Increased survival rate in extension stemmed TKA in obese patients at minimum 2 years follow-up.

PURPOSE: Total knee arthroplasty (TKA) is frequently performed for obese patients. TKA in this population shows a high rate of complication, particularly tibial component loosening. The aim of this study is to compare the survival rate of tibial components in obese population using TKA with stem versus without stem. METHODS: From a prospective database of 4216 TKA, obese patients [body mass index (BMI) > 30 kg m²] with primary TKA using a tibial short stem extension (30 mm) at a minimum follow-up of 2 years were retrospectively reviewed and compared to a matched control group (1:3 ratio) with a standard tibial stem. Inclusion criteria were BMI > 30 kg m², first knee surgery and 24 months minimum of follow-up. The primary outcome was revision for tibial aseptic loosening. Secondary outcomes were all-cause revisions and Knee Society Scores (KSS). RESULTS: The final study population consisted of 35 TKA with tibial extension stem versus 105 TKA with standard stem. The mean age was 69.2 and 69.5 years, respectively, with a mean follow-up of 52 months. Both groups were comparable before surgery. After 2 years of follow-up, we observed seven tibial loosening in the group without stem (6.6%) versus no tibial loosening in the stemmed group (p < 0.001). The difference in KSS knee score (83 versus 86; p = 0.06) and the KSS function score (73 versus 77; p = 0.84) were not statistically significant at the final follow-up. CONCLUSION: Using stemmed TKA for obese patients significantly decreased tibial loosening rate at minimum 2 years of follow-up. LEVEL OF EVIDENCE: Case-control study, Level III.

Increased survival rate for primary TKA with tibial short extension stems for severe varus deformities at a minimum of 2 years follow-up.

PURPOSE: The purpose of this study was to compare the clinical results, radiographic loosening and early complications between patients undergoing primary knee arthroplasty (TKA) with tibial short stem extension and those with standard stem for gross varus deformities at minimum two years after surgery. METHODS: From a prospective TKA database of 4216 patients, patients with a primary TKA with a tibial short stem extension (30 mm) for severe varus deformity (hip-kneeankle angle, HKA < 170°) and a minimum follow-up of 2 years, were reviewed and compared to a matched control group with tibial components with a standard stem, in a 1:3 ratio. Demographics, surgical parameters, pre- and postoperative alignment and outcome parameters were collected for all patients. The primary outcome was aseptic loosening of the tibial component. Secondary outcomes were knee society scores (KSS), postoperative HKA, general postoperative complications and implant survival rates. RESULTS: Forty-five patients with tibial short stem extensions (mean HKA 166.2°) were compared in a 1:3 ratio to a matched case-control group of 135 patients with standard stems (mean HKA 167.1°) at a mean follow-up of 57 and 64 months respectively after primary TKA. In the extension stem group, 4 patients encountered complications (8.9%) versus 12 patients in the standard stem group (8.9%). There were no cases of tibial component loosening in the short extension stem versus four cases in the standard stem group (3%). This difference was significant between groups, p = 0.04. CONCLUSION: In patients with varus deformities > 10°, undergoing primary total knee arthroplasty, prophylactic use of a tibial short extension stem may lead to less loosening of the tibial component. In this study, 3% of patient with big varus deformity without stemmed TKA had a tibial implant loosening versus 0% in the stemmed TKA group. LEVEL OF EVIDENCE: Level III, case-control study.

Greater medial tibial slope is associated with increased anterior tibial translation in females with an ACL-deficient knee.

