The risk of articular penetration during tibial nailing is well known, but the incidence of unrecognised damage to joint cartilage has not been described. We have identified this complication in the treatment of tibial fractures, described the anatomical structures at risk and examined the most appropriate site of entry for tibial nailing in relation to the shape of the bone, the design of the nail and the surgical approach. We studied the relationship between the intra-articular structures of the knee and the entry point used for nailing in 54 tibiae from cadavers. The results showed that the safe zone in some bones is smaller than the size of standard reamers and the proximal part of some nails. The structures at risk are the anterior horns of the medial and lateral menisci, the anterior part of the medial and lateral plateaux and the ligamentum transversum. This was confirmed by observations made after nailing 12 pairs of cadaver knees. A retrospective radiological analysis of 30 patients who had undergone tibial nailing identified eight at risk according to the entry point and the size of the nail. Unrecognised articular penetration and damage during surgery were confirmed in four. Although intramedullary nailing has been shown to be a successful method for treating fractures of the tibia, one of the most common problems after bony union is pain in the knee. Unrecognised intra-articular injury of the knee may be one cause of this

1. The use of a protein-free synthetic medium has provided a new technical approach to the study of fracture healing in vitro. 2. The tibiae of fourteen-day embryonic chicks were cut in half in the middle of the shaft, the fragments were placed in apposition and the explants grown in vitro for up to sixteen days. The process of bone repair was studied by means of histology and biochemical estimations. 3. The rate of growth in length of fractured bones was greater in an atmosphere containing 50 per cent of oxygen than in one with 20 per cent oxygen, thus emphasising the importance of an adequate oxygen supply for the regeneration of osteogenic cells. 4. The effect of varying the concentration of glucose in the medium was investigated. Two milligrams of glucose per millilitre was the most favourable for healing; higher levels caused fibroblastic changes in the cartilage cells and inhibited the proliferation of osteogenic cells at the fracture site. 5. Histological examination showed that many of the phenomena that occur in the repair of fractures in vivo can be reproduced in vitro in synthetic medium. Similar results were obtained whether the fracture was made in whole bones or in isolated shafts from which the cartilaginous ends had been removed; the latter are more favourable for biochemical study

Puppies in the second half of their growing period have been observed for one and a half to four and a half months after creation of a superficial femoral arteriovenous fistula on the right side. From measurements of the whole bone and from microradiographic and tetracycline-fluorophore studies of the diaphysial bone, it is believed that the following statistically significant phenomena may be attributed to the influence of the arteriovenous fistula. 1. All bones distal to the fistula are influenced in their growth. The tibia and metatarsals become heavier and larger, but retain normal shape. Although stimulation of longitudinal growth is small, it is significant for the tibiae and nearly significant for the femora in these short-term experiments. 2. The histological structure of the bones remains normal but quantitative changes are induced. The compact bone is more porous because of an increased number of osteones. Haversian turnover itself is affected in that the individual formation time of osteones tends to become longer, especially in the metatarsals. 3. Periosteal new bone formation is immediately stimulated, producing a flare of new bone. This accounts for the increase in diaphysial weight in the tibia but not in the metatarsals, where the same effect results from decreased resorption of old bone. 4. Endosteal new bone formation is depressed, especially in the metatarsals, resulting in an enlarged medullary cavity

The intermittent administration of parathyroid hormone (PTH) increases the formation of bone by stimulating osteoblastic activity. Our study evaluates the possibility that intermittent treatment with PTH (1-34) may also enhance the implant-bone fixation of stainless-steel screws. Twenty-eight rats received one screw in either one (n = 8) or in both (n = 20) proximal tibiae. We administered either PTH (1-34) in a dosage of 60 μg/kg/day (n = 14) or vehicle (n = 14) over a period of four weeks. At the end of this time, the degree of fixation was assessed by measuring the removal torque on one screw in each rat (n = 28) and the pull-out strength on the contralateral screw (n = 20). PTH increased the mean removal torque from 1.1 to 3.5 Ncm (p = 0.001) and the mean pull-out strength from 66 to 145 N (p = 0.002). No significant differences in body-weight or ash weight of the femora were seen. Histological examination showed that both groups had areas of soft tissue at the implant-bone interface, but these appeared less in the PTH group. These results indicate that intermittent treatment with PTH may enhance the early fixation of orthopaedic implants

