Named after Arthur Legg, Jacques Calve, and Georg Perthes, the orthopedic surgeons who in 1910 identified and studied the condition in young children, Legg-Calve-Perthes Disease is an orthopedic condition that characterizes with spontaneous wasting of the femoral head.
The condition is gradually progressive and the only war to salvage the leg is through surgical correction.
The condition is also known by the abbreviations LCPD and LCP, and it is described as a developmental abnormality that almost always affects small breed dogs. The exact origin of LCPD is unknown and is very similar to LCPD in humans.
What Does Lcpd Mean?
When it comes to Legg-Calve-Perthes disease, even pronouncing the name is challenging enough. However, this complicated term’s primary issue is a condition with an even more challenging word – avascular osteonecrosis.
But what is avascular osteonecrosis? Let us simplify this complicated medical term. In laymen’s terms, the word “avascular” translates to lack of blood supply, and the word “osteonecrosis” translates to bone death.
Consequently, avascular necrosis means that the bone is dying due to inadequate blood supply.
What Causes LCPD?
Sadly, the exact cause of LCPD is not determined. Even the three orthopedic surgeons who initially identified the condition disagreed regarding its cause and had different theories.
The leading theory is that LCPD occurs due to inadequate blood supply but what triggers the blood supply impairment is not yet established, but it is believed it is poor circulation.
However, the cascade of events that leads to the insufficient blood supply is suspected to be of inherited origin, at least in certain dog breeds. Legg favored this theory and remained the most widely-accepted theory until this day.
According to other popular theories:
- LCPD develops as a result of hormonal imbalances
- LCPD is caused by rickets – Calve favored this theory
- LCPD is a consequence of infective and degenerative arthritis – Perthes favored this theory
- LCPD develops due to inadequate blood supply caused by severe hip trauma
How Does LCPD Develop?
To explain how LCPD develops, it is best to start with a short anatomy lesson. Namely, the hip joint consists of two main parts – the socket formed by the pelvic bones and the femoral head as the “ball” that fits into the socket.
There is a cartilage between the head and the socket that basically acts like a cushion. When the dog’s leg and hip movement, the femoral head rotate within the socket, and the cartilage protects the two bone structures and wear and tear.
For the hip joint to function normally, it needs a constant supply of oxygen and nutrients. For this purpose, the hip joint is rich with blood vessels. The blood vessels are responsible for providing the vital oxygen and nutrients and removing waste from the joint.
LCPD occurs when the blood vessels supplying the femoral joint become compromised. When the blood supply is inadequate, the bone and cartilage cells start dying – a condition called avascular osteonecrosis.
Consequently, the femoral head becomes deformed, and the cartilage losses its cushioning features. These changes result in a poor-fitting joint – the ball cannot stay within the socket’s margins because of its altered shape.
Displaced, deformed, and highly disintegrated, the femoral head can fracture or collapse even at the slightest strain. Meanwhile, the rubbing between the head and the socket leads to arthritic changes.
All arthritic changes are linked with pain, so LCPD is an excruciating condition. The dying of the bone tissue is also painful. Because of the pain, dogs with LCPD start favoring the affected leg, and as the disease progresses, the favoring progress into limping.
How Many Types Of LCPD Exist?
From what is known, there are no different LCPD types. Although there are several suspected underlying causes and triggers, all affected dogs have the same clinical manifestation. The treatment protocols are also the same.
Which Are The Risk Factors For LCPD?
LCPD is almost exclusively a small breed dog medical issue. The condition almost always affects dogs weighing less than 20 Ibs. It is most frequently reported in miniature and small dogs of the toy and terrier groups.
According to The Orthopedic Association of America, LCPD occurs in the following breeds:
- West Highland White Terrier
- Scottish Terrier
- Manchester Terrier
- Yorkshire Terrier
- Australian Terrier
- Lakeland Terrier
- Jack Russel Terrier
- Border Terrier
- Fox Terrier
- Boston Terrier
- Cairn Terrier
- Welsh Terrier
- Silky Terrier
- Toy Poodle
- Cocker Spaniel
- Sheetland Sheepdog
- Miniature Pinscher
- Bichon Frise
- Miniature Schnauzer
A recent study quantified the risk of developing LCPD in different dog breeds. Based on the results, the Australian Shepherd is between 54 and 674 times more likely to develop LCPD than a mixed-breed dog; the Miniature Pinscher is between 31 and 164 times more likely, and the Pug – between 28 and 153 times.
LCPD usually develops when the dog, or better said the puppy, is between five and eight months old. However, it can develop in puppies as young as three and as old as 18 months of age.
LCPD is not a sex-related disease – it occurs with equal frequency in both males and females.
The clinical manifestation of LCPD depends on the condition’s advancement. In the beginning, the signs and symptoms are mild and then they progress to moderate and eventually to severe.
Generally speaking, a dog with LCPD will likely show the following signs and symptoms:
- Intermittent inability to walk
- Gradually progressing lameness or limping
- Reluctance to put weight on the affected leg
- Trouble getting up and going through stairs
- Favoring one leg or holding one leg up
- Stiffness of the affected limb
- Pain when the affected hip is touched
- Licking or chewing the hip area of the affected leg
- Anxiety, lethargy or even aggression due to pain
- Muscle atrophy on the affected leg
As mentioned, the specter of signs and symptoms varies based on the condition’s stage and advancement. However, almost all dogs with LCPD limp so simple limping is the most typical sign.
