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Background: Kinematic parameters predictive of pitch velocity have been evaluated in adolescent and collegiate baseball pitchers; however, they have not been established for high school or professional pitchers., Purpose: To create multiregression models using anthropometric and kinematics features most predictive for pitch velocity in high school and professional pitchers and compare them with prior multiregression models evaluating other playing levels., Study Design: Descriptive laboratory study., Methods: High school (n = 59) and professional (n = 337) baseball pitchers threw 8 to 12 fastballs while being evaluated with 3-dimensional motion capture (480 Hz). Using anthropometric and kinematic variables, multiregression models for pitch velocity were created for each group. A systematic review was conducted to determine previous studies that established kinematic models for ball velocity in youth, high school, and collegiate pitchers., Results: Leg length was predictive of pitch velocity for high school and professional pitchers ( P < .001 for both). When compared with previously established models for pitch velocity, almost all groups were distinct from one another when assessing age ( P maximum < .001), weight ( P max = .0095), and pitch velocity ( P max < .001). Stride length was a significant predictor for the youth/high school pitchers, as well as the current study's high school and professional pitchers ( P < .001 for all). Maximal shoulder external rotation (collegiate: P = .001; professional: P < .001) and maximal elbow extension velocity (high school/collegiate: P = .024; collegiate: P < .001; professional: P = .006) were shared predictors for the collegiate and current study's professional group multiregression models. Trunk flexion at ball release was a commonly shared predictor in the youth/high school ( P = .04), high school/collegiate ( P = .003), collegiate ( P < .001), and the current study's professional group ( P < .001)., Conclusion: Youth, high school, collegiate, and professional pitchers had unique, predictive kinematic and anthropometric features predictive of pitch velocity. Leg length, stride length, trunk flexion at ball release, and maximal shoulder external rotation were predictive features that were shared between playing levels., Clinical Relevance: Coaches, clinicians, scouts, and pitchers can consider both the unique and the shared predictive features at each playing level when attempting to maximize pitch velocity., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.N. has received grant support from Arthrex, education payments from Arthrex and SeaPearl, and hospitality payments from Zimmer Biomet and Stryker. M.C.C. has received grant support from Arthrex and DJO. J.J.R. has received grant support from Arthrex and hospitality payments from Smith+Nephew. J.S.D. has received education payments from Gotham Surgical; consulting fees from Arthrex, KCI, and Trice Medical; nonconsulting fees from Arthrex; and royalties from Arthrex and Linvatec. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2024.)

Isolated distal rectus femoris avulsions from the common quadriceps tendon are rare and may be missed due to the integrity of the remaining extensor mechanism. In healthy, active patients, surgical repair is recommended due to the potential for persistent pain, cramping, and weakness. In the case of isolated distal rectus femoris avulsions, however, there are important surgical considerations and differences when compared with the treatment of complete quadriceps tendon ruptures. This Technical Note describes an open repair of an isolated distal rectus femoris rupture with reinsertion into the common quadriceps tendon., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: A.C.K. is on the Editorial Board for Arthroscopy: The Journal of Arthroscopic and Related Surgery. J.J.R. is a consultant or advisor for Smith & Nephew. All other authors (E.K.A., H.N., O.M.J.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Segmental bone defects that are caused by trauma, infection, tumor resection, or osteoporotic fractures present significant surgical treatment challenges. Host bone autograft is considered the gold standard for restoring function but comes with the cost of harvest site comorbidity. Allograft bone is a secondary option but has its own limitations in the incorporation with the host bone as well as its cost. Therefore, developing new bone tissue engineering strategies to treat bone defects is critically needed. In the past three decades, the use of stem cells that are delivered with different scaffolds or growth factors for bone tissue engineering has made tremendous progress. Many varieties of stem cells have been isolated from different tissues for use in bone tissue engineering. This review summarizes the progress in using different postnatal stem cells, including bone marrow mesenchymal stem cells, muscle-derived stem cells, adipose-derived stem cells, dental pulp stem cells/periodontal ligament stem cells, periosteum stem cells, umbilical cord-derived stem cells, peripheral blood stem cells, urine-derived stem cells, stem cells from apical papilla, and induced pluripotent stem cells, for bone tissue engineering and repair. This review also summarizes the progress using exosomes or extracellular vesicles that are delivered with various scaffolds for bone repair. The advantages and disadvantages of each type of stem cell are also discussed and explained in detail. It is hoped that in the future, these preclinical results will translate into new regenerative therapies for bone defect repair.

Background: While an association between femoroacetabular impingement (FAI) and osteoarthritis (OA) has been reported, the mechanistic differences and transition between the 2 conditions is not fully understood. In FAI, cartilage lesions at the femoral head-neck junction can sometimes be visualized during hip arthroscopy., Purpose/hypothesis: The purpose of this study was to describe a unique dimpled pattern of superficial fissured cartilage lesions on the femoral head-neck junction at impingement site in patients with FAI syndrome (FAIS) and to evaluate the clinical, histological, and genetic phenotype of this cartilage. We hypothesized that the cartilage lesions may indicate risk for, or predict occurrence of, OA., Study Design: Controlled laboratory study., Methods: Six hips (6 patients; mean age, 34.2 ± 12.9 years; range, 19-54 years) with dimpled or fissured cartilage were included among patients who underwent hip arthroscopy for treatment of FAIS from October 2020 through December 2021. This affected cartilage (dimple-pattern group) and normal cartilage (control group) on the femoral head-neck junction were collected from the same patients and evaluated for histological quantification by Mankin scores and expression of proteins related to cartilage degeneration (eg, matrix metalloproteinase [MMP]-1, MMP-2, MMP-3, MMP-10, and MMP-12, tissue inhibitor of metalloproteinase [TIMP]-1 and TMP-2, aggrecan neopepitope CS846, and hyaluronic acid [HA]) with the use of Milliplex Multiplex Assays., Results: All 6 hips were of the mixed FAI subtype. Preoperatively, 4 of 6 hips had Tönnis grade 1 radiographic changes, which was associated with greater femoral head chondral damage visualized intraoperatively. Mankin scores for the normal cartilage group and the dimple-pattern group were 0.67 ± 0.82 and 3.3 ± 0.82, respectively. Dimple pattern fissured cartilage showed a significant increase in Mankin score ( P = .031) and a significant increase in protein expression of CS846 ( P = .031) compared with normal cartilage. There were no significant differences in MMPs, TIMPs, or HA levels between the 2 groups., Conclusion: The dimple pattern fissured cartilage, compared to normal cartilage, showed histologically significant cartilage degeneration and a significant increase in protein expression of CS846, a biomarker for early OA., Clinical Relevance: This lesion serves as helpful visual indicator of early degeneration of the cartilage of femoral head-neck junction caused by FAIS., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: C.S.B. has received royalties from Iota Biosciences for a United States patent (041263). J.H. has received royalties from Cook Myosite. M.J.P. has received education payments from Smith & Nephew, Conmed, Linvatec, Ossur, Arthrex, Siemens Medical Solutions; consulting fees from Smith & Nephew, MIS, Olatec, and NICE Recovery Systems; nonconsulting fees from Smith & Nephew, MIS, Olatec, NICE Recovery Systems, and Synthes; royalties from Linvatec, Smith & Nephew, Arthrosurface, Bledsoe, Conmed, DJO, Slack, and Elsevier; and holds shares in Arthrosurface, MJP Innovations, Vail Valley Surgery Center, Vail MSO Holdings, MIS, EFFRx, Olatec, Arthrex, Manna Tree Partners, Stryker, Trimble, 3M, Bristol Myers, Squibb, Pfizer, AbbVie, and Johnson & Johnson. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto. Ethical approval for this study was obtained from Vail Health Hospital (ref No. v7 092321)., (© The Author(s) 2024.)

