Swan neck deformity due to chronic radial collateral ligament injury of the little finger proximal interphalangeal joint.

We present seven cases of a relatively rare swan neck deformity resulting from chronic radial collateral ligament (RCL) injury of the proximal interphalangeal (PIP) joint in the little finger. All patients were middle-aged women (mean 51 years old, range 42-55), and the duration between the initial injury and surgery was 20 years (range 5-40). The chief complaint was painful snapping of the PIP joint. All patients had hyperextension and ulnar deviation of the PIP joint with mobile swan neck deformities that had not improved with conservative treatment. Radiographs revealed osteoarthritis and ulnar deviation of the PIP joints in all cases. We describe a method for reconstruction of both the palmar plate and the RCL of the affected PIP joint using a distally-based ulnar slip of flexor superficialis tendon. The prevention of PIP joint hyperextension was critical for successful resolution of symptoms; the aim of RCL augmentation was to prevent the recurrence of the deformity. LEVEL OF EVIDENCE: IV.

Motion Analysis of the Trapeziometacarpal Joint Using Three-dimensional Computed Tomography.

BACKGROUND: Zancolli theorized that the first metacarpal bone axially rotates on the semispheroidal part of the trapezium, which is controlled by ligaments. This study used three-dimensional computed tomography (3D-CT) to describe the motion of the first metacarpal bone on the trapezium. METHODS: 3D-CT images were taken of the left hand of 30 healthy volunteers (mean age [Formula: see text] years, 15 men and 15 women). They were divided into five groups: radial abduction, retroposition, adduction, palmar abduction, and opposition. The range of motion of radial abduction and palmar abduction of the trapeziometacarpal joint was measured from the first metacarpal bone to the second metacarpal bone. The range of motion of pronation was measured following Cheema's method. The main contacts of the joint surface of trapezium and the first metacarpal bone were determined on the 3D-CT images. RESULTS: Pronation of the trapeziometacarpal joint was [Formula: see text] in radial abduction, [Formula: see text] in retroposition, [Formula: see text] in adduction, [Formula: see text] in palmar abduction, and [Formula: see text] in opposition. Radial abduction was [Formula: see text] in radial abduction, [Formula: see text] in retroposition, [Formula: see text] in adduction, [Formula: see text] in palmar abduction, and [Formula: see text] in opposition. Palmar abduction was [Formula: see text] in radial abduction, [Formula: see text] in retroposition, [Formula: see text] in adduction, [Formula: see text] in palmar abduction, and [Formula: see text] in opposition. The contact surfaces of the trapezium and the first metacarpal bone were dorsal and ulnar in radial abduction, radial and ulnar in retroposition, and volar-ulnar and volarradial in opposition, respectively, while they were both central in adduction and both radial in palmar abduction. CONCLUSIONS: The range of motion of the trapeziometacarpal joint was 44° for radial abduction/adduction, 48° for palmar abduction/adduction, and 57° for pronation/supination. The varying contact surfaces of the trapezium and the first metacarpal bone enabled a wide range of motion.

An Osteochondroma Limiting Flexion of the Proximal Interphalangeal Joint in Hereditary Multiple Exostosis: a Case Report.

We describe a patient in which an osteochondroma, which resulted from hereditary multiple exostoses, limited flexion of the proximal interphalangeal (PIP) joint at birth. The tumor grew over the original distal head of the proximal phalanx, and the early appearance of a second ossification center on the base of the middle phalanx was observed. The mass was removed surgically when the patient was 17 months old. There was an improvement in the range of motion at a follow-up evaluation 3 years later. The tumor shape and the growth of the affected PIP joint are examined in detail.