Our study describes a posterolateral approach to the distal humerus for open reduction and internal fixation of displaced fractures of the lateral condyle. A total of 20 patients had open reduction and internal fixation over a four-year period using this approach, and at a mean follow-up of 12 months had full union, range of movement and no complications, either clinical or radiological. This approach is well suited to the exact visualisation and accurate reduction of this difficult fracture with minimal dissection of tissues

Aims

The incidence of atypical femoral fractures (AFFs) continues to increase. However, there are currently few long-term studies on the complications of AFFs and factors affecting them. Therefore, we attempted to investigate the outcomes, complications, and risk factors for complication through mid-term follow-up of more than three years.

Aims

Osteopetrosis (OP) is a rare hereditary disease that causes reduced bone resorption and increased bone density as a result of osteoclastic function defect. Our aim is to review the difficulties, mid-term follow-up results, and literature encountered during the treatment of OP.

Aims

Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity.

Between 1993 and 2000 we treated 14 patients with nonunion of fractures of the distal humerus; 11 had already had previous fixation which had failed. The mean time to surgery was 21 months after injury. All the fractures were very low which made it difficult to obtain a firm hold of the small distal fragment. The problem of fixation was addressed by inserting a Coventry infant hip screw into the humeral condyles. The screw has a thread of wide diameter which gives excellent purchase on the small distal fragment. The condyles can then be compressed on to the humeral shaft using a 4.5 mm narrow tibial dynamic plate. Of these 14 difficult cases of nonunion, 12 progressed to union

Aims

The treatment of late presenting fractures of the lateral humeral condyle in children remains controversial.

Coronal plane fractures of the posterior femoral condyle, also known as Hoffa fractures, are rare. Lateral fractures are three times more common than medial fractures, although the reason for this is not clear. The exact mechanism of injury is likely to be a vertical shear force on the posterior femoral condyle with varying degrees of knee flexion. These fractures are commonly associated with high-energy trauma and are a diagnostic and surgical challenge. Hoffa fractures are often associated with inter- or supracondylar distal femoral fractures and CT scans are useful in delineating the coronal shear component, which can easily be missed. There are few recommendations in the literature regarding the surgical approach and methods of fixation that may be used for this injury. Non-operative treatment has been associated with poor outcomes. The goals of treatment are anatomical reduction of the articular surface with rigid, stable fixation to allow early mobilisation in order to restore function. A surgical approach that allows access to the posterior aspect of the femoral condyle is described and the use of postero-anterior lag screws with or without an additional buttress plate for fixation of these difficult fractures.

Cite this article: Bone Joint J 2013;95-B:1165–71.

Aims

Demineralised bone matrix (DBM) is rarely used for the local delivery of prophylactic antibiotics. Our aim, in this study, was to show that a graft with a bioactive glass and DBM combination, which is currently available for clinical use, can be loaded with tobramycin and release levels of antibiotic greater than the minimum inhibitory concentration for Staphylococcus aureus without interfering with the bone healing properties of the graft, thus protecting the graft and surrounding tissues from infection.

It is becoming increasingly common for a patient to have ipsilateral hip and knee replacements. The inter-prosthetic (IP) distance, the distance between the tips of hip and knee prostheses, has been thought to be associated with an increased risk of IP fracture. Small gap distances are generally assumed to act as stress risers, although there is no real biomechanical evidence to support this.

The purpose of this study was to evaluate the influence of IP distance, cortical thickness and bone mineral density on the likelihood of an IP femoral fracture.

A total of 18 human femur specimens were randomised into three groups by bone density and cortical thickness. For each group, a defined IP distance of 35 mm, 80 mm or 160 mm was created by choosing the appropriate lengths of component. The maximum fracture strength was determined using a four-point bending test.

The fracture force of all three groups was similar (p = 0.498). There was a highly significant correlation between the cortical area and the fracture strength (r = 0.804, p <  0.001), whereas bone density showed no influence.

This study suggests that the IP distance has little influence on fracture strength in IP femoral fractures: the thickness of the cortex seems to be the decisive factor.

Cite this article: Bone Joint J 2014;96-B:1378–84.

