1. Joseph G. Craig, MB, ChB1, Kathryn E. Cramer, MD2, Dianna D. Cody, PhD1, David O. Hearshen, PhD1, Ruth Y. Ceulemans, MD1, Marnix T. van Holsbeeck, MD1 and William R. Eyler, MD1
3. Departments of Radiology (J.G.C., D.D.C., D.O.H., R.Y.C., M.T.v.H., W.R.E.)

1. Orthopaedic Surgery (K.E.C.), Henry Ford Hospital, 2799 W Grand Blvd, Detroit, MI 48202.

Abstract

PURPOSE: To examine growth plates of the distal femur and tibia with magnetic resonance (MR) imaging to detect bone bridges and other deformities in children.

MATERIALS AND METHODS: Thirteen children (nine boys and four girls, aged 5–13 years; mean age, 9.8 years) were referred because of suspected or known bone bridging of the growth plate. Among the 13 patients, 10 had Salter-Harris fractures of the knee or ankle, two had Blount disease, and one had neonatal sepsis. Fat-saturated spoiled gradient-recalled images enabled reconstruction of a three-dimensional model of the growth plate. Patients underwent one to four MR examinations.

RESULTS: Nine patients had bone bridging of less than 1% to 39% of the area of the growth plate. On MR images obtained in the growth plate of five patients, a stripe of low signal intensity indicated fracture. On MR images obtained in three patients, intrusions of growth plate cartilage into the metaphysis were seen to increase in depth over time. MR images obtained in four patients showed no bridges. In the two patients who underwent surgery, excellent correspondence was found between MR findings and surgical observations.

CONCLUSION: Marked undulation or splitting of the growth plate may occur with fixation of some cartilage in the metaphysis or epiphysis while growth continues. The configuration of the growth plate and bone bridges can be accurately mapped with MR imaging. Treatment planning is facilitated.

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– Discussion:
– bone bridge obliterates growth-plate cartilage & prevents growth;
– peripheral bone bridges predispose patient to angular deformities;
– most common sites of growth arrest include the distal tibia, distal femoral and distal ulnar physis;
– much less common sites include distal radius and proximal humerus;– Radiology:
– extent of bone bridge is demonstrated by CT scanning and tomograms;

– Indications for Bone Bridge Resection:
– resection is indicated if less than 1/3 to 1/2 of growth plate is involved;
– younger children tend to have a better prognosis w/ resection than older children;
– less than 2 years of remaining growth is a relative contra-indication for bone bridge resection;
– central bars are more amenable to resection than peripheral bars;
– ischemic or septic related bone bars have a poor prognosis w/ resection;– Technical Pearls:
– interposition of fat is easiest and most commonly used agent to prevent bone bridge formation (alternatives include silastic, methyl methacrylate, or free epiphysis)

Christy Ruhe was born with a form of dwarfism that left her 4-foot-3. She opted for painful, controversial surgery to grow.

February 15, 2004|  Gretchen Parker | Associated Press Writer

Two years ago, she couldn’t have reached the pedals.

Christy recently finished a procedure that surgically broke her bowed legs, then stretched and straightened them, an agonizing ordeal that would leave even her questioning how much she could endure.

Once 4-foot-3, she’s now just 2 inches shy of 5 feet.

She had always craved just a few more inches. Enough to drive any car and pump her own gas, or reach the pedals under the piano. Practical things, but seven inches would accomplish so much more.

To understand why Christy would put herself through the grueling surgeries and therapy is to understand a spirit determined to be as independent as possible.

Christy was born with achondroplasia, one of 200 forms of dwarfism. Her arms grew in proportion to her torso, but her little legs were severely bowed. At 5, surgeons broke her hips and realigned them. At her sixth birthday party, she lay in a full body cast.

But the more she grew, the more stubborn her legs became — always bending outward.

Limb lengthening might help straighten her legs, her pediatric orthopedic surgeon said, but he discouraged the idea.

“His reasoning was: ‘Why would you want to put yourself through that?’ ” said her mother, Rita Ruhe (pronounced ROO-ee).

