Inter-observer reliability of the Stulberg classification in the assessment of Perthes disease

Long-Term Outcomes at Skeletal Maturity of Combined Pelvic and Femoral Osteotomy for the Treatment of Legg-Calve-Perthes Disease

Surgical treatment for Legg-Calve-Perthes disease (LCPD) is recommended for older children with moderate to severe disease. We sought to determine whether double osteotomies lead to improved radiologic outcomes compared to reported non-operative outcomes. Patients older than 6 years of age diagnosed with LCPD lateral pillar B or C who were treated with pelvic and femoral osteotomies were included. Radiologic outcomes and leg-length discrepancies were assessed using the Stulberg classification and were compared with the current literature. Fifteen hips in fourteen patients were treated with double osteotomy for LCPD, and seven had lateral pillar C disease (47%). The mean age at surgery was 8.6 years (range, 7.2-10.4) and the mean age at follow-up was 20.2 years (range, 14.2-35.6). At a mean 11.6-year follow-up (range: 6.3-25.2), double osteotomy resulted in 40% of patients having Stulberg I/II scores, 27% having Stulberg III scores, and 33% having Stulberg IV/V scores. The mean leg-length discrepancy was 1.4 cm in lateral pillar C patients compared to 0.8 cm in lateral pillar B patients. Four patients underwent additional surgeries, including two who required total hip arthroplasty. Double osteotomy as an alternative surgical procedure for the treatment of LCPD did not show improved outcomes when compared to historic non-operative cohorts.

Radiological hip shape and patient-reported outcome measures in healed Perthes' disease

Aims

This study aimed to evaluate the relationship between hip shape and mid-term function in Perthes' disease. It also explored whether the modified three-group Stulberg classification can offer similar prognostic information to the five-group system.

Methods

A total of 136 individuals aged 12 years or older who had Perthes' disease in childhood completed the Patient-Reported Outcomes Measurement Information System (PROMIS) Mobility score (function), Nonarthritic Hip Score (NAHS) (function), EuroQol five-dimension five-level questionnaire (EQ-5D-5L) score (quality of life), and the numeric rating scale for pain (NRS). The Stulberg class of the participants' hip radiographs were evaluated by three fellowship-trained paediatric orthopaedic surgeons. Hip shape and Stulberg class were compared to PROM scores.

Results

A spherical hip was associated with the highest function and quality of life, and lowest pain. Conversely, aspherical hips exhibited the lowest functional scores and highest pain. The association between worsening Stulberg class (i.e. greater deviation from sphericity) and worse outcome persisted after adjustment for age and sex in relation to PROMIS (predicted mean difference -1.77 (95% confidence interval (CI) -2.70 to -0.83)), NAHS (-5.68 (95% CI -8.45 to -2.90)), and NRS (0.61 (95% CI 0.14 to 1.08)), but not EQ-5D-5L (-0.03 (95% CI -0.72 to 0.11)).

Conclusion

Patient-reported outcomes identify lower function, quality of life, and higher pain in aspherical hips. The magnitude of symptoms deteriorated with time. Hip sphericity (i.e. the modified three-group classification of spherical, oval, and aspherical) appeared to offer similar levels of detail to the five-group Stulberg classification.

The modified Stulberg classification is a strong predictor of the radiological outcome 20 years after the diagnosis of Perthes' disease

AIMS

The aim of this study was to assess the prognostic value of the modified three-group Stulberg classification, which is based on the sphericity of the femoral head, in patients with Perthes' disease.

METHODS

A total of 88 patients were followed from the time of diagnosis until a mean follow-up of 21 years. Anteroposterior pelvic and frog-leg lateral radiographs were obtained at diagnosis and at follow-up of one, five, and 21 years. At the five- and 21-year follow-up, the femoral heads were classified using a modified three-group Stulberg classification (round, ovoid, or flat femoral head). Further radiological endpoints at long-term follow-up were osteoarthritis (OA) of the hip and the requirement for total hip arthroplasty (THA).

RESULTS

There were 71 males (81%) and 17 females. A total of 13 patients had bilateral Perthes' disease; thus 101 hips were analyzed. At five-year follow-up, 37 hips were round, 38 ovoid, and 26 flat. At that time, 66 hips (65%) were healed and 91 (90%) were skeletally immature. At long-term follow-up, when the mean age of the patients was 28 years (24 to 34), 20 hips had an unsatisfactory outcome (seven had OA and 13 had required THA). There was a strongly significant association between the modified Stulberg classification applied atfive-year follow-up and an unsatisfactory outcome at long-term follow-up (p < 0.001). Between the five- and 21-year follow-up, 67 hips (76%) stayed in their respective modified Stulberg group, indicating a strongly significant association between the Stulberg classifications at these follow-ups (p < 0.001).

CONCLUSION

The modified Stulberg classification is a strong predictor of long-term radiological outcome in patients with Perthes' disease. It can be applied at the healing stage, which is usually reached five years after the diagnosis is made and before skeletal maturity. Cite this article: Bone Joint J 2021;103-B(12):1815-1820.

Leg length discrepancy in patients with Perthes' disease : a note of caution for the arthroplasty surgeon

AIMS

Perthes' disease (PD) often results in femoral head deformity and leg length discrepancy (LLD). Our objective was to analyze femoral morphology in PD patients at skeletal maturity to assess where the LLD originates, and evaluate the effect of contralateral epiphysiodesis for length equalization on proximal and subtrochanteric femoral lengths.

