Pelvic osteotomy techniques and comparative effects on biomechanics of the hip: a kinematic study

Advances in fixation strength of reorienting rectangular triple pelvic innominate osteotomies - A biomechanical investigation of two screw fixation techniques

BACKGROUND

Reorientating pelvic osteotomies are performed to prevent femoral-acetabular impingement or degenerative arthritis. A Toennis-Kalchschmidt triple pelvis innominate osteotomy is used in symptomatic patients. This study aimed to investigate the biomechanical behaviour of two different acetabular screw configurations for triple pelvis innominate osteotomy osteosynthesis.

METHODS

Two screw-orientation techniques in rectangular os ilium osteotomy were compared by osteotomising 12 artificial hemipelvises with triple pelvis innominate osteotomy protocol (fragment reorientation: 10.5° inclination and 10.0° anteversion) and randomising them in 2 groups (n = 6) for implantation with three 4.5 mm screws. Bidirectional group had a bidirectional screw orientation and Monoaxial group had a monoaxial direction of all three screws through iliac crest. All specimens were tested under progressively increasing cyclic loading until failure. Group-wise comparisons of acetabular cup medialisation, anteversion and inclination were evaluated via motion tracking at cycles 250, 500, 750, 1000, 1250, 1500, 1750, 2000, 2250, and 2500. Failure was defined as reaching 5° inclination or 5° anteversion.

FINDINGS

Acetabular cup medialisation (p ≤ 0.026), anteversion (p ≤ 0.021) and inclination (p ≤ 0.039) all increased significantly during testing in both groups. There were no significant differences for the group-wise comparisons at the cycle points defined in the methods (p ≥ 0.182). No significant differences were detected between groups for cycles to failure and failure load (p = 0.873).

INTERPRETATION

Bidirectional screw alignment does not lead to significant advantages compared to pure monoaxial if all three axial screws are evenly distributed over the osteotomy geometry. The triple pelvis innominate osteotomy is susceptible to changes in anteversion, inclination and medialisation under partial weight-bearing. Cautious rehabilitation protocols are recommended.

Sports activity after pelvic osteotomy for treatment of developmental dysplasia of the hip : A comparative study between the triple pelvic and periacetabular osteotomy techniques

BACKGROUND

Symptomatic dysplasia of the hip represents an indication for a bony correction of the acetabulum. In the last decades several operative procedures were established.

OBJECTIVE

The aim of the current study was to analyze whether the level of sports activity is higher in patients after periacetabular osteotomy (PAO) according to Ganz as a technique which preserves the posterior column compared to classical triple pelvic osteotomy (TPO) for treatment of developmental hip dysplasia.

MATERIAL AND METHODS

The study group included 102 patients treated with the classical TPO with already published clinical results, who were compared to 34 patients treated with PAO between 2012 and 2016. The clinical outcome scores included the modified Harris Hip Score, the Hip Osteoarthritis Outcome Score, the University of California, Los Angeles activity score and the visual analog scale.

RESULTS

After a mean follow-up of 4.4 years the clinical parameters improved significantly after PAO (p < 0.05). In comparison to the TPO group the clinical scores of the PAO group had inferior baseline values and a tendency to inferior follow-up results in the mHHS (p < 0.05) and HOOS (p > 0.05). After surgery, the PAO group showed a shift to medium and high impact sport activities.

CONCLUSION

The shorter time of postoperative partial weight bearing after PAO due to the preservation of the posterior column seemed not to have a positive impact on the clinical results or the sports activity compared to the TPO treated patients.

