The effect of army vest design on the occurrence of stress fractures and overuse injuries in female military recruits

INTRODUCTION

Stress fractures (SFs) occur when microdamage caused by repetitive mechanical load exceeds the biological load-bearing capacity of the bone. The study objective was to test whether a vest specifically designed and manufactured for female recruits, compared with the standard vest used on a regular basis by Border Police recruits, would reduce the incidence of SF in female Border Police recruits. Data based on reports of military personnel show that women are more likely to sustain SFs.

METHODS

A follow-up of 240 female Border Police infantry recruits, divided into two trial groups, was conducted from 2007 to 2009. Two different vests were evaluated-the standard special unit fighting vest, which was conventionally used by both men and women during basic training, and the new fighting vest, specially design for female body shape.

RESULTS

No significant difference was noted in the number of SFs between the two groups which may be attributed to increased weight of the new vest. There was a lower incidence of long bone SFs which may have been due to the superior vest design. The female Border Police Infantry recruits expressed great satisfaction with the new vest.

CONCLUSIONS

Increased effort should be invested to further reduce the weight of female combat gear, alongside efforts to improve fit and comfort.

2-Butoxyethanol model of haemolysis and disseminated thrombosis in female rats: a preliminary study of the vascular mechanism of osteoarthritis in the temporomandibular joint

Female rats develop haemolytic anaemia and disseminated thrombosis and infarction in multiple organs, including bone, when exposed to 2-butoxyethanol (BE). There is growing evidence that vascular occlusion of the subchondral bone may play a part in some cases of osteoarthritis. The subchondral bone is the main weight bearer as well as the source of the blood supply to the mandibular articular cartilage. Vascular occlusion is thought to be linked to sclerosis of the subchondral bone associated with disintegration of the articular cartilage. The aim of this study was to find out whether this model of haemolysis and disseminated thrombosis supports the vascular hypothesis of osteoarthritis. Six female rats were given BE orally for 4 consecutive days and the two control rats were given tap water alone. The rats were killed 26 days after the final dose. The mandibular condyles showed histological and radiological features consistent with osteoarthritis in three of the four experimental rats and in neither of the control rats. These results may support the need to explore the vascular mechanism of osteoarthritis further.

Biocompatibility of a polymeric implant for the treatment of osteomyelitis

We evaluated the biocompatibility of an injectable gelling polymeric device for the controlled release of gentamicin sulfate in the treatment of invasive bacterial infections in bone of male Wister rats. The biodegradable delivery carrier, poly(sebacic-co-ricinoleic-ester-anhydride), designated as p(SA:RA), was injected, with and without gentamicin, into the tibial canal. Rats were killed 3 weeks later. The tibiae were processed histologically, leaving the injectable polymer in situ. The local tissue reaction to the polymer with or without antibiotic consisted mainly of mild reactive fibroplasia/fibrosis and mild to moderate increased reactive bone formation. At this stage, no evidence for any active inflammatory response to the polymer was seen. Thus, the injection of p(SA:RA) was well tolerated and did not induce any signs of a progressive inflammatory reaction.

Bilateral femoral neck fractures in long-term steroid use for systemic lupus erythematosus and chronic lung disease

Bilateral femoral neck fractures present a rare injury. Only one report to our knowledge was not related to an acute severe traumatic event, and developed years after pelvic irradiation. Chronic steroid use may severely decrease bone strength, thus increasing the risk for such an injury. Patients with chronic lung disease and chronic inflammatory conditions are frequently treated with steroids such as prednisone at doses that may exceed 2.5 mg a day for long durations. Fractures at vulnerable sites such as the femoral neck may then follow without any severe trauma. Awareness of the detrimental effect of chronic steroid consumption on bone morphology, and familiarity with treatment alternatives to improve bone mass is important to prevent such a severe injury. We describe two cases of bilateral femoral neck fractures in women who were treated for years with orally administered prednisone. The rarity of such an injury of bilateral hip fractures and the fact that neither of the patients sustained major trauma, strongly suggests that both cases were related to impaired bone metabolism due to the effect of prolonged steroid consumption. The biological effects of different roots of steroid administration on bone turnover, as well as several strategies that can be implemented by clinicians to treat and prevent steroid induced osteoporosis and fractures, are further clarified in this article.

A prospective biomechanical study of the association between foot pronation and the incidence of anterior knee pain among military recruits

Excessive foot pronation has been considered to be related to anterior knee pain. We undertook a prospective study to test the hypothesis that exertional anterior knee pain is related to the static and dynamic parameters of foot pronation. Two weeks before beginning basic training lasting for 14 weeks, 473 infantry recruits were enrolled into the study and underwent two-dimensional measurement of their subtalar joint displacement angle during walking on a treadmill.

Of the 405 soldiers who finished the training 61 (15%) developed exertional anterior knee pain. No consistent association was found between the incidence of anterior knee pain and any of the parameters of foot pronation. While a statistically significant association was found between anterior knee pain and pronation velocity (left foot, p = 0.05; right foot, p = 0.007), the relationship was contradictory for the right and left foot. Our study does not support the hypothesis that anterior knee pain is related to excessive foot pronation.

