To review the results of the treatment of pilon fracture with percutaneous internal fixation and extrarticular ring fixation in neutralization, twenty-two fractures in twenty-one patients were included in the study. The mean follow-up time was 5.3 years. Five fractures were classified Ruedi-Algower type I, six were Ruedi-Algower type II and eleven Ruedi-Algower type III. Six were open fractures (3 Gustilo type III) and there were 19 associated fibular fractures (five were internally fIxed). Thirteen fractures (60%) were associated with metaphysealdiaphyseal dissociation (MDD). The majority of fractures were high energy (18 out of 22). General health outcome was assessed with the use of the SF-36 and functional outcome was evaluated with AOFAS score and Bone’s criteria.

The average AOFAS score for the study population was 79.4. The AOFAS scores decreased as the severity of the fracture increases and these differences were statistically significant between the Ruedi-Algower types I and III. The pilon fractures population scored lower in all SF-36 categories but mental health and energy and vitality when compared to an age matched population but statistically significant differences were only found in the categories of physical function and limitation due to health problems. 65% achieved excellent or good results according to Bone’s criteria. No significant differences were found in the union times in the MDD group (253 days) when compared to the fractures with no MDD (224 days), but this can be due to the high incidence of autograft in the MDD group (7 out of 13). All patients achieved full weight bearing at 6 weeks. Fourteen patients had superficial pin site infections (one needed screw removal) that settled with oral antibiotics. There was one case of non-union and two varus heels.

Conclusion: Good results are achieved treating pilon fractures with minimal internal fixation and the Sheffield ring fixator in neutralization but quality of life and functional scores significantly worsen in the most severe Ruedi-Algower type III fractures.

To review the results of limb lengthening and deformity correction in fibular hemimelia, fifty-five patients with fibular hemimelia underwent limb reconstruction at Sheffield Children’s Hospital. According to Achter-man and Kalamchi classification, twenty-six were classified as Type IA, six as Type IB and twenty-three as Type II fibular hemimelia. All patients had at least some shortening of ipsilateral femur but forty-nine had sig-nificant femoral deficiency. Lengthening of tibia and in significant cases femur was done using De Bastiani or Vilarrubias or Ilizarov methods. Ankle valgus and heel valgus were corrected through osteotomies either in the supramalleolar region or heel. Equinus was corrected by lengthening of tendoachelis with posterior soft tissue release and in severe cases using Ilizarov technique.

The average length gained was 4.2 cm (range 1 to 8) and the mean percentage of length increase was 15.82 (range 4.2 to 32.4). Mean bone healing index was 54.23 days/cm. Significant complications included knee subluxation, transient common paroneal nerve palsy, and recurrence of equinus and valgus deformity of foot. Overall alignment and ambulation improved in all patients. Knee stiffness due to cruciate deficient subluxations needed prolonged rehabilitation. Presence of 3-ray foot gives a better functional result and cosmetic acceptance by patients. The Ilizarov frame has the advantage to cross joints and lengthen at the metaphysis.

Limb reconstruction in fibular hemimelia using limb lengthening and deformity correction techniques improve functional status of involved lower limb.

We report a series of sixty corrections in fifty-five adult patients performed from 1989 to 2001 for complex deformities of the foot and ankle, using circular external fixation, with a mean follow up of 4.4 years. We studied the aetiology, pathophysiology of injury, clinical and radiological evaluation, and the method and outcome of treatment. The patients mean age was 37 years (range 16–65). 37 male. 18 females. 44 deformities were sequel of severe lower limb trauma; the others were due to neurological, congenital and iatrogenic causes. 38 patients had associated proximal pathology including non-union, malunion, shortening and deformities. This required simultaneous correction. In most patients, conventional surgery had failed to achieve correction and many of them were considered for amputation. The aim of surgery was correction of deformity in forty-two occasions and correction of deformity with ankle fusion in eighteen occasions.

For each patient, specific treatment goals were delineated that were realistically achievable. Initial complete correction was achieved in fifty-two patients; there was recurrence of the deformity in fourteen. Forty patients needed corrective osteotomies (16 ankles, 24 tibia and fibula). The results were classified as excellent in six patients, good in thirty-five patients, fair in eight patients, poor in six patients, five of whom had a below-knee amputation. Complications were minor and all resolved with appropriate therapy.

Conclusion: Circular external fixation offer a versatile and effective method of treatment of a variety of complex foot and ankle deformities; however, the surgeon should be familiar with both, their application and subsequent management. If foot and leg deformities coexist consider simultaneous correction. Corrective osteotomies may lead to less recurrence than soft tissue correction alone. Fusion should be considered where muscular imbalance or severe degenerative changes exists. In some cases with severe pathology; the only other option may be amputation.

To review the results of reconstruction of pseudoar-throsis and/or significant varus with retroversion of proximal femur in congenital longitudinal lower limb deficiencies, twenty-three of ninety-five patients with lower limb deficiencies underwent proximal femoral reconstruction at the Sheffield Children’s Hospital. All twenty-three underwent valgus derotation osteotomies to correct coxa vara and retroversion of femur. Seven patients also had pseudoarthrosis of the neck of femur. Three of these were treated with valgus derotation osteotomy and cancellous bone grafting, two with fibular strut grafts, one King’s procedure and one with excision of fibrous tissue and valgus derotation osteotomy. A variety of internal fixation devices and external fixator were used.

Seventeen of the twenty-three patients had valgus osteotomies repeated more than once (average 2.3) for recurrence of varus deformity. Average initial neck-shaft angle was 72 degrees, which improved to an average of 115 degrees after reconstruction.

All seven patients with pseudoarthroses underwent multiple procedures (average 3.3) to achieve union. Cancellous bone grafting was repeated twice in two patients to achieve union but all three with cancellous bone grafting underwent repeat osteotomies to correct residual varus. Two patients achieved union after fibu-lar strut grafting. One patient, who underwent excision of pseudoarthrosis, achieved union but had to undergo further valgus osteotomy. No particular advantage of any one-fixation device over the others was noted in achieving correction.

Early axis correction using valgus derotation oste-otomy is important in limb reconstruction when there is significant coxa vara and retroversion, although recurrence may require repeated osteotomies. Pseudoarthro-ses needed more aggressive surgery to achieve union.

Introduction: Circular fixators are widely utilised in orthopaedic surgery. Their biomechanical characteristics have been studied in some detail and it is known that the widest wire crossing angles yield maximum stability. Unfortunately, due to anatomical constraints, mechanically optimum wire crossing angles are seldom achievable, especially in the tibial diaphysis. Narrowed crossing angles are usually accepted thereby compromising sagittal plane bending stability. With a hybrid circular fixator, narrowed crossing angles exacerbate the problem of fracture site shear. It is hypothesised that by minimising slippage at the wire-bone interface by using threaded wires, stability can be maintained even with narrowed crossing angles. The aim of this study is to examine the effect of threaded wires on fracture site shear with a hybrid fixator.

Method: Bone-fixator models were created from nylon rods and the Orthofix Ring Fixator. Constructs with wire crossing angles of 70, 60, 45 and 30 degrees were loaded axially and in four point bending. Each construct was tested four times; the first test was not analysed. The whole fixator was then rebuilt and all tests repeated. Fracture motion (compression, angulation & shear) was measured using a strain gauge intersegmentary motion device and stiffness calculated by linear regression. Smooth & threaded wires were compared by univariate analysis of variance, which makes allowance for variation between individual frames.

Results: Axial stiffness was comparable to previous studies (85–96N/mm) with no difference between wire types. Threaded wires produced a 29% reduction in shear during axial compression (p=0.02). In four-point-bending, angulation stiffness (in the half-pin plane) was directly related to crossing angle and at all angles threaded wires were associated with a significant improvement. The table shows the effect of wire type on shear (in mm) measured in the plane of the half-pins for a 10Nm bending moment. Shear becomes appreciably higher with narrow crossing angles (almost 2mm) but this is effectively controlled by threaded wires.

Discussion: Of all the factors influencing fracture healing, the mechanical environment is one over which the surgeon has most control. It is generally accepted that excessive shear inhibits fracture healing. This study has shown that by using threaded wires in a circular frame, crossing angles can be narrowed without compromising stability. in particular they control undesirable shear motion seen with hybrid frames and narrow crossing angles. The principle is equally applicable to all-wire frames as they invariably are constructed with compromised crossing angles leading to reduced sagittal plane stability.

Purpose: The aim of this part retrospective and part prospective study was to establish the incidence of pinsite infections and assess evolution of changes in practice

Methods: Data was collected retrospectively and prospectively for pin site infections from the inception of limb reconstruction service viz. 1985 to January 2002. There were 812 patients, 1042 limb segments, and 9935 pins. The various external fixators used were limb reconstruction system (LRS) 549; Ilizarov 397; Sheffield ring fixator (SRF); Dynamic axial fixator (DAF) 35; LRS/Sequoia 8; LRS/Garche 7; and Pennig 5.

Results: The pin site infections were graded from 0 to 6 ( Saleh & Scott). There were no infections in 206 segments. The infection grade is shown below:

We changed our pin tract care practice from 1996. We had a significant decrease in pin tract infections since then (p< 0.0001). We also found that using Ilizarov wires had significantly less infections than with half pins used with monolateral fixators (p< 0.0001; linear trend, p= 0.0338). There were 48 patients that required hospital admissions for IV antibiotics. and of these 10 patients required debridement. There were no residual long lasting infections or chronic osteomyelitis.

Conclusion: Attention to detail in insertion of wires and half pins is crucial to avoid pin site infections. This audit supports the fact that external fixation is a safe method from the point of view of infection contrary to general belief.

