Total Elbow Arthroplasty

Incidence of and Risk Factors for Reoperation and Revision Following Total Elbow Arthroplasty with an Anatomic Convertible Prosthesis

BACKGROUND

Total elbow arthroplasty (TEA) remains a valuable tool for treating inflammatory, degenerative, and traumatic elbow conditions. This study aimed to understand the incidence of and risk factors for reoperation following TEA at a high-volume center utilizing an implant with a convertible linkage and the potential for anatomic lateral column reconstruction.

METHODS

All patients undergoing primary TEA with the Latitude prosthesis (Stryker) from July 2001 to May 2020 were identified. Patient characteristics, the surgical indication, and implant characteristics were obtained. Additionally, the indications and timing were identified for reoperations. Postoperative radiographs were analyzed to assess cement quality, implant position, lateral column reconstruction, and distal humeral bone loss.

RESULTS

Two hundred and nineteen TEAs were performed in 206 patients; 162 (74.0%) were in female patients, the mean patient age was 61 years (range, 23 to 95 years), and the mean follow-up was 11.8 years (range, 2 to 21 years). The most common indication for surgery was sequelae of trauma (36%). Ninety elbows (41.1%) required 200 reoperations at a mean of 19.6 months. Forty TEAs (18.3%) required revision of nonmodular implants, with 14 (6.4%) undergoing definitive explantation. The 5 and 10-year survivorship was 86.1% and 79.7%, respectively. The most common of the reasons for revision was aseptic loosening (53.8%), and the most common cause for non-revision reoperation was infection (23%). Younger age and greater follow-up duration were associated with greater revision and reoperation risks. Aseptic ulnar loosening was associated with a short ulnar stem length and component linkage (30% of short linked ulnar stems loosened; p < 0.001). Aseptic humeral loosening was associated with less-than-adequate cement-mantle quality (p = 0.04).

CONCLUSIONS

Extended follow-up of the Latitude prosthesis at a high-volume center demonstrates that TEA continues to be hampered by a high reoperation rate, primarily due to infection and aseptic loosening. Technical factors such as good cement-mantle quality, longer stem length, and unlinked implants may play a role in preventing aseptic loosening. Further work is required to optimize long-term outcomes following TEA through improved understanding of appropriate surgical indications, techniques, and implant utilization.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

The 5-Item Modified Frailty Index for Risk Stratification of Patients Undergoing Total Elbow Arthroplasty

BACKGROUND

Frailty, quantified using the 5-item modified frailty index (mFI-5), has been shown to predict adverse outcomes in orthopaedic surgery. The utility in total elbow arthroplasty (TEA) patients is unclear. We evaluated if increasing frailty would correlate with worse postoperative outcomes.

METHODS

A retrospective assessment of patients in the American College of Surgeons National Surgery Quality Improvement Program undergoing primary TEA was performed. The mFI-5 was calculated by assigning 1 point for each comorbidity (diabetes, hypertension, congestive heart failure, chronic obstructive pulmonary disease, and functionally dependent health status). Poisson regression was used to evaluate mFI-5 scores on complications, length of stay (LOS), and adverse discharge. A significance threshold was at P < .05.

RESULTS

In total, 609 patients were included; 34.5% (n = 210) were not frail (mFI = 0), 44.0% (n = 268) were slightly frail (mFI = 1), and 21.5% (n = 131) were frail (mFI ≥ 2). As mFI score increased from 0 to ≥ 2, the following rates increased: any complication (9.0%-19.8%), major complication (11.0%-20.6%), cardiac complication (0.0%-2.3%), hematologic complication (3.3%-9.2%), adverse discharge (2.9%-22.9%), and LOS from 2.08 to 3.97 days (all P < .048). Following adjustment, Poisson regression demonstrated patients with a mFI ≥ 2 had increased risk of major complication (risk ratio [RR]: 2.13; P = .029), any complication (RR: 2.49; P = .032), Clavien-Dindo IV complication (RR: 5.53; P = .041), and adverse discharge (RR: 5.72; P < .001).

CONCLUSIONS

Frailty is not only associated with longer hospitalizations, but more major complications and non-home discharge. The mFI-5 is a useful risk stratification that may assist in decision-making for TEA.

Intraoperative modification of total elbow arthroplasty implants

BACKGROUND

Modification of total elbow arthroplasty (TEA) implants may be necessary in selected patients with substantial anatomic bone deformity or those undergoing revision surgery. The purpose of this study was to investigate the prevalence and consequences of implant modifications during TEA at our institution. We hypothesized that TEA implant modification would be more common in revisions than in primary replacements, and that it would not be associated with worse clinical outcomes or increased rates of radiographic or surgical complications directly related to the implant modification.

METHODS

Elbows that had undergone TEA by any of 3 surgeons at our institution with use of intraoperative implant modification between January 1992 and October 2019 were retrospectively reviewed for the type of modification and complications. Complications were classified as definitely related, probably related, possibly related, or nonrelated to the implant's modification according to the consensus review by the 3 senior surgeons. A survey was sent out to surgeons outside of our institution to investigate whether intraoperative modification to TEA implants is a common clinical practice.

