Comparison of four chondral repair techniques in the hip joint: a biomechanical study using a physiological human cadaveric model.

OBJECTIVE: The objective of this study was to assess the biomechanical stability of three types of chondral flap repair techniques as well as a hydrogel scaffold implantation on the acetabular articular surface using a physiological human cadaveric model. METHODS: Chondral flaps were created in the antero-superior zone of the acetabulum in a series of human cadaveric hip joints. The chondral flap was repaired by fibrin glue, cyanoacrylate, suture technique and an agarose hydrogel scaffold sealed with fibrin glue using six hips in each case. After each repair, the specimens were mounted in a validated jig and tested for 1500 gait cycles. In order to determine the stability of the repair, specimens were evaluated arthroscopically at specific intervals. RESULTS: The fibrin glue and cyanoacrylate techniques were technically the easiest to perform arthroscopically, all flaps repaired with fibrin were detached at 50 cycles while those repaired with cyanoacrylate lasted for an average of 635 cycles. On the other hand, both the suture repair and scaffold implantation techniques were more technically challenging but were both stable till the endpoint of 1500 cycles. CONCLUSION: Fibrin glue on its own does not provide sufficient fixation to repair chondral flaps on the acetabular surface. Cyanoacrylate repairs universally failed midway through the testing protocol employed here, raising doubts as to the effectiveness of that technique. The suture and hydrogel scaffold technique were the most reliable for chondral repair at any given cycle. The results of this biomechanical study demonstrate the relative effectiveness of chondral repair and fixation techniques.

On the fate of particles liberated from hydroxyapatite coatings in vivo.

PURPOSE: Hydroxyapatite (HA) has been used as a coating for orthopaedic implants for over 30 years to help promote the fixation of orthopaedic implants into the surrounding bone. However, concerns exist about the fate of the hydroxyapatite coating and hydroxyapatite particles in vivo, especially in the wake of recent concerns about particulates from metal-on-metal bearings. METHODS: Here, we assess the mechanisms of particle detachment from coated orthopaedic devices as well as the safety and performance concerns and biomedical implications arising from the liberation of the particles by review of the literature. FINDINGS: The mechanisms that can result in the detachment of the HA coating from the implant can be mechanical or biochemical, or both. Mechanical mechanisms include implant insertion, abrasion, fatigue and micro-motion. Biochemical mechanisms that contribute to the liberation of HA particles include dissolution into extra-cellular fluid, cell-mediated processes and crystallisation of amorphous phases. The form the particles take once liberated is influenced by a number of factors such as coating method, the raw powder morphology, processing parameters, coating thickness and coating structure. CONCLUSIONS: This review summarises and discusses each of these factors and concludes that HA is a safe biomimetic material to use as a coating and does not cause any problems in particulate form if liberated as debris from an orthopaedic implant.

Osteoporotic hip fractures: the burden of fixation failure.

Osteoporotic hip fractures are a major cause of morbidity and mortality in the elderly. Furthermore, reduced implant anchorage in osteoporotic bone predisposes towards fixation failure and with an ageing population, even low failure rates represent a significant challenge to healthcare systems. Fixation failure in fragility fractures of the hip ranges from 5% in peritrochanteric fractures through to 15% and 41% in undisplaced and displaced fractures of the femoral neck, respectively. Our findings, in general, support the view that failed internal fixation of these fragility fractures carries a poor prognosis: it leads to a twofold increase in the length of hospital stay and a doubling of healthcare costs. Patients are more likely to suffer a downgrade in their residential status upon discharge with a consequent increase in social dependency. Furthermore, the marked disability and reduction in quality of life evident before salvage procedures may persist at long-term followup. The risk, of course, for the elderly patient with a prolonged period of decreased functioning is that the disability becomes permanent. Despite this, however, no clear link between revision surgery and an increase in mortality has been demonstrated in the literature.

Preliminary study of the feasibility and accuracy of percutaneous peri-acetabular screw insertion in a porcine model.

The aim of this pilot study was to assess a new method of training for peri-acetabular screw placement under indirect vision using standard C-arm fluoroscopy using a porcine model. Two novice orthopaedic residents placed 72 screws (36 each) about the acetabula of six porcine pelves under C-arm fluoroscopic guidance. Unsatisfactory screw position was noted in 22 of 72, with five instances of screw ingress into the hip joint. All of these cases occurred in the first half of each resident's series. Screw direction and final position improved over subsequent trials. This pilot study demonstrates that surgical simulation techniques are applicable in percutaneous screw fixation. Such an approach could be useful for both residents in training and more experienced surgeons who wish to perform this procedure in cases where it is appropriate.

Transient osteoporosis of the hip and spontaneous osteonecrosis of the knee: a common aetiology?