PURPOSE: The purpose of the study was to determine the correlation between medial tibial slope (MTS) and anterior tibial translation (ATT) in female patients with an ACL-deficient knee. It was hypothesized that female patients with a greater medial tibial slope had an increased anterior tibial translation compared to males. METHODS: MTS and ATT were analysed in 276 patients (138 females and 138 males) with a complete ACL rupture from 2012 to 2016. The mean age was 32 ± 12 years. Previous surgery or additional ligament injury was excluded. CT scan was used for measuring MTS. Meniscal findings were reported. Anterior tibial translation and side to side difference (SSD) were measured by bilateral Telos™ stress radiography with knee flexion of 20°. RESULTS: There was no significant difference in ATT between females (5.4 ± 3.9) and males (5.8 ± 4.2), nor was there a difference in MTS between females (9.8 ± 2.8) and males (9.8 ± 2.7). A positive correlation was found between MTS and ATT absolute (r = 0.35, p < 0.001) and side to side difference (r = 0.12, p = 0.03). MTS greater or equal to 11° significantly increased the ATT (p < 0.05). For each degree of increase of the MTS, increases in ATT absolute of 0.6 mm and SSD of 0.18 mm were observed. Greater MTS was identified as a risk factor for an increase of ATT in females (r = 0.37, p < 0.001) but not in males (r = - 0.1, n.s). Increases of 1° of MTS increased ATT 0.57 mm in female patients (p < 0.001). MTS was influential in ATT despite the presence (r = 0.28 [0.11, 0.44], p = 0.001) or absence (r = 0.48 [0.35, 0.6], p < 0.001) of meniscal lesions. CONCLUSIONS: Greater medial tibial slope is associated with increased anterior tibial translation in females with ACL-deficient knees compared to males, despite the presence or absence of meniscal lesions. This could be due to a quadriceps/hamstring imbalance in females and the ability of the hamstring muscles to moderate ATT. LEVEL OF EVIDENCE: III.

ACL reconstruction using a quadruple semitendinosus graft with cortical fixations gives suitable isokinetic and clinical outcomes after 2 years.

PURPOSE: The objective of this single-center randomized single-blinded trial was to assess the hypothesis that anterior cruciate ligament reconstruction (ACLR) using a four-strand semitendinosus (ST) graft with adjustable femoral and tibial cortical fixation produced good outcomes compared to an ST/gracilis (ST/G) graft with femoral pin transfixation and tibial bioscrew fixation. Follow-up was 2 years. METHODS: Patients older than 16 years who underwent primary isolated ACLR included for 1 year until August 2017 were eligible. The primary outcome measures were the subjective International Knee Documentation Committee (IKDC) score, isokinetic muscle strength recovery, and return to work within 2 years. The study was approved by the ethics committee. RESULTS: Of 66 eligible patients, 60 completed the study and were included, 33 in the 4ST group and 27 in the ST/G group. Mean age was 30.5 ± 8.9 years in the 4ST group and 30.3 ± 8.5 in the ST/G group (n.s.). No significant between-group differences were found for mean postoperative subjective IKDC (4ST group, 80.2 ± 12.5; ST/G group, 83.6 ± 13.6; n.s.), side-to-side percentage deficits in isokinetic hamstring strength (at 60°/s: ST group, 17% ± 16%; ST/G group, 14% ± 11%; n.s.) or quadriceps strength (at 60°/s: ST group, 14% ± 12%; ST/G group, 19% ± 17%; n.s.), return to work, pain during physical activities, side-to-side differential laxity, balance, loss of flexion/extension, or surgical complications. CONCLUSION: This trial demonstrates that functional outcomes after 4ST for ACLR with cortical fixations could be as good, although not better, than those obtained using ST/G. The 4ST technique spares the gracilis tendon, which thus preserves the medial sided muscle and thereby could improve function and limit donor-side morbidity. LEVEL OF EVIDENCE: Level I.

No difference in patellar position between mobile-bearing and fixed-bearing total knee arthroplasty for medial osteoarthritis: a prospective randomized study.

