Postoperative Infection Following Hip Arthroscopy in Patients Receiving Preoperative Intra-articular Injections: A Systematic Review and Meta-Analysis.

Intra-articular injections prior to hip arthroscopy are often used to diagnose and conservatively manage hip pathologies, such as femoroacetabular impingement, labral tears, and chondral lesions. As a diagnostic tool, the relief of hip pain following an intra-articular injection helps pinpoint the primary source of pain and assists surgeons in recommending arthroscopic intervention for underlying intra-articular pathologies. However, when injections are not sufficiently spaced apart in time prior to hip arthroscopy, there is an elevated risk of postoperative infection. This systematic review aims to assess whether preoperative intra-articular injections prior to hip arthroscopy are associated with an increased risk of postoperative infection and to determine the safety timeframe for administering such injections prior to the procedure. A comprehensive search was conducted in the PubMed, Embase, and Cochrane Library databases to identify studies examining the relationship between preoperative intra-articular injections and postoperative infection following hip arthroscopy. A meta-analysis was conducted to compare the risk of infection between patients who received injections prior to hip arthroscopy at varying intervals and those who did not receive any preoperative injections. Five studies were included (four level III and one level IV), which consisted of 58,576 patients (58.4% female). Injections administered anytime prior to hip arthroscopy posed a significantly higher risk of infection compared to no history of prior injections (risk ratio: 1.45, 95% confidence interval: 1.14-1.85, P = 0.003). However, upon subanalysis, the risk of infection was significantly higher among patients who received injections within three months prior to hip arthroscopy compared to those who did not receive injections (risk ratio: 1.55, 95% confidence interval: 1.19-2.01, P = 0.001). Additionally, no significant difference in infection risk was observed when injections were administered more than three months before hip arthroscopy compared to no injections (risk ratio: 1.05, 95% confidence interval: 0.56-1.99, P = 0.87). The findings suggest that patients undergoing hip arthroscopy who have previously received intra-articular injections may face a statistically higher risk of postoperative infection, particularly when the injection is administered within three months prior to hip arthroscopy. Consequently, surgeons should exercise caution and avoid administering intra-articular injections to patients scheduled for hip arthroscopy within the subsequent three months to mitigate the increased risk of infection.

Outcomes of Early Versus Delayed Manipulation Under Anesthesia for Stiffness Following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Stiffness following total knee arthroplasty (TKA) is often treated with manipulation under anesthesia (MUA). However, there is debate regarding the timing of MUA, with many recommending against MUA beyond 3 months after TKA. Therefore, the purpose of this systematic review was to evaluate the functional and clinical outcomes of early versus delayed MUA for stiffness following TKA. METHODS: A search following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines was performed in the PubMed, Embase, Scopus, and Cochrane databases in November 2023. Data regarding study characteristics, demographics, knee flexion and extension, patient-reported outcomes, complications, and revisions were collected. A quality assessment was performed using the Methodological Index for Non-randomized Studies. Included were 14 studies analyzing 13,445 knees, 72.1% of which underwent early MUA and 27.8% of which underwent delayed MUA. Of the 14 studies, 10 defined early MUA as being performed within 3 months of the index TKA. RESULTS: Pre-MUA and post-MUA knee flexion for the early/delayed groups was 71.3°/77.9° and 103.0°/96.1°, respectively. Upon meta-analysis, pre-MUA knee flexion was significantly higher in the delayed group (P = .003), whereas post-MUA flexion was similar in both groups (P = .36). The mean gain in knee flexion for the early and delayed groups was 32.0°/19.2°. The surgical complication and revision TKA rates for the early and delayed groups were 4.9%/10.3% and 5%/9%, respectively. A meta-analysis found the risk of surgical or medical complications and revision TKA to be significantly higher in the delayed MUA group (P < .00001 and = .002, respectively). CONCLUSIONS: Although post-MUA knee flexion was similar in patients undergoing early and delayed MUA following TKA, the mean gain in flexion for early patients was nearly double that of delayed patients. Delayed patients also had significantly higher risks of surgical or medical complications and revision TKA following MUA.

No Difference in Most Reported Outcome Measures for Allograft Versus Autograft for Hip Labral Reconstruction: A Systematic Review of Comparative Studies.

