An experimental model of osteoarthritis resulting from laxity of the joint was induced in eighteen mature dogs (at least two years old) by sectioning the anterior cruciate ligament of the right knee (stifle) with a stab incision, the left knee providing a control. A sham operation was also performed in three other dogs, in which a stab incision was made but the ligament left intact. The dogs were killed at various intervals from one to forty-eight weeks later. Morphological changes in bone, cartilage, synovial membrane and joint capsule were examined in all the joints and biochemical changes in the cartilage of three dogs killed after two, eight, and sixteen weeks. All the changes resulting from the operation progressed with time and became indistinguishable from those found in three dogs with natural osteoarthritis of the knee. There were no changes in the joints which had sham operations. As the time of onset is known, this experimental model in a larger species enables a study to be made of the biochemical as well as the morphological changes in the early stages of osteoarthritis

We analysed synovial fluid from 88 hips, 38 with osteoarthritis and 12 with well-functioning and 38 with loose hip prostheses. The levels of TNF-α, IL-1ß (71 hips) and IL-6 (45 hips) were measured using the ELISA technique. Joints with well-functioning or loose prostheses had significantly increased levels of TNF-α compared with those with osteoarthritis. Hips with aseptic loosening also had higher levels of IL-1ß but not of IL-6 compared with those without an implant. The levels of TNF-α and IL-1ß did not differ between hips with stable and loose prostheses. Higher levels of TNF-α were found in hips with bone resorption of type II and type III (Gustilo-Pasternak) compared with those with type-I loosening. The level of cytokines in joint fluid was not influenced by the time in situ of the implants or the age, gender or area of the osteolysis as measured on conventional radiographs. Our findings support the theory that macrophages in the joint capsule increase the production of TNF-α at an early phase probably because of particle load and in the absence of clinical loosening. Since TNF-α has an important role in the osteolytic process, the interfaces should be protected from penetration of joint fluid

We measured joint position sense in the knee by a new method which tests the proprioceptive contribution of the joint capsule and ligaments. The leg was supported on a splint, and held in several positions of flexion. The subjects' perception of the position was recorded on a visual analogue model and compared with the actual angle of flexion. Eighty-one normal and 45 osteoarthritic knees were examined, as were 10 knees with semi-constrained and 11 with hinged joint replacements. All were assessed with and without an elastic bandage around the knee. There was a steady decline in joint position sense with age in subjects with normal knees. Those with osteoarthritic knees had impaired joint position sense at all ages (p less than 0.001). Knee replacement improved the joint position sense slightly (p less than 0.02); semi-constrained replacement had a greater effect than hinged replacement. The effect of an elastic bandage in subjects with poor position sense was dramatic, improving accuracy by 40% (p less than 0.001). It is proposed that reduced proprioception in elderly and osteoarthritic subjects may be responsible for initiation or advancement of degeneration of the knee

Aims

We report the natural course of Baker’s cysts following total knee arthroplasty (TKA) at short- and mid-term follow-up.

1. The rates of vascularisation in 119 autogenous, homogenous and heterogenous bone grafts, placed in the femoral medullary cavity and under the renal capsule of rabbits, were studied. 2. Substantial differences have been found in the speed of vascular penetration and arrangement among autografts, homografts and heterografts : penetration of the heterogenous implant was six or more times slower. Moreover, large areas of the homografts and heterografts were often totally excluded from the circulation for as long as the research was continued (up to three months). Revascularisation of the cortical bone was slower and less profuse than in cancellous bone, keeping always the same respective proportion between the three types of bone we have described. The results on the kidney were much less constant, and I attribute this to the vascular peculiarities of the bed. 3. Vascular patterns peculiar to the time of implantation and type of graft are described. 4. Suggestive, even if not totally convincing, evidence was found of recanalisation of old vessels inside the graft by advancing vessels from the bed. 5. There is striking correlation between the rate of vascular penetration of the bone implants and their ultimate "take" or incorporation in the bed

Aims

The aim of this study was to examine whether tourniquet use can improve perioperative blood loss, early function recovery, and pain after primary total knee arthroplasty (TKA) in the setting of multiple-dose intravenous tranexamic acid.

Aims

Unicompartmental knee arthroplasty (UKA) has become a popular method of treating knee localized osteoarthritis (OA). Additionally, the posterior cruciate ligament (PCL) is essential to maintaining the physiological kinematics and functions of the knee joint. Considering these factors, the purpose of this study was to investigate the biomechanical effects on PCL-deficient knees in medial UKA.

