Aims

The migration percentage (MP) is one criterion used for surgery in dislocated or displaced hips in children with cerebral palsy (CP). The MP at which a displaced hip can no longer return to normal is unclear. The aim of this paper was to identify the point of no return of the MP through a large population-based study.

Hip displacement, defined in this study as a migration percentage (MP) of more than 40%, is a common, debilitating complication of cerebral palsy (CP). In this prospective study we analysed the risk of developing hip displacement within five years of the first pelvic radiograph. . All children with CP in southern and western Sweden are invited to register in the hip surveillance programme CPUP. Inclusion criteria for the two groups in this study were children from the CPUP database born between 1994 and 2009 with Gross Motor Function Classification System (GMFCS) III to V. Group 1 included children who developed hip displacement, group 2 included children who did not develop hip displacement over a minimum follow-up of five years. A total of 145 children were included with a mean age at their initial pelvic radiograph of 3.5 years (0.6 to 9.7). The odds ratio for hip displacement was calculated for GMFCS-level, age and initial MP and head-shaft angle. A risk score was constructed with these variables using multiple logistic regression analysis. The predictive ability of the risk score was evaluated using the area under the receiver operating characteristics curve (AUC). . All variables had a significant effect on the risk of a MP > 40%. The discriminatory accuracy of the CPUP hip score is high (AUC = 0.87), indicating a high ability to differentiate between high- and low-risk individuals for hip displacement. The CPUP hip score may be useful in deciding on further follow-up and treatment in children with CP. Cite this article: Bone Joint J 2015;97-B:1441–4

Aims. The purpose of this study was to compare the prevalence of hip displacement and dislocation in a total population of children with cerebral palsy (CP) in Scotland before and after the initiation of a hip surveillance programme. Patients. A total of 2,155 children with CP are registered in the Cerebral Palsy Integrated Pathway Scotland (CPIPS) surveillance programme, which began in 2013. Physical examination and hip radiological data are collected according to nationally agreed protocols. Methods. Age, Gross Motor Function Classification System (GMFCS) level, subtype of CP, migration percentage (MP), and details of hip surgery were analyzed for all children aged between two and 16 years taken from a time of census in March 2019 and compared to the same data from the initial registration of children in the CPIPS. Displacement of the hip was defined as a MP of between 40% and 99%, and dislocation as a MP of 100%. Results. A total of 1,646 children were available for analysis at the time of the census and 1,171 at their first registration in CPIPS. The distribution of age, sex, and GMFCS levels were similar in the two groups. The prevalence of displacement and dislocation of the hip before surveillance began were 10% (117/1,171) and 2.5% (29/1,171) respectively, and at the time of the census were 4.5% (74/1,646) and 1.3% (21/1,646), respectively. Dislocation was only seen in GMFCS levels IV and V and displacement seen in 90.5% (67/74) of these levels and 9.5% (7/74) in levels I to III. In total, 138 children had undergone hip surgery during the study period. The hip redisplaced after the initial surgery in 15 children; seven of these had undergone a second procedure and at the time of the census the hips in all seven had a MP < 40. Conclusion. Hip surveillance appears to be effective and has reduced the prevalence of hip displacement by over half and dislocation almost by half in these children. Cite this article: Bone Joint J 2020;102-B(3):383–387

Aims

The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England.

Between June 2001 and November 2008 a modified Dunn osteotomy with a surgical hip dislocation was performed in 30 hips in 28 patients with slipped capital femoral epiphysis. Complications and clinical and radiological outcomes after a mean follow-up of 3.8 years (1.0 to 8.5) were documented. Subjective outcome was assessed using the Harris hip score and the Western Ontario and McMaster Universities osteoarthritis index questionnaire. Anatomical or near-anatomical reduction was achieved in all cases. The epiphysis in one hip showed no perfusion intra-operatively and developed avascular necrosis. There was an excellent outcome in 28 hips. Failure of the implants with a need for revision surgery occurred in four hips. Anatomical reduction can be achieved by this technique, with a low risk of avascular necrosis. Cautious follow-up is necessary in order to avoid implant failure

Aims

The Uppföljningsprogram för cerebral pares (CPUP) Hip Score distinguishes between children with cerebral palsy (CP) at different levels of risk for displacement of the hip. The score was constructed using data from Swedish children with CP, but has not been confirmed in any other population. The aim of this study was to determine the calibration and discriminatory accuracy of this score in children with CP in Scotland.

Premature fusion of the triradiate cartilage was obtained surgically in 10 three-week-old rabbits, and compared with isolated fusion of the ilio-ischial and of the ilio-pubic limbs of the triradiate cartilage in two further groups of 10 rabbits. Complete fusion caused acetabular dysplasia five weeks after operation in all animals and hip dislocation at nine weeks in half of them; ilio-ischial fusion had a comparable effect. Ilio-pubic fusion had only a minimal effect on acetabular development. The posterior position of the ilio-ischial limb in the acetabulum and its predominance in the formation of the triradiate cartilage in quadrupeds may have contributed to its decisive effect on acetabular development

Aims

Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation.