PURPOSE: Total knee arthroplasty (TKA) is the treatment of choice for severe osteoarthritis of the knee. Many studies have been performed comparing mobile- and fixed-bearing designs; however, there are insufficient data regarding the patellar position in either system. This study aimed to compare the resultant patellar position with a mobile- versus a fixed-bearing TKA and the influence of both designs on clinical outcomes. MATERIALS AND METHODS: In this prospective randomized study, between 2007 and 2009, 160 TKA patients were assessed; 79 received a mobile-bearing and 81 received a fixed-bearing implant, for medial compartment osteoarthritis. A posteriorly stabilized, HLS Noetos knee prosthesis (Tornier, Saint-Ismier, France) was used in all cases. The only difference between the groups was whether the tibial component incorporated a fixed or mobile bearing. The patella was resurfaced in all cases. The International Knee Society Score (KSS) and the patellar tilt and translation were compared post-operatively. Patellar translation and patellar tilt analyses were subdivided into two subgroups (< 5 mm vs > 5 mm and < 5° vs > 5°). RESULTS: The KSS was not statistically different between the groups at a mean follow-up of 7.4 years (range 5-11 years). Patellar translation and patellar tilt were not statistically different between the groups. When considering the patellar translation subgroup analysis, a significantly increased risk of patellar translation, greater than 5 mm, was found in the mobile-bearing group compared to fixed-bearing group (OR = 2.3; p = 0.048) without generating any meaningful difference in clinical outcomes. CONCLUSION: The theoretical advantages of mobile-bearing implants compared to fixed-bearing implants were not demonstrated in this randomized study, at mid-term follow-up. In daily practice, the choice between mobile-bearing and fixed-bearing designs should be based on the experience and clinical judgment of the surgeon. LEVEL OF EVIDENCE: Prospective randomized study, level I.

Ten- to 16-Year Results of a Modern Cementless Dual-Mobility Acetabular Implant in Primary Total Hip Arthroplasty.

BACKGROUND: The purpose of this study is to assess the radiographic results, clinical outcomes, and survivorship of a modern cementless dual-mobility cup (DMC) implant as a primary THA with a minimum of 10 years follow-up. METHODS: This study retrospectively assessed a series of 310 primary THAs using a modern-generation cementless DMC (Saturne acetabular cup) between April 2001 and December 2005 at a single center. Patients were followed prospectively clinically and radiographically after surgery. Hips with follow-up less than 120 months were excluded from the study (5 lost to follow-up and 167 deceased). In total, a cohort of 138 hips were included for preoperative and postoperative analysis with an average follow-up of 152.4 months. All complications were collected, and a Kaplan-Meier survival analysis was performed. RESULTS: There was a significant increase in the mean Harris and Postel-Merle d'Aubigne scores between preoperative and postoperative cohorts (P < .001). No loosening of the cup and no acetabular osteolysis were found at final follow-up. No prosthetic dislocation, no intraprosthetic dislocation, and no infections were reported. The survival curve of THA in the total cohort (N = 310) was about 98% at 10 years with 3 stem revisions for femoral fracture. One psoas impingement was also described. CONCLUSION: This study showed no acetabular component failure and no reported cases of acetabular osteolysis with this DMC acetabular component retention at 10 years. No prosthetic or intraprosthetic dislocation was reported.

Return to Sport After Bilateral Single Stage Total Hip Arthroplasty Using the Direct Anterior Approach: A Case Control Study.

BACKGROUND: Total hip arthroplasty (THA) is currently performed on active patients with increasing functional demands. Single stage bilateral THA is indicated in younger patients in good general health. Our objective is to evaluate the return to sport (RTS) in patients who underwent bilateral single stage THA compared to unilateral THA. METHODS: This retrospective case control study was conducted between 2013 and 2017. All patients who underwent bilateral single stage THA were included. The control group had unilateral THA performed and was matched based on age, body mass index, gender, and surgery date (2 controls for each bilateral case). All surgeries were performed by a single senior surgeon using the direct anterior approach. The University of California Los Angeles activity score was collected at the last follow-up. A questionnaire regarding RTS, motivation, and satisfaction was assessed. RESULTS: Thirty-two patients were included in the study, of whom 21 were men. The average age was 60.7 ± 9.6 years, body mass index was 26 ± 4 kg/m2, and mean follow-up was 20.1 ± 11.6 months. Twenty-eight patients overall (87%) returned to sport after the procedure. Twenty-five of these (89%) returned to the same sport, and 17 (68%) participated at the same intensity. The average time to RTS was 4 ± 2.8 months. These results were at least as good as those after unilateral THA. The level of motivation of the patient was the only predictive factor for RTS (P < .001). CONCLUSION: Bilateral single stage THA via a direct anterior approach allows for RTS and to a similar level in the majority of patients in whom this procedure is indicated. LEVEL OF EVIDENCE: Comparative retrospective study, Level III.