Introduction: The Sheffield Ring Fixator (SRF) uses wires in the metaphysis and screws in the diaphysis for bone stabilisation. It has four 2mm wires tensioned to 1400N in two parallel groups to stabilise the ring in the metaphysis. For maximum stability, these parallel wires should cross at 60 degrees or greater and the position of the crossing should be in the centre of the bone. Fixation stability and clinical outcome may well depend on the accuracy of surgical application.

Aims: To review the consistency with which the SRF frames were applied by a single surgeon.

Materials and Methods: The fixators of 39 patients aged between 6 and 75 years of age (11.5 years mean age in children and 38.7 years mean age in adults) were examined. 7 patients had proximal and distal metaphyseal wires making a total of 46 recording sites. The angle of the wires was calculated using the number of holes between the wire clamps since each hole subtends an arc of 7.5 degrees. The crossing angles were divided into two groups with crossing angles of greater than 60 degrees and less than 60 degrees. The position of the crossing of the wires was determined by creating a cross section of the metaphyseal rings, reducing the size of the ring to 100mm and transposing a cross section of the tibia of the correct size and at the correct level. Scaling down the distances measured between the inner ring and the patient limb, the position of the cross section and consequently of the wire crossing was determined. Using contour lines the tibia was divided into four zones. Zone 1 was central tibia and zone 4 was the tibial cortex. All crossing within zone 1 and 2 were considered satisfactory, and zone 3 and 4 poor.

Results: 67.5% of patients had crossing angles greater than 60 degrees and 32.5 % had crossing angles of less than 60 degrees. 85% of the rings had zone 1 or 2 crossing positions. 6.5% of the rings had subcortical crossing positions and 8.5% of the rings had cortical crossing positions. 8.5% of rings had crossing angles of less than 60 degrees as well as wire crossing positions in zone 3 and 4.

Discussion: In a carefully controlled situation a surgeon’s surgical technique was consistent in 67.5% of the rings, with satisfactory crossing angles and wire crossing positions. Only 8.5 % of the rings had poor crossing angles and crossing positions. Inability to achieve ideals may be due to technical errors or anatomical variations. There were increased infection rates in patients with reduced crossing angles, however the position of the crossing had no apparent effect on infection rates and patient mobility. A further study would be required to separate the relative importance of these two factors on patient complications.

Fine-wire fixator systems have been used successfully for the treatment of fractures, malunions and for limb lengthening for many years. There has been much research investigating the biomechanical properties of these systems but this has been almost entirely centred on the mechanical properties of the fixator as a whole. Our knowledge of the interactions occurring at the interface between wire and bone remains sparse. To this end we devised an experimental model to analyse the distribution of pressure in cancellous bone surrounding a tensioned wire under loading conditions. The Sawbones cancellous bone material (type 1522-11) was cut into 65x30x40 mm blocks. A 2 mm olive wire was inserted into each block, parallel to the surface and along the 65 mm dimension. The distance from the wire to the surface was variable, from 0.5mm to 5mm in a 0.5mm increment. The wire was mounted on a 150 mm ring and tensioned to 1200 N against a load cell. The ring was rigidly mounted on a material testing machine and a second bone block was incorporated into the testing machine crosshead with a universal joint. Three grades of pressure-sensitive films (Low, Superlow and Ultralow) were sandwiched in turn between the testing block and cross head. The force applied was 175 N for 5 s. The developed film was scanned into a computer and a Matlab program was developed to analyse the pressure image. The results show three phases of pressure distribution. Very close to the wire there is a polar distribution of pressure that is, the pressure is concentrated towards the entry and exit points of the wire. At a depth of 1.5mm away from the wire the pressure becomes evenly distributed along the path of the wire in a beam-loading manner. At a distance of greater than 4mm from the wire there is even distribution of pressure throughout the bone. The peak pressures (6–8 MPa) were found closest to the wire. Most of the pressure measured was less than 1 MPa, which is less than the yield strength of cancellous bone (2–7 MPa, Li and Aspden, 1997). In contrast a similar analysis using threaded half pins under the same conditions showed far higher peak pressures (20 MPa), which were present deeper in the bone specimen. The pressure was concentrated toward the pin entry site and was not well distributed throughout the pin-bone interface. These results allow us to explain why ring fixators are superior to half pin fixators when used in metaphyseal bone.

Aim: To review the results of tibial lengthening and deformities correction in children using the Sheffield Ring Fixator.

Materials and methods: We have reviewed, retrospectively, 25 patients (average 12.2 years old) who underwent predominantly lengthening of the tibia using the Sheffield Ring fixator.

The average follow up was 25.7 months. 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 out come were then analysed.

Results: The most common indication for tibial lengthening in our series was for fibular hemimelia in 6 patients and achondroplasia in 4 and growth arrest secondary to trauma in 3. The mean lengthening of 48.1 mm (25–76). The mean accuracy of lengthening achieved was 85%.

11 patients had foot plate extension, and 5 had cross knee extension for unstable knee. 10 patients had bifocal osteotomy, and 8 patients had spontaneous SLR for femoral lengthening or correction.

The mean bone healing index was 49 days/cm (20–95). The mean maximum correction in any one plane was 150 (3–40), the site of the osteotomy was mainly metaphyseal at an average of 25% of the tibial length.

There were 5 grade II complications, 9 grades I complications and one type III complication. Thirteen patients had grade I pin site infection, three had grade II and 12 had no pin site problems.

A moderately strong relationship was identified between the BHI and a number of variables such as complications, maximum correction and pin site infection grade.

The analysis of the factors which may influence the BHI suggested a correlation between increasing angular correction and poor out come BHI.

Conclusion: In tibial lengthening in children there is a correlation between increasing angular correction and poor out come BHI

Aim: To review the outcome following growth plate arrest in distal femur and proximal tibia of different aetiology in adults.

Materials and methods: We have reviewed, retrospectively, eight adult patients with lower leg deformity in the distal femur and proximal tibia, as a sequelae of growth plate arrest of different aetiology. These patients underwent tibial and femoral, correction and lengthening. The total number was 8 patients, there were 6 male and 2 female, with an average age of 22.8 years (17–34.8) The average follow up was 32.9 months (7.9–51.4)

Results: Four patients had growth plate arrest following trauma (two patients were involved in road traffic accidents, one had Salter-Harris type V fracture of the proximal tibia and one had sport injury), two patients had iatrogenic growth plate arrest after internal fixation of tibial spine in one patient and after internal fixation of a popliteal muscle rupture in the other, one patient had Osgood Schlater disease, one patient had childhood osteomyelitis and one unknown pathology.

The average shortening was 34.8 mm (8–60), the average maximum deformity in any one plane was 19.8 degree (6–40).

All the patient underwent corrective surgery and lengthening, five patients had Sheffield Ring Fixator, two had Limb Reconstruction System and one had percutaneous osteotomy on Albizzia nail. The patients who underwent SRF and LRS stayed in the frame for an average 258 days (150–435)

The residual leg length discrepancy was 5.5 mm (0–12). There was three grade one complications, three grade two complications, and one patient had grade IV complication following compartment syndrome. Four patients had grade two pin site infection and three patients had grade one.

Conclusion: Growth plate arrest of the distal femur and proximal tibia can cause severe deformity and shortening of the lower limb in adult, and this deformity is amenable to correction in the end of growth using different techniques. We used Sheffield ring fixator in complex cases, to address both deformities and lengthening, while other techniques were used in less complex cases.

We present a series of 88 non-unions in which non-union, infection, bony alignment and length were addressed simultaneously, by using the Sheffield Ring Fixator.

The mean follow up was 50 months (range 6–110) after union, which was achieved in 90.5% of the patients. The mean deformity correction was 16.80 (range 60–320), and mean length gain was 12.5 mm (range 2–40 mm).

Smoking and infection had a statistical significant association with the time of healing, as healing of the non-union in over 18 months was more common in smoker and patients with infected non-union.

There was no statistical difference between the functional score (SF-36) between these patients and normal population, at a follow up of minimum 2 years, but that was significant between pre operative and less than one year follow up on one side, and more than 2 years follow up on the other.

Introduction and Aims: We report a series of 41 corrections in 36 adult patients performed for complex deformities of the foot and ankle using circular external fixation, with a mean follow-up of 4.4 years. The foot and ankle deformities were 18 hindfoot equines, two forefoot equines, six hindfoot and forefoot equines, eight equinovarus, two equinovalgus, one heel varus, four combination of these deformities. All patients had associated proximal pathology. These included seven shortening (six tibia, one femur), eight deformities (seven tibia, one femur), eight non-union (five infected non-union), (14) combination of these pathologies. All required simultaneous correction.

Method: We studied the aetiology, pathophysiology of injury, clinical and radiological evaluation, and the outcome of treatment. The patients’ mean age was 37 years (range 16–56). Thirty deformities were sequelae of severe lower limb trauma; the others were due to neurological, congenital and iatrogenic causes. In all patients, conventional surgical methods had failed to achieve correction and many of them were considered for amputation. We describe the operative strategy and technique.

Results: The aim of foot and ankle surgery was correction of deformity and contractures in 28 instances, correction of deformity and ankle fusion in 11 instances, and correction of deformity and ankle distraction in two instances. Thirty patients underwent bony corrective osteotomies, nine foot and ankle, 20 tibia and fibulae, one femur. For each patient, specific treatment goals were delineated that were realistically achievable. There were (78%) good to excellent results, (14%) fair result and (8%) poor results, which resulted in below knee amputation.

Conclusion: Circular external fixation offers a versatile and effective method of treatment of a variety of complex foot and ankle deformities. If foot and leg deformities coexist consider simultaneous correction. Fusion should be considered where muscular imbalance exists.

Objective: To compare the mechanical stability of fixation of bicondylar tibial plateau fractures using available internal and external fixation techniques.

