Beneficial effect of a zirconium-nitride-coated implant in total knee arthroplasty revision for suspected metal hypersensitivity.

INTRODUCTION: Revision of total knee arthroplasty (rTKA) for suspicion of metal hypersensitivity (MHS) may require hypoallergenic implants. Results for coated implants have not been reported. The aim of the present study was to assess short-term results and survival of rTKA for MHS using a multilayer implant coating. HYPOTHESIS: Multilayer implant coating improves functional results in rTKA, with survival comparable to primary coated implants. MATERIAL AND METHODS: A single-center retrospective observational study included 28 patients (30 knees) undergoing rTKA for MHS using a coated implant between May 2011 and November 2016. Exclusion criteria comprised implant malpositioning and history of infection in the affected knee. Clinical and radiological results were assessed on the International Knee Society (IKS) and SF-36 functional scores and Ewald radiological score. Survival was calculated on Kaplan-Meier estimation. RESULTS: Mean follow-up was 3.8 years. Mean IKS score increased by 40.2 points (40%) [range, 28.1-52.3] (p<0.05). Mean range of motion increased by 17° [range, 9.5-24.5°] (p<0.05). Mean physical and mental SF-36 components were respectively 44.7 and 46.1. Survivorship was 93%. DISCUSSION: There was significant functional improvement after rTKA for MHS. There were no short-term complications related to the zirconium nitrate coating. However, studies with longer follow-up will be needed for confirmation. LEVEL OF EVIDENCE: IV; retrospective study.

Clinical and radiological results after revision THA with distal locking stem: A cohort study of 44 patients.

BACKGROUND: Distal locking stems were developed in response to some complex revision procedures in total hip arthroplasty (THA), providing better axial and rotational stability. The aim of the present study was to assess medium-term clinical and radiological results of treatment with last-generation distal locking stem. HYPOTHESIS: Our hypothesis was that this implant provided a high survival rate. MATERIAL AND METHODS: A single-center retrospective observational study included all patients who underwent THA revision with distal locking stem between April 2013 and January 2015 in our university hospital. The implant was a curved distal-locking stem fully coated in grit-blasted titanium alloy and hydroxyapatite (HA) with a collar made of TiAlV. This concept is based on primary distal fixation by interlocking screws. The primary endpoint was surgical revision for implant exchange. RESULTS: A total of 47 procedures with distal locking stem were performed, 44 of which were included. Minimum follow-up was 5 years. Etiologies of revision comprised 25 femoral loosenings, 13 periprosthetic fractures, 3 infections, and 3 modular taper breakages. Six patients underwent re-revision (13%), with only 1 implant change (98% survival rate). Mean Harris and Oxford Hip scores at last follow-up were respectively 81±13.5 [range, 67.4-94.5] and 26±9⋅2 [range, 16.7-35.2]. Radiologically, no stem subsidence occurred, and bone ingrowth was obtained in all cases. DISCUSSION: Fully-coated distal locking stems showed a high survival rate. They provided strong initial fixation, allowing early full weight-bearing in these frail patients. LEVEL OF EVIDENCE: IV; retrospective series.

Sleep Deprivation Adversely Impacts Resident Performance for Simulated Arthroscopy.

PURPOSE: The purpose of the study was to assess the performance of residents in orthopaedics before and after a 24-hour shift on a shoulder arthroscopy simulator. The primary study endpoint was an overall performance score (OPS) generated by the simulator. METHODS: A prospective, comparative study of 120 simulator trials by 10 resident junior surgeons was performed in our university hospital's simulation center between May and November 2018. To avoid memorization bias, all participants performed the same exercise 10 times on a VirtaMed ArthroS simulator prior to the study. Each resident's performance (the OPS, the operating time, the proportion of procedures with iatrogenic lesions, the camera path length and the hook path length) in two different simulated arthroscopy exercise tasks was assessed once before and once after a 24-hour shift. This sequence was performed three times during the semester, and the change over time in performance was also evaluated. RESULTS: The OPS was significantly lower after the night shift (P = 0.035 for the first exercise, and P = 0.025 for the second). CONCLUSION: In a group of previously trained resident junior surgeons, overall performance with an arthroscopy simulator was significantly worse after a 24-hour shift. The study of secondary parameters of the OPS and the subgroup analysis based on the sleep time and Epworth score vary depending on the type of exercise performed arthroscopically. However, the use of a simulator after a night shift did not prevent the trainee from improving his/her level of performance over time. LEVEL OF EVIDENCE: II, a prospective, comparative study.

