Risk factors associated with non-union after triple pelvic osteotomy (Toennis and Kalchschmidt technique): a case-control study and review of the literature

Age and magnitude of acetabular correction impair bone healing after triple pelvic osteotomy

INTRODUCTION

The aim of this examination was to assess, which risk factors impair bone healing after triple pelvic osteotomy (TPO) in the treatment of symptomatic hip dysplasia.

METHODS

A consecutive series of 241 TPO was reviewed retrospectively. Of these, a set of five postoperative radiographs was available, performed in a standardized regimen in the first year after surgery. Two experienced observers had to agree on the existence of a non-union on the radiographs obtained 1 year after TPO. Both observers measured the lateral center edge angle (LCEA) and acetabular index (AI) on all radiographs. Besides patient-specific risk factors, the magnitudes of acetabular correction and the amounts of a detectable slight change in acetabular correction were assessed. Binary logistic regression analysis and chi-squared test were used to detect the impact of the risk factor on bone healing.

RESULTS

A total of 222 cases were left for further examination. In 19 of these, at least one osteotomy was not healed completely one year after surgery. Binary logistic regression showed a significant relationship between the risk factors "age" (p < 0.001; odds ratio (OR) 1.109 (95% CI 1.05-1.18)) as well as "magnitude of acetabular correction (LCEA)" (p = 0.01; OR 1.087 (95% CI 1.02-1.16)) and non-union. Pearson's chi-square test showed a relationship between the risk factor "wound healing disorder" and non-union (p < 0.001). LCEA and AI showed a slight increase from the first to the last follow-up (observer 1: 1.6° and 1.3°, resp.), but regression analysis for the risk factor "amount of postoperative change of acetabular correction (LCEA, AI)" did not show statistically significant values.

CONCLUSION

The age at surgery and the magnitude of acetabular correction negatively influenced the healing progress of the osteotomy sites. The amount of a slight postoperative change of LCEA and AI did not correlate with a non-union.

Screw fixation after tripe pelvic osteotomy is reliable: changes of acetabular correction are rare and do not correlate with risk factors

PURPOSE

The aim of this examination was to assess whether there is a change of acetabular correction after triple pelvic osteotomy (TPO) and if so, whether there is a correlation with patient-specific risk factors or with certain periods in the postoperative course.

METHODS

A consecutive series of 241 TPO was reviewed retrospectively. The close-meshed radiographic follow-up of the first 12 weeks comprised pelvic radiographs performed immediately after the procedure, 5 days, 6 and 12 weeks after TPO. Three observers measured the lateral center edge angle, acetabular index and the craniocaudal offset of the pubic osteotomy. Patient-specific risk factors (e. g. age, gender, body mass index, nicotine abuse) and certain periods in the postoperative course were correlated with a change of acetabular correction.

RESULTS

After application of the exclusion criteria, 225 hips were available for further examination. Intraclass correlation coefficient resulted in predominantly excellent agreement between the measurements of the three observers (0.74-0.91). In 27 cases (12%), the three observers agreed on a change of acetabular correction. In 18 cases (8%), there was a slight change, in 9 cases (4%), a relevant change. The latter entailed consequences in the postoperative aftercare. General equation estimation did not show any correlation between a change of acetabular correction and patient-specific risk factors or certain periods in the postoperative course (p = 0.79-0.99).

CONCLUSION

Every once treated hip should be followed-up with the same attention, irrespective of the apparent risk profile. There is no rationale to skip a radiographic follow-up in the first 12 weeks after TPO.

Preliminary results of rigid fixation (locking plate/screw) after triple pelvic osteotomy without a hip spica cast: A modified fixation method in 21 patients

Objectives

The aim of this study is to investigate whether rigid fixation after triple pelvic osteotomy (TPO) utilizing a 3.5-mm locking plate and screws without hip spica cast can provide enough stability and prevent correction loss in pediatric patients with developmental dysplasia of the hip (DDH) and Legg-Calvé-Perthes disease (LCPD).

Patients and methods

A total of 21 hips of 21 pediatric patients (9 males, 12 females; mean age: 9.3±2.0 years; range, 6 to 14 years) who underwent rigid fixation with locking plate/screws after TPO for DDH and LCPD between June 2015 and October 2018 were retrospectively analyzed. Preoperative, immediate postoperative, and six-month follow-up anteroposterior radiographs were compared for the Wiberg’s center-edge angle (CE), Sharp angle, acetabular coverage of the femoral head (ACFH), and center-head distance discrepancy (CHDD). The patient demographics, surgery time, perioperative complications were evaluated.

Results

Underlying diagnosis were DDH in 14 patients and LCPD in seven patients. In patients with DDH, postoperative evaluation showed significant increase in the mean CE angle (5.6±16.1° vs. 30.5±9.3°, respectively) and ACFH (46.4±16.8% vs. 84.5±12.1%, respectively), and a significant decrease in the mean Sharp angle (55.3±6.2° vs. 35.6±7.8°, respectively) and CHDD (14.6±10.7% vs. 6.2±5.6%, respectively). The final follow-up revealed that there was no correction loss in these parameters. In the patients with LCPD, postoperative evaluation showed a significant increase in the mean CE (20.1±11.1° vs. 38.3±9.6°, respectively) and ACFH (62.9±18% vs. 91.4±10.1%, respectively), and a significant decrease in the mean Sharp angle (46±3.6° vs. 25.2±5.5°, respectively). The final follow-up revealed that there was no correction loss in radiological parameters. No perioperative complications were noted.

Conclusion

Our study results suggest that rigid fixation construct with a 3.5-mm locking plate and screws without hip spica cast can provide adequate stability to allow early mobilization following TPO in children without any loss of correction, until bony healing at the osteotomy sites.