The effect of insoles on the incidence and severity of low back pain among workers whose job involves long-distance walking

The prevalence and incidence of low back pain in general society is high. Workers whose job involves walking long distances have an even higher tendency to suffer from low back pain. A positive effect of insoles in reducing low back pain was found in professional sports players. This was not examined on people whose job involves walking long distances. In this double blind prospective study we examined the effectiveness of insoles constructed in a computerized method to placebo insoles in 58 employees whose work entailed extensive walking and who suffered from low back pain. The evaluation was performed by the MILLION questionnaire, which is considered as a valid questionnaire for evaluation of low back pain. We calculated the differences of the pain intensity before and after the intervention, in the employees using the insoles manufactured by computer in comparison to the users of the placebo insoles. In each group, the analysis was performed in comparison to the baseline. A total of 81% of the employees preferred the real insoles as effective and comfortable in comparison to 19% of the users of the placebo insoles (P<0.05). The results of this study indicate a substantial improvement in the low back pain after the use of the true insoles. The average pain intensity according to the MILLION questionnaire before the use of the insoles was 5.46. However, after the use of the real insoles and the placebo insoles, the average pain intensity decreased to 3.96 and 5.11, respectively. The difference of the average pain intensity at the start of the study and after the use of the real insoles was significant: -1.49 (P=0.0001), whereas this difference after the use of the placebo insoles was not significant: -0.31 (P=0.1189). The reported severity of pain also decreased significantly: a level 5 pain and above was reported by 77% of the subjects at the start of the study. After the use of the real insoles only 37.9% of the subjects reported a similar degree of pain severity, and 50% of the subjects did so after the use of the placebo insoles (P< 0.05). We did not find a link between low back pain and other variables such as gender, age, number of offspring, work seniority, smoking, previous use of insoles and previous medication. This study demonstrates that the low back pain decreased significantly after the use of real insoles compared to placebo ones.

Histopathologic changes in dental and oral soft tissues in 2-butoxyethanol-induced hemolysis and thrombosis in rats*

BACKGROUND

2-Butoxyethanol (2-BE; ethylene glycol monobutyl ether) is extensively used as a solvent in surface coatings, such as lacquers, enamels, and varnishes in industrial and household cleaning products. Its major toxicity is manifested in the circulation, as it induces hemolytic anemia and thrombosis in various organs. While 2-BE has been implicated in the induction of anemia in different species, the rat has proven most sensitive, especially the female of this species. The purpose of this study was to document the effects of 2-BE on dentition, the periodontal ligament, the tongue, the salivary glands, and the oral mucosa in male and female Fischer 344 rats.

METHODS

The experiment included 40 rats divided into five groups. Four groups were exposed to 2, 3, or 4 daily doses of 2-BE, and a fifth group served as control. The rats were killed on days 2, 3, 4, and 29. The teeth and soft oral tissues were prepared for histopathologic observation.

RESULTS

The histopathologic analysis showed that the major effect of 2-BE was exerted on the odontoblasts of the incisors and on molars, with greater effect on the incisors. Foci of damaged muscle cells in the tongue were also observed. The blood vessels were dilated and congested, and a primary thrombosis was seen in the dental pulp.

CONCLUSIONS

The results of this study revealed a resemblance between the dental injuries in this rat model and those seen in sickle cell anemia in humans. This 2-BE animal model holds potential to assist in the discovery of preventive measures and/or treatment for dental injuries that occur in human diseases with hemolytic anemia.

Operative treatment for hip fractures in patients 100 years of age and older: is it justified?

OBJECTIVES

To evaluate a unique group of elderly patients over 100 years of age who had hip fractures.

DESIGN

Retrospective database analysis.

SETTINGS

Academic teaching hospital.

PATIENTS

All patients who had hip fractures between January 1990 and December 2001 and were over 100 years old were included.

INTERVENTION

In this study, we evaluated the age, gender, type of fracture, type of treatment, background disease, rehabilitation, and time until death of all patients over 100 years, whether treated operatively or nonoperatively.

RESULTS

Twenty-three patients (17 females and 6 males) were identified with ages ranging from 100 to 107 (mean: 101.8). The group had 4 subcapital and 19 pertrochanteric fractures and between 1 and 4 major background diseases. Four patients were treated nonoperatively (1 due to major pneumonia and 3 refused the operative procedure). Three of those 4 patients died in the same month of admission, and 1 patient died during the second month. Among the 19 patients who underwent operation, 17 patients have died, living between 0 and 78 months (mean: 13.8) postoperatively. Two are still alive (21 and 45 months) after the operation. Eight patients died prior to 6 months, and 11 lived more than a year after the operation. A comparison between these 2 groups showed greater major background disease in the patients who died prior to 6 months (P < 0.05).

CONCLUSIONS

Most hip fractures in patients over 100 years of age are pertrochanteric. Patients with 2 or more major background diseases have an increased risk for dying in the first 6 months after the operation. Most patients having operations in this age group had a postoperative reduction in mobility status and in performing basic activities of daily living.

Rehabilitation after knee immobilization in octogenarians with patellar fractures

Between January 1990 and December 1999, 14 octogenarians (8 women and 6 men) underwent surgery for comminuted patellar fracture. Average patient age was 83 years (range: 80-88 years). Follow-up ranged from 1-8 years (mean: 3.5 years). Ten of 14 patients were totally independent, whereas 4 patients used a cane for mobilization. Twelve patients had background diseases. Patients underwent operative treatment with tension band wires followed by cast immobilization (knee in approximately 10 degrees of flexion) for 6 weeks. Immediate full weight bearing was initiated in all patients, and intense rehabilitation was performed after cast removal to increase range of motion. Complete union was noted for all fractures. All patients but 1 had an active extension lag of 10 degrees-20 degrees before physiotherapy and maximum flexion was 70 degrees. After physiotherapy, 4 patients regained full active extension and all patients achieved >100 degrees of flexion. Twelve of 14 patients returned to their pre-injury functional level. A slight deterioration was noted in 2 patients. Although knee immobilization may cause severe limitation in range of motion, its use in elderly patients followed by intense rehabilitation is advocated and showed good results.

