We evaluated the histological changes before and after fixation in ten knees of ten patients with osteochondritis dissecans who had undergone fixation of the unstable lesions. There were seven males and three females with a mean age of 15 years (11 to 22). The procedure was performed either using bio-absorbable pins only or in combination with an autologous osteochondral plug. A needle biopsy was done at the time of fixation and at the time of a second-look arthroscopy at a mean of 7.8 months (6 to 9) after surgery.

The biopsy specimens at the second-look arthroscopy showed significant improvement in the histological grading score compared with the pre-fixation scores (p < 0.01). In the specimens at the second-look arthroscopy, the extracellular matrix was stained more densely than at the time of fixation, especially in the middle to deep layers of the articular cartilage.

Our findings show that articular cartilage regenerates after fixation of an unstable lesion in osteochondritis dissecans.

Digital radiography is becoming widespread. Accurate pre-operative templating of digital images of the hip traditionally involves positioning a calibration object at its centre. This can be difficult and cause embarrassment. We have devised a method whereby a planar disc placed on the radiographic cassette accounts for the expected magnification. Initial examination of 50 pelvic CT scans showed a mean hip centre distance of 117 mm (79 to 142) above the gluteal skin. Further calculations predicted that a disc of 37.17 mm diameter, placed on the cassette, would appear identical to a 30 mm sphere placed at the level of the centre of the hip as requested by our templating software. We assessed accuracy and reproducibility by ‘reverse calibration’ of 20 radiographs taken three months after hip replacement using simultaneous sphere and disc methods, and a further 20 with a precision disc of accurate size. Even when variations in patient size were ignored, the disc proved more accurate and reliable than the sphere.

The technique is reliable, robust, cost effective and acceptable to patients and radiographers. It can easily be used in any radiography department after a few simple calculations and manufacture of appropriately-sized discs.

Pelvic discontinuity with associated bone loss is a complex challenge in acetabular revision surgery. Reconstruction using ilio-ischial cages combined with trabecular metal acetabular components and morsellised bone (the component-cage technique) is a relatively new method of treatment.

We reviewed a consecutive series of 26 cases of acetabular revision reconstructions in 24 patients with pelvic discontinuity who had been treated by the component-cage technique. The mean follow-up was 44.6 months (24 to 68). Failure was defined as migration of a component of > 5 mm.

In 23 hips (88.5%) there was no clinical or radiological evidence of loosening at the last follow-up. The mean Harris hip score improved significantly from 46.6 points (29.5 to 68.5) to 76.6 points (55.5 to 92.0) at two years (p < 0.001). In three hips (11.5%) the construct had migrated at one year after operation. The complications included two dislocations, one infection and one partial palsy of the peroneal nerve.

Our findings indicate that treatment of pelvic discontinuity using the component-cage construct is a reliable option.

We present a retrospective review of a single-surgeon series of 30 consecutive lengthenings in 27 patients with congenital short femur using the Ilizarov technique performed between 1994 and 2005.

The mean increase in length was 5.8 cm/18.65% (3.3 to 10.4, 9.7% to 48.8%), with a mean time in the frame of 223 days (75 to 363). By changing from a distal to a proximal osteotomy for lengthening, the mean range of knee movement was significantly increased from 98.1° to 124.2° (p = 0.041) and there was a trend towards a reduced requirement for quadricepsplasty, although this was not statistically significant (p = 0.07). The overall incidence of regenerate deformation or fracture requiring open reduction and internal fixation was similar in the distal and proximal osteotomy groups (56.7% and 53.8%, respectively). However, in the proximal osteotomy group, pre-placement of a Rush nail reduced this rate from 100% without a nail to 0% with a nail (p < 0.001). When comparing a distal osteotomy with a proximal one over a Rush nail for lengthening, there was a significant decrease in fracture rate from 58.8% to 0% (p = 0.043).

We recommend that in this group of patients lengthening of the femur with an Ilizarov construct be carried out through a proximal osteotomy over a Rush nail. Lengthening should also be limited to a maximum of 6 cm during one treatment, or 20% of the original length of the femur, in order to reduce the risk of complications.

