Operative fixation is the treatment of choice for a rupture of the distal tendon of biceps. A variety of techniques have been described including transosseous sutures and suture anchors. The poor quality of the bone of the radial tuberosity might affect the
Previously, we showed that case-specific non-linear
finite element (FE) models are better at predicting the load to failure
of metastatic femora than experienced clinicians. In this study
we improved our FE modelling and increased the number of femora
and characteristics of the lesions. We retested the robustness of
the FE predictions and assessed why clinicians have difficulty in
estimating the
We compared time-dependent changes in the biomechanical properties of single-and double-row repair of a simulated acute tear of the rotator cuff in rabbits to determine the effect of the fixation techniques on the healing process. A tear of the supraspinatus tendon was created in 80 rabbits which were separated into two equal groups. A single-row repair with two suture anchors was conducted in group 1 and a double-row repair with four suture anchors in group 2. A total of ten intact contralateral shoulder joints was used as a control group. Biomechanical testing was performed immediately post-operatively and at four and eight weeks, and histological analysis at four and eight weeks. The mean
Aims. 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. Materials and Methods. 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). Results. At eight weeks, FiberTape alone or FiberTape-augmented autograft demonstrated increased biomechanical stability compared with autograft regarding ultimate
A total of 20 pairs of fresh-frozen cadaver femurs were assigned to four alignment groups consisting of relative varus (10° and 20°) and relative valgus (10° and 20°), 75 composite femurs of two neck geometries were also used. In both the cadaver and the composite femurs, placing the component in 20° of valgus resulted in a significant increase in
We tested four types of surgical
repair for
Aims. The traditional transosseus flexor hallucis longus (FHL) tendon
transfer for patients with Achilles tendinopathy requires two incisions
to harvest a long tendon graft. The use of a bio-tenodesis screw
enables a short graft to be used and is less invasive, but lacks
supporting evidence about its biomechanical behaviour. We aimed,
in this study, to compare the strength of the traditional transosseus
tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis
screw, in cyclical loading and ultimate load testing. Materials and Methods. Tendon grafts were undertaken in 24 paired lower-leg specimens
and randomly assigned in two groups using fixation with a transosseus
suture (suture group) or a tenodesis screw (screw group). The biomechanical
behaviour was evaluated using cyclical and ultimate loading tests.
The Student’s t-test was performed to assess statistically significant
differences in bone mineral density (BMD), displacement, the slope
of the load-displacement curves, and
We measured the initial fixation strength of a new graft, bone-hamstring-bone (BHB), for reconstruction of the anterior cruciate ligament (ACL) in 79 porcine knees and compared it with that of the normal porcine ACL and of the bone-patellar tendon-bone (BPB) graft. All specimens were subjected to ultimate
Aims. The aim of this study was to investigate the effect of a posterior
malleolar fragment (PMF), with <
25% ankle joint surface, on
pressure distribution and joint-stability. There is still little
scientific evidence available to advise on the size of PMF, which
is essential to provide treatment. To date, studies show inconsistent
results and recommendations for surgical treatment date from 1940. Materials and Methods. A total of 12 cadaveric ankles were assigned to two study groups.
A trimalleolar fracture was created, followed by open reduction
and internal fixation. PMF was fixed in Group I, but not in Group
II. Intra-articular pressure was measured and cyclic loading was
performed. Results. Contact area decreased following each fracture, while anatomical
fixation restored it nearly to its intact level. Contact pressure
decreased significantly with fixation of the PMF. In plantarflexion,
the centre of force shifted significantly posteriorly in Group II
and anteriorly in Group I.
The aim of this study was to compare the functional and radiological outcomes and the complication rate after nail and plate fixation of unstable fractures of the ankle in elderly patients. In this multicentre study, 120 patients aged ≥ 60 years with an acute unstable AO/OTA type 44-B fracture of the ankle were randomized to fixation with either a nail or a plate and followed for 24 months after surgery. The primary outcome measure was the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score. Secondary outcome measures were the Manchester-Oxford Foot Questionnaire, the Olerud and Molander Ankle score, the EuroQol five-dimension questionnaire, a visual analogue score for pain, complications, the quality of reduction of the fracture, nonunion, and the development of osteoarthritis.Aims
Methods
The risk of mechanical failure of modular revision hip stems is frequently mentioned in the literature, but little is currently known about the actual clinical failure rates of this type of prosthesis. The current retrospective long-term analysis examines the distal and modular failure patterns of the Prevision hip stem from 18 years of clinical use. A design improvement of the modular taper was introduced in 2008, and the data could also be used to compare the original and the current design of the modular connection. We performed an analysis of the Prevision modular hip stem using the manufacturer’s vigilance database and investigated different mechanical failure patterns of the hip stem from January 2004 to December 2022.Aims
Methods
We examined whether enamel matrix derivative
(EMD) could improve healing of the tendon–bone interface following
reconstruction of the anterior cruciate ligament (ACL) using a hamstring
tendon in a rat model. ACL reconstruction was performed in both
knees of 30 Sprague-Dawley rats using the flexor digitorum tendon.