Influence of Patella Height on Total Knee Arthroplasty: Outcomes and Survival.

BACKGROUND: The aim of this study is to assess clinical results of total knee arthroplasty (TKA) with pre-operative patella alta or patella baja, compared to TKA with pre-operative normal patellar height. METHODS: Patella height was measured using the Blackburne-Peel (BP) method in an initial, prospective cohort of 4103 TKAs performed at a single center. Three groups were defined: normal patella height (0.54 < BP index ≤ 1.06), patella alta (BP index >1.06), and patella baja (BP index ≤0.54). Pre-operative and post-operative clinical and radiological characteristics were collected and compared. All prostheses used a system of posterior stabilization by a third condyle. The primary outcome measure was the post-operative Knee Society Score. Statistical analysis was performed using Student's t-test and chi-squared test, with P < .05. RESULTS: Two hundred twenty-three TKAs with pre-operative patella alta, 307 TKAs with pre-operative patella baja, and 2248 with pre-operative normal patella height, mean follow-up 39.3 months (range 24-239), were ultimately included. Post-operatively, there was no difference between the 3 groups in terms of Knee Society Score (knee and function scores). Patella baja statistically decreased the maximal flexion (118.2° vs 115.5°, P = .002) and increased the rate of patellar fracture (0.9% vs 2%, P = .05). Finally, survival rates were similar in the 3 groups with each above 91% (±2%) at 10 years. CONCLUSION: Clinical and radiological results for TKAs with pre-operative patella alta and patella baja were comparable to TKAs with a normal pre-operative patellar height. Risk of post-operative patellar fracture increased for patients with pre-operative patella baja.

Increased Patellar Fracture Rate in Total Knee Arthroplasty With Preoperative Varus Greater Than 15°: A Case-Control Study.

BACKGROUND: Management of severe varus deformity requires soft tissue balancing for implantation of low-constraint knee prosthesis. Patellar complications have been rarely studied in this specific group. Our hypothesis was that severe genu varum (>15°) would increase the rate of patellar complications. METHODS: Using a prospective cohort of 4216 prostheses performed at a single center beginning in 1987, we analyzed 280 prostheses having preoperative varus greater than 15°, compared to 673 total knee arthroplasties (TKAs) with a preoperative hip-knee-ankle angle of 180° ± 2°. Preoperative and postoperative clinical and radiological characteristics were compared between the 2 groups, with particular attention paid to patellar complications. RESULTS: Average follow-up was 40.2 months (24-239). The mean preoperative Knee Society Score (KSS) was statistically higher in the normal (hip-knee-ankle angle 180° ± 2) axis group (62.65 vs 37.47, P = .001). At the last follow-up, no significant difference was found between the 2 groups in terms of postoperative KSS (87.5 in the varus group vs 87.3 in the normal axis group, P = .87). The rate of satisfied patients was identical between the 2 groups (85.3% vs 88.8%, P = .49). However, at mid-term, there were more patellar fractures in the varus group (2.9% vs 0.9%, P = .005). A significantly lower patellar height in both the varus group and the group of patella fractures (P < .001) was also found. CONCLUSION: TKA in severe varus knees produces a KSS equivalent to TKA in knees with a mechanical axis of 0 ± 2. The risk of patellar fracture could initiate a decline in patella resurfacing in patients with major varus deformation, especially in case of a preoperative patella baja.

Partial extensor mechanism allograft reconstruction for chronic patellar tendon disruption shows superior outcomes in native knees when compared to same technique following total arthroplasty.