With the growing number of primary arthroscopies performed, patients requiring revision hip arthroscopies for various issues is high including postoperative adhesion formation, a source of pain, mechanical symptoms, range of motion limitation, stiffness, and microinstability. Adhesions are a consequence of biological pathways that have been stimulated by injury or surgical interventions leading to an increased healing response. Preventative efforts have included surgical adjuncts during/after primary hip arthroscopy, biologic augmentation, and postoperative rehabilitation. Treatment options for adhesion formation includes surgical lysis of adhesions with or without placement of biologic membranes aimed at inhibiting adhesion reformation as well as systemic medications to further reduce the risk. Postoperative rehabilitation exercises have also been demonstrated to prevent adhesions as a result of hip arthroscopy. Ongoing clinical trials are further investigating pathways and prevention of adhesion formation.

Background: Throwing arm kinetics differ in pitchers at varying arm slot (AS) positions (frontal-plane arm position at ball release relative to the vertical axis)., Purpose: To determine how kinematic and kinetic values differ between professional and high school pitchers with varying AS positions, and whether these differences are similarly observed in both populations., Methods: High school (n = 130) and professional (n = 288) pitchers threw 8 to 12 fastballs under 3-dimensional motion capture technology. Pitchers in each cohort were subdivided based on mean AS position at ball release: AS 1 (least degree of AS: most overhand throwing styles), AS 2 (intermediate degree of AS: three-quarter throwing styles), or AS 3 (greatest degree of AS: most sidearm throwing styles). Kinetic and kinematic parameters were compared between groups., Study Design: Controlled laboratory study., Results: High school pitchers had a more overhand AS at ball release (50° ± 11°) compared with professional pitchers (58° ± 14°) ( P < .001). In both cohorts, AS 1 pitchers had significantly greater shoulder abduction (high school, P <0.001; professional, P <0.0001) and lateral trunk flexion (high school, P < 0.001; professional, P <0.0001) at ball release compared with AS 3 pitchers. Professional pitchers with an AS 3 position had significantly delayed timing of maximum upper trunk angular velocity compared with AS 1 pitchers (64% ± 7% vs 57% ± 7% of pitch time, respectively; P < .0001). A significant positive correlation between AS and elbow flexion torque was found in high school pitchers ( P = .002; β = 0.28), and a significant negative correlation between AS and elbow varus torque ( P < .001; β = -0.22) and shoulder internal rotation torque ( P < .001; β = -0.20) was noted in professional pitchers., Conclusion: AS position was related to shoulder abduction and trunk lateral tilt. Professional and high school pitchers with varying AS positions did not experience similar changes in throwing arm kinetics., Clinical Relevance: In professional pitchers, the earlier onset of maximum upper trunk angular velocity with overhand throwing style may reflect inappropriate pelvis-trunk timing separation, a parameter implicated in upper extremity injury, and the negative correlation between AS and elbow varus and shoulder internal rotation torque suggests that both excessive and minimal AS positions have negative implications., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: J.J.R. has received hospitality payments from Smith & Nephew. M.C.C. has received education payments from Liberty Surgical. J.S.D. has received education payments from Gotham Surgical; consulting fees from Arthrex, Merck Sharp & Dohme, and Trice Medical; nonconsulting fees from Arthrex; and royalties from Arthrex and Linvatec. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2023.)

Background: Glenohumeral osteophytes (OPs) can adversely influence postoperative range of motion (ROM) following shoulder arthroplasty due to mechanical impingement. Though commercial three-dimensional preoperative planning software (3D PPS) is available to simulate ROM before and after OP resection, little is known about the magnitude of effect OPs and their subsequent removal have on simulated glenohumeral ROM., Methods: Included patients were 1) indicated for reverse total shoulder arthroplasty (rTSA) using 3D PPS and 2) presented with glenoid and/or humeral head OPs on preoperative two-dimensional computed tomography (2D-CT) imaging. Thirty patients met the inclusion criteria (9 females, 21 males; mean age 70.45 ± 4.99 years, range 63-80 years). All subjects (n = 30) presented with humeral OPs (mean volume: 2905.16 mm 3 , range 109.1-11,246 mm 3 ), while 11 subjects also presented with glenoid OPs (mean volume 108.06 mm 3 , range 37.59-791.4 mm 3 ). Preoperative CTs were used to calculate OP volume (mm 3 ) and OP circumferential extent (clockface). Mean clockface position for circumferential humeral OPs originated at 6:09 (range 4:30-7:15) and extended to 8:51 (range 8:15-10:15). Mean clockface position for glenoid OPs originated at 3:00 (range 2:00-5:00) and extended to 6:16 (range 3:00-7:30). 3D implants on PPS were standardized to achieve 0° of version, 0° of inclination and 4 mm of net lateralization. Thirty-nine and thirty-six mm glenospheres were used for males and females, respectively. 3D PPS was used to evaluate simulated ROM differences before and after OP removal in the planes of adduction (ADD), abduction, internal rotation (IR), external rotation (ER), extension, and flexion. Impact of OP volume and circumferential extent on pre and postop removal ROM were also analyzed., Results: Humeral OP removal significantly increased impingement-free ADD, IR, ER, extension, and flexion. Removal of larger (mm 3 ) humeral OPs positively correlated with improvement in IR (R = 0.452, P  = .011), ER (R = 0.394, P  = .033), and flexion (R = 0.500, P  < .01). Greater circumferential extent of humeral OPs correlated with worse preremoval ROM in the planes of ADD (R = 0.364, P  = .02) and extension (R = 0.403, P  = .04), and improvements in ER postop removal (R = 0.431, P  = .03)., Conclusion: Humeral OP removal significantly increases impingement-free ADD, IR, ER, extension, and flexion in simulated 3D PPS models following rTSA. Magnitude of simulated ROM improvement is influenced by initial humeral OP volume and circumferential clockface extent. Surgeons should consider these effects when using 3D PPS for rTSA planning to optimize postoperative ROM prognostics., (© 2023 The Authors.)

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., Competing Interests: M.J.P. receives research support from Arthrex, Ossur, Siemens, and Smith + Nephew, Inc.; receives royalties from Bledsoe, ConMed, DJO, Elsevier, Linvatec, SLACK Inc., and Smith + Nephew, Inc.; is a shareholder of Arthrosurface, MJP Innovations, LLC, MIS, Vail Valley Surgery Center, Vail Valley Surgery Center, Steadman Philippon Surgery Center, Dillon Surgery Center, Vail MSO Holdings LLC, EffRx, Olatec, iBalance, Stryker, Trimble, Grocery Outlet, 3M, Bristol Myers Squibb, Pfizer, AbbVie, Johnson & Johnson, DocBuddy., (© The Author(s) 2023. Published by Oxford University Press.)

Osteoporosis and age-related bone loss increase bone fracture risk and impair bone healing. The need for identifying new factors to prevent or treat bone loss is critical. Previously, we reported that young MRL/MpJ mice have superior bone microarchitecture and biomechanical properties as compared to wild-type (WT) mice. In this study, MRL/MpJ mice were tested for resistance to age-related and long-term ovariectomy-induced bone loss to uncover potential beneficial factors for bone regeneration and repair. Bone tissues collected from 14-month-old MRL/MpJ and C57BL/6J (WT) mice were analyzed using micro-CT, histology, and immunohistochemistry, and serum protein markers were characterized using ELISAs or multiplex assays. Furthermore, 4-month-old MRL/MpJ and WT mice were subjected to ovariectomy (OV) or sham surgery and bone loss was monitored continuously using micro-CT at 1, 2, 4, and 6 months (M) after surgery with histology and immunohistochemistry performed at 6 M post-surgery. Sera were collected for biomarker detection using ELISA and multiplex assays at 6 M after surgery. Our results indicated that MRL/MpJ mice maintained better bone microarchitecture and higher bone mass than WT mice during aging and long-term ovariectomy. This resistance of bone loss observed in MRL/MpJ mice correlated with the maintenance of higher OSX + osteoprogenitor cell pools, higher activation of the pSMAD5 signaling pathway, more PCNA + cells, and a lower number of osteoclasts. Systemically, lower serum RANKL and DKK1 with higher serum IGF1 and OPG in MRL/MpJ mice relative to WT mice may also contribute to the maintenance of higher bone microarchitecture during aging and less severe bone loss after long-term ovariectomy. These findings may be used to develop therapeutic approaches to maintain bone mass and improve bone regeneration and repair due to injury, disease, and aging.