Osteonecrosis in a chemically induced rat model of human hemolytic disorders associated with thrombosis--a new model for avascular necrosis of bone

Bone injury occurs in human hemolytic disorders associated with thrombosis, such as beta-thalassemia and sickle cell disease. Exposure of rats to 2-butoxyethanol (BE) has been associated with hemolytic anemia, disseminated thrombosis, and infarction in multiple organs including bone. This rat model apparently mimics acute hemolysis and thrombosis in humans. To elucidate the extent of bone injury, male and female Fischer F344 rats were given 4 daily doses of 250 mg BE/5 ml water/kg of body weight. Tail vertebrae were studied by histopathology and magnetic resonance imaging (MRI). Thrombosis and infarction were seen in both sexes, but females were more severely affected. Lesions were characterized by extensive medullary fat necrosis, granulomatous inflammation, fibroplasia, growth plate degeneration, and new woven bone formation adjacent to necrotic bone trabeculae. MRI mean and standard deviation tissue-density data for both sexes indicated a significant (P < or = 0.05) decrease following 4-days treatment and a significant increase (P < or = 0.05) following an additional 24 days without treatment. Thus, MRI was useful in revealing BE-induced bone injury, which was predominantly necrotic initially and subsequently regenerative with proliferation of connective tissue and bone following postischemia recovery.

Dynamic force distribution during level walking under the feet of patients with chronic ankle instability

OBJECTIVES

To examine changes in the pattern of force transfer between the foot and the floor associated with chronically sprained ankles by measuring the peak forces and their timing under several regions of the feet during level walking.

METHODS

Twelve young male subjects (mean (SD) age 21 (2) years) with recurrent ankle sprains were studied. Seven of them had unilateral and bilateral chronic instability and laxity, and five had bilateral instability. Twelve healthy men (without orthopaedic or medical disease) served as a control group. Subjects walked at their own pace along a 7 m walkway, which included a Mini-EMED pressure distribution measuring system. The variables measured were relative peak force (fraction of body weight) and relative timing (fraction of stance time). These variables were measured under six regions of interest in each foot print: heel, midfoot, medial, central, and lateral forefoot, and toes.

RESULTS

(a) A significant delay to the time of peak force under the central and lateral forefoot and toes in subjects with chronic ankle instability. (b) A significant decrease in the relative forces under the heel and toes and an increase in the relative forces under the midfoot and lateral forefoot in subjects with chronic ankle instability. (c) In the patients with unilateral instability, there were no significant differences in any of the variables between the injured and non-injured foot.

CONCLUSIONS

In patients with chronic ankle instability, there is a slowing down of weight transfer from heel strike to toe off, a reduced impact at the beginning and end of the stance phase, and a lateral shift of body weight.

Subtalar distraction arthrodesis using a ramp cage

Subtalar distraction bone block arthrodesis has been described to treat late complications of displaced calcaneal fractures. A "ramp cage" can be used to restore the talocalcaneal relationship by providing stable correction in the coronal and sagittal dimensions.

Simultaneous distal radius and hip fractures in elderly patients--implications to rehabilitation

PURPOSE

The reasons for fractures in the elderly patients are multifactorial. Osteoporosis is considered to be the main pathology. Other reasons are the increase in fall frequency and the protective response to trauma. The most common sites at which these fractures occur are the hip, vertebra and distal radius. A combination of these is uncommon.

METHODS

All patients who were treated between January 1990 and December 2000 with a combination of distal radius and hip fractures and were older than 65-years were retrospectively evaluated. The following parameters were evaluated: age; sex; pre fall function; use of drugs; chronic and acute comorbidity; circumstance of the fall; hospitalization length of stay; treatment procedure; complications; and post-hospitalization rehabilitation.

RESULTS

Forty-six patients met the study's criteria. Group I consisted of 16 patients between 65-80 years, and group II consisted of the remaining 30 patients older than 80 years. All patients suffered low energy trauma. Ten out of the 16 patients in group I, and eight out of the 30 patients in group II were totally independent, while the remaining patients needed some help with activity of daily living (ADL). In all patients the simultaneous fractures were ipsilaterally. For 45 patients hospital stay ranged from 5-23 days. Twenty-eight patients were transferred to a geriatric rehabilitation centre. Twenty-six of them returned to their previous ADL after a period of 60 days on average. Among the 18 remaining patients, 11 gained full recovery (6 from group I and 5 from group II) and seven patients (5 from group II) had a slight reduction in ADL.

CONCLUSIONS

A combination of these fractures is probably more traumatic and occurs in the higher-age group. It is always located in the ipsilateral side. The double trauma represents a better pre-morbid condition relative to patients in the same age group, and thus it may serve as a prognostic indicator for success in rehabilitation.

[Scales for evaluation of the geriatric patient with hip fracture during the acute and rehabilitation phases]

The elderly population is increasing in the modern world. Societies in general and medical personnel are facing new ethical and medical dilemmas when treating extremely old patients. Many factors are known to cause fractures in elderly patients. Probably, the most important one is osteoporosis, which was shown to be the main pathology in elderly patients who fractured their hips. The increase in fall frequency, orientation to falls and the protective response to trauma were found to play a role in the pathogenesis as well. The rehabilitation of this group of patients is an important factor that helps to return the elderly patient to his or her own environment and to his or her skills prior to the falls. The decision of the potential for rehabilitation and the evaluation of the progress that the elderly does is very difficult and can vary substantially from one examiner to another. Reviewing the literature that exists on the evaluation of the geriatric patient with hip fracture during the acute and rehabilitation phases is our goal.

