Elbow arthroplasty using a convertible implant

Elbow joint loads during simulated activities of daily living: implications for formulating recommendations after total elbow arthroplasty

BACKGROUND

Overloading of the elbow joint prosthesis following total elbow arthroplasty can lead to implant failure. Joint moments during daily activities are not well contextualized for a prosthesis's failure limits, and the effect of the current postoperative instruction on elbow joint loading is unclear. This study investigates the difference in elbow joint moments between simulated daily tasks and between flexion-extension, pronation-supination, and varus-valgus movement directions. Additionally, the effect of the current postoperative instruction on elbow joint load is examined.

METHODS

Nine healthy participants (age 45.8 ± 17 years, 3 males) performed 8 tasks; driving a car, opening a door, rising from a chair, lifting, sliding, combing hair, drinking, emptying cup, without and with the instruction "not lifting more than 1 kg." Upper limb kinematics and hand contact forces were measured. Elbow joint angles and net moments were analyzed using inverse dynamic analysis, where the net moments are estimated from movement data and external forces.

RESULTS

Peak elbow joint moments differed significantly between tasks (P < .01) and movement directions (P < .01). The most and least demanding tasks were, rising from a chair (13.4 Nm extension, 5.0 Nm supination, and 15.2 Nm valgus) and sliding (4.3 Nm flexion, 1.7 Nm supination, and 2.6 Nm varus). Net moments were significantly reduced after instruction only in the chair task (P < .01).

CONCLUSION

This study analyzed elbow joint moments in different directions during daily tasks. The outcomes question whether postoperative instruction can lead to decreasing elbow loads. Future research might focus on reducing elbow loads in the flexion-extension and varus-valgus directions.

Static stability of novel uncemented elbow hemiarthroplasty stabilized with ligament reconstruction

BACKGROUND

The purpose of this study was to create a model to simulate treatment of unreconstructable distal humerus fractures with hemiarthroplasty. Stability was restored with a latest plate-system that simultaneously tensions medial and lateral collateral ligament grafts.

MATERIALS AND METHODS

Static varus and valgus elbow stability was tested in 11 cadaver elbows with intact ligaments and capsule at 5 flexion angles (0°, 30°, 60°, 90°, 120°). The elbows were then destabilized via release of all ligaments and capsular attachments. The distal humerus articular cartilage was excised and replaced with an uncemented hemiarthroplasty. Ligament reconstruction was subsequently performed, and elbow stability was measured and compared to the native state. Dimensions of the hemiarthroplasty component were compared to native elbow dimensions to assess and quantify any existing relationship to elbow stability.

RESULTS

A hemiarthroplasty was implanted in all specimens. A size mismatch occurred between the distal humerus trochlea and the olecranon fossa in all specimens and averaged 6.3 mm. Following ligament reconstruction, specimens reproduced the flexion angle-dependent stability of native elbows to both varus and valgus stress. On the medial side, elbow joint stability in mid-flexion was approximately 7% tighter after hemiarthroplasty. Laterally, the elbow was approximately 15% tighter after hemiarthroplasty and demonstrated peak stability in full flexion. The 3 assessed hemiarthroplasty components and bony dimensions did not exhibit any relationship between implant-bone mismatch and elbow stability after ligamentous reconstruction.

CONCLUSION

Cadaveric elbow specimens underwent uncemented hemiarthroplasty with soft tissue stabilization with a novel technique for ligament reconstruction. Following hemiarthroplasty and ligament reconstruction, these specimens maintained secure fixation between ligament and bone. Static stability was maintained at varying degrees of elbow flexion regardless of variable mismatch between the hemiarthroplasty component and the native olecranon fossa.

Functional outcomes and complications following convertible primary total elbow arthroplasty: A single surgeon series

BACKGROUND

The data on convertible total elbow arthroplasty are limited and primarily based on multiple centre/multiple surgeon series. The aim of this study was to report the mid-term functional outcomes, radiological findings, complications and survivorship of the Latitude total elbow arthroplasty performed by a single surgeon.

STUDY DESIGN & METHODS

The study included 13 patients (10 females, mean age of 72 years and varying indications) over eight years. The Oxford Elbow Score (OES), Mayo Elbow Performance Score (MEPS), range of movements (ROM), Subjective Elbow Value (SEV), satisfaction score (SS) and the revision rate of the implant per 100 observed component years (OCY) were assessed.

RESULTS

The mean follow-up was 5.9 years (3-10 years). The Oxford Elbow Score/Mayo Elbow Performance Score improved from 15 to 42 (p value < 0.005)/26% to 93% (p value < 0.005) respectively. The arc of extension-flexion/supination-pronation improved from 63° to 106° (p = 0.00002)/123° to 142° (p = 0.32) respectively. The Subjective Elbow Value/Satisfaction Score was 83/98 respectively. There was one re-operation for a deep infection. There were no radiologic signs of loosening and the revision rate was 0.15 per 100 observed component years.

CONCLUSIONS

With careful patient selection, convertible total elbow arthroplasty provides patients with good to excellent outcomes and substantial improvements in the range of movements.

Total elbow arthroplasty using an augmented reality-assisted surgical technique

BACKGROUND

Precision placement of implants in total elbow arthroplasty (TEA) using conventional surgical techniques can be difficult and riddled with errors. Modern technologies such as augmented reality (AR) and 3-dimensional (3D) printing have already found useful applications in many fields of medicine. We proposed a cutting-edge surgical technique, augmented reality total elbow arthroplasty (ARTEA), that uses AR and 3D printing to provide 3D information for intuitive preoperative planning. The purpose of this study was to evaluate the accuracy of humeral and ulnar component placement using ARTEA.

METHODS

Twelve upper extremities from human frozen cadavers were used for experiments performed in this study. We scanned the extremities via computed tomography prior to performing TEA to plan placement sites using computer simulations. The ARTEA technique was used to perform TEA surgery on 6 of the extremities, whereas conventional (non-ARTEA) techniques were used on the other 6 extremities. Computed tomography scanning was repeated after TEA completion, and the error between the planned and actual placements of humeral and ulnar components was calculated and compared.

