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 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.

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.

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.

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.

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.

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).

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.

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.

A cruciate-retaining implant can treat both knees of most windswept deformities when performed with calipered kinematically aligned TKA.

PURPOSE: Surgeons performing total knee arthroplasty (TKA) on the osteoarthritic valgus deformity often use a posterior stabilized (PS) and semi-constrained implants to substitute for the release of a contracted posterior cruciate ligament (PCL) instead of a cruciate retaining (CR) implant. Calipered kinematic alignment (KA) strives to retain the PCL and use a CR implant. The aim of this study of the windswept deformity was to determine whether the level of implant constraint, outcome scores, and alignment after bilateral calipered KA TKA are different between a pair of knees with a varus and valgus deformity in the same patient. METHODS: A review of a prospectively collected database identified all patients with a windswept deformity treated with bilateral TKA (n = 19) out of 2430 consecutive primary TKAs performed between 2014 and 2019. Operative reports determined the level of implant constraint. Patient response to the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) assessed outcomes at a mean follow-up of 2.3 years. Postoperative alignment was measured on an A-P computer tomographic scanogram of the limb. RESULTS: CR implants were used in 15 of 19 (79%) valgus deformities and 17 of 19 (89%) of varus deformities (n.s.). No knees required a semi-constrained implant. There was no difference in the median postoperative FJS and OKS (n.s.), and a 1° or less difference in the mean postoperative distal lateral femoral angle (p = 0.005) and proximal medial tibial angle (n.s.) between the paired varus and valgus knee deformity. CONCLUSION: Based on this small series, surgeons that use calipered KA TKA can expect to use CR implants in most patients with windswept deformity and achieve comparable outcome scores and alignment between the paired varus and valgus deformity. LEVEL OF EVIDENCE: IV.

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.

Posterior pelvic ring bone density with implications for percutaneous screw fixation.

BACKGROUND: Although the second (S2) and third (S3) sacral segments have been established as potential osseous fixation pathways for screw fixation, the S2 body has been demonstrated to have inferior bone density when compared to the body of the first (S1) sacral segment. Caution regarding the use of iliosacral screws at this level has been advised as a result. As transiliac-transsacral screws traverse the lateral cortices of the posterior pelvis, they may be relying on bone with superior density for purchase, which could obviate this concern. The objective of this study was to compare the bone density of the posterior ilium and sacroiliac joint to that of the sacral body at the first (S1), second (S2), and third (S3) sacral levels. MATERIALS AND METHODS: A retrospective case series was performed, reviewing the CT scans of 100 patients without prior pelvic trauma. Each CT was confirmed to have available osseous fixation pathways at the first (S1), second (S2), and third (S3) sacral segments. The bone density of the posterior ilium/sacroiliac joint (PISJ) and sacral body (SB) was measured using the embedded standardized Hounsfield units (HU) tool at each sacral level. RESULTS: The average S2 PISJ bone density (320.1) was significantly higher than the S1 (286.5) and S3 (278.9) PISJ (p < 0.0001) and S1 and S3 PISJ was not statistically different. The S1 sacral body bone density (231.1) was significantly higher than the S2 (182.1) and S3 (126.8) bone density (p < 0.0001). The PISJ bone density is greater than the sacral body at every sacral level (p < 0.0001). CONCLUSION: The S2 PISJ bone density is significantly greater than S1. The S1, S2, and S3 PISJ bone density is greater than the sacral body at all sacral levels, and the S1 body has higher bone density than the S2 and S3 bodies. These differences in bone density may have implications for the stability of posterior pelvic ring fixation constructs with regard to screw purchase. LEVEL OF EVIDENCE: Level III-Case cohort series.

Kinematically aligned TKA restores physiological patellofemoral biomechanics in the sagittal plane during a deep knee bend.

PURPOSE: Although patellofemoral complications after kinematically aligned (KA) TKA are infrequent, the patellar flexion angle and proximal-distal patellar contact location through flexion, and incidence of patellar loss of contact at full extension are unknown. The present study determined whether the patellar flexion angle and proximal-distal patellar contact location of a KA TKA performed with anatomic, fixed-bearing, posterior cruciate-retaining (PCR) components differed from those of the native contralateral knee during a deep knee bend, and determined the incidence of patellar loss of contact at full extension for KA TKA only. METHODS: During a deep knee bend from full extension to maximum flexion, both knees were imaged in a lateral view using single-plane fluoroscopy for 25 patients with a calipered KA TKA and a healthy native knee in the contralateral limb. The patellar flexion angle and proximal-distal patellar contact location were measured on images from full extension to maximum flexion in 30° increments. Paired t tests at each flexion angle determined the significance of the difference between the KA TKA knees and the native contralateral knees. In the KA TKA knees, the incidence of patellar loss of contact at full extension was determined. Patient-reported outcome scores also were recorded including the Oxford Knee Score. RESULTS: Mean patellar flexion angles were not different between the KA TKA knees and the native contralateral knees throughout the motion arc. The largest statistically significant difference in the mean proximal-distal patellar contact locations was 4 mm. The incidence of patellar loss of contact in the KA TKA knees at full extension was 8% (2 of 25 patients). The median Oxford Knee Score was 46 out of 48. CONCLUSIONS: Calipered KA TKA performed with anatomic, fixed-bearing, PCR components restored patellar flexion angles to native and largely restored the proximal-distal patellar contact locations, which at most differed from the native contralateral knee by approximately 10% of the mean proximal-distal patellar length. In the KA TKA knees, the incidence of patellar loss of contact was infrequent. These objective biomechanical results are consistent with the relatively high subjective patient-reported outcome scores herein and support the low incidence of patellofemoral complications following KA TKA previously reported. LEVEL OF EVIDENCE: Therapeutic, level III.