PURPOSE: To systematically review studies comparing outcomes of allograft versus autograft for hip labral reconstruction. METHODS: A systematic review following guidelines established by PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) was performed in 3 databases using the terms "labrum," "hip," "acetabulum," "reconstruction," "augmentation," "allograft," and "autograft." Data on study characteristics, patient demographic characteristics, follow-up time, patient-reported outcomes (PROs), rates of revision surgery, and rates of conversion to total hip arthroplasty (THA) were collected. RESULTS: Three studies were included, with Methodological Index for Non-randomized Studies (MINORS) scores ranging from 17 to 23. Among 92 patients receiving allografts, the mean ages ranged from 30.6 to 34.8 years; mean follow-up times, from 34.6 to 66.1 months; revision rates, from 0% to 23.6%; and conversion-to-THA rates, from 0% to 20%. Among 185 patients receiving autografts, the mean ages ranged from 34.6 to 35.9 years; mean follow-up times, from 32.7 to 80.8 months; revision rates, from 0% to 7.3%; and conversion-to-THA rates, from 0% to 6.7%. One study reported significantly higher revision rates in the allograft group. All studies reported no statistically significant differences in postoperative PROs, and all postoperative PROs significantly improved compared with preoperative PROs. Rates of achievement of the minimal clinically important difference and patient acceptable symptomatic state, reported by 1 study, were statistically similar between the 2 groups and ranged from 55.6% to 100% for the allograft group and from 53.8% to 84.6% for the autograft group. CONCLUSIONS: There were no significant differences between allograft and autograft patients in terms of postoperative PROs; however, all PRO measures were slightly higher in allograft patients. Both revision and conversion-to-THA rates were higher in allograft patients in 2 studies, with the level of significance being reached in terms of revision in 1 study. The third study reported zero revisions and conversions to THA in allograft and autograft patients. LEVEL OF EVIDENCE: Level III, systematic review of Level II and III studies.

41-75% of Patients Achieve a Patient Acceptable Symptomatic State After Endoscopic Repair of Hip Abductor Tendon Tears: A Systematic Review.

PURPOSE: To systematically review clinical and functional outcomes of endoscopic repairs of hip abductor tendon tears. METHODS: A search following guidelines established by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was performed in the PubMed, Embase, and Cochrane databases using variations of the terms "endoscopy," "gluteus medius," "hip abductor," "outcome," "success," and "failure." Data for patient demographics, tear severity and location, patient-reported outcomes (PROs), clinical benefit, and rates of retears and revision surgery were collected and tabulated. Forest plots depicting preoperative versus postoperative PROs were generated. Quality assessment was performed using the modified Coleman Methodology Score. RESULTS: In total, 13 studies, 3 Level III and 10 Level IV, were included in this review, with a total of 272 patients whose ages ranged from 46.0 to 66.9 years and follow-up times from 16.4 to 46.7 months. Most tears were isolated to the gluteus medius, with the number of partial- versus full-thickness tears being similar. Trendelenburg gait, reported by 4 studies, persisted in 0% to 13.6% of patients after repair. Of 9 studies reporting both preoperative and postoperative PROs at latest follow-up, 8 reported significant improvements in all PROs (P < .05). In 5 studies, rates of achieving minimal clinically important difference and patient-acceptable symptomatic state ranged from 50.0% to 93.3% and 40.7% to 75.0%, respectively. Surgical complication rates were 0% in 11 studies and 4.3% and 18.2% in 2 studies. Retear rates were 0% in 10 studies and ranged from 6.7% to 33.3% in 3 studies. Rates of revision due to retear, reported by 12 studies, were 0% in 8 studies and ranged from 2.2% to 13.0% in 4studies. CONCLUSIONS: Endoscopic repairs of both partial- and full-thickness hip abductor tendon tears have good-to-excellent PROs and low complication, retear, and revision rates. However, rates of minimal clinically important difference and patient-acceptable symptomatic state achievement rates are highly variable and less than favorable. LEVEL OF EVIDENCE: Level IV, a systematic review of Level III and IV studies.

Improved Functional Outcomes of Combined Hip Arthroscopy and Periacetabular Osteotomy at Minimum 2-Year Follow-Up.