METHODS

All patients treated for PD in our institution between January 2013 and June 2020 were reviewed retrospectively. Patients with unilateral PD, LLD of ≥ 5 mm, and long-leg standing radiographs at skeletal maturity were included. Total leg length, femoral and tibial length, articulotrochanteric distance (ATD), and subtrochanteric femoral length were compared between PD side and the unaffected side. Furthermore, we compared leg length measurements between patients who did and who did not have a contralateral epiphysiodesis.

RESULTS

Overall, 79 patients were included, of whom 21 underwent contralateral epiphysiodesis for leg length correction. In the complete cohort, the mean LLD was 1.8 cm (95% confidence interval (CI) 1.5 to 2.0), mean ATD difference was 1.8 cm (95% CI -2.1 to -1.9), and mean subtrochanteric difference was -0.2 cm (95% CI -0.4 to 0.1). In the epiphysiodesis group, the mean LLD before epiphysiodesis was 2.7 cm (95% CI 1.3 to 3.4) and 1.3 cm (95% CI -0.5 to 3.8) at skeletal maturity. In the nonepiphysiodesis group the mean LLD was 2.0 cm (95% CI 0.5 to 5.1; p = 0.016). The subtrochanteric region on the PD side was significantly longer at skeletal maturity in the epiphysiodesis group compared to the nonepiphysiodesis group (-1.0 cm (95% CI -2.4 to 0.6) vs 0.1 cm (95% CI -1.0 to 2.1); p < 0.001).

CONCLUSION

This study demonstrates that LLD after PD originates from the proximal segment only. In patients who had contralateral epiphysiodesis to balance leg length, this is achieved by creating a difference in subtrochanteric length. Arthroplasty surgeons need to be aware that shortening of the proximal femur segment in PD patients may be misleading, as the ipsilateral subtrochanteric length in these patients can be longer. Therefore, we strongly advise long-leg standing films for THA planning in PD patients in order to avoid inadvertently lengthening the limb. Cite this article: Bone Joint J 2021;103-B(11):1736-1741.

Asymmetrically increased femoral version with high prevalence of moderate and severe femoral anteversion in unilateral Legg-Calvé-Perthes disease

PURPOSE

To determine and stratify femoral version in Legg-Calvé-Perthes disease (LCPD), and to compare the femoral version between the LCPD hip and the contralateral unaffected hip.

METHODS

We performed a retrospective review of 45 patients with unilateral LCPD who had available CT scan through the hips and knees between January 2000 and June 2017. There were 34 (76%) male cases with a mean age of 14 years (sd 4.69). Two independent readers measured femoral version on the affected and the unaffected contralateral femur. Femoral version was classified as follows: severely decreased version (< 10°); moderately decreased (10° to 14°); normal femoral version range (15° to 20°); moderately increased (21° to 25°); and severely increased version (> 25°).

RESULTS

LCPD hips had predominantly increased femoral version (38% severely increased anteversion, 24% moderately increased anteversion), while 51% of the contralateral unaffected hips had normal femoral version (p < 0.001). LCPD hips had higher mean femoral version than the contralateral, unaffected side (mean difference = 13o; 95% confidence iterval 10o to 16o; p < 0.001). As the version of the affected hip increased, so did the discrepancy between sides. No effect of sex on the LCPD femoral version was detected (p = 0.34).

CONCLUSION

This study included a selected group of patients with unilateral LCPD and available CT scans obtained for surgical planning. The femoral version was asymmetric, with a high proportion of excessive anteversion observed at later stages of disease in the affected hips. Future studies will be necessary to determine the pathogenesis of increased femoral version associated with LCPD.

LEVEL OF EVIDENCE

Level IV, retrospective study.

The clinical and radiographic characteristics of avascular necrosis after pediatric femoral neck fracture: a systematic review and retrospective study of 115 patients

BACKGROUND

Avascular necrosis (AVN) after pediatric femoral neck fracture (PFNF) showed poor prognosis, but its clinical and radiographic characteristics remained unclear.

METHODS

A systematic review and a retrospective study were performed to evaluate the clinical and radiographic characteristics of patients with AVN after PFNF.

RESULTS

A total of 686 patients with PFNF and 203 patients with AVN from 21 articles were analyzed. Ratliff's classification was used in 178 patients, with types I, II, and III AVN accounting for 58.4%, 25.3%, and 16.3%, respectively. Ratliff's assessment was used in 147 patients, of whom 88.4% had an unsatisfactory prognosis. In retrospective study, 115 patients with a mean age of 13.6 ± 2.0 years were included. The mean interval between AVN and PFNF was 13.7 ± 9.5 months. At the time of diagnosis, 59.1% cases were symptomatic and 65.2% progressed to collapsed stage. Fifty (43.5%), 61 (53.0%), and 4 patients (3.5%) were defined as types I, II, and III , respectively, via Ratliff's classification. Thirteen (11.3%), 40 (34.8%), and 62 patients (53.9%) showed types A/B, C1, and C2 disease, respectively, via the JIC classification. Multivariate analysis demonstrated a strong relation between collapsed stage and symptomatic cases (OR = 6.25, 95% CI = 2.39-16.36) and JIC classification (OR = 3.41, 95% CI = 1.62-7.17).

