Primary Hip Arthroplasty Case Title: Ceramic on Monobloc Vitamin E Enhanced HXLP Titanium Spray Coated: THA with Impaction Autografting of the Acetabulum
Demographics
Age: 69 Sex: Male BMI: 28
Relevant Past Medical History
Principal pathologies: Hyperuricemia.
Previous surgical procedures: Appendectomy 40 years ago.
Medication: Allopurinol.
History of presenting complaint: Pain due to arthritis as potential contribution of high uric acid arthritis.
Clinical Examination
Symptoms: Pain, inability to walk and night pain. Range of motion: 0–90°, limited internal/ external rotation and the joint was locked in a protrusion type of deformity due to extensive
erosions. Unable to abduct and adduct.
Specific tests: Thomas positive in 25°.
Main disability: Pain all day long and inability to walk.
Scoring if available: HHS 65. Neurovascular evaluation: Intact.
Preoperative Radiological
Assessment/Imaging (Fig. 3.7)
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Fig. 3.7 Significant erosions of the right hip. Protrusion deformity with deepening of the inner plate with sclerotic margins. Loss of cancellous bone in the periphery of the socket. Bone quality in general reasonable for the age of the patient
Preoperative Planning
Diagnosis: Osteoarthritis of the right hip (Fig. 3.7).
Possible treatment options: Cemented or uncemented THA.
Chosen treatment method: Uncemented acetabular cup, vitamin E HXLP Mathys 56 mm/36 mm, uncemented femoral stem Mathys 10 STD and femoral head Mathys 36 L.
Selection of implants if applicable and rationale: Sufficient bone stock for uncemented implantation. A decision to enhance the acetabular cancellous bone stock using impaction autografting.
Surgical Note
Acetabular preparation: With the patient in lateral decubitus position, a direct superior approach was used to approach the hip. The acetabulum was easily exposed in a standard way, and the sequential reaming allowed a trial 56 × 36 mm acetabular component to be inserted. Reaming was difficult in places due to sclerosis. Smaller reamers are used to remove the sclerotic surface along with curved osteotomes. Eventually, a bleeding cancellous bone was exposed; however, the lack of cancellous bone stock and the medialization of the reaming were not acceptable. The decision was made to impaction autograft the acetabular bed using the large available patient’s femoral head. The cartilage and the osteophytes were removed using the saw and then the head was divided into several rounded segments before creating 1 cm cartilaginous bone chips. Tight impaction grafting using special impactors was then performed until the new bed was created. Trial socket insertion achieved better position and less medialization with good ream fit of the implant. The real implant was then inserted tightly to the proper direction. The design of this implant is hemispherical thus allowing a better fit to the periphery of the acetabular ream. There is no need for supporting screws.
Femoral preparation: The femur was prepared
using the appropriate rasps that compact the bone into an anatomical shape to fit the stem. The stem is collarless, double tapered, anatomic without shoulder and fully coated with hydroxyapatite. Easy rasping and trial reduction are used for assessing the leg length and the offset. A 36 mm ceramic head was used to achieve the final reduction (Fig. 3.8).
Postoperative Radiographs
(Fig. 3.8)
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Fig. 3.8 Evident impaction autografting of the acetabular bed bringing the floor more lateral compared to the preoperative radiograph. Proper fit of the socket and the stem and right orientation
Postoperative Management
Chemoprophylaxis and anticoagulant treatment period: Vancomycin 500 mg (one dose preoperatively, two doses postoperatively), cefuroxime 750 mg (one dose preoperatively, two doses postoperatively), enoxaparin 1 × 1 for the days of hospitalization and then rivaroxaban 10 mg 1 × 1 for thirty days.
Gait/limb loading until full loading: Partial weight-bearing for four weeks and then as tolerated.