Preliminary Results of a Novel Hybrid Cage Glenoid Compared to an All-Polyethylene Glenoid in Total Shoulder Arthroplasty

Bull Hosp Jt Dis (2013). 2015 Dec;73 Suppl 1:S86-91.

Abstract

Introduction: The aim of this study was to evaluate the preliminary outcomes of a hybrid cage glenoid design in comparison to pegged all-polyethylene glenoid components in anatomic total shoulder arthroplasty (aTSA).

Materials and methods: Ninety-two patients undergoing primary anatomic total shoulder arthroplasty with minimum two-year follow-up were reviewed. Forty-six patients had an ultra-high molecular weight polyethylene (UHMWPE) cemented pegged glenoid component, and 46 had a hybrid cage glenoid component. Patient data was retrospectively reviewed from prospectively acquired data in a multi-institutional IRB approved database. These age, gender, and follow-up matched patients were evaluated and scored preoperatively and a latest follow-up using the SST, UCLA, ASES, Constant, and SPADI scoring metrics. Additional measures included active abduction, elevation, and external rotation. Radiolucent line assessment of the glenoid was performed by use of a Grashey and axillary radiograph at latest follow-up. A Student's two tailed, unpaired t-test was used to identify differences in preoperative and postoperative results, where p < 0.05 denoted a significant difference.

Results: All patients demonstrated significant improvements in pain and function following treatment with the primary aTSA. The database contained three complications for the aTSA patients with a cage glenoid, and three complications for patients with a UHMWPE pegged glenoid. Radiographic data was available for 37 of 46 cage glenoid patients and 29 of 46 UHMWPE pegged glenoid patients. Five of 37 cage glenoid patients had a radiolucent line (13.5%) with an average radiographic line score of 0.22. Eight of 29 UHMWPE peg glenoid patients had a radiolucent line (27.6%) with an average radiographic line score of 0.57. Cage aTSA patients were associated with significantly less blood loss than aTSA UHMWPE pegged glenoid patients (avg. blood loss = 242 vs. 337; p = 0.022).

Conclusion: At minimum two-year follow-up, hybrid cage aTSA components show equal clinical outcomes to UHMWPE pegged glenoids. However, the hybrid cage components had significantly fewer radiolucent lines and less intra-operative blood loss. Additional and longer-term clinical and radiographic follow-up is necessary to confirm these promising early results.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Arthroplasty, Replacement / adverse effects
  • Arthroplasty, Replacement / instrumentation*
  • Biomechanical Phenomena
  • Databases, Factual
  • Female
  • Glenoid Cavity / diagnostic imaging
  • Glenoid Cavity / physiopathology
  • Glenoid Cavity / surgery*
  • Humans
  • Joint Prosthesis*
  • Male
  • Middle Aged
  • Pain Measurement
  • Polyethylene
  • Postoperative Complications / etiology
  • Prosthesis Design*
  • Radiography
  • Retrospective Studies
  • Shoulder Joint / diagnostic imaging
  • Shoulder Joint / physiopathology
  • Shoulder Joint / surgery*
  • Time Factors
  • Treatment Outcome

Substances

  • Polyethylene