Transcriptional time course after rotator cuff repair in 6 month old female rabbits.

Introduction: Rotator cuff tears are prevalent in the population above the age of 60. The disease progression leads to muscle atrophy, fibrosis, and fatty infiltration, which is not improved upon with surgical repair, highlighting the need to better understand the underlying biology impairing more favorable outcomes. Methods: In this study, we collected supraspinatus muscle tissue from 6 month old female rabbits who had undergone unilateral tenotomy for 8 weeks at 1, 2, 4, or 8 weeks post-repair (n = 4/group). RNA sequencing and enrichment analyses were performed to identify a transcriptional timeline of rotator cuff muscle adaptations and related morphological sequelae. Results: There were differentially expressed (DE) genes at 1 (819 up/210 down), 2 (776/120), and 4 (63/27) weeks post-repair, with none at 8 week post-repair. Of the time points with DE genes, there were 1092 unique DE genes and 442 shared genes, highlighting that there are changing processes in the muscle at each time point. Broadly, 1-week post-repair differentially expressed genes were significantly enriched in pathways of metabolism and energetic activity, binding, and regulation. Many were also significantly enriched at 2 weeks, with the addition of NIF/NF-kappaB signaling, transcription in response to hypoxia, and mRNA stability alongside many additional pathways. There was also a shift in transcriptional activity at 4 weeks post-repair with significantly enriched pathways for lipids, hormones, apoptosis, and cytokine activity, despite an overall decrease in the number of differentially expressed genes. At 8 weeks post-repair there were no DE genes when compared to control. These transcriptional profiles were correlated with the histological findings of increased fat, degeneration, and fibrosis. Specifically, correlated gene sets were enriched for fatty acid metabolism, TGF-B-related, and other pathways. Discussion: This study identifies the timeline of transcriptional changes in muscle after RC repair, which by itself, does not induce a growth/regenerative response as desired. Instead, it is predominately related to metabolism/energetics changes at 1 week post-repair, unclear or asynchronous transcriptional diversity at 2 weeks post-repair, increased adipogenesis at 4 weeks post-repair, and a low transcriptional steady state or a dysregulated stress response at 8 weeks post-repair.

Patient Age and Surgical Intervention as Risk Factors for the Development of Osteoarthritis After Posterior Shoulder Instability: A Population-Based Study.

Background: Diagnosis and treatment of posterior shoulder instability (PSI) has improved with advances in imaging and surgical technique. However, the relationship between PSI and osteoarthritis (OA) remains unclear. Purpose: To evaluate a population-based cohort to (1) determine the rate of symptomatic OA, (2) identify patient characteristic risk factors for OA, and (3) evaluate the effect of posterior capsulolabral repair on OA progression. Study Design: Case-control study; Level of evidence, 3. Methods: After review of 324 patient records, we included 115 patients (14 female, 101 male) diagnosed with PSI between January 1994 and July 2012 with an average follow-up of 12.5 years (range, 5-23 years). Medical records were reviewed for patient characteristics, injury characteristics, surgical details (if any), and radiographic progression of OA. Kaplan-Meier survival was used to estimate survival free of OA; characteristics associated with OA progression were determined via univariate Cox regression models, and associated 95% CIs and hazard ratios (HRs) are presented. Results: Overall, 14% (16/115) of patients had radiographic progression of symptomatic glenohumeral arthritis, with 5-year survival of 88.3% (95% CI, 79.7%-97.3%). Older age at the time of instability diagnosis was associated with arthritis progression (10-year unit HR, 1.95; 95% CI, 1.26-3.03). Patients who underwent surgery demonstrated increased radiographic progression of OA (HR, 4.03; 95% CI, 1.23-13.23). There was a trend of increased OA in patients treated with labral debridement compared with repair despite lower baseline levels of OA; however, this difference was not statistically significant (P = .09). Conclusion: Symptomatic glenohumeral arthritis is not seen routinely in patients with PSI. Although uncommon, an age of at least 30 years at the time of diagnosis and surgical intervention were identified as risk factors for developing symptomatic arthritis at long-term follow-up.

The "Second Hit" of Repair in a Rabbit Model of Chronic Rotator Cuff Tear.

