Radial head arthroplasty: a descriptive study of 970 patients in an integrated health care system

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.

The impact of anatomic alignment on radiocapitellar pressure following radial head arthroplasty

BACKGROUND

The incidence of radial head fractures is increasing, and radial head arthroplasty (RHA) is being more frequently used as treatment for irreparable fractures. Our objective was to compare radiocapitellar pressure between the native joint and 2 radial head prosthesis conditions: (1) a prosthetic head that was aligned to the forearm axis of rotation and (2) the same prosthesis with an axisymmetric nonaligned head.

METHODS

Ten cadaveric specimens received a pressfit radial head prosthesis (Align; Skeletal Dynamics) for both prosthetic testing conditions. Anatomic alignment (AL) was defined as the prosthetic head aligned to the forearm axis of rotation. Axisymmetric alignment (AX) was defined as the prosthetic radial head aligned to the axis of the prosthetic stem. Axial load was applied with the elbow in extension and the forearm pronated. Data were collected using a Tekscan 4000 sensor.

RESULTS

The mean pressure in the AL and AX groups were significantly higher than the mean pressure in the native joint. Compared with the native joint, the mean pressure was 19% higher in the AL group and 56% higher in the AX group. Peak pressure beyond 5 MPa occurred in 0 specimens in the native joint group, in 1 specimen (10%) in the AL group, and in 5 specimens (50%) in the AX group.

DISCUSSION

Our results demonstrated that a pressfit radial head prosthesis aligned with the forearm axis of rotation yields capitellar pressures that were more similar to the native condition than a nonaligned pressfit prosthesis. These findings suggest that anatomic alignment may optimize capitellar wear properties, improving the long-term durability of radial head arthroplasty.

Radial head replacement for acute complex elbow instability: a long-term comparative cohort study of 2 implant designs

BACKGROUND

Radial head fractures not amenable to reconstruction should be treated by radial head replacement (RHR) when there is associated elbow or forearm instability. There are multiple RHR designs with different philosophies, but 2 of the most commonly used implants include the anatomic press-fit radial head system and the loose-fit metallic spacer. There is little information available specifically comparing the long-term clinical and radiographic outcomes of these 2 systems. The objective of this study was to compare the long-term clinical and radiologic outcomes of 2 RHR designs in the context of complex acute elbow instability.

MATERIALS AND METHODS

Ninety-five patients with an average age of 54 years (range, 21-87 years) underwent an acute RHR (46 press-fit Acumed anatomic and 49 loose-fit Evolve metallic spacer) and were prospectively followed for an average of 61 months (range, 24-157 months). There were 34 terrible triads; 36 isolated RH fractures with medial, lateral, or longitudinal instability; and 25 RH fractures associated with a proximal ulnar fracture. Clinical outcome and disability were evaluated with the Mayo Elbow Performance Score (MEPS), the Oxford Elbow Score, and the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Pain and satisfaction were assessed using a visual analog scale. Radiographic analysis included presence of loosening, bone loss, and overstuffing related to the RHR.

RESULTS

Eight patients with an anatomic RHR (2 with overstuffing, 3 for stiffness, and 3 with loose implants) and 1 patient with a spacer (with stiffness) required implant removal. There were no significant differences between spacer RHR and anatomic RHR in arc of motion (120° vs. 113°, P = .14), pain relief (1 vs. 1.7, P = .135), MEPS (94 vs. 88; P = .07), Oxford Elbow Score (42.3 vs. 42.2, P = .4), or DASH score (12.2 vs. 14.4, P = .5). However, patients with a spacer RHR were significantly more satisfied (9 vs. 7.7; P = .004) than those with an anatomic implant. Radiographically, 19 anatomic implants had significant proximal bone loss and 10 showed complete lucent lines around the stem. Lucent lines were common around the spacer RHR. These radiographic changes were not always related to worse clinical outcomes.

CONCLUSION

Both the anatomic and spacer RHR designs can provide good clinical long-term outcomes. However, patients with a spacer showed a higher degree of satisfaction and those with an anatomic press-fit RHR had a higher revision rate, with radiographic changes that warrant continued follow-up.

