We compared wear particles from two different designs of total hip arthroplasty with polycrystalline alumina-ceramic bearings of different production periods (group 1, before ISO 6474: group 2, according to ISO 6474). The neocapsules and interfacial connective tissue membranes were retrieved after mean implantation times of 131 months and 38 months, respectively. Specimen blocks were freed from embedding media, either methylmethacrylate or paraffin and digested in concentrated nitric acid. Particles were then counted and their sizes and composition determined by SEM and energy-dispersive x-ray analysis (EDXA). The mean numbers and sizes of most alumina wear particles did not differ for both production periods, but the larger sizes of particle in group 1 point to more severe surface destruction. The increased metal wear in group 2 was apparently due to alumina-induced abrasion of the stems. In this study the concentrations of particles in the periprosthetic tissues were 2 to 22 times lower than those observed previously with polyethylene and alumina/polyethylene wear couples

Two hundred and forty-eight high-grade central osteosarcomata were treated by amputation or disarticulation; in 5.2 per cent the tumour recurred at the amputation site. The following causes may be responsible for local recurrence: the level of the amputation is too close to the tumour; there is an unrecognised intramedullary extension of the tumour; during a previous block resection tumour cells may have been seeded in the soft tissues; the primary tumour was too extensive even for radical surgery; "skip" metastases may have been present; iatrogenic tumour implantation may have occurred while a biopsy was being performed during the course of an amputation. Treatment of the primary osteosarcoma should take all these possibilities into account. In our experience adjuvant chemotherapy has not significantly changed the frequency of local recurrences which should be treated by radical operation or, if this is not possible, by irradiation; chemotherapy may be used as an adjuvant. The prognosis of local recurrences is bad

1. The semilunar cartilages are part of the rotator mechanism of the knee joint. 2. Movement of the weight-bearing knee comprises synchronous lateral rotation of the tibia with extension and medial rotation of the tibia with flexion. 3. When this synchrony is disturbed, injuries to the semilunar cartilages result. 4. Damage to the anterior two-thirds of the medial cartilage blocks lateral rotation of the tibia, with consequent physical signs that are pathognomonic of the retracted and the bowstring cartilage, which are the most common types of injury. 5. Each type of cartilage injury produces its own pattern of erosion of articular cartilage and its own sequence of symptoms as so-called arthritis develops. 6. The sequence of symptoms may be halted and often reversed by removal of the torn cartilage. Operation is warranted in most cases however long the history and whatever the age of the patient. 7. The development of medial retropatellar arthritis is explained. The symptoms are often relieved by removal of the medial semilunar cartilage and adequate post-operative rehabilitation

Aims

The Fassier Duval (FD) rod is a third-generation telescopic implant for children with osteogenesis imperfecta (OI). Threaded fixation enables proximal insertion without opening the knee or ankle joint. We have reviewed our combined two-centre experience with this implant.

Bone loss around replacement prostheses may be related to the activation of mononuclear phagocytes (MNP) by prosthetic wear particles. We investigated how osteoblast-like cells were regulated by human MNP stimulated by particles of prosthetic material. Particles of titanium-6-aluminium-4-vanadium (TiAlV) stimulated MNP to release interleukin (IL)-1β, tumour necrosis factor (TNF)α, IL-6 and prostaglandin E. 2. (PGE. 2. ). All these mediators are implicated in regulating bone metabolism. Particle-activated MNP inhibited bone cell proliferation and stimulated release of IL-6 and PGE. 2. The number of cells expressing alkaline phosphatase, a marker associated with mature osteo-blastic cells, was reduced. Experiments with blocking antibodies showed that TNFα was responsible for the reduction in proliferation and the numbers of cells expressing alkaline phosphatase. By contrast, IL-1β stimulated cell proliferation and differentiation. Both IL-1β and TNFα stimulated IL-6 and PGE. 2. release from the osteoblast-like cells. Our results suggest that particle-activated mono-nuclear phagocytes can induce a change in the balance between bone formation and resorption by a number of mechanisms

Aims

This study aims to evaluate a new home medical stretching device called the Self Treatment Assisted Knee (STAK) tool to treat knee arthrofibrosis.

