The use of joint-preserving surgery of the hip has been largely abandoned since the introduction of total hip replacement. However, with the modification of such techniques as pelvic osteotomy, and the introduction of intracapsular procedures such as surgical hip dislocation and arthroscopy, previously unexpected options for the surgical treatment of sequelae of childhood conditions, including developmental dysplasia of the hip, slipped upper femoral epiphysis and Perthes’ disease, have become available. Moreover, femoroacetabular impingement has been identified as a significant aetiological factor in the development of osteoarthritis in many hips previously considered to suffer from primary osteoarthritis. As mechanical causes of degenerative joint disease are now recognised earlier in the disease process, these techniques may be used to decelerate or even prevent progression to osteoarthritis. We review the recent development of these concepts and the associated surgical techniques. Cite this article: Bone Joint J 2014;96-B:5–18

Mixed Reality has the potential to improve accuracy and reduce required dissection for the performance of peri-acetabular osteotomy. The current work assesses initial proof of concept of MR guidance for PAO. A PAO planning module, based on preoperative computed tomography (CT) imaging, allows for the planning of PAO cut planes and repositioning of the acetabular fragment. 3D files (holograms) of the cut planes and native and planned acetabulum positions are exported with the associated spatial information. The files are then displayed on mixed reality head mounted device (HoloLens2, Microsoft) following intraoperative registration using an FDA-cleared mixed reality application designed primary for hip arthroplasty (HipInsight). PAO was performed on both sides of a bone model (Pacific Research). The osteotomies and acetabular reposition were performed in accordance with the displayed holograms. Post-op CT imaging was performed for analysis. Cutting plane-accuracy was evaluated using a best-fit plane and 2D angles (°) between the planned and achieved supra (SA)- and retroacetabular (RA) osteotomy and retroacetabular and ischial osteotomies (IO) were measured. To evaluate the accuracy of acetabular reorientation, we digitized the acetabular rim and calculated the acetabular opening plane. Absolute errors of planned and achieved operative inclination and anteversion (°) of the acetabular fragment, as well as 3D lateral-center-edge (LCE) angles were calculated. The mean absolute difference between the planned and performed osteotomy angles was 3 ± 3°. The mean absolute error between planned and achieved operative anteversion and inclination was 1 ± 0° and 0 ± 0° respectively. Mean absolute error between planned and achieved 3D LCE angle was 0.5 ± 0.7°. Mixed-reality guidance for the performance of pelvic osteotomies and acetabular fragment reorientation was feasible and highly accurate. This solution may improve the current standard of care by enabling reliable and precise reproduction of the desired acetabular realignment

To date there is no medical treatment alternative to surgery for osteolysis after THA. In this proof-of-concept clinical trial we examined the effect of a human monoclonal antibody against osteoclasts versus placebo on osteolytic lesion activity in patients undergoing revision surgery.

Patients scheduled for revision for symptomatic osteolysis were randomised (1:1) to receive either denosumab 60mg or placebo subcutaneously eight weeks prior to operation. At surgery, biopsies from the osteolytic membrane-bone interface were taken for histomorphometric analysis of osteoclast number. Secondary outcome measures included systemic bone turnover markers.

22 subjects completed the study (10 denosumab). The denosumab group had 83% (−63 to −97), P=0.011 fewer osteoclasts at osteolytic lesion sites, 87% lower osteoclast surface (−65 to −95, P=0.009), and 72% lower eroded surface (−35 to −93, P=0.020) versus the placebo group. At surgery, serum CTX-I, TRAP5b and PINP were 80% (−65 to −95, p<0.001), 57% (−40 to −90, p<0.001), and 44% (−41 to −65, p<0.001) lower in the denosumab versus placebo groups, respectively. The rate of adverse events (denosumab 6, placebo 7) were similar between groups (P>0.05).

These data provide a biological basis for a definitive clinical trial using pain, function and prosthesis survival as the study endpoints. As osteolysis/ aseptic loosening is the leading cause of prosthesis failure world-wide, the establishment of a non-surgical solution would reduce patient suffering and dramatically reducing the cost to healthcare economies.

