The integration of ‘Registry-based Randomised Control Trials’ (RRCT) into national registries has the potential to catalyse prospective research, enhancing the evidence base for practice. The aim of this study was to assess the feasibility of embedding a trial within the UK Non-Arthroplasty Hip Registry. This was a national observational, multi-centre study. Six pilot sites within the UK were provided with additional support for data collection. We compared the ability of these pilot sites to collect data with the ability of centres where no additional support was provided. We collected information on patient compliance, efficacy and adverse events of drugs routinely used after hip preserving surgery. The primary outcome measure was compliance with data collection in these centres at 30 and 90 days after surgery. Our intention was to assess the feasibility of, and factors influencing, the capturing data for interventional registry trials in the future. Two hundred and twenty-eight patients were enrolled in the Non-Arthroplasty Hip Registry during the study period (114 within pilot centres and 114 in non-pilot centres). Pilot centres had a mean follow-up compliance of 79% (30 days) and 69.4% (90 days) in contrast to 55% (30 days) and 47% (90 days) in the non-pilot centres (P = 0.009/P = 0.0058). The study revealed that supplementary administrative support resulted in improved compliance. However, deficient administration systems negatively impacted follow-up, and surgeon motivation emerged as a crucial determinant in ensuring robust follow-up. The lessons learned from this feasibility trial could be useful for any national registry embedding prospective, registry-based trials.

AimsThe aim of this study is to evaluate whether acetabular retroversion (AR) represents a structural anatomical abnormality of the pelvis or is a functional phenomenon of pelvic positioning in the sagittal plane, and to what extent the changes that result from patient-specific functional position affect the extent of AR.MethodsA comparative radiological study of 19 patients (38 hips) with AR were compared with a control group of 30 asymptomatic patients (60 hips). CT scans were corrected for rotation in the axial and coronal planes, and the sagittal plane was then aligned to the anterior pelvic plane. External rotation of the hemipelvis was assessed using the superior iliac wing and inferior iliac wing angles as well as quadrilateral plate angles, and correlated with cranial and central acetabular version. Sagittal anatomical parameters were also measured and correlated to version measurements. In 12 AR patients (24 hips), the axial measurements were repeated after matching sagittal pelvic rotation with standing and supine anteroposterior radiographs.ResultsAcetabular version was significantly lower and measurements of external rotation of the hemipelvis were significantly increased in the AR group compared to the control group. The AR group also had increased evidence of anterior projection of the iliac wing in the sagittal plane. The acetabular orientation angles were more retroverted in the supine compared to standing position, and the change in acetabular version correlated with the change in sagittal pelvic tilt. An anterior pelvic tilt of 1° correlated with 1.02° of increased cranial retroversion and 0.76° of increased central retroversion.ConclusionThis study has demonstrated that patients with symptomatic AR have both an externally rotated hemipelvis and increased anterior projection of the iliac wing compared to a control group of asymptomatic patients. Functional sagittal pelvic positioning was also found to affect AR in symptomatic patients: the acetabulum was more retroverted in the supine position compared to standing position. Changes in acetabular version correlate with the change in sagittal pelvic tilt. These findings should be taken into account by surgeons when planning acetabular correction for AR with periacetabular osteotomy.Cite this article: Bone Joint J 2024;106-B(2):128–135.

In 2018, the International Society for Hip Preservation Surgery (ISHA) initiated a series of Delphi consensus studies to identify the global hip preservation community's current opinion on best practices for different facets of hip preservation surgery. Arthroscopic procedures to treat hip pathologies, such as femoroacetabular impingement syndrome (FAIS) are now established in mainstream orthopaedic practice. This study establishes recommendations for the investigation of patients with suspected FAIS. The investigation has focused on the three phases of the diagnostic process-patient history, physical examination and special investigations. Our expert panel consisted of 174 international orthopaedic surgeons with expertise in hip preservation surgery, thereby making recommendations generalisable across the globe. After three rounds of survey and analysis with 174 participants per round, our study achieved consensus at a minimum agreement threshold of 80.0% on 55 statements pertaining to the assessment of patients with FAIS. We encourage our junior and senior hip arthroscopy colleagues internationally to consider these statements both to standardize the clinical and radiological assessment of patients with FAIS and to aid in the design of future research.