The procedure is controversial. The advocacy group Little People of America has taken an official stand against it, warning of the risks of long-term nerve and vascular damage.

But Christy, who lives in Pickerington, near Columbus, couldn’t get the idea out of her head.

Everything she did reminded her of the limitations of being 4-foot-3 in a world where most adults are at least a foot taller. She needed a footstool to wash her face at the bathroom sink or to flip a light switch. To drive a car, she needed extension pedals.

Her parents are not dwarfs; neither is her willowy older sister, Erin.

John and Rita Ruhe nurtured their daughter’s independence. But outside the Ruhe house, Christy would learn about alienation. Strangers would stare. Her legs were weak and, on walking trips, she lagged behind.

“I always felt like, why do I have to explain this? Why do I even care what they’re saying?” she said. “I did, of course. It’s impossible not to.”

At 22, Christy contacted Dr. Dror Paley and the International Center for Limb Lengthening, the clinic he co-founded with two other orthopedic surgeons at Sinai Hospital in Baltimore.

It’s now late September of 2001. Christy is focused on the changes unfolding in her own life, and the anticipation of her first limb-lengthening surgery is thrilling.

Her hospital gown drags on the floor as she slides off the bed onto a stepstool. She smiles widely at her nervous parents.

In the operating room, Paley’s plan is to break the thigh and shin bones of her left leg and stretch the bones for three or four months as they’re healing. A year later, he’ll lengthen the right leg.

Limb lengthening works by taking advantage of the body’s natural tendency to heal itself. The shin bones and femurs are broken and automatically begin to generate new bone. As they heal, they’re pulled apart to elongate them. The surgeries, which typically cost about $200,000 for both legs, are covered by insurance.

Paley cuts holes in Christy’s leg so that he can screw rods into the bone: seven in her thigh and five in her shin. Each is a foot long. Half the length protrudes from her skin, so Paley can attach them to a graphite brace that Christy will crank.

Paley bores the pins deep into the thick whiteness he sees on the X-rays.

Finding a good place to crack the bone, he first drills a tight chain of small holes. He puts a chisel to the perforation and pounds it hard with a mallet. The whirring and hammering make it sound like a construction site.

The pain is like an ocean that sucks her under again and again.

Christy lies on her stomach, and a physical therapist bends her knee as far as it will go. Muscles and nerves are stretching to meet the length of the new, soft bone.

The therapist pushes until she feels the soft tissue become elastic. It’s been only a few days since the first surgery.

Christy’s face reddens, and she rides the wave of pain with short breaths. She tries not to scream but can’t stop herself.

She wonders if the therapist knows what she’s doing. “This cannot be right!” she thinks.

(Page 2 of 2)

Aldegheri R, Renzi-Brivio L, Agostini S.

Source

Center of Pediatric Orthopaedics, Institute of Clinical Orthopaedics and Traumatology, University of Verona, Italy.

Abstract

Callotasis is a lengthening technique that involves slow, controlled distraction after subperiosteal-submetaphyseal osteotomy. The technique and its advantages over other methods are described. Results of lengthenings involving 270 operated bone segments (146 femurs and 124 tibias) in 140 patients are reviewed. Ninety-five patients had limb-length inequality and 45 had hypochondroplasia or achondroplasia. On average, 6.6 cm, or 24.6% of initial length, was gained. The mean healing index was 39; the complication rate was 13.3%.

PMID:   2924457       [PubMed – indexed for MEDLINE]

Me: It appears that callotasis is a very popular approach for people who have some form of dwarfism. 

From source link HERE

J Pediatr Orthop. 1987 Mar-Apr;7(2):129-34.

Limb lengthening by callus distraction (callotasis).

Me: I found this article when I was searching for more information on bone lengthening. It seems that the engineering students in this generation are trying their hands and finding better ways to do limb lengthening. What makes this so interesting is that the device they have as a prototype is a combination of the efforts of students in biomedical engineering and mechanical engineering. The device does the distraction of the bones by attaching to the  wires that goes through the bone in the external fixator method and slowly moves the wires apart from each other while still keeping the overall structure stable. The unique thing they have is the feedback mechanism which makes sure the device does not overdo a distraction.

