Internal rotational error of the tibial component is a major cause of pain after total knee replacement.

This study used CT analysis to determine the rotational alignment of 39 painful and 26 painless fixed-bearing total knee replacements (TKRs) from a cohort of 740 NexGen Legacy posterior-stabilised and cruciate-retaining prostheses implanted between May 1996 and August 2003. The mean rotation of the tibial component was 4.3 degrees of internal rotation (25.4 degrees internal to 13.9 degrees external rotation) in the painful group and 2.2 degrees of external rotation (8.5 degrees internal to 18.2 degrees external rotation) in the painfree group (p = 0.024). In the painful group 17 tibial components were internally rotated more than 9 degrees compared with none in the painfree group (p < 0.001). Additionally, six femoral components in the painful group were internally rotated more than 6 degrees compared with none in the painfree group (p = 0.017). External rotational errors were not found to be associated with pain. Overall, 22 (56.4%) of the painful TKRs had internal rotational errors involving the femoral, the tibial or both components. It is estimated that at least 4.6% of all our TKRs have been implanted with significant internal rotational errors.

Outcome, following significant delays in initial surgery, of ballistic femoral fractures managed without internal or external fixation.

We reviewed the clinical details and radiographs of 52 patients with ballistic fractures of the femur admitted to the International Committee of the Red Cross Hospital in Kenya (Lopiding), who had sustained injuries in neighbouring Sudan. In all cases there had been a significant delay in the initial surgery (> 24 hours), and all patients were managed without stabilisation of the fracture by internal or external fixation. Of the 52 patients, three required an amputation for persisting infection of the fracture site despite multiple debridements. A further patient was treated by an excision arthroplasty of the hip, but this was carried out at the initial operation as a part of the required debridement. All of the remaining 48 fractures healed. Four patients needed permanent shoe adaptation because of limb shortening of functional significance. Although we do not advocate delaying treatment or using traction instead of internal or external fixation, we have demonstrated that open femoral fractures can heal despite limited resources.

Continuing professional development for surgeons.

With the introduction of revalidation, continuing professional development (CPD) is becoming an increasingly important part of a surgeon's professional life. There is minimal existing information describing the CPD practices and attitudes of surgeons to CPD. This review describes the current CPD expectations of the General Medical Council and the current CPD activities and attitudes of surgeons, based around the results of an on-line study performed by the Royal College of Surgeons of Edinburgh.

Biomechanical testing of the fractured distal radius treated with a new bone cement--is it strong enough?

This study evaluates the in vitro ability of CAP, a bone graft substitute with osteointegration and osteoconductive properties, to restore the anatomy and strength of fractured distal radii. Ten pairs of cadaveric radii were imaged and tested to failure, simulating a fracture. The radii were reconstructed using CAP and were re-fractured and sequentially imaged. The deformities of the bones were determined through computerised evaluation of the radiographs. Radiographic analysis showed that CAP is capable of restoring the anatomy of the distal radius. The load and work required to fracture intact radii were compared to those required to fracture the reconstructed radii. The load to fracture was similar in the two situations. The work to fracture, however, was higher with reconstructed radii, suggesting that these are stronger than the original bones. Our study supports the hypothesis that CAP is capable of restoring the original anatomy and dimensions of the distal radius and re-establishing its mechanical strength.

A study of telephone screening and direct observation of surgical wound infections after discharge from hospital.

Post-discharge surveillance of surgical site infection is necessary if accurate rates of infection following surgery are to be available. We undertook a prospective study of 376 knee and hip replacements in 366 patients in order to estimate the rate of orthopaedic surgical site infection in the community. The inpatient infection was 3.1% and the post-discharge infection rate was 2.1%. We concluded that the use of telephone interviews of patients to identify the group at highest risk of having a surgical site infection (those who think they have an infection) with rapid follow-up by a professional trained to diagnose infection according to agreed criteria is an effective method of identifying infection after discharge from hospital.

Girdlestone resection arthroplasty following failed surgical procedures.

We retrospectively reviewed 43 patients who had undergone Girdlestone resection arthroplasty of the hip after failed total hip replacement or failed operations for hip trauma between 1990 and 2002. The indications were peri-prosthetic infection, aseptic loosening, recurrent dislocation and failed internal fixation for femoral neck fractures. Twenty-five patients died with an overall mortality of 58%. Out of 18 survivors, four patients had a prosthesis re-implanted and were excluded from the study. In 14 surviving patients followed-up for a mean of 44.5 months, the average age was 76 years. Adequate pain relief was achieved in 12 patients and infection was controlled in all. They all needed walking aids. The overall patient satisfaction was 10/14. We observed that patients who had had resection arthroplasty following failed operations for hip trauma had a higher mortality than those for failed total hip arthroplasty. Girdlestone arthroplasty is still a viable option to salvage irretrievably failed hips presenting technical difficulties in medically compromised patients. Limb shortening and the inevitable need for a walking aid should be clearly explained to patients during the consenting process in order to avoid unrealistic expectations.

