Dr Penna

I collected Links to information regarding Maxim® Complete Knee System in this page for my education and research.

This system is product of Biomet.

• Link to company booklet about the product
• Link to company booklet about surgical approach and technique
• Pubmed abstracts for Maxim Complete Knee system
• Patents Mentioning Maxim Complete Knee

Quote from Company Booklet

Building on over a decade of successful clinical results, Biomet continues its tradition of innovation by introducing the Maxim® Complete Knee System. This system is the result of combining the implant experience of Adolph V. Lombardi, M.D., and Bradley K. Vaughn, M.D., with the extensive engineering resources at Biomet. The union of these powerful forces has produced the most complete and user-friendly knee system available today.

One of the uncemented cup systems used at our hospital is Pinnacle acetabular cup system. I thought I will collect more information about this system. Post below contains some of the links and useful information about this system

This system is developed and marketed by Depuy Orthopaedics, Allegedly useds Variable Interface Prosthesis (VIP) taper technology (cant find this patent application yet in either google patents or us patents database). Though some patents mention name “Pinnacle acetabular cup”

Quote from company website

DEPUY introduces the PINNACLE Acetabular Cup System with patented Variable Interface Prosthesis (VIP) taper technology. The PINNACLE Acetabular Cup is designed to accommodate multiple advanced bearing materials and provide surgical options without compromise. Surgeons now have a choice between standard polyethylene, MARATHON Cross-linked Polyethylene and ULTAMET metal inserts, which all work within one acetabular shell.

More info - pubmed abstracts

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

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.

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

Molecular biology in orthopaedics is an evolving branch. It encompasses learning about gene expressions in various orthopaedic disorders to aspects of experimental treatment developments which include gene therapy for Arthritis.

Experimental treatments

• Intra articular transfer of IL-1 receptor antagonist (IL-1Ra) cDNA reduces disease in animal models of RA.
• Regional gene therapy to enhance bone repair

There are various centres which are pioneering in this field including

• Centre for Molecular Orthopaedics
• University of Hospitals Chicago Molecular orthopaedics department
• University of California, San Francisco Orthopaedic Trauma Institute Molecular biology lab
  
• Institute of Bioengineering and Nanotechnology, Singapore

There is also Society for Molecular Orthopaedics called

• International Society for Molecular Orthopaedics

Books about Molecular Orthopaedics

• Molecular Biology in Orthopaedics (synosium) by Randy N. Rosier, MD, PhD and Christopher H. Evans, PhD, DSc, Editors

Websites about Molecular Orthopaedics

• Molecularorthopaedics.org