PURPOSE: To evaluate patient-reported outcomes (PROs) and survivorship at minimum 2-year follow-up after combined hip arthroscopy and periacetabular osteotomy (PAO) performed in the setting of a single anesthetic event. METHODS: Patients who underwent combined hip arthroscopy (M.J.P.) and PAO (J.M.M.) between January 2017 and June 2020 were identified. Preoperative and minimum 2-year postoperative PROs including Hip Outcome Score-Activities of Daily Living (HOS-ADL), HOS-Sport, modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Osteoarthritis Index, 12-Item Short Form Survey Mental Component Scores (SF-12 MCS), and 12-Item Short Form Survey Physical Component Score were collected and compared in addition to revision rate, conversion to total hip arthroplasty (THA), and patient satisfaction. RESULTS: Twenty-four of 29 patients (83%) eligible for the study were available for 2-year minimum follow-up with a median follow-up time of 2.5 years (range, 2.0-5.0). There were 19 females and 5 males with mean age of 31 ± 12 years. Mean preoperative lateral center edge angle was 20° ± 5° and alpha angle was 71° ± 11°. One patient underwent reoperation for removal of a symptomatic iliac crest screw at 11.7 months after operation. Two patients, a 33-year-old woman and a 37-year-old man, were converted to THA at 2.6 and 1.3 years, respectively, following the combined procedure. Both patients had a Tönnis grade of 1 on radiographs, as well as bipolar Outerbridge grade III/IV defects requiring microfracture of the acetabulum. For patients who did not convert to THA (n = 22), there was significant improvement from before to after surgery for all scores (P < .05) except SF-12 MCS. The minimal clinically significant difference and patient-acceptable symptom state rates for HOS-ADL, HOS-Sport, and mHHS were 72%, 82%, 86%, and 95%, 91%, and 95%, respectively. Median patient satisfaction was 10 (range, 4 to 10). CONCLUSIONS: Single-stage combined hip arthroscopy with periacetabular osteotomy for patients with symptomatic hip dysplasia results in improvement in PROs and arthroplasty free survivorship of 92% at median 2.5 year follow-up. LEVEL OF EVIDENCE: Level IV, case series.

Outcomes of Arthroscopic Joint Preservation Techniques for Chondral Lesions in the Hip: An Updated Systematic Review.

PURPOSE: To systematically review outcomes of joint preservation procedures for chondral lesions of the hip through analysis of survival rates and patient-reported outcomes (PROs). METHODS: A literature search from 2018 to May 2023 was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in 3 databases: PubMed, Embase, and Google Scholar. Studies were included if they reported on outcomes of patients undergoing hip arthroscopy for the treatment of chondral lesions of the hip joint and if there were quantifiable postoperative outcome measures. Quality assessment was completed using the Methodological Index for Non-Randomized Studies criteria. RESULTS: Twenty-seven studies were included, with 20 noncomparative and 7 comparative studies. Microfracture (MFx) was the most common procedure, reported in 17 studies. Other procedures include autologous chondrocyte transplantation (ACT) (5 studies), autologous matrix-induced chondrogenesis (AMIC) (3 studies), and MFx in conjunction with CarGel (3 studies). Seven other novel procedures were reported in individual separate studies. Survival rates, defined by no revision surgery or conversion to total hip arthroscopy (THA) at latest follow-up, for MFx (14 studies), AMIC (3 studies), and MFx in conjunction with CarGel (3 studies) ranged from 59.1% to 100%, 92.9% to 100%, and 94.4% to 95.7%, respectively. Survival rates of ACT, biological reconstruction, debridement and abrasion, microfragmented autologous adipose tissue transplantation, and ChondroFiller gel were all reported once in separate studies with rates of 100%, 100%, 85.4%, 100%, and 92.3%, respectively. All studies included PROs, most reporting statistically significant improvements (P < .05) at the latest follow-up. CONCLUSIONS: Isolated MFx remained the most commonly performed technique, but with lower survival and higher conversion to THA rates than in studies before 2018. Novel techniques that were performed in conjunction with MFx or that avoided MFx altogether had higher overall survival rates despite being minimally performed. Most patients across all techniques demonstrated significant improvements in PROs. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.

Criteria-Based Rehabilitation Following Revision Hip Arthroscopy: A Clinical Commentary.