Total knee replacement and patellofemoral pain.

BACKGROUND: The decision to resurface the patella or not during total knee replacement (TKR) is a controversial issue. During primary TKR some surgeons routinely resurface the patella, others operate a selective policy and a third group never resurfaces the patella. AIM: This study attempts to investigate the relationship of patellofemoral knee pain and TKR. MATERIALS AND METHODS: This was a prospective, non-randomised, multi-centre outcome study of 638 primary Insall Burstein II total TKRs, and their effect upon patellofemoral pain. Of those enrolled 378 knees had pre-operative patellofemoral pain; 236 of these underwent patella resurfacing and 142 did not. There were no statistically significant differences in the post-operative incidence of patellofemoral pain between the groups treated with resurfacing of the patella and those in which the patella was left intact. In those knees that developed patellofemoral pain after TKR there was no significant difference as to whether the knee had had resurfacing done or not. CONCLUSION: Given that the cost of patella resurfacing is not insubstantial and that there are well-known complications resulting from it, we conclude that the role of patellar resurfacing for patellofemoral pain in knee arthritis remains unclear.

Peripheral bone mineral density in patients with distal radial fractures.

Fractures of the distal forearm are widely regarded as the result of "fragility". We have examined the extent to which patients with Colles' fractures have osteopenia. We measured the bone mineral density (BMD) in the contralateral radius of 235 women presenting with Colles' fractures over a period of two years. While women of all ages had low values for ultra-distal BMD, the values, in age-matched terms, were particularly low among premenopausal women aged less than 45 years. This result was not due to the presence of women with an early menopause. This large survey confirms and extends the findings from earlier small studies. We consider that it is particularly important to investigate young patients with fractures of the distal forearm to identify those with osteoporosis, to seek an underlying cause and to consider treatment.

Computerised measurement of tibiofemoral alignment.

Tibiofemoral alignment has a direct correlation with the survival of total knee arthroplasty. Traditionally, it has been measured using a goniometer on radiographs. We describe new software which measures this alignment on scanned radiographs by automatically detecting bones in the image. Two surgeons used conventional methods and two clerical officers used the computerised routine to assess 58 radiographs of the knee on two occasions. There were no significant differences between any of the paired comparisons. The largest mean difference detected was 1.19 degrees. Across all comparisons, the mean correlation was 0.755. A standardised routine for measuring tibiofemoral alignment was the greatest factor in reducing error in our study. These results show that non-medical staff can reliably use the software to measure tibiofemoral alignment. It has the potential to measure all the parameters recommended by the Knee Society.

Computerized analysis of radiographs in Colles' fractures.

Several radiographic parameters correlate with clinical outcome in distal radius fractures. This study describes a new, computerized routine that automatically defines the longitudinal axis of the radius, deriving the radial tilt, radial width, and radial height on anteroposterior radiographs of the wrist. The intraobserver and interobserver variability is reported in a series of 33 anteroposterior radiographs of the wrist. An edge-finding filter is used to determine accurately the cortices in several lines of each image. The midpoints between these two edges are used to determine the best-fit line, thereby defining the longitudinal axis of the bone. The operator marks the tip of the radial styloid and the lunate angle of the radius at the distal radioulnar joint. Radial shortening, widening, and loss of angle are calculated. The 33 radiographs were measured twice by two independent observers, and 12 sets of paired readings were analyzed using the two-tailed paired t test. The mean difference between readings was reduced to a fraction of degree or millimeter, virtually eliminating the intraobserver and interobserver errors. Thus, the current study shows the computer is a reliable and effective instrument for measuring radiographs. The computer-aided system of measurements can be extended to prostheses, fractures, and to other orthopaedic measurements.

A seven-year experience of data collection on the Insall-Burstein II total knee arthroplasty. A prospective study.

We describe a method of audit of a type of total knee replacement, including some details of the organisational difficulties of administering multicentre studies, and draw attention to how this can be done using industrial funding without prejudicing the study. This is a prospective record of 1439 patients who had an Insall-Burstein II (IBII) prosthesis implanted between 1990 and 1994. The data were collected using the American Knee Society scoring system. A method of storing radiographs digitally at low cost is also described. The results emphasise the need for the long-term collection of data on commonly used devices implanted by a cross-section of surgeons. We conclude that for most patients the IBII cemented, posteriorly stabilised, cruciate-substituting prosthesis will relieve pain and give excellent functional results throughout the patients' remaining years with a very small incidence of revision, except in cases of infection.

The influence of external knee moments on the outcome of total meniscectomy. A comparison of radiological and 3-D gait analysis measurements.

Twenty one individuals who had undergone unilateral total meniscectomy, and had no significant antero-posterior (AP) laxity underwent three dimensional (3-D) gait analysis, bilateral radiological assessment of varus/valgus alignment and tibio-femoral osteoarthritis (TFOA). Average foot progression angle during the stance phase of gait was not related to knee adduction moment. The findings support the previously noted correlation between varus/valgus alignment and TFOA. The dynamic gait parameter of the adduction moment in early stance did not correlate with either hip-knee-ankle angle or TFOA, thus the expected influence of external moments on outcome after meniscectomy was not found. Thus the correlation between varus/valgus alignment and TFOA can not be explained by a simple loading algorithm.

