Head-shaft angle is a risk factor for hip displacement in children with cerebral palsy

Background and purpose — Hip dislocation in children with cerebral palsy (CP) is a common and severe problem. The Swedish follow-up program for CP (CPUP) includes standardized monitoring of the hips. Migration percentage (MP) is a widely accepted measure of hip displacement. Coxa valga and valgus of the femoral head in relation to the femoral neck can be measured as the head-shaft angle (HSA). We assessed HSA as a risk factor for hip displacement in CP.

Patients and methods — We analyzed radiographs of children within CPUP from selected regions of Sweden. Inclusion criteria were children with Gross Motor Function Classification System (GMFCS) levels III–V, MP of < 40% in both hips at the first radiograph, and a follow-up period of 5 years or until development of MP > 40% of either hip within 5 years. Risk ratio between children who differed in HSA by 1 degree was calculated and corrected for age, MP, and GMFCS level using multiple Poisson regression.

Results — 145 children (73 boys) with a mean age of 3.5 (0.6–9.7) years at the initial radiograph were included. 51 children developed hip displacement whereas 94 children maintained a MP of < 40%. The risk ratio for hip displacement was 1.05 (p < 0.001; 95% CI 1.02–1.08). When comparing 2 children of the same age, GMFCS level, and MP, a 10-degree difference in HSA results in a 1.6-times higher risk of hip displacement in the child with the higher HSA.

Interpretation — A high HSA appears to be a risk factor for hip displacement in children with CP.     

A balanced approach for stable hips in children with cerebral palsy: a combination of moderate VDRO and pelvic osteotomy

Background

Hip reconstructive surgery in cerebral palsy (CP) patients necessitates either femoral varus derotational osteotomy (VDRO) or pelvic osteotomy, or both. The purpose of this study is to review the results of a moderate varisation [planned neck shaft angle (NSA) of 130°] in combination with pelvic osteotomy for a consecutive series of patients.

Methods

Patients with CP who had been treated at our institution for hip dysplasia, subluxation or dislocation with VDRO in combination with pelvic osteotomy between 2005 and 2010 were reviewed.

Results

Forty patients with a mean follow-up of 5.4 years were included. The mean age at the time of operation was 8.9 years. The majority were non-ambulant children [GMFCS I–III: n = 11 (27.5 %); GMFCS IV–V: n = 29 (72.5 %)]. In total, 57 hips were treated with both femoral and pelvic osteotomy. The mean pre-operative NSA angle of 152.3° was reduced to 132.6° post-operatively. Additional adductor tenotomy was performed in nine hips (16 %) at initial operation. Reimers’ migration percentage (MP) was improved from 63.6 % pre-operatively to 2.7 % post-operatively and showed a mean of 9.7 % at the final review. The results were good in 96.5 % (n = 55) with centred, stable hips (MP <33 %), fair in one with a subluxated hip (MP 42 %) and poor in one requiring revision pelvic osteotomy for ventral instability.

Conclusions

This approach maintains good hip abduction and reduces soft-tissue surgery. Moderate varisation in VDRO in combination with pelvic osteotomy leads to good mid-term results with stable, pain-free hips, even in patients with severe spastic quadriplegia.

     

Results and complications of percutaneous pelvic osteotomy and intertrochanteric varus shortening osteotomy in 54 consecutively operated GMFCS level IV and V cerebral palsy patients

Purpose

This retrospective study evaluated mid-to-long-term outcome of a minimally invasive percutaneous pelvic osteotomy (PPO) approach combined with varus derotational shortening osteotomy (VDRSO) and soft tissue release in children with severe CP.

Methods

A retrospective review was performed of all patients presenting with a diagnosis of CP with hip subluxation or dislocation treated surgically by simultaneous soft tissue release, VDRSO, and PPO between 2002 and 2015. Eligible patients included those with a diagnosis of spastic quadriplegia or CP GMFCS level IV or V with unilateral or bilateral hip subluxation or dislocation and surgical treatment of the deformity by simultaneous soft tissue release, VDRSO and PPO. All anterior–posterior (AP) radiographs of the pelvis were reviewed and Reimers migration percentage (MP) and acetabular angle (AA) were measured.

