We performed a meta-analysis of the English literature to assess the efficacy of four common regimes for thromboembolic prophylaxis after total knee arthroplasty: aspirin, warfarin, low-molecular-weight heparin (LMWH) and pneumatic compression. We reviewed 136 articles and abstracts published between January 1980 and December 1997. Papers not using routine venography and a lung scan or angiography to detect deep-venous thrombosis (DVT) and pulmonary emboli (PE) respectively, were excluded. Of the 136 studies, 23 with 6001 patients were selected.

The incidence of DVT was 53% (1701/3214) in the aspirin group, 45% (541/1203) in the warfarin group, 29% (311/1075) in the LMWH group, and 17% (86/509) in the pneumatic compression device group. Intermittent pneumatic compression devices and LMWH were significantly better than warfarin (p < 0.0001) or aspirin (p < 0.0001) in preventing DVT.

The incidence of asymptomatic PE was 11.7% in the aspirin group (222/1901), 8.2% (101/1229) in the warfarin group and 6.3% (24/378) in the pneumatic compression group. No studies with LMWH used routine lung scans. Warfarin and pneumatic compression were significantly better than aspirin in preventing asymptomatic PE (p < 0.05).

The incidence of symptomatic PE was 1.3% (23/1800) in the aspirin group, 0.4% (2/559) in the warfarin group, 0.5% (2/416) in the LMWH group and 0% (0/177) in the pneumatic compression group. No statistically significant difference was noted between the above prophylatic regimes due to the very small incidence of symptomatic PE.

Prophylaxis for thromboembolic disease in TKA may have to include a combination of some of the above regimes to incorporate their advantages.

We assessed proprioception in the knee using the angle reproduction test in 20 healthy volunteers, ten patients with acute anterior instability and 20 patients with chronic anterior instability after reconstruction of the anterior cruciate ligament (ACL). In addition, the Lysholm-knee score, ligament laxity and patient satisfaction were determined.

Acute trauma causes extensive damage to proprioception which is not restored by rehabilitation alone. Three months after operation, there remained a slight decrease in proprioception compared with the preoperative recordings, but six months after reconstruction, restoration of proprioception was seen near full extension and full flexion. In the mid-range position, proprioception was not restored. At follow-up, 3.7 ± 0.3 years after reconstruction, there was further improvement of proprioception in the mid-range position. There was no difference between open and arthroscopic techniques. The highest correlation was found between proprioception and patient satisfaction. After reconstruction of the ACL reduced proprioception may explain the poor functional outcome in some patients, despite restoration of mechanical stability.

The PROSTALAC functional spacer is made of antibiotic-loaded acrylic cement but has a small metal-on-polythene articular surface. We have used it as an interim spacer in two-stage exchange arthroplasty for infected total knee replacement. PROSTALAC allows continuous rehabilitation between stages as it maintains good alignment and stability of the knee and a reasonable range of movement. It also helps to maintain the soft-tissue planes, which facilitates the second-stage procedure.

We reviewed 45 consecutive patients, treated over a period of nine years. The mean follow-up was for 48 months (20 to 112). At final review, there was no evidence of infection in 41 patients (91%); only one had a recurrent infection with the same organism. There was improvement in the Hospital for Special Surgery knee score between stages and at final review. The range of movement was maintained between stages. Complications were primarily related to the extensor mechanism and stability of the knee between stages. Both of these problems decreased with refinement of the design of the implant.

The rate of cure of the infection in our patients was similar to that using other methods. Movement of the knee does not appear to hinder control of infection.

We have used a modified technique in five patients to correct winging of the scapula caused by injury to the brachial plexus or the long thoracic nerve during transaxillary resection of the first rib. The procedure stabilises the scapulothoracic articulation by using strips of autogenous fascia lata wrapped around the 4th, 6th and 7th ribs at least two, and preferably three, times.

The mean age of the patients at the time of operation was 38 years (26 to 47) and the mean follow-up six years and four months (three years and three months to 11 years). Satisfactory stability was achieved in all patients with considerable improvement in shoulder function. There were no complications.

