Dislocation

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In a luxation, the bone ends within a joint shift temporarily (see also >sprain) or permanently (luxation).
In a true luxation, the bone ends can partially or completely pop out of the joint, causing tears in the joint capsule and adjacent ligaments.

A dislocation refers to the complete displacement of joint surfaces relative to each other, where the joint partners lose their physiological connection. In contrast, a subluxation is when the joint surfaces are still partially in contact. In a dislocation, there is typically a tearing of the joint capsule and often damage to surrounding structures such as ligaments, tendons, and in some cases, nerves and blood vessels. This condition is extremely painful for the affected animal and leads to an immediate functional impairment of the affected joint.

Dislocations can occur in both dogs and cats, although the frequency of certain forms of dislocation differs between species. In dogs, patellar luxations (kneecap) and hip joint dislocations are particularly common, while in cats, temporomandibular joint and shoulder joint dislocations are observed more frequently. The anatomical peculiarities of each species play a decisive role here. Cats, for example, have higher joint mobility and elasticity of the ligamentous apparatus, which makes their joints more flexible on one hand, but can also make them more susceptible to certain forms of dislocation on the other.

Causes

The causes of dislocations in dogs and cats can generally be divided into two categories: traumatic and congenital or developmental dislocations.

Traumatic dislocations occur due to external force, such as those experienced in traffic accidents, falls from great heights (especially in cats), intense fights, or when a limb gets caught. The force exceeds the natural resilience of the joint-stabilizing structures. In cats, due to their lifestyle and movement patterns, jaw dislocations are not uncommon after trauma or even during intense yawning.

Congenital or developmental dislocations, on the other hand, are based on genetic factors or growth disorders. Patellar luxation in small dog breeds such as Chihuahuas, Yorkshire Terriers, or Toy Poodles is a classic example of this. This form of dislocation is facilitated by anatomical misalignments such as a too shallow groove for the kneecap or axial deviations of the limb. In larger dog breeds, severe forms of hip dysplasia can lead to dislocations.

Excessive athletic activity can also promote dislocations in predisposed animals. Dog sports involving rapid direction changes and jumps, such as agility, can lead to dislocations in anatomically predisposed animals. In cats, repeated jumps from great heights can impair joint stability in the long term.

Breed-specific predispositions also play an important role. In addition to the aforementioned small dog breeds prone to patellar luxation, Labrador Retrievers and German Shepherds, for example, show an increased susceptibility to elbow dislocations. In cats, breed-specific predispositions are less pronounced, however, certain breeding lines with extreme anatomical features may have an increased risk.

Symptoms

  • Dislocations are very painful
  • The affected joint can no longer be moved
  • Tears in the joint capsule vessels cause swelling and bruising around and in the joint
  • Partially palpable step formation and cavity in the joint area
  • Abnormal joint position

The clinical signs of a dislocation are usually acute and pronounced. Affected animals typically show a sudden onset of severe lameness, up to complete relief of the affected limb. However, the symptoms can vary depending on the affected joint and the extent of the injury.

In dogs and cats with a dislocation, the following characteristic symptoms can be observed: The affected joint appears fixed in an unnatural position and can no longer be moved physiologically. Due to the rupture of blood vessels in the joint capsule, significant swelling and bruising often occur in the joint area. Upon palpation, the veterinarian can often detect a step formation or an abnormal cavity in the joint area, as the joint surfaces are no longer correctly aligned.

Pain expression varies between animal species. While dogs often indicate pain by whimpering, howling, or aggressive behavior when touching the affected area, cats often show more subtle signs such as withdrawal behavior, reduced activity, or hissing when approaching the painful region.

In chronic or recurrent dislocations, such as those that can occur with patellar luxation, the symptoms are less dramatic. Here, one often observes intermittent lifting of the affected limb for a few steps, followed by normal weight-bearing when the kneecap spontaneously slides back into position. Cats with chronic jaw dislocation typically show difficulties eating and increased salivation.

Especially in traumatic dislocations, accompanying symptoms such as shock, increased heart rate, shallow breathing, and pale mucous membranes can occur, requiring immediate veterinary emergency care.

First Aid

  • The joint should not be moved anymore.
  • Do not attempt to put the joint back into the correct position. It could cause further damage to the cartilaginous joint surfaces as well as nerves, blood vessels, and ligaments in the region.
  • You can alleviate the swelling of the joint until you reach the veterinarian by cooling it with a wet bandage.
  • Fixing a dislocation is a matter for a veterinarian.

