Liner orientation change of dual mobility cup determined via 3D ultrasound imaging and motion analysis: A cadaver study.

BACKGROUND: A mobile polyethylene liner enables the dual mobility cup (DMC) to contribute to restoring hip joint range-of-motion, decreasing wear and increasing implant stability. However, more data is required on how liner orientation changes with hip joint movement. As a first step towards better understanding liner orientation change in vivo, this cadaver study focuses on quantifying DMC liner orientation change after different hip passive movements, using ultrasound imaging and motion analysis. HYPOTHESIS: The liner does not always go back to its initial orientation and its final orientation depends mainly on hip movement amplitude. METHODS: 3D ultrasound imaging and motion analysis were used to define liner and hip movements for four fresh post-mortem human subjects with six implanted DMC. Abduction and anteversion angles of the liner plane relative to the pelvis were measured before and after hip flexion, internal rotation, external rotation, abduction, adduction. RESULTS: Liner orientation changes were generally defined by angle variation smaller than 5°, with the liner nearly going back to its initial orientation. However, hip flexion caused liner abduction and anteversion angle variations greater than 15°. Except for hip adduction, only weak or no correlation was found between the final angle of the liner and the maximal hip joint movement amplitude. DISCUSSION: This study is the first attempt to quantify liner orientation change for implanted DMC via ultrasound imaging and constitutes a step forward in the understanding of liner orientation change and its relationship with hip joint movement. The hypothesis that the final liner abduction and anteversion angles depend mainly on hip movement amplitude was not confirmed, even if hip flexion was the movement generating the most liner orientation changes over 15°. This approach should be extended to in vivo clinical investigations, as measured liner angle variation could provide important support for the wear and stability claims made for DMC. LEVEL OF EVIDENCE: IV; cadaveric study.

Dual-mobility tripod cup for revision hip arthroplasty: long-term (five to fourteen years) evaluation of a new generation cementless implant.

PURPOSE: The aims of this study were to evaluate the survivorships of a new generation cementless DMC with tripod additional fixation in revision total hip arthroplasty and complications at a minimum five year follow-up. METHODS: One hundred and fifteen revisions (THA) treated with tripod DMC performed between 2009 and 2015 were included in this retrospective study. Acetabular defects were classified as Paprosky 1 (n = 38, 33%), 2 (n = 75, 65%) or 3 (n = 2, 2%). Unipolar or bipolar revision was performed for the following indications: aseptic acetabular loosening (63%), infection (14%), aseptic bipolar loosening (11%), instability (4%), aseptic femoral loosening (3%), ALVAL (3%) and iliopsoas impingement (2%). Mean follow-up was 9.4 years ± two (range, 5 to 14). RESULTS: At the final follow-up, a single episode of dislocation occurred within three months after the procedure (0.8%) with no revision. Three cases of aseptic loosening were diagnosed (2.6%). Four infections (3.5%) required reoperation: three required a two stage bipolar revision; one was treated by DAIR procedure. At the latest follow-up, the survivorship of the acetabular cup for aseptic loosening was 98% [95% CI (91.2-99.4)] and for any reasons was 94.4% [95% CI (90.1%-98.9%)]; the mean HHS improved from 60 points (range, 18-94 points) to 83 points (range, 37-100 points) (p < .001). CONCLUSION: This study reports a low complication rate in favour of the use of a tripod DMC in revision THA with a satisfactory survivorship at a ten year follow-up.

A single-centre experience of 29 total ankle replacement in haemophiliac patients: Therapeutic management, factor consumption and cost.

INTRODUCTION: In patients with haemophilia, repeated bleeding in large joints leads to chronic haemophilic arthropathy, a rare disease that can be managed surgically with ankle arthrodesis or with total ankle replacement (TAR). TAR has been reported to provide good surgical results in the medium/long-term and allow preservation of joint mobility but the medical therapeutic management of the patients has not been described. AIM: To describe the medical therapeutic management of TAR. METHODS: All patients with haemophilia A/B, with haemophilic ankle arthropathy, and who underwent TAR between April 2006 and October 2019 were retrospectively included. Factor consumption, perioperative and early complications, volume of blood lost, and orthopaedic data were collected. RESULTS: A total of 25 patients underwent 29 TAR (mean age was 44.7 years [range: 26-65]). In the 17 patients with HA without history of anti-FVIII inhibitor, the mean ± SD consumption the day of surgery was 116 ± 16 UI/kg when clotting factors were administered by continuous infusion, 106 ± 13 UI/kg when SHL factors were administered by bolus infusion, and 75 ± 22 UI/kg when EHL factors were administered by bolus infusion. During hospitalisation, the mean factor cost was €38,073 (83.7% of the total cost of surgery). Mean blood loss was significantly lower in patients treated with tranexamic acid (164 mL, range: 40-300) than in those not (300 mL, range: 70-800; p = .01). Six patients had haematoma. The 10-year survival free of any prosthesis removal/arthrodesis was estimated to be 92.2% (95% CI [83; 100]). CONCLUSION: The medical therapeutic management of TAR is complex, carried out by a multidisciplinary team but effective in avoiding the occurrence of complications.