Between November 1997 and December 2000 we performed 27 total hip replacements in 22 patients with high congenital dislocation of the hip using porous tantalum monoblock acetabular components implanted in the true acetabular bed. Clinical and radiological evaluation was performed at regular intervals for a mean of 10.2 years (8.5 to 12). The mean Harris Hip Score improved from 48.3 (15 to 65) pre-operatively to 89.5 (56 to 100) at the final follow-up. The mean Oxford Hip Score was 49.5 (35 to 59) pre-operatively and decreased to 21.2 (12 to 48) at one year and 15.2 (10 to 28) at final follow-up. Migration of the acetabular component was assessed with the EBRA software system. There was a mean migration of 0.68 mm (0.49 to 0.8) in the first year and a mean 0.89 mm (0.6 to 0.98) in the second year, after excluding one initial excessive migration. No revision was necessary for any reason, no acetabular component became loose, and no radiolucent lines were observed at the final follow-up.

The porous tantalum monoblock acetabular component is an implant offering adequate initial stability in conjunction with a modulus of elasticity and porosity close to that of cancellous bone. It favours bone ingrowth, leading to good mid-term results.

Aims

We report a prospective cohort study of the midterm results of surgical dislocation of the hip (according to Ganz) to perform resection of osteochondromas involving the femoral neck in patients with multiple hereditary exostoses (MHE).

Avascular necrosis is an iatrogenic complication of the treatment of congenital dislocation of the hip. In order to assess the incidence of this and other complications, we have reviewed a consecutive series of 211 children treated at some stage with the modified Denis Browne splint used in Adelaide. In 173 children treated with this splint alone for 238 subluxed or dislocated hips which were stable when reduced, six hips (2.5%) developed radiographic avascular necrosis, though there was progressive growth deformity in only one. There was a much higher incidence among cases treated for unstable reduction by tenotomy, plaster spica and then the splint, 20 of 33 hips (60.6%) showing radiographic signs, though only one led to progressive abnormality. Of seven patients treated by adductor tenotomy and the splint no case of avascular necrosis was encountered. In the whole series the incidence of significant long-term growth disturbance in children treated in this splint was 0.7%. The great majority of our cases of avascular necrosis were attributable to manipulation and plaster, not to the subsequent use of a splint.

We have studied the natural history of spontaneous dislocation of the hip in cerebral palsy, with particular reference to the pattern of neurological involvement. In patients with bilateral hemiplegia and severe involvement of the upper limbs the incidence of dislocation was very high (59%), while in those with diplegia and little involvement of the upper limbs, only 6.5% were affected. There was no evidence of dysplasia or instability of the hip in any of the patients with unilateral hemiplegia. A strong correlation was found between the stability of the hip and the patients' ability to walk. These findings have a bearing on clinical surveillance and also on the indications for prophylactic surgery.

A six-year-old girl with congenital sensory neuropathy with anhidrosis (CSNA) presented with bilateral hip dysplasia and subluxation on the right side.

Conservative treatment of the hips by closed reduction and a plaster cast was unsuccessful. When aged seven years the patient had an intertrochanteric varus rotation osteotomy on the right side, but subluxation was again evident after five months. A Salter-type pelvic osteotomy was carried out followed by immobilisation, but one year later subluxation was present in the right hip and dislocation in the left. At the age of nine years, the right femoral head resembled a Charcot joint, although walking ability was preserved.

In patients with CSNA, surgery may not always be advisable.

Arthrogryposis multiplex congenita (AMC) is a rare disease with multiple joint contractures. It is widely believed that bilaterally dislocated hips should not be reduced since movement is satisfactory and open reduction has had poor results. Since 1977 we have performed a new method of open reduction using an extensive anterolateral approach on ten hips in five children with AMC. The mean age at surgery was 31.5 months (17 to 64) and the mean follow-up was 11.8 years (3.8 to 19.5).

At the final follow-up all children walked without crutches or canes. Two managed independently, one required a long leg brace and two had short leg braces because of knee and/or foot problems. The clinical results were good in eight hips and fair in two and on the Severin classification seven hips were rated as good (group I or group II).

We recommend the extensive anterolateral approach for unilateral or bilateral dislocation of the hip in children with arthrogryposis or developmental dislocation of the hip.

