Hallucination Rates and Reference Accuracy of ChatGPT and Bard for Systematic Reviews: Comparative Analysis.

BACKGROUND: Large language models (LLMs) have raised both interest and concern in the academic community. They offer the potential for automating literature search and synthesis for systematic reviews but raise concerns regarding their reliability, as the tendency to generate unsupported (hallucinated) content persist. OBJECTIVE: The aim of the study is to assess the performance of LLMs such as ChatGPT and Bard (subsequently rebranded Gemini) to produce references in the context of scientific writing. METHODS: The performance of ChatGPT and Bard in replicating the results of human-conducted systematic reviews was assessed. Using systematic reviews pertaining to shoulder rotator cuff pathology, these LLMs were tested by providing the same inclusion criteria and comparing the results with original systematic review references, serving as gold standards. The study used 3 key performance metrics: recall, precision, and F1-score, alongside the hallucination rate. Papers were considered "hallucinated" if any 2 of the following information were wrong: title, first author, or year of publication. RESULTS: In total, 11 systematic reviews across 4 fields yielded 33 prompts to LLMs (3 LLMs×11 reviews), with 471 references analyzed. Precision rates for GPT-3.5, GPT-4, and Bard were 9.4% (13/139), 13.4% (16/119), and 0% (0/104) respectively (P<.001). Recall rates were 11.9% (13/109) for GPT-3.5 and 13.7% (15/109) for GPT-4, with Bard failing to retrieve any relevant papers (P<.001). Hallucination rates stood at 39.6% (55/139) for GPT-3.5, 28.6% (34/119) for GPT-4, and 91.4% (95/104) for Bard (P<.001). Further analysis of nonhallucinated papers retrieved by GPT models revealed significant differences in identifying various criteria, such as randomized studies, participant criteria, and intervention criteria. The study also noted the geographical and open-access biases in the papers retrieved by the LLMs. CONCLUSIONS: Given their current performance, it is not recommended for LLMs to be deployed as the primary or exclusive tool for conducting systematic reviews. Any references generated by such models warrant thorough validation by researchers. The high occurrence of hallucinations in LLMs highlights the necessity for refining their training and functionality before confidently using them for rigorous academic purposes.

Autophagy markers are decreased in bone of osteoporotic patients: a monocentric comparative study.

BACKGROUND: Osteoporosis (OP) is a pathology characterized by bone fragility affecting 30% of postmenopausal women, mainly due to estrogen deprivation and increased oxidative stress. An autophagy involvement is suspected in OP pathogenesis but a definitive proof in humans remains to be obtained. METHODS: Postmenopausal women hospitalized for femoral neck fracture (OP group) or total hip replacement (Control group) were enrolled using very strict exclusion criteria. Western blot was used to analyze autophagy level. RESULTS: The protein expression level of the autophagosome marker LC3-II was significantly decreased in bone of OP patients relative to the control group. In addition, the protein expression of the hormonally upregulated neu-associated kinase (HUNK), which is upregulated by female hormones and promotes autophagy, was also significantly reduced in bone of the OP group. CONCLUSIONS: These results demonstrate for the first time that postmenopausal OP patients have a deficit in bone autophagy level and suggest that HUNK could be the factor linking estrogen loss and autophagy decline. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT03175874, 2/6/2017.

The impact of confinement on orthopaedic and trauma surgical activity.

