The aim of this study was to investigate the incidence of dysplasia in the ‘normal’ contralateral hip in patients with unilateral developmental dislocation of the hip (DDH) and to evaluate the long-term prognosis of such hips. A total of 48 patients (40 girls and eight boys) were treated for late-detected unilateral DDH between 1958 and 1962. After preliminary skin traction, closed reduction was achieved at a mean age of 17.8 months (4 to 65) in all except one patient who needed open reduction. In 25 patients early derotation femoral osteotomy of the contralateral hip had been undertaken within three years of reduction, and later surgery in ten patients. Radiographs taken during childhood and adulthood were reviewed. The mean age of the patients was 50.9 years (43 to 55) at the time of the latest radiological review. In all, eight patients (17%) developed dysplasia of the contralateral hip, defined as a centre-edge (CE) angle < 20° during childhood or at skeletal maturity. Six of these patients underwent surgery to improve cover of the femoral head; the dysplasia improved in two after varus femoral osteotomy and in two after an acetabular shelf operation. During long-term follow-up the dysplasia deteriorated to subluxation in two patients (CE angles 4° and 5°, respectively) who both developed osteoarthritis (OA), and one of these underwent total hip replacement at the age of 49 years. In conclusion, the long-term prognosis for the contralateral hip was relatively good, as OA occurred in only two hips (4%) at a mean follow-up of 50 years. Regular review of the ‘normal’ side is indicated, and corrective surgery should be undertaken in those who develop subluxation. Cite this article: Bone Joint J 2014; 96-B:1161–6

In the majority of patients with slipped upper femoral epiphysis only one hip is involved at primary diagnosis. However, the contralateral hip often becomes involved over time. There are no reliable factors predicting a contralateral slip. Whether or not the contralateral hip should undergo prophylactic fixation is a matter of controversy. We present a number of essential points that have to be considered both when choosing to fix the contralateral hip prophylactically as well as when refraining from surgery and instead following the patients with repeat radiographs

Aims

The purpose of this study was to examine whether leg-length discrepancy (LLD) following unilateral total hip arthroplasty (THA) affects the incidence of contralateral head collapse and subsequent THA in patients with bilateral osteonecrosis, and to determine factors associated with subsequent collapse.

Aims. Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA. Methods. This study investigated patients with preoperative posterior hypermobility, defined as a change in sacral slope (SS) from standing to sitting (ΔSS. stand-sit. ) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at six weeks and a minimum of one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria. Results. A total of 136 patients were identified as having preoperative spinopelvic hypermobility. At one year after THA, 95% (129/136) of patients were no longer categorized as hypermobile on standing and sitting radiographs (ΔSS. stand-sit. < 30°). Mean ΔSS. stand-sit. decreased from 36.4° (SD 5.1°) at baseline to 21.4° (SD 6.6°) at one year (p < 0.001). Mean SS. seated. increased from baseline (11.4° (SD 8.8°)) to one year after THA by 11.5° (SD 7.4°) (p < 0.001), which correlates to an 8.5° (SD 5.5°) mean decrease in seated functional cup anteversion. Contralateral hip OA was the only radiological predictor of hypermobility persisting at one year after surgery. The overall reoperation rate was 1.5%. Conclusion. Spinopelvic hypermobility was found to resolve in the majority (95%) of patients one year after THA. The increase in SS. seated. was clinically significant, suggesting that current target recommendations for the hypermobile patient (decreased anteversion and inclination) should be revisited. Cite this article: Bone Joint J 2021;103-B(12):1766–1773

Aims. Cross-table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). The CTL measurements may differ by > 10° from CT scan measurements but the reasons for this discrepancy are poorly understood. Anteversion measurements from CTL radiographs and CT scans are compared to identify spinopelvic parameters predictive of inaccuracy. Methods. THA patients (n = 47; 27 males, 20 females; mean age 62.9 years (SD 6.95)) with preoperative spinopelvic mobility, radiological analysis, and postoperative CT scans were retrospectively reviewed. Acetabular component anteversion was measured on postoperative CTL radiographs and CT scans using 3D reconstructions of the pelvis. Two cohorts were identified based on a CTL-CT error of ≥ 10° (n = 11) or < 10° (n = 36). Spinopelvic mobility parameters were compared using independent-samples t-tests. Correlation between error and mobility parameters were assessed with Pearson’s coefficient. Results. Patients with CTL error > 10° (10° to 14°) had stiffer lumbar spines with less mean lumbar flexion (38.9°(SD 11.6°) vs 47.4° (SD 13.1°); p = 0.030), different sagittal balance measured by pelvic incidence-lumbar lordosis mismatch (5.9° (SD 18.8°) vs -1.7° (SD 9.8°); p = 0.042), more pelvic extension when seated (pelvic tilt -9.7° (SD 14.1°) vs -2.2° (SD 13.2°); p = 0.050), and greater change in pelvic tilt between supine and seated positions (12.6° (SD 12.1°) vs 4.7° (SD 12.5°); p = 0.036). The CTL measurement error showed a positive correlation with increased CTL anteversion (r = 0.5; p = 0.001), standing lordosis (r = 0.23; p = 0.050), seated lordosis (r = 0.4; p = 0.009), and pelvic tilt change between supine and step-up positions (r = 0.34; p = 0.010). Conclusion. Differences in spinopelvic mobility may explain the variability of acetabular anteversion measurements made on CTL radiographs. Patients with stiff spines and increased compensatory pelvic movement have less accurate measurements on CTL radiographs. Flexion of the contralateral hip is required to obtain clear CTL radiographs. In patients with lumbar stiffness, this movement may extend the pelvis and increase anteversion of the acetabulum on CTL views. Reliable analysis of acetabular component anteversion in this patient population may require advanced imaging with a CT scan. Cite this article: Bone Joint J 2021;103-B(7 Supple B):59–65

