We studied 70 consecutive patients with adolescent idiopathic scoliosis who underwent corrective surgery. They were divided into two groups. In the study group of 38 patients one or more modern blood-conservation measures was used peri-operatively. The 32 patients in the control group did not have these measures. Both groups were similar in regard to age, body-weight, the number of levels fused and the type of surgery.

Only two patients in the study group were transfused with homologous blood and these transfusions were ‘off-protocol’. Wastage of autologous pre-donated units was minimal (6 of 83 units). By contrast, all patients in the control group were transfused with homologous blood. In the study group there was a significant decrease (p = 0.005) in the estimated blood loss when all the blood-conservation methods were used.

The use of blood-conservation measures, the lowering of the haemoglobin trigger for transfusion and the education of the entire team involved in the care of the patient can prevent the need for homologous blood transfusion in patients undergoing surgery for adolescent idiopathic scoliosis.

Subluxation of the hip is common in patients with intermediate spinal muscular atrophy. This retrospective study aimed to investigate the influence of surgery on pain and function, as well as the natural history of subluxed hips which were treated conservatively. Thirty patients were assessed clinically and radiologically. Of the nine who underwent surgery only one reported satisfaction and four had recurrent subluxation. Of the 21 patients who had no surgery, 18 had subluxation at the latest follow-up, but only one reported pain in the hip. We conclude that surgery for subluxation of the hip in these patients is not justified.

We undertook a prospective, randomised study using a non-invasive transcranial Doppler device to evaluate cranial embolisation in computer-assisted navigated total knee arthroplasty (n = 14) and compared this with a standard conventional surgical technique using intramedullary alignment guides (n = 10). All patients were selected randomly without the knowledge of the patient, anaesthetists (before the onset of the procedure) and ward staff. The operations were performed by a single surgeon at one hospital using a uniform surgical approach, instrumentation, technique and release sequence. The only variable in the two groups of patients was the use of single tracker pins of the imageless navigation system in the tibia and femur of the navigated group and intramedullary femoral and tibial alignment jigs in the non-navigated group.

Acetabular Doppler signals were obtained in 14 patients in the computer-assisted group and nine (90%) in the conventional group, in whom high-intensity signals were detected in seven computer-assisted patients (50%) and in all of the non-navigated patients.

In the computer-assisted group no patient had more than two detectable emboli, with a mean of 0.64 (SD 0.74). In the non-navigated group the number of emboli ranged from one to 43 and six patients had more than two detectable emboli, with a mean of 10.7 (sd 13.5). The difference between the two groups was highly significant using the Wilcoxon non-parametric test (p = 0.0003).

Our findings show that computer-assisted total knee arthroplasty, when compared with conventional jig-based surgery, significantly reduces systemic emboli as detected by transcranial Doppler ultrasonography.

The routine use of surgical drains in total hip arthroplasty remains controversial. They have not been shown to decrease the rate of wound infection significantly and can provide a retrograde route for it. Their use does not reduce the size or incidence of post-operative wound haematomas. This prospective, randomised study was designed to evaluate the role of drains in routine total hip arthroplasty.

We investigated 552 patients (577 hips) undergoing unilateral or bilateral total hip arthroplasty who had been randomised to either having a drain for 24 hours or not having a drain. All patients followed standardised pre-, intra-, and post-operative regimes and were independently assessed using the Harris hip score before operation and at six, 18 and 36 months follow-up.

The rate of superficial and deep infection was 2.9% and 0.4%, respectively, in the drained group and 4.8% and 0.7%, respectively in the undrained group. One patient in the undrained group had a haematoma which did not require drainage or transfusion. The rate of transfusion after operation in the drained group was significantly higher than for undrained procedures (p < 0.042). The use of a drain did not influence the post-operative levels of haemoglobin, the revision rates, Harris hip scores, the length of hospital stay or the incidence of thromboembolism. We conclude that drains provide no clear advantage at total hip arthroplasty, represent an additional cost, and expose patients to a higher risk of transfusion.

The long-term effects of metal-on-metal arthroplasty are currently under scrutiny because of the potential biological effects of metal wear debris. This review summarises data describing the release, dissemination, uptake, biological activity, and potential toxicity of metal wear debris released from alloys currently used in modern orthopaedics. The introduction of risk assessment for the evaluation of metal alloys and their use in arthroplasty patients is discussed and this should include potential harmful effects on immunity, reproduction, the kidney, developmental toxicity, the nervous system and carcinogenesis.

