Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Example Input: Abstract: A retrospective review of the cases of fifteen patients with a three-part fracture of the proximal part of the humerus is presented. Fourteen of the fractures were treated with tension-band wiring and one, with an AO buttress plate. The patients were evaluated for pain, range of motion, strength, and function of the involved shoulder and the radiographic result at an average of fifty-four months after the injury. At follow-up, the shoulders had an average of 126 degrees of active elevation, 29 degrees of active external rotation, 81 degrees of active abduction, and internal rotation to the second lumbar vertebra. The only early complication was failure of fixation in the patient who had been treated with a buttress plate. In two patients, radiographic evidence of avascular necrosis of the humeral head later developed, and one of them required revision to a hemiarthroplasty. In conclusion, we recommend operative treatment for the healthy, active individual who has a three-part fracture of the proximal part of the humerus. We found that the best results with these difficult fractures are obtained using tension-band wiring.
Example Output: Aged

Example Input: Abstract: In this report, 11 cases of angiosarcoma of the head and neck are reviewed. The patients ranged in age from newborn to 78 years; mean age was 64 years. There were eight men and three women. Sites of involvement included the scalp and forehead, cheek, nose and ethmoid sinuses, neck, and mandible. Surgery was the primary method of treatment. The 2-year survival rate was 50% (5/10) and the 5-year survival rate was 22% (2/9). Regional metastases were seen in 18% (2/11). We found that the tumors were poorly circumscribed and spread horizontally within the dermis for considerable distances, especially in the scalp. Total surgical excision using frozen section control before reconstruction may offer the best chance for control of disease.
Example Output: Adolescence

Example Input: Abstract: From 1977 through 1984, 58 arterial reconstructions using glutaraldehyde-tanned human umbilical vein (H.U.V.) grafts were carried out: 41 femoropopliteal, 4 composite aortopopliteal (a Dacron graft was inserted proximally), 5 femorotibial, 6 axillofemoral, 1 femorofemoral, and 1 iliofemoral bypass. Autogenous saphenous vein was absent or inadequate in all patients. Limb salvage was the primary indication for surgery (89.7%). Five and 8 years cumulative patency rates were 42.8% and 35.1% respectively for all H.U.V. by-passes and 52.4% and 41.9% respectively for femoropopliteal by-passes. Four out of the 5 femorotibial by-passes failed during the first month following surgery. Two of the 6 axillofemoral and 3 of the 4 composite aortopopliteal by-passes thrombosed within 1 and 3 years after surgery, respectively. Perioperative mortality was 5.1%, while overall mortality was 17.2%. The following conclusions can be drawn from these results: H.U.V. grafts did not achieve cumulative patency rates superior to those reported with autogenous saphenous vein, in limb salvage situations, when the saphenous vein is not available, the H.U.V. graft offers acceptable salvage rates, results from the 8-year follow-up period demonstrate the durability and long-term patency of H.U.V. grafts.
Example Output:
Aged