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Arthroscopic procedures to treat hip pathologies such as femoroacetabular impingement (FAI) syndrome are now established in mainstream orthopaedic practice. Surgical techniques, rehabilitation protocols and outcomes are widely published. However, consensus on standards of practice remains to be determined. The International Hip Preservation Society (ISHA) has undertaken a research study to identify current areas of consensus across the global hip preservation community. The study focussed on consensus statements on the operative steps in the arthroscopic treatment of FAI syndrome. The study methodology was an online Delphi consensus method to collect aggregate opinions from hip preservation surgeons worldwide. Phase 1 of the planned three-phase study is presented here—focusing on consensus statements on the operative steps in the arthroscopic treatment of FAI syndrome. Ninety-nine statements achieved >80% consensus from a panel of 165 surgeons from six continents. This study is the first to evaluate global consensus on the arthroscopic treatment of FAI syndrome, as well as highlighting areas of contention and avenues for future research.

This study identifies optimal OKS values that discriminate post-operative (TKA) patient satisfaction and determines the variation in threshold values by patient characteristics and expectations. It is the first to identify patient improvement using measures (PoPC) that account for patient's pre-operative symptom severity. Of 365 primary TKA patients from a London district general hospital 84% were satisfied at 12 and 24 months. Whilst the overall OKS thresholds (follow-up, change, PoPC) were stable at 12 months (31, 11, 39.7%) and 24 months (35, 12, 38.9%), patients who were older (≥75years), were underweight/normal (BMI25), had pre-operative symptom severity (OKS≤15) and expected no pain post-surgery, required a greater (potential) improvement to be classed as satisfied. When reporting good patient outcomes, cohorts should be stratified accordingly.

Patient reported outcome measures (PROMs) are used to gauge clinical performance. The PROMs outcome programme at our centre achieves a preoperative data capture rate of 99%. This falls to 90.6%, 89%, 83% and 79% at the six-week, six-month, one-year and two-year time points, respectively. The study aims were to determine factors associated with patients who did not respond to outcome questionnaires following total hip replacement (THR), and the potential implications this may have when assessing patients following THRs. During the first year of the PROMs programme, 1,322 patients underwent unilateral primary THR at our institution. Of these, 1,311 completed preoperative questionnaires. Thirty-eight patients (2.9%) died within two years of surgery and have been excluded. For the remaining 1,273 patients, we identified those who did not return postoperative questionnaires at each of our review time points. Younger age, lower baseline EQ5D and Oxford Hip scores (OHS) were significantly associated with non-response (p

Summary Objectives To describe whether body mass index (BMI) is a clinically meaningful predictor of patient reported outcomes following primary total hip replacement (THR) surgery. Design Combined data from prospective cohort studies. We obtained information from four cohorts of patients receiving primary THR for osteoarthritis: Exeter Primary Outcomes Study (EPOS) ( n = 1431); EUROHIP ( n = 1327); Elective Orthopaedic Centre ( n = 2832); and St. Helier ( n = 787). The exposure of interest was pre-operative BMI. Confounding variables included: age, sex, SF-36 mental health, comorbidities, fixed flexion, analgesic use, college education, OA in other joints, expectation of less pain, radiographic K&L grade, ASA grade, years of hip pain. The primary outcome was the Oxford Hip Score (OHS). Regression models describe the association of BMI on outcome adjusting for all confounders. Results For a 5-unit increase in BMI, the attained 12-month OHS decreases by 0.78 points 95%CI (0.27–1.28), P -value 0.001. Compared to people of normal BMI (20–25), those in the obese class II (BMI 35–40) would have a 12-month OHS that is 2.34 points lower. Although statistically significant this effect is small and not clinically meaningful in contrast to the substantial change in OHS seen across all BMI groupings. In obese class II patients achieved a 22.2 point change in OHS following surgery. Conclusions Patients achieved substantial change in OHS after THR across all BMI categories, which greatly outweighs the small difference in attained post-operative score. The findings suggest BMI should not present a barrier to access THR in terms of PROMs.

