Coccygectomy for patients with chronic coccydynia: a prospective, observational study of 98 patients.

AIMS: The purpose of this prospective study was to evaluate the outcomes of coccygectomy for patients with chronic coccydynia. PATIENTS AND METHODS: Between 2007 and 2011, 98 patients underwent coccygectomy for chronic coccydynia. The patients were aged > 18 years, had coccygeal pain, local tenderness and a radiological abnormality, and had failed conservative management. Outcome measures were the Short Form 36 (SF-36), the Oswestry Disability Index (ODI) and a visual analogue scale (VAS) for pain. Secondary analysis compared the pre-operative features and the outcomes of patients with successful and failed treatment, two years post-operatively. The threshold for success was based on a minimum clinically important difference (MCID) on the ODI of 20 points. All other patients, including those lost to follow-up, were classified as failures. RESULTS: There was significant improvement in all ten components of the SF-36 (p < 0.05), the ODI (23 points) and VAS (39 points) (p < 0.0001). A total of 69 patients (70.4%) met the designated MCID threshold for a successful outcome. The failure group consisted of 25 patients (25.5%) who did not reach the MCID and four (4.1%) who were lost to follow-up. Six patients (6.1%) in the failure group had ODI scores that were no better or worse than that pre-operatively. The patients in whom treatment failed had significantly worse pre-operative scores for the ODI (p = 0.04), VAS (p = 0.02) and on five of ten SF-36 components (p < 0.04). They also had a higher incidence of psychiatric disorders, pre-operative opiate use and more than three comorbidities. TAKE HOME MESSAGE: Coccygectomy for chronic coccydynia results in significant improvement in patient-reported outcomes at two years. Failure is associated with certain pre-operative characteristics such as psychiatric illness, poor quality of life features, higher levels of pain, and use of opiates.

Osteogenic, stem cell and molecular characterisation of the human induced membrane from extremity bone defects.

OBJECTIVES: The biomembrane (induced membrane) formed around polymethylmethacrylate (PMMA) spacers has value in clinical applications for bone defect reconstruction. Few studies have evaluated its cellular, molecular or stem cell features. Our objective was to characterise induced membrane morphology, molecular features and osteogenic stem cell characteristics. METHODS: Following Institutional Review Board approval, biomembrane specimens were obtained from 12 patient surgeries for management of segmental bony defects (mean patient age 40.7 years, standard deviation 14.4). Biomembranes from nine tibias and three femurs were processed for morphologic, molecular or stem cell analyses. Gene expression was determined using the Affymetrix GeneChip Operating Software (GCOS). Molecular analyses compared biomembrane gene expression patterns with a mineralising osteoblast culture, and gene expression in specimens with longer spacer duration (> 12 weeks) with specimens with shorter durations. Statistical analyses used the unpaired student t-test (two tailed; p < 0.05 was considered significant). RESULTS: Average PMMA spacer in vivo time was 11.9 weeks (six to 18). Trabecular bone was present in 33.3% of the biomembrane specimens; bone presence did not correlate with spacer duration. Biomembrane morphology showed high vascularity and collagen content and positive staining for the key bone forming regulators, bone morphogenetic protein 2 (BMP2) and runt-related transcription factor 2 (RUNX2). Positive differentiation of cultured biomembrane cells for osteogenesis was found in cells from patients with PMMA present for six to 17 weeks. Stem cell differentiation showed greater variability in pluripotency for osteogenic potential (70.0%) compared with chondrogenic or adipogenic potentials (100% and 90.0%, respectively). Significant upregulation of BMP2 and 6, numerous collagens, and bone gla protein was present in biomembrane compared with the cultured cell line. Biomembranes with longer resident PMMA spacer duration (vs those with shorter residence) showed significant upregulation of bone-related, stem cell, and vascular-related genes. CONCLUSION: The biomembrane technique is gaining favour in the management of complicated bone defects. Novel data on biological mechanisms provide improved understanding of the biomembrane's osteogenic potential and molecular properties.Cite this article: Dr H. E. Gruber. Osteogenic, stem cell and molecular characterisation of the human induced membrane from extremity bone defects. Bone Joint Res 2016;5:106-115. DOI: 10.1302/2046-3758.54.2000483.

An unusual chest impalement.

We present the case of a 49-year old farmer, a combatant in communal clash over a piece of farmland on the Jos Plateau, who was impaled on his chest by a 13.5 cm long metal arrow, 56 hours prior to presentation. The arrow hit him tangentially on the left side of the chest and disappeared completely into his chest traversing the chest wall and lacerating the superior lingula segment of the lung but the tip of the arrow was only about 1.5 cm short of the pericardium. We are not aware of any report in literature on a patient in the West African sub-region who sustained and survived such serious chest impalement by a rigid object for more than two days before hospitalisation. Sustained public education and enforced legislature against the use of such lethal weapons will go a long way in preventing serious injuries of this nature.