INTRODUCTION: The aetiologies of transient osteoporosis of the hip (TOH) and spontaneous osteonecrosis of the knee (SONK) are still unknown. Both entities present with pain and extensive bone marrow oedema is seen on magnetic resonance imaging. METHODS AND MATERIALS: We describe a patient who presented with TOH and later also developed SONK. Initial magnetic resonance imaging findings of both the hip and the knee showed extensive bone marrow oedema and a subchondral fracture line suggesting that subchondral fractures might be of importance to the aetiology of both conditions. CONCLUSION: To our knowledge, this is the first case report that describes the occurrence of TOH and SONK in the same patient and introduces the possibility of a common aetiology.

In vitro assessment of human chondrocyte viability after treatment with local anaesthetic, magnesium sulphate or normal saline.

PURPOSE: Local anaesthetic agents are often used as an intra-articular analgesic following arthroscopic procedures. However, there is increasing evidence of a potential toxic effect to chondrocytes within the articular cartilage. The aim of this study was to compare the effect on human chondrocyte viability of treatment with bupivacaine, levobupivacaine and ropivacaine. The second aim was to compare the effect on chondrocyte viability of the local anaesthetics with magnesium, a potential alternative analgesic agent. METHODS: Chondrocytes were exposed to one of the local anaesthetic agents (levobupivacaine 0.13, 0.25, 0.5%; bupivacaine 0.13, 0.25, 0.5%; ropivacaine 0.19, 0.38, 0.75%), normal saline or 10% magnesium sulphate for 15 min. Cells exposed to cell culture media served as controls. Twenty-four hours after exposure, cell viability was assessed using the CellTiter 96® AQueous One Solution Cell Proliferation Assay. RESULTS: There was no significant difference in chondrocyte viability after treatment with either normal saline or magnesium sulphate. With the exception of 0.13% levobupivacine, all local anaesthetic treatment showed significantly greater toxic effects than either normal saline or magnesium sulphate. Statistically significant dose-dependent responses of decreasing cell viability were found with increasing local anaesthetic concentration. CONCLUSIONS: A dose-dependent reduction in chondrocyte viability after treatment with common local anaesthetic agents was confirmed. Local anaesthetic agents had a greater deleterious effect on chondrocytes than did 10% magnesium sulphate. These findings suggest the need for continuing caution with the use of intra-articular local anaesthetic. Magnesium sulphate is a potential alternative intra-articular analgesic agent.

Total Hip Arthroplasty in Mucopolysaccharidosis Type IH.

Children affected by mucopolysaccharidosis (MPS) type IH (Hurler Syndrome), an autosomal recessive metabolic disorder, are known to experience a range of musculoskeletal manifestations including spinal abnormalities, hand abnormalities, generalised joint stiffness, genu valgum, and hip dysplasia and avascular necrosis. Enzyme therapy, in the form of bone marrow transplantation, significantly increases life expectancy but does not prevent the development of the associated musculoskeletal disorders. We present the case of a 23-year-old woman with a diagnosis of Hurler syndrome with a satisfactory result following uncemented total hip arthroplasty.

Femoro-acetabular impingement and hip pain with conventionally normal x-rays.

There has in recent years been a fundamental change in the understanding of hip pain in the young adult and hip pain without plain radiographic findings of arthritis. Pain in these groups has long represented a diagnostic and therapeutic challenge. With new appreciation of hip biomechanics, pathological processes and the arrival of modern imaging modalities we now have a greater understanding of non-arthritic hip pathology. One of the commonest yet least well recognized 'new' diagnoses around the hip is femoro-acetabular impingement (FAI). FAI is a developmental condition of the hip joint that is associated with abnormal anatomical configuration and thus joint mechanics on either the femoral or acetabular sides or both. It is hypothesized to have a variety of precipitants and may ultimately lead to labral and chondral injury and what has previously been referred to as 'primary' or 'idiopathic' hip osteoarthritis.

Surgical trainees neuropraxia? An unusual case of compression of the lateral cutaneous nerve of the forearm.

Compression of the lateral cutaneous nerve of the forearm is an uncommon diagnosis but has been associated with strenuous upper limb activity. We report the unique case of a 32-year-old male orthopaedic trainee who suffered this nerve palsy as a result of prolonged elbow extension and forearm pronation while the single assistant during a hip resurfacing procedure. Conservative measures were sufficient for sensory recovery to be clinically detectable after 12 weeks.

Total hip replacement in patients with neurological conditions.

Neurological conditions affecting the hip pose a considerable challenge in replacement surgery since poor and imbalanced muscle tone predisposes to dislocation and loosening. Consequently, total hip replacement (THR) is rarely performed in such patients. In a systematic review of the literature concerning THR in neurological conditions, we found only 13 studies which described the outcome. We have reviewed the evidence and discussed the technical challenges of this procedure in patients with cerebral palsy, Parkinson's disease, poliomyelitis and following a cerebrovascular accident, spinal injury or development of a Charcot joint. Contrary to traditional perceptions, THR can give a good outcome in these often severely disabled patients.

