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Joint diseases often represent the major part of equine clinician's caseloads. The current study aimed to document the normal anatomy of the donkey shoulder and elbow joints using computed tomography, cadaver sections, and radiography. Seven adult donkeys were used in this study. The current study proved there were no pouches of the donkey shoulder joint. Communication between the joint capsule and bicipital bursa was observed only in two limbs of four used in the present work. The joint was without pericapsular ligaments. The glenohumeral ligament was identified by the thickening of the articular capsule cranially. The shoulder joint approach for intra-articular injection is located on the lateral aspect corresponding to the humerus greater tubercle. The elbow joint capsule is attached to the margins of the articular surfaces of the humerus, radius, and ulna bones. It was thick on the cranial surface of the joint but became thinner caudally. The joint capsule of the elbow joint formed a single pouch cranially and three pouches caudally. The joint had medial and lateral collateral ligaments. The current study recorded that the lateral collateral ligament of the donkey elbow joint was not divided as in the horse, only the medial collateral ligament was divided into two parts; the long cranial and short caudal part. Elbow joint approach for intra-articular injection was in the cranial pouch on the cranial border of the lateral collateral ligament. The data collected within this study will be useful as a normal reference for donkey practitioners.

Joint exposure with an extensive skin defect following soft tissue tumor resection might cause a refractory ulcer. Although a vascularized tissue transplant is ideal for ulcer treatment, it is a highly invasive procedure and usually unsuitable for older patients with general prostration. One-stage perifascial areolar tissue (PAT) and skin grafting combined with negative pressure wound therapy (NPWT) is less invasive and effective procedure for refractory wounds with exposed bones and tendons. This is the first case where this procedure was used to treat a wound that involved an exposed elbow joint with an extensive skin defect. An 80-year-old woman underwent wide excision to remove a leiomyosarcoma on the olecranon with reconstruction using an ipsilateral pedicled latissimus dorsi musculocutaneous flap. The distal three-quarter of the flap was necrosed owing to insufficient blood supply. Furthermore, an articular capsule deficit of 1.5 × 1.0 cm2 was found during necrotomy. The PAT was harvested from the lower abdomen as a non-vascularized tissue, and the articular capsule deficit was covered by overlapping on the granulation tissue around the deficit. Simultaneous split-thickness skin grafting combined with NPWT was applied on the PAT and residual skin defect. Wound healing was achieved in 4 weeks postoperatively without synovial fluid leakage. Elbow joint motion ranging from 0 to 120° was maintained 18 months postoperatively. This procedure helped achieve better wound healing and sufficient functional outcome. Furthermore, this can help decrease patients’ burden by preventing invasive resections associated with severe functional impairments or long-term rehabilitation requirements.

The plantaris muscle usually begins with a short, narrow belly in the popliteal fossa at the lateral supracondylar line of the femur and the knee joint capsule. Then it forms a long and slender tendon and usually inserts into the calcaneal tuberosity on the medial side of Achilles tendon. Nevertheless, many anatomical variations of distal attachment have been described. Cases of atypical proximal origin are reported less frequently. In this paper, we have presented a case of a two headed plantaris muscle. First head attached to the condyle of the femoral bone, medially and inferiorly to the lateral head of the gastrocnemius muscle. The second one originated from the popliteal surface of the femur, just above the intercondylar fossa. According to present literature, no such case with atypical proximal origin was presented. Such information has potentially clinical significance during the surgical procedures performed in the area of the popliteal fossa.

Introduction/Cases. Two pediatric patients presenting with benign bone tumors of the distal femur at the level of the suprapatellar fat pad developed late onset recurrent knee hemarthrosis following surgical treatment of the lesions. A sinus tract from the intramedullary bone to the knee capsule was discovered in both patients during surgical exploration. Resection of the sinus tract and full closure of the knee capsule resulted in no further recurrence. Conclusion. Postoperative knee effusions in patients following resection near the distal femur could represent hemarthrosis that require additional workup and treatment. Resection of the sinus tract successfully treats the hemarthrosis.

Objective: Developing robotic tools that introduce substantial changes in the surgical workflow is challenging because quantitative requirements are missing. Experiments on cadavers can provide valuable information to derive workspace requirements, tool size, and surgical workflow. This work aimed to quantify the volume inside the knee joint available for manipulation of minimally invasive robotic surgical tools. In particular, we aim to develop a novel procedure for minimally invasive unicompartmental knee arthroplasty (UKA) using a robotic laser-cutting tool. Methods: Contrast solution was injected into nine cadaveric knees and computed tomography scans were performed to evaluate the tool manipulation volume inside the knee joints. The volume and distribution of the contrast solution inside the knee joints were analyzed with respect to the femur, tibia, and the anatomical locations that need to be reached by a laser-cutting tool to perform bone resection for a standard UKA implant. Results: Quantitative information was determined about the tool manipulation volume inside these nine knee joints and its distribution around the cutting lines required for a standard implant. Conclusion: Based on the volume distribution, we could suggest a possible workflow for minimally invasive UKA, which provides a large manipulation volume, and deducted that for the proposed workflow, an instrument with a thickness of 5-8 mm should be feasible. Significance: We present quantitative information on the three-dimensional distribution of the maximally available volume inside the knee joint. Such quantitative information lays the basis for developing surgical tools that introduce substantial changes in the surgical workflow.

Background Approximately 9% of shoulder girdle injuries involve the acromioclavicular joint (ACJ). There is no clear gold standard or consensus on surgical management of these injuries, in part perpetuated by our incomplete understanding of native ACJ biomechanics. We have therefore conducted a biomechanical study to assess the stabilizing structures of the ACJ in superior-inferior (SI) translation and anterior-posterior (AP) translation. Methods Twenty fresh frozen cadaveric specimens were prepared and mounted onto a robotic arm. The intact native joint was tested in SI translation and AP translation under a 50-N displacing force. Each specimen was retested after sectioning of its stabilizing structures in the following order: investing fascia, ACJ capsular ligaments, trapezoid ligament, and conoid ligament. Their contributions to resisting ACJ displacements were calculated. Results In the intact native ACJ, mean anterior displacement of the clavicle was 7.9 ± 4.3 mm, mean posterior displacement was 7.2 ± 2.6 mm, mean superior displacement was 5.8 ± 3.0 mm, and mean inferior displacement was 3.6 ± 2.6 mm. The conoid ligament was the primary stabilizer of superior displacement (45.6%). The ACJ capsular ligament was the primary stabilizer of inferior displacement (33.8%). The capsular ligament and conoid ligament contributed equally to anterior stability, with rates of 23% and 25.2%, respectively. The capsular ligament was the primary contributor to posterior stability (38.4%). Conclusion The conoid ligament is the primary stabilizer of superior displacement of the clavicle at the ACJ and contributes significantly to AP stability. Consideration should be given to reconstruction of the ACJ capsular ligament for complete AP stability in high-grade and horizontally unstable ACJ injuries.

Many specific surgical procedures have been identified for treating the dislocation of chronic recurrent temporomandibular joints (TMJs). This article addresses an autologous blood injection (ABI) procedure for the TMJ diagnosis of chronic recurrent TMJ dislocation. A 22-year-old patient reported with chronic TMJ dislocation for 3 months. Autologous blood was injected into upper joint space and surrounding pericapsular tissue under local anesthesia. The patient was followed up regularly. The treatment was successful and the patient had no more dislocation of TMJ as inferred from favorable improvement in mouth opening. Autologous blood infusion (ABI) within the articular capsule and/or pericapsular space or joint depression, is one of the most negligibly intrusive treatments methodology for repetitive separations of TMJ, was as of now presented.