PURPOSE: Chronic patellar tendon disruption occurs mostly after total knee arthroplasty, and is a challenging complication to treat. We have previously described an original technique for reconstruction using extensor mechanism allograft. The goal of this study was to assess the results of this technique in TKA and native knees. METHODS: An observational, single centre, retrospective study was conducted. Nine patients in the TKA group and eight in the native knee group were included, all treated for chronic PT rupture. The operative technique included fresh-frozen allograft, in which the patella was fashioned into an hourglass shape and press-fit in a corresponding groove in the native patella. The primary outcome was failure of the graft defined by a residual extensor lag > 10°. RESULTS: The mean age was 68 in the TKA group and 51 in the native group. The minimum follow-up was 24 months and the mean follow-up respectively 42 and 39 months. 33% of allografts failed in the TKA group where none failed in the native knee group, with a mean extension lag of 12.2° (0-30) and 1.25° (0-5), respectively. All but the three failures presented with an extension lag < 10°. Four cases of patellar bone block distal migration, less than 1 cm, were recorded in the native knee group without clinical repercussion. CONCLUSIONS: The results of this original technique in the setting of chronic PT rupture were excellent for native knees at a minimum follow-up of 24 months. However, results were less satisfactory in the TKA group, due to the substantial rate of failure. LEVEL OF EVIDENCE III.

Total knee arthroplasty after varus distal femoral osteotomy vs native knee: similar results in a case control study.

PURPOSE: The aim of this study was to investigate the results of total knee arthroplasty (TKA) performed after varus distal femoral osteotomy (VrDFO), in comparison to a control group of TKAs performed as the primary intervention for arthrosis. Main hypothesis was that the medium term results for the two groups would be similar. METHODS: All TKAs performed after VrDFO were extracted from a single centre, prospective database of 4046 arthroplasties. A case-control study was performed with a control group comprising two TKAs performed as the primary intervention for each TKA after VrDFO, and matched for sex, age at intervention, body mass index, the type of arthrosis and the type of implant. All prostheses used a system of posterior stabilisation by a third median condyle (Laboritoire Tornier-Wright). The primary outcome measure was the post-operative Knee Society Score (KSS). RESULTS: Fourteen TKAs after VrDFO were identified, with a median follow-up of 42 months (12-102 months). The control group comprised 28 patients. There were no significant differences between groups in terms of the matching criteria. Pre-operatively, there were no differences between groups in terms of KSS (knee and function scores), range of motion (fixed-flexion and maximum flexion), and mechanical axes on long leg films. Operative duration was identical for the two groups. In the VrDFO group there was more lateral intra-operative laxity (p = 0.006), more intra-operative complications (patella tendon injuries, p = 0.0008), and more frequent need for screw support for the tibial component due to more severe lower limb deformity (p < 0.0001). No significant difference was found between groups with regards to the post-operative KSS; median knee score was 91.7 in the VrDFO group compared to 82.3 in the control group, and function score 70.6 compared to 77.8. Range of motion was comparable between groups with median maximum flexion in the VrDFO group of 115.7° and 110.9° in the control group. CONCLUSION: TKAs after VrDFO is uncommon and can carry an increased risk of intra-operative complications. Despite this, the medium term results are comparable to arthroplasty performed as a primary intervention. TKA should not be denied to patients with previous femoral osteotomy, but care must be taken with gap balancing and axis correction. LEVEL OF EVIDENCE: 3.

Risk factors for tibial implant malpositioning in total knee arthrosplasty-consecutive series of one thousand, four hundred and seventeen cases.