RESULTS

For humeral component placement, the mean positional error ± standard deviation of ARTEA vs. non-ARTEA was 1.4° ± 0.6° vs. 4.4° ± 0.9° in total rotation (P = .002) and 1.5 ± 0.6 mm vs. 8.6 ± 1.3 mm in total translation (P = .002). For ulnar component placement, the mean positional error ± standard deviation of ARTEA vs. non-ARTEA was 5.5° ± 3.1° vs. 19.5° ± 9.8° in total rotation (P = .004) and 1.5 ± 0.4 mm vs. 6.9 ± 1.6 mm in total translation (P = .002). Both rotational accuracy and translational accuracy were greater for joint components replaced using the ARTEA technique compared with the non-ARTEA technique (P < .05).

CONCLUSION

Compared with conventional surgical techniques, ARTEA had greater accuracy in prosthetic implant placement when used to perform TEA.

Results of Linked Convertible Total Elbow Arthroplasty for the Management of Distal Humeral Fractures in the Elderly

PURPOSE

Total elbow arthroplasty (TEA) is increasingly used for the management of comminuted distal humeral fractures in elderly patients. There are limited data on the outcome of modern elbow arthroplasty designs in larger patient cohorts. The aim of the current study was to review the outcomes and complications using a cemented convertible TEA system in a linked configuration in patients with distal humeral fractures.

METHODS

Patients with distal humeral fractures treated with TEA and a minimum of 2 years' follow-up were reviewed. Demographic information, patient-reported outcome, functional and radiographic outcome assessments, and complications were reported.

RESULTS

Forty patients met inclusion criteria; 35 were female. Median follow-up was 4 years (range, 2-13 years). Average age of patients at the index procedure was 79 ± 9 years. All implants were linked. Range of motion was: extension 16° ± 13°, flexion 127° ± 14°, supination 79° ± 11°, and pronation 73° ± 20°. Patient-reported outcome scores were: Patient-Rated Elbow Evaluation 37 ± 35, Quick-Disabilities of the Arm, Shoulder, and Hand 31 ± 31, and Mayo Elbow Performance Index 90 ± 18. Seven patients had heterotopic ossification. Lucent lines were noted predominantly in humeral implant zone V. No lucent lines were noted around the ulnar component in any radiographic zone. Complications occurred in 9 patients (22%) and 2 revisions were performed: one for infection and one for a late periprosthetic fracture.

CONCLUSIONS

Total elbow arthroplasty for fracture in elderly patients provides pain relief, functional range of motion, and good patient-reported outcome scores. No implant-related complications of this convertible implant system were encountered, but longer-term follow-up is needed.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Discovery® elbow system arthroplasty: results of 10-year follow-up

BACKGROUND

The semi-constrained Discovery® Elbow System (LimaCorporate, San Daniele del Friuli, Italy) allows varus-valgus laxity of 7° [8]. It has been reported to provide good pain relief and increased range of motion [5, 9] on mid-term follow-up. The aim of the study was to evaluate long-term outcomes of total elbow arthroplasty using the Discovery® Elbow System (LimaCorporate, San Daniele del Friuli, Italy).

MATERIALS AND METHODS

The Mayo Elbow Performance Score (MEPS) and elbow range of motion (ROM) were assessed. Plain radiographs were obtained to assess radiolucency in the humerus and ulna. The data were extracted from electronic patient records.

RESULTS

During the follow-up period of 105.4 (range 24.6-179.9) months, 132 patients (153 elbows) underwent surgery. The cause of surgery was rheumatoid arthritis in 105 (71%) cases, posttraumatic or primary arthritis in 17 (13%) and fracture in 10 (6%) patients. The total MEPS increased on average by 35.0 points. Elbow extension deteriorated by 5.0°. Respectively, flexion improved by 10.0° and pronation by 5.0°. The difference in supination was 0.0°. Pain severity improved by 2.5 points in motion and by 5.5 points at rest. During follow-up, 24 (16%) patients needed revision surgery. The most common cause for revision was periprosthetic fracture. Radiolucent lines were seen in all zones in both the ulna and the humerus. The Kaplan-Meier survival at 5 years was 88% and 79% at 10-14 years.

CONCLUSION

The Discovery® Elbow System provides good results in ROM and pain relief of the elbow. The revision rate was relatively high (16% of patients).

LEVEL OF EVIDENCE

IV.

A review of the New Zealand National Joint Registry to compare the outcomes of Coonrad-Morrey and Latitude total elbow arthroplasty

BACKGROUND

Total elbow arthroplasty has traditionally been used in the treatment of inflammatory arthropathy patients. More and more, however, its use is expanding to include acute trauma and sequelae of trauma. In New Zealand, the most commonly used prosthesis is the Coonrad-Morrey prosthesis, but the Latitude prosthesis has gained in popularity, with a 3-fold increase in implantation over the past 5 years.

METHODS

Prospectively collected national joint registry data were used to compare the survival rates of these prostheses. Underlying diagnoses, reasons for revision, and patient-reported outcome measures, as well as patient age and exact implants used, were all recorded. Statistical analysis involved survival analysis using Kaplan-Meier curves and the paired Student t test.

RESULTS

Over the 18-year study interval, the Coonrad-Morrey prosthesis has shown consistently lower revision rates than the Latitude prosthesis. This was true for both the linked and unlinked Latitude prostheses and was not affected by radial head replacement or underlying diagnosis. In all cases, the risk of revision for the Coonrad-Morrey prosthesis was reduced by at least 65% compared with the Latitude prosthesis.

CONCLUSION

This study using New Zealand Joint Registry data shows a lower failure rate of the Coonrad-Morrey elbow prosthesis compared with the Latitude prosthesis. The hazard ratio for a revision procedure for the Coonrad-Morrey prosthesis compared with the Latitude prosthesis was 0.28 (95% confidence interval, 0.14-0.55). This lower rate was evident irrespective of linkage and radial head replacement. The reason for the lower rate of revision with the Coonrad-Morrey prosthesis is likely multifactorial, but perhaps when used by lower-volume surgeons, the Coonrad-Morrey prosthesis may confer better implant longevity.

