Ulnar component surface finish influenced the outcome of primary Coonrad-Morrey total elbow arthroplasty

Management of the infected total elbow arthroplasty

Periprosthetic joint infection represents a devastating complication after total elbow arthroplasty. Several measures can be implemented before, during, and after surgery to decrease infection rates, which exceed 5%. Debridement with antibiotics and implant retention has been reported to be successful in less than one-third of acute infections, but still plays a role. For elbows with well-fixed implants, staged retention seems to be equally successful as the more commonly performed two-stage reimplantation, both with a success rate of 70% to 80%. Permanent resection or even amputation are occasionally considered. Not uncommonly, a second-stage reimplantation requires complex reconstruction of the skeleton with allografts, and the extensor mechanism may also be deficient. Further developments are needed to improve our management of infection after elbow arthroplasty.

[Elbow prosthesis after acute fractures : Indications and technique]

Good to very good clinical results can be achieved in older patients with the implantation of a total elbow prosthesis in cases of distal humeral fractures by taking the morphological features of the fractures, the bone quality as well as the individual patient requirements and variables into account. The most commonly used design is the cemented semiconstrained linked total elbow endoprosthesis. The unlinked prosthesis design and hemiarthroplasty require intact or adequately reconstructable musculoligamentous structures or condyles and a preserved or replaced radial head. The recommended weight limit after total elbow prosthesis as well as potential intraoperative and postoperative complications must be considered and discussed with the patients. A secondary total elbow arthroplasty is also possible after primary conservative treatment approaches, e.g., in the case of contraindicated surgery in the fracture situation, persistent pain and functional restrictions. This article provides an overview of the technique and the appropriate indications.

Primary total elbow arthroplasty

There have been significant improvements in surgical techniques and implant designs of elbow arthroplasty over the last five decades. These advances have resulted in improved outcomes and expansion of indications for total elow arthroplasty (TEA). As the proportion of TEAs being performed for inflammatory arthritis has been decreasing in recent years, TEAs are being performed more commonly for the management of acute distal humerus fractures in the elderly, post-traumatic sequelae, and primary osteoarthritis. Appropriate patient selection and meticulous attention to surgical technique including the surgical approach, implant positioning and fixation will result in acceptable outcomes. Future advances in the design, instrumentation, and surgical technique will allow for further improvement in outcomes as the indications for TEA continue to expand.

Quantitative ultrahigh-molecular-weight polyethylene wear in total elbow retrievals

BACKGROUND

The purpose of this study was to evaluate ultrahigh-molecular-weight polyethylene (UHMWPE) wear and damage from retrieved total elbow arthroplasty components and compare in vivo wear with wear produced in vitro.

METHODS

Explanted total elbow components were collected at revision surgery. UHMWPE damage was characterized visually, whereas penetration and wear were quantified using micro-computed tomography and gas pycnometry. Volumetric wear rates were compared with historical hip data, and wear data were compared with reported in vitro wear test data.

RESULTS

Humeral bushing damage primarily occurred in the form of burnishing, scratching, and pitting at the articular face in the region of contact with the ulnar component. Wear of the ulnar bushings was concentrated on the edge of the component at the point of contact with the axis pin. Pitting and embedded debris were dominant damage modes, in addition to burnishing and delamination. Backside wear was negligible. The median linear penetration rates of the lateral, medial, and ulnar bushings were 0.14 mm/yr (range, 0.01-0.78 mm/yr), 0.12 mm/yr (range, 0.03-0.55 mm/yr), and 0.11 mm/yr (range, 0.01-0.69 mm/yr), respectively. The volumetric wear rates of the lateral, medial, and ulnar bushings were 5.5 mm³/yr (range, 0.7-37.2 mm³/yr), 5.9 mm³/yr (range, 0.6-25.5 mm³/yr), and 5.5 mm³/yr (range, 1.2-51.2 mm³/yr), respectively.

CONCLUSIONS

The observed wear rates were similar to those reported in well-functioning total hip replacement patients with conventional UHMWPE bearings. We found limitations in reported in vitro testing resulting in wear that was not consistent with our retrieval data. We recommend further investigation to clinically validate in vitro simulation to provide appropriate loading protocols for elbow wear simulation.

Total Elbow Arthroplasty: Clinical Outcomes, Complications, and Revision Surgery

Total elbow arthroplasty is a common surgical procedure used in the management of advanced rheumatoid arthritis, posttraumatic arthritis, osteoarthritis, and unfixable fracture in elderly patients. Total elbow prostheses have evolved over the years and now include the linked, unlinked, and convertible types. However, long-term complications, including infection, aseptic loosening, instability, and periprosthetic fracture, remain a challenge. Here, we introduce each type of implant and evaluate clinical outcomes and complications by reviewing the previous literature.

