[A comparative study of three different fixation methods after subtrochanteric shortening osteotomy in total hip arthroplasty for Crowe type Ⅳ developmental dysplasia of the hip].

OBJECTIVE

To compare the effectiveness of three different fixation methods after subtrochanteric shortening osteotomy (SSO) in total hip arthroplasty (THA) for Crowe type Ⅳ developmental dysplasia of the hip (DDH).

METHODS

A clinical data of 63 patients (78 hips) with Crowe type Ⅳ DDH, who underwent THA with SSO between November 2014 and May 2019, was retrospectively analyzed. Among them, 18 patients (20 hips) obtained stability by intramedullary pressure provided by the S-ROM modular prostheses (group A); 22 patients (30 hips) underwent prophylactic binding by stainless steel wire after osteotomy and before stem implantation (group B); 23 patients (28 hips) were fixed with autogenous cortical strut grafts and stainless steel wire or cables (group C). There was no significant difference in gender, age, body mass index, affected limb side, and preoperative Harris score between groups ( P>0.05). The operation time, complications, imaging results, hip functional score of the three groups were recorded and compared.

RESULTS

There was no significant difference in the operation time between groups ( P>0.05). All incisions healed by first intention. All patients were followed up, and the follow-up time was 2.5-4.0 years (mean, 3.1 years) in group A, 1.5-5.5 years (mean, 3.2 years) in group B, and 1.0-5.0 years (mean, 1.6 years) in group C. There was no significant difference in Harris score or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between groups at 4 and 12 months after operation ( P>0.05). X-ray films showed that there was no significant difference in osteotomy healing rate at 4, 8, and 12 months after operation and the osteotomy healing time between groups ( P>0.05). There was no complications such as joint dislocation, prosthesis loosening, prosthetic joint infection, or heterotopic ossification during follow-up, except for the distal femoral fracture of 1 hip during operation in group B.

CONCLUSION

In THA for patients with Crowe type Ⅳ DDH, the stainless steel wire binding alone and autogenous cortical strut grafts combined with stainless steel wire or cable binding can not significantly promote the osteotomy healing compared with femoral prosthesis intramedullary compression fixation. For patients with nonmatched medullary cavity after SSO, it is recommended to apply autogenous cortical strut grafts with wire or cables for additional fixation.