Surgeons undertaking total hip arthroplasty (THA) routinely perform a distal femoral neck resection. It has been argued that retaining the femoral neck during THA can provide mechanical and biological advantages.The objectives of this study were to review: (1) the current evidence on the advantages of femoral neck preservation during THA and (2) the clinical and radiological outcome of neck-preserving femoral stems.A search of the English-language literature on neck-preserving THA and on the individual neck-preserving implants was performed using PubMed, Ovid SP and Science Direct.Studies have indicated that neck preservation offers superior tri-planar implant stability and allows more accurate restoration of the hip geometry and biomechanics. The trend towards tissue sparing surgery has contributed to the development of bone-conserving short-stem implants that offer variable levels of neck preservation. Despite an initial learning curve, these implants have generated promising early clinical results, with low revision rates and high outcome scores. However, radiological evaluation of some neck-preserving implants has detected a characteristic pattern of proximal femoral bone loss with distal cortical hypertrophy. The long-term implications of this finding are not yet known.Preserving the femoral neck during THA has biomechanical advantages. However, long-term outcome data are needed on neck-preserving femoral stems to evaluate on-going bone remodelling and assess implant performance and survival.

Objective: to identify pre-operative predictors of patient-reported outcomes of primary total knee replacement (TKR) surgery. Methods: the Elective Orthopaedic Centre database is a large prospective cohort of 1991 patients receiving primary TKR in south-west London from 2005 to 2008. The primary outcome is the 6-month post-operative Oxford Knee Score (OKS). To classify whether patients had a clinically important outcome, we calculated a patient acceptable symptom state (PASS) for the 6-month OKS related to satisfaction with surgery. Potential predictor variables were pre-operative OKS, age, sex, BMI, deprivation, surgical side, diagnosis, operation type, American Society of Anesthesiologists grade and EQ5D anxiety/depression. Regression modelling was used to identify predictors of outcome. Results: the strongest determinants of outcome include pre-operative pain/function—those with less severe pre-operative disease obtain the best outcomes; diagnosis in relation to pain outcome—patients with RA did better than those with OA; deprivation—those living in poorer areas had worse outcomes; and anxiety/depression—worse pre-operative anxiety/depression led to worse pain. Differences were observed between predictors of pain and functional outcomes. Diagnosis of RA and anxiety/depression were associated with pain, whereas age and gender were specifically associated with function. BMI was not a clinically important predictor of outcome. Conclusion: this study identified clinically important predictors of attained pain/function post-TKR. Predictors of pain were not necessarily the same as functional outcomes, which may be important in the context of a patient’s expectations of surgery. Other predictive factors need to be identified to improve our ability to recognize patients at risk of poor TKR outcomes

We present a novel arthroscopic-assisted technique to graft chondral defects and subchondral cysts of the acetabular socket using a synthetic osteochondral plug. Four patients with groin pain, solitary cysts in the roof of the acetabulum and radiographic evidence of early osteoarthritis were treated. A bone tunnel was prepared from the region of the iliac crest to the acetabular articular surface. A synthetic osteochondral plug was inserted in an ante-grade fashion and positioned flush with the lunate articular cartilage. The minimum follow-up from surgery was 8 months (mean 10 months, range 8 to 11 months). There were no peri-operative complications related to the procedure. All patients reported an improvement in symptoms and function at the latest follow-up. One of the patients underwent a re-look arthroscopy at 5 months for persistent dull groin and buttock pain. Capsular adhesions of the labrum were identified and released. The mean non-arthritic hip score improved from 53.8 (range 43.8 to 70) pre-operatively to 84.6 (range 78.8 to 87.5) at 6 months. Computed tomography and magnetic resonance imaging at 6 months confirmed the stability of the osteochondral plugs and on-going healing. This procedure offers an arthroscopic means to treat patients with solitary acetabular cysts and may prove effective for chondral grafting of denuded acetabular areas in early to moderate degenerative hip disease.

The human hip is subjected to several hundred million loading cycles during a lifetime. Hip instability and femoro-acetabular impingement cause damage to the rim of the acetabulum. The acetabular rim is a highly specialized structure known as the labro-acetabular complex. A unidirectional flow of synovial fluid has been identified in this region. The synovial fluid circulation is driven by the bellows-like movement of the zona orbicularis and depends on hip flexion and extension. Surgical repair of the damaged labro-acetabular complex should satisfy two goals. First, the labrum should be preserved or reconstructed when possible. Second, the precipitating cause of the labro-acetabular damage must be addressed.