Aims

Stiffness is a common complication after total knee arthroplasty (TKA). Pathogenesis is not understood, treatment options are limited, and diagnosis is challenging. The aim of this study was to investigate if MRI can be used to visualize intra-articular scarring in patients with stiff, painful knee arthroplasties.

Failure of normal acetabular development is inevitable in congenital dislocation of the hip when it is unrecognised until late infancy or early childhood. Numerous stabilising procedures have been described, one of the first being the shelf operation or acetabuloplasty. This procedure fell into disrepute because the shelf was often located too high or was too small to prevent upward migration of the femoral head. The technique described emphasises the importance of resecting the thickened capsule and exposing the lateral margin of the acetabulum to allow a substantial portion of the outer cortex of the ilium to be turned down both laterally and anteriorly over the femoral head. Twenty cases of acetabuloplasty have been followed up for an average period of nine years. The results have been assessed from the point of view of function, relief of pain, and degree of support of the femoral head as demonstrated radiologically. The shelf operation is a simple and safe procedure, and provided it gives adequate support to the subluxated femoral head it will ensure a stable, mobile joint capable of standing up to reasonable use for many years. If deterioration should occur in later life, total hip replacement may be undertaken more easily than if the joint had been allowed to undergo progressive subluxation

Aims

The treatment of tibial aplasia is controversial. Amputation represents the gold standard with good functional results, but is frequently refused by the families. In these patients, treatment with reconstructive limb salvage can be considered. Due to the complexity of the deformity, this remains challenging and should be staged. The present study evaluated the role of femoro-pedal distraction using a circular external fixator in reconstructive treatment of tibial aplasia. The purpose of femoro-pedal distraction is to realign the limb and achieve soft tissue lengthening to allow subsequent reconstructive surgery.

The primary source for the blood supply of the head of the femur is the deep branch of the medial femoral circumflex artery (MFCA). In posterior approaches to the hip and pelvis the short external rotators are often divided. This can damage the deep branch and interfere with perfusion of the head. We describe the anatomy of the MFCA and its branches based on dissections of 24 cadaver hips after injection of neoprene-latex into the femoral or internal iliac arteries. The course of the deep branch of the MFCA was constant in its extracapsular segment. In all cases there was a trochanteric branch at the proximal border of quadratus femoris spreading on to the lateral aspect of the greater trochanter. This branch marks the level of the tendon of obturator externus, which is crossed posteriorly by the deep branch of the MFCA. As the deep branch travels superiorly, it crosses anterior to the conjoint tendon of gemellus inferior, obturator internus and gemellus superior. It then perforates the joint capsule at the level of gemellus superior. In its intracapsular segment it runs along the posterosuperior aspect of the neck of the femur dividing into two to four subsynovial retinacular vessels. We demonstrated that obturator externus protected the deep branch of the MFCA from being disrupted or stretched during dislocation of the hip in any direction after serial release of all other soft-tissue attachments of the proximal femur, including a complete circumferential capsulotomy. Precise knowledge of the extracapsular anatomy of the MFCA and its surrounding structures will help to avoid iatrogenic avascular necrosis of the head of the femur in reconstructive surgery of the hip and fixation of acetabular fractures through the posterior approach

Aims

Responsiveness and ceiling effects are key properties of an outcome score. No such data have been reported for the original English version of the International Hip Outcome Tool 12 (iHOT-12) at a follow-up of more than four months. The aim of this study was to identify the responsiveness and ceiling effects of the English version iHOT-12 in a series of patients undergoing hip arthroscopy for intra-articular hip pathology at a minimum of one year postoperatively.

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.

Aims

In elderly patients with osteoarthritis and protrusio who require arthroplasty, dislocation of the hip is difficult due to migration of the femoral head. Traditionally, neck osteotomy is performed in situ, so this is not always achieved. Therefore, the purpose of this study is to describe a partial resection of the posterior wall in severe protrusio.

We studied the contributions of the long and short heads of the biceps (LHB, SHB) to anterior stability in 13 cadaver shoulders. The LHB and SHB were replaced by spring devices and translation tests at 90 degrees abduction of the arm were performed by applying a 1.5 kg anterior force. The position of the humeral head was monitored by an electromagnetic tracking device with or without an anterior translational force; with 0 kg, 1.5 kg or 3 kg loads applied on either LHB or SHB tendons in 60 degrees, 90 degrees or 120 degrees of external rotation; and with the capsule intact, vented, or damaged by a Bankart lesion. The anterior displacement of the humeral head under 1.5 kg force was significantly decreased by both the LHB and SHB loading in all capsular conditions when the arm was in 60 degrees or 90 degrees of external rotation. At 120 degrees of external rotation, anterior displacement was significantly decreased by LHB and SHB loading only when there was a Bankart lesion. We conclude that LHB and SHB have similar functions as anterior stabilizers of the glenohumeral joint with the arm in abduction and external rotation, and that their role increases as shoulder stability decreases. Both heads of the biceps have been shown to have a stabilising function in resisting anterior head displacement, and consideration should therefore be given to strengthening the biceps during rehabilitation programmes for chronic anterior instability of the shoulder