The other two most frequently reported signs to include loss of muscle mass and pain. How will the dog exhibit its pain depends mostly on the dog’s character and its pain tolerance level.
How Is LCPD Diagnosed?
The vet will start the diagnostic process with a full physical examination. The limping and muscle loss are the first signs to catch the vet’s eye and lay the suspicion of LCPD.
If the femoral head is already collapsed, the affected leg will be shorter. After the full physical examination, the vet will perform an orthopedic examination.
The orthopedic examination will reveal:
- Severe pain upon hip manipulation
- Crepitus (popping or grating sounds and feeling) upon hip joint manipulation
The vet will order an x-ray to confirm the diagnosis based on the findings. The x-ray is enough to ensure the LCPD diagnosis conclusively. Which changes does the x-ray image reveals depends on the LCPD’s progression.
In the early stages, the femur’s head will have strikingly lower density compared to the other femur portions. In the more advanced stages, there will be an evident flattening of the femoral head.
Arthritic changes and fractures are commonly accompanying radiographic signs.
How Is LCPD Treated?
The course of the treatment depends on the LCPD severity. Mild cases are usually managed with appropriate pain medicines. Luckily, there are many pain relief drugs explicitly formulated for dogs.
The most frequently used pain meds are from the non-steroid anti-inflammatory drugs group (NSAIDs). They can be safely used over a prolonged period and have minimum side-effects.
Weight management is an essential part of this conventional treatment approach. The dogs must keep lean and healthy body weight to prevent exerting the already diseased hip joint. Sadly, this approach is not sufficient for all dogs with mild LCPD.
Dogs that do not respond to medical management and dogs with advanced LCPD must have their hip joints surgically corrected. There are two surgical approaches:
Femoral Head Osteotomy (FHO)
This is the treatment of choice for dogs with LCPD. The procedure involves removing the diseased femoral head. Once the head is removed, the adjacent muscles and tissues will start healing and form scar tissue.
Eventually, the scar tissue will fill in the empty space created by the femoral head removal and act as a false yet well-functioning joint.
The procedure may seem radical but it actually works really well since the weight-bearing needs in small breeds are not as accented as in large dog breeds.
To be more illustrative, most dogs start bearing weight on the surgically fixed limb within one to two weeks. FHO is considered a salvaging technique whose goal is to eliminate the pain source (the femoral head).
Total Hip Replacement (THR)
This is a more advanced and complicated procedure. THR is considered in patients that do not respond to FHO and still experience pain. The procedure includes placing specifically designed implants that recreate the hip joint and allow full functionality.
All in all, THR seems like a more superior technique. However, studies show that both procedures have similar outcomes.
Therefore, and because of the FHO’s significantly lower invasiveness and cost, when a dog presents with LCPD, the first recommendation is FHO. Later on, if the dog does not respond as expected, the vet will recommend a THR.
Once the surgical correction is done, the dog will receive pain meds for some time – usually for the duration of the recovery period.
The vet will also recommend an individually tailored rehabilitation plan and advise a long-term use of chondroprotective supplements such as glucosamine and chondroitin.
How Much Does The LCPD Surgical Correction Cost?
Same as most surgeries, correcting a hip joint with LCPD comes with a hefty price tag.
The exact cost of the procedure depends on your geographic locale and the surgeon’s education, whether it is performed by a general practitioner or a board-certified vet surgeon.
All in all, it is rational to expect a price ranging between $1000 and $3000.
How Long Is The Recovery Period For LCPD?
The surgery fixes the issue, but the future recovery depends mostly on proper management. By adequate management, we maintain healthy body weight and proper rehabilitation therapy.
Dogs that have been through an LCPD corrective surgery must maintain lean body weight to prevent putting too much pressure on the corrected joint.
If the dog was already skinny before the surgery, keep the weight is the goal. If the dog overweight or obese, it will be placed on a unique dieting regimen.
The exact length of the recovery period depends on how long will the muscle mass rebuilding take which depends on how advanced LCPD was at the time of the surgical correction.
In general, the recovery period may last for as short as three to four months to as much as a year. However, eventually, almost all dogs make full recoveries and continue with their active and mischievous lives.
What Is The Prognosis For Dogs With LCPD?
The prognosis for dogs undergoing medical management is guarded. Although the condition is not life-threatening, it is definitely affecting the quality of life.
Even with the most individually-tailored pain management plan, the dog may still experience discomfort and be prevented from doing everyday activities.
For dogs with surgically corrected LCPD, the prognosis is excellent. It sounds surreal that a dog with such a severe condition can go back to living the same as it used before developing the LCPD.
The key to success is sticking to the rehabilitation (walking, swimming, and physical therapy) recommendations after the surgery.
Can LCPD Be Prevented?
Because of the condition’s inherited nature, LCPD can be prevented through responsible breeding practices. All dogs entering breeding programs must be tested for LCPD before being bred.
This is important because not all affected dogs show clinical signs – a dog with a low-grade LCPD may seem and act entirely normally.
The Orthopedic Foundation for animals has a special LCPD evaluation program.
The earliest age at which a dog can be evaluated is one year. Tested dogs are graded as LCPD free of LCPD affected based on a radiographic hip image.
Dogs that are LCPD positive are excluded from breeding programs, and their owners are advised to have them spayed or neutered as soon as possible.