AIMS:Acetabular retroversion is a recognized cause of hip impingement and can be influenced by pelvic tilt (PT), which changes in different functional positions. Positional changes in PT have not previously been studied in patients with acetabular retroversion.METHODS:Supine and standing anteroposterior (AP) pelvic radiographs were retrospectively analyzed in 69 patients treated for symptomatic acetabular retroversion. Measurements were made for acetabular index (AI), lateral centre-edge angle (LCEA), crossover index, ischial spine sign, and posterior wall sign. The change in the angle of PT was measured both by the sacro-femoral-pubic (SFP) angle and the pubic symphysis to sacroiliac (PS-SI) index.RESULTS:In the supine position, the mean PT (by SFP) was 1.05° (SD 3.77°), which changed on standing to a PT of 8.64° (SD 5.34°). A significant increase in posterior PT from supine to standing of 7.59° (SD 4.5°; SFP angle) and 5.89° (SD 3.33°; PS-SI index) was calculated (p < 0.001). There was a good correlation in PT change between measurements using SFP angle and PS-SI index (0.901 in the preoperative group and 0.815 in the postoperative group). Signs of retroversion were significantly reduced in standing radiographs compared to supine: crossover index (0.16 (SD 0.16) vs 0.38 (SD 0.15); p < 0.001), crossover sign (19/28 hips vs 28/28 hips; p < 0.001), ischial spine sign (10/28 hips vs 26/28 hips; p < 0.001), and posterior wall sign (12/28 hips vs 24/28 hips; p < 0.001).CONCLUSION:Posterior PT increased from supine to standing in patients with symptomatic acetabular retroversion. The features of acetabular retroversion were less evident on standing radiographs. The low PT angle in the supine position is a factor in the increased appearance of acetabular retroversion. Patients presenting with symptoms of hip impingement should be assessed by supine and standing pelvic radiographs to highlight signs of acetabular retroversion, and to assist with optimizing acetabular correction at the time of surgery. Cite this article: Bone Joint J 2022;104-B(7):786-791.

Background: Revision total hip arthroplasty (rTHA) is associated with an increased dislocation risk. Dual-mobility (DM) bearings have been used to address this issue. Such constructs offer increased range of motion and enhanced stability whilst avoiding some issues associated with fully-constrained devices. DM bearings have been used in our unit since 2013. Methods: All rTHA cases since 2013 were reviewed using the following criteria: (1) use of a DM bearing; (2) extensive soft tissue or bone loss resulting from ARMD, infection or multiple revisions, or requiring custom or megaprosthetic reconstruction; (3) minimum 2-month follow-up. Results: 52 cases were identified with a median of 2 previous operations (range 1-6) and mean follow-up of 14 (2-41) months. The Novae-Stick component was used in 50 cases, the Avantage in 2 and the Trident MDM in 1 case. 19 required acetabular reconstruction using trabecular metal and four required custom acetabular components. 19 required femoral reconstruction with a proximal or total femoral replacement. Postoperatively, 8 patients (15.4%) sustained a dislocation at a mean of 1.6 (range 1-3) months. 3 (5.8%) requiring re-revision. 1 required excision arthroplasty and 2 a constrained liner, 1 of which went on to have further instability. There were no intraprosthetic dislocations. Conclusions: Dual-mobility components are a viable option in the complex rTHA setting. Early dislocations can occur but the rate of instability is acceptable in this high-risk group.