PURPOSE: Total knee arthroplasty (TKA) malalignment may result in pain and limited range of motion. The present study assessed the influence of different surgeon's and patient's related factors on the post-operative tibial tray coronal alignment. METHODS: The charts and the x-rays of a continuous prospective series of 1417 TKAs operated upon between 1987 and 2015 were retrospectively reviewed. The long-leg AP views were performed at two months post-op and the tibial mechanical angle of the tibial tray was measured. Three groups were defined: varus (≤87° n = 167), valgus (≥93° n = 55) and well alignment (88° to 92° n = 1195). The influence of several pre-operative and peri-operative factors was investigated: surgeon handedness and experience (junior or senior), previous tibial osteotomies, Ahlbäck stage of osteoarthritits, pre-operative alignment, height and weight, age at surgery, approach (medial, lateral or tibial tubercle osteotomy), generation of implants, tray fixation, size of the tray and stem lenght. Univariate then multivariate analysis were performed to find out any correlation. RESULTS: Multivariate analysis showed a strong correlation between varus alignment of the tibial tray and pre-operative varus of the lower limb (p = 0.037), increased BMI (p = 0.016) and operated side opposite to the dominant surgeon's arm (p = 0.006). In a similar way a strong correlation was found between valgus alignment and pre-operative valgus of the limb (p = 0.026). CONCLUSION: Poor alignment of the tibial tray after TKA was associated with pre-operative malalignment of the lower limb, increased BMI and an index knee which was opposite to surgeon's dominant arm.

Equivalent wear performance of dual mobility bearing compared with standard bearing in total hip arthroplasty: in vitro study.

PURPOSE: Osteolysis in total hip arthroplasty (THA) depends on polyethylene wear and dictates the survival of the prosthesis. Dual mobility in THAs, which is claimed to reduce dislocation risk, has very good long-term clinical results. However, little is known about how the liner wears in this design, compared to the standard single mobility model. METHODS: A comparative study looking at wear of a conventional ultra-high-molecular-weight polyethylene liner, using gravimetric measurement, between dual mobility implants and standard implants, was performed on a simulator in accordance with a normed protocol based on the same dimensions, environmental conditions and stresses. A linear regression test was employed. RESULTS: Under the same conditions (loading, cycles, sterilization, material and surface roughness), the gravimetric wear (for conventional polyethylene) is comparable between a standard and a dual mobility cup. This correlates to ten year follow-up results of dual mobility cup. DISCUSSION - CONCLUSION: This in vitro equivalent wear serves to confirm the very good long-term clinical results observed with dual mobility bearing, whose use should not be restricted by concerns about increased polyethylene wear.

No influence of obesity on survival of cementless, posterior-stabilised, rotating-platform implants.

INTRODUCTION: This study compares survival and outcomes in four total knee arthroplasty (TKA) populations defined by baseline body mass index (BMI). We hypothesised that there would be no difference in survival between the groups. MATERIALS AND METHODS: Using an initial cohort of 1059 TKAs, BMI was systematically measured prior to surgery. A retrospective study was conducted and patients were accordingly allocated to four groups: normal or underweight (BMI < 25; n = 111), overweight (25 ≤ BMI < 30; n = 417), moderately obese (30 ≤ BMI < 35; n = 330) and severely or morbidly obese (BMI ≥ 35; n = 201). The pre- and postoperative clinical and radiographical profiles of the four groups were compared, along with any postoperative complications and the survival of each group. The minimum follow-up was 24 months. All implants had an ultra-congruent cementless posterior-stabilised rotating-platform design (Amplitude®). The primary endpoint was implant survival using Kaplan-Meier analysis. Statistical analysis was conducted using Chi-squared and Kruskal-Wallis H tests to compare the data with p < 0.05. RESULTS: A total of 94 knees from normal weight or underweight individuals were analysed, 346 from overweight, 281 from moderately obese and 159 from severely or morbidly obese. All knees had been operated on between 2002 and 2011 with an average follow-up of 61.7 (12-146) months. A greater degree of obesity was significantly correlated with young age at intervention (p < 0.001), as well as with a low average preoperative maximum flexion angle (p < 0.001) and KSS (p < 0.001). Postoperatively, there were no significant differences between the groups in terms of patient satisfaction (p = 0.9) or mechanical axial deviation evaluated with whole-leg standing radiography (mFTA, p = 0.3; mFA, p = 0.1; mTA, p = 0.3). The greater the degree of obesity, the lower the average postoperative maximum flexion angle (p < 0.001), KSS knee score (p < 0.001) and function score (p = 0.005). There was no significant difference between the groups in terms of total rate of postoperative complications (p = 0.9) or implant revision (p = 0.9), or in terms of 10-year implant survival (p = 0.4). CONCLUSIONS: Obesity does not affect mid-term implant survival, irrespective of BMI, but has a negative influence on functional outcomes and potential risk of postoperative complications.