The rabbit supraspinatus is a useful translational model for rotator cuff (RC) repair because it recapitulates muscle atrophy and fat accumulation observed in humans after a chronic tear (the "first hit"). However, a timeline of RC tissue response after repair, especially with regard to recent evidence of muscle degeneration and lack of regeneration, is currently unavailable. Thus, the purpose of this study was to characterize the progression of muscle and fat changes over time after the repair of a chronic RC tear in the rabbit model. Two rounds of experiments were conducted in 2017-2018 and 2019-2020 with N = 18 and 16 skeletally mature New Zealand White rabbits, respectively. Animals underwent left supraspinatus tenotomy with repair 8 weeks later. The unoperated right shoulder served as control. The rabbits were sacrificed at 1-, 2-, 4-, and 8-weeks post-repair for histological and biochemical analysis. Atrophy, measured by fiber cross-sectional area and muscle mass, was greatest around 2 weeks after repair. Active muscle degeneration peaked at the same time, involving 8% of slide areas. There was no significant regeneration at any timepoint. Fat accumulation and fibrosis were significantly increased across all time points compared to contralateral. Statement of Clinical Significance: These results demonstrate model reproducibility and a "second hit" phenomenon of repair-induced muscle atrophy and degeneration which partially recovers after a short time, while increased fat and fibrosis persist.

Progression of muscle loss and fat accumulation in a rabbit model of rotator cuff tear.

Rotator cuff (RC) tears present a treatment challenge due to muscle atrophy and degeneration, fatty infiltration, and fibrosis. The purpose of this study was to generate a high time-resolution model of RC tear in rabbits and to characterize the progression of architectural and histological changes. Thirty-five female New Zealand White rabbits (age: 6 months) underwent left supraspinatus tenotomy. Five rabbits were used to evaluate immediate muscle architectural changes. The remaining 30 rabbits underwent right shoulder sham surgery and sacrifice at 1, 2, 4, 8, or 16 weeks. Histology was used to quantify muscle fiber cross-sectional area (CSA), muscle degeneration and regeneration, and fat localized to inter- versus intrafascicular regions. Muscle fiber CSA decreased by 26.5% compared to sham at 16 weeks (effect of treatment, p < 0.0001). Muscle degeneration increased after tenotomy (effect of treatment, p = 0.0006) without any change in regeneration. Collagen and fat content increased by 4 weeks and persisted through 16 weeks. Interfascicular fat was increased at all time points, but intrafascicular fat was increased only at 1, 4, and 16 weeks posttenotomy. Intrafascicular fat adjacent to degenerating muscle fibers increased as well (effect of treatment, p < 0.0001; effect of time, p = 0.0102). Statement of clinical relevance: Rabbit supraspinatus tenotomy recapitulates key features of the pathophysiology of human RC tears, including muscle atrophy and degeneration, lack of regeneration, fat accumulation, and fibrosis.

Corrigendum: Transcriptional Time Course After Rotator Cuff Tear.

[This corrects the article DOI: 10.3389/fphys.2021.707116.].

Supraspinatus muscle architecture and physiology in a rabbit model of tenotomy and repair.

Chronic rotator cuff tears can cause severe functional deficits. Addressing the chronic fatty and fibrotic muscle changes is of high clinical interest; however, the architectural and physiological consequences of chronic tear and repair are poorly characterized. We present a detailed architectural and physiological analysis of chronic tear and repair (both over 8 and 16 wk) compared with age-matched control rabbit supraspinatus (SSP) muscles. Using female New Zealand White Rabbits (n = 30, n = 6/group) under 2% isoflurane anesthesia, the SSP was surgically isolated and maximum isometric force was measured at four to six muscle lengths. Architectural analysis was performed, and maximum isometric stress was computed. Whole muscle length-tension curves were generated using architectural measurements to compare experimental physiology to theoretical predictions. Architectural measures are consistent with persistent radial and longitudinal atrophy over time in tenotomy that fails to recover after repair. Maximum isometric force was significantly decreased after 16 wk tenotomy and not significantly improved after repair. Peak isometric force reported here are greater than prior reports of rabbit SSP force after tenotomy. Peak stress was not significantly different between groups and consistent with prior literature of SSP stress. Muscle strain during contraction was significantly decreased after 8 wk of tenotomy and repair, indicating effects of tear and repair on muscle function. The experimental length-tension data were overlaid with predicted curves for each experimental group (generated from structural data), exposing the altered structure-function relationship for tenotomy and repair over time. Data presented here contribute to understanding the physiological implications of disease and repair in the rotator cuff.NEW & NOTEWORTHY We utilize an established method to measure the length-tension relationship for the rabbit supraspinatus in normal, torn, and repaired muscles. We then perform architectural analysis to evaluate structural changes after tear and repair. Although peak isometric force is lower in the tear and repair groups, there are no differences in peak stresses across groups. These findings indicate persistent structural changes (both radial and longitudinal atrophy) and physiological deficiencies (decreased peak force and uncoupling structure-function relationship) after tenotomy that do not significantly recover after repair.

Transcriptional Time Course After Rotator Cuff Tear.