The use of surgery and yttrium 90 in the management of extensive and diffuse pigmented villonodular synovitis of large joints

OBJECTIVE

The surgical treatment of extensive diffuse pigmented villonodular synovitis (PVNS) of large joints alone is unsatisfactory, with high rates of local recurrence. Post-synovectomy adjuvant treatment with external beam radiation therapy or intra-articular injection of yttrium 90 (90Y) yielded better results. We report our experience with 10 cases treated with debulking surgery followed by intra-articular injection of 90Y.

PATIENTS AND METHODS

Between January 1989 and June 1998, 10 patients (eight males and two females aged 15-49 yr) with extensive diffuse PVNS were treated. In six patients the knee joint, in three patients the ankle joint, and in one patient the hip joint were involved. The 10 patients underwent 15 operations, one patient had three surgical procedures, and three patients underwent two surgeries (the intervals between re-operations for local recurrence were 2-4 yr). All patients had an intra-articular injection of 15-25 mCi (555-925 MBq) 90Y, 6-8 weeks after the last surgery.

RESULTS

Mean follow-up time was 6 yr (range 2.5-12 yr). All patients were followed using repeated computerized tomography (CT) scans, magnetic resonance imaging (MRI), plain X-ray films and bone scans semi-annually. In nine patients, neither evidence of disease nor progression of bone or articular destruction were noted. In one patient, stabilization of disease was achieved with no further evidence of bony or articular damage. No complications were noticed after surgery or after the intra-articular 90Y injection.

CONCLUSION

A combination of debulking surgery with intra-articular injection of 90Y for extensive diffuse PVNS of major joints is a reliable treatment method, with good results.

Surgical treatment of lumbar spinal stenosis in patients aged 65 years and older

Spinal stenosis syndrome affects mainly patients at their 5th-6th decades of life. The main goals of surgical treatment in the elderly are to allow the individual to walk longer distances, maintain the activities of daily living (ADL) and social life. Our aim was to evaluate the results of surgical treatment for lumbar spinal stenosis in elderly patients. All patients over 65 years of age who underwent surgery due to spinal stenosis syndrome between 1990 and 1998 were evaluated. There were 29 males and 17 females aged between 65 and 90 years. The clinical presentation included low back pain (89%), intermittent claudication (100%) and neurological involvement (87%). The radiological examination showed a frequent narrowing at the level L4-L5 in 93.5% of the patients. The results of the surgery in a mean follow-up of 22 months were good to excellent in 80% of the patients, fair in 11%, and poor in 9%. An improvement in the intensity of pain and in walking distances was noted in 89 and 85% of the patients, respectively. Improvement was achieved in the level of daily activity and in social lives in 57 and 61%, respectively. Major and minor complication rates were 6.5 and 19.5%, respectively. No mortality was noted in this series. Eighty-seven percent of the patients were satisfied with the results of the surgery. We conclude that Surgery for spinal stenosis is a successful and relatively safe procedure, also for patients aged over 65, and should be considered as a treatment option for these patients.

Stress fractures of the medial malleolus--review of the literature and report of a 15-year-old elite gymnast

Stress fracture of the medial malleolus is rare and not reported in children. We report a case of a 15-year-old elite gymnast with open physes sustaining a medial malleolar stress fracture. The patient was treated initially by rest and gradually returned to sport with full recovery. Two months later she developed a complete fracture of the medial malleolus of the same side. This was treated surgically by open reduction and internal fixation with a cancellous screw and soon after the operation she returned to full activities. Emphasis is given to the suspected mechanism which led to this unique fracture and to the hormonal aspects in the professional adolescent gymnast. We recommend surgical treatment of stress fracture of the medial malleolus especially for elite athletes, leading to early recovery and return to sports activities.

Deep skin slough following skin traction for hip fractures

INTRODUCTION

Elderly patients who fracture their hips are susceptible to complications associated with bed rest before surgery. In some institutions a skin traction device is used in order to relieve pain before surgery. The authors followed ten patients who developed severe (deep) skin slough and evaluated the relationship to the skin traction device. The need for use of a skin traction device is debated and the need for multidisciplinary treatment if this complication develops is emphasised.

PATIENTS AND METHODS

All patients who had serious skin slough between January and December 2000 were evaluated. A serious skin slough was defined as any new and abrupt case of a full-thickness skin loss involving damage or necrosis of subcutaneous tissue, but not through the underlying fascia and not extending to underlying bone, tendon or joint capsule. Preoperative assessment including background illness and medications, the application of a skin traction device, the type of surgery that was performed, and complications were noted.

RESULTS

Ten patients (nine females and one male) aged 76-90 years met the criteria of serious skin slough. The leading chronic illness was cardiovascular. Among these patients there were intertrochanteric fractures (n = 5), subcapital fractures (n = 4) and a subtrochanteric fracture (n = 1). In all patients a skin traction device was used. In seven out of the ten patients the skin slough occurred during or immediately after surgery. Other postoperative complications included uncontrolled glucose levels (> 130 mg/dl during fasting) (two cases) and urinary tract infections (two cases). The skin slough was treated with a daily wound care regimen by a trained nurse and included daily changing of wet dressings and application of Vaseline gauze. All patients were allowed immediate ambulation after the surgery and were discharged 9-15 days after the surgery. Although improvement of the slough was noted in all patients, none of them had fully recovered, and they had to continue treatment in outpatient clinics.