Revision of total hip arthroplasty by long locking stem with fully hydroxyapatite-coated modular metaphysis (Reef™): A continuous series of 78 cases at a minimum 2-year follow-up.

INTRODUCTION: Since the Wagner and Vives stems were introduced in the 1980s, the range of uncemented implants for femoral revision has grown with increasing demand. Cementless modular implants with a wide range of lengths and diameters improved adaptation to the bone and secondary metaphyseal integration. Data are sparse for the Reef™ locking stem (Depuy-Synthes, Saint-Priest, France) and we therefore conducted a retrospective study at more than 2 years' follow-up, in a continuous series of total hip arthroplasty (THR) revision procedures using this long fully-hydroxyapatite-coated modular locking stem, assessing (1) implant survival, (2) clinical and functional results, and (3) radiographic results. HYPOTHESIS: The study hypothesis was that all-cause≥2-year survival is>90%. PATIENTS AND METHODS: Between 2007 and 2018, 413 femoral stem exchanges were performed in our center, a Reef™ model being needed in 93 cases. Etiologies comprised: Vancouver B2 or B3 periprosthetic fracture (57%, n=53), aseptic loosening (33%, n=30), septic loosening (10%, n=9) and 1 case of aseptic non-union under the stem (1%, n=1). Clinical and functional assessment used Harris Hip Score (HHS), Postel Merle d'Aubigné score (PMA) and Oxford-12 Hip Score (OHS). Radiographic assessment used immediate postoperative views and last follow-up radiographs, assessing osseointegration, filling index and stress shielding. Implant survival was estimated following Kaplan-Meier with 95% confidence intervals. RESULTS: Mean follow-up was 6±3 years (range, 2-12). Last follow-up included 78 cases for analysis (12 deaths [13%] and 3 patients lost to follow-up before 2 years [3%]). Ten-year Reef™ implant survival was 98.7% (95% CI: 96.3-100) free of aseptic loosening (n=1) and 94% (95% CI: 87-100) for all causes (n=3). The failures related to aseptic loosening involved femoral stem fracture away from the modular part; the 2 cases of septic loosening did not undergo reimplantation for medical reasons. Preoperatively (scheduled surgeries, excluding periprosthetic fractures: n=40), mean HHS was 43±12 and 77±12 at last follow-up (81±13 in scheduled surgery [n=40] and 73±11 in emergency surgery for periprosthetic fracture [n=53]), mean PMA score was 13±2 and mean OHS was 26±9. The infection rate was 11% (n=9) including 7.6% new infection (n=6). The dislocation rate was 6% (n=5). The radiographic stress shielding rate was 11% (n=9) and significantly associated with low metaphyseal filling index (76±7% vs. 83±8% [p=0.009]). DISCUSSION: Like other recent data, the present good survival results support the trend for uncemented stems in femoral revision, as encouraged by the 1999 symposium of the French Society of Orthopedic Surgery and Traumatology (SoFCOT). Primary diaphyseal fixation enables secondary metaphyseal integration on an implant with modularity ensuring good bone adaptation. Close contact between the bone and hydroxyapatite surfaces is a key-point in the surgical strategy. LEVEL OF EVIDENCE: IV, retrospective study.

Kinetics of functional recovery after foot and ankle surgery. Comparison of EFAS and SF36 scores.

INTRODUCTION: The EFAS score is a new recently validated European quality of life score for foot and ankle surgery, comprising 6 questions on activities of daily living (ADL) and 4 on sport. The aim of the present study was to assess the kinetics of functional recovery on the EFAS and SF36 scores, and to assess correlations between the two at 0 to 6 months then 6 months to 1 year in a population of foot and ankle surgery patients, globally and per pathology. HYPOTHESIS: Hindfoot and ankle surgery requires at least 1 year's follow-up for assessment of recovery, whereas 6 months is sufficient to assess forefoot recovery. MATERIAL AND METHODS: A multicenter prospective cohort study included all patients undergoing surgery for foot and ankle pathology between December 2015 and July 2016. Statistical analysis, global and per pathology, was performed preoperatively and at 6 months and 1 year. RESULTS: In total, 98 patients were assessed at 1 year. In the global population, EFAS ADL score improved by 17.1±22.1 points (hindfoot, 16.9±24.6; forefoot, 19.7±21.4) and global SF36 score by 8.7±17.1 points (hindfoot, 10.2±19.1; forefoot, 9.6±15.9). Both scores progressed between 6 months and 1 year for hindfoot pathologies, whereas they remained constant after 6 months for the forefoot. The EFAS score showed weak correlation with SF36. CONCLUSION: Recovery kinetics differs according to type of foot and ankle pathology. The EFAS score is more suitable than the SF36. LEVEL OF EVIDENCE: II.