Hip revision arthroscopy is becoming an increasingly popular surgery for those with unsatisfactory outcomes following primary hip arthroscopy. With the relatively uncommon but potentially increased difficulty of rehabilitation from this surgery, a lack of established research regarding rehabilitative programs remains. Therefore, the purpose of this clinical commentary is to propose a criterion-based progression that considers the intricacies present following a hip revision arthroscopy from early rehabilitation through return to sport. Criteria are presented clearly to promote objective progression through rehabilitation as opposed to relying on time since surgery as revision surgeries do not always follow traditional tissue healing time-frames. This criterion based progression promotes range of motion (ROM), strength, gait, neuromuscular control, load introduction and gradual return to play. Level of Evidence: 5.

Improved Mental Health Status and Patient-Reported Outcomes After Hip Arthroscopy for Femoroacetabular Impingement.

BACKGROUND: Femoroacetabular impingement (FAI) is often a chronic problem, which can lead to a decrease in mental well-being. PURPOSE/HYPOTHESIS: The purpose of this study was to determine patient mental health improvement after hip arthroscopy and if this improvement correlated with improved outcomes. It was hypothesized that patients with low mental health (LMH) status would improve after hip arthroscopy for FAI and that their patient-reported outcomes (PROs) would significantly improve after surgery. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who underwent hip arthroscopy with labral repair between 2008 and 2015 were included. The minimum follow-up was 2 years. PROs included the modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), HOS-Sports (HOS-Sports), and 12-Item Short Form Health Survey (SF-12). The minimal clinically important difference and Patient Acceptable Symptom State (PASS) were determined for HOS-ADL, HOS-Sports, and the mHHS based on previously published studies. Patients who scored <46.5 on the SF-12 Mental Component Summary (MCS) were in the LMH group, and those who scored ≥46.5 were in the high mental health (HMH) group. RESULTS: In total, 120 (21%) of the 566 patients were in the LMH group and 446 (79%) patients were in the HMH group preoperatively. There was no difference in age or sex between groups. Patients in the LMH group had lower mHHS, HOS-ADL, and HOS-Sports at the mean 4-year follow-up and were less likely to reach PASS for the scores. Postoperatively, 84% (478/566) of the entire group was in the HMH group. A total of 88 (73%) of the LMH group improved to HMH. A multiple linear regression model for change in MCS identified independent predictors of changes in preoperative MCS to be LMH group preoperatively, change in HOS-Sports, and change in mHHS (r2 = 0.4; P < .001). CONCLUSION: HMH was achieved in 84% of the patients after hip arthroscopy for FAI. Improvement in MCS was correlated with function and activity, as indicated by a significant correlation with HOS-ADL and HOS-Sports. A small percentage of patients did see a decline in their MCS score. This study showed that patients with LMH scores before hip arthroscopy for FAI can improve to normal/high mental health, and this correlated with higher PROs.

Loose Body Versus Trochlear Biopsy Matrix-Induced Autologous Chondrocyte Implantation (MACI) MOCART Scores and IKDC Reported Outcomes in Pediatric Patients.

BACKGROUND: Matrix-induced autologous chondrocyte implantation (MACI) has shown promising results in the treatment of osteochondral lesions of the knee. A recent study showed similar viability comparing chondrocytes harvested from the intercondylar notch compared to those harvested from osteochondral loose bodies. However, there is limited evidence assessing how these different biopsies perform clinically. The goal of this study was to compare both radiographic and patient-reported outcomes in patients with patellar and femoral osteochondral lesions treated with MACI using either a standard intercondylar notch biopsy or an osteochondral loose body biopsy. METHODS: A retrospective study was performed on all pediatric autologous chondrocyte implantation procedures performed from 2014 to 2017 at a single institution. Patients were divided into 2 groups: one group had cartilage derived from a standard intercondylar notch biopsy (n=9) and the other group had cartilage derived from an osteochondral loose body found within the ipsilateral knee (n=10). At a minimum of 1-year postimplantation, magnetic resonance imagings of the operative knee were performed and the Magnetic Resonance Observation of Cartilage Repair Tissue Knee Score (MOCART 2.0) knee score was used to assess the integrity and quality of the cartilage repair tissue. Interclass correlation coefficients were calculated between the 2 groups. International Knee Documentation Committee (IKDC) outcome scores were determined at a minimum 2 years post-implantation. RESULTS: The interclass correlation coefficient between three independent examiners for the MOCART scoring was excellent at 0.94. With regards to the MOCART score, the loose body group had an insignificant 17-point lower median score at 63 [interquartile range (IQR): 58 to 89] compared to the intercondylar group at 80 (IQR: 65 to 90) ( P =0.15). There was no difference in IKDC scores with the loose body group having a median score of 82 (IQR: 65 to 95) and the intercondylar group having a median score of 84 (IQR: 53 to 99) ( P =0.90). CONCLUSION: These results demonstrate that osteochondral loose bodies can be used as viable harvest site in MACI procedures with no difference in functional and radiographic outcomes at 2 years postimplantation. This may limit both short and long-term donor site morbidity. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