Patella Distal Pole Fracture Treated Using Ipsilateral Hamstring Autograft Augmentation and No Additional Hardware.

Patellar lower-pole fractures occur in relatively young patients after eccentric contraction of the quadriceps or direct trauma. Early diagnosis and adequate treatment lead to excellent outcomes and prevent tendon retraction and scarring. The aim of surgical treatment is to restore articular congruence and reestablish the extensor mechanism of the knee. All surgical treatments (sutures and tension band wiring, separate vertical wiring or augmented with Krackow sutures, wiring through screws, basket plate, hook plate) use additional hardware. We propose a hardware-free technique using ipsilateral hamstring augmentation.

Bleeding and thromboembolism risk of standard antithrombotic prophylaxis after hip or knee replacement within an enhanced recovery program.

INTRODUCTION: Prevention of venous thromboembolism (VTE) generally consists of low molecular weight heparin (LMWH) or direct oral anticoagulants (DOACs) after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Enhanced recovery after surgery (ERAS) protocols may reduce the VTE risk after these procedures. The aim of this study was to compare the risk of VTE and the risk of bleeding complications in a non-selected population of primary THA and TKA cases done within an ERAS protocol. HYPOTHESIS: The risk of postoperative VTE after primary THA and TKA is lower than the risk of bleeding complications within an ERAS protocol. METHODS: This was a prospective observational study conducted on a national scale in France. All patients who underwent primary unilateral THA or TKA at one of 11 participating hospitals between October 2016 and October 2017 were enrolled and followed for 3 months. The occurrence of a VTE or major bleeding event was recorded. No patients were lost to follow-up at 3 months. RESULTS: Of the 1110 THA cases, there were 5 VTE (0.4%) and 19 bleeding events (1.7%). Of the 893 TKA cases, there were 9 VTE (1.0%) and 14 bleeding events (1.7%). There was no significant difference in the VTE incidence and bleeding event incidence after THA and TKA. The overall incidence of bleeding complications (1.7%) was significantly greater than the overall incidence of VTE complications (0.7%) (p=0.005). This was the case after THA (p=0.004) but not after TKA. DISCUSSION: The primary finding of this study is that bleeding complications are significantly more common than VTE complications after THA or TKA within an ERAS protocol. Based on these findings, the cost-benefit ratio of antithrombotic prophylaxis by LMWH or DOACs in this context should be reassessed. LEVEL OF EVIDENCE: IV; Prospective cohort study without control group.

Virtual reality simulator improves the acquisition of basic arthroscopy skills in first-year orthopedic surgery residents.