DISCUSSION

The main goal of treatment in elderly patients who fractured their hips is to return them to their previous activities of daily living. A skin traction device, although useful for many of the patients, has the disadvantage of causing serious skin slough. This complication can interfere with the normal curve of rehabilitation and cause prolonged hospital stay. Whenever this complication is expected, the application of the skin traction device should be avoided. Moreover, careful handling of the patients by physicians, physiotherapists and nurses is mandatory. If this complication develops, vigorous multidisciplinary care is recommended.

A combined intracapsular and extracapsular fracture of the hip

We report a case of an unusual hip fracture that involved the intracapsular area and continued vertically to the extracapsular region below the trochanteric line. The division between these two types of fractures is based on the anatomical site, the blood supply and the mechanical forces that act on the hip. This division is important and influences the different surgical techniques to treat these individual fractures. Femoral neck fractures (intracapsular), particularly those with displacement, can disrupt the blood supply to the femoral head and may be associated with an increased incidence of complications, especially non-union and avascular necrosis (AVN) of the femoral head. These fractures are usually treated either by reduction and fixation, or by hemiarthroplasty. Non-union and avascular necrosis following extracapsular fractures are rare. Treatment involves reduction of the fracture and insertion of a dynamic hip screw. The combination of these two types of fractures is extremely rare and creates a surgical problem without any optimal solution. The focus of this case report is placed on the mechanical axis and weight-bearing forces that play a role in the hip and on the optional surgical techniques in such a rare type of fracture in an elderly osteoporotic patient. (Hip International 2002; 1: 43-6).

Principles of first metatarsal osteotomies

Summarizing all the data while choosing the suitable procedure for hallux valgus deformity leads to classification of 3 main categories, which are based on the intermetatarsal angle (Table 1). Mild deformity has less than 15 degrees intermetatarsal angle, intermediate deformity has 15 degrees to 20 degrees intermetatarsal angle, and severe deformity has more than 20 degrees [table: see text] intermetatarsal angle. Every category may be divided further into low degree of DMAA (8 degrees) or high degree of DMAA (> 15 degrees). When choosing the correct procedure, the length of the first metatarsal has to be considered. In short first metatarsals, base angular osteotomies lead to further shortening of the metatarsal. Displacement osteotomies are preferred. In mild deformity, a distal osteotomy can be performed. If a mild deformity has a high DMAA, it can be corrected by a distal rotated chevron osteotomy. Intermediate deformity with a normal DMAA can be corrected by displacement osteotomies, and high DMAA can be corrected by rotated scarf of double osteotomy, which includes a base osteotomy to correct the intermetatarsal angle and a distal osteotomy, such as Riverdin, to correct the DMAA. Severe deformity can be corrected only by angular osteotomies. Inherently, these osteotomies increase the DMAA; they can be performed only in normal DMAA. Only a base angular osteotomy and distal rotation osteotomy can correct high levels of DMAA in severe intermetatarsal angles.

The effect of shoe sole composition on in vivo tibial strains during walking

To test the hypothesis that shoe sole composition can affect the level of bone strain and strain rates that contribute to the development of stress fractures, in vivo tibial strain measurements were made during treadmill walking while wearing four shoes which differed only in their sole composition. Soles of 65 Shore A polyurethane with an embedded heel air cell had significantly lower compression and shear strains and shear strain rates than soles of 65, 75 and a composite of 40/65 Shore A polyurethane with no embedded air cells. A sole composed of 65 Shore A polyurethane with an embedded air cell can potentially be protective against stress fracture in a walking shoe.

Hemolytic anemia, thrombosis, and infarction in male and female F344 rats following gavage exposure to 2-butoxyethanol

2-butoxyethanol (BE; ethylene glycol monobutyl ether) is used extensively in the manufacture of a wide range of domestic and industrial products which may result in human exposure and toxicity. BE causes severe hemolytic anemia in male and female rats and mice. In a recent report, female F344 rats exposed to 500 ppm BE by inhalation and sacrificed moribund on day 4 of treatment exhibited disseminated thrombosis associated with infarction in several organs. In contrast, no such lesions were observed in male rats similarly exposed to BE. Additional studies were therefore undertaken to compare the effects of BE in rats of both sexes. Rats received 250 mg BE/kg/day by gavage for 1, 2 or 3 days and were sacrificed 24 or 48 hr after the last dose. Control rats received 5 ml/kg water. Progressive time-dependent hemolytic anemia--macrocytic, hypochromic, and regenerative--was observed in both sexes of rats exposed to BE. Additionally, BE caused significant morphological changes in erythrocytes, first observed 24 hr after a single dose, including stomatocytosis, macrocytosis with moderate rouleaux formation, and spherocytosis. These morphological changes became progressively more severe as BE dosing continued and included the occasional occurrence of schistocytes and ghost cells, rouleaux formation in rats of both sexes, and an increased number of red blood cells with micronuclei in female rats. Overall, the progression of hemolytic anemia and morphological changes as a function of the number of days of exposure varied with gender and suggested a faster onset of hemolysis in female rats. The range of BE-related histopathological changes noted in both sexes was comparable; however, while these lesions were observed in female rats following a single dose, similar effects were first observed in males after 3 consecutive days of exposure to BE. Pathological changes involved disseminated thrombosis in the lungs, nasal submucosa, eyes, liver, heart, bones and teeth, with evidence of infarction in the heart, eyes, teeth and bones. Hemoglobinuric nephrosis and splenic extramedullary hematopoiesis were also noted. An apparent correlation between the severity of hemolytic anemia and subsequent disseminated thrombosis in BE-treated rats is proposed. Thrombosis may be related to intravascular hemolysis, which could be triggered by procoagulant release and/or alterations in erythrocyte morphology, as well as increased rigidity.

