Aims

The primary aim of this study was to address the hypothesis that fracture morphology might be more important than posterior malleolar fragment size in rotational type posterior malleolar ankle fractures (PMAFs). The secondary aim was to identify clinically important predictors of outcome for each respective PMAF-type, to challenge the current dogma that surgical decision-making should be based on fragment size.

Objectives

Overlap between the distal tibia and fibula has always been quoted to be positive. If the value is not positive then an injury to the syndesmosis is thought to exist. Our null hypothesis is that it is a normal variant in the adult population.

The aim of this study was to assess the accuracy of placement of pelvic binders and to determine whether circumferential compression at the level of the greater trochanters is the best method of reducing a symphyseal diastasis.

Patients were identified by a retrospective review of all pelvic radiographs performed at a military hospital over a period of 30 months. We analysed any pelvic radiograph on which the buckle of the pelvic binder was clearly visible. The patients were divided into groups according to the position of the buckle in relation to the greater trochanters: high, trochanteric or low. Reduction of the symphyseal diastasis was measured in a subgroup of patients with an open-book fracture, which consisted of an injury to the symphysis and disruption of the posterior pelvic arch (AO/OTA 61-B/C).

We identified 172 radiographs with a visible pelvic binder. Five cases were excluded due to inadequate radiographs. In 83 (50%) the binder was positioned at the level of the greater trochanters. A high position was the most common site of inaccurate placement, occurring in 65 (39%). Seventeen patients were identified as a subgroup to assess the effect of the position of the binder on reduction of the diastasis. The mean gap was 2.8 times greater (mean difference 22 mm) in the high group compared with the trochanteric group (p < 0.01).

Application of a pelvic binder above the level of the greater trochanters is common and is an inadequate method of reducing pelvic fractures and is likely to delay cardiovascular recovery in these seriously injured patients.

The purpose of this study was to assess the stability of a developmental pelvic reconstruction system which extends the concept of triangular osteosynthesis with fixation anterior to the lumbosacral pivot point. An unstable Tile type-C fracture, associated with a sacral transforaminal fracture, was created in synthetic pelves. The new concept was compared with three other constructs, including bilateral iliosacral screws, a tension band plate and a combined plate with screws. The pubic symphysis was plated in all cases. The pelvic ring was loaded to simulate single-stance posture in a cyclical manner until failure, defined as a displacement of 2 mm or 2°. The screws were the weakest construct, failing with a load of 50 N after 400 cycles, with maximal translation in the craniocaudal axis of 12 mm. A tension band plate resisted greater load but failure occurred at 100 N, with maximal rotational displacement around the mediolateral axis of 2.3°.

The combination of a plate and screws led to an improvement in stability at the 100 N load level, but rotational failure still occurred around the mediolateral axis. The pelvic reconstruction system was the most stable construct, with a maximal displacement of 2.1° of rotation around the mediolateral axis at a load of 500 N.

We reviewed retrospectively 45 patients (46 procedures) with bladder exstrophy treated by bilateral oblique pelvic osteotomy in conjunction with genitourinary repair.

The operative technique and post-operative management with or without external fixation are described. A total of 21 patients attended a special follow-up clinic and 24 were interviewed by telephone. The mean follow-up time was 57 months (24 to 108).

Of the 45 patients, 42 reported no pain or functional disability, although six had a waddling gait and two had marked external rotation of the hip. Complications included three cases of infection and loosening of the external fixator requiring early removal with no deleterious effect. Mid-line closure failed in one neonate managed in plaster. This patient underwent a successful revision procedure several months later using repeat osteotomies and external fixation.

The percentage pubic approximation was measured on anteroposterior radiographs pre-operatively, post-operatively and at final follow-up. The mean approximation was 37% (12% to 76%). It varied markedly with age and was better when external fixation was used. The wide range reflects the inability of the anterior segment to develop naturally in spite of close approximation at operation.

We conclude that bilateral oblique pelvic osteotomy with or without external fixation is useful in the management of difficult primary closure in bladder exstrophy, failed primary closure and secondary reconstruction.

1. Two cases of congenital diastasis of the inferior tibio-fibular mortise are described.

2. No previous description of this condition has been found in the literature.

3. it is suggested that the cause is osteochondrosis of the distal tibial epiphysis associated with a club foot.

Dr J. Robert Close has been good enough to point out a misquotation from his article, "Some Applications of the Functional Anatomy of the Ankle Joint"(Journal of Bone and Joint Surgery, 1956, 38-A, 761) in a later contribution by Mr M. G. H. Smith entitled "Inferior Tibio-fibular Diastasis Treated by Cross-screwing (Journal of Bone and Joint Surgery, 1963, 45-B, 737). Dr Close, in referring to tibio-fibular diastasis and deltoid ligament rupture with low fractures of the fibula, wrote (p. 780), "Treating diastasis therefore frequently means treatment for the deltoid lesion. When one realises that a certain amount of spreading apart of the malleoli and a certain amount of rotation of the fibula about the tibia are anatomical requirements for normal ankle motion the necessity for later removal of such internal fixation becomes obvious. Screws thus placed have been known to break during normal walking after the fractures have healed." In his paper Mr M. G. H. Smith, making mention of tibio-fibular movement, wrote, "This small range of movement of the fibula at the inferior tibio-fibular joint caused Close (1956) to recommend that screws placed across the joint to maintain reduction of diastasis be removed before weight bearing and movement were commenced. He stated that screws had broken when left in position." Further abbreviation by editorial staff led to the statement actually printed p. (737): "Close (1956) recommended the removal of screws that had been placed across the joint to maintain reduction of diastasis before movement was allowed, because the screws broke when left in position." The inadvertent change in sense unfortunately escaped attention, and we very much regret that Mr Close was thus misquoted

1. Twenty-three patients were treated by cross screwing for diastasis of the tibia and fibula in fractures at the ankle.

2. It is suggested that limitation of ankle dorsiflexion after this treatment was caused by the presence of a mechanical block to dorsiflexion by spur formation at the margins of tibia and talus.

3. An ordinary bone screw controlled the diastasis satisfactorily in twenty patients.

4. The screw did not interfere with movement at the inferior tibio-fibular joint because bone resorption about that part of the screw in the fibula allowed a small range of movement.

5. Discomfort from the screw was relieved by its removal.

1. Partial diastasis of the tibio-fibular syndesmosis is believed to be common, but it is often overlooked as a cause of recurrent sprains of the ankle.

2. The treatment of recurrent sprains of the ankle by stabilising the inferior tibio-fibular joint with a lag screw is described. The method has been used in seventy-five patients aged between sixteen and sixty-five years. The longest follow-up has been six years.