Hydroxyapatite-coated standard anatomical and customised femoral stems are designed to transmit load to the metaphyseal part of the proximal femur in order to avoid stress shielding and to reduce resorption of bone. In a randomised in vitro study, we compared the changes in the pattern of cortical strain after the insertion of hydroxyapatite-coated standard anatomical and customised stems in 12 pairs of human cadaver femora. A hip simulator reproduced the physiological loads on the proximal femur in single-leg stance and stair-climbing. The cortical strains were measured before and after the insertion of the stems.

Significantly higher strain shielding was seen in Gruen zones 7, 6, 5, 3 and 2 after the insertion of the anatomical stem compared with the customised stem. For the anatomical stem, the hoop strains on the femur also indicated that the load was transferred to the cortical bone at the lower metaphyseal or upper diaphyseal part of the proximal femur.

The customised stem induced a strain pattern more similar to that of the intact femur than the standard, anatomical stem.

We describe injuries to the posterior root of the medial meniscus in patients with spontaneous osteonecrosis of the medial compartment of the knee. We identified 30 consecutive patients with spontaneous osteonecrosis of the medial femoral condyle. The radiographs and MR imaging were reviewed. We found tears of the posterior root of the medial meniscus in 24 patients (80%). Of these, 15 were complete and nine were partial. Complete tears were associated with > 3 mm of meniscal extrusion. Neither the presence of a root tear nor the volume of the osteonecrotic lesion were associated with age, body mass index (BMI), gender, side affected, or knee alignment. The grade of osteoarthritis was associated with BMI.

Although tears of the posterior root of the medial meniscus were frequently present in patients with spontaneous osteonecrosis of the knee, this does not prove cause and effect. Further study is warranted.

Painful neuromas may follow traumatic nerve injury. We carried out a double-blind controlled trial in which patients with a painful neuroma of the lower limb (n = 20) were randomly assigned to treatment by resection of the neuroma and translocation of the proximal nerve stump into either muscle tissue or an adjacent subcutaneous vein. Translocation into a vein led to reduced intensity of pain as assessed by visual analogue scale (5.8 (sd 2.7) vs 3.8 (sd 2.4); p < 0.01), and improved sensory, affective and evaluative dimensions of pain as assessed by the McGill pain score (33 (sd 18) vs 14 (sd 12); p < 0.01). This was associated with an increased level of activity (p < 0.01) and improved function (p < 0.01).

Transposition of the nerve stump into an adjacent vein should be preferred to relocation into muscle.

We studied 217 patients with an unstable trochanteric or subtrochanteric fracture who had been randomly allocated to treatment by either internal fixation with a standard Gamma nail (SGN) or a Medoff sliding plate (MSP, biaxial dynamisation mode). Their mean age was 84 years (65 to 99) and they were reviewed at four and 12 months after surgery. Assessments of outcome included general complications, technical failures, revision surgery, activities of daily living (ADL), hip function (Charnley score) and the health-related quality of life (HRQOL, EQ-5D).

The rate of technical failure in patients with unstable trochanteric fractures was 6.5% (6/93) (including intra-operative femoral fractures) in the SGN group and 5.2% (5/96) in the MSP group. In patients with subtrochanteric fractures, there were no failures in the SGN group (n = 16) and two in the MSP group (n = 12). In the SGN group, there were intra-operative femoral fractures in 2.8% (3/109) and no post-operative fractures. There was a reduced need for revision surgery in the SGN group compared with the MSP group (8.3%; 9/108; p = 0.072). The SGN group also showed a lower incidence of severe general complications (p < 0.05) and a trend towards a lower incidence of wound infections (p = 0.05). There were no differences between the groups regarding the outcome of ADL, hip function or the HRQOL. The reduction in the HRQOL (EQ-5D_indexscore) was significant in both groups compared with that before the fracture (p < 0.005).