Rotator cuff (RC) tears are prevalent in the population above the age of 60. The disease progression leads to muscle atrophy, fibrosis, and fatty infiltration in the chronic state, which is not improved with intervention or surgical repair. This highlights the need to better understand the underlying dysfunction in muscle after RC tendon tear. Contemporary studies aimed at understanding muscle pathobiology after RC tear have considered transcriptional data in mice, rats and sheep models at 2-3 time points (1 to 16 weeks post injury). However, none of these studies observed a transition or resurgence of gene expression after the initial acute time points. In this study, we collected rabbit supraspinatus muscle tissue with high temporal resolution (1, 2, 4, 8, and 16 weeks) post-tenotomy (n = 6/group), to determine if unique, time-dependent transcriptional changes occur. RNA sequencing and analyses were performed to identify a transcriptional timeline of RC muscle changes and related morphological sequelae. At 1-week post-tenotomy, the greatest number of differentially expressed genes was observed (1,069 up/873 down) which decreases through 2 (170/133), 4 (86/41), and 8 weeks (16/18), followed by a resurgence and transition of expression at 16 weeks (1,421/293), a behavior which previously has not been captured or reported. Broadly, 1-week post-tenotomy is an acute time point with expected immune system responses, catabolism, and changes in energy metabolism, which continues into 2 weeks with less intensity and greater contribution from mitochondrial effects. Expression shifts at 4 weeks post-tenotomy to fatty acid oxidation, lipolysis, and general upregulation of adipogenesis related genes. The effects of previous weeks' transcriptional dysfunction present themselves at 8 weeks post-tenotomy with enriched DNA damage binding, aggresome activity, extracellular matrix-receptor changes, and significant expression of genes known to induce apoptosis. At 16 weeks post-tenotomy, there is a range of enriched pathways including extracellular matrix constituent binding, mitophagy, neuronal activity, immune response, and more, highlighting the chaotic nature of this time point and possibility of a chronic classification. Transcriptional activity correlated significantly with histological changes and were enriched for biologically relevant pathways such as lipid metabolism. These data provide platform for understanding the biological mechanisms of chronic muscle degeneration after RC tears.

Comparable clinical outcomes using knotless and knot-tying anchors for arthroscopic capsulolabral repair in recurrent anterior glenohumeral instability at mean 5-year follow-up.

PURPOSE: To compare rates of recurrent instability, revision surgery and functional outcomes following arthroscopic anterior capsulolabral repair for recurrent anterior instability using knot-tying versus knotless suture anchor techniques. METHODS:  Patients who had undergone arthroscopic anterior labrum and capsular repair for recurrent anterior glenohumeral instability using knotless anchors were identified. Those with minimum 2-year follow-up were matched (1:2) to knot-tying anchor repair patients. Rates of failure and recurrent instability were compared, as well as Visual Analog Scale (VAS), Single Assessment Numeric Evaluation (SANE), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), University of California Los Angeles (UCLA) and Rowe scores. RESULTS: One hundred and two patients (89 males, 13 females) with a mean age of 24.3 ± 9.6 were included. Repair was performed with knotless anchors in 34 and knot-tying anchors in 68 shoulders. At mean follow-up of 4.8 ± 2.5 years, re-dislocation rates between groups were not significantly different (knotless anchor: 9% versus knot-tying group: 15%, n.s.), but the knot-tying group showed a higher re-subluxation rate (p = 0.039). 12 (18%) revisions were performed in the knot-tying group at a mean 2.9 years after surgery and 1 (3%) revision in the knotless anchors group at 1.4 years (n.s.). There was no difference in mean VAS with use (1.3 ± 1.9 versus 0.8 ± 1.5, n.s.), SANE scores (91.8 ± 12.7 versus 92.0 ± 11.0, n.s.), QuickDASH scores (4.1 ± 5.5 versus 3.0 ± 6.5, n.s.), UCLA Shoulder Score (32.5 ± 3.6 versus 33.2 ± 3.1, n.s.), or Rowe scores (90.5 ± 18.5 versus 92.2 ± 16.6, n.s.) between knotless and knot-tying groups, respectively. VAS at rest was higher in the knotless group (0.7 ± 1.5 vs 0.1 ± 0.4, p = 0.021). CONCLUSIONS: Knotless anchors demonstrated similar rates of re-dislocation and revision surgery, and lower rates of recurrent subluxation, compared to knot-tying anchors. Patients achieved good-to-excellent functional outcomes. This supports the efficacy of knotless anchors as an alternative to knot-tying anchors for arthroscopic anterior labral repair of recurrent anterior shoulder dislocation. LEVEL OF EVIDENCE: III.

Osteomeniscal Impact Edema (OMIE): Description of a Distinct MRI Finding in Displaced Flap Tears of the Medial Meniscus, with Comparison to Posterior Root Tears.