Background: The aim of this study was to assess the innervation of the dorsal articular capsule of the wrist using modified Sihler’s staining. Materials and methods: Thirty dorsal wrist capsules were collected from 15 donors (both sides) within 12 hours of death. All the capsules were collected in the same manner — using the dorsal incision. The specimens were stained according to the protocol of the modified Sihler’s staining technique. The preserved capsules were analysed under 8–16× magnification of an optical microscope for the presence of major nerve trunks, their major and minor branches, and nerve connections. Results: The range of innervation visualised was that the posterior interosseous nerve innervated approximately 60% of the central part; the remaining area was innervated by the dorsal sensory branch of the radial nerve and medial antebrachial cutaneous nerve. The constant findings were the branches departing from the ulnar side of the posterior interosseous nerve and from the radial side, with an exception seen in 2 cases. A communicans branch between the posterior interosseous nerve and medial antebrachial cutaneous nerve was seen in all the specimens. The posterior interosseous nerve innervation extended beyond the level of the carpometacarpal joints II–V. Conclusions: The modified Sihler’s staining technique allows for transparent visibility of the nerves that innervate the dorsal wrist capsule. However, it does not allow as accurate assessment as does histological examination, especially regarding the evaluation of nerve endings. Nevertheless, this method provides a significantly larger area of nerve observation than is provided by histological examination.

Genicular nerve radiofrequency ablation has emerged as a treatment option for patients with painful knee osteoarthritis who have failed conservative management but who may not qualify or wish to avoid a surgical procedure. Radiofrequency ablation techniques targeting the genicular nerves have evolved as our understanding of the anatomy of the anterior knee joint capsule has become more defined. The article aims to review the basic anatomy of the anterior knee joint and both the traditional and revised approaches to nerve ablation.

Reconstruction of a complex knee defect is challenging, especially when complicated with osteomyelitis. Complex knee defect requires multi-component three-dimensional reconstruction using a chimeric flap. Although anterolateral thigh (ALT) flap is the most workhorse chimeric flap, another chimeric flap is required when ALT flap is not available. In this report, we present a case of complex knee defect successfully treated with a free triple-component chimeric deep inferior epigastric artery perforator (DIEP) flap transfer. A 36 year-old male sustained right above-knee amputation and Gustilo IIIB open fracture of the left patella after being run over by a train. Stump formation was performed for the right limb amputation, and the left knee wound resulted in skin necrosis complicated with patella osteomyelitis. After debridement, the left knee wound showed a 3 × 2 cm articular capsule defect, 5 × 2 cm exposed patella stump, and a 16 × 9 cm skin defect. A triple-component chimeric DIEP flap, containing a 7 × 3 cm rectus abdominis muscle (RAM), a 3 × 2 cm RAM's fascia, and a 23 × 10 cm skin was transferred. The RAM's fascia was used to reconstruct the joint, the RAM to cover the exposed patella's stump and the reconstructed joint, and the skin paddle to cover the skin defect. Six months after the surgery, the patient could walk without osteomyelitis recurrence, and there was no limitation in the left knee joint's range of motion. Although indication is limited, a multi-component chimeric DIEP flap may be an option for three-dimensional reconstruction of a complex defect.

Background An understanding of the insertional footprints of the capsular ligaments of the hip is important for preserving hip function and stability given the increasing number of minimally invasive hip surgeries being performed under a limited surgical view. However, it is difficult to detect these ligaments intraoperatively and many surgeons may not fully appreciate their complex anatomy. The aims of this study were to quantify the proximal and distal footprints of the iliofemoral ligament (ILFL) and ischiofemoral ligament (ISFL) and to estimate the location of the corresponding osseous landmarks on the proximal femur, which can be detected easily during surgery. Methods Twelve hip joints from Japanese fresh frozen cadavers were used. All muscle, fascia, nerve tissue, and vessels were removed to expose the intact capsular ligaments of the hip. The length and width of the proximal and distal footprints of the ILFL and ISFL were measured and their relationship to osseous structures was evaluated, including the intertrochanteric line, femoral neck, and lesser trochanter. Results The mean length of the distal medial arm of the ILFL footprint was 17.9 mm and the mean width was 9.0 mm. The mean length of the distal lateral arm of the ILFL footprint was 23.0 mm and the mean width was 9.7 mm. For the footprint of the medial arm, the insertion was in the distal third of the intertrochanteric line and that of the lateral arm was in the proximal 42% of this line. The mean distance from the lesser trochanter to the footprint of the medial arm was 24.6 mm. The mean length of the distal ISFL footprint was 11.3 mm and the mean width was 6.9 mm. The footprint of the distal ISFL was located forward of the femoral neck axis in all specimens. Conclusions Understanding the size and location of each capsular ligament footprint in relation to an osseous landmark may help surgeons to manage the hip capsule intraoperatively even under a narrow surgical view. The findings of this study underscore the importance of recognizing that the distal ISFL footprint is located relatively forward and very close to the distal lateral arm footprint.

The superior capsular reconstruction (SCR) is an arthroscopic surgical technique recently introduced as an effective solution to restore the defect of superior articular capsule in massive rotator cuff tears that cannot be repaired anatomically. The SCR retains static stability and inhibits the proximal humeral migration, thereby optimizing the force couples about the shoulder. In this surgical technique paper, we present our technique of SCR using a double bundle construct of long head of biceps tendon, called the "box" technique. It is always combined with partial rotator cuff repair.

Purpose To evaluate the MRI anatomy of the scapho-trapezial-trapezoidal (STT) ligament complex in asymptomatic and symptomatic individuals. Material and methods In this retrospective study, STT ligament complex of 42 (male 69%, median age 37.5 years) asymptomatic (n = 25) and symptomatic (n = 17) (defined as pain described over the STT joint) individuals was examined using a high-resolution 3D proton density-weighted isovoxel sequence (MR arthrogram) with multiplanar reconstructions. Two musculoskeletal radiologists independently assessed visibility, signal intensity (SI), morphology, and thickness of the radiopalmar scapho-trapezial ligament (rpSTL), palmar scapho-capitate capsular ligament (pSCL), palmar STT capsule (pSTTC), and dorsal STT capsule (dSTTC). Results Interreader agreement ranged from fair to good and intraclass correlations were good. The rpSTL was almost always visible (85.7%/80.1%; reader 1/reader 2). The pSCL and dSTTC were visible in all cases. The pSTTC was visible in only 52.4%/42.9%. Mean thickness of the rpSTL, pSCL, pSTTC, and dSTTC was 1.4 ± 0.5 mm/1.3 ± 0.5 mm, 2.8 ± 0.7 mm/2.7 ± 0.6 mm, 0.5 ± 0.5 mm/0.4 ± 0.4 mm, and 0.5 ± 0.3 mm/0.3 ± 0.3 mm. Both readers rated SI of the rpSTL significantly more often as increased in the symptomatic group (increased SI in asymptomatic group: 20%/15%; symptomatic group: 56%/50%) (p-values p-values ranging between 0.188 and 0.890). For all other ligaments, no significant differences were observed regarding ligament visibility, morphology, and thickness (p-values ranging between 0.274 and 1.000). Conclusion The anatomy of the STT ligament complex can consistently be visualized on high-resolution 3D MRI. Increased signal intensity of rpSTL is significantly more frequent in patients with radial-sided wrist pain.