Results

In total, 54 children and adolescents (34 boys, 20 girls) with CP GMFCS level IV and V were treated during study period: 38 (70.4%) classified GMFCS level IV and 16 (29.6%) classified GMFCS level V. A total of 64 consecutive hips underwent simultaneous PPO associated with VDRSO. Overall, at the time of chart and radiograph review, mean age was 9.1 ± 3.3 years (range 4–16.5) and mean follow-up was 43.9 ± 19.5 months (range 3–72). Mean migration percentage improved from 66.8 ± 19.8% (range 33–100) preoperatively to 8.1 ± 16.5% (range 0–70) at last follow-up. Mean acetabular angle improved from 32.7° ± 7.1° (range 20–50) preoperatively to 14° ± 6.7° (range 0–27) at last follow-up. Only one case of bone graft dislodgment was observed. We did not observe any cases of avascular necrosis of the femoral head. All operated hips were pain free at the time of last follow-up.

Conclusion

PPO through a less invasive surgical approach offers a valuable alternative to standard techniques as it gives similar outcome but with less muscle stripping and less time in surgery.

Level of evidence

III.

     

3D打印技术辅助髋臼成形术治疗脑瘫儿童髋关节脱位

目的:探讨通过3D打印技术明确髋臼发育不良类型选择最合适的髋臼成形术治疗脑瘫儿童髋关节脱位的适应证和临床疗效。方法:自2019年7月至2019年12月,采用3D打印技术辅助髋臼成形术治疗7例脑瘫儿童髋关节脱位,其中男3例,女4例;年龄3~8岁;左侧3例,右侧2例,双侧2例;2例髋关节半脱位,5例髋关节脱位。患儿术前均行骨盆-双股骨全长CT扫描。通过3D打印重建技术,判断髋臼发育不良类型:前侧2髋,前外2髋,外上1髋,后侧2髋,后外1髋,无发育不良1髋(未做髋臼成形术)。对8髋分别进行Pemberton,Dega和San Diego手术模拟,寻找最合适的手术方式并手术。比较术前和末次随访外移比例(migration percentage,MP),髋臼指数(acetabular index,AI),中心边缘角(center-edge angle,CEA),Shenton线和粗大运动功能分级(gross motor function classification system,GMFCS)的变化,并记录其并发症情况。结果:术后患者伤口愈合良好,无并发症发生。7例患者获随访,时间18~24个月。8髋Ⅰ期行软组织松解+股骨近端内翻去旋转短缩截骨+髋关节复位+髋臼成形术;1髋Ⅰ期行软组织松解+股骨近端内翻去旋转短缩截骨+髋关节复位术。MP由术前的58%~100%降至末次随访时的0~17.9%。AI由术前的25.0°~47.6°降至末次随访时的11.1°~25.3°。CEA由术前的0°改善至末次随访时的21.1°~48.5°。Shenton''线均由中断变为连续。其中5例GMFCS分级下降1级,2例无变化。结论:脑瘫儿童髋关节脱位中髋臼发育不良的类型多样,髋臼成形术适用范围也有差异,借助3D打印技术计算机模拟手术可选择最合适的手术方式并判断治疗效果,对脑瘫儿童髋关节脱位做到个体化、精准化治疗。     

To what extent can soft-tissue releases improve hip displacement in cerebral palsy?

Background and purpose — Hip displacement is frequent in nonambulatory children with cerebral palsy (CP) and treatment is controversial. This prospective study assesses the effectiveness of soft-tissue releases to treat hip subluxation, analyses prognostic factors for outcome, and identifies time to failure in hips with poor outcome.

Patients and methods — 37 children (16 girls) with hip subluxation were recruited from the population-based screening program for children with CP in Norway. They had consecutively undergone soft-tissue releases (bilateral tenotomies of adductors and iliopsoas) at a mean age of 5.0 (2.8–7.2) years. Functional classification was Gross Motor Function Classification System (GMFCS) level III in 9 children, level IV in 10, and level V in 18 children. The outcome was termed good if the patient had not undergone further hip surgery and if the migration percentage (MP) of the worst hip at the latest follow-up was <50%. The mean follow-up time was 7.3 (5.1–9.8) years.

Results — The outcome was good in all the ambulatory children and in 17 of 28 of the nonambulatory children. The only independent preoperative risk factor for poor outcome was MP ≥50%. The mean time to failure was 2.2 (1–5) years postoperatively and the reasons for failure were insufficient initial correction and later deterioration of displacement.

Interpretation — Bilateral soft-tissue release is recommended in both ambulatory and nonambulatory children with hip sub­luxation. The operation should be performed before the hip displacement reaches 50%.     

