Panagiotis D. Gikas

Current strategies for knee cartilage repair

Defects in knee articular cartilage (AC) can cause pain and disability and present the clinician with an extremely challenging clinical situation. This article describes the most up‐to‐date surgical techniques that aim to repair and/or regenerate symptomatic focal defects in AC, which include arthroscopic debridement, microfracture bone marrow stimulation and autologous osteochondral allografting, with an emphasis on autologous chondrocyte implantation. In the future, refinement of tissue‐engineering approaches promises to further improve outcome for these patients.

Nonbacterial osteitis: a clinical, histopathological, and imaging study with a proposal for protocol-based management of patients with this diagnosis

BackgroundNonbacterial osteitis (NBO), a term referring to sterile bone lesions with nonspecific histopathological features of inflammation, may be either unifocal or multifocal, acute (≤6 months) or chronic, and recurrent. Only when the condition is chronic, recurrent, and multifocal is it appropriate to use the term chronic recurrent multifocal osteomyelitis (CRMO). We present our clinical experience as the largest reported series of children with NBO to date.MethodsWe report a retrospective clinical, histopathological, and radiological study of 41 children with nonbacterial osteitis.ResultsOf 41 children (2–16 years of age) diagnosed with NBO in our institution over the last 6 years, 21 (51%) had recurrent disease and 18 (44%) had multifocal disease. The most common bones affected were the clavicle, femur, and tibia (in order of decreasing prevalence) accounting for 44 (63%) of a total of 70 lesions. Only one individual had SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis) and no other patients had evidence of bowel or skin disease. In the absence of evidence for an infective etiology, we recommend nonsteroidal anti-inflammatory agents as the firstline therapy and bisphosphonates only in cases of resistant disease.ConclusionsOn the basis of our findings, we propose using a patient questionnaire and protocol for investigating and managing patients who present with NBO to orthopedic surgeons. We predict that this will benefit patients with this disorder by improving our knowledge of the presenting signs and symptoms and related disorders, rationalizing the therapeutic approach, and allowing us to learn about the natural history of the disease.

Towards the in vivo prediction of fragility fractures with Raman spectroscopy

Fragility fractures, those fractures which result from low level trauma, have a large and growing socio‐economic cost in countries with aging populations. Bone‐density‐based assessment techniques are vital for identifying populations that are at higher risk of fracture, but do not have high sensitivity when it comes to identifying individuals who will go on to have their first fragility fracture. We are developing Spatially Offset Raman Spectroscopy (SORS) as a tool for retrieving chemical information from bone non‐invasively in vivo. Unlike X‐ray‐based techniques SORS can retrieve chemical information from both the mineral and protein phases of the bone. This may enable better discrimination between those who will or will not go on to have a fragility fracture because both phases contribute to bones mechanical properties. In this study we analyse excised bone with Raman spectroscopy and multivariate analysis, and then attempt to look for similar Raman signals in vivo using SORS. We show in the excised work that on average, bone fragments from the necks of fractured femora are more mineralised (by 5–10%) than (cadaveric) non‐fractured controls, but the mineralisation distributions of the two cohorts are largely overlapped. In our in vivo measurements, we observe similar, but as yet statistically underpowered, differences. After the SORS data (the first SORS measurements reported of healthy and diseased human cohorts), we identify methodological developments which will be used to improve the statistical significance of future experiments and may eventually lead to more sensitive prediction of fragility fractures.

Post-radiation sciatic neuropathy: a case report and review of the literature

BackgroundPost-radiation peripheral neuropathy has been reported in brachial and cervical plexuses and the femoral nerve.Case presentationWe describe a patient who developed post-radiation sciatic neuropathy after approximately 3 years and discuss the pathophysiology, clinical course and treatment options available for the deleterious effects of radiation to peripheral nerves.ConclusionThis is the first case of post-radiation involvement of the sciatic nerve reported in the literature.

Functional adaptation of long bone extremities involves the localized "tuning" of the cortical bone composition; evidence from Raman spectroscopy

Abstract. In long bones, the functional adaptation of shape and structure occurs along the whole length of the organ. This study explores the hypothesis that adaptation of bone composition is also site-specific and that the mineral-to-collagen ratio of bone (and, thus, its mechanical properties) varies along the organ’s length. Raman spectroscopy was used to map the chemical composition of long bones along their entire length in fine spatial resolution (1 mm), and then biochemical analysis was used to measure the mineral, collagen, water, and sulfated glycosaminoglycan content where site-specific differences were seen. The results show that the mineral-to-collagen ratio of the bone material in human tibiae varies by <5% along the mid-shaft but decreases by >10% toward the flared extremities of the bone. Comparisons with long bones from other large animals (horses, sheep, and deer) gave similar results with bone material composition changing across tens of centimeters. The composition of the bone apatite also varied with the phosphate-to-carbonate ratio decreasing toward the ends of the tibia. The data highlight the complexity of adaptive changes and raise interesting questions about the biochemical control mechanisms involved. In addition to their biological interest, the data provide timely information to researchers developing Raman spectroscopy as a noninvasive tool for measuring bone composition in vivo (particularly with regard to sampling and measurement protocol).

Evidence from Raman Spectroscopy of a Putative Link Between Inherent Bone Matrix Chemistry and Degenerative Joint Disease

Osteoarthritis (OA) is a common debilitating disease that results in degeneration of cartilage and bone in the synovial joints. Subtle changes in the molecular structure of the subchondral bone matrix occur and may be associated with cartilage changes. The aim of this study was to explore whether the abnormal molecular changes observed in the matrix of OA subchondral bone can be identified with Raman spectroscopy.

