Potential neurotoxicity of titanium implants: Prospective, in-vivo and in-vitro study.

Titanium dioxide (TiO2) is a frequently used biomaterial, particularly in orthopedic and dental implants, and it is considered an inert and benign compound. This has resulted in toxicological scrutiny for TiO2 in the past decade, with numerus studies showing potential pathologic downstream effects. Herein we describe case report of a 77-year-old male with subacute CNS dysfunction, secondary to breakdown of a titanium-based carotid stent and leading to blood levels 1000 times higher (3 ppm) than the reported normal. We prospectively collected tissues adjacent to orthopedic implants and found a positive correlation between titanium concentration and time of implant in the body (r = 0.67, p < 0.02). Rats bearing titanium implants or intravascularly treated with TiO2 nanoparticles (TiNP) exhibited memory impairments. A human blood-brain barrier (BBB) in-vitro model exposed to TiNP showed paracellular leakiness, which was corroborated in-vivo with the decrease of key BBB transcripts in isolated blood vessels from hippocampi harvested from TiNP-treated mice. Titanium particles rapidly internalized into brain-like endothelial cells via caveolae-mediated endocytosis and macropinocytosis and induced pro-inflammatory reaction with increased expression of pro-inflammatory genes and proteins. Immune reaction was mediated partially by IL-1R and IL-6. In summary, we show that high levels of titanium accumulate in humans adjacent to orthopedic implants, and our in-vivo and in-vitro studies suggest it may be neurotoxic.

Return to sports after chronic anterior exertional compartment syndrome of the leg: Conservative treatment versus surgery.

AIM: To evaluate whether surgical treatment for anterior chronic exertional compartment syndrome (CECS) of the lower leg will lead to full athletic activity recovery compared to conservative treatment. METHODS: Patients diagnosed with anterior CECS of the leg were offered surgical treatment, as surgery considered today to be the mainstay of treatment. Patients unwilling to be treated surgically were treated conservatively. They were followed up, assessing both groups for pain, functional status, and the Tegner sports activity score with comparisons at diagnosis and following treatment. RESULTS: Forty-three patients were treated for CECS (31; 72.1% with surgery and 12; 27.9% conservatively) with a mean follow-up of 28.15 (4.16-54.09) months. Reported pain improved at follow-up by 1.59 (0-6) points and by 4.27 ± (0-10) points in the conservatively and the surgically treated patient groups, respectively ( p = 0.014) with a mean change in the Tegner score of 0.09 (-5 to 5) and 3.22 (-4 to 7), respectively ( p = 0.009). Three patients in the conservatively treated group (25% of 12) and 24 patients in the operated group (77.4% of 31) reported full resumption of their pre-diagnosis activity level ( p = 0.001). CONCLUSION: This study supports surgery as the treatment of choice for anterior CECS of the leg with differential benefit for fasciotomy in terms of pain and return to pre-diagnosis athletic activity.

Coronal Knee Malalignment in Young Adults and Its Link to Body Measures.

Our aim was to report the prevalence of knee varus-valgus malalignment (KVVM) and its association with body mass index (BMI) and body height in a healthy and fit young adult population. Information on the disability codes associated with KVVM according to the Regulations of Medical Fitness Determination was retrieved from a medical database containing records of 17-year-old males and females before their recruitment into mandatory military service. Logistic regression models assessed the association between the BMI and body height to KVVM. The study cohort included 821,381 subjects (460,674 males and 360,707 females). The prevalence of KVVM was 0.9% in males and 0.6% for females. Under/overweight subjects were associated with higher prevalence of KVVM. The odds ratios (ORs) had a "J" curve pattern, increasing for underweight males and females, and even more so for above-normal BMIs (for obese males and for both overweight and obese females). The strongest association was between obese females and KVVM: an obese female had an OR of 22.864 (confidence interval [CI] = 20.683-25.725, p < 0.001) to have KVVM and an obese male had an OR of 4.483 (CI = 4.158-4.833 p < 0.001). When the BMI was analyzed as a continuous variable, each increase in one BMI unit was associated with an increase in OR of 7.6% for males and 24.1% for females. There is a strong association between BMI and KVVM in both underweight and overweight young adults. KVVM is more common in males, but most strongly associated with overweight and obese females.This is a Level III, case-control study.