Tönnis triple pelvic osteotomy for the management of late residual acetabular dysplasia: mid-term to long-term follow-up study of 54 patients

The authors reviewed 54 (58 hips) patients with acetabular dysplasia following developmental dislocation of the hip (DDH), treated by triple pelvic osteotomy according to the Tönnis technique. The aim of our study was to report the long-term clinical and radiographic results of the operation at a mean follow-up of 12 years (from 7 to 20). At diagnosis, all the hips were painful, the Wiberg angle measured less than 20°, and no radiographic signs of osteoarthritis were present. At follow-up, 82.7% of the operated hips showed either excellent or good results, according to Harris, and the Wiberg angle measured an average of 34° (from 26° to 45°). We encountered five complications: one acetabular malrotation and four asymptomatic ischial nonunions. In conclusion, we believe that, although Bernese periacetabular osteotomy is nowadays considered the gold standard for the surgical treatment of the dysplastic hip following DDH, Tönnis osteotomy represents a good treatment option: it is technically easy, enables direct visualization of the three osteotomies, leads to few complications, and its learning curve is short. The absence of radiographic signs of osteoarthritis and hip congruency before surgery are the basic requirements to achieve a successful result.

Can Salter osteotomy correct late diagnosed hip dysplasia: A retrospective evaluation of 49 hips after 6.7 years?

BACKGROUND

Surgical treatment of late diagnosed development dysplasia of the hip (DDH) remains challenging with several methods being described. We therefore retrospectively evaluated the outcome of Salter innominate osteotomy (SIO) in patients with fully-grown bone, to evaluate whether this surgical procedure allows sufficient acetabular correction.

MATERIAL AND METHODS

Between 2004-2012 SIO had been performed in 45 patients (49 hips) with late diagnosed DDH. The evaluation included pre- and postoperative radiographs (n=49), the complication rate (n=49) and the clinical outcome (WOMAC, HHS, UCLA) (n=34).

RESULTS

Mean age at surgery was 27.6 (16-51) with a follow-up of 6.7±2.7 (0.9-11.0) years. Radiologically, a good acetabular correction with a significant improvement of the Center Edge angle (15.4° to 34.9°), sharps angle (45.7° to 32.0°) and migration percentage (33.2% to 14.4%) (p<0.001) was found. Clinical results revealed a WOMAC of 13.9±13.3, UCLA of 7.8±2.1 and HHS of 85.0±11.8. Complications were noted for 10 patients (20%) with 7 (14%) requiring revision.

CONCLUSION

The results demonstrated that SIO achieved a satisfying acetabular correction and good clinical results in late diagnosed DDH. It therefore might be an option in some cases, although periacetabular osteotomy techniques are currently preferable used as they allow a wider range of acetabular correction.

LEVEL OF EVIDENCE

IV, retrospective observational study.

Fracture at the Ischio-Pubic Junction After Periacetabular Osteotomy in the Adolescent Population

INTRODUCTION

The Ganz periacetabular osteotomy (PAO) is a well-accepted surgical intervention for hip dysplasia. In the adolescent population it is performed in patients who are skeletally mature with symptoms related to acetabular dysplasia. Redistribution of stresses through the hemipelvis after PAO can lead to a fracture at the ischio-pubic junction (IPJ).

METHODS

This is an IRB-approved, retrospective analysis of adolescent patients treated with a PAO for acetabular dysplasia from 1999 to 2012 at a single institution. Radiographic measurements were performed to include the lateral center-edge angle, Sharp acetabular index, and acetabular index of the weight-bearing zone. These were measured preoperatively and at 6-weeks and 1 year postoperatively from a standing anterior posterior pelvis radiograph. Postoperative modified Harris hip scores (mHHS) were also analyzed. Patients over the age of 21 at time of surgery and those with <2 years of follow-up were excluded.

