Arthritis of the wrist is a painful disabling condition that has various causes and presentations. The traditional treatment has been a total wrist fusion at a price of the elimination of movement. However, forms of treatment which allow the preservation of movement are now preferred. Modern arthroplasties of the wrist are still not sufficiently robust to meet the demands of many patients, nor do they restore normal kinematics of the wrist. A preferable compromise may be selective excision and partial fusion of the wrist using knowledge of the aetiology and pattern of degenerative change to identify which joints can be sacrificed and which can be preserved.

This article provides an overview of the treatment options available for patients with arthritis of the wrist and an algorithm for selecting an appropriate surgical strategy.

Cite this article: Bone Joint J 2015;97-B:1303–8.

Despite being one of the most common orthopaedic operations, it is still not known how many arthroscopies of the knee must be performed during training in order to develop the skills required to become a Consultant. A total of 54 subjects were divided into five groups according to clinical experience: Novices (n = 10), Junior trainees (n = 10), Registrars (n = 18), Fellows (n = 10) and Consultants (n = 6). After viewing an instructional presentation, each subject performed a simple diagnostic arthroscopy of the knee on a simulator with visualisation and probing of ten anatomical landmarks. Performance was assessed using a validated global rating scale (GRS). Comparisons were made against clinical experience measured by the number of arthroscopies which had been undertaken, and ROC curve analysis was used to determine the number of procedures needed to perform at the level of the Consultants.

There were marked differences between the groups. There was significant improvement in performance with increasing experience (p < 0.05).

ROC curve analysis identified that approximately 170 procedures were required to achieve the level of skills of a Consultant.

We suggest that this approach to identify what represents the level of surgical skills of a Consultant should be used more widely so that standards of training are maintained through the development of an evidenced-based curriculum.

Cite this article: Bone Joint J 2015;97-B:1309–15.

The purpose of this study was to determine patient-reported outcomes of patients with mild to moderate developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) undergoing arthroscopy of the hip in the treatment of chondrolabral pathology. A total of 28 patients with a centre-edge angle between 15° and 19° were identified from an institutional database. Their mean age was 34 years (18 to 53), with 12 female and 16 male patients. All underwent labral treatment and concomitant correction of FAI. There were nine reoperations, with two patients requiring revision arthroscopy, two requiring periacetabular osteotomy and five needing total hip arthroplasty.

Patients who required further major surgery were more likely to be older, male, and to have more severe DDH with a larger alpha angle and decreased joint space.

At a mean follow-up of 42 months (24 to 89), the mean modified Harris hip score improved from 59 (20 to 98) to 82 (45 to 100; p < 0.001). The mean Western Ontario and McMaster Universities Osteoarthritis Index score improved from 30 (1 to 61) to 16 (0 to 43; p < 0.001). Median patient satisfaction was 9.0/10 (1 to 10). Patients reported excellent improvement in function following arthroscopy of the hip.

This study shows that with proper patient selection, arthroscopy of the hip can be successful in the young patient with mild to moderate DDH and FAI.

Cite this article: Bone Joint J 2015;97-B:1316–21.

We report patient-reported outcomes and complications associated with contemporary periacetabular osteotomy (PAO) surgery in treating symptomatic acetabular dysplasia and compare these outcomes with total hip arthroplasty (THA) in patients with similar demographic details. Two consecutive cohorts included patients between aged 18 to 40 years who had undergone either PAO (100 hips; 24 male, 76 female) or THA (55 hips; 18 male, 37 female). At a mean follow-up of 5.9 years (2 to 13), there was significant improvement in the modified Harris hip pain (p < 0.001, PAO and p < 0.001, THA), function (p < 0.001, PAO and p = 0.001, THA), and total scores (p < 0.001, PAO and p < 0.001, THA) within each cohort. There were no significant differences in the clinical outcome scores between the groups. Complication rates were low and similar in each cohort (p = 0.68). Similar to THA, contemporary PAO surgery is a clinically effective procedure that improves function and activity levels, provides pain relief and is associated with an acceptable complication rate.

Cite this article: Bone Joint J 2015;97-B:1322–7.

