Arthroscopic Repair of Dorsal Radiocarpal Ligament Tear – Report of Three Cases

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 atlantoaxial capsular ligaments and transverse ligament are the primary stabilizers of the atlantoaxial joint in the craniocervical junction: a finite element analysis

OBJECTIVEPrior studies have provided conflicting evidence regarding the contribution of key ligamentous structures to atlantoaxial (AA) joint stability. Many of these studies employed cadaveric techniques that are hampered by the inherent difficulties of testing isolated-injury scenarios. Analysis with validated finite element (FE) models can overcome some of these limitations. In a previous study, the authors completed an FE analysis of 5 subject-specific craniocervical junction (CCJ) models to investigate the biomechanics of the occipitoatlantal joint and identify the ligamentous structures essential for its stability. Here, the authors use these same CCJ FE models to investigate the biomechanics of the AA joint and to identify the ligamentous structures essential for its stability.METHODSFive validated CCJ FE models were used to simulate isolated- and combined ligamentous–injury scenarios of the transverse ligament (TL), tectorial membrane (TM), alar ligament (AL), occipitoatlantal capsular ligament, and AA capsular ligament (AACL). All models were tested with rotational moments (flexion-extension, axial rotation, and lateral bending) and anterior translational loads (C2 constrained with anterior load applied to the occiput) to simulate physiological loading and to assess changes in the atlantodental interval (ADI), a key radiographic indicator of instability.RESULTSIsolated AACL injury significantly increased range of motion (ROM) under rotational moment at the AA joint for flexion, lateral bending, and axial rotation, which increased by means of 28.0% ± 10.2%, 43.2% ± 15.4%, and 159.1% ± 35.1%, respectively (p ≤ 0.05 for all). TL removal simulated under translational loads resulted in a significant increase in displacement at the AA joint by 89.3% ± 36.6% (p < 0.001), increasing the ADI from 2.7 mm to 4.5 mm. An AACL injury combined with an injury to any other ligament resulted in significant increases in ROM at the AA joint, except when combined with injuries to both the TM and the ALs. Similarly, injury to the TL combined with injury to any other CCJ ligament resulted in a significant increase in displacement at the AA joint (significantly increasing ADI) under translational loads.CONCLUSIONSUsing FE modeling techniques, the authors showed a significant reliance of isolated- and combined ligamentous–injury scenarios on the AACLs and TL to restrain motion at the AA joint. Isolated injuries to other structures alone, including the AL and TM, did not result in significant increases in either AA joint ROM or anterior displacement.

Anatomical Consideration of the Anterolateral Ligament of the Knee

Many researchers have studied the structures of the anterolateral part of the knee. Several researchers have investigated the existence of the anterolateral ligament (ALL) and its frequency has been inconsistently reported. Therefore, we assessed whether the ALL is the anatomical true ligament and studied the morphological variations of this structure. Sixty-four Korean adult cadavers (120 knees, mean age: 79.1 years) were used for this study. The lateral part of the knee joint was carefully dissected with internal rotation of the tibia. We checked the existence and morphological features and measured the dimensions (length, width, and thickness) of the ALL. The ALL was clearly distinguished from the capsulo-osseous layer of the iliotibial tract and runs obliquely from the lateral femoral epicondyle to the tibial plateau. The ALL was found in 42.5% of the samples, and 15 cadavers had ALLs in both knees. There was no prevalence difference between females and males. Most of the anterior border of the ALL was blended with the knee capsule. Therefore, we concluded that this structure is a local thickening of the capsule in the anterolateral region of the knee, where it possibly developed against some external physical stress. Therefore, the ALLs in this present study can be defined as a capsular ligament of the knee and, as per the nomenclature of the capsular ligament, can be also called the ‘anterolateral (capsular) ligament’.

Anatomic Study and Reanalysis of the Nomenclature of the Anterolateral Complex of the Knee Focusing on the Distal Iliotibial Band: Identification and Description of the Condylar Strap

