The effect of humeral-fenestration diameter in Outerbridge-Kashiwagi arthroplasty on failure load of the distal humerus: a cadaveric biomechanical study

Surgical management for primary osteoarthritis of the elbow

The objective of this review is to summarize the surgical options for primary osteoarthritis of the elbow, reported clinical outcomes, and suggested indications in previous literatures. The surgical management of primary elbow arthritis has evolved because of an improved understanding of pathologic mechanisms and manifestations as well as the development of novel surgical techniques and devices. Osteocapsular arthroplasty (OCA), elbow debridement, distraction arthroplasty, and total elbow arthroplasty (TEA) have been employed for managing elbow osteoarthritis. Elbow debridement and OCA can be helpful in most cases of symptomatic elbow arthritis. TEA is usually recommended for end-stage arthritis in elderly patients after prosthetic implants have been in place for long periods or after complications. Distraction arthroplasty might find a place in the treatment of younger, active patients with end-stage arthritis.

Clinical outcomes of a combined arthroscopic and mini-open Outerbridge-Kashiwagi procedure for elbow osteoarthritis

BACKGROUND

To evaluate the short-term clinical outcomes of a modified Outerbridge-Kashiwagi (O-K) procedure in the treatment of elbow osteoarthritis.

METHODS

Between January 2012 and December 2016, 27 patients with elbow osteoarthritis were treated with a modified O-K procedure combining mini-open and arthroscopic technique in our institution. All patients with primary osteoarthritis and post-traumatic degenerative osteoarthritis of the elbow were included in the study if they had undergone the modified O-K procedure. Clinical outcomes were assessed using the visual analog scale (VAS), degree of flexion, extension loss, arc of motion, Mayo Elbow Performance Score (MEPS), and radiographs.

RESULTS

Twenty-five patients with a mean age of 47.2 years (range, 21-69 years) at surgery were followed up for a mean of 54.5 months (range, 27-86 months). The VAS improved from 8.0 ± 1.4 (range, 6-10) preoperatively to 1.3 ± 1.1 (range, 0-3) at the final follow-up (P < .001), degree of flexion from 115.2° ± 12.0° (range, 90°-135°) to 130.6° ± 6.3° (range, 120°-140°) (P < .001), extension loss from 31.2° ± 15.0° (range, 10°-60°) to 10.2° ± 7.7° (range, 0°-30°) (P < .001), arc of motion from 84.0° ± 18.8° (range, 55°-120°) to 120.4° ± 9.3° (range, 105°-135°) (P < .001), and MEPS from 55.8 ± 8.1 (range, 40-70) to 88.4 ± 7.2 (range, 70-100) (P < .001). Radiographs at the final follow-up showed that 9 patients (36%) had significant recurrence of bone formation within the fenestration of the olecranon fossa. One patient developed delayed-onset ulnar neuropathy, with only slight numbness in the ulnar nerve distribution 6 months after surgery.

CONCLUSIONS

The modified O-K procedure is safe and effective in pain relief and function restoration in patients with elbow osteoarthritis.

The effect of hole size on failure loads of the distal humerus fenestration in Outerbridge-Kashiwagi arthroplasty: A biomechanical study

OBJECTIVE

The aim of this study was to biomechanically assess the effect of humeral-fenestration size in the Outerbridge-Kashiwagi arthroplasty on the ultimate failure load of the distal humerus in a synthetic bone model.

METHODS

We biomechanically tested the influence of different humeral-fenestration sizes on the failure load of the distal humerus in Outerbridge-Kashiwagi arthroplasty. A total of 50 synthetic humerus models were divided into 5 groups based on the fenestration size: 10 mm, 12 mm, 15 mm, 18 mm, and 20 mm. All the samples were randomly assigned to receive either axial or anteroposterior (AP) loading and then loaded to failure at a rate of 2 mm/min on a material testing machine. The data regarding ultimate failure loads under the axial and AP loading were analyzed.

RESULTS

Under the AP loading, the mean ultimate failure loads of the 18 mm and 20 mm groups were lower than those of the other groups. Under the axial loading, the mean ultimate failure load of the 10 mm group was significantly greater than that of the 15 mm, 18 mm, and 20 mm groups. Additionally, the ultimate failure load of the 20 mm group was significantly lower than that of the 12 mm, 15 mm, and 18 mm groups.

CONCLUSION

The distal humeral fenestrations with a size greater than 18 mm may offer poor biomechanical properties in the Outerbridge-Kashiwagi ulnohumeral arthroplasty.