The problem of anterior cruciate ligament (ACL) reconstruction of the knee joint remains relevant, despite of significant number of designed surgical techniques for its reconstruction. Repeated ruptures of the restored ACL are recorded in 3–15 % of cases. Objective: to determine the morphological features of the knee joint tissues rearrangement in rabbits after implantation of a polypropylene mesh (PM) into the capsule defect. Methods: the study was performed on 50 rabbits weighing (694 ± 27) g. A capsule defect was formed on the right knee joint between the patellar ligament and the medial collateral ligament. In the experimental group (25 rabbits), the defect was repaired using PM, in the control group (25) — the edges of the defect were tightened and sutured with vicryl. A modified Vanderbilt University scale was used to assess the scarring process. Morphological analysis was performed. Results: no significant clinical differences in the state of the operated knee joint in the postoperative period were found between the groups. In the control group, from the 7th day after the surgery, the formation of dense connective tissue (scar) was observed. In animals of the experimental group, against the background of the formation of connective tissue around the PM, a significant thickening of the capsule and ligaments was observed at the points of contact with it. In 21 days after PM implantation, 51–75 % of its area showed ingrowth of connective tissue, after 45 — 75–100 %. After 2 months after the surgery, the relative area of dense connective tissue in the experiment was (68.12 ± 2.74) % versus (51.68 ± 4.22) % in the control.Conclusions: implantation of PM into the area of the knee joint capsule defect of rabbits between the patellar ligament and the medial collateral led to the formation of a larger volume of dense connective tissue at the final follow-up period (2 months). Ingrowth of connective tissue between cells and fibers of PM promotes the formation of a tight connection with the surrounding tissues, thereby strengthening area of traumatic injury.

Primary skin and soft tissue reconstruction of large defects around the knee may be a challenge for the plastic surgeon. Fasciocutaneous flaps play an essential role in achieving functional and aesthetic restoration. We present the surgical reconstruction of an extensive 3rd degree burn injury with knee joint capsule and ligaments involvement in a 51-year-old patient. Devitalized structures were firstly debrided and a supercharged reverse anterolateral thigh (RALT) flap was used to cover the resultant tissue defect. The ALT fascia was employed to reconstruct the damaged joint capsule in order to restore articular function. The supercharged RALT flap has a greater blood supply compared with standard flaps and enables us to use larger flaps to reconstruct extensive knee and proximal leg tissue defects.

Background Radiofrequency ablation (RFA) of the articular branches innervating the anterior knee capsule has been studied as a possible alternative to surgery for degenerative arthritis. However, the neurovascular topography of the anterior knee capsule remains unclear. Methods One leg from each of the 20 formalin-embalmed cadaveric specimens was investigated. Modified ablation points (MAPs) were evaluated for a possible alternative for conventional target points (CAPs). Results For the nerve to vastus medialis (NVM), the probability of identifying the nerve was higher at MAP compared with CAP (62.5% vs. 25%). The mean shortest distance from the nerve was shorter at MAP compared with CAP (18.0 mm vs. 29.9 mm). The probabilities and distances for other nerves were not significantly different between the points. However, the probability of identifying the artery was significantly lower at MAPs compared with CAPs for arteries (0%, 5.3%, and 0% vs. 84.2%, 84.2%, and 73.3% for superior medial genicular, superior lateral genicular, and inferior medial genicular artery, respectively). For the recurrent peroneal nerve (RPN), a new target point was set in MAPs. Conclusions The current landmark for genicular nerve procedures may not accurately target the correct nerve position, or reduce the risk for vessel damage. A more proximal target may reduce complications and increase the probability of successful procedures, although clinical correlation is needed.

Aims The anterior cruciate ligament (ACL) is known to have a poor wound healing capacity, whereas other ligaments outside of the knee joint capsule such as the medial collateral ligament (MCL) apparently heal more easily. Plasmin has been identified as a major component in the synovial fluid that varies among patients. The aim of this study was to test whether plasmin, a component of synovial fluid, could be a main factor responsible for the poor wound healing capacity of the ACL. Methods The effects of increasing concentrations of plasmin (0, 0.1, 1, 10, and 50 µg/ml) onto the wound closing speed (WCS) of primary ACL-derived ligamentocytes (ACL-LCs) were tested using wound scratch assay and time-lapse phase-contrast microscopy. Additionally, relative expression changes (quantitative PCR (qPCR)) of major LC-relevant genes and catabolic genes were investigated. The positive controls were 10% fetal calf serum (FCS) and platelet-derived growth factor (PDGF). Results WCS did not differ significantly among no plasmin versus each of the tested concentrations (six donors). The positive controls with PDGF and with FCS differed significantly from the negative controls. However, we found a trend demonstrating that higher plasmin concentrations up-regulate the expression of matrix metalloproteinase 13 ( MMP13), 3 ( MMP3), and tenomodulin ( TNMD). Conclusion The clinical relevance of this study is the possibility that it is not solely the plasmin, but also additional factors in the synovial fluid of the knee, that may be responsible for the poor healing capacity of the ACL. Cite this article: Bone Joint Res 2020;9(9):543–553.

The dorsal radiocarpal ligament (DRCL) is a dorsal capsular ligament with a significant role in carpal stability. We should consider the arthroscopic repair of the DRCL in cases of isolated DRCL tear or when the DCRL tear is the only clinically evident injury. Arthroscopic view of the DRCL tear is better through the volar radial portal. The purpose of the present article is to describe three cases of uncommon DRCL tear in patients with chronical dorsal wrist pain that were treated by arthroscopic repair. This condition can easily be unrecognized by the orthopedic surgeon if it is not specifically searched for. Good results are expected following the arthroscopic repair of an isolated DRCL tear; however, the contribution of the DRCL to the final outcome in combined repairs is difficult to isolate.

The plantaris is a small muscle that typically originates at the lateral supracondylar line of the femur and the knee joint capsule, from where it continues distally, forming a long and slender tendon. However, considerable controversy surrounds the status of this seemingly inconspicuous muscle: is it a residual muscle, or one that it is just developing? In addition, both the proximal and distal attachments are highly morphologically variable. These variations can lead to many diseases. Interestingly, the course of the PM tendon is also variable. The present case study presents a new description of a complex origin type and a rare course of the PM tendon. Understanding of the PM and its tendon has clear clinical value and is a significant indicator of the development of interest in this overlooked muscle.

This paper suggests a novel type of bio-inspired finger design in that the joints that compose the finger mimic the features of human finger joints. They have isomorphic structures but different movements, further, there is no friction between bones in the joint, and the joint has a compliance property in all the directions thanks to the elasticity of ligaments. In the proposed joints, a number of strings substitute the articular capsule and collateral ligaments based on the concept of a tensegrity structure. Ultimately, a compliant robotic finger based on the ligamentous structure of the human is proposed. In addition, adjusting the fixed positions of the strings without any structural change, the joint can have a rest position yielded from the elasticity of the strings, and thereby, the tendon is only needed to drive the finger. Especially, since the finger does not have any mechanical rotating parts such as bearings and bushes, it can freely operate even underwater. As the proposed finger design is a type of underactuated mechanism, it is able to realize active flexion, passive extension, and passive adduction and abduction.

