Clinical outcomes of cemented distal femur replacements with all-polyethylene tibial components for oncologic indications

Table 1 Patient demographics of the study cohort, including age, gender, race/ethnicity, American Society of Anesthesiologists score, body mass index, and length of follow-up, n (%)

Demographic variable	Value
Age (mean ± SD)	50.9 ± 20.7 yr
Gender
Male	22 (40.0)
Female	33 (60.0)
Race/Ethnicity
White	29 (52.7)
Hispanic or Latino	9 (16.4)
Black	4 (7.3)
Asian	5 (9.1)
Other	8 (14.5)
ASA score
1	10 (18.2)
2	21 (38.2)
3	21 (38.2)
4	3 (5.5)
Body mass index (mean ± SD)	29.7 ± 8.3 kg/m2
Follow-up (mean ± SD)	38.8 ± 54.9 mo

ASA: American Society of Anesthesiologists.

Table 2 Operative variables of the study cohort, including procedure type (primary vs revision), surgical indications, mode of failure according to the Henderson Classification, and number of previous knee surgeries on the operative knee, n (%)

Operative variable	Value
Procedure type
Primary	29 (52.7)
Revision	26 (47.3)
Surgical indications
Osteogenic sarcoma	22 (40.0)
Giant cell tumor	9 (16.4)
Metastatic carcinoma	8 (14.6)
Soft-tissue sarcomaa	4 (7.3)
Chondrosarcoma
High-grade	3 (5.5)
Low-grade	2 (3.6)
Synovial chondromatosis	2 (3.6)
Multiple myeloma	2 (3.6)
Non-Hodgkin's lymphoma	1 (1.8)
Pigmented villonodular synovitis	1 (1.8)
Neoplasm of unspecified behavior	1 (1.8)
Primary mode of failure, henderson classification
Type 1 (soft-tissue failure)	6 (10.9)
Type 2 (aseptic loosening)	5 (9.1)
Type 3 (structural failure)b	2 (3.6)
Type 4 (periprosthetic infection)	6 (10.9)
Type 5 (tumor progression)	1 (1.8)
Number of previous surgeries (mean ± SD)	1.1 ± 1.3 surgeries

^aSoft-tissue sarcomas included malignant fibrous histiocytoma, pleomorphic fibrosarcoma, and myxofibrosarcoma.

^bBoth cases of henderson type 3 failure were due to trunnionosis; there were no periprosthetic fractures observed in this cohort.

Table 3 Primary procedures for individuals requiring a revision distal femoral replacement

Primary procedure in the revision cohort (N = 26)
Category	Number of patients
Distal femoral replacement	12
Open reduction internal fixation for pathologic fracture	6
Curettage +/- cryoablation	6
Soft tissue resection	2

Table 4 Indication groupings for individuals requiring revision distal femoral replacement

Reason for revision
Category	Number of patients
Mechanical failure	11
Nonunion of prior pathological fracture	7
Tumor Progression	3
Definitive management of a prior open reduction internal fixation for a pathological fracture	2
Local recurrence	1
Infection	1
Soft tissue failure	1

Table 5 Univariate analysis comparing demographic characteristics and reoperation rates between the primary distal femoral replacement and revision distal femoral replacement subgroups, n (%)

	Primary DFR (n = 29)	Revision DFR (n = 26)	P value
Age (mean ± SD)	49.7 ± 20.6 yr	52.2 ± 21.1 yr	0.649
Gender			0.44
Male	13 (44.8)	9 (34.6)
Female	16 (55.2)	17 (65.4)
Body mass index (mean ± SD)	29.5 ± 8.5 kg/m2	30.0 ± 8.4 kg/m2	0.567
Follow-up (mean ± SD)	42.7 ± 61.4 mo	34.5 ± 47.5 mo	0.946
Complication requiring reoperation?	11 (37.9)	9 (34.6)	0.799
Total reoperations required (mean ± SD)	1.4 ± 2.6	1.0 ± 1.8	0.624

DFR: Distal femoral replacement.