In a previous study the prevalence of Raynaud’s phenomenon (RP) in patients with idiopathic carpal tunnel syndrome (CTS) was found to be 60% which is much higher than that in the general population. We undertook a further study of the same cohort of patients have both CTS and RP and who had an open release of the carpal tunnel, to observe the effects of the operation on RP. We observed whether the symptoms of RP improved, and repeated the cold provocation tests to see if the arterial pulse which was decreased before operation would recover. We rated the outcome as good when the patients showed both an improvement of the symptoms of RP and a normal pulse amplitude after exposure to cold, fair when the pulse amplitude recovered to more than two-thirds of that before exposure, and poor when cold hypersensitivity was persistent or showed the same degree of decreased pulse amplitude as observed before operation. Of the 18 patients with both conditions, ten (56%) had good and four (22%) fair results, with a mean recovery time of 4.2 months (6 weeks to 1 year) after operation.

If the vasospasm seen in RP is an expression of vasomotor irritation in the carpal tunnel, these findings suggest that local compression of vasomotor fibres in the carpal tunnel can also be relieved by the release of this structure. Careful consideration, however, is still required in treating patients with both conditions since in some cases. RP may be superimposed or it may have other origins.

A vascular necrosis of the lunate, first described by Kienböck, can be treated either conservatively or by various surgical procedures. We compared the results of 18 conservatively treated patients, all of whom had stage-2 or stage-3 disease, with those of 15 who underwent a radial shortening procedure. We evaluated pain, range of movement, grip strength and functional disability, and determined the progression of the disease by assessing radiologically carpal height, the width and flattening of the lunate, the radioscaphoid angle, the pattern of the fracture and sclerosis and cysts. The mean follow-up was for 3.6 years (1.5 to 9).

Patients treated by radial shortening had less pain and better grip strength than those managed conservatively. In some patients with stage-3 disease treated conservatively there was rapid deterioration to carpal collapse. Although radial shortening did not reverse or prevent carpal collapse, it slowed down the process in patients with stage-3 disease.

We recommend a radial shortening procedure for patients with severe pain and radiological signs of progressive carpal collapse.

We treated 31 hips in 30 patients with advanced osteoarthritis of the hip secondary to acetabular dysplasia, by valgus-extension femoral osteotomy. The mean follow-up was 12.7 years (10 to 17). Acetabuloplasty was added in ten severely dysplastic hips.

In 28 hips, radiological widening of the joint space was seen three years after operation, but in 12 had narrowed again by ten years. Survivorship analysis showed that the rate of survival was 82% using the pain score as the index of failure, and 72% based on radiological findings at ten years. Better long-term results were obtained in hips which had an acetabular head index greater than 70% or a roof osteophyte more than 5 mm in length three years after operation. Acetabuloplasty should be added for the hip which is severely dysplastic and with a poorly developed roof osteophyte.

There are few medium- and long-term data on the outcome of the use of proximal femoral structural allografts in revision hip arthroplasty. This is a study of a consecutive series of 40 proximal femoral allografts performed for failed total hip replacements using the same technique with a minimum follow-up of five years (mean 8.8 years; range 5 to 11.5 years). In all cases the stem was cemented into both the allograft and the host femur. The proximal femur of the host was resected in 37 cases.

There were four early revisions (10%), two for infection, one for nonunion of the allograft-host junction, and one for allograft resorption noted at the time of revision of a failed acetabular reconstruction. Junctional nonunion was seen in three patients (8%), two of whom were managed successfully by bone grafting, and bone grafting and plating respectively. Instability was observed in four (10%). Trochanteric nonunion was seen in 18 patients (46%) and trochanteric escape in ten of these (27%). The mean Harris hip score improved from 39 to 79. Severe resorption involving the full thickness of the allograft was seen in seven patients (17.5%). This progressed rapidly and silently, but has yet to cause failure of any of the reconstructions.

Profound resorption of the allograft may be related to a combination of factors, including a slow form of immune rejection, stress shielding and resorption due to mechanical disuse with solid cemented distal fixation, and the absence of any masking or protective effect which may be provided by the retention of the bivalved host bone as a vascularised onlay autograft. Although continued surveillance is warranted, the very good medium-term clinical results justify the continued use of structural allografts for failed total hip replacements with severe loss of proximal femoral bone.

