Zlig Surgery

Cruciate Repair & Replacement Surgery in Dogs

Zlig Surgery for Dogs at Southern Cross Veterinary Clinic – Offering a less invasive advanced orthopaedic solutions for torn ACLs. Learn about the innovative Zlig procedure, a direct ACL stabilisation method replacing the torn ligament.

What is Zlig Surgery for Dogs?

Zlig surgery is an orthopaedic surgery performed on dogs to replace a torn Anterior Cruciate Ligament (ACL) with an artificial implant known as the ‘Zlig’. It is not to be confused with the old fashioned ‘De angelis’ or ‘lateral suture’ surgery.

There currently exist several options to address a torn ACL (Anterior Cruciate Ligament) using traditional CCL (Cranial Cruciate Ligament) surgeries such as TTA (Tibial Tuberosity Advancement), TTO (Triple Tibial Osteotomy) and TPLO (Tibial Plateau Levelling Osteotomy). and the lateral suture or de angelis surgery. However, we at Southern Cross Veterinary Clinic, highly recommend considering Zlig surgery for the enhanced recovery, lack of a significant period of restriction or ‘cage rest’ post op.

The Zlig surgery is an innovative alternative to the aforementioned traditional approaches and stands out as being the only “Direct” ACL stabilisation procedure. This is because it directly replaces the torn ACL, unlike other “In-Direct” approaches which involve surgical modifications to the stifle (knee), enabling it to adapt to a torn ACL, or replacing the function of it with a potentially weaker nylon fibre (as in deangelis).

In the realm of human care, replacing a torn ACL is considered standard practice, and we at Southern Cross Vet advocate that the same standard should apply to dogs, however hamstring grafts like in people, don’t work for dogs. Over recent years, advancements in Zlig surgery for dogs have led to a reduction in health concerns and an enhancement in joint strength and stability, making it a much more viable option for pet parents to consider. This surgery can lead to an improved quality of life for your pet and gives them the chance to move around more freely as compared to others. In the immediate post op period as it DOESNT REQUIRE INTENSIVE CRATE REST LIKE OTHER TECHNIQUES DO.

 Benefits of Zlig vs TPLO, TTO, TTA other ACL treatments in dogs

The advantages of opting for the Zlig vs TPLO and other traditional cruciate repair techniques are: 

  • Accelerated Recovery Time: One compelling reason to choose the Zlig vs TPLO (Tibial Plateau Levelling Osteotomy) and other conventional treatments is its significantly shorter recovery time. Dogs undergoing the Zlig surgery typically regain normal limb functionality within days or a few weeks and do not require a strict crate rest period. In contrast, traditional cruciate repair surgery necessitates a minimum of 8-12 weeks of cage rest, and any complications can extend this period, adversely affecting your pet’s morale and quality of life. 
  • Addressing Medial Rotational Instability: The Zlig implant stands out due to its unique ability to address medial rotational instability resulting from an ACL (Anterior Cruciate Ligament) tear. Unlike other ACL repair techniques, the Zlig implant extends across the joint from the back of the femur to the front of the tibia, angling slightly from lateral to medial. This design prevents internal rotation, providing crucial stability to the knee joint. 
  • Potential Long-Term Joint Stability: cruciate repair techniques like de angelis can often lead to arthritis in dogs within 2-3 years post-surgery. In contrast, the Zlig implant offers a potential deviation from this outcome. The long-term stability provided by the Zlig implant has the potential to mitigate the development of arthritis in the stifle (knee) joint, offering a more sustainable solution. 
  • Suitability and Considerations: It’s essential to note that the Zlig ACL (Anterior Cruciate Ligament) implant is specifically tailored for dogs within the 5-45kg range. While the technique may be applicable to larger dogs, its suitability depends on their activity level and the load placed on the implant. In instances involving very large dogs, an option to enhance strength is the placement of two implants, albeit with an associated increase in cost. 


Like all surgery, Zlig cruciate surgery carries risk. While our rates are much better, the published literature shows that there is approximately a 20percent chance of weakening of the implant post op, meaning the more invasive surgery may be required. However our outcome rates are closer to 95%, which is highly successful.

Surgery at Southern Cross Veterinary Clinic

The Zlig surgery at Southern Cross Veterinary Clinic is currently performed by Dr Neil Hannan. Dr Hannan is known for performing complex orthopaedic and soft tissue surgery at Southern Cross Veterinary Clinic and is well known in the veterinary community for his surgical excellence. He also lectured many of the undergraduate students at the University of Sydney.  

Dr Hannan has dedicated his career to enhancing the lives of our furry friends through advanced surgical techniques. Watch as he explains the ins and outs of the Zlig procedure, including its benefits and why he prefers it over conventional CCL surgeries. 

Cost of the Surgery

The cost of the Zlig surgery for dogs is roughly AUD 7000 (including GST) at the time of publishing this on our website. We kindly advise you to call the clinic at 1300 DOC SAM (1300 362 726) to confirm the pricing closer to when you expect to have the surgery. 

While this procedure is slightly more costly as compared to the traditional cranial cruciate repair techniques, this procedure procedure may offer significant benefits and comfort levels not achievable in the short term with the other procedures. Investing in a Zlig implant to replace the torn ACL can also potentially decrease the risk of early-onset arthritis and significantly improve your dogs quality of life.  


We recommend that you give your dog as much rest as possible post the successful completion of the surgery as rest improves healing. While your dog may be able to use their legs once the surgery is done, we advise that you allow them short toilet walks initially only for the first 5-7days. You can slowly start taking your dogs on longer walks on the lead for another month or so before we recommend a higher level of activity. The individual recovery plan, we note, does vary and we will provide an in depth discussion about your individual pets plan once surgery is completed.


At Southern Cross Vet, we will be there for you and your fur baby at every step of their recovery. Not only are we available on call if you need any urgent help, but we also schedule post-surgery consultations to monitor your fur-baby’s progress. We are as committed as you are to providing them a full recovery! 

Remember, Southern Cross Veterinary Clinic at St Peters is now open 24/7 for Emergency Care and we also take After-hours appointments until MIDNIGHT. So, we are always there for your fur baby, whenever you need us! 

Give us a call at 1300 DOC SAM (1300 362 726), or click the button below to book an appointment now!