Aseptic loosening of cemented femoral stems results from migration of wear particles along the bone-cement interface, producing a foreign body reaction. After cement insertion, blood back pressure can disrupt the bone-cement interface, enabling this spread of wear particles. Our study investigates whether altering timing and speed of stem insertion can reduce this risk. We inserted mock “C-Stem” femoral components (De Puy-Synthes), using Smartset HV cement (De Puy-Synthes) into artificial femora, fitted with proximal and distal pressure transducers. Cement insertion began two, three or four minutes after mixing. Cement pressures were then allowed to settle for one minute and the stems were then inserted over durations of 25, 60 or 90 seconds.Background
Methods
Range of Motion (ROM) assessments are routinely used during joint replacement to evaluate joint stability before, during and after surgery to ensure the effective restoration of patient biomechanics. This study aimed to quantify axial torque in the femur during ROM assessment in total hip arthroplasty to define performance criteria against which hip instruments can be verified.
Abstract. Objectives. 1. To investigate the effect of revision total knee replacement (TKR) on gait kinematics in patients with a primary TKR and instability.2. To compare gait kinematics between patients with a well-functioning TKR and those with a primary TKR and symptoms of instability. Methods. This single-centre observational study is following patients who have had a revision TKR due to knee instability. Data was collected pre- and post-operatively at 8–12 week follow-up. The data was compared to a control group of 18 well-functioning TKR patients. Kinematic gait data was collected during routine clinics using a treadmill-based infrared 3D system (Vicon, Oxford, UK) and a published lower limb marker-set. Patients performed 15 strides at three different speeds: 0.6mph, self-selected, and a ‘slow walk’ normalised to leg length (Froude number 0.09). PROMs questionnaires were collected. NHS ethical approval was obtained. Results. Data was collected for 18 well-functioning TKR patients and 8 revision TKR patients pre- and post-operatively, but only 5 could walk at the normalised speed. When walking at a normalised speed (Froude 0.09), patients with a TKR with instability had reduced range of knee flexion (52° (sd 14)) compared to those with a well-functioning TKR (59° (sd 11)). Short term follow-up after a revision TKR operation demonstrated a stiffer knee (45° (sd 12)). However, those with revision TKR had a more flexed knee during stance phase. Conclusions. At short-term follow-up, this cohort of revision TKR patients appear to have reduced flexion range, while remaining more flexed during stance. This may represent a less efficient gait pattern, which may also adversely affect the implant[1].
The laterjet procedure is an important option in both primary and revision surgeries, especially in anterior shoulder instabilities that progress with glenoid bone loss. 12 patients who had a history of unsuccessful arthroscopic bankart repair and who underwent laterjet procedure in Ankara Atatürk Research and Training Hospital between 2013 and 2017 were included in the study and the patients were evaluated retrospectively. The mean age of the patients was calculated as 27.7 (range 21 to 38 years). Rowe and Walch-Duplay scores and operated shoulder (OS)-healthy shoulder (HS) range of motion (ROM) measurements were used to evaluate patients clinically and functionally. The mean follow-up time of the patients was calculated as 5.5±1.8 years. Firstly, no dislocation history was recorded in any patient afer the laterjet procedure. The mean Rowe score was calculated as 82.5 (range 60–100). Accordingly, 8 patients had excellent result, 3 patients had good result and 1 patient had fair result. The mean Walch-Duplay score was 81.4 (range 55–100). It was determined as excellent result in 6 patients, good result in 4 patients and fair result in 2 patients. Another data, joint ROM of the OS-HS of patients are shown in the table. There was some limitation in OS compared to the HS. p<0.05 value was accepted as statistically significant. While there was a statistically significant difference in external rotation (OS:35.2º, HS:56.4º)(p=0.003), internal rotation (OS:65.7º, HS:68.1º)(p=0.008) and flexion (OS:171.2º, HS:175.9º)(p=0.012) degrees but there was no statistically significant difference in abduction degrees (OS:164.3º, HS:170.4º) (p=0.089). In radiological evaluation, partial graft resorption was detected in 1 patient, but it was asymptomatic. The osteoarthritis which is one of the complications of laterjet procedure, was not detected radiologically. There are some limitations of the study. Firstly, it is a retrospective study. Secondly, the demographic features of the patients such as age, gender, profession and dominant hand are excluded. Thirdly, the mean follow-up time is not too long. Finally, some of the scales filled in are based on the patient's declaration, which may not yield sufficient objective results. In conclusion, the laterjet procedure is a suitable and reliable technique even for revision surgery in the treatment of anterior shoulder instability. It gives positive results in terms of shoulder stability and function. The major disadvantage was found to be the limitation of external rotation.
Degree of early integration of titanium alloy implants into bone is an important predictor of long term implant success in arthroplasty. The correlation between observations on early cell adhesion and the ability of modified surfaces to affect osseointegration of implants in in vivo models is unclear. We hypothesised that observation of increased focal adhesion complexes in early cultures of osteoblasts would correlate with increased osseointegration of treated implants in an animal model.
Ischaemic preconditioning is a process by which exposure of a tissue to a short period of non-damaging ischaemic stress leads to resistance to the deleterious effects of a subsequent prolonged ischaemic stress. It has been extensively described in the heart, but few studies have examined the possibility that it can occur in skeletal muscle. We have used a rat model of ischaemia of one limb to examine this possibility. Exposure of the hind limb to a period of ischaemia of five minutes and reperfusion for five minutes significantly protected the tibialis anterior muscle against the structural damage induced by a subsequent period of limb ischaemia for four hours and reperfusion for one hour. This protection was evident on examination of the muscle by both light and electron microscopy.
Summary Statement. Proximal femoral bony deficits present a surgical and biomechanical challenge to implant longevity in revision hip arthroplasty. This work finds comparable primary stability when a distally fixing tapered fluted stem was compared with a conical design in cadaveric tests. Introduction. Proximal bony deficits complicate revision hip surgery and compromise implant survival.
To explore the therapeutic potential of combining bone marrow-derived mesenchymal stem cells (BM-MSCs) and hydroxyapatite (HA) granules to treat nonunion of the long bone. Ten patients with an atrophic nonunion of a long bone fracture were selectively divided into two groups. Five subjects in the treatment group were treated with the combination of 15 million autologous BM-MSCs, 5g/cm3 (HA) granules and internal fixation. Control subjects were treated with iliac crest autograft, 5g/cm3 HA granules and internal fixation. The outcomes measured were post-operative pain (visual analogue scale), level of functionality (LEFS and DASH), and radiograph assessment.Objectives
Methods
In an attempt to increase the life of cementless prostheses, an hydroxyapatite-coated implant which releases a bisphosphonate has been suggested as a drug-delivery system. Our Our findings demonstrated that zoledronate did not impair the proliferation of human osteoblasts when used at concentrations below 1 μ A concentration of 0.01% of titanium particles did not impair the proliferation of either cell line. Zoledronate affected the alkaline phosphatase activity of murine osteoblasts through a chelation phenomenon. The presence of titanium particles strongly decreased the alkaline phosphatase activity of murine osteoblasts. We did not detect any synergic effect of zoledronate and titanium particles on the behaviour of both human and murine osteoblasts.