Background: Professional baseball pitchers sustain 75% of knee injuries while at the pitcher's mound, yet no pitching motion has been associated directly with such injuries. Stride width is a potential, modifiable risk factor worth investigating., Hypothesis: Increased stride width in both the positive and negative directions (deviations from neutral stride width) would correlate with increased incidence of knee injury in pitchers., Study Design: Descriptive laboratory., Level of Evidence: Level 5., Methods: Professional pitchers (n = 199) were evaluated with motion capture (480 Hz) while pitching. Injury history over 10 years was recorded at face-to-face interviews with pitchers. Players were subsequently grouped into stride width tertiles, compared for previous injury incidence of the lower extremities. Regressions were performed to observe performance benefits of stride width with ball velocity, accuracy, or consistency in pitch location as secondary outcomes., Results: Of the 40 lower extremity injuries reported, meniscal injury (27.5%) was the most common, followed by foot stress fracture (20.0%). Significant differences in injury incidence were noted between the least and most positive stride width tertiles: lower extremity (10.4% vs 25.8%, respectively; P = 0.03), knee (3.0% vs 15.2%, respectively; P = 0.02), and meniscal (0.0% vs 12.1%; P = 0.00). Stride width of pitchers with meniscal injury in the lead (32.6 ± 7.1 cm, n = 5; P = 0.02) and stance leg (33.5 ± 10.6 cm, n = 5; P = 0.03) was significantly more positive than that of uninjured pitchers (21.1 ± 11.5 cm, n = 164). No significant relationships were established between stride width and ball velocity ( P = 0.54) or pitch location metrics ( P > 0.05)., Conclusion: Pitchers with increased positive, stride width had significantly higher incidence of lower extremity injury (knee and meniscus). Wider, positive stride width may increase the degree of external rotation on the lead knee in a loaded state, which can place the medial side of the knee (and meniscus) at higher risk of injury., Clinical Relevance: Decreasing stride width may be beneficial for professional pitchers to reduce the rate of lower extremity injury, while also preserving performance metric outcomes.

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., (© 2022 The Authors.)

Nonunion following bone fracture and segmental bone defects are challenging clinical conditions. To combat this clinical dilemma, development of new bone tissue engineering therapies using biocompatible materials to deliver bone growth factors is desirable. This aim of this study is to use a heparin/polycation coacervate sustained-release platform to compare 5 bone morphogenetic proteins (BMPs) for promoting bone defect healing in a critical sized calvarial defect model. The in vitro 3D osteogenic pellet cultures assays demonstrated that BMPs 2, 4, 6, 7 and 9 all enhanced mineralization in vitro compared to the control group. BMP2 resulted in higher mineralized volume than BMP4 and BMP6. All BMPs and the control group activated the pSMAD5 signaling pathway and expressed osterix (OSX). The binding of BMP2 with coacervate significantly increased the coacervate average particle size. BMP2, 4, 6, & 7 bound to coacervate significantly increased the Zeta potential of the coacervate while BMP9 binding showed insignificant increase. Furthermore, using a monolayer culture osteogenic assay, it was found that hMDSCs cultured in the coacervate BMP2 osteogenic medium expressed higher levels of RUNX2, OSX, ALP and COX-2 compared to the control and BMPs 4, 6, 7 & 9. Additionally, the coacervate complex can be loaded with up to 2 μg of BMP proteins for sustained release. In vivo, when BMPs were delivered using the coacervate sustained release system, BMP2 was identified to be the most potent BMP promoting bone regeneration and regenerated 10 times of new bone than BMPs 4, 6 & 9. BMP7 also stimulated robust bone regeneration when compared to BMPs 4, 6 & 9. The quality of the newly regenerated bone by all BMPs delivered by coacervate is equivalent to the host bone consisting of bone matrix and bone marrow with normal bone architecture. Although the defect was not completely healed at 6 weeks, coacervate sustain release BMPs, particularly BMP2 and BMP7, could represent a new strategy for treatment of bone defects and non-unions., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: J.H. received Royalties from Cook Myocytes Inc., (Copyright © 2022. Published by Elsevier Ltd.)

Background: Bone morphogenetic protein 4 (BMP4) promotes the osteogenic differentiation and the bone regenerative potential of muscle-derived stem cells (MDSCs). BMP4 also promotes the self-renewal of both embryonic and somatic stem cells; however, BMP4 signaling activity significantly decreases with age. Cyclin-dependent kinase inhibitors P16 INK4A (P16) and P18 INK4C (P18) induce early G1-phase cell cycle blockade by targeting cyclin-dependent kinase 4/6. It is still unclear if BMP4 affects the bone regenerative potential of old MDSCs through regulation of P16 and P18 expression., Methods: Young and old MDSCs were isolated from 3 week (young) and 2-year-old (old) mice. In vitro cell proliferation and multipotent differentiation were performed for young and old MDSCs both before and after BMP4/GFP transduction. Cell cycle genes were analyzed using Q-PCR. The bone regenerative potential of young and old MDSCs transduced with BMP4/GFP were compared using Micro-CT and histological analysis. The bone regenerative potential of young and old MDSCs was also compared between single and double transduction (higher BMP4 levels expression). The cell proliferation, mitochondrial function and osteogenic differentiation was also compared in vitro between cells that have been transduced with BMP4GFP (single and double transduction). The correlation of bone regeneration capacity of young and old MDSCs with P16 and P18 expression was further evaluated at 10 days after cell transplantation using histology and western blot analysis., Results: Old murine MDSCs (MDSCs) exhibit reduced proliferation and multi-lineage differentiation potential with or without BMP4 stimulation, when compared to young murine MDSCs. Old MDSCs express significantly higher P16 and lower P18, with more cells in the G0/1 phase and fewer cells in the G2/M phase, compared to young MDSCs. Old MDSCs retrovirally transduced to express BMP4 regenerated less bone in a critical size skull defect in CD-1 nude mice when compared to young retrovirally transduced MDSCs expressing similar BMP4 levels and contribute less to the new regenerated new bone. Importantly, both young and old MDSCs can regenerate more bone when BMP4 expression levels are increased by double-transduction with the retroviral-BMP4/GFP. However, the bone regeneration enhancement with elevated BMP4 was more profound in old MDSCs (400% at 2 weeks) compared to young MDSCs (200%). Accordingly, P18 is upregulated while P16 is downregulated after BMP4 transduction. Double transduction did not further increase cell proliferation nor mitochondrial function but did significantly increase Osx expression in both young and old MDSCs. Old MDSCs had even significant higher Osx levels as compared to young MDSCs following double transduction, while a similar Alp expression was observed between young and old MDSCs after double transduction. In addition, at 10 days after cell transplantation, old MDSCs having undergone double transduction regenerated bone more rapidly as showed by Alcian blue and Von Kossa staining. Western blot assays demonstrated that old MDSCs after retro-BMP4/GFP double transduction have significantly lower P18 expression levels when compared to young BMP4-transduced MDSCs. In addition, P18 expression was slightly increased in old MDSCs after double transduction when compared to single transduction. P16 expression was not detectable for both young and two old BMP4/GFP transduced MDSCs groups., Conclusions: In summary, BMP4 can offset the adverse effect of aging on the osteogenic differentiation and the bone regenerative potential of old MDSCs via up-regulation of P18 and down-regulation P16 expression., (© 2022. The Author(s).)