Total Elbow Arthroplasty for Distal Humeral Fractures: A Ten-Year-Minimum Follow-up Study

BACKGROUND

Total elbow arthroplasty is commonly considered for elderly patients with comminuted distal humeral fractures. Satisfactory short-term outcomes have been reported, but long-term outcomes are unknown. Our purpose was to assess the long-term outcomes of total elbow arthroplasty after distal humeral fracture and to determine differences between elbows with or without inflammatory arthritis at the time of fracture.

METHODS

Forty-four total elbow arthroplasties were performed after distal humeral fracture; those patients were followed for a minimum of 10 years and were evaluated with regard to pain, motion, Mayo Elbow Performance Scores, complications, and reoperations. The outcomes in elbows with and without inflammatory arthritis were compared. Kaplan-Meier survivorship analysis was performed.

RESULTS

Total elbow arthroplasty provided good pain relief and motion; the mean visual analog scale for pain was 0.6, the mean flexion was 123°, and the mean loss of extension was 24°. The mean Mayo Elbow Performance Score was 90.5 points, with 3 patients scoring <75 points. Five elbows (11%) developed deep infection, treated surgically with component retention (3 acute) or resection (2 chronic). Implant revision or resection was performed in 8 elbows (18%): 3 for infections (1 reimplantation and 2 resections), 3 for ulnar loosening (associated with periprosthetic fracture in 1), and 2 for ulnar component fractures. Additional periprosthetic fractures were observed in 5 elbows. The survival rates for elbows with rheumatoid arthritis were 85% at 5 years and 76% at 10 years, and the survival rates for elbows without rheumatoid arthritis were 92% at both 5 and 10 years. The most relevant risk factor for revision was male sex (hazard ratio, 12.6 [95% confidence interval, 1.7 to 93.6]).

CONCLUSIONS

Selective use of total elbow arthroplasty to treat fractures of the distal part of the humerus for infirm, less active older patients and patients with inflammatory arthritis has acceptable longevity in surviving patients, but at the cost of a number of major complications.

LEVEL OF EVIDENCE

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

Primary elbow arthroplasty: problems and solutions

Prosthetic replacement of the elbow joint has continued to improve over time. Widespread implantation of certain designs has led to identification a few successful elements of elbow arthroplasty, as well as several opportunities for improvement. Current hot topics in elbow arthroplasty include triceps-preserving exposures, implantation of components with better-expected wear performance, management of the ulnar nerve, prevention of infection, and the development of successful cementless components. Total elbow arthroplasty has the potential to improve pain, function and quality of life for many patients with articular destruction secondary to inflammatory arthropathy or as a consequence of trauma. Continued advances in this field are key to make this operation as reliable and lasting as hip or knee arthroplasty.

Primary Linked Semiconstrained Total Elbow Arthroplasty for Rheumatoid Arthritis: A Single-Institution Experience with 461 Elbows Over Three Decades

BACKGROUND

Elbow arthroplasty is the treatment of choice for end-stage rheumatoid arthritis (RA). The purpose of this study was to determine the long-term outcome of a linked semiconstrained elbow arthroplasty implant design in patients with RA.

METHODS

Between 1982 and 2006, 461 primary total elbow arthroplasties using the Coonrad-Morrey prosthesis were performed in 387 patients with RA. Fifty-five of the arthroplasties were performed to treat concurrent traumatic or posttraumatic conditions. There were 305 women (365 elbows, 79%) and 82 men (96 elbows, 21%). Ten patients (10 elbows) were lost to follow-up, 9 patients (10 elbows) died, and 6 patients (6 elbows) underwent revision surgery within the first 2 years. For the 435 elbows (362 patients, 94%) with a minimum of 2 years of follow-up, the median follow-up was 10 years (range, 2 to 30 years).