We report on a radiographic screening programme at four months of age for infants who were clinically normal at neonatal examination but were considered to be 'at risk' for congenital dislocation of the hip because of their family history, breech presentation, or a persistent click. From a total population of 13,662 live births over a two-year period, 357 (2.6%) infants at risk were identified. Of these 46 had abnormal radiographs (six subluxations, 40 acetabular dysplasia). In 12 infants treatment resulted in a normal hip; 34 required no treatment but were followed up until their radiographs were normal and walking had begun. Of the 311 infants with normal radiographs, 256 (82%) were examined after 15 months of age; none had any detectable abnormality. We suggest that radiography of the hip at four months is a valuable adjunct to neonatal screening for infants at increased risk of congenital dislocation of the hip.

In this prospective study of 18 hips we compared the efficacy of ultrasound with CT in determining the position of the femoral head in a spica cast after closed or open reduction in children with developmental dysplasia of the hip. Ultrasound was performed through the perineal opening of the cast. With a transinguinal approach, the superior ramus of the pubis, the acetabulum, the femoral head and the femoral neck can be depicted in one plane. The CT and ultrasound images were blinded and reviewed by two of the authors. Ultrasound was inconclusive in the first two reductions since the perineal opening was too small to see all the landmarks in one plane. In the following 16 reductions the landmarks were well defined and interpretation of the CT and ultrasound was similar. The perineal opening in the spica cast should be made in such a way that the ultrasound probe can be positioned in the groin so that the landmarks can be shown in one plane.

Aims. Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP. Methods. We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement. Results. A total of 108 patients were enrolled. The mean preoperative MP was 58.3% (SD 31.7%), which improved to 9.1% (SD 15.6%) at the last follow-up. NSA and MHR improved from 156.5° (SD 11.5°) and 82.3% (SD 8.6%) to 126.0° (SD 18.5°) and 89.1% (SD 9.0%), respectively. Factors affecting the postoperative MHR were preoperative MP (p = 0.005), immediate postoperative MP (p = 0.032), and history of Dega osteotomy (p = 0.046). Conclusion. We found that hip sphericity improves with HRS. Preoperative MP, reduction quality, and acetabular coverage influence femoral head remodelling. We recommend that surgeons should consider intervention early before hip displacement progresses and that during HRS, definite reduction and coverage of the femoral head should be obtained. Cite this article: Bone Joint J 2021;103-B(1):198–203

Aims. Pelvic tilt is believed to affect the symptomology of osteoarthritis (OA) of the hip by alterations in joint movement, dysplasia of the hip by modification of acetabular cover, and femoroacetabular impingement by influencing the impingement-free range of motion. While the apparent role of pelvic tilt in hip pathology has been reported, the exact effects of many forms of treatment on pelvic tilt are unknown. The primary aim of this study was to investigate the effects of surgery on pelvic tilt in these three groups of patients. Methods. The demographic, radiological, and outcome data for all patients operated on by the senior author between October 2016 and January 2020 were identified from a prospective registry, and all those who underwent surgery with a primary diagnosis of OA, dysplasia, or femoroacetabular impingement were considered for inclusion. Pelvic tilt was assessed on anteroposterior (AP) standing radiographs using the pre- and postoperative pubic symphysis to sacroiliac joint (PS-SI) distance, and the outcomes were assessed with the Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and Harris Hip Score (HHS). Results. The linear regression model revealed a significant negative predictive association between the standing pre- and postoperative PS-SI distances for all three groups of patients (all p < 0.001). There was a significant improvement in all three outcome measures between the pre- and postoperative values (p < 0.05). Conclusion. There is a statistically significant decrease in pelvic tilt after surgery in patients with OA of the hip, dysplasia, and femoroacetabular impingement. These results confirm that surgery significantly alters the pelvic orientation. Pelvic tilt significantly decreased after total hip arthroplasty, periacetabular osteotomy, and arthroscopy/surgical hip dislocation. The impact of surgery on pelvic tilt should be considered within the therapeutic plan in order to optimize pelvic orientation in these patients. Cite this article: Bone Joint J 2022;104-B(9):1025–1031

Aims. The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI). Methods. This single-centre study focused on a cohort of 24 patients with cam- or pincer-type FAI, full-thickness femoral or acetabular chondral lesions, or osteochondral lesions ≥ 2 cm. 2. , who underwent surgical hip dislocation for FAI correction in combination with AMIC between March 2009 and February 2016. Baseline data were retrospectively obtained from patient files. Mid-term outcomes were prospectively collected at a follow-up in 2020: cartilage repair tissue quality was evaluated by MRI using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Patient-reported outcome measures (PROMs) included the Oxford Hip Score (OHS) and Core Outcome Measure Index (COMI). Clinical examination included range of motion, impingement tests, and pain. Results. A total of 12 hips from 11 patients were included (ten males, one female, mean age 26.8 years (SD 5.0), mean follow-up 6.2 years (SD 5.2 months)). The mean postoperative MOCART score was 66.3 (SD 16.3). None of the patients required conversion to total hip arthroplasty. Two patients had anterior impingement. External hip rotation was moderately limited in four patients. There was a correlation between MOCART and follow-up time (r. s. = -0.61; p = 0.035), but not with initial cartilage damage, age, BMI, or imaging time delay before surgery. PROMs improved significantly: OHS from 37.4 to 42.7 (p = 0.014) and COMI from 4.1 to 1.6 (p = 0.025). There was no correlation between MOCART and PROMs. Conclusion. Based on the reported mid-term results, we consider AMIC as an encouraging treatment option for large cartilage lesions of the hip. Nonetheless, the clinical evidence of AMIC in FAI patients remains to be determined, ideally in the context of randomized controlled trials. Cite this article: Bone Joint J 2024;106-B(5 Supple B):32–39