INTRODUCTION: Arthroscopy training using a virtual reality (VR) simulator is said to improve the training of orthopedic surgery residents, although it has never been evaluated in a large representative population of first-year residents. HYPOTHESIS: We hypothesized that first-year residents who train on a VR simulator would improve their basic arthroscopy skills more than residents who use other training methods. The primary aim was to compare various arthroscopy-learning techniques after 6 months of training. POPULATION AND METHODS: The study population consisted of 107 first-year residents who were tested twice on a VR arthroscopy simulator (December 2017 and June 2018). The residents were divided into three groups: no specific arthroscopy training (A), non-specific and one-off arthroscopy training (B), 6 months of VR arthroscopy simulator training (C). During the testing, they had to perform the Periscoping exercise (orientation of angled scope) and the Catch the Stars Glenohumeral exercise (extraction of loose bodies). The parameters analyzed were time (s), camera alignment relative to horizontal (%), camera path length (cm) and grasper path length (cm). RESULTS: After 6 months, there was a significant difference between groups during the Periscoping exercise in the time (A: 137.8 s; B: 126.7 s; C: 92.2 s) (p<0.0001), camera alignment (A: 93%; B: 98%; C: 97%) (p=0.0028), camera path length (A: 116.9cm; B: 112.5cm; C: 67.3cm) (p<0.0001) and during the Catch the Stars Glenohumeral exercise in the time (A: 112.2 s; B: 103 s; C: 61.4 s) (p<0.0001), camera path length (A: 46.3cm; B: 40.9cm; C: 32.9cm) (p<0.0153) and grasper path length (A: 146.4cm; B: 142.2cm; C: 95.8cm) (p<0.0001). DISCUSSION: The residents who participated in the VR arthroscopy simulator training program for 6 months had better results when performing practical exercises and standard arthroscopy tasks than those who did not receive any training or only received only one-off training. Their final performance indicated technical mastery that the other residents had not achieved. LEVEL OF EVIDENCE: II, Prospective, comparative, non-randomized study.

A comparison of bone union and complication rates between locking and non-locking plates in distal fibular fracture: Retrospective study of 106 cases.

BACKGROUND: Ankle fractures represents the third most frequent fracture in elderly patients. There is a current tendency to fix long bones fractures with locking plates. However, we rarely find published accounts about the use of locking plates in distal fibula fractures, except for biomechanical ones, studying human cadaveric fibula. OBJECTIVES: The main objective was to compare radiographic bone union rates at 6 and 12 weeks of follow up, then wound complications and hardware removal rates, and construct cost. STUDY DESIGN & METHODS: We retrospectively analyzed 105 patients who underwent surgery with locking plates or non-locking plates over a two-year period, out of which 42 patients were treated with non-locking plates (VIVES™ - StrykerⓇ) and 63 with locking plates (VariAx™ - StrykerⓇ,). We analyzed bone union on anterior posterior and lateral X-rays of the ankle. We collected data of wound complications and hardware removal from patient records. Multiple linear regression techniques were performed after identifying dependent variables. RESULTS: There was no significant difference between non-locking and locking plates in the radiographic bone union rate of distal fibula, respectively at 6 and 12 post-operative weeks (85.71% vs. 81%; p = 0.525 and 97.62% vs. 96.83%; p = 1). No significant difference was found in the wound complication rate between the two groups (11.9% vs. 11.12%; p = 0.9). No significant differences were found in the hardware removal rate, either with or without operative site's infection (respectively: 30.95% vs. 39.68%; p = 0.361 and 21.42% vs. 38.09%; p = 0.071). Cost efficiency is in the favor of non-locking plates. CONCLUSION: Non-locking constructs are as effective as locking constructs in the treatment of displaced distal fibula fractures at a substantially lower cost. High-quality randomized controlled trials are needed in the future to verify the finding of this study.

Resection of a Rare Metacarpal Distal Condyle Osteoid Osteoma.

INTRODUCTION: Osteoid osteoma is a benign bone-forming tumor with young male predilection. It occurs predominantly in the long bones. In the hand, osteoid osteoma is more commonly located in the phalanges and carpal bones. The metacarpals are the least common site for osteoid osteoma. Pain is the most common symptom. It usually increases at night and responds to nonsteroidal anti-inflammatory drugs. CASE PRESENTATION: The authors report the excision of an osteoid osteoma lying at the distal condyle of a metacarpal bone of the left hand. The clinical and radiological findings are exposed as well as the surgical management of the lesion. Pain and swelling disappeared after surgery, and there was no evidence of recurrence at follow-up. DISCUSSION: They discuss this rare location and further radiological examination that was used leading to the diagnosis. The imputation of the traumatic factor has been discussed, along with the different therapeutic possibilities and the advantages of a total excision while preserving the integrity of the adjacent ligament and joint space. CONCLUSION: The surgical alternative appears to be a satisfying treatment for osteoid osteoma in this particular superficial location. Both the exact pathogenesis and the contribution of the traumatic factor remain unclear.