We investigated the changes seen on serial metal artefact reduction magnetic resonance imaging scans (MARS-MRI) of metal-on-metal total hip arthroplasties (MoM THAs). In total 155 THAs, in 35 male and 100 female patients (mean age 70.4 years, 42 to 91), underwent at least two MRI scans at a mean interval of 14.6 months (2.6 to 57.1), at a mean of 48.2 months (3.5 to 93.3) after primary hip surgery. Scans were graded using a modification of the Oxford classification. Progression of disease was defined as an increase in grade or a minimum 10% increase in fluid lesion volume at second scan. A total of 16 hips (30%) initially classified as ‘normal’ developed an abnormality on the second scan. Of those with ‘isolated trochanteric fluid’ 9 (47%) underwent disease progression, as did 7 (58%) of ‘effusions’. A total of 54 (77%) of hips initially classified as showing adverse reactions to metal debris (ARMD) progressed, with higher rates of progression in higher grades. Disease progression was associated with high blood cobalt levels or an irregular pseudocapsule lining at the initial scan. There was no association with changes in functional scores. Adverse reactions to metal debris in MoM THAs may not be as benign as previous reports have suggested. Close radiological follow-up is recommended, particularly in high-risk groups.

Cite this article: Bone Joint J 2015;97-B:1328–37.

We present the results of 62 consecutive acetabular revisions using impaction bone grafting and a cemented polyethylene acetabular component in 58 patients (13 men and 45 women) after a mean follow-up of 27 years (25 to 30). All patients were prospectively followed. The mean age at revision was 59.2 years (23 to 82).

We performed Kaplan–Meier (KM) analysis and also a Competing Risk (CR) analysis because with long-term follow-up, the presence of a competing event (i.e. death) prevents the occurrence of the endpoint of re-revision.

A total of 48 patients (52 hips) had died or had been re-revised at final review in March 2011. None of the deaths were related to the surgery. The mean Harris hip score of the ten surviving hips in ten patients was 76 points (45 to 99).

The KM survivorship at 25 years for the endpoint ‘re-revision for any reason’ was 58.0% (95% confidence interval (CI) 38 to 73) and for ‘re-revision for aseptic loosening’ 72.1% (95% CI 51 to 85). With the CR analysis we calculated the KM analysis overestimates the failure rate with respectively 74% and 93% for these endpoints. The current study shows that acetabular impaction bone grafting revisions provide good clinical results at over 25 years.

Cite this article: Bone Joint J 2015;97-B:1338–44.

Sciatic nerve palsy following total hip arthroplasty (THA) is a relatively rare yet potentially devastating complication. The purpose of this case series was to report the results of patients with a sciatic nerve palsy who presented between 2000 and 2010, following primary and revision THA and were treated with neurolysis. A retrospective review was made of 12 patients (eight women and four men), with sciatic nerve palsy following THA. The mean age of the patients was 62.7 years (50 to 72; standard deviation 6.9). They underwent interfascicular neurolysis for sciatic nerve palsy, after failing a trial of non-operative treatment for a minimum of six months. Following surgery, a statistically and clinically significant improvement in motor function was seen in all patients. The mean peroneal nerve score function improved from 0.42 (0 to 3) to 3 (1 to 5) (p < 0.001). The mean tibial nerve motor function score improved from 1.75 (1 to 4) to 3.92 (3 to 5) (p = 0.02).The mean improvement in sensory function was a clinically negligible 1 out of 5 in all patients. In total, 11 patients reported improvement in their pain following surgery.

We conclude that neurolysis of the sciatic nerve has a favourable prognosis in patients with a sciatic nerve palsy following THA. Our findings suggest that surgery should not be delayed for > 12 months following injury.

Cite this article: Bone Joint J 2015;97-B:1345–9

The early failure and revision of bimodular primary total hip arthroplasty prostheses requires the identification of the risk factors for material loss and wear at the taper junctions through taper wear analysis. Deviations in taper geometries between revised and pristine modular neck tapers were determined using high resolution tactile measurements. A new algorithm was developed and validated to allow the quantitative analysis of material loss, complementing the standard visual inspection currently used.