Diagnosis

The diagnosis of a dislocation is made through a systematic clinical examination in combination with imaging techniques. First, the veterinarian conducts a thorough anamnesis to obtain information about the accident or pre-existing problems. Observing the gait pattern – if the animal can still walk – provides initial indications of the affected limb and the extent of functional impairment.

During the orthopedic examination, the veterinarian carefully palpates the affected joint and checks joint mobility. Due to the severe pain, this examination is often performed under sedation or anesthesia to avoid additional stress and pain for the animal. The veterinarian looks for abnormal joint positions, instabilities, and pain sensitivity.

Imaging techniques are essential for a definitive diagnosis. X-rays in at least two planes represent the gold standard and allow assessment of joint position as well as exclusion of accompanying fractures. In more complex cases or for more detailed imaging of soft tissue structures, advanced imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI) may be used. These methods are particularly valuable for assessing the extent of damage to ligaments, tendons, and cartilage surfaces.

For chronic or recurrent dislocations, such as patellar luxation, additional classification by severity is performed. For patellar luxation, four grades are distinguished:

  • Grade 1: The patella can be manually luxated but returns to position on its own
  • Grade 2: The patella luxates occasionally but can be manually repositioned
  • Grade 3: The patella is permanently luxated but can be manually repositioned
  • Grade 4: The patella is permanently luxated and cannot be repositioned

In some cases, diagnostic arthroscopy may be useful to directly visualize the extent of joint damage and simultaneously initiate therapeutic measures.

Further veterinary measures

A thorough clinical examination provides indications in traumatic dislocations whether ligaments are injured and whether nerves or blood vessels are additionally damaged.
This is usually followed by further examinations of the joint under general anesthesia as well as several X-rays.
If stability cannot be achieved after repositioning the joint parts to the correct anatomical position, surgery is necessary.
The unstable position of the kneecap, which is usually genetically determined in small breeds, occupies a certain special position. The cause is altered anatomical conditions, which can be successfully surgically stabilized using different methods depending on the initial situation.

Supplements

The treatment of dislocations depends on the type of affected joint, the cause of the dislocation, the severity, and the duration since onset. Basically, a distinction is made between conservative and surgical therapeutic approaches.

In fresh, uncomplicated dislocations, closed reduction under anesthesia can be attempted. Here, the dislocated joint is brought back into its physiological position through targeted manipulation. This is followed by stabilization with a bandage, splint, or cast for several weeks to give the injured ligaments time to heal. This method shows particularly good results for shoulder joint dislocations in cats and some forms of hip joint dislocation.

For more complex dislocations, recurrence, or when accompanying injuries such as ligament ruptures or cartilage damage are present, surgical intervention is necessary. The surgical techniques vary depending on the affected joint:

For patellar luxation, surgical measures include, depending on the severity, deepening of the sliding groove for the kneecap (trochleoplasty), transposition of the tibial tuberosity (to correct the pull direction of the quadriceps muscle), or tightening of the joint capsule. For hip joint dislocations, various techniques such as capsular tightening, insertion of artificial ligaments, or in severe cases, artificial hip joint replacement can be used.

Modern minimally invasive techniques are becoming increasingly important. Arthroscopically supported procedures allow for less tissue trauma and faster rehabilitation. In complex cases, individualized implants can be manufactured using 3D printing technology to ensure optimal anatomical fit.

Drug therapy accompanies both conservative and surgical treatments and includes analgesics for pain relief, anti-inflammatory drugs to reduce inflammation, and in some cases, muscle relaxants. Special caution is required when selecting medications for cats, as they may metabolize certain active ingredients such as non-steroidal anti-inflammatory drugs less effectively.

An essential component of therapy is physical rehabilitation, which ideally begins in the early postoperative phase. Controlled movement exercises, hydrotherapy on the underwater treadmill, laser therapy, and targeted massage techniques support the restoration of joint function and the development of stabilizing musculature.

Prognosis and aftercare

The prognosis after a dislocation depends on various factors, including the affected joint, the cause of the dislocation, the time between occurrence and treatment, and the presence of accompanying injuries. Generally, the earlier the treatment, the better the prognosis.

