Contraction history affects the in vivo quadriceps torque-velocity relationship in humans

We hypothesized that the history of contraction would affect the in vivo quadriceps torque-velocity relationship. We examined the quadriceps torque-velocity relationship of the human knee extensors at the descending and ascending limb of the torque-position relationship by initiating the knee extension at a knee angle position of 1.39 rad (80°) or 0.87 rad (50°) over a 0.52 rad (30°) range of motion under conditions of constant or linearly increasing velocity. Maximal voluntary isometric knee extension torque (M₀) was measured at 1.87 rad, 0.87 rad, and 0.35 rad, and concentric torque was measured. The subjects carried out ten maximal knee extensions at ten distinct velocities, each velocity ranging between 0.52 rad·s^–1 to 5.24 rad·s^–1 in steps of 0.52 rad·s^–1. Peak concentric torque was measured and mean torque calculated from the respective torque-time curves. Peak or mean torque, computed from the individual torque-time curves, and velocity data were fitted to the Hill equation under the four experimental conditions and the curve parameters computed. The M₀ was similar at 0.87 rad and 1.39 rad, but it was significantly lower at 0.35 rad. In the low-velocity domain of the torque-velocity curve where a plateau normally occurs, peak torque was always lower than M₀. Peak and mean torque were significantly greater under linearly increasing velocity conditions and the 1.39 rad starting knee position. Mean torque but not peak torque data could be well fitted to the Hill equation and the two computations resulted in significantly different Hill curve parameters including the concavity ratio, peak power, and maximal angular velocity. We concluded that the history of contraction significantly modifies the in vivo torque-velocity relationship of the human quadriceps muscle. Muscle mechanics and not neural factors may have accounted for the inconsistencies in the human torque-velocity relationships reported previously. Electronic Publication     

Arterial and lymphatic supply of the knee integuments

Summary The surgical approach to the anterior knee region carries a risk for postoperative integument infection and skin necrosis. A hypothesis is that surgical approach may damage integumental blood supply and additionally the lymphatic drainage from the foot and leg. The goal of this study was to describe the arteries and lymphatics directly affected by the antero-medial approach. Injection of the femoral a. was used to identify the femoral and popliteal aa. and their branches distributed to the integument of the anterior, medial and lateral aspects of the knee. Lymphatic injection into the plantar aspect of the first toe was also performed to identify the subdermal lymphatics traversing the area. Our results showed that most of the blood supply arises from the medial aspect of the knee integuments. However, subcutaneous arterial anastomoses provide a significant blood-supply when there is interruption of the medial vessels as seen in the medial surgical approach to the knee. Most of the lymphatic drainage originating from the foot crosses the knee region on the medial side, opposite or below the tibial tuberosity. Because the subdermal arterial network is well-developed, the medial approach for knee surgery does not endanger the anterior knee integuments as long as the lateral vascular supply is preserved. However, this approach may interrupt the lymphatic circulation, particularly in the case of an extended incision, which could explain postoperative edema and an increased rate of wound infection.

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Vascularisation artérielle et lymphatique des téguments du genou

Résumé L'abord chirurgical du genou présente un risque d'infection post-opératoire et de nécrose cutanée. Une hypothèse serait que la voie d'abord peut détruire la vascularisation artérielle et lymphatique qui draine la jambe et le pied. Le but de notre étude était de décrire la circulation artérielle et lymphatique impliquée dans la voie d'abord antéromédiale du genou. Des injections ont été utilisées pour identifier les aa. fémorale et poplitée et leurs branches qui se distribuent aux téguments de la région médiale et latérale du genou. Des injections lymphatiques ont été également utilisées pour localiser le réseau subdermique lymphatique de la région du genou. Nos résultats montrent que la majorité de l'apport artériel des téguments du genou provient de la partie médiale. Des anastomoses sub-cutanées entre les systèmes artériels latéral et médial permettent un apport artériel suffisant pour les téguments en cas d'interruption de l'apport médial. La plupart des vaisseaux lymphatiques provenant du pied et de la cheville croisent la région dorsale du pied de dehors en dedans à une distance variable de la tubérosité tibiale. Du fait du bon développement du réseau artériel sub-cutané, la voie d'abord médiale ne présente pas de risque de nécrose des téguments de la face antérieure du genou tant que l'apport latéral est préservé. Toutefois, elle peut être responsable de l'interruption des conduits lymphatiques, en particulier lorsque l'incision s'étend vers le bas, exposant aux lésions des collecteurs lymphatiques, ce qui expliquerait un dème post-opératoire et un taux accru d'infection.