From website GizMag HERE

Students create automated bone-lengthening device

By Randolph Jonsson        April 25, 2012

Whether it’s from injury, infection or malfunctioning genes, millions of children suffer from bone deformities at any given time. To help remedy the situation, doctors often resort to the painful practice of breaking the target bone and then repeatedly moving the ends apart as they attempt to grow together – a procedure known as distraction osteogenesis (DO), that has its share of risks and problems. Now, a team of undergrad students from Rice University (RU) in Texas has come up with a device they hope will make the lengthy process of bone-stretching both easier and safer for the young patients who have to endure it.

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• 
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“The process of limb lengthening – essentially creating a localized mini-growth spurt – works well for bones, but is very hard on the soft tissues such as nerves and blood vessels,” Gogola said. “This team has done an outstanding job of designing a creative solution. Their device not only protects the soft tissues, it will ultimately speed up the entire process.”

With current DO rigs, long pins are embedded on both sides of the break in the bone to be lengthened. These are then attached to a bulky threaded frame outside of the appendage with a drive screw that must be regularly adjusted manually several times a day with a hex wrench. This pushes the pins further apart as the bone heals, but before it sets, allowing the gentle elongation of the bone over a period of several months. It’s a burdensome task for patient and caregiver alike.

“The problem with the current device is that there’s a lot of room for error,” RU team member Kahn said. “You can imagine that one might forget to turn it once, or turn it the wrong way, or turn it too much. And a lot of problems can arise in the soft tissue and the nerves surrounding the bone,” she added. “That’s the limiting factor of this process. But LinDi implements a motor to make the distraction process nearly continuous.”

In fact, the battery-powered LinDi self-adjusts about 1,000 times a day, which allows it to better approximate bone growth. The team’s innovative inclusion of a force-feedback sensor – a first for DO devices – monitors stress loads on surrounding tissues and shuts the system down if levels get too high, thus averting unnecessary trauma from the process.

Short-term animal testing with the help of Shriners hospital staff allowed the students to fine tune the device and confirmed that it works as planned – a nice feather in the bonnet of the soon-to-be grads and a welcome relief for the countless children and their parents who stand to benefit from this new technology in the years to come.

Me: One a related note one of the commenters made a point that there was alreday a company in the 90s which had already developed a very similar device that could automate the distraction / stretching of the bone process. However there was no feedback mechanism that told the Automator to stop when the bone is distracted too far. From the comments on the article above…

“”A friend of mine did this nearly 15 years ago while working for a company called Autogenisys they automated the Ilizarov apparatus. While they they didn’t have a feed back system you didn’t have to manually adjust it either.””

Douglas Renfro
25th April, 2012 @ 09:40 pm PDT

Autogenesis Website link HERE

From the website….

The Automator

Applications:

• Ring Frame Lengthening
• Bone Transport
• Unilateral Frame Lengthening
• Joint Contracture
• Angular Deformity Correction.

Biological Advantages:

Research indicates that frequent distractions in small increments can promote superior muscle tissue and reduce the forces required to accomplish distraction (thereby reducing pain experienced by the patient). The Automator performs precise micro-distractions every few minutes minutes rather than every six hours as is typical with manual systems. Hence, the lengthening process is more similar to the body’s natural (continuous) growth process. Additionally patients and their families report less anxiety.

BACKGROUND:

The Automator was designed to provide an improved automated alternative to manual distraction methods. The device:

1. Costs the same or less than most manual distracters sold by large medical equipment manufacturers,
2. Allows patients to enjoy the psychological and physical benefits of high rhythm (small increment) corrections,
3. Allows for precision, flexibility, and reliability unavailable with manual systems, and
4. Does not introduce installation or operational complexity to the procedure.

Automated lengthening should be the standard of care for limb lengthening and deformity correction procedures.