The aim of this study was to define outcomes after total knee arthroplasty (TKA) in lymphoedema and lipoedema patients managed by a multidisciplinary team and daily compression bandaging. A retrospective study was performed in a single centre. Between 2007 and 2018, 36 TKA procedures were performed on 28 consecutive patients with a diagnosis of lymphoedema and lipoedema. Oxford Knee Scores (OKS), EuroQol-5D (EQ-5D) scores, satisfaction scores, radiographs, and complications were obtained at the final follow-up. Patients were admitted to the hospital up to two weeks prior to surgery and remained on the ward for daily compression bandaging by the specialist lymphoedema team. Over the study period, 36 TKAs were performed on 28 patients (5 males, 23 females) with a mean age of 71 years (range 54–90). Of these, 30 TKAs were in patients with lymphoedema, five with lipoedema, and one with a dual diagnosis. Overall, 28 TKAs (21 patients) were available at the final follow-up with a mean follow-up time of 61 months (range 9–138). The mean BMI was 38.5 kg/m2. The mean pre-operative and post-operative Oxford Knee Score increased from 18 (range 2–38) to 29 (range 10–54); p < 0.001. EQ-5D score increased from 0.48 (range 0.15–0.80) to 0.74 (0.34–1.00) (p < 0.001). Mean post-operative satisfaction was 7.6/10 (range 2–10), with 89.3% TKAs satisfied. Complications were one (4%, 1/28) deep vein thrombosis, one superficial wound infection, one prosthetic joint infection, one stiff knee requiring manipulation, and one intra-operative femoral fracture. Lymphoedema and lipoedema should not be seen as barriers to TKA if adopting a multidisciplinary approach.

Introduction: Instability accounts for 1/3 of revision total hip arthroplasty (rTHA) performed in the UK. Removal of well-fixed femoral stems in rTHA is challenging with a risk of blood loss and iatrogenic damage to the femur. The Bioball universal adaptor (BUA), a modular head neck extension adaptor, provides a mechanism for optimisation of femoral offset, leg length and femoral anteversion. This can avoid the need for femoral stem revision in selected cases. The aim of this study is to present the clinical results and rate of instability following revision with this BUA at a minimum of 2 years follow-up. Patients and methods: A review of our prospectively collected database was performed. All patients treated with the Bioball device were included. Clinical and radiologic review were performed pre- and post-surgery. Specific enquiry for instability was made. The Oxford Hip Score (OHS), EuroQol (EQ-5D) score and WOMAC scores were calculated pre-and post-operatively. Complications were recorded. Results: 32 rTHA procedures were performed using the Bioball device between 2013 and 2016. 4 patients did not wish to complete post-operative questionnaires. 2 patients (2/28, 7%) complained of recurrent dislocations following their rTHA procedure. 1 patient complained of instability but no dislocation. The median pre-operative EQ-5D was 0.195 (range -0.07-0.85), OHS was 20 (range 5-43) and WOMAC was 29.8 (range 15.5-52.3). The median EQ-5D was 0.85 (range 0.59-1), OHS was 39 (range 21-48) and WOMAC was 91.1 (range 44.5-99.2) at final follow-up. There were significant improvements in the EQ-5D (p =0.0009), OHS (p =0.0004) and WOMAC (p =0.0001). Conclusion: The BUA is associated with significant functional improvement and relatively low dislocation rates in revision THA. It is a viable option for use in the revision setting.

Background Serum C-reactive protein (CRP) is an important test in the initial diagnosis of prosthetic joint infection (PJI). There is no widely accepted algorithm for the resolution of PJI. Surgeons have traditionally used CRP to determine if the infection has resolved. However, this practice is not currently supported by significant data. Methods A retrospective analysis of our departmental arthroplasty database was conducted to determine mean values of CRP pre and postoperatively for PJI treated with the debridement, antibiotics and implant retention (DAIR) procedure, single-stage revision and two-stage revision. Receiver operating characteristic (ROC) curves were calculated to determine the sensitivity and specificity of CRP testing in diagnosing persistent infection. Results Of the 121 patients who had undergone treatment (75 hip replacements and 48 knee replacements), there were 26 cases of persistent infection. There was no statistical significance in the mean CRP values between successful and unsuccessful treatment groups. The areas under ROCs (AUCs) for CRP values predicting outcomes ranged from 0.46 to 0.73. Conclusion Our study does not support the use of serial CRP monitoring as an indicator of the successful eradication of PJI.