     

M. articularis genus Observations on arrangement and consideration of function

Summary On the basis of 44 adult Japanese cadavers, the mode of origin, insertion and innervation of the articularis genus muscle (m. articularis genus: AG) is described. All the muscle bundles that are inserted into the posterior aspect of the synovial membrane of the joint capsule as well as the suprapatellar bursa are defined as AG. The inserting fibers spread medially and laterally over the subsynovial connective tissue which is the outer layer of synovial membrane facing the femur. The fatty tissue between each muscle bundle gradually increases with depth. A few deeper muscle bundles of AG seem to be separated by a layer of fat from those of the superficial layer. The deepest muscle bundles arise from the anterior surface of the femur at a slighlty lower level than the proximal apex of the suprapatellar bursa. It is inserted into the synovial membrane at the level of the junction of the suprapatellar bursa and proper joint cavity when the knee is extended. It is difficult to distinguish AG from m. vastus intermedius (Vi) only on the basis of the manner of origin and the surrounding fatty tissue. The innervation is in common with that of Vi, namely, a few nerves which run down obliquely to the lower medial part of Vi.Dedicated to Professor Emeritus Tomoo Nakayama in commemoration of his 77th birthday     

Changes in extracellular potassium concentration in cat spinal cord in response to innocuous and noxious stimulation of legs with healthy and inflamed knee joints

Summary In 20 cats anaesthetized with alpha-chloralose and spinalized at the thoracolumbar junction we investigated the role of stimulation induced accumulation of extracellular potassium in the spinal cord in the processing of nociceptive discharges from the knee joint. For that we electrically stimulated the posterior articular nerve of the knee. We further performed innocuous and noxious stimulation of the knee and of other parts of the leg and studied the effect of an acute inflammation of the knee on [K⁺]₀ in the spinal cord. Innocuous stimulation of the skin (brushing or touching) and innocuous movements in the knee joint all induced rises in [K⁺]₀ which were maximal at recording depths of 1500 to 2200 m below the surface of the cord dorsum. Peak increases were 0.4 mM for touching the leg and 1.7 mM during rhythmic flexion/ extension of the knee joint. Noxious stimulation of the skin, the paw, the tendon and noxious movements of the knee joint also produced rises in [K⁺]₀, which were somewhat larger for the individual types of stimuli than those produced by innocuous intensities. Electrical stimulation of the posterior articular nerve induced rises in [K⁺]₀ by up to 0.6 mM. Stimulus intensities sufficient to activate unmyelinated group IV fibers were only slightly effective in raising [K⁺]₀ above the levels reached during stimulation of myelinated group II and III fibers. During development of an acute inflammation of the knee joint (induced by kaolin and carrageenan), increases in [K⁺]₀ and associated field potentials became larger by about 25%. We assume that this reflects an increase in neuronal responses. In conclusion, changes in [K⁺]₀ in the spinal cord are some-what larger during noxious stimulation than during innocuous stimulation. The absolute level reached depended more on the site and type of stimulation than on the actual stimulus intensity itself. Hence a critical role of spinal K⁺ accumulation for nociception is unlikely.     

