From a study of a total of 2,132 cases of Colles' fracture from the files of the Workmen's Compensation Board, New York State Department of Labor, New York City District, the following conclusions were drawn:

1. Colles' fracture constituted 60.0 per cent. of fractures of the radius.

2. Incidence of Colles' fracture among Workmen's Compensation Board cases, New York City District, in 1945 and 1949 was 1 per cent.

3. Of all carpal fractures, that of the navicular constituted 70.8 per cent.

4. The ratio of males to females in Colles' fracture was 58 per cent. to 42 per cent. for 1945 and 1949, whereas the male-to-female ratio for all Workmen's Compensation Board cases for the same years was 84 per cent. to 16 per cent.

5. The left radius was involved in Colles' fracture in 55.1 per cent. of the cases; the right in 44.9 per cent. These figures include 0.94 per cent. of bilateral Colles' fracture.

6. The incidence of compound fractures among Colles' fractures was 1.3 per cent.

7. In 91.6 per cent. of the cases, the mechanism of injury was a fall on the outstretched hand.

8. A considerable proportion of Colles' fractures showed one or more of the following: comminution, impaction, and extension into the radiocarpal joint.

9. Reduction of Colles' fracture was performed in 88.3 per cent. Of the total number of fractures, 3.7 per cent. were manipulated a second time, and 1.0 per cent. required a third manipulation. In only 1.6 per cent. of the total was open reduction performed. Of the 11.7 per cent.in which no reduction was performed, it was our conclusion that almost one half required such manipulation.

10. In the 471 cases in which it was known that anaesthesia was given for reduction, local anaesthesia was used in 36 per cent. and general (gaseous and intravenous) anaesthesia in the remaining 64 per cent.

11. The average duration of treatment was four months.

12. Physical therapy was used in 96.6 per cent. of the cases, exclusive of active and passive motion. This varied widely in type, frequency, and duration, without appearing to affect appreciably the ultimate results.

13. The average (mean) percentage loss of function (disability) in all patients with Colles' fracture was 24 per cent. loss of the hand, based upon the findings of the Workmen's Compensation Board medical examiners. The range of disability was 0 through 100 per cent. Of all patients with Colles' fractures 94 per cent. had a resultant disability of less than 50 per cent. loss.

14. The mean age of all patients with Colles' fracture was 48.2 years; the median and mode were fifty years; the range was fourteen to seventy-eight years inclusive.

15. The age distribution in Colles' fracture has been found to be significantly higher than that of all Workmen's Compensation Board cases for 1945 and 1949. Of all Workmen's Compensation Board cases, 68.6 per cent. of the injuries occurred in people under the age of fifty, whereas 51.4 per cent. of Colles' fractures were in people of fifty or over.

16. The percentage of disability in Colles' fracture increased directly with age, at a rate of approximately 4 per cent. loss of function per decade.

17. Residual deformity (as an inverse measure of adequacy of reduction and immobilization) has been found to have a direct correlation with disability, at a rate of 10 per cent. loss of function per grade of deformity (none, mild, moderate, marked).

18. The duration of immobilization in Colles' fracture had no effect upon final residual disability.

19. The most frequent defect in passive motion about the wrist was in palmar flexion, present in 94.5 per cent. of the cases; defect in dorsiflexion was found in 8O per cent. Limitation of rotation of the forearm was present in one third and limitation of lateral wrist motion in one half the cases.

20. Forty-eight per cent. showed restriction of motion of the digits (flexion and extension), with flexion defects being twice as frequent as extension; the distal interphalangeal joints were most often afflicted, and the index finger was the most, with the thumb the least, often involved digit.

21. One third of the patients with Colles' fracture showed residual diminution of the grip which was mild or moderate in severity in all but 3 per cent. of the total number of cases.

22. Non-union of Colles' fracture was found in 0.2 per cent. and delayed union in 0.7 per cent. of the cases. Other complications included traumatic neuritis (0.2 per cent.), causalgia (0.1 per cent.), Sudeck's atrophy (0.1 per cent.), Dupuytren's contracture (0.2 per cent.), persistent pain (2 per cent.), limitation of shoulder motion (1 per cent.), compound fracture (1.3 per cent.), concomitant navicular fracture (0.5 per cent.).

23. Fifty-three per cent. of the cases of Colles' fracture were accompanied by avulsion fracture of the ulnar styloid, and of these latter, one-fourth remained ununited.

24. The interval between injury and final Workmen's Compensation Board medical examination and award was twelve months (mean, median, and mode).