Iliopsoas impingement occurs in 4% to 30% of patients after undergoing total hip arthroplasty (THA). Despite a relatively high incidence, there are few attempts at modelling impingement between the iliopsoas and acetabular component, and no attempts at modelling this in a representative cohort of subjects. The purpose of this study was to develop a novel computational model for quantifying the impingement between the iliopsoas and acetabular component and validate its utility in a case-controlled investigation. This was a retrospective cohort study of patients who underwent THA surgery that included 23 symptomatic patients diagnosed with iliopsoas tendonitis, and 23 patients not diagnosed with iliopsoas tendonitis. All patients received postoperative CT imaging, postoperative standing radiography, and had minimum six months’ follow-up. 3D models of each patient’s prosthetic and bony anatomy were generated, landmarked, and simulated in a novel iliopsoas impingement detection model in supine and standing pelvic positions. Logistic regression models were implemented to determine if the probability of pain could be significantly predicted. Receiver operating characteristic curves were generated to determine the model’s sensitivity, specificity, and area under the curve (AUC).Aims
Methods
The acetabular labrum is a soft-tissue structure
which lines the acetabular rim of the hip joint. Its role in hip
joint biomechanics and joint health has been of particular interest
over the past decade. In normal hip joint biomechanics, the labrum
is crucial in retaining a layer of pressurised intra-articular fluid
for joint lubrication and load support/distribution. Its seal around
the femoral head is further regarded as a contributing to hip stability through
its suction effect. The labrum itself is also important in increasing
contact area thereby reducing contact stress. Given the labrum’s
role in normal hip joint biomechanics, surgical techniques for managing
labral damage are continuously evolving as our understanding of
its anatomy and function continue to progress. The current paper
aims to review the anatomy and biomechanical function of the labrum
and how they are affected by differing surgical techniques. Take home message: The acetabular labrum plays a critical role
in hip function and maintaining and restoring its function during
surgical intervention remain an essential goal. Cite this article:
Aims. Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated
The trend towards more minimal access has led to a series of instruments being developed to enable adequate access for Direct Anterior Approach (DAA) for hip arthroplasty. These include longer levers, hooks attached to the operating table and a series of special attachments to the operating table to position the leg and apply traction where necessary. The forces applied in this way may be transmitted locally, damaging muscle used as a fulcrum, or the knee and ankle joints when torque has to be applied to the femur through a boot. The arthroplasty surgeon's aim is to minimise the forces applied to both bone and
Surgical treatment of Hip PJI by resection of the infected implants and tissue and placement of a “spacer” which elutes antibiotic via antibiotic loaded cement is an accepted treatment option. There is some controversy over whether this “spacer” should be articulating or static. Proponents of the articulating option argue that there is improved function and maintenance of the
Ideally the hip arthroplasty should not be subject to bony or prosthetic impingement, in order to minimise complications and optimise outcomes. Modern 3d planning permits pre-operative simulation of the movements of the planned hip arthroplasty to check for such impingement. For this to be meaningful, however, it is necessary to know the range of movement (ROM) that should be simulated. Arbitrary “normal” values for hip ROM are of limited value in such simulations: it is well known that hip ROM is individualised for each patient. We have therefore developed a method to determine this individualised ROM using CT scans. CT scans were performed on 14 cadaveric hips, and the images were segmented to create 3d virtual models. Using Matlab software, each virtual hip was moved in all potential directions to the point of bony impingement, thus defining an individualised impingement-free 3d ROM envelope. This was then compared with the actual ROM as directly measured from each cadaver using a high-resolution motion capture system. For each hip, the ROM envelope free of bony impingement could be described from the CT and represented as a 3d shape. As expected, the directly measured ROM from the cadaver study for each hip was smaller than the CT-based prediction, owing to the presence of constraining