CONCLUSION

AVN after PFNF showed a tendency toward extensive necrotic lesions, presumably resulting in a rapid progression of femoral head collapse. And the symptoms and the JIC classification are other two risk factors of collapse progression.

Comparison of surgical and nonsurgical containment methods for patients with Legg-Calvé-Perthes disease of the onset ages between 6.0 and 8.0 years: Salter osteotomy versus a non-weight-bearing hip flexion-abduction brace

Since bone healing potential decreases with age, patients with Legg-Calvé-Perthes disease should receive treatment appropriate to their age group. Nonsurgical treatment is commonly applied to patients under 6.0 years of age at the onset and surgical treatment is recommended for those over 8.0 years of age, but it remains unclear which is better for those between 6.0 and 8.0 years. The aim of this retrospective study was to compare outcomes of Salter osteotomy and a non-weight-bearing brace in this age group. Inclusion criteria were unilateral Legg-Calvé-Perthes disease patients who were 6.0-8.0 years of age at the onset, who had more than 50% femoral head involvement without hinge abduction, and who underwent either Salter osteotomy (n = 35) or a non-weight-bearing hip flexion-abduction brace (n = 18). Radiological and clinical outcomes at skeletal maturity were compared between the two groups. The mean follow-up durations were 9.4 years in the Salter osteotomy group and 10.0 years in the brace group. There was no significant difference in the modified Waldenström classification at the beginning of treatment and the Catterall and modified lateral pillar classifications evaluated at the fragmentation stage between the groups. At skeletal maturity, the Stulberg classification, the sphericity deviation score, femoral head overgrowth, and the articulo-trochanteric distance were similar between the groups, but the Salter osteotomy group showed significantly smaller lateralization of the femoral head and better acetabular shape and coverage than the brace group: femoral head lateralization (P < 0.001), acetabular depth-to-width ratio (P = 0.002), Sharp angle (P < 0.001), lateral acetabular shape (P = 0.027), acetabular head index (P < 0.001). There was no significant difference in hip pain and motion between the groups. In this age group, Salter osteotomy provides better femoral head position and acetabular shape and coverage than a non-weight-bearing brace.

Long-term follow-up results of femoral varus osteotomy in the treatment of Perthes disease, and comparison of open-wedge and closed-wedge osteotomy techniques: A retrospective observational study

In this retrospective observational study, I aimed to report long-term follow-up results of femoral varus osteotomy in the treatment of Perthes disease patients who were between 6 and 8 years old at the onset of the disease with Herring B and C hip involvement. I also aimed to compare 2 different osteotomy techniques: open-wedge and closed-wedge femoral varus osteotomies.Patients with Perthes disease treated with femoral varus osteotomies were invited for final examination. Twenty two hips of 19 patients were evaluated. Mean follow-up period was 15.2 years. Patients were divided into 2 homogenous groups according to femoral osteotomy technique. In Group A (12 hips) open-wedge osteotomy, and in Group B (10 hips) closed-wedge osteotomy was performed.There were 15 male (78.9%) and 4 female (21.1%) patients. The median age at the onset of the disease was 7 years in Group A and B. The mean follow-up period was 16.2 years in Group A, and 11.4 years in Group B. According to Stulberg classification 5 hips (22.7%) were healed as Class I, 4 hips (18.2%) were healed as Class II, 12 hips (55.5%) were healed as Class III, and 1 hip (4.6%) was healed as Class IV. Also in Group A 4 hips (33.3%) were healed as Class I or II, 7 hips (58.3%) were healed as Class III, and 1 hip (8.3%) was healed as Class IV; in Group B 5 hips (50.0%) were healed as Class I or II, and 5 hips were healed as Class III (50.0%). There was no significant difference between the groups. According to Iowa scale, mean values were 92.6 in Group A and 92.4 in Group B. There was no significant difference between the groups. At the final follow-up mean center-edge angles of Group A and B were 16 and 22, the difference was significant.Long-term follow-up results showed that femoral varus osteotomy was an effective treatment method in Perthes disease patients who were between 6 and 8 years old with Herring B and C hip involvement at the onset of the disease. Hip joint congruency was obtained with femoral varus osteotomies, and closed-wedge osteotomy served more favorable center-edge angle results.

Outcome of the modified Dunn procedure in severe chronic or acute on chronic slipped capital femoral epiphysis

Background

In recent years, the modified Dunn osteotomy has gained popularity to treat slipped capital femoral epiphysis (SCFE) with various complication rates. Most studies included patients with different severities. This study aimed to determine (1) the radiological and clinical outcome, (2) the health-related quality of life, and (3) the incidence of avascular necrosis of the femoral head (AVN) in patients with severe chronic or acute on chronic SCFE treated by the modified Dunn procedure.

Methods

Out of 150 patients with SCFE treated at our institution between 2001 and 2014, 15 patients (mean age 12.9 years (range 11.8–15)) were treated by the modified Dunn procedure. Eight SCFE were chronic and 7 acute on chronic. All slips were severe with a mean Southwick slip angle (SSA) of 67° (range 60–80). Radiographic and clinical outcomes were measured. Mean time of follow-up was 3.8 years (range 1–10).

