Long-term Results of Developmental Hip Dysplasia Under Therapy With Pavlik Harness

INTRODUCTION

The Pavlik harness is a commonly used treatment for developmental dysplasia of the hip (DDH) of types IIc or worse, based on the Graf classification. This study aimed to assess the long-term follow-up outcomes after treating DDH with the Pavlik harness.

METHODS

Between 1995 and 2006, ultrasound screening was conducted on 7372 newborns within the first days of life. Among them, 203 dysplastic hips in 152 patients, whose sonograms were Graf type IIc or worse, were treated with Pavlik harness. Treatment was discontinued if the measurement indicated Graf type Ia/b. More than 20 years later (mean: 20.46 y), patients were invited for clinical evaluation (Oxford Hips Score, Schulthess Hip Score, Harris Hip Score) and radiologic examination (center-edge angle according to Wiberg and the Severis classification, the rate of roofing of the femoral head via the Reimers migration percentage, and the Sharp angle).

RESULTS

Of the 152 patients, 60 (39.5%) participants with 80 (39.4%) affected hips (57.7% type IIc, 7.9% type D, and 15.6% type IIIa/b) were reexamined. The average follow-up duration was 20.5 years, with a maximum of 25.9 years. According to the Severin's classification, only 2 (3.77%) patients, each with one affected hip, showed slight residual dysplasia. The Reimer's migration percentage indicated an average of almost 90% canopy cover in the patient collective studied. No avascular necrosis was found, and the Sharp angle showed an average of almost 38 degrees. Only 4 participants with each one affected hip showed residual dysplasia according to the Sharp angle. The clinical results were quite satisfying, as none of the patients experienced hip pain that significantly limited their everyday activities or sports engagement, requiring medical attention before this study.Conclusions:Conservative therapy of DDH (Graf type IIc, D, III) with the Pavlik harness has demonstrated very good therapeutic success and a very low rate of residual dysplasia (2.81%). Both the radiologic and clinical outcomes were highly satisfactory.

LEVEL OF EVIDENCE

Level IV.

Tendon transfer in foot drop: a systematic review

INTRODUCTION

Foot drop is a disorder that impairs walking and leads to tripping and falling. Tendon transfer (e.g., tibialis posterior tendon) is a typical secondary procedure in foot drop treatment. The purpose of this systematic review was to identify the most common tendon transfer techniques for treating foot drop and to analyze the reported functional outcomes. Furthermore, it was of interest if the type of surgical technique affects the functional outcome.

METHODS

A PubMed and MEDLINE literature search was performed according to PRISMA guidelines. The search terms used were ("tendon transfer" OR "tendon transposition") AND ("foot drop" OR "peroneal neuropathies"). Any study published before January 2020 was considered for inclusion. No case reports or reviews were included. Common outcome measures (Stanmore score, AOFAS, FAAM, AFO use, patient satisfaction and active ankle dorsiflexion) were evaluated. The quality of the included studies was assessed using the Coleman Methodology Score.

RESULTS

Of the 125 reviewed publications, 37 met the inclusion criteria. 42 cohorts were analyzed. The frequently reported tendon transfer technique was the tibialis posterior tendon transfer through the interosseus membrane. The most used fixation technique was tendon on tendon fixation; however in recent years, a tendon to bone fixation has gained popularity. There was an increase in Stanmore scores and AOFAS postoperatively and a decrease of AFO use postoperatively observed.

CONCLUSIONS

Due to various outcome measures and lack of preoperative assessment in the included studies, a meta-analysis of the pooled results was not possible. Nevertheless, the findings of this study show that tendon transfer increases mobility and self-independency leading to patient satisfaction. The choice of the surgical technique does not affect the outcome. A prospective collection of patient data and standardized outcome measures will be important to further analyze the efficacy of tendon transfer techniques.

