Radiocapitellar hemiarthroplasty for radiocapitellar arthritis: a report of three cases

Update on elbow arthroplasties with emphasis on imaging

Elbow arthroplasty is increasing in popularity and can be used to treat many conditions, such as trauma, primary and secondary osteoarthritis, inflammatory arthritis, and osteonecrosis. Total elbow arthroplasty (TEA) is reserved for patients with severe symptoms refractory to more conservative management. In addition to TEA, hemi-arthroplasty, interposition arthroplasty, and resection arthroplasty also play roles in the management of elbow pain. There are specific indications for each type of arthroplasty. Postoperative complications may occur with elbow arthroplasties and may be surgery or hardware related. Imaging is important in both pre-operative planning as well as in post-surgical follow-up. This article reviews the different types of elbow arthroplasties, their indications, their normal postoperative imaging appearances, and imaging findings of potential complications.

Anterior radial head subluxation in primary elbow osteoarthritis

PURPOSE

To investigate elbows with primary osteoarthritis (OA) for the presence of anterior radial head subluxation.

METHODS

A total of 71 patients with elbow osteoarthritis and 45 with lateral epicondylitis were initially identified. The baseline characteristics and preoperative elbow X-rays of consecutive patients that had been clinically confirmed with elbow OA or lateral epicondylitis between March 2011 and January 2020 were then retrospectively reviewed. The radiocapitellar ratio (RCR; the ratio of the displacement of the radial head about the diameter of the capitulum) was calculated using lateral views. These RCR values were compared between the OA and lateral epicondylitis cases.

RESULT

A significant increase was detected in RCR values between patients in elbow OA and the control group (13.2% (± 10.6) vs -1.2% (± 6.8), P<0.001). Based on receiver operating characteristic curves, RCR values had an excellent area under the curve (0.89) for the detection of elbow OA (Youden index, 0.69; sensitivity, 89%; specificity, 80%). Based on the ROC curve, the cutoff value of RCR was 0.04. Patients with RCR ≥ 0.04 had a significantly higher proportion of cases with elbow OA (risk ratio, 31.50 [95% CI, 11.17-88.82]) than those with RCR ˂ 0.04 (P ˂ 0.001).

CONCLUSION

Radial head subluxation is a radiographic finding associated with elbow OA and RCR ≥ 0.04 could be used as an aetiological factor for elbow OA diagnosis.

After failed radial head arthroplasty, what are the options? Risk factors and results of revisions in a multicenter study

Introduction

Few multicenter studies have analyzed the outcome of revision surgery of radial head arthroplasties (RHA) in the medium term follow up. The objective is twofold: to determine the factors associated with revision of RHAs and to analyze the results of revision with 2 surgical techniques: isolated removal of the RHA or revision with a new RHA (R-RHA).

Hypothesis

There are associated factors of RHA revision and RHA revision results in satisfactory clinical and functional outcomes.

Methods

Twenty-eight patients were included in this multicenter retrospective study, with all surgical indications for initial RHA being traumatic/post-traumatic. The mean age was 47 ± 13 years with a mean follow-up of 70 ± 48 months. This series included two groups: the isolated RHA removal group (n = 17) and the revision RHA with new radial head prosthesis (R-RHA) group (n = 11). Evaluation was clinical and radiological with univariate and multivariate analysis.

Results

Two factors associated with RHA revision were identified: a pre-existing capitellar lesion (p = 0.047) and a RHA placed for a secondary indication (<0.001). Revision for all 28 patients resulted in improved pain (pre-op Visual Analog Scale 4.7 ± 3 vs. post-op 1.57 ± 2.2, p < 0.001), mobilities (pre-op flexion 118 ± 20 vs. post-op 130 ± 13, p = 0.03; pre-op extension -30 ± 21 vs post-op -20 ± 15, p = 0.025; pre-op pronation 59 ± 12 vs post-op 72 ± 17, p = 0.04; pre-op supination 48 ± 2 vs post-op 65 ± 22, p = 0.027) and functional scores. Mobility and pain control were, for stable elbows, satisfactory in the isolated removal group. When the initial or revision indication was instability, the DASH (Disabilities of the Arm, Shoulder and Hand = 10 ± 5) and MEPS (Mayo Elbow Performance score = 85 ± 16) scores were satisfactory in the R-RHA group.

Discussion

In the case of a radial head fracture, RHA is a satisfactory first-line solution without pre-existing capitellar injury, its results being much weaker in the case of ORIF failure and fracture sequelae. In case of RHA revision, isolated removal or R-RHA adapted according to the pre-operative radio-clinical exam.

Level of evidence

IV.

Radial head replacement - A comprehensive review

Background

Radial head fractures represent 1-4% of all adult fractures and 1/3rd of elbow fractures (Kaas et al., 2010). Radial head is an important secondary stabilier of the elbow. The aim of the treatment of radial head fractures is to achieve stability and good functional outcome. Radial head replacement (RHR) is indicated when robust reconstruction and fixation of the fracture fragments is not possible.