Method: A bicondylar tibial plateau fracture was simulated on a uniform synthetic bone and tested with loading to failure. Following power calculations, seven tibias were used for each fixation method; five types of fixation were tested: 1) Dual plating. 2) Ring Fixator with inter-fragmentary screws. 3) Hybrid fixator (Ring-Bar) with interfragmentary screws. 4) Lateral plate and medial monolateral external fixator. 5) Lateral plate and medial interfragmentary screws. The specimens were tested in compression to failure. The vertical subsidence in either medial or lateral plateau was measured using an electrical transducer.

Results: In all cases the mode of failure was consistent with collapse occurring in the medial plateau. There was no significant difference in the ultimate strength between dual plating and the ring fixator [4218N, 4184N respectively; P=0.28, t test]. Failure was seen at lower loads with the other fixation systems (Table).

Conclusion: The Ring Fixator and dual plating demonstrated a greater strength and the most stable fixation, choice may depend on tissue viability and surgeon preference. Furthermore mobilisation of the patient may be undertaken earlier with more confidence using these two methods rather than less stable techniques.

Introduction and Aims: To review the existing classifications in characterising the pathologic morphology of congenital lower limb deficiencies (CLLLD) and their usefulness in planning limb reconstruction.

Method: Ninety-five patients undergoing limb reconstruction were classified using existing classifications. Predominantly femoral deficiencies were classified using Aitken, Amstutz, Hamanishi, Gillespie and Torode, Fixsen and Lloyd-Roberts, Kalamchi, and Pappas systems and fibular deficiencies were classified using Coventry and Johnston, Achterman and Kalamchi, and Birch systems.

Results: All patients with predominant deficiency of one segment (femoral or fibular) also had associated shortening of the other segment in the same limb. Acetabular dysplasia, knee instability due to cruciate insufficiency and lateral femoral condylar hypoplasia were found in both femoral and fibular deficiencies. None of the existing classification systems were able to represent the complete pathologic morphology in any given patient. Due consideration of alignment, joint stability and length discrepancy of affected limb as a whole at the planning stage of reconstruction could not be ascertained using these classification systems. Instead, it was useful to characterise the morphology of the involved limb using the following method:

Acetabulum: Dysplastic/Non-dysplastic

Conclusion: Existing classifications do not represent the complete morphology of the entire involved lower limb in CLLLD and therefore a systematic method of characterising the morphology of the lower limb is more useful in planning limb reconstruction.

Aims: To identify the distraction forces and contact pressures of the ankle joint at two different joint positions during articulated ankle distraction.

Material and Methods: Four amputated lower limbs were collected from patients undergoing amputation for vascular disease and frozen at -70° C. The ankle joint of the specimens were normal. Before use the limbs were thawed at room temperature for 24 hours. The skin and subcutaneous tissues were removed. A Sheffield ring fixator consisting of a proximal tibial ring and a foot plate connected through three threaded bars and hinges aligned with ankle axis was mounted on the limb. Force transducers were placed in the threaded bars between the tibial ring and the foot plate on the lateral, medial and posterior aspect of the ankle joint to measure the ankle distraction forces. Once the ankle distraction forces have been measured an anterior ankle arthrotomy was performed to permit the insertion of Fuji pressure sensitive film within the ankle joint. The limb-fixator construct was mounted in a loading machine and axially loaded on the tibia. The ankle joint was distracted at 2 mm intervals to a maximum of 20 mm. Pressure sensitive film was introduced in the ankle joint at each distraction interval and the tibia was axially loaded at 350, 700, 1050 and 1400N (half to two times body weight).

Results: The forces necessary to distract the ankle joint are almost double in the medial side than the lateral side. With 10° of plantarflexion the forces necessary to distract the lateral side increase by about 10%.

We found the center of pressure of the ankle joint to be situated in the antero-medial quadrant, close to the center of the ankle joint. Distraction of the ankle joint by 5 mm eliminated any contact pressures at the ankle joint when the tibia was loaded up to 700N (one time body weight). When the joint was distracted by 10 mm no contact pressures were found in the ankle when loaded up to 1400N (two times body weight)

Conclusions: With the ankle in the plantigrade position the forces necessary to distract the ankle joint are double in the medial side when compared to the lateral side. Plantarflexion increases the forces necessary to distract the lateral aspect of the ankle. This finding may have clinical implications when distracting ankle joints with equinus deformities as this can increase the risk of damaging the lateral ankle ligaments leading to ankle instability. In our opinion equinus deformities should be corrected before the start of ankle joint distraction.

The center of pressure of the ankle joint is situated in the antero-medial quadrant. Distraction of 5 mm will eliminate ankle contact pressure up to one times body weight whereas distraction of 10 mm will eliminate contact pressures up to two times body weight.

Introduction: Distraction osteogenesis has been used as a method of generating new bone in limb lengthening and deformity realignment; and is achieved in our unit though the use of the Sheffield Ring Fixator. The development of soft tissue tension creates an entirely different mechanical environment, and can often result in severe complications during treatment. Fixators must therefore be able to resist these forces. Furthermore, biomechanical modelling is very different from fracture and bone gap simulation.

The model developed in this study intended to look at linear distraction, i.e. lengthening.

Aims: To create a mechanical model that simulates the soft tissue effects during lengthening with an external fixator

To obtain a synthetic material with similar passive tensile properties to that measured in lengthened soft tissue

To measure the effect of tensioned synthetic soft tissue on osteotomy motion and multi-planar stiffness during cyclic loading.

Materials and Methods: A standard two 150mm ring frame was mounted on an acrylic rod, with a centrally placed osteotomy gap of 75mm. One ring was fixed with wires and the other with screws. An inter-fragmentary motion device was attached across the osteotomy, to measure axial, angular and shear deformation with both axial and off-axis loading.

Soft tissue tension was simulated with the use of neoprene rubber sheeting, attached to the nylon rod by Jubilee clips, with a gap anteriorly or medially. Extensive tensile testing was performed to determine the visco-elastic behaviour of the rubber, which showed it to be consistent and reliable. Tension of a similar magnitude to lengthened muscle (35–125N) was achieved, and could be accurately predicted for certain distraction lengths.

The stiffness of the frame was calculated from osteotomy motion with various distraction lengths both with the rubber attached and without.

Results: Tension in the soft tissues summates with the force applied in loading, with the effect of increasing the axial stiffness of the fixator by up to 70N, with a directly proportional relationship. It also acts as a restraint for shear and angulatory motion. In anterior and lateral loading positions however, the angulation stiffness remains low; this is thought to be due to the unequal distribution of soft tissues around the bony column, as seen in vivo. The stiffness of the frame is lowered by increasing the distance between rings; this effect can be counteracted by soft tissue tension in axial stiffness, but less so for angular and shear.

Conclusions: We conclude that osteotomy stability is dependent on soft tissue tension, and the magnitude of tension greatly alters the stiffness characteristics of the external fixator. This study highlights the important role of soft tissue tension in biomechanical modelling and clinical limb lengthening, and has exciting ramifications for future orthopaedic models.

Background: The stability of fracture fixation is influenced by the type of fixation, densitometric and geometric structure of the bone. DXA measures the integral mass of trabecular and cortical bone mineral but cannot discriminate between the structurally and mechanically separate constitutes. Distribution and organisation of bone mass (the geometric structure) has the final determination of the mechanical properties of bone. Pq CT scan is able to measure densitometric and geometric parameters of bone structure. However, there are no reports in the literature on the relationship between these measurements and the strength of fracture fixation. Our aim is to study the correlation between geometric and densitometric measurements of Pq CT scan, with the strength of fixation of bicondylar tibial plateau fractures and to assess the role of both trabecular and cancellous bone in that strength.

Method: Eight Fresh frozen human cadaveric tibias were collected from subjects without a medical history of skeletal pathology. The proximal 10% of the tibia was scanned in a peripheral quantitative computer tomography scanner 1mm thick transverse slides, the cancellous and cortical bone mineral density of the proximal tibia were measured. The geometrical parameters: cortical area, trabecular area, bone strength index (BSI) and the Stress strain index (SSI) as non invasive indicators of the mechanical strength of the bone, were also calculated. A bicondylar tibial plateau fracture was simulated, stabilised, and then tested. All tibias were fixed with Dual buttress plating using a standard AO technique. Cyclic axial compression tests were performed. Inter-fragmentary shear displacements were measured using four extensometers. Failure was defined as over 3mm displacement.

Results: Except for the cortical density, there was a strong correlation between failure load and geometric and densitometric parameters. The trabecular density was the best predictor of fixation strength of tibial plateau fracture.

Discussion: Trabecular density is a more reliable parameter to measure than the cortical density. Therefore, the fixation strength of tibial plateau fracture is dominantly influenced by the mechanical properties of cancelous bone. Cortical bone has a secondary role.

These results highlight the importance of fixation techniques that rely on cancellous bone anchoring such as tensioned fine wire fixation in tibial plateau fractures.

Objectives: To develop a non-invasive method to assess the wire tension quantitatively which can be used in clinic.

Background: Fine-wire external fixators are widely used in the fixation of fractures and limb reconstruction. A requirement of stable fixation is that the wires maintain their tension. Recent lab tests have shown that substantial reduction in wire tension occurred during the simulated operative procedures. Clinical experience also indicated that wire site discomfort might be related to loss in wire tension. It would be very helpful if the wire tension could be assessed quantitatively by a non-invasive method.

