A Newly Modified Salter Osteotomy Technique for Treatment of Developmental Dysplasia of Hip That Is Associated with Decrease in Pressure on Femoral Head and Triradiate Cartilage

MODIFIED SALTER PELVIC OSTEOTOMY FOR THE DDH TREATMENT

Objectives

Three pelvic osteotomies (Salter, Dega, Pemberton) are widely used in walking patients under seven years old for DDH treatment. We've proposed a modified Salter Pelvic Osteotomy (SPO), which has the advantages of the abovementioned osteotomies.

Methods

Short- and mid-term results were assessed in 19 patients after the modified SPO application. Patients were examined before and after the surgery, at 6 months postoperatively, and at follow-up.

Results

Acetabular Index (AI) before the surgery was 39.5 ± 7 °; after the surgery - 24.4 ± 5.5 °, at 6 months - 20.4 ± 5 ° (9-28), at follow-up - 14.5 ± 4 °; AI correction - 14.9 ± 5.5 °. Lateral Centre-Edge Angle at follow-up - 22.7 ± 4.7 °. Clinical results at follow-up were I / II McKay grade in 18 patients (94.7%); radiological results were I / II Severin class in 18 patients (94.7%).

Conclusion

Modified SPO improves the FH coverage in any direction; results after modified SPO are excellent and good in most patients. Level of Evidence IV; Case Series .

THE BIOMECHANICAL ANALYSIS OF PELVIC OSTEOTOMIES APPLIED FOR DDH TREATMENT IN PEDIATRIC PATIENTS

OBJECTIVE

The aim: This article aimed to evaluate biomechanical changes during the most commonly used pelvic osteotomies (Salter, Dega, Pemberton) for DDH treatment in pediatric patients.

PATIENTS AND METHODS

Materials and methods: Virtual pelvic models of 2- and 6-years old patients were created, material properties were assigned, pelvic osteotomies were simulated and biomechanical changes were evaluated using finite element analysis (FEA).

RESULTS

Results: It was revealed that the patient's age impacts pelvic bones and cartilage density (in younger patients the pelvic elements are more pliable - p<0.05). Stress distribution after each of the abovementioned pelvic osteotomy was assessed in 2- and 6-year-old patients' pelvic models. The new term "restriction point" was introduced, which means a place where restriction of acetabular deformity correction occurs.

CONCLUSION

Conclusions: It was found that there are no purely reshaping and reorientation pelvic osteotomies as previously believed; the pelvic ring acts as a unit in carrying out the applied load. Biomechanical overload of triradiate cartilage during Salter osteotomy in 2-year-old patients and in 2- and 6-year-old patients during Pemberton osteotomy was revealed; overload of the posterior cortical layer in the greater sciatic notch in 2-years old patient during Dega osteotomy was revealed.

Salter pelvic osteotomy for the treatment of Developmental Dysplasia of the Hip: assessment of postoperative results and risk factors

BACKGROUND

If non-surgical treatment of Developmental Dysplasia of the Hip (DDH) fails or if DDH is late-detected, surgery is necessary. Salter pelvic osteotomy (SPO) is an effective surgical option for such cases.

OBJECTIVES

To study the results after SPO; to evaluate risk factors; to reveal radiological parameters that may correlate with results.

METHODS

Results analysis in 17 patients (22 hips). Risk factors included those that do not depend on the surgeon (patient's age, value of the acetabular index (AI) preoperatively, DDH Tonnis grade) and those that depend on the surgeon (amount of AI correction). To radiological parameters which may correlate with the amount of AI correction we referred distance "d" and the lateral rotation angle.

RESULTS

SPO allows performing AI correction in ranges 24.1 ± 6.5°. Excellent and good clinical results were obtained in 95.5% of patients; excellent and good radiological results in 86.4% of patients. Risk factors that do not depend on the surgeon were older patient's age and higher preoperative AI values (p <0.05). The risk factor that depends on the surgeon was the amount of AI correction (p <0.05). The distance "d" was recognized as a radiological parameter that may indicate sufficient AI correction (p <0.05).

CONCLUSION

In older patients with a higher preoperative AI value the results will be predictably worse. The surgeon may influence the result with a greater amount of AI correction (which may also be indicated radiologically by the distance "d" values).

LEVEL OF EVIDENCE

IV, therapeutic, case series.