INTRODUCTION: On the 16th of March 2020, in the face of a health emergency declared in France, the government imposed containment measures whose impact on orthopaedic and trauma surgery remains to be demonstrated. The hypothesis of this study was that confinement reduced orthopaedic and trauma surgical activity. The main objective was to assess orthopaedic and trauma surgical activity during confinement and to compare it to the activity outside confinement. MATERIALS AND METHODS: This was a retrospective, monocentric, observational and comparative study of a continuous cohort of patients included during the confinement period of March 16th to May 11th, 2020. This cohort was retrospectively compared to a group of patients over the same non-confinement period in the previous year, from March 16th to May 11th, 2019. The primary outcome measured was the incidence rate of surgical activity in 2020 versus 2019 over an identical period. The secondary outcome was the analysis of the trauma identified. RESULTS: The number of patients operated on was significantly reduced during confinement: 194 patients were included in 2020, i.e. an incidence of 57 per 100,000 inhabitants against 772 patients included in 2019, i.e. an incidence of 227 per 100,000 inhabitants; p<0.001. Planned orthopaedic surgery decreased from an incidence rate of 147 in 2019 to 5 in 2020 per 100,000 inhabitants (p<0.001). Trauma surgery decreased from an incidence rate of 80 in 2019 to 50 in 2020 per 100,000 inhabitants (p: NS). We found a significant increase in patients over 65years of age during confinement, 70% compared to 61% in 2019; p=0.04. The rate of femoral neck fractures was significantly increased during confinement, 48.5% compared to 39.3% in 2019; p=0.03. Degenerative surgery was significantly reduced during confinement (p<0.001). DISCUSSION: This study shows that the surgical activity of orthopaedics and trauma was significantly reduced by confinement, with a difference in incidence of 170 per 100,000 inhabitants, thus confirming the hypothesis of the authors. This decrease is due to both the cessation of planned orthopaedics and the 40% decrease in the number of trauma patients. During confinement, the percentage of patients over the age of 65 with a fracture increased significantly. CONCLUSION: Confinement had a significant impact on orthopaedic and trauma surgical activity. LEVEL OF EVIDENCE: III; comparative and retrospective.

The Arthroscopic Trillat Procedure Is a Valuable Treatment Option for Recurrent Anterior Instability in Young Athletes With Shoulder Hyperlaxity.

PURPOSE: The purpose of this study is to report the outcomes of the all-arthroscopic Trillat procedure, combined with capsular plication, for the treatment of recurrent anterior instability in young athletes with shoulder hyperlaxity (external rotation >90°). METHODS: We performed a retrospective evaluation of patients with recurrent anterior instability and shoulder hyperlaxity who underwent an arthroscopic Trillat between 2009 and 2019. Patients with concomitant rotator cuff lesions or voluntary or multidirectional instability were excluded. The osteotomized coracoid was fixed above the subscapularis with a cannulated screw or a suture button; a capsular plication was systematically associated. We followed patients with x-rays, computed tomography scans, and Subjective Shoulder Value, visual analog scale, Walch, Constant, and Rowe scores. Mean follow-up was 56 months (24-145). RESULTS: Twenty-eight consecutive patients (30 shoulders) with a mean age of 25 years were identified, and all met criteria. The main finding under arthroscopy was a "loose shoulder" with anteroinferior capsular redundancy and no or few (10%) labrum tears, glenoid erosion (13%), or Hill-Sachs lesions (10%). At last follow-up, 90% of the shoulders (27/30) were stable, and 79% (19/24) of the patients practicing sports returned to their preinjury activity level. The Walch-Duplay and Rowe scores improved from 54 (38-68) to 81 (4-100) and 55 (30-71) to 84 (45-100), respectively, P < .001. CONCLUSIONS: The arthroscopic Trillat is an effective procedure for the treatment of recurrent anterior instability in young athletes with shoulder hyperlaxity but no substantial humeral or glenoid bone loss, allowing return to overhead/contact sports. LEVEL OF EVIDENCE: Level IV, retrospective study.

The Arthroscopic Trillat Procedure Is a Valuable and Durable Treatment Option for Recurrent Anterior Instability Associated With Massive Irreparable Cuff Tears.