The recognition of hips at risk of displacement in children with cerebral palsy (CP) is a difficult problem for the orthopaedic surgeon. The Gross Motor Function Classification System (GMFCS) and head–shaft angle (HSA) are prognostic factors for hip displacement. However, reference values for HSA are lacking. This study describes and compares the development of HSA in normal hips and children with CP. . We selected 33 children from a retrospective cohort with unilateral developmental dysplasia of the hip (DDH) (five boys, 28 girls) and 50 children (35 boys, 15 girls) with CP with GMFCS levels II to V. HSA of normal developing hips was measured at the contralateral hip of unilateral DDH children (33 hips) and HSA of CP children was measured in both hips (100 hips). Measurements were taken from the radiographs of the children at age two, four and seven years. The normal hip HSA decreased by 2° per year (p < 0.001). In children with CP with GMFCS levels II and III HSA decreased by 0.6° (p = 0.046) and 0.9° (p = 0.049) per year, respectively. The HSA did not alter significantly in GMFCS levels IV and V. . Between the ages of two and eight years, the HSA decreases in normal hips and CP children with GMFCS level, II to III but does not change in GMFCS levels IV to V. As HSA has a prognostic value for hip displacement, these reference values may help the orthopaedic surgeon to predict future hip displacement in children with CP. Cite this article: Bone Joint J 2015;97-B:1291–5

Aims. The diagnosis of developmental dysplasia of the hip (DDH) is challenging owing to extensive variation in paediatric pelvic anatomy. Artificial intelligence (AI) may represent an effective diagnostic tool for DDH. Here, we aimed to develop an anteroposterior pelvic radiograph deep learning system for diagnosing DDH in children and analyze the feasibility of its application. Methods. In total, 10,219 anteroposterior pelvic radiographs were retrospectively collected from April 2014 to December 2018. Clinicians labelled each radiograph using a uniform standard method. Radiographs were grouped according to age and into ‘dislocation’ (dislocation and subluxation) and ‘non-dislocation’ (normal cases and those with dysplasia of the acetabulum) groups based on clinical diagnosis. The deep learning system was trained and optimized using 9,081 radiographs; 1,138 test radiographs were then used to compare the diagnoses made by deep learning system and clinicians. The accuracy of the deep learning system was determined using a receiver operating characteristic curve, and the consistency of acetabular index measurements was evaluated using Bland-Altman plots. Results. In all, 1,138 patients (242 males; 896 females; mean age 1.5 years (SD 1.79; 0 to 10) were included in this study. The area under the receiver operating characteristic curve, sensitivity, and specificity of the deep learning system for diagnosing hip dislocation were 0.975, 276/289 (95.5%), and 1,978/1,987 (99.5%), respectively. Compared with clinical diagnoses, the Bland-Altman 95% limits of agreement for acetabular index, as determined by the deep learning system from the radiographs of non-dislocated and dislocated hips, were -3.27° - 2.94° and -7.36° - 5.36°, respectively (p < 0.001). Conclusion. The deep learning system was highly consistent, more convenient, and more effective for diagnosing DDH compared with clinician-led diagnoses. Deep learning systems should be considered for analysis of anteroposterior pelvic radiographs when diagnosing DDH. The deep learning system will improve the current artificially complicated screening referral process. Cite this article: Bone Joint J 2020;102-B(11):1574–1581

We evaluated the duration of hospitalisation, occurrence of infections, hip dislocations, revisions, and mortality following primary hip and knee replacement in 857 patients with Parkinson’s disease and compared them with 2571 matched control patients. The data were collected from comprehensive nationwide Finnish health registers. The mean follow-up was six years (1 to 13). The patients with Parkinson’s disease had a longer mean length of stay (21 days [1 to 365] vs 13 [1 to 365] days) and an increased risk for hip dislocation during the first post-operative year (hazard ratio (HR) 2.33, 95% confidence intervals (CI) 1.02 to 5.32). There was no difference in infection and revision rates, and one-year mortality. In longer follow-up, patients with Parkinson’s disease had higher mortality (HR 1.94, 95% CI 1.68 to 2.25) and only 274 (34.7%) were surviving ten years after surgery. In patients with Parkinson’s disease, cardiovascular and psychiatric comorbidity were associated with prolonged hospitalisation and cardiovascular diseases also with increased mortality. Cite this article: Bone Joint J 2014;96-B:486–91