Causes of prolonged hospital stay following low-energy fracture of the proximal femur: issues of most concern.

Hip fractures are an important cause of morbidity in the elderly and represent a significant proportion of acute orthopaedic admissions. We reviewed a consecutive series of hip fractures presenting to our unit over five years, obtaining demographic and clinical data from patient's medical records. Patients who remained in-patient for greater than fourteen days were analyzed for reasons responsible. We reviewed 717 consecutive hip fractures. The average length of stay was 28 days. Forty-nine percent of patients stayed in hospital greater than 14 days. Reasons for prolonged stay included both medical and social reasons. Direct postoperative complications were rarely responsible for prolonged hospital stay. Hip fractures constitute a significant burden on acute trauma services. Further strategies are needed to address both medical and social reasons for prolonged stay in hospital following hip fracture, as is a prospective national hip fracture audit to quantify the burden on the Irish health service.

Incidence of hip fractures in Dublin's north inner city.

Hip fractures are an important cause of morbidity and mortality in the elderly and represent an increasing burden on health service providers. There is significant regional and international variation in the incidence rates of such injuries, depending on age, sex and ethnic variations in populations. To date, there are no reported incidence rates for hip fractures in Ireland. Over a five year period, 717 low energy hip fractures were treated in the orthopaedic trauma unit of the Mater Misericordiae hospital. For this population, the female to male ratio was 3.3:1 (549 females and 166 males), the gender specific incidences were 470 per 100,000 and 179 per 100,000 for females and males, respectively. The overall age standardized rate was 341 per 100,000. This study quantifies the burden of hip fracture on a local population. With this knowledge, health service providers should be able to allocate appropriate resources for these patients in terms of acute and step-down care facilities.

Incidence of hip fracture in the Republic of Ireland and future projections: a population-based study.

SUMMARY: There are no previously published data for hip fracture incidence rates in the Republic of Ireland. The rates of fracture for the total population aged 50 years and over were 407 and 140 per 100,000 for females and males, respectively. Assuming a stable incidence rate, the absolute number of hip fractures occurring on an annual basis is expected to increase by 100% by the year 2026. Health care providers should accommodate these increases into future strategies. INTRODUCTION: Hip fractures are an important cause of morbidity in the elderly and represent an increasing burden on health service providers. Significant regional and international variation in incidence rates of hip fracture exists. In order for health service providers to be able to commit adequate resources to the care of hip fracture patients, accurate estimates of hip fracture numbers are required now and for the future. To date, there have been no reported incidence rates for hip fracture in the Republic of Ireland. METHODS: We performed a search of the national hospital in-patient enquiry database for all hip fractures occurring in the Republic of Ireland between 2000 and 2004. Population data was obtained from the 2002 national census data. Population projections were made for the years 2016 and 2026 to allow determination of expected hip fracture numbers for those years. RESULTS: The rates of hip fracture in the Irish population aged 50 years and over were 407 and 140 per 100,000 for females and males, respectively. Annual hip fracture numbers are expected to increase by 100% by the year 2026, assuming a stable incidence rate. CONCLUSION: Health service providers should take into account the expected increase in hip fracture numbers when allocating resources for the care of these patients in the mid-term future.

Down's syndrome and hip arthropathy.

We report a case of a 19 year old male with Down's syndrome who presented with severe functional disability and pain secondary to bilateral hip arthritis. He had longstanding developmental dysplasia of the hip (DDH) that had evolved into end stage arthritis. Following a comprehensive assessment and counselling, he underwent bilateral total hip replacements. At last follow up, he had excellent outcome for function and pain relief. This case highlights the good results achievable with aggressive management of musculo-skeletal conditions (especially hip arthropathy) in those with Down's syndrome and the need for increased recognition of these conditions.

Preconditioning and its clinical potential.

Preconditioning is emerging as a simple, safe and highly effective means of attenuating local and systemic effects of medical and surgical insult. Its enormous potential has not yet been harnessed and ongoing work will continue to bring it to the fore. This article covers the history, development and future clinical potential of preconditioning with particular regard to surgical insult.

Practice patterns in flexor tendon repair.