The Prevalence of Cruciate Ligament and Meniscus Knee Injury in Young Adults and Associations with Gender, Body Mass Index, and Height a Large Cross-Sectional Study.

Anterior cruciate ligament and meniscal injuries are associated with secondary osteoarthrosis which may lead to functional impairment and economic burden. The prevalence of knee injury has not been studied in depth. Our purpose was to report the prevalence of knee ligament and meniscal injuries and their associations with gender, body mass index (BMI), and height in young adults and to characterize individuals with meniscal injuries who gained full recovery. A cross-sectional, population-based study was conducted. Information on the disability codes of knee ligament and meniscal injury according to the Regulations of Medical Fitness Determination was retrieved from a medical database containing records of young prerecruits into mandatory service. Logistic regression assessed the association between genders, BMI, and body height to knee injuries. A total of 825,187 subjects were included. Prevalence of knee injuries was 0.35%. Males had 2.2-fold more knee injuries than females. Increased BMI was associated with increased prevalence of knee injury in both genders, more significantly in females (overweight and obese females had an odds ratio of 1.406 and 1.519, respectively, to suffer from concomitant meniscal and ligamentous knee injury). Being underweight was associated with a lower prevalence of knee injury. An above normal BMI was more significantly associated with meniscal and/or ligament injuries that did not fully recover (females > males). Body height was associated with isolated meniscal injury in both genders. We found an association between BMI, body height, and knee injury in both males and females. Higher body height and higher BMI might be risk factors for knee injuries. Higher BMI was associated with greater probability of disability coding. Meniscal and ligament injuries are more common among males.

[Chronic exertional compartment syndrome].

Chronic exertional compartment syndrome is an uncommon phenomenon first reported in the mid 50's. This condition is characterized by sharp pain during physical activity, causing reduction in activity frequency or intensity and even abstention. This syndrome is caused by elevation of the intra-compartmental pressure which leads to decreased tissue perfusion, thus ischemic damage to the tissue ensues. Chronic exertional syndrome is usually related to repetitive physical activity, usually in young people and athletes. The physical activity performed by the patient causes a rise in intra-compartmental pressure and thereby causes pain. The patient discontinues the activity and the pain subsides within minutes of rest. Chronic exertional syndrome is reported to occur in the thigh, shoulder, arm, hand, foot and gluteal region, but most commonly in the leg, especially the anterior compartment. The diagnosis of chronic exertional syndrome is primarily based on patients' medical history, supported by intramuscular pressure measurement of the specific compartment involved. Treatment of chronic exertional syndrome, especially the anterior and lateral compartment of the leg is mainly by surgery i.e. fasciotomy. If the patient is reluctant to undergo a surgical procedure, the conservative treatment is based on abstention from the offending activity, changing footwear or using arch support. However, the conservative approach is not as successful as surgical treatment.

Labor-related sacral stress fracture presenting as lower limb radicular pain.

In contrast to radicular pain during pregnancy, the incidence of postpartum radicular pain is rare. Sacral stress fractures are unusual but important causes for low-back and buttock pain and even postpartum radicular pain. To date, only 10 postpartum sacral stress fractures have been reported in the literature, with two descriptions of radicular pain as the presenting symptom. A 36-year-old woman, 7 days after her second delivery, presented with symptoms of spontaneous acute claudicating in conjunction with a left-leg radicular pain for 5 days. Imaging studies revealed a left sacral stress fracture. Bone mineral density was normal. The patient reported no pelvic, back, or radicular pain during the pregnancy, and had no history of menstrual irregularities, previous fracture, eating disorder, trauma or endocrine or metabolic diseases. No smoking or use of anticoagulation drugs was reported. Her obstetric and labor history showed no other risk factors. Epidural analgesia was used. Treatment consisted of toe-touch walking with crutches for 2 months, followed by full weight bearing, which resolved nearly all her symptoms. Clinicians should consider sacral fracture as a diagnostic possibility in postpartum and pregnant patients with lower back and/or buttock pain with or without radicular pain. Bone scintigraphy and computed tomography are considered harmful for the fetus. Magnetic resonance imaging, which is more suitable for pregnancy, is more sensitive than bone scintigraphy in revealing stress injuries of the bone. Physical examination and proper radiologic evaluation are the main keys for revealing the pathology.