Knee arthroplasties are designed to accommodate flexion, axial rotation and anteroposterior (AP) translation. Axial rotation during extension varies, with some rotating platform devices allowing unrestricted rotation while some conforming fixed-bearing designs almost none. The purpose of this study was to examine in vivo kinematics of a fixed-bearing medial rotation-type arthroplasty (MRK) during weight-bearing activities. Fifteen knees with a medial pivot TKA design were studied during step and pivot activities using lateral fluoroscopy and model-image registration. Average knee kinematics during the step activity showed little AP translation or rotation from 0 degrees -100 degrees flexion. During the pivot activity, the mean tibial internal rotation in individual knees was 7 degrees (3 degrees -19 degrees ). Mean condylar translations for individual knees were 3mm medially and 5mm laterally. The medial pivot prosthesis design provides anteroposterior stability during demanding activities, and exhibits a medial pivot motion pattern when subjected to twisting.

Valgus alignment of femoral resurfacing components has been advocated to reduce proximal femur loading and thus minimize the risk for femoral neck fractures. However, such reduction in loading may exacerbate undesirable stress shielding. This study examined the effect of extreme implant orientations (+/-15 degrees ) and stem canal overreaming on initial bone remodeling stimulus using finite element models. The changes in implant-cement interface stresses due to implant alignment were also evaluated. The valgus model showed increased initial bone resorption stimulus, which extended distally and peripherally around the femoral neck. The peak implant-cement interface shear stress for the varus model was 10.9 MPa, exceeding the interface shear strength. Overreaming of the stem canal eliminated distal tip loading, but proximal stress shielding was still unavoidable. These data show bone loading and interface fixation trends emanating from valgus and varus implant positions that will be of interest to practicing physicians.

The performance of total knee arthroplasty in deeply flexed postures is of increasing concern as the procedure is performed on younger, more physically active and more culturally diverse populations. Several implant design factors, including tibiofemoral conformity, tibial slope and posterior condylar geometry have been shown directly to affect deep flexion performance. The goal of this study was to evaluate the kinematics of a fixed-bearing, asymmetric, medial rotation arthroplasty design in moderate and deep flexion. Thirteen study participants (15 knees) with a medial rotation knee arthroplasty were observed performing a weight-bearing lunge activity to maximum comfortable flexion and kneeling on a padded bench from 90 degrees to maximum comfortable flexion using lateral fluoroscopy. Subjects averaged 74 years of age and nine were female. At maximum weight-bearing flexion, the knees exhibited 115 degrees of implant flexion (102 degrees-125 degrees) and 7 degrees (-3 degrees to 12 degrees) of tibial internal rotation. The medial and lateral condylar translated posteriorly by 2 and 5 mm, respectively. At maximum kneeling flexion, the knees exhibited 119 degrees of implant flexion (101 degrees-139 degrees ) and 5 degrees (-2 degrees to 14 degrees) of tibial internal rotation. The lateral condyle translated posteriorly by 11 mm. The medial rotation knee exhibited motion patterns similar to those observed in the normal knee, but less tibial rotation. The medially conforming articulation beneficially controls femoral AP position in deep flexion, in patients who require such motion as part of their lifestyle.

A sensitive and reproducible measurement of knee surgery outcomes is increasingly needed. However, it has been difficult to compare results because of numerous scoring systems and the publication of data in these systems. Our aim was to compare the more widely used American Knee Society score (AKSS) with the shorter Oxford Knee Score (OKS). The questionnaires were completed preoperatively and at 2, 5, and 10 years postoperatively. A negative correlation of -0.64 (P < .0001) between the OKS and AKSS and the Functional score at 2 years, and a correlation of -0.5 (P < .0001) at 5 and 10 years were found. However, excellent, good, fair, and poor OKS classifications did not correlate well with the AKSS grading (weighted kappa coefficient = 0.06-0.288). This study indicates that the OKS, with its easier analysis and higher compliance rate, can be used more directly to compare studies using the AKSS.

Before 2003, all NHS trusts charged locally determined prices for the provision of hip and knee arthroplasty services to their primary care trust (PCT). These charges could be fi xed irrespective of the activity provided (Department of Health (DH), 2002). In 2003–2004, the DH set up a national tariff system so that hospitals would charge PCTs per treatment performed. Similar treatments are grouped together under the same tariff and referred to as a Healthcare Resource Group (HRG).