The revision hip arthroscopy complex: capsular deficiency, labral deficiency, femoral over-resection and adhesions can result in good survivorship with revision hip arthroscopy.

To evaluate the patient-reported outcomes (PROs) and survivorship of combined arthroscopic hip labral reconstruction/augmentation, capsular reconstruction, femoral neck remplissage and lysis of adhesions. Patients ≥18 years old who underwent this combination of procedures during revision hip arthroscopy and were eligible for minimum 2-year follow-up were identified. PRO scores including Hip Outcome Score (HOS)-Activities of Daily Living scale, HOS-Sports scale, modified Harris Hip Score, Short Form 12, and Western Ontario & McMaster Universities Osteoarthritis Index, patient satisfaction and failure rates were analyzed. Seven patients (5 females and 2 males) with average age of 45.0 ± 5.2 (range: 40-54 years) met inclusion criteria. Patients had a median of 1 (range: 1-3) prior hip surgery at an outside institution. All patients had previously undergone femoral osteoplasty, and 85% (6/7) of patients had a labral repair performed. Four patients had no capsule closure performed in their prior procedures. Six patients were available for minimum 2-year follow-up. Two patients converted to total hip arthroplasty: one patient with four prior hip arthroscopies and the other had advanced osteoarthritis with outerbridge grade 3/4 defects requiring microfracture. Mean patient satisfaction was 7 (range: 2-9). At mean follow-up of 3 years, most patients who underwent the combination of labral reconstruction, capsular reconstruction, femoral neck remplissage and lysis of adhesions during revision hip arthroscopy demonstrated improved PROs. This salvage procedure has the potential to restore hip function in patients who have failed an initial hip arthroscopy procedure. In patients with these pathologies present and concomitant joint space narrowing, a total hip arthroplasty may be a more appropriate salvage option.

Arthroscopic Core Decompression for Avascular Necrosis of the Femoral Head Using Multiple Small-Diameter Tunnels.

Avascular necrosis of the femoral head (AVNFH) is a debilitating disease that requires early intervention to prevent subchondral collapse and irreversible damage leading to premature hip replacement. Patients presenting with AVNFH can have concomitant intra-articular pathology, including femoroacetabular impingement (FAI), that contributes to their hip pain and dysfunction. It is important to restore the native hip anatomy in addition to providing revascularization of necrotic areas to reduce pain, improve function, and maximize efforts to preserve the joint. The purpose of this Technical Note is to describe our preferred arthroscopic approach to core decompression through the femoral neck in combination with femoral osteoplasty to address AVNFH and FAI in a single-staged and minimally invasive procedure.

Surgical Treatment of Acetabular Dysplasia With Labral Tears.

Acetabular dysplasia results in abnormal forces across the hip joint and can result in both labral tears and cartilage degeneration. A continuum exists from classic dysplasia to normal acetabular morphology. Diagnosis is aided by several radiographic measurements and parameters including a lateral center edge angle of less than 20°, an anterior center edge angle of less than 20°, a Sharp's angle of greater than 42°, and a Tonnis angle of greater than 10°, or version abnormalities. When patients with acetabular dysplasia present with intra-articular hip pain, skeletal maturity, and preserved radiographic joint space, a periacetabular osteotomy (PAO) is considered as a surgical treatment option when conservative measures have failed. The Bernese PAO was developed in 1984 as a way for reorienting the acetabulum to restore more normal femoral head coverage and orientation. The long-term results of this procedure have been promising with 10-year and 20-year survivorships of approximately 85% and 60%, respectively. When dysplasia is coupled with a labral tear or other intra-articular pathology including focal chondral damage, ligamentum teres tears, or capsular defects, hip arthroscopy and PAO are performed. Although there is a paucity in the literature of the long-term evidence for the combined procedure, early results indicate improved patient reported outcome measures. Appropriate treatment of borderline hip dysplasia remains controversial.

