Distraction histiogenesis for treatment of Kienbock's disease: A 2- to 8-year follow-up.
BACKGROUND
Distraction histiogenesis is known to enhance vascularity and stimulate new tissue formation. Its use in Kienbock's disease is not reported in the literature, so we proposed to study the outcome after distraction histiogenesis in treating this condition.


METHODS
This prospective study comprised of six patients (two male and four female) with mean age 18.16 years (range 21-35 years) with clinicoradiologically diagnosed Lichtman stage II (n = 3) and stage III (n = 3) Kienbock's disease with a mean duration of symptoms 6.67 months. The ulnar variance was neutral in two and was negative in four patients treated with the application of Joshi external stabilization system (JESS) across the wrist. The gradual distraction was done at a rate of 0.5 mm/day. After the distraction of 5-7 mm, the distractors were kept static for 3 weeks. The wrist was mobilized by using hinged distractors for next 3 weeks. Later short cockup splint was used for further 4 weeks. At the end of minimum 2 years, an assessment was done on the basis of relief of symptoms, ability to perform activities of daily living, range of movement at wrist, grip strength, and on radiology (change in the density of bone and C:MC ratio i.e ratio of carpal height to third metacarpal height).


RESULTS
The mean follow-up was of 4.5 years (range 2-8 years). The average duration of treatment was 5.3 months (range 4.5-6 months), and the duration of distraction (both static and hinged) was 8 weeks. Clinically all the patients were relieved of the symptoms with an increase in the range of wrist movement (ulnar deviation increased from 20.8 degrees to 29.5 degrees , radial deviation from 17.5 degrees to 21 degrees , dorsiflexion from 37.5 degrees to 52.5 degrees , and palmer flexion from 38.3 degrees to 47.5 degrees ). At the last follow-up, activities of daily living were not affected, and all the patients were on their previous jobs without any fresh complaints. The average grip strength increased to 73-86% of normal. Radiologically the C:MC ratio (ratio of carpal height to third metacarpal height) did not show any significant improvement, but the density of lunate decreased.


CONCLUSIONS
Distraction histiogenesis when used in Lichtman stage II and III with negative or neutral ulnar variance gives good symptomatic relief, allowing return to normal activities. This study has also shown that reparative process is possible in avascular bone by distraction. The authors recommend further research in this modality of treatment.
Meena
Ds
D
Department of Orthopaedics, SMS Medical College and attached group of Hospitals, Jaipur, India.
Saini
Narender
N
Kundanani
Vishal
V
Chaudhary
Lokesh
L
Meena
Dinesh
D