沙浴治疗兔膝骨关节炎的实验研究

目的：研究沙浴对兔膝关节骨性关节炎(osteoarthritis OA)关节周围血流、膝关节滑膜及软骨的病理改变的影响，为中老年人膝骨关节炎的沙浴治疗提供依据。方法：青紫兰兔15只，成功建立OA动物模型13只，其中12只随机分成自由活动组(A)，自由活动加沙疗组(B)，健侧关节沙疗对照组(C)。在平均气温32℃情况下，将模型兔下半部分掩埋在干燥的40～50℃的海沙中，1次25～30min，1次／d。观察沙疗后即时的膝关节周围血流情况，以及经过沙疗10d和20d后膝关节滑膜及软骨的病理改变。结果：沙疗后患侧膝关节活动改善，膝关节周围血管内血流明显增加，膝关节滑膜细胞层次逐渐减少、炎症细胞明显减少，但软骨细胞退变改善在光学显微镜下不明显。结论：沙疗能增加治疗部位的血流，改善局部血液循环，促进炎症的消退，对正常关节无不利影响。     

关节镜下关节清理术治疗膝关节骨性关节炎(附234例疗效分析)

目的 对关节镜下清理术治疗膝关节骨性关节炎作用机理。优点及影响疗效的因素加以分析。方法 自1993-01-1998-06采用关节镜下清理术,治疗膝关节骨性关节炎患234例（246膝）。结果 随访24个月（6-60个月）,优良率为82.1%。结论 关节镜检有利于膝骨关节炎的早期诊治;依据膝关节痛和关节功能受限的原因,决定镜下清理术的方法和范围;灌注、刨 削、吸引系统,是否伴膝内外翻畸形及术后康复指导均影响其疗效。     

Role of high tibial osteotomy in medial compartment osteoarthritis of the knee: Indications,surgical technique and outcomes

Knee osteoarthritis (OA) is the most common joint disorder worldwide. In particular, primary knee OA often presents with a varus malalignment. This increases the loads going through the medial compartment resulting in cartilage degeneration and symptomatic arthritis. High tibial osteotomy (HTO) is the workhorse surgical procedure for treating medial knee OA. When performed precisely in the hands of an experienced surgeon, HTO can delay or avoid knee arthroplasty. Of note, outcomes of knee arthroplasty are at best unpredictable in patients of younger age. Hence, there is a growing need for joint preservation procedures for younger patients presenting with knee OA, of which HTO is one. Through this article, the authors of whom all are joint preservation surgeons with a special interest in osteotomy hope to share from their experience as well as the available literature on the indications, perioperative planning, surgical technique, outcomes as well as pearls and pitfalls of HTO.     

A short-term radiological and clinical comparison between the bi-cruciate and cruciate retaining total knee arthroplasty A retrospective case controlled study

PurposeThe aim of this study was to provide a short term comparison in radiological and clinical outcome between Bi-Cruciate Retaining (BCR)- and Cruciate Retaining (CR) Total Knee Arthroplasty (TKA).MethodsThe cohort consists of 122 patients undergoing a TKA with PSI, equally distributed over the BCR- and CR-TKA group. Perioperative conditions were observed and radiological images were analysed pre-, 6-weeks, and 1-year postoperative to quantify alignment differences between BCR- and CR-TKA. Preoperatively predicted templates were compared with the implanted size to determine predictive value. In addition mean range of motion and revision rates were determined in both groups.ResultsNo significant difference was observed in amount of outliers in component alignment between BCR- and CR-TKA. Outliers of the Hip-Knee-Ankle-Axis (HKA-axis) occurred significantly more frequent (P = 0.009) in the BCR-group (37.7%) compared to CR-TKA (18.0%). No clinically relevant differences regarding the predictive sizing of implant components was obtained. No significant differences were observed in revision rates (P = 1.000) and ROM (p = 0.425) between the BCR-groep and CR-group at 2-years FU.ConclusionThis study illustrates that although the HKA-axis was not fully restored, bi-cruciate retaining surgical technique for BCR-TKA is safe and effective with comparable radiological and clinical outcome as CR TKA. Randomized controlled trials with longer follow up on the HKA-axis alignment and clinical parameters are needed to confirm the presented results and should focus on possible cut off values concerning leg axis in order to define in what patients a BCR-TKA can safely be used.Level of evidence IVRetrospective Case Controlled Study.     