We report the clinical and radiographic outcome of a consecutive series of 138 hydroxyapatite-coated total knee replacements with a mean follow-up of 11 years (10 to 13). The patients were entered into a prospective study and all living patients (76 knees) were evaluated. The Hospital for Special Surgery knee score was obtained for comparison with the pre-operative situation. No patient was lost to follow-up. Radiographic assessment revealed no loosening. Seven prostheses have been revised, giving a cumulative survival rate of 93% at 13 years. We believe this to be the longest follow-up report available for an hydroxyapatite-coated knee replacement and the first for this design of Insall-Burstein II knee.

We reviewed the evidence for hip surveillance in children with cerebral palsy from the published literature.

Publications were identified using the Cochrane controlled trials register, the MEDLINE, EMBASE and CINAHL databases and by hand searching key journals and their references. Studies were included if they reported the frequency, associated risk factors or surveillance measures undertaken to identify subluxation or dislocation of the hip in children with cerebral palsy. Assessment of the quality of the methodology was undertaken independently by two researchers.

Four studies described the natural history, incidence and risk factors for dislocation of the hip. Two reported their surveillance results. Approximately 60% of children who were not walking by five years of age were likely to develop subluxation of the hip, with the greatest risk in those with severe neurological involvement. The introduction of surveillance programmes allowed earlier identification of subluxation and reduced the need for surgery on dislocated hips.

Surveillance can identify children most at risk of subluxation using radiological methods which are widely available.

Articular cartilage repair remains a challenge to surgeons and basic scientists. The field of tissue engineering allows the simultaneous use of material scaffolds, cells and signalling molecules to attempt to modulate the regenerative tissue. This review summarises the research that has been undertaken to date using this approach, with a particular emphasis on those techniques that have been introduced into clinical practice, via in vitro and preclinical studies.

We evaluated the use of surgical stabilisation for atlantoaxial subluxation after a follow-up of 24 years in 50 rheumatoid patients who had some degree of pain but no major neurological deficit.

The mortality of patients treated by atlantoaxial fusion was significantly lower than for those who received conservative treatment. The deaths resulted from infection or comorbid conditions. The significantly high relative risks of mortality from conservative treatment compared with surgical treatment were mutilating disease and susceptible factors on both of the HLA-DRB1 alleles. Relief from pain and neurological and functional recovery were better, and the radiological degree of atlantoaxial translocation was less in those who were surgically treated compared with those who were not. Two patients had superficial local infections after surgery. We conclude that prophylactic atlantoaxial fusion is better than conservative treatment in these patients.

The Birmingham hip resurfacing metal-on-metal arthroplasty was introduced in 1997 and has shown promising short- to mid-term results. We used radiostereophotogrammetric analysis (RSA) to study the stability of 20 resurfacing arthroplasties over a follow-up period of 24 months.

Radiological examinations for RSA were performed immediately after surgery and at two, six, 12 and 24 months after operation. Precision and detection of migration thresholds (non-zero movement) were calculated.

All the results corresponded well to those found in similar experimental arrangements with standard hip prostheses. Migration of the cup and vertical and mediolateral migration of the head were calculated. The values were low at two years compared with those of earlier studies of cemented femoral components in conventional total hip replacements indicating that there was no evidence of excessive early migration or loosening of the components.

We carried out a blinded prospective randomised controlled trial comparing 2-octylcyanoacrylate (OCA), subcuticular suture (monocryl) and skin staples for skin closure following total hip and total knee arthroplasty. We included 102 hip replacements and 85 of the knee.

OCA was associated with less wound discharge in the first 24 hours for both the hip and the knee. However, with total knee replacement there was a trend for a more prolonged wound discharge with OCA. With total hip replacement there was no significant difference between the groups for either early or late complications. Closure of the wound with skin staples was significantly faster than with OCA or suture. There was no significant difference in the length of stay in hospital, Hollander wound evaluation score (cosmesis) or patient satisfaction between the groups at six weeks for either hips or knees.

We consider that skin staples are the skin closure of choice for both hip and knee replacements.

The Department of Health and the Public Health Laboratory Service established the Nosocomial Infection National Surveillance Scheme in order to standardise the collection of information about infections acquired in hospital in the United Kingdom and provide national data with which hospitals could measure their own performance. The definition of superficial incisional infection (skin and subcutaneous tissue), set by the Center for Disease Control (CDC), should meet at least one of the defined criteria which would confirm the diagnosis and determine the need for specific treatment.

We have assessed the interobserver reliability of the criteria for superficial incisional infection set by the CDC in our current practice. The incisional site of 50 patients who had an elective primary arthroplasty of the hip or knee was evaluated independently by two orthopaedic clinical research fellows and two orthopaedic ward sisters for the presence or absence of surgical-site infection. Interobserver reliability was assessed by comparison of the criteria for wound infection used by the four observers using kappa reliability coefficients. Our study demonstrated that some of the components of the current CDC criteria were unreliable and we recommend their revision.