RESULTS

One hundred sixty-six patients (187 operated hips) at an average age of 15.6±2.5 were included. Twelve (6.4%) fractures at the IPJ were identified in 12 patients. Seven were identified on the initial postoperative films, whereas 5 were identified after the 6-week visit. Seven (58.3%) fractures had an associated superior posterior ramus nonunion. Six (50%) healed by 2 years after surgery; the remaining 6 (50%) went on to nonunion. Compared with those without a fracture, there was no significant difference in preoperative, 6 weeks postoperative, and final center-edge angle (P=0.94, 0.29, 0.27), Sharp acetabular index (P=0.95, 0.38, 0.16), or AIBWZ (P=0.37, 0.21, 0.54). There was no difference in postoperative mean modified Harris hip scores (P=0.63). Analysis of predisposing factors demonstrated that patients with Charcot-Marie-Tooth (CMT) disease were more likely to develop an IPJ fracture (P=0.001). Patients with an IPJ fracture were older (17.1 vs. 15.5, P=0.05). There was no difference based on patient sex (P=0.22).

DISCUSSION AND CONCLUSIONS

The incidence of fracture at the IPJ after PAO in the adolescent population is 6.4% with some occurring at the time of surgery. These fractures are also associated with a nonunion at the superior posterior ramus cut and an underlying diagnosis of Charcot-Marie-Tooth. These fractures are not clinically significant and in this series did not merit further intervention when identified.

LEVEL OF EVIDENCE

Level III.

Improved functional outcome with no decrease in hip strength 2 years following Ganz periacetabular osteotomies for adolescent hip dysplasia

To analyze outcomes of adolescents treated with a periacetabular osteotomies (PAO) with a minimum of 2 years of follow-up. Patients undergoing a PAO for adolescent hip dysplasia were analyzed preoperatively, 1 and 2 years postoperatively. In 32 dysplastic hips significant improvement was seen in all radiographic parameters. Gait speed, hip flexion pull-off power, and hip abductor moment impulse were unchanged postoperatively, whereas strength was maintained in 85% (abduction) and 95% (flexion). The Harris Hip Score increased from 67.1 to 77.9 to 81.3 at 1 and 2 years, respectively. Ganz PAO is effective in correcting dysplasia in adolescents radiographically and functionally.

Management of developmental dysplasia of the hip in young adults

The term developmental dysplasia of the hip (DDH) describes a spectrum of disorders that results in abnormal development of the hip joint. If not treated successfully in childhood, these patients may go on to develop hip symptoms and/or secondary osteoarthritis in adulthood. In this review we describe the altered anatomy encountered in adults with DDH along with the management options, and the challenges associated with hip arthroscopy, osteotomies and arthroplasty for the treatment of DDH in young adults.

Cite this article: Bone Joint J 2013;95-B:732–7.

Developmental dysplasia of the hip in the newborn: A systematic review

Developmental dysplasia of the hip (DDH) denotes a wide spectrum of conditions ranging from subtle acetabular dysplasia to irreducible hip dislocations. Clinical diagnostic tests complement ultrasound imaging in allowing diagnosis, classification and monitoring of this condition. Classification systems relate to the alpha and beta angles in addition to the dynamic coverage index (DCI). Screening programmes for DDH show considerable geographic variation; certain risk factors have been identified which necessitate ultrasound assessment of the newborn. The treatment of DDH has undergone significant evolution, but the current gold standard is still the Pavlik harness. Duration of Pavlik harness treatment has been reported to range from 3 to 9.3 mo. The beta angle, DCI and the superior/lateral femoral head displacement can be assessed via ultrasound to estimate the likelihood of success. Success rates of between 7% and 99% have been reported when using the harness to treat DDH. Avascular necrosis remains the most devastating complication of harness usage with a reported rate of between 0% and 28%. Alternative non-surgical treatment methods used for DDH include devices proposed by LeDamany, Frejka, Lorenz and Ortolani. The Rosen splint and Wagner stocking have also been used for DDH treatment. Surgical treatment for DDH comprises open reduction alongside a combination of femoral or pelvic osteotomies. Femoral osteotomies are carried out in cases of excessive anteversion or valgus deformity of the femoral neck. The two principal pelvic osteotomies most commonly performed are the Salter osteotomy and Pemberton acetabuloplasty. Serious surgical complications include epiphyseal damage, sciatic nerve damage and femoral neck fracture.