Recurrent hip instability after hip reconstruction in cerebral palsy children with spastic hip disease

BackgroundMigration percentage (MP) is widely used to evaluate hip stability in children with spastic cerebral palsy (CP). Orthopedic surgeons need more objective information to make a proper hip reconstruction surgical plan and predict the outcome.MethodsMedical records and plain radiographs of children with CP who underwent the hip reconstruction procedure for dysplasia were reviewed retrospectively.ResultsIn total, 253 operated hips (140 patients; 11.7 ± 3.3 years old) were included in this study. MP at pre-operative (T_pre) was 35.3 ± 22.5%; at immediate follow-up (T_post) was 5.9 ± 9.5%; at last follow-up (T_final) was 9.8 ± 10.8% (4.5 ± 2.3 years post-operative at age 16.3 ± 2.8 years). In hips with Melbourne Cerebral Palsy Hip Classification Scale (MCPHCS) grade 3 (n = 78), around 30–45% had an unsatisfactory outcome at T_post and T_final. However, hips categorized as other grades showed only 2.1–9.1% of unsatisfactory outcome. In less affected hips (pre-operative MP<30%, n = 122), 109 hips (89.3%) had varus derotation osteotomy only, the other 13 hips (10.7%) were combined with a pelvic osteotomy. In more severely affected hips (pre-operative MP ≥ 30%, n = 131), 26 hips (19.8%) had varus derotation osteotomy only, the other 105 hips (80.2%) were combined with a pelvic osteotomy.ConclusionsHips with pre-operative MP between 15 and 29% (MCPHCS grades 3) can be a higher risk group of recurrent hip instability after hip reconstruction surgery. Multiple indications beyond MP should be considered when indicating pelvic osteotomy or hip muscle release as combined procedures with varus femoral osteotomy for hip reconstruction in this milder group to achieve a consistent long-term satisfactory outcome.     

Utility of combined hip abduction angle for hip surveillance in children with cerebral palsy

Background:

Spontaneous hip lateralization complicates the management of non-ambulatory children with cerebral palsy (CP). It can be diagnosed early using radiographs, but it involves standardization of positioning and exposure to radiation. Hence, the aim of this study was to assess the utility of Combined hip abduction angle (CHAA) in the clinical setting to identify those children with CP who were at greater risk to develop spontaneous progressive hip lateralization.

Materials and Methods:

One hundred and three children (206 hips) with CP formed our study population. There were 48 boys and 55 girls aged 2–11 years (mean 5.03 years). 61 children were Gross Motor Function Classification System (GMFCS) level 5, while 42 were GMFCS level 4. Clinical measurements of CHAA were statistically correlated with radiographic measurements of Reimer''s migration percentage (MP) for bivariate associations using χ² and t tests.

Results:

CHAA is evaluated against MP which is considered as a reliable measure of hip subluxation. Thus, for CHAA, sensitivity was 74.07% and specificity was 67.35%. False-positive rate was 32.65% and false-negative rate was 25.93%.

Conclusions:

Our study shows that correlation exists between CHAA and MP, which has been proved to be useful for hip screening in CP children at risk of hip dislocation. CHAA is an easy, rapid, cost-effective clinical test which can be performed by paraclinical health practitioners (physiotherapists) and orthopedic surgeons.     

Adductor tenotomy in spastic cerebral palsy

Background?There is a risk of hip dislocation in children with spastic cerebral palsy. We evaluated the prophylactic effect of adductor tenotomy in patients with long-term follow-up.

Patients and methods?Our material comprised 78 patients (46 boys) with a mean age of 8 (2–17) years who underwent adductor tenotomy during the period 1986–1991. 40 patients had spastic diplegia and 38 had quadriplegia. For patients who had further hip surgery, follow-up was until the next hip operation. Those who had not undergone further surgery were invited to a follow-up examination. The migration percentage (MP) was measured on the preoperative and follow-up radiographs. The radiographic result was termed good if MP at follow-up was reduced or had increased less than 10%. The follow-up period was 10 (1.6–16) years, with a mean of 6 years for patients with later hip surgery and 13 years without such surgery.

Results?The clinical outcome was good in 51 cases, poor in 12, and uncertain in 15. The radiographic result was good in 39 of the 53 patients with radiographs available both preoperatively and at follow-up. The patients with good radiographic results had lower preoperative MP than those with poor results (MP 34% versus 49%) and lower preoperative acetabular index. The mean increase in MP (worst hip in each patient) was 1.9% per year, which is considerably less than that in nonoperated patients. Further hip surgery was necessary in 27 patients, because of increasing MP in 14 cases and for clinical reasons in 13.