Shoulder pain is a highly prevalent condition, often resulting in major life limitations, and requiring effective treatments. In this work, we explore the anatomical basis of a proposed approach to the regional anesthesia of the shoulder through a single injection under the subscapularis muscle. Bilateral experimental injections in shoulders from body donors (Radiolar (R) and Methylene-Blue) under the subscapular muscle (n = 11) and cadaveric systematic dissections of other 35 shoulders from body donors were performed. Injectate spread was then qualitatively assessed. Long axis of permeable foramina in the anterior aspect of the shoulder joint capsule was measured in centimeters using a digital caliper. More than 40% of specimens had at least one permeable space (Weitbrech and/or Rouviere foramina) communicating the subscapular bursa and the articular space. We further demonstrate that an ultrasonography-guided injection under the subscapularis muscle allows the spread of the injectate through the anterior, inferior and posterodorsal walls of the articular capsule, the subacromial bursa, and the bicipital groove, as well as into the articular space for some injections. The odds of accidental intraarticular injection decrease when injecting with low volumes. This anatomical study provides a detailed description of foramina between glenohumeral ligaments. Furthermore, the data shown in this work supports, as a proof of concept, a safe alternative for rapid and specific blockade of terminal sensory branches innervating the shoulder joint capsule. (c) 2021 Elsevier GmbH. All rights reserved.

Internal joint structures such as ligaments are rich with sensory receptors. How the central nervous system (CNS) uses the information provided by these receptors to modify motor commands or guide rehabilitation is still poorly understood. Here, we provide evidence that the sensory afferents originating from the receptors within the knee capsule affect the coordination of the quadriceps muscles in the rat. This result suggests the existence of control loops driven by these receptors. Lesions to internal joint structures should therefore not solely be considered as musculoskeletal injuries, but more broadly as neuromuscular injuries.

This paper suggests novel types of joint mechanisms composed of elastic strings and rigid bodies. All of the human hinge joints have the articular capsule and a pair of collateral ligaments. These fibrous tissues make the joint compliant and stable. The proposed mechanism closely imitates the human hinge joint structure by using the concept of tensegrity. The resultant mechanism has several characteristics shown commonly from both the tensegrity structure and the human joint such as compliance, stability, lightweight, and non-contact between rigid bodies. In addition, the role and feature of the human hinge joints vary according to the origins of a pair of collateral ligaments. Likewise, the locations of two strings corresponding to a pair of collateral ligaments produce different function and motion of the proposed mechanism. It would be one of the advantages obtained from the proposed mechanism. How to make a joint mechanism with different features is also suggested in this paper.

This research focuses on the anatomical insertion of the synovial capsule around the knee. The attachments of the capsule were measured in 50 knee MR imaging studies with large intraarticular effusion. Corresponding measurements were performed in 20 fresh frozen cadaveric specimens, for validation. Femoral and tibial capsular reflections were defined as the distances between the attachment sites of the capsule and the femoral or tibial joint line and they were recorded in three coronal planes (anterior/middle/posterior). On MR imaging, the lateral/medial femoral capsular reflection mean values were 6.5/4.57 cm, 2.74/1.74 cm and 1.52/1.99 cm in the anterior, middle and posterior plane, respectively. MR imaging-based measurements did not differ significantly compared to corresponding cadaveric measurements. The mean values of the lateral/medial tibial capsular reflection on MR imaging were 0.09/0.11 cm, 0.34/0.26 cm and 0.62/0.34 cm in the anterior, middle and posterior plane, respectively. On cadaveric dissection, the maximum mean value was 1.45 cm, measured on the lateral side of the anterior plane. Apart from the lateral aspect of the posterior plane, MR imaging measurements were significantly lower, compared to the corresponding cadaveric measurements. The greatest femoral and tibial capsular reflections were found on the anterior and lateral side of the anterior plane. MR imaging appears to underestimate the distal extent of the knee capsule. Anatomical details of the knee capsule should be considered for safe insertion of external fixator pins.

PURPOSE The lateral ankle ligament complex (LALC) is composed of anterior talofibular (ATFL), calcaneofibular (CFL), and posterior talofibular (PTFL) ligaments, all of which have a connection/continuous fiber. However, the structural link between the LALC and the articular capsule remains unknown. The goal of our study was to determine the connection between ATFL's inferior fascicle and the articular capsule. METHODS In this study, we utilized 84 formalin-fixed ankles to elucidate the structure of LALC. Between ATFL and CFL, the bundle number of ATFL and arciform fiber was investigated. The specimens were decalcified and sectioned coronally using a freezing microtome, in the case of double bundles of ATFL, to study the connection between the inferior fascicle of ATFL and the articular capsule. RESULTS ATFL had a single (25%), double (74%), and triple (1%) bundle number, respectively. The arciform fiber connecting the ATFL and the CFL was found in the superficial layer of all ankles (100%). There were two types of relationships between the inferior fascicle of ATFL and the articular capsule: 36 ankles (58%) were extracapsular, and 26 of 62 ankles (42%) were integrated with the inferior-lateral articular capsule. There are two kinds of relationships between the inferior fascicle of the ATFL and the articular capsule: extracapsular and integrated-capsular. CONCLUSIONS The inferior fascicle of ATFL has a variant and integrated-capsular type is reinforced inferior-lateral articular capsule and enters the joint to form continuous fibers with PTFL, making LALC. These anatomical findings are helpful in ultrasonography diagnosis and arthroscopic ankle surgery.

The management of pain in patients undergoing total knee arthroplasty (TKA) for chronic knee osteoarthritis (OA) has remained a challenge for the anesthesiologist regarding regional anesthesia as no single regional technique is adequate with regard to balancing effective analgesia with minimal muscle weakness. Severe postoperative pain following TKA has been shown to negatively impact patient outcomes and mortality. The genicular nerve block has recently been demonstrated to provide effective analgesia to the anterior and posterior knee capsule in recent studies. In this retrospective case series, we compare the efficacy of combined genicular nerve block (GNB) and adductor canal block (ACB) to only ACB in both primary and revision TKA patients. This combined novel approach for TKA patients can be utilized to improve patient pain scores and early ambulation, limiting the use of opioids and early discharge.

In vitro models of arthroplasty enable pre-clinical testing and inform clinical decision making. Repeated-measures comparisons maximise resource efficiency, but their validity without testing order randomisation is not known. This study aimed to identify if there were any large testing order effects for cadaveric models of knee and hip arthroplasty. First, the effect of testing order on total knee arthroplasty (TKA) biomechanics was assessed. Extension moments for TKAs (N = 3) implanted into the native knee (TKA-only) were compared to a dataset of TKAs (N = 24) tested after different combinations of partial knee arthroplasty (TKA-last). The effect of repeatedly testing the same knee five times over 36 h on patellofemoral and tibiofemoral kinematics was also quantified. Second, the effect of testing order on capsular ligament function after total hip arthroplasty (THA) was assessed. Randomisation was removed from a previously published dataset to create increasing and decreasing head size groups, which were compared with t-tests. All three TKA-only extension moments fell within the 95% CI of the TKA-last knees across the full range of knee flexion/extension. Repeated testing resulted in root-mean-squared kinematics errors within 1 mm, 1°, or 5% of total range of motion. Following THA, smaller head-size resulted in greater laxity in both the increasing (p = 0.01) and decreasing (p 0.001) groups. Testing order did not have large effects on either knee or hip arthroplasty biomechanics measured with in vitro cadaveric models.