Aims. The aim of this study was to evaluate the prosthesis characteristics and associated conditions that may modify the survival of total femoral endoprosthetic replacements (TFEPR). Patients and Methods. In all, 81 patients treated with TFEPR from 1976 to 2017 were retrospectively evaluated and failures were categorized according to the Henderson classification. There were 38 female patients (47%) and 43 male patients (53%) with a mean age at diagnosis of 43 years (12 to 86). The mean follow-up time was 10.3 years (0 to 31.7). A survival analysis was performed followed by univariate and multivariate Cox regression to identify independent implant survival factors. Results. The revision-free survival of the implant was 71% at five years and 63.3% at ten years. Three prostheses reached 15 years without revision. The mean Musculoskeletal Tumor Society score in the group was 26 (23 to 28). The mechanisms of failure were infection in 18%, structural failures in 6%, tumour progression in 5%, aseptic loosening in 2%, and soft-tissue failures in 1%. Prostheses used for primary reconstruction after oncological resections had lower infection rates than revision implants (8% vs 25%; p = 0.001). The rates of infection in silver-coated and non-silver-coated prosthesis were similar (17.4% vs 19.%; p = 0.869). The incidence of hip dislocation was 10%. Rotating hinge prosthesis had a lower failure rate than fixed hinge prosthesis (5.3% vs 11%). After Cox regression, the independent factors associated with failures were the history of previous operations (hazard ratio (HR) 3.7; p = 0.041), and the associated arthroplasty of the proximal tibia (HR 3.8; p = 0.034). At last follow-up, 11 patients (13%) required amputation. Conclusion. TFEPR offers a reliable reconstruction option for massive bone loss of the femur, with a good survival when the prosthesis is used as a primary implant. The use of a rotating hinge at the knee and dual mobility bearing at the hip may be adequate to reduce the risk of mechanical and soft-tissue failures. Infection remains the main concern and there is insufficient evidence to support the routine use of silver-coated endoprosthesis. Cite this article: Bone Joint J 2019;101-B:522–528

Haefeli PC, Marecek GS, Keel MJB, Siebenrock KA, Tannast M. Patients undergoing surgical hip dislocation for the treatment of acetabular fractures show favourable long-term outcome. Bone Joint J;2017;99-B:508-515

Aims. Despite the presence of screening programmes, infants continue to present with late developmental dysplasia of the hip (DDH), the impact of which is significant. The aim of this study was to assess infants with late presenting dislocation of the hip despite universal clinical neonatal and selective ultrasound screening. Patients and Methods. Between 01 January 1997 to 31 December 2011, a prospective, longitudinal study was undertaken of a cohort of 64 670 live births. Late presenting dislocation was defined as presentation after three months of age. Diagnosis was confirmed by ultrasound and plain radiography. Patient demographics, referral type, reason for referral, risk factors (breech presentation/strong family history) and clinical and radiological findings were recorded. Results. There were 31 infants with an irreducible dislocation of the hip, an incidence of 0.48 (95% confidence interval (CI) 0.34 to 0.68) per 1000 live births. Of these, 18 (0.28 (95% CI 0.17 to 0.44) per 1000 live births; 58%) presented late. All infants had a documented normal newborn clinical examination and no abnormality reported in the six to eight week check. Of the 18 late presenting cases 72% (n = 13) had no risk factors: 16 were referred by GPs and two were late due to administrative issues (missed appointments). The mean time to diagnosis was 62.4 weeks (19 to 84). Conclusion. Despite universal clinical neonatal and selective ultrasound screening, late cases of irreducible hip dislocation still occur. We recommend an update of the national screening programme for DDH, a review of training and education of healthcare professionals involved in the physical examination of neonates and infants, and the addition of a further assessment after the six to eight week check. Cite this article: Bone Joint J 2017;99-B:1250–5