Methods: An apparatus based on a LVDT (Linear Variable Differential Transformer) was developed to apply a constant transverse force to a wire and measure its deflection with respect to another parallel wire. An unstable oblique fracture was created in a Sawbones tibia and stabilized by a Sheffield Ring Fixator. The deflection of the testing wire was measured in four tests: (1) Two parallel wires fixation, tensioned reference wire, variable clamp to bone distance; (2) Two parallel wires fixation, loose reference wire, 80mm clamp-bone distance. (3) Two groups of parallel wires fixation with 70° crossing angle, tensioned reference wire, 80mm clamp-bone distance; (4) Two groups of parallel wires fixation with 70° crossing angle, tensioned reference wire, 80mm clamp-bone distance, osteotomy site fixed with a lag screw to simulate a stable fracture or a healing fracture. Fracture stiffness in the above conditions was derived from previous work. Stepwise multiple variable regression analyses were performed to determine the relationship between wire deflection and wire tension, clamp-bone distance, number of wires, reference wire tension, and fracture stiffness.

Results: The reference wire tension and fracture stiffness was excluded from the regression equation, indicating that they did not affect the wire deflection. The regression equation containing only the testing wire tension had an adjusted R-square value of 0.521, while the equation containing the testing wire tension and clamp-bone distance had the R-square values of 0.854. The addition of the number of wires to the regression equation resulted in a slight increase of the R-square value (0.862).

Conclusion: The wire deflection and the clamp-bone distance are the two most important factors that affect wire deflection. The measurement of wire deflection has the potential to predict wire tension and the effect of clamp-bone distance must be considered. Further work is required to refine the apparatus for clinical use.

Introduction and Aims: A previous study showed the inhibitory effect of 30% metaphyseal lengthening on tibial growth (Lee 1993). This study was to investigate the effect of 30% diaphyseal lengthening of tibia on tibial growth plate and growth.

Method: 32 immature rabbits were equally divided into two groups: lengthening and sham. A bilateral external fixator was applied to the tibia and a mid-diaphyseal osteotomy performed. The lengthening group had their tibia distracted on the fifth day after the surgery at a rate of 0.4 mm twice daily until the achievement of 30% lengthening. In each group, half were sacrificed at the end of lengthening and another half after an additional five weeks. Standard radiographs were used to measure the lengths of the tibiae from the most proximal part of the intercondylar eminence to the most distal part of the medial malleollus. The actual length gained was measured by subtracting the pre-operative distance from the lengthened distance using the central points of two middle wires in the tibia as reference points. Specimens from the proximal and distal tibia were sectioned longitudinally in the midcoronal plane and the mean growth plate thickness was calculated from several measurements taken at the middle third of both medial and lateral halves of the section.

Results: In the sham group, the thickness of the growth plates continued to increase with skeletal development showing an increase in total tibial length compared with the contra-lateral control. In contrast, the lengthening group showed no increase in total tibial length compared to the contra-lateral control, suggesting that the stimulation due to the osteotomy may be matched by an inhibitory effect of 30% lengthening.

Conclusion: Thirty percent diaphyseal lengthening of tibia did not change the longitudinal growth of the tibia.

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.

At Sheffield Children’s Hospital 40 children with leg length discrepancies (caused variously by sepsis, trauma, hemihypertrophy, congenital longitudinal deficiencies) were assessed using three clinical methods: measuring blocks in the standing erect position, supine measurement from the anterior superior iliac spine to the medial malleolus, and prone measurement with the knees flexed, which allowed separate measurement of femoral and tibial discrepancies. All were then subjected to comparative CT scanogram.

The mean age of the 24 boys and 16 girls was 10 years (5 to 16). Children with abnormal pelvic architecture or a fixed pelvic obliquity were excluded from the study. The mean clinical length discrepancy was 29 mm (0 to 80 mm). The mean CT scanogram measurement was 26.4 mm (0 to 75 mm). The mean difference between clinical measurements taken prone and CT scanogram measurements was only 3.6 mm (0 to 14). There was little difference in the accuracy of measuring femoral and tibial discrepancies clinically or by CT scanogram. The prone method of measurements is a useful adjunct to Staheli’s rotational profile in the prone position.

Introduction We have reviewed the clinical outcome and complications of Monofocal and Bifocal Callotasis for lower limb lengthening in children with Achondroplasia.

Methods Between August 1986 and January 1999, 57 children with Achondroplasia had lower limb lengthening. Monofocal callotasis had been carried out in 147 Segments of 44 children and bifocal callotasis in 38 segments of 17 children. Complications were noted and final outcomes recorded.

Results The 29 children who completed the programme gained an average of 20 cms in height. For all patients, the mean length gained per segment was roughly nine centimetres. Average Bone Healing Index in the mono-focal lengthening group was 39.9 days/cm and in the bifocal lengthening group 33.6 days/cm. Complications were staged and graded and the average was 2.8 complications per lengthened segment. Most were pin-site related and occurred during stage of distraction. Twenty percent of the segments required further axis corrections. Most patients regained their pre-operative range of motion. Serious irreversible complications were seen in only two patients and included a physeal bar and psychological disturbances. Functional outcome analyses are planned.

Conclusions Limb lengthening for short stature due to Achondroplasia can be confidently undertaken with favourable results in most cases. Bifocal lengthening is an alternative technique with quicker consolidation time.

Aims: To review the results of reconstruction of pseudoarthrosis and/or significant varus with retroversion of proximal femur in congenital longitudinal lower limb deficiencies. Methods: 23 of 95 patients had proximal femoral reconstruction. 7 had pseudoarthrosis of the neck of femur and the remaining had significant coxa vara with retroversion of femur. 3 patients with pseudoarthroses were treated with valgus derotation osteotomy and cancellous bone grafting, 2 with fibular strut grafts, 1 King’s procedure and 1 with excision of fibrous tissue and valgus derotation osteotomy. Remaining patients underwent valgus derotation osteotomies. A variety of internal fixation devices and external fixators were used. Results: All patients with pseudoarthroses underwent multiple procedures to achieve union. 3 with cancellous bone grafting underwent repeat osteotomies to correct residual varus and 2 had grafting repeated twice. 2 patients achieved union after fibular strut grafting. One patient, who underwent excision of pseudoarthrosis, achieved union but had to undergo further valgus osteotomy. The remaining 17 patients with coxa vara and retroversion of femur also had valgus osteotomies repeated more than once (average 2.3) for recurrence of varus deformity. There were significant numbers of implant failures. Average initial neck-shaft angle of 72 degrees improved to 115 degrees after reconstruction. Conclusion: Achieving union of pseudoarthrosis and early axis correction using valgus derotation osteotomy with a view to later lengthening is important in limb reconstruction. Recurrence may require repeated osteotomies and pseudoarthrosis may need more aggressive surgery to achieve union. Muscle slides and soft tissue releases decrease the stress on implant and maintain correction.

Aims: is to evaluate the efficiency of the Sheffield Ring Fixator (SRF) in the management of posttraumatic tibial Deformity. Introduction: Correction of tibial deformity as a consequence of malunion or injury to the growth plate is challenging. Progressive correction is usually necessary due to the low compliance of the anatomical compartments. The SRF provides an effective solution. Materials and Methods: a consecutive series of 30 patients with posttraumatic tibial deformity treated by progressive correction using the SRF between 1997 and 2000. The mean age was 33 years (range 18 to 65). Cases were analysed to ascertain the degree of deformity, treatment time, final outcome in terms of the accuracy of correction of deformity, and incidence of complications. Results: Full correction was achieved in 27 of the 30 cases: two patients had residual angular deformities of 7 and 10 degrees and one had 15mm residual shortening. Satisfactory bone formation occurred in all cases. There were no significant complications. The mean correction time was dependent on whether or not lengthening had been performed (72 and 53 days respectively). From this study the correction time can be estimated as 2 days per degree plus an extra 0.5 days per degree for every centimetre of length to be gained. Conclusion: Knowledge of the efficiency of the system will enable an estimation of treatment times to be made thereby facilitating the setting of goals for both patient and surgeon. Accuracy of correction and total treatment times were satisfactory suggesting that the fixation system was both stable and yet sufficiently elastic to permit good bone healing

Objective: To examine the relationship between three measurements of bone quality and bone strength of the tibial plateau, and the relationships between these measurements. Methods: The bone quality of sixteen cadaveric tibias was assessed for density and architecture using three methods: DXA, pQCT, and spectral analysis of digitised radiographs. These bone quality measurements were correlated with the þxation strength of a bicondylar plateau fracture, obtained by mechanical testing. Results: All three techniques correlate strongly with the mechanical strength of the þxed tibial plateau, with the highest correlation being with DXA (r=0.81, P< 0.001), and pQCT (r=0.79, P< 0.001); followed by spectral analysis (r= 0.5, P,0.01). DXA correlates strongly with pQCT (r=0.95, P< 0.001); Whereas, spectral analysis has a weaker correlation with both DXA (r=0.65, P< 0.01), and pQCT (r=0.69, P< 0.01). Discussion: This is the þrst study of bone quality assessment in the tibial plateau, and as with studies at other sites, DXA showed that BMD has the best correlation with mechanical failure. Both DXA and pQCT are a reßection of density assessment which explains the strong correlation seen. However, the strength of bone is a function of not just quantity and density but also its structure. This was assessed using spectral analysis which involves image processing and pattern recognition algorithm of the trabecular structure. This measures structure only and this may explain the lower correlation with bone strength. Nevertheless we feel that further analysis may demonstrate a speciþc use of this technique to compliment either DXA or PqCT in providing complete assessment of the bone.

