Andreas Roposch

Flexible Intramedullary Nailing for the Treatment of Unicameral Bone Cysts in Long Bones

Background: Unicameral bone cyst is characterized by its tenacity and risk of recurrence. Pathological fracture is common and is often the presenting symptom. The objective of the present study was to evaluate the results of flexible intramedullary nailing for the treatment of a unicameral bone cyst with or without a pathological fracture. Methods: Flexible intramedullary nailing for the treatment of a unicameral bone cyst was performed in thirty-two patients. Thirty of these patients presented with a pathological fracture; twenty-four were managed immediately with intramedullary nailing, and the other six had been managed conservatively at other clinics before they were referred to our department. The remaining two cysts were detected incidentally. The cyst was located in the humerus in twenty-one patients, in the femur in nine, and in the radius in two. The mean age of the patients at the time of surgery was 9.8 years, and the mean duration of follow-up was 53.7 months. Radiographic evaluation was performed according to the criteria of Capanna et al., and the cyst was classified as completely healed, healed with residual radiolucency (osteolysis), recurred, or having no response. Results: The healing period ranged from three to 105 months. Fourteen cysts healed completely, and sixteen healed with residual radiolucent areas visible on radiographs. There was recurrence of two cysts that had healed with residual radiolucency. All of the cysts in the present study responded to treatment. A change of nails was necessary in nine patients, as the nails had become too short after bone growth. No major complications were observed. Conclusions: Flexible intramedullary nailing provides early stability, which allows early mobilization and thus obviates the need for a plaster cast and decreases the prevalence of the most common complication: a pathological fracture. This method of treatment also allows for an early return to normal activity.

The effect of the femoral head ossific nucleus in the treatment of developmental dysplasia of the hip. A meta-analysis.

BACKGROUND The role of the presence of the femoral head ossific nucleus as a risk factor for the development of osteonecrosis of the femoral head in infants with developmental dysplasia of the hip has been investigated in several small studies, but the results have been inconsistent. The purpose of the present study was to determine the effect of the presence of the ossific nucleus on the development of osteonecrosis. METHODS A systematic review of the medical literature from 1966 to 2007 was performed. Two independent reviewers evaluated all articles. Interrater agreement was determined, and the quality of evidence was evaluated. A meta-analysis was then performed with the main outcome defined as the development of osteonecrosis of the femoral head two years after reduction. RESULTS Six observational studies (five retrospective and one prospective) met the inclusion criteria. Inconsistency was found in that half of the studies demonstrated a protective effect of the ossific nucleus on the development of osteonecrosis whereas half of the studies did not. A meta-analysis (including 358 patients) showed no significant effect of the presence of the ossific nucleus on the development of grades-I through IV osteonecrosis, with forty-one cases of osteonecrosis (19%) found in infants in whom the ossific nucleus had been present at the time of hip reduction compared with thirty cases (22%) in the group without an ossific nucleus (relative risk=0.75, 95% confidence interval=0.46 to 1.21). When only radiographic changes of grade II or worse were considered to represent osteonecrosis, a significant difference in the prevalence of osteonecrosis was found, with fourteen cases of osteonecrosis (7%) in infants with an ossific nucleus compared with eighteen cases (16%) in those without an ossific nucleus (relative risk=0.43, 95% confidence interval=0.20 to 0.90). A subgroup analysis showed that the presence of the ossific nucleus reduced the probability of osteonecrosis by 60% (relative risk=0.41, 95% confidence interval=0.18 to 0.91) after closed reduction, but no significant effect was found in patients treated with open reduction (relative risk=1.14, 95% confidence interval=0.62 to 2.07). All studies demonstrated methodological weaknesses compromising the quality of evidence. CONCLUSIONS We did not find that the presence of the ossific nucleus had a significant effect on the development of osteonecrosis of any grade after hip reduction in infants with developmental dysplasia of the hip. The meta-analysis suggested that the presence of the ossific nucleus has a protective effect against the development of the more severe forms of femoral head osteonecrosis. However, the quality of evidence is moderate, and additional research is likely to have an important impact on the confidence in the estimate of the effect and may change this estimate.

