ISAKOS: 2019 Congress in Cancun, Mexico
ISAKOS

2019 ISAKOS Biennial Congress ePoster #1233

 

Proximal Tibiofibular Dislocation versus Fibular Head Osteotomy in a Closing-Wedge High Tibial Osteotomy: Radiological and Clinical Repercussion on the Stability of the Lateral Compartment of the Knee, a Prospective Randomized Study

Raúl Torres-Claramunt, PhD, Barcelona SPAIN
Pedro Hinarejos-Gomez, MD, PhD, Barcelona SPAIN
Juan F. Sánchez-Soler, MD, Barcelona SPAIN
Aleix Sala, MD, Barcelona SPAIN
Joan Leal-Blanquet, MD, PhD, Barcelona SPAIN
Xavier Pelfort, PhD, Igualada, Barcelona SPAIN
Joan C. Monllau, MD, PhD, Prof., Esplugues de Llobregat, Barcelona SPAIN

Parc de Salut Mar, Barcelona, SPAIN

FDA Status Not Applicable

Summary

Proximal tibiofibular dislocation during a CWHTO produces radiological lateral instability when is compared with a fibular head osteotomy.

Abstract

Purpose

To determine if the proximal tibiofibular joint (TFJ) dislocation increased lateral compartment gapping more than a fibular head osteotomy (FHO) following a closing-wedge high tibial osteotomy (CWHTO). A second objective was to determine if lateral compartment gapping affects clinical outcomes.

Methods

Prospective randomized clinical study. The study included 36 patients; 18 in group 1 (fibular head osteotomy) and 18 in group 2 (tibiofibular joint dislocation). An a priori sample size was calculated. To detect a difference of 2mm in both groups with a=0.05 and a power of 80%, 18 patients were needed in each group. A maximum patient loss of 10% of was considered.
Both groups were comparable in terms of age, sex, BMI, previous femorotibial angle and the number of corrected degrees. All the patients were studied preoperatively and 6 months postoperatively with varus-stress radiograph at full extension and 30° of knee flexion in both knees. Lateral compartment gapping was measured in millimetres. The knee section of the Knee Society Score (KSS) was used to assess clinical stability.
Statistics; Mean and standard deviations were calculated for each continuous variable. The results were statistically analysed and compared by using the Student’ t-test for parametric data with a normal distribution. In the case of a non-parametric distribution, the Mann-Whitney test was used. The SPSS program was used for the statistical analysis and a p-value of 0.05 was considered statistically significant.

Results

The difference between the pre- and post-operative measurements relative to the gapping in the knee lateral compartment at 0º degrees of knee flexion was 1.3mm (SD1.8) in group 1 and 4.5mm (SD2.4) in group 2 (p=0.006). At 30° of knee flexion, this difference was 1.9mm (SD1.2) in group 1 and 5.2mm (SD3.1) in group 2 (p=0.01). The differences in gapping in the healthy knee were not statistically different.
Preoperatively, both groups presented similar KSS knee values: Group 1 with 54.7 (SD11.7) and group 2 with 54.8 (SD11.1) (n.s.). Postoperatively, these values were also similar in both groups: Group 1 with 93.2 (SD 7.4) and group 2 with 93.5 (SD 5.5) (n.s.).

Conclusion

In patients who have undergone a CWHTO, TFJ dislocation increases knee lateral compartment gapping when compared to a FHO at 0° and 30° of knee flexion. However, this fact does not have any repercussion on the clinical and functional status of the knee measured with the KSS.