Analysis of an explanted dual mobility cup after 21 years, parabolic wear pattern: A case report.

CASE: A dual mobility cup was implanted in 1983 in a 43-year woman. After 31 years of normal function, we analysed the explanted materials with modern techniques. CONCLUSION: Volumetric wears of the small and large articulations of the dual-mobility construct were similar. For the first time, we demonstrated that the dual-mobility liner underwent parabolic (not linear) wear during the period of implantation.

Talo-navicular and calcaneo-cuboid fusion with PEEK H-pode™ vs. Titanium Maxlock™ locking plates: Comparison of functional and radiographic outcomes.

BACKGROUND: Locking plates are increasingly used to achieve hindfoot fusion. The objective of this study was to compare hindfoot fusion outcomes with the PEEK H-pode™ (Biotech™) locking plate and the titanium Maxlock™ (Tornier-Wright™) locking plate. HYPOTHESIS: A polyetheretherketone (PEEK) H-pode™ locking plate provides similar fusion rates to a titanium Maxlock™ locking plate for talo-navicular and calcaneo-cuboid arthrodesis. METHODS: We conducted a retrospective comparative study in 39 patients (including 21 [54%] with pes planovalgus and 11 [28%] with neurological equinovarus deformities) who underwent talo-navicular and/or calcaneo-cuboid fusion, usually combined with subtalar fusion. The first 17 patients (January 2014-February 2016) were managed with Maxlock™ locking plates and the next 22 patients (March 2016-August 2018) with H-pode™ locking plates. These two cohorts of consecutive patients were comparable regarding age, sex distribution, body mass index, and comorbidities. At last follow-up more than 1year after surgery, we compared functional scores, pain intensity, and fusion assessed by radiographs and computed tomography (CT) (threshold set at 33%). RESULTS: Mean follow-up was 42months (range: 34-63months) in the Maxlock™ group and 25months (range: 12-36months) in the H-pode™ group. At last follow-up, the two groups were not significantly different for the mean values of the American Orthopedic Foot & Ankle Society score, European Foot & Ankle Society score, and visual analogue scale pain score. Neither were the two groups significantly different for talo-navicular and calcaneo-cuboid fusion by CT. In the Maxlock™ group, we found non-significant trends towards a higher proportion of patients with talo-navicular nonunion (18% vs. 5% in the H-pode™ group) and weaker talo-navicular fusion in patients with pes planovalgus (60.8% vs. 82.0%, respectively). Radiographic results overestimated the fusion rates. DISCUSSION: Talo-navicular and calcaneo-cuboid fusion was not significantly different with H-pode™ and Maxlock™ locking plates. CT was more accurate than standard radiography to assess fusion. These results underline the usefulness of PEEK locking plates for talo-navicular and calcaneo-cuboid fusion; moreover, the radiolucency of PEEK facilitates the interpretation of radiographs. LEVEL OF EVIDENCE: IV.

Accuracy and precision of the measurement of liner orientation of dual mobility cup total hip arthroplasty using ultrasound imaging.

The Dual Mobility Cup (DMC) was created in 1974 to prevent dislocation and decrease wear. However, the movement of the polyethylene liner in vivo remains unclear. The aims of this study were to visualise liner positions and quantify the accuracy of the liner plane orientation for static positions, using ultrasound imaging. DMC reconstruction and angle between cup and liner were evaluated on isolated submerged DMCs by comparing 3D laser scans and ultrasound imaging. Moreover, the abduction and anteversion angles of the liner plane relative to the pelvis orientation were calculated via combined motion analysis and 3D ultrasound imaging on four fresh post-mortem human subjects with implanted DMC. On submerged DMC, the mean angle error between ultrasound imaging and 3D scan was 1.2°. In cadaveric experiments, intra-operator repeatability proved satisfactory, with low range value (lower than 2°) and standard deviation (lower than 1°). The study demonstrates the feasibility of measuring liner orientation on submerged and ex vivo experiments using ultrasound imaging, and is a first step towards in vivo analysis of DMC movement.

An anatomical study of the meniscal roots of the knee: landmarks for its surgical reconstruction and implications for knee surgeons.