Purpose: To determine whether preoperative magnetic resonance imaging (MRI) can reliably predict labral width in primary hip arthroscopy., Methods: Patients who underwent primary hip arthroscopy with labral repair performed by a single surgeon from January 2008 to December 2015 were identified retrospectively from a prospectively collected database. The width of the labrum was measured intraoperatively at the time of surgery. Two orthopaedic surgeons performed labral width measurements on MRI at 3 standardized locations using the clock-face method at 2 time points, 4 weeks apart. Interobserver and intraobserver reliabilities were calculated, and comparisons were performed between intraoperatively measured labral widths and MRI measurements at the 3 positions., Results: Fifty-eight patients who underwent primary hip arthroscopy were enrolled in the study. The average labral width measurements at the 3-, 12-, and 9-o'clock positions were 6.8 mm (standard deviation [SD], 1.1), 6.9 mm (SD, 1.3 mm), and 6.2 mm (SD, 0.9 mm), respectively, on MRI compared with 7.2 mm (SD, 1.5 mm), 7.8 mm (SD, 2.3 mm), and 7.3 mm (SD, 1.6 mm), respectively, when measured intraoperatively. The intraoperative measurements were larger than the MRI measurements at all 3 locations, with significant differences at the 12-o'clock ( P  = .008) and 9-o'clock ( P < .001) positions. The positive predictive value of the MRI measurements was 92% at the 3-o'clock position, 89% at the 12-o'clock position, and 94% at the 9-o'clock position for identifying a labral width of 6 mm or greater., Conclusions: Measuring labral width on MRI yielded, on average, a value that is smaller than the intraoperatively measured width in primary hip arthroscopy procedures. MRI can predict a labral width of 6 mm or greater in at least 89% of cases, which will assist in operative planning., Clinical Relevance: The clinical implications of this research include identifying the rare patients in whom more advanced hip arthroscopy procedures may be indicated, such as labral augmentation, in instances of inadequate labral volume that will adequately restore the biomechanics of the suction seal., (© 2022 The Authors.)

Purpose: The purpose of this study was to compare outcomes between anterior shoulder instability patients with and without glenolabral articular disruption (GLAD) lesions after undergoing arthroscopic Bankart repair and to evaluate potential risk factors for inferior outcomes and recurrent instability., Methods: Prospectively collected data were retrospectively reviewed for patients who underwent arthroscopic Bankart repair with and without GLAD lesions at a minimum of 2 years follow-up. Consecutive patients were matched by age, sex, and number of anchors. Patient-reported outcomes (PROs) were evaluated before and after surgery, including American Shoulder and Elbow Surgeons, Single Assessment Numeric Evaluation, Quick Disabilities of the Arm, Shoulder and Hand, Short Form-12 score, and satisfaction. Recurrent dislocation, subjective instability, and reoperation were analyzed. Additionally, PROs were assessed on the basis of GLAD lesion characteristics., Results: A total of 54 patients (27 GLAD, 27 control) with a mean age of 28.9 ± 11.6 years were analyzed at mean 4.5 ± 1.9 years (range, 2-9 years) follow-up. Thirty-eight (70.3%) of the participants were male. Patients in both groups experienced significant improvements in all PROs ( P ≤ .006 for all measures) and reported high median satisfaction (scale 1-10: 10 vs 10, P  = .290) at final follow-up. Two patients in the GLAD cohort and 1 in the control cohort underwent reoperation ( P  = .588). Four (14.8%) patients in each group reported recurrent dislocation ( P  = 1.0). Additionally, 2 (7.4%) GLAD patients and 1 (3.7%) control patient reported subjective shoulder instability after surgery ( P  = 1.0). No significant differences in PROs were observed based on anchor/labral advancement or treatment with microfracture, nor were significant correlations observed between GLAD lesion size and PROs ( P > .05 for all)., Conclusion: Arthroscopic Bankart repair in patients with GLAD lesions resulted in significantly improved outcomes with high satisfaction, which was no different when compared with those without GLAD lesions., Level of Evidence: Level III, retrospective comparative study., (© 2022 The Authors.)

Background and Aims: Previous work has shown that oral losartan can enhance microfracture-mediated cartilage repair in a rabbit osteochondral defect injury model. In this study, we aimed to determine whether oral losartan would have a detrimental effect on articular cartilage and bone homeostasis in the uninjured sides., Methods: New Zealand rabbits were divided into 4 groups including normal uninjured (Normal), contralateral uninjured side of osteochondral defect (Defect), osteochondral defect plus microfracture (Microfracture) and osteochondral defect plus microfracture and losartan oral administration (10 mg/kg/day) (Losartan). Rabbits underwent different surgeries and treatment and were sacrificed at 12 weeks. Both side of the normal group and uninjured side of treatment groups tibias were harvested for Micro-CT and histological analysis for cartilage and bone including H&E staining, Herovici's staining (bone and cartilage) Alcian blue and Safranin O staining (cartilage) as well as immunohistochemistry of losartan related signaling pathways molecules for both cartilage and bone., Results: Our results showed losartan oral treatment at 10 mg/kg/day slightly increase Alcian blue positive matrix as well as decrease collagen type 3 in articular cartilage while having no significant effect on articular cartilage structure, cellularity, and other matrix. Losartan treatment also did not affect angiotensin receptor type 1 (AGTR1), angiotensin receptor type 2 (AGTR2) and phosphorylated transforming factor β1 activated kinase 1 (pTAK1) expression level and pattern in the articular cartilage. Furthermore, losartan treatment did not affect microarchitecture of normal cancellous bone and cortical bone of tibias compared to normal and other groups. Losartan treatment slightly increased osteocalcin positive osteoblasts on the surface of cancellous bone and did not affect bone matrix collagen type 1 content and did not change AGTR1, AGTR2 and pTAK1 signal molecule expression., Conclusion: Oral losartan used as a microfracture augmentation therapeutic does not have significant effect on uninjured articular cartilage and bone based on our preclinical rabbit model. These results provided further evidence that the current regimen of using losartan as a microfracture augmentation therapeutic is safe with respect to bone and cartilage homeostasis and support clinical trials for its application in human cartilage repair., Competing Interests: J.H received Royalties from Cooke Myocytes annually. M.J.P, Education payments from Linvatec (2015); speaking fees and consulting fees from Smith & Nephew (through 2018), Synthes GmbH (2019); royalties from DJO (2015/16), Linvatec (through 2018), and Smith & Nephew (2015/16); and hospitality payments from Siemens Medical Solutions (2016). All other authors have no competing interest to disclose., (© 2022 The Authors.)

Purpose: To evaluate and compare patient-reported outcomes (PROs) after isolated greater tuberosity (GT) fracture fixation versus acute rotator cuff repair (RCR) at a minimum of 2 years., Methods: Patients who underwent isolated GT fracture fixation were compared in a 1-to-3 fashion with patients who underwent arthroscopic RCR for an acute rotator cuff tear by a single surgeon from January 2006 and to July 2018. Data were prospectively collected and retrospectively reviewed. PROs were compared pre- and postoperatively as well as between groups (American Shoulder and Elbow Surgeons [ASES], General Health Short Form-12 Physical Component [SF-12 PCS], Single Assessment Numerical Evaluation [SANE], Quick Disabilities of the Arm, Shoulder, and Hand [QuickDASH], and satisfaction). Reoperation rates were analyzed., Results: A total of 57 patients (14 with isolated GT fracture fixation, mean age 45.7 years; and 43 who underwent ARCR for acute tears, mean age 56.6 years) were evaluated ( P  = .050). ASES scores significantly improved from 39.7 to 94.1 ( P  = .018) in the isolated GT fracture fixation group and from 51.0 to 95.2 ( P < .001) in acute RCR group. At final follow-up, mean QuickDASH scores were 8.9 and 7.9 ( P  = .677) and SANE scores were 91.1 and 87.3 ( P  = .616) for the GT and acute RCR groups, respectively. The median satisfaction was 10/10 for the GT group and 10/10 for the RCR group. Additional comparison of patients who underwent double-row repair for an acute rotator cuff tear or isolated GT fracture revealed no significant difference in outcomes ( P > .404)., Conclusion: Minimum 2-year PROs after fixation of isolated GT fractures show relatively high outcome scores whether treated by open reduction and internal fixation or arthroscopic fixation using a double-row bridging technique. The improvements in PROs are similar to those achieved with acute rotator cuff tears that were fixed arthroscopically with RCR. Further analysis of these results suggest that the functional outcomes of tendon-to-bone healing with linked, double-row rotator cuff repairs are similar to those of bone-to-bone healing as seen with GT fractures., Level of Evidence: III, retrospective comparative study., (© 2022 The Authors.)