The algorithm was applied to a sample of 27 retrievals (in situ from 2.9 to 38.1 months) of the withdrawn Rejuvenate modular prosthesis. The mean wear volumes on the flat distal neck piece taper was 3.35 mm³ (0.55 to 7.57), mainly occurring in a characteristic pattern in areas with high mechanical loading. Wear volume tended to increase with time to revision (r² = 0.423, p = 0.001). Implant and patient specific data (offset, stem size, patient’s mass, age and body mass index) did not correlate with the amount of material loss observed (p >  0.078). Bilaterally revised implants showed higher amounts of combined total material loss and similar wear patterns on both sides. The consistent wear pattern found in this study has not been reported previously, suggesting that the device design and materials are associated with the failure of this prosthesis.

Cite this article: Bone Joint J 2015;97-B:1350–7.

This study reports on the first 150 consecutive Oxford cementless unicompartmental knee arthroplasties (UKA) performed in an independent centre (126 patients). All eligible patients had functional scores (Oxford knee score and high activity arthroplasty score) recorded pre-operatively and at two- and five-years of follow-up. Fluoroscopically aligned radiographs were taken at five years and analysed for any evidence of radiolucent lines (RLLs), subsidence or loosening. The mean age of the cohort was 63.6 years (39 to 86) with 81 (53.1%) males. Excellent functional scores were maintained at five years and there were no progressive RLLs demonstrated on radiographs. Two patients underwent revision to a total knee arthroplasty giving a revision rate of 0.23/100 (95% confidence interval 0.03 to 0.84) component years with overall component survivorship of 98.7% at five years. There were a further four patients who underwent further surgery on the same knee, two underwent bearing exchanges for dislocation and two underwent lateral UKAs for disease progression. This was a marked improvement from other UKAs reported in New Zealand Joint Registry data and supports the designing centre’s early results.

Cite this article: Bone Joint J 2015;97-B:1358–63.

Macrodactyly of the foot is a rare but disabling condition. We present the results of surgery on 18 feet of 16 patients, who underwent ray amputation and were followed-up for more than two years at a mean of 80 months (25 to 198).

We radiologically measured the intermetatarsal width and forefoot area pre-operatively and at six weeks and two years after surgery. We also evaluated the clinical results using the Oxford Ankle Foot Questionnaire for children (OxAFQ-C) and the Questionnaire for Foot Macrodactyly.

The intermetatarsal width and forefoot area ratios were significantly decreased after surgery. The mean OxAFQ-C score was 42 (16 to 57) pre-operatively, improving to 47 (5 to 60) at two years post-operatively (p = 0.021). The mean questionnaire for Foot Macrodactyly score two years after surgery was 8 (6 to 10).

Ray amputation gave a measurable reduction in foot size with excellent functional results. For patients with metatarsal involvement, a motionless toe, or involvement of multiple digits, ray amputation is a clinically effective option which is acceptable to patients.

Cite this article: Bone Joint J 2015;97-B:1364–9.

This article is a systematic review of the published literature about the biomechanics, functional outcome and complications of intramedullary nailing of fractures of the distal radius.

We searched the Medline and EMBASE databases and included all studies which reported the outcome of intramedullary (IM) nailing of fractures of the distal radius. Data about functional outcome, range of movement (ROM), strength and complications, were extracted. The studies included were appraised independently by both authors using a validated quality assessment scale for non-controlled studies and the CONSORT statement for randomised controlled trials (RCTs).

The search strategy revealed 785 studies, of which 16 were included for full paper review. These included three biomechanical studies, eight case series and five randomised controlled trials (RCTs).

The biomechanical studies concluded that IM nails were at least as strong as locking plates. The clinical studies reported that IM nailing gave a comparable ROM, functional outcome and grip strength to other fixation techniques.

However, the mean complication rate of intramedullary nailing was 17.6% (0% to 50%). This is higher than the rates reported in contemporary studies for volar plating. It raises concerns about the role of intramedullary nailing, particularly when comparative studies have failed to show that it has any major advantage over other techniques. Further adequately powered RCTs comparing the technique to both volar plating and percutaneous wire fixation are needed.

Cite this article: Bone Joint J 2015;97-B:1370–6.

We report our experience of performing an elbow hemiarthroplasty in the treatment of comminuted distal humeral fractures in the elderly patients.

A cohort of 42 patients (three men and 39 women, mean age 72; 56 to 84) were reviewed at a mean of 34.3 months (24 to 61) after surgery. Functional outcome was measured with the Mayo Elbow Performance Score (MEPS) and range of movement. The disabilities of the arm, shoulder and hand questionnaire (DASH) was used as a patient rated evaluation. Complications and ulnar nerve function were recorded. Plain radiographs were obtained to assess prosthetic loosening, olecranon wear and heterotopic bone formation.

