculate the EPSV cutoff value for presence of CAC, which was 226 cm/s (sensitivity: 0.957, specificity: 1.000, AUC: 0.997, 95% confidence interval: 0.99–1). The IPSV was lower in the positive group than in the negative group in all cases (EPSV − IPSV range: 68–199 cm/s).ConclusionOur results showed that if arterial compression hook sign determined by B-mode ultrasound, EPSV > 226 cm/s, and IPSV decreases by ≥ 68 cm/s, then CAC can be detected with high specificity.Graphic abstract      

Effects of slouching and muscle contraction on the strain of the iliolumbar ligament

The study consisted of biomechanical modelling and in vitro experiments. The objective of the study was to find a mechanical cause of acute low back pain (LBP) in everyday situations. The precise mechanism producing LBP is still under discussion. Most biomechanical studies link the concepts of stooped postures and buckling instability of the spine under high compressive load. No biomechanical model addresses situations with small or neglectable compressive spinal load. The proposed conceptual model describes strain on the iliolumbar ligaments (ILs) when slouching from standing upright. Delayed or absent recruitment of back muscles that protect against hyperkyphosis of the lumbar spine is a conditional factor. Erector spinae and multifidus muscle forces are included, representing a bifurcation in back muscle force: one part acting on the iliac bones and one part acting on the sacrum. The multifidus muscle action on the sacrum may produce nutation which can be counteracted by pelvic floor muscles, which would link back problems and pelvic floor problems. The effect of simulated muscle tension on the ILs and the L5-S1 intervertebral disc angle was measured using embalmed specimens. Forces were applied to simulate erector spinae and sacral part of multifidus tension, bilateral up to 100 N each. Strain gauge sensors registered elongation of the ILs. Explorative biomechanical model calculations show that dynamic slouching, driven by upper body weight and (as an example) rectus abdominis muscle force may produce failure load of the spinal column and the ILs. The quasi-static test on embalmed specimens showed a significant increase of IL elongation with simulated rectus abdominis muscle force. Adding erector spinae or multifidus muscle tension eased the ILs. Sudden slouching of the upright trunk may create failure risk for the spine and ILs. This loading mode may be prevented by controlling loss of lumbar lordosis with erector spinae and multifidus muscle force.     

Synaptic organization of thalamocortical axon collaterals in the perigeniculate nucleus and dorsal lateral geniculate nucleus

We examined the synaptic targets of large non-gamma-aminobutyric acid (GABA)-ergic profiles that contain round vesicles and dark mitochondria (RLD profiles) in the perigeniculate nucleus (PGN) and the dorsal lateral geniculate nucleus (dLGN). RLD profiles can provisionally be identified as the collaterals of thalamocortical axons, because their ultrastrucure is distinct from all other previously described dLGN inputs. We also found that RLD profiles are larger than cholinergic terminals and contain the type 2 vesicular glutamate transporter. RLD profiles are distributed throughout the PGN and are concentrated within the interlaminar zones (IZs) of the dLGN, regions distinguished by dense binding of Wisteria floribunda agglutinin (WFA). To determine the synaptic targets of thalamocortical axon collaterals, we examined RLD profiles in the PGN and dLGN in tissue stained for GABA. For the PGN, we found that all RLD profiles make synaptic contacts with GABAergic PGN somata, dendrites, and spines. In the dLGN, RLD profiles primarily synapse with GABAergic dendrites that contain vesicles (F2 profiles) and non-GABAergic dendrites in glomerular arrangements that include triads. Occasional synapses on GABAergic somata and proximal dendrites were also observed in the dLGN. These results suggest that correlated dLGN activity may be enhanced via direct synaptic contacts between thalamocortical cells, whereas noncorrelated activity (such as that occurring during binocular rivalry) could be suppressed via thalamocortical collateral input to PGN cells and dLGN interneurons.     

Evidence for nonreciprocal organization of the mouse auditory thalamocortical-corticothalamic projection systems

We tested the hypothesis that information is routed from one area of the auditory cortex (AC) to another via the dorsal division of the medial geniculate body (MGBd) by analyzing the degree of reciprocal connectivity between the auditory thalamus and cortex. Biotinylated dextran amine injected into the primary AC (AI) or anterior auditory field (AAF) of mice produced large, "driver-type" terminals primarily in the MGBd, with essentially no such terminals in the ventral MGB (MGBv). In contrast, small, "modulator-type" terminals were found primarily in the MGBv, and this coincided with areas of retrogradely labeled thalamocortical cell bodies. After MGBv injections, anterograde label was observed in layers 4 and 6 of the AI and AAF, which coincided with retrogradely labeled layer 6 cell bodies. After MGBd injections, thalamocortical terminals were seen in layers 1, 4, and 6 of the secondary AC and dorsoposterior AC, which coincided with labeled layer 6 cell bodies. Notably, after MGBd injection, a substantial number of layer 5 cells were labeled in all AC areas, whereas very few were seen after MGBv injection. Further, the degree of anterograde label in layer 4 of cortical columns containing labeled layer 6 cell bodies was greater than in columns containing labeled layer 5 cell bodies. These data suggest that auditory layer 5 corticothalamic projections are targeted to the MGBd in a nonreciprocal fashion and that the MGBd may route this information to the nonprimary AC.     

