Subscapularis atrophy and function after arthroscopic Trillat procedure.

INTRODUCTION: Several studies have reported a strength deficit in internal rotation (IR) following a Latarjet procedure, which can persist for months or even years. The arthroscopic Trillat procedure does not require splitting the subscapularis muscle, potentially making it less damaging. HYPOTHESIS: The arthroscopic Trillat procedure does not cause any atrophy or strength deficit in the subscapularis muscle. METHODS: This was a single center, retrospective study of patients treated between 2013 and 2021. Included were patients who had chronic anterior shoulder instability with an indication for surgical stabilization using an arthroscopic Trillat procedure and who underwent a CT scan before surgery and a second one at 6 months postoperative. The following morphological parameters were measured on all the rotator cuff muscles: cross-sectional area (CSA), thickness and fatty infiltration using the mean muscle attenuation (MMA) measurement. Isokinetic tests were done 1 year post-surgery. RESULTS: One hundred seventeen patients underwent arthroscopic Trillat surgery between 2013 and 2021; 58 were included, 30 were analyzed and 17 patients underwent isokinetic testing. The CSA of the subscapularis was significantly smaller by 5.3% (17.0 vs. 16.1; p = 0.03). None of the other rotator cuff muscles had a smaller CSA. The MMA of the subscapularis increased significantly while the MMA of the external rotators decreased postoperatively. No strength deficit was found at 1 year postoperative in the internal and external rotators. DISCUSSION: The arthroscopic Trillat procedure produces minor atrophy of the subscapularis muscle at 6 months, with no strength deficit at 1 year postoperative. Several studies have reported a deficit in internal rotation strength after a Latarjet procedure, ranging from 6% to 19% depending on the study. LEVEL OF EVIDENCE: IV.

Functional outcomes and center of rotation restoration in total hip arthroplasty after acetabular fracture: A review of 367 hips.

BACKGROUND: Total hip arthroplasty (THA) after acetabular fracture is typically performed months or years later for posttraumatic arthritis after initial conservative treatment. But THA can be performed earlier after open reduction and internal fixation (ORIF) of the fracture. The aim of this study was to determine which strategy is best. The primary outcome measure was the radiological restoration of the hip's center of rotation (COR). The secondary outcome measures were the incidence of complications and the hip's functional scores. MATERIALS AND METHODS: A multicenter cohort was analyzed by splitting patients into three groups: group A (THA within 3weeks of fracture); group B (THA deferred after early ORIF); group C (THA more than 3weeks after fracture, without ORIF). Group B was separated into two subgroups: B- (THA less than 1year after ORIF) and B+ (THA more than 1year after ORIF). The demographics, surgical techniques, COR superior and lateral migration coefficient and functional scores (HHS, HOOS-PS and FJS) were recorded. The functional scores were gathered using PROMs. RESULTS: In all, 367 patients were included: 108 in group A, 69 in group B-, 113 in group B+ and 77 in group C. The mean follow-up was 5.8years [3.4 months-35years]. The mean age of the patients was 69.2years [SD 15; 26-101], 52years [SD 16; 19-83], 49years [SD 16; 16-85] and 58.1years [SD 17; 13-94], respectively (p<0.01). The mean ASA score was 2.13 [SD 0.70], 1.84 [SD 0.65], 1.67 [SD 0.63] and 1.79 [SD 0.60], respectively (p<0.01). A complex Letournel fracture was present in 63 patients (61%), 46 patients (71%), 48 patients (49%) and 38 patients (62%), respectively (p<0.01). A reinforcement cage was implanted in 38 patients (69%), 16 patients (62%), 5 patients (12%) and 19 patients (66%), respectively (p<0.01). Cement was used in 45 patients (45%), 23 patients (35%), 19 patients (18%) and 21 patients (32%), respectively (p<0.01). A graft was needed in 46 patients (46%), 35 patients (53%), 17 patients (16%) and 21 patients (48%), respectively (p<0.01). Posterior ORIF was done in 40 patients (46%), 32 patients (55%), 64 patients (61%) and 9 patients (82%), respectively (p<0.01). The COR lateral migration coefficient was significantly higher in group C with a mean of +0.17 (SD 0.85) [-0.27 to +6] compared to the other groups (p=0.02). The COR superior migration coefficient was comparable between groups, with a mean of +0.77 (SD 2.26) [-0.99 to 27], p>0.05. There were complications in 10 patients (9.2%), 6 patients (8.7%), 6 patients (5.3%) and 3 patients (3.9%), respectively, with no significant difference between groups. The PROMs were completed by 51% of patients. At the final review, the mean HHS was 79.2 (SD 21.8) and the mean HOOS-PS was 77.7 (SD 20.1) in the entire cohort, p>0.05. The mean FJS by group was 55.9 (30.2), 47.7 (SD 36.4), 66.1 (SD 30.4) and 65.8 (SD 30.3), respectively (p=0.02). DISCUSSION AND CONCLUSION: The B strategy (B+) yielded good outcomes in terms of function and COR restoration. When using this strategy, anterior ORIF preserves the native hip for a subsequent THA through a posterior approach. Strategy C also produces good functional outcomes but shifts the COR laterally. This study confirms the poor results of strategy A in previous publications. When the prognosis is poor, immediate mobilization after anterior ORIF followed by THA within 1year appears to be a good strategy (group B-). LEVEL OF EVIDENCE: IV, observational study.

