Arthroscopic hip procedures have increased dramatically over the last decade as equipment and techniques have improved. Patients who require hip arthroscopy for femoroacetabular impingement on occasion require surgery on the contralateral hip. Previous studies have found that younger age of presentation and lower Charlson comorbidity index have higher risk for requiring surgery on the contralateral hip but have not found correlation to anatomic variables. The purpose of this study is to evaluate the factors that predispose a patient to requiring subsequent hip arthroscopy on the contralateral hip. This is an IRB-approved, single surgeon retrospective cohort study from an academic, tertiary referral centre. A chart review was conducted on 310 primary hip arthroscopy procedures from 2009-2020. We identified 62 cases that went on to have a hip arthroscopy on the contralateral side. The bilateral hip arthroscopy cohort was compared to unilateral cohort for sex, age, BMI, pre-op alpha angle and centre edge angle measured on AP pelvis XRay, femoral torsion, traction time, skin to skin time, Tonnis grade, intra-op labral or chondral defect. A p-value <0.05 was deemed significant. Of the 62 patients that required contralateral hip arthroscopy, the average age was 32.7 compared with 37.8 in the unilateral cohort (p = 0.01) and BMI was lower in the bilateral cohort (26.2) compared to the unilateral cohort (27.6) (p=0.04). The average alpha angle was 76.3. 0. in the bilateral compared to 66. 0. in the unilateral cohort (p = 0.01). Skin to skin time was longer in cases in which a contralateral surgery was performed (106.3 mins vs 86.4 mins) (p=0.01). Interestingly, 50 male patients required contralateral hip arthroscopy compared to 12 female patients (p=0.01). No other variables were statistically significant. In conclusion, this study does re-enforce existing literature by stating that younger patients are more likely to require contralateral hip arthroscopy. This may be due to the fact that these patients require increased range of motion from the hip joint to perform activities such as sports where as older patients may not need the same amount of range of motion to perform their activities. Significantly higher alpha angles were noted in patients requiring contralateral hip arthroscopy, which has not been shown in previous literature. This helps to explain that larger CAM deformities will likely require contralateral hip arthroscopy because these patients likely impinge more during simple activities of daily living. Contralateral hip arthroscopy is also more common in male patients who typically have a larger CAM deformity. In summary, this study will help to risk stratify patients who will likely require contralateral hip arthroscopy and should be a discussion point during pre-operative counseling. That offering early subsequent or simultaneous hip arthroscopy in young male patients with large CAMs should be offered when symptoms are mild

Laterality and bilaterality have been reported as prognostic variables in DDH outcomes. However, there is little clarity across the literature on the reporting of laterality in developmental dysplasia of the hip (DDH) due to the variability in severity of the condition. It is widely accepted that the left hip is most frequently affected; however, the true incidence of unilateral left, unilateral right and bilateral cases can be hard to quantify and compare across studies. The purpose of this study was to examine laterality accounting for graded severity in a multicentre, international prospective observational study of infants with hip dysplasia in order to demonstrate the complexity of this issue. A multicentre, prospective database of infants diagnosed with DDH between the ages of 0 and 18 months was analysed from 2010 to April 2015. Patients less than six months were enrolled in the study if at least one hip was frankly dislocated. Patients between 6 and 18 months were enrolled if they had any form of hip dysplasia. Each hip was classified as reduced, dysplastic, dislocatable/subluxable, dislocated reducible or dislocated irreducible. Baseline diagnosis was used to classify patients into a graded laterality category accounting for hip status within the DDH spectrum. A total of 496 patients were included in the analysis; 328 were <6 months old at diagnosis and 168 were between 6 and 18 months old. Of these patients, 421 had at least one frankly dislocated hip. Unilateral left hip dislocations were most common, with 223 patients, followed by unilateral right and bilateral dislocations with 106 and 92 respectively. Stratifying these patients based on status of the contralateral hip, 54 unilateral left and 31 unilateral right dislocated patients also had a dysplastic or unstable contralateral hip. There were significantly fewer bilateral patients in the 6–18 month group (p=0.0005). When classifying laterality by affected hip, bilaterality became the predominant finding, comprising 42% of all patients. The distribution of unilateral left, unilateral right and bilateral cases was greatly impacted by the method of classification. Distinct patterns were seen when considering dislocated hips only, or when considering both dislocated and dysplastic/unstable hips. Findings from this multicentre prospective study demonstrate the necessity to account for the graded severity in hip status when reporting DDH laterality. In order to accurately compare laterality across studies, a standardised, comprehensive classification should be established, as contralateral hip status may impact prognosis and treatment outcomes