Continuous intra-articular patient-controlled analgesia in a cancer patient with a pathological hip fracture. A case report

Pain management is one of the major goals to achieve in treating terminal patients. Managing severe pain with drug therapy by using a combination of narcotics, non-narcotics, and adjuvant drugs provides the best results for most patients. In patients with fractures due to bone metastases there is a relative indication for operative treatment if the patient is expected to survive the operation and to recover in the postoperative period. In this case report a terminal 48 year-old female with a pathological femoral neck fracture is presented. No operative treatment was offered because of her bad general status. Pain control was maintained by continuous administration of local analgesics directly into the intra-articular femoral space, through a system of patient-controlled analgesia (PCA). The visual-analogue pain scale (VAS), which was maximal before beginning of this treatment, was markedly reduced during the treatment, and was again elevated to maximum after the intra-articular catheter was removed. Although continuous regional analgesia to a fractured bone which involves the joint is not a generally acceptable method and carries some risks it has a role in a selected group of patients.

The contribution of the medial calcaneal osteotomy to the correction of flatfoot deformities

HYPOTHESES/PURPOSE

The success of the medial displacement calcaneal osteotomy in correcting flatfoot deformities is likely to be the result of a shift of the Achilles tendon forces on the hindfoot. The purpose of this study was twofold: 1) to define the contribution of the Achilles tendon to the flatfoot deformity, and 2) to define the effect of a calcaneal medial displacement osteotomy.

METHODS

We used six different experimental dynamic stages: 1) intact foot without Achilles loading; 2) intact foot with Achilles loading; 3) flatfoot without medial calcaneal displacement osteotomy and without Achilles loading; 4) flatfoot without medial calcaneal displacement osteotomy but with Achilles loading; 5) flatfoot with medial calcaneal displacement osteotomy but without Achilles loading; and 6) flatfoot with medial calcaneal displacement osteotomy and with Achilles loading. The experimental flaffoot was developed by releasing the posterior tibial tendon, spring ligament, and plantar fascia and applying 7,000 cycles of axial fatigue load (range, 700 to 1,400 N; 1-Hz frequency). To simulate the phase of midstance, the peroneus longus, peroneus brevis, flexor digitorum longus, and flexor hallucis longus tendons were grasped by clamps, connected to pneumatic actuators, and loaded with precalculated forces. Anteroposterior and lateral radiographs were obtained for each stage on which the following measurements were made: talonavicular coverage angle, talar-first metatarsal angle, talocalcaneal angle, and height of the medial cuneiform. These measurements were compared with a one-way ANOVA.

RESULTS

Between stages 1 and 2, all measurements were statistically insignificant. Between stages 3 and 4, for all measurements, Achilles tendon loading aggravated the flatfoot deformity (p < 0.05). After medial calcaneal osteotomy (stages 5 and 6), the Achilles tendon contributed less to the arch-flattening. We found that the medial displacement osteotomy plays an important role in reducing and/or delaying the progress of flatfoot deformity.

CONCLUSIONS/SIGNIFICANCE

In the flatfoot, loading of the Achilles tendon increases the deformity. Medial calcaneal osteotomy significantly decreases the arch-flattening effect of this tendon and therefore limits the potential increase of the deformity.

Experimental flatfoot model: the contribution of dynamic loading

The goal of this study was to determine if the application of muscle forces (simulating the dynamic phase of the midstance part of gait) had an effect on flatfoot deformity. We created a flatfoot model in each of seven cadaver foot specimens by grasping the Achilles, peroneus longus, peroneus brevis, flexor digitorum longus, and flexor hallucis longus tendons with soft-tissue vice clamps connected via wire cables to pneumatic cylinders. The experiment included four stages: 1) initial static axial loading; 2) axial loading after 3,000 load cycles (average, 735 N; range, 70 to 1400 N); 3) axial loading after releasing the spring ligament and plantar fascia; and 4) axial loading after an additional 3,000 load cycles. At each stage, both static (with axial loading only) and dynamic (axial loading with tensioning of the tendons to simulate the muscle forces at midstance) conditions were evaluated radiographically. No change was observed between the static and dynamic conditions in the first two phases of the experiment. After the third phase, changes in the talar-first metatarsal angle and the height of the medial cuneiform were noted, particularly in the dynamic condition. These and additional radiographic changes were magnified in the fourth phase, but only in the dynamic condition. We concluded that, to create an effective flatfoot model, the medial structures, including the spring ligament and possibly the plantar fascia, must be severed. Cyclic loading of the foot further increased the arch flattening, and this effect was magnified by dynamic loading.