Infection and Mortality Rate in Hepatitis C and Cirrhotic Patients Undergoing Hip and Knee Replacement.

Liver disease carries significant risk in total joint arthroplasty (TJA). The authors sought to investigate the complications in hepatitis C virus (HCV) and cirrhosis patients after TJA. PRISMA guidelines extracted ten studies and meta-analytic analysis was performed. Five hundred and twenty-seven patients with liver disease underwent TJA. The complication rate was 38.9%, with 8% infection at 57 months. Cirrhotic patients had higher complication and infection rates compared to HCV patients (p < 0.001, p < 0.039, respectively). Mortality in cirrhosis patients was 17.8% at 36 months. Studies suggested Child Pugh Class A patients had significantly lower complications than Class B or C. One study revealed lower MELD (Model for End-Stage Liver Disease) scores < 10 carry a low mortality risk of 9.8% compared with 32% mortality if MELD score 10 or above. Cirrhosis has significant infection and mortality risk in total hip and knee arthroplasty. Surgeons can risk stratify these patients by MELD score and Child Pugh Class. (Journal of Surgical Orthopaedic Advances 31(1):001-006, 2022).

Reoperations are few and confined to the most valgus phenotypes 4 years after unrestricted calipered kinematically aligned TKA.

PURPOSE: The present study determined the postoperative phenotypes after unrestricted calipered kinematically aligned (KA) total knee arthroplasty (TKA), whether any phenotypes were associated with reoperation, implant revision, and lower outcome scores at 4 years, and whether the proportion of TKAs within each phenotype was comparable to those of the nonarthritic contralateral limb. METHODS: From 1117 consecutive primary TKAs treated by one surgeon with unrestricted calipered KA, an observer identified all patients (N = 198) that otherwise had normal paired femora and tibiae on a long-leg CT scanogram. In both legs, the distal femur-mechanical axis angle (FMA), proximal tibia-mechanical axis angle (TMA), and the hip-knee-ankle angle (HKA) were measured. Each alignment angle was assigned to one of Hirschmann's five FMA, five TMA, and seven HKA phenotype categories. RESULTS: Three TKAs (1.5%) underwent reoperation for anterior knee pain or patellofemoral instability in the subgroup of patients with the more valgus phenotypes. There were no implant revisions for component loosening, wear, or tibiofemoral instability. The median Forgotten Joint Score (FJS) was similar between phenotypes. The median Oxford Knee Score (OKS) was similar between the TMA and HKA phenotypes and greatest in the most varus FMA phenotype. The phenotype proportions after calipered KA TKA were comparable to the contralateral leg. CONCLUSION: Unrestricted calipered KA's restoration of the wide range of phenotypes did not result in implant revision or poor FJS and OKS scores at a mean follow-up of 4 years. The few reoperated patients had a more valgus setting of the prosthetic trochlea than recommended for mechanical alignment. Designing a femoral component specifically for KA that restores patellofemoral kinematics with all phenotypes, especially the more valgus ones, is a strategy for reducing reoperation risk. LEVEL OF EVIDENCE: Therapeutic, Level III.

Superior gluteal artery injury risk from third sacral segment transsacral screw insertion.