The effect of commercially available EMD (EMDOGAIN), a preparation
of matrix proteins from developing porcine teeth, was evaluated.
In the left knee joint the space around the tendon–bone interface
was filled with 40 µl of EMD mixed with propylene glycol alginate
(PGA). In the right knee joint PGA alone was used. The ligament
reconstructions were evaluated histologically and biomechanically
at four, eight and 12 weeks (n = 5 at each time point). At eight weeks,
EMD had induced a significant increase in collagen fibres connecting
to bone at the tendon–bone interface (p = 0.047), whereas the control
group had few fibres and the tendon–bone interface was composed
of cellular and vascular fibrous tissues. At both eight and 12 weeks,
the mean
Different calcaneal plates with locked screws were compared in an experimental model of a calcaneal fracture. Four plate models were tested, three with uniaxially-locked screws (Synthes, Newdeal, Darco), and one with polyaxially-locked screws (90° ± 15°) (Rimbus). Synthetic calcanei were osteotomised to create a fracture model and then fixed with the plates and screws. Seven specimens for each plate model were subjected to cyclic loading (preload 20 N, 1000 cycles at 800 N, 0.75 mm/s), and
The aim of this study was to assess the clinical and radiological outcomes of an antiprotrusio acetabular cage (APC) when used in the surgical treatment of periacetabular bone metastases. This retrospective cohort study using a prospectively collected database involved 56 patients who underwent acetabular reconstruction for periacetabular bone metastases or haematological malignancy using a single APC between January 2009 and 2020. The mean follow-up was 20 months (1 to 143). The primary outcome measure was implant survival. Postoperative radiographs were analyzed for loosening and failure. Patient and implant survival were assessed using a competing risk analysis. Secondary parameters included primary malignancy, oncological treatment, surgical factors, length of stay in hospital, and postoperative complications.Aims
Methods
The purpose of this study was to assess the stability of a developmental pelvic reconstruction system which extends the concept of triangular osteosynthesis with fixation anterior to the lumbosacral pivot point. An unstable Tile type-C fracture, associated with a sacral transforaminal fracture, was created in synthetic pelves. The new concept was compared with three other constructs, including bilateral iliosacral screws, a tension band plate and a combined plate with screws. The pubic symphysis was plated in all cases. The pelvic ring was loaded to simulate single-stance posture in a cyclical manner until failure, defined as a displacement of 2 mm or 2°. The screws were the weakest construct, failing with a load of 50 N after 400 cycles, with maximal translation in the craniocaudal axis of 12 mm. A tension band plate resisted greater
Acute distal biceps tendon repair reduces fatigue-related pain and minimizes loss of supination of the forearm and strength of flexion of the elbow. We report the short- and long-term outcome following repair using fixation with a cortical button techqniue. Between October 2010 and July 2018, 102 patients with a mean age of 43 years (19 to 67), including 101 males, underwent distal biceps tendon repair less than six weeks after the injury, using cortical button fixation. The primary short-term outcome measure was the rate of complications. The primary long-term outcome measure was the abbreviated Disabilities of the Arm, Shoulder and Hand (QuickDASH) score. Secondary outcomes included the Oxford Elbow Score (OES), EuroQol five-dimension three-level score (EQ-5D-3L), satisfaction, and return to function.Aims
Methods
Using 26 cadaver shoulders, we produced a standard defect in the supraspinatus tendon and performed one of three types of repair. Their strength was found by testing in tension the force required to produce a gap of 3 mm, then 6 mm, and finally total disruption of the repair. The use of a polyethylene patch to spread the forces over the lateral bone surface and of extra sutures to grasp the tendon end raised by 2.6 times the load at which a 3 mm gap in the repair occurred and by 1.7 times the
We used 15 pairs of femora from fresh human cadavers to study the effects of the size and location of the entry hole for an intramedullary nail on the strength of the femur. Right femora were used as controls. Left femora in group 1 had a 10 mm entry hole in the 'ideal' location in the piriformis fossa. Group 2 had a 14 mm entry hole in the same position and group 3 had a 14 mm entry hole anterior to this on the superior aspect of the femoral neck. Femora were equipped with strain gauges and loaded to failure in compression. There was reduced stiffness and
We aimed to determine the optimal method of inserting a screw into polymethylmethacrylate (PMMA) cement to enhance fixation. We performed six groups of ten axial pull-out tests with two sizes of screw (3.5 and 4.5 mm AO cortical) and three methods of insertion. Screws were placed into 'fluid' PMMA, into 'solid' PMMA by drilling and tapping, or into 'curing' PMMA with quarter-revolution turns every 30 seconds until the PMMA had hardened. After full hardening, we measured the maximum