Aims. This study analysed the clinical and radiological outcome of anatomical reduction of a moderate or severe stable slipped capital femoral epiphysis (SCFE) treated by subcapital osteotomy (a modified Dunn osteotomy) through the surgical approach described by Ganz. . Patients and Methods. We prospectively studied 31 patients (32 hips; 16 females and five males; mean age 14.3 years) with SCFE. On the Southwick classification, ten were of moderate severity (head-shaft angle > 30° to 60°) and 22 were severe (head-shaft angle > 60°). Each underwent open reduction and internal fixation using an intracapsular osteotomy through the physeal growth plate after safe surgical hip dislocation. Unlike the conventional procedure, 25 hips did not need an osteotomy of the apophysis of the great trochanter and were managed using an extended retinacular posterior flap. . Results. Clinical outcome was assessed using the range of movement and the Harris Hip (HHS), Western Ontario and McMaster Universities Osteoarthritis (WOMAC), and Merle d’Aubigné scores, while radiological measurements included slip and alpha angles. The mean duration of follow-up was 24.1 months (12 to 40). . There was a significant improvement in all clinical and radiological measurements after treatment (p < 0.001). Post-operative major complications were one deep infection and one case of femoral head collapse. . Conclusion. These findings suggest that a modified Dunn osteotomy carried out through Ganz approach is a safe and effective method of treating the stable SCFE with a high degree of slip. . Cite this article: Bone Joint J 2016;98-B:1283–8

Aims. This study reports the mid-term results of total hip arthroplasty (THA) performed using a monoblock acetabular component with a large-diameter head (LDH) ceramic-on-ceramic (CoC) bearing. Patients and Methods. Of the 276 hips (246 patients) included in this study, 264 (96%) were reviewed at a mean of 67 months (48 to 79) postoperatively. Procedures were performed with a mini posterior approach. Clinical and radiological outcomes were recorded at regular intervals. A noise assessment questionnaire was completed at last follow-up. Results. There were four re-operations (1%) including one early revision for insufficient primary fixation (0.4%). No hip dislocation was reported. The mean University of California, Los Angeles (UCLA) activity score, 12-Item Short-Form Health Survey (SF-12) Mental Component Summary (MCS) score, SF-12 Physical Component Summary (PCS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and Forgotten Joint Score (FJS) were 6.6 (2 to 10), 52.8 (25.5 to 65.7), 53.0 (27.2 to 66.5), 7.7 (0 to 63), and 88.5 (23 to 100), respectively. No signs of loosening or osteolysis were observed on radiological review. The incidence of squeaking was 23% (n = 51/225). Squeaking was significantly associated with larger head diameter (p < 0.001), younger age (p < 0.001), higher SF-12 PCS (p < 0.001), and UCLA scores (p < 0.001). Squeaking did not affect patient satisfaction, with 100% of the squeaking hips satisfied with the surgery. Conclusion. LDH CoC THAs have demonstrated excellent functional outcomes at medium-term follow-up, with very low revision rate and no dislocations. The high incidence of squeaking did not affect patient satisfaction or function. LDH CoC with a monoblock acetabular component has the potential to provide long term implant survivorship with unrestricted activity, while avoiding implant impingement, liner fracture at insertion, and hip instability. Cite this article: Bone Joint J 2018;100-B:1434–41

Aims

Abduction bracing is commonly used to treat developmental dysplasia of the hip (DDH) following closed reduction and spica casting, with little evidence to support or refute this practice. The purpose of this study was to determine the efficacy of abduction bracing after closed reduction in improving acetabular index (AI) and reducing secondary surgery for residual hip dysplasia.

Aims

Isolated acetabular liner exchange with a highly crosslinked polyethylene (HXLPE) component is an option to address polyethylene wear and osteolysis following total hip arthroplasty (THA) in the presence of a well-fixed acetabular shell. The liner can be fixed either with the original locking mechanism or by being cemented within the acetabular component. Whether the method used for fixation of the HXLPE liner has any bearing on the long-term outcomes is still unclear.

1. There is an increasing prevalence in the evidence of prenatal extended knee postures in the legs of newborn, from normal births to breech deliveries and to babies with hip displacements. The extended knee postures are also commoner in female births. 2. Babies with reducible hip displacements appear to be born more often in summer as the result of winter conceptions. Spontaneous recovery is very high, with or without splintage. 3. Irreducible hip displacement does not respond to splintage during the first six months of life. Even with adductor tenotomy, there is a great risk of acetabular and femoral epiphysial damage. This is thought to be due to incarceration of the limbus, present at birth