INTRODUCTION. Combining novel diverse population-based software with a clinically-demonstrated implant design is redefining total hip arthroplasty. This contemporary stem design utilized a large patient database of high-resolution CT bone scans in order to determine the appropriate femoral head centers and neck lengths to assist in the recreation of natural head offset, designed to restore biomechanics. There are limited studies evaluating how radiographic software utilizing reference template bone can reconstruct patient composition in a model. The purpose of this study was to examine whether the application of a modern analytics system utilizing 3D modeling technology in the development of a primary stem was successful in restoring patient biomechanics, specifically with regards to femoral offset (FO) and leg length discrepancy (LLD). METHODS. Two hundred fifty six patients in a non-randomized, post-market multicenter study across 7 sites received a primary cementless fit and fill stem. Full anteroposterior pelvis and Lauenstein cross-table lateral x-rays were collected preoperatively and at 6-weeks postoperative. Radiographic parameters including contralateral and operative FO and LLD were measured. Preoperative and postoperative FO and LLD of the operative hip were compared to the normal, native hip. Clinical outcomes including the Harris Hip Score (HHS), Lower Extremity Activity Scale (LEAS), Short Form 12 (SF12), and EuroQol 5D Score (EQ-5D) were collected preoperatively, 6 weeks postoperatively, and at 1 year. RESULTS. The mean age is 62 years old (range 32 – 75), 136 male and 120 female, BMI 29.7. The preoperative FO and LLD of the operative hip were 43.5 mm (±9.0 mm) and 3.0 mm (±6.5 mm) compared to the native contralateral hip, respectively. The postoperative FO and LLD were 46.4 mm (±8.7 mm) and 1.6 mm (±7.6 mm) compared to the native contralateral hip, respectively. The change in FO on the operative side was 3.0 mm (±7.2 mm) (p<0.0001) and the change in LLD from preoperative to 6-weeks postoperative was 1.6 mm (±8.4 mm) (p=0.0052) (Figure 1), demonstrating the ability of this stem design to recreate normal hip biomechanics in this study. The HHS increased considerably from a preoperative score of 55.9 to 78.4 at 6 weeks and 92.7 at 1 year. Clinically significant improvements were also seen at 1 year in the LEAS (+2.3), SF12 PCS (+16.3), and EQ-5D TTO (+0.26) and the EQ-5D VAS (+15.7). DISCUSSION and CONCLUSION. This study demonstrated that recreation of normal anatomic leg length and offset is possible by utilizing a modern fit and fill stem that was designed by employing an advanced anthropomorphic database of CT scans. We hypothesize that when surgeons utilize this current fit and fill stem design, it will allow them to accurately recreate a patient's natural FO and leg length, assisting in the restoration of patient biomechanics. Summary Sentence. In this study, modern design methods of a press-fit stem using 3D modeling tools recreated natural femoral offset and leg length, assisting in the restoration of patient biomechanics

The elements of my routine pre-operative planning include skin and scar assessment, the limb length (physical exam and radiographic assessments), the socket type, the stem type, and radiographic templating. Blood management is rarely an issue for primary total hips today and I generally do not recommend pre-operative autologous donation. I currently use a low molecular weight heparin for venous thromboembolic prophylaxis for most all patients. All of my patients have pre-operative medical clearance from a hospital intensivist. A press-fit modular cementless socket is my “workhorse”, although I occasionally use supplemental fixation with spikes (low bone density) or screws (shallow or otherwise deficient hemisphere). Cemented fixation is reserved for hips with radiation necrosis. I use a dual-offset tapered cementless stem in most cases but will use a modular stem in dysplastic, post-traumatic, or severely osteoporotic femurs. I template every case. My goals are to determine component sizes - “the part inside the bone” and improve the biomechanics of the hip – “the part outside the bone”. Sizing is relatively straightforward. For the socket, I use the teardrop and the superior bony edge as landmarks for size and position. I use a Johnson's lateral view radiograph to assess socket version and anterior osteophytes. With a tapered stem, proximal fit on the AP radiograph is the goal and the stem does not need to be canal filling. For the neck resection, I reference off the lesser trochanter. Medialisation of the hip center of rotation (COR) decreases the moment arm for body weight; increasing the femoral off-set lengthens the lever arm for the abductor muscles. These changes in hip biomechanics have a double benefit: a reduction in required abductor forces and lower joint reaction forces. There is accumulating clinical evidence that such favorable alterations in biomechanics can improve clinical outcomes and reduce wear. Higher femoral offset has been associated with greater hip abduction motion and abductor muscle strength. In two independent studies, higher femoral offset has been associated with a significant reduction in polyethylene wear. The traditional arthroplasty goal has been to re-create the offset of the operated hip. In an analysis of 41 patients with one arthritic hip and one clinically and radiographically normal hip (Rolfe et al., 2006 ORS), we found that the horizontal femoral offset of the arthritic hip was, on average, 6mm less than that of the normal, contralateral hip. Considering this, and with medialisation of the COR, is it reasonable to make the femoral offset a few millimeters greater than that pre-op. With modular trial components, final offset and limb-length adjustments are made intra-operatively by assessing soft tissue tension, joint stability and range of motion. Applying these principles in a consecutive series of 40 hips, the hip center of rotation was medialised by 5.6mm and the horizontal femoral offset was increased by an average of 9.5mm, being larger than the normal, contralateral hip by an average of 5.2mm. This combination increased the net biomechanical advantage (NBA) of the diseased hip to an average of 12.5% more than the normal, contralateral hip. The increase in femoral offset is compensated for by medialising the center of rotation. The average lateralisation of the proximal femur of 3.9mm did not cause trochanteric bursitis or other pain. When the offset is right, soft tissue tension can be maintained without over-lengthening. In this series, 2.9mm average lengthening resulted in the reconstructed limb being an average of 1.1mm shorter than the normal side

