[Analysis of Fit of the Ascension® PyroCarbon PIP Total Joint Component Heads]

[Anatomy of the metacarpophalangeal and proximal interphalangeal finger joint with respect to arthroplasty]

BACKGROUND

Precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint is the basis for both indication and implantation of a finger joint prosthesis. Currently available finger joint prostheses inadequately take into account individual, ethnological, gender, age, and side differences. They can remain compromised despite the possible combination of their components.

OBJECTIVES

To elucidate which problems of finger joint arthroplasty exist due to the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joints.

METHODS

The anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint are described, and the problems and solutions of finger joint arthroplasty are presented.

RESULTS

Despite precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint, not all problems of finger joint arthroplasty have been solved. However, a modular surface replacement appears promising for the proximal interphalangeal joint.

CONCLUSIONS

Artificial joint replacement of the metacarpophalangeal and proximal interphalangeal joint is difficult with regard to morphology, small bone dimensions, complex biomechanics, and the strain of the hand. Further improvements, especially in design, should be achieved by exact anatomical imitation.

[Arthrodesis of the proximal interphalangeal joint of fingers with tension band wire]

OBJECTIVE

Arthrodesis of the proximal interphalangeal joint of fingers in a functional and pain-free position.

INDICATIONS

Primary and secondary osteoarthritis, traumatic joint destruction, posttraumatic malposition, instability, joint destruction due to infection, irreparable extensor and/or flexor tendon lesion, recurrent flexion deformity in Dupuytren's disease, arthritis (e. g., rheumatoid arthritis, psoriatic arthritis), failed resection arthroplasty, failed prosthesis, congenital disorder (e. g., camptodactyly).

CONTRAINDICATIONS

Persistent joint infection.

SURGICAL TECHNIQUE

Resection of the proximal phalanx head and the middle phalanx base, arthrodesis with figure-of-eight tension band wire in a functional position.

POSTOPERATIVE MANAGEMENT

Plaster of Paris cast with arthrodesis position of the affected finger and intrinsic plus position of at least one adjacent finger for 2 weeks, custom-made finger splint for 4 weeks.

RESULTS

A total of 15 of 16 patients with an arthrodesis of the proximal interphalangeal finger joint of the dominant hand by tension band wire were followed up after an average of 31 months. None was affected by the arthrodesis in everyday live. All patients were very satisfied with the result. Nine of 15 patients were free of pain both at rest and with activity. The average DASH score was 48 points. Grip strength averaged 29 kg, 7 % stronger than the contralateral hand.