Objective: To compare the mechanical stability of þxation of bicondylar tibial fractures using available internal and external þxation techniques. Method: A bicondylar tibial fracture was simulated on a uniform synthetic bone and tested with loading to failure. Following power calculations, seven tibias were used for each þxation method;þve types of þxation were tested: 1)Dual plating. 2)Ring Fixator with interfragmentary screws. 3)Hybrid þxator (Ring-Bar) with interfragmentary screws. 4)Lat-eral plate and medial monolateral external þxator. 5)Lateral plate and medial interfragmentary screws. The specimens were tested in compression to failure. The vertical subsidence in either medial or lateral plateau was measured using an electrical transducer. Results: In all cases the mode of failure was consistent with collapse occurring in the medial plateau. There was no signiþcant difference in the ultimate strength between dual plating and the ring þxator [4218N, 4184N respectively; P=0.28, t test]. Failure was seen at lower loads with the other þxation systems

Conclusion: The Ring Fixator and dual plating demonstrated a greater strength and the most stable þxation, choice may depend on tissue viability and surgeon preference. Furthermore mobilisation of the patient may be undertaken earlier with more conþdence using these two methods rather than less stable techniques.

Aim: To determine the Inter & Intra-observer Agreement in Assessment & Classiþcation of Non-unions of fractures based on Radiological appearance. Methods: X-rays of 100 adult patients with established non-union (NU) were selected by random sampling, excluding cases with poor quality x-rays. Common denominators of various classiþcation/assessment systems were selected for study. Observers were selected in 3 categories (2 in each): Senior Limb Reconstruction specialist, Musculoskeletal Radiologists & senior trainees. 6 weeks were allowed between the 2 sets of observations.

Data was analysed by calculating kappa coefþcients (95% CI) Results: Radiologists were unable to comment on vascularity.

Conclusion: Agreement in common denominators except hypertrophic/atrophic NU is poor. Radiographic analysis of non-union remains poor indicating the need for further study to see whether identiþable diagnostic, therapeutic & prognostic features exist

Aims: To review the results of limb lengthening and deformity correction in fibular hemimelia. Methods: Fifty-five patients with fibular hemimelia underwent limb reconstruction at Sheffield Children’s Hospital. According to Achterman and Kalamchi classification, twenty-six were classified as Type IA, six as Type IB and twenty-three as Type II fibular hemimelia. All patients had at least some shortening of ipsilateral femur but forty-nine had significant femoral deficiency. Lengthening of tibia and in significant cases femur was done using either De Bastiani, Vilarrubias or Ilizarov methods. Ankle valgus and heel valgus were corrected through osteotomies either in the supramalleolar region or heel. Equinus was corrected by lengthening of tendoachelis with posterior soft tissue release and in severe cases using Ilizarov technique. Results: The average length gained was 4.2 cm (range 1 to 8) and the mean percentage of length increase was 15.82 (range 4.2 to 32.4). Mean bone healing index was 54.23 days/cm. Significant complications included knee subluxation, transient common paroneal nerve palsy, and recurrence of equinus and valgus deformity of foot. Overall alignment and ambulation improved in all patients. Knee stiffness due to cruciate deficient subluxations needed prolonged rehabilitation. Presence of 3-ray foot gives a better functional result and cosmetic acceptance by patients. The Ilizarov frame has the advantage to cross joints and lengthen at the metaphysis. Conclusion: Limb reconstruction in fibular hemimelia using limb lengthening and deformity correction techniques improve functional status of involved lower limb.

Objective: To assess the inßuence of bone density on the þxation strength of bicondylar tibial plateau fractures. Method: Sixteen cadaver tibias were randomised into two groups to receive either dual plating or ring external þxation to stabilise a bicondylar tibial plateau fracture created with a standard method. The randomisation was stratiþed by BMD measured by DXA (above and below the mean). Cyclic axial compression tests were performed with increasing peak loads. Inter-fragmentary shear displacements were measured using four extensometers. Failure was deþned as over 3mm displacement. Results: There was a strong correlation between failure load and BMD [r=0.81, P< 0.001]. The mean failure load of the low BMD group (2701 N) was signiþcantly less than that with the high BMD (4530 N) [t-test=0.003]. The failure loads of the two þxation groups were not signiþcantly different (3520 N for the dual plating and 3710 N for the external þxation) [t-test=0.78]. BMD had a signiþcant effect on the failure load in the dual plating group [t-test=0.03], but not in the external þxation group [t-test=0.1]. Discussion: Failure of þxation has been reported as a common complication of bicondylar tibial plateau fractures with a rate as high as 30%. Osteoporosis and poor bone quality are considered important contributory factors. In our study this inßuence was evident with plating, but not with ring þxation. Ring þxation may be the preferred method of þxation for tibial plateau fractures in the elderly and osteoporotic patients.

Aims: To review the hip subluxations or dislocations occurring during femoral lengthening in patients with congenital longitudinal lower limb deficiencies. Methods: Sixty-three patients with congenital longitudinal lower limb deficiencies underwent femoral lengthening using either De Bastiani, Villarubias or Ilizarov technique. Acetabular index, medial joint space, CE angle of Wiberg, acetabular angle of Sharp and neck-shaft angle were measured on anteroposterior radiographs of hip before, during and after lengthening. Acetabulum was considered dysplastic when the Sharp angle was more than 45 degrees. Hip was considered to be subluxed when the medial joint space increased during lengthening. Results: During femoral lengthening, eleven hips subluxed as measured by the increase in medial joint space and one hip dislocated. All these hips had a pre-operative acetabular index more than 25 degrees, CE angle less than 20 degrees and Sharp angle more than 45 degrees. The average neck-shaft angle was 75 degrees. Following subluxation, lengthening was stopped and the hips were reduced in hip spica after adductor and sartorius tenotomies. In one patient femoral shortening and acetabuloplasty had to be done to reduce the sub-luxation. No case of avascular necrosis or chondrolysis was noted. Conclusions: Hip subluxation during femoral lengthening of congenital longitudinal lower limb deficiencies tends to occur when there is associated ace-tabular dyplasia and femoral coxa vara. Careful preoperative assessment, if need be hip reconstruction prior to lengthening and close monitoring during lengthening is recommended.

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.

Aims: To review the presentation, progression, treatment, and outcome of congenital posteromedial bow of tibia. Methods: Seventeen patients were studied using radiographs and medical records retrospectively. The time period was from 1989 to 2002. Data was collected with special reference to deformity correction and lengthening. Complications were analysed. Results: Eight of the patients were male and nine female; eleven of them had deformity correction and lengthening, whereas two are awaiting surgery, two underwent contralateral epiphysiodeses and one, periosteal stripping. Twelve were treated with the Ilizarov device, seven with LRS. The range of discrepancy pre – operatively was from 3 to 8.8 cm. Mean length gained was 3.7 cm with residual discrepancy within 0.6 cm. Complications noted were minor grades of infection and 3 patients required further corrective surgery. The bone-healing index was 62 days per cm. There was some decrease in ankle movement noted, this was unchanged or improved post-operatively. Conclusion: Successful simultaneous deformity correction and lengthening for this condition is possible. The Ilizarov frame provided more benefits in reducing complications. This is the largest series of lengthening and correction of this deformity published and the residual deformity and initial length discrepancy is greater than previously stated.

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.

Aim: To determine the ultra-structural morphology of bone in CLLLD.

Materials and Methods: Bone biopsies were taken from 8 patients with CLLLD undergoing surgery for limb reconstruction procedures. Specimens were fixed and processed for Electron microscopy using standard processing protocol. Ultra-thin araldite sections were stained with uranyl acetate and lead citrate and viewed in Philips CM12 electron microscope. Muscle biopsies were also undertaken.

Results: There were 5 boys and 3 girls of a mean age of 8.8 years (range 3 to 14 years). 6 had predominantly femoral deficiencies and 2 had combined femoral and fibular deficiencies. All specimens showed abnormal collagen fibril morphology. They showed variable diameter with irregular outlines in transversely section bundles and appeared unravelled in longitudinally sectioned bundles. The osteoid was disorganised in 4 of the 8 specimens and osteoblasts showed necrotic changes in 5 out of 8 specimens. Patchy mineralisation and increased proteoglycan distribution was observed in 3 out of 8 specimens.

Conclusion: Bone in CLLLD shows ultra-structural changes in collagen and osteoblasts that may account for the retarded bone growth and poor regenerate formation that occurs during limb lengthening in these patients.

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.

Aim: To assess the outcome of operative treatment of joint deformities using circular external fixators in arthrogryposis

Materials and Methods: 16 cases were identified in 9 children, who underwent application of Ilizarov external fixation from 1989 to 2000 at the Sheffield Children’s Hospital for progressive correction of knee and foot deformities. This treatment modality was combined with either a soft tissue release, soft tissue distraction or a bony correction. Clinical outcomes were assessed, and comparisons were made between the different treatment modalities. Results: Three fixed flexion deformities of the knee treated with progressive correction and soft tissue distraction all achieved initial correction, but recurred some time after removal of fixators. Out of five club-feet treated with an Ilizarov frame with progressive soft tissue distraction alone, three deformities recurred despite long term splinting. The remaining eight club-foot deformities were treated with a bony procedure combined with gradual correction in the circular frame, and all corrections were maintained at follow up. The average treatment time in the fixator was 17 weeks (12–50 weeks), and the average follow up time was 36 months. Complications included 4 pin track sepses, 1 osteitis requiring a sequestrectomy, 1 transient neurapraxia and 1 fracture following removal of the fixator.

Conclusion: The treatment of joint deformities in arthrogryposis remains challenging and difficult, and complications do occur. Combining the Ilizarov device with a bony procedure seems to have superior results and less recurrence of deformities than pure progressive soft tissue correction.

Objective: To review the hip subluxations or dislocations occurring during femoral lengthening in patients with congenital longitudinal lower limb deficiencies.

Methods: Sixty-three patients with congenital longitudinal lower limb deficiencies underwent femoral lengthening using either De Bastiani, Villarubias or Ilizarov technique. Acetabular index, medial joint space, CE angle of Wiberg, acetabular angle of Sharp and neck-shaft angle were measured on anteroposterior radiographs of hip before, during and after lengthening. The Acetabulum was considered dysplastic when the Sharp angle was more than 45 degrees. Hip was considered to be subluxed when the medial joint space increased during lengthening.