Results

Anatomical reduction was achieved in all cases. Good radiological results according to the Stulberg Classification (grade 1 + 2) and the Sphericity Deviation Score (< 30) were found in 9 out of 13 patients at the last follow-up. Clinical and functional outcome analysis revealed good results in 8 out of 10 patients (Harris Hip Score > 80). The quality of life measured by the Nottingham Health Profile (NHP) was described good in 10 out of 10 patients. Four out of 15 patients developed an AVN.

Conclusions

The modified Dunn procedure has a great potential to restore proximal femur geometry in severe chronic or acute on chronic SCFE. It should be considered only if there is no other possibility to restore proximal femur geometry, as is the case in severe slips, due to the risk of AVN.

Agreement of radiographic measurements and patient-reported outcome in 61 patients with Legg-Calvé-Perthes disease at mean follow-up of 28 years

It is unclear how patient-reported outcome in patients with Legg-Calvé-Perthes disease (LCPD) is correlated with radiographic outcome. It was therefore the aim of our long-term follow-up to evaluate the agreement of patient-reported outcome measures (PROM) with radiographic outcome in patients with a history of unilateral LCPD and a femoral head involvement of more than 50%. We further investigated to what extent the functional outcome (range of motion and Trendelenburg sign) correlates with PROM and radiographic outcome. At a mean follow-up of 28 years (15-42), 61 patients were investigated clinically and by plain radiography to evaluate the sphericity deviation score, femoral head enlargement and femoral neck growth inhibition. The patients also completed questionnaires for generic measures of health-related quality-of-life (ED-5D, EQ-visual analogue scale), the joint-specific Harris hip score and the nonarthritic hip score questionnaire. The radiographic measures sphericity deviation score, femoral head enlargement and femoral neck growth inhibition were strongly correlated with the joint-specific PROMs (Harris hip score and nonarthritic hip score) but not with EQ-5D and EQ-visual analogue scale. Inferior range of flexion and abduction and a positive Trendelenburg sign were associated with an inferior patient-reported outcome. Our findings highlight the importance of supporting femoral head re-modelling and containment and balancing trochanteric and femoral neck growth in patients with LCPD. To capture the whole picture of the outcome after LCPD, future studies should include a combination of radiographic measurements and joint-specific and generic outcome scores. Level of Evidence: Level III.

The Pathogenesis and Treatment of Legg-Calvé-Perthes Disease

Legg-Calvé-Perthes disease is a childhood hip condition in which the blood supply to the capital femoral epiphysis is interrupted, causing osteonecrosis and chondronecrosis that lead to progressive deformity of the femoral head and secondary degenerative osteoarthritis in later life. The etiology of Legg-Calvé-Perthes disease remains unclear, with both biological and mechanical factors playing important roles in the pathogenesis of the condition. The treatment of Legg-Calvé-Perthes disease remains controversial but is dependent on several salient factors, including the age at clinical onset, the extent of epiphyseal involvement, the stage of the disease, and the degree of femoral head deformity. The literature supports operative containment treatment in the early stage of disease. Such treatment has led to improved femoral head sphericity with better patient outcomes in multicenter prospective cohort studies. The number of hips that need to be treated operatively in order to achieve a modest treatment effect remains high. Multicenter prospective cohort studies have shown that 6 to 7 patients need to be managed to create 1 spherical femoral head that would not have otherwise occurred.

Radiographic classifications in Perthes disease

Background and purpose - Different radiographic classifications have been proposed for prediction of outcome in Perthes disease. We assessed whether the modified lateral pillar classification would provide more reliable interobserver agreement and prognostic value compared with the original lateral pillar classification and the Catterall classification. Patients and methods - 42 patients (38 boys) with Perthes disease were included in the interobserver study. Their mean age at diagnosis was 6.5 (3-11) years. 5 observers classified the radiographs in 2 separate sessions according to the Catterall classification, the original and the modified lateral pillar classifications. Interobserver agreement was analysed using weighted kappa statistics. We assessed the associations between the classifications and femoral head sphericity at 5-year follow-up in 37 non-operatively treated patients in a crosstable analysis (Gamma statistics for ordinal variables, γ). Results - The original lateral pillar and Catterall classifications showed moderate interobserver agreement (kappa 0.49 and 0.43, respectively) while the modified lateral pillar classification had fair agreement (kappa 0.40). The original lateral pillar classification was strongly associated with the 5-year radiographic outcome, with a mean γ correlation coefficient of 0.75 (95% CI: 0.61-0.95) among the 5 observers. The modified lateral pillar and Catterall classifications showed moderate associations (mean γ correlation coefficient 0.55 [95% CI: 0.38-0.66] and 0.64 [95% CI: 0.57-0.72], respectively). Interpretation - The Catterall classification and the original lateral pillar classification had sufficient interobserver agreement and association to late radiographic outcome to be suitable for clinical use. Adding the borderline B/C group did not increase the interobserver agreement or prognostic value of the original lateral pillar classification.

The outcome and prognostic factors in children with bilateral Perthes' disease: a prospective study of 40 children with follow-up over five years

AIMS

The aims of this study were to describe the course of non-operatively managed, bilateral Perthes' disease, and to determine specific prognostic factors for the radiographic and clinical outcome.