Methods

This article explores history and evolution, anatomical considerations, biomechanics, implant designs, indications, surgical outcomes and controversies in radial head replacement based on current evidence.

Results

There is a wide range of RHR designs available without conclusive evidence to support the superiority of one design over the other. Ranges of motion, functional outcomes and complication were comparable among different designs with a high incidence of complications reported in many studies.

Conclusion

RHR remains a good option in unreconstructible radial head fractures, with potential to regain excellent function. It is imperative to continue with the quest to innovate and improve on current designs, to reduce complications in the long term.

Radiocapitellar Arthroplasty: Systematic Review

Introduction

Primary elbow osteoarthritis affects approximately 2% of the population, and has been treated with arthroplasty. However, total elbow arthroplasty (TEA) implants currently have severe weight limitations and issues with longevity. In patients with unicompartmental arthritis, unicompartmental arthroplasty may be used instead of TEA. We describe the use of Uni-Elbow Radio-Capitellum and Lateral Resurfacing Elbow for radiocapitellar arthroplasty (RCA) in this article.

Methods

Reviewers independently searched databases for keywords, such as radiocapitellar arthroplasty, RCA, uni-elbow radiocapitellum, UNI-E, and lateral resurfacing elbow, LRE. The measured outcomes of interest were the change in motion arc and patient-reported outcome scores. Studies that were not of appropriate quality determined by the Cochrane risk of bias summary tool and review studies were excluded.

Results

RCA resulted in a postoperative 38.3° ± 28.5° increase in elbow flexion-extension (P < .001), and 35.2° ± 28.6° increase in elbow pronation-supination (P < .001). Mayo Elbow Performance Score was significantly increased by 44.8 ± 12.6. DASH Score saw a significant reduction by 45.0 ± 14.6 points (P < .001), while the American Shoulder and Elbow Surgeons Score increased by 47.0 ± 10.6 points (P < .001). Of the 105 adult patients 16.2% experienced complications such as minor stiffness, ulnar neuropathy, component loosening, or radial head UNI-E stem failure. Reported complications were higher in the UNI-E group than in the LRE group.

Conclusion

RCA has shown promise as an option to treat radiocapitellar arthritis, particularly when excising the radial head causes lateral column instability.

Avoiding Articular Breakthrough in Screw Fixation of Radial Head Fractures

Background

Methods

Results

Conclusion

Radial Head Prosthetic Replacement in Adolescents: A Report of 5 Cases

BACKGROUND

The management of severe radiocapitellar joint pathologies in young patients is challenging. Radial head arthroplasty (RHA) is a treatment option in the adult population, but most surgeons avoid implementing it in younger patients, and there are no published results for patients younger than 16 years.

METHODS

Our retrospective cohort describes 5 patients (4 male 1 female) who underwent cementless modular RHA at an average age of 14 years (range: 13 to 15). The preoperative diagnoses were post-traumatic radiocapitellar incongruity and arthrosis because of previous Salter-Harris type 3 or 4 fractures of the radial head in 3 cases; and axial instability of the forearm following failed radial head excision in 2 cases. Because of the complexity of the elbow pathology in these cases, all underwent concomitant procedures including: contracture release (5 cases), corrective ulnar osteotomy (2 cases), distal ulnar shortening osteotomy, excision of radioulnar synostosis, microfracture of the capitellum, and partial excision of the medial triceps (1 case each). Collected data included patient-reported outcomes, visual analog scale pain score at rest and during physical activity and radiographic assessment of arthritis and prosthesis loosening.

RESULTS

Average clinical follow-up was 8 years (range: 3 to 13). All 5 patients were pain-free at rest, and 3 reported moderate elbow pain (visual analog scale: 5 to 6) with physical activity. At an average radiographic follow-up of 3 years (range: 0.5 to 5), 3 patients showed mild progression of elbow arthrosis, but there were no signs of progressive capitellar erosion or implant loosening. Only 1 complication was noted-development of heterotopic ossification in 1 patient, which required open heterotopic ossification excision and contracture release 2 years following the RHA. None of the patients required prosthesis revision or removal.

CONCLUSION

RHA was successful in improving pain and axial forearm stability in this very small series of adolescent patients. Concerns regarding long-term longevity and complications still exist. Considering the lack of other reliable treatment options, RHA may be indicated in this challenging patient population.

LEVEL OF EVIDENCE

Level IV: therapeutic study-case series.

The Essex-Lopresti Injury:: Evaluation and Treatment Considerations

This article describes evaluation and treatment considerations for Essex-Lopresti injuries. Specific information about pattern recognition and treatment options is provided.

Radiocapitellar arthroplasty: a consecutive case series with 2 to 6 years' follow-up

BACKGROUND

The aim of this study was to analyze indications, outcomes, and complications in patients treated with radiocapitellar arthroplasty.