Shoulder Stabilization Technique Using the Medial Glenohumeral Ligament in Patients With the Buford Complex.

The Buford complex is an anatomic variation defined as the association of a cordlike middle glenohumeral ligament (MGHL) and an absent anterosuperior labrum. It can be challenging to properly identify on preoperative imaging and remains mostly an arthroscopic finding. It may, however, lead to problematic situations when encountered during an arthroscopic soft-tissue stabilization procedure, as the treatment of choice in such cases is a bone block. Moreover, reattaching the MGHL to the anterior border of the glenoid rim has traditionally not been recommended because it theoretically leads to severe restriction in external rotation. This technical note describes arthroscopic stabilization for anterior traumatic glenohumeral instability associated with the Buford complex. The cordlike MGHL is used to reconstruct a neo-labrum, associated with an anteroinferior glenohumeral ligament plication. Glenohumeral stabilization using the cordlike MGHL of the Buford complex may be an efficient alternative to a bone block procedure.

Does combined anterior cruciate ligament and anterolateral ligament reconstruction improve return to sport?

PURPOSE: Only 50-65% of patients return to their previous sporting level after ACL rupture. The literature reports a reduced rate of graft rupture when an anterolateral ligament reconstruction (ALLR) is associated with ACL reconstruction. ACL reconstruction combined with ALL allows a higher return to sport at pre-injury level than isolated reconstruction in patients playing pivot-contact sports. METHODS: A retrospective, single-centre study between 2012 and 2020 comparing reconstruction by hamstring tendon technique, isolated ACLR vs ACL with ALLR. An isokinetic test was performed at 6 months post-operatively and patients were re-contacted at a minimum 2-year follow-up to assess their level and delay to return to sport, graft rupture rate and functional evaluation. RESULTS: 83 patients were included, 42 in ACLR group and 41 in ACL + ALLR group. Four patients were lost to follow-up and 79 patients were analysed. No significant difference was found on the level of return to sport (28.2% vs. 42.5%; p = 0.18), return to competition (43% vs. 60%; p = 0.18), delay to sports return, isokinetic assessment, functional scores, but a significant difference was found on graft rupture rate in favour of ALLR (12.8% vs. 0%; p = 0.02). CONCLUSION: In our study, the addition of an ALL to ACL reconstruction did not improve pre-injury sports recovery or return to competition. STUDY DESIGN: Cohort study, level of evidence 4.

Radiological signs of femoroacetabular impingement are linked to pelvic version in asymptomatic subjects.

INTRODUCTION: With the recent interest in hip-spine relationship, the link between femoroacetabular impingement (FAI) and the lumbar-pelvic-femoral complex (LPFC) appears decisive. The objectives of this study were (1) to compare the pelvic version, as well as (2) all the parameters of the LPFC between two populations of healthy subjects, comparing those with radiological signs of FAI to those without and finally, (3) to evaluate the LPFC parameters according to the type of FAI. HYPOTHESIS: Asymptomatic subjects with radiological signs of FAI had superior pelvic anteversion. MATERIALS AND METHOD: This retrospective study was based on a prospective cohort of 118 voluntary asymptomatic patients including 62 men (52.5%) with a mean age of 25.6 years±4.4 (19-39). The following parameters: pelvic version (PV), pelvic incidence (PI), lumbar lordosis (LL), sacral slope (SS), hip flexion, intrinsic (IER) and extrinsic (EER) extension reserve were measured using EOS imaging™ in the reference standing position and the lunge position. The radiological signs of FAI (cam, pincer, mixed) were identified on these acquisitions then separated into 2 groups. The first was the group presenting with one or more images of FAI (FAI+) and the second group with no images of FAI (FAI-). RESULTS: There were 143 hips in the FAI+ group compared to 93 hips in the FAI- group. There were 36.4% cams and 45% pincers. With an average of 9.08°±7.81 (-11.0; 27.0) versus 12.33°±8.94 (-5.0; 55.0), the PV was significantly lower (p=0.022) in the FAI+ group compared to the FAI- group. A post-hoc power analysis on the primary outcome (PV) confirmed sufficient power (1-ß=0.809). Compared to the FAI- group, the cam group presented a significantly lower IER and EER (respectively p=0.014 and p=0.047). The comparative analysis between the FAI- and pincer groups found a significant difference in PI (p=0.001), PV (p<0.001), IER (p=0.017) and hip flexion (p<0.001), SS in lunge position (p=0.031) and EER (p=0.039). CONCLUSION: Asymptomatic subjects with radiographic signs of FAI present with weak pelvic version when standing. This pelvic hyper-anteversion is mainly found in the event of a radiological pincer sign. LEVEL OF EVIDENCE: III, retrospective comparative study.

