Hydroxyapatite Crystal Thickness and Buckling Phenomenon in Bone Nanostructure During Mechanical Tests.

An investigation of bone samples taken from the left ulna of New Zealand white rabbits, with and without stresses and hysteresis loop, was undertaken using Small Angle X-ray Scattering technique. The purpose of this study is to investigate the nanostructural changes in the mean size of hydroxyapatite crystals thickness (T) during different mechanical conditions. The experiments were performed using bone samples aged 2 and 4 weeks, with and without strontium ranelate treatment, after compressive load and hysteresis loop. We did not observe any clear effects of strontium ranelate on the bones since the MANOVA test for epiphysis and diaphysis were found. On the other hand, a significant difference appears in epiphysis between 2 and 4 weeks. Furthermore, a reduction in the mean size of hydroxyapatite crystal thickness was observed when the loading pressure force increased, due to the buckling phenomenon. A return of memory points in the elastic region of the bone was observed. The significance of these results lays on the development of nanoproducts, with properties that are closer to the actual bone structure.

Wound closure of leg fasciotomy: comparison of vacuum-assisted closure versus shoelace technique. A randomised study.

BACKGROUND: Fasciotomies, though essential for the prevention and management of compartment syndromes, may increase morbidity and prolong hospitalisation. Two widely applied methods of delayed primary closure are compared in leg fasciotomy wounds. PATIENTS AND METHODS: Two groups, each of 25 patients with leg fasciotomies due to fractures and soft tissue injuries, who were randomly assigned to be treated either by vacuum assisted closure (VAC®, n=42 wounds, group V) or by the shoelace technique (n=40 wounds, group S), were evaluated in this study. Wound length, time to definite closure, complications, need for additional interventions and daily treatment costs were data collected and statistically assessed. RESULTS: Wound closure time was significantly higher in group V compared to group S (p=0.001; 95% CI of the difference, 1.8-6.3 days). Five group V patients required split thickness skin grafts. In six group S patients, the vessel loops had to be replaced. The mean daily cost of negative pressure therapy alone was 135 euro (range 117-144 euro), whilst the mean daily cost of treatment for the shoelace technique was 14 euro ranging from 8 to 18 euro (p=<0.001). CONCLUSIONS: Both VAC® and the shoelace technique are safe, reliable and effective methods for closure of leg fasciotomy wounds. VAC® requires longer time to definite wound closure and is far more expensive than the shoelace technique, especially when additional skin grafting is required.

Vitamin D and bone disease.

Vitamin D is important for normal development and maintenance of the skeleton. Hypovitaminosis D adversely affects calcium metabolism, osteoblastic activity, matrix ossification, bone remodeling and bone density. It is well known that Vit. D deficiency in the developing skeleton is related to rickets, while in adults is related to osteomalacia. The causes of rickets include conditions that lead to hypocalcemia and/or hypophosphatemia, either isolated or secondary to vitamin D deficiency. In osteomalacia, Vit. D deficiency leads to impairment of the mineralisation phase of bone remodeling and thus an increasing amount of the skeleton being replaced by unmineralized osteoid. The relationship between Vit. D and bone mineral density and osteoporosis are still controversial while new evidence suggests that Vit. D may play a role in other bone conditions such as osteoarthritis and stress fractures. In order to maintain a "good bone health" guidelines concerning the recommended dietary intakes should be followed and screening for Vit. D deficiency in individuals at risk for deficiency is required, followed by the appropriate action.

Juxtacortical clavicular chondrosarcoma: diagnostic dilemmas: case report and review of literature.

Juxtacortical chondrosarcoma is a rare primary malignant cartilaginous tumor accounting for 0.2% of all bone tumors. Wide surgical resection is the treatment of choice for juxtacortical chondrosarcomas. Accurate preoperative diagnosis is important in ensuring appropriate management, staging, and treatment of the patient. A combination of radiographs, three-dimensional imaging with computerized tomography (CT) scan and magnetic resonance imaging (MRI) can typically allow accurate diagnosis of juxtacortical chondrosarcomas. Bone scan and chest x-ray or CT chest scans are indicated for appropriate staging of the patient. Pet scan, ultrasound, bone scan, etc. are not typically needed for the diagnosis. Certainly, pulmonary imaging and bone scan are required for staging and could be commented upon.