Background: The capsulo-osseous layer (COL), short lateral ligament, mid–third lateral capsular ligament, lateral capsular ligament, and anterolateral ligament (ALL) are terms that have been used interchangeably to describe what is probably the same structure. This has resulted in confusion regarding the anatomy and function of the anterolateral complex of the knee and its relation to the distal iliotibial band (ITB). Purpose: To characterize the macroscopic anatomy of the anterolateral complex of the knee, in particular the femoral condylar attachment of the distal ITB. We identified a specific and consistent anatomic structure that has not been accurately described previously; it connects the deep surface of the ITB to the condylar area and is distinct from the ALL, COL, and Kaplan fibers. Study Design: Descriptive laboratory study. Methods: Sixteen fresh-frozen human cadaveric knees were used to study the anterolateral complex of the knee. Standardized dissections were performed that included qualitative and quantitative assessments of the anatomy through both anterior (n = 5) and posterior (n = 11) approaches. Results: The femoral condylar attachment of the distal ITB was not reliably identified by anterior dissection but was in all posterior dissections. A distinct anatomic structure, hereafter termed the “condylar strap” (CS), was identified between the femur and the lateral gastrocnemius on one side and the deep surface of the ITB on the other, in all posteriorly dissected specimens. The structure had a mean thickness of 0.88 mm, and its femoral insertion was located between the distal Kaplan fibers and the epicondyle. The proximal femoral attachment of the structure had a mean width of 15.82 mm, and the width of the distal insertion of the structure on the ITB was 13.27 mm. The mean length of the structure was 26.33 mm on its distal border and 21.88 mm on its proximal border. The qualitative evaluation of behavior in internal rotation revealed that this anatomic structure became tensioned and created a tenodesis effect on the ITB. Conclusion: There is a consistent structure that attaches to the deep ITB and the femoral epicondylar area. The orientation of fibers suggests that it may have a role in anterolateral knee stability. Clinical Relevance: This new anatomic description may help surgeons to optimize technical aspects of lateral extra-articular procedures in cases of anterolateral knee laxity.

Multiscale modelling of the human lumbar facet capsular ligament: analysing spinal motion from the joint to the neurons

Due to its high level of innervation, the lumbar facet capsular ligament (FCL) is suspected to play a role in low back pain (LBP). The nociceptors in the lumbar FCL may experience excessive deformation and generate pain signals. As such, understanding the mechanical behaviour of the FCL, as well as that of its underlying nerves, is critical if one hopes to understand its role in LBP. In this work, we constructed a multiscale structure-based finite-element (FE) model of a lumbar FCL on a spinal motion segment undergoing physiological motions of flexion, extension, ipsilateral and contralateral bending, and ipsilateral axial rotation. Our FE model was created for a generic FCL geometry by morphing a previously imaged FCL anatomy onto an existing generic motion segment model. The fibre organization of the FCL in our models was subject-specific based on previous analysis of six dissected specimens. The fibre structures from those specimens were mapped onto the FCL geometry on the motion segment. A motion segment model was used to determine vertebral kinematics under specified spinal loading conditions, providing boundary conditions for the FCL-only multiscale FE model. The solution of the FE model then provided detailed stress and strain fields within the tissue. Lastly, we used this computed strain field and our previous studies of deformation of nerves embedded in fibrous networks during simple deformations (e.g. uniaxial stretch, shear) to estimate the nerve deformation based on the local tissue strain and fibre alignment. Our results show that extension and ipsilateral bending result in largest strains of the lumbar FCL, while contralateral bending and flexion experience lowest strain values. Similar to strain trends, we calculated that the stretch of the microtubules of the nerves, as well as the forces exerted on the nerves' membrane are maximal for extension and ipsilateral bending, but the location within the FCL of peak microtubule stretch differed from that of peak membrane force.

Wrist Swelling in Kienböck's Disease

Background and Purpose Wrist swelling is a frequent clinical manifestation of Kienböck's disease, but no study has reported the site and pathology of wrist swelling in this disease. The aim of this study is to elucidate the site and pathology of wrist swelling in Kienböck's disease. Materials and Methods Dorsal and palmar soft tissue thicknesses of the wrist were measured on standard lateral radiographs of the wrist in 26 patients with Kienböck's disease and 30 subjects without intra-articular lesion. Axial magnetic resonance imaging (MRI) views were examined to detect the site of swelling. The dorsal capsular ligament in three patients with Kienböck's disease underwent histological examination. Results Radiographic study confirmed dorsal wrist swelling in 24 of 26 (92%) patients examined compared with the contralateral unaffected wrists. MRI demonstrated thickening of the dorsal capsular ligament and extensor layer with synovial proliferation. Histological examination revealed nonspecific chronic inflammation. Conclusion Dorsal wrist swelling in Kienböck's disease is a common manifestation and constitutes a part of pathology of Kienböck's disease, although further study is required to clarify the relation between wrist swelling and etiology of Kienböck's disease. Level of Evidence This is a Level III study.