METHODS

This prospective analysis of clinical and radiographic results included 16 elbows in 15 patients.

RESULTS

This study included 4 men and 11 women (mean age, 51.9 years; age range, 32-65 years). The mean follow-up period was 3.4 years (range, 2-6 years). The indications were post-traumatic (n = 10) and primary radiohumeral osteoarthritis (n = 6). A mean of 2 surgical procedures (range, 0-4) had been performed before radiocapitellar arthroplasty. The mean Mayo Elbow Performance Score significantly improved from 46 points to 85 points (P < .01). The arc of motion improved from 106° to 117° (P = .27). Radiographic ulnohumeral degeneration progressed in 40% of cases but was not symptomatic in any. Subsequent surgery was required in 5 elbows (31%). Revision of the radial head component was necessary in 4 patients (25%). In 3 patients this was a result of loosening of the stem. The radial component was subsequently removed because of persistent pain in 1. Radiographic loosening not requiring revision was found in 2 patients.

CONCLUSION

The overall Mayo Elbow Performance Score was good to excellent after radiocapitellar arthroplasty. Both the revision and reoperation rates were high, and one should consider this before performing this procedure. Loosening of the radial head component was a problem. An improved fixation technique or an adaptation of the design is needed before this type of surgery can be recommended as a standard procedure.

Radiocapitellar prosthetic arthroplasty: short-term to midterm results of 19 elbows

BACKGROUND

Few studies have discussed the short-term results of radiocapitellar (RC) prosthetic arthroplasty (PA). In this study, we assessed the short-term to midterm functional and radiographic results of elbows after RC PA. Our secondary aim was to assess the survival of the RC PA.

METHODS

We included 19 elbows in 18 patients with a mean follow-up of 35 months (range, 12-88 months). Patients were examined for instability and range of motion and were assessed using Mayo Elbow Performance Index and Oxford Elbow Score at any subsequent visits. RC PA was the primary treatment in 16 elbows, and 3 were revision radial head arthroplasty with concomitant capitellar resurfacing.

RESULTS

Range of motion, pain, and functional scores improved significantly from the preoperative to the final follow-up visit. Categoric grouping of the final Mayo Elbow Performance Index outcome scores showed 9 excellent, 5 good, 3 fair, 0 poor, and 2 missing data. However, stability of the elbow remained unchanged. There was no pain in 11 patients, mild pain in 5, and moderate pain in 3. Radiographic assessment showed no significant progress in ulnohumeral arthritis, although 3 elbows showed osteoarthritis progression to a higher grade. There were no major complications, including infection, revision, disassembly of the components, or conversion to total elbow arthroplasty. Survival of the RC PA was 100%.

CONCLUSION

Elbow arthritis seems to become stationary after RC PA. Symptomatic RC osteoarthritis would probably benefit from RC PA regardless of the etiology.

Radial shortening osteotomy reduces radiocapitellar contact pressures while preserving valgus stability of the elbow

PURPOSE

Shortening osteotomy of the proximal radius might represent a potential salvage procedure in symptomatic radiocapitellar osteoarthritis, which could decrease radiocapitellar load while preserving the native radial head. In an in-vitro biomechanical investigation, we sought to determine whether shortening osteotomy of the proximal radius (1) decreases the radiocapitellar joint pressure upon axial loading and (2) retains valgus stability of the elbow. In addition, the anatomic configuration of the lesser sigmoid notch was evaluated to assess possible contraindications.

METHODS

Axial loading (0-400 N) and valgus torque (7.5 N m) over the full range of motion were applied to 14 fresh-frozen specimens before and after shortening osteotomy of the proximal radius by 2.5 mm. Radiocapitellar and ulnohumeral load distribution during axial compression was evaluated using a digital pressure mapping sensor. Valgus displacement was analyzed with a 3D camera system. The inclination angle (α) of the lesser sigmoid notch was assessed via 50 CT scans.

RESULTS

Up to axial loading of 250 N, shortening osteotomy caused a significant decrease in radiocapitellar contact pressures (p < 0.041). Valgus stability of specimens did not differ before and after shortening osteotomy (n.s.). The mean inclination angle (α) of the lesser sigmoid notch was 11.3° ± 6.3°. 46% had an inclination angle of ≤ 10° (type I). 46% had an inclination angle of 11°-20° (type II). In 8%, the inclination angle was >20° (type III).

CONCLUSION

Shortening osteotomy of the proximal radius can decrease radiocapitellar contact pressures during axial loading of up to 250 N. Primary valgus stability is not relevantly influenced by this procedure. In few patients, shortening osteotomy may cause radioulnar impingement of the radial head at the distal edge of the lesser sigmoid notch due to an inclination angle of >20°. Shortening osteotomy might be a promising treatment option to decrease pain levels in case of isolated radiocapitellar osteoarthritis.