Aims. Increasingly, patients with bilateral hip arthritis wish to undergo staged total hip arthroplasty (THA). With the rise in demand for arthroplasty, perioperative risk assessment and counselling is crucial for shared decision making. However, it is unknown if complications that occur after a unilateral hip arthroplasty predict complications following surgery of the contralateral hip. Patients and Methods. We used nationwide linked discharge data from the Healthcare Cost and Utilization Project between 2005 and 2014 to analyze the incidence and recurrence of complications following the first- and second-stage operations in staged bilateral total hip arthroplasty (BTHAs). Complications included perioperative medical adverse events within 30 to 60 days, and infection and mechanical complications within one year. Conditional probabilities and odds ratios (ORs) were calculated to determine whether experiencing a complication after the first stage of surgery increased the risk of developing the same complication after the second stage. Results. A total of 13 829 patients (5790 men and 8039 women) who underwent staged BTHAs were analyzed. The mean age at first operation was 62.9 years (14 to 95). For eight of the 12 outcomes evaluated, patients who experienced the outcome following the first arthroplasty had a significantly increased probability and odds of developing that same complication following the second arthroplasty, compared with those who did not experience the complication after the first surgery. This was true for digestive complications (OR 25.67, 95% confidence interval (CI) 13.86 to 46.08; p < 0.001), urinary complications (OR 6.48, 95% CI 1.7 to 20.73; p = 0.01), haematoma (OR 12.17, 95% CI 4.55 to 31.14; p < 0.001), deep vein thrombosis (OR 4.82, 95% CI 2.34 to 9.65; p < 0.001), pulmonary embolism (OR 12.03, 95% CI 2.02 to 46.77; p = 0.01), deep hip infection (OR 534.21, 95% CI 314.96 to 909.25; p < 0.001), superficial hip infection (OR 1574.99, 95% CI 269.83 to 9291.81; p < 0.001), and mechanical malfunction (OR 117.49, 95% CI 91.55 to 150.34; p < 0.001). Conclusion. The occurrence of certain complications after unilateral THA is associated with an increased risk of the same complication occurring after staged arthroplasty of the contralateral hip. Patients who experience these complications after unilateral hip arthroplasty should be appropriately counselled regarding their risk profile prior to undergoing staged contralateral hip arthroplasty. Cite this article: Bone Joint J 2019;101-B(6 Supple B):77–83

There have been several studies examining the association between the morphological characteristics seen in acetabular dysplasia and the incidence of the osteoarthritis (OA). However, most studies focus mainly on acetabular morphological analysis, and few studies have scrutinised the effect of femoral morphology. In this study we enrolled 36 patients with bilateral acetabular dysplasia and early or mid-stage OA in one hip and no OA in the contralateral hip. CT scans were performed from the iliac crest to 2 cm inferior to the tibial tuberosity, and the morphological characteristics of both acetabulum and femur were studied. . In addition, 200 hips in 100 healthy volunteer Chinese adults formed a control group. The results showed that the dysplastic group with OA had a significantly larger femoral neck anteversion and a significantly shorter abductor lever arm than both the dysplastic group without OA and the controls. Femoral neck anteversion had a significant negative correlation with the length of the abductor lever arm and we conclude that it may contribute to the development of OA in dysplastic hips. Cite this article: Bone Joint J 2014; 96-B:1586–93