It is postulated that the stiffness of current acetabular designs compromises long-term component stability. We present a novel acetabular component design that is horseshoe shaped and has a large diameter bearing. It is made from composite materials and is designed to match the stiffness of subchondral bone. It is intended that stress shielding will be minimised and that the distribution of stress will be improved. The mechanical and biological suitability of the composite has been confirmed. A range of standard and non-standard, pre-clinical, tests have established the robustness and safety of the new component. The efficacy of the new design has been evaluated by clinical trial on 50 patients. Optimal results were obtained using the hydroxyapatite (HA) coated cups. Our results support the new design concept, with the caveat that biological fixation is imperative. Minor design modifications are recommended.

In a prospective 2-year study we have used dual-energy X-ray absorptiometry to measure periprosthetic bone mineral density (BMD) following implantation of a novel, "physiological", acetabular component designed using composite materials.The acetabular components were implanted in hydroxyapatite (HA) and HA-removed options. They were implanted in conjunction with a cemented femoral component in 50 female patients who presented with displaced, subcapital, fractures of the neck of the femur. Regions of interest (ROI) were defined according to De Lee and Charnley. BMD during follow-up was compared with immediate postoperative values for the affected limb.The mean precision error (CV%) was 1.01%, 2.26% and 1.12%, for ROI I, II and III respectively. The mean change in BMD, for both cups, was analyzed. There was no significant difference between the BMD changes induced with the HA- and non-HA-coated cups.After an initial fall in BMD in all 3 ROI at 6 months, ROI I and ROI II showed return to baseline BMD by 2 years. ROI III showed no significant decrease in BMD beyond 6 months, but did not return to baseline levels. Statistical analysis revealed no significant decrease in BMD in ROI I and ROI II at 2 years, compared with immediate postoperative values. The changes in BMD reflect a pattern of maximally reduced stress in the non-weight-bearing zone (ROI III), with preservation of bone density in weight bearing zones ROI I and ROI II. These results support the design principles of the Cambridge cup.

Background: An assessment of the effect of surgical repair or reconstruction on the function of the hip labrum is critical to the advancement of hip preservation surgery; however, validated models of the hip that allow the quantification of labral function in functional joint positions have yet to be developed. Purpose: To evaluate (1) whether intra-articular pressures within the hip are regulated by fluid transport between the labrum and femoral head and (2) whether the sealing capacity of the labrum varies with joint posture. Study Design: Descriptive laboratory study. Methods: The sealing ability of the hip labrum was measured during fluid infusion into the central compartments of 8 cadaveric specimens. Additionally, the pathway of fluid transfer from the central to the peripheral compartment was assessed via direct visualization in 3 specimens. The effect of joint posture on the sealing capacity of the labrum was determined by placing all 8 specimens in 10 functional postures. The relationship between pressure resistance and 3-dimensional motion of the femoral head within the acetabulum was quantified using motion analysis and computer modeling. Results: Resistance to fluid transport from the central compartment of the hip was directly controlled by the labrum during loading. Maximum pressure resistance was affected by joint posture ( P = .001). Specifically, positions that increased external rotation of the joint (pivoting) provided an improved seal, while positions that increased flexion combined with internal rotation (stooping) augmented the ease of fluid transport from the central to the peripheral compartment. Maximum pressure resistance was associated with the distance between the labrum and femoral head during pivoting. Conclusion: This study demonstrated that the transfer of fluid from the central compartment of the hip occurs at the junction of the labrum and femoral head. Joint position was shown to strongly affect the sealing function of the labrum and was attributable to the distance between the labrum and femoral head in certain positions. Clinical Relevance: Altering the relationship between the labrum and femoral head may disrupt the sealing ability of the labrum, potentially leaving the joint at risk for pathological changes with time.

Acetabular component extraction following intra-pelvic migration of a total hip replacement can be hazardous to pelvic tissues, vessels and organs. Acetabular component removal is usually performed using an abdominal retroperitoneal approach. We describe a closed reduction of the acetabular component using a traction/manipulation technique. This manoeuvre can be used in cases of intra-pelvic acetabular component migration where the surface contour of the acetabular component is uncomplicated and an interposition membrane separates the implant from adjacent intra-pelvic structures.