Forearm Instability: Anatomy, Biomechanics, and Treatment Options

The forearm unit consists of the radius and ulna, a complex and interrelated set of joints (distal radioulnar joint, proximal radioulnar joint) and the soft tissue stabilizers between the 3 bones. Distally, this is represented by the triangular fibrocartilage complex at the wrist, proximally by the annular ligament at the elbow, and in the forearm by the interosseous membrane. Disruptions in any of these structures may lead to forearm instability, with consequences at each of the remaining structures.

[Chronic bony instability of the elbow joint]

The high stability of the elbow joint is provided by the congruent articular surfaces in combination with soft tissue stabilizers. The main osseous contributor of elbow stability is the coronoid, which is therefore referred to as a primary stabilizer. The radial head as a secondary stabilizer together with the medial collateral ligament assures valgus stability and together with the coronoid it assures posterolateral stability. Insufficiency of the osseous stabilizers may lead to difficulties in the treatment of chronic dislocation and complex instability. Thereby reconstruction of the osseous constraints of the elbow joint is not performed in isolation from addressing insufficient soft-tissue stabilizers. Bony stabilizers and reconstructional procedures are discussed in this review.

Radiocapitellar prosthetic arthroplasty in traumatic and post-traumatic complex lesions of the elbow

Radiocapitellar prosthetic arthroplasty is a fascinating new option in the treatment of complex lesions of the elbow. The device has been developed in order to treat primitive and post-traumatic radiocapitellar degenerative arthritis, while preserving the ulnohumeral joint of the elbow. Compared to a radial head resection, it avoids valgus and axial instability of the elbow and forearm preventing ulnohumeral degeneration. Seven patients have been reviewed with a mean of follow-up of 40 months. Two of them presented with an acute trauma and five of them with a post-traumatic degenerative arthritis involving the radial compartment of the elbow. The patients' evaluation was performed using DASH and Mayo elbow performance score (MEPS). Implant overstuffing, loosening and degenerative changes of the ulnohumeral joint have been monitored with X-ray controls. All patients presented with a marked improvement in elbow function, no signs of overstuffing or ulnohumeral degeneration were observed. Two patients developed a clinically asymptomatic aseptic loosening of the radial press-fit stem. The radiocapitellar prosthetic arthroplasty shows convincing results in the treatment of symptomatic radiocapitellar degenerative arthritis. It has also been effective in acute trauma scenarios in the presence of major osteoarticular wearing or loss of the entire radiocapitellar joint.

Central Band Interosseous Membrane Reconstruction For Forearm Longitudinal Instability

BACKGROUND

The Essex-Lopresti injury results from injuries to the stabilizing structures of the forearm, the radial head, the interosseous membrane, and the triangular fibrocartilage complex.

CASE DESCRIPTION/LITERATURE REVIEW

We describe principles in approaching the patient with an acute or chronic Essex-Lopresti injury and describe surgical techniques to address these challenging cases both in the acute and chronic setting and describe outcomes of these techniques.

CLINICAL RELEVANCE

Further research into the role of the interosseous ligament in providing longitudinal and transverse stability to the forearm is likely to change our understanding of the Essex-Lopresti injury and alter management strategies.

Management of the Essex-Lopresti Injury

Essex-Lopresti injuries (ELIs) are characterized by fracture of the radial head, disruption of the forearm interosseous membrane, and dislocation of the distal radioulnar joint. This injury pattern results in axial and longitudinal instability of the forearm. Initial radiographs may fail to reveal the full extent of the injury, and therefore diagnosis in the acute setting requires a high index of suspicion. Early recognition and treatment are preferred as failure to fully treat the problem may result in chronic wrist pain from ulnar abutment or chronic elbow pain from radiocapitellar arthrosis. In this article the presentation, relevant anatomy, and management options for ELIs are overviewed, and a summary of outcomes reported in the literature is provided. Additionally, the preferred surgical technique of the senior author is presented, which involves reconstruction of the interosseous membrane with a local pronator rerouting autograft.

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.

From radial head to radiocapitellar to total elbow replacement: A case report

•

Overstuffing is a serious yet avoidable complication of radial head arthroplasty.

•

Overstuffing severely alters elbow joint kinematics and leads to capitellar erosion.

•

Radiocapitellar arthroplasty can be a salvage procedure in such cases.

•

Limited clinical data is available thus far regarding radiocapitellar arthroplasty.

•

The possibility for early failure due to ulnohumeral erosion has to be considered.

Introduction

Radiocapitellar arthroplasty represents a possible treatment option for isolated osteoarthritis of the radial column. We report the first case of early failure of this procedure.