The influence of the sacral slope on pelvic kinematics and clinical manifestations in femoroacetabular impingement.

INTRODUCTION: The radiological study of the sagittal alignment of the spine in static and dynamic positions has allowed a better understanding of the clinical results of total hip prostheses. According to the Roussouly classification, the sacral slope in a standing position characterizes the patient with a stiff spine (less than 35̊) or a flexible spine (greater than 35̊). The objectives of this study were to compare, in a population of patients operated on for femoroacetabular impingement (FAI), firstly, the kinematics of the lumbar-pelvic-femoral complex and secondly, the clinical presentation depending on whether the spine is stiff or flexible. HYPOTHESIS: Patients with stiff spines (SS<35̊) were "hip users" and had less ability to compensate for their hip pathology. MATERIAL AND METHOD: This prospective and comparative multicenter study was conducted with patients operated on arthroscopically for FAI between 2020 and 2021. All patients included received preoperative EOS imaging of the lower limbs and spine, in standing and seated positions. The following parameters were measured: pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), and sacral slope (SS), as well as dynamic parameters (intrinsic mobility of the hip: delta standing/sitting femoral sacral angle, and of the pelvis: delta standing/sitting sacral slope). The functional result was evaluated at 1 year. RESULTS: In the stiff spine group, 62 patients were included versus 138 in the flexible spine group. The mean follow-up was 15.1±3.3 months (9.2-24.3). Nineteen patients were lost to follow-up and there were 2 revisions for iterative arthroscopy. Intrinsic pelvic mobility and intrinsic hip mobility were 16̊±13.5 (-12; 44) and 44.5̊±28.5 (-9; 99) respectively in the stiff spine group. In the flexible spine group, these same measurements were 22̊±11.5 (-30; 45) and 29.7̊±22.7 (-33; 82) respectively. In the stiff spine group, the symptoms occurred at a significantly younger age: 28.3 years±9.5 (18-51) versus 31 years±8 (18-54) (p=0.017). DISCUSSION: The sacral slope is a determining factor in the kinematics of impingement and the appearance of symptoms. The sacral slope helps define the concept of a "hip user" in symptomatic FAI. LEVEL OF EVIDENCE: IV.

Labral tears in hip dysplasia and femoroacetabular impingement: A systematic review.

INTRODUCTION: Hip dysplasia and femoroacetabular impingement are pathologies whose impact on the function and survival of the hip joint is no longer debated. Labral tears may be present and impact the prognosis of the causal pathology. Labral tear management lacks consensus and still raises several questions, thus we conducted a systematic analysis to clarify: 1) What is its prevalence in hip dysplasia and femoroacetabular impingement? 2) Does it modify the symptomatology of the causal pathology? 3) Is its repair better than resection or abstention? MATERIAL AND METHOD: A systematic literature review was carried out following the PRISMA guidelines, using the Medline and Embase databases and including all articles in French or English, written until June 2022 referring to labral tears in hip dysplasia and femoroacetabular impingement. The articles were analyzed by 2 surgeons in order to select them according to a predefined algorithm. 1) Articles were selected by title from the search results. 2) A selection based on the abstract was then made. 3) A final selection was made upon complete reading. 4) In the event of a discrepancy during the selection, a third co-author was contacted for a final decision. 5) Data extraction was then carried out by the two readers using a preformatted sheet. RESULTS: Of the 1177 articles identified, 43 articles were kept for the final analysis. The prevalence of labral tears was on average 78.80±4.7% [17 to 100%] in dysplasia and 93.8±16.8% [33% to 100%] in impingement. The review did not reveal any symptomatology specific to the labral tear. In dysplasia, 5 comparative studies were analyzed. A single study on shelf arthroplasties demonstrated the negative impact of a labral tear in the event of resection on survival compared to no tear (83% versus 15.2% (p=0.048)). Regarding impingements, 8 comparative studies were analyzed. At 7 years of follow-up, only one study found a significant and clinically relevant functional gain in terms of MCID (minimal clinically important difference) for labral repair compared to debridement on the mHHS score (p=0.008), SF-12 score (p=0.012), and pain scale (p=0.002). One study showed superiority of repair over labral debridement in terms of 10-year survival (78% 95% CI [64-92%] vs 46% 95% CI [26-66%] (p=0.009)). DISCUSSION: The literature analysis was heterogeneous with a few comparative studies and predominantly short periods of follow-up. Understanding labral pathology and its impact requires differentiating between the different tear categories and proposing treatment to restore or preserve the biomechanical properties of the joint. LEVEL OF EVIDENCE: IV, Systematic Review of Level 1-4 Evidence.