PURPOSE: The purpose of the present study is to report the mid- and long-term clinical and radiologic outcomes of the arthroscopic Trillat for the treatment of recurrent anterior instability in patients with chronic massive irreparable rotator cuff tears (MIRCTs) and maintained active shoulder motion where reverse shoulder arthroplasty (RSA) is not indicated. METHODS: Twenty-one consecutive patients (mean age 61 years) were identified and retrospectively reviewed. All patients had recurrent anterior dislocations and conserved active forward elevation and active external rotation. The MIRCTs included a retracted (stage 3) supraspinatus tear in 14%, a supra- and infraspinatus tear in 76.5%, and a 3-tendon tear in 14%. A closed-wedge osteotomy of the coracoid was performed, and the coracoid was fixed above the subscapularis with a cannulated screw (10 cases) or suture buttons (11 cases). We followed patients with x-rays and computed tomography scan at 6 months, along with Subjective Shoulder Value, visual analog scale, Walch, Constant, and Rowe scores. The mean clinical and radiographic follow-up was 58 months (24-145 months). RESULTS: Overall, 96% (20/21) of the patients had a stable and functional shoulder and were satisfied with the procedure; no patient lost active shoulder motion. The Subjective Shoulder Value increased from 44% (10%-75%) to 94% (80%-100%), P < .001. The Constant and Rowe scores improved from 60 (25-81) to 81 (66-96) and from 54 (35 to 65) to 92 (70-100), respectively (P < .001). Among the 13 patients practicing sports before surgery, 10 (77%) went back to sports. At last follow-up, only 1 patient was revised to RSA. CONCLUSIONS: The arthroscopic Trillat procedure is a valuable and durable option for the treatment of recurrent anterior dislocations in older patients with chronic MIRCTs and conserved active shoulder motion. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Comparative study of bilateral total hip arthroplasty in one or two stages.

INTRODUCTION: Bilateral total hip arthroplasty (Bi THA) for disabling bilateral hip osteoarthritis can be performed in one or two operative sessions. The objective of this study was to compare the complication rates of a group of patients who had bilateral THA in one operating session (Bi-1S THA) to a matched group of patients who had bilateral THA in two separate operating sessions (Bi-2S THA). MATERIALS AND METHODS: This retrospective case-control study compared 84 Bi-1S THA matched to 84 Bi-2S THA by age, gender, diagnosis, ASA score (1-2) and surgical approach. The minimum follow-up was 12 months. Complication rates, total blood loss, number of blood transfusion units, and functional outcomes were assessed. RESULTS: Twelve patients (14.3%) in the Bi-1S THA group had minor or major complications, compared to twenty-one (25%) in the Bi-2S THA group (p=0.08): there were fewer minor complications in the Bi-1S THA group and a similar rate of major complications amongst the two groups. Total blood loss estimated using the OSTHEO formula was significantly lower in patients operated on by Bi-1S THA (1853±753mL versus 2804±1012mL, p <0.0001). The number of blood transfusion units was similar between the groups (0.5±0.8 versus 0.3±1.4 respectively, p=0.55). No significant difference was found regarding the functional results. CONCLUSION: Under the conditions of this study, bilateral total hip arthroplasty in one operative session leads to fewer minor complications, and a similar rate of major complications, when compared to bilateral total hip arthroplasty in two separate sessions. This strategy can therefore be recommended for ASA 1 and 2 patients, under the age of 80 with disabling bilateral osteoarthritis. LEVEL OF EVIDENCE: III, retrospective comparative study.

The reliability of the Neer classification for proximal humerus fractures: a survey of orthopedic shoulder surgeons.

Background: The Neer classification is among the most widely used systems to describe proximal humerus fractures (PHF) despite the poor interobserver agreement. The purpose of this study was to verify whether or not blinded shoulder surgeons and trainees agree with the authors of articles published in the highest impact-factor orthopedic journals. Methods: All articles regarding PHF published between 2017 and 2019 in the top 10 orthopedic journals as rated by impact factor were searched. Articles were included if the authors used the Neer classification to describe at least 1 PHF in the figures. Figures were extracted without the legend, and X-rays ± computed tomography scan images were included when available. An international survey was conducted among 138 shoulder surgeons who were asked to record the Neer classification for each de-identified radiograph in the publications. The type of fracture mentioned in the legend of the published figure was considered as the gold standard. Results: Survey participants agreed with the published article authors in 55% of cases overall (range 6%-96%, n = 35). The most common response disagreed with the article authors in 13 cases (37%), underestimating the number of parts in 11 of 13 cases. The interobserver agreement between the 138 responders was fair (k = 0.296). There was an association between the percentage of concordant answers and greater experience (number of years of shoulder surgery practice) of the responders (P = .0023). The number of parts, the number or type of available imaging modalities, and the geographic origin of participants did not influence the agreement between responders and authors. Discussion: In more than one-third of cases, specialized shoulder surgeons disagree with article authors when interpreting the Neer classification of de-identified images of PHF in published manuscripts. Morphologic classification of PHF as the sole basis for treatment algorithms and surgical success should be scrutinized.