Management of rheumatoid arthritis of the elbow with a convertible total elbow arthroplasty

BACKGROUND

Total elbow arthroplasty (TEA) is commonly performed in patients with rheumatoid arthritis (RA). The purpose of this study was to compare outcomes and complications of unlinked and linked TEA using a convertible system in patients with RA.

METHODS

All patients with RA who underwent TEA at a single center with a minimum of 2 years' follow-up were reviewed. Demographic information, patient-reported outcome scores, functional outcome assessments, and radiographic parameters were evaluated at most recent follow-up.

RESULTS

We evaluated 82 patients (27 with unlinked TEA and 55 with linked TEA) with RA. The mean age at surgery was 61 ± 10 years, with a mean follow-up period of 6 ± 4 years. Demographic characteristics were similar between groups, with the exception of longer follow-up in the unlinked group (8 years vs. 5 years, P = .001). No differences in range of motion were noted. Elbow strength was similar other than pronation strength (74% ± 8% for unlinked vs. 100% ± 8% for linked, P = .03). The mean Mayo Elbow Performance Index was 83 ± 16; Patient Rated Elbow Evaluation score, 15 ± 18; and QuickDASH (short version of the Disabilities of the Arm, Shoulder and Hand questionnaire) score, 34 ± 20. No differences in the rates of reoperation (17% vs. 24%, P = .4), complications (32% vs. 31%, P = .4), or revisions (13% vs. 17%, P = .3) were found between unlinked and linked devices. Four patients with instability, all with unlinked designs, underwent revision to a linked design. Four patients, all with linked designs, underwent revision for aseptic loosening of smooth short-stem ulnar components.

CONCLUSION

TEA using a convertible implant design provides good patient-reported outcomes at mid-term follow-up in patients with RA. Our study was unable to detect a difference in the use of either unlinked or linked implant designs; further large comparison trials are needed.

Outcomes After Hemiarthroplasty of the Elbow for the Management of Posttraumatic Arthritis: Minimum 2-Year Follow-up

BACKGROUND

Hemiarthroplasty (HA) of the elbow represents an alternative to total elbow arthroplasty (TEA) without the associated activity restrictions. This study reviews our experience with distal humerus HA with minimum 2-year follow-up.

METHODS

Between 2002 and 2012, 16 elbows underwent HA for posttraumatic arthritis of the elbow. Patients were followed for a minimum of 2 years or until revision surgery. Outcome measures included pre- and postoperative Mayo Elbow Performance Scores (MEPSs), complications, and revisions.

RESULTS

Mean age at arthroplasty was 45 years, and follow-up averaged 51 months. All patients had previously undergone one or more surgical procedures at the elbow (average of 1.5 procedures). At follow-up, five had undergone additional surgery; two were revised to TEA. In surviving implants, the range of motion at follow-up was markedly improved from preoperative motion. The MEPS for the remaining HA included five excellent results, three good results, five fair results, and one poor result.

DISCUSSION

Elbow HA is an option for young or active patients with end-stage elbow posttraumatic arthritis who are unwilling to accept activity limitations. However, high rates of revision surgery and revision to TEA occur after HA for posttraumatic osteoarthritis of the elbow. Only 57% of patients with surviving implants had a good to excellent MEPS, although improvement in the range of motion was predictable.

[Elbow prostheses in rheumatic diseases]

When the elbow is destroyed due to rheumatic diseases, the joint can be replaced by a prosthesis and total arthroplasty. Improved pharmaceutical treatment for rheumatic diseases has, however, reduced the number of implantations in these patients. Reported 10-year survival rates of the implant currently achieve 81-90%.; however, due to limited long-term survival of the implant and high complication rates, total elbow arthroplasty should still be used with caution. Continuous technical improvements in the available prostheses and in surgical techniques could lead in the future to a decline in complications, such as aseptic loosening and infections.

Early results of Latitude primary total elbow replacement with a minimum follow-up of 2 years

BACKGROUND

The aim of this study was to present outcomes of primary Latitude total elbow replacement (TER) with a minimum follow-up of 2 years.

METHODS

A retrospective cohort study was undertaken with prospective outcome data collection for the latest outcome. Included were 63 consecutive primary Latitude TERs in 58 patients performed during a period of 5 years at a specialist orthopedic hospital.

RESULTS

The mean age of the patients was 62 years (33-85 years). Five primary TERs (4 patients) were lost to follow-up. The primary diagnosis was rheumatoid arthritis in 49, osteoarthritis in 8, and trauma in 6 elbows. The mean flexion-extension arc was 75° preoperatively and 97° postoperatively. Mean postoperative Elbex pain score was 19/100, and function score was 37/100. Mean postoperative scores were 42/100 for the Quick Disabilities of the Arm, Shoulder, and Hand and 38/50 for the elbow-specific American Shoulder and Elbow Surgeons assessment. Four patients died of unrelated causes, and 8 of 63 underwent further surgical intervention, including explantation and conversion from unlinked to linked implant. On radiographic review of 41 surviving TERs, aseptic radiologic loosening was observed of the humeral component in 4 elbows and of the ulnar component in 9. Seven elbows had no radial component, and of the remaining 34 elbows, 16 (47%) had signs of loosening of the radial implant. Complications included 1 heterotopic ossification, 1 olecranon fracture, and 3 further procedures for ulnar nerve entrapment.

CONCLUSION

The results indicate that the early outcome of Latitude TER is comparable to that of other prostheses. There is concern about early radiologic loosening of the radial component.

Total Elbow Arthroplasty: Why and How

Introduction

Elbow arthroplasty is a relatively infrequent orthopaedic procedure that can be performed in multiple ways according to the type of prosthesis that is used and the needs of the individual patient.