Knee Flexion Angle Following Total Knee Arthroplasty Relates to a Preoperative Range of Motion of the Hip

BackgroundMany factors have been reported to affect postoperative range of knee flexion after total knee arthroplasty (TKA); however, no study has reported the impact of preoperative range of motion of the hip to the postoperative flexion angle of the knee thus far.MethodsOf 38 consecutive patients who underwent posterior-stabilized TKA, we assessed 21 patients after excluding 17 patients who met exclusion criteria. The range of motion of the knee and the hip, age, body-mass index, serum albumin level, HbA1c, Kellgren–Lawrence grade, knee extension strength and radiological femorotibial angle as well as postoperative knee flexion angle at three months were evaluated. The preoperative data and the knee flexion angle at three months after TKA were compared using Spearman''s rank correlation coefficient.ResultsKnee flexion angle at three months after TKA was positively correlated with preoperative flexion (ρ = 0.616, p = 0.007) and external rotation angle (ρ = 0.576, p = 0.012) of the hip as well as preoperative knee flexion angle (ρ = 0.797, p = 0.001). There were no correlations between postoperative knee flexion angle and other preoperative data.ConclusionsPatients with restricted flexion and/or external rotation of the hip may have contractures of Gluteus maximus, Gluteus medius and Tensor fasciae latae, which can cause hypertension of iliotibial tract. It may cause decreased internal rotation of the tibia when the knee is flexed, which affects postoperative knee flexion angle, thus limited flexion and/or external rotation of the hip might restrict knee flexion angle following TKA.     

前交叉韧带保残重建术中保残策略病例对照研究

目的：比较前交叉韧带保残重建与非保残重建、保留残端重建与保留残根重建的临床疗效。方法：自2014年3月至2017年12月采用自体腘绳肌腱单束重建前交叉韧带断裂患者204例,根据前交叉韧带重建方式不同分为保留残端重建组（A组）、保留残根重建组（B组）和清理残端残根的非保残重建组（C组）。A组76例,男37例,女39例,年龄16~43（28.80±5.41）岁,受伤至手术时间2~11（3.68±1.04）周,采用保留残端前交叉韧带重建术。B组64例,男39例,女25例,年龄18~41（28.42±5.60）岁,受伤至手术时间2~10（3.36±1.68）周,采用保留残根前交叉韧带重建术。C组64例,男37例,女27例,年龄18~43（29.10±6.11）岁,受伤至手术时间3~11（3.54±1.46）周,采用清理残端残根的非保残重建术。术前、术后24个月采用膝关节活动度（range of motion,ROM）观察膝关节屈伸活动范围。术前及术后6、12、24个月采用Lysholm评分和国际膝关节文献委员会（International Knee Documentation Committee,IKDC）评分评估膝关节功能。结果：所有患者术后伤口Ⅰ期愈合,无血管、神经损伤及关节感染等并发症发生。所有患者获随访,A组随访24.00~45.96（35.52±14.40）个月,B组27.96~48.00（37.56±10.68）个月,C组24.00~66.00（37.08±13.44）个月,3组随访时间比较差异无统计学意义（P>0.05）。术后6个月,A组Lysholm评分（82.52±5.24）分,IKDC评分（79.92±3.44）分,高于B组的（80.74±3.14）分和（78.21±4.63）分,且高于C组的（79.22±3.63）分和（76.63±3.80）分（P<0.05）;术后12个月,A组Lysholm评分（89.84±5.13）分,IKDC评分（87.90±3.93）分,高于B组的（85.74±6.04）分和（83.62±5.64）,且高于C组的（82.83±3.43）分和（79.21±4.04）分（P<0.05）。结论：前交叉韧带保残重建术与非保残重建术相比保留了前交叉韧带残端组织,有利于促进肌腱移植物愈合和重塑,加速关节功能恢复。保残重建术中妥善固定残端组织,恢复其张力,是影响术后疗效的关键因素。