Presentation of case

We present the case of a 41-year old male who sustained a terrible triad injury to his right elbow and subsequently underwent radial head arthroplasty. Due to overstuffing of the radial head prosthesis, capitellar erosion occurred and radiocapitellar arthroplasty was thus performed. Only one year later, conversion of the radiocapitellar replacement to total elbow arthroplasty was required as a result of progressive ulnohumeral osteoarthritis.

Discussion

According to the currently limited clinical data, radiocapitellar arthroplasty provides satisfactory results. However, biomechanical analysis shows that available prostheses do not sufficiently reproduce the radiocapitellar anatomy. The design of the prosthesis might thus have contributed to the rapid progression of ulnohumeral erosion following radiocapitellar arthroplasty although the poor outcome may also be attributed to the trauma itself along with the inadequate initial treatment.

Conclusions

The indication for radiocapitellar arthroplasty warrants careful consideration given the results of biomechanical analysis and the early failure due to progressive ulnohumeral erosion seen in the present case.

The effect of radial head implant shape on radiocapitellar kinematics during in vitro forearm rotation

BACKGROUND

A number of radial head implants are in clinical use for the management of radial head fractures and their sequelae. However, the optimal shape of a radial head implant to ensure proper tracking relative to the capitellum has not been established. This in vitro biomechanical study compared radiocapitellar joint kinematics for 3 radial head implant designs as well as the native head.

METHODS

Eight cadaveric upper extremities were tested using a forearm rotation simulator with the elbow at 90° of flexion. Motion of the radius relative to the capitellum was optically tracked. A stem was navigated into a predetermined location and cemented in place. Three unipolar implant shapes were tested: axisymmetric, reverse-engineered patient-specific, and population-based quasi-anatomic. The patient-specific and quasi-anatomic implants were derived from measurements performed on computed tomography models.

RESULTS

Medial-lateral and anterior-posterior translation of the radial head with respect to the capitellum varied with forearm rotation and radial head condition. A significant difference in medial-lateral (P = .03) and anterior-posterior (P = .03) translation was found between the native radial head and the 3 implants. No differences were observed among the radial head conditions except for a difference in medial-lateral translation between the axisymmetric and patient-specific implants (P = .04).

CONCLUSIONS

Radiocapitellar kinematics of the tested radial head implants were similar in all but one comparison, and all had different kinematics from the native radial head. Patient-specific radial head implants did not prove advantageous relative to conventional implant designs. The shape of the fixed stem unipolar radial head implants had little influence on radiocapitellar kinematics when optimally positioned in this testing model.

Outcomes of bipolar radial head prosthesis to treat complex radial head fractures in 22 patients with a mean follow-up of 50 months

BACKGROUND

Radial head replacement is indicated to treat complex proximal radial fractures that are not amenable to internal fixation.

HYPOTHESIS

Implantation of a bipolar radial head prosthesis after radial head excision ensures stability of the elbow and forearm, thereby promoting ligament healing and restoring elbow function.

MATERIAL AND METHODS

Twenty-two patients managed with implantation of a bipolar radial head prosthesis (Guepar(®)) were evaluated after a mean follow-up of 50 months. The procedure was performed in the acute setting in 16 patients, including 13 with associated injuries; and at the stage of sequelae in 6 patients.

RESULTS

Prosthesis removal was required in 4 patients. Of the remaining 18 patients, 14 (77%) had satisfactory Mayo Elbow Performance Score values, 14 (77%) little or no functional impairment, and 11 (61%) little or no pain. Mean motion arcs were 100° in flexion-extension and 143° in pronation-supination. Mean elbow strength in flexion and mean wrist strength were 67% and 86%, respectively, of those on the contralateral normal side. Radio-lucent lines were visible around the prosthesis in 5 patients, radial neck osteolysis in 10 patients, and capitellar erosion in 7 patients. Seven patients each experienced a complication. Early revision surgery to treat elbow instability was required in 6 patients.

DISCUSSION

Outcomes after Guepar(®) bipolar radial head prosthesis implantation were disappointing in patients with complex radial head fractures seen in the acute or chronic setting. The associated injuries to bones and ligaments and the measures taken to repair them influence the prognosis. The complication rate is non-negligible and seems to increase over time.

LEVEL OF EVIDENCE

IV, retrospective study.

Radial head arthroplasty: state of the art

Radial head arthroplasty has joined the armamentarium of options for the treatment of complex radial head fractures, elbow instability, and arthritic conditions. A variety of implants has been introduced in the past decade; these differ in metallic composition, design, and method of fixation. Good short- and intermediate-term outcomes have been reported with the use of loose-fitting prostheses. Press-fit devices restore stability and improve pain and motion but are associated with a greater likelihood of implant loosening, leading to revision surgery. Postoperative elbow stiffness, pain, ulnar nerve palsy, posterior interosseous nerve palsy, and heterotopic ossification have all been reported following radial head surgery, but these complications are likely related to the trauma sustained by the elbow. Adequate knowledge of the surgical indications, types of implants, and surgical technique are essential for a satisfactory outcome when a radial head prosthesis is used for the treatment of nonreconstructable radial head fractures.