A giant cell tumor of the tendon sheath (GCTTS) is a benign, soft tissue (synovial membrane) tumor that frequently involves the fingers. However, the localized form of the GCTTS can be rarely seen in large joints such as knees, ankles, and shoulders. GCTTS may occur due to questionable etiology that includes inflammation, trauma, or chromosomal abnormalities. This is a case of a 30-year-old female, who presented with a painful mass in her right knee. Examination revealed a palpable, tender, slightly mobile mass lateral to the patella. MRI demonstrated a cystic lesion that underwent excision. Data from the reported cases imply that local recurrence was observed in 10%-20% of patients due to incomplete primary resection. Physicians should consider the likelihood of a GCTTS when an intra-articular knee prominence is found. Early diagnosis and appropriate treatment can help with rapid clinical improvement.

Background The preservation of soft tissues is an important factor for preventing dislocation after total hip arthroplasty. Anatomical studies have revealed that the inferior iliofemoral ligament (ILFL) contributes significantly to the native stability of the hip. This study aimed to investigate the anatomical structures of the iliocapsularis muscle (ICM) and ILFL from a surgical perspective. Methods In total, we assessed 50 hip specimens from 25 embalmed cadavers. The size and location of ICM and ILFL (at the upper, middle, and lower parts of the femoral head) were assessed in a neutral position. The ratio of ICM and ILFL widths to the femoral head was evaluated. Results The mean ICM and ILFL widths were 7.5 and 14.6, 12.0 and 14.2, and 12.8 and 15.2 mm at the upper, middle, and lower levels, respectively. The mean ICM thicknesses were 1.3, 9.0, and 9.1 mm at the upper, middle, and lower levels, respectively. The distributions of ICM and ILFL from the lateral edge of the femoral head were 21.1%–37.4% and 4.9%–36.5%, 9.5%–35.6% and 7.9%–38.7%, and 11.0%–38.7% and 9.5%–42.4% at the upper, middle, and lower levels, respectively. Conclusion ICM and ILFL were located at the anterolateral side of the femoral head, and the medial edge of the ILFL corresponded to that of the ICM. ICM can serve as a landmark for preserving ILFL in total hip arthroplasty using the anterior approach.

Background In the absence of frank craniocervical dissociation, there is a lack of consensus regarding what patterns of craniocervical junction ligamentous injuries require occipital-cervical fusion. This study was undertaken to examine the integrity of the craniocervical junction ligaments and analyze clinical outcomes in patients who underwent occipital-cervical fusion for craniocervical junction injury. Methods Adult patients requiring occipital-cervical fusion were identified retrospectively utilizing keyword searches in cervical computed tomography and magnetic resonance imaging reports between 2012 and 2020 using Nuance mPower software (Nuance, Burlington, MA). The cervical magnetic resonance imaging examinations for these patients were reviewed for craniocervical ligamentous injury by two neuroradiologists. Descriptions of craniocervical junction injuries, demographic information, clinical history, surgical management, and global outcomes were recorded. Results Nine adult patients were identified with an acute, post-traumatic craniocervical junction injury requiring occipital-cervical fusion. All nine patients demonstrated a ligamentous tear in at least one of the four major craniocervical junction ligaments - the occipital condylar-C1 capsular ligaments, alar ligaments, tectorial membrane, and posterior atlantooccipital membrane. The tectorial membrane was the most commonly torn ligament followed by the alar ligament(s), posterior atlantooccipital membrane, and capsular ligament(s). There was wide variability in the number of major craniocervical junction ligaments torn, ranging from one ligament to all four ligaments. Four patients suffered persistent neurologic deficits following surgery. Conclusion Craniocervical injury is best evaluated by cervical magnetic resonance imaging. In the absence of overt craniocervical dissociation, we propose that an injury of the tectorial membrane in the adult population may indicate patients with significant craniocervical instability, possibly necessitating occipital-cervical fusion.

ObjectiveThis study aimed to develop a comprehensive but easy to apply histologic grading system to score osteoarthritic changes in the whole knee joint for both spontaneous and posttraumatic osteoarthritis (OA) mouse models.MethodsThe new OA grading scheme was developed based on extensive literature review and the authors’ experience in mouse OA models with relatively long periods of observation (up to 24 months of age or 24-week post-surgery). Semi-quantitative assessments of the histopathologic OA changes were applied to all four quadrants of the knee. Grading elements per quadrant were defined as follows: cartilage (0-7) including three new grading elements for early- and late-stage OA, respectively; osteophyte (0-2) covering chondro-osteophytes in both outer and inner joint margins; subchondral bone (0-2) containing subchondral bone thickening and destruction; synovitis (0-2) comprised of both synovial plica and intercondylar notch; and peri-articular tissues (0-2) highlighting ectopic chondrogenesis and ossification in the knee capsule, ligament, and musculature.ResultsStatistical analyses showed that the new grading system had high intra- and inter-observer reproducibility (Pearson’s correlation coefficients r >0.9) for both experienced and novice scorers. Sensitivity and reliability analyses confirmed the ability of the new system to detect minimal OA progression between two timepoints with a two-week interval and to accurately identify tissue-specific OA severity within the knee joint.ConclusionsThe comprehensive histologic grading system presented here covers all-stage osteoarthritic changes in all major knee joint tissues of mice, which enable us to score OA severity for the whole joint reproducibly and accurately without software-assisted time-consuming measurements.

Anterolateral ligament (ALL) was recently described as an important structure to control the pivot-shift phenomenon in the knee. Doubts remain regarding its origin and histological properties. The purpose of this study was to identify the ALL histological structure comparing its characteristics with those of the anterior cruciate ligament (ACL) and joint capsule. ALL was harvested in 25 knees during a total knee arthroplasty (TKA) and histologically evaluated investigating for orientation of fibers, adipose tissue, presence of proprioceptors and synovial like coating. Analysis showed significant differences in several aspects between capsule and ALL; analogies were found comparing the ALL with ACL.

Background Traumatic arthrotomy of the knee (TAK) involves the violation of the knee capsule. TAK differs from simple lacerations because it requires operative management to prevent resultant septic arthritis. The diagnostic test of choice in the emergency department is the saline load test (SLT). SLT sensitivity ranges from 34% to 99%, depending on volume used. Computed tomography (CT) is a possible alternative, using intra-articular air as a diagnostic marker. Ultrasound can identify air in various tissues, given its highly echogenic nature. Objective We sought to determine the sensitivity and specificity of ultrasound for detecting intra-articular air in cadaveric knee joints. Methods Soft embalmed cadavers were utilized. The knees were block randomized to having 1 mL of air injected into the joint or sham skin injection. Two blinded, expert operators scanned the knees with a high-frequency linear transducer. The sensitivity and specificity were calculated. Results Twenty knees were included. Knees that had any prior dissection were excluded from analysis. Ten knees were randomized for air injection. The pooled sensitivity was 0.65 (95% confidence interval [CI] 0.41–0.85) with a specificity of 0.75 (95% CI 0.48–0.93). Mean time taken was 143 s. Conclusions Ultrasound may have utility in evaluation of TAK. There were limitations. Some knees had effusions with echogenic material present, which could have led to false-positive results. It is also unknown how much air is typical of TAK. One milliliter was used based on previous work with CT. The use of ultrasound for diagnosis of TAK warrants further study.