PATIENTS AND METHODS

We identified 40 children with a mean age of 5.9 years (1.8 to 13.5), who were managed non-operatively for bilateral Perthes' disease from our prospective, multicentre study of this condition, which included all children in Norway who were diagnosed with Perthes' disease in the five-year period between 1996 and 2000. All children were followed up for five years. The hips were classified according to the Catterall classification. A modified three-group Stulberg classification was used as an outcome measure, with a spherical femoral head being defined as a good outcome, an oval head as fair, and a flat femoral head as a poor outcome.

RESULTS

Concurrent, simultaneous bilateral Perthes' disease was seen in 23 children and 17 had the sequential onset of bilateral disease. The mean delay in onset for the second hip in the latter group was 1.9 years (0.3 to 5.5). The five-year radiographic outcome was good in 30 (39%), fair in 25 (33%) and poor in 21 (28%) of the hips. The strongest predictors of poor outcome were > 50% necrosis of the femoral head, with odds ratio (OR) 19.6, and age at diagnosis > 6 years (OR 3.3). Other risk factors for poor outcome were the timing of the onset of disease, where children with the sequential onset of bilateral disease had a higher risk than those with the concurrent onset of bilateral disease (p = 0.021, chi-squared test). Following a diagnosis of Perthes' disease in one hip, there was a 5% chance of developing it in the contralateral hip.

CONCLUSION

These results imply that we need to distinguish between children with concurrent onset and those with sequential onset of bilateral Perthes' disease, as the outcomes may be different. This has not been previously described. Children with concurrent onset of bilateral disease had a similar outcome to our previous series of those with unilateral disease, whereas children with sequential onset of bilateral disease had a worse prognosis. The increased risk of developing Perthes' disease in the contralateral hip in those with unilateral disease is important information for the child and parents.

Skeletal immaturity, rostral sparing, and disparate hip morphologies as biomechanical causes for Legg-Calvé-Perthes' disease

Legg-Calvé-Perthes' (Perthes') disease is a developmental disease of the hip joint that may result in numerous short and long term problems. The etiology of the disease remains largely unknown, but the mechanism is believed to be vascular and/or biomechanical in nature. There are several anatomical characteristics that tend to be prevalent in children with Perthes' disease, namely: skeletal immaturity, reduced height, and rostral sparing. We present an overview of the literature, summarizing the current understanding of the pathogenesis, particularly related to how the formation of the vasculature to the femoral epiphysis places children aged 5-8 at a higher risk for Perthes' disease, how skeletal immaturity and rostral sparing could increase the probability of developing Perthes' disease, and how animal models have aided our understanding of the disease. In doing so, we also explore why Perthes' disease is correlated to latitude, with populations at higher latitudes having higher incidence rates than populations closer to the Equator. Finally, we present five hypotheses detailing how Perthes' disease could have a biomechanical cause. Clin. Anat. 29:759-772, 2016. © 2016 Wiley Periodicals, Inc.

The presentation of Legg-Calvé-Perthes disease in females

PURPOSE

Legg-Calvé-Perthes disease (LCPD) is uncommon in girls. The presentation of LCPD in female patients has been reported as later in onset and associated with certain high-impact activities. Our aim is to characterize the presentation of female LCPD at a large center, with particular attention to the clinical and radiographic features of late-onset disease (>ten years of age). We perceived an increasing burden of late-onset disease with adult-like radiographic features.

METHODS

All patients presenting to a single large urban children's hospital from 1990-2014 with a diagnosis of LCPD were reviewed. Demographic, clinical, and radiographic data for all female patients were examined and compared to historical norms.

RESULTS

Four-hundred and fifty-one patients presented with LCPD in the study period, of which 82 (18.2 %) were female. The average age at presentation was 6.58 years in girls, which is similar to the classically reported mean age. Fourteen patients participated in high-impact repetitive activities or those with deep flexion and abduction, although few were late presenters. There were four female patients who presented for initial diagnosis >ten years of age.

CONCLUSIONS

There was a paucity of late-onset LCPD in girls in the study population, and the females with LCPD had a very similar age and character to their presentation as did males. Although their presentation is infrequent, three of four older females with LCPD were engaged in high-level physical activity, and their disease may be attributed to high-impact, repetitive athletics.

LEVEL OF EVIDENCE

Case series, Level IV.

Rotational open-wedge osteotomy improves treatment outcomes for patients older than eight years with Legg-Calve-Perthes disease in the modified lateral pillar B/C border or C group

PURPOSE

Since 2003, we have been performing rotational open-wedge osteotomy (ROWO) for older children with severe Legg-Calve-Perthes disease (LCPD). We compared the treatment outcomes before and after the introduction of ROWO for patients aged ≥ eight years, classified in the modified lateral pillar B/C border or C group.

METHODS

Before the introduction of ROWO, conservative treatment (non-weight bearing [NWB]) was performed for all cases between 1986 and 2002, whereby there were 34 hips (NWB group). The median patient age, at the first visit, was 9.1 years. According to the lateral pillar classification, 21 hips were categorized into the B/C border group and the others into the C group. Meanwhile, 14 consecutive hips underwent ROWO combined with NWB between 2003 and 2008 (ROWO+NWB group). The median patient age, at the first visit, was 9.1 years. Six hips were in the lateral pillar B/C border group and the others were classified into the C group. There were no significant differences in pre-treatment patients' demographic data.