Silicone ring tourniquet versus pneumatic cuff tourniquet in carpal tunnel release: a randomized comparative study.

BACKGROUND: The aim of the present study was to compare the pain levels resulting from the use of a silicone ring tourniquet (SRT) to those resulting from the use of a classic pneumatic cuff tourniquet (PT) in patients undergoing carpal tunnel release under local anesthesia. MATERIALS AND METHODS: Fifty patients that underwent carpal tunnel release under local anesthesia were randomized using the technique of stratified randomization by minimization. A forearm tourniquet was applied: a standard PT was used in 25 patients, and an SRT was used in the other 25 patients (the model of SRT used was selected according to the standard systolic blood pressure). Patient demographics and complications were recorded. Pain levels were assessed with the visual analogue scale and were recorded (a) just after tourniquet application, (b) 5 min after tourniquet application, and (c) just before tourniquet removal. RESULTS: There was no statistical significant difference in patient demographics between the two groups. The mean tourniquet time was similar for both groups (p = 1.000). The difference between the mean final pain level and the mean initial pain level was statistically significant for the SRT group (p = 0.010) and highly statistically significant for the PT group (p < 0.001). The mean final pain level for the PT group was higher than that for the SRT group (p = 0.043). CONCLUSIONS: According to the findings of this study, in patients who underwent carpal tunnel release under local anesthesia, the pain levels at the end of the operation and those just before the removal of the tourniquet were higher in the PT group than in the SRT group of patients.

Mechanical characterization of bone graft substitute ceramic cements.

The aim of this laboratory work was to study the compressive and flexural characteristics of various commercially available bone graft substitute (BGS) ceramic cements, in their initial as-mixed condition, and compare them to polymethylmethacrylate (PMMA). The tested biomaterials were two different calcium phosphate cements, two different calcium sulphate cements, one nanocrystalline hydroxyapatite and one PMMA cement. All biomaterials were prepared according to manufacturers instructions and the methodology described in ISO 5833 (2002) for acrylic bone cement was followed, as the one closest approaching in vivo requirements. All BGS cements had a brittle behaviour and when subjected to mechanical stress they all failed under sudden crack propagations in their bulk. Both in compression and bending, all BGS cements failed under loads lower than those of PMMA. In compression, the calcium sulphate extra strength cement showed a strength value of approximately 60% of PMMA, the other cements following at a distance. In bending, all BGS cements showed strengths below 22% of PMMA. However, due to limited number and fragility of specimens, calculated bending strengths can only be considered as indicative figures with limited comparative value. The results of this in vitro study showed a varying mechanical performance between tested BGS ceramic cements, whilst all of them exhibited lower compression and bending strength than the selected PMMA. These findings, of course, cannot be directly extrapolated to surgical or clinical implications, since the adopted in vitro context does not necessarily reflect the actual in vivo conditions met by such biomaterials.

Bilateral transient bone marrow edema or transient osteoporosis of the knee in pregnancy.

Transient osteoporosis or transient bone marrow edema is an uncommon self-limiting condition of unknown etiology. The most commonly affected joint is the hip, followed by the knee, ankle, and the foot. Simultaneous involvement of both hips has been reported exclusively in pregnant women. Bilateral knee involvement during pregnancy seems to be extremely rare. We present a case of bilateral transient bone marrow knee edema during pregnancy with complete resolution of symptoms and radiological findings after 10 months.

Polymorphisms of the vitamin D receptor gene and stress fractures.