Aims. The risk factors for abnormal spinopelvic mobility (SPM), defined as an anterior rotation of the spinopelvic tilt (∆SPT) ≥ 20° in a flexed-seated position, have been described. The implication of pelvic incidence (PI) is unclear, and the concept of lumbar lordosis (LL) based on anatomical limits may be erroneous. The distribution of LL, including a unusual shape in patients with a high lordosis, a low pelvic incidence, and an anteverted pelvis seems more relevant. Methods. The clinical data of 311 consecutive patients who underwent total hip arthroplasty was retrospectively analyzed. We analyzed the different types of lumbar shapes that can present in patients to identify their potential associations with abnormal pelvic mobility, and we analyzed the potential risk factors associated with a ∆SPT ≥ 20° in the overall population. Results. ΔSPT ≥ 20° rates were 28.3%, 11.8%, and 14.3% for patients whose spine shape was low PI/low lordosis (group 1), low PI anteverted (group 2), and high PI/high lordosis (group 3), respectively (p = 0.034). There was no association between ΔSPT ≥ 20° and PI ≤ 41° (odds ratio (OR) 2.01 (95% confidence interval (CI)0.88 to 4.62), p = 0.136). In the multivariate analysis, the following independent predictors of ΔSPT ≥ 20° were identified: SPT ≤ -10° (OR 3.49 (95% CI 1.59 to 7.66), p = 0.002), IP-LL ≥ 20 (OR 4.38 (95% CI 1.16 to 16.48), p = 0.029), and group 1 (OR 2.47 (95% CI 1.19; to 5.09), p = 0.0148). Conclusion. If the PI value alone is not indicative of SPM, patients with a low PI, low lordosis and a lumbar apex at L4-L5 or below will have higher rates of abnormal SPM than patients with a low PI anteverted and high lordosis. Cite this article: Bone Jt Open 2023;4(9):668–675

Dislocation is a serious complication to be avoided in total hip arthroplasty (THA) and its incidence risk increases in revision surgery. Combined anteversion (CA) of the cup and stem is a concept for appropriate implant positioning; however, the effect of functional changes in femoral rotation has not been well investigated. The aim of this study was to investigate whether functional CA, considering femoral rotation, is associated with dislocation in patients undergoing revision THA. Seventy-three patients who underwent revision THA and had at least one year of follow-up with pre- and postoperative supine CT imaging were included. Cup and stem were placed with a target combined angle of 37.3° using Widmer's formula. Anatomical and functional CA was calculated postoperatively using the following formula: Anatomical CA: cup anteversion + 0.7 × anatomical stem anteversion; Functional CA: cup anteversion + 0.7 × (anatomical stem anteversion + femoral rotation). Patient demographics, cup and stem angles, CA and their relationship to dislocation were statistically evaluated. Dislocation was observed in 12 patients. In these dislocated cases, there were no significant differences in cup angle, stem angle and anatomical CA compared to non-dislocated cases. However, dislocated cases showed significantly higher values of functional CA [52.7 ± 17.5° (range, 5.9–69.3) vs. 36.0 ± 12.5° (range, 8.6–68.8), p=0.009] and significant deviation from identical CA [17.3 ± 9.6° (range, 2.8–32) vs. 7.5 ± 7.1° (range, 0.1–28.7), p=0.010]. Functional CA considering femoral rotation was associated with dislocation in revision THA patients. This finding suggests that consideration of femoral rotation may be necessary for implant positioning in revision THA