Functional recovery after total hip/knee replacement in obese people: A systematic review.

OBJECTIVE: Several studies have investigated the influence of body mass index (BMI) on functional gain after total hip replacement (THR) or total knee replacement (TKR) in osteoarthritis, with contradictory results. This systematic literature review was conducted to ascertain whether obesity affects functional recovery after THR or TKR in the short (<1 year), medium (<3 years) and long term (>3 years). METHODS: The study was registered with PROSPERO and conducted according to the PRISMA guidelines. A systematic literature search was conducted across Medline and EMBASE databases for articles published between 1980 and 2020 that investigated patient-reported measures of functional recovery after THR and TKR in participants with osteoarthritis and obesity (defined as BMI ≥30 kg/m2). RESULTS: Twenty-six articles reporting on 68,840 persons (34,955 for THR and 33,885 for TKR) were included in the final analysis: 5 case-control studies, 21 cohort studies (9 for THR only, 10 for TKR only and 2 for both). The average minimum follow-up was 36.4 months, ranging from 6 weeks to 10 years. Most studies found significantly lower pre-operative patient-reported functional scores for participants with obesity. After THR, there was a small difference in functional recovery in favor of those without obesity in the short term (<6 months), but the difference remained below the minimal clinically important difference (MCID) threshold and disappeared in the medium and long term. After TKR, functional recovery was better for those with obesity than those without in the first year, similar until the third year, and then decreased thereafter. CONCLUSIONS: Although there is a paucity of high-quality evidence, our findings show substantial functional gains in people with obesity after total joint replacement. Functional recovery after THR or TKR does not significantly differ, or only slightly differs, between those with and without obesity, and the difference in functional gain is not clinically important. PROSPERO NUMBER: CRD42018112919.

Experimental study of risk of medial hinge fracture during distal femoral varus osteotomy.

INTRODUCTION: Lateral opening wedge distal femoral osteotomy (LOWDFO) is indicated for isolated lateral osteoarthritis in the valgus morphotype. Medial hinge fracture is a factor for poor prognosis. The present study had two aims: (1) to assess the impact of a temporary K-wire on hinge fracture risk; and (2) to assess the impact of LOWDFO opening speed. HYPOTHESIS: The main study hypothesis was that a temporary hinge K-wire reduces hinge fracture risk. The second hypothesis was that faster opening speed increases fracture risk. MATERIAL AND METHOD: Twenty femurs were produced by 3D printing from a CT database, reproducing LOWDFO anatomy. The ABS® polymer showed the same breaking-point behavior as human bone. Ten specimens were included in the "K-wire" group (KW+) and 10 in the "No K-wire" group (KW-). To determine high and low speed, a motion-capture glove was used by 2 operators, providing 3D modeling of the surgeon's hand. High speed was defined as 152mm/min and low speed as 38mm/min. The KW+ and KW- groups were subdivided into high- and low-speed subgroups (HS, LS) of 5 each. Compression tests were conducted using an Instron® mechanical test machine up to hinge fracture. The main endpoint was maximum breaking-point force (N); the secondary endpoints were maximum displacement (mm) and maximum speed (min) at breaking point. RESULTS: The K-wire significantly increased maximum breaking-point force (LS, 143.08N vs. 93.71N, p<0.01; and HS, 186.98N vs. 95.22N, p<0.01), but not maximum displacement (LS, 26.17mm vs. 24.11mm, p=0.31; and HS 26.18mm vs. 23.66mm, p=0.14) or maximum time (LS, 27.07s vs. 24.94s, p=0.31; and HS, 5.24s vs. 4.73s, p=0.14). Speed did not affect maximum force (KW+, 143.08N vs. 186.98N, p=0.06; and KW-, 93.71N vs. 95.22N, p=0.42) or maximum displacement (KW+, 26.17mm vs. 26.18mm, p=1; and KW-, 24.11mm vs. 23.66mm, p=0.69). Only maximum time was greater at low speed (KW+, 27.07s vs. 5.24s, p>0.01; and KW-, 24.94s vs. 4.73s, p<0.01), which is obvious for constant distance. DISCUSSION: The first study hypothesis was confirmed, with significantly lower hinge fracture risk with the K-wire, independently of opening speed. The second hypothesis was not confirmed. The study was performed under strict experimental conditions, unprecedented to our knowledge in the literature. However, complementary clinical studies are needed to confirm the present findings. LEVEL OF EVIDENCE: IV, experimental study.