The purpose of this study was to investigate the influence of surgical approach on femoral stem version in THA. This was a retrospective database review of 830 THAs in 830 patients that had both preoperative and postoperative CT scans. All patients underwent staged bilateral THAs and received CT-based 3D planning on both sides. Stem version was measured in the second CT-scan and compared to the native neck axis measured in the first CT-scan, using the posterior condyles as the reference for both. Cases were performed by 104 surgeons using either a direct anterior (DAA, n=303) or posterior (PA, n=527) approach and one of four stem designs: quadrangular taper, calcar-guided short stem, flat taper and fit-and-fill. Sub-analyses investigated changes in version for low (≤5°), neutral (5–25°) and high (≥25°) native version subgroups and for the different implant types. Native version was not different between approaches (DAA = 12.6°, PA = 13.6°, p = 0.16). Overall, DAA stems were more anteverted relative to the native neck axis vs PA stems (5.9° vs 1.4°, p<0.001). This trend persisted in hips with high native version (3.2° vs -5.3°, p<0.01) and neutral native version (5.3° vs 1.3°, p<0.001), but did not reach significance in the low native version subgroup (8.9° vs 5.9°, p=0.13). Quadrangular taper, calcar-guided, and flat taper stem types had significantly more anteversion than native for DAA, while no differences were found for PA. Stems implanted with a direct anterior approach had more anteversion than those implanted with a posterior approach. The smaller surgical field,
Traditional mechanical debridement can only remove visibly infected tissue and is unable to completely clear all the biofilm that hides within muscle crevices and nerves. This study aims to determine the results of single-stage revision using noncontact low frequency ultrasonic debridement in treating chronic periprosthetic joint infections (PJI). A prospective study of consecutive patients requiring single-stage revision for chronic PJI was performed since August 2021. After mechanical debridement, an 8‑mm handheld non‑contact low‑frequency ultrasound probe was used for ultrasonic debridement at a frequency of (25±5) kHz and power of 90% for 5 minutes. Each ultrasound lasted 10 seconds with 3‑seconds intervals. The probe was repeatedly sonicated among all
Dislocation following revision THA remains a leading cause of failure. Integrity of the abductor muscles is a major contributor to stability. Large diameter heads (LDH), Dual Mobility (DM) and Constrained Acetabular Liners (CAL) are enhanced stability options but the indication for these choices remains unclear. We assessed an algorithm based on Gluteus Medius (GM) deficiency to determine bearing selection. Default choice with no GM damage was a LDH. GM deficiency with posterior muscle intact received DM and CAL for GM complete deficiency with loss of posterior muscle. Consecutive revision THA series followed to determine dislocation, all-cause re-revision and Oxford Hip Score (OHS). 311 revision THA with mean age 70 years (32–95). At a mean follow-up of 4.8 years overall dislocation rate 4.1% (95%CI 2.4–7.0) and survivorship free of re-revision 94.2% (95%CI 96.3–91.0). Outcomes:. Group 1 - LDH (36 & 40mm) n=164 / 4 dislocations / 7 re-revisions. Group 2 - DM n=73 / 3 dislocations / 4 re-revisions. Group 3 - CAL n=58 / 5 dislocations / 7 re-revisions. Group 4 - Other (28 & 32mm) n=16 / 1 dislocation / no re-revisions. Mean pre-op OHS: 19.6 (2–47) and mean post-op OHS: 33.9 (4–48). Kaplan-Meier analysis at 60 months dislocation-free survival was 96.1% (95% CI: 93.0–97.8). There was no difference between survival distributions comparing bearing choice (p=0.46). Decision making tools to guide selection are limited and in addition
Dual Mobility (DM) Total Hip Replacements (THRs) were introduced to reduce dislocation risk, which is the most common cause of early revision. The in-vivo mechanics of these implants is not well understood, despite their increased use in both elective and trauma settings. Therefore, the aim of this study was to comprehensively assess retrieved DM polyethylene liners for signs of damage using visual inspection and semi-quantitative geometric assessment techniques. Retrieved DM liners (n=20) were visually inspected for the presence of seven established modes of polyethylene damage. If embedded debris was identified on the external surface, its material composition was characterised using energy-dispersive x-ray analysis (EDX). Additionally, each liner was geometrically assessed for signs of wear/deformation using a validated methodology. Visual inspection of the liners revealed that scratching and pitting were the