The biomechanical differences of rotational acetabular osteotomy, Chiari osteotomy and shelf procedure in developmental dysplasia of hip

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.

Arthroscopic labral repair combined with less invasive open-shelf acetabuloplasty for patients with developmental dysplasia of the hip

Hip arthroscopy has become widely used for intra-articular lesions, such as labral tears and femoral acetabular impingement. However, its use in patients with developmental dysplasia of the hip (DDH) has been controversial and has historically demonstrated mixed results, as acetabular dysplasia may cause instability due to insufficient bony coverage of the femoral head, thus causing excessive stress on the repaired labrum and cartilage. We devised a combined hip arthroscopic labral repair and a less invasive open-shelf procedure using a small skin incision as an anterolateral portal in hip arthroscopy. This novel procedure may improve the stability of the repaired labrum with a bony covering in a minimally invasive manner. Moreover, the shelf procedure can be performed under direct vision in a comparatively safe and precise manner. In total, 13 hips with DDH underwent the procedure for labral tears. All patients were females, with a mean age of 30 years. The mean follow-up period was 33 months. The mean Harris hip score improved from 74.2 to 93.6, and Oxford Hip score improved from 32.4 to 19.3. According to the Tönnis classification, the grade of arthritis preoperatively was grade 0 for nine hips and grade I for four hips. No radiographic progression of osteoarthritis was observed. It is possible that this novel procedure could be an effective treatment for labral tears with DDH and may prevent the early onset of secondary osteoarthritis. In this technical tip, we describe hip arthroscopic labral repair combined with a less invasive open-shelf acetabuloplasty in further detail.

Collagen I in the Hip Capsule Plays a Role in Postoperative Clinical Function in Patients With Developmental Dysplasia of the Hip

The aims of the present study is to evaluate the roles of collagen I and III in the hip capsule in the postoperative clinical function of patients with developmental dysplasia of the hip (DDH). Hip capsules from 155 hips of 120 patients were collected during surgery. The patients were divided into three groups according to age: I: 2-3.5 years; II: 3.5-5 years; and III: 5-6 years. Patient clinical function and radiographic outcomes were evaluated with the McKay scores and Severin classification. The expression of collagen I and III was detected through immunohistochemistry and quantitative reverse transcription polymerase chain reaction (RT-PCR) and analyzed according to age, sex, degree of dislocation and McKay classification. All patients received open reduction and pelvic osteotomy and/or femoral shortening osteotomy and achieved good results on the basis of postoperative X-ray imaging. The average follow-up time was 3.4 years (range 2-4.3 years). There were no changes in the expression of collagen III in the different groups. The expression of collagen I according to age and sex was not significantly different. Lower expression of collagen I was observed in DDH patients with a higher degree of dislocation according to the Tonnis grade. The highest expression of collagen I was detected in the group with poor clinical function according to the McKay classification. Collagen I is correlated with the degree of dislocation and is a risk factor for poor clinical function in DDH patients. Collagen I is correlated with the degree of hip dislocation and poor clinical function in DDH patients.

Endoscopic Shelf Acetabuloplasty for Treating Acetabular Large Bone Cyst in Patient With Dysplasia

Acetabular bone cyst is usually associated with dysplastic secondary osteoarthritis of the hip joint. Acetabular reorientation osteotomy is one of the most common therapeutic options for treating patients with hip dysplasia. However, it may be too invasive for athletes and can also lead to some complications including intraoperative fracture and postoperative bone necrosis especially in patients with acetabular large bone cysts. Endoscopic shelf acetabuloplasty offers a less invasive option for athletic patients with dysplasia of severity greater than those indicated for isolated hip arthroscopy. This Technical Note demonstrates endoscopic shelf acetabuloplasty with bone grafting, simultaneously addressing a large bone cyst and acetabular undercoverage, as part of a comprehensive approach addressing chondrolabral pathology while restoring capsular integrity in an athlete with moderate dysplasia.

Computer-Assisted Optimization of the Acetabular Rotation in Periacetabular Osteotomy Using Patient's Anatomy-Specific Finite Element Analysis

Periacetabular osteotomy (PAO) is a complex surgical procedure to restore acetabular coverage in the dysplastic hip, and the amount of acetabular rotation during PAO plays a key role. Using computational simulations, this study assessed the optimal direction and amount of the acetabular rotation in three dimensions for a patient undergoing PAO. Anatomy-specific finite element (FE) models of the hip were constructed based on clinical CT images. The calculated acetabular rotation during PAO were 9.7°, 18°, and 4.3° in sagittal, coronal, and transverse planes, respectively. Based on the actual acetabular rotations, twelve postoperative FE models were generated. An optimal position was found by gradually varying the amount of the acetabular rotations in each anatomical plane. The coronal plane was found to be the principal rotational plane, which showed the strongest effects on joint contact pressure compared to other planes. It is suggested that rotation in the coronal plane of the osteotomized acetabulum is one of the primary surgical parameters to achieve the optimal clinical outcome for a given patient.