Effect of knee flexion angle on Achilles tendon force and ankle joint plantarflexion moment during passive dorsiflexion.

Early mobilization exercises are advocated following Achilles tendon (AT) repair, but forces on the repair during passive range of motion are unknown. The extent to which these forces change with flexion of the knee is also not known. Estimated AT forces were measured using 3 models: cadaveric, uninjured subjects, and in both legs of subjects 6 weeks following unilateral AT repair. For cadaveric testing, estimated AT force was recorded using a force transducer while cycling the ankle from 10 degrees plantarflexion to maximum dorsiflexion at 3 different knee flexion angles (0 degrees , 45 degrees , and 90 degrees ). For in vivo testing, subjects were seated in an isokinetic dynamometer, and their ankles passively cycled from plantarflexion to dorsiflexion with the knee extended and flexed 50 degrees . Passive plantarflexion moment recorded by the dynamometer was converted to AT force by estimating the AT moment arm. In the cadaveric model, knee flexion reduced estimated AT forces during dorsiflexion by more than 40% (P < .036). In vivo testing showed that estimated AT force was reduced in knee flexion in healthy subjects (P < .001) and in the uninvolved leg AT repair subjects (P = .021), but not in the AT repaired leg (P = .387). Normal AT showed a marked reduction in estimated AT force with knee flexion which was not present in repaired AT. This could be because of elongation of the repair, causing more slack in the tendon that would need to be taken up before force transmission occurs. ACFAS Level of Clinical Evidence: 4.

Percutaneous pinning using threaded pins as a treatment option for unstable two- and three-part fractures of the proximal humerus: a retrospective study.

A retrospective study was designed to evaluate the results of closed reduction and percutaneous pinning using threaded pins as a treatment option for fractures of the humeral head. Patients who suffered two- and three-part fractures of the proximal humerus treated by this method of fixation were included. Fifty patients (32 females and 18 males) with an average age of 50 years were clinically evaluated at an average of 2.5 years after this procedure (range 1-4 years). The Constant score was used to evaluate the clinical outcome. Preoperative and postoperative X-rays were also assessed. Out of 50 patients, 18 (36%) obtained excellent results, 17 (34%) good results, eight (16%) fair results and seven (14%) achieved only poor results. The average Constant score was 81 (range 60-100). Fractures confined to the surgical or anatomical neck generally did better than those associated with a greater tuberosity fragment (average score 86 versus 78). Patients who required shaft stabilisation and in addition to reduction and fixation of the greater tuberosity showed a lower average score (68). There were no cases of avascular necrosis, neurovascular complications or deep infections. A significant loss of fracture position due to failure of internal fixation occurred in seven cases, three of these patients underwent revision surgery. Closed reduction and percutaneous pinning offers a good fracture position and stability with minimal soft tissue damage. We recommend that displaced two- and three- part fractures of the humeral head should be treated in this manner. However these patients should be monitored closely for a period of four weeks, since secondary displacement and failure of fixation can occur in this period. Careful patient selection may minimise these complications.

Component removal in revision total hip arthroplasty.

Component removal is a time-consuming yet necessary step during revision hip surgeries. Because of the diversity of the components and the methods used to secure them, an equal diversity of approaches and tools are necessary for component removal. Careful and detailed preoperative planning is mandatory, the mode of failure must be understood, and detailed imaging should be available to the surgeon. Understanding the basic principles and indications for each of the techniques would optimize outcome. We review the approaches, tools, and techniques for component removal in revision hip procedures in stepwise sequence.