Radiocapitellar prosthetic arthroplasty: a report of 6 cases and review of the literature

BACKGROUND

Radiocapitellar prosthetic arthroplasty has recently been introduced to treat isolated degenerative arthritis of the radiocapitellar joint. Although this procedure is conceptually attractive and sound in situations in which radial head resection is inadequate, clinical experience is still limited. Its role in the treatment of isolated radiocapitellar degenerative arthritis in the ligamentous-intact elbow and forearm is not yet defined. Our purpose was to report the short-term results of 6 patients who were treated by radiocapitellar prosthetic arthroplasty for isolated radiocapitellar degenerative arthritis in the ligamentous-intact elbow, as well as to provide a review of the literature.

METHODS

Six patients were treated by radiocapitellar prosthetic arthroplasty for isolated degenerative arthritis of the radiocapitellar joint in the ligamentous-intact elbow. Their medical records were reviewed, and each patient was seen in the office. The mean follow-up period was 50 months (range, 30-64 months).

RESULTS

The implant survival rate was 100%. Pain improved in all patients and all patients were satisfied. The mean flexion-extension arc increased from 98° (range, 75°-115°) to 110° (range, 105°-120°) (P = .17), and the mean pronation-supination arc increased from 133° (range, 75°-115°) to 143° (range, 120°-170°) (P = .34). The mean Disabilities of the Arm, Shoulder and Hand score was 24.3 (range, 6.7-52.5). According to the Mayo Elbow Performance Score, there were 3 excellent and 3 good results.

CONCLUSION

The short-term follow-up results of radiocapitellar prosthetic arthroplasty for isolated radiocapitellar degenerative arthritis in the ligamentous-intact elbow and forearm seem favorable.

LEVEL OF EVIDENCE

Level IV, case series, treatment study.

Radial head, radiocapitellar and total elbow arthroplasties: a review of recent literature

The outcome of prosthetic elbow surgery is continually evolving. We thoroughly reviewed the literature on this issue to analyse the indications, outcomes and complications of the numerous types of implants currently in use. Radial head replacement is recommended in comminuted fractures of the radial head and in post-traumatic conditions. Medium- and long-term results prove to be satisfactory in the majority of cases, with no evidence to indicate that some prostheses (monopolar vs. bipolar; cemented vs. press-fit) are more effective than others; nonetheless, the bipolar-cemented implant was found to be associated with a lower revision rate than other prostheses. Unicompartmental arthroplasty has recently been used for the treatment of osteoarthritis and rheumatoid arthritis when the lateral compartment is prevalently involved; the results reported to date have been encouraging, although further studies are warranted to confirm the validity of these implants. Total elbow arthroplasty is performed in a range of conditions, including distal humerus fractures in the elderly and elbow arthritis. In the former condition, linked elbow replacement yields excellent results with few complications and a low revision rate. In elbow arthritis, total elbow arthroplasty is indicated when patients suffer from disabling pain, stiffness and/or instability that prevent them from performing daily activities. Unlinked elbow arthroplasty, which is used above all in rheumatoid arthritis, also yields satisfactory results, although the risk of instability persists. The use of linked elbow arthroplasty, which yields similar results but lower revision rates, has consequently increased. Lastly, the results yielded by linked elbow prosthesis in post-traumatic conditions are good, although not quite as good as those obtained in rheumatoid arthritis. Early mechanical failure may occur in younger and more active patients after elbow arthroplasty. However, the careful selection of patients who are prepared to accept functional limitations imposed by elbow implants will enable indications for elbow arthroplasty to be extended to young subjects, particularly when no other therapeutic options are available.

[Endoprosthetics of acute radial head fractures]

Radial head arthroplasty is the treatment of choice for non-reconstructble radial head fractures. Solid prostheses made of metal or pyocarbon can restore valgus stability of the elbow independent of design or stem fixation. Short-term and mid-term results show mostly good to excellent results without any evident differences between the different prosthesis philosophies. In order to obtain good results it is important to implant the prosthesis correctly without overfilling and to judge concomitant ligament injuries correctly. This article discusses the anatomical and biomechanical basis of radial head arthroplasty as well as the surgical technique and radiological diagnosis of overfilling.

Elbow arthritis: current concepts

Elbow arthritis is a debilitating condition manifesting as a painful, stiff elbow. The purpose of this article is to provide an update and analyze current management, treatment options, and outcomes of treatment for elbow arthritis. This article focuses on recent developments in the treatment for elbow arthritis. Nonsurgical management may provide symptomatic relief in the majority of patients in the early stages of the disease process. 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 the treatment of elbow arthritis.