PURPOSE: The aim of this anatomical study was to describe the anatomy of the meniscal roots and their relationships with respect to the main adjacent structures in order to improve their surgical reconstruction. METHODS: Fourteen knees were included. The mean age of the donors was 92 years (range 89-96). We studied the general characteristics of the anterior and posterior roots of the medial meniscus and lateral meniscus by measuring their widths at their base and area. We investigated the relations between anterior and posterior roots of the medial and lateral menisci with respect to the anterior and posterior cruciate ligaments (ACL and PCL). RESULTS: The mean width of the anterior root of the lateral meniscus was 10.5 ± 1.4 mm. The mean width of the anterior root of the medial meniscus was 10 ± 1.5 mm. The mean width of the posterior root of lateral meniscus was 11.4 ± 1.4 mm. The mean width of the posterior root of medial meniscus was 10.5 ± 1.0 mm. The mean distance between the anterior cruciate ligament and the anterior root of lateral meniscus was 9.8 ± 2.9 mm, for the medial meniscus it was 15.9 ± 3.4 mm. The mean distance between the posterior cruciate ligament and the posterior root of the lateral meniscus was 11.5 ± 2.7 mm, for the medial meniscus, it was 11 ± 2.6 mm. CONCLUSION: The anterior and posterior meniscal roots have precise landmarks, and this article contributes to define the location of the meniscal roots with respect to their adjacent anatomical structures: ACL, PCL and intercondylar tubercle. Having precise measures of the distances between the meniscus roots and these structures allows knee surgeons to perform ACL reconstruction, meniscal root repair and meniscal allograft transplantation.

Impact of smoking cessation on healing after foot and ankle surgery.

INTRODUCTION: Perioperative smoking is the main risk factor for the development of postoperative cutaneous wound healing complications. We require that all patients undergoing elective foot and ankle surgery stop smoking (6 weeks before and 3 months after) and this abstinence is monitored with a preoperative cotinine test. We therefore wanted to understand how this impacted wound healing in elective foot and ankle surgery: do wounds heal differently in patients who quit smoking for surgery, former smokers and nonsmokers? HYPOTHESIS: Our hypothesis was that patients who stopped smoking for an upcoming surgery had the same wound healing complications as nonsmokers and former smokers. MATERIALS AND METHODS: This was a historical, single-center, single-surgeon cohort study of adult patients who underwent an elective ankle or foot surgery between June 2016 and July 2017. Patients were divided into 3 groups: group 1 smokers who stopped for surgery, group 2 former smokers, and group 3 nonsmokers. The primary endpoint was the occurrence of wound healing complications during the wound care consult scheduled 3 weeks after surgery. RESULTS: A total of 256 patients with a mean age of 58±14.2 years (range, 18-88) were included. Group 3 had more women and a lower BMI than the other groups, but all the other demographic characteristics were similar. Smoking cessation was achieved in group 1 on average 2.5±1.3 months (range, 1-6) before surgery. There were a total of 20 wound healing complications or 7.5% of the cohort: 13% in group 1, 11.1% in group 2 and 6.4% in group 3. The univariate analysis found that the odds ratio was 2.3 when comparing Group 1 to Group 3 and 1.85 when comparing group 2 to group 3 (p=413). No significant risk factors for wound healing complications were found. DISCUSSION/CONCLUSION: Smoking cessation for foot and ankle surgery seems to limit the risk of wound healing complications, with results close to those of former smokers and nonsmokers. Mandatory smoking cessation before surgery could be one of the solutions to prevent this frequent complication. LEVEL OF EVIDENCE: III.

97 HINTEGRA ankle prostheses: Results and survival at more than 5 years' follow-up.

BACKGROUND: In Europe, fixed-bearing implants predominate again in total ankle replacement (TAR). The present single-center single-surgeon study assesses the Hintegra® mobile-bearing implant (NEWDEAL). METHODS: Between November 2008 and November 2015, 97 Hintegra® were implanted in 94 patients: mean age, 62.4±10.9 years (26-83); 59% (57/97) male; normal mean body-mass index (BMI), 27.5 ± 4.3 kg/m2. Indications mainly comprised posttraumatic (40.2%), instability (29.9%) and primary osteoarthritis (16.5%). 17.5% of patients had prior surgery during the previous 6 months (9 fusions, 8 ligament reconstructions, and 4 osteotomies); in 59.8%, other procedures were associated to TAR. Functional, clinical and radiological follow-up was conducted at 1 year, 2 years and last follow-up (>5 years). RESULTS: Ninety-four TARs were analyzed at a mean 81 ± 21.6 months (19-124). Revision-free survival was 76% (95% confidence interval (95%CI): 0.66-0.8), and explantation-free survival 92% (95%CI: 0.85-1) with 10 cases of curettage and 5 explantations. Mean AOFAS score improved from 41.8 ± 12.5 (21-69) to 77.5 ± 16.5 (24-100) up (p < 0.001); 75% of patients had no or only mild pain (p < 0.001). Clinical ranges of motion were 8.0 ± 7.1° dorsiflexion (p < 0.001) and 35.1 ± 9.4° plantar flexion (preoperatively, 34.1 ± 7.9°) (p = 0.71). Radiologically, tibial components were well-positioned; 87% of talar components were well-centered. Global ankle range of motion was 23.5 ± 10.2° (5-48) (p = 0.17). 54.6% of TARs showed posterior tibial calcification at follow-up. Risk of severe cyst (>1 cm) on CT was 36% (95%CI: 23-47) at a mean 77 ± 21.9 months (18-123). CONCLUSION: Hintegra® TAR incurred a low risk of revision, and is a reliable option for ankle osteoarthritis. LEVEL OF EVIDENCE: IV.