BACKGROUND: Despite their emerging therapeutic relevance, there are many discrepancies in anatomical description and terminology of the articular nerves supplying the human knee capsule. This cadaveric study aimed to determine their origin, trajectory, relationship and landmarks for therapeutic purpose. METHODS: We dissected 21 lower limbs from 21 cadavers, to investigate the anatomical distribution of all the articular nerves supplying the knee joint capsule. We identified constant genicular nerves according to their anatomical landmarks at their entering point to knee capsule and inserted Kirschner wires through the nerves in underlying bone at those target points. Measurements were taken, and both antero-posterior and lateral radiographs were obtained. RESULTS: The nerve to vastus medialis, saphenous nerve, anterior branch of obturator nerve and a branch from sciatic nerve provide substantial innervation to the medial knee capsule and retinaculum. The sciatic nerve and the nerve to the vastus lateralis supply sensory innervation to the supero-lateral aspect of the knee joint while the fibular nerve supplies its infero-lateral quadrant. Tibial nerve and posterior branch of obturator nerve supply posterior aspect of knee capsule. According to our findings, five constant genicular nerves with accurate landmarks could be targeted for therapeutic purpose. CONCLUSION: The pattern of distribution of sensitive nerves supplying the knee joint capsule allows accurate and safe targeting of five constant genicular nerves for therapeutic purpose. This study provides robust anatomical foundations for genicular nerve blockade and radiofrequency ablation.

Background The relationship of Common peroneal nerve (CPN) to the posterolateral corner of the knee joint is important for surgeons who perform total knee arthroplasty to avoid injury to the nerve during surgery. This relationship varies among different races on account of anthropometry. This study aims to evaluate the anatomical location of this nerve in Indian patients using an MRI based reference system. Methods 213 knee magnetic resonance images (MRIs) were evaluated in axial plane 8 mm below the joint line for distance of the CPN from the closest posterolateral capsule. The angle of the CPN from the center of the tibial anteroposterior axis and relation of CPN with respect to the popliteus were evaluated. A comparative analysis of these measurements among Caucasian, Chinese and Indian patients was made to evaluate for any differences. Results The mean distance between the CPN and the knee capsule was 15.55 mm (range, 7.8–26.2 mm). The mean angle of the CPN from the center of the AP axis was 50.1° (range, 38–63). CPN was found to be in line with the popliteus from center of the knee in 62% cases. There was no significant difference among the different races among the measured parameters (p > 0.005). Conclusion This study establishes a “danger zone” and a “safe zone” to avoid CPN injury in total knee arthroplasty in Indian patients and identifies anatomic landmarks to localize the nerve before the soft-tissues release in order to avoid direct injury.

Background After a trauma, exuberant tissue healing with fibrosis of the joint capsule can lead to posttraumatic joint stiffness (PTJS). Losartan and atorvastatin have both shown their antifibrotic effects in different organ systems. Objective The purpose of this study was the evaluation of the influence of losartan and atorvastatin on the early development of joint contracture. In addition to joint angles, the change in myofibroblast numbers and the distribution of bone sialoprotein (BSP) were assessed. Study design and methods In this randomized and blinded experimental study with 24 rats, losartan and atorvastatin were compared to a placebo. After an initial joint injury, rat knees were immobilized with a Kirschner wire. Rats received either losartan, atorvastatin or a placebo orally daily. After 14 days, joint angle measurements and histological assessments were performed. Results Losartan increased the length of the inferior joint capsule. Joint angle and other capsule length measurements did not reveal significant differences between both drugs and the placebo. At cellular level both losartan and atorvastatin reduced the total number of myofibroblasts (losartan: 191±77, atorvastatin: 98±58, placebo: 319±113 per counting field, p

The metabolic, reparative and plastic properties, as well as the functional activity of the multiorgan synovial environment of the knee joint, are organically and functionally related to their morphology and blood supply. The aim of our research was to determine the general biological and specific features of the structural organization and vascularization of the knee joint capsule in animals with different supports, locomotion and body weight. A complex of morphological research methods is used in this work: anatomical, histological, neurohistological. Used neurohistological method of impregnation in its own algorithm. The structural organization of synovial and fibrous capsule, histotopography of intraorganic vessels was studied on 43 objects of various groups of animals. The selection of animals was carried out according to the type of limb specialization to the substrate. Animals were taking into account the ecology, types of support, the nature of locomotion and the speed of movement – phalanoid animals – a domestic horse, a domestic bull and a finger animal – a domestic dog and a domestic cat. As a result of the complex comparative-morphological study the general patterns of the structural organization of the articular capsule, the general-biological and species-specific features of the angioarchitectonics and angiotopography were established. The zones of the most intense intraorganic vascularization and the topography of the vascular fields and glomeruli of the articular capsule are shown. The zones of intensive vascularization are localized: in the domestic bull – in the medial, dorsal, lateral parts, vascular glomeruli – in the lateral; in the domestic horse – in all parts of the capsule, vascular glomeruli – in the plantar area; in the domestic dog – in the medial, dorsal, plantar parts, vascular glomeruli – in the plantar area; in a domestic cat, the same type of angioarchitectonics is observed, the vascular fields and glomeruli are absent. The more intense angioarhitectonics in the capsule of the knee joint in phalanoid animals (horse, cattle) than in the finger (dog, cat) possibly due to the different nature of the support and type of locomotion, is determined. Key words: vascular fields, vascular glomeruli, angioarchitectonics, knee joint, joint capsule, domestic horse, domestic bull, domestic dog, domestic cat.

Introduction The superior articular capsule complements the rotator cuff's function in shoulder stability. With irreparable rotator cuff tears, superior capsular reconstruction (SCR) improves dynamic glenohumeral (GH) joint kinematics. We present a novel method of SCR in cadaveric shoulders using the long head of bicep (LHB) tendon instead of previously explored fascia lata autograft, thereby reducing harvest site and suture anchor associated complications. Hypothesis This novel method of SCR using the LHB is feasible biomechanically in restoring shoulder stability in irreparable supraspinatus tendon tear. Materials and methods Seven cadaveric shoulders were tested in a custom shoulder testing system. Superior translation of the humerus, subacromial contact pressure and area, and glenohumeral range of motion were tested at 0°, 30°, and 60° of glenohumeral abduction in the following conditions: (1) intact shoulder, (2) simulated complete supraspinatus tendon tear, (3) modified SCR using LHB, (4) and modified SCR using LHB and side-to-side repair augmentation. Results The complete cuff tear shifted the humeral head superiorly as compared to the intact shoulder. Subacromial peak contact pressure was also increased at 30° and 60° while contact area was increased at 0° and 30°. The modified SCR both with and without side-to-side repair shifted the humeral head inferiorly at 30° and 60°, with contact area further reduced at 60°. Both techniques had comparable results for contact pressure and total rotational range of motion. Conclusion The LHB with appropriate distal insertion on the greater tuberosity restores shoulder stability in irreparable rotator cuff tears by re-centering the humeral head on the glenoid. Level of evidence Basic science study, biomechanical testing.