Introduction. Hip Arthrodesis had been considered as a useful surgical option in young adult patient with high activity demands suffering from osteoarthritis of the hip. Although the procedure surely eliminates pain of the hip joint, it can also cause disorders of the adjacent joints in addition to the complete loss of motion, might consequently deteriorate the activity of daily living. The purpose of this retrospective study was to investigate the efficacy and drawback of hip arthrodesis, focusing on the effect of this procedure on the adjacent joints. Materials and Methods. From 1976 to 1989, 29 hip arthrodesis were performed and 22 hips were followed up (1 died, 6 lost). Disorders led to arthrodesis were septic arthritis (1 hip), post-traumatic (1), osteonecrosis (1), primary osteoarthritis (3), and secondary osteoarthritis due to DDH (16). The average age at surgery was 38 years (range, 19–53 years, 6 men and 16 women). Hip arthrodesis was indicated for young active adults with end stage osteoarthritis, who had normal or mild osteoarthritis in contralateral hip and needed physical labor. The hip was positioned in 30 degrees of flexion, 0 to 5 degree of external rotation, and 0 to 5 degree of abduction. Clinical and radiographic assessment was done for these patients. The clinical follow-up consisted of questionnaire which assessed ability of typical Japanese daily living movement and patient's satisfaction. The condition of the adjacent joints was evaluated clinically and radiographically. Results. After an average follow-up of 22 years (range15-28), no patients complained of pain in the fused hip joint. On the other hand, pain in the adjacent joints was seen frequently. Seventeen (77%) of 22 patients had low back pain and one of these patients, who had severe low back pain, required conversion of arthrodesis to THA. Ten patients (45%) had contralateral hip pain and 8 (36%) of whom subsequently needed THA. All patients who required THA had early stage osteoarthritis when they underwent arthrodesis. Ten patients (45%) had knee pain (5 in the ipsilateral and 5 in the contralateral knee). Radiographic progression of osteoarthritis in adjacent joints was also seen frequently, namely, 9 in lumbar spine, 11 in contralateral hip, 6 in ipsilateral and 6 in contralateral knee. Although pain in the involved hip disappeared, activity of daily living was severely deteriorated (impossible to clip nail: 88%, ride a bicycle: 94%, use a Japanese toilet: 75%, sit in Japanese style: 50%). As a result, only 4 patients (18%) were satisfied with the hip arthrodesis. Discussion. The satisfaction of hip arthrodesis was unexpectedly poor despite of pain relief of involved hip joint. One of essential reasons was activity of daily living in Japanese style, which requires relatively deep flexion in hip and knee. Compensation of limited movement in hip might cause pain and progression of osteoarthritic change in adjacent joints. Another vital reason was that we indicated this procedure for bilateral DDH case whose contralateral hip had early stage osteoarthritis, ended up with THA in most cases

The elements of my routine pre-op. planning include skin and scar assessment, the limb length (physical exam and radiographic assessments), the socket type, the stem type, and radiographic templating. Blood management is rarely an issue for primary total hips today and I generally do not recommend pre-operative autologous donation. I currently use a low molecular weight heparin for venous thromboembolic prophylaxis for most all patients. All of my patients have pre-operative medical clearance from a hospital intensivist. A press-fit modular cementless socket is my “workhorse,” although I occasionally use supplemental fixation with spikes (low bone density) or screws (shallow or otherwise deficient hemisphere). Cemented fixation is reserved for hips with radiation necrosis. I use a dual-offset tapered cementless stem in most cases but will use a modular stem in dysplastic, post-traumatic, or severely osteoporotic femurs. I template every case. My goals are to determine component sizes - “the part inside the bone” and improve the biomechanics of the hip – “the part outside the bone”. Sizing is relatively straight forward. For the socket, I use the teardrop and the superior bony edge as landmarks for size and position. I use a Johnson's lateral view radiograph to assess socket version and anterior osteophytes. With a tapered stem, proximal fit on the AP radiograph is the goal and the stem does not need to be canal filling. For the neck resection, I reference off the lesser trochanter. Medialisation of the hip centre of rotation (COR) decreases the moment arm for body weight; increasing the femoral off-set lengthens the lever arm for the abductor muscles. These changes in hip biomechanics have a double benefit: a reduction in required abductor forces and lower joint reaction forces. There is accumulating clinical evidence that such favourable alterations in biomechanics can improve clinical outcomes and reduce wear. Higher femoral off-set has been associated with greater hip abduction motion and abductor muscle strength. In two independent studies, higher femoral off-set has been associated with a significant reduction in polyethylene wear. The traditional arthroplasty goal has been to re-create the off-set of the operated hip. In an analysis of 41 patients with one arthritic hip and one clinically and radiographically normal hip (Rolfe et al., 2006 ORS), we found that the horizontal femoral off-set of the arthritic hip was, on average, 6 mm less than that of the normal, contralateral hip. Considering this, and with medialisation of the COR, is it reasonable to make the femoral off-set a few millimeters greater than that pre-op. With modular trial components, final off-set and limb-length adjustments are made intra-operatively by assessing soft tissue tension, joint stability and range of motion. Applying these principles in a consecutive series of 40 hips, the hip centre of rotation was medialised by 5.6 mm and the horizontal femoral off-set was increased by an average of 9.5 mm, being larger than the normal, contralateral hip by an average of 5.2 mm. This combination increased the net biomechanical advantage of the diseased hip to an average of 12.5% more than the normal, contralateral hip. The increase in femoral off-set is compensated for by medialising the COR. The average lateralisation of the proximal femur of 3.9 mm did not cause trochanteric bursitis or other pain. When the offset is right, soft tissue tension can be maintained without over-lengthening. In this series, 2.9 mm average lengthening resulted in the reconstructed limb being an average of 1.1 mm shorter than the normal side

Introduction. The objective of our study was to determine the extent to which the quality of the biomechanical reconstruction when performing hip replacement influences gait performances. We aimed to answer the following questions: 1) Does the quality of restoration of hip biomechanics after conventional THR influence gait outcomes? (question 1), and 2) Is HR more beneficial to gait outcomes when compared with THR? (question 2). Methods. we retrospectively reviewed 52 satisfied unilateral prosthetic hip patients (40 THRs and 12 HRs) who undertook objective gait assessment at a mean follow-up of 14 months. The quality of the prosthetic hip biomechanical restoration was assessed on standing pelvic radiograph by comparison to the healthy contralateral hip. Results. We were unable to detect any statistically significant correlation between the radiographical parameters and the gait data, for THR patients. In stress conditions (inclination or declination of the ramp), the gait was more symmetric in the HR group, compared to the THR group. Discussion/Conclusions. We found that slight variations in the quality of the hip biomechanical restoration had little effect on gait outcomes of THR patients, and HR generated a more physiological gait under stress conditions than well-functioning THR