RESULTS

At the latest follow-up, according to the Stulberg classification, there were 19 class II hips, 13 class III hips, and two class IV hips in the NWB group. In the ROWO+NWB group, there were 12 class II hips, two class III hips, and no class IV hips.

CONCLUSIONS

The application of ROWO combined with NWB in the treatment of older children with severe LCPD improved their outcomes, compared to those obtained by NWB treatment alone.

Shelf acetabuloplasty for containment in the early stages of Legg-Calve-Perthes disease

BACKGROUND

To evaluate the effectiveness of shelf acetabuloplasty in the containment of extruded hips without hinge abduction in early stages of Legg-Calve-Perthes disease, we present a retrospective series of 44 patients (45 hips) treated between August 1999 and February 2010, which included 34 boys and 10 girls with a mean age at diagnosis of 7.4 years (range, 3.9 to 15.3).

METHODS

All patients presented with sclerosis or early fragmentation stages. The average time from diagnosis to surgery was 2.1 months (range, 0 to 8.2) and the mean time to heal was 40.4 months (range, 20 to 82.2). The Reimer migration and the deformity indices were measured on initial, preoperative, postoperative, and healed x-rays. The average deformity index at 3 of those 4 timepoints was significantly related to their final Stulberg classification. CE angles increased and Sharp angles decreased significantly as a result of treatment.

RESULTS

At the healed stage and consistent with other published series, 84.4% of patients were Stulberg III or less, denying any pain, and with full range of movement, whereas 15.6% were classified as Stulberg IV.

CONCLUSIONS

We defend that shelf acetabuloplasty should be performed early in the disease and, uniquely, we propose that the indication for treatment should be guided by the deformity and the Reimer migration indices.

LEVEL OF EVIDENCE

IV.

The acetabulum in Perthes' disease: a prospective study of 123 children

PURPOSE

We assessed the radiographic changes of the acetabulum during the course of Perthes' disease and investigated whether they were associated with femoral head sphericity 5 years after diagnosis.

METHODS

We studied 123 children with unilateral Perthes' disease, femoral head necrosis more than 50 % and age at diagnosis 6 years or older. Pelvic radiographs were taken at onset, 1 year and 5 years after diagnosis. Sharp's angle, acetabular depth-to-width ratio (ADR) and lateral acetabular inclination were measured.

RESULTS

Compared to the unaffected hips, the Perthes' hips developed significantly higher Sharp's angles (p < 0.001) and a higher proportion with an upward-sloping lateral acetabular margin (Perthes' hips: 49 %, unaffected hips 1 %). The mean ADR values were significantly lower on the affected side at all stages (p < 0.001). ADR values at diagnosis were associated with a more spherical femoral head at the 5-year follow-up [odds ratio (OR) 1.012, 95 % confidence interval (CI) 1.002-1.022, p = 0.016]. None of the other acetabular parameters were significantly associated with the femoral head shape 5 years after diagnosis.

CONCLUSION

The acetabulum developed an increasingly dysplastic shape in the course of Perthes' disease. Early dysplastic changes of the acetabulum were not associated with a poor radiological outcome 5 years after diagnosis. Routine measurement and monitoring of acetabular changes in plain radiographs were of little prognostic value and can, therefore, hardly be recommended in clinical practice.

Unfavorable hip stress distribution after Legg-Calvé-Perthes syndrome: a 25-year follow-up of 135 hips

To study the effect of hip and pelvis geometry on development of the hip after Perthes disease, we determined the resultant hip force and contact hip stress distribution in a population of 135 adult hips of patients who had been treated for Perthes disease in childhood. Contra-lateral hips with no record of disease were taken as the control population. Biomechanical parameters were determined by mathematical models for resultant hip force in one-legged stance and for contact hip stress, which use as an input the geometrical parameters assessed from anteroposterior radiographs. The mathematical model for stress was upgraded to account for the deviation of the femoral head shape from spherical. No differences were found in resultant hip force and in peak contact hip stress between the hips that were in childhood subject to Perthes disease and the control population, but a considerable (148%) and significant (p < 0.001) difference was found in the contact hip stress gradient index, expressing an unfavorable, steep decrease of contact stress at the lateral acetabular rim. This finding indicates an increased risk of early coxarthritis in hips subject to Perthes disease.

Varus femoral osteotomy improves sphericity of the femoral head in older children with severe form of Legg-Calvé-Perthes disease

BACKGROUND

In the Norwegian prospective study on Legg-Calvé-Perthes disease (LCPD), we found varus femoral osteotomy gave better femoral head sphericity at a mean of 5 years postoperative than physiotherapy in children older than 6.0 years at diagnosis with femoral head necrosis of more than 50%. That study did not include separate analyses for hips with 100% necrosis and those with a percentage of necrosis between 50% and 100%.

QUESTIONS/PURPOSES

We asked whether (1) femoral osteotomy improves femoral head sphericity at followup in all patients with more than 50% femoral head necrosis or in selected groups only and (2) there is a critical age between 6.0 and 10.0 years over which femoral osteotomy does not improve the prognosis.