Capitellar excision and hemiarthroplasty affects elbow kinematics and stability

INTRODUCTION

Capitellar hemiarthroplasty is proposed as a reconstructive option for isolated capitellar deficiency, but there is limited data on its effect on elbow biomechanics. This study assessed the effect of capitellar excision with and without replacement on elbow kinematics and stability, and evaluated 2 different implant surface shapes.

MATERIALS AND METHODS

Ten cadaveric arms were tested with an upper extremity joint simulator. Each arm underwent computer tomography scanning for implant sizing and computer-assisted implantation. Kinematic data were obtained using an electromagnetic tracking system during elbow flexion, with the arm oriented in the valgus, varus, and vertical positions. Implants were placed through an extended lateral epicondylar osteotomy using computer-assisted techniques. A repeated-measures design compared 2 implants (anatomical and spherical) to the native capitellum control and capitellar excision states. Outcomes were maximum varus-valgus laxity and rotation of the ulna with respect to the humerus.

RESULTS

Excision of the capitellum increased the varus-valgus laxity up to 3.1° in active elbow flexion, with the forearm in pronation but not in supination. Both capitellar implant designs maintained normal varus-valgus laxity in both active and passive elbow flexion. Excision of the capitellum increased external ulnar rotation during active flexion in the vertical and valgus positions up to 1.5°, while both implants restored normal ulnar rotation. The kinematics and stability of the elbows were similar for both implant designs.

CONCLUSION

The capitellum appears to have a role as a valgus and external rotational stabilizer of the ulnohumeral joint. This instability was corrected by both designs of capitellar hemiarthroplasty.

Posttraumatic elbow stiffness

Early posttraumatic elbow contractures may be treated with a combination of manipulation with the patient under anesthesia followed by bracing.Extrinsic contractures of the elbow may be treated with open or arthroscopic release, whereas intrinsic and combined contractures may require tissue release as well as partial or total arthroplasty.

Elbow kinematics after radiocapitellar arthroplasty

PURPOSE

Radiocapitellar arthroplasty has been proposed as a reconstructive option for combined radial head and capitellar deficiency. The purpose of this study was to assess the impact of radiocapitellar replacement on elbow kinematics. We hypothesized that with the medial collateral ligament (MCL) intact, radiocapitellar arthroplasty would replicate normal kinematics, and that a radiocapitellar arthroplasty would more closely approximate normal kinematics than an elbow with a deficient lateral column or with a deficient MCL.

METHODS

We tested 7 cadaveric arms in an upper extremity joint simulator. Each arm underwent computed tomographic scanning to aid implant size selection and computer-assisted implant insertion. We obtained kinematic data using an electromagnetic tracking system during elbow flexion. The capitellar and radial head implants were placed through an extended lateral epicondylar osteotomy. We sectioned the anterior bundle of the MCL, leaving the flexor-pronator mass intact. Outcomes of interest were varus-valgus and rotational kinematics of the ulnohumeral joint.

RESULTS

The radiocapitellar arthroplasty showed no difference in kinematics compared with the postosteotomy control. The MCL-deficient elbow showed more valgus angulation and more external ulnar rotation than the control or radiocapitellar arthroplasty in the pronated, valgus loaded position. The deficient lateral column demonstrated increased external ulnar rotation kinematics during active elbow flexion.

CONCLUSIONS

Radiocapitellar arthroplasty can restore normal elbow kinematics with the MCL intact. If the MCL is deficient, radiocapitellar arthroplasty does not restore normal kinematics.

CLINICAL RELEVANCE

Radiocapitellar arthroplasty should be considered in cases of lateral column deficiency because it maintains normal elbow kinematics during active motion. Whereas radiocapitellar arthroplasty improves the stability of the MCL-deficient elbow with deficiency of the lateral column, reconstruction of the MCL may further improve normal kinematics.

Open debridement and radiocapitellar replacement in primary and post-traumatic arthritis of the elbow: a multicenter study

BACKGROUND

Postmortem and clinical studies have shown an early and prevalent involvement of the radiohumeral joint in primary and secondary arthritis of the elbow. The lateral resurfacing elbow (LRE) prosthesis has recently been developed for the treatment of lateral elbow arthritis. However, few data have been published on LRE results.

MATERIALS AND METHODS

A prospective multicenter study was designed to assess LRE preliminary results. There were 20 patients (average age, 55 years). Preoperative diagnosis were primary osteoarthritis in 11 and post-traumatic osteoarthritis in 9. All patients underwent open debridement and LRE prosthesis. Patients were evaluated preoperatively and postoperatively with the Mayo Elbow Performance Score (MEPS), modified American Shoulder Elbow Surgeons (m-ASES) elbow assessment, and the Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH). Mean follow-up was 22.6 months.

RESULTS

At the last follow-up, the mean improvement of MEPS and m-ASES was 35 (P = .001) and 34 (P = .001) respectively; the average Quick DASH decreased by 29 (P = .001). Average range of motion was improved by 35° (P = .001). MEPI results were excellent in 12 patients, good in 2, and fair and poor in 3 each. Mild overstuffing was observed in 5 patients, and an implant malpositioning in 3. The implant survival rate was 100%.