most common damage modes on either surface. Burnishing was observed on 50% and 15% of the internal and external surfaces, respectively. In addition, embedded debris was identified on 25% of the internal and 65% of the external surfaces. EDX analysis of the debris identified several materials including iron, titanium, cobalt-chrome, and tantalum. Geometric analysis demonstrated highly variable damage patterns across the liners. The results of this study provide insight into the in-vivo mechanics of DM bearings. For example, the results suggest that the internal bearing (i.e., between the head and liner) acts as the primary articulation site for DM-THRs as evidenced by a higher incidence of burnishing and larger, more concentrated regions of penetration across the liners’ internal surfaces. Furthermore, circumferential, and crescent-shaped damage patterns were identified on the articulating surfaces of the liners thus providing evidence that these components can rotate within the acetabular shell with varying degrees of mobility. The mechanics of DM bearings are complex and may be influenced by several factors (e.g.,
The direct anterior approach (DAA) is a popular minimally invasive approach for total hip arthroplasty (THA). It usually involves ligation of the lateral femoral circumflex artery's ascending branch (a-LFCA), which contributes to the perfusion of the tensor fasciae latae (TFL) muscle. Periarticular muscle status and clinical outcome were assessed after DAA-THA after a-LFCA preservation versus ligation. We evaluated surgical records of 161 patients undergoing DAA-THA with tentative preservation of the a-LFCA by the senior author between May and November 2021. Among 92 eligible patients, 33 (35 hips) featured successful preservation, of which 20 (22 hips, 13 female) participated in the study. From 59 patients with ligated a-LFCA, 26 (27 hips, 15 female) were enrolled, constituting the control group. MRI and clinical examinations were performed at 17–26 months to analyze volume and fatty infiltration of the TFL, gluteus medius and gluteus minimus muscles relative to the contralateral non-THA hip (15 preserved, 18 ligated). Clinical and radiographic data was retrospectively extracted from patient files. Patient-reported outcomes (PROMs) were added from the THA registry. There was a relative difference in TFL muscle volume of -6.27 cm. 3. (−9.89%, p=0.018) after a-LFCA preservation versus -8.6 cm. 3. (=11.62%, p=0.002) after ligation, without group differences (p>0.340). a-LFCA preservation showed lower relative TFL fatty infiltration (p=0.10). Gluteal muscle status was similar between sides and groups. Coxa valga morphology was more frequent in a-LFCA preservation (83%) than ligation (17%). Clinical outcomes showed high patient satisfaction in both groups, without difference in PROMs, but less anterolateral soft-tissue swelling after a-LFCA preservation (p<0.001). Despite excellent clinical results in both groups, preservation of the a-LFCA was associated with less TFL fatty infiltration and
Executing an extended retinacular flap containing the blood supply for the femoral head, reduction osteotomy (FHO) can be performed, increasing the potential of correction of complex hip morphologies. The aim of this study was to analyse the safety of the procedure and report the clinical and radiographic results in skeletally mature patients with a minimum follow up of two years. Twelve symptomatic patients (12 hips) with a mean age of 17 years underwent FHO using surgical hip dislocation and an extended
After a hip fracture, infections are common, but signs of infection resemble those of systemic inflammatory response to trauma and surgery, and conventional infection markers lack specificity. Plasma-calprotectin, a novel marker of neutrophil activation, has shown potential as an infection marker in ER and ICU settings. To investigate if plasma-calprotectin is superior compared to conventional infection biomarkers after hip fracture. Prospective cohort study of hip fracture patients admitted to our department. Calprotectin, procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) count were measured in blood plasma upon admission and on day 3 post-surgery. Patients with infection (pneumonia, UTI, sepsis, SSI, other
Cobalt chrome alloy is commonly used in joint replacement surgery. However, it is recognised that some patients develop lymphocyte mediated delayed type hypersensitivity (DTH) responses to this material, which may result in extensive bone and
Background. Instability is one of the most common complications after total hip arthroplasty (THA), particularly when using the posterior approach. Repair of the posterior capsule has proven to significantly decrease the incidence of posterior hip dislocation. The purpose of the present study is to evaluate if braided polyblend suture provides a stronger repair of the posterior