Introduction. Total hip arthroplasty (THA) is a physically demanding procedure where the surgeon is subject to fatigue with increased energy expenditure comparable to exercise[1]. Robotic technologies have been introduced into operating rooms to assist surgeons with ergonomically challenging tasks and to reduce overall physical stress and fatigue[2]. Greater exposure to robotic assisted training may create efficiencies that may reduce energy expenditure[3]. The purpose of this study was to assess surgeon energy expenditure during THA and perceived mental and physical demand. Methods. 12 THAs (6 cadavers) randomized by BMI were performed by two surgeons with different robotic assisted experience. Surgeon 1 (S1) had performed over 20 robotic assisted THAs on live patients and Surgeon 2 (S2) had training on 1 cadaver with no patient experience. For each cadaver, laterality was randomized and manual total hip arthroplasty (MTHA) was performed first on one hip and robotic assisted total hip arthroplasty (RATHA) on the contralateral hip. A biometric shirt collected surgeon data on caloric energy expenditure (CEE) throughout acetabular reaming (AR) and acetabular implantation (AI) for each THA procedure. Surgeon mental and physical demand was assessed after each surgery. Scores were reported from 1–10, with 10 indicating high demand. A paired sample t-test was performed between MTHA and RATHA within each surgeon group with a confidence interval of (α =0.05). Results. Each surgeon demonstrated greater CEE during MTHA, Figure 1. Surgeon CEE during MTHA was greater for S1(100±28.1 cals) compared to RATHA(83.5±0.34 cals), with no significant difference (p>0.05, p=0.49). Energy expenditure was greater for S2 during MTHA(83.5±16.3 cals) compared to RATHA(75.3±0.71 cals) with no significance (p>0.05, p=0.68). RATHA resulted in a decrease in average CEE for each surgeon with a reduction of 16.5% for S1 and 9.8 % for S2. Surgeon task time during MTHA was greater for S1(14.7±3.2 mins) compared to RATHA(12.3±4.93 mins), with no significance (p>0.05, p=0.46). Average task time was greater for S2 during MTHA(10.0±2.65 mins) compared to RATHA(8.7±2.89 mins) with no significant differences (p>0.05, p=0.66). Average mental and physical demand was less for RATHA compared to MTHA, Figure 2. Average physical demand reported during AR for MTHA(5.5±1.2) was greater than RATHA(4.3±2.0, p=0.08). Average physical demand was greater for AI for MTHA(6±1.3) than RATHA(3.7±2.1, p=0.29). Average mental demand was significantly greater during AR for MTHA(5.7±1.03) when compared to RATHA(3.2±1.5, p=0.007). Average mental demand was greater during AI for MTHA(6.2±1.2) than RATHA(2.3±1.5, p=0.051). Conclusion. Regardless of prior surgical experience, both surgeons had reduced caloric expenditure when performing RATHA as compared to MTHA. For the surgeon with more RATHA experience, there was a greater percent reduction in caloric expenditure between surgical interventions. Both surgeons had similar percent reductions in time for RATHA compared to MTHA. Each surgeon noted increased mental and physical demand during MTHA. The trends suggest RATHA may reduce surgeon energy expenditure and time to perform acetabular reaming and implant insertion for THA. The pilot data suggests that there may be a relationship between energy expenditure and surgeon experience. This could be explored in future studies with a larger surgeon population. For any figures or tables, please contact the authors directly

Introduction. Prophylactic pinning of the contralateral hip in the treatment of slipped upper femoral epiphysis (SUFE) has been shown to be safer than continued observation of the contralateral hip. This treatment remains controversial due to the potential for harm caused to an apparently unaffected hip. There is evidence that pinning of an already slipped epiphysis causes growth disturbance of the proximal femur, however this has been questioned in that the slip occurs at the hypertrophic layer of the growth plate with no damage to the germative layer. Aim. To determine whether prophylactic pinning affects subsequent growth of the unaffected hip in cases of unilateral SUFE. Method. In order to determine the effect of prophylactic pinning we compared radiographs of skeletally mature patients who had either undergone prophylactic pinning (group 1), pinning of the affected side only (group 2), and adults with no history of SUFE (group 3). We measured the articulo-trochanteric distance (ATD) and calculated the ratio of the trochanteric-trochanteric distance to articulo-trochanteric distance. These measures have been used in previous studies and have been shown to be reliable indicators of disturbed proximal femoral growth. As this was a pilot study we recruited 8 to each group. Results. The absolute sum of the ATDs were 219mm (average 27.3mm) Group 1, 213mm (average 26.6mm) Group2 and 258mm (average 32.5mm). The average trochanter-trochanter: ATD ratio in group 1 was 2.7 (1.9–3.8) compared to 2.7 (2.3–3.2) and 2.3 (1.9–2.7) in groups 2 and 3 respectively. Conclusion. Our results suggest no difference in subsequent growth between hips that are prophylactically pinned and those that are not. Abnormal growth was observed in unpinned hips suggesting undiagnosed SUFE in some cases. In this series pinning had no effect on proximal femoral growth in patients with SUFE