It has been suggested that transient osteoporosis or the bone marrow oedema syndrome (BMOS) may be the initial phase of osteonecrosis of the femoral head (ONFH) and that there may be a common pathophysiology. In this study, we have assessed the MR images of 200 consecutive patients with ONFH in respect of the BMO pattern in order to test this hypothesis.

This pattern was not observed in the early stage of ONFH. The initial abnormal finding detected on the MR images was an abnormal band of intensity at the junction between the necrotic area and the normal bone. Structural damage of the head seems to result in the appearance of the BMO pattern and the development of pain in ONFH. There was no finding to support the existence of a continuum between BMOS and ONFH.

The calcar femorale is a vertical plate of bone lying deep to the lesser trochanter and is formed as a result of traction of the iliopsoas which separates the femoral cortex into two distinct layers, the calcar femorale and the medial femoral cortex. They fuse together proximally to form the medial femoral neck. A stem placed centrally will abut against the calcar femorale with little or no space for cement. Clearing of the calcar will offer space for a cement layer, which will support the stem proximally on the posterior aspect. We compared two consecutive groups of Charnley low-friction arthroplasties, with and without clearing of the calcar.

In 330 patients who had an arthroplasty without clearing the calcar, there were ten revisions for aseptic loosening of the stem and six other stems were considered ‘definitely loose’, giving a rate of failure of 4.8%. In 111 patients in whom the calcar was cleared there was only one revision for aseptic loosening and no stems were classed as ‘definitely loose’, giving a rate of failure of 0.9%.

Survivorship analysis has again shown the need for long-term follow-up; the differences became clear after ten years but because of the relatively small numbers, statistical analysis is not yet applicable.

We now clear the calcar femorale routinely and advocate optimal access to the medullary canal and insertion of the stem in the area of the piriform fossa.

We studied 23 patients with spondylolysis of the fifth lumbar vertebra (L5) and 20 with spondylolytic spondylolisthesis at this level. All were more than 40 years of age. The transverse processes at L5 were significantly wider in the former group than in the latter. We also dissected 56 cadavers to study the morphological relationship between the transverse process of L5 and the iliolumbar ligament, and found that the wider transverse process is associated with increased width of the posterior band of the iliolumbar ligament.

If a patient with pars defects has wide transverse processes at L5, the lumbosacral junction may be stabilised by wide posterior bands of the iliolumbar ligament and the fifth lumbar vertebra by the ligament, preventing anterior displacement.

We studied 32 patients with central cord syndrome who were managed conservatively. Six were under 50 years of age (group 1), 16 between 50 and 70 years (group 2) and ten over 70 years (group 3).

At the time of discharge all patients in group 1 could walk independently and had good bladder control compared with 11 (69%) and 14 (88%) in group 2 and four (40%) and two (20%) in group 3, respectively.

At follow-up after a mean of 8.6 years (4 to 15), ten patients had died leaving 22 in the study. All those in group 1 were alive, could walk independently and had bladder control. In group 2, 13 were alive of whom ten (77%) could walk independently and nine (69%) had bladder control. In group 3 only three were alive of whom only one was independent and none had bladder control.

Function at discharge as measured by the ASIA motor scoring system was usually maintained or improved at follow-up, but patients over 70 years of age at injury did poorly.

We performed a prospective, randomised study on 110 patients more than 50 years old with fractures of the distal radius to compare the outcome of conservative treatment with that using remodellable bone cement (Norian skeletal repair system, SRS) and immobilisation in a cast for two weeks.

Patients treated with SRS had less pain and earlier restoration of movement and grip strength. The results at one year were satisfactory in 81.54% of the SRS patients and 55.55% of the control group. The rates of malunion were 18.2% and 41.8%, respectively. There was a significant relationship between the functional and radiological results. Soft-tissue extrusion was present initially in 69.1% of the SRS patients; most deposits disappeared progressively, but persisted in 32.73% at one year.

We conclude that the injection of a remodellable bone cement into the trabecular defect of fractures of the distal radius provides a better clinical and radiological result than conventional treatment.

Revision operations after fracture of the hip are costly, in both monetary and personal terms. We have assessed whether these costs applied equally to all complications after the primary procedure. We studied 3154 consecutive patients with fracture of the hip and analysed the complications and financial implications related to reoperation within one year of injury. The results showed that revision surgery is not always associated with a significant increase in morbidity, financial cost or mortality, but is directly related to the underlying complication.