We investigated the effect of calcitonin in the prevention of acute bone loss after a pertrochanteric fracture and its ability to reduce the incidence of further fractures in the same patient. Fifty women aged between 70 and 80 years who had a pertrochanteric fracture of the hip were randomly allocated to group A (200 IU of nasal salmon calcitonin daily for three months) or group B (placebo). Patients in group A showed a significantly higher level of total alkaline phosphatase and osteocalcin on the 15th day after injury and a significantly higher level of bone alkaline phosphatase on the 90th day after surgery. These patients also had significantly lower levels of urinary C-telopeptide (CrossLaps) on the 15th, 45th and 90th days after injury and lower levels of urinary hydroxyproline on the 15th and 45th days after injury. Patients in group A had significantly higher bone mineral density at all recorded sites except the greater trochanter at three months and one year after operation. After a four-year period of clinical observation, five patients (24%) in group B sustained a new fracture, in four of whom (20%) it was of the contralateral hip. Our findings show that calcitonin reduces acute bone loss in patients with pertrochanteric fractures and may prevent the occurrence of new fractures of the contralateral hip in the elderly

Aims. The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA). Patients and Methods. A total of 28 patients (23 male, five female; mean age, 56 years (25 to 73)) awaiting Birmingham HRA volunteered for this prospective gait study, with an age-matched control group of 26 healthy adults (16 male, ten female; mean age, 56 years (33 to 84)). The Oxford Hip Score (OHS) and gait analysis using an instrumented treadmill were used preoperatively and more than two years postoperatively to measure the functional change attributable to the intervention. Results. The mean OHS improved significantly from 27 to 46 points (p < 0.001) at a mean of 29 months (12 to 60) after HRA. The mean metal ion levels at a mean 32 months (13 to 60) postoperatively were 1.71 (0.77 to 4.83) µg/l (ppb) and 1.77 (0.68 to 4.16) µg/l (ppb) for cobalt and chromium, respectively. When compared with healthy controls, preoperative patients overloaded the contralateral good hip, limping significantly. After HRA, patients walked at high speeds, with symmetrical gait, statistically indistinguishable from healthy controls over almost all characteristics. The control group could only be distinguished by an increased push-off force at higher speeds, which may reflect the operative approach. Conclusion. Patients undergoing HRA improved their preoperative gait pattern of a significant limp to a symmetrical gait at high speeds and on inclines, almost indistinguishable from normal controls. HRA with an approved device offers substantial functional gains, almost indistinguishable from healthy controls. Cite this article: Bone Joint J 2019;101-B:1423–1430

We have compared the biomechanical nature of the reconstruction of the hip in conventional total hip arthroplasty (THA) and surface replacement arthroplasty (SRA) in a randomised study involving 120 patients undergoing unilateral primary hip replacement. The contralateral hip was used as a control. Post-operatively, the femoral offset was significantly increased with THA (mean 5.1 mm; −2.8 to 11.6) and decreased with SRA (mean −3.3 mm; −8.9 to 8.2). Femoral offset was restored within . sd. 4 mm in 14 (25%) of those with THA and in 28 (57%) of the patients receiving SRA (p < 0.001). In the THA group, the leg was lengthened by a mean of 2.6 mm (−6.04 to +12.9), whereas it was shortened by a mean of 1.9 mm (−7.1 to +2.05) in the SRA group, compared with the contralateral side. Leg-length inequality was restored within . sd. 4 mm in 42 (86%) of the SRA and 33 (60%) of the THA patients. The radiological parameters of acetabular reconstruction were similar in both groups. Restoration of the normal proximal femoral anatomy was more precise with SRA. The enhanced stability afforded by the use of a large-diameter femoral head avoided over-lengthening of the limb or increased offset to improve soft-tissue tension as occurs sometimes in THA. In a subgroup of patients with significant pre-operative deformity, restoration of the normal hip anatomy with lower pre-operative femoral offset or significant shortening of the leg was still possible with SRA

Aims

To investigate the extent of bone development around the scaffold of custom triflange acetabular components (CTACs) over time.

Aims

Spinopelvic pathology increases the risk for instability following total hip arthroplasty (THA), yet few studies have evaluated how pathology varies with age or sex. The aims of this study were: 1) to report differences in spinopelvic parameters with advancing age and between the sexes; and 2) to determine variation in the prevalence of THA instability risk factors with advancing age.

Aims

The aim of this study was to evaluate the reliability and validity of a patient-specific algorithm which we developed for predicting changes in sagittal pelvic tilt after total hip arthroplasty (THA).