Multi-column modelling of lake Geneva for climate applications.

The interaction between large inland water bodies and the atmosphere impacts the evolution of regional weather and climate, which in turn affects the lake dynamics, thermodynamics, ice-formation, and, therefore, ecosystems. Over the last decades, various approaches have been used to model lake thermodynamics and dynamics in standalone mode or coupled to numerical atmospheric models. We assess a turbulence-closure [Formula: see text] multi-column lake model in standalone mode as a computationally-efficient alternative to a full three-dimensional hydrodynamic model in the case of Lake Geneva. While it struggles to reproduce some short-term features, the multi-column model reasonably reproduces the seasonal mean of the thermal horizontal and vertical structures governing heat and mass exchanges between the lake surface and the lower atmosphere (stratified period, thermocline depth, stability of the water column). As it requires typically two orders of magnitude less computational ressources, it may allow a two-way coupling with a RCM on timescales or spatial resolutions where full 3D lake models are too demanding.

Bilateral Traumatic Maculopathy after Closed-Globe Injury in Context of National Lockdown: A Case Report.

The aim of this study is to report a case of bilateral traumatic maculopathy in a 19-year-old male following blunt trauma during 2020 coronavirus disease-2019 national lockdown. Descriptive case report based on data from clinical records, patient observation, and analysis of diagnostic tests. A previously healthy, 19-year-old male presented for a visit in our department at 15-20 National Ophthalmology Institute with complaints of bilateral decreased visual acuity. A history of recent blunt trauma caused by resistance band was reported. Fundus examination recorded fibrosis and inferior preretinal hemorrhages on both eyes. Peripheral retinal examination was normal. Optical coherence tomography showed bilateral increased reflectivity, disruption of the inner/outer segment, and loss of the external limiting membrane. The 6-week follow-up did not show a major recovery. Early detection of posterior segment damage after blunt trauma remains primordial despite worldwide pandemic.

Stiffness after unicompartmental knee arthroplasty: Risk factors and arthroscopic treatment.

INTRODUCTION: One of the principal complications after total knee arthroplasty (TKA) is stiffness. There are no publications concerning stiffness after unicompartmental knee arthroplasty (UKA). Study objectives were to describe the incidence of stiffness after UKA, to look for risk factors, and to describe safe and effective arthroscopic treatment. METHODS: There were 240 UKA performed between March 2016 and January 2019 included. Robotic-assisted surgery was performed in 164 patients and mechanical instrumentation in 76 patients. Stiffness was defined as flexion < 90° or a flexion contracture > 10° during the first 45 post-operative days. Patients with stiffness were treated with arthroscopic arthrolysis. Several factors were studied to look for risk factors of stiffness: body mass index, gender, age, mechanical or robotic instrumentation, preoperative flexion, previous meniscectomy, and anticoagulant treatment. Arthrolysis effectiveness was evaluated by flexion improvement and UKA revision rate. RESULTS: 22 patients (9%) developed stiffness. Mechanical instrumentation significantly increased the risk of stiffness with OR = 0.26 and p = 0.005. Robotic-assisted surgery decreased the risk of stiffness by five-fold. Before arthrolysis, mean knee flexion was 79°, versus 121° (53% improvement) after arthroscopic arthrolysis. Only 2 patients (9%) underwent UKA revision after arthrolysis. DISCUSSION: Stiffness after UKA is an important complication with an incidence of 9% in this study. Arthroscopic arthrolysis is a safe and effective treatment with a range of motion improvement of > 50%. Robotic-assisted surgery significantly decreases the risk of postoperative stiffness. LEVEL OF EVIDENCE: Level III, therapeutic study, retrospective cohort study.