We report the three-year results of a new flexible, horseshoe-shaped acetabular cup, with a carbon fibre reinforced polyetheretherketone (CFR-PEEK) bearing surface. The 3 mm thick composite cup is designed to conserve acetabular bone stock and reproduce a near-physiological stress distribution to the adjacent bone. The cup is intended to articulate against a large diameter ceramic femoral head to produce a low-wear bearing couple that generates minimal wear debris. A prospective, two-centre clinical study of the MITCH PCR cup was started in January 2007, to verify its safety and performance. Twenty-five MITCH PCR cups were implanted by three surgeons. There were 12 men and 13 women, with a mean age of 67.9 years (range 57.4 to 74.9). The mean Oxford hip score improved from 19.6 (SD 7.5) preoperatively to 43.5 (SD 7) at 3 years. The mean Harris hip score improved from 52.9 (SD 7) to 91.4 (SD 13.8) and the Euroqol-5D score increased from 62.6 (SD 18.4) to 82.8 (SD 19). One revision of the acetabular cup was undertaken at 21 months for squeaking. This has been investigated and modification of the articular geometry has resolved the problem, on in-vitro testing. Radiological analysis showed good early osseointegration of the MITCH PCR cup. However at three years, five cases of acetabular component migration and calcar resorption were observed. Three patients have subsequently undergone revision of the acetabular cup, at 41, 42 and 50 months respectively. The cause of the osteolysis is the subject of on-going investigation.

After the first early failures, proximal femoral epiphyseal replacement is becoming popular again. Prosthesis-to-bone load transfer is critical for two reasons: stress shielding is suspected of being responsible for a number of failures of early epiphyseal prostheses; stress concentration is probably responsible of the relevant number of early femoral neck fractures in resurfaced patients. The scope of this work was to experimentally investigate the load transfer of a commercial epiphyseal prosthesis (Birmingham Hip Replacement (BHR)) and an innovative prototype proximal epiphyseal replacement. To investigate bone surface strain, ten cadaveric femurs were instrumented with 15 triaxial strain gauges. In addition the cement layer of the prototype was instrumented with embedded gauges to estimate the strain in the adjacent trabecular bone. Six different loading configurations were investigated, with and without muscles. For the BHR prosthesis, significant stress shielding was observed on the posterior side of the head—neck region (the strain was halved); a pronounced stress concentration was observed on the anterior surface (up to five times in some specimens); BHR was quite sensitive to the different loading configurations. For the prototype, the largest stress shielding was observed in the neck region (lower than the BHR; alteration less than 20 per cent); some stress concentration was observed at the head region, close to the rim of the prosthesis (alteration less than 20 per cent); the different loading configurations had similar effects. Such large alterations with respect to the pre-operative conditions were found only in regions where the strain level was low. Conversely, alterations were moderate where the strain was higher. Thus, prosthesis-to-bone load transfer of both devices has been elucidated; the prototype preserved a stress distribution closer to the physiological condition.

Hip resurfacing is a bone-conserving procedure with respect to proximal femoral resection, but there is debate in the literature as to whether the same holds true for the acetabulum. We have investigated whether the Birmingham hip resurfacing conserves acetabular bone. Between 1998 and 2005, 500 Birmingham hip resurfacings were performed by two surgeons. Between 1996 and 2005 they undertook 700 primary hip replacements, with an uncemented acetabular component. These patients formed the clinical material to compare acetabular component sizing. The Birmingham hip resurfacing group comprised 350 hips in men and 150 hips in women. The uncemented total hip replacement group comprised 236 hips in men and 464 hips in women. Age- and gender-matched analysis of a cohort of patients for the sizes of the acetabular components required for the two types of replacement was also undertaken. Additionally, an analysis of the sizes of the components used by each surgeon was performed. For age-matched women, the mean outside diameter of the Birmingham hip resurfacing acetabular components was 2.03 mm less than that of the acetabular components in the uncemented total hip replacements (p < 0.0001). In similarly matched men there was no significant difference (p = 0.77). A significant difference was also found between the size of acetabular components used by the two surgeons for Birmingham hip resurfacing for both men (p = 0.0015) and women (p = 0.001). In contrast, no significant difference was found between the size of acetabular components used by the two surgeons for uncemented total hip replacement in either men or women (p = 0.06 and p = 0.14, respectively). This suggests that variations in acetabular preparation also influence acetabular component size in hip resurfacing.