Slope-decreasing anterior closing wedge proximal tibial osteotomies using the freehand technique are accurate to within 2̊.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction requires a detailed analysis of the posterior tibial slope (PTS) as excessive values may cause the reconstruction to fail and require a slope-decreasing anterior closing wedge tibial osteotomy combined with revision of the failed ACL reconstruction. The main purpose of this study was to assess the accuracy of correction after slope-decreasing anterior closing wedge tibial osteotomy in cases of chronic anterior instability caused by ACL rerupture. MATERIALS AND METHODS: This single-center retrospective study included 19 patients (20 knees) operated on by slope-decreasing anterior closing wedge tibial osteotomy combined with a second revision ACL reconstruction. The mean age was 22.4±3.3 years and the mean follow-up was 12.7±4.4 months. The preoperative planning was based on lateral calibrated X-rays of the entire tibia. The height of the closing wedge, which corresponded to the base of the osteotomy, was measured in millimeters. The procedure was performed using the freehand technique. The accuracy of the correction was defined as the difference between the desired preoperative PTS and the postoperative PTS achieved. An inter- and intraobserver analysis was performed. RESULTS: The mean preoperative PTS was 13.9±2̊ and the mean postoperative PTS was 4.0±1.7̊. The mean PTS correction was 10.1±2.1̊ with a planned target of 5.4±1.8̊. The accuracy obtained between the planned target and the postoperative corrections was 1.7±1.1̊. The regression analysis showed that the accuracy of the PTS correction was not influenced by the patient's age, BMI, excessive preoperative PTS, or degree of correction achieved (p>0.05). CONCLUSION: Slope-decreasing anterior closing wedge tibial osteotomies performed using the freehand technique for ACL graft rerupture can correct an excessive PTS within 2̊ of the planned slope correction. This accuracy is not determined by demographic factors, excessive preoperative PTS or degree of correction achieved. LEVEL OF EVIDENCE: IV; retrospective cohort study.

Experimental investigation of the risk of lateral cortex fracture during valgus tibial osteotomy.

BACKGROUND: Valgus-producing medial opening-wedge proximal tibial osteotomies (V-MOW-PTO) are used to treat isolated medial-compartment knee osteoarthritis in patients with varus malalignment. A fracture of the lateral cortical hinge is a risk factor for poor outcomes. Implantation of a protective K-wire has been suggested to prevent this complication. The primary objective of this bench study was to assess the ability of a protective K-wire to prevent lateral cortical fractures. The secondary objective was to evaluate the influence of the opening speed on fracture risk during the osteotomy. HYPOTHESIS: The primary hypothesis was that a protective K-wire decreased the risk of hinge fracture. The secondary hypothesis was that this risk was greater when the opening speed was high. MATERIALS AND METHODS: We performed an experimental study of 20 simulated thermoplastic-polymer (ABS) tibias obtained by 3D printing to assess the effects of wedge-opening speed (high vs. low) and presence of a protective K-wire (yes vs. no). The opening rates were determined in a preliminary study of Sawbone® specimens opened using a distractor. The opening rate was measured using an accelerometer via a motion-capture glove. After assessing several high and low opening speeds, we selected 38mm/min and 152mm/min for the study. We divided the 20 ABS specimens into four groups of five each: high speed and K-wire, low speed and K-wire, high speed and no K-wire, and low speed and no K-wire. The force was applied using an Instron™ testing machine until construct failure. The primary outcome measure was the load at failure (N) and the secondary outcome measures were the displacement (mm) and maximum time to failure (s). RESULTS: At both speeds, values were significantly higher with vs. without a K-wire for load to failure (low: 253.3N vs. 175.5N, p<0.01; high: 262.2N vs. 154.1N, p<0.01), displacement (low: 11.1mm vs. 8.7mm, p<0.01; high: 11mm vs. 8.9mm; p=0.012), and maximal time to failure (low: 11.4 s vs. 8.9 s; p=0.012; high: 2.2 s vs. 1.8 s; p=0.011). Thus, the osteotomy opening speed seemed to have no influence on the risk of lateral cortex fracture. DISCUSSION: Our main hypothesis was confirmed but our secondary hypothesis was refuted: a protective K-wire significantly decreased the risk of hinge fracture, whereas the osteotomy opening speed had no influence. To our knowledge, this is the first published study assessing the potential influence of opening speed on risk of lateral cortex fracture. Our findings were obtained in the laboratory and should be evaluated in clinical practice. LEVEL OF EVIDENCE: IV, experimental study.

Patient specific instrumentation allow precise derotational correction of femoral and tibial torsional deformities.