Dorsiflexion contracture after the Weil osteotomy: results of cadaver study and three-dimensional analysis

For metatarsalgia caused by a dislocated lesser metatarsophalangeal (MTP) joint and isolated over-long lesser metatarsals, surgical treatment options without sacrificing the joint are limited. Recently, the Weil osteotomy has been advocated for the treatment of this deformity. In our experience, preliminary results with this technique have revealed a high rate of dorsiflexion contracture of the MTP joints at follow-up. We performed a cadaver study and a three-dimensional analysis on sawbones to investigate this phenomenon. In the cadaveric portion of this study, the second MTP joints of two fresh-frozen cadavers were dissected; the entire ray, with the metatarsal shaft, MTP joint, toe, and plantar fascia, was removed en bloc. After gross anatomic structures were photographed, a Weil osteotomy was performed at 25 degrees relative to the long axis of the metatarsal shaft. The positions of muscles, ligaments, and tendons were noted and photographed before and after the osteotomy. In the sawbones portion of this study, a Weil osteotomy was performed at four different angles (25 degrees, 30 degrees, 35 degrees, and 40 degrees) relative to the long axis of the metatarsal. To ensure reproducibility, the sawbone models were fixed proximally to a vertical milling machine with the second metatarsals inclined 15 degrees to simulate the anatomic position. After making the cut, the plantar fragment was translated along the dorsal fragment proximally for a distance of 5 mm. Before and after the osteotomy, selected x, y, and z coordinates were obtained using a Microscribe 3D digitizer. Data analysis was performed with Microsoft Excel, and ANOVA was used to determine significant differences (p < 0.05) between the various osteotomies. Analysis of the cadaver dissection revealed that after the Weil osteotomy, the tendons of the interosseous muscles move dorsally with respect to the axis of the MTP joint due to the depression of the plantar fragment of the metatarsal. The loss of their flexion effect on the joint permits the pull of the extensor to dorsiflex the toe. The size of the depression for the various osteotomies averaged: 25 degrees osteotomy, 3.03 mm (range, 1.8 to 3.8 mm); 30 degrees osteotomy, 3.2 mm (range, 1.9 to 4.0 mm); 35 degrees osteotomy, 3.5 mm (range, 1.7 to 5.7 mm); and 40 degrees osteotomy, 4.2 mm (range, 2.8 to 6.4 mm). Amounts of shortening relative to the long axis of the metatarsal for the various osteotomies averaged: 25 degrees osteotomy, 5.03 mm (range, 4.77 to 5.30 mm); 30 degrees osteotomy, 4.59 mm (range, 3.47 to 5.19 mm); 35 degrees osteotomy, 4.27 mm (range, 2.87 to 5.00 mm); and 40 degrees osteotomy, 3.65 mm (range, 3.20 to 4.31 mm). According to our analysis, depression of the plantar fragment always occurs after a Weil osteotomy. This depression changes the center of rotation of the MTP joint, and the interosseous muscles then act more as dorsiflexors than as plantarfexors.

Fractures of the lateral process of the talus in children

Fractures of the lateral process of the talus are an uncommon injury, which are often misdiagnosed as severe ankle sprain. This error may result in inappropriate treatment of an intraarticular fracture, with subsequent posttraumatic arthrosis. To date, only one fracture of a lateral talar process has been reported in a child, in whom delayed diagnosis and initial mismanagement led to a suboptimal result. The sport of 'snowboarding', which is gaining in popularity, has been significantly associated with fractures of the lateral talar process, leading some authors to dub this fracture 'Snowboarder's Fracture'. This and the ever-increasing incidence of major trauma lead us to believe that this fracture will be encountered more frequently, even in the pediatric population, as the two factors mentioned do not pass over this group. We report lateral talar process fractures in two children: one in a 9-year-old girl and one in an 11-year-old boy, the latter associated with talar neck and body fractures. Timely diagnosis enabled prompt open reduction and internal fixation, preventing subtalar arthrosis. We discuss the pertinent anatomy and mechanism, and present the clinical picture, imaging studies and treatment. Two important points are exemplified by these cases. First, this fracture, although rare, does occur in children, and should be sought in appropriate settings. Second, despite the severe talar injury in the 11 year old, early diagnosis and intervention conserved foot function.

Spondylolysis as a cause of low back pain in swimmers

Low back pain (LBP) has recently become a common complaint in swimmers. The differential diagnosis of LBP in swimmers includes muscle and ligament sprains, Scheuerman disease, herniated disc, facet joint injury, tumors, infections, and spondylolysis. Although spondylolysis or listhesis is a frequent injury in the athlete, mainly in weightlifters, wrestlers, gymnasts, divers and ballet dancers, it is infrequently reported in swimmers. We have recently encountered four adolescent elite swimmers who complained of low back pain and were diagnosed as having spondylolysis. Three of the patients were either breast-strokers or butterfly swimmers. Plain radiography demonstrated the lesion in two patients. Increased uptake in bone scan was noted in all patients. CT was performed only in two patients and revealed the lesion in both. One patient was diagnosed within two weeks, and the diagnosis in the others was deferred for 2-7 months. The patients were treated successfully by reducing the intensity of their training program and the use of a corset for at least three months. Repeated hyperextension is one of the mechanisms for spondylolysis in athletes as is the case in breast-strokers and butterfly style swimmers. LBP in swimmers should raise the suspicion of spondylolysis. Plain radiography and bone scan should be performed followed by SPEC views, CT, or MRI as indicated. If the case is of acute onset as verified by bone scan, a Boston or similar brace should be used for 3 to 6 months in conjunction with activity modification and optional physical therapy. Multidisciplinary awareness of low back pain in swimmers, which includes trainers, sport medicine physicians, and physical therapists, should lead to early diagnosis and appropriate treatment.

Do high impact exercises produce higher tibial strains than running?