RESULTS

At the most recent follow-up, 49 (11%) of the elbows had undergone component revision or removal (deep infection, 10 elbows; and mechanical failure, 39 elbows). Eight additional elbows were considered to have radiographic evidence of loosening. For surviving implants followed for a minimum of 2 years, the median Mayo Elbow Performance Score (MEPS) was 90 points. Bushing wear was identified in 71 (23%) of the surviving elbows with a minimum of 2 years of radiographic follow-up; however, only 2% of the elbows had been revised for isolated bushing wear. The rate of survivorship free of implant revision or removal for any reason was 92% (95% confidence interval [CI] = 88% to 94%) at 10 years, 83% (95% CI = 77% to 88%) at 15 years, and 68% (95% CI = 56% to 78%) at 20 years. The survivorship at 20 years was 88% (95% CI = 83% to 92%) with revision due to aseptic loosening as the end point and 89% (95% CI = 77% to 95%) with isolated bushing exchange as the end point. Risk factors for implant revision for any cause included male sex, a history of concomitant traumatic pathology, and implantation of an ulnar component with a polymethylmethacrylate surface finish.

CONCLUSIONS

Elbow arthroplasty using a cemented linked semiconstrained elbow arthroplasty provides satisfactory clinical results in the treatment of RA with a reasonable rate of survivorship free of mechanical failure at 20 years. Although bushing wear was identified on radiographs in approximately one-fourth of the patients, revision for isolated bushing wear was uncommon.

LEVEL OF EVIDENCE

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

Medium-term clinical results of a linked total elbow replacement system

Medium-term results of the Discovery elbow replacement are presented. We reviewed 51 consecutive primary Discovery total elbow replacements (TERs) implanted in 48 patients. The mean age of the patients was 69.2 years (49 to 92), there were 19 males and 32 females (37%:63%) The mean follow-up was 40.6 months (24 to 69). A total of six patients were lost to follow-up. Statistically significant improvements in range movement and Oxford Elbow Score were found (p < 0.001). Radiolucent lines were much more common in, and aseptic loosening was exclusive to, the humeral component. Kaplan-Meier survivorship at five years was 92.2% (95% CI 74.5% to 96.4%) for aseptic loosening. In four TERs, periprosthetic infection occurred resulting in failure. A statistically significant association between infection and increased BMI was found (p = 0.0268). Triceps failure was more frequent after the Mayo surgical approach and TER performed after previous trauma surgery. No failures of the implant were noted. Our comparison shows that the Discovery has early clinical results that are similar to other semi-constrained TERs. We found continued radiological surveillance with particular focus on humeral lucency is warranted and has not previously been reported. Despite advances in the design of total elbow replacement prostheses, rates of complication remain high.

What design and material factors impact the wear and corrosion performance in total elbow arthroplasties?

The survivorship of total elbow arthroplasties is lower than surgeons and patients would like it to be, especially in patients with posttraumatic arthritis of the elbow. To improve durability, it is important to understand the failure modes of existing implants. Total elbow arthroplasties were designed primarily for low-demand rheumatoid patients. As surgical indications have extended to more active patient populations, the mechanical performance of current designs must meet an increased mechanical burden. Evaluating the degree to which they do this will guide conclusions about which contemporary devices might still meet the need and, as importantly, what design and material changes might be needed to improve performance. WHERE ARE WE NOW?: The reasons for failures of total elbow arthroplasties include infection, loosening, polyethylene wear, locking mechanism failure, periprosthetic fracture, implant fracture, and instability. Implant design factors that have influenced wear include implant constraint, material, coatings, and metal backing. Surgical factors associated with increased wear and subsequent total elbow arthroplasty failure include soft tissue balancing and restoration of alignment and implant positioning. WHERE DO WE NEED TO GO?: A clear need exists for improving the performance of total elbow arthroplasty. Many of the failures that have limited the survivorship of elbow arthroplasties thus far are mechanical in nature with wear-related problems a dominating influence. Much of what we know about the results of total elbow arthroplasty is from small studies frequently involving the designer of the implant. The establishment of total elbow arthroplasty registries coupled with the increasing regulatory burden of postmarket surveillance would lead to a better understanding of the complications and survivorship of elbow arthroplasties. Another primary goal must be to achieve a better understanding of the biomechanics of the normal elbow and how the mechanics are altered after the insertion of elbow arthroplasty components. HOW DO WE GET THERE?: Improving the performance and survivorship of total elbow arthroplasty will require the integration of clinical and implant performance data gained through the establishment of registries with a concerted basic science effort to better understand the functional loads across the joint and to incorporate these loads into experimental and computational models to allow assessment of design and material changes intended to improve durability.

The outcome of total elbow arthroplasty in juvenile idiopathic arthritis (juvenile rheumatoid arthritis) patients

BACKGROUND

Elbow prosthetic replacement in patients with juvenile idiopathic arthritis (JIA) can be complicated and technically challenging. Thus, we sought to evaluate the clinical benefit and the prosthetic longevity of primary semiconstrained linked total elbow arthroplasty (TEA) performed to treat these patients.