Determining the reliability of the graf classification for hip dysplasia

We sought to establish the levels of interrater reliability and intrarater reliability of the Graf classification among orthopaedic surgeons in their final training year and who learned the method by instructed teaching or self study. Using standard teaching material developed by Graf, two groups of senior orthopaedic residents at the same training level received structured teaching sessions (Group A, n = 2) or performed self study (Group B, n = 2). Interrater reliability and intrarater reliability were determined (Cohens weighted kappa). Proportions of correctly rated sonograms were compared between groups, implications of misclassifications were analyzed, and sensitivity analyses were performed. Interrater reliability was 0.59 (95% CI = 0.32-0.85) for Group A, and 0.47 (95% CI = 0.14-0.79) for Group B. Intrarater reliability showed an overall kappa of 0.57 (95% CI = 0.35-0.78) in Group A, and 0.47 (95% CI = 0.19-0.75) in Group B. The proportion of correctly rated sonograms between groups was similar in the original dataset and in the sensitivity analysis. Misclassifications influencing treatment were infrequent; one patient would have received unwarranted treatment and three patients would not have received warranted treatment. The Graf classification showed moderate reliability. Using self study, it can be learned almost, but not quite as effectively as by a structured program.Level of Evidence: Diagnostic Study, Level I (testing of previously developed diagnostic criteria on consecutive patients [with universally applied reference “gold” standard]). See the Guidelines for Authors for a complete description of levels of evidence.

Effect of innominate and femoral varus derotation osteotomy on acetabular development in developmental dysplasia of the hip.

BACKGROUND Open reduction for the treatment of hip dislocation due to developmental dysplasia of the hip in children of walking age is frequently combined with either a femoral varus derotation osteotomy or an innominate osteotomy; however, it remains unclear which of these procedures is preferable in terms of subsequent hip development. The purpose of the present study was to compare acetabular development in patients managed for dislocation of the hip with open reduction combined with one of the two osteotomies. METHODS Patients between fifteen months and four years of age with hip dislocations that were treated at two different centers were compared. At one center, open reduction combined with a femoral varus derotation osteotomy was performed (thirty-eight patients), and at the other, open reduction combined with an innominate osteotomy was performed (thirty-three patients). In each group, one surgeon performed all of the operations. A total of 490 postoperative radiographs that were made over a mean follow-up period of 6.2 years were analyzed. We compared the change in acetabular index as well as several other radiographic criteria of acetabular development and hip stability over time. RESULTS After osteotomy, the acetabular index improved in both groups; however, the acetabular index in patients who underwent a varus derotation osteotomy never improved as much as that in patients who underwent an innominate osteotomy, with a mean difference of 9.5 after four years (p < 0.0001). Similarly, the innominate osteotomy group demonstrated better acetabular architecture and hip stability over time as quantified by the change in the acetabular floor thickness (p = 0.03), lateral centering ratio (p < 0.0001), and superior centering ratio (p < 0.0001). CONCLUSIONS In the present series, acetabular remodeling after open hip reduction and innominate osteotomy was more effective for reversing acetabular dysplasia and maintaining hip stability than open reduction combined with a femoral varus derotation osteotomy was. Long-term follow-up is necessary to determine whether the more favorable hip development following innominate osteotomy is associated with a lower incidence of premature degenerative hip disease.

An incomplete periacetabular osteotomy for treatment of neuromuscular hip dysplasia.

Standard innominate osteotomies that are recommended for treatment of the typical form of developmental dysplasia of the hip are not recommended for dysplasia associated with neuromuscular disorders. A periacetabular osteotomy that permitted accurate correction of the posterolateral acetabular deficiency was done on 40 patients (50 hips). The purpose of this study was to present the surgical technique, to evaluate whether it can improve acetablular dysplasia, and to provide stable hips. The patients had a mean age of 9.5 years at the time of surgery. The medial cortex of the ilium was left intact, whereas the supraacetabular and retroacetabular cancellous bone, and posterolateral cortical bone were cut. The posterior cut extended down to the triradiate cartilage, or through its former site, respectively. Forty-one hips were evaluated at a mean followup of 5.3 years (range, 2–11.7 years) after surgery. The mean acetabular index improved from 32° preoperatively to 12° at followup. The mean migration percentage improved from 77% to 13%. A redislocation or unstable hip occurred in two patients. According to caregivers, surgery improved personal care, positioning, and comfort. This osteotomy decreases the radius of the elongated acetabulum, provides coverage by articular cartilage particularly at the posterolateral aspect of the acetabulum, and preserves the entire medial wall of the ilium. Level of Evidence: Therapeutic study, Level IV (case series—no, or historical control group)

Functional outcomes in children with osteonecrosis secondary to treatment of developmental dysplasia of the hip.