BACKGROUND: There is a considerable volume of literature describing new and supposedly superior methods of flexor tendon repair. AIM: The purpose of this study was to assess the flexor tendon techniques currently used in the Republic of Ireland. METHODS: A postal survey was conducted of all consultant plastic surgeons and consultant orthopaedic surgeons who were members of the Irish Hand Surgery Society. RESULTS: The response rate was 90% (27/30). A simple running peripheral suture was used by 73% (P = 0.03) and the Kessler was the core suture of choice for 68% (P = 0.06). A significant number of respondents use non-absorbable suture materials for core (P = 0.0028) and peripheral suture (P < 0.0001). Seventy-seven percent sutured the flexor sheath where possible (P = 0.009). CONCLUSIONS: Notwithstanding the proposed advantages of newer techniques, it is evident from this study that the two-stranded Kessler core and simple running peripheral suture remains the most popular flexor tendon repair, with sheath closure preferred by the majority of respondents.

The effect of thermal preconditioning of the limb on flexor tendon healing.

Thermal preconditioning reduces inflammation by inducing cytoprotective heat shock proteins. We evaluated the role of limb thermal preconditioning in a rabbit model of flexor tendon repair. The treatment groups underwent limb preconditioning by elevating the limb temperature to 41.5 degrees C for 20 minutes. The animals were sacrificed three and six weeks after flexor tendon repair. Heat shock protein72 expression of the treated limb was measured at 18 hours. Macroscopic analysis demonstrated a significant decrease in adhesion formation in the three week treatment group. The inflammatory infiltrate was significantly reduced for both treatment groups. The difference in ultimate tensile strength was not significant. We conclude that thermal preconditioning of the limb before flexor tendon repair decreases inflammation and adhesion formation in a rabbit model and has the potential to improve clinical outcome of flexor tendon surgery.

Diathermy versus scalpel incisions for hemiarthroplasty for hip fracture: a randomised prospective trial.

As the age profile of our population expands, we can expect subsequent increase in patients presenting with intracapsular fracture. The onus remains on the surgeon to make all reasonable efforts to find new and innovative means of reducing associated morbidity and mortality of the treatment of these injuries. This challenge is particularly relevant in the elderly and in patients with multiple co-morbidities. In this study, 100 patients were randomly allocated into two groups. One group had dissection to the level of the hip joint under direct diathermy control; the other group had dissection using a scalpel with supplementary electrocautery. Intraoperative total blood loss prior to dissection of the abductors was measured by collecting blood using wound swabs using a local protocol and results were statistically analysed using PROC GLM SAS. We demonstrate a clear advantage in the use of diathermy to create a hip incision showing a significant reduction in wound-related blood loss and a reduction, whilst not statistically significant, in total operative blood loss using diathermy incision. Larger randomised prospective trials are necessary to study the effects of this intervention in a larger patient population so that these end-points can be adequately assessed.

Relating undergraduate musculoskeletal medicine curricula to the needs of modern practice.

BACKGROUND: International studies have demonstrated significant discrepancies between undergraduate musculoskeletal curricula and the needs of modern medical practice. AIMS: To determine the prevalence of musculoskeletal disorders in primary care, General Practitioners, assessment of their undergraduate musculoskeletal training and that considered ideal for several clinical skills, and the relative importance of the ability to recognise selected clinical presentations. METHODS: A postal survey of 200 General Practitioners using a detailed questionnaire. RESULTS: The response rate was 50.5%, with respondents being an average 18.5 years in practice. They saw a mean 140.3 patients/week (range 10-270) of which 17.4% presented with musculoskeletal complaints (range 5-50%). Respondents felt their musculoskeletal education was poor, with a significant difference between it and their ideal (p = 0.007). The most important skill for a graduating doctor was history taking, examination and appropriate investigation of a musculoskeletal problem. The most important clinical presentation was recognition of traumatic quadriplegia. CONCLUSIONS: A large proportion of primary care in Ireland is devoted to musculoskeletal complaints, however, there are deficiencies perceived in undergraduate musculoskeletal education. A review of undergraduate musculoskeletal curricula, emphasising the clinically relevant aspects of this discipline is needed.

Staphylococcal diaphyseal subacute osteomyelitis of the ulna in a child: an unusual cause of post-traumatic forearm swelling.

Paediatric subacute osteomyelitis (SAO) presents a diagnostic and therapeutic challenge to clinicians. Typically located in the metaphysis of long bones, diaphyseal SAO of the upper limb is rare. We present the case of a three-year-old girl referred to our fracture clinic as an occult fracture following trauma to her forearm with normal initial radiographs. Follow-up radiographs one week later showed cortical erosion of the distal ulna, while a subsequent MRI scan showed soft tissue swelling with an area of high signal in the distal ulna. A limited biopsy diagnosed staphylococcal subacute osteomyelitis of the ulna. The patient responded to high dose antibiotic therapy and made a full recovery. We present this case to highlight the high index of suspicion required to diagnose and appropriately manage this insidious condition, which may easily be confused with any number of benign and malignant bony lesions and provide a review of the relevant literature.