BACKGROUND: Rotational malalignment deformities of the lower limb in adults mostly arise from excessive femoral anteversion and/or excessive external tibial torsion. The aim of this study was to assess the correction accuracy of a patient specific cutting guides (PSCG) used in tibial and femoral correction for lower-limb torsional deformities. METHODS: Forty knees (32 patients) were included prospectively. All patients had patellofemoral pain or instability with torsional malalignment for which a proximal tibial (HTO) or distal femoral (DFO) or a double-level osteotomy (DLO) had been performed. Accuracy of the correction between the planned and the postoperative angular values including femoral anteversion, tibial torsion, coronal and sagittal alignment were assessed after tibial and/or femoral osteotomy. RESULTS: Forty knees were included in this study. In cases of HTO, the correction accuracy obtained with PSCG was 1.3 ± 1.1° for tibial torsion (axial plane), 0.8 ± 0.7° for MPTA (coronal plane) and 0.8 ± 0.6° for PPTA (sagittal plane). In cases of DFO, the correction accuracy obtained with PSCG was 1.5 ± 1.4° for femoral anteversion (axial plane), 0.9 ± 0.9° for LDFA (coronal plane) and 0.9 ± 0.9° for PDFA (sagittal plane). The IKSG was improved from 58.0 ± 13.2° to 71.4 ± 10.9 (p = 0.04) and the IKSF from 50.2 ± 14.3 to 87.0 ± 6.9 (p < 0.001). CONCLUSIONS: Using the PSCG for derotational osteotomy allows excellent correction accuracy in all the three planes for femoral and tibial torsional deformities associated with patellofemoral instability. Level of clinical evidence II, prospective cohort study.

Comparison of five methods for locked-plate fixation of complex diaphyseal fractures.

BACKGROUND: Peri-prosthetic fractures (PPFs) are steadily rising in number due to population ageing and increased performance of joint replacement procedures. Although PPFs without implant loosening are usually managed by internal fixation, no consensus exists regarding the optimal construct. The primary objective of this study was to compare five constructs, and the secondary objective was to compare sub-groups of mono-cortical screw constructs, with the goal of identifying the method most appropriate for diaphyseal fracture fixation when prosthetic material is present within the intra-medullary canal. HYPOTHESIS: The primary hypothesis was that fixation using bi-cortical screws, i.e., the current reference standard, was superior over other fixation methods. The secondary hypothesis was that adding double cerclage to mono-cortical screw fixation provided the greatest mechanical strength. MATERIALS AND METHODS: Synthetic osteoporotic bone was used to compare five methods for locking-screw fixation of a femoral diaphyseal plate. One method involved bi-cortical screws and four methods mono-cortical screws, with no cerclage wire, a single cerclage wire on either side positioned near or at a distance from the fracture, and two cerclage wires on both sides of the fracture. A complex fracture was simulated by creating a 2-cm diaphyseal gap. Load-to-failure was determined by applying compression loading along the anatomical axis of the femur. RESULTS: Bi-cortical screw fixation provided greater mechanical strength than did three of the four mono-cortical screw constructs. The exception was the mono-cortical-screw and double-cerclage construct, for which no significant difference was found compared to bi-cortical screw fixation. Thus, mono-cortical screw fixation with double cerclage may be the best alternative when presence of an implant in the intra-medullary canal precludes bi-cortical screw fixation. CONCLUSION: The findings from this study have clear implications for clinical practice. The study hypotheses were partly confirmed. The absence of a significant difference between the reference-standard bi-cortical screw fixation method and mono-cortical screw fixation with double cerclage, combined with the results regarding the secondary objective, suggest that mono-cortical screws plus double cerclage deserve preference in patients with an intra-medullary implant. Clinical studies are needed to assess the results of this bench study. LEVEL OF EVIDENCE: IV, bench study.

Gait analysis dataset of healthy volunteers and patients before and 6 months after total hip arthroplasty.

Clinical gait analysis is a promising approach for quantifying gait deviations and assessing the impairments altering gait in patients with osteoarthritis. There is a lack of consensus on the identification of kinematic outcomes that could be used for the diagnosis and follow up in patients. The proposed dataset has been established on 80 asymptomatic participants and 106 patients with unilateral hip osteoarthritis before and 6 months after arthroplasty. All volunteers walked along a 6 meters straight line at their self-selected speed. Three dimensional trajectories of 35 reflective markers were simultaneously recorded and Plugin Gait Bones, angles, Center of Mass trajectories and ground reaction forces were computed. Gait video recordings, when available, anthropometric and demographic descriptions are also available. A minimum of 10 trials have been made available in the weka file format and C3D file to enhance the use of machine learning algorithms. We aim to share this dataset to facilitate the identification of new movement-related kinematic outcomes for improving the diagnosis and follow up in patients with hip OA.

Is the lateral tibial spine a reliable landmark for planning tibial or femoral valgus osteotomies?

