Patient-specific 3D-printed shelf implant for the treatment of hip dysplasia tested in an experimental animal pilot in canines

Abstract

The concept of a novel patient-specific 3D-printed shelf implant should be evaluated in a relevant large animal model with hip dysplasia. Therefore, three dogs with radiographic bilateral hip dysplasia and a positive subluxation test underwent unilateral acetabular augmentation with a 3D-printed dog-specific titanium implant. The contralateral side served as control. The implants were designed on CT-based pelvic bone segmentations and extended the dysplastic acetabular rim to increase the weight bearing surface without impairing the range of motion. Outcome was assessed by clinical observation, manual subluxation testing, radiography, CT, and gait analysis from 6 weeks preoperatively until termination at 26 weeks postoperatively. Thereafter, all hip joints underwent histopathological examination. The implantation and recovery from surgery was uneventful. Clinical subluxation tests at the intervention side became negative. Imaging showed medialization of the femoral head at the intervention side and the mean (range) CE-angle increased from 94° (84°–99°) preoperative to 119° (117°–120°) postoperative. Gait analysis parameters returned to pre-operative levels after an average follow-up of 6 weeks. Histology showed a thickened synovial capsule between the implant and the femoral head without any evidence of additional damage to the articular cartilage compared to the control side. The surgical implantation of the 3D shelf was safe and feasible. The patient-specific 3D-printed shelf implants restored the femoral head coverage and stability of dysplastic hips without complications. The presented approach holds promise to treat residual hip dysplasia justifying future veterinary clinical trials to establish clinical effectiveness in a larger cohort to prepare for translation to human clinic.

Acetabular rim extension using a personalized titanium implant for treatment of hip dysplasia in dogs: short-term results

“…The titanium implants were designed at University Medical Centre Utrecht from preoperative CT images of the complete pelvis as described by Willemsen et al ( 24 ), using Mimics (version 24, Materialise, Leuven, Belgium) for segmentation of the DICOM files and 3-Matic (version 16, Materialise, Leuven, Belgium) for implant design. Like the implants described by Willemsen et al ( 24 , 25 ), the implants consisted of two subsections as follows: the implant–bone interface or attachment part and the acetabular rim extension part ( Figure 2 ). The attachment part was designed with a porous inner shell (1 mm sized Dode-Medium unit cell) and incorporated four screw holes and an additional ventral ilium flange for ease of positioning.…”

“…As a novel application of shelf arthroplasty, Willemsen et al ( 24 , 25 ) reported a patient-specific 3-dimensional (3D) printed titanium shelf implant for ACEtabular rim eXtension (ACE-X). The implant was designed according to computed tomography (CT) imaging of the pelvis and hip joints of individual dogs to optimally extend the dorsal acetabular rim and provide adequate coverage of the femoral head.…”

“…The implant was designed according to computed tomography (CT) imaging of the pelvis and hip joints of individual dogs to optimally extend the dorsal acetabular rim and provide adequate coverage of the femoral head. In a proof-of-concept pilot study, the ACE-X implant diminished hip laxity and restored coverage of dysplastic hip joints in three clinically unaffected dogs without complication ( 24 , 25 ). However, the short-term efficacy and safety of this novel patient-specific titanium shelf implant in clinically affected dogs suffering from HD remained to be investigated.…”

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

“…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 assessments 17 . 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.…”

Additive Manufacturing of Titanium Implants for Skull Reconstruction in 2 Dogs after Bone Tumour Excision

“…Additive manufacturing (AM) has been introduced in the medical field in the last decade, gaining popularity specifically in the field of maxillofacial, orthopaedic, oncological and spine surgery. [1][2][3][4][5][6][7][8][9][10] The availability of materials and printers has led to lower costs of patient-specific threedimensional (3D) implants in human medicine bringing them also within the scope of the veterinary field. 11 The use of individualized implants is the latest development in implant technology and offers a wide variety of opportunities and applications.…”