Factors associated with hospital stay length, discharge destination, and 30-day readmission rate after primary hip or knee arthroplasty: Retrospective Cohort Study.

BACKGROUND: In France and in the US, predictions for 2030 include an increased number of total hip arthroplasty (THA) and total knee arthroplasty (TKA) procedures together with an overall trend towards shorter hospital stays. Predictors of hospital length of stay (LOS) include the day of surgery, discharge destination, and patient comorbidities. Available data are conflicting, however, and to our knowledge predictors of LOS after THA or TKA have not been evaluated in France. Improved knowledge of these predictors would be expected to increase patient care efficiency. The objectives of this study were: (1) to determine whether the above-listed factors predict LOS after THA or TKA, (2) to identify predictors of discharge to a rehabilitation unit and of readmission within 30 days after surgery. HYPOTHESIS: Both patient-related factors unamenable to modification and modifiable organisational factors are associated with LOS after THA or TKA. MATERIAL AND METHODS: This large single-centre retrospective cohort study included all adults who underwent primary THA or TKA at our university hospital between 1 January 2015 and 31 December 2016. Non-inclusion criteria were revision arthroplasty, THA with femoral or acetabular reconstruction, TKA using a constrained hinged implant, and fracture as the reason for arthroplasty. Preoperative parameters, type of arthroplasty, and postoperative care were recorded. RESULTS: We included 938 patients with THA and 725 patients with TKA. By multivariate analysis, the likelihood of being discharged by day 5 decreased with older age (HR, 0.986; 95%CI: 0.98-0.99) and was lower by 13% in females (HR, 0,871; 95%CI: 0.77-0.986), by 39% in patients with diabetes (HR, 0.606; 95%CI: 0.5-0.73), by 68% in patients discharged to rehabilitation units (HR, 0.322; 95%CI: 0.267-0.389), and by 27% in patients who had arthroplasty on a Friday (HR, 0.733; 95%CI: 0.631-0.852). Factors predicting discharge to rehabilitation unit were older age, female gender, chronic obstructive pulmonary disease, anxiety-depressive disorder, and a history of stroke. Risk factors for 30-day readmission were male gender, obesity, and discharge to rehabilitation unit. DISCUSSION: In this study, predictors of LOS were identified using a survival model that considered age as a continuous variable, separate comorbidities, and the discharge destination. Our findings are consistent with earlier reports and confirm the strong associations linking LOS to diabetes, day of surgery, and discharge destination in France. We also identified predictors of discharge to rehabilitation and of readmission within 30 days. LEVEL OF EVIDENCE: IV, retrospective observational cohort study.

Congenital dislocation of the knee in a three-year-old-child with Larsen syndrome: Treatment with a hexapod-type external fixator.

Congenital knee dislocation (CDK) is a rare condition, and its treatment is subject to debate. Here, we report on a new treatment for CDK (using a hexapod-type external fixator, HEF) in a three-year-old child with Larsen syndrome and grade III anterior dislocations of both knees. The left knee was treated with serial splints, whereas an HEF was used to treat an irreducible dislocation of the right knee. Two HEF aluminium rings were applied surgically. The procedure involved a distraction of the knee, then tibial posterior translation, and lastly progressive flexion. The clinical and radiological outcomes were good; after four years of follow-up, the right knee had stabilized and had a range of motion of 110°. We conclude that as an innovative, effective option for the management of CDK, the use of an HEF may constitute a relatively advantageous alternative to quadriceps tenotomy.

Morphometric Tibial Implant Decreases Posterior Overhang Rate and Improves Clinical Outcomes: Results of a Prospective, Matched Controlled Study.

