Radiostereometric analysis of keeled versus pegged glenoid components in total shoulder arthroplasty: a randomized feasibility study

Abstract

Radiostereometric analysis of keeled versus pegged glenoid components in total shoulder arthroplasty: a randomized feasibility study Background: This study aimed to assess differences in the fixation and functional outcomes between pegged and keeled all-polyethylene glenoid components for standard total shoulder arthroplasty. Methods:Patients were randomized to receive a keeled or pegged all-polyethylene glenoid component. We used model-based radiostereometric analysis (RSA) to assess glenoid fixation and subjective outcome measures to assess patient function. Followup examinations were completed at 6 weeks and 6, 12 and 24 months after surgery. Modifications to the RSA surgical, imaging and analytical techniques were required throughout the study to improve the viability of the data.Results: Stymied enrolment resulted in only 16 patients being included in our analyses. The RSA data indicated statistically greater coronal plane migration in the keeled glenoid group than in the pegged group at 12 and 24 months. Functional outcome scores did not differ significantly between the groups at any follow-up. One patient with a keeled glenoid showed high component migration after 24 months and subsequently required revision surgery 7 years postoperatively.

A randomized prospective study comparing migration of hydroxyapatite and non-hydroxyapatite coated glenoid components using radiostereometric analysis

“…In a further study by Gascoyne,7 where pegged and keeled all-polyethylene glenoid components were assessed in 16 patients using RSA analysis, statistically greater coronal plane migration was discovered in keeled glenoid implants at 12 and 24 months. Functional outcome scores did not differ significantly between the groups at any follow-up.…”

A comparison of pegged vs. keeled glenoid components regarding functional and radiographic outcomes in anatomic total shoulder arthroplasty: a systematic review and meta-analysis

“…of participantsTotal no. of shoulders with radiolucency at final follow-upASES scoreConstant scoreRevision rateEdwards et al, 16 2010PrimaryKeeled24190.077Pegged2150Fox et al, 18 2009VariousKeeled11840.101Pegged3580.006Gascoyne et al, 22 2017UnspecifiedKeeled873.50.125Pegged796.40Nuttall et al, 40 2007PrimaryKeeled108465Pegged107862Rahme et al, 43 2009PrimaryKeeled129700.077Pegged148700.071Roche et al, 44 2017UnspecifiedKeeled541682.969.3Pegged111468368.9Throckmorton et al, 47 2010PrimaryKeeled5039Pegged50…”

“…With respect to follow-up, there were no short follow-up studies, whereas the mean for moderate follow-up studies was 66.75 ± 3.95 and the mean for long follow-up studies was 69.1 ± 0.28 for both keeled and pegged components combined. In addition, 3 of the 7 studies reported ASES scores 22, 40, 44. This included 85 patients with keeled components and 142 with pegged components.…”

“…When we examined the mean revision rate as a function of follow-up time, there were no studies with a short follow-up, whereas the mean revision rate for moderate follow-up studies was 3% ± 5% and that for long follow-up studies was 10% ± 11% for both keeled and pegged components combined. Regarding the comparative studies, 4 reported revision rates 16, 18, 22, 43. This included a total of 1231 patients with keeled components and 400 patients with pegged components.…”

“…In addition, basic science, retrospective, and prospective studies have suggested that keeled designs have a propensity to develop more radiolucency over time than pegged designs 21, 33, 48, 52. Although the literature suggests that using pegged glenoid components may result in decreased radiolucency over time, it is unclear whether this relation directly correlates with superior long-term clinical outcomes 22 …”