In order to identify the risk factors and the incidence of post-operative spinal epidural haematoma, we analysed the records of 14 932 patients undergoing spinal surgery between 1984 and 2002. Of these, 32 (0.2%) required re-operation within one week of the initial procedure and had an International Classification of Diseases (ICD)-9 code for haematoma complicating a procedure (998.12). As controls, we selected those who had undergone a procedure of equal complexity by the same surgeon but who had not developed this complication. Risks identified before operation were older than 60 years of age, the use of pre-operative non-steroidal anti-inflammatories and Rh-positive blood type. Those during the procedure were involvement of more than five operative levels, a haemoglobin < 10 g/dL, and blood loss > 1 L, and after operation an international normalised ratio > 2.0 within the first 48 hours. All these were identified as significant (p < 0.03). Well-controlled anticoagulation and the use of drains were not associated with an increased risk of post-operative spinal epidural haematoma.

Between January 1998 and December 1998, 82 consecutive patients (86 hips) underwent total hip arthroplasty using a trabecular metal monoblock acetabular component. All patients had a clinical and radiological follow-up evaluation at six, 12 and 24 weeks, 12 months, and then annually thereafter. On the initial post-operative radiograph 25 hips had a gap between the outer surface of the component and the acetabular host bed which ranged from 1 to 5 mm. All patients were followed up clinically and radiologically for a mean of 7.3 years (7 to 7.5). The 25 hips with the 1 to 5 mm gaps were studied for component migration at two years using the Einzel-Bild-Roentgen-Analyse (EBRA) digital measurement method. At 24 weeks all the post-operative gaps were filled with bone and no acetabular component had migrated. The radiographic outcome of all 86 components showed no radiolucent lines and no evidence of lysis. No acetabular implant was revised. There were no dislocations or other complications. The bridging of the interface gaps (up to 5 mm) by the trabecular metal monoblock acetabular component indicates the strong osteoconductive, and possibly osteoinductive, properties of trabecular metal.

We performed a prospective, randomised controlled trial of unicompartmental knee arthroplasty comparing the performance of the Acrobot system with conventional surgery. A total of 27 patients (28 knees) awaiting unicompartmental knee arthroplasty were randomly allocated to have the operation performed conventionally or with the assistance of the Acrobot. The primary outcome measurement was the angle of tibiofemoral alignment in the coronal plane, measured by CT. Other secondary parameters were evaluated and are reported.

All of the Acrobot group had tibiofemoral alignment in the coronal plane within 2° of the planned position, while only 40% of the conventional group achieved this level of accuracy. While the operations took longer, no adverse effects were noted, and there was a trend towards improvement in performance with increasing accuracy based on the Western Ontario and McMaster Universities Osteoarthritis Index and American Knee Society scores at six weeks and three months. The Acrobot device allows the surgeon to reproduce a pre-operative plan more reliably than is possible using conventional techniques which may have clinical advantages.

Between July 2000 and April 2004, 19 patients with bilateral spastic cerebral palsy who required an assistive device to walk had combined lengthening-transfer of the medial hamstrings as part of multilevel surgery. A standardised physical examination, measurement of the Functional Mobility Scale score and video or instrumented gait analysis were performed pre- and post-operatively. Static parameters (popliteal angle, flexion deformity of the knee) and sagittal knee kinematic parameters (knee flexion at initial contact, minimum knee flexion during stance, mean knee flexion during stance) were recorded. The mean length of follow-up was 25 months (14 to 45).

Statistically significant improvements in static and dynamic outcome parameters were found, corresponding to improvements in gait and functional mobility as determined by the Functional Mobility Scale. Mild hyperextension of the knee during gait developed in two patients and was controlled by adjustment of their ankle-foot orthosis. Residual flexion deformity > 10° occurred in both knees of one patient and was treated by anterior distal femoral physeal stapling. Two children also showed an improvement of one level in the Gross Motor Function Classification System.

We investigated the effect of stimulation with a pulsed electromagnetic field on the osseointegration of hydroxyapatite in cortical bone in rabbits. Implants were inserted into femoral cortical bone and were stimulated for six hours per day for three weeks.

Electromagnetic stimulation improved osseointegration of hydroxyapatite compared with animals which did not receive this treatment in terms of direct contact with the bone, the maturity of the bone and mechanical fixation. The highest values of maximum push-out force (F_max) and ultimate shear strength (σ_u) were observed in the treated group and differed significantly from those of the control group at three weeks (F_max; p < 0.0001; σ_u, p < 0.0005).