Case Study: Robotic Total Hip Replacement in a 48-year-old male

A 48-year-old male presented to our office with complaints of worsening pain in the left hip. The patient stated that the pain was present since he was a child but gradually worsened over the past 4 years. He reported undergoing surgery in the Dominican Republic as a child on his left hip. He was unable to recall what was the surgery and why it was needed.

He reported he was the firstborn child born and his parents told him he was born with a complicated delivery. After initial surgery as a child he remembers, he was put in a special Plaster of Paris cast. As a growing child, he was healthy and able to sit, squat and walk without discomfort.

He reported walking with a limp as noticed by his parents but the limp was painless. He was given a shoe raise to help walk without a limp. Over the past 4 years, the pain in the left hip gradually started worsening. He had recently moved to the United States 3 years ago and consulted a physician for hip pain who advised him of a hip replacement.

The pain was located in the left groin radiating to his buttock and left knee. The pain was described as a dull ache to a sharp pain which was moderate in intensity (6/10). The limping increased as the intensity of pain increased with activities such as walking, going up and down the stairs, bending, squatting, and getting up from a chair.

He used over the counter medications such as Advil, Motrin, and Tylenol for pain but the relief was temporary. He had tried physical therapy and heat pads but with no relief. He stated the inability to walk for a prolonged period, sit cross-legged and squat. He worked at a local grocery store and his work involved driving, lifting and moving objects.

He was distressed with his increasing disability and wanted to inquire about the option of total hip replacement. He was a nonsmoker, nondrinker and his past medical history included dyslipidemia controlled with medications. He denied any known drug allergies. His family history was negative for any hip dysplasia. He denied any childhood infection of the left hip with discharge.

His physical examination revealed a steady, coordinated antalgic gait with a lurch towards the left side. The stance phase of the left side was reduced. The left shoulder was at a lower level than the right. There was presence of functional scoliosis with convexity towards the right side which disappeared on bending forward.

The left anterior superior iliac spine was at a lower level than the right. The left buttock and thigh bulk was reduced and atrophied compared to the right. Both the patella and medial malleolus were at the same level. There was a mild exaggeration of the lumbar lordosis.

On spine examination, there was a scar on the left groin consistent with old surgery. There was no fullness in the Scarpa’s triangle. Keeping the limbs parallel, the left ASIS was at a higher level than the right. There was no bony globular mass in the left gluteal region. There was no broadening or thickening of the left greater trochanter.

There was tenderness on the left anterior joint line. Squaring the pelvis revealed an adduction deformity of 5 degrees. There was leg length discrepancy with apparent shortening greater than the true shortening. On the Thomas test, there was flexion deformity of 10 degrees.

On digital palpation, the left greater trochanter was at a higher level than the right. Adduction was possible from 5 degrees to 35 degrees, and flexion from 10 degrees to 110 degrees. The internal and external rotation were painful.

The examination of the contralateral hip, bilateral knees and ankles were normal. There was no evidence of other congenital deformities such as metatarsal adductus, talipes calcaneovalgus or torticollis. The distal neurological examination was normal and bilateral lower extremity pulses were palpable with good volume.

X-ray showing the AP view of the pelvis with both hip joints

X-ray showing the AP and limited lateral view of the left hip.

Imaging revealed severe degenerative changes of the left hip. There was severe joint space narrowing, deformity of the acetabulum and femoral head, subchondral sclerosis and osteophyte formation.

After careful consideration of the patient’s conditions, he was advised a robotic hip replacement. Risks, benefits, and alternatives were discussed with the patient at length. He agreed to go ahead with the procedure.

OPERATIONS:

1. Robotic hip replacement
2. Placement of external fixator.
3. Removal of the external fixator.
4. Physician-directed fluoroscopy, less than one hour.

IMPLANTS USED: Titanium shell 48 mm with a 32-mm inner diameter with two cancellous screws (6.5 x 30 mm and 6.5 x 16 mm) with a 127-degree neck stem with a 32-mm plus 4 ceramic femoral head.

DESCRIPTION OF PROCEDURE: The patient was brought to the operating room. After obtaining informed consent, signing the correct surgical site, the risks, benefits, and alternatives were extensively discussed with the patient as well as her husband- and sister prior to the procedure. The patient was brought to the operating room and anesthesia was obtained by the anesthesiologist.

The left lower extremity was then draped and prepped in the usual sterile manner. The external fixator was placed over the iliac crest, and the arrays were set up for the robot. The incision was then made for the left hip centered over the greater trochanter.

Skin and subcutaneous tissues were then incised. The fascia was then divided, the gluteus tendon proximal part was then released. The hip was then dislocated. The head was then visualized. The neck resection was then performed. The head was then removed.

Attention was then turned to the acetabulum. Before dislocating the hip, the markers were placed at the correct level over the patella, the greater trochanter, and the acetabulum. After the head was removed, acetabulum was then exposed, and the acetabulum was then marked.

Reaming was performed by the robot, and the final shell was then placed into the correct position in the correct abduction and anteversion with robotic assistance. Two screws were then used for additional fixation.

The poly was then placed over the shell. The position of the cup was cross-checked with the cup checked prior to the placement of the polyethylene. Attention was then turned towards the femur. The femur was then sequentially broached. The final broach was left into position, and the trunnion and the head were then placed into position.

The hip was then relocated, trialed through a full range of motion, and the hip was found to be stable in a physiological range of motion. The hip was then dislocated. Final components were then placed into position, and the hip was then reduced again. A thorough lavage was given.

At this point, it was realized that the hip was a little short, and therefore, the ceramic head was then removed and was re-trialed with a +4 head. The hip was found to be stable with a +4 head. The +4 head was therefore used for the final implant.

Thorough lavage was given. The drill holes were made in the greater trochanter through transosseous tunnels and the posterior soft tissue structures were then tacked to the greater trochanter through these tunnels.

The fascia was closed with Ethibond, cutaneous tissue was closed with 0-Vicryl, subcuticular tissues were closed with 2-0 Vicryl, the skin was closed using staples.

The arrays over the iliac crest were then removed. The pins were then removed, and cutaneous tissues were .closed with 0-Vicryl, subcuticular tissues were closed with 2-0 Vicryl, the skin was closed using staples. Sterile dressing was then applied over the wound, and the patient was then transferred to the postoperative care unit in stable condition.

After the procedure was performed, an x-ray was done, and the prosthesis was visualized in the correct position.

Postoperative x-ray of the pelvis with both hip joints in the AP view.

The patient was given an abduction pillow postoperative. He was educated about hip precautions, and weight-bearing was allowed as tolerated. Deep vein thrombosis prophylaxis was started in the form of aspirin 325 mg BID. The patient was stable and discharged the following day. There was no distal neurological deficit.

The pain was managed well with medications. Sutures were removed on the 14th day uneventfully. Outpatient physical therapy was started focusing on gait training, fall prevention, range of motion, strengthening, balance, and coordination. Three months postoperative, the patient reported zero pain and was happily walking back to his baseline. He follows as needed.

Disclaimer – Patient’s name, age, sex, dates, events have been changed or modified to protect patient privacy.