Subscapularis tears have been found to occur in the setting of subcoracoid impingement and are related to the narrowing of the coracohumeral interval. The advancement of arthroscopic techniques has allowed for improved identification and treatment of this historically overlooked pathology. Challenges of arthroscopic subscapularis treatment include nearby neurovascular structures, tendon retraction, and adhesions, which are further complicated by diminished arthroscopic visualization, resulting from the concomitant subcoracoid impingement. The purpose of this Technical Note is to describe our preferred technique for arthroscopic management of subscapularis tears in the setting of subcoracoid impingement that is simple and reproducible, as well as cost-effective and efficient with limited additional morbidity to that of a standard diagnostic shoulder arthroscopy., (© 2021 The Authors.)

Background: The prevalence of findings on shoulder magnetic resonance imaging (MRI) is high in asymptomatic athletes of overhead sports., Purpose/hypothesis: The purpose of this study was to determine the prevalence of atypical findings on MRI in shoulders of asymptomatic, elite-level climbers and to evaluate the association of these findings with clinical examination results. It was hypothesized that glenoid labrum, long head of the biceps tendon, and articular cartilage pathology would be present in >50% of asymptomatic athletes., Study Design: Cross-sectional study; Level of evidence, 3., Methods: A total of 50 elite climbers (age range, 20-60 years) without any symptoms of shoulder pain underwent bilateral shoulder examinations in addition to dedicated bilateral shoulder 3-T † MRI. Physical examinations were performed by orthopaedic sports medicine surgeons, while MRI scans were interpreted by 2 blinded board-certified radiologists to determine the prevalence of abnormalities of the articular cartilage, glenoid labrum, biceps tendon, rotator cuff, and acromioclavicular joint., Results: MRI evidence of tendinosis of the rotator cuff, subacromial bursitis, and long head of the biceps tendonitis was exceptionally common, at 80%, 79%, and 73%, respectively. Labral pathology was present in 69% of shoulders, with discrete labral tears identified in 56%. Articular cartilage changes were also common, with humeral pathology present in 57% of shoulders and glenoid pathology in 19% of shoulders. Climbers with labral tears identified in this study had significantly increased forward elevation compared with those without labral tears in both active ( P = .026) and passive ( P = .022) motion., Conclusion: The overall prevalence of intra-articular shoulder pathology detected by MRI in asymptomatic climbers was 80%, with 57% demonstrating varying degrees of glenohumeral articular cartilage damage. This high rate of arthritis differs significantly from prior published reports of other overhead sports athletes., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: M.N.S. has received education payments from Southern Edge Orthopaedics. C.P.H. has received consulting fees from Smith & Nephew. T.R.H. has received hospitality payments from Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2022.)

Traditionally, total shoulder arthroplasty is performed using a deltopectoral approach through which the glenohumeral joint is accessed by mobilization of the subscapularis. Despite several variations on the subscapularis management techniques, postoperative complications, including subscapularis deficiency and lower functional outcomes, remain an area for improvement. The purpose of this Technical Note is to describe in detail our technique for management of the subscapularis in the setting of a stemless humeral implant through which the repair is planned and almost entirely performed at the beginning of the case, prior to the subscapularis peel. This technique aims to improve outcomes after total shoulder arthroplasty by 1) avoiding the anatomic implant with anchor drilling, 2) improving procedure efficiency, and 3) anatomically "repairing" the subscapularis prior to takedown by placing anchors exactly at the repair-tension site.

Axillary nerve compression is a rare cause of posterolateral shoulder pain. Once the diagnosis is confirmed and after failure of conservative measures, open procedures have been the mainstay of treatment for several decades. More recently, arthroscopic techniques have been proposed, which offer several advantages, including improved access to difficult locations, better visualization, and less surgical morbidity. The objective of this Technical Note is to describe an arthroscopic neurolysis of the axillary nerve from the inferior humeral pouch, through the quadrilateral space and into the subdeltoid recess., (© 2021 The Authors.)

Background: The therapeutic efficacy of orthobiologic therapies for rotator cuff repair is difficult to evaluate owing to reporting inconsistences. In response, the Minimum Information for Studies Evaluating Biologics in Orthopaedics (MIBO) guidelines were developed to ensure standard reporting on orthobiologic therapies., Purpose: To systematically review clinical studies evaluating platelet-rich plasma (PRP) for full-thickness rotator cuff repair and adherence to MIBO guidelines., Study Design: Scoping review; Level of evidence, 4., Methods: A search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using PubMed, EMBASE, and the Cochrane Library databases. Inclusion criteria were clinical studies reporting on rotator cuff tears (≥1 cm) surgically repaired with PRP. Patient demographics, biologic intervention, and adherence to the MIBO guidelines were systematically reviewed., Results: A total of 19 studies (1005 patients) were included in this review. Across all studies, 58.5% of the MIBO checklist items for PRP were reported. Out of 47 checklist items, 19 were reported in over 85% of studies, whereas 22 were reported in less than half of studies. Details of whole-blood processing and characteristics, as well as PRP processing and characteristics, were reported inconsistently, and no study provided adequate information to enable the precise replication of preparation protocols for PRP., Conclusion: This systematic review highlights the current reporting deficiencies within the scientific literature of important variables for evaluating PRP for full-thickness rotator cuff repair. There was widespread variability among published studies that evaluate PRP for this application and, more specifically, studies were limited by inconsistent universal reporting of whole-blood and PRP processing and postprocessing characteristics. To improve our understanding of biologic efficacy and to promote repeatability, stricter adherence to the MIBO guidelines is necessary. We propose that the checklist limitations be addressed and that modification of the MIBO guidelines be considered to improve the reporting of individual components within certain categories., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: J.J.R. has received financial support from ProofPoint Biologics and hospitality payments from Smith & Nephew. P.J.M. has received financial support from ProofPoint Biologics, royalties from Arthrex, Medbridge, and Springer; consulting fees from Arthrex; research support from Arthrex, Ossur, Siemens, VuMedi, and Smith & Nephew; and hospitality payments from Arthrosurface, Gemini Mountain Medical, Stryker, and Sanofi-Aventis; and holds stock in Vu Medi. J.H. has received financial support from ProofPoint Biologics and royalties from CookMyosite. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2021.)

Extensive glenoid labral tears, whether the result of repetitive instability or first-time dislocation, compromise the mechanical stability of the glenohumeral joint due to disruption of the anterior, inferior, posterior, and/or superior portions of the labrum. These lesions often result in recurrent multiplanar instability and pain that is nonresponsive to conservative management and difficult to diagnose due to variability in clinical presentation and advanced imaging findings. Arthroscopic repair techniques to address symptomatic shoulder instability have showed positive patient-reported outcomes, low failure rates, and high return-to-sport rates. The evolution of knotless suture anchors offers a fixation method that has proven to be functionally equivalent to knotted suture anchors while avoiding the risks of knotted anchors (knot loosening, knot migration, articular abrasion) and allowing easier placement and decreased operative time. The purpose of this technique is to describe our preferred method to treat a 270° labral tear through arthroscopic knotless anchor repair and demonstrate the expanded application of this technique for extensive glenoid labral pathology.

CA4+ is a novel cationic iodinated contrast agent utilized for contrast-enhanced microCT (CECT). In this study, we compared CA4+ CECT for cartilage quantification of unfixed and neutral buffered formalin (NBF)-fixed rabbit distal femur cartilage after 8-, 24- and 30-hours of contrast agent diffusion. The stability of CA4+ binding to cartilage after PBS soak and decalcification was also investigated by CECT. We further assessed the feasibility of cartilage histology and immunohistochemistry after CA4+ CECT. Contrast-enhanced CA4+ labeled unfixed and NBF-fixed cartilage tissues facilitate articular cartilage quantification and accurate morphological assessment. The NBF fixed tissues demonstrate higher cartilage intensity and imaging characteristics distinct from subchondral bone than unfixed tissues while maintaining stable binding even after decalcification with 10% EDTA. The unfixed tissues labeled with CA4+, after CECT imaging and decalcification, are amenable to H&E, Alcian blue, and Safranin O staining, as well as Col2 immunohistochemistry. In contrast, only H&E and Alcian blue staining can be accomplished with CA4+ labeled NBF fixed cartilage, and CA4+ labeling interferes with downstream immunohistochemistry and Safranin O staining, likely due to its positive charge. In conclusion, CA4+ CECT of NBF fixed tissues provides high quality microCT cartilage images and allows for convenient quantification along with feasible downstream H&E and Alcian blue staining after decalcification. CA4+ CECT of unfixed tissues enables researchers to obtain both quantitative microCT as well as cartilage histology and immunohistochemistry data from one set of animals in a cost-, time-, and labor-efficient manner., Competing Interests: JH received Royalties from Cooke Myocytes annually. Dr. Philippon, Education payments from Linvatec (2015); speaking fees and consulting fees from Smith & Nephew (through 2018), Synthes GmbH (2019); royalties from DJO (2015/16), Linvatec (through 2018), and Smith & Nephew (2015/16); and hospitality payments from Siemens Medical Solutions (2016)., (AJTR Copyright © 2021.)