Our findings indicate that the SGN showed good results in both trochanteric and subtrochanteric fractures. The limited number of intra-operative femoral fractures did not influence the outcome or the need for revision surgery. Moreover, the SGN group had a reduced number of serious general complications and wound infections compared with the MSP group. The MSP in the biaxial dynamisation mode had a low rate of failure in trochanteric fractures but an unacceptably high rate when used in the biaxial dynamisation mode in subtrochanteric fractures.

The negative influence of an unstable trochanteric or subtrochanteric fracture on the quality of life was significant regardless of the surgical method.

We have developed a new tensor for total knee replacements which is designed to assist with soft-tissue balancing throughout the full range of movement with a reduced patellofemoral joint. Using this tensor in 40 patients with osteoarthritis we compared the intra-operative joint gap in cruciate-retaining and posterior-stabilised total knee replacements at 0°, 10°, 45°, 90° and 135° of flexion, with the patella both everted and reduced.

While the measurement of the joint gap with a reduced patella in posterior-stabilised knees increased from extension to flexion, it remained constant for cruciate-retaining joints throughout a full range of movement. The joint gaps at deep knee flexion were significantly smaller for both types of prosthetic knee when the patellofemoral joint was reduced (p < 0.05).

There are few data available regarding the association between hallux valgus and pain or functional limitation. We determined the prevalence of hallux valgus in a rural Korean population aged between 40 and 69 years, and its association with pain and function. A total of 563 subjects was examined using the foot health status questionnaire, the Short Form-36 questionnaire and weight-bearing anteroposterior radiographs.

Hallux valgus was present in 364 subjects (64.7%). It did not significantly correlate with age and was more common in women. Of the 364 subjects, 48 (13.2%) had moderate or greater deformity, defined as a hallux valgus angle > 25°. This was significantly associated with pain, worse function and worse foot health. The putative risk factors associated with painful hallux valgus were female gender, low educational attainment and the presence of pain in the knee.

This study compared the effect of a computer-assisted and a traditional surgical technique on the kinematics of the glenohumeral joint during passive abduction after hemiarthroplasty of the shoulder for the treatment of fractures. We used seven pairs of fresh-frozen cadaver shoulders to create simulated four-part fractures of the proximal humerus, which were then reconstructed with hemiarthroplasty and reattachment of the tuberosities. The specimens were randomised, so that one from each pair was repaired using the computer-assisted technique, whereas a traditional hemiarthroplasty without navigation was performed in the contralateral shoulder. Kinematic data were obtained using an electromagnetic tracking device.

The traditional technique resulted in posterior and inferior translation of the humeral head. No statistical differences were observed before or after computer-assisted surgery.

Although it requires further improvement, the computer-assisted approach appears to allow glenohumeral kinematics to more closely replicate those of the native joint, potentially improving the function of the shoulder and extending the longevity of the prosthesis.

We performed a meta-analysis to evaluate the relative efficacy of regional and general anaesthesia in patients undergoing total hip or knee replacement. A comprehensive search for relevant studies was performed in PubMed (1966 to April 2008), EMBASE (1969 to April 2008) and the Cochrane Library. Only randomised studies comparing regional and general anaesthesia for total hip or knee replacement were included.

We identified 21 independent, randomised clinical trials. A random-effects model was used to calculate all effect sizes. Pooled results from these trials showed that regional anaesthesia reduces the operating time (odds ratio (OR) −0.19; 95% confidence interval (CI) −0.33 to −0.05), the need for transfusion (OR 0.45; 95% CI 0.22 to 0.94) and the incidence of thromboembolic disease (deep-vein thrombosis OR 0.45, 95% CI 0.24 to 0.84; pulmonary embolism OR 0.46, 95% CI 0.29 to 0.80).

Regional anaesthesia therefore seems to improve the outcome of patients undergoing total hip or knee replacement.

