Total knee arthroplasty with long tibial stem for tibial stress fractures with knee osteoarthritis: Two birds with one stone

Abstract

Purpose: The treatment and outcome of tibial stress fractures concomitant with knee osteoarthritis (OA) are complicated. The aim of this study was to evaluate the functional and radiological outcome of total knee arthroplasty with long tibial stem as a treatment for patients having knee OA and tibial stress fracture.

Methods: Patients who were diagnosed to have proximal tibia stress fracture along with knee OA at our institution between June 2013 and November 2018 were included in our study. All patients underwent total knee arthroplasty with long tibial stem. Preoperative and postoperative functional assessments were done according to range of movement of the knee joint, knee society score and knee injury and OA outcome score. Descriptive analysis was carried out by mean and standard deviation for quantitative variables, frequency and proportion for categorical variables.

Results: Twelve patients were included in the study. All patients were found to have stress fractures in the proximal half of tibia and extra-arthrosis. Four patients had non-union/delayed union, and 8 patients had acute fractures. The average preoperative range of movement was 88.1°, which improved to 116.3° at 3 months following surgery. It was found that the fracture has healed in all cases. Mean knee society score improved from 32.9 preoperatively to 89.3 at 1 year follow-up. Knee injury and OA outcome score improved from a mean score of 28.3 preoperatively to 81.1 at 1 year follow-up.

Conclusion: Stress fractures can occur in the proximal tibia in patients with knee OA. Total knee arthroplasty with tibial stem provides a suitable solution for both conditions. Additional plating or bone graft is unlikely to be required.

Keywords: Osteoarthritis; Stress fracture; Tibial stem; Total knee arthroplasty.

Fig. 1

Intraoperative instrumentation and technique. (A) Tibia stem extension attached to tibial tray; (B) Hand reamers used for serial reaming; (C) Tibial baseplate cementation before being inserted; and (D) Hand reaming of tibial intramedullary canal prior to placement of stem.

Fig. 2

Illustrative case of a 67-year-old female with OA and fresh proximal tibia stress fracture. (A) Anteroposterior and lateral radiographs of left knee of a 67-year-old female patient, showing decreased medial joint space, osteophytes and genu varum deformity. Tibial stress fracture is noted in the posterolateral aspect of tibia at the level of junction of metaphysis and diaphysis. (B) Post total knee arthroplasty radiograph showing tibial stem of size 12 mm × 150 mm crossing the tibial stress fracture site.

Fig. 3

Illustrative case of 64-year-old female having OA and non-union of proximal tibia stress fracture. (A) Anteroposterior and lateral radiographs of left knee and leg of a 64-year-old female patient, with left knee OA, which was being managed conservatively with analgesics. (B) Radiographs show stress fracture in proximal tibia. (C) After 6 months of conservative management of stress fracture, radiographs show fracture line still visible, and fracture of fibula at the same level. (D) Radiographs after she underwent total knee arthroplasty with tibial stem of size 10 mm × 150 mm. (E) Radiographs show complete union of all 4 cortices of tibia 3 months after surgery. Fibula fracture also appears united. (F) Radiographs show no signs of loosening of implants and no fractures 5 years after surgery.