Product Description:

• Continuous Distraction: The Automator  causes 1/240 mm adjustments 24 hrs per day according to the rate selected. Accuracy is maintained within 1/48 mm.
• Compact: The self contained design involves no external cables, batteries, or programming module. Each Automator weighs approximately 6oz.
• Programmable: Rate settings include 0.5, 0.75, 1.0, 1.25, 1.5, 2.0, and 4.0 mm/day. The device may be set for distraction, compression, or cyclical motion (used for loading a fracture site). Rate and directional settings may be changed by the physician at any time.
• Convenient: Brackets facilitate installation. The Automator is water resistant, and it requires minimal maintenance.
• Efficient: Automator batteries last more than four months when lengthening at 1mm per day. The device can distract against more than 250 lbs.
• Versatile: The device may be installed on ring or unilateral frames regardless of the distance between rings or frame components.

 

Hall BK, Miyake T.

Source

Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.

Abstract

Cell condensation is a pivotal stage in skeletal development. Although prechondrogenic condensations normally exist for some 12 h, duration can vary. Variation is seen both between condensations for different cartilages (Meckel’s vs. elastic ear cartilage) and within a single condensation from which more than one skeletal element will form, as in the three components of the single first arch chondrogenic condensation. Understanding how duration of the condensation phase is established–how the condensation phase is entered and exited during cell differentiation–remains a major area for future study. During chondrogenesis, cell-specific products such as collagen types II and IX and cartilage proteoglycan appear concomitant with condensation. Therefore, during chondrogenesis, condensation precedes commitment of cells as prechondroblasts. During osteogenesis, however, differentiation of preosteoblasts precedes condensation. Therefore, during osteogenesis, condensation amplifies the number of committed osteogenic cells. Further comparative analysis of skeletogenesis should provide us with a more rigorous understanding of cell commitment, when differentiation is initiated, how commitment and differentiation are measured and the relationship of condensation to onset of differentiation. Current knowledge of molecules characteristic of condensations focused attention on extracellular matrix and cell surface components on the one hand, and on growth factors homeobox genes and transcription factors on the other. We have drawn together the molecular data for pre-chondrogenic condensations in diagrammatic form in Figure 2. Three major phases of chondrogenesis are identified: (a) epithelial-mesenchymal interactions that precede condensation, (b) condensation itself, and (c) cell differentiation. Although we label the third phase differentiation, it is important to recognize that phases a and b also constitute aspects of chondroblast cell differentiation (see Dunlop and Hall, 1995 for a discussion of this point. The pre-condensation phase is characterized by expression of Hox genes, growth factors (TGF-beta and BMP-2) and the cell surface proteoglycan receptor, syndecan-1. Expression of Msx-1 and Msx-2, growth factors and syndecan continues into the condensation phase. Other molecules, such as versican, syndecan-3 and tenascin, present in low concentrations before condensation, are up-regulated during condensation. Yet other molecules–Hox genes, transcription factors, growth factors (activin, BMP-4 and -5, GDF-5), cell adhesion molecules and proteoglycans–are only expressed during the condensation phase, while the transcription factor Pax-1, fibronectin, hyaluronan and hyaladherin are expressed both during and after condensation. During condensation mRNAs for collagen types II and IX and for the core protein of cartilage proteoglycan are up-regulated. Late in condensation and increasingly thereafter, the protein products of these genes accumulate as chondroblasts differentiate (see Fig. 2 for details). Not all the molecules present before, during of after condensation can be placed into causal sequences. Some however can. In Figure 3 we summarize the causal sequences discussed in this paper as they relate to initiation of condensation and to transit from condensation to overt differentiation during chondrogenesis. Condensations form following activation of at least three pathways: (1) Initiation of epithelial-mesenchymal interactions by tenascin, BMP-2, TGF beta-1 and Msx-1 and -2. (2) Up-regulation of N-CAM by activin. (3) Up-regulation of fibronectin by TGF-beta, further enhancing N-CAM accumulation (Fig. 3). It is by these three pathways that condensations are initiated and grow. Transition from condensation to overt cell differentiation is under both positive and negative control (Fig. 3). Syndecan blocks fibronectin and so blocks N-CAM accumulation, preventing accumulation of additional cell

PMID: 8901191     [PubMed – indexed for MEDLINE] 

Bioessays. 2000 Feb;22(2):138-47.

All for one and one for all: condensations and the initiation of skeletal development.