Progressive lateralization and constant hip geometry in children with DDH, NDH, and LCPD following hip reconstructive surgery: a cohort study of 73 patients with a mean follow-up of 4.9 years

BACKGROUND

Pelvic and femoral osteotomies have been effective methods to treat developmental dysplasia of the hip (DDH), neurogenic dislocation of the hip (NDH), and Legg-Calvé-Perthes disease (LCPD). The aim of this study was to evaluate the mid-term results after hip reconstruction in children with DDH, NDH, and LCPD.

METHODS

In a retrospective study, X-rays of 73 children (2-19 years) with DDH, NDH, and LCPD were measured before, 3 months, and at final follow-up (FU) after hip reconstructive surgery (open reduction, and femoral and/or pelvic osteotomy ± soft-tissue procedures between 2008 and 2018). Measurement of hip geometry included acetabular index (AI), center-edge angle (CE), and Reimers migration index (RMI). Mean follow-up time at final FU was 4.9 years. P value was set P < 0.05.

RESULTS

After surgery (femoral osteotomy: 84 hips, Salter innominate osteotomy: 21 hips, Pemberton osteotomy: 30 hips, open reduction: 28 hips, Chiari osteotomy: 4 hips, and soft-tissue release: 24 hips), hip geometry parameters improved significantly. Nevertheless, at final FU, there was deterioration in hip geometry with femoral head lateralization (RMI) compared to the data at 3 months after surgery (RMI: preop/3 months/final FU: 40.6 ± 16.1%/6.1 ± 9.0/15.4 ± 16.0%; CE: 11.3° ± 20.0°/30.2° ± 9.5°/27.9 ± 15.4°; AI: 28.8° ± 9.6°/19.1° ± 7.6°/18.3 ± 7.6°). Sub-group analysis did not show differences concerning the progression of RMI in DDH, NDH, and LCPD at final FU. Regardless of basic disease, the lateralization was observed in all three groups (DDH, NDH, and LCPD) and statistically significant comparing X-rays 3 months postoperatively to maximum follow-up (DDH; NDH; LCPD: 2.7 ± 6.8%/7.6 ± 10.1%; 13.7 ± 15.3%/22.8 ± 19.8%; 1.7 ± 4.1%/14.9 ± 11.3%). Additional soft-tissue release techniques in patients with DDH or NDH did not show postoperative differences with statistical significance. Concerning surgical techniques, a connection between the lower RMI and the procedure of osteotomy of the ilium was found. In 25 patients, (34%) complications were observed: superficial skin lesions in 8, deep skin lesions in 3, contraction of adductors in 3, subluxation in 2, dislocations of the cast in 2, osteonecrosis of the femoral head in 2 cases, reluxation in 1, infection of the implanted plate in 1, compliance problem in 1, delayed bone healing in 1, and contraction of knee flexors in 1 case.

DISCUSSION

The basic results of this study show a significant improvement of hip geometry at a follow-up of 4.9 years and prove findings of previously published literature. Moreover, the study was able to show a progression of RMI in all patient groups, which have undergone reconstructive surgery, despite basic hip geometry data (AI, CE angle) did not change. Those findings were independent from underlying pathology. Complications were counted in 34% of the patients and involved all known adverse events after hip reconstructive surgery. This makes clear why annual follow-up checks are needed not to miss the right indication for revision surgery.

CLINICAL RELEVANCE

Evidence level: Level IV, case series.

TRIAL REGISTRATION

This manuscript is part of a prospective randomized clinical trial, registered in the German Clinical Trials Register DRKS-ID: DRKS00016861.

Foam Splint versus Spica Cast-Early Mobilization after Hip Reconstructive Surgery in Children-Preliminary Data from a Prospective Randomized Clinical Trial

BACKGROUND

Surgical hip joint reconstruction may be the method of choice for children and adolescents with developmental dysplasia of the hip (DDH), as well as neurogenic dislocation of the hip (NDH) and Legg-Calvé-Perthes disease (LCPD). Following pelvic surgery, immobilization using a spica cast is considered to be the gold standard, despite the fact that casting may cause complications, such as hygienic problems, skin lesions, neurological deficits, and rigidity of the adjacent joints. An alternative for postoperative immobilization is a foam splint. The purpose of this randomized controlled trial was to compare spica cast and foam splint immobilization after hip reconstruction in children and adolescents with DDH, NDH, and LCPD.

