Shigeo Ishijima, Veterinarian, Ishijima Animal Hospital
Introduction
Currently, canine radial ulna fractures are primarily treated by surgery or casting. Surgery allows precise repair of the fracture line, but there are risks of stress shielding due to metal fixation, impaired recovery due to deterioration of bone quality, and implant failure1,2,3). The implant that fixes the fracture is prone to healing disorders and delays because it interrupts blood flow to the bone marrow, and the more firmly it is fixed, the more impaired recovery occurs due to decreased bone density and deterioration of bone quality, with little recovery in axial apatite orientation even after 7 months2). After surgery, exercise is restricted for several months to prevent implant curvature and fracture, but it is difficult to manage an active dog to run and jump for several months. Casting is primarily the treatment of choice for fissure fractures, but fractures with dislocation are not indicated, and long-term immobilization results in muscle atrophy, decreased bone density4) and bone curvature. Mechanical stability and mechanical stimulation are necessary for fracture healing, but conventional treatment methods are incompatible.
Objective.
In 2018, our clinic developed a new treatment method for healing radial ulna fractures in dogs with a tubular cast that fits the leg three-dimensionally and completely (“3D cast”) (“3D cast treatment method”). The purpose of this study was to establish a 3D cast treatment method for radius ulna fractures in dogs, and to investigate the effect of age and surgical history on the healing period and the effect of age and surgical history in 181 cases treated with a 3D cast.
Materials and Methods
3D casting treatment method
Two types of casts are used during the inflammatory and repair phases of the fracture.
As soon as possible after the injury, manual manipulation is used to correct the alignment, and motion is restricted by applying a sheene fixation with interventional traction.
A 3D cast is made from a plaster cast of the foot mold of the affected limb, which fits perfectly, is lightweight, and durable. 3D casts can be applied to the affected limb to stabilize the torsional and shearing directions of the fracture while allowing the patient to walk, run, and jump. and running and jumping. Axial pressure applied to the fracture site during walking induces bone marrow stem cells to differentiate into osteoblasts and repair the fracture through indirect bone healing.
Method of immobilization immediately after injury
A, Hair clipping and mark the fracture line by palpation.
B, Apply inelastic tape to the affected limb like a tag, alternating laterally. Use a JL wrist splint (Fujihira Kogyo Co., Ltd.) for large or long-legged dogs and a Kishigami plastic splint for smaller dogs. Fix the sheene to the elbow side of the fracture and secure it to the body. Next, tag the toe side of the fracture line with inelastic tape to allow inward traction. Holding the elbow side, the opposite hand is used to pull the toes together to align the upper and lower fracture line and secure the inelastic tape and sheene on the toes.
C, Keep the affected limb covered with elastic tape from the elbow to the end and allow the patient to rest for 1 week.
3D cast fabrication method
D, Mold the affected limb using dental impression material.
E, After about 1 minute to harden, make a vertical incision with an ointment spatula or paper knife.
F. Pull out the foot.
G. Pour plaster into the impression material to make a plaster model of the foot.
H. Wrap 1.1 mm thick acrylic foam around the fracture line near the center. 3D casts are made about 1/2 to 2/3 the length of the radius in small dogs.
I. Wrap the top with a double layer of resin cast in a spiral shape. For large dogs, triple wrap.
J. Mark the resin cast with a marker. Write the front in the vertical direction, the fracture line in the horizontal direction, and the paw mark at the bottom. The vertical cut of the debridement should be stepped in the center.
How to apply a 3D cast
K, Apply an inelastic tape approximately 3 times as long as the cast on the left and right longitudinal sides of the affected limb.
L, Apply the cast by aligning the fracture line on the affected limb with the fracture line marker on the cast.
M, Fold the tape back toward the elbow.
N, Cover the entire 3D cast with elastic tape.
How to adjust a 3D cast
If a gap develops between the affected limb and the 3D cast, cut the longitudinal line slightly to adjust the fit; remove the cast every other week to clean the skin.