Prosthetic joint infection (PJI) remains one of the major challenges facing orthopaedic surgeons. There is a paucity of evidence on non-operative management of PJI. We present the results of prolonged antibiotic suppression therapy (PSAT) in PJI from a single centre. A retrospective study was performed. Twenty-six patients were included. Two patients were excluded due to the lack of follow-up data. Failure was defined as admission for sepsis from the joint or amputation. Average age was 72 years (range 35–93). Mean Charlson co-morbidity index was 4.3. Mean follow-up was 3.2 years (range 1.3–5.7). Staphylococcal species were isolated in 11 cases (44%) (MRSA 1, MSSA 5, Staph. epidermidis 4 and Staph Pasteuri 1). Other bacteria included E. Coli (2), Streptococci spp. (3), Propionebacterium acnes (1) and Pseudomonas aeruginosa (1). Four cases were polymicrobial infection (16%), and no organisms were identified in two cases (8%). Candida albicans was identified in one case. All cases of bacterial infection were treated with prolonged oral doxycycline or amoxicillin. Twenty patients (80%) received 6 weeks of intravenous antibiotics prior to commencing prolonged oral antibiotics. Two patients experienced persistent symptoms and required amputation (both TKA). Two patients experienced sepsis but were treated successfully with IV antibiotics alone. The success rate of PSAT was 84% (21/25) successful at an average 3.2-year follow-up. Prolonged suppressive antibiotic therapy is a viable option for the management of PJI with a low incidence of complications.

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 prospective study evaluates outcomes and reoperation rates for unicompartmental knee arthroplasty (UKA) from a single non-designer surgeon using relatively extended criteria of degenerative changes of grade 2 or above in either or both non-operated compartments.

The burden of periprosthetic fractures is increasing with increasing volumes of total hip arthroplasty. These injuries often occur in older patients with more significant co-morbidity and osteopenia. Management of these injuries is often resource intensive and can present significant socioeconomic challenges. Understanding the principles of surgical management these cases and recognising when fixation or replacement is required is critical. The aim of this article is to present a contemporary evidence-based review of the surgical fixation options for management of periprosthetic fractures in the presence of well-fixed or loose components.

Background: Total knee arthroplasty (TKA), aiming at neutral mechanical alignment (MA), inevitably modifies the patient's native knee anatomy. Another option is kinematic alignment (KA), which aims to restore the original anatomy of the knee. The aim of this study was to evaluate the variations in lower limb anatomy of a patient population scheduled for TKA, and to assess the use of a restricted KA TKA protocol and compare the resulting anatomic modifications with the standard MA technique.Methods: A total of 4884 knee computed tomography scans were analyzed from a database of patients undergoing TKA with patient-specific instrumentation. The lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and hip-knee-ankle angle (HKA) were measured. Bone resections were compared using a standard MA and a restricted KA aiming for independent tibial and femoral cuts of maximum +/- 5 degrees deviation from the coronal mechanical axis and a resulting overall coronal HKA within +/- 3 degrees of neutral.Results: The mean preoperative MPTA was 2.9 degrees varus, LDFA was 2.7 degrees valgus, and overall HKA was 0.1 degrees varus. Using our protocol, 2475 knees (51%) could have undergone KA without adjustment. To include 4062 cases (83%), mean corrections of 0.5 degrees for MPTA and 0.3 degrees for LDFA were needed, significantly less than with MA (3.3 degrees for MPTA and 3.2 degrees for LDFA; P < .001).Conclusion: The range of knee anatomy in patients scheduled for TKA is wide. MA leads to greater modifications of knee joint anatomy. To avoid reproducing extreme anatomy, the proposed restricted KA protocol provides an interesting hybrid option between MA and true KA. (C) 2017 Elsevier Inc. All rights reserved.