Aims. The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance. Methods. A prospective cohort study was conducted with 101 patients with end-stage hip OA scheduled for THA (mean age 67.4 years (SD 9.5), 51.5% female (n = 52)). Patients were assessed at baseline as well as after three and months. Primary outcome was cognitive performance measured by d2 Test of Attention at six months, Trail Making Test (TMT), FAS-test, Rivermead Behavioural Memory Test (RBMT; story recall subtest), and Rey-Osterrieth Complex Figure Test (ROCF). The improvement of cognitive performance was analyzed using repeated measures analysis of variance. Results. At six months, there was significant improvement in attention, working speed and concentration (d2-test; p < 0.001), visual construction and visual memory (ROCF; p < 0.001), semantic memory (FAS-test; p = 0.009), verbal episodic memory (RBMT; immediate recall p = 0.023, delayed recall p = 0.026), as well as pain (p < 0.001) with small to large effect sizes. Attention, concentration, and visual as well as verbal episodic memory improved significantly with medium effect sizes over η. 2. partial. = 0.06. In these cognitive domains the within-group difference exceeded the minimum clinically important difference. Conclusion. THA is associated with clinically relevant postoperative improvement in the cognitive functions of attention, concentration, and memory. These data support the concept of a broad interaction of arthroplasty with central nervous system function. Cite this article: Bone Joint J 2022;104-B(3):331–340

Aims. The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck. Methods. Long-leg standing radiographs of patients undergoing realignment surgery around the knee were used. The hip-knee-ankle angle (HKA) and the vertical orientation of the femoral neck in relation to the floor were measured, prior to surgery and after osteotomy-site-union. Linear regression was performed to determine the influence of knee alignment on the vertical orientation of the femoral neck. Results. The cohort included 147 patients who underwent knee realignment-surgery. The mean age was 51.5 years (SD 11). Overall, 106 patients underwent a valgisation-osteotomy, while 41 underwent varisation osteotomy. There was a significant association between the orientation of the knee and the coronal neck-orientation. In the varus group, the median orientation of the femoral neck was 46.5° (interquartile range (IQR) 49.7° to 50.0°), while in the valgus group, the orientation was 52.0° (IQR 46.5° to 56.7°; p < 0.001). Linear regression analysis revealed that HKA demonstrated a direct influence on the coronal neck-orientation (β = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002). Linear regression also showed that realignment surgery was associated with a significant influence on the change in the coronal femoral neck orientation (β = 5.6 (95% CI 1.5 to 9.8); p = 0.008). Conclusion. Varus or valgus knee alignment is associated with either a more horizontal or a more vertical femoral neck orientation in standing position, respectively. Subsequently, osteotomies around the knee alter the vertical orientation of the femoral neck. These aspects are of importance when planning osteotomies around the knee in order to appreciate the effects on the adjacent hip joint. The concept may be of even more relevance in dysplastic hips. Cite this article: Bone Jt Open 2021;2(12):1057–1061

Aims. Total hip arthroplasty (THA) is a very successful and cost-effective operation, yet debate continues about the optimum fixation philosophy in different age groups. The concept of the 'cementless paradox' and the UK 'Getting it Right First Time' initiative encourage increased use of cemented fixation due to purported lower revision rates, especially in elderly patients, and decreased cost. Methods. In a high-volume, tertiary referral centre, we identified 10,112 THAs from a prospectively collected database, including 1,699 cemented THAs, 5,782 hybrid THAs, and 2,631 cementless THAs. The endpoint was revision for any reason. Secondary analysis included examination of implant survivorship in patients aged over 70 years, over 75 years, and over 80 years at primary THA. Results. Cemented fixation had the lowest implant survival in all age groups, with a total ten-year survivorship of 97.0% (95% confidence interval (CI) 95.8 to 97.8) in the cemented group, 97.6% (95% CI 96.9 to 98.1) in the hybrid group, and 97.9% (95% CI 96.9 to 98.6) in the cementless group. This was not statistically significant (p = 0.092). There was no age group where cemented fixation outperformed hybrid or cementless fixation. Conclusion. While all fixation techniques performed well at long-term follow-up, cemented fixation was associated with the lowest implant survival in all age groups, including in more elderly patients. We recommend that surgeons should carefully monitor their own outcomes and use fixation techniques that they are familiar with, and deliver the best outcomes in their own hands. Cite this article: Bone Joint J 2022;104-B(2):206–211