Indications & Contraindications

Step 1 Preparation and Positioning of the Patient

Place the patient in the lateral decubitus position or in the supine position with the arm draped, allowing for easy manipulation of the elbow during the procedure.

Step 2 Incision

Palpate and mark the local osseous landmarks, ulnar nerve, and incision, and then make a posterior incision to allow 360° access to the elbow joint as well as to allow decompression or transposition of the ulnar nerve.

Step 3 Approach—The Superficial Layer

Perform the superficial approach, including a decompression of the ulnar nerve, and properly visualize the triceps tendon attachment on the proximal part of the ulna and both epicondyles.

Step 4 Approach—The Deep Layer

Mobilize the triceps to allow visualization of the articular surfaces of the ulna, humerus, and radius, while taking care to protect the ulnar nerve.

Step 5 Preparation of the Osseous Structures

Prepare the humerus and ulna in conformance with the technique that is described for the prosthesis and take care to restore the anatomical flexion-extension axis of the elbow.

Step 6 Placement of the Prosthesis

When all trial components are in place, reduce the joint to test the stability of the elbow.

Step 7 Closure of the Elbow

When all of the definitive components of the total elbow arthroplasty are in place, close the surgical wound in layers as the anatomy is restored.

Step 8 Postoperative Care

After surgery, a wound dressing is applied and physical rehabilitation is started to maximize the functional outcome.

Results

In our study of the mid-term results of a convertible total elbow arthroplasty, based on 58 elbow arthroplasties, patients had significant improvement in range of movement, function, and pain at 6 months postoperatively⁸.

Pitfalls & Challenges

Distal Humeral Hemiarthroplasty Versus Total Elbow Arthroplasty for Acute Distal Humeral Fractures

For acute distal humeral fractures not amenable to open reduction and internal fixation, total elbow arthroplasty has become an established alternative. However, lifelong activity restrictions designed to prevent early mechanical failure make this a poor option for some patients. This has led to a renewed interest in distal humeral hemiarthroplasty. Using modern implants and techniques, distal humeral hemiarthroplasty has shown outcomes comparable to those of total elbow arthroplasty at short- to mid-term follow-up, with an overall higher but different complication rate. Long-term data are needed, but the available literature suggests that distal humeral hemiarthroplasty be considered as another option on the treatment spectrum in select patient populations. [Orthopedics. 2017; 40(1):13-23.].

[Post-traumatic osteoarthritis of the elbow joint : Endoprosthetic options in young patients]

BACKGROUND

In young patients, post-traumatic osteoarthritis of the elbow is a rare condition. Whereas clinical manifestations often differ from radiological findings, pain and stiffness are variably combined in symptomatic forms. In deciding whether to perform surgery, the patient's age, activity level, and symptoms, as well as the location and severity of the osteoarthritis have to be taken into account. Elbow joint instability has to be identified to stop the post-traumatic osteoarthritic progress. If joint preserving surgical methods fail, diverse options for partial or total joint replacement are available.

THERAPY

The treatment goal in young patients, therefore, is to reduce pain with a sufficient range of elbow motion.

Short-term clinical results of revision elbow arthroplasty using the Latitude total elbow arthroplasty

Aims

Revision total elbow arthroplasty (TEA) is often challenging. The aim of this study was to report on the clinical and radiological results of revision arthroplasty of the elbow with the Latitude TEA.

Patients and Methods

Between 2006 and 2010 we used the Latitude TEA for revision in 18 consecutive elbows (17 patients); mean age 53 years (28 to 80); 14 women. A Kudo TEA was revised in 15 elbows and a Souter-Strathclyde TEA in three. Stability, range of movement (ROM), visual analogue score (VAS) for pain and functional scores, Elbow Functional Assessment Scale (EFAS), the Functional Rating Index of Broberg and Morrey (FRIBM) and the Modified Andrews’ Elbow Scoring System (MAESS) were assessed pre-operatively and at each post-operative follow-up visit (six, 12 months and biennially thereafter). Radiographs were analysed for loosening, fractures and dislocation. The mean follow-up was 59 months (26 to 89).

Results

The ROM of the elbow did not improve significantly. The mean EFAS and MAESS scores improved significantly six months post-operatively (18.6 points, standard deviation (sd) 7.7; p = 0.03 and 28.8 points, sd 8.6; p = 0.006, respectively) and continued to improve slightly or reached a plateau. The mean pain scores at rest (Z = -3.2, p = 0.001) and during activity (Z = -3.2, p = 0.001), and stability (Z = -3.0, p = 0.003) improved significantly six months post-operatively. Thereafter scores continued to improve slightly or a plateau was reached. There were no signs of loosening.

Conclusion

Revision surgery using the Latitude TEA results in improvement of functionality, reduced pain and better stability of the elbow. Improvement of ROM of the elbow should not be expected. Cite this article: Bone Joint J 2016;98-B:1086–92.

The posttraumatic stiff elbow: an update

Posttraumatic elbow stiffness is a disabling condition that remains challenging to treat despite improvement of our understanding of the pathogenesis of posttraumatic contractures and new treatment regimens. This review provides an update and overview of the etiology of posttraumatic elbow stiffness, its classification, evaluation, nonoperative and operative treatment, and postoperative management.

Total elbow arthroplasty in distal humeral nonunion: clinical and radiographic evaluation after a minimum follow-up of three years

BACKGROUND

Total elbow arthroplasties (TEAs) are usually indicated in chronic inflammatory arthropathies. This procedure has also recently been used in complex distal humeral fractures and nonunions in selected patients. This study analyzed the clinical and radiographic outcomes in patients treated for nonunions around the elbow region with a minimum follow-up of 3 years.

METHODS

Between May 2002 and June 2012, 20 patients affected with distal humeral nonunions were treated with TEA. All patients were assessed clinically using the Mayo Elbow Performance Score and radiographically to evaluate the positioning of the prosthetic components and signs of loosening. Statistical analyses were performed to investigate the presence of clinical and radiographic variables as predictive factors of poor functional outcomes.