OBJECTIVES: Iliosacral (IS) and transsacral (TS) screws are commonly used to stabilize pelvic ring injuries. The course of the superior gluteal artery (SGA) can be close to implant insertion paths. The third sacral segment (S3) has been described as a viable osseous fixation pathway (OFP) but the proximity of the SGA to the S3 screw path is unknown. METHODS: Fifty uninjured patients with contrasted pelvic computed tomograms (CTA) were identified with an S3 path large enough for a 7.0 mm TS screw. Starting sites for S1 IS or TS, S2 and S3 TS screws were located on the volume rendered lateral CTA image and transferred onto the surface rendered 3D CTA with the SGA clearly visible. The distance from screw start sites to the SGA was measured. A distance less than 3.5 mm was considered likely for injury. RESULTS: The average distances from screw start sites to the SGA were 23.0 ± 7.9 mm for S1 IS screws, 14.3 ± 6.4 mm for S2 TS screws and 25.9 ± 6.5 mm for S3 TS screws. No S1 IS screws, 5 S2 TS screws (10%), and no S3 TS screws were projected to cause injury to the SGA. CONCLUSIONS: The osseous start site and soft tissue path for an S3 TS screw is remote from the SGA. The S1 IS and S3 TS pathways are further away from the SGA while the S2 TS pathway is closer and may theoretically pose a higher injury risk in patients with an available S3 OFP.

CT scans better assess lateral wall morphology of "stable appearing" intertrochanteric (IT) femur fractures and predict early failure of sliding hip screw (SHS) fixation.

To compare the efficacy of plain x-ray images and computed tomography (CT) to assess the morphology of the lateral wall (LW) component of intertrochanteric (IT) femur fractures and determine predictors of early fixation failure. DESIGN: Retrospective cohort study. SETTING: Level-one trauma center. PATIENTS/PARTICIPANTS: One hundred forty-two adult patients with IT fractures treated with either a sliding hip screw (SHS) or a cephalomedullary nail (CMN) who had both pre-op plain x-ray images and CT scans with at least 6 weeks of follow-up were reviewed. INTERVENTION: Preoperative CT scan and plain radiographs of the affected hip. MAIN OUTCOME MEASUREMENTS: Lateral wall assessment based on plain x-rays versus CT imaging in relation to implant failure. RESULTS: One hundred forty-two patients met inclusion criteria, 105 patients treated with a CMN, and 37 with a SHS. There was a poor correlation between the assessment of the LW on plain x-ray images and CT scans. Failures in the SHS group were significantly associated with all CT measurements (P < .05) but not with plain film LW assessment (P = .66). Fifteen patients had an early implant failure (6 CMN, 9 SHS). There were no statistically significant associations between any radiographic measurement (plain images and CT) and CMN failures. CONCLUSIONS: Plain film images are not accurate for assessing lateral wall morphology/integrity and are not predictive of SHS implant failures. Our novel CT measurements were effective at detecting lateral wall patterns at risk for treatment failure with SHS implants.Level of Evidence: Level III.

Lower extremity CT angiograms and their effect on kidney function in orthopedic trauma patients.

OBJECTIVES: To evaluate the frequency of unindicated CT Angiograms (CTAs) obtained at our institution and the association between contrast-induced nephropathy (CIN) and decreased glomerular filtration rate (GFR). DESIGN: Retrospective case series SETTING: Academic Level 1 trauma center PATIENTS/PARTICIPANTS: Patients aged 18 years and older with CTAs following lower-extremity (LE) trauma between 2010-2018. INTERVENTION: CTAs performed in 257 LEs and corresponding pre- and post-contrast renal function labs in these LE trauma patients. MAIN OUTCOME MEASUREMENTS: The primary outcome was vascular injury requiring intervention. Secondary outcomes were CIN and the association of CIN with decreased GFR and injury severity score (ISS). RESULTS: There was no indication (no hard signs of vascular injury, ABI>0.9) for CTA in 121 patients (61%) of the total 199 patients. Of the 78 patients with signs of vascular injury or ABI<0.9, 35 (45%) had positive CTAs and 15 (19.2%) required vascular intervention. Of the 121 unindicated patients, 26 (21%) had positive CTAs and 1 (0.008%), a knee dislocation, required vascular intervention. In 155 patients with renal function labs, initial GFR<60ml/min was a risk factor for CIN as compared to GFR>60ml/min (p=0.001). Rate of CIN did not correlate with Injury Severity Score (ISS). CONCLUSIONS: CTAs are obtained more often than indicated and initial GFR<60ml/min is a risk factor for developing CIN, irrespective of the trauma burden. CTAs should be reserved for when hard signs of vascular injury or ABI<0.9, especially in those patients with decreased renal function. LEVEL OF EVIDENCE: Level IV.

Aging Decreases the Ultimate Tensile Strength of Bone-Patellar Tendon-Bone Allografts.