BACKGROUND

Bone must have sufficient strength to withstand both instantaneous forces and lower repetitive forces. Repetitive loading, especially when bone strain and/or strain rates are high, can create microdamage and result in stress fracture

AIM

To measure in vivo strains and strain rates in human tibia during high impact and moderate impact exercises.

METHODS

Three strain gauged bone staples were mounted percutaneously in a rosette pattern in the mid diaphysis of the medial tibia in six normal subjects, and in vivo tibial strains were measured during running at 17 km/h and drop jumping from heights of 26, 39, and 52 cm.

RESULTS

Complete data for all three drop jumps were obtained for four of the six subjects. No statistically significant differences were found in compression, tension, or shear strains with increasing drop jump height, but, at the 52 cm height, shear strain rate was reduced by one third (p = 0.03). No relation was found between peak compression strain and calculated drop jump energy, indicating that subjects were able to dissipate part of the potential energy of successively higher drop jumps by increasing the range of motion of their knee and ankle joints and not transmitting the energy to their tibia. No statistically significant differences were found between the principal strains during running and drop jumping from 52 cm, but compression (p = 0.01) and tension (p = 0.004) strain rates were significantly higher during running.

CONCLUSIONS

High impact exercises, as represented by drop jumping in this experiment, do not cause higher tibial strains and strain rates than running and therefore are unlikely to place an athlete who is accustomed to fast running at higher risk for bone fatigue.

In-vivo strain measurements to evaluate the strengthening potential of exercises on the tibial bone

Mechanical loading during physical activity produces strains within bones. It is thought that these forces provide the stimulus for the adaptation of bone. Tibial strains and rates of strain were measured in vivo in six subjects during running, stationary bicycling, leg presses and stepping and were compared with those of walking, an activity which has been found to have only a minimal effect on bone mass. Running had a statistically significant higher principal tension, compression and shear strain and strain rates than walking. Stationary bicycling had significantly lower tension and shear strains than walking. If bone strains and/or strain rates higher than walking are needed for tibial bone strengthening, then running is an effective strengthening exercise for tibial bone.

In vivo strain measurements to evaluate the strengthening potential of exercises on the tibial bone

Mechanical loading during physical activity produces strains within bones. It is thought that these forces provide the stimulus for the adaptation of bone. Tibial strains and rates of strain were measured in vivo in six subjects during running, stationary bicycling, leg presses and stepping and were compared with those of walking, an activity which has been found to have only a minimal effect on bone mass.

Running had a statistically significant higher principal tension, compression and shear strain and strain rates than walking. Stationary bicycling had significantly lower tension and shear strains than walking. If bone strains and/or strain rates higher than walking are needed for tibial bone strengthening, then running is an effective strengthening exercise for tibial bone.

Using bone's adaptation ability to lower the incidence of stress fractures

In three prospective epidemiologic studies of the effect of pre-military-induction sport activities on the incidence of lower extremity stress fractures during infantry basic training, recruits who played ball sports (principally basketball) regularly for at least 2 years before basic training had a significantly lower incidence of stress fractures (13.2%, 16.7%, and 3.6% in the three studies, respectively) than recruits who did not play ball sports (28.9%, 27%, and 18.8%, respectively). Preinduction running was not related to the incidence of stress fracture. To assess the tibial strain environment during these sport activities, we made in vivo strain measurements on three male volunteers from the research team. Peak tibial compression and tension strain and strain rates during basketball reached levels 2 to 5.5 times higher than during walking and about 10% to 50% higher than during running. The high bone strain and strain rates that occurred in recruits while playing basketball in the years before military induction may have increased their bone stiffness, according to Wolff's Law. The stiffer bone could tolerate higher stresses better, resulting in lower strains for a given activity and a lower incidence of stress fractures during basic training.

'Epiphyseal dysgenesis' in Laurence-Moon-Biedl-Bardet syndrome

Ten patients with Laurence-Moon-Biedl-Bardet syndrome were investigated. They all belonged to one large family within which several intermarriages had taken place. We found that, apart from the already described abnormalities, these patients suffered from dysgenesis of the following epiphyses: vertebrae, proximal femur, proximal tibia, capitellum, tarsal navicular, and the distal epiphysis of the first metatarsal. The degree of polydactyly, a prominent feature of this syndrome, varied from patient to patient, ranging from a wide fifth metatarsal or metacarpal to a complete sixth digit. As in other epiphyseal dysgenesis, a pseudoepiphysis of the distal first metacarpal was present. One patient (the eldest) was tetraparetic due to severe spinal stenosis.

Fracture of the posterior body of the talus--the hidden fracture

Fractures of the entire posterior process of the talus are rare and may be easily missed. Both the ankle joint and the subtalar joint are involved. This leads to malunion and early degenerative changes. We describe four patients with fractures of the posterior process of the talus which were initially missed. The patients were treated conservatively, and early mobilization or cast immobilization did not change the poor late results. The pitfalls in the diagnosis and imaging evaluation of such fractures are discussed.

A comparison of the effect of shoes on human tibial axial strains recorded during dynamic loading

Percutaneous axial extensometers were mounted on the medial cortex of the midtibial diaphysis in seven male volunteers and the effect of three different shoes on in vivo peak-to-peak axial compression-tension strains measured during dynamic loading. Zohar shoes had lower axial strains and strain rates during treadmill walking than Nike Air Max running shoes or Israeli infantry boots. During running on a running track, there was no statistically significant difference between the axial strains or strain rates between the shoes tested. Shoe gear can modify tibial strains and strain rates that contribute to the development of tibial stress fractures.