The main challenges in hip arthrodesis takedown include the decision to perform fusion takedown and the technical difficulties of doing so. In addition to the functional disadvantages of hip fusion, the long-term effects of hip arthrodesis include low back pain and in some cases ipsilateral knee pain. Indications for fusion conversion to THA include arthrodesis malposition, pseudoarthrosis, and ipsilateral knee, low back, contralateral hip problems, and functional disadvantages of ipsilateral hip fusion. When deciding whether or not to take down fusion, consider the severity of the current problem, risks of takedown and likely benefits of takedown. Best results of fusion takedown occur if abductor function is likely to be present. If the abductors are not likely to function well, dearthrodesis may still help, but the patient will have a profound Trendelenburg or Duchenne gait and risk of hip instability will be higher. Abductor assessment can be performed by determining if the abductors contract on physical exam and determining if the previous form of fusion spared the abductors and greater trochanter. EMG and MRI also can be performed to assess the abductors, but value in this setting is unproven. Before dearthrodesis establish realistic expectations: most patients will gain hip motion—but not normal motion, most will see improvement in back/knee pain, but many will become cane-dependent for life. The main technical issues to overcome involve exposure, femoral neck osteotomy, acetabular preparation, and femoral fixation. Exposure can be conventional posterior, anterolateral or direct anterior with an in-situ femoral neck cut. In complex cases, a transtrochanteric approach is often helpful. The in-situ neck cut is facilitated by fluoroscopy or intraoperative radiograph to make sure the cut is at the correct level and at the correct angle. Be careful not to angle into the pelvis with the cut. Acetabular preparation is more complex because anatomic landmarks often are absent or distorted. Try to find landmarks including ischium, ilium, teardrop, and fovea. Confirm location with fluoroscopy as reaming commences and during reaming. Depth of reaming can be improved by using the fovea (if present) and teardrop on fluoroscopy. Cup fixation is usually an uncemented cup, fixed with multiple screws because bone quality typically is compromised. Femoral fixation is at the surgeon's discretion, recognizing the proximal bone may be distorted in some cases. Postoperative management includes protected weight bearing as needed and heterotopic bone prophylaxis in selected patients

Background. The aim of this study is to analysis the ability of these patients, treated with MOMHR, to resume sport activities by gait analysis and clinical evaluations. Metal on metal hip resurfacing (MOMHR) is indicated to treat symptomatic hip osteoarthritis in young active patients. These patients require a high level of function and desire to resume sport activities after surgery. Study Design & Methods. 30 consecutive male patients playing high impact sports with unilateral hip osteoarthritis and normal contralateral hip were included in the study, they were treated with MOMHR by the same surgeon. No patients were lost to follow. The mean age at operation was 39.1 years (range 31 to 46). Primary diagnosis was osteoarthritis. OHS, HHS, UCLA activity score were completed at pre-operative time, six months and one year after surgery. Functionally, gait analysis was performed in all patients 6 months and one year after surgery. A stereophotogrammetric system (Smart-DX, BTS, Milano, Italy, 10 cameras, 250Hz) and two platforms (9286BA Kistler Instrumente AG, Switzerland) were used. Cluster of 4 markers were attached on the skin of each bone segment, a number of anatomical landmarks were calibrated and segment anatomical frames defined, markers were positioned by the same operator. Walking, running and squat jump were analyzed and strength and range of movement of the hips and knees were calculated. Results. At follow-up times the survival rate for the whole cohort was 100%. The mean pre-op OHS was 28.1 points (range 15.0 to 38.0), at 6 months after surgery was 44.5 points (range 44 to 48), at one year after surgery was 47.9 points (range 45 to 48). The mean pre-op HHS was 54.7 points (range 33.1 to 73.4), at 6 months after surgery was 96.7 points (range 93.4 to 100), at one year after surgery was 99.7 points (range 95.7 to 100). The mean pre-op UCLA activity score was 2.7 (range 2 to 4), at 6 months after surgery was 7.4 (range 5 to 10), at one year after surgery was 8.6 (range 7 to 10). At 6 months after surgery, patients showed a reduction of the differences between the operated and the contralateral side during walking, running and squat jumping. (p<0.01). One year after the operation there were no differences. At 3 months after surgery the mean hip flexion extension range of motion was in the normal hips 41±1.7 and in the operated hips 37.3±2.1; at 6 months after surgery the mean hip flexion extension range of motion was in the normal hips 45.4±1.8 and in the operated hips 42.0±1.7; At 1 year after surgery the hip flexion extension range of motion was in the normal hips 42.9±1.7 and in the operated hips 45.5±1.4. (p=0.001). Conclusions. Our gait analysis study shows that the biomechanical function of the operated hip is completely recovered 1 year after MOMHR operation. As a consequence sport activities can be successfully resumed. MOMHR is a good choice for young and active patients affected by hip osteoarthritis requiring a high level of activity