Comparison of femoral head translation following eccentric rotational acetabular osteotomy and rotational acetabular osteotomy

PURPOSE

Eccentric rotational acetabular osteotomy (ERAO) is a modification of rotational acetabular osteotomy (RAO); it has been reported that ERAO allows the femoral head to translate medially and distally. However, no study has compared femoral head translation following RAO or ERAO. The purpose of this study was to compare immediate postoperative translation of the femoral head after RAO and ERAO in comparison with the preoperative position by radiological methods.

METHODS

Patients treated by RAO or ERAO between 2006 and 2014 were retrospectively evaluated. 19 hips (17 patients) were treated with RAO, and 25 hips (22 patients) were treated with ERAO. The acetabular roof angle and the location of the femoral head were measured on anteroposterior pelvic radiographs.

RESULTS

The mean preoperative acetabular roof angle was 20.9° in the RAO group and 22.0° in the ERAO group, showing no significant difference. The mean acetabular roof angle immediately postoperatively was -0.5° in the RAO group and -0.4° in the ERAO group, again showing no significant difference. The mean femoral head translation immediately postoperatively was 3.1 mm (95% confidence interval (CI), 1.5-4.7 mm) laterally and 3.0 mm (95% CI, 1.3-4.7 mm) proximally in the RAO group and 0.8 mm (95% CI, -0.7-2.3 mm) medially and 2.8 mm (95% CI, 1.5-4.1 mm) distally in the ERAO group; this difference was very highly significant (p<0.001).

CONCLUSIONS

In contrast with RAO, ERAO resulted in significant femoral head translation both medially and distally immediately postoperatively.

Long-term results of a modified Spitzy shelf operation for residual hip dysplasia and subluxation. A fifty year follow-up study of fifty six children and young adults

PURPOSE

The purposes of this study were to establish long-term outcome of the Spitzy shelf-operation and evaluate whether the procedure would delay osteoarthritis.

METHODS

During 1954-1976, 56 patients (70 hips) underwent Spitzy shelf operation at a mean age of 11.9 years (5 to 22). Indications included residual hip dysplasia or subluxation with Centre-Edge angle < 20°. We used survival analysis with conversion to total hip replacements as end-point. For patients without total hip replacement, information was provided from case records and radiographs. Avascular necrosis was assessed in pre-Spitzy radiographs, when available. Kaplan-Meier product-limit method was used to estimate survival function of the Spitzy shelf operation. Survival was assessed by Cox regression. Univariable Cox regression was performed separately for each variable. Potential predictors (p-value < 0.10) were entered into a multivariable regression model; p-value < 0.05 was considered significant.

RESULTS

Mean survival of the shelf procedure was 39.9 years (21 to 53). Survival fell from 83 % 30 years post-operatively, to 22 % at 50 years. Fifty-three hips (76 %) had undergone total hip replacement at mean age of 49.4 years (33 to 64). Seventeen hips had not received total hip replacement, mean survival 47.9 years (39 to 53).

CONCLUSION

The study showed that Spitzy shelf-operation had satisfactory long-term outcome with hip-survival in almost 90 % at patient age 40 years. The results indicate that Spitzy shelf-operation postpone total hip replacement. We consider Spitzy shelf-operation a good alternative in patients above 8 years. In younger children the procedure is not recommended due to increased frequency of graft resorption.

Analyses of outcomes of one-stage operation for treatment of late-diagnosed developmental dislocation of the hip: 864 hips followed for 3.2 to 8.9 years

Background

The one-stage procedure for treatment of older developmental dislocation of the hip (DDH) is used widely. However, the best age group for this operation is still unknown. The aims of our study were to evaluate middle-term outcomes of one-stage surgical treatment of a large number of patients with late-diagnosed DDH, and to explore the best age group for treatment.

Methods

We retrospectively reviewed 652 patients with a total of 864 hip joints with DDH, all aged >18 months. All the hip joints were treated with one-stage procedures including open reduction, pelvic osteotomy, and femoral shortening. The patients were divided into three groups according to age at surgery: Group I: 1.5–2.5 years; Group II: 2.5–8 years; and Group III: >8 years. The latest clinical and radiographic outcomes, complications and avascular necrosis (AVN) of the femoral head were evaluated and compared among the three groups.

Results

The mean age at surgery was 5.8 years (range: 1.5–13.2 years). The average time of follow-up was 6.2 years (range: 3.2–8.9 years). A total of 79.4% of good or excellent outcomes were obtained for clinical functional evaluation according to the McKay classification. For radiographic outcomes, 732 hips (84.7%) were classified as good or excellent according to the Severin classification. A total of 27.4% of all hips had a poor outcome according to the Kalamchi and MacEwen classification for AVN. The poorest outcomes were observed for clinical, radiographic and AVN results in Group III (p < 0.001). Compared with Group I, the better results for clinical and AVN outcomes were found in Group II (p < 0.001). However, similar clinical outcomes were observed between Groups I and II (p > 0.05). A significantly higher incidence of redislocation and residual acetabular dysplasia was observed in Tonnis grade II and III hip dislocation (p < 0.001).

Conclusions

One-stage treatment of late-diagnosed DDH had a good outcome in young and middle group. Younger patients achieved better results than older patients. However, the best age group was 2.5–8 years. Tonnis grade II and III DDH is a risk factor for redislocation and residual acetabular dysplasia after the one-stage operation.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-401) contains supplementary material, which is available to authorized users.