This study aimed to determine the long-term functional, clinical and radiological outcomes in patients with Schatzker IV to VI fractures of the tibial plateau treated with an Ilizarov frame. Clinical, functional and radiological assessment was carried out at a minimum of one year post-operatively. A cohort of 105 patients (62 men, 43 women) with a mean age of 49 years (15 to 87) and a mean follow-up of 7.8 years (1 to 19) were reviewed. There were 18 type IV, 10 type V and 77 type VI fractures. All fractures united with a mean time to union of 20.1 weeks (10.6 to 42.3). No patient developed a deep infection. The median range of movement (ROM) of the knee was 110^o and the median Iowa score was 85.

Our study demonstrates good long-term functional outcome with no deep infection; spanning the knee had no detrimental effect on the ROM or functional outcome.

High-energy fractures of the tibial plateau may be treated effectively with a fine wire Ilizarov fixator.

Cite this article: Bone Joint J 2015;97-B:1693–7.

Radiological evidence of post-traumatic osteoarthritis (PTOA) after fracture of the tibial plateau is common but end-stage arthritis which requires total knee arthroplasty is much rarer.

The aim of this study was to examine the indications for, and outcomes of, total knee arthroplasty after fracture of the tibial plateau and to compare this with an age and gender-matched cohort of TKAs carried out for primary osteoarthritis.

Between 1997 and 2011, 31 consecutive patients (23 women, eight men) with a mean age of 65 years (40 to 89) underwent TKA at a mean of 24 months (2 to 124) after a fracture of the tibial plateau. Of these, 24 had undergone ORIF and seven had been treated non-operatively. Patients were assessed pre-operatively and at 6, 12 and > 60 months using the Short Form-12, Oxford Knee Score and a patient satisfaction score.

Patients with instability or nonunion needed total knee arthroplasty earlier (14 and 13.3 months post-injury) than those with intra-articular malunion (50 months, p < 0.001). Primary cruciate-retaining implants were used in 27 (87%) patients. Complication rates were higher in the PTOA cohort and included wound complications (13% vs 1% p = 0.014) and persistent stiffness (10% vs 0%, p = 0.014). Two (6%) PTOA patients required revision total knee arthroplasty at 57 and 114 months. The mean Oxford knee score was worse pre-operatively in the cohort with primary osteoarthritis (18 vs 30, p < 0.001) but there were no significant differences in post-operative Oxford knee score or patient satisfaction (primary osteoarthritis 86%, PTOA 78%, p = 0.437).

Total knee arthroplasty undertaken after fracture of the tibial plateau has a higher rate of complications than that undertaken for primary osteoarthritis, but patient-reported outcomes and satisfaction are comparable.

Cite this article: Bone Joint J 2015;97-B:532–8.

The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017).

Cite this article: Bone Joint J 2013;95-B:1406–9.

We investigated a new intramedullary locking nail that allows the distal interlocking screws to be locked to the nail. We compared fixation using this new implant with fixation using either a conventional nail or a locking plate in a laboratory simulation of an osteoporotic fracture of the distal femur. A total of 15 human cadaver femora were used to simulate an AO 33-A3 fracture pattern. Paired specimens compared fixation using either a locking or non-locking retrograde nail, and using either a locking retrograde nail or a locking plate. The constructs underwent cyclical loading to simulate single-leg stance up to 125 000 cycles. Axial and torsional stiffness and displacement, cycles to failure and modes of failure were recorded for each specimen. When compared with locking plate constructs, locking nail constructs had significantly longer mean fatigue life (75 800 cycles (sd 33 900) vs 12 800 cycles (sd 6100); p = 0.007) and mean axial stiffness (220 N/mm (sd 80) vs 70 N/mm (sd 18); p = 0.005), but lower mean torsional stiffness (2.5 Nm/° (sd 0.9) vs 5.1 Nm/° (sd 1.5); p = 0.008). In addition, in the nail group the mode of failure was either cut-out of the distal screws or breakage of nails, and in the locking plate group breakage of the plate was always the mode of failure. Locking nail constructs had significantly longer mean fatigue life than non-locking nail constructs (78 900 cycles (sd 25 600) vs 52 400 cycles (sd 22 500); p = 0.04).

The new locking retrograde femoral nail showed better stiffness and fatigue life than locking plates, and superior fatigue life to non-locking nails, which may be advantageous in elderly patients.