Hydroxyapatite-coated Collars Reduce Radiolucent Line Progression in Cemented Distal Femoral Bone Tumor Implants

BackgroundAseptic loosening of massive bone tumor implants is a major cause of prosthesis failure. Evidence suggests that an osteointegrated hydroxyapatite (HA)-coated collar would reduce the incidence of aseptic loosening around the cemented intramedullary stem in distal femoral bone tumor prostheses. Because these implants often are used in young patients with a tumor, such treatment might extend the longevity of tumor implants. Questions/purposes We asked whether (1) HA-coated collars were more likely to osteointegrate; (2) HA collars were associated with fewer progressive radiolucent lines around the stem-cement interface; and (3) HA-coated collars were associated with less bone loss at the bone-shoulder implant junction?MethodsTwenty-two patients were pair-matched to one of two groups—either (1) implants with a HA-coated ingrowth collar (HA Collar Group); or (2) implants without an ingrowth collar (Noncollar Group). Age, sex, and length of followup were similar in both groups. HA-coated collars were developed and used at our institution from 1992 to address the high failure rate attributable to aseptic loosening in patients with massive bone tumor implants. Before this, smooth titanium shafts were used routinely adjacent to bone at the transection site. The minimum followup was 2 years (mean, 7 years; range, 2–12 years). Radiographs obtained throughout the followup period were analyzed and osteointegration at the shaft of the implant quantified. Radiolucent line progression around the cemented stem was semi-quantitatively assessed and cortical bone loss at the bone-shoulder implant junction was measured during the followup period.ResultsComparison of the most recent radiographs showed nine of 11 patients had osteointegrated HA collars, whereas only one patient in the Noncollar Group had osteointegration (p > 0.001). The radiolucent line score quantified around the cemented stem was lower in the HA Collar Group when compared with the Noncollar Group (p = 0.001). Results showed an increase in cortical bone loss at the bone-shoulder implant junction in the Noncollar Group when compared with the HA Collar Group (p < 0.001).ConclusionsOsteointegration at the implant collar resulted in fewer radiolucent lines adjacent to the intramedullary cemented stem and decreased cortical bone loss immediately adjacent to the transection site. These results suggest that the HA collar may help reduce the risk of aseptic loosening in patients with this type of implant, but longer followup and a larger prospective comparison series are necessary to prove this more definitively.

Destructive synovial hemangioma of the hip resembling pigmented villonodular synovitis.

We report a case of synovial hemangioma of the hip causing joint destruction severe enough to warrant arthroplasty in a 32-year-old man who presented with a 2-year history of hip pain and worsening limp. Plain radiographs demonstrated advanced degenerative changes of the hip articular surface. Magnetic resonance imaging revealed changes consistent with pigmented villonodular synovitis throughout the joint and erosion of the acetabular bone. A total hip arthroplasty was performed, and histopathologic examination of the resected tissue demonstrated synovial hemangioma. This case, unique in the literature, demonstrates the destructive capacity and diagnostic pitfalls of synovial hemangioma.

Mixed methods evaluation of the Getting it Right First Time programme - improvements to NHS orthopaedic care in England: study protocol

BackgroundOrthopaedic procedures, such as total hip replacement and total knee replacement, are among the commonest surgical procedures in England. The Getting it Right First Time project (GIRFT) aims to deliver improvements in quality and reductions in the cost of NHS orthopaedic care across the country. We will examine whether the planned changes have delivered improvements in the quality of care and patient outcomes. We will also study the processes involved in developing and implementing changes to care, and professional and organisational factors influencing these processes. In doing so, we will identify lessons to guide future improvement work in other services.Methods/designWe will evaluate the implementation of the GIRFT programme, and its impact on outcomes and cost, using a mixed methods design. Qualitative methods will be used to understand the programme theory underlying the approach and study the effect of the intervention on practice, using a case study approach. This will include an analysis of the central GIRFT programme and local provider responses. Data will be collected via semi-structured interviews, non-participant observation, and documentary analysis. Quantitative methods will be used to examine ‘what works and at what cost?’ We will also conduct focus groups with patients and members of the public to explore their perceptions of the GIRFT programme. The research will draw on theories of adoption, diffusion, and sustainability of innovation; its characteristics; and contextual factors at provider-level that influence implementation.DiscussionWe will identify generalisable lessons to inform the organisation and delivery of future improvement programmes, to optimise their implementation and impact, both within the UK and internationally. Potential challenges involved in conducting the evaluation include the phased implementation of the intervention in different provider organisations; the inclusion of both retrospective and prospective components; and the effects of ongoing organisational turbulence in the English NHS. However, these issues reflect the realities of service change and its evaluation.

Osteoclast-rich Lesions of Bone: A Clinical and Molecular Overview

Abstract Osteoclast-rich lesions of bone represent morphologically similar entities, many of which behave in a clinically distinct manner. Common to all osteoclast-rich lesions is the presence of innumerable osteoclast-like giant cells, which are capable of resorbing bone. Although there are some specific morphological features associated with particular osteoclast-rich lesions, the key to distinguishing the various entities from one another is their distinctive clinical and radiographic characteristics, and more recently they can be separated on the basis of a genetic signature. The pathogenesis by which this group of lesions develops is diverse, and includes disorders arising from germline mutations (cherubism, Noonan syndrome, neurofibromatosis type 1, and at least some non-ossifying fibromas), neoplasias arising from somatic genetic changes (giant cell tumor of bone, chondroblastoma, aneurysmal bone cyst, clear cell chondrosarcoma, and metabolic disorders (hyperparathyroidism), and finally degenerative processes associated with reparative change may also be osteoclast-rich. Advances in identifying the genetic abnormalities associated with many of these lesions not only allows the provision of robust tissue diagnoses but allows the consequences of the genetics events at a molecular level to be deciphered and will reveal more about this spectrum of disease providing the opportunity for the development of novel therapeutic approaches.