RESULTS

A total of 106 implant components were modified during 94 of 731 TEA procedures (13%) in 84 of 560 patients. Implant modifications were performed in 60 of 285 revision cases (21%) compared with 34 of 446 (8%) primary cases (P < .0001). These included shortening the stem in 40 (44%), bending the stem in 16 (15%), notching the stem in 16 (15%), tapering the stem in 9 (9%), and a combination of 2 or more of these modifications in 19 implants (17%). Among the 55 index surgeries available for complication analysis, 40 complications occurred in 28 index surgeries (11 primary and 17 revisions; 25 patients), making the overall complication rate 51%. Of these 40 complications, 23 were considered independent of any implant modification. Of the remaining 17 complications, 9 were considered nonrelated to the implant modification, 6 were possibly related, and 2 were probably related to the implant modification. Therefore, the complication rate possibly related or probably related to implant modification was 15% (8 of 55). No complication was classified as definitely related to the implant modification. No implant breakage or malfunction occurred after any modification. A total of 442 survey responses were received representing 29 countries, of which 144 surgeons (39%) performed modification to implants during TEA procedures.

DISCUSSION

This study confirmed our hypothesis that modification of TEA implants is not uncommon at our institution, particularly in revision arthroplasty. Surgeons should keep in mind that complications possibly related or probably related to implant modification were at minimum 15% and could have been as high as 30% if the patients lost to follow-up had all had complications. Implant modification may be necessary in some cases but should be exercised with thoughtful consideration and caution.

Outcomes of radial head implants in total elbow arthroplasty

BACKGROUND

There is no consensus on the management of the radial head in total elbow arthroplasty (TEA). In 3-part TEA designs, options include radial head retention, excision, or arthroplasty. Biomechanical studies suggest improved varus-valgus stability with radial head implants in unlinked total elbows. Unfortunately, complications with radial head implants have been common with historical designs. The aim of this study was to evaluate the clinical and radiographic outcomes of radial head implants in a current 3-part TEA and identify risk factors for mechanical failure.

METHODS

We performed a retrospective review of radial head implants with a 3-part convertible TEA from 2001 to 2016. Clinical outcomes, functional scores, and radiographic outcomes were recorded. The preoperative radiocapitellar alignment was measured using the radiocapitellar ratio (RCR). Statistics include descriptive statistics, t tests, logistic regression, and Kaplan-Meier survival curves.

RESULTS

We identified 44 TEAs in 40 patients, with a mean follow-up period of 7.2 years. The average age at surgery was 58 ± 11 years; 80% of the TEAs were performed in women. The indication for surgery was rheumatoid arthritis in 86%; of the implants, 61% were unlinked. The average preoperative RCR was 10.7 ± 17.9. Postoperatively, 2 radial head implants (5%) were subluxated, 6 (14%) were dissociated, and 2 (5%) were dissociated with implant dislocation on radiographic review. The revision rate for radial head subluxation, dissociation, or dislocation was 7% (n = 3). Univariate logistic regression showed that male sex (P = .002), abnormal preoperative RCR (P = .02), linked implant (P = .03), and older age (P = .04) were risk factors for radial head subluxation, dissociation, or implant dislocation. A multivariate model with all 4 variables did not demonstrate statistical significance.

CONCLUSION

The incidence of radial head arthroplasty subluxation, dissociation, or implant dislocation was high (23%). In a univariate logistic regression model, male sex, abnormal preoperative RCR, and linked implants were all statistically significant risk factors for mechanical failure of the radial head implant. Our multivariate model did not show any statistically significant independent risk factors. Polyethylene wear or loosening of the radial head implants was not observed in this study; failure of the bipolar linkage was the principal mode of failure. Although further study is required, caution should be used when considering inserting a radial head implant in male patients with significant preoperative radiocapitellar malalignment. Radial head subluxation or dissociation is not an absolute indication for revision in an asymptomatic patient. Improvements in radial head implant designs in TEA are needed.

Mid- to long-term survivorship of the cemented, semiconstrained Discovery total elbow arthroplasty

BACKGROUND

The incidence of total elbow arthroplasty (TEA) is increasing, and an improved understanding of elbow kinematics and biomaterials has driven advances in implant design. In modern practice, cemented, semiconstrained devices are most frequently used. The Discovery TEA has demonstrated promising early results, although there are a paucity of follow-up studies and no dedicated mid- to long-term series. We therefore present the longest, most complete such study to date.

METHODS

A prospectively maintained local joint registry was interrogated to yield a consecutive series of Discovery TEAs performed at a single non-design center. The minimum follow-up period was set at 5 years. Revision procedures and TEAs performed for acute trauma were excluded. The primary outcome was survivorship of the implant. The secondary outcomes included clinical, radiographic, and patient-reported outcomes.

RESULTS

We identified 67 TEAs in 58 patients for inclusion at a mean of 98.5 ± 20.4 months from surgery. Four cases (6%) were lost to follow-up, and implant survival was censored accordingly. The implant was revised in 14 cases (20.9%). The Kaplan-Meier method showed an implant survivorship rate of 76.8% at 119 months. A significant difference in survival was found between dominant and nondominant elbows (P = .012, Breslow test), with elbow dominance conferring a 4.5-fold increased risk of revision (relative risk, 4.5; 95% confidence interval, 1.1-18.5). Pooled clinical outcomes (70.9% follow-up at minimum of 60 months and median of 77.8 months) were also determined.

CONCLUSIONS

We present the longest-term and most complete single-center follow-up study of the Discovery TEA to date. Further long-term survival studies are required to elucidate the performance of this implant compared with more established designs. We have also demonstrated differences in implant survivorship owing to hand dominance for the first time.