Bone marrow edema (BME) can be a late finding in osteoarthritis or a sign of subchondral insufficiency. The purpose of this study was to describe the magnetic resonance imaging (MRI) finding we refer to as "osteomeniscal impact edema" (OMIE), or reactive BME adjacent to a displaced meniscus flap tear. In addition, this edema pattern is compared with a control group of medial meniscus posterior root tears (MMPRT) with subchondral insufficiency edema. MRI records from 2000 to 2017 were retrospectively reviewed for studies that showed the presence of a medial meniscus displaced flap tear and an adjacent area of BME. The selected MRIs were matched to an equal number of MMPRT MRI studies. All MRI studies were assessed for cartilage surface grade using the modified Outerbridge classification system and for the extent of accompanying structural abnormalities using the whole-organ magnetic resonance imaging score. Descriptive statistics and hypothesis testing were utilized to compare the MRI findings between groups. Twenty-two flap tear (OMIE group) patients with a mean age of 57 (SD: 15) and 22 root tear (MMPRT) group patients with a mean age of 61 (SD: 10) were included. MRIs in the OMIE group showed a distinctive pattern of focal, peripheral edema adjacent to the meniscus flap tear, compared with more diffuse, central edema in the MMPRT group. Quantitatively, MRIs of the MMPRT group showed significantly worse mean femoral Outerbridge scores (3.72 vs. 2.68, p < 0.0001), more severe central (1.63 vs. 0.5, p = 0.0007) and posterior (0.31 vs. 0.0, p = 0.04) subchondral edema grades, and a higher incidence of tibial subchondral fractures (3 vs. 0, p = 0.036). Meniscus flap tears may present with a distinct MRI pattern of focal, adjacent, peripheral edema, which we refer to as OMIE. Patients with meniscus flap tears showed significantly less arthritic change, lower subchondral edema grades, and a lower incidence of insufficiency fractures and subchondral collapse compared with the diffuse overload edema pattern found with root tears. The Level of Evidence for this study is III.

Midterm Outcomes following Acute Repair of Grade III Distal MCL Avulsions in Multiligamentous Knee Injuries.

There is limited evidence guiding management of medial collateral ligament (MCL) avulsions or functional disruptions distal to the medial joint line. This study aims to determine outcomes of a series of patients with grade III distal MCL injuries managed with acute surgical repair. Patients with grade III, distal MCL injuries, with or without multiligament involvement were identified. Demographic, clinical examination, and midterm patient-reported outcomes (PRO) data were collected. Clinical follow-up included physical examination and ligamentous stress testing at a minimum of 6 months. PROs included Lysholm's knee scoring scale, Tegner's activity score, and subjective International Knee Documentation Committee (IKDC) scores at minimum of 2 years follow-up. Of the 24 eligible patients, outcomes data were available for 20 (83%). Of the 20 included patients, 16 had a concomitant anterior cruciate ligament (ACL) injury, 3 had ACL and posterior cruciate ligament (PCL) injuries, and 1 had an isolated MCL injury. Mean time from injury to surgery was 5 weeks. At mean clinical follow-up of 20.3 months, all patients showed valgus stability and satisfactory range of motion (ROM). Anteroposterior stability was normal in all but one patient who demonstrated a 2+ posterior drawer but with firm end points. At a mean follow-up of 5.7 years for PROs, mean Lysholm's score was 91.5 (standard deviation [SD] = 12.2), median Tegner's activity score was 7 (range, 4-9), and mean subjective IKDC score was 88.8 (SD: 9.9). The surgical repair of grade III distal MCL injuries delivered satisfactory clinical and functional outcomes. Future comparative studies with larger patient samples are needed.

Nonoperative Management of Posterior Shoulder Instability: An Assessment of Survival and Predictors for Conversion to Surgery at 1 to 10 Years After Diagnosis.

PURPOSE: To (1) define the rate of delayed surgery, between 1 and 10 years after injury, in a population-based study of patients with posterior shoulder instability (PSI), (2) evaluate predictive factors associated with delayed repair, and (3) identify differences between the nonoperative and operative groups at long-term follow-up. METHODS: A population-based retrospectively reviewed study of all patients with PSI from January 1, 1994, to December 31, 2015, was performed. Inclusion required a clinical diagnosis of PSI combined with supporting imaging. Complete medical records were reviewed for 2,091 potential cases. Kaplan-Meier estimates were used to calculate survival. Landmark survival analysis was performed to identify predictors of conversion to surgery. RESULTS: The study included 143 patients with PSI, 79 of whom were managed nonoperatively for at least 1 year after diagnosis. After the first year, survival free of surgery was 78.3% at 1 year, 63.1% at 5 years, and 51.5% at 10 years. There was a trend toward increased surgery in patients with a body mass index > 35 (P = .10; hazard ratio = 2.32; confidence interval, 0.8-6.8). Nonthrowing athletes (including contact/weight-lifting athletes) showed a trend toward an increased risk for surgery (P = .07). Patients who underwent surgery were significantly more likely to have progression in arthritis (P = .02; hazard ratio = 4.0; confidence interval, 1.2-13.2). CONCLUSIONS: Nonoperative management was performed for at least 1 year in over half of patients diagnosed with PSI. Overall, long-term follow-up demonstrates that 46% of these patients converted to surgery between 1 and 10 years after initial diagnosis. Ultimately, 70% of patients diagnosed with PSI go on to surgical intervention. Patients who underwent surgery at any time point were at an increased risk of radiographic progression of arthritis at a minimum of 5 years of follow-up. LEVEL OF EVIDENCE: Level III, cohort study.