90-day outcomes and factors for complications following radial head arthroplasty for Mason Type III and IV radial head fractures

PURPOSE

The aim of this study is to evaluate 90-day outcomes and complications following radial head arthroplasty (RHA) for Mason Type III and IV radial head fractures (RHFs) and determine factors predisposing patients to early complications and revision surgery.

METHODS

Patients undergoing RHA for Mason Type III and IV RHFs were identified retrospectively from an institutional database. Postoperative complications, reoperations, elbow range of motion, radiographs and concomitant injuries on the ipsilateral upper extremity were reviewed. Additionally, injuries were sub-classified as low-energy trauma (LET) or high-energy trauma (HET). Univariate logistic regression was performed to evaluate the risk for complications using patient factors not limited to the presence of concomitant ligamentous or bony injuries. P values < 0.05 were considered statistically significant.

RESULTS

Seventy four patients were included in our study with an average follow-up time of 12.7 months. Complications within 90-days of operation occurred in 8.1% of patients: heterotopic ossification (4.1%), superficial wound dehiscence (2.7%), and posterior interosseous nerve palsy (1.4%). No patients required readmission or revision surgery in the 90-day postoperative period. Univariate regression analysis did not demonstrate a significant association between diabetes, ASA status, HET versus LET, or the presence of concomitant injury. Concomitant injuries were found in 92% of patients.

CONCLUSION

Radial head arthroplasty for RHFs demonstrates a low complication rate in the short-term. Diabetes, ASA class, high versus low energy trauma, and presence of concomitant injury were not found to be associated with higher complication rates in the 90-day postoperative period.

LEVEL OF EVIDENCE

Level of evidence IV, retrospective case series.

Clinical and radiological outcome of Mason-Johnston types III and IV radial head fractures treated by an on-table reconstruction

Background

Only few methods treating comminuted radial head fractures have been established providing sufficient joint reconstruction, restoring radial length and enabling early joint mobilization. When an anatomical reconstruction using open reduction and internal fixation is not possible, radial head resection or primary arthroplasty is often conducted. An “Ex situ/on-table” reconstruction is widely disregarded but can be an option. The purpose of this study was to evaluate the functional and radiological outcome of comminuted radial head fractures treated with an “on-table” reconstruction and internal fixation using a low profile plate.

Methods

Fourteen patients who sustained a radial head fracture (9 Mason-Johnston type III and 5 Mason-Johnston type IV) and were treated with an “on-table” reconstruction between 2010 and 2020 were evaluated retrospectively. The patients mean age was 41.3 years (range 21–69). The clinical evaluation included active range of motion, grip strength, pain level and elbow stability. The functional outcome was assessed using the Disability of Arm, Shoulder and the Hand (DASH) score, Mayo Elbow Performance Index (MEPI), Broberg and Morrey score. The radiological examination included a.p. and lateral views of the injured elbow to evaluate nonunions, loss of reduction, joint alignment, avascular radial head necrosis, heterotopic ossifications and posttraumatic osteoarthritis.

Results

The inclusion rate was 74% with a mean follow-up of 50 months (range 16–128). The mean elbow flexion of the injured side was 126° (range110–145°) with an average extension loss of 8° (range 0–40°). Pronation was 65° (15–90°) and supination 66° (5–90°). The mean MEPI was 87 points (range 45–100). The mean DASH score was 13 points (range 1–88). According to the Broberg and Morrey functional scoring system, the average score was 92 points (range 88–100). Complete bone union was achieved in 9 cases, partial union in 4 cases and nonunion in one case. There were no signs of avascular necrosis of the radial head. Signs of post-traumatic osteoarthritis were seen in 11 cases. Five patients needed an implant removal due to a radio-ulnar impingement and one patient a revision surgery due to the nonunion and implant breakage.

Conclusions

An on-table (ex situ) reconstruction of the radial head is a reliable option with a good clinical outcome and low complication rate in the surgical treatment of comminuted radial head fractures. It can restore joint alignment and maintain radial length. The risk for avascular necrosis is neglectable, and the bone healing rate is high.