Relationships of the superficial fibular nerve and sural nerve with respect to the lateral malleolus: implications for ankle surgeons.

PURPOSE: Superficial fibular nerve (SFN) and sural nerve are at risk during osteosynthesis of the lateral malleolus. The aim of this anatomical study was to describe the relationships of the superficial fibular and sural nerves with respect to the lateral malleolus. METHODS: Nine corpses (18 ankles) were dissected, using a direct lateral approach. Measurements were recorded between the fibula and the nerves, and the pattern variations of the SFN were recorded for both right and left side to assess intra-individual variability. RESULTS: Distance between the tip of the lateral malleolus and the piercing of fascia cruris was 111 ± 26 mm for type 1 pattern, and range was 46-161 mm all types included. 78% (14 SFN) were type 1 pattern, 17% (3 SFN) were type 2 pattern, and 5% (1 SFN) were type 3 pattern. 44% (4 specimen) had a type 1 pattern SFN on one ankle and another pattern on the other ankle. The sural nerve was always observed just posterior to the lateral malleolus. CONCLUSION: This study demonstrated a great inter-individual variability especially for the SFN, but also an intra-individual variability with frequent different patterns between right and left leg. It is important to know the anatomical variations of the SFN and sural nerve to decrease the risk of intra operative nerve injury during direct lateral approach of lateral malleolus.

Cementless hydroxyapatite-coated stem with dual mobility and posterior approach in over-80 year-old patients with osteoarthritis: Rates of dislocation and periprosthetic fracture at a mean 8 years' follow-up.

BACKGROUND: Straight cementless stems are common in primary total hip arthroplasty (THA) in the elderly, but controversial due to higher risk of loosening and periprosthetic fracture (PPF). Apart from registries, results for the Corail implant and dual mobility (DM) in over-80 years-old are not known, notably in case of systematic association to a DM cup. We therefore performed a retrospective analysis of Corail implants in patients aged≥80years at implantation for osteoarthritis of the hip, assessing 1) PPF rate and survival for cementless straight stems associated to DM cups, 2) complications, and dislocation in particular, and 3) clinical scores. HYPOTHESIS: PPF and dislocation rates are low in THA with cementless straight stem associated to DM cup in patients aged≥80years. PATIENTS METHODS: A retrospective study was conducted in our department for the period July 2007 to December 2012. Inclusion criteria were age≥80years, with primary THA for osteoarthritis. Exclusion criteria were revision procedure and femoral neck fracture. One hundred and twenty-eight consecutive THAs were included, in 120 patients, with a minimum 5years' follow-up. Clinical results were assessed on Harris Hip Score (HHS) and Oxford Hip Score (OHS). Data were collected for PPF or dislocation and other complications. RESULTS: At a mean 8±1 years' follow-up (range, 5-10 years), 66 patients (55%, for 68 hips) were alive, 48 (40%, for 54 hips) had died, and 6 (5%, for 6 hips) were lost to follow-up. Median age at surgery was 83years (range, 80-93years). Mean OHS at last follow-up was 41±6 (range, 21-48) and HHS 83±14 (range, 23-100) with mean gain of 32 points (95% CI, [28-36]; p<0.001)). There were 2 cases (1.6%) of PPF, at 2 and 65months, and no dislocations or cases of aseptic loosening. There were 2 cases (1.6%) of intraoperative calcar fracture, treated by wire cerclage with immediate complete weight-bearing, without further complications. With death as a competing risk, cumulative 10-year incidence of femoral stem revision was 1.6% [95% CI: 0.4-6.5], and cumulative incidence of all-cause revision was 4.1% [95% CI: 1.7-9.7]. DISCUSSION: In an over-80 year-old population, primary THA with straight cementless stem and 2nd generation dual mobility cup was an effective option with low risk of PPF or dislocation after a minimum 5-year of follow-up. LEVEL OF EVIDENCE: IV; retrospective study.

Outcomes and survival of a modern dual mobility cup and uncemented collared stem in displaced femoral neck fractures at a minimum 5-year follow-up.