Conventional non-steroidal anti-inflammatory drugs (NSAIDs) and newer specific cyclo-oxygenase-2 (cox-2) inhibitors are commonly used in musculoskeletal trauma and orthopaedic surgery to reduce the inflammatory response and pain. These drugs have been reported to impair bone metabolism. In reconstruction of the anterior cruciate ligament the hamstring tendons are mainly used as the graft of choice, and a prerequisite for good results is healing of the tendons in the bone tunnel. Many of these patients are routinely given NSAIDs or cox-2 inhibitors, although no studies have elucidated the effects of these drugs on tendon healing in the bone tunnel.

In our study 60 female Wistar rats were randomly allocated into three groups of 20. One received parecoxib, one indometacin and one acted as a control. In all the rats the tendo-Achillis was released proximally from the calf muscles. It was then pulled through a drill hole in the distal tibia and sutured anteriorly. The rats were given parecoxib, indometacin or saline intraperitoneally twice daily for seven days. After 14 days the tendon/bone-tunnel interface was subjected to mechanical testing.

Significantly lower maximum pull-out strength (p < 0.001), energy absorption (p < 0.001) and stiffness (p = 0.035) were found in rats given parecoxib and indometacin compared with the control group, most pronounced with parecoxib.

Human articular cartilage samples were retrieved from the resected material of patients undergoing total knee replacement. Samples underwent automated controlled freezing at various stages of preparation: as intact articular cartilage discs, as minced articular cartilage, and as chondrocytes immediately after enzymatic isolation from fresh articular cartilage. Cell viability was examined using a LIVE/DEAD assay which provided fluorescent staining. Isolated chondrocytes were then cultured and Alamar blue assay was used for estimation of cell proliferation at days zero, four, seven, 14, 21 and 28 after seeding. The mean percentage viabilities of chondrocytes isolated from group A (fresh, intact articular cartilage disc samples), group B (following cryopreservation and then thawing, after initial isolation from articular cartilage), group C (from minced cryopreserved articular cartilage samples), and group D (from cryopreserved intact articular cartilage disc samples) were 74.7% (95% confidence interval (CI) 73.1 to 76.3), 47.0% (95% CI 43 to 51), 32.0% (95% CI 30.3 to 33.7) and 23.3% (95% CI 22.1 to 24.5), respectively. Isolated chondrocytes from all groups were expanded by the following mean proportions after 28 days of culturing: group A ten times, group B 18 times, group C 106 times, and group D 154 times.

This experiment demonstrated that it is possible to isolate viable chondrocytes from cryopreserved intact human articular cartilage which can then be successfully cultured.

We describe the survivorship of the Medial Rotation total knee replacement (TKR) at ten years in 228 cemented primary replacements implanted between October 1994 and October 2006, with their clinical and radiological outcome. This implant has a highly congruent medial compartment, with the femoral component represented by a portion of a sphere which articulates with a matched concave surface on the medial side of the tibial insert.

There were 78 men (17 bilateral TKRs) and 111 women (22 bilateral TKRs) with a mean age of 67.9 years (28 to 90). All the patients were assessed clinically and radiologically using the American Knee Society scoring systems. The mean follow-up was for six years (1 to 13) with only two patients lost to follow-up and 34 dying during the period of study, one of whom had required revision for infection.

There were 11 revisions performed in total, three for aseptic loosening, six for infection, one for a periprosthetic fracture and one for a painful but well-fixed replacement performed at another centre.

With revision for any cause as the endpoint, the survival at ten years was 94.5% (95% CI 85.1 to 100), and with aseptic loosening as the endpoint 98.4% (95% CI 93 to 100). The mean American Knee Society score improved from 47.6 (0 to 88) to 72.2 (26 to 100) and for function from 45.1 (0 to 100) to 93.1 (45 to 100). Radiological review failed to detect migration in any of the surviving knees.

The clinical and radiological results of the Medial Rotation TKR are satisfactory at ten years. The increased congruence of the medial compartment has not led to an increased rate of loosening and continued use can be supported.