Anterior Cruciate Ligament Reconstruction With Hamstring Autograft: A Matched Cohort Comparison of the All-Inside and Complete Tibial Tunnel Techniques.

BACKGROUND: Surgical reconstruction of the anterior cruciate ligament (ACL) is one of the most common orthopaedic procedures, with an estimated 100,000 to 175,000 procedures performed annually. Recently, the all-inside reconstruction technique has come into favor and is theorized to be superior to the complete tibial tunnel technique. PURPOSE: To compare clinical and patient-reported outcomes (PROs) for hamstring autograft ACL reconstruction (ACLR) performed with an all-inside versus a complete tibial tunnel technique. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who underwent hamstring autograft ACLR via either an all-inside approach (femoral and tibial sockets) or a complete tibial tunnel approach (femoral socket and full-length, transtibial tunnel) at a single institution between July 2011 and July 2015 were reviewed. Demographic information, preoperative comorbidities, surgical details, physical examination findings, and follow-up outcomes were extracted from the medical record. Physical examination data included pivot-shift, Lachman, and range of motion examinations, whereas PROs included the Tegner activity scale, Lysholm score, and International Knee Documentation Committee (IKDC) score at a minimum of 2 years after surgery. Return to sport and risk factors for failure were analyzed. RESULTS: A total of 82 patients (mean ± SD age, 25.8 ± 10.2 years) who underwent all-inside reconstruction (median PRO follow-up, 30.1 months; range, 24.7-72.9 months) and 54 patients (mean ± SD age, 21.1 ± 7.3 years) who underwent complete tibial tunnel reconstruction (median PRO follow-up, 25.8 months; range, 23.9-74.5 months) met the inclusion criteria. PRO scores at latest follow-up were comparable between the all-inside versus the complete tibial tunnel groups (Lysholm score, 93.8 vs 94.4, P = .621; IKDC score, 93.5 vs 93.3, P = .497; Tegner activity score, 6.4 vs 6.8, P = .048). Complications (including graft failure) were experienced by 20% of patients in the all-inside group compared with 24% in the complete tibial tunnel group (P = .530). Graft failure before the final follow-up was experienced by 10% of patients in the all-inside group compared with 19% in the complete tibial tunnel group (P = .200). Mean return to sport was 12.5 months in the all-inside group versus 9.9 months in the complete tibial tunnel group (P = .028). CONCLUSION: All-inside and complete tibial tunnel hamstring autograft ACLR resulted in excellent physical examination findings and PROs at minimum 2-year follow-up. Both techniques successfully restored knee stability and patient function.

Successful Return to Sport Following Distal Femoral Varus Osteotomy.

OBJECTIVE: Distal femoral varus osteotomy (DFVO) is an effective treatment for unloading valgus knee malalignment; however, there is limited evidence on the ability for patients to return to athletics following this procedure. The purpose of this study is to report the functional outcomes and rate of return to sport for athletes that underwent DFVO. DESIGN: A consecutive series of athletes that had undergone DFVO were retrospectively reviewed. Radiographs were assessed to determine preoperative and postoperative alignment. Institutional registries were used to collect preoperative and postoperative Marx Activity Scale, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form scores, and return to sport. RESULTS: Thirteen patients (8 males, 5 females) with a mean age of 24 years (range 17-35 years) and a mean follow-up of 43 months (range 24-74 months) were included in the study. Six patients underwent medial closing wedge DFVO versus 7 patients who underwent lateral opening wedge DFVO. Nine of 13 had concomitant chondral, meniscal, or ligamentous procedures performed. The mean alignment correction was 8° (range 5°-13°). All patients were able to successfully return to sport at a mean of 11 months (range 9-13 months). Furthermore, all 13 patients demonstrated an improvement in both Marx Activity Scale (4-11; P < 0.01) and IKDC scores (53-89; P < 0.01) after surgery. CONCLUSIONS: Correction of valgus knee malalignment through DFVO-either medial closing wedge or lateral opening wedge-can reliably result in improvement in function and return to sport. Concomitant chondral, meniscal, and ligamentous pathology should be addressed.

