We analysed static
We analysed the static
Many biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots. A total of 24 fresh-frozen porcine shoulders were used. The infraspinatus tendons were sharply dissected and randomly repaired by one of three techniques: SB repair (SB group), DRS repair (DRS group), and DRS with medial row knots repair (DRSK group). Specimens were tested to failure. In addition, 3 mm gap formation was measured and ultimate failure load, stiffness, and failure modes were recorded.Aims
Methods
In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading. Torque-rotation curves were obtained from nine cadaveric hips to define the rotational restraint contributions of the capsular ligaments in 36 positions. A ligament model was developed to determine the line-of-action and effective moment arms of the medial/lateral iliofemoral, ischiofemoral, and pubofemoral ligaments in all positions. The functioning ligament forces and stiffness were determined at 5 Nm rotational restraint. In each position, the contribution of engaged capsular ligaments to the joint reaction force was used to evaluate the net force vector generated by the capsule.Aims
Methods
1. With the object of perfecting the design of footwear for feet anaesthetic from leprosy, pressures on the soles of feet during walking were measured with transducers sufficiently thin to be worn inside ordinary shoes. 2. It was found that anaesthetic feet without deformity or muscle imbalance did not produce significantly higher pressures than normal feet during barefoot walking on a flat surface. The pressure distribution under drop feet with active posterior tibial muscles differed from normal, with increased pressure under the lateral forefoot and decreased pressures elsewhere. 3. Loss of toes or function of the toes results in high, sharp pressure peaks under the anterior end of the foot during push-off. In deformed feet these pressures are usually concentrated at one or two small areas. 4. In anaesthetic feet the prevention of trophic ulceration largely depends on the even distribution of pressure over the sole of the foot. 5. Moulding by carefully placed arch supports or metatarsal bars effectively redistributes plantar pressure. 6. A shoe with a rigid sole pivoting on a rocker near the centre of the foot most effectively reduces pressures under the forefoot of shortened, deformed feet. 7. We recommend the use of insoles made of microcellular rubber (approximately 1 5 degrees shore). 8. The importance of studying each deformed foot for areas of high pressure before fitting shoes is stressed; a pressure-indicating
The purpose of this study was to identify the changes in untreated long head of the biceps brachii tendon (LHBT) after a rotator cuff tear and to evaluate the factors related to the changes. A cohort of 162 patients who underwent isolated supraspinatus with the preservation of LHBT was enrolled and evaluated. The cross-sectional area (CSA) of the LHBT on MRI was measured in the bicipital groove, and preoperative to postoperative difference was calculated at least 12 months postoperatively. Second, postoperative changes in the LHBT including intratendinous signal change, rupture, dislocation, or superior labral lesions were evaluated with seeking of factors that were correlated with the changes or newly developed lesions after rotator cuff repair.Aims
Methods
Ideal component sizing may be difficult to achieve in unicompartmental knee arthroplasty (UKA). Anatomical variants, incremental implant size, and a reduced surgical exposure may lead to over- or under-sizing of the components. The purpose of this study was to compare the accuracy of UKA sizing with robotic-assisted techniques versus a conventional surgical technique. Three groups of 93 medial UKAs were assessed. The first group was performed by a conventional technique, the second group with an image-free robotic-assisted system (Image-Free group), and the last group with an image-based robotic arm-assisted system, using a preoperative CT scan (Image-Based group). There were no demographic differences between groups. We compared six parameters on postoperative radiographs to assess UKA sizing. Incorrect sizing was defined by an over- or under-sizing greater than 3 mm.Aims
Methods
The aim of this study was to compare the osseous reactions elicited by all-suture, polyetheretherketone (PEEK), and two different biodegradable anchors used during rotator cuff repair. Transosseous-equivalent rotator cuff repair was performed in 73 patients. The patients were divided into two groups, in both of which two different medial-row anchors were used. In group 1, anchor A comprised 30% β-tricalcium phosphate (TCP) + 70% fast-absorbing poly lactic-co-glycolic acid copolymer (85% polylactic acid enantiomers + 15% polyglycolic acid) and anchor B comprised all-sutures. In group 2, anchor C comprised 23% micro β-TCP + 77% polylactic acid enantiomers and anchor D comprised PEEK polymer. There were 37 patients in group 1 and 36 patients in group 2. The presence and severity of fluid collection around anchors and healing of the rotator cuff were assessed using MRI scans, approximately one year postoperatively. The severity of the collection was graded as 0 (no perianchor fluid signal), 1 (minimal perianchor fluid), 2 (local collection of fluid), 3 (fluid collection around the whole length of the anchor but of a diameter less than twice the anchor diameter), or 4 (fluid collection around the whole length of the anchor and of a diameter greater than twice the anchor diameter).Aims
Patients and Methods