METHODS

Between 1983 and 2005, 29 elbows in 24 patients (20 women and 4 men) had been replaced because of JIA. The mean age was 37 years (range, 24-68 years). Because of underlying deformity, the implant contour was modified for 9 elbows (31%) and a customized implant was inserted in 5 elbows (17%). The mean follow-up duration was 10.5 years (range, 4.6-20.1 years).

RESULTS

During the follow-up period, 8 elbows underwent reoperation, including 6 (21%) that underwent implant revision. At most recent follow-up, 22 elbows (76%) subjectively had a satisfactory overall functional result. The mean Mayo Elbow Performance Score was 78 points (range, 50-100 points), with 18 elbows graded as having an excellent or good result. Compared with preoperative range of motion, the mean extension-flexion arc improved from 65° ± 44° to 89° ± 35° (P = .01), mean flexion improved from 113° ± 23° to 126° ± 26° (P = .02), and mean extension improved from 48° ± 25° to 37° ± 26° (P = .08). By use of the Kaplan-Meier survivorship method, the rate of TEA survival from any revision was 96.4% (95% confidence interval, 89.8%-100%) and 79.9% (95% confidence interval, 65.1%-97.5%) at 5 years and 10 years, respectively.

CONCLUSION

Primary TEA for JIA patients is technically challenging and frequently requires implant modification or custom designs. These patients might have high complication and revision rates. However, most benefit from the intervention for a long term.

Aseptic loosening rate of the humeral stem in the Coonrad-Morrey total elbow arthroplasty. Does size matter?

BACKGROUND

Aseptic implant loosening is one of the most common complications leading to revision surgery in total elbow arthroplasty. Different humeral stem lengths are available with varying designs. In general, the decision of which stem length to use depends on the surgical diagnosis or simply the surgeon preference. Often, the longer stem is used for post-traumatic or revision cases while for rheumatoid patients the shorter stem is preferred. There are no data in the literature to favor one humeral stem size over the other according to the diagnosis.

METHODS

We analyzed the total elbow joint database of the Coonrad-Morrey design at our institution for aseptic loosening leading to revision and compared the revision rate and the survival of the 4- and 6-inch humeral stems.

RESULTS

Overall, revision for aseptic humeral loosening is infrequent and occurred in only 16 of 711 total elbow arthroplasties during a mean follow-up of 88 months. There was no significant difference in the revision rate between the 2 stem lengths (1.9% for the 4-inch stems and 2.6% for the 6-inch stem).

CONCLUSION

Revision rate was correlated to the surgical diagnosis and was significantly higher for post-traumatic patients than for rheumatoid patients (5.1% vs 0.66%, P < .001). Of interest, and possibly not surprising, the mean time to revision was shorter for the 4-inch stems than it was for the 6-inch stems (37 vs 95 months, P = .034).

The Effect of Stem Circumferential Grooves on the Stability at the Implant-Cement Interface

The application of stem surface treatments and finishes are common methods for improving stem-cement interface stability in joint replacement systems; however, success of these surfaces has been variable. As opposed to applying a treatment or finish, altering stem design through changing the surface topography of the base stem material may offer some advantages. This study compared the effect of stem circumferential grooving on the torsional and axial stability of cemented stems. Fifteen metal stems were machined from cobalt chrome to have smooth (n = 5) or circumferential-grooved surfaces, where groove depth and spacing was either 0.6 mm (n = 5) or 1.1 mm (n = 5). Stems were potted in aluminum tubes using bone cement, left 24 h to cure, and placed in a materials testing machine for testing using a cyclic staircase loading protocol at 1.5 Hz. All stems were tested independently in compression and torsion on separate testing days, using the same stems repotted with new cement. Motion of the stem was tracked, and failure was defined either as rapid increase in stem motion, or completion of the loading protocol. Statistical analysis was used to compare interface strength and stem motion prior to failure. Grooved stems demonstrated increased interface strength (p < 0.001) and reduced motion (p < 0.01) compared to smooth stems under compression. In torsion, no significant difference was found in strength among the grooved and smooth stems (p = 0.10); however, grooved 1.1 mm demonstrated greatest interface motion prior to catastrophic failure (p < 0.01). Overall, circumferential-grooved stems offered improved stability under compression, and comparable stability in torsion, relative to the smooth stems.

Results with a minimum of 10 years follow-up of the Coonrad/Morrey total elbow arthroplasty

INTRODUCTION

Few series have evaluated the long-term results of total elbow arthroplasty (TEA).

