Aims

Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques.

The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate.

We describe a direct method of measuring the tightness of plaster casts. Tightness was measured weekly in 23 consecutive patients with Colles' fractures. Six had objective signs of algodystrophy nine weeks after the fracture. In these patients the plaster cast was significantly tighter during the first three weeks than in patients who did not develop algodystrophy. The complex relationship between these findings is discussed.

Our previous reports on the pathological anatomy and operative treatment of intra-articular fractures of the calcaneum failed to take account of the fracture pattern anterior to the posterior facet of the subtalar joint. We have reviewed our experience of 63 operative cases and have studied fractures with axial and coronal CT scans reconstructed onto plastic model bones. A constant anterolateral fragment exists, which is displaced by an extended lateral approach to the fracture. If it is unrecognised and unreduced, union in a displaced position may limit hindfoot eversion and disrupt the calcaneocuboid joint. We describe techniques for reduction and fixation of the fragment.

We made a prospective study of the incidence and natural history of algodystrophy and associated changes in bone mineral density in the ankles and feet of 60 consecutive patients who had suffered unilateral fractures of the tibial shaft. At bone union, 18 patients showed signs of algodystrophy. Its development was independent of the type of fracture management and of the severity of injury. Patients with algodystrophy lost significantly more bone mineral than did those without but the degree of this loss was independent of the type of treatment and of the time to fracture union. In most cases the symptoms resolved within six months of fracture union but in four patients they were still present at one year and two of these had not returned to work.

The classification of intra-articular fractures of the calcaneum described in part I is related to an operative approach which allows accurate reduction and stable fixation of the fracture fragments. An extended lateral incision is used to avoid sural nerve damage and problems of soft-tissue healing. In type 3 fractures, access to the lateral joint fragment requires an osteotomy of the lateral wall, but after this the lateral joint fragment can be rotated out of the subtalar joint to allow transcalcaneal reduction of the medial wall. Reduction of the body fragment and lateral joint fragment on to the sustentacular fragment allows the three fragments to be stabilised by a 3.5 mm Y-shaped reconstruction plate. Our early results have been successful in terms of fracture reduction and the restoration of heel shape and joint congruity, but extended follow-up will be necessary to define the indications for this difficult procedure.

We have studied the radiographic and CT features of 120 displaced intra-articular fractures of the calcaneum in order to define the pathological anatomy. In 96% of cases, the CT scans identified three main fragments: sustentacular, lateral joint and body. The sustentacular fragment was often rotated into varus, the lateral joint fragment into valgus and the body fragment impacted upwards, in varus and displaced laterally. The displacement of these fragments varied according to which of three fracture types was present, as defined by the composition of the fractured lateral wall of the calcaneum. In type 1 it was formed by the lateral joint fragment alone; in type 2 by both body and lateral joint fragments; and in type 3 by the body fragment alone. Fracture fragment displacement differs from that previously described, in that true uniform depression of the lateral joint fragment is rare.

We describe the use of intramedullary reconstruction nails in the treatment of 14 patients with pathological subtrochanteric fractures and coexisting metastases in the femoral shaft. After nailing, all patients were free from pain and regained mobility. They were followed up clinically and radiologically until death from the primary disease. There were no mechanical failures even when a less than ideal reduction had been achieved.

The results of 276 cemented revision total hip arthroplasties performed for aseptic failure between 1977 and 1986 have been reviewed. The mean time between revision and review was 75 months (range 30 to 144). Of 220 cases available for review, 159 were assessed clinically and radiographically, and 32 by postal questionnaire. Eighteen hips required further revision, 12 for loosening, two for sepsis, two for persistent pain, and one each for fracture and recurrent dislocation. A further six hips were radiologically and symptomatically loose. Pain was mild or absent in 83%. Over half were able to walk a mile or more; 70% flexed more than 70 degrees; 15% had a flexion deformity, but in only 7% was this more than 10 degrees. The mean Harris hip score was 74. Survival at five years was 95% and at 10 years, 77%.

We report the results of a prospective study of the incidence of algodystrophy following Colles' fracture in 60 patients, using sensitive or quantitative techniques for the assessment of each feature of the syndrome. Nine weeks after fracture, 24 patients had evidence of vasomotor instability, 23 had significant tenderness of the fingers and 23 had lost finger movement. These three abnormalities were significantly associated (p less than 0.001). Swelling was also significantly associated with these three variables. There was no statistical association between the occurrence of algodystrophy and the patient's age or sex, the severity of the fracture, the number of reductions performed or the adequacy of the reduction. We conclude that algodystrophy constitutes a precisely definable and quantifiable syndrome which is more common than has been suspected.

We report nine cases of irreducible congenital dislocation of the knee which were treated by early operation with good results. All were resistant to conservative measures and operation was performed at an average age of nine months. The essential abnormality was a short quadriceps muscle together with subluxation of the hamstring muscles to lie anterior to the axis of knee flexion. The quadriceps tendon was lengthened by VY-plasty and in six cases additional length was gained by proximal mobilisation of the muscle. After operation all the patients were able to walk.

Seven pectoralis major transfers in children suffering from bilateral paralysis of elbow flexion due to arthrogryposis or to trauma are reported. A technique is described in which the muscle is mobilised from the clavicle to allow the tendon of insertion to be attached to the biceps tendon at the elbow. The biceps tendon was found to be present and could be mobilised forwards in all the arthrogrypotic elbows. Subjectively, the results were considered by patients or parents to be very good in six cases and fair in one. Elbow flexion power against gravity and against some resistance was achieved in all patients except one. The overall function was very good in one elbow, good in two, fair in three and poor in only one. The merits of the various procedures described for the restoration of elbow flexion in arthrogryposis are discussed. It is concluded that total pectoralis major transfer by the method described here has given the best results.