INTRODUCTION: A valgus osteotomy around the knee is a conservative procedure performed to unload the medial tibiofemoral compartment. However, the optimal postoperative alignment target remains controversial. Many studies have applied a "Fujisawa point" at 62.5%. The results of recent studies suggest decreasing the range of the mechanical axis target correction to 50-55%. The primary purpose of this study was to define the mean position of the lateral tibial spine in healthy patients from a reproducible 3-dimensional (3D) analysis. The study hypothesis was that the apex of the lateral tibial spine was a reliable and reproducible landmark for planning valgus osteotomies and preventing overcorrections. MATERIALS AND METHODS: The study included 1140 patients: 560 women and 580 men, with a mean age of 61.7±16.5 years (18-98) and a mean body mass index (BMI) of 24.9±4.9kg/m2 (13.3-54.6). This analysis was done with the Stryker Orthopaedics Modeling and Analytics (SOMA) system which uses a database of computed tomography (CT) scans and 3D bone models. A statistical assessment was performed to determine the mean position of the lateral tibial spine. These measurements were then compared according to ethnicity, sex, age, BMI, knee side (right and left) and the overall mechanical axis of the leg. RESULTS: The mean tibial plateau width was 72.9±5.7mm (59.1-91.1). The mean position of the lateral tibial spine was 53.6±1.1% (48.9-57.2). The mean position of the medial tibial spine was 48.4±2.5% (43.6-56.1) while the center of the tibial spines was 51.0±1.5% (46.4-56.1). Africans had a significantly more lateral mean tibial spine position than Asians (54.7% vs. 53.3%, p=0.001), Caucasians (54.7% vs. 53.7%, p=0.002) and Middle Easterners (54.7% vs. 53.6%, p=0.034). CONCLUSION: The lateral tibial spine is a simple and reproducible bony landmark. This landmark can be used when planning valgus osteotomies aiming for a "Fujisawa point" at 54%. LEVEL OF EVIDENCE: IV.

Coronal and sagittal alignment of the lower limb in Caucasians: Analysis of a 3D CT database.

INTRODUCTION: Lower limb alignment is a major determinant of long-term outcomes after osteotomy or total knee replacement. The aim of this paper is to define the mean values of coronal and sagittal lower limb alignment for Caucasians as a function of sex using 3D reconstructions from CT-scans. MATERIALS AND METHODS: The analysis involved 586 Caucasian patients (269 males and 317 females) who had their hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), posterior proximal tibial angle (PPTA), lateral and medial proximal posterior tibial angles (LPPTA/MPPTA), posterior distal femoral angle (PDFA), and non-weightbearing joint convergence angle (nwJLCA) measured. This analysis was performed using a CT-scan-based modelling system (SOMA). Differences between sexes and morphotypes (neutral, varus and valgus) were analyzed statistically. RESULTS: The mean HKA was 180±2.57°, LDFA 86.1±1.87°, MPTA 86.1±2.15°, PPTA 84.6±2.58°, LPPTA 84.9±3.17°, MPPTA 85.1±3.21°, PDFA 85.3±1.50° and nwJLCA 0.82±1.32°. There was a significant difference between sexes for the HKA (180.3±2.46° and 179.0±2.52°), LDFA (85.6±1.90° and 86.8±1.61°), MPPTA (84.7±3.06° and 85. 6±3.31°). The neutral morphotype was more frequent in women than men (78% vs. 73%), the varus morphotype was more frequent in men than women (20% vs. 7.6%) and the valgus morphotype was more frequent in women than men (15% vs. 6.7%). CONCLUSION: Normal parameters for lower limb alignment in Caucasian patients were described in the coronal and sagittal planes. There was a significant influence of sex in the coronal plane, which was not found in the sagittal plane. LEVEL OF EVIDENCE: IV; retrospective cohort study.

Arthroscopic Trillat technique for chronic post-traumatic anterior shoulder instability: outcomes at 2 years of follow-up.

BACKGROUND: The purpose of this study was to assess the outcomes of a new arthroscopic Trillat technique at a 2-year follow-up. Our current hypothesis was that this technique could be used for the effective treatment of chronic post-traumatic unidirectional anterior shoulder instability, and that the recurrence and complication rates, external rotation, and functional outcomes would be as good as those of the reference technique. METHODS: Between April 2012 and August 2016, all patients older than 16 years who underwent the arthroscopic Trillat technique for unidirectional chronic post-traumatic anterior shoulder instability at the Dijon University Hospital (France), after the failure of well-conducted medical and rehabilitation treatment with at least 24 months of follow-up, were included. Criteria for noninclusion were association with posterior and/or inferior instabilities, voluntary instabilities, and glenoid bone loss greater than 20%. Patients attended follow-up with their surgeon before the intervention, in the immediate postoperative period, at 6 weeks, 3 and 6 months, and then by an independent observer for the last evaluation. Patients were then examined clinically with scores such as Constant, Rowe and Walch-Duplay scores, and subjective shoulder value, for shoulder range of motion, and radiographically (anteroposterior and Lamy's lateral x-rays of the operated shoulder). RESULTS: Forty-nine patients and 52 shoulders were included, with a mean follow-up of 40 months (range, 24-71 months). The recurrence rate of instability was 3.8% (2 of 52). No conversion to arthrotomy was necessary. No intraoperative complications, postoperative neurological lesions, or sepsis were observed. The mean Constant score was 92.1 (77.5-100) points, Walch-Duplay 82.9 (40-100), Rowe 81.73 (5-100), and subjective shoulder value 86.1 (50-100) at the last follow-up. The arm at side external rotation limitation averaged 8.4° (-25° to 40°) and the external rotation with 90° arm abduction limitation 0.34° (-5° to 15°). Forty-one patients (79%) resumed their sports activity at the same level. Fifty patients (96%) were satisfied to very satisfied. One patient developed nonunion of the coracoid process and subsequently underwent a Latarjet procedure with a good outcome. CONCLUSIONS: The arthroscopic Trillat procedure offers good outcomes as a first-line treatment for chronic anterior post-traumatic glenohumeral instability. It should be excluded in cases of glenoid loss greater than 20%.