Aims. A clicky hip is a common referral for clinical and sonographic screening for developmental dysplasia of the hip (DDH). There is controversy regarding whether it represents a true risk factor for pathological DDH. Therefore a 20-year prospective, longitudinal, observational study was undertaken to assess the relationship between the presence of a neonatal clicky hip and pathological DDH. Patients and Methods. A total of 362 infants from 1997 to 2016 were referred with clicky hips to our ‘one-stop’ paediatric hip screening clinic. Hips were assessed clinically for instability and by ultrasound imaging using a simplified Graf/Harcke classification. Dislocated or dislocatable hips were classified as Graf Type IV hips. Results. The mean age at presentation was 13.8 weeks (12.8 to 14.7). In all 351 out of 362 children (97.0%) had Graf Type I hips (normal) that required no treatment. Nine children (2.5%) had Graf Type II hips but all resolved to Graf Type I hips on follow-up scans. One child (0.3%) had Graf Type III hip dysplasia and one child (0.3%) had an irreducible hip dislocation. The two pathological hips were associated with unilateral limited hip abduction. Mean referrals increased from 12.9 to 23.3 each year (p = 0.002) from the first decade of the study to the second, driven by increasing primary care referrals (5.5 versus 16.7 per year, p < 0.001). Conclusion. Most clicky hips required no treatment other than reassurance to parents. Clicky hips with a normal hip examination should be considered a variant of normal childhood and not a risk factor for DDH. However, an abnormal hip examination including unilateral limited hip abduction should prompt urgent further investigations. Cite this article: Bone Joint J 2017;99-B:1533–6

Literature surrounding artificial intelligence (AI)-related applications for hip and knee arthroplasty has proliferated. However, meaningful advances that fundamentally transform the practice and delivery of joint arthroplasty are yet to be realized, despite the broad range of applications as we continue to search for meaningful and appropriate use of AI. AI literature in hip and knee arthroplasty between 2018 and 2021 regarding image-based analyses, value-based care, remote patient monitoring, and augmented reality was reviewed. Concerns surrounding meaningful use and appropriate methodological approaches of AI in joint arthroplasty research are summarized. Of the 233 AI-related orthopaedics articles published, 178 (76%) constituted original research, while the rest consisted of editorials or reviews. A total of 52% of original AI-related research concerns hip and knee arthroplasty (n = 92), and a narrative review is described. Three studies were externally validated. Pitfalls surrounding present-day research include conflating vernacular (“AI/machine learning”), repackaging limited registry data, prematurely releasing internally validated prediction models, appraising model architecture instead of inputted data, withholding code, and evaluating studies using antiquated regression-based guidelines. While AI has been applied to a variety of hip and knee arthroplasty applications with limited clinical impact, the future remains promising if the question is meaningful, the methodology is rigorous and transparent, the data are rich, and the model is externally validated. Simple checkpoints for meaningful AI adoption include ensuring applications focus on: administrative support over clinical evaluation and management; necessity of the advanced model; and the novelty of the question being answered.

Cite this article: Bone Joint J 2022;104-B(12):1292–1303.

Dislocation is one of the most common causes of patient and surgeon dissatisfaction following hip replacement and to treat it, the causes must first be understood. Patient factors include age greater than 70 years, medical comorbidities, female gender, ligamentous laxity, revision surgery, issues with the abductors, and patient education. Surgeon factors include the annual quantity of procedures and experience, the surgical approach, adequate restoration of femoral offset and leg length, component position, and soft-tissue or bony impingement. Implant factors include the design of the head and neck region, and so-called skirts on longer neck lengths. There should be offset choices available in order to restore soft-tissue tension. Lipped liners aid in gaining stability, yet if improperly placed may result in impingement and dislocation. Late dislocation may result from polyethylene wear, soft-tissue destruction, trochanteric or abductor disruption and weakness, or infection. Understanding the causes of hip dislocation facilitates prevention in a majority of instances. Proper pre-operative planning includes the identification of patients with a high offset in whom inadequate restoration of offset will reduce soft-tissue tension and abductor efficiency. Component position must be accurate to achieve stability without impingement. Finally, patient education cannot be over-emphasised, as most dislocations occur early, and are preventable with proper instructions. Cite this article: Bone Joint J 2013;95-B, Supple A:67–9

We have tested the reliability of a recently reported classification system of hip morphology in adolescents with cerebral palsy in whom the triradiate cartilage was closed. The classification is a six-grade ordinal scale, based on the measurement of the migration percentage and an assessment of Shenton’s arch, deformity of the femoral head, acetabular deformity and pelvic obliquity. Four paediatric orthopaedic surgeons and four physiotherapists received training in the use of the classification which they applied to the assessment of 42 hip radiographs, read on two separate occasions. The inter- and intra-observer reliability was assessed using the intraclass correlation coefficient and found to be excellent, with it ranging from 0.88 to 0.94. The classification in our study was shown to be valid (based on migration percentage), and reliable. As a result we believe that it can now be used in studies describing the natural history of hip displacement in cerebral palsy, in outcome studies and in communication between clinicians

Aims

It has been well documented in the arthroplasty literature that lumbar degenerative disc disease (DDD) contributes to abnormal spinopelvic motion. However, the relationship between the severity or pattern of hip osteoarthritis (OA) as measured on an anteroposterior (AP) pelvic view and spinopelvic biomechanics has not been well investigated. Therefore, the aim of the study is to examine the association between the severity and pattern of hip OA and spinopelvic motion.