Same-day bilateral total knee replacement versus unilateral total knee replacement: A comparative study.

INTRODUCTION: Bilateral total knee arthroplasty (TKA) in a single session is rarely done in France, mainly due to the increased risk of perioperative and late complications. The primary objective of this study was to compare the complication rates of same-day bilateral TKA (TKA bilat) with that of unilateral TKA (TKA unilat). The hypothesis was bilateral TKA increases the rate of early and late complications in a group of selected patients (ASA 1 or 2, less than 80 years of age). MATERIAL AND METHODS: Retrospective comparative study of 91 bilat TKA and 182 unilat TKA cases operated on between 2009 and 2016 (1 bilat TKA paired with 2 controls). The patients were matched based on age, sex, indication and ASA score. The minimum follow-up was 2 years. Mortality along with early and late complications were documented. The secondary endpoints were implant survival, functional outcomes, and patient satisfaction. RESULTS: The early mortality rate was zero in both groups. The early complication rate was lower in the bilat TKA group (9%) than in the unilat TKA group (22%) (p<0.001). The late complications did not differ between groups. Implant survival at 5 years was 99% (95% CI=[95.6-99.7]) in the bilat TKA group and 97% (95% CI=[92.8-98.8]) in the unilat TKA group. The autologous blood transfusion rate was 33% in the bilat TKA group and 2.2% in the unilat TKA group (p<0.001). There was no difference between groups in the satisfaction rate or the KOOS and New IKS scores. A larger share of patients in the unilat TKA group (54%) said they had forgotten about their knee than in the bilat TKA group (43%) (p=0.036). DISCUSSION: There were few early complications in the bilat TKA group. There was no significant difference in the number of late complications, survival, functional scores, or patient satisfaction between the two groups. The transfusion rate was higher in the bilat TKA group, while the forgotten knee rate was higher in the unilat TKA group. CONCLUSION: Our hypothesis was not confirmed: in the context of this study, in patients who are ASA 1 or 2, and less than 80 years old, same-day bilateral TKA does not increase the complication rate relative to unilateral TKA. LEVEL OF EVIDENCE: III, comparative study of continuous paired cases.

Tensioning device increases coracoid bone block healing rates in arthroscopic Latarjet procedure with suture-button fixation.

BACKGROUND: There is growing interest in using suture buttons for coracoid fixation to avoid the complications associated with screws during the Latarjet procedure. However, achieving bone block healing is critical for successful shoulder stabilization and return to sport. The purpose of this study was to assess and compare the healing rates and positioning of the coracoid bone block fixed with cortical suture buttons that were either manually tensioned (using a knot pusher) or mechanically tensioned (using a tensioning device) during arthroscopic Latarjet procedures. METHODS: This prospective, nonrandomized, comparative study enrolled 69 consecutive patients (mean age, 27 years) who underwent an arthroscopic guided Latarjet procedure with suture-button fixation. Hand tensioning was performed in the first 34 shoulders, whereas the next 35 shoulders underwent mechanical tensioning. Twelve patients (17%) had a history of failed Bankart stabilization. The characteristics of the patients in each group in terms of age, sex, type of sport, bone loss, number of previous failed surgical procedures, smoking, and length of follow-up were comparable. Intraoperatively, the tensioning device was set at 100 N successively 3 times until complete immobilization of the bone block was confirmed, as assessed with a probe. The primary outcome measure was coracoid bone block union and position on computed tomography scan images at 6 months' follow-up. Secondary outcome measures included functional outcome scores, shoulder stability, return to sports, and complications at last follow-up. RESULTS: Overall, the rate of bone block healing was 74% (25 of 34 patients) in the hand-tensioning group and 94% (33 of 35 patients) in the mechanical tensioning group (P = .043). Smoking was an independent risk factor associated with nonunion (P < .001) in each group. Patient age, size of the preoperative glenoid bone defect (<20% or >20%), and a history of surgery were not found to have any influence. The tensioning modality did not affect the bone block position, which was subequatorial in 92% of the cases and flush with the glenoid rim in 92%. At a mean of 34 months of follow-up (range, 24-62 months), 96% of the patients (65 of 69) had a stable shoulder and 87% returned to sports. At final follow-up, no significant difference in clinical scores was noted between the groups; no neurologic or hardware complications were observed. CONCLUSION: Mechanical tensioning achieves significantly higher healing rates than hand tensioning during the arthroscopic Latarjet procedure with suture-button fixation. The use of a suture-tensioning device is a key step to the suture-button fixation technique during arthroscopic Latarjet procedures. By making the suture-button construct rigid, the tensioning device transforms the initially flexible suture into a "rigid fixation", similar to a bolt (or a rivet).