Our aim was to evaluate the association between VDR polymorphisms and calcaneal Stiffness Index (SI) with stress fractures in a case control study including male military personnel. Thirty- two patients with stress fractures were matched with 32 uninjured healthy volunteers (controls), by gender, age, height, body weight, and level of physical activity. The two groups were genotyped for the FokI, BsmI, ApaI, and TaqI polymorphisms of the VDR gene with PCR-RFLP method. In addition, calcaneal SI was measured by heel quantitative ultrasound in both groups. Data were analyzed by chi-squared test and logistic regression analysis. The f allele was significantly more frequent in patients than in controls (p=0.013), while the B allele showed such a tendency without reaching statistical significance (p=0.052). Among the entire cohort, a 2.7-fold and a 2.0-fold increase in risk of stress fractures was associated with the f and B alleles (OR, 2.7, 95% CI, 1.2-5.9; p=0.014 and OR, 2.0, 95% CI, 1.0-4.1; p=0.053, respectively). No statistically significant association was found between the incidence of stress fractures and t or a alleles. Decreased T-scores were also associated with the presence of f and B alleles. Mean values of T-scores of SI were statistically significantly lower in patients than in controls (p=0.018). These results suggest that the FokI and BsmI polymorphisms of the VDR gene could be associated with increased risk of stress fractures among military personnel. Moreover, a low calcaneal SI could represent a measurable index of this increased risk.

Anterior cruciate ligament reconstruction: outcome using a patellar tendon bone (PTB) autograft (one bone block technique).

OBJECTIVE: The aim of this study was to determine the outcome of anterior cruciate ligament (ACL) reconstruction using a patellar tendon bone autograft (one bone block technique). METHOD: We retrospectively evaluated a case series of patients who had received arthroscopic ACL reconstructions using patellar tendon bone autograft. Fifty-four (54) ACL reconstructions were evaluated at a mean of 38 months (range 25-62 months). Clinical assessment was made using a modified Lysholm score, documentation of International Kappanee Documentation Committee (lKappaDC), the anterior knee pain questionnaire of Shelbourne and Trumper, and by KappaTau-Rolimeter arthrometric analysis. Radiographic assessments were also performed. RESULTS: Arthrometric analysis showed that 51 knees (94%) were graded Alpha or Beta with a median laxity of 2 mm, postoperatively. The Lysholm score improved postoperatively from 70 to 89. The patellar position in terms of congruence angle did not show any significant change, and the final shortening of the patellar tendon using the Insall-Salvati ratio was 6.07%. Only three patients complained of moderate pain on kneeling, one patient was unable to participate in strenuous works and one patient complained of harvest-site tenderness. CONCLUSION: It is concluded that the use of patellar tendon autograft with a single tibial-tubercule bone block and a strip of patellar periosteum have the advantages of being available and comparable in terms of graft size and strength and shows satisfactory results with reduced anterior knee pain.

Vacuum-assisted closure downgrades reconstructive demands in high-risk patients with severe lower extremity injuries.

BACKGROUND: Primary soft tissue reconstruction in complex leg injuries is mandatory in order to protect exposed tissues; however, it may be precluded by the patient's clinical status or by local wound conditions. This retrospective study aims to evaluate the use of negative pressure as an adjunct to delayed soft tissue reconstruction in patients with complex lower limb trauma. MATERIAL AND METHODS: Forty-two patients with 49 complex lower limb injuries were treated with Vacuum assisted closure (VAC) 48 hours after bone fixation, vascular repair and surgical debridement. Wound swab cultures were obtained before and after every VAC application. Duration of therapy, wound flora, final reconstructive technique required, outcome and follow-up period were retrieved from medical records. RESULTS: Twenty-four male and eighteen female patients were recruited, with a mean age of 47 years. All were treated with VAC therapy for 15-42 days. Reconstruction was delayed due to the patients' critical condition, advanced age, medical co-morbidities, heavily exuding wounds and questionable viability of soft tissues. Patients were followed up for 90-895 days. Two wounds healed spontaneously, 6 were managed with delayed direct suture, 31 with split thickness skin grafts and 9 required local cutaneous, fasciocutaneous or muscular flaps. One patient died due to fat embolism. Wound bacterial flora progressively decreased in all but one patient. Scar formation was aesthetically acceptable by the patients while function depended on the initial injury. CONCLUSIONS: Negative pressure is a safe and effective adjunct to delayed soft tissue reconstruction in high-risk patients with severe lower extremity injuries, minimizing reconstructive requirements and therefore postoperative morbidity.