Background . Fibrin sealant has been used as a scaffold to deliver genetically modified human muscle-derived stem cells (hMDSCs) for bone regeneration. Alternatively, autologous blood clots are safe, economic scaffolds. This study compared autologous blood clot (BC) with fibrin sealant (FS) as a scaffold to deliver lenti-BMP2/GFP-transduced hMDSCs for bone regeneration. Methods . In vitro osteogenic differentiation was performed using 3D pellet culture and evaluated using microCT and Von Kossa staining. The lenti-GFP transduced cells were then mixed with human blood for evaluation of osteogenic differentiation. Furthermore, a murine critical- sized calvarial defect model was utilized to compare BC and FS scaffolds for lenti-BMP2/GFP-transduced hMDSCs mediated bone regeneration and evaluated with micro-CT and histology. Results . Lenti-BMP2/GFP transduced hMDSCs formed significantly larger mineralized pellets than non-transduced hMDSCs. hMDSCs within the human blood clot migrated out and differentiated into ALP + osteoblasts. In vivo, BC resulted in significantly less new bone formation within a critical-sized calvarial bone defect than FS scaffold, despite no difference observed for GFP + donor cells, osteoclasts, and osteoblasts in the newly formed bone. Conclusions . Human lenti-BMP2/GFP-transduced hMDSCs can efficiently undergo osteogenic differentiation in vitro. Unexpectedly, the newly regenerated bone in BC group was significantly less than the FS group. The autologous blood clot scaffold is less efficacious for delivering stem cells for bone regeneration than fibrin sealant.

Purpose: To perform a systematic review comparing clinical outcomes, radiographic outcomes, and complication rates after acute (surgery ≤6 weeks from injury) versus chronic (surgery >6 weeks from injury) acromioclavicular joint reconstructions for grade III injuries using modern suspensory fixation techniques., Methods: We performed a systematic review of the literature examining acute versus chronic surgical treatment of Rockwood grade III acromioclavicular joint separations using the Cochrane registry, MEDLINE database, and Embase database over the past 10 years according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The inclusion criteria included techniques using suspensory fixation, a minimum study size of 3 patients, a minimum follow-up period of 6 months, human studies, and English-language studies. The methodology of each study was evaluated using the Methodological Index for Non-randomized Studies (MINORS) tool for nonrandomized studies and the revised Cochrane risk-of-bias (RoB 2) tool for randomized controlled trials., Results: The systematic review search yielded 20 studies with a total of 253 patients. There were 2 prospective randomized controlled trials, but most of the included studies were retrospective. On comparison of acute surgery (≤6 weeks) and chronic surgery (>6 weeks), individual studies reported a range of Constant scores of 84.4 to 98.2 and 80.8 to 94.1, respectively. The ranges of radiographic coracoclavicular distances reported at final follow-up also favored acute reconstructions, which showed improved reduction (9.2-15.7 mm and 11.7-18.6 mm, respectively). The reported complication rates ranged from 7% to 67% for acute reconstructions and from 0% to 30% for chronic reconstructions., Conclusions: The ranges in the Constant score may favor acute reconstructions, but because of the heterogeneity in the surgical techniques in the literature, no definitive recommendations can be made regarding optimal timing., Level of Evidence: Level IV, systematic review of Level I through IV studies., (© 2021 Published by Elsevier on behalf of the Arthroscopy Association of North America.)

Posterior shoulder instability is increasingly recognized and diagnosed in young athletes. These patients often present with vague shoulder pain rather than the frank instability commonly seen with anterior instability. Three common causes of posterior shoulder instability are congenital retroversion, a single traumatic event, or repetitive microtrauma with erosive effects. The critical determination when deciding on the appropriate treatment of posterior shoulder instability is the presence and degree of glenoid bone loss. In patients without bone loss, arthroscopic procedures have a high success rate with a failure rate of less than 10% and an 89% return-to-sport rate. The determination of the critical amount of bone loss that would permit an arthroscopic procedure is controversial, but recent reports that attempt to quantify the critical bone loss value posteriorly have ranged from 13.5% to 20%. This Technical Note describes our preferred method of open surgical treatment of posterior shoulder instability with posterior glenoid bone loss using an intra-articular distal tibial allograft., (© 2021 by the Arthroscopy Association of North America. Published by Elsevier.)

Complete radial tears of the meniscus render the entirety of the meniscus functionally incompetent (known as an ameniscal state); therefore, attempts at repair are essential. Although various techniques have been described, repair failures continue to frequently occur, especially with the medial meniscus. Inside-out repair and anchoring of the preserved meniscus to both the capsule and tibia may offer the advantage of a more robust repair. The objective of this Technical Note is to describe a method of repair for complete radial tears of the medial meniscus using a combination of inside-out sutures and secondary reinforcement to the tibia using all-suture knotless anchors., (© 2021 Published by Elsevier on behalf of the Arthroscopy Association of North America.)

Meniscal tears treated with partial meniscectomies have been shown to significantly increase contract pressures within the tibiofemoral joint, and a complete focal meniscal deficiency may render the entirety of the meniscus functionally incompetent. Although various techniques of meniscal transplantation have been described, these techniques may require the excision of a considerable amount of healthy meniscal tissue. Furthermore, failures continue to frequently occur. Therefore, attempts to restoring normal knee kinematics and biomechanical forces are essential. Segmental meniscus allograft transplantations may offer the advantage of a robust repair by both maintaining knee biomechanics and biology while maximizing preservation of native meniscal tissue. Also, most meniscal deficiency involves only a portion of the meniscus, and thus we developed this technique to segmentally transplant only the deficient portion. The purpose of this Technical Note is to describe a technique of segmental medial meniscus allograft transplantation in a patient with focal medial meniscus deficiency.

Popliteal tendon tears without concomitant damage to the cruciate ligaments or other posterolateral corner ligaments are rare entities with few studies reporting on their existence, with rare case reports discussing their treatment. Continued pain, instability, and effusions are typical symptoms, with magnetic resonance imaging being the main tool for diagnosis. Furthermore, monosodium urate crystals that induce gout have been shown to collect in the popliteal groove and thus may lead to degeneration and isolated tearing. Most case reports have reviewed arthroscopic debridement of the tendon in patients with continued pain. However, in the young athletic population, open repair, if the tissue appears to be of adequate quality, should be a consideration. The use of suture anchors to restore the popliteus to its anatomic footprint is desired. This Technical Note describes a safe and reliable technique for open popliteal tendon repair of an isolated avulsion injury., (© 2020 by the Arthroscopy Association of North America. Published by Elsevier.)