Arthroscopic Lateral Patellar Facetectomy and Lateral Release Can Be Recommended for Isolated Patellofemoral Osteoarthritis.

PURPOSE: To analyze the clinical outcomes and survival curve of arthroscopic lateral patellar facetectomy and lateral release for isolated patellofemoral osteoarthritis (PFOA). METHODS: All patients undergoing arthroscopic lateral patellar facetectomy and lateral release between January 2008 and January 2018 were evaluated retrospectively. The inclusion criteria were 1) diagnosis of isolated symptomatic lateral PFOA, 2) PFOA with kissing lesions (defined as a lesion on both the patella and trochlea, which were in direct contact, 3) arthroscopic lateral patellar facetectomy and lateral release, and 4) two-year minimum follow-up. Evaluation included preoperative and postoperative subjective International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS) scores, and visual analogue pain scale (VAS). The primary end point determining the survival curve was revision of lateral facetectomy. RESULTS: A retrospective analysis was conducted of 61 consecutive arthroscopic lateral patellar facetectomy and lateral release procedures, performed in 55 patients for a diagnosis of isolated PFOA. Five patients were lost to follow-up, leaving 56 knees (50 patients) available at a mean follow up of 7.5 years (range: 2-10). The cohort included 37 women and 13 men with a mean age of 59 years (range: 34-87). Nine patients (18%) underwent revision surgery: six total knee replacements (TKR), two high tibial osteotomies, and one revision arthroscopic lateral patellar facetectomy. The mean time from arthroscopic facetectomy to TKR was 51 months (range: 10-114). The survival curve rate was 86% at 7.5 years. Both KOOS and IKDC scores improved significantly. These results are confirmed by an analysis of MCID. The mean VAS decreased from 6.98 ± 1.2 preoperatively to 2.06 ± 1.6 at the last follow-up (ΔCI95% = [-5.6; -4.4]; P = .0001). CONCLUSION: Arthroscopic lateral patellar facetectomy and lateral release for isolated PFOA demonstrates sustained significant improvement in knee clinical outcome scores and pain with a low rate of complications and revision surgery at mid-term follow-up. This operation can be recommended in cases of symptomatic isolated PFOA. LEVEL OF EVIDENCE: IV, case series.

High tibial flexion osteotomy for symptomatic ligamentous genu recurvatum.

