Dr Penna

Today I have seen  total hip replacement useing Mathys RM Classic cup with exeter stem. This cup is quite interesting because it is polyethelene cup which is inserted using uncemented technique. It has surface coating of pure titanium (one which we used). Reading company website they also have cup with hydroxy appetite coating. Outcome is quite good (96.7% at 15 yrs according to company)

Types of cups available

• Full profile cup
• Bevelled cup
• Bevelled metal-metal (metamys) cup
• Revision cup

Latest abstracts about Mathys cup from Pubmed rss feed aggregated at IBJS

A team of scientists at Cold Spring Harbor Laboratory has just published research identifying an enzyme called Brk that may serve as a target for future drugs developed to fight ErbB2-positive tumors. ErbB2 is a member of a family of enzymes called receptor tyrosine kinases — cell-surface molecules that goad cells into proliferating when they sense growth cues in the environs of cells that express them. It turns out that the over-production of ErbB2 in breast cancers is due to a gene mutation that results in the accumulation of multiple copies of the erbB2 gene.

Other genes that undergo such “amplification” due the duplication of DNA segments include brk, which is the gene that instructs cells to manufacture the enzyme Brk. This enzyme is absent in healthy cells but is found at high levels in a majority of breast cancers. As some of these cancers also over-express ErbB2, the CSHL team wondered whether the offending genes, erbB2 and brk, are mutated in tandem, or “co-amplified.” This idea in turn raised the possibility that the proteins encoded by these genes are also co-activated and feed into the same proliferation-promoting pathway.

Aside from hurrying along tumor progression, Brk was also found to diminish the effectiveness of ErbB2-inhibiting drugs on tumor growth. Brk-inhibitors might also be useful on their own or as combined with ErbB2 inhibiting drugs. The CSHL scientists speculate that these drugs might fight tumors that never react to or become resistant to ErbB2-inhibitors.

It always facinates me how media can change the way things are potrayed. For example media can change all together way olympic medal ranking can be done just to appease their readers or veiwers. Take for example American media and Olympic medal rankings. Till Athens 2004 Olympics the ranking was based on number of golds recived by individual contries (Link from USA today).  But now all of a sudden the ranking is based on total number of medals (Link from usatoday). If the media cannot accept loosing now what are they going to write in 20 to 50 years time when china will be polictical, economic and military superpower. I guess then the US mass media will try to replicate what communist goverment media did in cold war era Soviet contries.

Today I learnt about Lautenbach procedure for treatment of Chronic Osteomyelitis. This procedure was developed and used by Charles Lautenbach surgeon form South Africa. This procedure involves sequestrectomy, saucerisation until you see bleeding bone (paprika sign), thorough wash out with pulse lavage and leaving a special drain through which we can deliver antibiotics like Teicoplanin, Gentamycin and anticoagulant streptokinase. This drain is retained for almost 4 weeks for local delivery of antibiotics to reduce recurrence of infection.

Information Links

• RJAH Instititute of Orthopaedics - Lautenbach procedure

Useful Abstracts

• The management of chronic osteomyelitis using the Lautenbach method :MA Hashmi, P Norman, M Saleh - Journal of Bone & Joint Surgery, British Volume, 2004 - JBJS
• Management of chronic osteomyelitis with modified Lautenbach procedure :Gudena R, Mehta J, Male K,Evans C, Morgan-Jones R

Hyaluronic hydrogels developed by Carnegie Mellon University researchers may provide a suitable scaffolding to enable bone regeneration. The hydrogels, created by Newell Washburn, Krzysztof Matyjaszewski and Jeffrey Hollinger, have proven to encourage the growth of preosteoblast cells, cells that aid the growth and development of bone.

Currently, physicians are able to treat patients with damaged bone tissue, like those who have bone fractures that fail to heal, using demineralized bone matrix, a biological material obtained from cadavers. Demineralized bone matrix is rich in growth factor proteins which signal bone cells in the area to multiply and form complex bone tissue, while other proteins in the matrix regulate the activity of the growth factors. Demineralized bone matrix is in limited supply, and because it comes from a human donor, there is a risk of transmitting viruses to the recipient.

Members of the Washburn lab have been developing synthetic alternatives to demineralized bone matrix. In the work being presented today, they created a flexible hydrogel using biologically active and degradable hyaluronic acid. Hydrogels, which are considered to be the state-of-the-art in tissue design, are made from polymers that swell in water to form a gel-like material. They interact with growth factors much like demineralized bone matrix does, providing scaffolding for bone cells to proliferate and form new tissue. The researchers found that, in vitro, the hydrogels promoted cell proliferation, differentiation and mineralization of pre-osteoblast cells.

Further research by the group has created a hybrid hydrogel that incorporates a nanogel structure. This new hydrogel promotes the differentiation of cells, much like the hyaluronic acid gel while also releasing nanogels in a controlled and targeted manner. The researchers hope that this structure could be used to partner tissue engineering with gene therapy.

The results of the trial of an MVA-based AIDS vaccine candidate (TBC-M4), which was conducted in Chennai, indicated that the vaccine candidate had acceptable levels of safety and was well tolerated.

The proportion of volunteers whose immune systems responded to the vaccine candidate suggests the candidate holds promise. The trial was done using two doses of the candidate vaccine. After three injections, 82 percent of the volunteers who received a low dose and 100 percent of those who received a high dose registered immune responses to the vaccine. The 100 percent response rate is greater than that seen with the majority of AIDS vaccine candidates tested in humans to date. However the strength and diversity of these immune responses were modest. It may be possible to boost the immune response, if this vaccine is used in combination with other candidate AIDS vaccines.

The Phase I clinical trial was initiated in January 2006 at the Tuberculosis Research Center (TRC), an Indian Council of Medical Research (ICMR) institute in Chennai, and was completed in February 2008. This trial was conducted under the aegis of a Memorandum of Understanding (MoU) between the Government of India—through the Indian Council of Medical Research (ICMR) and the National AIDS Control Organization (NACO)—and the not-for-profit International AIDS Vaccine Initiative (IAVI). YRG CARE, based in Chennai, collaborated with TRC to mobilize the community around the Phase I trial.

About the Phase I MVA-based (TBC-M4) AIDS vaccine trial

The trial was a double blind, dose-escalation, randomized, placebo-controlled trial, which was initiated after receiving all necessary regulatory and ethical clearances. The objectives of such a Phase I trial are to evaluate the safety of the vaccine candidate and to gather preliminary results of immune responses induced by the candidate. The total duration of the trial was approximately 24 months. The volunteers recruited for this trial were 32 healthy, HIV-uninfected men and women between 18 and 50 years of age, from all socio-economic strata. Three intra-muscular injections of TBC-M4 or placebo were administered to the volunteers.

LCS stands for Low contact stress. It is one of the knee replacement systems approved by FDA in 1980. The system contains primary cruciate-retaining and cruciate-sacrificing components as well as revision options. Fixed all-poly as well as rotating mobile-bearing patellae are available. Cemented and cementless fixation options are available. Advantages according to the company website include low incidence of patello femoral complications and long term survior ship exceeding 96%. Indications and contraindications for use of this prosthesis are detailed here(company website).

Some useful documents for reference

• LCS Complete Design rationale
• LCS Complete Extension Gap First Completion Instruments Surgical Technique
• LCS Complete Knee System Mileston Mini Instruments Surgical Technique
• LCS Complete Knee System Surgical Technique
• LCS Complete Surgical Technique Milestone Instruments MBT Tray Preparation

High resolution real CT data is rendered on the remote server. iPhone is used as interactive client. This the application from ZIOSOFT

More medical software applications on iPhone 3g