Small differences in tibial contact locations following kinematically aligned TKA from the native contralateral knee.

PURPOSE: Kinematically aligned (KA) TKA strives to restore native limb and knee alignments without ligament release with the premise that knee function likewise will be closely restored to native to the extent enabled by the components used. This study determined differences in anterior-posterior (AP) tibial contact locations of a KA TKA performed with asymmetric, fixed bearing, posterior cruciate-retaining (PCR) components from those of the native contralateral knee and also determined the incidence of posterior rim contact of the tibial insert during a deep knee bend and a step-up. METHODS: Both knees were imaged using single-plane fluoroscopy for 25 patients with a calipered KA TKA and a native knee in the contralateral limb. AP tibial contact locations in each compartment were determined following 3D model-to-2D image registration. Differences in mean AP tibial contact locations in each compartment between the KA TKA knees and the native contralateral knees were analysed. Contact locations either on or beyond the most posterior point of the tibial insert determined the occurrence of posterior rim contact. RESULTS: Mean AP tibial contact locations for both native and KA TKA knees remained relatively centred in the medial compartment but moved posterior in the lateral compartment during flexion. In both the medial and lateral compartments, differences in mean AP tibial contact locations between the KA TKA knees and the native contralateral knees were more posterior and greatest at 0° flexion for both activities (4 mm, p = 0.0009 and 7 mm, p < 0.0001 for deep knee bend and 6 mm, p < 0.0001 and 8 mm, p < 0.0001 for step-up in the medial and lateral compartments, respectively). The incidence of posterior rim contact of the tibial insert was 16% (4 of 25 patients) but the lowest Oxford Knee Score was 43 for these patients. The median Oxford Knee Score for all patients was 46 (out of 48). CONCLUSIONS: Calipered KA TKA with asymmetric, fixed bearing, PCR components resulted in mean AP tibial contact locations which were relatively centred in the compartments and differed at most from those of the native contralateral knee by approximately 15% of the AP dimension of a mid-sized tibial baseplate. Although posterior rim contact occurred in some patients, all such patients had high patient-reported outcome scores. LEVEL OF EVIDENCE: Therapeutic, Level III.

Assessment of Cartilage Growth After Biopsy of Osteochondral Loose Bodies in Adolescent Knees for Use in Autologous Chondrocyte Implantation.

BACKGROUND: The goal of this study is to determine whether harvested cartilage from an osteochondral loose body maintains the same viability for implantation as cartilage harvested from the traditional locations within the adolescent knee for autologous chondrocyte implantation (ACI). METHODS: A retrospective study was performed on all ACI procedures performed from 2014 to 2017 at a single institution. Biopsies were derived from 2 groups: osteochondral loose body verses the intercondylar notch. The viability, yield, identity, potency, and density were obtained from each sample in addition to basic demographics and concomitant injuries. A total of 12 patients with osteochondral loose bodies 14.6 (SD=2.9) and 20 patients 13.6 (SD=3.3) with intercondylar notch biopsies were evaluated for the study. RESULTS: In the microscopic and histologic comparison, there was no significant difference in viability: 94% in the loose bodies and 93% in the intercondylar notch groups, identity: 7.4 d5L versus 6.3 d5L, or yield. Minimum yield is presented as different units in Carticel (1.2×10 cells/vial) and matrix-induced ACI (>8500 relative fluorescent units) products; however, there was no difference between groups and all samples were above the acceptable limit. Minimum identity value is recorded as d5L> -2.00 and all samples were above this limit. In addition, no sample had signs of contamination or endotoxin in either group. CONCLUSION: These results demonstrate an alternative method for obtaining cartilage biopsies in ACI procedures that may limit short-term and long-term donor site morbidity. LEVEL OF EVIDENCE: Level III.

Is There a Force Target That Predicts Early Patient-reported Outcomes After Kinematically Aligned TKA?