Results: During femoral lengthening, eleven hips sub-luxed as measured by the increase in medial joint space and one hip dislocated. All these hips had a preoperative acetabular index more than 25 degrees, CE angle less than 20 degrees and Sharp angle more than 45 degrees. The average neck-shaft angle was 75 degrees. Following subluxation, lengthening was stopped and the hips were reduced in hip spica after adductor and sartorius tenotomies. In one patient femoral shortening and acetabulo-plasty had to be done to reduce the subluxation. No case of avascular necrosis was noted.

Conclusion: Hip subluxation during femoral lengthening of congenital longitudinal lower limb deficiencies tends to occur when the acetabular index is more than 25 degrees, Sharp angle is more than 45 degrees, CE angle is less than 20 degrees and when there is associated femoral coxa vara. Careful preoperative assessment is required, and if need be hip reconstruction prior to lengthening. Close monitoring during lengthening is recommended.

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.

Increased incidence of complications has been reported when lengthening limbs with underlying bone disorders such as dysplasias and metabolic bone diseases. There is a paucity of literature on limb lengthening in Osteogenesis Imperfecta (OI), probably due to the concern that the bone containing abnormal collagen may not tolerate the external fixators for a long term and there may not be adequate regenerate formation from this abnormal bone.

We performed limb lengthening and deformity correction of nine lower limb long bones in six children with OI. Four children were type I and two were type IV OI as per Sillence classification. The mean age was 14.7 years. All six children had lengthening for femoral shortening and three of them also had lengthening for tibial shortening on the same side. Angular deformities were corrected during lengthening. Five limb segments were treated using a monolateral external fixator and four limb segments were treated using an Ilizarov external fixator. In three children, previously inserted femoral intramedullary nails were left in situ during the course of femoral lengthening. The average lengthening achieved was 6.26 cm. Limb length discrepancies were corrected to within 1.5 cm of the length of the contralateral limb in five children. In one child with fixed pelvic obliquity and spinal scoliosis, functional leg length was achieved. The mean healing index was 33.25 days/cm of lengthening. Among the complications significant ones included, one deep infection, one fracture through the midshaft of the femur, and development of anterior angulation deformity after the removal of the fixator in one tibia. Abnormal bone of OI tolerated the external fixator throughout the period of lengthening without any incidence of migration of wires and screws through the soft bone when distraction forces were applied. The regenerate bone formed within the time that is normally expected in limb lengthening procedures performed for other conditions. We conclude that despite abnormal bone characteristics, limb reconstruction to correct limb length discrepancy and angular deformity can be done safely in children with OI.

We reviewed the outcome of 30 patients treated with an Ilizarov frame for resistant clubfoot deformity. Each patient was assessed using objective and subjective outcome measures. We used clinical examination, X-ray analysis, pedobarography and gait analysis and the Activities Scale for Kids questionnaire, developed and validated by The Hospital for Sick Children, Toronto, Canada.

The average questionnaire score was 83. This suggested a good subjective outcome when compared to the average score of 38 achieved by children with untreated clubfoot. Patients were into 2 groups using this score. Patients scoring over 75 were considered to have a good outcome and those scoring less than 75 were considered to have a bad outcome. The objective results were then compared.

We found no difference between the 2 groups using clinical examination and X-ray. Pedobarography showed lower pressures in the bad subjective group, in particular virtually no pressure was generated under the heel when walking.

The pressure distribution also showed the bad group to have the pressure balance towards the front of the foot over the 5^th metatarsal head.

Gait analysis showed differences. The bad group had increased pelvic obliquity and increased pelvic movement suggesting an inefficient gait, increased hip abduction in swing, hyperextension of the knee on loading and decreased dorsiflexion of the ankle in swing when compared to the good group.

Our conclusions were that subjectively this group of patients did well after surgical treatment using an Ilizarov frame.

Clinical examination can show significant intra- and inter-observer error and X-ray is unreliable in children whose feet are congenitally deformed. Pedobarography and gait analysis seem to correlate better with subjective outcome. We know that a good foot is a functional foot and it may be that functional assessment is a more appropriate means of assessing results of treatment in these patients.

The results of the first 100 consecutive patients treated in our tertiary referral non-union practice have been previously reported. The purpose of this report is to review this group together with a further 280 cases treated between 1991 and 2000. The principles of management remain the same, namely restoration of alignment, stabilisation and stimulation, however in the more recent cases increasing use of distraction, bone transport and bifocal techniques as well as single stage lengthening and correction of soft tissue contractures have been used to eliminate limb strength discrepancies. A total of 380 consecutive established non-unions treated between 1987 and 2000 were reviewed. Twenty-nine patients were lost to follow up (five deceased). There were 159 atrophic, 89 hypertrophic and 103 infected cases, with 319 cases as a result of trauma, and 32 cases as a consequence of planned surgery. The majority involved the tibia with 162 cases, followed by femoral non-unions with 51 cases and the remainder involving upper limb and smaller bones. At the time of review, 8 had abandoned treatment and 25 remained ununited. Twenty-one cases ended with amputations: 14 infected, 4 atrophic and 3 cases due to excessive pain following patients request.

Union was achieved in 297 cases (85% overall union rate), representing 90% of atrophic, 89% of hypertrophic and 73% of the infected non-unions. A comparison is made between the first hundred previously unreported series of 280 cases. The overall union rates have improved from 80% to 85%, with an increase in union rates noted predominantly in the atrophic group. Infected cases remain more of a problem and challenging with lower healing rates. There was no statistical difference in union rates between smokers and non-smokers, but slower times to union and increased complication rates were noted in the heavy smokers (< 40/day). The non-union profiles, pathogenesis and change in treatment options are discussed.

Introduction

Ankle arthrodesis is an accepted method of treatment for severe ankle pathology but no single method is universally successful. Compression is usually applied across the ankle joint and maintained with either internal or external fixation; both are associated with complications like infection, non-union, and pain.

Material and Method

We present our results and describe the surgical technique in managing 21 difficult cases using fine wire external frames in the salvage of severe ankle pathology. Nine cases were non-unions following internal fixation of distal tibial intra-articular fractures, seven were patients in whom two or three previous attempts at arthrodesis had been unsuccessful, and five patients had severe degenerative osteo-arthritis of the ankle joint.

Results

A sound arthrodesis was achieved in 19 out of 21 cases giving a union rate of 90.4%. The median period of fixation was 21 weeks, followed by a mean period of cast immobilisation of eight weeks. All except three developed pin site inflammation. Using Mazur’s functional ankle score there were twelve good results, five fair, two poor and two failures.

Conclusion

A fusion rate of 90.4% was achieved using this method. We recommend it for the salvage of failed arthrodesis or severe fracture non-union, particularly in the presence of infection.

The aim was to study the use of limb reconstruction techniques in the management of Ollier’s Dysplasia over a period of 25 years.

This was a retrospective review of case records and radiographs of patients who had lower limb reconstruction for deformity and limb length discrepancy. There were a total of 9 patients of whom 7 had reached maturity and four of these were still under follow up.

The major aims of surgery were to correct lower limb length discrepancy and deformity. A total of twenty segments were operated upon. These were 11 femurs and 9 tibiae. In some segments repeated surgery was required. 41 index and 54 secondary procedures were necessary giving an average of 10.5 procedures per patient. The most common problems were difficulty in fixation in abnormal bone, premature consolidation reflecting the rich osteogenic potential and growth related recurrence of deformities and discrepancy. The mean length gained was 13.8 cms per patient. Healing of regenerate occurred with radiologically normal appearance even in chondro-dysplastic areas. All patients who had completed treatment had a satisfactory mechanical axis and the mean length discrepancy was 1.7 cms.

Patients with Ollier’s dysplasia appear to respond well to limb reconstructive surgery. It is possible to correct severe limb length discrepancies and angular deformities. Surgeons should be aware of the possibility of premature healing and should consider faster lengthening rates of up to 1.5 mms per day. Distraction should begin early by day 5 or less. Immature patients should be warned about the possibility of recurrence of deformity and possible need for repeated surgery.

To evaluate the medium term results of the Lautenbach procedures for the treatment of chronic osteomyelitis [COM] in long bones.

Cohort of 17 patients (18 segments) prospectively treated. Mean age 37 years. High-energy trauma effecting 8 tibia (6 open) & 9 femora (5 open). Duration of COM was mean 12. 5 years (1–31 years). Discharging sinus present in all. Lautenbach procedure comprises intramedullary reaming/debridement to 13 mm and establishment of local antibiotic delivery system, cavity analysis for volume and culture. The end point is 3 clear culture results of the irrigate, improvement in blood indices and reduction of cavity volume.

Mean treatment time 27 days (14–48). Mean hospital stay 38 days. Two needed revision of Lautenbach procedure and one local debridement for recurrence of infection. 7 non-unions needed further fixation. 2 needed Papineau grafting and 3 had further limb lengthening procedures. Mean follow-up is 3. 3 years. 4 patients have been discharged, 1 awaiting THR.

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

To evaluate the effects of smoking on fracture healing in a non-union population.

A consecutive cohort of 104 patients with 107 non-unions managed by external fixation was reviewed. 75% were regular smokers compared to the regional average of 3 0%. 5 8 male and 20 female smokers, matched with the non-smoking group. Patients’ records and x-rays were evaluated; where information was missing patients were contacted by phone/post. Scoring was recorded from our own prospective database.

The smokers underwent 2. 6 procedures per segment with a mean treatment time of 17. 43 months (4–64) compared to 1. 9 and 10. 9 (2. 5–24) respectively in non-smoking group. The total hospital stay was 66% greater in the smoking group (41. 12 vs 27. 4 days).