Purpose. Femoroacetabular impingement (FAI) may contribute to the development of early onset hip osteoarthritis (OA). A cam lesion (or pistol grip deformity) of the proximal femur reduces head-neck offset resulting in cam type FAI. The alpha angle is a radiographic measurement recommended for diagnosis of cam type FAI. The purpose of this study was to determine if patients that develop end stage hip OA prior to 55 years of age have radiographic evidence of cam type FAI. Method. The anteroposterior (AP) pelvis and lateral hip radiographs of 244 patients (261 hips) who presented to our institution for hip arthroplasty or hip fracture fixation between 2006 and 2008 were retrospectively reviewed. Three cohorts were compared: 1) patients with end stage hip OA < 55 years old (N=76); 2) patients with end stage hip OA > 55 years old (N=84); 3) hip fracture patients > 65 years old without radiographic evidence of hip arthritis were used as controls (N=101). Patients with inflammatory arthritis, avascular necrosis and post-traumatic hip OA were excluded. Alpha angles were measured on the AP pelvis and lateral radiographs by three coauthors using ImageJ 1.43 software (National Institutes of Health, USA). For patients with end stage hip OA, AP alpha angles were measured on both the hip with OA and the contralateral hip. Lateral alpha angles were measured only on the hip with OA. For patients with hip fracture, AP alpha angles were measured on the non-fractured hip and lateral alpha angles were measured on the fractured hip. A one-way ANOVA with post hoc Tukeys HSD test was used to compare the AP and lateral alpha angles for the three cohorts. Results. The intraclass correlation coefficient (ICC) for the three coauthors measuring AP and lateral alpha angles was 0.85 and 0.86 respectively, indicating excellent inter-rater agreement. Patients < 55 years old with end stage hip OA had the largest AP and lateral alpha angles (82.711.6 degrees AP and 63.918.5 degrees lateral). These angles were significantly larger (p<0.01 for both comparisons) than patients > 55 years old with end stage hip OA (71.717.8 degrees AP and 55.518.0 degrees lateral) and hip fracture patients without hip OA (52.710.9 degrees AP and 44.411.4 degrees lateral). Comparing AP alpha angles of the contralateral hips, the mean AP alpha angle for patients < 55 years old with hip OA (70.813.2 degrees) was significantly larger (p=0.04) than patients > 55 years old with hip OA (64.516.2 degrees) which in turn was significantly larger (p<0.01) than the hip fracture patients (52.710.9 degrees). Conclusion. Patients < 55 years old with hip OA had the largest mean AP and lateral alpha angles, significantly larger than patients > 55 years old with hip OA and hip fracture patients without hip OA. Thus young patients with end stage hip OA do have radiographic evidence of cam type FAI. Furthermore, this case-controlled study suggests that cam type FAI may contribute to the development of early onset hip OA

Patients with longstanding hip fusion are predisposed to symptomatic degenerative changes of the lumbar spine, ipsilateral knee and contralateral hip. In such patients, conversion of hip arthrodesis to hip replacement can provide relief of such symptoms. However, this is a technically demanding procedure associated with higher complication and failure rates than routine total hip replacement. The aim of this study was to determine the early functional results and complications in patients undergoing hip fusion conversion to total hip replacement, performed or supervised by a single surgeon, using a standardised approach and uncemented implants. We hypothesised that a satisfactory functional improvement can be achieved in following conversion of hip fusion to hip replacement. Eighteen hip fusions were converted to total hip replacements. A constrained acetabular liner was used in 3 hips. Mean follow up was 5 years (2 to 15 years). Two (11%) hips failed, requiring revision surgery and two patients (11%) had injury to the peroneal nerve. Heterotopic ossification developed in 7 (39%) hips, in one case resulting in joint ankylosis. No hips dislocated. Conversion of hip fusion to hip replacement carries an increased risk of heterotopic ossification and neurological injury. We advise prophylaxis against heterotopic ossification. When there is concern about hip stability we suggest that the use of a constrained acetabular liner is considered. Despite the potential for complications, this procedure had a high success rate and was effective in restoring hip function

Combined acetabular and femoral anteversion (CA) of the hip following total hip arthroplasty (THA) is critical to the hip function and longevity of the components. However, no study has been reported on the accuracy in restoration of CA of the hip after operation using robotic assistance and conventional free-hand techniques. The purpose of this study was to evaluate if using robotic assistance in THA can better restore native CA than a free-hand technique. Twenty three unilateral THA patients participated in this study. Twelve of them underwent a robotic-arm assisted THA (RIO® Robotic Arm Interactive Orthopedic System, Stryker Mako., Fort Lauderdale, FL, USA) and eleven received a free-hand THA. Subject specific 3D models of both implanted and non-implanted hips were reconstructed using post-operative CT scans. The anteversion and inclination of the native acetabulum and implanted cup were measured and compared. To determine the differences of the femoral anteversion between sides, the non-implanted native femur was mirrored and aligned with the remaining femur of the implanted side using an iterative closest point algorithm. The angle between the native femoral neck axis and the prosthesis neck axis in transverse plane was measured as the change in femoral anteversion following THA. The sum of the changes of the acetabular and femoral anteversion was defined as the change of CA after THA. A Wilcoxon signed rank test was performed to test if the anteversion of the navigation and free-hand THAs were different from the contralateral native hips (α = 0.05). The acetabular anteversion were 22.0°±7.4°, 35.9°±6.5° and 32.6°±22.6° for the native hips, robotic assisted THAs and free-hand THAs, respectively, and the corresponding values of the acetabular inclinations were 52.0°±2.9°, 35.4°±4.4° and 43.1°±7.1°. The acetabular anteversion was increased by 12.2°±11.1° (p=0.005) and 12.5°±20.0° (p=0.102) for the robotic assisted and the free-hand THAs. The femoral anteversion was increased by 6.3°±10.5° (p=0.077) and 11.0°±13.4° (p=0.014) for the robotic assisted and free-hand THAs, respectively. The CA were significantly increased by 18.5°±11.7° (p<0.001) and 23.5°±26.5° (p=0.019) for the robotic assisted and the free-hand THAs. The changes of the CA of the free-hand THAs varied in a larger range than those of the robotic assisted THAs. This study is the first to evaluate the changes in acetabular and femoral anteversions of the hips after robotic assisted and free-hand THAs using the contralateral native hip as a control. The results demonstrate that both the navigation and free-hand THAs significantly increased the CA compared to the contralateral native hips, but the changes of the robotic assisted THAs (18.5°±11.7°) were smaller and varied less than those of the free-hand THAs (23.5°±26.5°). These data suggest that the robotic assisted THA can better restore the native hip CAs with higher repeatability than the free-hand technique. Further studies are needed to investigate the effects of the hip anteversion changes on the in-vivo function of the hip and the long-term outcomes in THA patients

