Mid-term results similar for hemi, total shoulder arthroplasty

Researchers noted that two-year follow-up findings mirror five to 10 year differences between the groups.

CHICAGO — Surgeons have debated whether total shoulder arthroplasty or hemiarthroplasty provides optimal treatment for osteoarthritis patients. Now, emerging results from a new study indicate comparable outcomes.

Researchers examining 97 patients who received either hemi- or total shoulder arthroplasty (TSA) discovered no significant differences between the groups on the Visual Analog Scale (VAS) for pain (P=.30) and the simple shoulder test (SST; P=.26) at both two years postop and longer-term follow-up (P=.71 and P=.83, respectively), according to the study.

“Our results with hemiarthroplasty at two years were equivalent to the results at five to 10 years. So, we did not see an increase in symptoms as time went on in these patients who we thought were treated correctly with a hemi arthroplasty,” Charles A. Rockwood, Jr., MD, a professor at the University of Texas Health Science Center in San Antonio, said during his presentation at the American Academy of Orthopaedic Surgeons 73rd Annual Meeting.

Hemi vs. TSA

Rockwood and his colleagues followed a consecutive cohort of patients with a minimum five-year follow-up treated for primary or secondary osteoarthritis (OA) between 1990 and 1997. All patients received the Global Advantage prosthesis (DePuy Orthopedics).

Surgeons performed TSA in patients with more than 20° of glenoid erosion. Pitted glenoids and those with a double contour that could not be corrected also received TSA. Surgeons performed hemiarthroplasty when patients had a smooth, eburnated glenoid or “when the glenoid that failed was concentric and there was minimal or no subluxation,” Rockwood said.

The TSA group included 47 patients (33 men and 14 women) with a mean age of 57 years. The hemiarthroplasty group included 50 patients (29 men and 21 women) with a mean age of 63 years. The researchers followed TSA patients for a mean 6.2 years and hemiarthroplasty patients for 7.5 years, according to the study.

Using Gruen’s zonal analysis for the humerus, they found no luncencies in 52% of cases and 1 mm of lucency in 48%.

The researchers characterized the TSA glenoids using a system by Lazarus et al, Rockwood said. They rated 50% of the keeled implants as Grade 4 or 5 for lucency, while all pegged implants were grouped as Grade 3 or lower.

Clinical outcomes

Both treatment groups experienced complications. “Three patients of the total group had to be revised to a [hemiarthroplasty],” Rockwood said. Two patients received a keel prosthesis and one patient had a five-peg implant. One patient in the hemiarthroplasty group was revised to TSA and three patients received a repair with pectoralis major transfer.

Despite these differences, the researchers found similar clinical results at two-year follow-up in VAS scores, clinical shoulder tests and ASES scales for both treatment groups, Rockwood said.

Hemiarthroplasty patients had a VAS score of 14.9 and SST scores of 9.4. TSA patients had VAS scores of 10.9 and SST scores of 9.5. When the researchers questioned patients regarding pain during sleep, hemiarthroplasty patients reported a mean score of 12.4 points vs. 18 points among TSA patients, according to the study.

The similarities between the groups remained consistent at last follow-up. Hemiarthroplasty patients had a VAS pain score of 18.6, while TSA patients had a score 20.4. “At follow-up, there was no statistical difference in flexion, external rotation or internal rotation between hemi and total [groups],” Rockwood said.

Although the researchers found no clinical significant differences between the groups, Rockwood noted that surgeons may find it less difficult to convert a hemiarthroplasty to a TSA. He also stressed the importance of surgical indications when choosing between the operations.

For more information:
Wirth MA, Southworth C, Rockwood CA . Mid-term results of hemi-arthroplasty vs. total shoulder arthroplasty: 5 year minimum follow-up. #280. Presented at the American Academy of Orthopaedic Surgeons 73rd Annual Meeting. March 22-26, 2006. Chicago.