102 non-unions healed, including seven who required revision surgery, six of whom were smokers. In smoking group five went on to amputation and three had residual infection. The entire non-smoking group healed after primary surgery except a 70 years old lady who was converted to intramedullary nailing.

The final assessment of the bony and functional results was performed by the method described by Paley and Catagni (JBJS 77A 1995).

When considered in the context of regional statistics for smoking there was a trend towards non-union in smokers [P< 0. 05].

We conclude that smoking adversely affects both primary fracture healing and non-union treatment.

The aim of this study is to evaluate the efficiency of the Sheffield Ring Fixator (SRF) in the management of tibial deformity.

Tibial deformity correction is challenging and requires an efficient system with strong bony fixation.Progressive correction is usually necessary due to the low compliance of the anatomical compartments. The SRF provides an effective solution, employing a combination of wire and screw fixation for metaphyseal corrections and all screw fixation for diaphyseal corrections.

We reviewed a consecutive series of 50 patients with tibial deformity treated by progressive correction using the SRF between 1997 and 2000. The mean age was 33 years (range 18 to 65). Thirty nine cases were due to post-traumatic deformity and eleven as sequelae of childhood disease. Cases were analysed to ascertain the degree of deformity, treatment time, final outcome in terms of the accuracy of correction of deformity, and incidence of complications.

All patients had significant angular deformity and 12 had a rotational deformity. 21 patients had clinically significant shortening. The mean deformities were: varus 10.5, valgus 13, posterior 11.8, anterior 20.6 (giving a mean oblique plane deformity of 24° ) rotation 17° and 26mm of shortening. Full correction was achieved in 45 of the 50 cases: Three patients had residual angular deformities of 5,7 and 10 degrees and two had residual shortening (15mm& 5mm). Satisfactory bone formation occurred in all cases. There were no significant complications. The mean correction time was dependent on whether or not lengthening had been performed (72 and 53 days respectively). From this study the correction time can be estimated as 2 days per degree plus an extra 0.5 days per degree for every centimetre of length to be gained.

A knowledge of the efficiency of the system will enable estimation of treatment times to be made thereby facilitating the setting of goals for both patient and surgeon. Correction and total treatment times were satisfactory suggesting that the fixation system was both stable and yet sufficiently elastic to permit good bone healing. Even when the rotation translation systems were used prescribed movements led to satisfactory corrections suggesting few if any losses in the system. The SRF provides a strong and efficient system for the accurate and controlled correction of tibial deformities.

To determine the Inter & Intra-observer Agreement in Assessment & Classification of Non-unions of fractures based on Radiological appearance.

Medical records and X-rays of patients who attended the Limb Reconstruction Clinic (1987 to 2000) in a University Hospital for fracture non-union were studied. X-rays of one hundred adult patients with established non-union were selected by random sampling.

Common denominators of various classification / assessment systems were selected for study. Observers were selected in 3 categories (2 in each): Senior Limb Reconstruction specialist, Consultant Musculoskeletal Radiologists, Senior trainees (Post-FRCS Orth).

Data was analysed by calculating kappa coefficients (95% confidence intervals). Kappa measures between observer agreements having been corrected for chance.

Radiologists were unable to comment on vascularity. (S= substantial, M= moderate, F= fair & P= poor)

It would appear that the agreement for classification of atrophic/hypertrophic non-union is good all round (both inter & intra). Within this classification, radiologists showed better agreement than trainees whose results were better than Orthopaedic specialists. Agreement of healing potential & infection was fair to poor only. Radiographic analysis of non-union remains poor indicating the need for further study to see whether identifiable features exist.

To assess the outcome of bicondylar tibial fractures, treated prospectively with fine wire fixation in the Limb Reconstruction Service.

Twenty patients with mean age 56 years with bicondylar tibial plateau fractures, were treated at the author’s institution with fine wire fixation over a three-year period. Ten followed road traffic accidents and four followed high-energy falls; The remainder mainly in the elderly resulted from a simple fall. There were four Schatzeker type V, and sixteen type VI. Four were open fractures (Gustilo grade III); Seven patients sustained associated fractures at the same time. They were treated according to a prospective protocol and were followed up for an average of thirty months, (11 – 51). The protocol included CT Scan Guided planning, closed reduction if possible and percutaneous interfragmentary screw fixation to reconstruct the articular surface, under image intensifier control; The external fixator was applied in neutralization. Mobilization and full weight bearing was encouraged as early as possible

Ten patients started full weight bearing between four and six weeks post operatively, in nine cases with other injuries weight bearing was delayed. All patients healed with an average time in the fixator of eighteen weeks, (9–25).

Fifteen patients had a range of movement from Zero to at least 120 degrees flexion. Using Rasmussen’s functional and radiological scoring system, fifteen out of twenty scored good or excellent. Complications included deep vein thrombosis in one patient, loss of fracture reduction in three, superficial pin tract infection which resolved with local pin care and a short courses of antibiotic in five patients, there was no deep infection.

The Sheffield hybrid external fixator is strong, permits early fracture recovery and weight bearing and may have significantly contributed to the high rate of good results in this group, of which more than 50% were over sixty years old. This technique is recommended for treatment of this difficult fracture.

Experience has shown that oblique fractures can be slow to heal and this has been attributed to excess shear at the fracture site. We routinely treat fractures with hybrid external fixation. In previous studies, olive wires placed through the fracture site reduced shear and this has improved healing times. When the fracture is oblique in the sagittal plane, anatomical constraints prevent the use of olive wires and a new solution is required.

A sawbone tibia with a distal sagittal plane oblique fracture (70° obliquity) was stabilised with a Sheffield Hybrid Fixator. In a pilot study various methods of fixation were tested and six were chosen for further testing. Since the pull-out strength of threads in the plastic bone was poor, olive wires cut behind the olive were used as a mechanically equivalent model for the push-pull system. Seventy degree steerage pins could not be used so 25° pins were tested instead. Cyclic compressive forces (at 10mm/min) of up to 200N axially and in four off-axis positions were applied using a universal testing machine. Fracture site linear motion in three dimensions was measured using an inter-fragmentary motion device, sampled at 100Hz. A standard frame was tested before and after each adaptation and all six methods were applied sequentially to each model.

The results suggest that: I) Arched wires are effective especially under greater bends, 2) Push-pull wires are effective and provide a minimally disruptive solution, 3) Steerage pins are effective especially at steeper obliquities but this may not always be practical, and 4) Placing a half pin in the distal fragment is beneficial but less effective than the use of 2 transverse half pins acting in a compression system (Hutson technique).

The validation of a new classification of the external fixator screw-bone interface.

Screw loosening significantly affects the stability of an external fixator, however radiographs are normally taken to assess bone healing and not screw loosening. This study was performed to assess the inter and intra-observer reliability of radiographic features of external fixator screw loosening. Eight observers were shown plain radiographs of 120 external fixator bone-screw interfaces on two occasions, and were asked to grade the screws according to the following features.

Solid screw.

The overall kappa value for this study was 0.29, with the component values ranging from 0.15 to 0.41. To determine if the reliability could be improved, two observers classified 192 digitised radiographs of external fixator screws. On the first occasion the radiographs were shown at a size, brightness and contrast equal to the original film. On the second occasion the radiographs were subjected to image enhancement and magnification. This showed improvement in all the kappa values, the overall value increasing to 0.39, with similar improvements in the component parts. Unfortunately no observations were made of loose screws, therefore, two observers were asked to classify 160 digitised images of screws which were selected with a bias in their outcome, to remain solid or become loose. The observers obtained a kappa value > 0.50 for loose screws.

A classification system for the bone-screw interface is of value both in research and clinical practice. Despite the fact that standard radiographic views were used the classification system described shows satisfactory inter and intra-observer reliability and this improved when digital enhancement was applied.

Previous studies in animal models of limb lengthening have shown a wide spectrum of histopathological changes during distraction phase. Much less is known about the structural response of muscle during the consolidation phase. This study aimed to observe and score changes in morphology, weight, length and maximal perimeter of gastrocnemius during the distraction and consolidation phases.

Thirty two immature New Zealand white rabbits were divided into two equal groups: lengthening and sham. In each group, half of the rabbits were killed at the end of lengthening and half 5 weeks later. A bilateral external fixator was applied to tibia and a mid-diaphysis osteotomy performed. The lengthening rate was 0.4 mm twice daily with an initial delay of 7 days. 30% lengthening was achieved in 4 to 5 weeks. After sacrifice, the whole gastrocnemius was taken from its attachments. Its weight, length and maximal perimeter were measured. At the middle of belly, a specimen 0.5cm in length was taken from the medial gastrocnemius for H& E and Masson trichrome staining. A scoring system was used to achieve a semi-quantitative analysis of the histopathological changes in gastrocnemius.

No abnormal changes were observed in the sham side. Degeneration, atrophy and endomysial fibrosis were all found in the lengthened side. The scores of histopathological changes between the end of lengthening and 5 weeks later showed a decreasing trend, but no significant difference. The weight and perimeter decreased and length increased in the lengthening side. The weight, perimeter and length of gastrocnemius in both lengthening and control sides increased at 5 weeks after the end of lengthening.

Muscular atrophy, as shown by a decrease in weight, perimeter and muscle fibre size, occurred and might be due to the combined effect of continuous muscle stretching and inactivity. Continuous stretching of muscles beyond a certain point produced damage. Some studies reported that damage to muscle fibres, which has been shown as degeneration and fibrosis in this study, can release and activate satellite cells. As myoblast precursors, satellite cells become myoblasts, which proliferate and fuse into the microlesioned areas, regenerating and repairing myofibrils. Also, the immature muscles have more active abilities of proliferation, regeneration, growth and healing. In this study gastrocnemius growth shown by an increase in weight, perimeter and length occurred during the consolidation phase of 5 weeks. The mean scores of histopathological changes in gastrocnemius decreased during consolidation period, indicating some recovery of damage to muscle. It is not clear whether this reflects a normal response, which would have been seen in other studies had samples been taken later or whether it is a unique response of the immature animal.