METHODS

In a prospective randomized clinical trial, children and adolescents (age: 4-14 years), who received hip reconstructive surgery (osteotomy of the ilium and proximal femur, open reduction, soft tissue techniques) for DDH, NDH, and LCPD were included. Patient recruitment, group allocation, surgery, and aftercare were carried out in a department for orthopaedic surgery in Central Europe. Standardized questionnaires SF-36 (Short Form-36), EQ-5D (Euro Quality of Life 5D and CPCHILD (Caregiver Priorities and Child Health Index of Life with Disabilities) were gathered before, six, and twelve weeks after surgery from each patient. Group one received a spica cast and group two a foam splint for a period of six weeks postoperatively. There was no difference in surgical treatment.

RESULTS

Twenty-one out of thirty planned patients were enrolled in the study. One patient had to be excluded because of a lack of compliance. All quality of life (QOL) scores showed a significant reduction at the 6-week follow-up compared to the preoperative assessment. After twelve weeks, the scores came back close to the preoperative values. A significant reduction was seen in the spica cast group pre- vs. postoperatively for the variables CPCHILD (81% vs. 64%, p = 0.001), EQ-5d (65% vs. 45%, p = 0.014), and SF-36 (85% vs. 74%, p = 0.004). The corresponding values for the foam splint group also presented a reduction for all scores, but without statistical significance. Complications occurred in five cases.

CONCLUSIONS

Recent retrospective studies suggest that foam splint immobilization after hip reconstruction surgery is a safe and feasible method, promising fewer complications compared to spica casting. The preliminary results of this prospective randomized clinical trial show an improvement of the scores when using a foam splint compared to the conventionally used spica cast. Benefits for the patients may be fewer adverse events and no need to undergo a second round of anaesthesia for recasting. Data suggest higher patient and caretaker satisfaction in the foam splint group.

High Reoperation Rate in Mobile-Bearing Total Ankle Arthroplasty in Young Patients

Background and Objectives: Due to inferior survival rates compared to hip and knee arthroplasty, total ankle arthroplasty (TAA) was previously mainly recommended for older and less active patients. However, given the encouraging survival rates and clinical outcomes of modern generations of TAA, some authors have also advocated TAA in young patients. Thus, the aim of this study was to evaluate age related reoperation, revision and survival rates of third-generation mobile-bearing TAAs. Materials andMethods: In this retrospective study, 224 consecutive TAA patients with a minimum follow up (FU) of 2 years were analyzed. Patients were retrospectively assigned to two study groups (Group A: age < 50 years; Group B: age ≥ 50 years). Revision was defined as secondary surgery with prothesis component removal, while reoperation was defined as a non-revisional secondary surgery involving the ankle. Results: After a mean FU of 7.1 ± 3.2 years, the reoperation rate (Group A: 22.2%; Group B: 5.3%; p = 0.003) and revision rate (Group A: 36.1%; Group B: 13.8%; p = 0.003) were higher within Group A. An age of under 50 years at time of surgery was associated with higher reoperation (odds ratio (OR): 6.54 (95% CI: 1.96–21.8); p = 0.002) and revision rates (OR: 3.13 (95% CI: 1.22–8.04); p = 0.018). Overall, lower patient age was associated with higher reoperation (p = 0.009) and revision rates (p = 0.001). Conclusions: The ideal indication for TAA remains controversial, especially regarding patient age. The findings of this study show high reoperation and revision rates in patients aged under 50 years at time of surgery. Therefore, the outcomes of this study suggest that the indication for TAA in young patients should be considered very carefully and that the association between low patient age and high reoperation rate should be disclosed to all eligible patients.

Results after spica cast immobilization following hip reconstruction in 95 cases: is there a need for alternative techniques?

INTRODUCTION

Developmental dysplasia of the hip (DDH), neurogenic dysplasia of the hip (NDH), and Perthes disease often require surgical treatment. Spica casting is a common postoperative immobilization. The purpose of this study was to evaluate the complications related to the immobilization.