Skeletal scintigraphy, which has now been established as a useful and accurate method of detecting early skeletal metastases and assessing their response to treatment, has been investigated for its pathological basis. Histological examination of several hundred necropsy specimens, from sixty-eight patients who died from malignant disease, showed a significant increase of osteoid and immature woven bone in the presence of metastatic cancer. Tumour-cell suspensions of the VX2 carcinoma were injected into the medullary cavity or on to the periosteal surface of the ilia or tibiae of New Zealand white rabbits. A combination of bone destruction and new bone formation, similar to the autopsy material, was seen. There were at least two mechanisms for the new bone production. Initially, intramembranous ossification was seen in the fibrous stroma surrounding the tumour. Once the cortex was involved and cortical bone destruction had occurred, large amounts of woven bone resembling fracture callus were laid down. The new bone had a markedly increased avidity for boneseeking isotopes, indicating why skeletal scintigraphy was useful. A further twenty rabbits, in whose ilia the VX2 carcinoma was growing, were treated by local irradiation. When treatment was successful the tumour was destroyed, the production of new bone ceased, and the lesion lost its increased avidity for bone-seeking isotopes, indicating that skeletal scintigraphy could be used to assess the response of skeletal metastases to therapy

We aimed to highlight the relationship between age and the architectural properties of trabecular bone, to outline the patterns in which the variations in these properties take place, and to investigate the influence of the architecture on the mechanical properties of trabecular bone in growing animals. We studied 30 lambs in three age groups and 20 sheep in two age groups. Cubes of subchondral bone were cut from the proximal tibia according to a standardised protocol. They were serially sectioned and their architectural properties were determined. Similar cubes were obtained from the identical anatomical position of the contralateral tibia and their compressive mechanical properties measured. The values obtained from the skeletally immature and mature individuals were compared. Multiple regression analyses were performed between the architectural and the mechanical properties. The bone volume fraction, the mean trabecular volume, the architectural and the mechanical anisotropy, the elastic modulus, the bone strength, the energy absorption to failure, and the elastic energy correlated positively with increasing age whereas the connectivity density, the bone surface density, the ultimate strain, the absorption of viscoelastic energy and the relative loss of energy correlated inversely. The values of all variables were significantly different in the skeletally mature and immature groups. We determined the patterns in which the variations took place. The bone volume fraction of the trabecular bone tissue was found to be the major predictor of its compressive mechanical properties. Together with the mean trabecular volume and the bone surface density, it explained 81% of the variations in the compressive elastic modulus of specimens obtained from the contralateral tibiae

Aims

Cementless unicompartmental knee arthroplasty (UKA) has advantages over cemented UKA, including improved fixation, but has a higher risk of tibial plateau fracture, particularly in Japanese patients. The aim of this multicentre study was to determine when cementless tibial components could safely be used in Japanese patients based on the size and shape of the tibia.

Abstract

The medial malleolus, once believed to be the primary stabilizer of the ankle, has been the topic of conflicting clinical and biomechanical data for many decades. Despite the relevant surgical anatomy being understood for almost 40 years, the optimal treatment of medial malleolar fractures remains unclear, whether the injury occurs in isolation or as part of an unstable bi- or trimalleolar fracture configuration. Traditional teaching recommends open reduction and fixation of medial malleolar fractures that are part of an unstable injury. However, there is recent evidence to suggest that nonoperative management of well-reduced fractures may result in equivalent outcomes, but without the morbidity associated with surgery. This review gives an update on the relevant anatomy and classification systems for medial malleolar fractures and an overview of the current literature regarding their management, including surgical approaches and the choice of implants.

Cite this article: Bone Joint J 2019;101-B:512–521.

Objectives

Cortical and cancellous bone healing processes appear to be histologically different. They also respond differently to anti-inflammatory agents. We investigated whether the leucocyte composition on days 3 and 5 after cortical and cancellous injuries to bone was different, and compared changes over time using day 3 as the baseline.

Aims

It is increasingly appreciated that coordinated regulation of angiogenesis and osteogenesis is needed for bone formation. How this regulation is achieved during peri-implant bone healing, such as osseointegration, is largely unclear. This study examined the relationship between angiogenesis and osteogenesis in a unique model of osseointegration of a mouse tibial implant by pharmacologically blocking the vascular endothelial growth factor (VEGF) pathway.

Aims

Little is known about the effect of haemorrhagic shock and resuscitation on fracture healing. This study used a rabbit model with a femoral osteotomy and fixation to examine this relationship.

Aim

It has been suggested that the use of a pilot-hole may reduce the risk of fracture to the lateral cortex. Therefore the purpose of this study was to determine the effect of a pilot hole on the strains and occurrence of fractures at the lateral cortex during the opening of a high tibial osteotomy (HTO) and post-surgery loading.

Rebound growth after hemiepiphysiodesis may be a normal event, but little is known about its causes, incidence or factors related to its intensity. The aim of this study was to evaluate rebound growth under controlled experimental conditions.

A total of 22 six-week-old rabbits underwent a medial proximal tibial hemiepiphysiodesis using a two-hole plate and screws. Temporal growth plate arrest was maintained for three weeks, and animals were killed at intervals ranging between three days and three weeks after removal of the device. The radiological angulation of the proximal tibia was studied at weekly intervals during and after hemiepiphysiodesis. A histological study of the retrieved proximal physis of the tibia was performed.