RESULTS

The Mayo Elbow Performance Score of the affected arm improved significantly between the preoperative period and follow-up. Results were good or excellent in 90% of the patients even if a high rate of complications (30%) was encountered. The development of complications after surgery and stages II, III, and IV radiolucency, according to the Morrey criteria, were predictive factors of poor outcomes.

CONCLUSIONS

According to the satisfactory results observed in this study, TEA could be indicated in selected patients aged older than 70 years with low functional demands and affected with distal humeral nonunions in which obtaining a stable fixation is difficult.

Mid-term clinical results of a modern convertible total elbow arthroplasty

Unlinked, linked and convertible total elbow arthroplasties (TEAs) are currently available. This study is the first to report the clinical results of the convertible Latitude TEA. This was a retrospective study of a consecutive cohort of 63 patients (69 primary TEAs) with a mean age of 60 years (23 to 87). Between 2006 and 2008 a total of 19 men and 50 women underwent surgery. The mean follow-up was 43 months (8 to 84). The range of movement, function and pain all improved six months post-operatively and either continued to improve slightly or reached a plateau thereafter. The complication rate is similar to that reported for other TEA systems. No loosening was seen. Remarkable is the disengagement of the radial head component in 13 TEAs (31%) with a radial head component implanted.

Implantation of both the linked and the unlinked versions of the Latitude TEA results in improvement of function and decreased pain, and shows high patient satisfaction at mid-term follow-up.

Cite this article: Bone Joint J 2015; 97-B:681–8.

Post-traumatic osteoarthritis of the elbow

Post-traumatic osteoarthritis of the elbow is an uncommon condition in which the clinical manifestations are often at variance with the radiological findings. In symptomatic forms, pain and stiffness are variably combined. When non-operative management fails, the decision to perform surgery is taken on a case-by-case basis depending on age, activity level, patient discomfort, and osteoarthritis location and severity as assessed by CT scan arthrography. Elbow instability or subluxation should be sought. Post-traumatic elbow osteoarthritis raises difficult therapeutic problems in young patients. The goal of treatment is to obtain a low level of pain with sufficient motion range to ensure good function, while preserving future surgical options and delaying elbow arthroplasty to the extent possible.

Linking of total elbow prosthesis during surgery; a biomechanical analysis

BACKGROUND

Presently, 2 types of elbow prostheses are used: unlinked and linked. The Latitude total elbow prosthesis allows the surgeon to decide during the implantation whether the prosthesis is placed unlinked or linked, and whether the native radial head is retained, resected, or replaced. The purpose of this study is to assess and to compare the varus and valgus laxity of the unlinked and linked version of the latitude total elbow prosthesis with: (1) the native radial head preserved, (2) the native radial head excised, and (3) the native radial head replaced by a radial head component.

METHODS

Biomechanical testing was performed on 14 fresh-frozen upper limb specimens.

RESULTS

Linking the prosthesis predominantly influences the valgus laxity of the elbow.

DISCUSSION/CONCLUSION

Linking the Latitude total elbow prosthesis results in increased valgus stability. In the linked version of the total elbow prosthesis, the radial head only plays a small part in both valgus and varus stability. An unlinked situation is not advised in absence of a native radial head or in case of inability to replace the radial head.

Stability of the unlinked Latitude total elbow prosthesis: a biomechanical in vitro analysis

BACKGROUND

The purpose of this study is to assess the valgus and varus laxity of the unlinked version of the Latitude total elbow prosthesis and the effects of radial head preservation or replacement.

METHODS

Biomechanical analysis of the valgus and varus laxity of the unlinked Latitude was performed in fourteen upper limb specimens in the following conditions: (1) native elbow, (2) native elbow after the surgical approach and closing all layers again, (3) elbow with humeral and ulnar component implanted, unlinked, with the native radial head preserved, (4) elbow with humeral and ulnar component implanted, unlinked, with the native radial excised, (5) elbow with humeral, ulnar, and radial head component implanted.

FINDINGS

After implantation of the Latitude total elbow prosthesis both the valgus and varus laxity slightly increase from mid to maximal flexion when compared to the native elbow after surgical approach. The unlinked Latitude total elbow prosthesis provides both valgus and varus stability in elbows with intact ligamentous constraints. With intact ligamentous constraints the radial head component only slightly contributes to the stability of the elbow after implantation of the unlinked Latitude total elbow prosthesis.

INTERPRETATION

The unlinked Latitude total elbow prosthesis provides both valgus and varus stability in elbows with intact ligamentous constraints. The radial head component contributes only slightly to the stability.

The effect of implant malalignment on joint loading in total elbow arthroplasty: an in vitro study

HYPOTHESIS

Aseptic loosening is one of the leading causes of failure in total elbow arthroplasty. Incorrect implant positioning and alignment in other joints such as the knee have been found to lead to excessive loading and wear. Although similar alignment difficulties exist in the elbow, the effect of implant malalignment on wear-inducing loads is not yet known. This in vitro study determined the effect of anterior malpositioning and varus-valgus and internal-external malrotations on humeral stem loading in total elbow arthroplasty.

METHODS AND MATERIALS

Computer-navigated linked elbow arthroplasty was conducted in 8 cadaveric elbows. A modular, instrumented humeral component was used to measure loading during simulated elbow motion while the position of the ulna relative to the humerus was recorded.

RESULTS

Loading increased for all malaligned implant positions tested (P < .05). During simulation of implant malpositioning, combinations of internal-external and varus-valgus malrotations that tended to preserve the line of action of the elbow flexors had lower loads than combinations that did not.

DISCUSSION

This in vitro study showed that loading does increase after humeral component malalignment; however, further studies are required to determine the long-term effects on polyethylene wear and component loosening.

The Kudo humeral component as primary hemiarthroplasty in distal humeral fractures

BACKGROUND

Treatment of intra-articular fractures of the distal humerus in the elderly is challenging. In patients with very distal fractures and severe comminution, primary arthroplasty has been advocated. Recently, a few reports have described promising results of hemiarthroplasty. This study describes the medium-term results of using the Kudo humeral implant (Biomet Ltd, Bridgend, U.K.) as replacement of the distal humerus.