Background: Coracoid transfer procedures have been increasingly utilized for anterior shoulder instability with associated glenoid bone loss 1 . Unfortunately, in a young, high-risk patient population, these procedures can fail secondary to traumatic causes but also because of bone graft resorption or malposition or hardware prominence, among other reasons 2 . In active patients, revision glenoid reconstruction may be indicated. Distal tibial osteoarticular allografts have been utilized to treat recurrent anterior shoulder instability for several years 3 . Recently, this technique has been applied to cases of failed Latarjet procedures in order to reconstitute the absent glenoid bone stock 4 , demonstrating excellent clinical outcomes at a minimum follow-up of 3 years 2 ., Description: The procedure is performed in the beach-chair position. First, a diagnostic shoulder arthroscopy is performed to assess the cartilaginous surfaces, to examine the Hill-Sachs lesion and its engagement, and to remove any loose bodies. Next, the prior deltopectoral incision is developed, and the deltopectoral interval is utilized to visualize the subscapularis. The subscapularis is split at the junction of its upper two-thirds and lower one-third. Careful dissection is used to develop the subscapularis split from lateral to medial because the prior coracoid transfer affects the native neurovascular anatomy medially. If substantial coracoid bone remains from the previous transfer, a conjoined tendon tenotomy can be performed to further aid in visualization 5 . Next, any associated hardware is removed, and the coracoid bone remnant is removed. The glenoid defect is sized, and the osseous glenoid bed is prepared. A fresh-frozen distal tibial allograft is then fashioned, washed of marrow elements, and enhanced with platelet-rich plasma before being fixed to the glenoid with use of 2 cortical screws in a lagged fashion. The capsule and subscapularis split are then closed to complete the repair., Alternatives: Alternatives to revision glenoid reconstruction with distal tibial allograft include reconstruction with an iliac crest autograft, distal clavicular autograft, revision coracoid transfer, or nonoperative treatment through rehabilitation and activity modification., Rationale: In cases of failed coracoid transfer for anterior shoulder instability with associated glenoid bone loss, distal tibial allograft is the superior revision treatment option for several reasons: it allows for an osteoarticular graft, offers flexibility in terms of graft size, and requires no donor-site morbidity. Distal tibial allograft allows active, high-risk patients to have restored and maintained stability with low complication and graft-resorption rates 2 ., Expected Outcomes: Glenoid reconstruction with a distal tibial allograft is associated with improved patient-reported outcomes from preoperatively, as well as recurrence rates of <10% and graft-union rates of >90% 2 ., Important Tips: Initiating the procedure with an arthroscopic evaluation allows for a complete diagnostic examination, including the Hill-Sachs lesion, articular cartilage, and rotator cuff, as well as removal of any loose bodies, which are frequently present and sometimes difficult to visualize and access during the open procedure.A subscapularis split allows for maintenance of the subscapularis insertion on the lesser tuberosity as well as minimal disruption of the muscle fibers.A conjoined tendon tenotomy can provide improved access for hardware removal if the coracoid bone graft from the prior transferred coracoid is present.A 5.5-mm arthroscopic burr is utilized to decorticate the anterior aspect of the glenoid, which facilitates graft union because the burr allows built-in suction capability during constant irrigation, minimizing the possibility of heat necrosis.The distal tibial allograft is thoroughly lavaged to remove residual marrow elements prior to insertion in order to diminish potential immunogenicity.Two solid, fully threaded 3.5-mm cortical screws are placed in a lagged fashion to fix the distal tibial allograft to the glenoid., Competing Interests: Disclosure: The authors indicated that no external funding was received for any aspect of this work. On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one or more of the authors checked “yes” to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work and “yes” to indicate that the author had other relationships or activities that could be perceived to influence, or have the potential to influence, what was written in this work (http://links.lww.com/JBJSEST/A317)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Isolated lateral compartment arthritis or focal chondral defects in the setting of genu valgum in young, active individuals can be treated with a varus-producing distal femoral osteotomy with or without cartilage treatment. Both medial closing-wedge and lateral opening-wedge techniques have been described, with neither demonstrating clear superiority. The objective of this Technical Note is to describe a technique of biplanar medial opening-wedge with controlled reduction using an articulated tensioning device to achieve a safe, reproducible result., (© 2020 by the Arthroscopy Association of North America. Published by Elsevier.)

Ruptures of the patellar tendon are rare but potentially devastating injuries reported to occur most commonly in active males in their third and fourth decades of life. Repair failure rates have been reported to range between 2% and 50% based on surgical technique used. There are several inherent challenges associated with revision patellar tendon repair, including quadriceps atrophy, contracture, tissue loss, excessive scarring, and improper patella height. There remains no consensus regarding ideal revision patellar tendon repair technique. The purpose of this Technical Note is to describe our preferred method for revision patellar tendon repair using suture anchors and allograft augmentation with adjustable loop suspensory fixation. On the basis of recent studies, we have carefully chosen our fixation and augmentation methods that have shown biomechanical promise, while allowing the surgeon to carefully titrate the patellar tendon length and accommodate for some patellar tendon tissue loss., (© 2020 by the Arthroscopy Association of North America. Published by Elsevier.)

In the setting of femoroacetabular impingement, the acetabular labrum may be torn or pathologic, and it must be surgically repaired to restore the native suction seal and hip function. However, the current methods of arthroscopic suture passage commonly result in some degree of disruption of the chondrolabral junction, with penetration and shuttling of the repair sutures. Novel instrumentation and surgical techniques have aimed to repair the acetabular labrum with decreased violation of the intrasubstance fibers to provide anatomic eversion/inversion of the labrum to restore the suction seal. In this Technical Note, we describe a method of suture passage through the use of a self-grasping suture-passing device that allows for anatomic labral repair while maintaining the chondrolabral junction as well as minimizing iatrogenic damage the labrum intrasubstance fibers., (© 2020 by the Arthroscopy Association of North America. Published by Elsevier.)

Treatment of severe acromioclavicular joint injuries remains controversial and has evolved over the past 4-plus decades. Although several variations on reconstruction exist, an ideal technique will likely use a combination of coracoclavicular ligament reconstruction with suture backup stabilization, minimal drill holes to reduce the risk of fracture, arthroscopic-assisted guidance for anatomic graft and suture placement in and around the coracoid, and fluoroscopic-aided reduction to ensure an anatomic acromioclavicular joint. The objective of this Technical Note is to describe an arthroscopic-assisted coracoclavicular ligament reconstruction with allograft using fluoroscopically guided and cerclage-controlled anatomic reduction of the acromioclavicular joint., (© 2020 by the Arthroscopy Association of North America. Published by Elsevier.)

Long head of the biceps (LHB) pathology is a prevalent cause of shoulder pain. Arthroscopic tenotomy and tenodesis are performed for treatment at increasing frequency. When LHB pathology is the only glenohumeral intra-articular pathology that needs to be addressed, and an LHB tenotomy or subpectoral LHB tenodesis is planned, it is unnecessary and potentially harmful to establish an anterior rotator interval portal. The objective of this Technical Note is to describe a minimally invasive technique for LHB tenotomy at the supraglenoid tubercle without the need for establishing an accessory portal., (© 2020 by the Arthroscopy Association of North America. Published by Elsevier.)

Purpose of Review: Hip arthroscopy and its indications continue to expand. Understanding the durability of hip arthroscopic procedures remains important not only for counseling patients, but also for determining the success of certain procedures or in certain populations. Survivorship is defined as the proportion of hip arthroscopy patients who have not yet gone on to periacetabular osteotomy (PAO), total hip arthroplasty (THA), and/or revision surgery. The purpose of this review is to summarize the recent literature pertaining to survivorship after certain hip arthroscopic procedures and certain special populations., Recent Findings: There is yet to be level 1 evidence published with relation to survivorship following hip arthroscopy. The best evidence in the recent literature is contained in just rew long-term prospective studies demonstrating good to excellent survivorship following hip arthroscopy for femoroacetabular impingement (FAI). Unfortunately, the follow-up for other conditions treated by hip arthroscopy is more limited. In summary, hip arthroscopy indications continue to expand. The most common indication for surgery is FAI, and its recently published long-term survivorship demonstrates excellent durability. Other hip arthroscopic procedures, including labral reconstruction, adjunctive procedures such as capsular closure, and special populations such as athletes, also demonstrate excellent survivorship in shorter term follow-up. Further prospective research is needed to further define survivorship of various hip conditions, associated procedures, and special populations commonly treated with hip arthroscopy.