Double level knee osteotomy using patient-specific cutting guides is accurate and provides satisfactory clinical results: a prospective analysis of a cohort of twenty-two continuous patients.

PURPOSE: Double level osteotomy (DLO) (femoral and tibial) is a technically demanding procedure for which pre-operative planning accuracy and intraoperative correction are key factors. The aim of this study was to assess the accuracy of the achieved correction using patient-specific cutting guides (PSCGs) compared to the planned correction, its ability to maintain joint line obliquity (JLO), and to evaluate clinical outcomes and level of patient satisfaction at a follow-up of two years. METHODS: A single-centre, prospective observational study including 22 patients who underwent DLO by PSCGs between 2014 and 2018 was performed. Post-operative alignment was evaluated and compared with the target angular values to define the accuracy of the correction for the hip-knee-ankle angle (ΔHKA), medial proximal tibial angle (ΔMPTA), lateral distal femoral angle (ΔLDFA), and posterior proximal tibial angle (ΔPPTA). Pre- and post-operative JLO was also evaluated. At two year follow-up, changes in the KOOS sub-scores and patient satisfaction were recorded. The Mann-Whitney U test with 95% confidence interval (95% CI) was used to evaluate the differences between two variables; the paired Student's t test was used to estimate evolution of functional outcomes. RESULTS: The mean ΔHKA was 1.3 ± 0.5°; the mean ΔMPTA was 0.98 ± 0.3°; the mean ΔLDFA was 0.94 ± 0.2°; ΔPPTA was 0.45 ± 0.4°. The orientation of the joint line was preserved with a mean difference in the JLO of 0.4 ± 0.2. At last follow-up, it was recorded a significant improvement in all KOOS scores, and 19 patients were enthusiastic, two satisfied, and one moderately satisfied. CONCLUSION: Performing a DLO using PSCGs produces an accurate correction, without modification of the joint line orientation and with good functional outcomes at two year follow-up.

Femoral and Tibial Bony Risk Factors for Anterior Cruciate Ligament Injuries Are Present in More Than 50% of Healthy Individuals.

BACKGROUND: Anterior cruciate ligament (ACL) injuries are multifactorial events that may be influenced by morphometric parameters. Associations between primary ACL injuries or graft ruptures and both femoral and tibial bony risk factors have been well described in the literature. PURPOSE: To determine values of femoral and tibial bony morphology that have been associated with ACL injuries in a reference population. Further, to define interindividual variations according to participant demographics and to identify the proportion of participants presenting at least 1 morphological ACL injury risk factor. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Computed tomography scans of 382 healthy participants were examined. The following bony ACL risk factors were analyzed: notch width index (NWI), lateral femoral condylar index (LFCI), medial posterior plateau tibial angle (MPPTA), and lateral posterior plateau tibial angle (LPPTA). The proportion of this healthy population presenting with at least 1 pathological ACL injury risk factor was determined. A multivariable logistic regression model was constructed to determine the influence of demographic characteristics. RESULTS: According to published thresholds for ACL bony risk factors, 12% of the examined knees exhibited an intercondylar notch width <18.9 mm, 25% had NWI <0.292, 62% exhibited LFCI <0.67, 54% had MPPTA <83.6°, and 15% had LPPTA <81.6°. Only 14.4% of participants exhibited no ACL bony risk factors, whereas 84.5% had between 2 and 4 bony risk factors and 1.1% had all bony risk factors. The multivariate analysis demonstrated that only the intercondylar notch width (P < .0001) was an independent predictor according to both sex and ethnicity; the LFCI (P = .012) and MMPTA (P = .02) were independent predictors according to ethnicity. CONCLUSION: The precise definition of bony anatomic risk factors for ACL injury remains unclear. Based on published thresholds, 15% to 62% of this reference population would have been considered as being at risk. Large cohort analyses are required to confirm the validity of previously described morphological risk factors and to define which participants may be at risk of primary ACL injury and reinjury after surgical reconstruction.