preoperative preparation and sterile draping techniques for dog limb surgery

Extracapsular 3D-Printed Implant for Restoring Hip Stability in Canines

Hip dysplasia (HD) in dogs manifests due to a bad fit between the hip socket (acetabulum) and the femoral head resulting in subluxation of the hip joint. It affects mainly young medium- to large-breed dogs, resulting in joint cartilage deterioration, and ultimately, severe osteoarthritis (OA) leading to chronic pain and low quality of life1,2. The overall prevalence of hip dysplasia in dogs is 15.56%, which varies widely based on breed and classification systems3,4.
Apart from lifestyle changes, hip dysplastic dog patients are treated with antiinflammatory and analgesic drugs to control pain and maintain mobility4. In case of hip laxity in young adult dogs, the only surgical resort is double (DPO) or triple pelvic osteotomy (TPO), a procedure involving two or three full cuts of the pelvic bones to expand the coverage of the femoral head. However, complications after osteotomies are common and the progression of OA is still observed5,6,7,8,9. Once severe OA and chronic pain have developed, only high-impact complex surgery like total hip replacement (THR) or salvage femoral head and neck ostectomy (FHO) remain10. However, FHO presents less favorable outcomes in large breed dogs and necessitates prolonged physical therapy for the restoration of limb function11. Furthermore, THR is technically challenging and inherently associated with severe complications12,13,14. Therefore, effective hip dysplasia therapy necessitating only low-impact surgery and with a lower complication risk is required before this end stage is achieved.
The 3-dimensional (3D)-printed personalized hip implant (3DHIP) is a first-of-a-kind treatment for canine hip dysplasia developed with the intention to offer a minimal traumatic dog-specific implant that restores hip joint stability. The technique involves a titanium implant to treat mainly young adult (6 months to 2 years old) dog patients with a dysfunctional hip joint showing hip laxity grade B (borderline) to D (moderate) according to the F&#233;d&#233;ration Cynologique Internationale (FCI)15. After computed tomography (CT) imaging of the dysplastic joint, an implant is designed following the specific anatomy of the hip joint in a personalized manner to extend the dorsal acetabular rim, thereby preventing hip joint subluxation and restoring hip joint stability.
A previous canine cadaver study revealed that the implant enhanced femoral head coverage and demonstrated failure under an impact force of 1,330 &#177; 320 Newtons16. Subsequently, a pilot study with experimental dogs demonstrated enhanced femoral head coverage, reduced hip laxity, and increased weight bearing by force plate analysis. Furthermore, examination of the intervened hips at 6 months post-implantation revealed normal volume and a smooth surface of both the femoral head and acetabulum cartilage, accompanied by joint capsule hypertrophy based on gross and histological assessments17. Upon confirmation of the efficacy and safety of the implant and treatment concept, a clinical investigation was carried out on client-owned dogs suffering from hip dysplasia. The short-term study revealed that the benefits of the 3D-printed acetabular rim extension implant are a personalized, good fit of the implant to the acetabulum restoring hip joint stability, decreased pain-related activities, and a low-impact surgical procedure18. Application of the implant requires access to the ventrocaudal aspect of the iliac body and the craniodorsal aspect of the hip joint. In this paper, we describe our surgical planning and surgical procedure with a modified craniodorsal approach to the hip joint as a manual for implantation of the 3DHIP in dogs affected by hip dysplasia.

Author Spotlight: A Novel 3D-Printed Titanium Implant for Minimally Invasive Treatment of Hip Dysplasia in Young Dogs

Surgical Technique of the 3-Dimensional-printed Personalized Hip Implant for the Treatment of Canine Hip Dysplasia

The scope of our research is the application of a new surgical treatment, 3D hip, for young dogs with hip dysplasia characterized by hip laxity. The 3D hip implant is a patient-specific 3D-printed titanium implant that is designed to extend the dorsal acetabular rim of the hip joint and leads to joint stability and resolution of hip pain. Hip dysplasia is a common orthopedic disease in young dogs that can be treated surgically by invasive techniques like pelvic osteotomy to hip replacement and femoral head and neck incision.So there is a need for minimally invasive procedure like the 3D hip implant, which can be treated bilaterally with rapid recovery preserving the joint. The 3D hip is laser-printed with titanium powder using a direct metal printing machine. Printing is computer-guided by the CT scan of the dog's pelvis, ensuring sufficient dorsal acetabular rim extension for perfect fit placement, and reversing the hip laxity to immediate joint stability.Accuracy of the 3D hip implant placement is evaluated during surgery using fluoroscopy, but it may be affected by changes of bone and joint between the day of CT scan and the day of surgery or the lead time. So a reduction in lead term to two weeks would be ideal. The modified surgical hip approach provides an adequate view of the dorsal acetabular rim of the hip joint for implant placement.The 3D hip implant increases femoral head coverage, decreases laxity of the dysplastic hip joint, and shortens recovery time. Bilateral application in one operative session is the major benefit of the 3D hip procedure.