The mean angulation achieved at three weeks was 34.7° (standard deviation (sd) 3.4), and this remained unchanged for the study period of up to two weeks. By three weeks after removal of the implant the mean angulation had dropped to 28.2° (sd 1.8) (p < 0.001). Histologically, widening of the medial side was noted during the first two weeks. By three weeks this widening had substantially disappeared and the normal columnar structure was virtually re-established.

In our rabbit model, rebound was an event of variable incidence and intensity and, when present, did not appear immediately after restoration of growth, but took some time to appear.

Cite this article: Bone Joint J 2015;97-B:862–8.

Objectives

An important measure for the diagnosis and monitoring of knee osteoarthritis is the minimum joint space width (mJSW). This requires accurate alignment of the x-ray beam with the tibial plateau, which may not be accomplished in practice. We investigate the feasibility of a new mJSW measurement method from stereo radiographs using 3D statistical shape models (SSM) and evaluate its sensitivity to changes in the mJSW and its robustness to variations in patient positioning and bone geometry.

The optimum cementing technique for the tibial component in cemented primary total knee replacement (TKR) remains controversial. The technique of cementing, the volume of cement and the penetration are largely dependent on the operator, and hence large variations can occur. Clinical, experimental and computational studies have been performed, with conflicting results. Early implant migration is an indication of loosening. Aseptic loosening is the most common cause of failure in primary TKR and is the product of several factors. Sufficient penetration of cement has been shown to increase implant stability.

This review discusses the relevant literature regarding all aspects of the cementing of the tibial component at primary TKR.

Cite this article: Bone Joint J 2013;95-B:295–300.

Objectives

Small animal models of fracture repair primarily investigate indirect fracture healing via external callus formation. We present the first described rat model of direct fracture healing.

Tibial nonunion represents a spectrum of conditions which are challenging to treat, and optimal management remains unclear despite its high rate of incidence. We present 44 consecutive patients with 46 stiff tibial nonunions, treated with hexapod external fixators and distraction to achieve union and gradual deformity correction. There were 31 men and 13 women with a mean age of 35 years (18 to 68) and a mean follow-up of 12 months (6 to 40). No tibial osteotomies or bone graft procedures were performed. Bony union was achieved after the initial surgery in 41 (89.1%) tibias. Four persistent nonunions united after repeat treatment with closed hexapod distraction, resulting in bony union in 45 (97.8%) patients. The mean time to union was 23 weeks (11 to 49). Leg-length was restored to within 1 cm of the contralateral side in all tibias. Mechanical alignment was restored to within 5° of normal in 42 (91.3%) tibias. Closed distraction of stiff tibial nonunions can predictably lead to union without further surgery or bone graft. In addition to generating the required distraction to achieve union, hexapod circular external fixators can accurately correct concurrent deformities and limb-length discrepancies.

Cite this article: Bone Joint J 2015;97-B:1417–22.

Objectives

There remains a lack of data on the reliability of methods to estimate tibial coverage achieved during total knee replacement. In order to address this gap, the intra- and interobserver reliability of a three-dimensional (3D) digital templating method was assessed with one symmetric and one asymmetric prosthesis design.

We compared the complications and outcome of tibial lengthening using the Ilizarov method with and without the use of a supplementary intramedullary nail. In a retrospective case-matched series assembled from 176 patients with tibial lengthening, we matched 52 patients (26 pairs, group A with nail and group B without) according to the following criteria in order of importance: 1) difference in amount of lengthening (± 2 cm); 2) percentage difference in lengthening (± 5%); 3) difference in patient’s age (± seven years); 4) aetiology of the shortening, and 5) level of difficulty in obtaining the correction. The outcome was evaluated using the external fixator index, the healing index and an outcome score according to the criteria of Paley. It was found that some complications were specific to group A or B respectively, but others were common to both groups.

The outcome was generally better in lengthenings with a nail, although there was a higher incidence of rectifiable equinus deformity in these patients.

The ability to predict load-bearing capacity during the consolidation phase in distraction osteogenesis by non-invasive means would represent a significant advance in the management of patients undergoing such treatment. Measurements of stiffness have been suggested as a promising tool for this purpose. Although the multidimensional characteristics of bone loading in compression, bending and torsion are apparent, most previous experiments have analysed only the relationship between maximum load-bearing capacity and a single type of stiffness. We have studied how compressive, bending and torsional stiffness are related to the torsional load-bearing capacity of healing callus using a common set of samples of bone regenerate from 26 sheep treated by tibial distraction osteogenesis.

Our findings showed that measurements of torsional, bending and compressive stiffness were all suitable as predictors of the load-bearing capacity of healing callus. Measurements of torsional stiffness performed slightly better than those of compressive and bending stiffness.