We treated 15 patients with atrophic nonunion of a diaphyseal fracture of the humerus with an associated bony defect using an autogenous cancellous bone graft and a plate to bridge the defect. There were nine men and six women with a mean age of 48 years. The mean length of the bony defect was 3 cm.

At a mean follow-up of 30 months only one fracture failed to unite. This suggests that, in the presence of a well-vascularised envelope of muscle, the application of an autogenous cancellous bone graft in conjunction with a bridging plate represents a good alternative to more demanding surgical techniques.

We explored the role of iron overload, deficiency of vitamin C and alcohol abuse in the aetiology of cervical and intertrochanteric fractures of the neck of the femur as a result of minor trauma. We studied prospectively 72 patients (45 men, 27 women). Levels of serum iron markers, vitamin C and alcohol markers were measured. Consumption of alcohol was estimated using questionnaires. The findings were compared with those of an age- and gender-matched control group. The mean age of the men was 59.5 years and of the women 66.9 years, with a male predominance. In the men, iron overload, as shown by high levels of serum ferritin (p < 0.001) and deficiency of vitamin C (p < 0.03), as well as abuse of both Western and the traditional type of alcohol, appear to be important aetiological factors. In women, alcohol abuse was also common, but iron markers and levels of vitamin C did not differ significantly from the control group.

Congenital talipes equinovarus is a common anomaly which can now be diagnosed prenatally on a routine ultrasound scan at 20 weeks of gestation. Prenatal counselling is increasingly offered to parents with affected fetuses, but it is difficult to counsel parents if there is a chance that the fetus may not have talipes. Our study correlates the prenatal ultrasound findings of 14 infants diagnosed as having unilateral or bilateral talipes during their routine 20-week ultrasound scan with their clinical findings at birth and the treatment received.

No feet diagnosed as talipes on the ultrasound scan were completely normal at birth and therefore there were no true false-positive results. One foot graded as normal at 20 weeks was found to have a mild grade-1 talipes at birth, but did not require treatment other than simple stretches. A total of 32% of feet required no treatment and so could be considered functional false-positive results on the scan. Serial casting was required by 13% of feet and surgical treatment by 55%. The severity of the talipes is difficult to establish before birth. A number of patients are likely to need surgical treatment, but a proportion will have talipes so mildly that no treatment will be required. In counselling parents at 20 weeks, orthopaedic surgeons need to know whether or not there is a small chance that the ultrasound diagnosis could be wrong and also that the talipes may be so mild that the foot will not require treatment.

We used a combined cuboid/cuneiform osteotomy to treat residual adductus deformity in idiopathic and secondary club feet. The mean follow-up for 27 feet (22 idiopathic, four arthrogrypotic and one related to amniotic band syndrome) was 5.0 years (2.0 to 9.8). All healed uneventfully except for one early wound infection. No further surgery was required in the 22 idiopathic club feet but four of five with secondary deformity needed further surgery. At follow-up all patients with idiopathic and two with secondary club feet were free from pain and satisfied with the result. In the idiopathic feet, adductus of the forefoot, as measured by the calcaneal second metatarsal angle, improved on average from 20.7 ± 2.0° to 8.9 ± 1.8° (p < 0.05). In four feet, with a follow-up of more than six years, there was complete recurrence of the deformity. In the secondary club feet, there was no improvement of the adductus. We conclude that in most, but not all, idiopathic club feet a cuboid/cuneiform osteotomy can provide satisfactory correction of adductus deformity. Those with secondary deformity require other procedures.

Werner’s syndrome is a rare condition usually presenting as premature ageing in adults. Over a period of 30 years we have followed two siblings with extensive musculoskeletal manifestations including a soft-tissue tumour, insufficiency fractures, nonunion and tendonitis, with associated problems of management. The literature is reviewed.

We studied the effectiveness of a local injection of 1 ml of 2% mepivacaine into the sheath of the flexor tendon in 64 fingers and found it to be a safe procedure giving satisfactory anaesthesia.

We present a case of superior dislocation of the patella trapped by interlocked osteophytes. Unlike previous reports, in which the mechanism resulted from a blow to the inferior pole, it is postulated that increased load on the extensor mechanism, combined with patella alta and patellofemoral osteophytes, caused locking of the knee in extension.