The incidence of dorsal radiocarpal ligament tears in patients having diagnostic wrist arthroscopy for wrist pain

PURPOSE: The goal of this study was to examine the incidence of dorsal radiocarpal ligament (DRCL) tears in patients having diagnostic arthroscopy for chronic wrist pain. METHODS: A chart review was performed of 64 patients who had diagnostic wrist arthroscopy for chronic wrist pain that was refractory to conservative measures. For each case, interosseous ligament instability/tears were graded according to the Geissler classification. Tears of the triangular fibrocartilage complex and the presence or absence of a DRCL tear were noted. RESULTS: There were 35 of 64 wrists (in 64 patients) with DRCL tears. The average duration of wrist pain prior to treatment was 20 months. Only 10 patients could recall a specific injury. Five patients had an isolated DRCL tear. A scapholunate interosseous ligament injury was identified in 13 patients, of whom 7 had a concomitant DRCL tear. A lunotriquetral interosseous ligament injury was present in 7 patients, of whom 2 had a concomitant DRCL tear. Two patients had a capitohamate ligament tear: 1 of these patients had a DRCL tear. There were 7 patients with a solitary triangular fibrocartilage complex tear: 6 of 7 were in association with a DRCL tear. One patient had a chronic ulnar styloid nonunion and a DRCL tear. Two or more lesions were present in 23 patients; DRCL tears were present in 12. CONCLUSIONS: DRCL tears are commonly seen with injuries to the primary wrist stabilizers. Recognition of this condition and further research into treatment methods are needed. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.     

不同手术方法治疗胫骨髁间棘撕脱骨折的临床疗效分析

目的 观察不同手术方法治疗胫骨髁间棘撕脱骨折的疗效.方法 1995年10月至2005年10月应用3种手术方法治疗胫骨髁间棘撕脱骨折患者49例:切开复位内固定17例(A组);关节镜下复位内固定19例(B组);有限切开加关节镜辅助复位内固定13例(C组).平均随访时间4.6年.结果 A、B、C 3组伸膝功能正常分别为35.5%、16.O%和38.0%;轻度异常分别为35.5%、11.0%和23.0%;中度异常29.0%、47.0%和31.0%;重度异常0、26.0%和8.0%.3组屈膝正常分别为82.0%、78.0%和84.0%;轻度异常12.0%、11.0%和8.0%;中度异常6.0%、11.0%和8.0%.Laehman和前抽屉试验阳性率3组分别为35.0%、45.0%和38.0%,轴移试验阳性率3组分别为11.0%、16.O%和13.0%.Lysholm 评分3组平均分别为98.6分、97.3分和98.2分;Tegner评分分别为6.6分、6.4分和6.7分,KT-2000检查胫骨前移分别平均为6.9 mm、7.1 mm和6.6 mm;健患侧对比差异分别平均为1.4 mm、1.7 mm和1.5 mm,除伸膝功能A组与B组比较差异有统计学意义外(P=0.02,P＜0.05),其他各种指标组间比较均无显著统计学意义(P＞0.05).结论 有限切开辅助关节镜下适当的过度复位和三维、坚强内固定是治疗胫骨髁间棘撕脱骨折较为理想的方法.     

自体腘绳肌腱单、双束重建前交叉韧带临床比较研究

目的 比较自体腘绳肌腱单、双束重建前交叉韧带的临床效果.方法 2005年5月至12月采用双束重建前交叉韧带患者33例(双束组),单束重建患者41例(单束组),均采用自体半腱肌腱和股薄肌腱.双束组4例失访,随访时间14～22个月,平均18个月;单束组8例失访,随访时间14-21个月,平均18个月.采用国际膝关节评分委员会评分标准(IKDC),Lysholm和Tegner评分、KT-2000及Biodex肌力测试评价.结果 双束组IKDC,Lysholm和Tegner评分分别由术前的60、66、4分显著上升至术后的85、94、6分.KT-2000在134 N下30°和90°位移情况由术前的5.8和2.4 mm减少为术后1.2和1.1 mm(P＜0.01).双束组伤侧膝关节伸膝及屈膝的峰力矩在60°/s下,相对于正常侧分别为81%和87%,120°/s下为76%和85%.各项值均显著低于对侧(P＜0.01).尽管在30°位KT-2000测量值和伸膝肌力的恢复方面,双束重建较单束重建表现出了更好的趋势,但功能评分,KT测量值和BIODEX测量的结果,单、双束组差异无统计学意义.结论 自体胭绳肌腱单、双束重建前交叉韧带均可以恢复膝关节稳定,改善关节功能,双束重建患者在30°位前后稳定性和伸膝肌力方面表现出了较单束重建更好的趋势.     