INTRODUCTION: Symptomatic Ligamentous Genu Recurvatum (SLGR) is characterized by an asymmetrical hyperextension of the knee associated with pain and a feeling of instability occurring even during walking. The ligamentous origin of the recurvatum is linked to a sprain in hyperextension responsible for a rupture of the posterior structures that may be associated or not with a rupture of the cruciate ligaments. HYPOTHESIS: Tibial Flexion Osteotomy (TFO) allows control of a SLGR without rupture of the cruciate ligaments secondary to a sprain in hyperextension. MATERIAL AND METHODS: Ten patients (12 knees) including 8 women, aged 30.8 years on average (16-52) with asymmetrical SLGR secondary to a hyperextension sprain without rupture of the cruciate ligaments underwent TFO. An anterior tibial tuberosity (ATT) osteotomy was performed with an associated trans-tuberosity anterior opening wedge osteotomy of the tibia in the sagittal plane. The ATT was secured by two compression screws with lowering of the patella culminating from the opening wedge procedure. The genu recurvatum angle (GRA), tibial slope (TSangle) and patellar height according to the Caton-Deschamps index (CDI) were established. All patients were assessed using the IKDC and Lecuire scores (anatomical and functional scores). RESULTS: The average follow-up was 4.2 years (12-106 months). The GR angle was 7.3±3.2° preoperatively versus 22.7±4.1° postoperatively (p<0.01). The TS angle averaged 95.5±2.3° preoperatively versus 104.0±3.7° postoperatively (p<0.01). The CDI decreased from 1.17±0.21 preoperatively to 0.83±0.11 postoperatively (p<0.01). The IKDC and Lecuire scores improved. CONCLUSION: Trans-tuberosity high tibial flexion osteotomy is an effective strategy in cases of Symptomatic Ligamentous Genu Recurvatum without rupture of the cruciate ligaments secondary to a hyperextension sprain, and with constitutional hyperlaxity. This procedure allows significant clinical improvement and correction of the recurvatum deformity in the medium term. LEVEL OF EVIDENCE: IV, retrospective descriptive study.

Outpatient shoulder prostheses: Feasibility, acceptance and safety.

INTRODUCTION: Outpatient surgery in France is defined by the national authority for health (HAS) as a scheduled surgery enabling same-day discharge without any increased risk to the patient. With the advent of enhanced recovery after surgery, outpatient lower limb arthroplasty has become a common procedure. However, only 1.1% of knee arthroplasties in France were performed on an outpatient basis in 2017. OBJECTIVES: 1) assess early morbidity and mortality after outpatient shoulder arthroplasties to validate eligibility and safety criteria; and 2) assess patient acceptance of outpatient surgery. METHODS: A single-center study with the following inclusion criteria: primary shoulder arthroplasty, American Society of Anesthesiology (ASA) score I or II, no cognitive impairment, and no coronary artery or thromboembolic diseases. Analgesia was provided by bupivacaine via a peripheral nerve catheter in the first 72 hours followed by oral analgesics. Patients were discharged if the post-anesthetic discharge scoring system (PADSS) was>9/10 and the visual analog scale (VAS) was<5/10. Postoperative telephone interviews were carried out on D1, D2 and D3 to assess pain with the numerical rating scale and to collect data on their analgesic consumption. All patients were seen by an independent observer at one and six months for a clinical and radiologic follow-up and at 90 days during a consultation with the senior surgeon. The primary endpoint was the 90-day morbidity and mortality rate (readmissions, rehospitalizations, and minor and major complications). A satisfaction questionnaire was collected at one and six months. RESULTS: Thirty-six patients were offered an outpatient shoulder arthroplasty between February 2016 and February 2018: 12 (33%) refused with no valid reasons and 24 patients agreed to the procedure (seven hemiarthroplasties, nine anatomic shoulder arthroplasties and eight reverse shoulder arthroplasties). The mean age at surgery was 70 years (55-82), mean body mass index (BMI) was 26 (21-32) and 14 patients were ASA II (66%). Three patients (12%) refused same-day discharge despite a PADSS score>9/10 and adequate pain management. Two patients (8%) were not discharged home on the same day as the surgery for medical reasons (one for pain and one for high blood pressure). No readmissions or complications were reported for the 19 outpatient arthroplasties. None of the outpatients used opioids. All patients were satisfied with their functional outcome, 84% were satisfied with the outpatient management and 17% felt they were insufficiently monitored and regretted that they were not hospitalized. CONCLUSIONS: 1) outpatient shoulder arthroplasty can be safely proposed to selected patients with low comorbidities, regardless of their age and type of implant; 2) the acceptance rate for outpatient shoulder arthroplasty remained low among our patient population. These results should incite us to better educate patients about outpatient surgery. LEVEL OF EVIDENCE: IV; retrospective study.

SECEC Grammont Award 2017: the prejudicial effect of greater tuberosity osteotomy or excision in reverse shoulder arthroplasty for fracture sequelae.