Mononuclear osteoclast precursors are present in the wear-particle-associated macrophage infiltrate found in the membrane surrounding loose implants. These cells are capable of differentiating into osteoclastic bone-resorbing cells when co-cultured with the rat osteoblast-like cell line, UMR 106, in the presence of 1,25(OH)₂ vitamin D₃. In order to develop an in vitro model of osteoclast differentiation which more closely parallels the cellular microenvironment at the bone-implant interface in situ, we determined whether osteoblast-like human bone-derived cells were capable of supporting the differentiation of osteoclasts from arthroplasty-derived cells and analysed the humoral conditions required for this to occur.

Long-term co-culture of arthroplasty-derived cells and human trabecular-bone-derived cells (HBDCs) resulted in the formation of numerous tartrate-resistant-acid-phosphatase (TRAP) and vitronectin-receptor (VNR)-positive multinucleated cells capable of extensive resorption of lacunar bone. The addition of 1,25(OH)₂ vitamin D₃ was not required for the formation of osteoclasts and bone resorption. During the formation there was release of substantial levels of M-CSF and PGE₂. Exogenous PGE₂ (10⁻⁸ to 10⁻⁶M) was found to stimulate strongly the resorption of osteoclastic bone. Our study has shown that HBDCs are capable of supporting the formation of osteoclasts from mononuclear phagocyte precursors present in the periprosthetic tissues surrounding a loose implant. The release of M-CSF and PGE₂ by activated cells at the bone-implant interface may be important for the formation of osteoclasts at sites of pathological bone resorption associated with aseptic loosening.

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.

Our aim was to determine the relationship between age and the mechanical and physical properties of trabecular bone, to describe the patterns in which the variations in these properties take place, and to investigate the influence of the physical properties on the mechanical characteristics of trabecular bone during growth. We used 30 lambs in three age groups and 20 sheep in two age groups. Cubes of subchondral bone were cut from the proximal tibia according to a standardised protocol. We performed non-destructive compression tests of the specimens in three orthogonal directions and compression tests to failure in the axial direction. The physical properties of the specimens were also determined. The data were correlated with age and compared in skeletally immature and mature animals. Multiple regression analyses were performed between the mechanical and the physical properties.

Age correlated positively with elastic modulus, bone strength, energy absorption to failure, elastic energy, mechanical anisotropy ratio, tissue density, apparent density, apparent ash density, and bone mineral content, and inversely with ultimate strain, viscoelastic energy absorption, relative energy loss, the collagen content of bone and the percentage porosity. The values of all variables were significantly different in the skeletally mature and immature groups. The apparent density of trabecular bone tissue was found to be the major predictor of its compressive mechanical properties. Together with the content of bone muscle and bone collagen, the apparent density could explain 84% of the variation in the elastic modulus, whereas only a small portion of the variation in ultimate strain could be explained by the variation in apparent density.

We aimed to highlight the relationship between age and the architectural properties of trabecular bone, to outline the patterns in which the variations in these properties take place, and to investigate the influence of the architecture on the mechanical properties of trabecular bone in growing animals. We studied 30 lambs in three age groups and 20 sheep in two age groups. Cubes of subchondral bone were cut from the proximal tibia according to a standardised protocol. They were serially sectioned and their architectural properties were determined. Similar cubes were obtained from the identical anatomical position of the contralateral tibia and their compressive mechanical properties measured. The values obtained from the skeletally immature and mature individuals were compared. Multiple regression analyses were performed between the architectural and the mechanical properties.

The bone volume fraction, the mean trabecular volume, the architectural and the mechanical anisotropy, the elastic modulus, the bone strength, the energy absorption to failure, and the elastic energy correlated positively with increasing age whereas the connectivity density, the bone surface density, the ultimate strain, the absorption of viscoelastic energy and the relative loss of energy correlated inversely. The values of all variables were significantly different in the skeletally mature and immature groups. We determined the patterns in which the variations took place. The bone volume fraction of the trabecular bone tissue was found to be the major predictor of its compressive mechanical properties. Together with the mean trabecular volume and the bone surface density, it explained 81% of the variations in the compressive elastic modulus of specimens obtained from the contralateral tibiae.