Cite this article: Bone Joint J 2014;96-B:114–21.

Filling the empty holes in peri-articular locking plates may improve the fatigue strength of the fixation. The purpose of this in vitro study was to investigate the effect of plugging the unused holes on the fatigue life of peri-articular distal femoral plates used to fix a comminuted supracondylar fracture model.

A locking/compression plate was applied to 33 synthetic femurs and then a 6 cm metaphyseal defect was created (AO Type 33-A3). The specimens were then divided into three groups: unplugged, plugged with locking screw only and fully plugged holes. They were then tested using a stepwise or run-out fatigue protocol, each applying cyclic physiological multiaxial loads.

All specimens in the stepwise group failed at the 770 N load level. The mean number of cycles to failure for the stepwise specimen was 25 500 cycles (sd 1500), 28 800 cycles (sd 6300), and 26 400 cycles (sd 2300) cycles for the unplugged, screw only and fully plugged configurations, respectively (p = 0.16). The mean number of cycles to failure for the run-out specimens was 42 800 cycles (sd 10 700), 36 000 cycles (sd 7200), and 36 600 cycles (sd 10 000) for the unplugged, screw only and fully plugged configurations, respectively (p = 0.50). There were also no differences in axial or torsional stiffness between the constructs. The failures were through the screw holes at the level of comminution.

In conclusion, filling the empty combination locking/compression holes in peri-articular distal femur locking plates at the level of supracondylar comminution does not increase the fatigue life of the fixation in a comminuted supracondylar femoral fracture model (AO 33-A3) with a 6 cm gap.

Several bisphosphonates are now available for the treatment of osteoporosis. Porous hydroxyapatite/collagen (HA/Col) composite is an osteoconductive bone substitute which is resorbed by osteoclasts. The effects of the bisphosphonate alendronate on the formation of bone in porous HA/Col and its resorption by osteoclasts were evaluated using a rabbit model. Porous HA/Col cylinders measuring 6 mm in diameter and 8 mm in length, with a pore size of 100 μm to 500 μm and 95% porosity, were inserted into a defect produced in the lateral femoral condyles of 72 rabbits. The rabbits were divided into four groups based on the protocol of alendronate administration: the control group did not receive any alendronate, the pre group had alendronate treatment for three weeks prior to the implantation of the HA/Col, the post group had alendronate treatment following implantation until euthanasia, and the pre+post group had continuous alendronate treatment from three weeks prior to surgery until euthanasia. All rabbits were injected intravenously with either saline or alendronate (7.5 μg/kg) once a week. Each group had 18 rabbits, six in each group being killed at three, six and 12 weeks post-operatively. Alendronate administration suppressed the resorption of the implants. Additionally, the mineral densities of newly formed bone in the alendronate-treated groups were lower than those in the control group at 12 weeks post-operatively. Interestingly, the number of osteoclasts attached to the implant correlated with the extent of bone formation at three weeks.

In conclusion, the systemic administration of alendronate in our rabbit model at a dose-for-weight equivalent to the clinical dose used in the treatment of osteoporosis in Japan affected the mineral density and remodelling of bone tissue in implanted porous HA/Col composites.

The treatment of infected exposed implants which have been used for internal fixation usually involves debridement and removal of the implant. This can result in an unstable fracture or spinal column. Muscle flaps may be used to salvage these implants since they provide soft-tissue cover and fresh vascularity. However, there have been few reports concerning their use and these have concentrated on the eradication of the infection and successful soft-tissue cover as the endpoint. There is no information on the factors which may influence the successful salvage of the implant using muscle flaps.

We studied the results and factors affecting outcome in nine pedicled muscle flaps used in the treatment of exposed metal internal fixation with salvage of the implant as the primary endpoint. This was achieved in four cases. Factors predicting success were age < 30 years, the absence of comorbid conditions and a favourable microbiological profile. The growth of multiple organisms, a history of smoking and the presence of methicillin-resistant Staphylococcus aureus on wound cultures indicated a poor outcome. The use of antibiotic beads, vacuum-assisted closure and dressing, the surgical site, the type of flap performed and the time from primary surgery to flap cover were not predictive of outcome.