The mean extension deficit was 23.5° (0° to 60°) and mean flexion was 126.8° (90° to 145°) giving a mean arc of 105.5° (60° to 145°). The mean MEPS was 90 (50 to 100) and a mean DASH score of 20 (0 to 63). Four patients had additional surgery for limited range of movement and one for partial instability. One elbow was revised due to loosening, two patients had sensory ulnar nerve symptoms, and radiographic signs of mild olecranon wear was noted in five patients.

Elbow hemiarthroplasty for comminuted intra-articular distal humeral fractures produces reliable medium-term results with functional outcome and complication rates, comparable with open reduction and internal fixation and total elbow arthroplasty.

Cite this article: Bone Joint J 2015;97-B:1377–84.

We assessed the age-related differences in the use of total shoulder arthroplasty (TSA) and outcomes, and associated time-trends using the United States Nationwide Inpatient Sample (NIS) between 1998 and 2010. Age was categorised as < 50, 50 to 64, 65 to 79 and ≥ 80 years. Time-trends in the use of TSA were compared using logistic regression or the Cochran Armitage test.

The overall use of TSA increased from 2.96/100 000 in 1998 to 12.68/100 000 in 2010. Significantly lower rates were noted between 2009 and 2010, compared with between 1998 and 2000, for: mortality, 0.1% versus 0.2% (p = 0.004); discharge to an inpatient facility, 13.3% versus 14.5% (p = 0.039), and hospital stay > median, 29.4% versus 51.2% (p < 0.001).

The rates of use of TSA/100 000 by age groups, < 50, 50 to 64, 65 to 79 and ≥ 80 years were: 0.32, 4.62, 17.82 and 12.56, respectively in 1998 (p < 0.001); and 0.65, 17.49, 75.27 and 49.05, respectively in 2010 (p < 0.001) with an increasing age-related difference over time (p <  0.001). Across the age categories, there were significant differences in the proportion: discharged to an inpatient facility, 3.2% versus 4.2% versus 14.7% versus 36.5%, respectively in 1998 (p < 0.001) and 1.8% versus 4.3% versus 12.5% versus 35.5%, respectively in 2010 (p <  0.001) and the proportion with hospital stay > median, 39.7% versus 40.2% versus 53% versus 69%, respectively in 1998 (p < 0.001) and 17.2% versus 20.6% versus 28.7% versus 50.7%, respectively in 2010 (p < 0.001).

In a nationally representative sample, we noted a time-related increase in the use of TSA and increasing age-related differences in outcomes indicating a changing epidemiology of the use of TSA. Age-related differences in outcomes suggest that attention should focus on groups with the worst outcomes.

Cite this article: Bone Joint J 2015;97-B:1385–9.

There is no universally agreed definition of cauda equina syndrome (CES). Clinical signs of CES including direct rectal examination (DRE) do not reliably correlate with cauda equina (CE) compression on MRI. Clinical assessment only becomes reliable if there are symptoms/signs of late, often irreversible, CES. The only reliable way of including or excluding CES is to perform MRI on all patients with suspected CES. If the diagnosis is being considered, MRI should ideally be performed locally in the District General Hospitals within one hour of the question being raised irrespective of the hour or the day. Patients with symptoms and signs of CES and MRI confirmed CE compression should be referred to the local spinal service for emergency surgery.

CES can be subdivided by the degree of neurological deficit (bilateral radiculopathy, incomplete CES or CES with retention of urine) and also by time to surgical treatment (12, 24, 48 or 72 hour). There is increasing understanding that damage to the cauda equina nerve roots occurs in a continuous and progressive fashion which implies that there are no safe time or deficit thresholds. Neurological deterioration can occur rapidly and is often associated with longterm poor outcomes. It is not possible to predict which patients with a large central disc prolapse compressing the CE nerve roots are going to deteriorate neurologically nor how rapidly. Consensus guidelines from the Society of British Neurological Surgeons and British Association of Spinal Surgeons recommend decompressive surgery as soon as practically possible which for many patients will be urgent/emergency surgery at any hour of the day or night.