Simultaneous dislocation of the radial head and distal radio-ulnar joint. A case report.

Isolated dislocation of the distal radio-ulnar joint and isolated dislocation of the radial head in adults are not common injuries. A simultaneous dislocation of the radial head and distal radio-ulnar joint with no other injury seems to be extremely rare since only one report was found in the English literature. A similar case, but with some differences in presentation and treatment is reported.

Maggot infestation (myiasis) of external fixation pin sites in diabetic patients.

Diabetic patients, and especially elderly patients in a low-nutritional or immunocompromised state, are prone to a variety of opportunistic infections. 'Myiasis' is a term that refers to non-iatrogenic infestation of tissues by larvae, commonly known as maggots, of dipterous flies. Myiasis as a complication of fracture treatment by means of external fixation of long bones has not been reported. We present three diabetic patients, who suffered maggot infestation of their external fixation pin holes, and their outcome. Diabetes, immobilization, poor hygiene and low immune status are predisposing factors for developing myiasis, an extremely rare complication for external fixation of fractures.

Stress fractures in military men and bone quality related factors.

The aetiology of stress fractures is multifactorial, and many risk factors have been implicated. The aim of this study was to explore the relationship between stress fractures, factors and biochemical markers related to bone metabolism, and calcaneal stiffness index measured by quantitative ultrasound in a case control study including male military personnel beyond basic training. Thirty-two male patients with stress fractures were matched with 32 uninjured-healthy volunteers by age, height, body weight and level of physical performance. A questionnaire concerning the calcium intake, alcohol consumption and smoking was completed, the values of several biochemical markers were measured from blood samples, and calcaneal quantitative ultrasound was measured by heel ultrasound for all participants. Statistically significant higher levels of albumin (4.59 +/- 0.28 vs. 4.40 +/- 0.25, p = 0.006) and lower levels of serum osteocalcin (6.26 +/- 1.74 vs. 7.40 +/- 1.80, p = 0.012), mean values of T-scores (- 0.21 +/- 0.95 vs. 0.33 +/- 0.82, p = 0.018) and Z-scores (- 0.14 +/- 0.81 vs. 0.33 +/- 0.71, p = 0.016) were found among patients compared to controls. Based on the results, it seems that a decreased bone turnover and a low calcaneal stiffness index may be related to the incidence of stress fractures amongst male military personnel.

Post-operative pain after knee arthroscopy and related factors.

The aim of this study was to explore the intensity of post-arthroscopy knee pain during the first 24 hours, and to study the influence of pre-operative pain, tourniquet time and amount of surgical trauma on post-arthroscopy pain. In 78 male patients that underwent elective arthroscopic menisectomy or diagnostic arthroscopy of the knee, preoperative and post-operative pain were registered using the Visual Analogue Scale. Variance for repeated measures and for independent observations was analysed. Supplementary analgesia was required for 23% of the patients, more often in the recovery room and between 2 and 8 hours postoperatively. Of all factors analyzed, only time was statistically significant in determining the level of post-operative pain. Supplementary analgesia was required only in patients that underwent operative arthroscopy, and more often in patients with tourniquet time of more than 40 minutes. In conclusions, post-operative time is the most significant factor related to the post-arthroscopy knee pain.

Intramuscular haemangioma of the extensor pollicis brevis muscle with periosteal reaction of the radius: a case report and review of the literature.

We report the rare case of a histologically proven mixed-type intramuscular haemangioma, adjacent to the periosteum of the radius, that caused a periosteal reaction. We also carried out a review of the literature relevant to this case. A 28-year-old male professional drummer presented with an 8-month history of pain and swelling of the dorsal aspect of the right radius. Diagnosis was established on the basis of plain radiographs and magnetic resonance imaging, and was confirmed by histology. The lesion was treated solely by resection of the soft-tissue mass. The patient remained asymptomatic 4 years post-operatively, with no radiographic signs of recurrence. From a review of the literature, it is evident that the terminology for haemangiomas causing regional bone changes is unclear. A new classification of the intramuscular haemangiomas is proposed in order to distinguish between lesions that, according to current knowledge, exhibit radiological and clinical areas of overlap.