HYPOTHESIS: The aim was to evaluate risk factors for complications, revision, and mid- to long-term outcomes after reverse shoulder arthroplasty (RSA) implanted for proximal humeral fracture sequelae (PHFS). METHODS: The radiographs of 98 patients (mean age, 68 years) who underwent RSA for the treatment of PHFS were reviewed at a minimum 5-year follow-up. PHFS were divided into 4 types according to the Boileau classification: type 1 (46 cases), type 2 (6 cases), type 3 (12 cases), and type 4 (34 cases). The tuberosities underwent osteotomy in 28 cases and excision in 12 (all type 3 or 4 PHFS). The mean follow-up period was 8.4 years (range, 5-14 years). RESULTS: The functional results and rate of RSA survival without revision (85% vs. 100% at 10 years, P = .007) were significantly lower for types 3 and 4 vs. types 1 and 2. Overall, our findings showed that RSA for PHFS is not the panacea that surgeons once believed: At a mean follow-up of 8.5 years (range, 5-14 years), 59% of the patients in our series had fair or poor results. Patients who underwent tuberosity osteotomy or excision had lower functional results (adjusted Constant score, 69% vs. 88%; P < .001), more postoperative complications (32% vs. 9%, P = .003), and a higher revision rate (15% vs. 2%, P = .017). Patients who underwent tuberosity osteotomy or excision at the time of RSA were at risk of postoperative prosthetic instability and humeral stem loosening. The absence of the greater tuberosity at last radiographic follow-up was predictive of higher rates of complications and revisions, as well as a poorer final outcome. Previous fracture fixation was associated with a higher rate of complete tuberosity resorption (56% vs. 33%, P = .026) and with higher rates of postoperative complications (27% vs. 13%, P = .099) and reinterventions (17% vs. 2%, P = .018). CONCLUSION: The functional results and rates of complications and revision depend on the type of fracture sequelae and tuberosity management. Patients with more severe (type 3 and 4) fracture sequelae who undergo tuberosity osteotomy or excision are at risk of having a poorer functional result and higher rates of complications and revision with lower survival. Previous fracture fixation is also a prejudicial factor.

Sacroiliac joint syndrome after lumbosacral fusion.

INTRODUCTION: One-third of low back pain cases are due to the sacroiliac (SI) joint. The incidence increases after lumbosacral fusion. A positive Fortin Finger Test points to the SI joint being the origin of the pain; however, clinical examination and imaging are not specific and minimally contributory. The gold standard is a test injection of local anesthetic. More than 70% reduction in pain after this injection confirms the SI joint is the cause of the pain. The aim of this study was to evaluate the decrease in pain on a Numerical Rating Scale (NRS) after intra-articular injection into the SI joint. We hypothesised that intra-articular SI injection will significantly reduce SI pain after lumbosacral fusion. METHODS: All patients with pain (NRS>7/10) suspected of being caused by SI joint syndrome 1 year after lumbosacral fusion with positive Fortin test were included. Patients with lumbar or hip pathologies or inflammatory disease of the SI joint were excluded. Each patient underwent a 2D-guided injection of local anesthetic into the SI joint. If this failed, a second 2D-guided injection was done; if this also failed, a third 3D-guided injection was done. Reduction of pain on the NRS by>70% in the first 2 days after the injection confirmed the diagnosis. Whether the injection was intra-articular or not, it was recorded. Ninety-four patients with a mean age of 57 years were included, of which 70% were women. RESULTS: Of the 94 patients, 85 had less pain (90%) after one of the three injections. The mean NRS was 8.6/10 (7-10) before the injection and 1.7/10 after the injection (0-3) (p=0.0001). Of the 146 2D-guided injections, 41% were effective and 61% were intra-articular. Of the 34 3D-guided injections, 73% were effective and 100% were intra-articular. DISCUSSION: This study found a significant decrease in SI joint-related pain after intra-articular injection into the SI joint in patients who still had pain after lumbosacral fusion. If this injection is non-contributive when CT-guided under local anesthesia, it can be repeated under general anesthesia with 3D O-arm guidance. This diagnostic strategy allowed us to confirm that pain originates in the SI joint after lumbosacral fusion in 9 of 10 patients. CONCLUSION: If the first two CT-guided SI joint injections fail, 3D surgical navigation is an alternative means of doing the injection that helps to significantly reduce SI joint-related pain after lumbosacral fusion. LEVEL OF EVIDENCE: IV, retrospective study.