Cite this article: Bone Joint J 2015;97-B:1390–4

The aim of this study was to determine whether obesity affects pain, surgical and functional outcomes following lumbar spinal fusion for low back pain (LBP).

A systematic literature review and meta-analysis was made of those studies that compared the outcome of lumbar spinal fusion for LBP in obese and non-obese patients. A total of 17 studies were included in the meta-analysis. There was no difference in the pain and functional outcomes. Lumbar spinal fusion in the obese patient resulted in a statistically significantly greater intra-operative blood loss (weighted mean difference: 54.04 ml; 95% confidence interval (CI) 15.08 to 93.00; n = 112; p = 0.007) more complications (odds ratio: 1.91; 95% CI 1.68 to 2.18; n = 43858; p < 0.001) and longer duration of surgery (25.75 mins; 95% CI 15.61 to 35.90; n = 258; p < 0.001). Obese patients have greater intra-operative blood loss, more complications and longer duration of surgery but pain and functional outcome are similar to non-obese patients. Based on these results, obesity is not a contraindication to lumbar spinal fusion.

Cite this article: Bone Joint J 2015;97-B:1395–1404.

Cardiac disease in patients with ankylosing spondylitis (AS) has previously been studied but not in patients with a kyphosis or in those who have undergone an operation to correct it.

The aim of this study was to measure the post-operative changes in cardiac function of patients with an AS kyphosis after pedicle subtraction osteotomy (PSO).

The original cohort consisted of 39 patients (33 men, six women). Of these, four patients (two men, two women) were lost to follow-up leaving 35 patients (31 men, four women) to study. The mean age of the remaining patients was 37.4 years (22.3 to 47.8) and their mean duration of AS was 17.0 years (4.6 to 26.4). Echocardiographic measurements, resting heart rate (RHR), physical function score (PFS), and full-length standing spinal radiographs were obtained before surgery and at the two-year follow-up.

The mean pre-operative RHR was 80.2 bpm (60.6 to 112.3) which dropped to a mean of 73.7 bpm (60.7 to 90.6) at the two-year follow-up (p = 0.0000). Of 15 patients with normal ventricular function pre-operatively, two developed mild left ventricular diastolic dysfunction (LVDD) at the two-year follow-up. Of 20 patients with mild LVDD pre-operatively only five had this post-operatively. Overall, 15 patients had normal LV diastolic function before their operation and 28 patients had normal LV function at the two-year follow-up.

The clinical improvement was 15 out of 20 (75.0%): cardiac function in patients with AS whose kyphosis was treated by PSO was significantly improved.

Cite this article: Bone Joint J 2015;97-B:1405–10.

We evaluated the impact of lumbar instrumented circumferential fusion on the development of adjacent level vertebral compression fractures (VCFs). Instrumented posterior lumbar interbody fusion (PLIF) has become a popular procedure for degenerative lumbar spine disease. The immediate rigidity produced by PLIF may cause more stress and lead to greater risk of adjacent VCFs. However, few studies have investigated the relationship between PLIF and the development of subsequent adjacent level VCFs.

Between January 2005 and December 2009, a total of 1936 patients were enrolled. Of these 224 patients had a new VCF and the incidence was statistically analysed with other covariants. In total 150 (11.1%) of 1348 patients developed new VCFs with PLIF, with 108 (72%) cases at adjacent segment. Of 588 patients, 74 (12.5%) developed new subsequent VCFs with conventional posterolateral fusion (PLF), with 37 (50%) patients at an adjacent level. Short-segment fusion, female and age older than 65 years also increased the development of new adjacent VCFs in patients undergoing PLIF. In the osteoporotic patient, more rigid fusion and a higher stress gradient after PLIF will cause a higher adjacent VCF rate.

Cite this article: Bone Joint J 2015;97-B:1411–16.

Tibial nonunion represents a spectrum of conditions which are challenging to treat, and optimal management remains unclear despite its high rate of incidence. We present 44 consecutive patients with 46 stiff tibial nonunions, treated with hexapod external fixators and distraction to achieve union and gradual deformity correction. There were 31 men and 13 women with a mean age of 35 years (18 to 68) and a mean follow-up of 12 months (6 to 40). No tibial osteotomies or bone graft procedures were performed. Bony union was achieved after the initial surgery in 41 (89.1%) tibias. Four persistent nonunions united after repeat treatment with closed hexapod distraction, resulting in bony union in 45 (97.8%) patients. The mean time to union was 23 weeks (11 to 49). Leg-length was restored to within 1 cm of the contralateral side in all tibias. Mechanical alignment was restored to within 5° of normal in 42 (91.3%) tibias. Closed distraction of stiff tibial nonunions can predictably lead to union without further surgery or bone graft. In addition to generating the required distraction to achieve union, hexapod circular external fixators can accurately correct concurrent deformities and limb-length discrepancies.