BACKGROUND Osteonecrosis of the femoral head is a major potential complication following the treatment of developmental dysplasia of the hip. It remains unclear if the radiographic changes associated with osteonecrosis are clinically relevant. METHODS In the present cross-sectional study, we determined the relationship between morphological changes on radiographs (classified with use of the Bucholz-Ogden system) and health-related quality of life (assessed with the Health Utilities Index Mark 3 [HUI3]; maximum score, 1), physical function (assessed with the Activities Scale for Kids [ASK]; maximum score, 100), and hip function (assessed with the Childrens Hospital Oakland Hip Evaluation Scale [CHOHES]; maximum score, 100). The study group included seventy-two children (mean age, 14 ± 2.5 years) with a diagnosis of osteonecrosis of the hip secondary to the treatment of developmental dysplasia of the hip. Patient assessments were standardized (intraclass correlation coefficient, ≥0.93). Radiographs were graded by three experts according to consensus. Analyses were adjusted for the number of previous surgical procedures on the hip and for the severity of residual hip dysplasia. RESULTS The median ASK score was 97 (interquartile range, 93 to 100), the median CHOHES score was 86 (interquartile range, 77 to 96), and the median HUI3 score was 1 (interquartile range, 0.9 to 1). The ASK summary scores were nearly equal (median, >90) across all radiographic grades. Adjusted mean scores showed a downward shift with worse radiographic grades. The ASK scores (p = 0.004) and CHOHES scores (p = 0.006) differed across radiographic grades, with Bucholz-Ogden grade-I and II hips demonstrating significantly better scores than grade-III and IV hips. DISCUSSION Osteonecrosis secondary to the treatment of developmental dysplasia of the hip is a relatively benign condition in children and teenagers. While it was associated with limited hip function, it was not associated with physical disability. However, we speculate that this function will decline with increasing age. With regard to clinical outcome, Bucholz-Ogden grade-I hips are similar to grade-II hips and grade-III hips are similar to grade-IV hips.

Osteonecrosis complicating developmental dysplasia of the hip compromises subsequent acetabular remodeling.

BackgroundOsteonecrosis of the femoral head secondary to treatment of developmental dysplasia of the hip (DDH) affects acetabular remodeling but the magnitude of this effect is unclear.Questions/purposesUsing four measures of acetabular development, we (1) determined whether acetabular remodeling differed in hips with and without osteonecrosis; and (2) determined the impact of severity of osteonecrosis contributing to acetabular remodeling.MethodsWe retrospectively reviewed 95 patients (118 hips) treated for DDH by closed or open reduction with or without femoral osteotomy between 1992 and 2006. We evaluated serial radiographs from the time when a stable reduction had been achieved. In 902 radiographs taken over 19 years, we measured the acetabular index and three other indices of hip development. Patients were followed for a mean of 8 years (range, 1–19 years). At last followup, 86 of the 118 hips (73%) had osteonecrosis according to the criteria by Bucholz and Ogden.ResultsThe acetabular index improved with time in all hips but the magnitude of improvement was larger in hips without osteonecrosis. The adjusted mean acetabular index at 14 years was 17° for hips with osteonecrosis (95% CI, 15°–18°) and 10° for hips without osteonecrosis (95% CI, 7°–13°). The lateral centering ratio improved after reduction to a normal value less than 0.85 in both groups but the rate of change with 0.06 versus 0.05 was higher in hips with osteonecrosis. The superior centering ratio was worse at all times in hips with osteonecrosis with a mean difference of 0.04. If only radiographic changes of Grades II and greater were considered osteonecrosis, the mean adjusted acetabular index at 14 years was 17.7° (15.6°–19.7°) for hips with osteonecrosis and 12.4° (10.3°–14.4°) for hips without osteonecrosis.ConclusionsAlthough radiographic indices improved consistently with time in hips without osteonecrosis, hips with osteonecrosis had abnormal indices of acetabular remodeling throughout followup. Osteonecrosis of the femoral head inhibited acetabular remodeling.Level of EvidenceLevel III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Association between the ossific nucleus and osteonecrosis in treating developmental dysplasia of the Hip: updated meta-analysis

BackgroundA meta-analysis concluded that there was no effect of the femoral head ossification and the incidence of osteonecrosis in the treatment of developmental dysplasia of the hip (DDH), unless only osteonecrosis grades II-IV were considered. The meta-analysis, limited due to the small number of studies available at that time, identified a need for an update as further research emerges. We observed a trend in recent years towards delaying treatment of DDH in the absence of an ossified nucleus. Numerous new publications on this topic encouraged us to update the 2009 meta-analysis.MethodsWe performed a systematic review of the literature from 1967 to 2016 and included studies that reported on the treatment of DDH, the ossific nucleus and osteonecrosis. Two independent reviewers evaluated all articles. We performed a meta-analysis with the main outcome defined as the development of osteonecrosis of the femoral head at least two years after closed or open reduction.ResultsOf four prospective and ten retrospective studies included in the systematic review, 11 studies (1,021 hips) met the inclusion criteria for the meta-analysis. There was no significant effect of the ossific nucleus on the development of all grades of osteonecrosis (relative risk, 0.88; 95% confidence interval, 0.56–1.41) or osteonecrosis grades II–IV (0.67; 0.41–1.08). In closed reductions, the ossific nucleus halved the risk for developing osteonecrosis grades II–IV (0.50; 0.26–0.94).ConclusionsBased on current evidence there does not appear to be a protective effect of the ossific nucleus on the development of osteonecrosis. In contrast to the previous meta-analysis, this update demonstrates that this remains the case irrespective of the grade of osteonecrosis considered relevant. This updated meta-analysis is based on twice as many studies with a higher quality of evidence.

