Kurt E. Bos

Three-dimensional carpal kinematics in vivo ☆

OBJECTIVE The purpose of this study was to accurately quantify three-dimensional in vivo kinematics of all carpal bones in flexion and extension and radial and ulnar deviation. DESIGN AND METHODS The right wrists of 11 healthy volunteers were imaged by spiral CT with rotational increments of 5 degrees during ulnar-radial deviation and of five of them also during flexion-extension motion. One regular-dose scan was used and the subsequent scans during wrist motion were performed with one-tenth of the regular dose. A three-dimensional matching technique using the internal structure of the bones was developed to trace the relative translations and rotations of the carpal bones very accurately. RESULTS Most of our results are in concordance with previously published in vitro data. We could, among others, substantiate proof to the statement that there is more than one kinematic pattern of the scaphoid. Furthermore, we could accurately describe small adaptive intercarpal motions in vivo of the distal carpal row. CONCLUSIONS To our knowledge, this is the first time the three-dimensional in vivo kinematics of all eight carpal bones is quantified accurately and non-invasively. RELEVANCE Kinematics of an injured wrist can be compared to these reference data. It may become possible that in this way a ligament lesion can be detected with high specificity and sensitivity, and that no other diagnostic modality will be needed. With these data we made animations with which the complex movements of the bones during different motions of the wrist can be viewed. In the future it may become possible that this analysis provides valuable information on the long-term results of operative interventions and possibly predicts results of operative techniques.

Treatment of volar instability of the metacarpophalangeal joint of the thumb by volar capsulodesis

The metacarpophalangeal joint bears most of the stresses to which the thumb ray is subjected. Instability of this joint results in considerable functional impairment of the hand. Volar instability may be secondary to trauma, rheumatoid arthritis, or adduction spasms in cerebral palsy. The resulting hyperextension causes pain and weakness of pinch (Fig 1). Various techniques have been described to correct this deformity. We prefer a volar capsulodesis as first described by Filler (1976), in which the whole volar plate is reinserted. Detailed knowledge of the complicated volar anatomy is essential. We have treated eight patients (two bilaterally) with this technique, all with satisfactory results.

The ulno-carpal abutment syndrome: follow-up of the wafer procedure

Seven wrists in six patients with ulno-carpal abutment syndrome were treated by a subchondral distal ulna resection (wafer procedure). The average follow-up was 36 months. Wrist function was evaluated using a clinical scoring chart. The parameters were pain, range of motion, grip strength and activities. One patient had a poor result, one a fair result and the remaining had good to excellent results. In all cases grip strength showed dramatic improvement. Complications were limited to palpable subcutaneous nylon sutures requiring removal in three patients and extensor carpi ulnaris tendinitis in one.

A very large neurilemmoma of the anterior interosseous nerve

A very large neurilemmoma of more than 15 years duration, arising from the anterior interosseous nerve, is reported. To our knowledge, this is the largest ever described. While the symptoms and all other diagnostic findings suggested that the neurilemmoma originated from the median nerve, it needed angiography to provide the final diagnosis.

Activity of the extrinsic finger flexors during mobilization in the Kleinert splint

This study investigated the activity of the extrinsic finger flexor muscles during active extension in the Kleinert splint. Electromyographic data on the activity of the profundus and superficialis flexor muscles in 10 healthy subjects were recorded with use of fine needle electrodes. The subjects exercised in the original Kleinert splint as well as in several modifications of the splint, which varied with respect to (1) wrist position, (2) position in which extension of the metacarpophalangeal joint was blocked, (3) number of fingers dynamically splinted, (4) nature of the spring mechanism, (5) amount of resistance, and (6) use of a palmar pulley. Persistent flexor muscle activity during active extension was observed in the majority of subjects. This coactivity was more often observed for the superficialis muscle than for the profundus muscle. The least amount of coactivity was found when extension was least resisted. This study does not support the concept that the flexor muscles relax during resisted extension in the Kleinert splint.

Spontaneous healing of a non-union of the scaphoid

We describe a case of a symptomatic non-union of the scaphoid in a 19-year-old man which spontaneously healed 3 years after the injury.

A Post-Traumatic Ankylosis of the Lunate and Scaphoid to the Radius

A case of post-traumatic radiocarpal ankylosis is described.

Rupture of a flexor pollicis longus tendon in Scheie's syndrome. Case report.

We describe a case of Scheies syndrome with a closed rupture of the flexor pollicis longus tendon, probably caused by a combination of extrinsic and intrinsic tendon changes. Early detection of carpal tunnel syndrome in all patients who have some form of mucopolysaccharidosis in which this is a universal occurrence (such as Scheies syndrome), is recommended. Release of the carpal tunnel prevents long term complications, as described in this case report.