Interpretation?Adductor tenotomy reduced the trend towards lateral displacement of the hip joints. The operation had a favorable outcome in approximately two-thirds of the patients. The operation should be performed before the MP reaches 50%.     

Hip resurfacing with femoral osteotomy for painful subluxed or dislocated hips in patients with cerebral palsy

The painful subluxed or dislocated hip in adults with cerebral palsy presents a challenging problem. Prosthetic dislocation and heterotopic ossification are particular concerns. We present the first reported series of 19 such patients (20 hips) treated with hip resurfacing and proximal femoral osteotomy. The pre-operative Gross Motor Function Classification System (GMFCS) was level V in 13 (68%) patients, level IV in three (16%), level III in one (5%) and level II in two (11%). The mean age at operation was 37 years (13 to 57). The mean follow-up was 8.0 years (2.7 to 11.6), and 16 of the 18 (89%) contactable patients or their carers felt that the surgery had been worthwhile. Pain was relieved in 16 of the 18 surviving hips (89%) at the last follow-up, and the GMFCS level had improved in seven (37%) patients. There were two (10%) early dislocations; three hips (15%) required revision of femoral fixation, and two hips (10%) required revision, for late traumatic fracture of the femoral neck and extra-articular impingement, respectively. Hence there were significant surgical complications in a total of seven hips (35%). No hips required revision for instability, and there were no cases of heterotopic ossification. We recommend hip resurfacing with proximal femoral osteotomy for the treatment of the painful subluxed or dislocated hip in patients with cerebral palsy.     

Hip surveillance and management of the displaced hip in cerebral palsy

Introduction

This article provides an overview of the management of a displaced hip in children with cerebral palsy and considers surveillance programmes, principles of surgical reconstruction and options for the salvage of an unreconstructable hip in these children.

Conclusion

Hip dislocation in CP is potentially preventable if children are included from an early age in a surveillance programme that includes repeat radiographic and clinical examinations, and preventive treatment for hips that are displacing. A surveillance programme should be based on the child’s age, GMFCS level and migration percentage (MP), and surgical prevention may be considered in children with a MP exceeding 33 %.     

Severe hip displacement reduces health-related quality of life in children with cerebral palsy

Background and purpose — Hip displacement is common in children with severe cerebral palsy (CP) and can cause problems such as pain, contractures, and nursing difficulties. Caregiver priorities and child health index of life with disabilities (CPCHILD) is a recently developed measure of health-related quality of life (HRQL) in children with severe CP. The associations between CPCHILD scores and hip displacement have not been investigated. We explored the effect of hip displacement on HRQL.

Patients and methods — 67 children were recruited from the population-based Norwegian CP register. Mean age was 9 (7–12) years. There were 40 boys. Gross motor function classification system (GMFCS) distribution was 12 level III, 17 level IV, and 38 level V. Hip displacement was assessed by radiographic migration percentage (MP). The criterion for hip displacement was MP of the worst hip of ≥40%. Primary caregivers responded to 5 of the 6 domains of the CPCHILD questionnaire.

Results — Hip displacement was found in 18 children and it was significantly associated with lower scores on the CPCHILD domains 3 (Comfort and Emotions) and 5 (Health), but not with domains 1 (Activities of Daily Living/Personal Care), 2 (Positioning, Transfer, and Mobility), and 6 (Overall Quality of Life). GMFCS level V was a significant predictor of low scores in all the domains.

Interpretation — For the assessment of HRQL in children with severe CP and hip problems, we propose a modified and simplified version of the CPCHILD consisting of 14 of 37 questions. This would reduce the responders’ burden and probably increase the response rate in clinical studies without losing important information.     

Development of the hip joints in unoperated children with cerebral palsy: A radiographic study of 76 patients

Background?The aims of the present study were to assess the development of hip dysplasia in children with bilateral spastic cerebral palsy and to evaluate the factors that influence the progression.

Patients and methods?76 children, 42 with spastic quadriplegia and 34 with diplegia, were included in the study. Their mean age at the first radiographic examination was 3.5 (1–11) years. The patients were followed up until operative treatment (54 subjects) or until the most recent radiograph in those who did not undergo hip surgery. The mean length of follow-up was 4.8 (1–13) years. On the initial and most recent radiographs, the migration percentage (MP) was measured, which is the percentage of the femoral head lateral to the acetabular rim.