PURPOSE: The purpose of this study was to determine whether aging imparts a clinically significant effect on the (1) mechanism of graft failure and (2) structural, material, and viscoelastic properties of patellar tendon allografts by evaluating these properties in younger donors (≤30 years of age) and older donors (>50 years of age). METHODS: A total of 34 younger (≤30 years of age) and 34 older (>50 years of age) nonirradiated, whole bone-tendon-bone allografts were prepared for testing by isolating the central third of the patellar tendon using a double-bladed 10-mm width scalpel under a 10-N load to ensure uniformity of harvest. Bone blocks were potted in polymethylmethacrylate within custom molds. Tendon length and cross-sectional area were measured using an area micrometer. A mechanical loading system was used to precondition the grafts for 100 cycles with a load between 50 N and 250 N (1 Hz). A creep load (500 N) was then applied at a rate of 100 mm/min (10 minutes). Grafts were allowed to recover at 1 N (10 minutes), followed by pull-to-failure at a rate of 100% strain per second. Mechanisms of failure (midsubstance vs avulsion) were noted and the structural, material, and viscoelastic properties calculated and compared between groups. RESULTS: There were 33 (97%) midsubstance tears in the younger group and 28 (82%) in the older group (P = .034). Younger grafts showed greater ultimate load to failure (1,782 N [1,533, 2,032] vs 1,319 N [1,103, 1,533]) (P = .006) and ultimate tensile stress (37.4 MPa [32.4, 42.4] vs 27.5 MPa [22.9, 32.0]) (P = .006). There were no significant differences in displacement (P = .595), stiffness (P = .950), strain (P = .783), elastic modulus (P = .114), creep displacement (P = .881), and creep strain (P = .614). CONCLUSIONS: This in vitro study suggests that aging weakens the bone-tendon junction and decreases the ultimate tensile strength of patellar tendon allografts. However, aging did not affect the displacement, strain, stiffness, elastic modulus, creep displacement, or creep strain of patellar tendon allografts. CLINICAL RELEVANCE: Surgeons should be aware that patellar tendon allografts from donors >50 years of age have a lower ultimate tensile stress than donors ≤30 years of age.

Preoperative 3D Modeling and Printing for Guiding Periacetabular Osteotomy.

INTRODUCTION: Achieving adequate acetabular correction in multiple planes is essential to the success of periacetabular osteotomy (PAO). Three-dimensional (3D) modeling and printing has the potential to improve preoperative planning by accurately guiding intraoperative correction. The authors therefore asked the following questions: (1) For a patient undergoing a PAO, does use of 3D modeling with intraoperative 3D-printed models create a reproducible surgical plan to obtain predetermined parameters of correction including lateral center edge angle (LCEA), anterior center edge angle (ACEA), Tonnis angle, and femoral head extrusion index (FHEI)? and (2) Can 3D computer modeling accurately predict when a normalized FHEI can be achieved without the need for a concomitant femoral-sided osteotomy? METHODS: A retrospective review was conducted on 42 consecutive patients that underwent a PAO. 3D modeling software was utilized to simulate a PAO in order to achieve normal LCEA, ACEA, Tonnis angle, and FHEI. If adequate FHEI was not achieved, a femoral osteotomy was simulated. 3D models were printed as intraoperative guides. Preoperative, simulated and postoperative radiographic ACEA, LCEA, Tonnis angle, and FHEI were measured and compared statistically. RESULTS: A total of 40 patients had a traditional PAO, and 2 had an anteverting-PAO. The simulated LCEA, ACEA, Tonnis angle, and FHEI were within a median difference of 3 degrees, 1 degrees, 1 degrees, and 0% of postoperative values, respectively, and showed no statistical difference. Of those that had a traditional PAO, all 34 patients were correctly predicted to need a traditional acetabular-sided correction alone and the other 6 were correctly predicted to need a concomitant femoral osteotomy for a correct prediction in 100% of patients. CONCLUSION: This study demonstrates that for PAO surgery, 3D modeling and printing allow the surgeon to accurately create a reproducible surgical plan to obtain predetermined postoperative hip coverage parameters. This new technology has the potential to improve preoperative/intraoperative decision making for hip dysplasia and other complex disorders of the hip.