The goal of the operation is limb-sparing resection of tumors
arising from the proximal tibia with adequate surgical margins and
local tumor control. Implantation of a constrained tumor prosthesis
with an alloplastic reconstruction of the extensor mechanism to
restore painless joint function and loading capacity of the
Primary bone and soft tissue sarcomas. Benign or semimalignant
aggressive lesions. Metastatic disease (radiation resistance and/or
Poor physical status. Extensive metastatic disease with life
expectancy <6 months. Tumor penetration through the skin.
Local infection or recalcitrant osteomyelitis. Poor therapeutic
compliance. Large popliteal extraosseous tumor masses with
infiltration of neurovascular structures.
A single incision is made from the anteromedial aspect of the distal
femur to the distal one third of the medial lower leg. Preparation
of large medial and lateral fasciocutaneous flaps. The popliteal
vessels are explored through a medial approach by releasing the pes
anserinus and semimembranosus tendon, mobilizing the medial
gastrocnemius muscle and detaching the soleus muscle from the tibial
margo medialis. The anterior tibial artery and vein are ligated. If
the knee joint is free of tumor, circumferential dissection of the
knee capsule is performed and the patellar ligament is dissected. An
osteotomy of the tibia shaft is performed with safety margins
according to preoperative planning. In order to obtain adequate
surgical margins, in some cases an en bloc resection of the
tibiofibular joint becomes necessary. Therefore, the peroneal nerve
is exposed. Parts of the M. tibialis anterior, a portion of the M.
soleus and the entire M. popliteus are left on the resected tibial
bone. After implantation of the prosthesis and coupling of the
femoral and tibial component, the extensor mechanism is
reconstructed using an alloplastic cord. It is passed transversely
through the distal end of the quadriceps tendon looping the proximal
margin of the patella. Both ends are passed distally through a
subsynovial tunnel and are fixed under adequate pretension in a
metal block of the tibial component. The detached hamstrings and
remaining ligaments can be fixed on preformed eyes of the
prosthesis. A medial gastrocnemius muscle flap is used to provide
soft tissue coverage of the tibial component.
Immobilization and elevation of the extremity for 5 days, then
flap conditioning. Mobilization in a hinged knee brace locked in
extension for 6 weeks without weight bearing. During this time
active flexion with a stepwise progress, isometric quadriceps
training. Then beginning of straight leg raising exercises, stepwise
unlocking of the brace with 30° every 2 weeks.
Weight-bearing is increased by 10 kg/week. Thrombosis
prophylaxis until full weight-bearing. At follow-up, patients are
monitored for local recurrence and metastases using history,
physical examination and radiographic studies.
Between 1988 and 2009, endoprosthetic replacement and alloplastic
reconstruction of the extensor mechanism after resection of tibial
bone tumors was performed in 17 consecutive patients
(9 females and 8 males) with a mean age of 31.1 years
(range 11-65 years). There were no local recurrences. Until
now, 5 patients have died of tumor disease. One or more
operative revisions were necessary in 53.9% of the patients.
According to Kaplan-Meier survival analysis, the implant survival at
5 years was 53.6% and 35.7% at 10 years, respectively. In
2 cases, a distal transfemoral amputation had to be performed
due to deep infection. There were 3 cases of tibial stem
revision due to implant failure and aseptic loosening, respectively.
In 3 patients, the hinge of the prosthesis had to be revised.
Impaired wound healing occurred in 2 cases. Peroneal nerve
palsy was observed in 3 patients with recovery in only one. The
mean Oxford knee score for 9 of the 12 living patients was
30.7 ± 7.5 (24-36). No patient had a clinically
relevant extension lag. The mean range of motion at the last
follow-up was 90.2° ± 26.7 (range
35-130°). All patients were well satisfied with their
Holzapfel B M, Pilge H, Toepfer A, Jakubietz R G, Gollwitzer H,
Rechl H, von Eisenhart-Rothe R, Rudert M. [Proximal tibial
replacement and alloplastic reconstruction of the extensor mechanism
after bone tumor resection]. Oper Orthop Traumatol 2012; 24:247-62.