Results?The mean MP of the side with the largest displacement was 25% (-18–66) at the initial radiographic examination and 51% (9–100) at the last follow-up. The mean increase in MP was 7% (-2–33) per year. Linear multiple regression revealed that gait function and age were the most important variables that influenced the rate of MP progression. Children who could not walk had significantly greater MP progression per year (12%) than those who walked with or without support (2%). In the quadriplegics, the maximal yearly increase in MP was 13% under 5 years of age and 7% in older children. This difference was statistically significant, whereas no significant difference in relation to patient age was seen in the diplegics.

Interpretation?There is a pronounced trend towards displacement of the hips in quadriplegic CP patients who are under 5 years of age and cannot walk. Because hip dislocation may lead to severe problems, close follow-up is important in finding the appropriate time for hip surgery in order to avoid progression towards dislocation. The risk of severe hip dysplasia is considerably less in spastic diplegia.??     

Hip displacement in relation to age and gross motor function in children with cerebral palsy

Purpose

Hip dislocation in cerebral palsy (CP) is a serious complication. By radiographic screening and prophylactic surgery of children at risk most dislocations can be prevented. CPUP, the Swedish CP registry and follow-up program, includes annual radiographic examinations of children at Gross Motor Function Classification System (GMFCS) levels III–V. Data from CPUP were analysed to assess the risk of hip displacement in relation to GMFCS levels and age.

Methods

All children at GMFCS levels III–V (N = 353) whose first radiographic screening occurred before 3 years of age were followed between the ages 2–7 years. Migration percentages (MPs) were recorded annually (1,664 pelvic radiographs) and analysed using discrete time survival analysis.

Results

The risk of hip displacement between 2 years and 7 years of age was significantly (p < 0.05) higher for children at GMFCS level V during the entire study period. The risk was highest at 2–3 years of age and decreased significantly (p < 0.001) with each year of age (OR = 0.71, 95 % CI 0.60–0.83). The cumulative risk at age 7 years for those at GMFCS V for MP ≥ 40 % was 47 % (95 % CI 37–58). The corresponding risk at GMFCS IV was 24 % (16–34) and at GMFCS III 23 % (12–42).

Conclusions

Children at GMFCS V have a significantly higher risk of hip displacement compared with children at GMFCS III–IV. The risk is highest at 2–3 years of age. The results support a surveillance program including radiographic hip examinations as soon as the diagnosis of severe CP is suspected.     

Percutaneous pelvic osteotomy in cerebral palsy patients: Surgical technique and indications

AIM: To describe the surgical technique of and indications for percutaneous pelvic osteotomy in patients with severe cerebral palsy.METHODS: Twenty-one non-ambulatory children and adolescents (22 hips) were consecutively treated with percutaneous pelvic osteotomy, which was used in conjunction with varus, derotational, shortening femoral osteotomy and soft tissue release, to correct progressive hip subluxation and acetabular dysplasia. The age, gender, Gross Motor Function Classification System level, side(s) of operated hip, total time of follow-up, immediate post-operative immobilization, complications, and the need for revision surgery were recorded for all patients.RESULTS: Seventeen patients (81%) were classified as GMFCS level IV, and 4 (19%) patients were classified as GMFCS level V. At the time of surgery, the mean age was 10.3 years (range: 4-15 years). The mean Reimers’ migration percentage improved from 63% (range: 3%-100%) pre-operatively to 6.5% (range: 0%-70%) at the final follow-up (P < 0.05). The mean acetabular angle (AA) improved from 34.1° (range: 19°-50°) pre-operatively to 14.1° (range: 5°-27°) (P < 0.05). Surgical correction of MP and AA was comparable in hips with open (n = 14) or closed (n = 8) triradiate cartilage (P < 0.05). All operated hips were pain-free at the time of the final follow-up visit, although one patient had pain for 6 mo after surgery. We did not observe any cases of bone graft dislodgement or avascular necrosis of the femoral head.CONCLUSION: Pelvic osteotomy through a less invasive surgical approach appears to be a valid alternative with similar outcomes to those of standard techniques. This method allows for less muscle stripping and blood loss and a shorter operating time.     