For fresh, traumatic dislocations without significant accompanying injuries, the prognosis is usually good to very good after correct repositioning and adequate follow-up care. Shoulder joint dislocations in cats, for example, have a success rate of over 80% after successful closed reduction. For patellar luxations of grades 1 and 2, complete restoration of joint function can be expected in about 90% of cases after surgical correction.

Complicated dislocations with extensive soft tissue damage, accompanying fractures, or pre-existing degenerative changes have a more guarded prognosis. There is an increased risk of developing post-traumatic arthritis or chronic instability in these cases.

Aftercare plays a crucial role in treatment success and includes several components:

Movement restriction in the early phase after repositioning or surgery is essential to allow healing of the injured structures. Depending on the affected joint and type of treatment, this phase can last between two and eight weeks. During this time, dogs should only be walked on a short leash, while cats should ideally be kept in a confined space.

Structured rehabilitation begins with passive range of motion exercises and gradually progresses to active exercises and controlled increase in weight-bearing. An individually tailored rehabilitation program can shorten the healing time and improve functional outcomes. Modern rehabilitation concepts include hydrotherapy, laser therapy, therapeutic ultrasound, and targeted massage techniques.

Regular veterinary check-ups with clinical examinations and, if necessary, follow-up X-rays are important to monitor the healing process and detect complications early. Particular attention is paid to joint stability, range of motion, and signs of pain or inflammation.

Weight management is an often underestimated aspect of aftercare. Excess weight puts additional stress on the joints and can delay the healing process or increase the risk of recurrent dislocations. An adjusted diet with optimal calorie intake and, if necessary, the use of joint-supporting dietary supplements such as glucosamine, chondroitin, and omega-3 fatty acids can support the healing process.

Summary

Dislocations in dogs and cats represent a common orthopedic condition that can occur both traumatically and developmentally. The complete displacement of joint surfaces leads to severe pain and functional limitations. While patellar and hip joint dislocations are more common in dogs, jaw and shoulder joint dislocations are more frequently observed in cats.

Diagnosis includes a thorough clinical examination and imaging procedures, with X-rays being the gold standard. Treatment depends on the type and severity of the luxation and can range from closed reduction with subsequent immobilization to complex surgical interventions. Modern surgical techniques and minimally invasive procedures have significantly improved treatment outcomes in recent years.

The prognosis is usually good with early and adequate treatment, with consistent aftercare and structured rehabilitation having a decisive influence on the functional outcome. In the long term, there is a risk of post-traumatic arthrosis in severe luxations, which requires continuous monitoring and, if necessary, symptomatic therapy.

Preventive measures such as weight control, appropriate physical activity, and responsible breeding selection for hereditary forms of luxation can reduce the risk of luxations. Close cooperation between pet owners, veterinarians, and physiotherapists is the key to optimal treatment outcomes and a good quality of life for affected animals.

Outlook on current research

Research in the field of luxation treatment in dogs and cats continues to evolve. Current studies focus on various innovative approaches aimed at improving both diagnosis and therapy.

In the field of diagnostic imaging, new high-resolution MRI protocols allow for more detailed visualization of soft tissue structures such as ligaments, tendons, and cartilage. This improved imaging helps to detect subtle damages and optimize therapy planning. Dynamic examination techniques also allow assessment of joint function under load, which is particularly important for intermittent luxations.

In the surgical field, increasingly biomechanically optimized implants are being developed that allow for more stable fixation with less tissue irritation. The use of biocompatible materials with bone-like mechanical properties reduces the risk of implant loosening and failure. Personalized implants manufactured using 3D printing technology based on CT data of the individual patient enable optimal anatomical fit and improved functionality.

Regenerative therapy approaches are gaining importance. The application of stem cells, platelet-rich plasma (PRP), and growth factors aims to promote the healing of damaged cartilage and ligaments. Initial clinical studies show promising results, especially in the treatment of accompanying cartilage damage after luxations.

Genetic research is making progress in identifying genes associated with hereditary forms of luxation, especially patellar luxation. This could lead to genetic tests in the future that allow for more targeted breeding selection and reduce the prevalence of these diseases.

In the field of rehabilitation, computer-assisted gait analysis and pressure measurement plates are increasingly being used to objectively document the rehabilitation process and individually adjust therapy. Virtual reality and robot-assisted therapy systems, already established in human medicine, are being adapted for veterinary use.