Cervical spine finite element models reported in biomechanical literature usually represent a static morphology. Not considering morphology as a model parameter limits the predictive capabilities for applications in personalized medicine, a growing trend in modern clinical practice. The objective of the study was to investigate the influence of variations in spinal morphology on the flexion-extension responses, utilizing mesh-morphing-based parametrization and metamodel-based sensitivity analysis. A C5-C6 segment was used as the baseline model. Variations of intervertebral disc height, facet joint slope, facet joint articular processes height, vertebral body anterior-posterior depth, and segment size were parametrized. In addition, material property variations of ligaments were considered for sensitivity analysis. The influence of these variations on vertebral rotation and forces in the ligaments were analyzed. The disc height, segmental size, and body depth were found to be the most influential (in the cited order) morphology variations; while among the ligament material property variations, capsular ligament and ligamentum flavum influenced vertebral rotation the most. Changes in disc height influenced forces in the posterior ligaments, indicating that changes in the anterior load-bearing column of the spine could have consequences on the posterior column. A method to identify influential morphology variations is presented in this work, which will help automation efforts in modeling to focus on variations that matter. This study underscores the importance of incorporating influential morphology parameters, easily obtained through computed tomography/magnetic resonance images, to better predict subject-specific biomechanical responses for applications in personalized medicine.

Tenosynovial giant cell-tumor is a benign tumor of the synovial layer of the joints; for a long time to characterize this nosology, the term “villous- nodular synovitis” was used and considered it as a kind of inflammatory post-traumatic process in the joint capsule, and only in-depth studies of the properties of TSGCT at the molecular and cytogenetic levels proved its neoplastic nature. The purpose — to determine the peculiarities of approaches to differential diagnosis of TSGCT with exudative-proliferative syndromes, based on the clinical and morphological studies of biopsy-resection material. The study was performed on 95 cases of TSGCT of diffuse type of different localization, 56 cases of rheumatoid arthritis and 48 cases of non-specific post-traumatic pigmented synovitis. Grades of expressiveness of morphological indicators were evaluated according to the visual-analog scale from low to high with an increase of x100. Hypertrophic, hyperplastic and inflammatory changes in the articular capsule in cases of nonspecific pigmented synovitis are limited to a synovial layer. Hemosiderin is found in the cytoplasm of synovial cells and in siderophages. Nodular and solid proliferators, signs of invasion in adjacent tissues, are absent, which is an important feature in the differential diagnosis of lesions of the joint capsule, rich in clusters of macrophage siderocytes. At histological examination in isolated tissues in patients with rheumatoid arthritis signs of chronic non-specific productive-infiltrative and exudative inflammation of different activity were found — a cluster of mononuclears and plasmacites with the formation of small lymphoid follicles in its own synovial plate, hyperemia of the microcirculatory bed, and fibrin layers. The difference between the described synovitis from TSGCT is the absence of nodular proliferators, infiltrative changes in the deep departments of the capsule, hemorrhages, clumps of hemosiderin and large epithelioid synovitis, which is characteristic of tumors. TSGCT is characterized by polymorphism of histological changes and different degrees of prevalence in joint structures, which in many cases complicates its differential diagnosis.

According to the acknowledged recommendations of the multidisciplinary "Study Group on Forensic Age Diagnostics," the indicator "medial clavicular ossification" carries the potential of delivering decisive evidence to proof age majority "beyond reasonable doubt" regarding age-disputed individuals within legal procedures. Yet, sternoclavicular thin-slice computed tomography, representing its preferred imaging modality, not rarely exhibits peculiar morphologies of the site, sometimes difficult to understand from the usually obtained, axial sections together with coronal reformations. Because of that, we utilized 3D-rendering of acquired CT data in 224 cases with the purpose to gain additional visualization of certain questionable appearances. Concerning reliable classification of medial clavicular ossification in line with the typologies of Schmeling et al. and Kellinghaus et al., it is concluded that such means of illustration contribute to recognition of polygonal or irregular, epiphyseal formations including the not-assessable shape variant "multiple, medial, secondary ossification centres" and of calcification of the articular capsule.

Introduction The plantaris muscle (PM) is a small, fusiform muscle located between the gastrocnemius muscle (GM) and soleus muscle (SM). PM supports movements of the knee and ankle. This muscle presents a great variability, and also has a high clinical significance. Nevertheless, data concerns morphology and morphometry of the origin of PM in human fetuses are scarce. Material and methods Forty-seven spontaneously-aborted human fetuses (23 male, 24 female) aged 18–38 weeks of gestation were examined. The morphology and morphometry of the origin of PM were evaluated. Results PM was present in 74 lower limbs (78.7%), and absent on 20 limbs (21.3%). We distinguished VI types of the proximal attachment of PM. Belly width and thickness, as well as thickness of the tendon and MT junction differed significantly between types of PM origin. Conclusions We distinguished six (I–VI) types of origin of PM in human fetuses. The most common type was type Ia, characterized by an attachment to the lateral head of GM, lateral femoral condyle and to the knee joint capsule. Our results of PM anatomical variation in fetuses will pave the way for detailed comparisons with studies carried out on adult cadavers.

The human lumbar facet capsule, with the facet capsular ligament (FCL) that forms its primary constituent, is a common source of lower back pain. Prior studies on the FCL were limited to in-plane tissue behavior, but due to the presence of two distinct yet mechanically different regions, a novel out-of-plane study was conducted to further characterize the roles of the collagen and elastin regions. An experimental technique, called stretch-and-bend, was developed to study the tension-compression asymmetry of the FCL due to varying collagen fiber density throughout the thickness of the tissue. Each healthy excised cadaveric FCL sample was tested in four conditions depending on primary collagen fiber alignment and regional loading. Our results indicate that the FCL is stiffest when the collagen fibers (1) are aligned in the direction of loading, (2) are in tension, and (3) are stretched − 16% from its off-the-bone, undeformed state. An optimization routine was used to fit a four-parameter anisotropic, hyperplastic model to the experimental data. The average elastin modulus, E, and the average collagen fiber modulus, ξ, were 13.15 ± 3.59 kPa and 18.68 ± 13.71 MPa (95% CI), respectively.

The costotransverse joints (CTJs) are small arthrodial joints which articulate with the costal tuberosity on the transverse process of the thoracic vertebrae. CTJs are composed of oval-shaped facets with a major axis, vertical at the upper vertebrae and almost horizontal at the lower vertebrae. This position explains the different movements of the ribs: the cranial ribs move on the sagittal plane and the caudal ribs on the transverse plane. Movements in directions other than these usual CTJ spatial planes can cause inflammation resulting in a stinging pain in the space between the scapula and thoracic spine. We studied 15 subjects with paravertebral pain compatible with CTJ pathology. Mean age was 29 years, 11 females/4 males. In 12 patients, the non-dominant limb was affected. US imaging was carried out using linear 12 MHz and 9 MHz probes. Scanning was performed following the long axis of the rib (transverse plane) and the short axis (sagittal plane). Sagittal scanning is the method of choice for detection of possible joint effusion and comparison with undamaged joints above and below. US identified joint effusion correlating with the site of pain in all patients. Thickening of the posterior costotransverse capsular ligament was detected in six patients mainly affecting the first thoracic vertebrae. Power Doppler showed intraarticular hypervascularization in four patients. US imaging should be performed as a first-line examination in the evaluation of patients with stinging pain in the paravertebral region. US evidence of effusion within the joints is a sure sign of involvement of these structures.