To assess the results and complications of this method in a consecutive study of 99 segments with a 5 year follow up

The Vilarrubias method of limb lengthening aims to reduce soft tissue tension and protect joints in order to achieve longer lengthenings with fewer complications. Between 1988–1993 we operated on 99 segments using a modification of this method. The procedure combines a Wagner fixator with percutaneous soft tissue releases, static joint splintage and non-weightbearing mobilisation in a semi-reclining wheelchair. During the consolidation phase the fixator is removed and a moulded plaster applied. In Sheffield we used the Orthofix lengthener and permitted weight bearing and dynamisation in the consolidation phase. The criteria for patient selection were a lengthening aim of greater than 20% of the original bone length or other at risk features (Saleh and Hamer). There were 54 children, 19 with short stature and 35 with asymmetry, age range 4–19 years.

The mean length gained was 92 mm (range 21–173) and the mean BHI 41.3 days/cm (range 16.9–308). In 19 patients there were no complications. In the remainder there were 47 pin site problems, 33 flexion contractures, 33 angular deformities and 15 stress fractures. There were no deep infections or neurological sequelae. Some complications such as flexion contracture; angulation of the regenerate and stress fracture could be secondary to excessive soft tissue tension. Therefore, the length gained and BHI was compared for segments with these complications and those without, using the Students t test, and this was not significant (p> 0.15).

The method appears effective in achieving long lengthenings. Callus formation was satisfactory despite long periods non weight bearing. Considering the lengthening aims and high-risk cases it compares favourably with other reported series. We believe it remains an effective technique for cases of intermediate complexity.

To review healing rates, complications, alignment, length and function in non-unions treated with Mono-lateral External Fixation.

A cohort of 110 patients (113 segments) treated for non-union, by mono-lateral external fixation in Sheffield between 1987 and 1996 is reviewed. There were 83 males and 27 females with a mean age of 37.2 years. 67 patients had high-energy injuries and there were 56 open fractures. There were 60 tibiae, 38 femora and the rest were upper limb long bones with a mean of 3.2 previous procedures. The mean duration of non-union was 23.4 months (range 3–123). There were 64 monofocal procedures with 41 supported in neutralisation, 20 in compression and three in distraction. There were 49 bifocal procedures (33 compression distraction and 16 bone transport). 71 segments required a bone graft.

The success rate using the initial fixator was 90%. Clinical and radiological union was achieved in 109 segments (96.5%) although seven required further fixation and one subsequently went on to amputation for ischamia. All five amputations were in smokers and three were directly related to vascular failure.

The mean hospital stay was 21.12 days and the mean number of operations per patients was 2.55.The mean time to bony union was 12.69 months (range 2.5-64). The Length gained mean 4.5 cm (range 1.5-12 cm). Angular correction achieved 12° (range 2-39°); The bony and functional results were assessed at the end of treatment by system described by Paley & Catagni (JBJS 77A, 1995).

Monolateral external fixation can provide stable fixation for the treatment of established non-unions. The fracture environment may be carefully controlled and angulation and length corrected simultaneously. Interestingly 11 out of 12 problem cases were in smokers.

As the number of patients being offered multifocal procedures in limb reconstruction surgery has increased a study was performed to compare single stage and staged procedures.

A retrospective analysis of all multifocal procedures (more than two sites) performed between 1988 and 1997 was carried out looking at treatment times, results and complication rates. A total of 51 multifocal procedures were performed. The mean number of sites operated on was 3.8 per patient for single stage and 4 per patient for staged. There were 18 single stage and 33 staged operations. There were 29 performed on the paediatric age group for indications such as achondroplasia and short stature. The rest were in adults where the main indications were related to complex trauma management and their complications. External Fixation was the principle method of treatment.

The total hospital stay averaged 18 days for single stage procedures and 29 days for staged. Of the single stage cases 12 had one operation with a mean of 1.33 operations (including surgery for complications) compared to staged procedures which had an average of 2.8 operations (range 2–5 ). In addition, the total treatment time (time of first surgery to discharge) was more for staged surgery, 5 years compared to 3.6 years. In the single stage group 9 patients (50%) had at least one significant post operative complication (2 severe, 7 moderate) and in the staged group 19 (57%) had significant complications (3 severe, 16 moderate). There was no detectable difference in the final clinical result obtained between the groups.

From this study we would conclude that single stage procedures carry no increased risk and are of benefit to patients because of the shorter hospitalisation, reduction in the number of operations and general anaesthetics and the reduced time to final outcome.

To assess the outcome of Quadricepsplasty in limb reconstruction for stiff knees, and to analyze the contributing factors.

Thirteen patients underwent quadricepsplasty over the last 11-years for severe extension contractures of the knee, in the Limb Reconstruction Service. Ten cases were posttraumatic treated with External fixation, and three were non-traumatic causes, with an average interval between injury and quadricepsplasty of 10 years (range, 2–55). Eight patients had leg lengthening with an average of 6.5cm (range, 3–14), with simultaneous deformity correction. Post-operatively all the patients had continued passive motion except one with a fused hip.

Two to six weeks post-operatively, nine patients necessitated manipulation under anesthesia due to noteable loss of movement.

Preoperatively the average flexion was 24°(10–40), which improved in the operating room to 98°. After an average follow up of 15 months post-operatively they lost a mean of 18° flexion, with a final flexion 80°. Three patients developed an extension lag of 10° post-operatively. Two had deep infection with unsatisfactory results. Using Judet’s classification, we had 8 (53%) excellent or good, 6 (40%) fair, and one poor (7%) result.

The unsatisfactory results were associated with deep infection, long fixator time and a long interval between injury and quadricepsplasty.

Quadricepsplasty provides good results for severe extension contraction of the knee. Judet’s technique of disinsertion and muscle sliding addresses the problem of pin site tethering on the lateral side of the femur. Since this procedure is not free of complications and always demands intensive postoperative rehabilitation, it should be reserved for patients with severe extension contraction.

We reviewed 351 cases of nonunion treated between 1987 and 2000. The principles of management included restoration of alignment, stabilisation and stimulation. More recently we used distraction and bone transport, bifocal techniques, single stage lengthening and correction of soft tissue contractures.

The ununited fractures resulted from trauma in 319 cases and in 32 were the sequelae of planned surgery. There were 159 atrophic, 89 hypertrophic and 103 infected nonunions. Nonunion occurred in the tibia in 162 patients, in the femur in 51 and in the upper limbs and other smaller bones in the rest.

At the time of this review, nine patients had abandoned treatment and 25 fractures remained ununited. Amputation had been performed on 20 patients, two at the request of patients with intractable pain, 14 following infection and four because of atrophy. Union was achieved in 297 cases (85%), including 90% of the atrophic, 89% of the hypertrophic and 73% of the infected nonunions. We found no statistically significant difference between the results of patients who smoked and non-smokers, but patients who smoked heavily healed more slowly.

Hybrid fixation is now an established modality of treatment for articular fractures of the proximal and distal tibia. However, there is a lack of consensus over the management of non-articular metaphyseal fractures extending into the diaphysis. Despite sophisticated techniques, intramedullary nailing remains difficult and has relatively high rates of malunion and nonunion. Plate fixation may produce satisfactory results, but its use is limited where there is major extension into the diaphysis or where the soft tissues are compromised.

Since 1995, we have used hybrid external fixation in the treatment of such fractures in 24 male and 16 female patients of mean age 54 years (15 to 92). Mostly sustained in road traffic accidents, there were 26 closed and 14 open fractures, seven of which were Gustillo type IIIB. There were 26 distal tibial, seven proximal and seven tibial shaft fractures.

Metaphyseal fixation consisted of two rings with tension wires, diaphyseal fixation of screws. We used additional rings in segmental diaphyseal fractures or used olive compression wires across the fracture when additional stability was required. Hybrid fixation was the primary procedure in 25 patients and a secondary procedure, performed within eight weeks of injury, in 15. All patients went on to union in a mean of 45 weeks, but 10 required additional procedures such as bone-grafting, additional insertion of olive wire and soft-tissue procedures. Residual malunion in six patients required adjustment with frame fixation, with minimal clinical significance. We had three pin-tract infections and one deep infection, which resolved after sequestrectomy.

When choosing a fixation system, it must be taken into account that high-energy tibial fractures may be slow to unite and that deep infection is related to the degree of soft-tissue injury. We believe hybrid fixation is a safe and minimally invasive treatment option. Careful attention to reduction and soft-tissue management, followed by early functional rehabilitation, can reduce healing times.

The Orthofix acute correction template has been developed for multiplanar deformity corrections, with or without lengthening, using a monolateral external fixation system such as the limb reconstruction system (LRS). Pin placement is achieved by marrying the template onto the particular deformity in the frontal, sagittal and rotational planes, so that after the osteotomy the pins can be rearranged by manipulating the fragments to permit application of the standard Orthofix fixation system. The options of compression, dynamisation or lengthening through the osteotomy sites remain available should they be required in the reconstructive procedure.

We have found the template useful in correcting multiplanar deformities intra-operatively. This is followed by internal fixation and removal of the external fixator at the end of the procedure. Internal fixation of diaphyseal and metaphyseal osteotomies is achieved with intramedullary nailing and blade fixation respectively.

This technique simplifies complex procedures, following careful planning by accurate pin placement. The fragments are compressed before definitive internal fixation. The correct mechanical axis is checked radiologically before stable fixation.

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.