BACKGROUND: Four mechanical alignment force targets are used to predict early patient-reported outcomes and/or to indicate a balanced TKA. For surgeons who use kinematic alignment, there are no reported force targets. To date the usefulness of these mechanical alignment force targets with kinematic alignment has not been reported nor has a specific force target for kinematic alignment been identified. QUESTIONS/PURPOSES: (1) Does hitting one of four mechanical alignment force targets proposed by Gustke, Jacobs, Meere, and Menghini determine whether a patient with a kinematically aligned TKA had better patient-reported Oxford Knee and WOMAC scores at 6 months? (2) Can a new force target be identified for kinematic alignment that determines whether the patient had a good/excellent Oxford Knee Score of ≥ 34 points (48 best, 0 worst)? METHODS: Between July 2017 and November 2017, we performed 148 consecutive primary TKAs of which all were treated with kinematic alignment using 10 caliper measurements and verification checks. A total of 68 of the 148 (46%) TKAs performed during the study period had intraoperative measurements of medial and lateral tibial compartment forces during passive motion with an instrumented tibial insert and were evaluated in this retrospective study. Because the surgeon and surgical team were blinded from the display showing the compartment forces, there was no attempt to hit a mechanical alignment force target when balancing the knee. The Oxford Knee Score and WOMAC score measured patient-reported outcomes at 6 months postoperatively. For each mechanical alignment force target, a Wilcoxon rank-sum test determined whether patients who hit the target had better outcome scores than those who missed. An area under the curve (AUC) analysis tried to identify a new force target for kinematic alignment at full extension and 10°, 30°, 45°, 60°, 75°, and 90° of flexion that predicted whether patients had a good/excellent Oxford Knee Score, defined as a score of ≥ 34 points. RESULTS: Patients who hit or missed each of the four mechanical alignment force targets did not have higher or lower Oxford Knee Scores and WOMAC scores at 6 months. Using the Gustke force target as a representative example, the Oxford Knee Score of 41 ± 6 and WOMAC score of 13 ± 11 for the 31 patients who hit the target were not different from the Oxford Knee Score of 39 ± 8 (p = 0.436) and WOMAC score of 17 ± 17 (p = 0.463) for the 37 patients who missed the target. The low observed AUCs (from 0.56 to 0.58) at each of these flexion angles failed to identify a new kinematic alignment force target associated with a good/excellent (≥ 34) Oxford Knee Score. CONCLUSIONS: Tibial compartment forces comparable to those reported for the native knee and insufficient sensitivity of the Oxford Knee and WOMAC scores might explain why mechanical alignment force targets were not useful and a force target was not identified for kinematic alignment. Intraoperative sensors may allow surgeons to measure forces very precisely in the operating room, but that level of precision is not called for to achieve a good/excellent result after calipered kinematically aligned TKA, and so its use may simply add expense and time but does not improve the results from the patient's viewpoint. LEVEL OF EVIDENCE: Level III, therapeutic study.

The medial epicondyle of the distal femur is the optimal location for MRI measurement of semitendinosus and gracilis tendon cross-sectional area.

PURPOSE: Graft diameter ≥ 8 mm reduces the risk of failure after anterior cruciate ligament reconstruction (ALCR) with hamstring tendon autograft. Pre-operative measurement of gracilis (GT) and semitendinosus (ST) cross-sectional area using MRI has been utilized but the optimal location for measurement is unknown. The main purpose of this study was to examine the cross-sectional areas of GT + ST at different locations and develop a model to predict whether a doubled hamstring graft of GT + ST will be of sufficient cross-sectional area for ACLR. METHODS: A retrospective review was performed of 154 patients who underwent primary ACLR using doubled hamstring autograft. Cross-sectional area measurements of GT + ST on pre-operative MRI axial images were made at three locations: medial epicondyle (ME), tibiofemoral joint line (TJL), and tibial physeal scar (TPS) and calculated the correlation of intra-operative graft size for each location using the Pearson's correlation coefficient. A receiver operating characteristic (ROC) established a threshold that would predict graft diameter ≥ 8 mm. RESULTS: Measurement of GT + ST at the ME had a stronger correlation (r = 0.389) to intra-operative graft diameter than measurements at the TJL (r = 0.256) or TPS (r = 0.240). The ROC indicated good predictive value for hamstring graft diameter ≥ 8 mm based on MRI measurement at the ME with the optimal threshold with the highest sensitivity and specificity as 18 mm2. CONCLUSION: Cross-sectional area measurement of GT + ST at the ME correlated most closely to intra-operative diameter of a doubled hamstring autograft compared to measurements at the TJL or the TPS. As graft diameter < 8 mm is correlated with higher failure rates of ACL surgery, the ability to pre-operatively predict graft diameter is clinically useful. LEVEL OF EVIDENCE: Level III, prognostic study.

Mortality During Total Hip Periprosthetic Joint Infection.

BACKGROUND: We sought to understand the mortality rate of periprosthetic joint infection (PJI) of the hip undergoing 2-stage revision for infection. METHODS: Database search, yielding 23 relevant studies, totaled 19,169 patients who underwent revision for total hip PJI. RESULTS: One-year weighted mortality rate was 4.22% after total hip PJI. Five-year mortality was 21.12%. Average age was 65 years. When comparing the national age-adjusted risk of mortality and the reported 1-year mortality risk in this systematic review, the risk of death after total hip PJI is significantly increased (odds ratio 3.58, P < .001). CONCLUSION: The mortality rate during total hip revision for infection is high. When counseling a patient regarding complications of this disease, death should be discussed.