Prosthetic overhang is the most effective way to prevent scapular conflict in a reverse total shoulder prosthesis

Background and purpose?Controversies still exist about whether there is any effect of operative approach on survival of hip prostheses. We compared long-term survival of primary total hip arthroplasties in a welldefined study population from a national prospective population-based registry with regard to the three most commonly used surgical approaches.

Methods?We assessed prosthesis survival according to surgical approach (the lateral with or without trochanteric osteotomy, and the posterolateral) for 19,304 Charnley and 6,002 Exeter total hip arthroplasties performed from 1987 to 2004.

Results?For Charnley total hip arthroplasties, lateral approach with trochanteric osteotomy had a lower probability of revision than lateral approach without trochanteric osteotomy (RR = 0.6, 95% CI: 0.5–0.8). The lower revision rate was due to fewer revisions for aseptic loosening and dislocation. The differences had declined in the latest time period (1995–2004). We observed no differences between lateral approach without trochanteric osteotomy and posterolateral approach, except that there were more revisions due to dislocation in the posterolateral approach group (RR = 1.9, 95%CI: 1.1–3.2). No statistically significant differences were observed for Exeter total hip arthroplasties.

Interpretation?For Charnley prostheses, the lateral approach with trochanteric osteotomy gave a reduced revision risk compared to the other approaches, which was due to fewer revisions for dislocation, and in the first time period also fewer revisions due to aseptic loosening.     

The Effect of Electric Current on the Healing time of Crural Fractures

Background and purpose — Uncemented stems are increasingly used in revision hip arthroplasty, but only a few studies have analyzed the outcomes of uncemented and cemented revision stems in large cohorts of patients. We compared the results of uncemented and cemented revision stems.

Patients and methods — 1,668 uncemented and 1,328 cemented revision stems used in first-time revisions due to aseptic loosening between 1999 and 2016 were identified in the Swedish Hip Arthroplasty Register. Kaplan–Meier analysis was used to investigate unadjusted implant survival with re-revision for any reason as the primary outcome. Hazard ratios (HR) for the risk of re-revision were calculated using a Cox regression model adjusted for sex, age, head size, concomitant cup revision, surgical approach at primary and at index revision surgery, and indication for primary total hip arthroplasty.

Results — Unadjusted 10-year survival was 85% (95% CI 83–87) for uncemented and 88% (CI 86–90) for cemented revision stems. The adjusted HR for re-revision of uncemented revision stems during the first year after surgery was 1.3 (CI 1.0–1.6), from the second year the HR was 1.1 (CI 0.8–1.4). Uncemented stems were most often re-revised early due to infection and dislocation, whereas cemented stems were mostly re-revised later due to aseptic loosening.

Interpretation — Both uncemented and cemented revision stems had satisfactory long-term survival but they differed in their modes of failure. Our conclusions are limited by the fact that femoral bone defect size could not be investigated within the setting of the current study.     

The unstable hip in children with cerebral palsy: does an acetabuloplasty add midterm stability?

PurposeThis study addresses whether an additional pelvic procedure is superior to a varus derotation osteotomy femur (VDRO) alone in unstable hips in children with cerebral palsy (CP).MethodsAll patients had unstable hips utilising the Melbourne Cerebral Palsy Hip Classification System (MCPHCS). We compared one group that underwent VDRO alone with one that had a combination of VDRO and Dega osteotomy (VDRO+). Measurements were taken before surgery, postoperatively, two years after surgery and at latest follow-up. Generalised estimating equations were used to account for known and unknown correlations between hips from bilateral cases.ResultsIn total, 74 hips in 57 children fulfilled the inclusion criteria. There was no outcome difference between Gross Motor Function Classification System levels III, IV and V. Age at time of operation ranged from three to 16 years (mean 9.8 years). Mean follow-up was 49.1 months. In the VDRO group (28 hips) migration percentage (MP) changed from 61% preoperative to a final value of 35.7%. In the VDRO+ group (46 hips) the MP changed from 64.4% to 19.3%. At final follow-up 15 hips (54%) were stable in the VDRO group, 37 hips (83%) in the VDRO+ group. The odds ratio (OR) of hip stability at final follow-up was 3.5-times higher in the VDRO+ group versus the VDRO group (OR = 3.9; 95% confidence interval = 1.5 to 9.7; p = 0.004).ConclusionReconstruction of unstable hips via VDRO + Dega in children with CP provides a higher likelihood of long-term stability than an isolated VDRO.Level of EvidenceLevel III, retrospective comparative study     