Eight-plates are used to correct varus-valgus deformity (VVD) or limb-length discrepancy (LLD) in children and adolescents. It was reported that these implants might create a bony deformity within the knee joint by change of the roof angle (RA) after epiphysiodesis of the proximal tibia following a radiological assessment limited to anteroposterior (AP) radiographs. The aim of this study was to analyze the RA, complemented with lateral knee radiographs, with focus on the tibial slope (TS) and the degree of deformity correction. A retrospective, single-centre study was conducted. The treatment group (n = 64 knees in 44 patients) was subclassified according to the implant location in two groups: 1) medial hemiepiphysiodesis; and 2) lateral hemiepiphysiodesis. A third control group consisted of 25 untreated knees. The limb axes and RA were measured on long standing AP leg radiographs. Lateral radiographs of 40 knees were available for TS analysis. The mean age of the patients was 10.6 years (4 to 15) in the treatment group and 8.4 years (4 to 14) in the control group. Implants were removed after a mean 1.2 years (0.5 to 3).Aims
Methods
The extensive variation in axial rotation of tibial components can lead to coronal plane malalignment. We analyzed the change in coronal alignment induced by tray malrotation. We constructed a computer model of knee arthroplasty and used a virtual cutting guide to cut the tibia at 90° to the coronal plane. The virtual guide was rotated axially (15° medial to 15° lateral) and with posterior slopes (0° to 7°). To assess the effect of axial malrotation, we measured the coronal plane alignment of a tibial tray that was axially rotated (25° internal to 15° external), as viewed on a standard anteroposterior (AP) radiograph.Aims
Methods
To evaluate graft healing of decellularized porcine superflexor tendon (pSFT) xenograft in an ovine anterior cruciate ligament (ACL) reconstruction model using two femoral fixation devices. Also, to determine if pSFT allows functional recovery of gait as compared with the preoperative measurements. A total of 12 sheep underwent unilateral single-bundle ACL reconstruction using pSFT. Two femoral fixation devices were investigated: Group 1 (n = 6) used cortical suspensory fixation (Endobutton CL) and Group 2 (n = 6) used cross-pin fixation (Stratis ST). A soft screw was used for tibial fixation. Functional recovery was quantified using force plate analysis at weeks 5, 8, and 11. The sheep were euthanized after 12 weeks and comprehensive histological analysis characterized graft healing at the graft-bone interface and the intra-articular graft (ligamentization).Aims
Methods
Options for the treatment of intra-articular ligament injuries are limited, and insufficient ligament reconstruction can cause painful joint instability, loss of function, and progressive development of degenerative arthritis. This study aimed to assess the capability of a biologically enhanced matrix material for ligament reconstruction to withstand tensile forces within the joint and enhance ligament regeneration needed to regain joint function. A total of 18 New Zealand rabbits underwent bilateral anterior cruciate ligament reconstruction by autograft, FiberTape, or FiberTape-augmented autograft. Primary outcomes were biomechanical assessment (n = 17), microCT (µCT) assessment (n = 12), histological evaluation (n = 12), and quantitative polymerase chain reaction (qPCR) analysis (n = 6).Aims
Materials and Methods
The long head of the biceps (LHB) is often resected in shoulder surgery and could therefore serve as a cell source for tissue engineering approaches in the shoulder. However, whether it represents a suitable cell source for regenerative approaches, both in the inflamed and non-inflamed states, remains unclear. In the present study, inflamed and native human LHBs were comparatively characterized for features of regeneration. In total, 22 resected LHB tendons were classified into inflamed samples (n = 11) and non-inflamed samples (n = 11). Proliferation potential and specific marker gene expression of primary LHB-derived cell cultures were analyzed. Multipotentiality, including osteogenic, adipogenic, chondrogenic, and tenogenic differentiation potential of both groups were compared under respective lineage-specific culture conditions.Objectives
Methods
Bone is one of the most highly adaptive tissues in the body, possessing the capability to alter its morphology and function in response to stimuli in its surrounding environment. The ability of bone to sense and convert external mechanical stimuli into a biochemical response, which ultimately alters the phenotype and function of the cell, is described as mechanotransduction. This review aims to describe the fundamental physiology and biomechanisms that occur to induce osteogenic adaptation of a cell following application of a physical stimulus. Considerable developments have been made in recent years in our understanding of how cells orchestrate this complex interplay of processes, and have become the focus of research in osteogenesis. We will discuss current areas of preclinical and clinical research exploring the harnessing of mechanotransductive properties of cells and applying them therapeutically, both in the context of fracture healing and de novo bone formation in situations such as nonunion. Cite this article:
Anterior cruciate ligament (ACL) reconstruction
is commonly performed and has been for many years. Despite this, the
technical details related to ACL anatomy, such as tunnel placement,
are still a topic for debate. In this paper, we introduce the flat
ribbon concept of the anatomy of the ACL, and its relevance to clinical
practice. Cite this article:
Since long-term outcome of teres major tendon transfer surgery
for irreparable posterosuperior rotator cuff (RC) tears is largely
unknown, the primary aim of this study was to evaluate the long-term
outcome of the teres major transfer. We also aimed to report on
the results of a cohort of patients with a similar indication for
surgery that underwent a latissimus dorsi tendon transfer. In this prospective cohort study, we reported on the long-term
results of 20 consecutive patients with a teres major tendon transfer
for irreparable massive posterosuperior RC tears. Additionally,
we reported on the results of the latissimus dorsi tendon transfer
(n = 19). The mean age was 60 years (47 to 77). Outcomes included
the Constant score (CS), and pain at rest and during movement using
the Visual Analogue Scale (VAS).Aims
Patients and Methods