CONCLUSION

LRE showed promising results in this prospective investigation. Most patients had an uneventful postoperative course and have shown a painless elbow joint, with satisfactory functional recovery at short-term follow-up. Further studies with longer follow-up are warranted.

A morphological analysis of the humeral capitellum with an interest in prosthesis design

INTRODUCTION

Although interest in capitellar arthroplasty is increasing, the morphology of the capitellum has not been fully characterized. Our purpose was to quantify the anthropometric features of the capitellum with an interest in arthroplasty design. We hypothesized that the shape is more complex than originally believed, and cannot be accurately modeled as a spherical structure.

METHODS

Fifty cadaveric human elbows underwent helical computer tomography scans. After reconstruction and establishment of a coordinate system for the distal humerus, circle-fits were applied to each of the 1-mm-thick slices. Sagittal radii of curvature were calculated every 10° of flexion around each circle (0-130° of flexion). A single transverse radius was calculated at 60° of flexion. The surface of the capitellum was described by sagittal and transverse radii of curvature and the footprint by height and width. These pairs of parameters were correlated to determine their strength of association.

RESULTS

The average height was 23.2 ± 2.9 mm (range, 18.3-29.5), while the average width was 13.9 ± 2.3 (range, 9-19). The sagittal radius of curvature was 11.6 ± 1.4 mm (range, 8.7-14.8), and the transverse radius was 14.0 ± 3.0 mm (range, 9.6-20.9). Correlations of height and width and sagittal and transverse radii were significant (R = .547, .705) (P < .01). Sagittal and transverse radii and height and width were significantly different (P < .001 for each pair).

CONCLUSION

The capitellum does not have a spherical surface or a circular footprint. There is substantial variability in the relationship between the height and width, and between the surface radii, that may be difficult to replicate with an off-the-shelf implant.

The impact of capitellar arthroplasty on elbow contact mechanics: Implications for implant design

BACKGROUND

Radiocapitellar arthroplasty is indicated for capitellar deficiency. Although current implants employ a spherical capitellar surface, the capitellum is elliptical. This has implications for congruency and wear in capitellar arthroplasty. Our objective was to evaluate the contact mechanics of radiocapitellar arthroplasty. We hypothesized that capitellar replacement would decrease joint contact area relative to the native articulation; and an anatomical implant design would replicate more normal contact morphology than a spherical implant.

METHODS

Eight paired humeri and radii were potted in a custom jig. A compressive load of 85N was applied with the articulation flexed at 45° in neutral forearm rotation. Joint casts were made and the articular contact area and shape were quantified. Anatomical and spherical capitellar implants were tested against the native radial head (hemiarthroplasty).

FINDINGS

The contact areas for the anatomical and spherical hemiarthroplasties were 59 and 51% of the native articulation (P<0.005), while the unicompartmental arthroplasties' contact areas were 84 and 89% (anatomical, spherical) of the native articulation (P<0.01). No implant was superior in recreating the native contact shape.

INTERPRETATION

Placement of any capitellar implant resulted in a large decrease in contact area when articulating with a native radial head. This suggests that the radial head cartilage would see a marked increase in contact pressure relative to the native articulation. The unicompartmental arthroplasties demonstrated an even larger reduction in contact area, raising concern about accelerated surface wear. Further investigation needs to correlate these contact mechanics to cartilage wear and implant longevity.

Hemiarthroplasty of the ulnohumeral and radiocapitellar joints

Hemiarthroplasty involves replacement of the distal portion of the humerus without replacement of the ulna. This article reviews the literature on hemiarthroplasty of the ulnohumeral and radiocapitellar joints. It discusses the indications and outcomes of the technique and summarizes the author's experiences and results.

Primary osteoarthritis and posttraumatic arthritis of the elbow

Arthritis of the elbow resulting from either prior trauma or primary osteoarthritis is similar in that the end result is often a combination of pain and stiffness, but the location of the disorder can be different. Treatment decisions must be made on a case-by-case basis taking into account patient age, level of demand, and location and degree of degenerative changes. This article focuses primarily on the unique pathogenesis and general treatment rationale for primary osteoarthritis and posttraumatic arthritis of the elbow.

Interosseous membrane reconstruction for the Essex-Lopresti injury

The Essex-Lopresti lesion, or radioulnar longitudinal dissociation, results from an axial load to the forearm with injury to the radial head and disruption of the interosseous membrane and the distal radioulnar joint. Unfortunately, an appreciation of the true extent of injury is not always realized in the acute setting, and patients present later with persistent or new reports of forearm discomfort and wrist and elbow pain. Reconstruction of the central band of the interosseous membrane with a bone-patellar tendon-bone graft is useful in the chronic setting and is described.

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.