Aims. Although the short stem concept in hip arthroplasty procedure shows acceptable clinical performance, we sometimes get unexplainable radiological findings. The aim of this retrospective study was to evaluate changes of radiological findings up to three years postoperatively, and to assess any potential contributing factors on such radiological change in a Japanese population. Methods. This is a retrospective radiological study conducted in Japan. Radiological assessment was done in accordance with predetermined radiological review protocol. A total of 241 hips were included in the study and 118 hips (49.0%) revealed radiological change from immediately after surgery to one year postoperatively; these 118 hips were eligible for further analyses. Each investigator screened whether either radiolucent lines (RLLs), cortical hypertrophy (CH), or atrophy (AT) appeared or not on the one-year radiograph. Further, three-year radiographs of eligible cases were reviewed to determine changes such as, disappeared (D), improved (I), stable (S), and progression (P). Additionally, bone condensation (BC) was assessed on the three-year radiograph. Results. CH was observed in 49 hips (21.1%), AT was observed in 63 hips (27.2%), and RLLs were observed in 34 hips (14.7%) at one year postoperatively. Among 34 hips with RLLs, 70.6% showed change of either D or I on the three-year radiograph. BC was observed in younger patients more frequently. Conclusion. The Fitmore stem works well in a Japanese population with favourable radiological change on hips with RLLs. Longer-term follow-up is required to determine clinical relevance. Cite this article: Bone Jt Open 2022;3(1):20–28

There remains confusion in the literature with regard to the spinopelvic relationship, and its contribution to ideal acetabular component position. Critical assessment of the literature has been limited by use of conflicting terminology and definitions of new concepts that further confuse the topic. In 2017, the concept of a Hip-Spine Workgroup was created with the first meeting held at the American Academy of Orthopedic Surgeons Annual Meeting in 2018. The goal of this workgroup was to first help standardize terminology across the literature so that as a topic, multiple groups could produce literature that is immediately understandable and applicable. This consensus review from the Hip-Spine Workgroup aims to simplify the spinopelvic relationship, offer hip surgeons a concise summary of available literature, and select common terminology approved by both hip surgeons and spine surgeons for future research. Cite this article: Bone Joint J 2019;101-B:808–816

We aimed to demonstrate the clinical safety of a novel anatomic cementless ceramic hip resurfacing device. Concerns around the safety of metal on metal arthroplasty have made resurfacing less attractive, while long term function continues to make the concept appealing. Biolox Delta ceramic is now used in more than 50% of all hip arthroplasties, suggesting that it's safety profile is acceptable. We wondered if a combination of these concepts might work?. The preclinical testing of anatomic hip resurfacing device developed by our group was presented last year. A twenty patient safety study was designed. Patients had to be between the ages of 18 and 70. The initial size range was restricted to femoral heads between 46 and 54, representing the common sizes of hip resurfacing. The primary outcomes were clinical safety, PROMs and radiological control. Secondary outcomes include CTRSA and metal ion levels. 20 patients were recruited, aged 30–69. 7 were women and 13 were men. There were no operative adverse events in their operations undertaken between September 2017 and February 2018. One patient had a short episode of atrial fibrillation on the second postoperative day, and no other complications. At three months the median oxford hip score had risen from 27 (range 14–38) to 46 (31–48). Cobalt and chromium levels were almost undetectable at 3 months. Fixation appeared satisfactory in all patients, with no migration detected in either component. CTRSA is in process. The initial safety of a novel cementless ceramic resurfacing device is demonstrated by this data. The 10 year, 250 case efficacy study will continue in 5 other European centres

