Summary

We evaluated short-term outcomes at least 2 years after dome-shaped high tibial osteotomy (HTO) combined with all-inside anterior cruciate ligament reconstruction (ACL) in patients with persistent ACL insufficiency accompanied by pain due to varus deformity in 19 knees. Dome-shaped HTO allowed for a relatively high degree of valgus correction and decreased the steep posterior tibial slope.

Abstract

Purpose

This study aimed to evaluate short-term outcomes at least 2 years after dome-shaped high tibial osteotomy (HTO) combined with all-inside anterior cruciate ligament reconstruction (ACL) in patients with persistent ACL insufficiency accompanied by pain due to varus deformity.

Methods

The study enrolled 19 knees of 18 patients (nine males, nine females). The mean patient age was 58 years (range: 41–70 years) and the mean postoperative follow-up period was 31 months (24–49 months). The study outcome was the status of the reconstructed ACL based on preoperative and postoperative JOA (Japanese Orthopaedic Association)-OA scores, the Lysholm score, and X-ray images, as well as arthroscopic evaluation during the HTO plate-removal procedure. Before surgery, the mean JOA-OA score was 65.0±13.5, the mean Lysholm score was 47.2±16.2, the mean femoro-tibia angle in a standing position (standing FTA) was 183.8±3.4° (180–190°), and the mean side-to-side difference in KT-1000 measurements was 4.1±1.3 mm (3–7 mm).

Results

At the final follow-up, the mean JOA-OA score, Lysholm score, and side-to-side difference in KT-1000 measurements improved to 93.1±6.0 (P<0.00001), 94.2±5.8 (P<0.00001), and -0.2 ±0.8 mm (P<0.00001), respectively. Postoperative X-ray imaging showed that the mean standing FTA decreased to 168.0±3.3° (P<0.00001), and the mean posterior tibial slope angle decreased to 5.0±3.6° (from 6.9±2.6° preoperatively; P=0.024). The pre- and postoperative mean Insall-Salvati ratio of the patella was 1.03±0.20 and 0.94±0.18 (P=0.033), respectively, and the pre- and postoperative mean Caton-Deschamps index was 0.94±0.19 and 0.82±0.16 (P=0.008), respectively, indicating a mild decrease in the height of the patella after surgery. Arthroscopy was performed on 17 knees at the time of plate removal at a mean of 16 months after surgery, and no knees graft rupture was found. The reconstructed ACL graft in these 13 knees were successful with good tension of the graft and no looseness. However, a cyclops lesion was observed in one knee, and looseness of the anterior fibers of the graft was observed in three knees. One patient showed non-union at the osteotomy site and underwent additional surgery.

Conclusion

The combination of dome-shaped HTO with all-inside ACL generally alleviated pain and instability of the knee. X-ray imaging showed that the posterior tibial slope was decreased while the height of the patella was mildly reduced. Arthroscopy at the time of plate removal showed that no patients had graft rupture, although one knee had a cyclops and three knees had looseness of the anterior fibers of the graft. Dome-shaped HTO allows for a relatively high degree of valgus correction and decreases the steep posterior tibial slope that causes excessive load on the ACL. Therefore, its use in combination with ACL reconstruction seems to be effective.