Background: Blade plates are frequently used for internal fixation following proximal femoral varus rotational osteotomy to treat hip dysplasia in children with cerebral palsy. Recently, cannulated blade plates with the option for a proximal locking screw have demonstrated ease of insertion and low complication rates. Although there are two commonly used blade plates with a proximal screw option, no comparison of their biomechanical profiles has been undertaken., Questions/purposes: Our study sought to compare the structural properties under axial loading, as well as the biomechanical contribution of a proximal screw, of two different 90° cannulated blade plates designed for pediatric proximal femurs. Plate A has a hole distal to the blade designed to attach a plate inserter, through which a 3.5-mm non-locking cortical screw could be placed. Plate B has a threaded hole distal to the blade designed to accept a 3.5-mm locking screw., Methods: Plate A and plate B were inserted into 33 left pediatric synthetic proximal femurs. Axial loading to failure of plate A with and without a proximal screw was compared to that of plate B with and without a proximal screw. An additional 10 samples using plate B, with and without a proximal locking screw, were tested in tension to quantify the effect of the proximal screw on pullout strength., Results: Plate B failed at a higher axial load than plate A. The addition of a proximal screw did not affect the axial load to failure for either plate. Pullout testing revealed that blade plates fixed with the proximal screw failed in tension at a significantly higher load (856.3 ± 120.9 N) than those without proximal fixation (68.1 ± 9.3 N, p  < 0.001)., Conclusions: Plate B failed at a higher axial load in biomechanical testing, likely related to differences in its design. The addition of a proximal screw did not increase the axial loading properties of the blade plate construct but did increase the pullout strength by a factor of 12. These results may be used to influence implant selection and post-operative rehabilitation following proximal femoral osteotomies in children., Competing Interests: Conflict of InterestJoseph J. Ruzbarsky, MD, Ishaan Swarup, MD, Matthew R. Garner, MD, Kathleen Meyers, MS, Folorunsho Edobor-Osula, MD, Roger Widmann, MD, and David M. Scher, MD, report that OrthoPediatrics provided some of the blade plates used in this study. David M. Scher, MD, also reports receiving personal fees as a consultant from OrthoPediatrics, during the conduct of this study., (© Hospital for Special Surgery 2019.)

Background: Medial opening-wedge high tibial osteotomy (HTO) is one of the most common and effective HTO techniques, in which the proximal tibia is cut medially, leaving an intact lateral hinge of bone that can be opened to a variable amount for the desired correction, but the technical complications of lateral cortex fracture and intra-articular fracture are well described. The lateral bone hinge for medial opening-wedge HTO is crucial. If the hinge is too small, the tibia can fracture and become unstable, requiring further fixation. If the hinge is too large, the osteotomy can propagate into the joint as an intra-articular fracture when opening the osteotomy., Purpose: We propose a new technique that utilizes digital preoperative templating to improve the accuracy of the cut. Preoperative digital templating may allow the surgeon to reproducibly obtain a lateral bone hinge of 10 mm, while also reducing radiation exposure relative to the traditional fluoroscopically assisted technique., Methods: Ten cadaver extremities from five cadavers were matched into pairs and randomized into two groups: those with and without preoperative templating. The templating protocol measures the distance between two points on the medial and lateral cortices, and 20 mm is subtracted to determine the depth of the saw cut (10 mm for the hinge and another 10 mm because the proximal tibia is oval in shape). The control method was done by making the cut using fluoroscopy with tactile feedback. Postoperative computed tomography scans were obtained of all legs to measure the width of the lateral bone hinge. Intraoperative fluoroscopy used during both techniques and the numbers of fluoroscopy shots were recorded., Results: We found neither the treatment group with preoperative planning nor the control group with the conventional technique had bone hinge widths that were different from the ideal 10 mm. The average hinge widths for the treatment and control groups were 11.2 and 11.5 mm, respectively. However, the treatment group was exposed to significantly less intraoperative fluoroscopy during the osteotomy cut. The average total number of fluoroscopy shots was 2.2 in the treatment group versus 6.3 for the control group., Conclusions: This new preoperative planning technique achieves similar accuracy of the lateral bone hinge when compared to current methods but exposes the patient, surgeon, and staff to significantly less intraoperative radiation., Competing Interests: Elad Spitzer, MD, Joseph J. Ruzbarsky, MD, John B. Doyle, BA, Kaitlyn L. Yin, BA, declare they have no conflict of interest. Robert G. Marx, MD, MSc, FRCS, reports receiving research funding from DePuy Synthes to support this work, as well as book royalties from Springer and Demos Health and Deputy and Associate Editorships at Journal of Bone and Joint Surgery outside this work.All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2013.N/ADisclosure forms provided by the authors are available with the online version of this article.

Background: Early surgical intervention for hip fractures in the elderly has proven efficacious. However, surgical delays commonly occur in this patient population due to comorbid conditions that put these patients at a high risk for hypotension-related complications of general or neuraxial anesthesia or anticoagulants that delay the safe use of neuraxial anesthesia., Questions/purposes: The questions/purposes of this study are (1) to investigate if a fascia iliaca block in conjunction with light to moderate sedation could provide adequate analgesia throughout open surgery for intertrochanteric hip fractures (AO/OTA 31-1) without requiring conversion to general anesthesia with airway support and (2) to assess its perioperative complication profile., Methods: A retrospective chart review was conducted to identify patients with intertrochanteric hip fractures who underwent anesthesia with a fascia iliaca block over a 1.5-year period., Results: In the six patients identified, there were no intraoperative conversions to general anesthesia requiring airway support. Additionally, there were no intraoperative complications, no mortalities within 30 days, 2 patients on anticoagulation who required a blood transfusion, and a single patient who developed a postoperative hospital-acquired pneumonia that resolved with an antibiotic course., Conclusions: In this series of patients, we demonstrate that a fascia iliaca block can reliably be utilized as the primary anesthetic for patients undergoing surgical fixation of intertrochanteric hip fractures, with an acceptable perioperative complication profile. Although concomitant sedation was provided with the block, this anesthesia strategy has the potential to reduce preoperative delays and minimize the overall burden of sedative and anesthetic medications in a geriatric population. These initial findings may serve as a basis for future, higher-quality prospective and comparative studies., Competing Interests: Compliance with Ethical StandardsThis protocol was IRB approved on 2/22/2016 at the New York Presbyterian Queens. Joseph J. Ruzbarsky, MD; Isaac P. Lowenwirt, MD; Elan M. Goldwyn, MD; and Vitaly Kotlyar, MD, have declared that they have no conflict of interest. Elizabeth B. Gausden, MD, has received funding from the Samuel and May Rudin Foundation.All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 (5).Informed consent was waived from all patients for being included in the study.Disclosure forms provided by the authors are available with the online version of this article.

Differentiating septic arthritis of the pediatric hip from other causes of hip pain and effusion continues to present a diagnostic challenge for the clinician. Although septic arthritis traditionally has been reported to have a synovial white blood cell count of 75,000 cells/mm3 or greater, lower counts can be seen in this condition. In cases where a synovial sample has been obtained and the cell count falls in the intermediate range between 25,000 and 75,000 cells/mm(3), it is unclear what proportion of these cases may be truly septic hips. In this evidence-based review, we examine Heyworth et al's study focusing on the predictive value of this intermediate white cell count range in a Lyme-endemic region.

Background: Hip dysplasia is prevalent in nonambulatory children with cerebral palsy, and may contribute to a decreased quality of life (Lonstein in J Pediatr Orthop 6:521-526, 1). Reconstructive procedures such as a femoral varus derotation osteotomy with or without a pelvic osteotomy are commonly employed with the goal of achieving and maintaining well reduced hips., Purposes: The goals of this study are both to characterize the complications of reconstructive procedures and to identify risk factors that may contribute to these complications., Patients and Methods: A retrospective analysis was conducted among 61 nonambulatory children (93 hips) with cerebral palsy who underwent a femoral varus derotation osteotomy, with or without an open reduction and/or pelvic osteotomy, from 1992 through 2008 at our institution. The average patient age was 8.1 years (2.6-14.7) and the mean follow-up time was 5.9 years (2.1-15.9)., Results: The cumulative complication rate per patient including failures to cure was 47.6 %. Spica casting was found to be a risk factor for all complications (P = 0.023); whereas patients younger than 6 years old (P = 0.013) and children with a tracheostomy (P = 0.004) were found to be risk factors for resubluxation following surgery., Conclusions: Although reported complication rates of hip reconstructive procedures performed upon children with cerebral palsy have varied considerably, those with more severe disease have experienced more complications. We report our tertiary referral center's complication rate and our institutional experiences with risk factors for complications and failures to cure., Level of Evidence: IV, Retrospective case series.