INTRODUCTION:Metal ion release from wear and corrosion at the femoral head-stem taper junction can evoke local adverse reactions to metal debris (ARMD). In a specific large-diameter head (LDH) total hip arthroplasty (THA) system, ceramic femoral heads of 44 to 48 mm are available with a titanium (Ti) adaptor sleeve, while heads of 36- to 40-mm come without sleeves. The hypothesis of this study is that the Ti adaptor sleeve with LDH ceramic-on-ceramic (CoC) bearings will not cause wear or corrosion at the taper junction and, thus, will not generate high whole blood Ti ion levels.METHODS:We compared whole blood Ti levels at minimum 1-year follow-up in 27 patients with unilateral primary LDH CoC THA with head sizes ranging from 36 to 48 mm using a Ti stem and acetabular component.RESULTS:Although Ti ion levels in patients with 36- to 40-mm head diameters without Ti sleeve were found to be statistically significantly higher (2.3 μg/l: 1.6-3.1, SD 0.44) compared to those with a Ti sleeve (1.9 μg/l: 1.6-2.2, SD 0.19) (p = 0.020), the found difference has no clinical importance. No patients presented clinical signs of ARMD, and the clinical results in both groups were similar.CONCLUSIONS:LDH CoC THA Ti levels were low and probably related to unavoidable passive corrosion of implant surfaces. Measurement of Ti in subjects with ceramic LDH, with or without Ti adaptor sleeve, did not disclose undirected signs of trunnionosis.

OBJECTIVES:The purpose of this study was to compare the intra-operative benefits and the clinical outcomes from kinematic or mechanical alignment for total knee arthroplasty (TKA) in patients undergoing revision of failed unicompartmental kneel arthroplasty (UKA) to TKA.METHODS:Ten revisions were performed with a kinematic alignment technique and 11 with a mechanical alignment. Measurements of the hip-knee-ankle angle (HKA), the lateral distal femoral angle (LDFA), and the medial proximal tibial angle (MPTA) were performed using long-leg radiographs. The need for augments, stems, and constrained inserts was compared between groups. Clinical outcomes were compared using the WOMAC score along with maximum distance walked as well as knee range of motion obtained prior to discharge. All data was obtained by a retrospective review of patient files.RESULTS:The kinematic group required less augments, stems, and constrained inserts than the mechanical group and thinner polyethylene bearings. There were significant differences in the lateral distal femoral angle (LDFA) and the medial proximal tibial angle (MPTA) between the two groups (p<0.05). The mean WOMAC score obtained at discharge was better in the kinematic group as was mean knee flexion. At last follow up of 34 months for the kinematic group and 58 months for the mechanical group, no orthopedic complications or reoperations were recorded.CONCLUSION:Although this study has a small patient cohort, our results suggest that kinematic alignment for TKA after UKA revision is an attractive method. Further studies are warranted.