The main challenges in hip arthrodesis takedown include the decision to perform fusion takedown and the technical difficulties of doing so. In addition to the functional disadvantages of hip fusion, the long-term effects of hip arthrodesis include low back pain and in some cases ipsilateral knee pain. Indications for fusion conversion to THA include arthrodesis malposition, pseudoarthrosis, and ipsilateral knee, low back, contralateral hip problems, and functional disadvantages of ipsilateral hip fusion. When deciding whether or not to take down a fusion, consider the severity of the current problem, risks of takedown and likely benefits of takedown. Best results of fusion takedown occur if abductor function is likely to be present. If the abductors are not likely to function well, dearthrodesis may still help, but the patient will have a profound Trendelenburg or Duchenne gait and risk of hip instability will be higher. Abductor assessment can be performed by determining if the abductors contract on physical exam and determining if the previous form of fusion spared the abductors and greater trochanter. EMG and MRI also can be performed to assess the abductors, but value in this setting is unproven. Before dearthrodesis establish realistic expectations: most patients will gain hip motion—but not normal motion, most will see improvement in back/knee pain, but many will become cane-dependent for life. The main technical issues to overcome involve exposure, femoral neck osteotomy, acetabular preparation, and femoral fixation. Exposure can be conventional posterior, anterolateral or direct anterior with an in situ femoral neck cut. In complex cases, a transtrochanteric approach is often helpful. The in situ neck cut is facilitated by fluoroscopy or intra-operative radiograph to make sure the cut is at the correct level and at the correct angle. Be careful not to angle into the pelvis with the cut. Acetabular preparation is more complex because anatomic landmarks often are absent or distorted. Try to find landmarks including ischium, ilium, teardrop, and fovea. Confirm location with fluoroscopy as reaming commences and during reaming. Depth of reaming can be improved by using the fovea (if present) and teardrop on fluoroscopy. Cup fixation is usually an uncemented cup, fixed with multiple screws because bone quality typically is compromised. Femoral fixation is at the surgeon's discretion, recognizing the proximal bone may be distorted in some cases. Post-operative management includes protected weight bearing as needed and heterotopic bone prophylaxis in selected patients

Introduction:. Total hip arthroplasty (THA) is extremely effective in treating debilitating arthritic conditions of the hip. With the many modular prosthetic designs available, surgeons can now precisely construct mechanical parameters such as femoral offset (FO). Although several studies have investigated relationships between offset choice and hip abductor strength, hip range of motion, and prosthetic wear rate, there is scarce data on the effect of FO on pain and functional outcomes following THA. The objective of this study was to assess the effect of restoring FO (within varying degrees compared to the contralateral non-diseased hip [CL]) on physical function, mental well-being, pain, and stiffness outcomes as measured by the Short Form 12 Health Survey (SF-12) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) at post-operative follow-up. Methods:. We prospectively collected data on 249 patients that underwent unilateral THA with no or minimal disease of the contralateral hip. Baseline data collection included: age, gender, diagnosis, femoral head size, type of stem, and pre-operative SF-12 and WOMAC scores. Post-operative SF-12 and WOMAC scores were recorded during annual follow-up visits. Post-operative FO was retrospectively measured on standard anteroposterior (AP) pelvis radiographs and compared to FO of CL. FO was measured as the perpendicular distance from the femoral head center of rotation to the anatomic axis of the femur with appropriate adjustments made for image magnification. Patients were categorized into one of three groups: decreased femoral offset (dFO, less than −5 mm compared to CL), normal femoral offset (nFO, between −5 and +5 mm of CL), and increased femoral offset (iFO, greater than +5 mm compared to CL). Results:. In all, 31 patients were categorized into dFO, 163 categorized into nFO, and 55 categorized into iFO. At baseline, the groups differed in categorical diagnoses (p = 0.01). Further analysis revealed a higher percentage of posttraumatic arthritis in dFO as compared to nFO and iFO (12.9%, 1.2%, and 1.8%, respectively). Moreover, a higher percentage of hip dysplasia was present in iFO as compared to nFO and dFO (14.5%, 3.6%, and 6.5%, respectively). Pre-operatively, dFO had lower WOMAC Pain scores than nFO and iFO (29.68, 43.39, and 43.63, respectively; p < 0.005). (Please see Table 1 for comparison of baseline characteristics between groups.) All other pre-operative demographic and survey characteristics were similar. At most recent post-operative follow-up, dFO had lower WOMAC Physical Function scores than nFO and iFO (72.03, 83.23, and 79.51, respectively; p < 0.02) (see Table 2). Discussion:. Reduction of patients' native FOs by greater than 5 mm during THA can lead to inferior levels of physical function. Furthermore, increasing FO by greater than 5 mm did not lead to increased levels of pain nor decreased levels of function