Introduction. The purpose of this study was to evaluate the long term changes in bone mineral density (BMD) following implantation of a low-modulus composite femoral component designed to closely match the stiffness of the proximal femur and minimize stress shielding. Specifically, we asked: 1) How does BMD in the proximal femur change with time and with Gruen zone location; 2) Does BMD in the proximal femur stabilize after two years of implantation?. Methods. We retrospectively reviewed a subgroup of sixteen patients who had preoperative and postoperative DEXA scans in an FDA multi-center prospective trial of this composite stem. Five of these sixteen patients returned for long-term DEXA scans at a mean 22.0 years post-op (range 21.2–22.6 years). BMD in the 7 Gruen zones at final follow-up was compared to immediate post-operative and 2-year follow-up values. Percentage change was calculated and change in BMD was plotted against time from immediate post-operative measurements to each subsequent follow-up. Results. At the time of last follow-up, all stems were well fixed with signs of extensive osteointegration. There were no mechanical implant failures. In Gruen zone 1, patients underwent an overall decrease or little change in BMD, though one patient experienced a notable increase from initial post-op to the latest follow-up. The overall mean (+ SD) annual percent change in BMD in Gruen zone 1 was −0.31% ± 1.09%. When considering the change from the two-year DEXA scan to latest follow-up, two patients demonstrated a decrease in BMD and three patients demonstrated an increase in BMD in Gruen zone 1. All patients demonstrated progressive increase in BMD in Gruen zones 2, 3, 4, 5, and 6 from the initial post-op scan until last follow-up with mean annual percent changes ranging from 0.59% ± 0.50% in Gruen zone 6 to 2.78% ± 2.49% in Gruen zone 3. In our cohort, BMD progressively decreased with time in Gruen zone 7 for all patients with a mean decrease of 1.78% + 0.38% annually from the time of the initial post-op DEXA scan until last follow-up. This was consistent with prior reports with shorter term follow-up. Conclusions. Despite the extensively porous coated design of this stem and concerns about distal fixation and related stress shielding, we observed consistent DEXA scan evidence of increases in BMD in Gruen zones 2–6 and limitation of decreases in BMD exclusively to zone 7 and to a lesser extent zone 1. This is unlike reported results with several other extensively porous coated and proximally porous coated implants designed to obtain proximal fixation. These increases in BMD occurred despite the potential age-related decreases in BMD in the proximal femur that one would anticipate over the mean 22-year follow-up in this study. Clearly, “normal” physiologic loading of bone after THA is determined by a complex interaction between location of ingrowth, location and extent of endosteal contact of the implant in the proximal femur, stiffness of the stem and other implant design and patient related factors. The long-term observations of this study suggest that effective loading of the proximal femur occurs with this low-modulus stem and that this concept may have a role in the future of THA

Aims

The aims of this study were to validate the Forgotten Joint Score-12 (FJS-12) in the postoperative evaluation of periacetabular osteotomy (PAO), identify factors associated with joint awareness after PAO, and determine the FJS-12 threshold for patient-acceptable symptom state (PASS).

Aims

Periacetabular osteotomy (PAO) is widely recognized as a demanding surgical procedure for acetabular reorientation. Reports about the learning curve have primarily focused on complication rates during the initial learning phase. Therefore, our aim was to assess the PAO learning curve from an analytical perspective by determining the number of PAOs required for the duration of surgery to plateau and the accuracy to improve.

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.

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The aim of this study was to identify the optimal lip position for total hip arthroplasties (THAs) using a lipped liner. There is a lack of consensus on the optimal position, with substantial variability in surgeon practice.

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In this study, we aimed to visualize the spatial distribution characteristics of femoral head necrosis using a novel measurement method.

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The aims of this study were to determine the incidence and factors for developing periprosthetic joint infection (PJI) following hemiarthroplasty (HA) for hip fracture, and to evaluate treatment outcome and identify factors associated with treatment outcome.

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The Single Assessment Numerical Evalution (SANE) score is a pragmatic alternative to longer patient-reported outcome measures (PROMs). The purpose of this study was to investigate the concurrent validity of the SANE and hip-specific PROMs in a generalized population of patients with hip pain at a single timepoint upon initial visit with an orthopaedic surgeon who is a hip preservation specialist. We hypothesized that SANE would have a strong correlation with the 12-question International Hip Outcome Tool (iHOT)-12, the Hip Outcome Score (HOS), and the Hip disability and Osteoarthritis Outcome Score (HOOS), providing evidence for concurrent validity of the SANE and hip-specific outcome measures in patients with hip pain.

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Transfusion after primary total hip arthroplasty (THA) has become rare, and identification of causative factors allows preventive measures. The aim of this study was to determine patient-specific factors that increase the risk of needing a blood transfusion.