The duration of systemic antibiotics following first-stage surgery is contentious. Our Institution's philosophy is to perform an aggressive debridement, high concentration of targeted antibiotics through cement beads and systemic prophylactic antibiotics alone. In the presence of significant
Aims. Previous research has demonstrated increased early complication rates following total hip arthroplasty (THA) in obese patients, as defined by body mass index (BMI). Subcutaneous fat depth (FD) has been shown to be an independent risk factor for wound infection in cervical and lumbar spine surgery, as well as after abdominal laparotomy. The aim of this study was to investigate whether increased peritrochanteric FD was associated with an increased risk of complications in the first year following THA. Methods. We analyzed prospectively collected data on a consecutive series of 1,220 primary THAs from June 2013 until May 2018. The vertical
Background. Fully constrained liners are used to treat recurrent dislocations or patients at high risk after total hip replacements. However, they can cause significant morbidities including recurrent dislocations, infections, aseptic loosening and fractures. We examine long term results of 111 patients with tripolar constrained components to assess their redislocation and failure rate. Questions/purposes. The purpose of this study was to assess survivorship, complications and functional outcomes at a minimum 10 years after the constrained tripolar liners used in our institute. Methods. We retrospectively identified 111 patients who had 113 revision tripolar constrained liners between 1998 and 2008. Eighty-nine were revised due to recurrent dislocations, 11 for pseudotumor with deficient abductors, and 13 for periprosthetic infection with loss of
Hip arthroscopy is a rapidly expanding technique that has a steep learning curve. Simulation may have a role in helping trainees overcome this. However there is as yet no validated hip arthroscopy simulator. This study aimed to test the construct validity of a virtual reality hip arthroscopy simulator. Nineteen orthopaedic surgeons performed a simulated arthroscopic examination of a healthy hip joint in the supine position. Surgeons were categorized as either expert (those who had performed 250 hip arthroscopies or more) or novice (those who had performed fewer than this). Twenty-one targets were visualized within joint; nine via the anterior portal, nine via the anterolateral and three via the posterolateral. This was followed by a task testing basic probe examination of the joint in which a series of eight targets were probed via the anterolateral portal. Each surgeon's performance was evaluated by the simulator using a set of pre-defined metrics including task duration, number of
Introduction. Open and arthroscopic hip debridement may be used for treatment of femoral acetabular impingement (FAI). There is a paucity of evidence regarding the efficacy of one over the other. Aim. To compare survivorship in terms of further surgical procedure at five years, in patients having undergone either arthroscopic or open hip debridement. Methods. Using our institutional database, we identified all post learning curve arthroscopic and open hip debridement cases with five years of follow up. Patients were matched based on age, gender and Tonnis grade. The primary outcome measure was 5 year survivorship to total hip arthroplasty (THA). Secondary outcome measures included 5 year survivorship to further (non THA) procedures on the joint. Radiological parameters were analysed including femoral neck version, sourcil, centre-edge and alpha angles. Results. A total of 390 arthroscopic and 1316 open operations were identified. Following exclusion and matching 102 (62 female, 39 male) cases were available for analysis in each group. Mean age was 36 years (range 17–51). At 5 years 14.8% of arthroscopic debridement patients and 5.9% of open debridement patients had undergone THA (p =0 .038). There was no statistical difference in secondary outcome measures. Discussion. A significantly higher percentage of patients undergoing arthroscopic debridement went on to THA when compared to matched patients receiving open debridement. We acknowledge the limitations of this study. However, despite the increasing prevalence of arthroscopic surgery to treat FAI, our results would suggest that open debridement may still remain the gold standard intervention. Further investigation, ideally in the form of an RCT, is warranted. Conclusion. In our case matched series, despite the longer rehabilitation and greater