La restauration de l’alignement anatomique lors de l’arthroplastie totale du genou (PTG) pourrait être un moyen d’en améliorer les résultats cliniques. Cette technique a été initialement décrite ; soit avec des instruments à usage unique personnalisés, ce qui est associé à des coûts importants ; soit avec l’instrumentation standard en mesurant les épaisseurs d’os réséqués (measured resection), ce qui ne fournit aucune information peropératoire sur les alignements obtenus. Déterminer si la chirurgie assistée par ordinateur permet de reproduire l’anatomie native des patients, de simplifier l’équilibre ligamentaire durant la PTG et de procurer des résultats cliniques favorables. La navigation a été utilisée pour réaliser une coupe anatomique du fémur distal et du tibia proximal chez 100 prothèses totales de genou (PTG) consécutives non sélectionnées. La résection était modifiée seulement lorsque les angles obtenus auraient été en dehors d’une zone sécuritaire prédéfinie (orientation coronale combinée de ± 3 degrés et/ou coupe fémorale ou tibiale indépendante de ± 5 degrés). L’angle HKA, l’angle latéral distal fémoral (ALDF) et l’angle médial proximal tibial (AMPT) ont été mesurés à partir d’une radiographie debout des membres inférieurs avant et après PTG. L’évaluation clinique a été effectuée à l’aide des questionnaires de WOMAC et KOOS. Le suivi moyen est de 2,4 ans (intervalle 1,0–3,7 DS 0,8). La moyenne de l’ALDF était de 2,1 degrés valgus en préopératoire (9,2 valgus à 3,7 varus, DS 2,5) et de 1,8 degré valgus en postopératoire (5,7 valgus à 4,2 varus, DS 2,0) (p = 0,41). La moyenne préopératoire de l’AMPT était de 3,0 degrés varus (10,6 valgus à 10,2 varus, DS 3,2) et de 2,4 degrés varus en postopératoire (4,0 valgus à 6,8 varus, DS 2,2) (p = 0,03). La moyenne du score WOMAC s’est améliorée en passant de 49,4 (29–85 DS 12,8) à 24,7 (0–73, SD 16,5) (p < 0,001) et le score moyen du KOOS de 37,1 (7,2–77,2 DS 13,0) à 65,1 (26,8–100 DS 16) (p < 0,001). Cinq genoux (5 %) ont nécessité un relâchement ligamentaire : 4 avaient un alignement en valgus et 1 en varus. Deux genoux (2 %) ont nécessité un relâchement de l’aileron rotulien latéral pour optimiser l’alignement patellaire. Utiliser la navigation pour recréer un alignement anatomique lors d’une PTG permet de prévoir l’alignement final du membre et des composants et d’effectuer une correction partielle de l’anatomie dans les cas extrêmes, pouvant ne pas convenir à une PTG. Cette technique aide à préserver l’isométrie ligamentaire et procure une amélioration satisfaisante des scores fonctionnels. IV (rétrospectif).

Background: Kinematic alignment for total knee arthroplasty (TKA) may be one way of improving outcomes. Previous studies have either used patient-specific instrumentation, which adds cost, or standard instrumentation, which provides no intraoperative feedback on resection alignment.Hypothesis: To determine if computer navigation could reproduce native patient anatomy and simplify ligament balance during TKA whilst giving satisfactory improvements in functional scores at early follow-up.Materials and methods: Computer navigation was used for kinematic distal femoral and proximal tibial cuts in 100 consecutive and unselected TKAs. Resections were modified only if measured angles fell outside a pre-defined safe range of combined coronal orientation within +/- 3 degrees of neutral and/or independent femoral or tibial cuts within +/- 5 degrees. Pre- and postoperative measurements of the hip-knee-ankle (HKA) angle, the lateral distal femoral angle (LDFA) and the medial proximal tibial angle (MPTA) were taken using long-leg standing radiographs. Clinical evaluation was with the WOMAC and KOOS scales.Results: Mean follow-up was 2.4 years (range 1.0-3.7, SD 0.8). The mean pre-op LDFA was 2.1 degrees valgus (9.2 valgus to 3.7 varus, SD 2.5) and 1.8 degrees valgus post-op (5.7 valgus to 4.2 varus, SD 2.0) (P=0.41). The mean pre-op MPTA was 3.0 degrees varus (10.6 valgus to 10.2 varus, SD 3.2) and 2.4 degrees varus post-op (4.0 valgus to 6.8 varus, SD 2.2) (P=0.03). The mean WOMAC score improved from 49.4 (29-85, SD 12.8) to 24.7 (0-73, SD 16.5) (P<0.001) and the mean KOOS score from 37.1 (7.2-77.2, SD 13.0) to 65.1 (26.8-100, SD 16) (P<0.001). Five knees (5%) required additional ligament release, four with valgus OA and one with varus OA. Two knees (2%) required lateral retinacular release for patellar tracking.Discussion: Computer navigation for kinematic TKA provides the operating surgeon with full control and feedback at each step, whilst also allowing partial correction of more extreme anatomy that might be unsuitable for recreation during TKA. This technique helps to preserve ligament isometry and produces satisfactory improvements in functional scores. (C) 2015 Elsevier Masson SAS. All rights reserved.