INTRODUCTION: The choice of implant type for total hip replacement in the treatment of femoral neck fractures remains debated. Some authors advocate for the systematic use of cemented stems, while others do not use dual mobility first-line. We therefore conducted a retrospective study using a dual mobility cup (DMC) and an uncemented collared stem (UCS) in order to: (1) confirm the low dislocation rate in this indication, (2) assess other surgical complications, in particular periprosthetic fractures, (3) ensure that these benefits are maintained over time, at a minimum follow-up of 5 years and, (4) assess the rate of revision of the implants. HYPOTHESIS: Our hypothesis was that the dual mobility dislocation rate for the treatment of femoral neck fractures was lower than for bipolar hemiarthroplasties or single mobility hip prostheses. PATIENTS AND METHODS: A retrospective study of 244 femoral neck fractures (242 patients) treated with DMC and UCS was conducted, between 2013 and 2014. The mean age was 83±10 years (60-104). The occurrence of dislocation, periprosthetic fracture, infection of the surgical site, loosening, reoperation and revision were investigated. The HOOS Joint Replacement (JR) score was collected. The cumulative incidence with mortality was used as a competing risk. RESULTS: The mean follow-up was 6 years±0.5 (5-7). At the last follow-up, 108 patients (50%) had died. Twenty-three patients (9.5%) were lost to follow-up. One case of symptomatic aseptic loosening of DMC was observed. The cumulative incidence of dislocations and periprosthetic fractures at 5 years were 2% (95% CI: 0.9-5.4) and 3% (95% CI: 1.2-6), respectively. The 5-year cumulative incidence of surgical site infections was 3.5% (95% CI: 1.8-7). The cumulative incidence of reoperations at 5 years was 7% (95% CI: 4.5-11). The causes of reoperation were periprosthetic fracture (n=6), infection (n=8), postoperative hematoma (n=2) and cup malposition (n=2). The cumulative incidence of a revision at 5 years was 2.7% (95% CI: 1.2-6). The cumulative incidence of a surgical complication from any cause at 5 years was 9% (95% CI: 6.7-14.8). The mean HOOS JR score was 79±5 (52-92). DISCUSSION: The cumulative incidence of dislocation at 5 years is low and other surgical complications (including periprosthetic fractures) do not increase during this period for DMC associated with UCS, in femoral neck fractures. The use of this type of implant is reliable in the treatment of femoral neck fractures. LEVEL OF EVIDENCE: IV; retrospective study without control group.

Incidence and risk factors for bilateral proximal femoral fractures.

BACKGROUND: Proximal femoral fractures (PFFs) are a public health issue due to their high frequency. The frequency of a second PFF on the other side is estimated at 10%. This estimation is controversial, however, and the risk factors have not been evaluated in a large population of French patients. The objective of this retrospective case-control study was to determine: (1) the incidence of second PFFs and (2) their risk factors. HYPOTHESIS: The incidence of second PFFs is >2% after 1 year and >5% after 3 years. MATERIAL AND METHODS: We conducted a case-control study in a population of consecutive patients managed surgically for PPF at the Lyon Sud Hospital between 2013 and 2014. We analysed the following clinical factors: age, sex, body mass index (BMI), institutionalisation, the Parker score, the American Society of Anesthesiologists score (ASA), comorbidities, and the use of psychoactive drugs. RESULTS: We included 474 PFFs (trochanter, n=240 and neck, n=234) of which 36 were bilateral. The contralateral fracture occurred within 1 year of the first fracture in 6/474 (1.3%) cases and within 3 years in all 36 cases (7.6%). The case-control study comprised 49 cases with bilateral PFF and 161 controls with no second hip fracture within 3 years. Risk factors for a second hip fracture were age older than 90 years (odds ratio [OR]=5.44; 95% confidence interval [95%CI], 112-2642 (p=0.002)) and a history of heart disease (OR, 2.18; 95%CI, 1.06-4.47 [p=0.03]). A Parker score≥6 was protective (OR, 0.84; 95%CI, 0.71-0.99 [p=0.03]). Mortality after 3 years was 42% (201/474), and 13% (63/474) of patients were lost to follow-up. DISCUSSION: Age older than 90 years, a Parker score below 6, and a history of heart disease are risk factors for a second PFF within 3 years after the first PFF. LEVEL OF EVIDENCE: III; case-control study.

Rotating Hinge Knee Arthroplasty for Revision Prosthetic-Knee Infection: Good Functional Outcomes but a Crucial Need for Superinfection Prevention.