A Population Pharmacokinetic Analysis of Continuous Infusion of Cloxacillin during Staphylococcus aureus Bone and Joint Infections.

Intravenous administration of antibiotics is recommended during the early phase of methicillin-susceptible S. aureus (MSSA) bone and joint infection (BJI). We sought to compare the plasma concentrations of cloxacillin administered alternately by continuous and intermittent infusion (CI and ItI) in patients with MSSA BJI. In this prospective crossover trial, patients were randomly assigned to receive either 3 days of CI (two 75-mg/kg 12-h cloxacillin infusions per day) and then 3 days of ItI (four 37.5-mg/kg 1-h cloxacillin infusions per day) or vice versa. The drug concentration measurement was performed on day 3 of each type of administration at 1, 6, and 11 h and at 1, 2, 3, 4, and 6 h after the beginning of CI and ItI, respectively. We used the nonparametric algorithm NPAG to estimate population pharmacokinetic (PK) parameters. The final model was used to perform pharmacokinetic/pharmacodynamic (PK/PD) simulations and calculate the probabilities of target attainment (PTA) for several ItI and CI dosing regimens. We considered two PK/PD targets of time spent above the MIC for free cloxacillin concentrations (fT>MIC): 50 and 100%. Eighty-four concentrations from 11 patients were analyzed. A two-compartment model adequately described the data. ItI with q6h regimens and short 1-h infusions of 2,000 or 3,000 mg were associated with low PTA, even for the low target (50% fT>MIC) while 3-h infusions and continuous infusions (6 to 12 g/day) were associated with a PTA of >90% for an MIC up to 0.5 mg/liter. These results support the use of prolonged or continuous infusion of cloxacillin in patients with BJI.

One-session bilateral total knee replacement: Late complications and survivorship.

INTRODUCTION: The early morbidity and mortality of one-session bilateral total knee arthroplasty (1-session BTKA) has been reported in the medical literature. However, there is less information about the long-term clinical impact of this strategy. The aim of this study was to report on the late complications (>90 days), clinical outcomes (KOOS and new KSS) along with the survivorship of 1-session BTKA. We hypothesised that 1-session BTKA will cause few late complications and that the implant survival will meet the criteria of the National Institute for Health and Clinical Excellence (NICE). METHODS: This single-centre retrospective study analysed a cohort of ASA-1 and ASA-2 patients who underwent 1-session BTKR over an 8-year period (2009 to 2016). The cohort consisted of 116 patients (66% women, 34% men) with mean age at inclusion of 69 years (32-85 years); 22% of patients were ASA-1 and 78% were ASA-2. The implant-related, infection-related or mechanical complications that occurred more than 90 days after the operation, the clinical outcomes (KOOS and New KSS) and radiological outcomes, along with the survivorship were determined during the scheduled follow-up visits at 3 months, 6 months and 1 year postoperative and during the long-term follow-up or during an intercurrent event. RESULTS: No patients were lost to follow-up. Fifteen complications occurred (6.5%): four infections, four patellar problems (three cases of clunk syndrome and one of patellofemoral pain), four cases of stiffness, two of unexplained pain and one femoral periprosthetic fracture. Eight patients were readmitted to the hospital (7%); seven were reoperated (3%) and two implants were revised (1%). The functional outcomes (KOOS and New KSS) were significantly improved and 87% of patients were satisfied or very satisfied with this procedure. At a mean follow-up of 5 years, the survivorship estimated using the Kaplan-Meier method was 98.4% (95% CI: 0.933-0.996). CONCLUSION: Performing 1-session BTKA is a reliable strategy as it produces a low rate of late complications, excellent medium-term functional outcomes and survivorship that meets NICE criteria, thus confirming our hypothesis. LEVEL OF EVIDENCE: IV, retrospective case series.