In a prospective, consecutive study we determined the frequency of common symptoms and signs in 300 patients with lumbar nerve-root compression syndromes. We compared 100 patients with disc herniation (mean age 43 years), 100 with lataral spinal stenosis (41 years) and 100 with central spinal stenosis (65 years), using a standard protocol of common signs and symptoms. The diagnoses were established by one or more of myelography, CT, MRI and nerve-root block, and all were confirmed at operation. The preoperative duration of symptoms was significantly shorter in patients with disc herniation. Pain at rest, at night, and on coughing was as common in lateral stenosis as in disc herniation, but regular consumption of analgesics was more common in patients with disc herniation. Positive straight-leg-raising tests were more common in disc herniation than in lateral stenosis and were uncommon in central stenosis. Motor disturbances were seen most often in central spinal stenosis, especially patellar reflex changes. Sensory disturbances were most common in patients with complete disc herniation

Seven subjects with normal joints were tested for active and passive position sense of ankle inversion, peroneal reflex reaction time to sudden ankle inversion, and postural stability during single-leg stance. The tests were performed before and after regional block of the ankle and foot with local anaesthetic. Passive position sense, assessed with the muscles relaxed, was greatly impaired by anaesthesia but active position sense, with the calf muscles activated, was preserved, and the peroneal reaction time to sudden ankle inversion was not altered. The magnitude of postural sway during single-leg stance was also unchanged by anaesthesia of the ankle and foot. The results suggest that the afferent input from intact lateral ankle ligaments is important in sensing correct placement of the foot at heel-strike, but that this input can be replaced by afferent information from active calf muscles. Afferent input from these muscles seems also to be responsible for dynamic ankle protection against sudden ankle inversion and is adequate to allow stable single-leg stance

Objectives

This study investigated the biomechanical performance of decellularized porcine superflexor tendon (pSFT) grafts of varying diameters when utilized in conjunction with contemporary ACL graft fixation systems. This aimed to produce a range of ‘off-the-shelf’ products with predictable mechanical performance, depending on the individual requirements of the patient.

Osteomyelitis was induced in the tibiae of rabbits by injecting a suspension of Staphylococcus aureus and sodium tetradecylsulphate, a sclerosing agent. These rabbits were then divided into two groups: one group remained untreated and the other was fed a diet containing sodium salicylate. Two and four weeks after induction of osteomyelitis the tibiae taken from untreated rabbits with osteomyelitis and incubated in vitro released significantly more prostaglandin E and F than the control uninjected or uninfected tibiae. Tibiae taken from rabbits treated with sodium salicylate showed minimal radiographic changes and a significantly decreased release of prostaglandin E and F compared to the untreated rabbits. Prostaglandins are known to be potent bone resorbing agents and the results of this study suggest that they may also be involved in the destruction of bone which is characteristic of osteomyelitis. The treatment of rabbits with osteomyelitis using anti-inflammatory drugs, which block synthesis of prostaglandins, in addition to antibiotics, may prevent the destruction of bone and possible sequestration thereby decreasing the risk of chronic disease

Aims

Proliferation, migration, and differentiation of anterior cruciate ligament (ACL) remnant and surrounding cells are fundamental processes for ACL reconstruction; however, the interaction between ACL remnant and surrounding cells is unclear. We hypothesized that ACL remnant cells preserve the capability to regulate the surrounding cells’ activity, collagen gene expression, and tenogenic differentiation. Moreover, extracorporeal shock wave (ESW) would not only promote activity of ACL remnant cells, but also enhance their paracrine regulation of surrounding cells.

Dissatisfaction following total knee arthroplasty is a well-documented phenomenon. Although many factors have been implicated, including modifiable and nonmodifiable patient factors, emphasis over the past decade has been on implant alignment and stability as both a cause of, and a solution to, this problem. Several alignment targets have evolved with a proliferation of techniques following the introduction of computer and robotic-assisted surgery. Mechanical alignment targets may achieve mechanically-sound alignment while ignoring the soft tissue envelope; kinematic alignment respects the soft tissue envelope while ignoring the mechanical environment. Functional alignment is proposed as a hybrid technique to allow mechanically-sound, soft tissue-friendly alignment targets to be identified and achieved.

Cite this article: Bone Joint J 2020;102-B(3):276–279.

Aims

Elective operating was halted during the COVID-19 pandemic to increase the capacity to provide care to an unprecedented volume of critically unwell patients. During the pandemic, the orthopaedic department at the Aneurin Bevan University Health Board restructured the trauma service, relocating semi-urgent ambulatory trauma operating to the isolated clean elective centre (St. Woolos’ Hospital) from the main hospital receiving COVID-19 patients (Royal Gwent Hospital). This study presents our experience of providing semi-urgent trauma care in a COVID-19-free surgical unit as a safe way to treat trauma patients during the pandemic and a potential model for restarting an elective orthopaedic service.