MATERIALS AND METHODS

In a retrospective analysis, we included 83 patients (95 hips), who underwent hip reconstructive surgery between 2008 and 2018. We had 43 female and 40 male patients. Age reached from 3 months to 19 years. All patients were treated with a spica cast postoperatively for a 6-week protocol. Complications were analyzed using the full medical documentation and classified according to Clavien-Dindo.

RESULTS

We had complications in 23 patients (27.7%). We counted superficial skin lesions in seven, deep skin lesions in three, spasticity of adductors in three, subluxation in two, infection of the plate in one, fracture of the plate in one, compliance problem in one, dislocations of the cast in two, reluxation in one, delayed bone healing in one and spasticity of knee flexors in one case. According to the classification of Clavien-Dindo, we were able to count ten type I, four type II, nine type III, zero type IV and zero type V adverse events.

CONCLUSION

The usage of a spica cast after hip reconstructive surgery is still the most popular way of aftertreatment. It has a low complication rate, which may be lowered by well-applied casts and foam padding. Known complications such as spasticity in patients with cerebral palsy, skin lesions, and pressure sores should be observed and avoided. Shorter protocols for immobilization with the usage of foam padding and foam splints lead to less complications.

CLINICAL RELEVANCE

Evidence level level IV, case series.

Crystallinity-Based Product Design: Utilizing the Polymorphism of Isotactic PP Homo- and Copolymers

The polymorphism of isotactic polypropylene (iPP) in combination with the strong response of this polymer to nucleation can be utilized for expanding the application range of this versatile polymer. Based on three “case studies” related to β-iPP pressure pipes, ethylene-propylene (EP) random copolymers for thin-wall injection molding and transparency and sterilization resistance of cast films we demonstrate ways of combining polymer composition, nucleation and process settings to achieve the desired application performance. The importance of considering interactions between polymer design, nucleation and processing parameters for designing application properties is highlighted.

PP-based Model Compounds as Tools for the Development of High-impact-ethylene-propylene Copolymers

The development of heterophasic PP-copolymers, which are necessary in many applications because of their specific property profile, requires large capacities in pilot plants (or at least in bench-scale reactors) for a systematic variation of the matrix and elastomer properties. A possible alternative are model compounds, where the different components are blended in an extruder. The possibility to evaluate three main influence factors on mechanics of such systems, namely the viscosity ratio between matrix and elastomer phase, the phase compatibility and the composition of the elastomer phase, is demonstrated in a series of investigations. Morphology investigations based on transmission electron micrographs have proven to be an indispensable tool for obtaining systematic information about such blend systems, which can be further used for the development of reactor-based systems.

Nucleation of Polypropylene Homo- and Copolymers

The combination of moderately slow crystal growth at large undercoolings together with the practical absence of sporadic nucleation makes isotactic polypropylene (iPP) an ideal material for controlled nucleation. In this review the different types of nucleating agents – inorganic and organic, particulate and soluble – for the different crystal modifications of iPP (α, β and γ) are presented together with their working mechanism and criteria for activity. The interaction between polymer type, nucleating agent and processing conditions in determining mechanical and optical properties conclude the survey.

Tensile tests of polymers at low temperatures in the environmental scanning electron microscope: an improved cooling platform

The investigation of the fracture behavior of polymers in the environmental scanning electron microscope (ESEM) can provide information about the correlation between the microstructure of a specimen and the macroscopic stress-strain characteristic. As the mechanical properties of polymers change dramatically at the glass transition temperature, cooling of the specimens during the tensile tests can yield very valuable information about the influence of individual components of polymer blends on the fracture behavior of the material. A serious problem in this connection is the poor heat conductivity of polymers. A commercially available cooling platform, which can be mounted on the tensile stage used for the tests was substantially modified to both enhance the heat transfer between platform and specimen, and to minimize the temperature gradient along the specimen. The first experiments on modified polypropylene specimens already delivered some unexpected results. Fibril-like structures appeared at the crack tip that would not be expected at temperatures below the glass transition temperature of the polymer blend.