Introduction: Management of chronic infection following total knee arthroplasty (TKA) is challenging. Rotating hinged prostheses are often required in this setting due to severe bone loss, ligamentous insufficiency, or a combination of the two. The nature of the mechanical and septic complications occurring in this setting has not been well-described. The aim of this study was to evaluate patient outcomes using a hinge knee prosthesis for prosthetic knee infections and to investigate risk factors for implant removal. Methods: This was a retrospective cohort study that included all patients treated in our tertiary level referral center between January 2009 and December 2016 for prosthetic knee infection with a hinge knee prosthesis. Only patients with a minimum 2-year of follow-up were included. Functional evaluation was performed using international knee society (IKS) "Knee" and "Function" scores. Survival analysis comparing implant removal risks for mechanical and septic causes was performed using Cox univariate analysis and Kaplan-Meier curves. Risk factors for implant removal and septic failure were assessed. Results: Forty-six knees were eligible for inclusion. The majority of patients had satisfactory functional outcomes as determined by mean IKS scores (mean knee score: 70.53, mean function score: 46.53 points, and mean knee flexion: 88.75°). The 2-year implant survival rate was 89% but dropped to 65% at 7 years follow-up. The risk of failure (i.e., implant removal) was higher for septic etiology compared to mechanical causes. Patients with American society of anesthesiologists (ASA) score>1, immunosuppression, or with peripheral arterial diseases had a higher risk for septic failure. Patients with acute infection according to the Tsukayamaclassification had a higher risk of failure. Of the 46 patients included, 19 (41.3%) had atleast one infectious event on the surgical knee and most of these were superinfections (14/19) with new pathogens isolated. Among pathogens responsible for superinfections (i) cefazolin and gentamicin were both active in six of the cases but failed to prevent the superinfection; (ii) cefazolin and/or gentamicin were not active in eight patients, leading to alternative systemic and/or local antimicrobial prophylaxis consideration. Conclusions: Patients with chronic total knee arthroplasty (TKA) infection, requiring revision using rotating hinge implant, had good functional outcomes but experienced a high rate of septic failure, mostly due to bacterial superinfection. These patients may need optimal antimicrobial systemic prophylaxis and innovative approaches to reduce the rate of superinfection.

Prospective analysis of intraoperative radiation dose in foot and ankle surgery using mini-C-arm fluoroscopy. Continuous series of 1064 procedures.

INTRODUCTION: Foot and ankle surgeons make daily use of mini-C-arm fluoroscopes. The present study aimed to quantify associated radiation doses. HYPOTHESIS: X-ray exposure for foot and ankle surgeons using a mini-C-arm fluoroscope is below the nuclear safety authority authorized doses of 20 mSv/year for the whole body and crystalline lens, 150 mSv/year for the thyroid and 500 mSv/year for the skin and limbs. MATERIAL AND METHODS: A single-center, single-surgeon prospective series was treated between February 2014 and December 2017. Doses emitted by the mini-C-arm (15cm field) were recorded during 1,064 operations. Doses received by the surgeon were recorded by 3 passive dosimeters (thorax, eyes and hands) and 1 active dosimeter. The significance threshold was set at p<0.05. RESULTS: A total of 64.4% of procedures concerned the forefoot, 35.3% the hindfoot and ankle, and 0.3% were strictly percutaneous. Mean dose-area product (DAP) per procedure was 3.9 cGy/cm2±7: in forefoot surgery, 1.1 cGy/cm2±0.9, and in hindfoot and ankle surgery 8.7 cGy/cm2±9.7 (p<0.05), for mean irradiation times of 7.6s±5.3 and 36.7s±35.5 respectively and image numbers 4.1±2.7 and 18.7±20.5. Total ankle replacement was associated with the highest doses: 20.1 cGy/cm2±14.7. Mean daily active dosimetry was 2.2µSv±1.4. Mean annual dose to the hand, crystalline lens and deep (Hp(10)) and shallow (Hp(0.07)) whole body was respectively 1.28 mSv, 0.6 mSv, 0.31 mSv and 0.19 mSv. The highest annual exposure was recorded for the hands: 2.68 mSv in 2015. There was a significant linear relationship between daily active dosimetry and daily emission: daily active dosimetry=(DAP×0.11)+0.54, for a correlation coefficient of 0.77. DISCUSSION/CONCLUSION: The exposure of foot and ankle surgeons using mini-C-arms was well below threshold, and also lower than in the literature. LEVEL OF EVIDENCE: IV.

Association Between Short-, Intermediate-, and Long-term Mortality and Myocardial Injury After Noncardiac Surgery After Hip Fracture Surgery: A Retrospective Cohort.