Introduction. In comminuted intertrochanteric fractures, various operative options have been introduced. The purpose of this study was to determine whether there were differences in clinical and radiologic outcomes among bipolar hemiarthroplasty(BH), compression hip screw(CHS) and proximal femur nail antirotatory(PFNA) in treating comminuted intertrochanteric fractures(AO type, A2(21, 22, 23)). Materials and Methods. We retrospectively evaluated total 150 patients(BH:50, CHS:50, PFNA: 50) who were operated due to intertrochanteric fractures from March 2010 to Dec 2012 and were older than 65 years at the time of surgery. We compared these three groups for radiologic and clinical outcomes at 12 months postoperatively, including Harris hip score, ability of ambulation(Koval stage), visual analogue scale and radiologic limb length discrepancy(shortening). Landmark and radiologic length was checked. –A: postoperative length. –A’: POD 1year. –B: immediate posteopative contralateral length(from hip center to distal tip of lesser trochanter). –B’: POD 1year contralateral length(from hip center to distal tip of lesser trochanter). –. Limb length(shortening) was adjusted considering difference of magnification. = {A × (B’/B)}− A’. Results. There was no statistical significance among three groups in clinical outcomes including Harris hip score, ability of ambulation(Koval stage), visual analogue scale. However, there was significant differences in radiologic limb discrepancy in plain radiographs at 12 months postoperatively.(radiologic shortening- BH: 2.3mm, PFNA: 3.0mm, CHS:5.1mm, p=0.000). Conclusions. There were no clinical differences among BH, PFNA and CHS in this study. However, notable differences were observed in limb length discrepancy according to selection of operative methods

Introduction. Improvements in function after THA can be evaluated using validated health outcome surveys but studies have shown that PROMs are unreliable in following the progress of individuals. Formal gait lab analysis is expensive, time consuming and fixed in terms of location. Inertial Measurement Units (IMUs) containing accelerometers and gyroscopes can determine aspects of gait kinematics in a portable package and can be used in the outpatient setting (Figure 1). In this study multiple metrics describing gait were evaluated pre- and post THA and comparisons made with the normal population. Methods. The gait of 55 patients with monarthrodial hip arthrosis was measured pre-operatively and at one year post-surgery. Patients with medical co-morbidity or other condition affecting their gait were excluded. Six IMUs aligned in the sagittal plane were attached at the level of the anterior superior iliac spines, mid-thigh and mid-shank. Data was analysed using proprietary software (Figure 2). Each patient underwent a conventional THA using a posterolateral approach. An identical test was performed one year after surgery. 92 healthy individuals with a normal observed gait were used as controls. Results. In the pre-operative test the range of movement in the sagittal plane of both the ipsilateral hip (mean range 20.4) and the contra-lateral non-diseased hip (35.3 degrees) was reduced compared to the control group (40.5 degrees), (P<0.001). The pre-operative range of motion of both knees was also reduced compared with normal (P<0.001). Pelvic movement on the ipsilateral side was increased. After one year the range of movement of the ipsilateral hip significantly improved (Mean range 28.9 deg SD 6.6) but did not attain normal values (P<0.001). Movement measured in the contralateral hip reduced further from its pre-operative value with a mean difference of −5.25 degrees (95% CI −8.06 to −2.43). Measurements of the symmetry of movement were increased. Knee movement on both sides increased but not to normal values (p<0.001). In contradistinction, there was bilateral increased coronal movement at the thigh and calf a year after surgery. Discussion and Conclusion. Gait after routine THA does not return to normal on the ipsilateral or contralateral side. Pathology in one hip causes bilateral gait abnormality that can be quantified by movement at the pelvis, hip, thigh and knee. The ability of a patient to walk normally after surgery will depend on many factors including details of the hip operation such as accurate recreation of the biomechanics of the joint and physical therapy regimens. Advances in technology now allow assessment of gait in large number of patients in the clinic setting and will better allow us to establish the important factors to improve patients gait and thereby potentially improve further satisfaction and PROMS scores. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

We Present the results of radiographic assessment of limb length and offset measurements of the first 50 Corin Mini Hips done at Yeovil District Hospital. All reconstructed Hips were compared with the contra lateral hip for leg length and offset restoration using the method of Murphy et al 2007. Excellent matching with the contralateral hip in terms of leg length and offset were found in 78% of hips and fair matching in 22%. The mean leg length discrepancy was 4 mm and mean offset discrepancy was 2 mm. Our results show that despite using a different paradigm to conventional hip replacements, this stem allows accurate restoration of hip geometry

The mean age of patients with osteonecrosis reported in series in our literature is 38 to 53. Thus, performing a total hip replacement on a patient who would need a procedure to last 40–45 years is a concern. Patients with osteonecrosis of the hip require some type of surgical treatment. Without treatment, a large majority of femoral heads in patients even with Ficat stage I osteonecrosis will collapse or become symptomatic. A common scenario is a patient who first presents to the orthopaedic surgeon with severe arthritis secondary to osteonecrosis in one hip and a normal appearing radiograph on the asymptomatic contralateral side. Performing a total hip on the severe arthritic hip is usually not debated. A MRI will commonly show Ficat stage I osteonecrosis on the asymptomatic contralateral hip. Some method of core decompression is a reasonable choice if it is non-steroid induced, small more medially positioned lesion, but not for other Ficat stage 1 lesions or those with more advanced stages. The problem is convincing the patient to have anything done when they are asymptomatic. Because results with total hip replacement for patients with osteonecrosis of the hip have significantly improved, most patients with a symptomatic hip prefer arthroplasty as treatment. Arthroplasty has become the predominant surgical treatment for osteonecrosis of the hip in the United States. 88% of procedures performed on 6,400 patients with osteonecrosis in 2008 reported in the Nationwide Inpatient Sample Database of the hip were total hip replacements. From 16 years earlier, the number of procedures performed had almost doubled and the percentage use of arthroplasty as the performed treatment had increased by 13%. I expect both numbers will continue to increase