Cite this article: Bone Joint J 2015;97-B:1417–22.

Systemic antibiotics reduce infection in open fractures. Local delivery of antibiotics can provide higher doses to wounds without toxic systemic effects. This study investigated the effect on infection of combining systemic with local antibiotics via polymethylmethacrylate (PMMA) beads or gel delivery.

An established Staphylococcus aureus contaminated fracture model in rats was used. Wounds were debrided and irrigated six hours after contamination and animals assigned to one of three groups, all of which received systemic antibiotics. One group had local delivery via antibiotic gel, another PMMA beads and the control group received no local antibiotics. After two weeks, bacterial levels were quantified.

Combined local and systemic antibiotics were superior to systemic antibiotics alone at reducing the quantity of bacteria recoverable from each group (p = 0.002 for gel; p = 0.032 for beads). There was no difference in the bacterial counts between bead and gel delivery (p = 0.62).

These results suggest that local antibiotics augment the antimicrobial effect of systemic antibiotics. Although no significant difference was found between vehicles, gel delivery offers technical advantages with its biodegradable nature, ability to conform to wound shape and to deliver increased doses. Further study is required to see if the gel delivery system has a clinical role.

Cite this article: Bone Joint J 2015;97-B:1423–7.

Controversy remains whether the contralateral hip should be fixed in patients presenting with unilateral slipped capital femoral epiphysis (SCFE). This retrospective study compares the outcomes and cost of those patients who had prophylactic fixation with those who did not.

Between January 2000 and December 2010 a total of 50 patients underwent unilateral fixation and 36 had prophylactic fixation of the contralateral hip. There were 54 males and 32 females with a mean age of 12.3 years (9 to 16). The rate of a subsequent slip without prophylactic fixation was 46%. The risk of complications was greater, the generic health measures (Short Form-12 physical (p < 0.001) and mental (p = 0.004) summary scores) were worse. Radiographic cam lesions in patients presenting with unilateral SCFE were only seen in patients who did not have prophylactic fixation. Furthermore, prophylactic fixation of the contralateral hip was found to be a cost-effective procedure, with a cost per quality adjusted life year gained of £1431 at the time of last follow-up.

Prophylactic fixation of the contralateral hip is a cost-effective operation that limits the morbidity from the complications of a further slip, and the diminished functional outcome associated with unilateral fixation.

Cite this article: Bone Joint J 2015;97-B:1428–34.

Pelvic obliquity is a common finding in adolescents with cerebral palsy, however, there is little agreement on its measurement or relationship with hip development at different gross motor function classification system (GMFCS) levels.

The purpose of this investigation was to study these issues in a large, population-based cohort of adolescents with cerebral palsy at transition into adult services.

The cohort were a subset of a three year birth cohort (n = 98, 65M: 33F, with a mean age of 18.8 years (14.8 to 23.63) at their last radiological review) with the common features of a migration percentage greater than 30% and a history of adductor release surgery.

Different radiological methods of measuring pelvic obliquity were investigated in 40 patients and the angle between the acetabular tear drops (ITDL) and the horizontal reference frame of the radiograph was found to be reliable, with good face validity. This was selected for further study in all 98 patients.

The median pelvic obliquity was 4° (interquartile range 2° to 8°). There was a strong correlation between hip morphology and the presence of pelvic obliquity (effect of ITDL on Sharpe’s angle in the higher hip; rho 7.20 (5% confidence interval 5.59 to 8.81, p < 0.001). This was particularly true in non-ambulant adolescents (GMFCS IV and V) with severe pelvic obliquity, but was also easily detectable and clinically relevant in ambulant adolescents with mild pelvic obliquity.

The identification of pelvic obliquity and its management deserves closer scrutiny in children and adolescents with cerebral palsy.

Cite this article: Bone Joint J 2015;97-B:1435–40.

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.