Osteotomy indications expand to malalignment, instability patients

Italian surgeon believes high tibial osteotomies and distal femoral osteotomies are gaining acceptance.

With recent technique and indication changes, high tibial and distal femoral osteotomies are regaining popularity for treating cartilage pathology, malalignment and instability simultaneously.

“The indications of the high tibial osteotomy (HTO) and the distal femoral osteotomy (DFO) [now] include patients with a malalignment who are undergoing microfracture, grafting, periosteal resurfacing, autologous chondrocyte implantation and meniscal transplantation,” Giancarlo Puddu, MD, of Clinica Valle Giulia in Rome, said at the 6th Symposium of the International Cartilage Repair Society.

However, success with osteotomies depends on a number of factors, including selecting the right indications, patient awareness, precise preoperative X-rays, accurate preoperative planning, good technique and postoperative rehabilitation, according to Puddu, who is also a member of the Orthopaedics Today International editorial board.

Role of osteotomy

Osteotomy shifts the mechanical axis and unloads degenerated cartilage, thereby relieving the patient’s symptoms, permitting cartilage healing and repair and delaying total knee arthroplasty, Puddu said.

In particular, HTO shifts the mechanical axis to a point 62% across the tibial plateau from medial to lateral, as shown in previous studies, Puddu said. The DFO, on the other hand, shifts the mechanical axis 45% to 50% off the tibial plateaus.

To determine if a patient is a candidate for osteotomy, Puddu suggested that surgeons obtain the Rosenberg view of the knees, as well as standing X-rays to measure the mechanical axis of the legs.

MRIs provide another indication for osteotomy. “Often ... an MRI can push the doctor to make an osteotomy, and so it is very important to help make a difficult decision,” Puddu said.

Patient indications for HTO include the following:

overload of the medial or lateral compartment;
symptoms of medial or lateral meniscus loss;
varus knee ligament instability stretching the lateral secondary restraint;
cartilage damage in the medial or lateral femoro/tibial condyles; and
initial osteoarthrosis in the medial or lateral compartments.

DFO conditions include early cartilage deterioration after lateral menescectomy, congenital femoral valgus and initial lateral compartment arthritis, Puddu said.

Puddu prefers an opening wedge osteotomy rather than a closed wedge osteotomy, “because one cut is more precise than two,” he said. With an opening wedge osteotomy, “It is possible to fine-tune the osteotomy during the surgery, it doesn’t need a fibular osteotomy, it doesn’t need a muscular detachment, it preserves all the bone stock for a total knee replacement, and it doesn’t make any medial displacement of the tibial mechanical axis [as found in a] closing wedge osteotomy.”

Puddu said he usually fills the osteotomy gap with iliac crest, but other fill options include the osteochondral autograft transfer system, harvesting two cortical/calcaneous bone cylinders from the iliac crest, allograft or bone substitute such as Hatric (hydroxyapatite and tricalcium phosphate, Arthrex Inc.), and more recently, platelet-rich plasma with bone pieces of the tibial metaphysis.

Ideal consolidation is typically achieved between two and three months postop. Postoperative treatment includes a range of motion (ROM) brace, continuous passive motion, partial weight-bearing at 30 to 45 days and full weight-bearing at 45 days to 60 days — all depending on the patient’s weight, Puddu said.

For DFO, patients are allowed partial weight-bearing at 45 days to 60 days and full weight-bearing at 60 days to 75 days, again depending on patient weight, he added.

Case review

Puddu reviewed his first 36 HTO cases (22 men, 14 women) at a long-term follow-up of eight to 10 years. The average patient age was 49 years.

Preoperative International Knee Documentation Committee (IKDC) scores showed 22 patients in the “abnormal knee” range and 14 patients in the “severely abnormal knee” range. Postoperative scores showed a shift to 27 “near normal knees” and nine “abnormal knees.”

To measure IKDC scores in DFO cases, Puddu reviewed 20 patients, including six men and 14 women, with an average age of 43 years.

At preop, IKDC scores showed 15 patients in the “abnormal knee” range and five in the “severely abnormal knee” range. Again, at eight- to 10-year follow-up, most patients improved in IKDC category: 16 in the “near normal knee” range and four in the “abnormal knee” range, Puddu said.

“We can never get an excellent result because with the IKDC rating, we can gain one category but we may never get a normal knee,” he said.

For more information:
Puddu G. The role of osteotomy procedures in bio-arthroplasty. #4a-C. Presented at the 6th Symposium of the International Cartilage Repair Society. Jan. 8-11, 2006. San Diego.