MATERIALS AND METHODS

Fifteen patients with a Coonrad/Morrey total elbow implant were reviewed with a minimum follow-up of 10 years. There were nine women and six men with a mean age of 55 years at surgery. The aetiology was rheumatoid arthritis in eight cases, post-traumatic arthritis in five, psoriatic arthritis in one, and sequelae of neonatal septic arthritis in one. The TEA was performed as primary surgery in ten cases and during a revision surgery in four.

RESULTS

At 136 months average follow-up (120-160), MEPS was 82 ± 14 points (range 60-100) with a Quick DASH score of 41 points (range 13-83). Fourteen patients had no or slight pain and six had a functional range of motion. Elbow function was normal in eight of 15 patients. Radiolucent lines were found around the humerus in six cases (all of them incomplete) and around the ulnar component in eight (five of them complete) with loosening and migration of the ulnar stem occurring in two cases. Wear of the bushings was moderate in five cases and severe in two. There were ten complications with a revision needed in three cases. Revision-free survival rate for the implant was 100% at 5 years and 90% at 10 and 13 years.

DISCUSSION

The Coonrad/Morrey total elbow gives long-term satisfactory results. Increased incidence of radiolucent lines around the ulnar stem and bushing wear with longer follow-up is of concern and represents the failure mode for this total elbow arthroplasty implant.

LEVEL OF EVIDENCE

IV.

The effect of stem surface treatment and material on pistoning of ulnar components in linked cemented elbow prostheses

BACKGROUND

The ulnar component of a total elbow replacement can fail by "pistoning." Stem surface treatments have improved stability at the stem-cement interface but with varied success. This study investigated the role of surface treatment and stem substrate material on implant stability under axial loading.

MATERIALS AND METHODS

Sixty circular stems (diameter, 8 mm) made of cobalt chrome (n = 30) or titanium (n = 30) had different surfaces: smooth, sintered beads, and plasma spray. The surface treatment length was either 10 mm or 20 mm. Stems were potted in bone cement, allowed to cure for 24 hours, and tested in a materials testing machine under a compressive staircase loading protocol. Failure was defined as 2 mm of push-out or completion of the protocol. Two-way analyses of variance compared the effects of surface treatment and substrate material on interface strength and motion.

RESULTS

Significant interactions were found between surface treatment and substrate material for both interface strength and motion (P < .05). For titanium, the 20-mm beaded stems had greater interface strength than all other stems (P < .05) and had less motion than the 10-mm plasma-spray and smooth stems (P < .05). For cobalt chrome, the 20-mm beaded stems showed greater interface strength (P < .05) and similar motion (P > .05) to the 20-mm plasma-spray stems (P < .05), which outperformed all other stems (P < .05). Mechanisms of catastrophic failure varied: smooth stems debonded at the stem-cement interface, beaded stems experienced debonding of the beads from the stem, and plasma-spray stems showed loss of frictional force between the surface treatment and cement.

DISCUSSION AND CONCLUSION

Stem surface treatment can enhance ulnar component stability but is dependent on substrate material.

Characterization of wear debris in total elbow arthroplasty

BACKGROUND

The purpose of this study was to evaluate wear debris in periprosthetic tissues at the time of revision total elbow arthroplasty. Polyethylene, metallic, and bone cement debris were characterized, and the tissue response was quantified.

MATERIALS AND METHODS

Capsular and medullary tissue samples were collected during revision surgery. Polyethylene debris was characterized by scanning electron microscopy after tissue digestion. The concentrations of metal and cement debris were quantified by inductively coupled plasma mass spectrometry. Tissue response was graded with a semiquantitative histologic method.

RESULTS

Polyethylene particle size varied from the submicron range to over 100 μm. The mean diameter ranged from 0.6 μm to about 1 μm. Particles in the synovial tissues were larger and less abundant than those in tissues from the medullary canal. Cement, titanium alloy, and low levels of cobalt-chrome debris were also present, with cement predominating over metal debris. Histiocyte response was associated with small polyethylene particles (0.5-2 μm), and giant cells were associated with large polyethylene particles (>2 μm). Histiocyte scores positively correlated with the polyethylene particle number and the presence of metal.

DISCUSSION

We have shown that periprosthetic tissues of total elbow patients who have undergone revision for loosening and osteolysis contain polyethylene, cement, and metal debris. Although the polyethylene particles were of a size and shape that have been previously shown to result in activation of phagocytic cells, osteolysis after total elbow arthroplasty is a multimodal process. Because of the presence of multiple wear particle sources, a cause-and-effect relationship between polyethylene debris and osteolysis cannot be established with certainty.