Aims

Type IIIB open tibial fractures are devastating high-energy injuries. At initial debridement, the surgeon will often be faced with large bone fragments with tenuous, if any, soft-tissue attachments. Conventionally these are discarded to avoid infection. We aimed to determine if orthoplastic reconstruction using mechanically relevant devitalized bone (ORDB) was associated with an increased infection rate in type IIIB open tibial shaft fractures.

Femoroacetabular impingement (FAI) is a significant cause of osteoarthritis in young active individuals but the pathophysiology remains unclear. Increasing mechanistic studies point toward an inflammatory component in OA. This study aimed to characterise inflammatory cell subtypes in FAI by exploring the phenotype and quantification of inflammatory cells in FAI versus OA samples.

Ten samples of labrum were obtained from patients with FAI (confirmed pathology) during open osteochondroplasty or hip arthroscopy. Control samples of labrum were collected from five patients with osteoarthritis undergoing total hip arthroplasty. Labral biopsies were evaluated immunohistochemically by quantifying the presence of macrophages (CD68 and CD202), T cells (CD3), mast cells (mast cell tryptase) and vascular endothelium (CD34).

Labral biopsies obtained from patients with FAI exhibited significantly greater macrophage, mast cell and vascular endothelium expression compared to control samples. The most significant difference was noted in macrophage expression (p<0.01). Further sub typing of macrophages in FAI using CD202 tissue marker revealed and M2 phenotype suggesting that these cells are involved in a regenerate versus a degenerate process. There was a modest but significant correlation between mast cells and CD34 expression (r=0.4, p<0.05) in FAI samples.

We provide evidence for an inflammatory cell infiltrate in femoroacetabular impingement. In particular, we demonstrate significant infiltration of mast cells and macrophages suggesting a role for innate immune pathways in the events that mediate hip impingement. Further mechanistic studies to evaluate the net contribution and hence therapeutic utility of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early hip impingement.

Background

Tightrope fixation has been suggested as an alternative to screw stabilisation for distal tibiofibular joint diastasis that provides stability but avoids the problems of rigid screws across the joint. Recent case series (of 6 and 16 patients) have however, reported soft tissue problems and infections in 19–33% of patients. This study aims to review treatment and complications of distal tibiofibular diastasis fixation in our unit with the use of Tightrope or diastasis screws.

Early failure of metal-on-metal (MoM) total hip replacements (THR) is now well established. We review 93 consecutive patients with CPT¯ stems MoM THR. Our series demonstrates a new mechanism of failure, which may be implant combination specific.

Between January 2005 and June 2009, 93 consecutive MoM total hip replacements were preformed using CPT stems by 3 surgeons at our unit. 73 CPT¯ stems, Metasul¯ Large Diameter Heads (LDH) with Durom¯ acetabulae and 20 CPT¯ stems, Metasul¯ 28mm diameter heads in Allofit¯ shells (zimmer). Clinical outcomes were collected prospectively before surgery, at 3 months, 1 year, 2 years, 3 years, and at 5 years post surgery. Revision for any cause was taken as the primary endpoint and the roentgenograms and explanted prostheses were analyzed for failure patterns.

In the LDH/Durom¯ group a total of 13 (18%) patients required revision (figs. 1) at a median of 35 months (range 6-44). 6 (8%) for periprosthetic fracture. All 6 periprostethic fractures were associated with minimal or no trauma and all had ALVAL identified histologically.

To date there have been no failures in the CPT¯/28mm head Allofit¯ group. Several failures demonstrated bone loss in Gruen zones 8 ± 9 ± 10 (fig. 2).

We demonstrate an unacceptably high rate of failure in CPT¯ MoM LDH hip replacements, with a high failure secondary to periprosthetic fracture and postulate a mechanism associated with local toxicity to metal ions. We strongly advise against this combination of prosthesis.

Specific radiological features identified by Brandser and Marsh were selected for the analysis of acetabular fractures according to the classification of Letournel and Judet. The method employs a binary approach that requires the observer to allocate each radiological feature to one of two groups. The inter- and intra-observer variances were assessed. The presence of articular displacement, marginal impaction, incongruity, intra-articular fragments and osteochondral injuries to the femoral head were analysed by a similar method. These factors were termed ‘modifiers’ and are generally considered when planning operative intervention and, critically, they may influence prognosis.

Six observers independently assessed 30 sets of plain radiographs and CT scans on two separate occasions, 12 weeks apart. They were asked to determine the presence or absence of specific radiological features. This simple binary approach to classification yields an inter- and intra-observer agreement which ranges from moderate to near-perfect (κ = 0.49 to 0.88 and κ = 0.57 to 0.88, respectively). A similar approach to the modifiers yields only slight to fair inter-observer agreement (κ = 0.20 to 0.34) and slight to moderate intra-observer agreement (κ = 0 to 0.55).