BACKGROUND: Tibial implant's positioning in total knee arthroplasty (TKA) requires a compromise between implant's rotation and bone coverage. We hypothesized that morphometric tibial trays (MTTs) would improve implant positioning and clinical outcomes as compared with symmetrical tibial trays. METHODS: Thirty-three patients were included prospectively according to the following criteria: age from 18 to 85 years, body mass index <35 kg/m2, and posterostabilized cemented TKA performed for primary arthritis. Patients were matched for age, gender, body mass index, and preoperative international knee society (IKS) scoring system and Knee Injury and Osteoarthritis Outcome Score (KOOS) pain score, in a 1:1 fashion with patients from a prospectively collected database receiving a symmetrical tibial tray TKA. Tibial implant's rotation, bone coverage, and the percentage of patients with a posterior overhang (PO) >3 mm were assessed using computerized tomography. The IKS and the KOOS were compared at 3-year follow-up. RESULTS: Bone coverage (90% vs 88%, P = .07) and rotation (mean difference 0.7 ± 3°; P = .69) were not different between the 2 groups. The percentage of patient with a PO was lower in the morphologic group (2/33 vs 14/33, P = .01, odds ratio = 10.3 [2.12-50.24]). Functional scores were superior in the morphometric group: IKS (mean difference 20 ± 21 points; P = .0005), mainly due to a difference in the IKS pain subscore (mean difference 11 ± 15 points; P = .0002). According to the multivariate analysis, an MTT had a positive, independent effect on IKS pain (P = .006) and KOOS pain subscores (P = .03) at the last follow-up. CONCLUSION: The use of an MTT in TKA did not modify the tibial implant position in the axial plane; however, it decreased implant's posterior overhang and improved functional scores. The clinical improvement was mainly found on pain scores.

Fixation augmentation using calcium-phosphate bone substitute improves outcomes of complex tibial plateau fractures. A matched, cohort study.

INTRODUCTION: Injectable cements have been developed to improve fixation's stability and thus obtain early return to adequate joint function. We aimed to compare post-operative radiographic and clinical outcomes of patients suffering from a complex tibial plateau fracture (TPF) fixed with calcium-phosphate bone substitutes (CPBS) augmentation to a matched group of patients with identical fracture pattern, treated with the same fixation's type, but augmented with bone grafting. METHODS: After local ethic committee approval, we retrospectively identified in a prospectively collected database, patients with complex comminuted metaphyseal and epiphysial bicondylar TPF (Schatzker type VI) admitted in our emergency department between January 2011 and December 2013. From those, 23 patients (14 males, 9 females) were treated with CPBS (Quickset-CP®, Graftys, Aix-en-Provence, France) fixation augmentation. Patients' mean age were 44.4 years. We then created a control group using a 1:1 matching process on gender, age, fracture pattern, and method of fixation. Patients were evaluated prospectively at 3, 6, and then every six  months using radiographic (AP/ML views) and clinical criteria (knee osteoarthritis outcomes score (KOOS) and EuroQOL-5D). RESULTS: Articular step-off and variation of articular step-off were significantly lower in the CPBS groups (mean step-off 1.4 ± 1.9 (0.5-6.5 mm) and mean step-off Δ = 0.3 ± 0.4 (0.5-2.2 mm)) than in the control group (mean step-off 3.6 ± 2.1 (1-7.5 mm) and mean step-off Δ = 2.2 ± 2 (0.5-7 mm) p < 0.01). At last follow-up, patients of the control group presented a higher rate of step-off > 2 mm and step-off Δ > 2 mm (respectively, 56 and 35%) than patients of the CPBS group (26 and 9%). Odd ratio of, respectively, 3.6 (95% CI (1.08-12.7) and p = 0.03) and 5.6 (95% CI (1.04-30.1) and p = 0.03).At mean follow-up of 29 months, KOOS pain subscore was significantly better in patients of the CPBS group (85.3 ± 12.1) than in control patients (74.2 ± 10.4 and p = 0.03). CONCLUSION: The present study demonstrates that calcium-phosphate bone substitute used as synthesis augmentation improves mid-term radiological outcomes of patients suffering from complex tibial plateau fracture. Series reporting outcomes from a larger number of patients and longer follow-up must confirm clinical benefits and safety of this method.