Although sprains of the hallux metatarsophalangeal (MTP) joint ligaments occur in barefooted martial arts athletes, few studies discuss the surgical treatments for lateral collateral ligament damage. We report herein a case of lateral collateral ligament repair for chronic hallux MTP joint instability. A 21-year-old male collegiate sumo wrestler injured his left hallux by snagging it on a sumo straw bale at 14 years of age. After entering university (4 years after the injury), he could no longer put weight on his foot at the left hallux; his athletic performance deteriorated, and he was referred to our department by his doctor. He had instability in the MTP joint of the left hallux, and magnetic resonance imaging revealed a tear in the attachment of the lateral collateral ligament to the metatarsal bone. Conservative treatment, such as taping, did not improve the symptoms; thus, surgery was performed, which consisted of passing a strong suture attached to the capsular ligament through a burr hole made in the metatarsal bone and fixing it to the burr-hole wall using an anchor. Postoperatively, the patient's joint instability improved, and he returned to competitive wrestling 4 months after surgery. He was able to put weight on his left hallux, and his athletic performance improved. The follow-up period after surgery was 2 years. In competitive sumo wrestling, hallux weakness and joint instability lead to a significant reduction in performance. Thus, ligament repair is an effective treatment for hallux MTP joint instability that cannot be treated by conservative means.

There are countless morphological variations among the muscles, tendons, ligaments, arteries, veins and nerves of the human body, many of which remain undescribed. Anatomical structures are also subject to evolution, many disappearing and others continually emerging. The main goal of this pilot study was to describe a previously undetected anatomical structure, the plantaris ligamentous tendon, and to determine its frequency and histology. Twenty-two lower limbs from 11 adult cadavers (11 left, and 11 right) fixed in 10% formalin were examined. The mean age of the cadavers at death was 60.1 years (range 38–85). The group comprised six women and five men from a Central European population. All anatomical dissections of the leg and foot area accorded with the pre-established protocol. Among the 22 lower limbs, the PLT was present in 16 (72.7%) and absent in six (27.3%). It originated as a strong fan-shaped ligamentous tendon from the superior part of the plantaris muscle, the posterior surface of the femur and the lateral aspect of the knee joint capsule. It inserted to the ilio-tibial band. Histologically, a tendon and ligament were observed extending parallel to each other. A new anatomical structure has been found, for which the name plantaris ligamentous tendon is proposed. It occurs around the popliteal region between the plantaris muscle, the posterior surface of the femur, and the ilio-tibial band.

1.1 Rationale of application: X-ray-free diagnosis and therapy of fractures and capsular ligament injuries/instabilities in the area of the outer ankle and the lateral foot.

OBJECTIVE. The purpose of this study was to investigate the performance of MRI criteria for identifying meniscal ramp lesions in children with concomitant anterior cruciate ligament (ACL) tear, with arthroscopy used as the reference standard. MATERIALS AND METHODS. This retrospective study included 85 children who underwent a preoperative MRI examination and arthroscopically guided primary ACL reconstruction between June 1, 2017, and December 31, 2019. Blinded to arthroscopic findings, two radiologists reviewed all MRI examinations and reached consensus on the presence or absence of an effusion and various findings within the medial and lateral tibiofemoral joints. Chi-square, Fisher exact, independent t, and Mann-Whitney U tests were used to compare MRI findings between patients with and without arthroscopically confirmed meniscal ramp lesions. RESULTS. At arthroscopy, 35 children (23 boys and 12 girls; mean [± SD] age, 15.7 ± 2.0 years) had ramp lesions and 50 children (22 boys and 28 girls; mean age, 15.1 ± 2.4 years) had intact meniscocapsular junctions. Knees in which a ramp lesion was observed were significantly more likely to have MRI findings of a medial meniscus tear (p = .005), peripheral meniscal irregularity (p = .001), junctional T2-weighted signal (p < .001), and a meniscocapsular ligament tear (p < .001). No significant difference was found between children with and without ramp lesions with regard to the presence of an effusion (p = .65) or a lateral meniscus tear (p = .08) or the extent of medial and lateral tibial plateau marrow edema (p = .67 and p = .83, respectively). CONCLUSION. MRI findings associated with an arthroscopic diagnosis of meniscal ramp lesion include medial meniscus tear, peripheral meniscal irregularity, junctional fluidlike signal, and capsular ligament tear.

The purpose of this study was to investigate if the anterolateral ligament of the knee (ALL) is present in the human fetus and describe its topography along with other structures of the region. Forty human fetuses knee joints, at mean age 34 weeks (± 2.57 weeks), fixed in 10% formalin, were submitted to cross-sectional dissection and mesoscopic analysis. The ALL was not identified, although the usual topography of the region was identified in all specimens: skin, subcutaneous tissue, iliotibial tract (ITT), fibular collateral ligament, popliteal muscle tendon, lateral meniscus, patellar ligament, infrapatellar fat pad, lateral patellar retinaculum, knee joint capsule, lateral inferior genicular vessels, and the biceps femoris tendon. The ITT reveals anterior (n = 12) and lateral thickening (n = 17) in some specimens. This thickening was found in both knees of the same subject in 6/20 specimens. The anterolateral ligament of the knee is not a congenital or solid structure. Our results suggest that the ALL may be a deep layer of the ITT or part of the knee joint capsule, or its identification is evaluator dependent.

Osteoarthritis (OA) is a whole joint disease that affects all joint tissues, with changes in the articular cartilage (AC), subchondral bone and synovium. Pathologies in menisci and ligaments, however, are rarely analysed, although both are known to play vital roles in the mechanical stability of the joint. The aim of our study was to describe the pathological changes in menisci and ligament during disease development in murine spontaneous and post-traumatic surgically-induced OA and to quantify tissue mineralisation in the joint space using µCT imaging during OA progression.Knees of Str/ort mice (spontaneous OA model; 26-40wks) and C57CBA F1 mice following destabilisation of medial meniscus (DMM) surgery (post-traumatic OA model; 8wks after DMM), were used to assess histological meniscal and ligament pathologies. Joint space mineralised tissue volume was quantified by µCT.Meniscal pathological changes in Str/ort mouse knees were associated with articular cartilage lesion severity. These meniscal changes included ossification, hyperplasia, cell hypertrophy, collagen type II deposition and SOX9 expression in the fibrous region near the attachment to the knee joint capsule. Anterior cruciate ligaments exhibited extracellular matrix changes and chondrogenesis particularly at the tibial attachment site, and ossification was seen in collateral ligaments. Similar changes were confirmed in the post-traumatic DMM model. µCT analysis showed increased joint space mineralised tissue volume with OA progression in both the post-traumatic and spontaneous OA models.Modifications in meniscal and ligament mineralisation and chondrogenesis are seen with overt AC degeneration in murine OA. Although the aetiology and the consequences of such changes remain unknown, they will influence stability and load transmission of the joint and may therefore contribute to OA progression. In addition, these changes may have important roles in movement restriction and pain, which represent major human clinical symptoms of OA. Description of such soft tissue changes, in addition to AC degradation, should be an important aspect of future studies in mouse models in order to furnish a more complete understanding of OA pathogenesis.Summary statementThis manuscript describes histological changes in mouse knee joints in two models of osteoarthritis and correlates joint space mineralised tissue volume measured by µCT with disease severity.