Case Report: Arthroscopic "Debridement Antibiotics and Implant Retention" With Local Injection of Personalized Phage Therapy to Salvage a Relapsing Pseudomonas Aeruginosa Prosthetic Knee Infection.

Bacteriophages are viruses that specifically target bacteria. They are considered to have a high potential in patients with prosthetic joint infection (PJI), as they have a synergistic anti-biofilm activity with antibiotics. We report here the case of an 88-year-old man (63 kg) with relapsing Pseudomonas aeruginosa prosthetic knee infection. The patient had severe alteration of the general status and was bedridden with congestive heart failure. As prosthesis explantation and/or exchange was not feasible, we proposed to this patient the use of phage therapy to try to control the disease in accordance with the local ethics committee and the French National Agency for Medicines and Health Products Safety (ANSM). Three phages, targeting P. aeruginosa, were selected based on their lytic activity on the patient's strain (phagogram). Hospital pharmacist mixed extemporaneously the active phages (initial concentration 1 ml of 1 × 1010 PFU/ml for each phage) to obtain a cocktail of phages in a suspension form (final dilution 1 × 109 PFU/ml for both phages). Conventional arthroscopy was performed and 30 cc of the magistral preparation was injected through the arthroscope (PhagoDAIR procedure). The patient received intravenous ceftazidime and then oral ciprofloxacin as suppressive antimicrobial therapy. Under this treatment, the patient rapidly improved with disappearance of signs of heart failure and pain of the left knee. During the follow-up of 1 year, the local status of the left knee was normal, and its motion and walking were unpainful. The present case suggests that the PhagoDAIR procedure by arthroscopy has the potential to be used as salvage therapy for patients with P. aeruginosa relapsing PJI, in combination with suppressive antimicrobial therapy. A Phase II clinical study deserves to be performed to confirm this hypothesis.

Arthroscopic "Debridement and Implant Retention" With Local Administration of Exebacase (Lysin CF-301) Followed by Suppressive Tedizolid as Salvage Therapy in Elderly Patients for Relapsing Multidrug-Resistant S. epidermidis Prosthetic Knee Infection.

Exebacase, a recombinantly produced lysin has recently (i) reported proof-of-concept data from a phase II study in S. aureus bacteremia and (ii) demonstrated antibiofilm activity in vitro against S. epidermidis. In patients with relapsing multidrug-resistant (MDR) S. epidermidis prosthetic knee infection (PKI), the only surgical option is prosthesis exchange. In elderly patients who have undergone several revisions, prosthesis explantation could be associated with definitive loss of function and mortality. In our BJI reference regional center, arthroscopic debridement and implant retention with local administration of exebacase (LysinDAIR) followed by suppressive tedizolid as salvage therapy is proposed for elderly patients with recurrent MDR S. epidermidis PKI with no therapeutic option or therapeutic dead end (for whom revision or transfemoral amputation is not feasible and no other oral option is available). Each use was decided in agreement with the French health authority and in accordance with the local ethics committee. A written consent was obtained for each patient. Exebacase (75 mg/mL; 30 mL) was administered directly into the joint during arthroscopy. Four patients (79-89 years old) were treated with the LysinDAIR procedure. All had several previous prosthetic knee revisions without prosthesis loosening. Three had relapsing PKI despite suppressive antibiotics following open DAIR. Two had clinical signs of septic arthritis; the two others had sinus tract. After the LysinDAIR procedure, no adverse events occurred during arthroscopy; all patients received daptomycin 8 mg/kg and linezolid 600 mg bid (4-6 weeks) as primary therapy, followed by tedizolid 200 mg/day as suppressive therapy. At 6 months, recurrence of the sinus tract occurred in the two patients with sinus tract at baseline. After >1 year follow up, the clinical outcome was favorable in the last two patients with total disappearance of clinical signs of septic arthritis even if microbiological persistence was detected in one of them. Exebacase has the potential to be used in patients with staphylococci PKI during arthroscopic DAIR as salvage therapy to improve the efficacy of suppressive antibiotics and to prevent major loss of function.