Adductor tenotomy in spastic cerebral palsy. A long-term follow-up study of 78 patients

BACKGROUND: There is a risk of hip dislocation in children with spastic cerebral palsy. We evaluated the prophylactic effect of adductor tenotomy in patients with long-term follow-up. PATIENTS AND METHODS: Our material comprised 78 patients (46 boys) with a mean age of 8 (2-17) years who underwent adductor tenotomy during the period 1986-1991. 40 patients had spastic diplegia and 38 had quadriplegia. For patients who had further hip surgery, follow-up was until the next hip operation. Those who had not undergone further surgery were invited to a follow-up examination. The migration percentage (MP) was measured on the preoperative and follow-up radiographs. The radiographic result was termed good if MP at follow-up was reduced or had increased less than 10%. The follow-up period was 10 (1.6-16) years, with a mean of 6 years for patients with later hip surgery and 13 years without such surgery. RESULTS: The clinical outcome was good in 51 cases, poor in 12, and uncertain in 15. The radiographic result was good in 39 of the 53 patients with radiographs available both preoperatively and at follow-up. The patients with good radiographic results had lower preoperative MP than those with poor results (MP 34% versus 49%) and lower preoperative acetabular index. The mean increase in MP (worst hip in each patient) was 1.9% per year, which is considerably less than that in nonoperated patients. Further hip surgery was necessary in 27 patients, because of increasing MP in 14 cases and for clinical reasons in 13. INTERPRETATION: Adductor tenotomy reduced the trend towards lateral displacement of the hip joints. The operation had a favorable outcome in approximately two-thirds of the patients. The operation should be performed before the MP reaches 50%.     

Association between changes in global femoral offset after total hip arthroplasty and function,quality of life,and abductor muscle strength: A prospective cohort study of 222 patients

Background and purpose — There is no consensus on the association between global femoral offset (FO) and outcome after total hip arthroplasty (THA). We assessed the association between FO and patients’ reported hip function, quality of life, and abductor muscle strength.

Patients and methods — We included 250 patients with unilateral hip osteoarthritis who underwent a THA. Before the operation, the patient’s reported hip function was evaluated with the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and quality of life was evaluated with EQ-5D. At 1-year follow-up, the same scores and also hip abductor muscle strength were measured. 222 patients were available for follow-up. These patients were divided into 3 groups according to the postoperative global FO of the operated hip compared to the contralateral hip, as measured on plain radiographs: the decreased FO group (more than 5 mm reduction), the restored FO group (within 5 mm restoration), and the increased FO group (more than 5 mm increment).

Results — All 3 groups improved (p?Interpretation — A reduction in global FO of more than 5 mm after THA appears to have a negative association with abductor muscle strength of the operated hip, and should therefore be avoided.     

Hip-joint congruity after Dega osteotomy in patients with cerebral palsy: long-term results

Introduction

Neurogenic hip dislocation is quite common in children with cerebral palsy (CP). The purpose of this study was to evaluate the long-term outcome of single-event multilevel surgery (SEMLS) in combination with hip reconstruction by using a periacetabular osteotomy as described by Dega concerning post-operative remodeling and plasticity of the femoral head post-operatively.

Methods

A total of 72 patients with CP as the primary disease and in whom a complex surgical hip reconstruction was performed during SEMLS between 1998 and 2004 were included in the study. There were 45 men and 27 women, with a median age of 7.6 (4.7–16.3) years at the time SEMLS was performed. The mean follow-up time was 7.7 years (4.9–11.8). X-rays were taken before and after surgery, and Rippstein 1 and 2 were used for follow-up. As the most reliable value for decentration, migration percentage (MP) as described by Reimers was used. To measure hip-joint cover at follow-up, the centre-edge angle was used. The hip was divided into four different categories according to sphericity and congruity. Using this approach, we could evaluate joint remodeling.

Results

Pre-operatively, the mean MP measured by X-ray was 68 %. Directly after surgery, this value decreased on average by 12 % and at the long-term follow-up was 16.0 % on average. A high rate of incongruence was observed on X-rays taken directly after surgery: 66 hip joints were classified as incongruent. The number of aspherical and incongruent joints decreased to 54 at the follow-up examination.

Conclusion

Data of our study with high plasticity of the hip joint suggest that even if the femoral head is deformed and a persistent incongruency after surgery is expected, hip reconstruction can be recommended.