MATERIAL AND METHODS

Eight women (mean age, 79 years) were treated. Follow-up was conducted at a mean of 4 years after the procedure and consisted of the Mayo Elbow Performance Score (MEPS), radiographic images, and range of motion (ROM).

RESULTS

All patients had a good or excellent outcome according to the MEPS. Mean ROM was 31° to 126°. Radiographic signs of attrition of the ulna were observed in 3 patients but did not correlate with the functional outcome. A periprosthetic fracture occurred in 1 patient 3 years after the index operation, and ROM was unsatisfactory in 1 patient. No other complications were observed.

CONCLUSION

The use of the Kudo humeral implant as a hemiarthroplasty resulted in a reasonable functional outcome in the medium-term, but the radiographic signs of attrition suggest that the implant is not recommended as a hemiprosthesis.

Long-term effectiveness of Sorbie-QUESTOR elbow arthroplasty: single surgeon's series of 15 years

With increasing usage of many types of total elbow replacements, there is a continuing need for clinical series that report survivorship, complications and revisions, and performance of single types of implants over extended time periods. The purpose of this study was to assess the long-term effectiveness of all implants of the Sorbie-QUESTOR (SQ) unlinked surface arthroplasty conducted by a single surgeon (C.S.) over 15 years at a single site, and to determine whether there were diagnostic group differences. Between 1995 and 2002, 51 S-Q prosthetic elbows were implanted into 44 patients. The patient groups were hemophilia, rheumatoid arthritis, and "other," which included osteoarthritis, traumatic arthritis, psoriatic arthritis, and reactive arthritis. Annual evaluations included scores of pain, range of motion, and function. The most recent annual evaluation was included in the data set. Details of complications and revisions were recorded. The hemophiliac group had the best survival outcomes at 87.5%. Eighteen prostheses required revision or removal with all but 3 retained or replaced. Postoperatively, 73% rated their pain as 'slight' or 'none'. The hemophilia and rheumatoid arthritis groups made very large total flexion/extension gains. The rheumatoid arthritis group made significant forearm motion gains. Average functional assessment gains were nearly 2 grades of 5 functional levels and were significant for all groups. The S-Q surface arthroplasty has demonstrated long-term effectiveness in patients with a variety of elbow joint pathologies showing reduction in pain, large gains in joint range and function, and good long-term survival.

Stem abutment affects alignment of the humeral component in computer-assisted elbow arthroplasty

OBJECTIVES AND HYPOTHESIS

The humeral component in total elbow arthroplasty has limited geometric modularity, and the extent to which this affects accurate positioning is unknown. The objectives of this study were to (1) validate the accuracy of a computer-assisted implant alignment technique, and (2) identify variations in distal humeral morphology that affected computer-assisted implant alignment. This was achieved by implanting both an unmodified humeral component and an implant with a reduced stem using computer assistance. We hypothesized that implantation of a humeral component with a reduced stem length would be more accurate than implantation of the standard length stem. In addition, we hypothesized that the variation in flexion-extension (FE) varus-valgus angulation would significantly affect computer-assisted implant alignment.

MATERIALS AND METHODS

Computer-assisted alignment of the implant articulating axis with the humeral FE axis was performed on 13 cadaveric humeri for both the regular and modified humeral component. Navigation was based on alignment of the prosthesis with a preoperative plan and registration of this plan to the humerus.

RESULTS

Implant alignment was significantly improved for the reduced stem. Alignment error of the reduced stem averaged 1.3 ± 0.5 mm in translation and 1.2° ± 0.4° in rotation, compared with 1.9 ± 1.1 mm and 3.6° ± 2.1° for the regular stem. Humeral varus-valgus angulation significantly affected alignment of the unmodified stem.

DISCUSSION

A humeral component with a fixed valgus angulation cannot be accurately positioned in a consistent fashion without sacrificing alignment of the FE axis. Improved accuracy of implant placement can be achieved by introducing a family of humeral components, with 3 valgus angulations of 0°, 4° and 8°.

Complications of total elbow arthroplasty

Modifications in implant design and improvements in surgical technique have expanded the applications of total elbow arthroplasty. Complications associated with reconstructive elbow surgery persist, however, often leading to profound and sometimes nonsalvageable disability. The most recognized complications include implant loosening, periprosthetic fracture, implant failure, infection, triceps insufficiency, and nerve palsy. Although far fewer elbow arthroplasties than lower extremity arthroplasties are performed, the proportion of complications is greater with elbow arthroplasty, and the outcomes of secondary reconstruction are less favorable.

Rheumatoid arthritis of the elbow

Rheumatoid arthritis (RA) is the most common form of inflammatory arthropathy. RA is considered a disease of synovial joints, although it can cause various extra-articular manifestations. The synovium appears to be the primary target; however, investigations are ongoing to determine the exact etiology and pathoanatomy.

Unlinked and convertible total elbow arthroplasty

Total elbow arthroplasty (TEA) is still in its infancy if we compare it with other arthroplasties such as knee or hip. TEA designs have been evolving with experience; however, long-term outcome data remain limited. The designs of total elbow prostheses can be subdivided into 3 general categories: unlinked, linked, and convertible devices. This article focuses on unlinked and convertible prostheses.

Linked total elbow arthroplasty

This article provides an overview of the current state of linked total elbow arthroplasty. Discussed are the general indications for using a linked implant and currently available implants. Disease-specific indications, contraindications, surgical technique, and rehabilitation are discussed. The overall results and disease-specific results, as well as complications after a linked elbow arthroplasty, are reviewed.

The Kudo 5 total elbow replacement in the treatment of the rheumatoid elbow

Between September 1993 and September 1996, we performed 34 Kudo 5 total elbow replacements in 31 rheumatoid patients. All 22 surviving patients were reviewed at a mean of 11.9 years (10 to 14). Their mean age was 56 years (37 to 78) at the time of operation. All had Larsen grade IV or V rheumatoid changes on X-ray. Nine (three bilateral replacements and six unilateral) had died from unrelated causes. One who had died before ten years underwent revision for dislocation.