Incidence of posterior shoulder instability and trends in surgical reconstruction: a 22-year population-based study.

BACKGROUND: The incidence of posterior shoulder instability (PSI) in the general population is not well defined. This study aimed to define the population-based incidence of PSI and describe trends in incidence and surgery rates. METHODS: The study population included 143 patients (16 females, 127 males) diagnosed with new-onset PSI between January 1, 1994, and December 31, 2015. Medical records were reviewed to extract patient data. Age- and sex-specific incidence rates were calculated and adjusted to the 2010 United States population. Poisson regression was performed to examine trends by timeline, sex, and age. RESULTS: Age- and sex- adjusted annual incidence of PSI was 4.64 per 100,000 person-years, and posterior dislocation was 1.30 per 100,000 person-years. Peak PSI incidence for males and females was at 14 to 19 years (31.82 and 5.23 per 100,000 person-years). PSI incidence was higher in males than females (8.86 vs. 1.07 per 100,000 person-years, P < .001). The 5-year cumulative risk of surgery for patients with PSI was 53.1% between 1996 and 2002, 59.9% between 2003 and 2008, and 87.5% between 2009 and 2015. Patients with PSI between 2009 and 2015 had a significantly increased rate of surgery (hazard ratio, 2.2; 95% confidence interval, 1.4-3.6; P = .001) compared with those between 1996 and 2002. CONCLUSION: The age- and sex- adjusted incidence of PSI in the general population was 4.64 per 100,000 person-years. There is a significantly greater incidence of PSI in males than females, with both sexes peaking at 14 to 19 years and incidence rates remaining elevated throughout the third and fourth decades of life. The incidence of PSI remained stable over time; however, the rate of surgical intervention increased significantly, from 53.1% of patients between 1996 and 2002 to 87.5% of patients between 2009 and 2015.

High tibial osteotomy with modern PEEK implants is safe and leads to lower hardware removal rates when compared to conventional metal fixation: a multi-center comparison study.

PURPOSE: Various implant materials have been used in medial, opening-wedge high tibial osteotomy (HTO) including traditional metal and modern polyetheretherketone (PEEK) implants. The purpose of this study was to compare metal and PEEK implants and determine safety, varus deformity correction, as well as short- to mid-term hardware removal and arthroplasty rates. METHODS: HTO performed with metal and PEEK implants were reviewed between 2000 and 2015 at two institutions with a minimum of 2 years follow-up. Postoperative complications, radiographic measures, and osteotomy union were compared between groups using Kruskal-Wallis and Fisher's exact testing. Survival free of hardware removal and arthroplasty was compared between groups using Kaplan-Meier testing. Risk factors for HTO conversion to arthroplasty were examined using Cox proportional hazards regression. RESULTS: Ninety-five HTOs were performed in 90 patients (59 M, 31 F) using 50 metal and 45 PEEK implants. Mean follow-up was 4.2 years (range 2.0-16.5). Two metal and two PEEK HTO patients experienced nonunions, resulting in revision HTO at a mean of 1.0 years postoperatively (range 0.4-1.4 years). Both implant groups demonstrated similar, significant improvements in coronal deformity, with mean angulation improving from 6.0° and 5.4° varus preoperatively to 1.1° and 1.0° valgus postoperatively for the metal (p < 0.01) and PEEK groups (p < 0.01), respectively. 2- and 5-year hardware removal-free survival was 94% and 94% for PEEK, which was significantly superior to 80% and 73% observed for metal (p = 0.02). 2- and 5-year arthroplasty-free survival was similar for the metal (98% and 94%) and PEEK groups (100% and 78%) (n.s.). HTO performed for focal cartilage defects was observed to demonstrate decreased arthroplasty risk (HR 0.36, p = 0.03) when compared to HTO performed for osteoarthritis. CONCLUSIONS: Both metal and PEEK implants were found to be effective in obtaining and maintaining coronal varus deformity correction, with 88% overall arthroplasty-free survival at 5 years. Metal fixation demonstrated a higher rate of hardware removal while HTO performed for medial compartment osteoarthritis predicted conversation to arthroplasty. LEVEL OF EVIDENCE: III.

The Rapidly Assessed Predictor of Intraoperative Damage (RAPID) Score: An In-Clinic Predictive Model for High-Grade Acetabular Chondrolabral Disruption.