BACKGROUND Metal-on-metal bearings, as used in total hip arthroplasty prostheses that have a large-diameter femoral head, were proposed as an option for treating young and active patients with degenerative hip disorders. Despite the theoretical improved performance of large metal articulations with regard to wear, metal ion levels produced by total hip arthroplasty prostheses in which a large-diameter femoral head is used have not been thoroughly evaluated. METHODS From 173 eligible patients, 144 patients were allocated to undergo a unilateral total hip arthroplasty with use of metal-on-metal components and a large-diameter femoral head. The purpose of this study was to compare the amount of metal ion release (chromium, cobalt, and titanium) from four different types of prostheses from four different implant manufacturers (Biomet, DePuy, Smith & Nephew, and Zimmer). RESULTS For cobalt ion levels, a significant difference was found between the different types of total hip arthroplasty prostheses with a large-diameter femoral head at three, six, twelve, and twenty-four months, but only in male patients or patients with a femoral head size of 50 mm or greater. The highest mean cobalt levels at all follow-up periods were observed with the Zimmer implant and the lowest with the Biomet implant. Titanium ion levels were highest in the Zimmer group at all follow-up periods, whereas no difference between groups was found for chromium. At the most recent follow-up, one hip was revised after the development of an adverse local tissue reaction. Of concern was the observation at the time of revision surgery of black metallic deposits inside the adapter sleeve and on the prosthetic femoral neck. CONCLUSIONS This investigation revealed that metal ion release differs greatly between various total hip arthroplasty implants with a large-diameter femoral head. The sources of metal ion production are numerous, but it is hypothesized that wear and corrosion at the junction between the adapter sleeve and the femoral stem in some patients may be responsible for the elevated cobalt ion levels that were found in the Zimmer group. On the other hand, an adapter sleeve made of titanium, such as the one used with the Biomet large-diameter-head total hip arthroplasty, is an unlikely contributor to the release of cobalt ions. Current technology or design of some total hip arthroplasty systems that make use of a large-diameter femoral head may not yet allow the use of modular large heads with a metal-on-metal articulation, especially in young, active male patients whose activities generate high loads at the hip joint. Further research is needed to better understand the favorable design characteristics of modular junctions in metal-on-metal total hip arthroplasty implants that make use of large-diameter femoral heads.

This report details the reconstruction of the anterior cruciate ligament in an 18-year-old man with Ehlers-Danlos syndrome (EDS). The reduced mechanical properties of the tissue in EDS can pose a challenge to the orthopaedic surgeon. In this case, we describe the use of a hamstring autograft combined with a Ligament Advanced Reinforcement System (LARS). There was a good radiographical, clinical, and functional outcome after two years. This technique gave a successful outcome in the reconstruction of the ACL in a patient with EDS and therefore may help surgeons faced with the same clinical scenario.

Kinematic total knee arthroplasty (TKA) is an emerging technique, but concerns remain around the effect of implanting the prosthesis in more anatomic orientations. Native knees show variation in joint line orientation relative to the tibial mechanical axis but the joint line remains parallel to the floor when standing. This study was undertaken to evaluate joint line obliquity relative to the floor when weight-bearing after kinematic TKA to see if a similar effect occurs.