METHODS

We treated 70 patients with unilateral LCPD, age at diagnosis of more than 6.0 years, and femoral head necrosis of more than 50% with varus femoral osteotomy between 1996 and 2000. We classified necrosis using the Catterall classification. We established a control group of 51 similar children who received physiotherapy. At the 5-year followup visit, the hips were graded according to femoral head shape: spherical, ovoid, or flat.

RESULTS

At 5-year followup, there was no difference between the treatment groups in radiographic outcome in Catterall Group 3 hips. In Catterall Group 4 hips, femoral head sphericity was better in the osteotomy group, with flat femoral heads in 14% compared to 75% after physiotherapy. The same trend toward better head sphericity occurred when the lateral pillar classification was used.

CONCLUSIONS

In children aged 6.0 to 10.0 years, in whom the whole femoral head is affected, femoral head sphericity 5 years after femoral osteotomy was better than that after physiotherapy.

Low early failure rates using a surgical dislocation approach in healed Legg-Calvé-Perthes disease

BACKGROUND

Hip deformity secondary to Legg-Calvé Perthes disease (LCPD) may result in femoroacetabular impingement (FAI) and ultimately osteoarthritis. Observations made with the surgical hip dislocation approach have improved our understanding of the pathologic mechanics of FAI. However, owing to concerns about complications related to the vascularity, the role of surgical hip dislocation in the treatment of healed LCPD remains controversial.

QUESTIONS/PURPOSES

We present an algorithm to treat deformities associated with healed LCPD and asked (1) whether femoral head-neck osteochondroplasty and other procedures performed with the surgical hip dislocation approach provide short-term clinical improvement; and (2) is the complication rate low enough to be acceptable.

METHODS

We retrospectively reviewed 29 patients (19 males, 10 females; mean age, 17 years; range, 9-35 years) with symptomatic LCPD between 2001 and 2009. All patients underwent a surgical hip dislocation approach and femoral head-neck osteochondroplasty and 26 patients had 37 additional procedures performed. Clinical improvement was assessed using the WOMAC index. The minimum followup was 12 months (mean, 3 years; range, 12-70 months).

RESULTS

WOMAC scores improved at final followup (8 to 4 for pain, 21 to 13 for function, and 4 to 2 for the stiffness subscales). No patients had osteonecrosis, implant failure, deep infection, or nonunion. Three patients underwent THA at 1, 3, and 6 years after their index procedure.

CONCLUSIONS

Using the surgical hip dislocation approach as a tool to dynamically inspect the hip for causes of FAI, we were able to perform a variety of procedures to treat the complex deformities of healed LCPD. In the short term, we found improvement in WOMAC scores with a low complication rate.

Osteochondral mosaicplasty of the femoral head

Young adults with osteochondral lesions of the femoral head are at risk of rapid progression to symptomatic arthritis of the hip joint. Between January 2008 and July 2009, 10 patients were treated for femoral cartilage damage by a osteochondral mosaicplasty of the femoral head through a trochanteric flap with dislocation of the hip. The consecutive series had the following exclusion criteria: acetabular chondropathy, age above 25 years, and femoral head osteonecrosis. Patients were followed up after surgery using the Oxford-12 score, Harris hip score and the Merle d'Aubigné score, and activity assessed by the UCLA and Devane scores. Radiological evaluation by computed tomographic (CT) arthrography was undertaken in all patients at 6 months and plain radiographs. Mean follow-up was 29.2 months (20-39 months). The Postel Merle d'Aubigné score improved from the pre-operative period to the latest follow-up, from 10.5 points (8-13) to 15.5 points (12-17). Global range of motion increased from 175.4° (140-215) to 210.7° (175-240). All radiological investigations at latest follow-up showed that the autograft plugs were well-incorporated at the site of osteochondroplasty in the femoral head with intact cartilage over them and smooth interfaces between articulating bony surfaces. Osteochondral autograft transplantation may be a new alternative option for osteochondral lesions of the femoral head, but this has to be confirmed with longer follow-up and in a larger number of patients. The results of similar surgery in the knee have been mixed, and in the hip the technique is demanding, requiring familiarity with surgical hip dislocation.

Pathophysiology, classifications, and natural history of Perthes disease

Since the original reports of Legg-Calvé-Perthes disease (LCPD), much research effort has been undertaken to improve understanding of this idiopathic hip disorder. This article focuses on the current knowledge of the pathophysiology, classifications, and natural history of LCPD. Although the cause of LCPD remains largely unknown, some insight has been gained on its pathophysiology through experimental studies using animal models of ischemic necrosis. The few available clinical studies on the natural history of LCPD suggest that femoral head deformity is well tolerated in short and intermediate terms, but 50% of patients develop disabling arthritis in the sixth decade of life.

[Legg-Calvé-Perthes disease]

BACKGROUND

Legg-Calvé-Perthes disease is characterized by avascular necrosis of the head of the femur. This article deals with the epidemiology, possible causes, treatment and prognostic factors connected with the disease.

MATERIAL AND METHOD

The article is based on a non-systematic literature search and own clinical practice, with special emphasis on a Norwegian countrywide study of children with Legg-Calvé-Perthes disease.