BACKGROUND: The preoperative assessment of cartilage lesions is critical to surgical planning and decision making. The accurate radiographic determination of acetabular cartilage damage has remained elusive for modern imaging modalities, including magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA). While risk factors have been individually described, no multivariable system exists for predicting high-grade cartilage damage. PURPOSE: To determine the preoperative predictors of grade 3 to 4 acetabular labrum articular disruption (ALAD) lesions. STUDY DESIGN: Case-control study; Level of evidence, 3. Cohort study (diagnosis); Level of evidence, 1. METHODS: Retrievable radiographs were reviewed from primary hip arthroscopic procedures performed at 2 high-volume institutions between December 2007 and April 2017. The predictive value of demographic and radiographic factors for the intraoperative documentation of ALAD grade 3 to 4 damage was analyzed and entered into a multivariable model, and a statistically guided scoring system for the damage risk was created using the Akaike information criterion. The scoring system was then prospectively validated on 167 patients who underwent primary hip arthroscopy between April 2017 and February 2018. RESULTS: A total of 652 primary hip arthroscopic procedures in 614 patients (390 female, 224 male; mean age, 33.2 ± 12.5 years; mean body mass index, 26.9 ± 5.5 kg/m2) from 2007 to 2017 were analyzed. Male sex (odds ratio [OR], 3.11; P < .01), age ≥35 years (OR, 1.96; P < .01), cam morphology (alpha angle >55°) (OR, 2.96; P < .01), and Tönnis grade 1 to 2 (grade 1: OR, 4.14; P < .01, and grade 2: OR, 9.29; P < .01) were univariate risk factors for intraoperatively documented high-grade damage. A multivariable scoring system, the Rapidly Assessed Predictor of Intraoperative Damage (RAPID) score (0-5 points), was generated based on sex, Tönnis grade, and cam morphology. Patients with increasing RAPID scores had an increasing risk of damage, with a 10.5% risk for those with 0 points and an 88.0% risk for those with 5 points (P < .01). The area under the curve was 0.75 for the study group and 0.76 for the validation group (P = .94). CONCLUSION: While preoperative MRI has diagnostic value for hip arthroscopic surgery, the RAPID score provides added benefit as a readily employable, in-clinic system for predicting high-grade cartilage damage. The discriminatory value of the RAPID score compares favorably with previous MRI and MRA studies. This information will help the clinician and patient plan for high-grade damage and identify potential targets for cartilage treatment.

Comparative Outcomes of Radial and Bucket-Handle Meniscal Tear Repair: A Propensity-Matched Analysis.

BACKGROUND: Full-thickness radial meniscal tears render the meniscus nonfunctional and have historically been treated with partial meniscectomy. As preservative techniques evolve for radial repair, comparisons with other tear patterns are necessary to evaluate repair efficacy and prognosis. PURPOSE: To assess clinical outcomes and reoperation rates of radial meniscal repair and to compare them to bucket-handle meniscal repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Radial and bucket-handle meniscal tears without concurrent root injuries undergoing surgical repair at a single institution between 2007 and 2015 were analyzed, including both all-inside and inside-out suturing techniques. Propensity matching was performed on the basis of age at surgery, sex, meniscus laterality, body mass index (BMI), and concomitant anterior cruciate ligament reconstruction (ACLR) using a comparison pool of 70 bucket-handle repairs. Reoperation-free survival rates and Tegner, visual analog scale (VAS) for pain, and International Knee Documentation Committee (IKDC) scores were analyzed. RESULTS: Twenty-four patients (18 male, 6 female; mean age, 22.8 ± 11.9 years) who underwent repair of a radial meniscal tear were followed for a mean of 3.5 years (range, 2.0-6.3 years). Significant postoperative improvements in VAS scores at rest and with use and IKDC scores were noted postoperatively ( P < .001). Five patients (20.8%) required a reoperation. Subsequently, 18 patients with radial tears (mean age, 19.1 ± 9.1 years; 12 male; mean BMI, 27.0 ± 6.2 kg/m2; 3 medial; 11 ACLR) were propensity matched to 18 patients with bucket-handle tears (mean age, 20.8 ± 5.1 years; 13 male; mean BMI, 25.0 ± 3.5 kg/m2; 3 medial; 11 ACLR). The matched radial and bucket-handle groups demonstrated similar ( P = .17) reoperation-free survival rates at 2 years (88.9% and 94.4%, respectively) and 5 years (77.8% and 87.7%, respectively). VAS and IKDC scores improved significantly after surgery ( P < .001), with no difference noted between the groups ( P ≥ .17). Patients with radial and bucket-handle meniscal repairs achieved mean postoperative Tegner scores (6.6 and 6.6, respectively) not significantly different from their preinjury levels (6.9 and 6.7, respectively) ( P ≥ .32). CONCLUSION: Satisfactory clinical outcomes are achievable for radial meniscal tear repair at short-term follow-up. In a robustly matched comparison, radial and bucket-handle meniscal tears demonstrate similar improvements in VAS and IKDC scores, restoration of preoperative Tegner scores, and acceptable reoperation rates. Full-thickness radial meniscal tears should be considered for repair.

