Biomechanical studies involving all-wire and hybrid types of circular frame have shown that oblique tibial fractures remain unstable when they are loaded. We have assessed a range of techniques for enhancing the fixation of these fractures. Eight models were constructed using Sawbones tibiae and standard Sheffield ring fixators, to which six additional fixation techniques were applied sequentially.

The major component of displacement was shear along the obliquity of the fracture. This was the most sensitive to any change in the method of fixation. All additional fixation systems were found to reduce shear movement significantly, the most effective being push-pull wires and arched wires with a three-hole bend. Less effective systems included an additional half pin and arched wires with a shallower arc. Angled pins were more effective at reducing shear than transverse pins.

The choice of additional fixation should be made after consideration of both the amount of stability required and the practicalities of applying the method to a particular fracture.

We performed limb lengthening and correction of deformity of nine long bones of the lower limb in six children (mean age, 14.7 years) with osteogenesis imperfecta (OI). All had femoral lengthening and three also had ipsilateral tibial lengthening. Angular deformities were corrected simultaneously. Five limb segments were treated using a monolateral external fixator and four with the Ilizarov frame. In three children, lengthening was done over previously inserted femoral intramedullary rods.

The mean lengthening achieved was 6.26 cm (mean healing index, 33.25 days/cm). Significant complications included one deep infection, one fracture of the femur and one anterior angulation deformity of the tibia. The abnormal bone of OI tolerated the external fixators throughout the period of lengthening without any episodes of migration of wires or pins through the soft bone. The regenerate bone formed within the time which is normally expected in limb-lengthening procedures performed for other conditions.

We conclude that despite the abnormal bone characteristics, distraction osteogenesis to correct limb-length discrepancy and angular deformity can be performed safely in children with OI.

We describe our medium-term results for the management of chronic osteomyelitis in long bones using the Lautenbach procedure. Seventeen consecutive patients (18 segments) were treated prospectively. Osteomyelitis had been present for a mean of 12.5 years (1 to 31). A discharging sinus was present in all cases. Nine of the associated fractures had failed to unite and a further two needed correction of malunion. The Lautenbach procedure involves debridement, intramedullary reaming and the insertion of double-lumen tubes to establish both a local antibiotic delivery system and cavity analysis for volume and culture. The end-point of treatment is when the irrigate produces three consecutive clear cultures with improvement in the blood indices and obliteration of the cavity volume.

The mean length of treatment was 27 days (14 to 48). One patient required a second procedure and another local debridement for recurrence of the infection. Two patients had Papineau grafting because of cortical defects. All the patients have subsequently remained free from infection. After treatment 11 had internal or external fixation for treatment of non- or malunion or a joint replacement, including two successful limb-lengthening procedures. Two further patients, while cured of infection, underwent amputation for other reasons. The mean length of follow-up was 75 months.

This procedure allows precise control over the osteomyelitis until objective assessment suggests that infection has been cleared and the cavity obliterated.

We recommend this procedure for long-standing complex cases in which basic techniques using debridement and antibiotics have failed.

Fine-wire accepted as a minimally external fixation is invasive technique, which can provide better outcomes than traditional open methods in the management of complex fractures of the tibial plateau. Available fixators vary in their biomechanical stability, and we believe that a stable beam-loading system is essential for consistently good outcomes. We assessed, prospectively, the clinical, radiological and general health status of 20 of 21 consecutive patients with complex fractures of the tibial plateau who had been treated using a standard protocol, with percutaneous screw fixation and a neutralisation concept with a fine wire beam-loading fixator allowing early weight-bearing.

Bony union was achieved in all patients, with 85% having good or excellent results. Full weight-bearing started during the first six weeks in 60% of patients. The general health status assessment correlated well with the knee scores and reflected a satisfactory outcome.

We have reviewed, retrospectively, all children with a lower limb deformity who underwent an acute correction and lengthening with a monolateral fixator between 1987 and 1996. The patients were all under the age of 19 years and had a minimum follow-up of eight months after removal of the fixator. A total of 41 children had 57 corrections and lengthening. Their mean age was 11.3 years (3.2 to 18.7) and there were 23 girls and 18 boys.

The mean maximum correction in any one plane was 23° (7 to 45). In 41 bony segments (either femur or tibia) a uniplanar correction was made while various combinations were carried out in 16. The site of the osteotomy was predominantly diaphyseal, at a mean of 47% (17% to 73%) of the total bone length and the mean length gained was 6.4 cm (1.0 to 17.0).

Univariate analysis identified a moderately strong relationship between the bone healing index (BHI), length gained, maximum correction and grade-II to grade-III complications. For logistic regression analysis the patients were binary coded into two groups; those with a good outcome (BHI ≤ 45 days/cm) and those with a poor outcome (BHI > 45 days/cm). Various factors which may influence the outcome were then analysed by calculating odds ratios with 95% confidence intervals.

This analysis suggested a dose response between increasing angular correction and poor BHI which only reached statistical significance for corrections of larger magnitude. Longer lengthenings were associated with a better BHI while age and the actual bone lengthened had little effect.