BACKGROUND: For more than 20 years, hip fracture 1-year mortality has remained around 20%. An elevation of the postoperative troponin peak within 72 hours (myocardial injury after noncardiac surgery [MINS]) is associated with a greater risk of short-term mortality in the general population. However, there seem to be conflicting results in the specific population who undergo hip fracture surgery, with some studies finding an association between troponin and mortality and some not. The objective of the present study was to investigate the association of MINS and the short- (before 28th day), intermediate- (before 180th day), and long-term (before 365th day) mortality after hip fracture surgery. METHODS: We conducted a single-center retrospective cohort of patients undergoing hip fracture surgery from November 2013 to December 2015. MINS was defined as postoperative troponin peak within the 72 hours >5 ng/L. Four MINS subgroups were defined according to the value of troponin peak (ie, ≥5-<20, ≥20-<65, ≥65-<1000, and ≥1000 ng/L). To document the association between the different mortality terms and the troponin peak, odds ratio (OR) and adjusted OR (aOR) associated with their 95% confidence interval (CI) with the log of the scaled troponin peak within 72 hours were estimated, with and without patients presenting a postoperative acute coronary syndrome (ACS). Cox proportional hazards modeling was used to estimate hazard ratio (HR) and adjusted HR (aHR) of death between the no MINS and MINS subgroups. The adjustment was performed on the main confounding factors (ie, sex, American Society of Anesthesiologists [ASA] physical status, dementia status, age, and time from admission to surgery). RESULTS: Among 729 participants, the mean age was 83.1 (standard deviation [SD] = 10.8) years, and 77.4% were women; 30 patients presented an ACS (4%). Short-, intermediate-, and long-term mortality were at 5%, 16%, and 23%, respectively. The troponin peak was significantly associated with all terms of mortality before and after adjustment and before and after exclusion of patients presenting an ACS. HR and aHR for each subgroup of troponin level were significantly associated with an increased probability of survival, except for the 5 to 20 ng/L group for which aHR was not significant (1.75, 95% CI, 0.82-3.74). In the landmark analysis, there was still an association between survival at the 365th day and troponin peak after the short- and intermediate-term truncated mortality. CONCLUSIONS: MINS is associated with short-, intermediate-, and long-term mortality after hip fracture surgery. This could be a valuable indicator to determine the population at high risk of mortality that could benefit from targeted prevention and possible intervention.

Rheumatoid Forefoot Reconstruction in Nonrheumatic Patients: Lesser Metatarsal Head Resection versus Osteotomy.

In the literature, first metatarsophalangeal joint arthrodesis with lesser metatarsal head resection seems to be a reliable procedure in rheumatoid foot deformity. Maybe this procedure could be proposed in nonrheumatoid severe forefoot deformity (hallux valgus angle >40° and lesser metatarsophalangeal dislocation). The aim of this study was to compare radiological and clinical outcomes between lesser metatarsal head resection and lesser metatarsal head osteotomy in nonrheumatoid patients. Thirty-nine patients (56 feet) suffering from well-defined nonrheumatoid severe forefoot deformity were retrospectively enrolled in our institution between 2009 and 2015. Metatarsal head resection and metatarsal head osteotomy represented 13 patients (20 feet) and 26 patients (36 feet), respectively. In this observational study, a rheumatoid population (21 patients) was included as the control. The clinical outcome measures consisted of American Orthopaedic Foot and Ankle Society score, Foot and Ankle Ability Measurement, and Short Form-36. The radiological outcomes were: intermetatarsal angle, hallux valgus angle, and metatarsophalangeal alignment. Mean follow-up was 24 months. Satisfaction rate was, respectively, 92% for resection, 91% for osteotomy procedure, and 80% for surgery in rheumatoid patients. Short Form-36 global score was, respectively, 80.7 (52.5-96.4), 76 (57.7-93), and 68.3 (22.6-86). No functional outcome difference was found between resection and osteotomy procedures, except that the metatarsal head resection group had poorer results in sports activities than the osteotomy group. Complications were similar between osteotomy and resection (p > .05). The radiological outcomes were improved significantly from preoperative to postoperative. First metatarsophalangeal joint arthrodesis with lesser metatarsal head resection in nonrheumatoid severe forefoot deformity might be a good therapeutic option.

Articular Noise After THA Using Delta CoC Bearings Has Little Impact on Quality of Life.

BACKGROUND: To report clinical outcomes and survival at a minimum of 10 years of a consecutive series of uncemented total hip arthroplasty (THA) with fourth-generation ceramic-on-ceramic (CoC) bearings and determine the incidence of articular noises, their risk factors, and impact on quality of life (QoL). METHODS: From a series of 456 CoC THAs, there were 25 revisions, 38 deceased, and 36 lost to follow-up. The remaining 357 hips were assessed at 11.1 ± 0.7 years (range, 10-14) using the Forgotten Joint Score, Oxford Hip Score, and a questionnaire on articular noises. Kaplan-Meier survival was calculated, and multivariable analysis was performed to determine associations between articular noise and patient/surgical factors. RESULTS: The 10-year survival was 96.3% for the cup, 96.5% for the stem, and 94.2% for all components. The Forgotten Joint Score was 79 ± 26 (range, 0-100), and Oxford Hip Score was 16 ± 7 (range, 12-60). The mean impact of articular noises on QoL was 1.8 ± 2.9 (range, 0-9): considered negligible in 60 hips (16%), moderate in 27 hips (7%), and severe in only 13 hips (4%). Multivariable analyses revealed that the incidence of articular noise decreased with age (odds ratio [OR], 0.94; P = .001), body mass index (OR, 0.85; P = .001), and in hips implanted with 32-mm (vs 36 mm) heads (OR, 0.18; P = .030). CONCLUSION: Of 100 hips (28%) that reported some articular noises 10 years after CoC THA, the impact of articular noises on QoL was negligible for most patients. Although larger heads can improve mobility and reduce risks of dislocations, surgeons must be aware that increasing head size could also increase risks of articular noises, notably in young and active patients.