RESULTS

The incidence of Legg-Calvé-Perthes disease varies in different countries and regions. Those who are older than six years at the time of diagnosis and have over 50% femoral head necrosis have a worse prognosis than younger children where the necrosis is less extensive. Treatment has been discussed extensively over the past 100 years, and still varies considerably. The Norwegian countrywide investigation showed that the results in children who were over six years at the time of diagnosis and had more than 50% femoral head necrosis were significantly better after varus femoral osteotomy than after physiotherapy or orthosis. This agrees with the only other prospective study that has been published.

INTERPRETATION

Operative treatment should be considered in children who are six years old or older and have over 50% femoral head necrosis when the diagnosis Legg-Calvé-Perthes disease is made. Those who are younger than six years at the time of diagnosis or who have less than 50% femoral head necrosis should be treated symptomatically. Abduction orthosis has no place in the treatment of Legg-Calvé-Perthes disease.

Treatment outcome in the most severely affected Legg-Perthes patients, comparing prolonged traction in abduction with femoral varus derotation treatment

PURPOSE

Compare conservative and operative treatment in the most severely affected Legg-Perthes disease patients.

METHODS

29 patients (14 conservative and 15 operative) with 32 affected hips (16 conservative and 16 operative) were evaluated, all Catterall 3 or 4. The conservative group, with a median age-at-onset of 4.8 (range, 2.5-9.5) years, was treated by a rigorous regime of traction in abduction for an average of two years. Follow-up was performed at a median of 28.6 (range, 17.4-31.6) years with a median patient age of 34.1 (range, 19.9-39.3) years. The operative group, with a median age-at-onset of 4.7 (range, 2.0-7.8) years, was treated by femoral varus derotation osteotomy. Follow-up was performed at a median of 14 (range, 8-21.4) years, with a median patient age of 20.7 (range, 12.8-28) years.

RESULTS

Median age-at-onset (P = 0.16) and Catterall classification (P = 0.29) were comparable. No differences could be found for the Stulberg classification (P = 0.83), functional parameters (Harris Hip score and Merle d'Aubigné and Postel), and leg-length differences. Career choices were similar for both patient groups, as well.

CONCLUSIONS

Given methodological issues, femoral varus derotation osteotomy did not show apparent better results than the conservative containment regime in Catterall 3 and 4 patients with a median age-at-onset around 4.8 years. This result is fairly similar to recent literature suggesting a conservative approach in most severely affected patients with a young age-at-onset. However, based on unacceptable socioeconomic issues, the conservative regime evaluated in the present study cannot be justified, nowadays.

Prognostic value of modified lateral pillar classification in Legg-Calvé-Perthes disease

Background

To evaluate the usefulness of the modified lateral pillar classification as a prognostic factor in Legg-Calvé-Perthes disease (LCPD).

Methods

Thirty nine patients diagnosed with lateral pillar C in LCPD from May, 1977, to October, 2001 were reviewed, and their skeletal maturity was followed. The mean follow up duration was 12 years and 7 months (4 years, 6 months to 24 years, 9 months). Lateral pillar C classification was divided into C1 (50-75% collapse of the lateral pillar) and C2 (> 75%). All radiological and clinical prognostic factors were evaluated. The final results were evaluated according to the Stulberg classification.

Results

Twenty one and 18 of the affected hips were in groups C1 and C2, respectively. According to the Stulberg classification, the final results of group C1 were better than those of C2 (p = 0.002). Patients with more head-at-risk signs had significantly poorer outcomes.

Conclusions

The modified lateral pillar classification has significant value for predicting the prognosis of LCPD.

Prognostic factors and outcome of treatment in Perthes' disease: a prospective study of 368 patients with five-year follow-up

This nationwide prospective study was designed to determine prognostic factors and evaluate the outcome of different treatments of Perthes' disease. A total of 28 hospitals in Norway were instructed to report all new cases of Perthes' disease over a period of five years and 425 patients were reported and followed for five years. Of these, 368 with unilateral disease were included in the present study. The hips were classified radiologically according to a modified two-group Catterall classification and the lateral pillar classification. A total of 358 patients (97%) attended the five-year follow-up, when a modified three-group Stulberg classification was used as a radiological outcome measure. For patients over six years of age at diagnosis and with more than 50% necrosis of the femoral head (152 patients), the surgeons at the different hospitals had chosen one of three methods of treatment: physiotherapy (55 patients), the Scottish Rite abduction orthosis (26), and proximal femoral varus osteotomy (71). Of these hips, 146 (96%) were available for the five-year follow-up. The strongest predictor of outcome was femoral head involvement of more or less than 50% (odds ratio (OR) = 7.76, 95% confidence interval (CI) 2.82 to 21.37), followed by age at diagnosis (OR = 0.98, 95% CI 0.92 to 0.99) and the lateral pillar classification (OR = 0.62, 95% CI 0.40 to 0.98). In children over six years at diagnosis with more than 50% of femoral head necrosis, proximal femoral varus osteotomy gave a significantly better outcome than orthosis (p = 0.001) or physiotherapy (p = 0.001). There was no significant difference between the physiotherapy and orthosis groups (p = 0.36), and we found no difference in outcome after any of the treatments in children under six years (p = 0.73). We recommend proximal femoral varus osteotomy in children aged six years and over at the time of diagnosis with hips having more than 50% femoral head necrosis. The abduction orthosis should be abandoned in Perthes' disease.