Preoperative Preparation and Sterile Draping Techniques for Dog Limb Surgery

To begin, hang the affected limb of an anesthetized dog placed in lateral recumbency. Secure the dog using a vacuum bean bag positioner. Scrub the limb twice with 4%chlorhexidine gluconate solution, followed by spraying it with 70%ethanol twice.Place four surgical waterproof drapes around the surgical site. Secure and cover the distal limb with a sterile waterproof sock. Then, add a layer of sterile cohesive wrap for additional protection.Cover the exposed skin of the entire surgical area with an iodine-impregnated drape.

preoperative-preparation-sterile-draping-techniques-for-dog-limb

Research

JoVE Journal

Biology

Hip dysplasia causes major disability in dogs. Treatment options are limited to palliative treatment (e.g., pain relief, physical exercise, lifestyle changes, and weight control) or invasive surgeries such as pelvic osteotomies and total hip arthroplasty. Hence, a strong unmet need exists for an effective and dog-friendly solution that enhances the quality of life of man&#39;s best friend. We fill this treatment gap by offering a minimally traumatic and extraarticular, dog-specific, 3-dimensional-printed, hip implant (3DHIP) that restores hip joint stability. The surgical treatment using a 3DHIP implant is less invasive than osteotomies and can be performed bilaterally in one surgical session. The 3DHIP implant extends the dorsal acetabular rim of the dysplastic hip joint thereby increasing coverage of the femoral head and inhibiting joint subluxation with fast recovery. Sufficient access to the dorsal acetabular rim and ventral border of the iliac body together with optimal fitting and fixation of the implant are key steps for a successful 3DHIP implantation and imply the need for a specific approach. The present article aims to showcase this innovative surgical technique with tips and tricks as a surgical manual for implantation of the 3DHIP implant in dogs affected by hip dysplasia.

This work describes a novel surgical technique for extracapsular implantation of a personalized, 3-dimensional-printed, joint-preserving implant. This novel treatment aims to restore hip stability in young adult dogs suffering from hip dysplasia with laxity by uniquely reproducing the anatomical shape of the acetabular rim of the hip joint.

Hip dysplasia causes major disability in dogs. Treatment options are limited to palliative treatment (e.g., pain relief, physical exercise, lifestyle ...

Dog Hip Joint Access and Acetabular Rim Extension Using the 3DHIP Implant Placement 

To begin, identify the tip of the greater trochanter, the cranial border of the proximal femur, the iliac wing, and the ischiatic tuber on the anesthetized dog. Then draw a line to make a skin incision. Perform the Ortolani subluxation test to confirm hip subluxation before making an incision.Incise the skin sharply with a surgical knife, starting from the cranial dorsal iliac spine. Then turn ventrally along the cranial border of the proximal femur and stop distally to the greater trochanter. Make an incision through the subcutaneous fat down to the fascia.Sharply separate and incise the superficial leaf of the fascia lata muscle along the cranial border of the biceps femoris muscle. Retract the biceps femoris muscle caudally. After identifying the fatty triangle, separate it with blunt-tipped dissecting scissors and index finger to provide access to deeper layers.Using a surgical knife, incise the intermuscular septum between the superficial gluteal muscle, the middle gluteal muscle, and the tensor fascia lata muscle. With a handheld retractor, separate and retract the superficial and middle gluteal muscles dorsally to expose the insertion of the deep gluteal muscle. Use blunt-tipped dissecting scissors to undermine the deep gluteal muscle close to the greater trochanter.Pre-place a stay suture on the deep gluteal tendon approximately one to 1.5 centimeters proximal from its insertion on the greater trochanter. Using a surgical knife, perform a complete deep gluteal tenotomy close to the bone. Use blunt-tipped dissection scissors to free the deep gluteal muscle from the underlying joint capsule.Then with the help of the periosteal elevator and index finger, subperiosteally elevate the deep gluteal muscle from the ileum and retract it dorsally. Using a periosteal elevator, partially free the iliacus muscle from the caudoventral border of the iliac shaft, and identify the insertion of the rectus femoris muscle. Remove all remaining soft tissue from the exposed iliac shaft for accurate positioning of the 3D hip implant.Scratch the periosteum to stimulate bone ingrowth for secondary implant fixation. Identify the articularis coxae muscle, caudal to the rectus femoris muscle overlying the joint capsule. Check the 3D hip implant before positioning and check the locking mechanism of the drill guide on the implant.Confirm a positive Ortolani subluxation test before implantation. Fit the 3D hip implant into the iliac shaft, ensuring the implant's flange hook under the ventral border of the exposed caudoventral iliac shaft, just cranial to the bony prominence. Check that the rim extension part of the implant overlays the craniodorsal part of the hip joint capsule without capturing any deep gluteal muscle.Verify the implant position by visualizing and probing for optimal bone contact in all four exposed screw holes. Then confirm the absence of space between the iliac flange and the caudoventral iliac shaft. Drill the hole for the first screw.Then measure the screw length and temporarily fix the implant in the desired position with one titanium self-tapping locking screw. After intraoperative fluoroscopy of the hip joints, ensure that the curvature of the rim extension part of the implant is congruent with the curvature of the femoral head and acetabular rim. Once correct positioning is confirmed, insert three titanium self-tapping locking screws in the remaining screw holes to fix the implant to the ileal shaft.Next, execute flexion, extension, and abduction movements of the hip joint to check for femoral head or neck impingement. Perform the Ortolani subluxation test to confirm the reversal of hip laxity. Reattach the cut ends of the insertional tendon of the deep gluteal muscle using a locking loop suture pattern and one to two mattress synthetic, absorbable, monofilament sutures.Repair the gluteal fascia and tensor fascia lata in a simple interrupted pattern. Close the subcutaneous tissue with an absorbable suture and skin with a non-absorbable suture in a simple interrupted pattern. To confirm the implant positioning and screw placement, perform postoperative imaging, consisting of CT scan of the hips or hip orthogonal radiographs in lateral oblique, and ventral/dorsal views.