Release of the transverse carpal ligament alone is associated with elevated pressure beneath the distal volar forearm fascia in a cadaver model of carpal tunnel syndrome

PURPOSE: The purpose of this study is to determine whether release of the distal volar forearm fascia (DVFF) is necessary at the time of median nerve decompression for carpal tunnel syndrome. METHODS: Five fresh-frozen cadaver specimens were mounted vertically with the hand dependent and a 2.27-kg weight suspended from the fingers. A pressure sensor wire was used to measure pressures starting just distal to the transverse carpal ligament (TCL). The wire was withdrawn proximally in 5-mm increments and into the forearm until pressure was below 10 mm Hg. An incision in the forearm was extended distally until the pressure sensor was found. The distance from this point to the distal volar wrist crease was measured. The TCL was released, keeping the DVFF intact, and the experiment was repeated. Paired t-tests determined whether there were statistically significant differences between measurements before and after TCL release. RESULTS: Average peak pressure under the intact TCL was 57.8 +/- 10.1 mm Hg. Average peak pressure under the DVFF with the TCL intact was 61.2 +/- 43.6 mm Hg. Following release of the TCL, average peak pressure beneath the TCL significantly decreased to 14.0 +/- 9.0 mm Hg, whereas average peak pressure at the intact DVFF increased to 64.8 +/- 48.7 mm Hg. Average locations where DVFF pressure became less than 10 mm Hg with an intact TCL and with released TCL were 4.30 +/- 1.8 cm and 4.00 +/- 1.8 cm proximal to the distal volar wrist crease, respectively. There was no significant difference between DVFF pressures before or after TCL release. CONCLUSIONS: In a cadaver model of carpal tunnel syndrome, release of the TCL alone is associated with persistent pressures >30 mm Hg in the region of the DVFF. Release of the TCL did not significantly change the location of the pressure drop-off under the DVFF.     

The effect of medial collateral ligament repair tension on elbow joint kinematics and stability

PURPOSE: Medial collateral ligament (MCL) repair is commonly performed for the management of acute or subacute instability after elbow dislocations and fracture-dislocations. The effectiveness of transosseous repair of the MCL, as is typically performed clinically, in restoring the normal kinematics and stability of the elbow is of interest as is the effect of MCL tensioning on the initial stability of the elbow. The purpose of this study was to determine whether suture repair of the MCL is able to restore the normal kinematics and stability of the elbow and to determine the optimal initial MCL repair tension. METHODS: Six cadaveric upper extremities were mounted in an upper limb joint simulator. Simulated active and passive elbow flexion was generated while the kinematics were measured with the arm in the dependent and the valgus gravity-loaded orientations. After testing the intact elbow, the MCL was released at its humeral attachment and repaired using a transosseous suture technique at three different repair tensions: 20, 40, and 60 N. RESULTS: Medial collateral ligament repair using a transosseous suture technique restored the kinematics and stability of the MCL-deficient elbow. Motion pathways were affected by the magnitude of initial MCL tension. For all arm orientations and forearm positions, the 20-N and 40-N repairs were not statistically different from each other or from the intact MCL. The 60-N repairs, however, were often statistically different than the other groups, suggesting an overtightening that tended to pull the ulna into a varus position-especially in the midrange of flexion. CONCLUSIONS: These data suggest that MCL repair using transosseous sutures provide adequate joint stability to permit early motion. There is a broad range of acceptable tensions for MCL repair, which is a favorable, clinically relevant finding. Clinical studies are needed to validate these in vitro results.     

The effect of the annular ligament on kinematics of the radial head

PURPOSE: There is evidence that the radial head translates during pronation and supination. This study measured radial head movement and the location of the pronation-supination axis of the forearm with and without the annular ligament. METHODS: Thirteen cadaveric arms were attached to a custom-built frame. Pronation and supination were achieved by actuation of the pronator teres and biceps tendons, respectively. Motion was captured by video cameras via marker arrays attached to the distal radius, distal ulna, humerus, and radial head. Three pronation-supination trials were performed with the annular ligament intact and the elbow positioned at 90 degrees . The sequence was repeated after transection of the annular ligament. RESULTS: The radial head traveled an average of 2.1 mm in the anteroposterior direction and 1.6 mm in the mediolateral direction during forearm rotation. After annular ligament resection, travel of the radial head increased by an average of 44% in the mediolateral direction and by 24% in the anteroposterior direction. On average, the mean pronation-supination axis (screw displacement axis) passed 1.4 mm +/- 1.9 medial to the center of the capitellum and through the center of the ulnar head. Loss of the annular ligament did not change the location of the pronation-supination axis. CONCLUSIONS: During forearm rotation, the radial head travels to a greater extent in the anteroposterior direction than in the mediolateral direction. Loss of the stabilizing effect of the annular ligament increases the travel mediolaterally more than anteroposteriorly. The pronation-supination axis of the forearm is nearly constant and is not affected by annular ligament transection.