Weighted Diagnostic Criteria for Developmental Dysplasia of the Hip

OBJECTIVE To establish clinical diagnostic criteria for developmental dysplasia of the hip (DDH) that model the practices of expert clinicians. STUDY DESIGN Of 23 clinical criteria for the diagnosis of DDH, ranked in order of diagnostic importance by international consensus, the 7 most highly ranked were placed in all possible combinations to create unique case vignettes. Twenty-six experts rated 52 vignettes for the presence of DDH. We modeled the data to determine which of the 7 criteria were associated with a clinicians opinion that the vignette represented DDH. From the resulting regression coefficients, for each vignette we calculated a probability of DDH. An independent panel rated the same vignettes using a visual analog scale response. We correlated the visual analog scale ratings with probabilities derived from the model. RESULTS Our model identified 4 of 7 criteria as predictive of DDH (P < .001): Ortolani/Barlow test (β = 3.26), limited abduction (β = 1.48), leg length discrepancy (β = 0.74), and first-degree family history of DDH (β = 1.39). There was substantial correlation between the probability of DDH predicted by the model and that derived from an independent expert panel (r = 0.73; P < .001). CONCLUSION Weighted clinical criteria for inferring the likelihood of DDH produced consistent results in the judgment of 2 separate groups of experts. Using these weights, nonexperts could establish the probability of DDH in a manner approaching the practice of clinical experts.

The Genetic Epidemiology of Developmental Dysplasia of the Hip: A Genome-Wide Association Study Harnessing National Clinical Audit Data

Background Developmental dysplasia of the hip (DDH) is a common, heritable condition characterised by abnormal formation of the hip joint, but has a poorly understood genetic architecture due to small sample sizes. We apply a novel case-ascertainment approach using national clinical audit (NCA) data to conduct the largest DDH genome-wide association study (GWAS) to date, and replicate our findings in independent cohorts. Methods We used the English National Joint Registry (NJR) dataset to collect DNA and conducted a GWAS in 770 DDH cases and 3364 controls. We tested the variant most strongly associated with DDH in independent replication cohorts comprising 1129 patients and 4652 controls. Results The heritable component of DDH attributable to common variants was 55% and distributed similarly across autosomal and the X-chromosomes. Variation within the GDF5 gene promoter was strongly and reproducibly associated with DDH (rs143384, OR 1.44 [95% CI 1.34-1.56], p=3.55x10−22). Two further replicating loci showed suggestive association with DDH near NFIB (rs4740554, OR 1.30 [95% CI 1.16-1.45], p=4.44x10−6) and LOXL4 (rs4919218, 1.19 [1.10-1.28] p=4.38x10−6). Through gene-based enrichment we identify GDF5, UQCC1, MMP24, RETSAT and PDRG1 association with DDH (p<1.2x10−7). Using the UK Biobank and arcOGEN cohorts to generate polygenic risk scores we find that risk alleles for hip osteoarthritis explain <0.5% of the variance in DDH susceptibility. Conclusion Using the NJR as a proof-of-principle, we describe the genetic architecture of DDH and identify several candidate intervention loci and demonstrate a scalable recruitment strategy for genetic studies that is transferrable to other complex diseases. Key Messages We report the first genome-wide scan for DDH in a European population, and the first to use national clinical audit data for case-ascertainment in complex disease. The heritable component of DDH attributable to common variants is 55% and is distributed similarly across autosomal and the X-chromosomes. Variation within the GDF5 gene promoter is strongly and reproducibly associated with DDH, with fine-mapping indicating rs143384 as the likely casual variant. Enrichment analyses implicate GDF5, UQCC1, MMP24, RETSAT and PDRG1 as candidate targets for intervention in DDH. DDH shares little common genetic aetiology with idiopathic osteoarthritis of the hip, despite sharing variation within the GDF5 promoter as a common risk factor.