1. It has been shown that in experimental rickets the well known changes in the epiphysial cartilage which so seriously affect growth are accompanied by severe interference with the progress of the metaphysial vessels into the growth cartilage. 2. Further evidence has been found that, by the repeated increase in their number, the cartilage cells occupying the more distal part of the proliferative segment become more and more affected by their remoteness from the epiphysial vessels, which supply the transudates to these cells. At a given distance these cells are affected and change, becoming hypertrophic, with increasingly large vacuolae, and are rich in glycogen and alkaline phosphatase. 3. The hypertrophic cells alter the nature of the intercellular substance they deposit and this becomes calcifiable. Provided that the metaphysial vessels are situated at an appropriate distance–about three cell capsules away–and that the blood has its necessary components, calcification occurs. 4. Calcification produces the advancing, rigid multitubular structure within which the progressing metaphysial vessels are protected. 5. The interruption of calcification by the withdrawal of fat-soluble vitamins breaks down the whole mechanism of growth and stops the vessels growing into their proper position. The administration of the required vitamins re-establishes the normal sequence of events and allows the vessels to play their decisive role in osteogenesis. 6. Any mechanism which causes the interruption of the vascular progression, whether from metaphysial ischaemia (Trueta and Amato 1960), from severe pressure (Trueta and Trias 1961) or from lack of calcification by withdrawing the fat-soluble vitamins, equally interrupts growth

1. Léri's pleonosteosis is characterised by broadening and deformity of the thumbs and great toes, flexion contracture of the interphalangeal joints, limited movement of other joints, and often a Mongoloid facies. Four such cases are described. 2. A review of the twenty reports in the literature, and the cases now described, shows that the deformities are due to capsular contracture rather than deformity of bone. 3. In one patient there was striking evidence of fibro-cartilaginous thickening of the anterior carpal ligaments. It is suggested that the primary pathological change in pleonosteosis may be in the joint capsules rather than in the epiphyses. 4. The patient with thickening of the anterior carpal ligaments had bilateral median palsy from carpal tunnel compression. 5. The causes of carpal tunnel compression of the median nerve are reviewed. Acute compression may be due not only to dislocation of the semilunar bone but to haemorrhage in the palm. Late compression by bone may occur twenty to fifty years after injury. Late compression without bone abnormality has been attributed to occupational stress, but it is suggested that pathological thickening of the anterior carpal ligament may be the cause. 6. The patient with pleonosteosis and bilateral median palsy had also bilateral Morton's metatarsalgia with large digital neuromata. 7. Plantar digital neuritis has already been shown to be an ischaemic nerve lesion preceded by degenerative changes in the digital artery. The significance of the fibrous tunnel through which the artery passes to reach the digital cleft is considered

We revised seven alumina-blasted cementless hip prostheses (Ti-alloy stems, cp Ti threaded sockets) with low- or high-carbon Co-alloy bearings at a mean of 20.1 months after implantation because of pain and loosening. Histological examination of the retrieved periprosthetic tissues from two cases in which the implant was stable and three in which the socket was loose showed macrophages with basophilic granules containing metal and alumina wear particles and lymph-cell infiltrates. In one of the two cases of stem loosening the thickened neocapsule also contained definite lymphatic follicles and gross lymphocyte/plasma-cell infiltrates. Spectrometric determination of the concentration of elements in periprosthetic tissues from six cases was compared with that of joint capsules from five control patients undergoing primary hip surgery. In the revisions the mean concentration of implant-relevant elements was 693.85 μg/g dry tissue. In addition to Cr (15.2%), Co (4.3%), and Ti (10.3%), Al was predominant (68.1%) and all concentrations were significantly higher (p < 0.001) than those in the control tissues. The annual rates of linear wear were calculated for six implants. The mean value was 11.1 μm (heads 6.25 μm, inserts 4.82 μm). SEM/EDXA showed numerous fine scratches and deep furrows containing alumina particles in loosened sockets, and stems showed contamination with adhering or impacted alumina particles of between 2 and 50 μm in size