Those patients with a maximum angulatory correction of less than 30° in any one plane had an acceptable consolidation time with few major complications. The technique is suitable for femoral deformity and shortening, but should be used with care in the tibia since the risk of a compartment syndrome or neurapraxia is much greater.

An innovative Kirschner (K-) wire point was developed and compared in fresh pig femora in terms of drilling efficiency and temperature elevation with the trochar and diamond points currently used in clinical practice. The tips of thermal couples were machined to the defined geometry and the temperature measured during drilling. Using the same drill speed (rev/min) and feed rate, the new K-wire point produced the lowest thrust force and torque as measured by a Kistler dynamometer. Drill point temperatures were highest with the trochar geometry (129 ± 6°C), followed by the diamond (98 ± 7°C). The lowest temperatures were recorded with the Medin K-wire (66 ± 2°C). On repeated drilling it could be used for up to 30 holes before reaching the less satisfactory drill performance of the diamond tip. The new K-wire provides a better alternative as it requires less effort for insertion, generates less heat and may be re-used.

Relapsed congenital talipes equinovarus is difficult to assess and treat. Pedobarography provides dynamic measurement of the pressures under the foot, and may be used in the assessment of these patients both before and after operation.

Our findings showed a statistically significant difference in the distribution of pressure across the foot after treatment by the Ilizarov technique.

Osteotomies are commonly carried out in orthopaedic surgery, particularly in limb reconstruction. Complications are uncommon provided that sufficient care is taken and a sound technique used. We describe three cases of formation of false aneurysm after osteotomy, with acute, delayed and asymptomatic onset. The diagnosis was supported by ultrasound investigation, and confirmed by angiography. Embolisation with coils was a successful method of treatment. We recommend a safe method of osteotomy with good bone exposure and adequate soft-tissue protection.

We present a series of ten hypertrophic nonunions in which bony alignment and length were restored and union induced by external fixation and callus distraction. The mean length gained was 3.5 cm (1 to 6) and the mean angular correction was 13.5° (0 to 40). The mean treatment time was 10.2 months (3 to 15) and mean follow-up was 40 months (6 to 71). There have been no refractures or loss of correction or length.

The technique of callus distraction at a site of hypertrophic nonunion can correct shortening and angulation as well as induce bony union. No extra equipment is needed beyond readily-available external fixation systems.

We report the results in the first 16 patients treated in Sheffield using bifocal techniques for diaphyseal bone loss and deformity secondary to trauma. Eight patients had bone-transport and eight had compression-distraction methods. At a mean follow-up of 24 months all 16 had excellent or good results with union of the fracture, correction of deformity and normal or near normal leg length. There were no major complications. Mean treatment times were 16 months for bone transport and 9.8 months for compression-distraction. Bone transport was more complicated requiring an average of 2.2 additional operations compared with only one for compression-distraction. Femoral cases had shorter treatment indices than tibial cases but had less favourable outcomes.

Broad, depressed pin-site scars often remain after the use of external fixators. We describe a new method of surgical revision which combines W-plasty to break up the outline of the scar, with burial of a dermal island to improve the surface contour. We obtained excellent results with this technique in five patients (19 scars).

Forty patients with acute complete rupture of the calcaneal tendon were managed conservatively and randomly allocated to treatment groups using either cast immobilisation for eight weeks, or cast immobilisation for three weeks, followed by controlled early mobilisation in a Sheffield splint. The splint is an ankle-foot orthosis which holds the ankle in 15 degrees of plantar flexion, but allows some movement at the metatarsophalangeal joints. It is removed to allow controlled movement during physiotherapy. Patients treated with the splint regained mobility significantly more quickly (p less than 0.001) and preferred the splint to the plaster cast. The range of dorsiflexion at the ankle improved more rapidly after treatment in the splint (p less than 0.001), and patients were able to return to normal activities sooner. Recovery of the power of plantar flexion was similar in the two treatment groups, and no patient had excessive lengthening of the tendon. One re-rupture occurred in each group.

The rigidity of a sliding compression screw and three cannulated lag screws in the treatment of subcapital fractures was compared in five pairs of female cadaver femora. There were no significant differences between the compressive strength, bone density, cortical thickness or Singh index of the bones in each pair. A subcapital fracture was standardised using a perpendicular saw cut across the femoral neck. A uniaxial 'load test system' with force and length measurement facilities was used to mimic cyclical stressing applied in vivo at a frequency of 0.5 Hz from 0 to 3 times body-weight. There was no significant difference between the fixation afforded by the sliding compression screw and three lag screws. Bone quality was the single most important factor in the stability of the bone implant unit.

The gait pattern of five amputees was recorded by visual observation and also by a quantitative measurement system. The results were compared with the gait pattern predicted from biomechanical analysis. Visual observation was found to be an unreliable clinical skill. The observers recorded only 22.2% of the predicted gait deviations and were unable to comment on 15.6% of all the required observations. The gait parameters which were difficult to assess visually, namely step length and step time, are considered by most workers to be of particular value as diagnostic clinical indicators in gait assessment. The measurement system used was accurate in recording gait deviations and picked up 3.4 times as many deviations as visual observation. This report demonstrates the inadequacy of visual observation as a diagnostic method and emphasises the need for measurements.