Of the 22 total elbow replacements reviewed six had required revision, four for aseptic loosening (one humeral and three ulnar) and two for infection. Post-operatively, one patient had neuropraxia of the ulnar nerve and one of the radial nerve. Two patients had valgus tilting of the ulnar component.

With revision as the endpoint, the mean survival time for the prosthesis was 11.3 years (95% confidence interval (10 to 13) and the estimated survival of the prosthesis at 12 years according to Kaplan-Meier survival analysis was 74% (95% confidence interval 0.53 to 0.91).

Of the 16 surviving implants, ten were free from pain, four had mild pain and two moderate. The mean arc of flexion/extension of the elbow was 106° (65° to 130°) with pronation/supination of 90° (30° to 150°) with the joint at 90° of flexion. The mean Mayo elbow performance score was 82 (60 to 100) with five excellent, ten good and one fair result.

Good long-term results can be expected using the Kudo 5 total elbow replacement in patients with rheumatoid disease, with a low incidence of loosening of the components.

Linked semi-constrained total elbow prosthesis in chronic arthritis: results of 18 cases

During the second half of the 1900s, total elbow joint replacement began its ascent. Since then, many prosthetic models have been used. The main objective of elbow joint replacement in arthritic diseases is to decrease pain, increase joint stability and improve overall range of motion. In this study, 18 patients affected with elbow arthritis were treated with the Coonrad-Morrey and Discovery total elbow prostheses. All patients were assessed clinically before and after surgery using the Mayo Elbow Performance Score, the Disabilities of the Arm, Shoulder and Hand questionnaire and through radiograph analysis. Excellent and good results were observed in 88.9% of the cases at a mean follow-up of 5 years. Significant statistical differences in all parameters between preoperative and final follow-up values confirm the efficacy of these devices.

Cementless fixation of radial head implants is affected by implant stem geometry: an in vitro study

BACKGROUND

Metal radial head implants are widely used for the management of unreconstructible fractures. However, the effect of implant stem design on initial fixation and stability is unknown. This study determined the effects of radial head stem geometry on the initial stability of the uncemented implant. It was hypothesized that cortical contact and hence increased fixation would be achieved with an increased stem diameter, stem length and a tapered shape.

METHODS

Eleven radii received five implants with differing stem geometries: short and long undersized, short and long optimally sized and short tapered. Inferiorly-directed compressive loads were applied successively to the anterior, posterior, medial and lateral edges of the implants. Maximum contralateral radial head "lift-off" was quantified by the distance between bone and implant surface markers.

FINDINGS

The short and long undersized implants experienced greater micromotion with approximately 100 microm and 160 microm more lift-off respectively (P<0.02). The remaining optimally sized and tapered implants averaged 50 microm. There was greater motion for the undersized implants loaded at the lateral position (P0.005).

INTERPRETATION

This study shows that filling the diameter of the medullary canal is more important than filling the length of the canal. The taper did not offer any additional advantages compared to the straight stem, suggesting that reaming of bone to accept the taper did not produce enhanced initial purchase. If rigid initial implant fixation is desired with an uncemented radial head implant, a canal-filling stem reduces initial implant micromotion to less than 50 microm which may enhance bone ingrowth.

Image-based navigation improves the positioning of the humeral component in total elbow arthroplasty

HYPOTHESIS

Implant alignment in total elbow arthroplasty (TEA) is a challenging and error-prone process using conventional techniques. Identification of the flexion-extension (FE) axis is further complicated for situations of bone loss. This study evaluated the accuracy of humeral component alignment in TEA. We hypothesized that an image-based navigation system would improve humeral component positioning, with navigational errors less than or approaching 2.0 mm and 2.0 degrees .

MATERIALS AND METHODS

Implantation of a modified commercial TEA humeral component was performed with and without navigation on 11 cadaveric distal humeri. Navigated alignment was based on positioning the humeral component with the aid of a computed tomography (CT)-based preoperative plan registered to landmarks on the distal humerus. Alignment was performed under 2 scenarios of bone quality: (1) an intact distal humerus, and (2) a distal humerus without articular landmarks.

RESULTS

Navigation significantly improved implant alignment accuracy (P < .001). Navigated implant alignment was 1.2 +/- 0.3 mm in translation and 1.3 degrees +/- 0.3 degrees in rotation for the intact scenario. For the bone loss scenario, navigated alignment error was 1.1 +/- 0.5 mm and 2.0 degrees +/- 1.3 degrees . Non-navigated alignment was 3.1 +/- 1.3 mm and 5.0 degrees +/- 3.8 degrees for the intact scenario and 3.0 +/- 1.6 mm and 12.2 degrees +/- 3.3 degrees for the bone loss scenario.

DISCUSSION

Image-based navigation improves the accuracy and reproducibility of humeral component placement in TEA. Implant alignment errors for the navigated alignments were below the target of 2.0 degrees and 2 mm that is considered standard for most navigation systems. Non-navigated implant alignment error was significantly greater for the bone loss scenario compared with the intact scenario.

CONCLUSIONS

Implant malalignment may increase the likelihood of early implant wear, instability, and loosening. Improved implant positioning will likely lead to fewer complications and greater prosthesis longevity.

A comparison of registration techniques for computer- and image-assisted elbow surgery

Optimal function following elbow replacement surgery is dependent on the accurate replication of the elbow's flexion-extension axis. Currently, position and orientation of the axis are estimated from visual landmarks. In order to develop computer-assisted techniques to more accurately define this axis, a surface-based registration technique employing a hand-held laser scanner was evaluated against a conventional paired-point registration method to determine whether it produced improved alignment of the flexion-extension axis of the elbow. Registration error was 0.8 +/- 0.3 mm for surface-based registration, compared with 1.9 +/- 1.0 mm for the conventional registration method. These results suggest that the implementation of a surface-based registration technique may lead to a more accurate axis determination and improved clinical outcomes following elbow replacement surgery.