Factors affecting fracture healing after intramedullary nailing of the tibial diaphysis for closed and grade I open fractures.

As there is little information on the factors that influence fracture union following intramedullary nailing of the tibia we retrospectively investigated patient-, injury- and treatment-related factors in 161 patients with closed or grade I open fractures of the tibial diaphysis. The patients were reviewed until clinical and radiological evidence of union at a mean of 13.3 months (4 to 60). Multivariate statistical analysis using a Cox proportional hazards model showed that the risk of failure of union increased by 2.38 times for highly comminuted fractures, by 3.14 times when nail dynamisation was applied, and by 1.65 times when the locking screws failed. In fractures with no or only minimal comminution the risk of nonunion increased if the post-reduction gap was > or = 3 mm.

Haemangiomas around the knee mimicking medial meniscal tears. Report of two cases and review of the literature.

There are few reports in the English literature of extra-articular lesions simulating intra-articular pathology of the knee. Two cases of histologically confirmed haemangiomas related to the distal femur, presenting with knee pain suggestive of medial meniscal damage, are reported. A 27-year-old woman presented with persistent anteromedial right knee pain despite having undergone two arthroscopies for medial meniscal damage. An MRI showed a soft tissue mass on the medial side of the distal femoral metaphysis. The symptoms resolved only after open resection of the lesion. Histology showed a periosteal haemangioma. The second patient, a 24-year-old woman, complained of posteromedial left knee pain for 3 months. Although a medial meniscal tear was suspected, an MRI showed a soft tissue mass close to the bone of the distal femoral diaphysis. The symptoms resolved after open resection of the lesion. Histology showed a soft tissue haemangioma. Both patients were asymptomatic with normal MRI scans 6 to 12 months postoperatively. Although meniscal tears can present in young patients without a history of trauma, an MRI is extremely useful in diagnosing other lesions causing similar symptoms. Haemangiomas around the knee are rare, in particular periosteal haemangiomas of the distal femur as no report has been found in the English literature.

"Floating thumb metacarpal" or complete dislocation of the thumb metacarpal: a case report and review of the literature.

We present a case of a patient with a simultaneous dislocation of the metacarpophalangeal (MP) and the carpometacarpal (CMC) joint of the thumb as an isolated injury, and we review the relevant literature. We found only three previous reports in the literature, two reports as an isolated injury and another similar injury combined with a carpometacarpal fracture-dislocation of all four fingers. A closed reduction of both joints followed by an open repair of the torn ulnar collateral ligament of the MP joint and Kirschner-wire (K-wire) stabilization of the CMC joint led to a good result at 1 year. This rare injury has been described as a "complete dislocation of the thumb metacarpal" or as a "simultaneous dislocation of the MP and CMC joints of the thumb". We suggest it is a "floating thumb metacarpal".

The causes and mechanisms of meniscal injuries in the sporting and non-sporting environment in an unselected population.

The aim of this study was to establish the aetiology and circumstances of meniscal injuries in the general adult population. We studied a group of patients who underwent arthroscopy under the care of the same surgeon between 1991 and 1998 (1236 patients). The study group included 392 patients, aged 18 to 60 years, with no previous knee injury, surgery or arthritis, with normal X-rays and meniscal injuries proven at arthroscopy. No professional athletes were included in the study group. The patients with Sports injuries (mean age 33 years) accounted for 32.4% of cases. The patients with Non-sporting injuries (mean age 41 years) accounted for 38.8% of tears. 71.9% of these happened in activities of daily living (and half of this group sustained their tear by squatting or ascent from this position). Patients without identifiable injury (mean age 43 years) represented 28.8% of cases. Male:Female ratio was 4:1. Medial tears accounted for two thirds of cases. This type of study, not undertaken since the advent of MRI or arthroscopy, shows that in the general population, two thirds of meniscal tears occurred in the absence of sporting activities, frequently within the ambit of every day activities and in the absence of the classic injury mechanism. Ascent from a squat is a common mechanism of injury not widely described or emphasised.