Hip resurfacing is being performed more frequently in the United Kingdom. The possible benefits include more accurate restoration of leg length, femoral offset and femoral anteversion than occurs after total hip arthroplasty (THA). We compared anteroposterior radiographs from 26 patients who had undergone hybrid THA (uncemented cup/cemented stem), with 28 who had undergone Birmingham Hip Resurfacing arthroplasty (BHR). We measured the femoral offset, femoral length, acetabular offset and acetabular height with reference to the normal contralateral hip. The data were analysed by paired t-tests. There was a significant reduction in femoral offset (p = 0.0004) and increase in length (p = 0.001) in the BHR group. In the THA group, there was a significant reduction in acetabular offset (p = 0.0003), but femoral offset and overall hip length were restored accurately. We conclude that hip resurfacing does not restore hip mechanics as accurately as THA

Aims

The aim of this study was to examine the implant accuracy of custom-made partial pelvis replacements (PPRs) in revision total hip arthroplasty (rTHA). Custom-made implants offer an option to achieve a reconstruction in cases with severe acetabular bone loss. By analyzing implant deviation in CT and radiograph imaging and correlating early clinical complications, we aimed to optimize the usage of custom-made implants.

We reviewed the clinical outcome of arthroscopic femoral osteochondroplasty for cam femoroacetabular impingement performed between August 2005 and March 2009 in a series of 40 patients over 60 years of age. The group comprised 26 men and 14 women with a mean age of 65 years (60 to 82). The mean follow-up was 30 months (12 to 54). The mean modified Harris hip score improved by 19.2 points (95% confidence interval 13.6 to 24.9; p < 0.001) while the mean non-arthritic hip score improved by 15.0 points (95% confidence interval 10.9 to 19.1, p < 0.001). Seven patients underwent total hip replacement after a mean interval of 12 months (6 to 24 months) at a mean age of 63 years (60 to 70). The overall level of satisfaction was high with most patients indicating that they would undergo similar surgery in the future to the contralateral hip, if indicated. No serious complications occurred. Arthroscopic femoral osteochondroplasty performed in selected patients over 60 years of age, who have hip pain and mechanical symptoms resulting from cam femoroacetabular impingement, is beneficial with a minimal risk of complications at a mean follow-up of 30 months

Aims

Pelvic incidence (PI) is a position-independent spinopelvic parameter traditionally used by spinal surgeons to determine spinal alignment. Its relevance to the arthroplasty surgeon in assessing patient risk for total hip arthroplasty (THA) instability preoperatively is unclear. This study was undertaken to investigate the significance of PI relative to other spinopelvic parameter risk factors for instability to help guide its clinical application.

The reported prevalence of an asymptomatic slip of the contralateral hip in patients operated on for unilateral slipped capital femoral epiphysis (SCFE) is as high as 40%. Based on a population-based cohort of 2072 healthy adolescents (58% women) we report on radiological and clinical findings suggestive of a possible previous SCFE. Common threshold values for Southwick’s lateral head–shaft angle (≥ 13°) and Murray’s tilt index (≥ 1.35) were used. New reference intervals for these measurements at skeletal maturity are also presented. At follow-up the mean age of the patients was 18.6 years (17.2 to 20.1). All answered two questionnaires, had a clinical examination and two hip radiographs. There was an association between a high head–shaft angle and clinical findings associated with SCFE, such as reduced internal rotation and increased external rotation. Also, 6.6% of the cohort had Southwick’s lateral head–shaft angle ≥ 13°, suggestive of a possible slip. Murray’s tilt index ≥ 1.35 was demonstrated in 13.1% of the cohort, predominantly in men, in whom this finding was associated with other radiological findings such as pistol-grip deformity or focal prominence of the femoral neck, but no clinical findings suggestive of SCFE. This study indicates that 6.6% of young adults have radiological findings consistent with a prior SCFE, which seems to be more common than previously reported. Cite this article: Bone Joint J 2013;95-B:452–8

We retrospectively examined the long-term outcome of 96 asymptomatic hips in 96 patients with a mean age of 49.3 years (16 to 65) who had radiological evidence of femoroacetabular impingement. When surveillance commenced there were 17, 34, and 45 hips with cam, pincer, and mixed impingement, respectively. Overall, 79 hips (82.3%) remained free of osteoarthritis for a mean of 18.5 years (10 to 40). In contrast, 17 hips (17.7%) developed osteoarthritis at a mean of 12 years (2 to 28). No statistically significant difference was found in the rates of development of osteoarthritis among the three groups (p = 0.43). Regression analysis showed that only the presence of idiopathic osteoarthritis of the contralateral diseased hip was predictive of development of osteoarthritis on the asymptomatic side (p = 0.039). We conclude that a substantial proportion of hips with femoroacetabular impingement may not develop osteoarthritis in the long-term. Accordingly, in the absence of symptoms, prophylactic surgical treatment is not warranted

Aims

The aims of this study were to compare clinically relevant measurements of hip dysplasia on radiographs taken in the supine and standing position, and to compare Hip2Norm software and Picture Archiving and Communication System (PACS)-derived digital radiological measurements.