Computer assisted surgery of the distal humerus can employ contralateral images for pre-operative planning, registration, and surgical intervention

BACKGROUND

Bone loss at the distal humerus can lead to errors in the identification of the elbow's flexion-extension axis. Referencing the anatomy of the contralateral (uninjured) elbow may prove beneficial in accurately defining this axis. The objective of this study was to compare distal humeral morphology between paired specimens and determine whether geometric differences exist.

METHODS

Medical CT images of 25 paired, dry cadaveric, distal humeri were acquired and a range of anatomic characteristics were measured, following registration of each pair to a common coordinate system.

RESULTS

The anthropometric features of the distal humerus were similar from side-to-side, with differences on the order of 1.0 degrees and 0.5 mm.

CONCLUSIONS

Preoperative imaging of the contralateral normal elbow may be employed in patients with peri-articular bone loss, where referencing anatomic landmarks of the injured side is not possible.

Elbow arthritis: current concepts

The purpose of this article is to provide an update and analyze current management, treatment options, and outcomes of elbow arthritis. This article focuses on studies that have been published in the past 5 years. Nonoperative management may provide symptomatic relief in the early stages of the disease process for most patients. Surgical treatment is guided by disease etiology and severity, patient age, and functional demands. Arthroscopic or open synovectomy, debridement arthroplasty, and interposition arthroplasty are generally recommended for the young and active patient population, whereas for low-demand and elderly patients with end-stage painful arthritis, total elbow arthroplasty is considered a more suitable surgical option. Advances in arthroscopic techniques and implant design have led to substantial improvements in treatment of elbow arthritis.

Role of an anterior flange on cortical strains through the distal humerus after total elbow arthroplasty with a latitude implant

PURPOSE

Anterior flanges have been added to the humeral components of some total elbow arthroplasty systems to improve load transfer to the humerus and thereby reduce stress shielding in an effort to decrease the incidence of loosening. Either a wedge of bone or bone cement is placed between the anterior surface of the humerus and the flange. The purpose of this study was to quantify the cortical strains in the humerus as a function of these implantation options.

METHODS

Five cadaveric distal humeri were fitted with bending strain gauges at 2 levels on the diaphysis and axial strain gauges at 1 level. Each specimen was subjected to cantilevered bending and axial compressive loads. Subsequently, a humeral prosthesis was inserted, and testing was repeated with 3 materials behind the flange: no graft (simulating an implant with no flange), a wafer of cancellous bone, and a block of bone cement.

RESULTS

The presence of an anterior flange had no significant effect on load transfer through the distal humerus regardless of graft material. This was found to be consistent for both bending and axial loading modes at all gauge levels; however, the supporting collar effect of the implant may have influenced axial compression results.

CONCLUSIONS

These results suggest that for the Latitude humeral component studied, the placement of bone or bone cement behind the anterior flange may not influence the cortical strains in the distal humerus under bending loads. However, a flange may still influence cortical strains using another implant with different geometric and material properties than the currently studied design.

The effect of anatomic landmark selection of the distal humerus on registration accuracy in computer-assisted elbow surgery

Incorrect selection of the flexion-extension axis of the elbow may be an important cause of failure following total elbow arthroplasty. Axis selection can be improved by locating it on a pre-operative image and registering the image to the subject intra-operatively. However, registration is dependent on the availability of anatomic landmarks that may be distorted or absent because of tumors, arthritis, dislocations, or fractures. This study determined the anatomic landmarks required to register surface data accurately to a pre-operative image of the distal humerus. Registration error for landmarks unlikely to be compromised by severe bone loss was 1.1 +/- 0.2 mm in translation and 0.4 +/- 0.1 degrees in rotation. These results suggest that a close alignment of a pre-operative image with intra-operative surface data can be achieved using only a relatively small portion of the distal humerus that is readily available to the surgeon, and unlikely to be compromised, even in the setting of significant articular bone loss.

Primary osteoarthritis of the elbow: current treatment options

In the elbow, as in other joints, primary osteoarthritis is characterized by pain, stiffness, mechanical symptoms, and weakness. But primary osteoarthritis of the elbow is unique in that there is relative preservation of articular cartilage and maintenance of joint space, with hypertrophic osteophyte formation and capsular contracture. Medical treatment and physical therapy may be initiated in the early stages of the disease process. Surgical treatment options include arthroscopic osteocapsular débridement, open ulnohumeral arthroplasty, distraction interposition arthroplasty, and total elbow arthroplasty. The potential for instability and loosening following total elbow arthroplasty in the setting of primary osteoarthritis limits the clinical application of this procedure. This patient population is generally younger than that recommended for total elbow arthroplasty, and their higher functional demands have limited the long-term success of this treatment option. The improvement in arthroscopic débridement techniques is perhaps the greatest advancement in the treatment of osteoarthritis of the elbow in recent years.

The posttraumatic stiff elbow: a review of the literature

Loss of motion is a common complication of elbow trauma. Restoration of joint motion in the posttraumatic stiff elbow can be a difficult, time-consuming, and costly challenge. In this review of the literature, the biologic response to trauma and the possible etiologic events that may lead to fibrosis of the capsules and heterotopic ossification will be discussed, as well as nonsurgical and surgical management of stiffness and expected outcomes of treatment.

Elbow hemiarthroplasty for acute reconstruction of intraarticular distal humerus fractures: a preliminary report involving 4 patients

We treated 4 female patients (mean age 80) with complex intraarticular acute fracture of the distal humerus with a Kudo humeral component, i.e. a hemiarthroplasty. All fractures were considered impossible to treat with open reduction and internal fixation. At mean 10 (3-14) months, 3 patients had an excellent result and 1 a good result according to the Mayo elbow performance score. We conclude that a hemiarthroplasty may be a valuable alternative in elderly patients with complex fractures of the distal humerus.