The development of minimally invasive techniques is progressing. Arthroscopically assisted reconstructions of ligaments and capsular structures allow for less tissue traumatization and faster rehabilitation. These techniques are continuously being refined and extended to other joints and indications.

Despite these promising developments, there is still a need for research, particularly regarding the long-term results of new therapeutic approaches and the optimization of prevention strategies. Interdisciplinary collaboration between veterinarians, biomechanics experts, materials scientists, and geneticists will be crucial to further improve the treatment of luxations in dogs and cats.

Frequently asked questions (FAQs)

  1. What is meant by a dislocation in dogs?
    A dislocation (joint dislocation) is an injury in which the bones of a joint completely or partially (subluxation) shift from their normal position. This can damage the joint capsule and surrounding structures such as ligaments or tendons. Commonly affected joints in dogs include the shoulder, hip, knee, and elbow joints. A dislocation differs from a sprain or strain in that the joint surfaces no longer meet normally.

  2. What are the causes and risk factors for dislocation in dogs?

    • Traumatic events: Falls, collisions with vehicles, violent fights, or sports injuries can trigger a dislocation.
    • Congenital malpositions: Some breeds have congenital anatomical peculiarities that lead to unstable joints (e.g., patellar luxation in smaller breeds).
    • Obesity: Excessive body weight puts additional stress on the joints and can increase the risk of injuries.
    • Degenerative diseases: Wear and tear (e.g., arthritis) or weakness in ligaments and tendons can impair joint stability and promote dislocation.

  3. What symptoms indicate a dislocation?

    • Sudden lameness or reluctance to put weight on the affected leg
    • Severe pain during movements in the corresponding joint
    • Abnormal position of the limb (e.g., twisted or crooked leg)
    • Swelling or hematomas around the joint
    • Appeasement behavior (licking, favoring, whimpering) or aggression when touched
    • A typical sign can be an audible crack during the accident or the absence of normal joint mobility.

  4. How is a dislocation diagnosed and treated?

    • Clinical examination: The veterinarian checks the gait, carefully palpates the affected joint, and looks for instability.
    • Imaging techniques: X-rays are the gold standard to confirm a dislocation and rule out possible bone fractures. Additionally, an ultrasound or CT scan may be useful if soft tissues (e.g., ligaments, menisci) need to be examined more closely.
    • Treatment methods:
      • Reduction: The joint is carefully repositioned (often under sedation or anesthesia) into the anatomically correct position.
      • Splinting / Stabilization: Depending on the severity of the injury, the joint is immobilized or stabilized using straps, sutures, or implants.
      • Surgery: For severe dislocations, complicated ligament injuries, or recurrent dislocations, surgical intervention may be necessary. The joint is reconstructed and stabilized, e.g., through artificial ligaments or by relocating bone attachments.
      • Physiotherapy: To support healing and restore joint function, physiotherapy is often recommended.

  5. How can one prevent dislocations in dogs?

    • Weight control: A healthy body weight reduces stress on the joints.
    • Adequate exercise: Moderate, regular training strengthens muscles, ligaments, and tendons.
    • Consider breed-specific risks: For breeds prone to patellar luxation or hip dysplasia, targeted muscle-building training and regular veterinary check-ups are advisable.
    • Avoiding high stress peaks: Rapid turns, jumps from great heights, or excessive athletic strain can increase the risk of injuries.
    • Early detection: At the first signs of lameness or pain, a veterinarian should be consulted to intervene early before severe joint damage or dislocations occur.

Conclusion: Dislocations are painful and potentially consequential joint injuries in dogs that require prompt action. Professional diagnosis and treatment by a veterinarian are crucial to restabilize the affected joint and avoid long-term complications.

Literature

  • Löwe, G. and Löwe, O. (2021). Emergencies in Dogs and Cats – A Veterinary Guide. Kynos-Verlag. 208 p.
  • Schulz KS, Hayashi K, Fossum TW. Diseases of the joints. In: Fossum TW, ed. Small Animal Surgery. 5th ed. Philadelphia: Elsevier; 2019:1134-1279.
  • DeCamp CE, Johnston SA, Déjardin LM, Schaefer SL. Handbook of Small Animal Orthopedics and Fracture Repair. 5th ed. St. Louis: Elsevier; 2020.
  • Witte PG, Scott HW. Conditions of the feline patellar ligament in cats with and without medial patellar luxation. Veterinary and Comparative Orthopaedics and Traumatology. 2020;33(3):177-181.
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