A study of 181 cases of radial ulna fractures in dogs treated with a 3D cast.
The cases are 181 cases (2019-2023) of complete fractures of the radius and ulna that presented to our hospital. The ages of 50 cases were less than 2-6 months old, 65 cases were less than 6-12 months old, 39 cases were less than 1-2 years old, 19 cases were 2-9 years old, and 8 cases were 10-18 years old. One hundred seventy-two (95%) weighed less than 1-5 kg, and 9 (5%) weighed more than 5 kg. Subjects included 1 4 patients aged 1-16 years with a history of fracture at the same site within 6 months after surgery, and 97 patients who had used NSAIDs prior to treatment, including 9 patients who had used NSAIDs for more than 7 days. Treatment of comminuted fractures and postoperative fusion failures were not included.
Healing period was defined as from the date of first visit until the fracture was rigid pseudostratified and a crosslinked union formed; to determine the effect of fracture healing time, age, and history of surgery on the 3D casting treatment method.
result
All head fractures healed with a median time of 45 days. The minimum was 10 days and the maximum was 176 days. The average duration of cast immobilization was 7 days for the splint and 38 days for the 3D cast.
The 3D cast was lightweight and fit the affected limb perfectly, allowing the patient to walk without discomfort. The patient walked awkwardly in the early stages of application, but was able to run and jump as the pseudobone increased. The deposition pseudobone was first created on the concave side of the fracture, then increased on the convex side, and the fracture area gradually thickened with pseudobone as the dog continued to walk. The 3D cast was durable enough with no breakage due to the dog’s exercise. Treatment was terminated when the soft pseudostructure became hard pseudostructure and cross-linked union was formed.
Median healing time by age was 31.5 days for those less than 6 months old, 44 days for those 6 months to 1 year old, 62 days for those 1 to 2 years old, and 74 days for those 2 years old and older, all with significant differences (P<0.05). There were no significant differences between those 2 to 9 years old and 10 to 18 years old. 12 cases (6.6%) had healing longer than 100 days using the 3D casting treatment method. The 12 cases (6.6%) healed more than 100 days using the 3D casting method, including 5 cases with a history of fracture surgery within 6 months and 3 cases who used NSAIDs for more than 7 days in the early stages of fracture. The dog with the longest healing time of 176 days had a history of surgery and used NSAIDs for 7 days prior to treatment. 3 dogs (1.6%) had re-fractured at the same site within 6 months after bone fusion with the 3D cast treatment method.
There was a significant difference between patients with a history of fracture surgery (N=14, 1-16 years) with a median of 76.5 days and a mean of 87 days and those with age >1 year and no history of fracture (N=52, 1-18 years) with a median of 64.5 days and a mean of 68.7 days. (P<0.05)
consideration
Weight-bearing and muscle contraction during the early repair phase are most effective in healing fractures5, 6). Bones in the early repair phase are unstable and not strong enough to withstand walking, but walking becomes possible with the application of a 3D cast. Axial pressure loading is applied vertically while preventing fracture shearing and rotational dislocation during walking. Repair of fractures by indirect bone fusion is easy to recognize because the bone gradually thickens. After healing, the thickened bone is remodeled and returns to its original thickness and structure7).
It is known that there is a significant difference in the healing period between dogs under one year old and adult dogs8). In the present study, there was a significant difference by age from less than 6 months to 2 years of age, and the healing period remained the same and repair was maintained even in older dogs over 2 years of age.
The median time for surgical fracture healing was 60~79.5 days9, 10), with subsequent plate removal taking 89 days9) and a treatment period of approximately 5 months; the slower healing compared to the 3D cast treatment method and re-fracture after surgery may be due to delayed remodeling.
Clinical Significance
The 3D casting treatment method is non-invasive, does not restrict movement, and allows for age-specific prediction of healing time. The treatment can be performed at general veterinary clinics and can be widely disseminated.
For more information, please contact
Phone: 0471-46-1047
E-mail: ishijima2013@gmail.com
References
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