Surgical treatment of skeletal metastases in proximal tibia: a multicenter case series of 74 patients

Figures & data

Figure 1. Causal pathways in directed acyclic graphs in the variable selection. Exposure of interest = implant survival, outcome = implant survival, suggested covariates, sex, age, diagnosis, metastatic load, radiotherapy.

Figure 2. Surgical treatment methods: tumor prosthesis (A), total knee arthroplasty with long cemented stems (B), osteosynthesis using plate and cement (C).

Table 1. Patient characteristics (N = 74). Values are count unless otherwise specified

Male/Female	55/29
Impending fracture	64
Preoperative radiotherapy	12
Primary tumor
Renal cell carcinoma	29
Melanoma	8
Colon carcinoma	6
Non-small-cell lung carcinoma	5
Sarcoma	5
Myeloma	5
Breast carcinoma	5
Prostate carcinoma	3
Esophagus	2
Bladder	2
Lymphoma	2
Retinoblastoma	1
Squamocellular	1
Median age, years ^a	64 (18–86)
Mean follow-up, months ^a	12 (0–210)
Mean size, cm^a	6.3 (3–16)
Operative method
Tumor prosthesis	31
Total knee arthroplasty with
long cemented stems	10
Osteosynthesis and cement	33
Complications	19
Complications according to
Henderson’s classification	18
Type 1	2
Type 2	0
Type 3	2
Type 4	8
Type 5	6
Revision surgery	13

^a Range in parenthesis

Figure 3. Implant survival.

Figure 4. Implant survival stratified by surgical method in a competing risk model.

Figure 5. Implant survival stratified by radiotherapy in a competing risk model.

Table 2. Complications

Type	Infection	Osteo- synthesis problem	Tumor progression	Permanent nerve palsy	Fatal pulmonary embolism
Tumor prosthesis	8/11	0	1/11	2/11	0
TKA with long cemented stems	0	0	0	0	0
Osteosynthesis with cement	0	2/8	5/8	0	1/8

Table 3. Treatment of complications

Type	DAIR	2-stage revision	Amputation	Conversion to prosthesis	Re-osteo- synthesis
Tumor prosthesis	1/7	2/7	4/7	0	0
TKA with long cemented stems	0	0	0	0	0
Osteosynthesis with cement	0	0	1/6	3/6	2/6

Table 4. Complications and radiotherapy

Type	n	Infection	Osteo- synthesis problem	Tumor progression	Permanent nerve palsy	Fatal pulmonary embolism
Tumor prosthesis (n = 31)
Preoperative radiotherapy	5	2	0	1	0	0
No preoperative radiotherapy	26	6	0	0	2	0
TKA with long cemented stems (n = 10)
Preoperative radiotherapy	0	–	–	–	–	–
No preoperative radiotherapy	10	0	0	0	0	0
Osteosynthesis with cement (n = 33)
Preoperative radiotherapy	7	0	1	1	0	0
No preoperative radiotherapy	26	0	1	1	0	1