The lateral ligament complex is the primary constraint to posterolateral rotatory laxity of the elbow, and if it is disrupted during surgery, posterolateral instability may ensue. The Wrightington approach to the head of the radius involves osteotomising the ulnar insertion of this ligament, rather than incising through it as in the classic posterolateral (Kocher) approach. In this biomechanical study of 17 human cadaver elbows, we demonstrate that the surgical approach to the head can influence posterolateral laxity, with the Wrightington approach producing less posterolateral rotatory laxity than the posterolateral approach.

Several experimental models have been used to produce intravascular fat embolism. We have developed a simple technique to induce fat embolism using corn oil emulsified with distilled water to form fatty micelles. Fat embolism was produced by intravenous administration of these fatty micelles in anaesthetised rats, causing alveolar oedema, haemorrhage and increased lung weight.

Histopathological examination revealed fatty droplets and fibrin thrombi in the lung, kidney and brain. The arteriolar lumen was filled with fatty deposits. Following fat embolism, hypoxia and hypercapnia occurred. The plasma phospholipase A₂, nitrate/nitrite, methylguidanidine and proinflammatory cytokines were significantly increased. Mass spectrometry showed that the main ingredient of corn oil was oleic acid.

This simple technique may be applied as a new animal model for the investigation of the mechanisms involved in the fat embolism syndrome.

We investigated whether simultaneous bilateral sequential total hip replacement (THR) would increase the rate of mortality and complications compared with unilateral THR in both low- and high-risk groups of patients.

We enrolled 978 patients with bilateral and 1666 with unilateral THR in the study. There were no significant pre-operative differences between the groups in regard to age, gender, body mass index, diagnosis, comorbidity as assessed by the grading of the American Society of Anesthesiologists (ASA), the type of prosthesis and the duration of follow-up. The mean follow-up was for 10.5 years (5 to 13) in the bilateral THR group and 9.8 years (5 to 14) in the unilateral group.

The peri-operative mortality rate of patients who had simultaneous bilateral THR (0.31%, three of 978 patients) was similar to that of patients with unilateral THR (0.18%, three of 1666 patients). The peri-operative mortality rate of patients in the bilateral group was similar in high risk and low risk patients (0.70%, two of 285 patients vs 0.14%, one of 693 patients) and this was also true in the unilateral THR group (0.40%, two of 500 patients vs 0.09%, one of 1166 patients). Patients with bilateral THR required more blood transfusions and a longer hospital stay than those in the unilateral THR group. There was no significant difference (p = 0.32) in the overall number of complications between the groups. This was also true for the low-risk (p = 0.81) vs high-risk (p = 0.631) patients.

Our findings confirm that simultaneous sequential bilateral THR is a safe option for patients who are considered to be either high or low risk according to the ASA classification.

We describe a method for stabilising the distal radioulnar joint using a double breasted slip of extensor retinaculum.

This is a retrospective series of 30 patients with a painful wrist secondary to instability of the distal radioulnar joint. The results were assessed by a modified Mayo Score. The mean follow-up was for 38.1 months (13 months to 8 years).

Twelve patients had excellent, 16 good and 2 fair outcomes. One patient had experienced temporary numbness in the distribution of the dorsal branch of the ulnar nerve. The modified Mayo wrist score increased from a pre-operative mean of 23.89 (10 to 50) to a final mean of 94.4 (85 to 100).

Stabilisation of the distal radioulnar joint by the method of using a double breasted slip of the extensor retinaculum gives satisfactory results. The procedure is simple and reproducible.

Mechanical failure because of wear or fracture of the polyethylene tibial post in posteriorly-stabilised total knee replacements has been extensively described. In this study of 12 patients with a clinically and radiologically successful NexGen LPS posteriorly-stabilised prosthesis impingement of the anterior tibial post was evaluated in vivo in three dimensions during gait using radiologically-based image-matching techniques.

Impingement was observed in all images of the patients during the stance phase, although the NexGen LPS was designed to accommodate 14° of hyperextension of the component before impingement occurred. Impingement arises as a result of posterior translation of the femur during the stance phase. Further attention must therefore be given to the configuration of the anterior portion of the femoral component and the polyethylene post when designing posteriorly-stabilised total knee replacements.