The effect of quadriceps excision on functional results after distal femoral resection and prosthetic replacement of bone tumors.

Although resection and reconstruction with a prosthesis is an accepted form of treatment for tumors of the distal femur, minimal effort has been made to correlate the functional result with the degree of adjacent muscle excision. From 1983 to 1986, 65 patients had distal femoral resection and prosthetic reconstruction. Ten patients had only the vastus intermedius excised (Group A), 30 patients had excision of the vastus intermedius plus either the vastus medialis or lateralis (Group B), nine patients had only the rectus femoris spared (Group C), and 16 patients had the entire quadriceps excised or conversion of the previous arthrodesis (Group D). Based on the rating system of the Musculoskeletal Tumor Society, satisfactory results were obtained in 70% of Group A patients (30% excellent and 40% good), with no poor results. In group B, 80% had good or excellent results and 7% poor results. In Group C, 78% of the patients had good results but no excellent results, whereas Group D had only 50% satisfactory results. The parameters that most often led to functional impairment were restricted motion and inadequate extensor powers. Muscle transfers, however, (flexors to extensors) were effective only in Group C patients. With proper technique and prosthetic design, satisfactory results can be achieved after distal femoral resection and prosthetic reconstruction, even after extensive quadriceps excision.