Ischaemia threatening an injured limb gives rise to the syndrome of pain, pallor, paralysis, and pulselessness. It is due to arterial injury by laceration, compression, intra-mural rupture or contusion, or to arterial spasm with or without demonstrable local arterial damage. The differentiation of spasm without local injury from organic obstruction is not possible by clinical methods. The suggested plan of treatment and of management is:. 1. General systemic investigation (blood-pressure, blood-count, coagulation time, etc.). 2. Removal of all external pressure. 3. Resuscitation. 4. Direct attempt to relieve the obstruction by operation. 5. Post-operative care. The operative procedure recommended is:. 1. Manipulative reduction of the fracture if possible. 2. Proximal control of the artery. 3. Arteriography. 4. Exposure of the occluded artery (unless contra-indicated by time factors and by the anatomy of the collateral circulation), liberation and mobilisation of the vessel, repair by suture where such is necessary and possible, and arterectomy only forirreparable local damage. 5. The provision of sympathetic block by injection or by sympathectomy. The important elements of post-operative care are:. 1. To maintain the blood-pressure while cooling the limb and heating the patient

Aims

Cementless unicompartmental knee arthroplasty (UKA) has advantages over cemented UKA, including improved fixation, but has a higher risk of tibial plateau fracture, particularly in Japanese patients. The aim of this multicentre study was to determine when cementless tibial components could safely be used in Japanese patients based on the size and shape of the tibia.

Aims

Cementless acetabular components rely on press-fit fixation for initial stability. In certain cases, initial stability is more difficult to obtain (such as during revision). No current study evaluates how a surgeon’s impaction technique (mallet mass, mallet velocity, and number of strikes) may affect component fixation. This study seeks to answer the following research questions: 1) how does impaction technique affect a) bone strain generation and deterioration (and hence implant stability) and b) seating in different density bones?; and 2) can an impaction technique be recommended to minimize risk of implant loosening while ensuring seating of the acetabular component?

Introduction

In response to the COVID-19 pandemic, there was a rapidly implemented restructuring of UK healthcare services. The The Royal National Orthopaedic Hospital, Stanmore, became a central hub for the provision of trauma services for North Central/East London (NCEL) while providing a musculoskeletal tumour service for the south of England, the Midlands, and Wales and an urgent spinal service for London. This study reviews our paediatric practice over this period in order to share our experience and lessons learned. Our hospital admission pathways are described and the safety of surgical and interventional radiological procedures performed under general anaesthesia (GA) with regards to COVID-19 in a paediatric population are evaluated.

A total of 57 patients, aged between 23 and 86 years, with complex regional pain syndrome (CRPS) type 1 nine weeks after an isolated closed fracture of the distal radius, was randomised to receive either serial intravenous regional blockade (IVRB) with 15 mg of guanethidine in 30 ml of 0.5% prilocaine or serial IVRB with 30 ml of normal saline at weekly intervals until the tenderness in their fingers had resolved or they had received a maximum of four IVRBs. The analgesic efficacy was assessed at 24 hours, 48 hours and one week after each procedure by the dolorimetry ratio and verbal pain scores, and at intervals up to six months after the fracture. There was no significant difference in the number of IVRBs administered or in finger tenderness, stiffness or grip strength between the two groups. The guanethidine group experienced more pain in the affected hand (p = 0.025) and at six months had more vasomotor instability (p < 0.0001) compared with the control group. IVRB using guanethidine offers no significant analgesic advantage over a normal saline placebo block in the treatment of early CRPS type 1 of the hand after fracture of the distal radius. It does not improve the outcome of this condition and may delay the resolution of vasomotor instability when compared with the placebo

Aims

Cigarette smoking has a negative impact on the skeletal system, causes a decrease in bone mass in both young and old patients, and is considered a risk factor for the development of osteoporosis. In addition, it disturbs the bone healing process and prolongs the healing time after fractures. The mechanisms by which cigarette smoking impairs fracture healing are not fully understood. There are few studies reporting the effects of cigarette smoking on new blood vessel formation during the early stage of fracture healing. We tested the hypothesis that cigarette smoke inhalation may suppress angiogenesis and delay fracture healing.