Bone mineral density of the radius in patients with Colles' fracture.

To ascertain whether patients with Colles' fracture should be investigated for osteoporosis and the risk of future fractures, we measured the bone mineral density of the distal radius of the other arm in 31 women patients and compared the results with those of a control group of 289 normal women. We divided the patients into two groups, those younger than 66 years and those older. In 25 patients we found values for bone mineral density which were lower than one standard deviation below the mean value for their age. Younger patients had a deficit greater than that expected for their ages. We believe that women with Colles' fracture should be evaluated routinely for osteoporosis, particularly if they are under 66 years of age.

Prediction of bone strength from cancellous structure of the distal radius: can we improve on DXA?

Recent studies show that structural parameters of bone, obtained from computerized image analysis of radiographs, can improve the noninvasive determination of bone strength when used in conjunction with bone density measurements. The present study was designed to assess the ability of image features alone to predict the mechanical characteristics of bones. A multifactorial model was used to incorporate simultaneously a number of characteristics of the image, including periodicity and spatial orientation of the trabeculae. Fifteen pairs (29 specimens) of unembalmed human distal radii were used. The cancellous bone structure was determined using computerized spectral analysis of their radiographic images and the bones were tested to failure under compression. Multilayered perceptron neural networks were used to integrate the various image parameters reflecting the periodicity and the spatial distribution of the trabeculae and to predict the mechanical strength of the specimens. The correlation between each of the isolated image parameters and bone strength was generally significant, but weak. The values of mechanical parameters predicted by the neural networks, however, had a very high correlation with those observed, namely 0.91 for the load at fracture and 0.93 for the ultimate stress. Both these correlations were superior to those obtained with dual-energy X-ray absorptiometry and with the cross-sectional area from CT scans: 0.87 and 0.49 respectively. Our observation suggests that image parameters can provide a powerful noninvasive predictor of bone strength. The simultaneous use of various parameters substantially improved the performance of the system. The multifactorial architecture applied is nonlinear and possibly more effective than traditional multicorrelation methods. Further, this system has the potential to incorporate other non-image parameters, such as age and bone density itself, with a view to improving the assessment of the risk of fracture for individual patients.

Total meniscectomy in adolescence. A thirty-year follow-up.

We have carried out a prospective, longitudinal 30-year review of 95 adolescents who underwent total meniscectomy in one knee, and have compared the results with those observed 13 years earlier. All the medical records were scrutinised. Of the 63 patients reviewed clinically, 47 reported decreased sporting activity, although subjective satisfaction rose by 3% to 71%. The scores on the WOMAC osteoarthritis index differed significantly between patients grouped by subjective global assessment. Satisfactory function scores increased from 48% to 60%. In the 53 patients consenting to bilateral radiography of the knee, the incidence of narrowing of the articular cartilage in the operated knee increased significantly between the reviews (19% to 36%). Progression of degenerative change paralleled reduction in activity. Outcome measures were best after medial, intermediate after lateral and worst after double meniscectomy.

Lower limb muscle dysfunction may contribute to foot ulceration in diabetic patients.

OBJECTIVES: To investigate the relationship between in-shoe plantar foot pressure and the co-ordinated activity of five lower limb muscles of diabetic patients, who are known to have a higher risk of foot morbidity. DESIGN: A portable six channel electromyographic system has been designed, developed and synchronised in real time with a 16 channel piezoelectric transducer in-shoe pressure measuring device, Gaitscan. BACKGROUND: So far, no one has tried to establish a relationship between in-shoe foot pressure distribution and muscle activity of the lower limb in diabetes. The measurement of phasic muscle activity has been related to foot pressure and compared to a control group of normal volunteers. METHODS: Twenty nine diabetic subjects and 22 healthy non-diabetic volunteers have been studied by recording electromyography of lower leg muscles and in-shoe foot pressure measurements simultaneously. RESULTS: In diabetic subjects, the period of contact pressure was greater than in normal control subjects (P<0.003). The initial forefoot time to contact with the ground was shorter in diabetics when compared to controls, indicating a faster forefoot contact. Of the dorsiflexor muscles, the Anterior Tibialis, normally contracting eccentrically at heel strike, was subject to a measurable delay in the initiation of contraction, of mean difference of 180 ms (P<0.001), in diabetic subjects when compared to the normal controls. CONCLUSIONS: The late firing of Tibialis Anterior means that its normal modulating role in lowering the foot to the ground after heel strike through eccentric contraction is disturbed. The result is that the foot reaches the foot flat stage in a less ordered manner, subjecting it to high plantar pressures. RELEVANCE: The results obtained may assist in planning realignment procedures of the foot and help prevent development of ulcers on the sole of the foot in high risk diabetic subjects.