Cartilage defects of the hip cause significant pain and may lead to arthritic changes that necessitate hip replacement. We propose the use of fresh osteochondral allografts as an option for the treatment of such defects in young patients. Here we present the results of fresh osteochondral allografts for cartilage defects in 17 patients in a prospective study. The underlying diagnoses for the cartilage defects were osteochondritis dissecans in eight and avascular necrosis in six. Two had Legg-Calve-Perthes and one a femoral head fracture. Pre-operatively, an MRI was used to determine the size of the cartilage defect and the femoral head diameter. All patients underwent surgical hip dislocation with a trochanteric slide osteotomy for placement of the allograft. The mean age at surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months (3 to 74). The mean Harris hip score was significantly better after surgery (p < 0.01) and 13 patients had fair to good outcomes. One patient required a repeat allograft, one patient underwent hip replacement and two patients are awaiting hip replacement. Fresh osteochondral allograft is a reasonable treatment option for hip cartilage defects in young patients. Cite this article: Bone Joint J 2014;96-B(11 Supple A):11–16

Aims

To examine the long-term outcome of arthrodesis of the hip undertaken in a paediatric population in treating painful arthritis of the hip. In our patient population, most of whom live rurally in hilly terrain and have limited healthcare access and resources, hip arthrodesis has been an important surgical option for the monoarticular painful hip in a child.

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The use of a porous metal shell supported by two augments with the ‘footing’ technique is one solution to manage Paprosky IIIB acetabular defects in revision total hip arthroplasty. The aim of this study was to assess the medium-term implant survival and radiological and clinical outcomes of this technique.

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To analyze whether the addition of risk-based criteria to clinical examination-based selective ultrasound screening would increase the rates of early detected cases of developmental dysplasia of the hip (DDH) and decrease the rate of late detected cases.

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Oxidized zirconium (OxZi) and highly cross-linked polyethylene (HXLPE) were developed to minimize wear and risk of osteolysis in total hip arthroplasty (THA). However, retrieval studies have shown that scratched femoral heads may lead to runaway wear, and few reports of long-term results have been published. The purpose of this investigation is to report minimum ten-year wear rates and clinical outcomes of THA with OxZi femoral heads on HXLPE, and to compare them with a retrospective control group of cobalt chrome (CoCr) or ceramic heads on HXLPE.

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Accurate diagnosis of chronic periprosthetic joint infection (PJI) presents a significant challenge for hip surgeons. Preoperative diagnosis is not always easy to establish, making the intraoperative decision-making process crucial in deciding between one- and two-stage revision total hip arthroplasty (THA). Calprotectin is a promising point-of-care novel biomarker that has displayed high accuracy in detecting PJI. We aimed to evaluate the utility of intraoperative calprotectin lateral flow immunoassay (LFI) in THA patients with suspected chronic PJI.

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Radiological residual acetabular dysplasia (RAD) has been reported in up to 30% of children who had successful brace treatment of infant developmental dysplasia of the hip (DDH). Predicting those who will resolve and those who may need corrective surgery is important to optimize follow-up protocols. In this study we have aimed to identify the prevalence and predictors of RAD at two years and five years post-bracing.

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Surgical approaches that claim to be minimally invasive, such as the direct anterior approach (DAA), are reported to have a clinical advantage, but are technically challenging and may create more injury to the soft-tissues during joint exposure. Our aim was to quantify the effect of soft-tissue releases on the joint torque and femoral mobility during joint exposure for hip resurfacing performed via the DAA.

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The sacroiliac joint (SIJ) is the only mechanical connection between the axial skeleton and lower limbs. Following iliosacral resection, there is debate on whether reconstruction of the joint is necessary. There is a paucity of data comparing the outcomes of patients undergoing reconstruction and those who are not formally reconstructed.

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Perthes’ disease (PD) is a childhood hip disorder that can affect the quality of life in adulthood due to femoral head deformity and osteoarthritis. There is very little data on how PD patients function as adults, especially from the patients’ perspective. The purpose of this study was to collect treatment history, demographic details, the University of California, Los Angeles activity score (UCLA), the 36-Item Short Form survey (SF-36) score, and the Hip disability and Osteoarthritis Outcome score (HOOS) of adults who had PD using a web-based survey method and to compare their outcomes to the outcomes from an age- and sex-matched normative population.

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Nonagenarians (aged 90 to 99 years) have experienced the fastest percent decile population growth in the USA recently, with a consequent increase in the prevalence of nonagenarians living with joint arthroplasties. As such, the number of revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) in nonagenarians is expected to increase. We aimed to determine the mortality rate, implant survivorship, and complications of nonagenarians undergoing aseptic revision THAs and revision TKAs.

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To clarify the mid-term results of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, combined with structural allograft bone grafting for severe hip dysplasia.