Internal Fixation of Unstable Osteochondritis Dissecans: Do Open Growth Plates Improve Healing Rate?

BACKGROUND: Osteochondritis dissecans (OCD) is a disorder of unknown origin that can affect knees in skeletally mature and immature patients. Surgical management is an important cornerstone of treatment for unstable OCD lesions. PURPOSE: To determine the (1) healing rate after internal fixation of unstable OCD between skeletally immature and mature knees, (2) risk factors for failure, and (3) patient-reported outcomes among healed patients. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A multicenter retrospective cohort study was conducted with patients who underwent internal fixation of unstable knee OCD lesions from 2000 to 2015. Skeletal immaturity was defined as open or partially open physes. Healing was assessed through clinical findings and imaging. Definitive reoperation for the same OCD lesion was classified as failure. RESULTS: Among 87 patients included, 66 (76%) had healed lesions at ≥2 years postoperatively, while 21 (24%) failed. Skeletal maturity made no significant difference in failure rate (risk ratio, 0.68; 95% CI, 0.29-1.72; P = .40). For skeletally immature patients, lateral versus medial condylar location conferred an increased hazard of 18.2 (95% CI, 1.76-188.07; P < .01). Multivariate analysis factoring in skeletal maturity showed that lateral condylar location was an independent risk factor for failure (hazard ratio, 4.25; 95% CI, 1.47-19.85; P < .01). Mean patient-reported outcome scores (International Knee Documentation Committee [IKDC] and Knee injury and Osteoarthritis Outcome Score [KOOS]) increased significantly after surgery, except the KOOS symptoms score for the skeletally mature group. Final scores (mean ± SD) were as follows at a mean follow-up of 60 months (range, 24-166): IKDC, 83.5 ± 20.2; KOOS pain, 89.7 ± 14.1; KOOS symptoms, 87.4 ± 18.4; KOOS activities of daily living, 93.9 ± 12.7; KOOS sports, 80.7 ± 25.9; KOOS quality of life, 78.9 ± 23.1. CONCLUSION: Skeletally immature and mature patients heal at comparable rates after internal fixation of OCD lesions, resulting in functional and subjective improvement. Lateral femoral condylar lesion location is an independent risk factor for failure.

Are Results of Arthroscopic Labral Repair Durable in Dysplasia at Midterm Follow-up? A 2-Center Matched Cohort Analysis.

BACKGROUND: Studies assessing dysplasia's effect on hip arthroscopy are often limited to the short term and unable to account for demographic factors that may vary between dysplastic and nondysplastic populations. PURPOSE: To determine the midterm failure rate and patient-reported outcomes of arthroscopic labral repair in the setting of dysplasia and make subsequent failure and outcome comparisons with a rigorously matched nondysplastic control group. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Primary arthroscopic labral repair cases at 2 centers from 2008 to 2011 were reviewed. Patients with lateral center edge angle (LCEA) <25° were matched to nondysplastic controls by age, sex, laterality, body mass index (BMI), Tönnis grade, and capsular repair per a 1:2 matching algorithm. Groups were compared with a visual analog scale (VAS) for pain, modified Harris Hip Score (mHHS), and Hip Outcome Score-Sports Specific Subscale (HOS-SSS) to determine predictors of outcome and failure. RESULTS: Forty-eight patients with dysplasia (mean LCEA, 21.6°; range, 13.0°-24.9°; n = 25 with capsular repair) were matched to 96 controls (mean LCEA, 32.1°; range, 25°-52°; n = 50 with capsular repair) and followed for a mean of 5.7 years (range, 5.0-7.7 years). Patients achieved mean VAS improvements of 3.3 points, mHHS of 19.5, and HOS-SSS of 29.0 points ( P < .01) with no significant differences between the dysplasia and control populations ( P > .05). Five-year failure-free survival was 83.3% for patients with dysplasia and 78.1% for controls ( P = .53). No survival or outcomes difference was observed between patients with dysplasia who did or did not have capsular repair ( P ≥ .45) or when comparing LCEA <20° and LCEA 20° to 25° ( P ≥ .60). BMI ≤30 was associated with increased revision surgery risk ( P < .01). Age >35 years ( P < .05) and Tönnis grade 0 radiographs ( P < .01) predicted failure to reach minimal clinically important differences. CONCLUSION: With careful selection and modern techniques, patients with dysplasia can benefit significantly and durably from arthroscopic labral repair. The dysplastic cohort had outcomes and failure rates similar to those of rigorously matched controls at midterm follow-up. Subanalyses comparing LCEA <20° and LCEA 20° to 25° are presented for completeness; however, this study was not designed to detect differences in dysplastic subpopulations. BMI ≤30 was associated with increased revision risk. Age >35 years and Tönnis grade 0 radiographs predicted failure to achieve minimal clinically important differences.